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PART1U1T1、In addition to the various power transformers, two special-purpose transformers are used with electric machinery and power systems. The first of these special transformers is a device specially designed to sample a high voltage and produce a low secondary voltage directly proportional to it. Such a transformer is a potential transformer. A power transformer also produces a secondary voltage directly proportional to that the potential transformer is designed to handle only a very small current. The second type of special transformer is a device designed to provide a secondary current much smaller than but directly proportional to its primary current. This device is called a current transformer.除了各种电源变压器、两个专用变压器使用电动机械和电力系统。
第一个特殊变压器是一个高电压设备专门设计的样品和生产较低的二次电压成正比。
这样一个变压器电压互感器。
电力变压器也产生二次电压成正比的电压互感器的设计目的是处理只有一个很小的电流。
中外交替口译英语Alternating Chinese-English Interpretation is a vital skill in today's globalized world. As international communication and cooperation become increasingly prevalent, the ability to seamlessly translate between Chinese and English is in high demand. This specialized form of interpretation requires not only linguistic fluency, but also deep cultural understanding and lightning-fast reflexes.At its core, alternating Chinese-English interpretation involves the real-time conversion of spoken language between the two vastly different tongues. A skilled interpreter must be able to listen intently to the source language while almost simultaneously formulating an accurate and natural-sounding translation in the target language. This process requires superb multitasking abilities as the interpreter's brain processes incoming information, retrieves relevant vocabulary and grammatical structures, and produces coherent and contextually appropriate output.The challenges inherent in this task are manifold. Chinese and English exhibit stark contrasts in syntax word order, grammaticalgender, and countless other structural elements. An interpreter must be able to instantly recognize these differences and restructure the message accordingly without losing any of the original meaning or nuance. Fluency in both languages is of course essential, but professional-level interpreters must go far beyond mere language skills.Cultural fluency is equally critical in alternating Chinese-English interpretation. Concepts, idioms, and references that are implicit and intuitive to native speakers of one language may be completely foreign to those from the other linguistic and cultural background. Experienced interpreters must be able to identify these gaps and provide appropriate explanations or substitutions in real time. They must also be adept at navigating the protocols, customs, and unspoken rules that govern interactions between Chinese and Western counterparts.Furthermore, the role of an interpreter in a high-stakes bilingual exchange goes beyond just translation. They serve as cultural ambassadors, facilitating mutual understanding and productive collaboration. A skilled interpreter can pick up on subtle social cues, diffuse tensions, and find creative ways to bridge linguistic and cultural divides. Their ability to deftly handle sensitive situations and delicate power dynamics is just as important as their linguistic agility.Of course, the physical and cognitive demands of alternating Chinese-English interpretation should not be underestimated. Interpreters must maintain laser-sharp focus for extended periods, processing a constant stream of information and generating real-time responses. The mental fatigue can be overwhelming, requiring rigorous training, strict self-care routines, and the ability to quickly recover and re-energize.Despite these challenges, the field of alternating Chinese-English interpretation offers immense professional and personal rewards. Interpreters play a vital role in enabling productive exchanges between Chinese and English speakers, unlocking new opportunities for business, diplomacy, academia, and beyond. They bear witness to history in the making and contribute directly to cross-cultural cooperation and global understanding.Moreover, the skills honed through this specialized work are highly transferable. Alternating Chinese-English interpreters develop exceptional language facility, cultural agility, multitasking prowess, and crisis management abilities - all of which are valued in a wide range of fields. Many interpreters leverage their unique expertise to transition into roles as translators, language instructors, international relations specialists, or consultants.In conclusion, alternating Chinese-English interpretation is ademanding yet incredibly rewarding profession. It requires a rare combination of linguistic fluency, cultural competence, cognitive agility, and interpersonal savvy. Those who excel in this field serve as vital conduits between the Chinese and English-speaking worlds, fostering mutual understanding and enabling transformative exchanges. As global interconnectedness continues to deepen, the need for skilled Chinese-English interpreters will only grow, making it a career path ripe with opportunity and impact.。
河南科技Henan Science and Technology化工与材料工程总第873期第2期2024年1月收稿日期：2023-06-07基金项目：“一带一路”水与可持续发展科技基金项目（2021490511）。
作者简介：江文彬（1995—），男，硕士生，研究方向：水文地质；丁力（1996—），男，硕士生，研究方向：地质工程与地质资源。
通信作者：闫亚景（1986—），女，博士，讲师，研究方向：岩土力学和斜坡稳定性研究。
基于阿尔奇定律的双重介质模型溶质运移试验研究江文彬丁力闫亚景江承阳吕玲君孙天宇（华北水利水电大学，河南郑州450046）摘要：【目的】由于天然孔隙介质中存在物理化学非均质性，在这种复杂的非均质性含水层中，以往的现场试验数据显示溶质在非均质介质运移过程中无法用菲克扩散定律对流弥散方程（Advection-Dispersion Equation ，ADE ）来描述。
本研究采用高密度电法证实溶质在非均质介质中非菲克运移。
【方法方法】本研究采用石英砂、沸石两种不同基质构建双重介质物理模型（Models of Dual-Domain Mass Transfer ，DDMT ），采用高密度电法测定系统ERT21实时检测和采集数据，在实验室利用Nacl 溶液开展示踪试验，利用阿尔奇定律分析溶质运移试验研究。
【结果】试验结果浓度穿透曲线在后期发生“拖尾”现象；在沸石柱实验中，观察到流体电导率（σf ）和体积电导率（σb ）之间的滞后现象，这表明流体在不可动领域和可动领域之间的交换。
而在沙子柱试验中，未观察到σf 和σb 之间的滞后现象，可以忽略质量传递行为；滞后现象的形状与大小由水动力学特征和基质属性控制，水动力学是影响拖尾时长的因素之一，渗透系数会影响溶质运移的过程。
【结论】通过试验观察和地球物理数据分析，直接量化了实验室尺度下的异常质量传递行为，通过地球物理方法测量的导电率（σb ）对于移动和不动领域都具有敏感性，从而提供了与标准采样方法相比的独特优势。
备考2023高考英语-考点单词过关+语法填空过关训练5语法填空解-常见语法易错点1：one of +the+adj最高级+n复数。
2：to do不定式表目的3：表被动（by提示词），情态动词+V-ed4：（and,but,or并列句）：（一）：词性---形容词，副词，名词可数不可数，保持一致（二）：n词单复数（三）：时态保持一致---最常考过去时5：常考特殊句型，短语：（一）：Start doing/start to do sth begin doing/ begin to do sth（二）: It is/was +a/adj+ (for sb)+to do sth（三）：Avoid doing stop doing enjoy oneself6: 现在分词V-ing表主动，过去分词V-ed表被动7：序数词：one, two, three----first, second, third8:结构：the+n.+ of9:Adv常考结构：结构1：_______ +动词，或者动词+______.结构2：__________+形容词。
结构3：_______,+一个完整的句子。
副词作状语，修饰整个句子。
10：whatever, whenever, wherever , however引导句子（句子不缺成分）11：Adj常考结构：Adj+n.12:人称代词：eg: she----考her, hers, herself13: V的否定形式：eg: appear—disagree like----dislikeAdj的否定形式：eg: possible—impossible believable---unbelievableCareful---careless speech---speechless14:常考时态：时间状语有：recently, already, so far, yet, lately, in the past…, by…，for+时间段.考点----用现在完成时have/has done结构（注意：看是不是主动或被动-have been done）15: 常与比较级连用的词：even, much,far, thanTo do不定式表目的，往往表示比较级【考点总结-1】（一）：单词词性：1.必考点---连词，冠词，名词，动词2.常考点---副词，形容词，代词，介词，数词（二）：句型：必考定语从句，常考状语从句和名词性从句（三）：语篇的逻辑关系：1：短文上下文的时态是否一致。
北京市西城区2023—2024学年度第二学期期末试卷高二英语2024. 7 本试卷共14页，共140分。
考试时长120分钟。
考生务必将答案写在答题卡上，在试卷上作答无效。
第Ⅰ卷（共83分）Ⅰ. 听力理解（共三节，30分）第一节：（共4小题；每小题2分，共8分）听下面四段对话，每段对话后有一道小题，从每题所给的A、B、C三个选项中选出最佳选项。
每段对话你将听一遍。
1. Where is Daisy from?A. America.B. Italy.C. Greece.2. What does the woman plan to do during the summer vacation?A. Go to Paris.B. Visit her cousins.C. Start a night school.3. Who will give the report on Friday?A. The man.B. The woman.C. The woman’s assistant.4. Where will the man have dinner?A. In his home.B. At his aunt’s place.C. In his grandfather’s house.第二节：（共6小题；每小题2分，共12分）听下面三段对话或独白，每段对话或独白后有两道小题，从每题所给的A、B、C三个选项中选出最佳选项。
每段对话或独白你将听两遍。
