Planning under uncertainty for reliable health care robotics
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与公司建立合作关系英文作文Partnership with Corporations: A Gateway to Growth and Innovation.In today's rapidly evolving business landscape, forging strategic partnerships with corporations has become paramount for organizations seeking to scale their operations, enhance their offerings, and drive innovation. By leveraging the resources, capabilities, and networks of these industry giants, companies can unlock a wealth of opportunities to accelerate their growth and establish a competitive edge.Benefits of Corporate Partnerships.The benefits of establishing partnerships with corporations are multifaceted and can vary depending on the specific objectives of the organization. However, some of the most common advantages include:Access to capital: Corporations often possess substantial financial resources that can be invested injoint ventures, product development, and marketing initiatives. This can provide a significant boost to companies seeking to expand their operations or bring new products to market.Expanded market reach: By partnering with corporations, organizations can gain access to their vast distribution channels and customer bases. This allows them to expandtheir market reach, increase sales, and build brand awareness on a larger scale.Access to expertise and technology: Corporations typically have access to specialized expertise, cutting-edge technology, and research and development capabilities that can be leveraged to enhance the products and servicesof their partners. This can lead to innovative breakthroughs and improved operational efficiency.Increased credibility and reputation: Aligning with reputable corporations can enhance the credibility andreputation of organizations, bolstering their standing within the industry and among potential customers.Risk mitigation: Partnerships with corporations can help organizations mitigate risks and manage uncertainty by providing a reliable source of support and guidance. Thisis particularly valuable in volatile or rapidly changing markets.Types of Corporate Partnerships.There are various types of corporate partnerships, each designed to fulfill specific business objectives. Some of the most common types include:Joint ventures: Joint ventures involve the creation of a new, separate entity that is jointly owned and operated by two or more companies. This type of partnership allows organizations to pool their resources and expertise to pursue a common goal.Strategic alliances: Strategic alliances are non-equity partnerships where two or more companies agree to collaborate on specific projects or initiatives. This can include joint marketing campaigns, product development partnerships, or research and development collaborations.Licensing agreements: Licensing agreements allow one company (the licensor) to grant another company (the licensee) the right to use its intellectual property, such as patents, trademarks, or copyrights. This can provide organizations with access to valuable technologies or brand recognition without the need for direct investment.Distribution partnerships: Distribution partnerships involve agreements between manufacturers or suppliers and retailers or distributors to facilitate the sale and distribution of products or services. This can help companies expand their market reach and access new customer segments.Establishing a Successful Partnership.Building a successful corporate partnership requirescareful planning and execution. Organizations should consider the following key factors:Identify the right partners: It is essential to identify potential partners whose goals, values, and capabilities align with your own. Conduct thorough research and due diligence to ensure a mutually beneficial relationship.Develop a clear partnership agreement: The partnership agreement should clearly outline the roles, responsibilities, and expectations of each partner. It should also address issues such as intellectual property ownership, financial arrangements, and dispute resolution.Foster effective communication: Open and regular communication is vital for the success of any partnership. Establish clear channels of communication and hold regular meetings to ensure that both partners are on the same page.Monitor progress and make adjustments: Partnerships are not static arrangements. They require ongoingmonitoring and adjustment to ensure that they continue to meet the evolving needs of both parties. Regular reviews should be scheduled to assess progress and make any necessary changes.Conclusion.In the competitive business environment of today, forging strategic partnerships with corporations has become a powerful tool for growth and innovation. By leveraging the resources, capabilities, and networks of industry giants, organizations can unlock a wealth of opportunities to expand their operations, enhance their offerings, and achieve their business objectives. By carefully identifying the right partners, developing clear agreements, fostering effective communication, and monitoring progress, companies can build successful partnerships that drive mutual success and create lasting value.。
机器人顶刊论文机器人领域内除开science robotics以外,TRO和IJRR是机器人领域的两大顶刊,最近师弟在选择研究方向,因此对两大顶刊的论文做了整理。
TRO的全称IEEE Transactions on Robotics,是IEEE旗下机器人与自动化协会的汇刊,最新的影响因子为6.123。
ISSUE 61 An End-to-End Approach to Self-Folding Origami Structures2 Continuous-Time Visual-Inertial Odometry for Event Cameras3 Multicontact Locomotion of Legged Robots4 On the Combined Inverse-Dynamics/Passivity-Based Control of Elastic-Joint Robots5 Control of Magnetic Microrobot Teams for Temporal Micromanipulation Tasks6 Supervisory Control of Multirotor Vehicles in Challenging Conditions Using Inertial Measurements7 Robust Ballistic Catching: A Hybrid System Stabilization Problem8 Discrete Cosserat Approach for Multisection Soft Manipulator Dynamics9 Anonymous Hedonic Game for Task Allocation in a Large-Scale Multiple Agent System10 Multimodal Sensorimotor Integration for Expert-in-the-Loop Telerobotic Surgical Training11 Fast, Generic, and Reliable Control and Simulation of Soft Robots Using Model Order Reduction12 A Path/Surface Following Control Approach to Generate Virtual Fixtures13 Modeling and Implementation of the McKibben Actuator in Hydraulic Systems14 Information-Theoretic Model Predictive Control: Theory and Applications to Autonomous Driving15 Robust Planar Odometry Based on Symmetric Range Flow and Multiscan Alignment16 Accelerated Sensorimotor Learning of Compliant Movement Primitives17 Clock-Torqued Rolling SLIP Model and Its Application to Variable-Speed Running in aHexapod Robot18 On the Covariance of X in AX=XB19 Safe Testing of Electrical Diathermy Cutting Using a New Generation Soft ManipulatorISSUE 51 Toward Dexterous Manipulation With Augmented Adaptive Synergies: The Pisa/IIT SoftHand 22 Efficient Equilibrium Testing Under Adhesion and Anisotropy Using Empirical Contact Force Models3 Force, Impedance, and Trajectory Learning for Contact Tooling and Haptic Identification4 An Ankle–Foot Prosthesis Emulator With Control of Plantarflexion and Inversion–Eversion Torque5 SLAP: Simultaneous Localization and Planning Under Uncertainty via Dynamic Replanning in Belief Space6 An Analytical Loading Model for n -Tendon Continuum Robots7 A Direct Dense Visual Servoing Approach Using Photometric Moments8 Computational Design of Robotic Devices From High-Level Motion Specifications9 Multicontact Postures Computation on Manifolds10 Stiffness Modulation in an Elastic Articulated-Cable Leg-Orthosis Emulator: Theory and Experiment11 Human–Robot Communications of Probabilistic Beliefs via a Dirichlet Process Mixture of Statements12 Multirobot Reconnection on Graphs: Problem, Complexity, and Algorithms13 Robust Intrinsic and Extrinsic Calibration of RGB-D Cameras14 Reactive Trajectory Generation for Multiple Vehicles in Unknown Environments With Wind Disturbances15 Resource-Aware Large-Scale Cooperative Three-Dimensional Mapping Using Multiple Mobile Devices16 Control of Planar Spring–Mass Running Through Virtual Tuning of Radial Leg Damping17 Gait Design for a Snake Robot by Connecting Curve Segments and ExperimentalDemonstration18 Server-Assisted Distributed Cooperative Localization Over Unreliable Communication Links19 Realization of Smooth Pursuit for a Quantized Compliant Camera Positioning SystemISSUE 41 A Survey on Aerial Swarm Robotics2 Trajectory Planning for Quadrotor Swarms3 A Distributed Control Approach to Formation Balancing and Maneuvering of Multiple Multirotor UAVs4 Joint Coverage, Connectivity, and Charging Strategies for Distributed UAV Networks5 Robotic Herding of a Flock of Birds Using an Unmanned Aerial Vehicle6 Agile Coordination and Assistive Collision Avoidance for Quadrotor Swarms Using Virtual Structures7 Decentralized Trajectory Tracking Control for Soft Robots Interacting With the Environment8 Resilient, Provably-Correct, and High-Level Robot Behaviors9 Humanoid Dynamic Synchronization Through Whole-Body Bilateral Feedback Teleoperation10 Informed Sampling for Asymptotically Optimal Path Planning11 Robust Tactile Descriptors for Discriminating Objects From Textural Properties via Artificial Robotic Skin12 VINS-Mono: A Robust and Versatile Monocular Visual-Inertial State Estimator13 Zero Step Capturability for Legged Robots in Multicontact14 Fast Gait Mode Detection and Assistive Torque Control of an Exoskeletal Robotic Orthosis for Walking Assistance15 Physically Plausible Wrench Decomposition for Multieffector Object Manipulation16 Considering Uncertainty in Optimal Robot Control Through High-Order Cost Statistics17 Multirobot Data Gathering Under Buffer Constraints and Intermittent Communication18 Image-Guided Dual Master–Slave Robotic System for Maxillary Sinus Surgery19 Modeling and Interpolation of the Ambient Magnetic Field by Gaussian Processes20 Periodic Trajectory Planning Beyond the Static Workspace for 6-DOF Cable-Suspended Parallel Robots1 Computationally Efficient Trajectory Generation for Fully Actuated Multirotor Vehicles2 Aural Servo: Sensor-Based Control From Robot Audition3 An Efficient Acyclic Contact Planner for Multiped Robots4 Dimensionality Reduction for Dynamic Movement Primitives and Application to Bimanual Manipulation of Clothes5 Resolving Occlusion in Active Visual Target Search of High-Dimensional Robotic Systems6 Constraint Gaussian Filter With Virtual Measurement for On-Line Camera-Odometry Calibration7 A New Approach to Time-Optimal Path Parameterization Based on Reachability Analysis8 Failure Recovery in Robot–Human Object Handover9 Efficient and Stable Locomotion for Impulse-Actuated Robots Using Strictly Convex Foot Shapes10 Continuous-Phase Control of a Powered Knee–Ankle Prosthesis: Amputee Experiments Across Speeds and Inclines11 Fundamental Actuation Properties of Multirotors: Force–Moment Decoupling and Fail–Safe Robustness12 Symmetric Subspace Motion Generators13 Recovering Stable Scale in Monocular SLAM Using Object-Supplemented Bundle Adjustment14 Toward Controllable Hydraulic Coupling of Joints in a Wearable Robot15 Geometric Construction-Based Realization of Spatial Elastic Behaviors in Parallel and Serial Manipulators16 Dynamic Point-to-Point Trajectory Planning Beyond the Static Workspace for Six-DOF Cable-Suspended Parallel Robots17 Investigation of the Coin Snapping Phenomenon in Linearly Compliant Robot Grasps18 Target Tracking in the Presence of Intermittent Measurements via Motion Model Learning19 Point-Wise Fusion of Distributed Gaussian Process Experts (FuDGE) Using a Fully Decentralized Robot Team Operating in Communication-Devoid Environment20 On the Importance of Uncertainty Representation in Active SLAM1 Robust Visual Localization Across Seasons2 Grasping Without Squeezing: Design and Modeling of Shear-Activated Grippers3 Elastic Structure Preserving (ESP) Control for Compliantly Actuated Robots4 The Boundaries of Walking Stability: Viability and Controllability of Simple Models5 A Novel Robotic Platform for Aerial Manipulation Using Quadrotors as Rotating Thrust Generators6 Dynamic Humanoid Locomotion: A Scalable Formulation for HZD Gait Optimization7 3-D Robust Stability Polyhedron in Multicontact8 Cooperative Collision Avoidance for Nonholonomic Robots9 A Physics-Based Power Model for Skid-Steered Wheeled Mobile Robots10 Formation Control of Nonholonomic Mobile Robots Without Position and Velocity Measurements11 Online Identification of Environment Hunt–Crossley Models Using Polynomial Linearization12 Coordinated Search With Multiple Robots Arranged in Line Formations13 Cable-Based Robotic Crane (CBRC): Design and Implementation of Overhead Traveling Cranes Based on Variable Radius Drums14 Online Approximate Optimal Station Keeping of a Marine Craft in the Presence of an Irrotational Current15 Ultrahigh-Precision Rotational Positioning Under a Microscope: Nanorobotic System, Modeling, Control, and Applications16 Adaptive Gain Control Strategy for Constant Optical Flow Divergence Landing17 Controlling Noncooperative Herds with Robotic Herders18 ε⋆: An Online Coverage Path Planning Algorithm19 Full-Pose Tracking Control for Aerial Robotic Systems With Laterally Bounded Input Force20 Comparative Peg-in-Hole Testing of a Force-Based Manipulation Controlled Robotic HandISSUE 11 Development of the Humanoid Disaster Response Platform DRC-HUBO+2 Active Stiffness Tuning of a Spring-Based Continuum Robot for MRI-Guided Neurosurgery3 Parallel Continuum Robots: Modeling, Analysis, and Actuation-Based Force Sensing4 A Rationale for Acceleration Feedback in Force Control of Series Elastic Actuators5 Real-Time Area Coverage and Target Localization Using Receding-Horizon Ergodic Exploration6 Interaction Between Inertia, Viscosity, and Elasticity in Soft Robotic Actuator With Fluidic Network7 Exploiting Elastic Energy Storage for “Blind”Cyclic Manipulation: Modeling, Stability Analysis, Control, and Experiments for Dribbling8 Enhance In-Hand Dexterous Micromanipulation by Exploiting Adhesion Forces9 Trajectory Deformations From Physical Human–Robot Interaction10 Robotic Manipulation of a Rotating Chain11 Design Methodology for Constructing Multimaterial Origami Robots and Machines12 Dynamically Consistent Online Adaptation of Fast Motions for Robotic Manipulators13 A Controller for Guiding Leg Movement During Overground Walking With a Lower Limb Exoskeleton14 Direct Force-Reflecting Two-Layer Approach for Passive Bilateral Teleoperation With Time Delays15 Steering a Swarm of Particles Using Global Inputs and Swarm Statistics16 Fast Scheduling of Robot Teams Performing Tasks With Temporospatial Constraints17 A Three-Dimensional Magnetic Tweezer System for Intraembryonic Navigation and Measurement18 Adaptive Compensation of Multiple Actuator Faults for Two Physically Linked 2WD Robots19 General Lagrange-Type Jacobian Inverse for Nonholonomic Robotic Systems20 Asymmetric Bimanual Control of Dual-Arm Exoskeletons for Human-Cooperative Manipulations21 Fourier-Based Shape Servoing: A New Feedback Method to Actively Deform Soft Objects into Desired 2-D Image Contours22 Hierarchical Force and Positioning Task Specification for Indirect Force Controlled Robots。
