Learning a highly structured motion model for 3D human tracking
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了解中国学生课外阅读的情况英语作文全文共3篇示例,供读者参考篇1Title: Understanding the Situation of Chinese Students' Extracurricular ReadingIntroductionIn today's fast-paced and competitive society, the importance of extracurricular reading for students cannot be overstated. It not only broadens their knowledge and enhances their language skills but also helps them develop critical thinking and creativity. In China, where education is highly valued, extracurricular reading has become an integral part of students' academic pursuits.Current Situation of Extracurricular Reading in ChinaExtracurricular reading in China is a popular activity among students of all ages. While some students read for pleasure, others do so to improve their academic performance. In recent years, the Chinese government has also taken steps to promote extracurricular reading by launching initiatives such as the National Reading Promotion Month and the Reading for Allcampaign. These efforts have helped raise awareness about the importance of reading beyond the classroom and have encouraged students to read more widely.One of the most common forms of extracurricular reading in China is reading for academic purposes. Many students read textbooks, reference books, and academic journals to supplement their classroom learning. This is especially true for students preparing for exams such as the Gaokao (the national college entrance examination) and the CET (College English Test). Reading academic materials not only helps students excel in their exams but also provides them with a solid foundation for future academic and professional success.Apart from academic reading, Chinese students also engage in recreational reading. They read novels, short stories, poetry, and non-fiction books on a wide range of topics. Popular genres include science fiction, fantasy, romance, and self-help. Reading for pleasure allows students to relax, unwind, and escape from the pressures of school life. It also helps them develop a love for reading that can last a lifetime.Challenges and SolutionsDespite the benefits of extracurricular reading, Chinese students face several challenges in cultivating reading habits.One of the main challenges is the heavy workload and pressure of school. Many students have to juggle multiple assignments, exams, and extracurricular activities, leaving them with little time for reading. To address this issue, schools and parents can encourage students to prioritize reading by assigning less homework and providing more opportunities for independent reading.Another challenge is the lack of access to reading materials. While major cities in China have well-stocked libraries and bookstores, students in rural areas and small towns may not have the same level of access to books. To overcome this barrier, the government can invest in building more libraries, bookmobiles, and digital reading platforms in underserved areas. Schools can also create reading corners and book clubs to promote a culture of reading among students.ConclusionExtracurricular reading plays a crucial role in the academic and personal development of Chinese students. By expanding their knowledge, improving their language skills, and nurturing their creativity, reading can empower students to succeed in school and beyond. To support students in their extracurricular reading endeavors, it is essential for schools, parents, andpolicymakers to work together to address challenges and create a conducive reading environment. Only by fostering a culture of reading can we ensure that Chinese students continue to thrive in the ever-evolving world of education and beyond.篇2Understanding the Situation of Chinese Students' Extracurricular ReadingIntroduction:In today's fast-paced world, where digital devices and social media are prevalent, the importance of reading for students cannot be overstated. Reading not only helps to improve language skills, critical thinking, and creativity, but also broadens students' horizons and enhances their overall academic performance. In China, extracurricular reading has long been encouraged as a means to supplement formal education and foster a lifelong love for learning. However, the reality of students' engagement in extracurricular reading varies greatly, with some fully embracing it and others struggling to find the time and motivation. In this essay, we will explore the current situation of extracurricular reading among Chinese students,examining the challenges they face and suggesting ways to promote a culture of reading.The Importance of Extracurricular Reading:Extracurricular reading plays a crucial role in developing students' literacy skills, expanding their knowledge, and fostering a love for learning. Through reading books, articles, and other materials outside of the classroom, students are exposed to a wide range of topics, perspectives, and writing styles, which can enhance their critical thinking abilities and creativity. Moreover, extracurricular reading can help students improve their language proficiency, vocabulary, and reading comprehension, which are essential for academic success in school and beyond. By encouraging students to read widely and regularly, educators can instill in them a passion for learning and a lifelong habit of reading.Current Situation of Extracurricular Reading Among Chinese Students:While the benefits of extracurricular reading are well-known, the reality is that many Chinese students struggle to find the time and motivation to read outside of their required coursework. With the increasing academic pressure and competition for top schools and universities, students often prioritize theirschoolwork and extracurricular activities over reading for pleasure. Additionally, the widespread use of digital devices and social media has made it easier for students to spend their free time on entertainment rather than reading. As a result, many students lack the reading habits and skills necessary to fully take advantage of the benefits of extracurricular reading.Challenges Faced by Chinese Students in Extracurricular Reading:Several factors contribute to the challenges that Chinese students face in engaging in extracurricular reading. Firstly, the heavy workload and demands of the Chinese education system leave little time for students to pursue reading for pleasure. With hours of homework, test preparation, and extracurricular activities to juggle, many students find it difficult to carve out time for reading. Secondly, the lack of access to quality reading materials, such as libraries, bookstores, and digital resources, limits students' exposure to diverse reading materials. In rural areas and underprivileged