听第5段材料，回答第5至第6小题。
5. Why can’t the man attend the event?A. Because he doesn’t know how to help.B. Because he thinks it is nothing serious.C. Because he has a family emergency to handle.6. What will the man probably do next?A. Accept donations.B. Help out in other ways.C. Send the woman more information.听第6段材料，回答第7至第8小题。
电力职称英语试题及答案一、选择题（每题2分，共20分）1. The primary function of a transformer is to:A. Convert voltage levelsB. Amplify electrical signalsC. Rectify alternating currentD. Filter electrical noise答案：A2. In an electric power system, the term "load" refers to:A. The source of electrical powerB. The electrical equipment that consumes powerC. The transmission lines that carry powerD. The protective devices for circuits答案：B3. Which of the following is not a type of electrical fault?A. Short circuitB. OverloadC. Ground faultD. Surge protection答案：D4. The unit of electrical power is the:A. VoltB. AmpereC. WattD. Ohm答案：C5. The purpose of a circuit breaker is to:A. Provide a path for excess currentB. Maintain a constant voltage levelC. Protect the circuit from overcurrentD. Convert AC to DC答案：C二、填空题（每题1分，共10分）6. The three main components of an electric power system are the _______, transmission, and distribution.答案：generation7. The SI unit for electrical resistance is the _______.答案：ohm8. In a parallel circuit, the total resistance is always_______ than any individual resistance.答案：lower9. The process of converting mechanical energy intoelectrical energy is known as _______.答案：generation10. A fuse is a type of protective device that operates by_______ when the current exceeds a safe level.答案：melting三、简答题（每题5分，共30分）11. Explain the difference between AC and DC power systems. 答案：AC (Alternating Current) power systems use a current that regularly reverses direction, while DC (Direct Current) power systems use a current that flows in one direction only.12. What is the significance of Ohm's Law in electrical engineering?答案：Ohm's Law is fundamental in electrical engineering asit relates the voltage (V), current (I), and resistance (R) in a simple electrical circuit, expressed as V = IR, allowing for calculations of these quantities.13. Describe the role of a generator in an electric power system.答案：A generator is a device that converts mechanical energy into electrical energy, serving as the primary source of power in an electric power system.14. What are the functions of a capacitor in an electrical circuit?答案：A capacitor in an electrical circuit can store energy, filter signals, and block direct current while allowing alternating current to pass.四、计算题（每题5分，共20分）15. Calculate the total resistance in a circuit with two resistors in parallel, where R1 = 100 ohms and R2 = 200 ohms.答案：\( R_{total} = \frac{R1 \times R2}{R1 + R2} = \frac{100 \times 200}{300} = \frac{20000}{300} = 66.67 \) ohms16. If a 12-volt battery is connected to a 3-ohm resistor, what is the current flowing through the resistor?答案：\( I = \frac{V}{R} = \frac{12}{3} = 4 \) amperes17. What is the power consumed by a 5-ohm resistor with a current of 2 amperes flowing through it?答案：\( P = I^2 \times R = 2^2 \times 5 = 4 \times 5 = 20 \) watts18. If a 240-volt AC motor draws a current of 5 amperes, what is the apparent power?答案：\( S = V \times I = 240 \times 5 = 1200 \) volt-amperes五、论述题（每题10分，共20分）19. Discuss the importance of energy efficiency in power systems and how it can be achieved.答案：Energy efficiency is crucial in power systems as it reduces energy consumption, lowers operational costs, and decreases environmental impact. It can be achieved through various means such as using high-efficiency equipment, optimizing system operations, and implementing demand-side management strategies.20. Explain the concept of smart grids and their advantages over traditional power systems.答案：Smart grids are advanced power systems that use digital technology and automation to improve the efficiency, reliability, and sustainability of electricity production anddistribution. They offer numerous advantages over traditional systems, including better demand response, enhanced grid stability, and the ability to integrate renewable energy sources more effectively.。
DESIGN DETAILSX440 AUTOMATIC VOLTAGEREGULATOR (AVR)SPECIFICATION, INSTALLATION AND ADJUSTMENTS General description Technical specificationSX440 is a half-wave phase-controlled thyristor type Automatic Voltage Regulator (AVR) and forms part of the excitation system for a brush-less generator.In addition to regulating the generator voltage, the AVR circuitry includes under-speed and sensing loss protection features. Excitation power is derived directly from the generator terminals.Positive voltage build up from residual levels is ensured by the use of efficient semiconductors in the power circuitry of the AVR.The AVR is linked with the main stator windings and the exciter field windings to provide closed loop control of the output voltage with load regulation of +/- 1.0%.In addition to being powered from the main stator, the AVR also derives a sample voltage from the output windings for voltage control purposes. In response to this sample voltage, the AVR controls the power fed to the exciter field, and hence the main field, to maintain the machine output voltage within the specified limits, compensating for load, speed, temperature and power factor of the generator.A frequency measuring circuit continually monitors the generator output and provides output under-speed protection of the excitation system, by reducing the output voltage proportionally with speed below a pre-settable threshold. A manual adjustment is provided for factory setting of the under frequency roll off point, (UFRO). This can easily be changed to 50 or 60 Hz in the field by push-on link selection.Provision is made for the connection of a remote voltage trimmer, allowing the user fine control of the generator's output.An analogue input is provided allowing connection to a Newage Power Factor controller or other external devices with compatible output.The AVR has the facility for droop CT connection, to allow parallel running with other similarly equipped generators. INPUTVoltage 190-264VacFrequency 50-60 Hz nominalPhase 1Wire 2OUTPUTVoltage max 90V dc at 207V ac inputCurrent continuous 4A dcIntermittent 6A for 10 secsResistance 15 ohms minimumREGULATION+/- 1% (see note 1)THERMAL DRIFT0.04% per deg. C change in AVR ambient (note 2)TYPICAL SYSTEM RESPONSEAVR response 20msFiled current to 90% 80 msMachine Volts to 97% 300msEXTERNAL VOLTAGE ADJUSTMENT+/-10% with 1 k ohm 1 watt trimmer (see note 3)UNDER FREQUENCY PROTECTIONSet point 95% Hz (see note 4)Slope 170% down to 30 HzUNIT POWER DISSIPATION12 watts maximumBUILD UP VOLTAGE4 Volts @ AVR terminalsANALOGUE INPUTMaximum input +/- 5V dc (see note 5)Sensitivity 1v for 5% Generator Volts (adjustable)Input resistance 1k ohmQUADRATURE DROOP INPUT10 ohms burdenMax. sensitivity: 0.07 A for 5% droop 0PFMax. input: 0.33AENVIRONMENTALVibration 20-100Hz 50mm/sec100Hz – 2kHz 3.3gOperating temperature -40 to +70 o CRelative Humidity 0-70 o C 95% (see note 6)Storage temperature -55 to +80 o C NOTES1. With 4% engine governing.2. After 10 minutes.3. Applies to Mod status S onwards. Generator de-ratemay apply. Check with factory.4. Factory set, semi-sealed, jumper selectable.5. Any device connected to the analogue input must befully floating (galvanically isolated from ground), with an insulation strength of 500V ac.6. Noncondensing.DESIGN DETAILThe main functions of the AVR are:Potential Divider and Rectifier takes a proportion of the generator output voltage and attenuates it. The potential divider is adjustable by the AVR Volts potentiometer and external hand trimmer (when fitted). The output from the droop CT is also added