2025年山东省济南市英语中考仿真试题与参考答案一、听力部分(本大题有20小题,每小题1分,共20分)1、Listen to the conversation:Man: Hi, Sarah, did you finish reading the book borrowed from the library?Woman: Yes, but it took me longer than expected. I’ll have to renew it online so that someone else doesn’t check it out before I can return it.Question: Why does the woman need to renew the book online?A)She hasn’t finished reading it.B)She wants to keep it longer.C)She forgot where she put it.D)She wants to reserve another copy.Answer: B) She wants to keep it longer.Explanation: The woman mentions that it took her longer than expected to finish the book, implying she needs more time with it. Therefore, she plans to renew it online to prevent others from checking it out before she can return it, indicating she wishes to extend her borrowing period.2、Listen to the conversation:Woman: Excuse me, could you tell me how to get to the nearest post office?Man: Sure, go straight down this street until you reach the second traffic light. Turn left, and then take the first right. You won’t miss it.Question: How should the woman get to the post office?A)Go straight, turn right at the first traffic light, then take the first left.B)Go straight, turn left at the second traffic light, then take the first right.C)Turn left at the first traffic light, then take the second right.D)Turn right at the second traffic light, then take the first left.Answer: B) Go straight, turn left at the second traffic light, then take the first right.Explanation: The man clearly instructs the woman to go straight until the second traffic light, turn left there, and then take the first right after that. Thus, option B provides the correct directions as given in the conversation.3、You will hear a short conversation between two students about their weekend plans. Listen carefully and answer the question.Question: What does the second student suggest doing this weekend?A. Going to the movies.B. Visiting a museum.C. Having a picnic in the park.Answer: CExplanation: The second student suggests having a picnic in the park, as mentioned in the conversation. The other options are not mentioned by either student.4、You will hear a short interview with a chef. Listen carefully and answer the question.Question: What is the chef’s favorite ingredient to use in their dishes?A. Garlic.B. Olive oil.C. Lemon.Answer: CExplanation: The chef states in the interview that their favorite ingredient to use in their dishes is lemon, making option C the correct answer. The other options are not mentioned as the chef’s favorite ingredient.5、Listen to the following conversation and answer the question.M: Hi, Sarah, how was your weekend?W: Oh, it was great! I went hiking with my friends in the mountains. The scenery was beautiful.M: That sounds amazing. Did you enjoy it?W: Yes, I did. We also stopped at a small restaurant for lunch. The food was delicious.M: I wish I could have joined you.W: Maybe next time.Question: What did Sarah do during her weekend?Answer: She went hiking with her friends.Explanation: In the conversation, Sarah mentions that she went hiking with her friends in the mountains, which is the correct answer to the question.6、Listen to the following dialogue and answer the question.M: Good morning, Professor Smith. I need to talk to you about my research paper.W: Good morning, John. What’s the problem?M: Well, I’m having trouble finding reliable source s for my topic.W: I see. Have you tried the library’s online databases?M: Yes, but they’re not very user-friendly.W: You can also ask the library staff for help. They’re very knowledgeable.M: That’s a good idea. I’ll go and ask them.W: Sure, John. I’m sure you’ll find what you need.Question: What is the main problem that John is facing?Answer: He is having trouble finding reliable sources for his research paper.Explanation: In the dialogue, John expresses his difficulty in finding reliable sources for his research paper, which is the main problem mentioned in the conversation.7.You will hear a conversation between two friends discussing their favorite movie. Listen carefully and answer the following question:What movie does the girl like?A. TitanicB. AvatarC. Star WarsD. The GodfatherAnswer: B. AvatarExplanation: In the conversation, the girl mentions that her favorite movie is Avatar, a science fiction film directed by James Cameron.8.You will hear a short talk about the benefits of reading. Listen carefully and answer the following question:What is one of the benefits of reading mentioned in the talk?A. Improves memoryB. Enhances creativityC. Boosts confidenceD. Increases intelligenceAnswer: B. Enhances creativityExplanation: In the talk, the speaker discusses how reading can be a great source of inspiration and can help in enhancing creativity.9.Listen to the conversation between two friends discussing their plans for the weekend. Answer the following question:What does the man suggest doing for the weekend?A. Going to the movies.B. Visiting a museum.C. Hiking in the mountains.Answer: BExplanation: The man mentions that he heard there is a new exhibit at the museum, which suggests that he is interested in visiting a museum for the weekend.10.Listen to a short dialogue between a teacher and a student about a school project. Answer the following question:What is the main issue the student is facing with the project?A. The topic is too broad.B. The deadline is too soon.C. The student is not sure where to start.Answer: CExplanation: The student expresses uncertainty about where to start the project, indicating that the main issue is the lack of a starting point rather than the topic or deadline.11.Listen to the following dialogue and choose the best answer to complete the sentence.A. The man is planning a vacation.B. The woman is asking for directions.C. They are discussing the weather.Answer: BExplanation: In the dialogue, the woman is asking the man for directions to the nearest coffee shop. The conversation revolves around giving directions, making option B the correct answer.12.Listen to the following conversation and answer the question.Qu estion: What is the woman’s profession?A. A teacherB. A doctorC. A lawyerAnswer: CExplanation: In the conversation, the man mentions that he has heard about the woman’s legal expertise. The woman confirms this, indicating that she isa lawyer. Therefore, option C is the correct answer.13.Listen to the following conversation between two friends, and answer the question.A: Hey, did you hear about the new movie that just came out?B: Yeah, I did! It looks amazing. What do you think it’s about?A: Well, from the trailers, it seems to be about a time-travel adventure.B: Oh, that sounds interesting. I can’t wait to see it!Question: What are the two friends discussing?Answer: The new movie that just came out.14.Listen to the following short dialogue and answer the question.M: I can’t believe it’s already time for the final exam. I’ve been so busy with my projects.W: Yeah, it’s true. But I think you’ve done well, so don’t worry too much.M: Thanks, I apprecia te that. I just hope I’ve studied enough.W: You have. You’ve put in a lot of effort, and that’s what counts.Question: What is the main topic of the conversation?Answer: The upcoming final exam.15.You will hear a short conversation between two friends. Listen carefully and choose the best answer to the question that follows.Question: What is the woman’s main concern about the movie?A. The movie is too long.B. The movie is not suitable for children.C. The movie is too expensive.D. The movie is not playing in her area.Answer: BExplanation: The woman expresses her concern about the movie not being appropriate for children, suggesting that she is worried about the content or themes.16.You will hear a short interview with a local chef. Listen carefully and answer the question that follows.Question: What is the chef’s favorite type of cuisine to cook?A. ItalianB. MexicanC. JapaneseD. AmericanAnswer: CExplanation: The chef explicitly mentions that their favorite type of cuisine to cook is Japanese, which is the correct answer.17.Listen to the conversation between two friends, and answer the question.What are they discussing?A)The weatherB) A new movieC) A recent sports eventAnswer: C)Explanation: The conversation starts with the first speaker mentioning the recent World Cup, which indicates they are discussing a sports event.18.Listen to the dialogue and choose the correct response for the question.Who is making the suggestion?A)The manB)The womanC)BothAnswer: A)Explanation: The man is the one making the suggestion. He says, “Let’s go to that new Italian restaurant on Main Street tonight,” which clearly indicates he is the one proposing an idea.19.You will hear a conversation between two friends discussing their weekend plans. Listen carefully and choose the best answer to each question.A. What are they planning to do on Saturday?1.Go to the movies.2.Visit a museum.3.Have a picnic.Answer: 2. Visit a museum.Explanation: The man mentions that he wants to visit the new art museum in town, so the correct answer is option 2.20.Listen to a short interview with a famous author. Answer the following question based on what you hear.A. What is the author’s favorite book?1.”To Kill a Mockingbird.”2.”Pride and Prejudice.”3.”1984.”Answer: 3. “1984.”Explanation: In the interview, the author expresses her love for George Orwell’s “1984,” making option 3 the correct answer.二、阅读理解(30分)Title: The Great MigrationRead the following passage:The Great Migration was a mass movement of African Americans from the rural Southern United States to the urban Northeast, Midwest, and West during the early 20th century. This migration was primarily driven by the desire for better job opportunities, improved living conditions, and the chance to escape the harsh realities of racial segregation and violence in the South.The migration began in the 1910s and reached its peak in the 1940s and 1950s. Many African Americans left their homes in the rural South, traveling by train, car, and on foot to seek a new life in the North. The journey was often difficult and dangerous, with many facing discrimination and violence along the way.Once in the North, many African Americans found that the living conditions were not as ideal as they had hoped. They often worked in low-paying jobs andfaced discrimination in housing, education, and public services. Despite these challenges, the Great Migration had a profound impact on American society, leading to significant changes in the cultural, social, and political landscapes of the United States.Questions:1.What was the main reason for the Great Migration during the early 20th century?A) To improve agricultural practices in the SouthB) To seek better job opportunities and escape racial segregationC) To follow family members who had already moved NorthD) To participate in the World War I2.Which of the following best describes the living conditions of African Americans in the North after the Great Migration?A) They lived in luxurious apartments and enjoyed high-paying jobsB) They faced discrimination and worked in low-paying jobsC) They lived in segregated neighborhoods and had access to the same public services as whitesD) They returned to the South due to the harsh living conditions in the North3.What was the overall impact of the Great Migration on American society?A) It led to the collapse of the Southern economyB) It resulted in the complete racial integration of the United StatesC) It contributed to significant changes in the cultural, social, and political landscapes of the United StatesD) It had no long-term effects on American societyAnswers:1.B) To seek better job opportunities and escape racial segregation2.B) They faced discrimination and worked in low-paying jobs3.C) It contributed to significant changes in the cultural, social, and political landscapes of the United States三、完型填空(15分)Complete the passage by choosing the most appropriate word or phrase from the options below for each blank.Three years ago, when I first moved to London, I found myself in a situation that was both exciting and challenging. The city was [1], with its towering skyscrapers and bustling streets. I had [2] a language course to improve my English, but the [3] of finding an apartment was not as easy as I had thought.I spent hours [4] through online listings, but many of the apartments were either too expensive or in locations that were too [5]. Finally, after much searching, I found a cozy flat in a quieter neighborhood. It was not perfect, but it was home.1.A. quietB. livelyC. boringD. deserted2.A. enrollingB. decliningC. hesitatingD. postponing3.A. processB. challengeC. opportunityD. experience4.A. skimmingB. ignoringC. rushingD. rejecting5.A. expensiveB. crowdedC. isolatedD. unappealing Answers:1.B. lively2.A. enrolling3.A. process4.A. skimming5.D. unappealing四、语法填空题(本大题有10小题,每小题1分,共10分)1、In the past, many families used to______(go) to the cinema every weekend.答案:go解析:本题考查动词的时态。
Use of the circuit approach to solve large EMC problems??用电路方法来解决大规模EMC中的问题Comptes Rendus PhysiqueLike electromagnetic topology, the equivalent electric circuit theory can be transposed to solve large electromagnetic systems. Compared to measures into a cavity, an analogy with coupled circuits will be made. Kron's formalism has been chosen to describe the system of equations. We will use a hyper matrix impedance with sub-matrix describing some interactions of the system. The inverse of the impedance matrix will give us scattering parameters S21 between a transmitting and a receiving antenna installed in the cavity. Next, a second receiver will be added outside the cavity. The aim of this article is to show the interest of Kron's method applied to complex systems, in which many of physical phenomena are involved.Au même titre que la topologie électromagnétique, la théorie des circuits électriques peut être transposée pour la résolution de problèmes électromagnétiques complexes. En prenant pour base des expériences réalisées sur une cavité, nous allons procéder à une analogie avec des circuits couplés. Puis, à l'aide du formalisme de Kron, nous décrirons une super matrice impédance dans laquelle figurerons des sous-matrices révélatrices des différents couplages mis en jeu. L'inversion de cette matrice mènera finalement à la détermination du coefficient de transfert S21 liant un monopole émetteur et un premier monopole récepteur installé dans cette cavité. Un second monopole récepteur sera ensuite mis en place à l'extérieur de la cavit é.Model for radiation emission EMC measurement at OATS: Issues and approaches? MeasurementOpen area-test site (OATS) is envisaged to be one of the key components in measuring radiation emissions for new electronics products in noisy environment, providing flexible high resolution backhaul over expensive anechoic chamber for early investigation. While single chamber cost suffer from range of operating frequencies constraints, equipping OATS with flexible ambient masking module (FAM) can significantly alleviate the ambient problem and increase the aggregate precision available to electronics product to meet local electromagnetic compatibility (EMC) standards. The goal of this classification algorithm is to characterize source generated data concealed within ambient and then to categorize them according to their attribute. In this paper we examine the unique constraint of site attenuation and identify the key factors governing assignment schemes, with particular reference to interference, precision of transducers and noise profiles. After presenting the taxonomy of existing kind of pass type data assignment, we describe a real time data assignment architecture which incorporates the radiation emissions together with class issues in order to minimize interference with ambient and how its integration can be exploited to achieve chamber efficiency is discussed. The preliminary performance results validate the design choices of the parameters and confirm the potential impact of the price paid.Article Outline1. Introduction2. Taxonomy of data assignment schemes for radiated emission2.1. Ambient assignment2.2. Complete-pass data assignment2.3. Quasi-pass data assignment2.4. Average-pass data assignment3. FAM: a new data assignment scheme and architecture4. Proposed algorithm5. Comparison of two scenarios6. Performance evaluation7. Testbed implementation7.1. Testbed7.2. Hardware compatibility8. ConclusionAcknowledgementsReferencesVitaeA comprehensive simulation model for immunity prediction in integrated circuits with respect to substrate injection?Microelectronics JournalThis paper presents a comprehensive modelling methodology for the electromagnetic immunity of integrated circuits (ICs) to direct power injection (DPI). The aim of this study is to predict the susceptibility of ICs by the means of simulations performed on an appropriate electrical model of different integrated logic cores located in the same die. These cores are identical from a functional point of view, but differ by their design strategies. The simulation model includes the whole measurement setup as well as the integrated circuit under test, its environment (PCB, power supply) and the substrate model of each logic core. Simulation results and comparisons with measurement results demonstrate the validity of the suggested model. Moreover, they highlight the interest of the aforementioned protection strategies against electromagnetic disturbances.Article Outline1. Introduction2. Description of the test chip3. Direct power injection (DPI) method: set-up and modelling3.1. Set-up of the injection system3.2. Modelling of the injection system and the PCB3.3. Modelling of the integrated circuit package and bonding3.4. Modelling of CESAME cores3.4.1. Substrate modelling for the NORM core3.4.2. Substrate modelling for the ISO core3.4.3. Substrate modelling for the RC core4. Results5. Discussion and comparison among results5.1. Measurement results5.2. Simulation results6. ConclusionIntroduction to BESIII EMC sub-trigger system??Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated EquipmentThe Electromagnetic Calorimeter (EMC) sub-trigger system is one of the important parts of the trigger system of the BESIII spectrometer. Together with the conditions from the other sub-trigger systems, cluster-related and energy-related trigger conditions are provided to the Global Trigger system for effective selection of events interested and rejection of backgrounds. Total two types of PCB boards are designed to implement the whole functions, which are Trigger Cell and energy Block Adding (TCBA) and Energy Adding and Cluster Counting (EACC). Simulations and hardware arrangement of the EMC sub-trigger system are introduced in this paper.Article Outline1. Introduction2. Simulation of the EMC sub-trigger system2.1. Determination of TC2.2. Energy threshold of the TC2.3. Trigger efficiency of EMC trigger subsystem3. Trigger conditions of EMC trigger subsystem3.1. Isolated cluster finding3.2. Definition of the energy blocks3.3. Trigger conditions4. Hardware scheme of EMC trigger subsystem4.1. Scheme of TCBA board4.2. Scheme of EACC board4.3. Technique adopted in EMC sub-trigger system5. SummaryAcknowledgementsReferencesComparison among emission and susceptibility reduction techniques for electromagnetic interference in digital integrated circuits?Microelectronics JournalThis paper presents a comparative study of susceptibility reduction techniques for electromagnetic interference (EMI) in digital integrated circuits (ICs). Both direct power injection (DPI) and very-fast transmission-line pulsing (VF-TLP) methods are used to inject interference into the substrate of a single test chip. This IC is built around six functionally identical cores, differing only by their EMI protection strategies (RC protection, isolated substrate, meshed power supply network) which were initially designed for low emission design rules. The ranking of three of thesecores in terms of electromagnetic immunity is then compared with the one of their radiated emission, thanks to near-field scanning (NFS) measurements. This leads to the establishing of design guidelines for low EMI in digital ICs.Article Outline1. Introduction2. Description of the test chip3. Immunity measurements3.1. Immunity criterion3.2. Direct power injection (DPI)3.2.1. Description3.2.2. Results3.3. Very fast transmission line pulsing (VF-TLP)3.3.1. Purpose3.3.2. Measurement method3.3.3. Results4. Emission measurement4.1. Measurement method4.2. Results5. Comparison between immunity and emission results6. ConclusionAcknowledgementsReferencesThe accurate calibration of EMC antennas in compact chambers — Measurements and uncertainty evaluations??Computer Standards & InterfacesAbstractThe accurate knowledge of the antenna factor is a fundamental requirement for reliable electromagnetic compatibility (EMC) measurements in emissions, immunity and human exposure tests. According to international standards, the calibration of EMC antennas requires close-to-ideal test sites (or calibration test sites), characterized by very large sizes of the ground plane and of the empty space volume above it (free-space behaviour). On the other hand a great number of EMC test sites are available and designed for measurements at 3?m distance, therefore it would be very convenient to calibrate antennas in such facilities at the cost of an acceptable loss of accuracy. In this paper, the authors investigate the suitability of compact semi-anechoic chambers (standard chambers, compliant for measurements at 3?m distance from the equipment under test) for reliable antenna factor calibrations. As an application, the calibration of a common broadband biconical antenna in the 200–1000?MHz frequency range is here considered and analysed. A detailed experimental analysis is offered for estimating all the relevant uncertainty contributions.Article Outline1. Introduction2. The proposed approach3. Experimental results4. ConclusionsAcknowledgementsReferencesElectromagnetic characterization of chiral auxetic metamaterials for EMC applications??Computer Standards & InterfacesA new class of auxetic materials, a hexachiral honeycomb structure with good mechanical properties, is investigated through computer simulation and measurement. The electromagnetic properties for shielding applications are taken into account. This new material shows some interesting EMC properties (e.g. ??40?dB transmittance at 2.4?GHz) and promises better performance using different insertion techniques. Article Outline1. Introduction2. Computer simulation2.1. Test details2.2. Accuracy of the results2.3. Convergence stability analysis2.3.1. Frequency domain analysis2.3.2. Time domain analysis2.4. Computational efficiency2.5. Parametric analysis3. Measurements3.1. Measurements detail3.2. Measurement results4. ConclusionsAcknowledgementsThe UltraBattery—A new battery design for a new beginning in hybrid electric vehicle energy storage?Journal of Power SourcesThe UltraBattery, developed by CSIRO Energy Technology in Australia, is a hybrid energy storage device which combines an asymmetric super-capacitor and a lead–acid battery in single unit cells. This takes the best from both technologies without the need for extra, expensive electronic controls. The capacitor enhances the power and lifespan of the lead–acid battery as it acts as a buffer during high-rate discharging and charging, thus enabling it to provide and absorb charge rapidly during vehicle acceleration and braking.The initial performance of the prototype UltraBatteries was evaluated according to the US FreedomCAR targets and was shown to meet or exceed these in terms of power, available energy, cold cranking and self-discharge set for both minimum and maximum power-assist hybrid electric vehicles (HEVs). Other laboratory cycling tests showed a fourfold improvement over previous state-of-the-art lead–acid batteries under theRHOLAB test profile and better life than commercial nickel/metal hydride (NiMH) cells used in a Honda Insight when tested under the EUCAR HEV profile.As a result of this work, a set of twelve 12?V modules was built by The Furukawa Battery Co., Ltd. in Japan and were fitted into a Honda Insight instead of the NiMH battery by Provector Ltd. The battery pack was fitted with full monitoring and control capabilities and the car was tested at Millbrook Proving Ground under a General Motors road test simulation cycle for an initial target of 50?000 miles which was extended to 100?000 miles. This was completed on 15th January 2008 without any battery problems. Furthermore, the whole test was completed without the need for any conditioning or equalisation of the battery pack.Article Outline1. Introduction2. Experimental3. Results and discussion4. Vehicle demonstration4.1. The test cycle4.2. Typical test data5. ConclusionsAcknowledgementsReferencesStatic analysis for functionally graded piezoelectric actuators or sensors under a combined electro-thermal load??European Journal of Mechanics - A/SolidsBased on the theory of piezoelasticity, a functionally graded piezoelectric sandwich cantilever under an applied electric field and/or a heat load is studied. All materials may be arbitrary functional gradients in the thickness direction. The static solution for the mentioned problems is presented by the Airy stress function method. As a special case, assuming that the material composition varies continuously in the direction of the thickness according to a power law distribution, a comprehensive parametric study is conducted to show the influence of electromechanical coupling (EMC), functionally graded index, temperature change and thickness ratio on the bending behavior of actuators or sensors. The distribution of electric field or normal stress in present FGPM actuators is continuous along the thickness, which overcomes the problem in traditional layered actuators. The solution facilitates the design optimization for different piezoelectric actuators and has another potential application for material parameter identification.Article Outline1. Introduction2. Basic equations3. Static analysis based on the Airy stress function method3.1. Thermal filed3.2. General solution3.3. FGPM actuator3.4. FGPM thermal sensors4. Numerical results and discussion4.1. Comparisons and effect of the electromechanical coupling (EMC)4.2. Parametric studies for FGPM actuators4.3. Parametric study for FGPM thermal sensors5. Results and conclusionsAcknowledgementsAppendix A. AppendixReferencesVerification of a commercial implementation of the Macro-Monte-Carlo electron dose calculation algorithm using the virtual accelerator approach??Zeitschrift für Medizinische PhysikIn this work, the accuracy of the implementation of the Macro Monte Carlo electron dose calculation algorithm into the radiation therapy treatment planning system Eclipse is evaluated. This implementation – called eMC – uses a particle source based on the Rotterdam Initial Phase-Space model. A three-dimensional comparison of eMC calculated dose to dose distributions resulting from full treatment head simulations with the Monte Carlo code package EGSnrc is performed using the ‘virtual accelerator’ approach. Calculated dose distributions are compared for a homogeneous tissue equivalent phantom and a water phantom with air and bone inhomogeneities. The performance of the eMC algorithm in both phantoms can be considered acceptable within the 2%/2?mm Gamma index criterion. A systematic underestimation of dose by the eMC algorithm within the air inhomogeneity is found.ZusammenfassungIn dieser Arbeit wird die Implementierung des Macro-Monte-Carlo Dosisberechnungsalgorithmus für Elektronen im Bestrahlungsplanungssystem Eclipse untersucht, welche dort eMC genannt wird. Als Quellenmodell dient ein modifiziertes “Rotterdam Initial Phase-Space model”. Unter Verwendung eines virtuellen Beschleunigers werden dreidimensionale Dosisverteilungen, resultierend aus Monte-Carlo-Beschleunigerkopfsimulationen mit EGSnrc, mit denen des Bestrahlungsplanungssystems verglichen. Ein homogenes gewebe?quivalentes Phantom und ein Wasserphantom mit Inhomogenit?ten aus Luft und Knochen werden hierzu verwendet. Die Dosisberechnungsgenauigkeit in beiden Phantomen basiert auf einem Gamma-Index-Test mit 2%/2?mm akzeptabel. In Luft findet eine deutliche systematische Untersch?tzung der Dosis durch den eMC-Algorithmus statt.Article Outline1. Introduction2. Methods2.1. Electron Monte Carlo (eMC) Algorithm2.2. Virtual Accelerator Approach2.3. EGSnrc calculations2.4. Phantoms2.5. Dose comparison3. Results and Discussion3.1. eMC Input Data3.2. Homogeneous Phantom3.3. Trachea and Spine Phantom4. ConclusionAcknowledgementsZwitterionic imidazolium compounds with high cathodic stability as additives for lithium battery electrolytes??A series of imidazolium-based zwitterionic compounds having both a propylsulfonate group at 3-position and an ester group at 1- or 2-position are synthesized and their interactions with LiPF6 are investigated. FT-IR study and theoretical calculation using density functional theory show that the interactions of the zwitterionic compound with LiPF6 varies significantly with the location of the ester group on the imidazolium ring. The electrochemical stability of the imidazolium-based zwitterionic compound is significantly improved by introducing an ester group at the C-2 position of the imidazolium ring. Cycle performance tests show that the initial cell capacity remains almost unchanged up to 100 cycles at 1/2?C when 2.5?wt.% of 2-(acetoxymethy)-1-butylimidazolium-3-propylsulfonate is added to the model electrolyte consisting of ethylene carbonate (EC), dimethyl carbonate (DMC), and ethylmethyl carbonate (EMC) (EC/DMC/EMC?