communities, the lack of resources and infrastructure further exacerbate the problem of limited access to books and other reading materials. Finally, the lack of parental support and encouragement for reading can also hinder students' interest and motivation to read extracurricularly.Without role models or mentors to guide them in developing a reading habit, students may struggle to find the intrinsic motivation to read on their own.Promoting a Culture of Reading Among Chinese Students:To address the challenges of extracurricular reading among Chinese students, it is essential to promote a culture of reading that values and prioritizes reading for pleasure and personal growth. Educators, parents, and policymakers can play a crucial role in fostering a love for reading among students by implementing the following strategies:1. Integrating reading into the school curriculum: Schools can incorporate reading assignments, book clubs, and literacy programs into the curriculum to encourage students to read widely and critically. By providing structured opportunities for students to engage with diverse reading materials, educators can instill in them a love for reading that goes beyond academic requirements.2. Creating reading-friendly environments: Schools and communities can establish reading corners, libraries, and digital platforms to make reading materials more accessible and inviting to students. By providing a variety of books, magazines,and online resources, educators can inspire students to explore new genres and topics that pique their interests.3. Encouraging parental involvement: Parents can support their children's reading habits by modeling good reading behaviors at home, providing access to age-appropriate reading materials, and engaging in meaningful conversations about books. By showing an interest in their children's reading preferences and progress, parents can help cultivate a lifelong love for reading in their children.4. Leveraging technology for reading: In the digital age, technology can be a powerful tool for promoting extracurricular reading among students. Schools and communities can leverage online platforms, e-books, audiobooks, and educational apps to make reading more interactive and engaging for students. By incorporating technology into reading activities, educators can cater to students' diverse learning styles and preferences.Conclusion:In conclusion, extracurricular reading plays a vital role in enhancing students' academic performance, critical thinking skills, and overall well-being. While many Chinese students face challenges in engaging in extracurricular reading, there are numerous strategies that educators, parents, and policymakerscan implement to promote a culture of reading among students. By creating reading-friendly environments, integrating reading into the school curriculum, encouraging parental involvement, and leveraging technology for reading, we can help students develop a lifelong love for learning and reading. As we continue to strive for excellence in education, let us not forget the transformative power of a good book in shaping the minds and hearts of our future generations.篇3Title: Understanding the Situation of Extracurricular Reading Among Chinese StudentsIntroductionExtracurricular reading plays a crucial role in the educational development of students, helping them improve their language skills, critical thinking abilities, and overall academic performance. In China, the culture of extracurricular reading has gained prominence in recent years, with many students actively engaging in reading activities outside of their regular school curriculum. This essay aims to explore the current situation of extracurricular reading among Chinese students, including thetypes of books they prefer, the benefits they derive from reading, and the challenges they face in cultivating a reading habit.Types of Books Preferred by Chinese StudentsChinese students exhibit a diverse range of preferences when it comes to extracurricular reading materials. While some students enjoy reading classic literature and historical texts, others prefer modern fiction and fantasy novels. Popular genres among Chinese students include romance, mystery, science fiction, and self-help books. Additionally, many students are drawn to bestselling international authors such as J.K. Rowling, Dan Brown, and Haruki Murakami, whose works have been translated into Chinese.Benefits of Extracurricular Reading for Chinese StudentsExtracurricular reading offers numerous benefits for Chinese students, both academically and personally. Reading helps students improve their language skills, expand their vocabulary, and enhance their writing abilities. It also exposes them to different cultures, perspectives, and ideas, fostering a sense of empathy and understanding towards others. Furthermore, reading can stimulate critical thinking and analytical skills, enabling students to solve problems creatively and think independently. Overall, extracurricular reading contributes to theholistic development of Chinese students, preparing them for academic success and personal growth.Challenges in Cultivating a Reading Habit among Chinese StudentsDespite the many benefits of extracurricular reading, Chinese students face several challenges in cultivating a reading habit. One significant challenge is the heavy academic workload and competitive educational environment in China, which leaves students with limited time and energy for leisure reading. Additionally, the prevalence of digital distractions such as smartphones, social media, and online games can deter students from picking up a book. Moreover, the lack of access to quality reading materials and libraries in some rural areas of China poses a barrier to fostering a reading culture among students. To address these challenges, educators, parents, and policymakers need to promote the importance of reading, provide students with access to diverse reading materials, and create a supportive environment that encourages and rewards reading habits.ConclusionIn conclusion, extracurricular reading plays a vital role in the educational development of Chinese students, offering numerous benefits for their academic success and personalgrowth. By understanding the types of books preferred by students, as well as the challenges they face in cultivating a reading habit, educators and parents can support and encourage students to engage in reading activities outside of the classroom. Ultimately, promoting a culture of extracurricular reading among Chinese students can enrich their learning experience, broaden their horizons, and empower them to become lifelong learners.。