to this signal. An isolating transformer is included allowing connection to various winding configurations. A rectifier converts the a.c. input signal into d.c. for further processing.The Sensing Loss Detector is an electronic changeover switch, which normally connects the Amplifier (Amp) to the Voltage Sensing input and automatically changes over to the Power input when the normal sensing voltage is lost.The DC Mixer adds the Analogue input signal the Sensing signal.The Amplifier (Amp) compares the sensing voltage to the Reference Voltage and amplifies the difference (error) to provide a controlling signal for the power devices. The Ramp Generator and Level Detector and Driver infinitely control the conduction period of the Power Control Devices and hence provides the excitation system with the required power to maintain the generator voltage within specified limits.The Stability Circuit provides adjustable negative ac feedback to ensure good steady state and transient performance of the control system.The Low Hz Detector measures the period of each electrical cycle and causes the reference voltage to be reduced approximately linearly with speed below a presettable threshold. A Light Emitting Diode gives indication of underspeed running.The Synchronising circuit is used to keep the Ramp Generator and Low Hz Detector locked to the generator waveform period.The Low Pass Filter prevents distorted waveforms affecting the operation of the AVR control circiutPower Control Devices vary the amount of exciter field current in response to the error signal produced by the Amplifier.Suppression components are included to prevent sub cycle voltage spikes damaging the AVR components and also to reduce the amount of conducted noise on the generator terminals..The Power Supply provides the required voltages for the AVR circuitry.Hand Trimmer Analogue Input DroopFITTING AND OPERATINGSUMMARY OF AVR CONTROLSCONTROL FUNCTION DIRECTIONVOLTS TO ADJUST GENERATOR OUTPUT VOLTAGE CLOCKWISE INCREASES OUTPUT VOLTAGE STABILITY TO PREVENT VOLTAGE HUNTING CLOCKWISE INCREASE THE DAMPING EFFECTUFRO TO SET THE UFRO KNEE POINT CLOCKWISE REDUCES THE KNEE POINTFREQUENCYDROOP TO SET THE GENERATOR DROOP TO 5% AT 0PF CLOCKWISE INCREASES THE DROOPVTRIM TO OPTIMISE ANALOGUE INPUT SENSITIVITY CLOCKWISE INCREASES THE GAIN OR SENSITIVITY ADJUSTMENT OF AVR CONTROLSVOLTAGE ADJUSTMENTThe generator output voltage is set at the factory, but can be altered by careful adjustment of the VOLTS control on the AVR board, or by the external hand trimmer if fitted. Terminals 1 and 2 on the AVR will be fitted with a shorting link if no hand trimmer is required.CAUTION Do not increase the voltage above the rated generator voltage. If in doubt, refer to the rating plate mounted on the generator case.CAUTION Do not ground any of the hand trimmer terminals as these could be above earth potential. Failure to observe this could cause equipment damage.If a replacement AVR has been fitted or re-setting of the VOLTS adjustment is required, proceed as follows: CAUTION1. Before running generator, turn the VOLTS control fully anti-clockwise.2. Turn remote volts trimmer (if fitted) to midway position.3. Turn STABILITY control to midway position.4. Connect a suitable voltmeter (0-300V ac) acrossline to neutral of the generator.5. Start generator set, and run on no load at nominal frequency e.g. 50-53Hz or 60-63Hz.6. If the red Light Emitting Diode (LED) is illuminated, refer to the Under Frequency Roll Off (UFRO) adjustment.7. Carefully turn VOLTS control clockwise until rated voltage is reached.8. If instability is present at rated voltage, refer to stability adjustment, then re-adjust voltage if necessary.9. Voltage adjustment is now completed.FITTING AND OPERATINGTD_SX440 AVR_03.06_04_GBBarnack Road • Stamford • Lincolnshire • PE9 2NB Tel: 00 44 (0)1780 484000 • Fax: 00 44 (0)1780 484100© 2006 Cummins Generator Technologies Limited.STABILITY ADJUSTMENTThe AVR includes a stability or damping circuit to provide good steady state and transient performance of the generator.The correct setting can be found by running the generator at no load and slowly turning the stability control anti-clockwise until the generator voltage starts to become unstable.The optimum or critically damped position is slightly clockwise from this point (i.e. where the machine volts are stable but close to the unstable region).OPTIMUM RESPONSE SELECTIONThe stability selection ‘jumper’ should be correctly linked, A-B, B-C or A-C at the bottom of the board for the frame size of the generator, (see drawing).UNDER FREQUENCY ROLL OFF (UFRO) ADJUSTMENTThe AVR incorporates an underspeed protection circuit which gives a volts/Hz characteristic when the generator speed falls below a presettable threshold known as the "knee" point.The red Light Emitting Diode (LED) gives indication that the UFRO circuit is operating.The UFRO adjustment is preset and sealed and only requires the selection of 50 / 60Hz using the jumper link.For optimum setting, the LED should illuminate as the frequency falls just below nominal, i.e. 47Hz on a 50Hz system or 57Hz on a 60Hz system.DROOP ADJUSTMENTGenerators intended for parallel operation are fitted with a quadrature droop C.T. which provides a power factor dependent signal for the AVR. The C.T. is connected to S1, S2 on the AVR.The DROOP adjustment is normally preset in the works to give 5% voltage droop at full load zero power factor.Clockwise increases the amount of C.T. signal injected into the AVR and increases the droop with lagging power factor (cos Ø). With the control fully anti-clockwise there is no droop.TRIM ADJUSTMENTAn analogue input (A1 A2) is provided to connect to the Newage Power Factor Controller or other devices. It is designed to accept dc signals up to +/- 5 volts.CAUTION Any devices connected to this input must be fully floating and galvanically isolated from ground, with an insulation capability of 500 Vac. Failure to observe this could result in equipment damage.The dc signal applied to this input adds to the AVR sensing circuit. A1 is connected to the AVR 0 volts. Positive on A2 increases excitation. Negative on A2 decreases excitation.The TRIM control allows the user to adjust the sensitivity of the input. With TRIM fully anti-clockwise the externally applied signal has no effect. Clockwise it has maximum effect.Normal setting is fully clockwise when used with a Newage Power Factor Controller.。
电信沟通的利弊英语作文Title: Pros and Cons of Telecommunication in English Communication。
In the contemporary world, telecommunication has become an indispensable part of our daily lives, profoundly impacting how we communicate with one another. From the emergence of the telephone to the advent of the internet, telecommunication has revolutionized the way information is transmitted across vast distances. However, like any technological advancement, it brings both advantages and disadvantages. In this essay, we will delve into the pros and cons of telecommunication in English communication.Advantages of Telecommunication:1. Global Connectivity: Telecommunication bridges the geographical gaps, allowing people from different parts of the world to communicate effortlessly. Through emails, video calls, and instant messaging, individuals can connectwith others irrespective of their location, fostering global friendships and collaborations.2. Enhanced Efficiency: Communication through telecommunication channels is swift and convenient. With just a few clicks, one can convey messages instantaneously, eliminating the delays associated with traditional mail services. This rapid exchange of information promotes efficiency in various sectors such as business, education, and healthcare.3. Cost-Effective: Compared to traditional methods of communication, telecommunication is often more cost-effective. Long-distance calls made through internet-based platforms are significantly cheaper than conventional telephone services, making it accessible to a broader segment of the population.4. Flexibility: Telecommunication offers unparalleled flexibility in communication. Whether it's a formal conference call or a casual chat with friends, individuals can communicate at their convenience, without beingconstrained by time or location.5. Accessibility: Telecommunication tools are increasingly accessible to people of all ages and backgrounds. With the proliferation of smartphones and internet connectivity, even remote areas now have access to telecommunication services, bridging the digital divide.Disadvantages of Telecommunication:1. Impersonal Communication: Despite its convenience, telecommunication often lacks the personal touch associated with face-to-face interactions. Tone, body language, and facial expressions, crucial elements of effective communication, may be lost in digital exchanges, leading to misunderstandings and misinterpretations.2. Security Concerns: The transmission of sensitive information over telecommunication channels poses significant security risks. Hackers and cybercriminals exploit vulnerabilities in networks to intercept data, leading to breaches of privacy and confidentiality.Instances of identity theft and financial fraud are rampant in the digital age, raising concerns about the security of telecommunication systems.3. Dependency on Technology: As society becomes increasingly reliant on telecommunication technology, there is a growing dependency on gadgets and internet connectivity. In the event of technical glitches or network outages, communication channels may be disrupted, causing inconvenience and disruption to daily activities.4. Social Isolation: Excessive reliance on telecommunication for interpersonal communication can lead to social isolation and alienation. Spending long hours glued to screens can detract from real-world interactions, leading to feelings of loneliness and disconnect from society.5. Digital Divide: Despite advancements in telecommunication technology, there still exists a digital divide, with marginalized communities lacking access to essential telecommunication services. This digital divideexacerbates existing inequalities, limiting opportunities for socio-economic advancement.In conclusion, telecommunication has revolutionized the way we communicate, offering unparalleled convenience and connectivity. However, it is essential to recognize the inherent challenges and limitations associated with telecommunication, including issues of security, impersonality, and social isolation. By addressing these challenges and striving for inclusivity, we can harness the power of telecommunication to create a more connected and cohesive global community.。
全文分为作者个人简介和正文两个部分：作者个人简介：Hello everyone, I am an author dedicated to creating and sharing high-quality document templates. In this era of information overload, accurate and efficient communication has become especially important. I firmly believe that good communication can build bridges between people, playing an indispensable role in academia, career, and daily life. Therefore, I decided to invest my knowledge and skills into creating valuable documents to help people find inspiration and direction when needed.正文：网络隐私保护与信息扩展英语作文全文共3篇示例，供读者参考篇1Online Privacy and the Double-Edged Sword of InformationIn the vast digital landscape we inhabit today, the concept of privacy has taken on new dimensions and complexities. As students navigating the intricate web of online networks, we findourselves grappling with the delicate balance between protecting our personal information and embracing the boundless opportunities for knowledge and connection that the internet offers.The insatiable thirst for data in our digital age has given rise to a culture of information sharing that often overshadows concerns about privacy. Social media platforms, search engines, and countless online services thrive on the collection and analysis of our personal data, promising tailored experiences and targeted advertisements in exchange for our digital footprints. However, this trade-off raises critical questions about the extent to which our private lives should be laid bare in the pursuit of convenience and personalization.One of the most significant challenges we face is the ubiquitous tracking and profiling of our online activities. Cookies, web beacons, and other invisible trackers silently monitor our browsing habits, preferences, and interests, creating detailed profiles that can be exploited for commercial or even malicious purposes. This pervasive surveillance not only infringes on our privacy but also raises concerns about the potential misuse of our data, from targeted advertising to identity theft andcyber-attacks.Moreover, the digital breadcrumbs we leave behind can have far-reaching consequences, especially in the realm of education and employment. Prospective colleges and employers increasingly scrutinize our online presence, and a singleill-advised post or comment can tarnish our reputations and jeopardize our future prospects. It is a sobering reminder that the internet has a long memory, and our digital footprints can haunt us long after we have moved on.Yet, amidst these privacy concerns, we must also acknowledge the immense value that the free flow of information brings to our educational pursuits. The internet has become a vast repository of knowledge, offering unprecedented access to a wealth of resources, research materials, and diverse perspectives. Online forums, collaborative platforms, and educational websites have revolutionized the way we learn, facilitating global exchanges of ideas and fostering intellectual discourse.Furthermore, the ability to connect and collaborate with peers from around the world has opened up new avenues for cross-cultural understanding and innovative problem-solving. Online communities and virtual classrooms have broken down geographical barriers, allowing us to engage with diverseperspectives and gain insights that would have been impossible in the pre-digital era.As students, we must strike a delicate balance between safeguarding our privacy and embracing the transformative potential of information sharing. This requires a multifaceted approach, encompassing personal responsibility, technological safeguards, and regulatory frameworks.On a personal level, we must cultivate digital literacy and adopt responsible online practices. This includes being mindful of the information we share, regularly reviewing and adjusting our privacy settings, and employing robust security measures such as strong passwords and two-factor authentication. Additionally, we should exercise caution when engaging with unfamiliar websites or online services, and be vigilant against potential phishing attempts or other cyber threats.However, individual efforts alone are not enough; technological solutions and industry-wide initiatives are crucial in protecting our online privacy. Privacy-enhancing technologies, such as end-to-end encryption, anonymous browsing, and data minimization techniques, can help shield our personal information from prying eyes. Furthermore, companies and service providers must prioritize data protection and implementrobust security measures to safeguard user information from breaches and unauthorized access.Lastly, governments and regulatory bodies play a vital role in establishing legal frameworks and guidelines to protect consumer privacy rights. Comprehensive data protection laws, coupled with strict enforcement and oversight mechanisms, can help rein in unchecked data collection practices and empower individuals with greater control over their personal information.In the end, the digital age has ushered in a paradox: the more information we share, the more vulnerable we become, yet the more we withhold, the more opportunities we may miss. As students, it is our responsibility to navigate this complex landscape with wisdom and discernment, striking a balance between privacy protection and the pursuit of knowledge.We must embrace the transformative power of information while remaining vigilant against its potential misuse. By fostering a culture of responsible information sharing, leveraging technological solutions, and advocating for robust regulatory frameworks, we can harness the vast potential of the digital world while safeguarding our fundamental right to privacy.Only then can we truly unlock the boundless possibilities of learning, innovation, and personal growth in the ever-evolving digital frontier.