=?1/1/1 v/v/v), whereas the capacity of the cell containing an unsubstituted or methyl-substituted imidazolium compound at the C-2 position, 1-(acetoxymethyl)imidazolium-3-propylsulfonate or 1-(acetoxymethyl)-2-methylimidazolium-3-propylsulfonate as an additive, starts to decrease rapidly just after a few cycles.Article Outline1. Introduction2. Experimental2.1. Synthesis of 1-methyl-2-(hydroxymethyl)imidazole (1a)2.2. Synthesis of 1-methyl-2-(acetoxymethyl)imidazole (2a)2.3. Synthesis of 1-methyl-2-(acetoxymethyl)imidazolium-3-propylsulfonate (3a) 2.4. Instruments2.5. Computational details3. Results and discussion3.1. Thermal properties3.2. Electrochemical properties3.3. Cell performance3.4. FT-IR experiments3.5. Theoretical calculations4. ConclusionsAcknowledgementsReferencesNumerical simulation of a Reverberation Chamber with a stochastic collocationmethod??Comptes Rendus PhysiqueAn original numerical modelling of Mode Stirred Reverberation Chamber used in Electromagnetic Compatibility is proposed. This method relies on an analogy between a reverberation chamber and an enclosure whose walls' conductivity is randomly characterised. The distribution law of this parameter is obtained by measurements. Applying a stochastic collocation method enables one to numerically assess electromagnetic field from a low number of empty cavity (without stirrer) simulations. Thus this approach notably reduces CPU time allowing more complex simulations. RésuméCet article propose une méthodologie originale pour la modélisation numérique de Chambres Réverbérantes à Brassage de Modes utilisées en Compatibilité Electromagn étique. Cette approche repose sur une analogie entre une chambre réverbérante et une cavité dont les parois sont caractérisées par une conductivité aléatoire. La loi de distribution de ce paramètre est établie à partir de mesures. L'application d'une méthode de collocation stochastique permet alors de déterminer numériquement le champ électromagnétique gr?ce à un faible nombre de simulation d'une cavité sans brasseur. Cette méthodologie conduit ainsi à une amélioration importante en temps de calcul autorisant des simulations plus complexes.Improved complex filter applied in enhancing EFT/B immunity at a coal mine monitoring substation??Journal of China University of Mining and TechnologyA monitoring system is an important guarantee of safety in a production mine. However, not all monitoring substations pass the electrical fast transient/burst (EFT/B) immunity test and the explosion-proof test simultaneously. To enhance the immunity, the values of capacitance and inductance should be increased, which are actually limited by coal mine explosion-proof standards. Hence, for the first time, an active filter was applied in an electromagnetic interference (EMI) output filter. As a result, the interference within 30 MHz clearly weakened, but the frequency spectrum had a wide range. An EMI input filter and ferrite beads were adopted to restrain higher frequency interference. An output interference spectrogram of the substation was obtained with an analyzer. The results indicate that the improved complex filtering markedly help to control interference. With the support of improved complex filtering and other enhancing immunity means about I/O ports, the substation managed to pass both the EFT/B immunity test and the explosion-proof test synchronously. We conclude that improved complex filtering is of vital importance in enhancing the electromagnetic compatibility (EMC) of the coal mine monitoring system.A review of the features and analyses of the solid electrolyte interphase in Li-ion batteries??Electrochimica ActaThe solid electrolyte interphase (SEI) is a protecting layer formed on the negative electrode of Li-ion batteries as a result of electrolyte decomposition, mainly duringthe first cycle. Battery performance, irreversible charge “loss”, rate capability, cyclability, exfoliation of graphite and safety are highly dependent on the quality of the SEI. Therefore, understanding the actual nature and composition of SEI is of prime interest. If the chemistry of the SEI formation and the manner in which each component affects battery performance are understood, SEI could be tuned to improve battery performance. In this paper key points related to the nature, formation, and features of the SEI formed on carbon negative electrodes are discussed. SEI has been analyzed by various analytical techniques amongst which FTIR and XPS are most widely used. FTIR and XPS data of SEI and its components as published by many research groups are compiled in tables for getting a global picture of what is known about the SEI. This article shall serve as a handy reference as well as a starting point for research related to SEI.Article Outline1. Introduction2. Formation and features of the SEI2.1. Components of SEI2.2. Changes in SEI at elevated temperatures2.3. Influence of SEI on battery performance2.4. Influence of SEI on exfoliation of graphite3. Factors affecting SEI3.1. Type of carbon3.2. Pretreatment of carbon3.3. Electrolyte composition3.4. Other factors4. Characterization of SEI4.1. Fourier transform infrared spectroscopy (FTIR)4.2. Limitations of FTIR4.3. X-ray photoelectron spectroscopy (XPS)4.4. Limitations of XPS5. Conclusion5.1. Features of an ideal SEIAcknowledgementsReferencesComparison among emission and susceptibility reduction techniques for electromagnetic interference in digital integrated circuits??Microelectronics JournalThis paper presents a comparative study of susceptibility reduction techniques for electromagnetic interference (EMI) in digital integrated circuits (ICs). Both direct power injection (DPI) and very-fast transmission-line pulsing (VF-TLP) methods are used to inject interference into the substrate of a single test chip. This IC is built around six functionally identical cores, differing only by their EMI protection strategies (RC protection, isolated substrate, meshed power supply network) which were initially designed for low emission design rules. The ranking of three of thesecores in terms of electromagnetic immunity is then compared with the one of their radiated emission, thanks to near-field scanning (NFS) measurements. This leads to the establishing of design guidelines for low EMI in digital ICs.Article Outline1. Introduction2. Description of the test chip3. Immunity measurements3.1. Immunity criterion3.2. Direct power injection (DPI)3.2.1. Description3.2.2. Results3.3. Very fast transmission line pulsing (VF-TLP)3.3.1. Purpose3.3.2. Measurement method3.3.3. Results4. Emission measurement4.1. Measurement method4.2. Results5. Comparison between immunity and emission resultsElectromagnetic characterization of chiral auxetic metamaterials for EMC applications?The importance of heat evolution during the overcharge process and the protection mechanism of electrolyte additives for prismatic lithium ion batteries?In this work, the rate of heat generation in the overcharge period for 103450 prismatic lithium ion batteries (LIBs) of the LiCoO2–graphite jellyroll type with a basic electrolyte consisting of 1?M LiPF6–PC/EC/EMC (1/3/5 in weight ratio) has been found to be more important than the gas evolution which was traditionally considered as the main reason in the overcharge protection mechanism. The cell voltage, charge current, and skin temperature were monitored during the charge process. For a single battery or batteries in parallel, LIBs without any additives is an acceptable design if the cell voltage is not charged above 4.55?V under the common charge program. The rate of heat generation from the polymerization of 3?wt% cyclohexyl benzene (CHB) is high enough to cause the explosion or thermal runaway of a battery, which is not found for an LIB containing 2?wt% CHB?+?1?wt% tert-amyl benzene (TAB). In the 12?V overcharge test at 1C, the thermal fuse was broken by the high skin temperature (ca. 80?°C) due to the polymerization of 3?wt% CHB, which was also the case for LIBs containing 2?wt% CHB?+?1?wt% TAB. The disconnection of the thermal fuse, however, did not interrupt the thermal runaway of LIBs without any additives because the battery voltage was too high (ca. 4.9?V). The influence of specific surface area of active materials in the anode on the polymerization kinetics of additives has to be carefully considered in order to add correct amount of overcharge protection agents. Article Outline1. Introduction2. Experimental3. Results and discussion4. ConclusionsAcknowledgementsReferencesCarbonate-modified siloxanes as solvents of electrolyte solutions for rechargeable lithium cells?Influence of mixing carbonate-modified siloxanes into LiPF6-ethylene carbonate (EC)/ethylmethyl carbonate (EMC) (mixing volume ratio?=?3:7) mixed solvent electrolytes on charge–discharge cycling properties of lithium was examined. As the solute, 1?M (M: mol?L?1) LiPF6 was used. As siloxanes, 4-(2-trimethylsilyloxydimethylsilylethyl)-1,3-dioxolan-2-one and 4-(2-bis(trimethylsilyloxy)methylsilylethyl)-1,3-dioxolan-2-one were investigated. These siloxanes are derivatives of butylene cyclic carbonate or vinyl ethylene carbonate. Charge–discharge cycling efficiencies of lithium metal anodes improved and an impedance of anode/electrolyte interface decreased by mixing siloxanes, compared with those in 1?M LiPF6-EC/MEC alone. Slightly better cycling behavior of natural graphite anode was obtained by adding siloxanes. Si–C/LiCoO2 cells exhibited better anode utilization and good cycling performance by using 1?M LiPF6-EC/MEC?+?siloxane electrolytes. Thermal behavior of electrolyte solutions toward graphite–lithium anodes was evaluated with a differential scanning calorimeter. By adding siloxanes, temperature starting the large heat-output of graphite–lithium anodes with 1?M LiPF6-EC/MEC electrolyte solutions shifted to higher temperature about 100?°C. However, amount of heat-output did not decrease by adding siloxanes.Article Outline1. Introduction2. Experimental2.1. Preparation of electrolyte solutions2.2. Charge–discharge cycling tests of lithium anodes and LiCoO2 cells2.3. Thermal stability tests of electrolyte solutions2.4. AC impedance and conductivity measurements3. Results and discussion3.1. Electrolyte conductivity3.2. Charge–discharge cycling properties of lithium metal anodes in the electrolyte solutions with siloxanes3.3. AC impedance measurement results for interface between lithium electrode and electrolyte solutions3.4. Model for interface between lithium electrode and electrolyte solutions3.5. Charge–discharge cycling properties of lithium in graphite anodes in electrolyte solutions with siloxanes3.6. Charge–discharge cycling properties of Si–C anode/LiCoO2 cells with siloxane electrolytes。
Planning is an essential aspect of life that can significantly impact ones success and happiness.It is the process of setting goals,making decisions,and organizing resources to achieve those goals.Here are some reasons why planning is crucial in life:1.Clarity of Goals:Planning helps in setting clear and achievable goals.It allows individuals to define what they want to achieve in the short and long term,providing a roadmap for their future.2.Efficient Use of Time:By planning,you can allocate your time effectively.It helps in prioritizing tasks and ensuring that you focus on what is most important,reducing the chances of wasting time on less critical activities.3.Resource Management:Planning involves assessing the resources you have and how to best use them.This includes financial planning,career planning,and even planning for your personal life to ensure you have the necessary resources to achieve your goals.4.Risk Management:Life is full of uncertainties.Planning helps in identifying potential risks and developing strategies to mitigate them.This foresight can save you from unexpected setbacks.5.Increased Productivity:When you have a plan,you are more likely to stay focused and motivated.This leads to increased productivity as you work towards your set goals.6.Personal Growth:Planning for personal development,such as learning new skills or improving existing ones,can lead to personal growth and a more fulfilling life.7.Financial Stability:Financial planning is a key component of life planning.It helps in managing your income,savings,investments,and expenses,leading to financial stability and security.8.Career Advancement:Planning your career path can help you make informed decisions about your professional development,leading to promotions,better job opportunities,and career satisfaction.9.Health and Wellbeing:Planning for your health involves setting goals for physical fitness,mental health,and overall wellbeing.It can lead to a healthier lifestyle and improved quality of life.10.Retirement Planning:Planning for retirement is crucial to ensure that you have enough savings to maintain your desired lifestyle after you stop working.In conclusion,planning is a fundamental tool for shaping your life in a way that aligns with your values,aspirations,and circumstances.It requires selfawareness,discipline, and the ability to adapt to changes.By embracing the habit of planning,you can navigate the complexities of life with more confidence and purpose.。
如何把控未来不确定因素的英语作文全文共3篇示例,供读者参考篇1Managing Uncertainties: A Student's Guide to Navigating the FutureAs students, we often find ourselves caught up in the whirlwind of academic demands, social pressures, and personal aspirations. Amidst this chaos, the future looms like an enigmatic puzzle, riddled with uncertainties that can seem daunting and overwhelming. However, it is precisely these uncertainties that make the journey ahead thrilling and ripe with opportunities for growth and self-discovery.The first step in managing uncertainties is to embrace them wholeheartedly. Instead of perceiving them as obstacles, we must view them as catalysts for personal and intellectual development. Uncertainties challenge us to step out of our comfort zones, to think critically, and to devise innovative solutions. By embracing the unknown, we cultivate resilience, adaptability, and a growth mindset – invaluable assets in an ever-changing world.Secondly, it is imperative to develop a deep understanding of ourselves – our strengths, weaknesses, values, and aspirations. This self-awareness serves as a compass, guiding us through the maze of uncertainties. When we know our core values and what truly matters to us, we can make decisions with greater clarity and conviction, even in the face of ambiguity. Regularly reflecting on our experiences, seeking feedback from trusted mentors, and engaging in self-evaluation can aid in this process of self-discovery.Furthermore, we must learn to embrace flexibility and open-mindedness. The future is constantly shifting, and rigid adherence to predetermined plans can often lead to disappointment and frustration. By remaining adaptable and receptive to new opportunities, we increase our chances of capitalizing on unforeseen possibilities. This mindset encourages us to embrace change as a natural part of life, rather than perceiving it as a threat.Cultivating a diverse network of supportive individuals is also crucial in navigating uncertainties. Surrounding ourselves with people from diverse backgrounds, perspectives, and experiences enriches our understanding of the world and exposes us to different viewpoints. This exposure can broadenour horizons, challenge our assumptions, and ultimately equip us with the tools to navigate uncertainties more effectively.Moreover, continuous learning and skill development are vital in managing uncertainties. The world is rapidly evolving, and the skills that are relevant today may become obsolete tomorrow. By committing ourselves to lifelong learning and actively seeking opportunities to acquire new knowledge and abilities, we ensure that we remain adaptable and competitive in an ever-changing landscape.Finally, it is essential to maintain a positive and optimistic outlook. Uncertainties can often breed anxiety and fear, but dwelling on negative emotions only serves to undermine our resilience and decision-making abilities. Instead, we must cultivate a mindset of hope and possibility, recognizing that every challenge presents an opportunity for growth and personal transformation.In conclusion, managing uncertainties in the future is a multifaceted endeavor that requires a combination ofself-awareness, adaptability, continuous learning, and a positive mindset. By embracing these principles, we can navigate the uncertainties of the future with confidence, resilience, and a sense of excitement for the possibilities that lie ahead. Thejourney may be unpredictable, but it is precisely this unpredictability that makes the pursuit of our dreams so exhilarating and rewarding.