篇2The Tug-of-War: Internet Privacy vs. Information ExpansionIn our digital age, the internet has become an indispensable part of our daily lives, revolutionizing the way we communicate, work, and access information. However, as technology advances, a delicate balance emerges between preserving our online privacy and fueling the insatiable demand for information expansion. This tug-of-war between these two forces has sparked heated debates and raised critical questions about the boundaries we must navigate in the virtual realm.On one side of the tug-of-war stands the fundamental right to privacy – a cornerstone of individual freedom and autonomy. The internet, while offering boundless opportunities, has also become a breeding ground for invasive data collection practices, cybercrime, and unwarranted surveillance. Our digital footprints, from browsing histories to social media activities, are constantly tracked, analyzed, and commodified, often without our explicit consent. This erosion of privacy has far-reaching implications,from personal security concerns to the potential for discrimination and manipulation.As students, we are particularly vulnerable to these threats. Our online activities, from research to social interactions, leave a trail of sensitive information that could be exploited by malicious actors or misused by institutions with vested interests. The consequences of privacy breaches can be severe, ranging from identity theft and cyberbullying to reputational damage and compromised academic integrity.On the other side of the tug-of-war lies the unstoppable march of information expansion. The internet has democratized knowledge, breaking down barriers and empowering individuals with access to a vast repository of information. This abundance of data has fueled innovation, fostered global collaboration, and facilitated the free exchange of ideas – principles that are fundamental to academic pursuits and intellectual growth.As students, we are the beneficiaries of this information explosion. Online resources, digital libraries, and open-source platforms have revolutionized the way we learn, conduct research, and engage with diverse perspectives. The ability to access and share knowledge transcends geographical boundaries, enabling us to connect with scholars, experts, andpeers from around the globe, enriching our educational experiences.However, the tension between these two forces is palpable. The more information we share and consume online, the more vulnerable we become to privacy infringements. Conversely, overzealous protection of privacy can stifle the free flow of information, hindering progress and limiting our ability to engage with the global intellectual community.Finding the delicate balance between these competing forces is a complex endeavor that requires a multifaceted approach. On an individual level, we must actively cultivate digital literacy and adopt robust cybersecurity practices, such as using strong passwords, enabling two-factor authentication, and exercising caution when sharing personal information online. Additionally, we should critically evaluate the privacy policies and data practices of the platforms and services we utilize, advocating for greater transparency and user control over their personal data.Institutions, including educational establishments, also play a crucial role in this endeavor. They must prioritize the implementation of robust data protection measures, adhere to strict ethical guidelines, and provide comprehensive digitalcitizenship education to empower students with the knowledge and skills to navigate the online world safely and responsibly.Governments and policymakers bear the responsibility of crafting fair and effective regulatory frameworks that strike a balance between protecting individual privacy rights and fostering an environment conducive to innovation and information sharing. Legislation such as the General Data Protection Regulation (GDPR) in the European Union and the California Consumer Privacy Act (CCPA) in the United States are steps in the right direction, but ongoing dialogue and international cooperation are necessary to ensure harmonized and effective data protection standards.Furthermore, technology companies and service providers must prioritize privacy-by-design principles, implementing robust encryption, anonymization techniques, and user-centric data control mechanisms. They should embrace ethical data practices, minimizing data collection and ensuring transparent and meaningful consent processes.Ultimately, the tug-of-war between internet privacy and information expansion is a complex and multifaceted challenge that requires a concerted effort from all stakeholders. As students, we must embrace our role as active participants inshaping the digital landscape, advocating for our privacy rights while embracing the transformative power of information expansion.By fostering a culture of digital responsibility, advocating for robust privacy protections, and actively engaging in the discourse surrounding these issues, we can navigate this delicate balance and harness the full potential of the internet while safeguarding our fundamental rights and liberties.The path forward may be fraught with challenges, but it is a journey we must undertake collectively, guided by the principles of ethics, transparency, and a deep commitment to preserving the integrity of knowledge and the sanctity of individual autonomy in the digital age.篇3Online Privacy and the Expanding Information AgeAs a student living in the digital era, I can't help but feel both excited and apprehensive about the rapid expansion of information and technology. On one hand, the internet has revolutionized the way we learn, communicate, and access knowledge. But on the other hand, concerns over online privacy and data protection have become increasingly prevalent.In today's world, we are constantly generating data through our online activities – from social media posts and search queries to online purchases and location tracking. This wealth of personal information is a goldmine for companies and organizations seeking to better understand and target consumers. However, the misuse or unauthorized access of this data can have severe consequences for individuals' privacy and security.One of the primary threats to online privacy is the widespread practice of data collection and tracking by tech giants and advertisers. Companies like Google, Facebook, and Amazon have built their empires on the ability to gather and analyze user data, which they then use to deliver targeted ads and personalized experiences. While this can be convenient for users, it also raises concerns about the extent of information being collected and how it is being used.Another issue is the prevalence of cyber crimes, such as hacking, identity theft, and online fraud. As we increasingly rely on digital platforms for sensitive activities like banking and healthcare, the risk of having our personal and financial information compromised grows exponentially. High-profile data breaches at major companies and organizations haveexposed millions of people's personal data, highlighting the vulnerability of our online presence.Despite these concerns, the benefits of the information age are undeniable. The internet has opened up a world of knowledge and opportunities that were previously inaccessible to many. Online education platforms have made learning more accessible and affordable, while social media has facilitated global connectivity and the exchange of ideas. Furthermore, the digital revolution has spawned countless innovations in fields like healthcare, finance, and entertainment, improving our quality of life in countless ways.So, how can we strike a balance between embracing the advantages of the information age while protecting our online privacy? One approach is to advocate for stronger data protection laws and regulations. Governments and international organizations have been working to establish guidelines and policies to safeguard user privacy and hold companies accountable for data misuse. The European Union's General Data Protection Regulation (GDPR) and the California Consumer Privacy Act (CCPA) are examples of such efforts.At the individual level, we can take proactive measures to protect our online privacy. This includes being cautious aboutthe information we share online, using strong passwords and two-factor authentication, and regularly updating our software and security protocols. Additionally, we can support companies and services that prioritize user privacy and data protection, sending a clear message that consumers value their digital rights.It is also crucial to educate ourselves and others, especially younger generations, about the importance of online privacy and the potential risks associated with oversharing personal information. Schools and educational institutions have a responsibility to incorporate digital literacy and cybersecurity into their curricula, equipping students with the knowledge and skills to navigate the online world safely and responsibly.As we continue to embrace the benefits of the information age, it is essential to remember that our personal data is a valuable commodity that must be protected. By advocating for stronger privacy laws, practicing good cyber hygiene, and prioritizing digital literacy, we can enjoy the advantages of technology while safeguarding our privacy and security.In conclusion, the expansion of information and technology has brought both tremendous opportunities and significant challenges when it comes to online privacy. As students andcitizens of the digital world, it is our responsibility to strike a balance between embracing innovation and protecting our fundamental right to privacy. By staying informed, being proactive, and supporting efforts to secure our digital rights, we can ensure that the information age remains a force for progress and empowerment, rather than a threat to our individual liberties.。
Electric Power Exchanges with Sensitivity Matrices An Experimental AnalysisMartin Drozda12Los Alamos National Laboratory3Los Alamos,POBOX1663,MS M997,NM87545AbstractWe describe a fast incremental method for power flows computation tailored for electric power mar-kets.Fast in the sense that it can be used for real time powerflows computation,and incremen-tal in the sense that it computes any additional in-crease/decrease in line congestion caused by a par-ticular(n-lateral)contract.Incremental methods of-fer a powerful way of dealing with congestion con-tingency,improve informationflows among market entities,and are easy to understand.In this docu-ment we provide basic scaling properties for elec-tric power markets using this method,and compare it with methods using(linearized)powerflow code. The author is in the process of obtaining a patent on methods,algorithms,and procedures described in this paper.1IntroductionDeregulated electric power market assigns new re-sponsibilities and tasks to market entities.The task of system operator is to keep powerflows in an elec-tric grid within limits.The task of electric power ex-change is to couple power producers and consumers. Furthermore,power exchange has to communicate with system operator to ensure stability of the grid after contracted power is injected at a generator bus, 1Author visiting from Slovak Academy of Sciences,Institute of Control Theory and Robotics,Slovak Republic.2drozda@3The Los Alamos National Laboratory strongly supports aca-demic freedom and a researcher’s right to publish;therefore,the Laboratory as an institution does not endorse the viewpoint of a publication or guarantee its technical correctness.Research sup-ported by the US Department of Energy under contract W-7405-ENG.and taken out at a load bus.This simple interaction schema encompasses a multitude of problems that were subdued when the centralized utility compa-nies ruled the electricity world.Nowadays,a power exchange has to face tens of thousand of contracts seeking settlement each hour.For each contract it needs to be decided whether the contract is feasi-ble,i.e.,complying with security guidelines of the power grid.This is done by system operator,and ideally,he should run a powerflow code,and con-sider projected powerflows.This requires a fast method of powerflow computation.Furthermore, additional power injection is going to influence mar-ket situation.Increase/decrease in line congestion forces consumers to buy power from different pro-ducers as they have to obey the very same security guidelines.The power exchange usually tries to in-tervene and designs a set of rules aimed to resolve congestion.This is done by charging for additional congestion caused by a contract.Several schemata were suggested for congestion fee computation.We can divide them into three groups:contract path, point-to-point,and realflow.The realflow meth-ods ensure the fairest pricing but are computation-ally very expensive.Some simplifications were pro-posed,e.g.,flow gates[8].In this document we describe a fast incremental method for powerflows computation.Fast in the sense that it can be used for real time powerflows computation,and incre-mental in the sense that it computes any additional increase/decrease in line congestion caused by a par-ticular(n-lateral)contract.Our method is based on sensitivity analysis of the underlying power grid.For the analysis we used a standard linearized powerflow code.Let n be number of buses,and m number of lines.We se-quentially inject a unit amount of power into each bus,and compute the increase in powerflows on0-7803-7087-2/01/$10.00c 2001IEEE1each line.This way we obtain a sensitivity ma-trix of n×m cells.The matrix can also be com-puted analytically.The matrix is static,and needs to be re-computed each time physical parameters of the power grid change.This problem has been ad-dressed by a distinct paper[6]from our team,and we can re-compute sensitivity matrices for a mod-erate grid size,e.g.,ERCOT within a few minutes (1-2).Computation of incremental powerflows is achieved by a single multiplication with injection vector.Injection vectors for bilateral contracts have the property of being very sparse,thus,the multi-plication reduces to multiplication/addition of four numeric values.Our experiments show that we speed up contract ap-proval/disapproval by system operator significantly. Computational time grows linearly in the number of lines,whereas in case of a standard linearized power flow code the computational time grows polynomi-ally.This for example means that in case of ER-COT we were able to speed up the process more than120times.With this method we were able to simulate markets of ERCOT or WSCC on a single PC(500MHz,256MB).Moreover,we are able not only approve/disapprove contract in real time,but also compute increase/decrease in line congestion caused by the contract,thus,giving data needed by power exchange for congestion management.This document is organized as follows:in Section2 we give an overview of the market implemented in ELISIMS,a software tool for simulating elec-tric power markets;in Section3we give an insight into the incremental method,and we show how it is used by system operator to approve/disapprove con-tracts;in Section4we show basic scaling properties of electric power exchanges using this method,and compare it with electric power exchanges using(lin-earized)powerflow code to compute powerflows. 