篇2How to Manage Future UncertaintiesAs a student, the future often feels like a vast unknown filled with endless possibilities and uncertainties. From deciding on a career path to navigating personal relationships and financial responsibilities, there are so many variables that can make the road ahead seem daunting. However, learning to embrace and manage uncertainty is a crucial life skill that can help us not only survive but thrive in an ever-changing world.Firstly, it's important to understand that uncertainty is an inherent part of life. No matter how much we plan or prepare, there will always be factors beyond our control that can disrupt our best-laid plans. The key is to develop a mindset that allows us to adapt and pivot when faced with unexpected circumstances. This requires cultivating resilience, flexibility, and a willingness to continuously learn and grow.One approach to managing uncertainty is to focus on what we can control. While we may not be able to predict the future,we can take proactive steps to shape our circumstances and position ourselves for success. This could involve developing valuable skills, building a strong network of supportive relationships, and maintaining a healthy lifestyle that fosters mental and physical well-being.Developing a growth mindset is also crucial. Instead of viewing setbacks or challenges as failures, we can reframe them as opportunities for learning and personal growth. By embracing a mindset that values continuous improvement and sees obstacles as temporary, we can better navigate the uncertainties that life throws our way.Another important aspect of managing uncertainty is cultivating a sense of purpose and meaning. When we have a clear understanding of our values, goals, and what truly matters to us, it becomes easier to weather the storms of uncertainty. Having a strong sense of purpose can provide us with the motivation and resilience to persevere through difficult times and make decisions that align with our long-term aspirations.It's also essential to build a support system of trusted individuals who can offer guidance, encouragement, and diverse perspectives. Surrounding ourselves with a network of mentors, friends, and family members who can provide emotional andpractical support can be invaluable when facing uncertain times. They can offer insights, advice, and a listening ear, helping us to navigate challenges and explore new opportunities.In addition to these personal strategies, it's important to recognize that uncertainty is not just an individual experience but also a societal and global phenomenon. As students, we can play a role in shaping a more sustainable and equitable future by engaging with global issues and contributing our unique perspectives and talents.One way to do this is by staying informed about current events, emerging technologies, and global trends that may impact our future. This could involve reading reputable news sources, attending lectures or workshops, or participating in discussions and debates on relevant topics. By expanding our knowledge and understanding of the world around us, we can better anticipate and adapt to potential changes or disruptions.Furthermore, we can actively participate in addressing global challenges by volunteering, advocating for causes we believe in, or exploring entrepreneurial or innovative solutions. By taking action and contributing our ideas and efforts, we can help shape a future that is more resilient, inclusive, and prepared to tackle the uncertainties that lie ahead.Ultimately, managing future uncertainties is a lifelong journey that requires a combination of personal growth, strategic planning, and a willingness to adapt and evolve. It's a journey that demands courage, resilience, and a willingness to embrace change as an opportunity for growth and discovery.As students, we have the unique advantage of being at a formative stage in our lives, where we can actively cultivate the mindsets, skills, and support systems that will help us navigate the uncertainties that lie ahead. By embracing uncertainty as an inevitable part of life and developing strategies to manage it, we can not only survive but thrive in an ever-changing world.So let us embrace the unknown with open minds and resilient spirits, recognizing that while the future may be uncertain, it is also full of potential and opportunity for those who are willing to adapt, learn, and grow. By managing uncertainty effectively, we can shape our own destinies and contribute to a better, more resilient world for ourselves and generations to come.篇3How to Handle Future UncertaintiesThe future is a vast unknown, a canvas of infinite possibilities awaiting us. As we navigate through life's winding paths, uncertainties loom around every corner, casting shadows of doubt and apprehension. However, it is in our capacity to embrace these uncertainties that we find the key to unlocking our full potential and shaping our destinies.Uncertainty is an inescapable reality, intertwined with the very fabric of existence. From the unpredictable twists of global events to the personal challenges that life throws our way, we are constantly confronted with situations that defy our attempts at control. It is a humbling reminder that, despite our best efforts, the future remains an enigma, a puzzle that demands our adaptability and resilience.Yet, it is precisely this uncertainty that fuels the fires of human ingenuity and growth. If life were a predictable, linear journey, we would stagnate, trapped in the complacency of the familiar. Uncertainties challenge us to think outside the box, to explore uncharted territories, and to discover innovative solutions that propel us forward.Embracing uncertainty requires a shift in mindset, a willingness to let go of the illusion of control and embrace the unknown with open arms. It demands that we cultivate a growthmindset, recognizing that every setback is an opportunity to learn, adapt, and evolve. By reframing our perspective, we can transform uncertainties from daunting obstacles into catalysts for personal and professional growth.One of the most powerful tools in our arsenal for navigating uncertainties is the art of preparation. While we cannot predict the future with absolute certainty, we can equip ourselves with the knowledge, skills, and resources necessary to tackle whatever challenges may arise. This might involve continuous learning, developing a diverse skill set, building a strong support network, or cultivating financial stability. By laying a solid foundation, we increase our ability to weather the storms of uncertainty and seize emerging opportunities.Furthermore, embracing uncertainty requires a healthy dose of adaptability and flexibility. Life is a constantly evolving tapestry, and our ability to pivot and adjust course in response to changing circumstances is paramount. This might mean reconsidering our goals, reevaluating our priorities, or exploring alternative pathways when our initial plans encounter roadblocks. Rigidity in the face of uncertainty only breeds frustration and stagnation, while an open and adaptable mindset allows us to flow with the currents of change.Effective communication and collaboration are also vital tools in our quest to navigate uncertainties. By fostering open dialogue, sharing perspectives, and leveraging the collective wisdom of our peers and mentors, we can gain valuable insights and support systems that strengthen our ability to tackle the unknown. Collaboration breeds synergy, allowing us to pool our resources, brainstorm innovative solutions, and support one another through challenging times.Moreover, it is essential to cultivate a sense of resilience and perseverance when facing uncertainties. Setbacks and failures are inevitable, but it is our ability to bounce back, learn from our mistakes, and maintain unwavering determination that ultimately determines our success. Resilience is the bedrock upon which we build our capacity to weather the storms of uncertainty and emerge stronger on the other side.Finally, it is crucial to embrace a sense of curiosity and wonder when confronted with uncertainties. Rather than viewing the unknown as a source of fear or trepidation, we can choose to embrace it as an opportunity for exploration and discovery. By approaching uncertainties with an open mind and a thirst for knowledge, we can uncover new possibilities, gain valuable insights, and expand our horizons in ways we never imagined.In the grand tapestry of life, uncertainties are not obstacles to be feared or avoided; rather, they are the threads that weave together the richness and depth of our experiences. By embracing these uncertainties with a growth mindset, adaptability, resilience, and a spirit of curiosity, we can transform them from daunting challenges into catalysts for personal growth, innovation, and self-discovery.The path ahead may be shrouded in uncertainty, but it is in our power to navigate these uncharted waters with courage, wisdom, and a deep commitment to our own growth and development. Every obstacle we overcome, every uncertainty we embrace, is a stepping stone towards a future of limitless potential, where we can shape our destinies and leave an indelible mark on the world around us.。
稳定的工作还是满意的工作英语作文The Dilemma of Stability Versus Satisfaction in Career Choices.In the realm of career decisions, the quest forstability often competes with the pursuit of satisfaction. This dilemma is not unique to any generation or culture, but it is perhaps more pronounced in modern times, where economic uncertainties and changing work landscapes have added new complexities to the equation. The allure of a stable job, with regular paychecks and predictable working conditions, is understandable. Yet, the quest for personal fulfillment and growth often leads individuals towards paths that might not offer the same degree of stability.The stability factor is appealing because it promises a sense of security. It's about having a roof over your head, food on the table, and the peace of mind that comes from knowing that your income will not fluctuate wildly.Stability in a job can also translate into stability inone's social and personal life, as it often leads to predictable schedules and reliable working hours. For many, this is a crucial factor, especially in times of economic uncertainty or personal vulnerability.Moreover, a stable job often comes with a sense ofsocial approval. There is a certain respectability attached to having a traditional, well-paying job that is recognized by society as a marker of success. This is not to say that other career paths are not respectable, but the perceptionof stability often leads to a certain level of approval and acceptance from one's peers and community.However, the quest for satisfaction is equally compelling. Satisfaction comes from doing work that aligns with one's values, interests, and talents. It's aboutwaking up every morning and looking forward to going to work, not dreading the thought of another day at the office. Satisfaction can be derived from making a meaningful contribution, from feeling like you are part of something bigger than yourself, or from simply enjoying the processof doing your job.The problem with the stability versus satisfaction dilemma is that it's not always a clear-cut choice. Sometimes, a seemingly stable job might leave you feeling unfulfilled and uninspired, while a more risky path might offer greater satisfaction but come with its own set of uncertainties. This is where the individual's self-awareness and career planning skills become crucial.It's important to take an honest assessment of one's values, interests, and long-term goals. What kind of workdo you find fulfilling? What are you passionate about? What skills and talents do you possess that can be leveraged ina career? Answers to these questions can help guide one towards a more satisfying career path, even if it doesn't offer the same level of stability as a more traditional job.On the other hand, it's also essential to be realistic about one's expectations. Stability, after all, is not abad thing. It can provide the financial security needed to pursue other interests or to take risks in other areas of life. It can also give you the peace of mind to focus onpersonal growth and development, knowing that your basic needs will be met.In conclusion, the choice between stability and satisfaction is not an easy one. It requires a deep understanding of oneself, an honest assessment of one's values and goals, and the willingness to take risks and embrace uncertainty. Ultimately, the best career path is one that offers a balance between the two, allowing individuals to grow and thrive both professionally and personally.。
o开头的英文形容准确可靠的词语In the realm of descriptive linguistics, words that begin with the letter 'O' and convey a sense of accuracy and reliability are not only fascinating but also quite potent in their ability to communicate precision. One such word is "objective," which denotes a lack of bias, judgment, or prejudice, leading to a fair and accurate representation of facts or situations. This term is often used in scientific discourse, where data must be presented without the influence of personal feelings or opinions.Another term that fits this description is "omniscient," typically used to describe a narrator in literature who has a complete and accurate understanding of all characters and events within a story. This perspective allows for a reliable and comprehensive portrayal of the narrative, leaving no room for uncertainty or partiality."Omnipotent" is also a word that conveys a sense of ultimate power or authority, often used in theological contexts to describe a deity's ability to perform any action with perfect accuracy and reliability. In a broader sense, it can refer to any entity or person possessing complete control and influence over outcomes, ensuring that their actions are precise and dependable.In the field of mathematics, the concept of an "ordinal" number is used to represent the position or rank of an item in a sequential order, which is a precise and reliable way to describe its placement. Ordinal numbers are essential in various aspects of daily life and scientific research, providing an accurate method to quantify and compare elements within a set.The word "orthodox" is traditionally associated with ideas, practices, or beliefs that are established and accepted as accurate and reliable. While it often refers to conventional religious practices, it can also apply to any methodology or theory that is widely regarded as correct and trustworthy due to its long-standing validation and acceptance.In technology and computing, "open-source" is a term used to describe software for which the original source code is made freely available and may be redistributed andmodified. This approach is considered reliable because it allows for peer review and community collaboration, ensuring that the software is accurate, secure, and efficient."Operational" is a term that signifies something is in working order or ready for use. In the context of machinery, systems, or processes, being operational implies that they are functioning correctly and can be relied upon to perform their intended tasks accurately and effectively.Lastly, "optimal" is a word that describes the most favorable condition or the highest level of effectiveness. When something is deemed optimal, it is considered the best possible choice or solution, given the circumstances, ensuring accuracy and reliability in achieving the desired outcome.These words, all beginning with 'O,' serve as powerful tools in the English language to articulate concepts of accuracy and reliability. They provide a means to express certainty and dependability across various domains, from literature and religion to mathematics and technology. The precision these terms offer is invaluable in conveying clear, trustworthy information that stands up to scrutiny and fosters understanding and confidence in communication. 。
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I.Listening ComprehensionSection ADirections:In Section A,you will hear ten short conversations between two speakers.At the end of each conversation,a question will be asked about what was said.The conversations and the questions will be spoken only once.After you hear a conversation and the question about it,read the four possible answers on your paper,and decide which one is the best answer to the question you have heard.1.A.At 8:00.B.At 8:45.C.At 8:55.D.At 9:15.2.A.Looking for a job.B.Making an appointment.C.Building a website.D.Asking for a present.3.A.In a museum. B.In a cafeteria. C.In a clinic. D.In a company office.4.A.She has a tight budget this year.B.She is saving money for new clothes.C.She doesn’t like the meat pie.D.She is trying to lose weight.5.A.The man is a productive novelist.B.The man hasn’t designed the plot.C.The man is struggling for the front cover.D.The man hasn’t made a list of the characters.6.A.Ask Lily to wait.B.Find a meeting spot.C.Check the schedule of the train.D.Make a phone call.7.A.She is looking forward to the show.B.She is clear about the show.C.She can’t bet with her husband.D.She dislikes the topicpresented.8.A.He is not surprised at the woman’s playing at a concert.B.He suggests that the woman should have a good sleep.C.He fully understands the woman’s feeling.D.He has sleeping problems due to worry.9.A.The man has bought the wrong model car.B.The man has enlarged the model car too much.C.The woman is also keen on collecting model cars.D.The woman thinks it unwise to keep spending on model cars.10.A.She prefers to live on her own. B.The man’s apartment is too small.C.She gives priority to the budget.D.The man is selfish to make the offer.Section BDirections:In Section B,you will hear two short passages and one longer conversation,and you will be asked several questions on each of the short passages and the longer conversation.The short passages and the longer conversation will be read twice,but the questions will be spoken only once. When you hear a question,read the four possible answers on your paper and decide which one is the best answer to the question you have heard.Questions11through13are based on thefollowing passage.11.A.He will remain physically active.B.He can reduce the chance of injury.C.He can enjoy the sunrise while exercising.D.He will have a better appetite for breakfast.12.A.In the morning. B.In the afternoon.C.In the evening.D.At noon.13.A.The best time to exercise is any time of the day.B.Regardless of time and sexes,exercise is beneficial.C.Different time to exercise will bring the same effect.D.Different forms of exercise do good to one’s reaction.Questions14through16are based on thefollowing passage.14.A.The effects of having bad dreams. B.The latest experiments on dreams.C.The reasons why people dream.D.The scientists who study dreams.15.A.By persevering in their attempts.B.By analyzing the puzzle carefully.C.By cooperating with other participants.D.By taking a nap and dreaming of the puzzle.16.A.It can remind us of our ancestors.B.It can foretell dangers ahead of us.C.It can relieve our stress in daily life badly.D.It can make us tough when under pressure.Questions17through20are based on thefollowing conversation.17.A.Write down her name and address. B.Show some kind of identification.C.Copy some letters from friends.D.Pass her driving test.18.A.She has a habit of reading in libraries.B.She needs to read after the move to relax.C.She wants to make reading a part of her holiday.D.She wishes to know more about the local policy.19.A.He is patient and helpful. B.He is quiet and sharp.C.He is creative and inspiring.D.He is curious and kind.20.A.Passports are more useful than driving license in the service industry.B.Librarians can play the role of the police when it comes to identities.C.The number of books one can borrow is decided by the catalogue.D.There are alternatives to prove one’s identity in a library.II.Grammar and VocabularySection ADirections:After reading the passage below,fill in the blanks to make the passage coherent and grammatically correct.For the blanks with a given word,fill in each blank with the proper form of the given word;for the other blanks,use one word that best fits each blank.Clues at Ancient Lake Site Reveal Earliest Known Cooked MealScientists have found the earliest known evidence of cooking at an archaeological site in Israel. The discovery has suggested prehistoric humans were able to deliberately make fires to cook food at least780,000years ago.The detailed study of fish teeth unearthed at the Gesher Benot Ya’aqov site revealed that some of our early ancestors—most likely Homo erectus(直立猿人)believed to be the first hominin(古人族) __21__(migrate)outside Africa—were able to cook fish,said Dr.Irit Zohar,a researcher at Tel Aviv University’s Steinhardt Museum of Natural History.No human remains__22__(find)at the site before,but the stone tools matched__23__found at Homo erectus sites across Africa,Zohar said.She said the lake would have been shallow,and it might have been easy to catch large fish like the extinct Luciobarbus longiceps,which__24__grow up to6.5 feet(2meters),by hand.This is an incredibly important discovery__25__the shift to eating cooked meals meant humans spent less energy on the intensive work of searching for and digesting raw food,freeing up__26__ (much)time to develop new social and behavioral systems.“Diet has had a big impact on the evolution of our species.It has been suggested__27__the consumption of meat in particular contributed to the increase in relative brain size of our early Homo ancestors—but they risked__28__(contract)diseases while consuming the uncooked meat which was likely to be contaminated by infective bacteria,”Linscott said.“Cooking,however,kills bacteria and increases the energetic value of meat,__29__(create)a new reliable food source for early hominins.Understanding when this happened is therefore a topic of great interest,because it might help to explain__30__our hominin ancestors evolved the way in which they did.”Section BDirections:Fill in each blank with a proper word chosen from the box.Each word can be used only once.Note that there is one word more than you need.A.motivateB.accidentallyC.highlightingD.plantationsE.engagingF.apparentG.purposeH.sensitiveI.increasinglyJ.decentK.treatBall-Rolling Bumble Bees Just Wanna Have FunPlaytime isn’t just for b-kept bumble bees roll small wooden balls around for no __31__purpose other than fun,a new study reveals.It supports evidence that bees experience pleasure, __32__the importance of protecting them in the wild and treating them well in their natural habitats.“It is super cool,”says Elizabeth Tibbetts,an evolutionary biologist at the University of Michigan.“We usually think about insects as being so different that they lack complex behaviors.”But not everyone is convinced the behavior is in fact play.Lars Chittka,a behavioral ecologist at Queen Mary University of London,and his colleagues__33__came across the new evidence.The team was studying how bumble bees learn complex behaviors from their comrades by training the insects to move wooden balls to specific locations.If a bee moved a ball to the right place,it got a sugary__34__.The researchers noticed that some bees moved the balls even when no reward was offered.They just seemed to like going back to them and playing around with them and rolling them all over the place.The careful design of the experiments has convinced him the bees are indeed__35__in play.Because play implies a capacity to experience emotions,documenting it in insects could have __36__implications.Insects are__37__being raised for animal feed,and there are no regulations governing their welfare.Honey bees are also known to become stressed and more__38__to disease and bee communities collapse when industrialized beekeepers transport them long distances on trucks to__39__and vast fields without diverse flowers nearby,Chittka says.The researchers hope their findings might also__40__greater fellow feeling for—and protection of—wild insects.III.Reading ComprehensionSection ADirections:For each blank in the following passage there are four words or phrases marked A,B,C and D.Fill in each blank with the word or phrase that best fits the context.If people actually embrace the concept of stress,it can make them stronger,smarter and happier,a Stanford expert says.One reason why how you think about stress matters is that it changes how you__41__stress. Viewing stress as__42__leads people to cope in ways that are less helpful,whether it’s dragging your feet to avoid stress,or imagining worst-case scenes.__43__,viewing stress more positively seems to encourage people to cope in ways that help them thrive,whether it’s tackling the source of stress,__44__social support or finding meaning in it.Choosing to see the upside of stress isn’t about__45__the fact that stress can be harmful.It’s about trying to balance your mindset so that you feel less overwhelmed and__46__about the fact that your life is stressful.Psychologists have found that the ability to embrace stress requires a high__47__ for uncertainty.You have to be able to understand that two__48__opposite things can be true at the same time.It can be true that__49__something stressful can make you sick or depressed,and it can also be true that the same stressful experience can ultimately make you stronger,more compassionate and more resilient over time.Stress is most likely to be harmful when the following conditions are__50__:it feels against your will,out of your control and utterly lacking in meaning.If you can__51__any of these conditions—by finding some meaning in it—you can reduce the harmful effects of stress.Rather than being a sign that something is wrong with your life,feeling stressed can be a(n) __52__of how engaged you are in activities and relationships that are personally meaningful.One simple mindset reset that can help us face and find the good in the stress in our lives is to view it as a(n)__53__to learn and grow.The ability to learn from stress is__54__into the basic biology of the stress response.This is why putting people through practice stress is a key__55__ technique for NASA astronauts,emergency responders,elite athletes and others who have to thrive under high levels of stress.41.A.contribute to B.agree to C.respond to D.object to42.A.beneficial B.distracting C.reliable D.harmful43.A.In fact B.In contrast C.What’s more D.After all44.A.seeking B.arousing C.requiring D.embracing45.A.draining B.analyzing C.reversing D.denying46.A.confused B.unfortunate C.hopeless D.serious47.A.tolerance B.demand C.anxiety D.preference48.A.generally B.seemingly C.inevitably D.significantly49.A.putting off ing up with C.taking care of D.going through50.A.present B.controversial C.constant D.equal51.A.mask B.alter C.enhance D.trace52.A.code B.origin C.monument D.indicator53.A.vacancy B.substitute C.opportunity D.illustration54.A.turned B.built C.broken D.divided55.A.instrumental B.conflicting C.intentional D.trainingSection BDirections:Read the following three passages.Each passage is followed by several questions or unfinished statements.For each of them there are four choices marked A,B,C and D.Choose the one that fits best according to the information given in the passage you have just read.(A)Arens,a driver of a delivery company,was making his rounds near a pond in Bozeman,Montana, when he heard an unearthly sound.It was December2018,and about15feet from the frozen banks was the source of that cry—a half-submerged brown-and-white wirehaired dog,struggling to hold on to a thin layer of ice.How she got there no one knows,but an elderly man was already on the scene,determined to save her.He’d entered the pond in a rowboat and was hacking a way at the ice with a rock to create a path to the dog.It was slow going,and Arens,44,thought he stood a better chance.He took off his clothes,even though the temperature was-30℃,and jumped into the rowboat.His heart beating fast,Arens slid closer to the dog and used the other man’s rock to smash away atthe ice.He gave himself a strong pull and slipped off the boat,crashing into16feet of freezing water. He resurfaced in time to see the dog going ing nervous energy to keep warm,he swam about five feet toward her,grabbed hold of her collar,and pulled her to the ice.He then boosted the dog into the boat and slid it back to the shore,where anxious bystanders carried the dog to the home of the rowboat owner.Once in the house himself,Arens jumped into a warm shower with the dog until they both felt warmer.A few more minutes in the pond,the vet(兽医)told Arens,and she would have likely suffered heart failure.The next day,Arens was back working in the same neighborhood when the dog’s owner came over to thank him for saving Sadie.Arens says,“That special delivery was the highlight of my career.”56.What does the underlined word“hacking”in paragraph three most probably mean?A.cuttingB.findingC.mendingD.adopting57.Why does Arens think“he stood a better chance”(in paragraph four)according to the passage?A.He was able to jump into the rowboat.B.He had better nerves to keep warm.C.He had an advantage in age.D.He was a faster swimmer.58.Which of the following statements is true about the incident?A.After saving the dog,Arens carried her home.B.Arens jumped into the river on seeing the dog.C.The dog was hunting when she fell into the water.D.Without Aren’s help,the dog could hardly survive.59.What is the main idea of the passage?A.A story of a pet lover.B.A special delivery of a driver.C.A dog suffering from heart attack.D.A fight against freezing water.