2The marketFor our simulation tool(ELISIMS[3])we have cho-sen to implement the so called continuous nodal market.It is a market with nodal prices as op-posed to markets with zone prices.We have de-signed the market as a24hour forward market with no possibility of spot trading.The market allows only bilateral contracts which are processed in the order they come.The electric power price at each node is a function of the electric power price for the given hour and given generator,and transmission cost.The transmission costs are based on conges-tion.In early versions of ELISIMS we have imple-mented congestion fee computation based on con-tract paths.At present,we use real-flow computa-tion methods based on sensitivity matrices.The con-tract paths were computed as the shortest path from a generator to a customer.To compute the short-est path we used Dijkstra’s shortest path algorithm (see[2]).Next,we describe mechanisms of our market to make you accustomed with the interplay among all the market entities:customers,power producers (generators),system operator,and power exchange. System operator is an entity which is responsible for stability and security of the grid(under cooperation with transmission operators and owners);it runs the network from the physical point of view,i.e.,it op-erates buses,branches,controls grid network limits etc.It does not have any obligations against cus-tomers,producers,or brokers and actually it should be completely independent from all other entities. On request from the power exchange gives answers on whether a new contract is going to preserve all security and stability parameters of the network.To cope with this task,the system operator runs a power flow code.Based on the projected powerflows, he reasons about future security conditions on the power grid.The powerflows computation is done in real time.There are tens of thousand of contracts awaiting approval each hour.However,it is not only approval or disapproval of contracts that are in the scope of his responsibilities.Markets entities need strong hints in order to modify a disapproved con-tract,and as well,they need to understand trends in power grid congestion.Power exchange is an entity that runs the market itself.It collects orders from consumers,produc-ers,and brokers and tries to clear them.Congestion management is an important factor in the process of market functioning.Congestion changes behavior of everyone.The once cheap power becomes un-transportable from the point of production,and con-sumers are forced to seek alternative power produc-ers.On the other hand,producers cannot sell their power to an arbitrary consumer due to line conges-tion.The power exchange intervenes in this situa-tion,and designs a set of rules to control conges-tion.This is mostly done by charging fees for any additional congestion that a contract may cause.Foran exact and fair congestion fee computation,the power exchange needs closely cooperate with the system operator.The system operator has strong tools to provide the power exchange with all nec-essary information.He runs a powerflow code for each contract clearing.The system operator also needs to supply the power exchange with incremen-tal data about changing line congestion.In other words,he needs to run a powerflow code that com-putes incremental powerflows,and the computation needs to be doable in real time.Now,suppose you are a customer willing to buy some power to satisfy your needs.You submit your request to the power exchange.The power exchange finds the cheapest power producers from the point of view of power price,and congestion fees connected to the contract approval.The power exchange co-operates with system operator on contract approval, and seeks approval.The system operator either ap-proves or disapproves the contract,and supplies the power exchange with incremental data about line congestion.This data is used to compute real-flow congestion fees,and adjusts the approximate con-gestion fees computed by power exchange in order tofind the cheapest producer.ELISIMS is written in ANSI/ISO C/C++for UNIX/Linux environment.The tool is capable of using two kinds of powerflow codes.First of the two is the powerflow code developed at the Uni-versity of Texas at Arlington,which is a well tested non-linear powerflow code.The other one is a lin-earized version of powerflow code developed at the Los Alamos National Laboratory.Due to the ne-cessity to start the simulation from zero loads and power generation(i.e.black start),we found the lin-earized version easier to use.The computational er-ror of the linearized version is,in the case of electric power market,acceptable.We note that running powerflow code of any kind is the most computational time consuming procedure in our simulation.It can consume85–95%of used processor time.In our case the used hardware was a PC based on an Intel Pentium III500MHz processor and256MB of memory.Running the simulation on the ERCOT network with the linearized powerflow code took us2hrs12mins to simulate one real-time hour4(i.e.52hrs48mins to run the whole24hrs 4Parameters of the network were:topology=ERCOT,num-ber of buses=4,527,size of contracts=6.2MW,capacity of branches=ERCOT,demand/power available ratio=0.86.Num-market).88%of this time was spent to run the power flow code.[5]contains basic results on scalability of electric power exchanges using linearized power flow code.3Sensitivity matrixLet us have a power network of n buses,and l lines. Let q=[q1,...,q n]T to be an injection vector,and let limit=[limit1,limit2,...,limit l]to be a vec-tor of residual line limits.Residual line limits rep-resent amount of remaining capacity on each line. The sensitivity matrix of the underlying system is an n×l matrix.Let i be an arbitrary bus.Then the i-th column of the matrix represents the incremental change on each line caused by injection of a unit amount of power into the i-th bus.Let us now assume that there is a contract that needs to get evaluated with respect to the limits of a power grid.Let the contract to be a bilateral contract.In this case the injection vector is going to be a sparse vector of two entries.One for the generator bus i, and one for the load bus j.To check against the limits of the power grid we need to recall columns i and j from the sensitivity matrix.Let us assign s i and s j to columns i and j,respectively,i.e.,s i and s j are now injection sensitivity vectors for bus i and j.In the case of a bilateral contract(single generator,single consumer)the following inequality has to be satisfied to preserve line limits in a power grid:q×(s i+s j)≤limit.This can be generalized for multilateral contracts. Let the number of parties in such a contract to