(B)The UK doesn’t have the best reputation regarding food waste.Luckily,it’s easy to learn how to change these unsustainable habits,so that you can easily reduce unnecessary waste and save a pretty penny.1.Plan your mealsWhen you don’t have a clear idea of what you want to eat,it’s easy to pick up more than you need,especially when items are on offer.It might seem like a great short-term option,but it can cause you to spend much more money in the long term,resulting in unnecessary food waste.Planning your meals for the week in advance can be a great way to avoid this issue altogether.Work out what you plan to eat and when,and how much.Whether you’re shopping online or in-person,you can get only what you need—both saving your money and reducing the potential for food waste.2.Store your products correctlyThere are many tips that can help to keep produce fresh.For example,potatoes,carrots and other root vegetables last longest if they are kept in the dark.Fresh fruit and vegetables,like grapes,shouldn’t be kept with ethylene-producing products(including bananas and apples)as they make other fresh produce ripen and rot more quickly.You can also find many ways to keep food by using water.For example,store half cut vegetables,such as carrots,potatoes,in water in the fridge,to help them last longer than if they were stored dry.3._______________________Almost three quarters of food wasted could still be eaten,meaning that the food is not spoiled,and is fine for consumption.Many people aren’t aware“best before”dates are suggestions,rather than rules.In contrast, however,the“use by”date refers to the last date a food is fit for consumption,and should be watched carefully for safety.When it comes to consuming food,use your senses:look at and smell the food.If it smells good and looks fine,the produce is more than likely completely fit to be eaten and enjoyed.60.The passage is intended to______.A.instruct the public to preserve foodB.offer tips on planning meals in advanceC.help people develop some sustainable habitsD.change the UK’s reputation as a big food waster61.According to the passage,which of the following is true?A.To avoid food waste,shopping online and in person.B.To make fresh food ripen more quickly,keep them with bananas.C.To avoid waste,don’t throw away any food after the“use by”date.D.To keep potatoes longer,cut them into halves and store them in dark.62.Which of the following can be the best subtitle for“3______”?A.Save your moneyB.Enhance your food consumptione your senseD.Follow your“best before”date(C)A database that follows the world’s fossil fuel production,reserves,and release of carbon was launched on Monday.The launch comes out at the same time as two important climate talks happening at the international level.One is the climate talks at the United Nation’s General Assembly in New York which began on September13.The other is COP27in Sharm El Skeikh which began in November.It really matters to environmental sustainability.The database is called The Global Registry of Fossil Fuels.It includes data from over50,000oil, gas,and coal fields in89countries.That covers75percent of the world’s reserves,production,and release of carbon into the atmosphere.And it is available for public use,a first for a collection of this size.Until now,there has been private data available for purchase,and research of the world’s fossil fuel usage and reserves.The International Energy Agency also keeps public data on oil,gas,and coal. But it centers on the demand for those fossil fuels.This new database,however,looks at what is yet to be burned.The information could help environmental groups to pressure leaders for stronger policies reducing the amount of carbon they release.The database was developed by Carbon Tracker.It is a nonprofit organization that researches changes in energy use and their effects on financial markets.Global Energy Monitor also helped develop the database.It is an organization that follows different energy projects around the world.Mark Campanale,a founder of Carbon Tracker,said he hopes the database will empower groups to hold governments accountable.He said that civil groups need to have more information on whatgovernments are planning to do in terms of giving permits for coal,oil,and gas.He said they need to,“…actually begin to challenge this permitting process.”He thought that it is very important that the world should reduce carbon output.In the research,Carbon Tracker found that the United States and Russia still have enough underground and unused fossil fuel to go over the world’s remaining amount of carbon budget.The carbon budget is the point at which the world will go over the set amount of1.5degrees Celsius of warming.Campanale said investors should be holding the world’s largest fossil fuel companies responsible when they approve new fuel mining projects.Campanale said the hope is that the investment community will use the data to begin to challenge the investment plans of companies which still plan to expand oil,gas,and coal projects.“We already have enough extractable fossil fuels to cook the planet. We can’t afford to use them all—or almost any of them at this point.”he added.63.The Global Registry of Fossil Fuels is special compared with other similar data available because ______.A.it aims at reducing the amount of carbonB.it records the world’s demand for fossil fuelC.it keeps data on fossil fuel public to the worldD.it centers on the remaining amount of fossil fuel64.According to the passage,______is a leading developer of the new database launched on Monday.A.the United Nation’s General AssemblyB.the International Energy AgencyC.Carbon TrackerD.Global Energy Monitor65.According to the passage,which of the following does Mark Campanale most probably suggest?A.There are still enough fossil fuel to mine both in the United States and Russia.B.The community should question companies’planning to mine coal,oil and gas.C.The new database is developed to help investment groups challenge plans for mining.D.The government should rely on the new database to prevent mining plan of companies.66.What’s the writer’s attitude towards the launch of the new database?A.Positive.B.Flexible.C.Critical.D.Ironical.Section CDirections:Read the following passage.Fill in each blank with a proper sentence given in the box. Each sentence can be used only once.Note that there are two more sentences than you need.A.Gratitude can also make us feel good physically.B.Therefore,it’s easy to tell that gratitude is advantageous to us.C.It is the feeling of being grateful and wanting to express our thanks.D.It can help promote stronger relationships with family,friends or even colleagues.E.One reason for this,is that gratitude stops us from reflecting on negative emotions.F.It is a deeper appreciation for someone or something that makes us feel a positive emotion.Why gratitude is good for youGratitude is more than just saying“thank you”to someone who has helped us or given us a gift. ____67____And this positive emotion can be good for our health—our emotional and physical health, as well as the health of our relationships.Let’s start by looking at the emotional or mental health benefits of expressing gratitude.There have been many studies,as described in a2018paper from the Greater Good Science Center titled “The Science of Gratitude”,showing that writing a gratitude letter to another person or writing in a gratitude journal,if done regularly,improves mental health.____68____But even if we don’t share our writing with anyone,like in a journal,the act of completing the exercise alone makes us happier and more satisfied with life.And this gets better with time.As we are essentially training our brain to be more in tune with noticing the positive,after several weeks or months,this becomes more intuitive. And so,the more we express gratitude,the more positive we feel.____69____There are studies linking a gratitude practice to better sleep quality,better eating habits,and reduced infection in people who have had heart problems.So gratitude is clearly good for us, but is it also good for the people in our lives?The simple answer is“yes”.When shared—spoken or written—gratitude is about feeling valued and helping others feel valued too.____70____And that’s on top of all the other ways gratitude is clearly good for us.Maybe we should all stop counting sheep or counting calories and start counting our blessings instead?IV.Summary WritingDirections:Read the following passage.Summarize the main idea and the main point(s)of the passage in no more e your own words as far as possible.71.Want to join the online fitness program?Online training is one of the fastest growing section of the fitness industry.A2015study found that more than half of all smartphone users had downloaded a fitness or health app.If you’re considering joining the online fitness community,consider these benefits and drawbacks.There are many reasons that online training may work for you.As long as you have access to pre-downloaded videos or a WiFi connection for streaming videos,you can work out wherever you are.Besides,compared with similar offline programs,most online fitness programs range in cost between $10and$20per month.This is due in part to the wider audience and the greater opportunity to sell programs to more people.All this growth is incredibly positive—it provides health and fitness resources to the general consumer wherever they happen to be,without requiring access to a gym or fitness studio.But it’s not without problems.The first thing to think about when considering an online fitness program is“know yourself.”If you struggle with self-motivation,you don’t like exercising at home,and you prefer a social workout environment,online fitness may not be for you.Not to mention the fact that very few online fitness programs enable the instructor to see you,check your form,and offer modifications or corrections based on your performance.This means you might perform exercises incorrectly,or even unsafely, without knowing it,which is particularly concerning for beginners and those recovering from injuries, as they’re more likely to perform exercises incorrectly.Therefore,like any training format,there are pros and cons to consider when deciding if it is right for you.Take time and make the most suitable decision to reap more benefits.V.TranslationDirections:Translate the following sentences into English,using the words given in the brackets. 72.请核对一下购物单,免得漏了什么东西。
The4th International Conference on Field and Service Robotics,July14–16,2003Planning under Uncertainty for Reliable Health Care Robotics Nicholas Roy Geoffrey Gordon Sebastian Thrunnickr@ ggordon@ thrun@School of Computer ScienceCarnegie Mellon UniversityPittsburgh,PA15213AbstractWe describe a mobile robot system,designed to assist residents of an retirement facility.This system is being de-veloped to respond to an aging population and a predicted shortage of nursing professionals.In this paper,we discuss the task offinding and escorting people from place to place in the facility,a task containing uncertainty throughout the problem.Planning algorithms that model uncertainty well such as Partially Observable Markov Decision Processes(POM-DPs)do not scale tractably to most real world problems. We demonstrate an algorithm for representing real world POMDP problems compactly,which allows us tofind good policies in reasonable amounts of time.We show that our algorithm is able tofind moving people in close to optimal time,where the optimal policy would start with knowledge of the person’s location.1IntroductionWe describe a mobile robot system,designed to assist residents of an retirement facility.This system is being de-veloped to respond to an aging population and a predicted shortage of nursing professionals.Previously,we have re-ported on work focused on the task of reminding people of events(e.g.,appointments)and accompanying them to these events[1,2].In this paper,we discuss the task of finding and escorting people from place to place in the fa-cility.This problem contains many common aspects of real world uncertainty:the state of the world is not completely known(the initial position of the person in the environ-ment is unknown),the state changes(people are free to move around),and sensor noise can lead to perceptual er-rors.These sources of uncertainty,if unmodelled,can lead to sub-optimal behaviour on the part of the robot.Unfortunately,the kind of planning that is required for reliable robot operation is difficult to approximate with sim-ple heuristics for handling the uncertainty,so we must use a planning methodology that explicitly models the real-world uncertainty.One such model is the Partially Ob-servable Markov Decision Process(POMDP),but conven-tional approaches tofinding policies for POMDPs are often intractable for the size of problems we wish to address.We will take advantage of dimensionality reduction tech-niques tofind low-dimensional representations that can be planned for much more easily,by using structure inher-ent in many real world domains.For example,Principal Components Analysis(PCA)is well-suited to dimension-ality reduction for data on or near a linear manifold in the higher-dimensional space.Unfortunately,POMDP belief manifolds are rarely linear;in particular,sparse beliefs are usually very non-linear.We therefore transform the data into a space where it does lie near a linear manifold;the algorithm which does so(while also correctly handling the transformed residual errors)is called Exponential Family PCA(E-PCA)[3,4].E-PCA will allow us to represent POMDPs with only a handful of dimensions,even for be-lief spaces with thousands of dimensions.We will demon-strate the use of this planning technique on the problem of how tofind a person whose location is initially unknown. 2Finding PeopleThe problem we wish to solve is how tofind people in a health care facility as quickly as possible.The robot is assumed to begin with a grid map of the environment, but no knowledge of where the person might be located, in which grid cell of the map.The robot can move about the environment to look for the person,and receives sensor information when the robot can and cannot see the person. Our implementation is based on a laser-rangefinder,but this work is independent of the particular sensing modality.We assume a probabilistic state estimator that provides probability distributions over where people might be lo-cated.We will refer to this a distributions as a“belief”of the person’s location.The belief is updated over time after each action and observation from the robot according to a(a)Pearl(b)Pearl inLongwood(c)Pearl in LongwoodFigure1:(a)Pearl,the Nursebot(b)&(c)Pearl interacting with residents of Longwood at Oakmont.well-formed probabilistic rules[5].The planning task can then be phrased as one of choosing the next action,based on the current belief,as depicted infigure2.Not shown in thisfigure is the true state of the world,which is also not observable by the agent.Figure2:The execution process forfinding people.The observation is generated according to an emission probability model conditioned on the current state,that is hidden from the controller.The controller only has access to the observation,not the true state generating the observation.The Partially Observable Markov Decision Process is a decision-theoretic model for planning successfully with beliefs.The POMDP is solved by defining a“value func-tion”over the space of beliefs,which assigns a value and action to each belief.By iteratively updating the value function appropriately,the value function can be made to converge to the greatest expected reward from each belief, and the action that will achieve that reward in expectation. The POMDPfinds a policy that maximises the expected sum of future(possibly discounted)rewards of the agent executing the policy;for the problem offinding people,we can write a reward function for each possible configuration of the world such that the maximum reward is achieved for finding people fastest.There are a large number of value function approaches [6,7]that explicitly compute the expected reward of ev-ery belief.Such approaches produce complete policies(the optimal action for every belief),and can guarantee this op-timality under a wide range of conditions.However,find-ing a value function this way is usually computationally intractable[6,8].Large POMDPs are generally very difficult to solve es-pecially with standard value iteration techniques.Main-taining a full value function over the high-dimensional be-lief space entailsfinding the expected reward of every pos-sible belief under the optimal policy.In reality,most POM-DP policies generate only a small percentage of possible beliefs.For example,a mobile robot tracking a person is extremely unlikely to ever encounter a belief about the per-son’s pose that resembles a checkerboard.If the execu-tion of a POMDP is viewed as a trajectory inside the be-lief space,trajectories for most large,real world POMDPs lie on low-dimensional manifolds embedded in the belief space.So,POMDP algorithms that compute a value func-tion over the full belief space do a lot of unnecessary work. 3Dimensionality ReductionIn order tofind the low-dimensional manifold for repre-senting our belief space,we take advantage of dimension-ality reduction techniques.One possible technique that we could consider is Principal Component Analysis1(PCA). We collect a data set of beliefs X,and use PCA tofind a low-dimensional representation;so long as the collected data set is representative of the beliefs we will encounter during the execution of the people-finding plan,then we should be able to track the current belief on the low-dimen-sional manifold accurately.PCA operates byfinding a set of feature vectors U= {u1,...,u n}that minimise the loss functionL(U,V)=||X−UV||2(1) 1Also known as Singular Value Decomposition0.60.811.21.41.61.822.2051015202530A v e r a g e K L D i v e r g e n c eNumber of BasesPCA KL Divergence(a)Conventional PCA 0.020.030.040.050.060.070.080.090.1051015202530A v e r a g e K L D i v e r g e n c eNumber of BasesE-PCA KL Divergence(b)E-PCAFigure 3:A comparison of the reconstruction quality of conventional PCA and E-PCA,using a probabilistic distance measure,Kullback-Leibler diver-gence,on a people-tracking data set.Notice that even with 30bases,the PCA performs poorly and has very high variance in reconstruction quality.The E-PCA error falls rapidly initially,and the variance in error is low,indicating consistent performance across the entire data set.(Note the different scales on the Y axes.)where X is the original data and V is the matrix of low-dimensional coordinates of X .This particular loss func-tion assumes that the data lie near a linear manifold,and that displacements from this manifold are symmetric and have the same variance everywhere.(For example,i.i.d.Gaussian errors satisfy these requirements.)Unfortunately,probability distributions for POMDPs rarely form a linear subspace.In addition,squared error loss is inappropriate for modelling probability distributions:it does not enforce positive probability predictions.We use exponential family PCA to address this prob-lem.Other nonlinear dimensionality-reduction techniques [9,10]could also work for this purpose,but would have different domains of applicability.Exponential family Prin-cipal Component Analysis [3](E-PCA)varies from con-ventional PCA by adding a link function,in analogy to generalised linear models,and modifying the loss function appropriately.As long as we choose a link function that corresponds to an exponential family distribution log like-lihood,and as long as the link and loss functions to match each other,there will exist efficient algorithms for finding U and V given X .By picking particular link functions (with their matching losses),we can reduce the model to an SVD.In our case the entries of X are non-negative,and we wish to ensure accurate representation of low-probability events.Consequently,a link and loss function that cor-respond to the Poisson distribution are most appropriate 2.The corresponding link function is¯X=f (UV )=exp(UV )(2)2Examples of other choices are the Exponential distribution,the multi-nomial,the Beta,etc.The Gaussian is also an Exponential family distri-bution,but a Gaussian link and loss function reduce to conventional PCA.(taken component-wise)and its associated loss function isL (U,V )=exp(UV )−X ◦UV(3)where the “matrix dot product”A ◦B is the sum of productsof corresponding elements.It is worth noting that using the Poisson loss for dimensionality reduction is related to Lee and Seung’s non-negative matrix factorisation [11].Gor-don [12,4]has a Newton’s Method solution for computing U and V quickly.In figure 3,we compared the error in the low-dimension-al representations,for a sample set of 500beliefs taken from the person tracking problem for the environment sho-wn in figure 4.Figure 3(a)shows the average Kullback-Leibler divergence (a distance metric for probability dis-tributions)between the high-dimensional belief set and the low-dimensional representation,using conventional PCA to find the low-dimensional representation.We see that the distance is large,does not improve quickly with more dimensions,and the representation quality is largely in-consistent,as denoted by the wide error bars.Figure 3(b)shows the same evaluation (average KL divergence)where E-PCA was used to find the low-dimensional representa-tion.In this case,the error is small,improves quickly ini-tially,and is consistent across the entire data set,in all ways outperforming conventional PCA.We can also look at a sample representation to assess the quality of the representation.Figure 4shows an exam-ple of the tracking process in progress.The true position of the person is unknown,and the robot instead maintains a probability distribution over possible poses of the person.The small grey dots show particles drawn from the original distribution.As the robot moves around the environment,sensor information is integrated into the distribution.The space of possible distributions is 1961-dimensional,for an(a)Originaldistribution(b)ReconstructionFigure4:Examples of distributions in the Longwood at Oakmont retirement facility.The small grey dots show particles drawn from the original distribution;the higher the probability,the denser the particles.(a)An example distribution of potential positions of the person being searched for.This distribution is represented using1961dimensions.(b)The same distribution,reconstructed using only6dimensions.The true position of the person is not observable by the robot at a distance.environment53×37m discretised into1m grid cells,and 1dimension for each grid cell.However,by taking ad-vantage of the E-PCA decomposition we can generate a faithful representation of the space of actual distributions in only6dimensions.Figure4(b)shows the original distri-bution projected to the low-dimensional space and then re-constructed.Although this is a lossy projection,the recon-struction is accurate for planning purposes.Remember that the task is not to reconstruct only the distribution shown in figure4a,but to be able to represent all of the distributions that we expect to see as points in the6-dimensional space. 4PlanningGiven the belief features acquired through E-PCA,it remains to compute the policy.Unfortunately,the non-linearity of the E-PCA projection prevents any guarantees of value function convexity over the low-dimensional space, which means that standard POMDP value iteration tech-niques cannot be used tofind policies on the low-dimension-al manifold directly.Instead,we approximate the low-dimensional space discretely,converting the POMDP into a belief space MDP.During execution,the action taken at each time step is taken from the discrete belief state that is closest to the current actual belief.Our conversion algorithm from POMDP to MDP is a variant of the Augmented MDP,or Coastal Navigation al-gorithm[13],using belief features instead of entropy.We can compute the model reward function R(s i)easily from the reconstructed beliefs,using R(b)=b·R(s).To learn the transition function p(b i|a,b j),we can sample states from the reconstructed beliefs,sample observations from those states,and incorporate those observations to producenew belief states.Table1outlines the steps of this algo-rithm.1.Collect sample beliefse E-PCA to generate low-dimensional belief features3.Convert low-dimensional space into discrete space S4.Learn belief transition probabilities T(s i,a,s j),and re-ward function R(s i).5.Perform value iteration on new model,using states S,transition probabilities T and R.Table1:Algorithm for planning in low-dimensional belief space.The state space can be discretised in a number of ways, such as laying a grid over the belief features or using dis-tance to the closest training beliefs to divide feature space into V oronoi regions.Thrun[14]has proposed nearest-neighbor discretisation in high-dimensional belief space; we propose instead to use nearest-neighbour in a low-di-mensional feature space,where neighbors should be more closely related.In order tofind a good policy,we must be sure to dis-cretise carefully.In some regions of the low-dimensional manifold,beliefs that are close together we can cluster into the same,large discrete cell without hurting performance. In other regions of the belief space,the cells must be much smaller,in order to distinguish different beliefs that require different actions.This leads to a variable resolution repre-sentation of the low-dimensional manifold.We typically do not have enough belief samples initially to determine the full discretisation across the entire space; in places the discretisation will be insufficientlyfine.Wecompensate by periodically re-evaluating the model at each grid cell,and splitting the grid-cell into smaller discrete cells where the model disagrees with some statistics of the real world.A number of different statistics have been suggested for testing the model against data from the real world [15],such as reduction in reward variance,or value function disagreement.We have opted instead for a simpler criterion of transition probability disagreement,although one improvement we are exploring is to use the Kolmogor-ov-Smirnov criterion for reducing expected reward disagree-ment [16].5PerformanceRobot start2413(a)Optimal trajectoryRobot start2341Current robot position(b)Sub-optimal trajectoryFigure 5:Example trajectory.(a)Even for this very simple environment,in order to maximise the likelihood of finding the person,the trajectory is relatively complicated.(b)The more obvious,sub-optimal trajectory allows some probability mass to “leak”into already-explored regions.Figure 5(a)shows an example trajectory for a simple environment 3.Even for this very simple problem,the tra-jectory is relatively complicated.The robot starts at the far end of the corridor,with the person’s position com-pletely unknown (the initial belief is uniform over the en-tire space).The robot travels past the open door on the right,part way down the corridor,returns to explore the room,and then finishes the corridor.This trajectory en-sures that by the time the robot is finished exploring the room,the person must either have been found,or be at the far end of the corridor –there is no possibility for the per-son to escape into already-explored sections of the envi-ronment.This is an example of the kind of planning we3Forthis environment,the original space was 47m ×17m with a0.2m resolution,for 20,230grid cells,reduced to 6dimensions.hope to see –our planner has found a strategy that is not obvious,nor easy to capture using simple heuristics.Fig-ure 5(b)shows a more obvious but sub-optimal trajectory in mid-execution.Notice the probability mass that appears in the already-explored region near the robot start location,causing the robot eventually to retrace its steps.The opti-mal strategy in figure 5(a)explicitly avoids this problem.Figure 6shows a quantitative comparison of our tech-nique and other possible heuristics.The horizontal line is the baseline,“True MDP”situation where the position of the person is always known correctly,that is,there is no hidden state.This algorithm is essentially cheating,but serves as a useful lower bound in that the robot find the per-son as quickly as possible every iteration.The “Closest”heuristic takes the robot to the nearest grid cell where the person might be.The “Densest”heuristic takes the robot to the location where the most particles are visible.The “MDP”heuristic takes the robot to the maximum-likelihood location (the single grid cell with the most particles).The “E-PCA 72”and “E-PCA 260”is a comparison of the E-PCA plans before state splitting (with 72low-dimensional belief states)and after iterative refinement of the manifold (to 260low-dimensional belief states).The “E-PCA 260”is clearly the best performing algorithm,able to find the person almost as quickly as the fully-observable planner.100150200250Closest DensestMDP E-PCA 72E-PCA 260A v e r a g e r e w a r dPlannerPerformance of Different PlannersTrue MDPFigure 6:A comparison of different planning methods,including some simple heuristic planners.The“True MDP”method is the lower-bound “cheating”solution which assumes that the true position of the robot is always known.The optimal method under uncertainty is the “E-PCA-260”method,which also learns the optimal state decomposition.6Related WorkThere have been a number of recent advances in solv-ing large POMDPs.Poupart &Boutilier [17]make use of a similar dimensionality reduction technique,however,their representation requires a linear combination of bases to represent arbitrary data,which is a strong limitation on the compression they can achieve.(Figure 3(a)demonstrates the limitation of linear representations.)Pineau et al.[18]have had success infinding approximate value functions quickly,but again their approach has not scaled to the size of the problems discussed in this paper.Policy search algorithms[8,19]have addressed some large problems.We suggest that a large part of the success of policy search is due to the fact that it focuses compu-tation on relevant belief states.A disadvantage of policy search,however,is that can be data-inefficient across prob-lems:many policy search techniques have trouble reusing sample trajectories generated from old policies.Our ap-proach focuses computation on relevant belief states,but also allows us to use all relevant training data to estimate the effect of any policy.Related research has developed heuristics which reduce the belief space representation.In particular,entropy-based representations for heuristic control[20]and full value-function planning[13]have been tried with some success. However,these approaches make strong assumptions about the kind of uncertainties that a POMDP generates.By per-forming principled dimensionality reduction of the belief space,our technique should be applicable to a wider range of problems.7ConclusionWe have demonstrated a system forfinding and tracking people in the health care setting.The problem offinding people is computationally difficult in many environments, because of the high degree of uncertainty.Planners that do not reason intelligently about this uncertainty can take arbi-trarily long to perform such real world tasks.The Partially Observable Markov Decision process is a planner that can reason about uncertainty,but is typically held not to scale to large problems.We have shown that by taking advantage of dimension-ality reduction techniques,we can represent POMDP prob-lems compactly,and therefore generate good plans.We used a variant of PCA called Exponential family PCA(E-PCA)tofind a low-dimensional manifold one which typ-ical beliefs lie,and compute a value function over that manifold using a function approximator.We have also shown that naive function approximation is not sufficient forfinding good plans.Our experimental results indicate that the optimal plan can be sensitive to small changes to the function approximation in different regions of the low-dimensional manifold.By appropriate use of statistical tests,we are able tofind good variable resolution repre-sentations for the value function that lead to good policies. 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