be b. The injection vector q becomes a vector of b non-zero entries,and the inequality becomes:q×bi=1s i≤limit.The left size of the inequality represents incremen-tal change of line congestion caused by the b-lateral contract.ber of branches for ERCOT is5,412.Number of contracts neces-sary to settle one real time hour was approximately5,700.Figure1:Scaling of computation time needed to compute sensitivity matrices with respect to number of buses.4ExperimentIn this section we present results that we got running ELISIMS with sensitivity matrices.4.1Computing sensitivity matricesIn the previous section we gave a definition of sen-sitivity matrix.Now,we show how to compute sen-sitivity matrices efficiently on any desktop PC com-puter.For this purpose we used a linearized version of powerflow code.Hence,we prefer a heuristic method to a direct analytical method.In our ap-proach we start with a power network with no power injection on either generator or consumer side.We assume a lossless power grid.Now,we sequen-tially and separately inject1MW of power into each bus.We follow the sign convention where generator injections have positive value,and vice-versa load buses(consumers)out-flows(consumptions)have negative values.After injecting1MW into a given bus we run the linearized powerflow code and ana-lyze powerflows that this injection caused.By do-ing so for each bus separately we obtain a sensitiv-ity matrix of dimension n×l,where n is number of buses and l is number of lines(branches).We have implemented this algorithm and ran numer-ous experiments.Our hardware was a PC(Intel III 500MHz,256MB RAM,Linux).Infigure1we de-pict scaling characteristics for computation of sensi-tivity matrices.We have done this for a random net-work of1,000–6,000buses.We were unable to com-pute sensitivity matrices for networks with a larger number of buses on a(single-processor)PC with limited memory.Nevertheless,this gives a good idea how much time one will need to compute a sensitivity matrix.Under random network we un-derstand a tree graph with random degree(2–5)for each node and10%edges(randomly)added among nodes.This random addition of edges makes the graph(network)to be a non-tree graph.We have used this kind of network in our previous paper[5]. It gives a quite conservative image of real power networks,and all measurable propertiesfluctuate at their upper bounds.However,a closer look at real network unveils that these are almost tree structures with a tangle of additional lines around bigger con-glomerations.One can argue that use of sensitivity matrices can be very cumbersome because of the need to recom-pute them at every change of physical parameters of power network.However,this does not happen so frequently,and in case of scheduled maintenance the system operator can get prepared well ahead.Nev-ertheless,we have designed a distributed method for computation of sensitivity matrices with much more favorable speed and scaling characteristics,see[6]. This method gives a possibility to recompute a sen-sitivity matrix for a power grid of size of ERCOT,or WSCC within a few minutes.A more serious prob-lem is the size of memory needed to store sensitiv-ity matrices.Indeed,if we imagine a huge power network such as the one in the US with projected number of customers reaching150million this can be a considerable problem.Fortunately,the num-ber of lines is going to be relatively e of local methods for computation and look-up of in-jection sensitivity vectors can be probably very suc-cessfully used.At present,we can store a sensitivity matrix for ERCOT or WSCC on a desktop PC with a few gigabytes of memory–without exploring a distributed memory,or other approaches.4.2Running time of an electric power ex-change using sensitivity matrixIn this section,we will present two experiments:the first one is running an electric power exchange us-ing a linearized powerflow code,and the other one is running using the underlying sensitivity matrix. We have taken thefirst experiment from our previ-ous paper[5]which discusses approaches using lin-earized powerflow codes in more detail.To reason about efficiency of sensitivity matrices weFigure 2:Scaling of an electric power exchange with respect to number of buses using a linearized power flowcode.Figure 3:Scaling of an electric power exchange with respect to number of buses using underlying sensitivity matrix.have decided to run a series of simulations.The only independent variable we use is number of buses,and the only dependent variable we use is time within which an electric power exchange clears all con-tracts for a 24-hour period (single business day).In Figure 2we depict this situation with use of a lin-earized power flow code,and in Figure 3we do the same for the sensitivity matrix.We can clearly see that sensitivity matrices offer a reasonable speed-up compared to the approach us-ing linearized power flow code.The networks that we have used in these experiments are the random networks described in previous subsection.As we have already mentioned these represent a quite con-servative view of real power networks.We have run this experiment also for ERCOT,the power net-work of the state of Texas.ERCOT is a network of with 4,527buses,and 5,412power lines.With a linearized power flow code we were able to run a single business day in 52hrs 48mins,and with the underlying sensitivity matrix this time shrunk to mere 30minutes.This does not come as a surprise because from previous experiments described in [5]we know that roughly 88%of computation time is spent in running power flow code.Cutting down on time spent in this part of the code one can extremely speed up the whole clearing process what leads to an increased reliability of the whole process and eases up pressure on the system operator.5ConclusionsIn the paper we have presented an incremental ap-proach to power flows computation tailored for elec-tric power exchanges.We have run a series of exper-iments to be able to reason about efficiency of this approach.We have found out that using sensitivity matrices in the process of clearing an electric power market can lead to a significant speed-up and thus to improved reliability of the electric grid.In case of ERCOT,the power network of the state of Texas,we have managed to cut running time from almost 53hrs down to 30minutes.We consider this speed-up worth of notice and future research.The weakness of sensitivity matrices stems from the problem of their storage.They create densely pop-ulated matrix of injection sensitivity vectors.In the case we have to deal with 150million customers the matrix can be very big,though,the other dimension which is number of lines will probably stay fixed or will only slowly increase in the future.We believe that use of local methods can ease up this problem.Also,distributed memory storage methods can be considered.However,in most practical cases,one will only need to store a network of size of ERCOT or WSCC what is possible on a single PC with a few gigabytes of memory.The advantage of sensitivity matrices is that they can become public data accessible to anyone connected to electric power business.They increase informa-tion flows and can significantly reduce number of unnecessary contract approval requests submitted to the system operator.With sensitivity matrices each entity of power market will be able to evaluate its own business decisions before they are made,and the decision helper software will be run on a PCbased computer.Moreover,this method of powerflows computation is inherently incremental.We consider this feature to be a big advantage over other methods as it posi-tively contributes to congestion management. 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