晋升管理制度英语1. IntroductionPromotion management is a critical aspect of human resource management within an organization. It involves the processes and methods used to identify, select and promote employees to higher levels of responsibility and compensation within the organization. A well-structured promotion management system ensures that the right employees are recognized and rewarded for their contributions, while also providing opportunities for professional growth and career advancement. This document outlines the key components of an effective promotion management system, including the criteria for promotion, the process for selection, and the communication and implementation of promotions within the organization.2. Criteria for PromotionThe first step in establishing a promotion management system is to define the criteria for promotion. This involves identifying the knowledge, skills, and attributes that are required for success at the next level within the organization. These criteria may vary depending on the nature of the job and the level of responsibility, but typically include factors such as performance, experience, leadership skills, and potential for growth.Performance is the most important criterion for promotion. Employees should demonstrate a track record of delivering results and achieving their performance objectives. This may be assessed through performance appraisals, feedback from managers and peers, and objective measures such as sales targets or production metrics.Experience is also an important consideration for promotion. Employees should have a certain level of experience in their current role before being considered for promotion. This may be measured in terms of years of service or specific achievements and responsibilities.Leadership skills are critical for higher-level positions. Employees should demonstrate the ability to lead and manage teams, inspire and motivate others, and make sound decisions in challenging situations.Finally, potential for growth is a key criterion for promotion. Employees should show a willingness and ability to learn and develop new skills, take on new challenges, and contribute to the long-term success of the organization.3. The Promotion ProcessOnce the criteria for promotion have been established, the next step is to define the process for selecting candidates for promotion. This involves identifying potential candidates, assessing their qualifications against the established criteria, and making decisions about who to promote.Identifying potential candidates for promotion may be done through a variety of methods, including nominations from managers, self-nominations from employees, and talent reviews or succession planning processes. It is important to ensure that all employees have equal opportunity to be considered for promotion, and that the process is transparent and fair.Assessing qualifications against the established criteria may involve a combination of assessments, such as performance appraisals, interviews, and evaluations of experience and potential. This may be done by a promotion committee or panel, which may include managers, HR representatives, and other relevant stakeholders.Making decisions about who to promote may involve a final review and approval by senior management or the executive team. This ensures that promotions are aligned with the strategic objectives of the organization and that the right employees are being selected for higher levels of responsibility.4. Communication and ImplementationOnce decisions have been made about who to promote, the next step is to communicate and implement the promotions within the organization. This involves notifying the selected candidates of their promotion, as well as communicating the promotions to other employees and stakeholders.Communication with the selected candidates should be done in a timely and respectful manner. This may involve a personal conversation with their manager, a formal letter of promotion, or a meeting with the HR department. It is important to clearly outline the new responsibilities, compensation, and reporting relationships associated with the promotion, as well as any other relevant details.Communication with other employees and stakeholders should also be done in a considerate and transparent manner. This may involve announcing the promotions in a company-wide meeting, updating the organization chart or employee directory, and providing opportunities for questions or feedback from employees. It is important to recognize the achievements of the promoted employees, as well as the ongoing contributions of all employees to the success of the organization.Implementing the promotions involves making any necessary changes to HR systems, payroll and benefits, and other administrative processes. This may involve updating employee records, job descriptions, and performance objectives, as well as providing training and support to the promoted employees as they transition to their new roles.5. Monitoring and EvaluationThe final step in the promotion management system is to monitor and evaluate the effectiveness of the promotions. This involves tracking the performance and success of thepromoted employees, as well as assessing the impact of promotions on the organization as a whole.Monitoring the performance and success of the promoted employees may involve regular check-ins with their managers, performance appraisals, and assessments of their ability to meet the expectations of their new roles. It is important to provide support and guidance to promoted employees as they adjust to their new responsibilities, and to provide opportunities for feedback and development.Assessing the impact of promotions on the organization may involve tracking key performance indicators, such as employee engagement, turnover, and productivity. It is important to ensure that promotions are having a positive impact on the organization, and that they are contributing to the achievement of strategic objectives.In conclusion, a well-structured promotion management system is critical for the success of an organization. By establishing clear criteria for promotion, defining a process for selection, and communicating and implementing promotions effectively, organizations can ensure that the right employees are recognized and rewarded for their contributions. Monitoring and evaluating the effectiveness of promotions is also important for ensuring the long-term success of the promotion management system and the organization as a whole.。
2015事业单位c类作文范文英文回答:In the intricate tapestry of life, where threads of aspirations, challenges, and opportunities intertwine, individuals are presented with a myriad of choices that shape their professional destinies. Navigating the complexities of career paths requires careful consideration of one's unique talents, goals, and values. The decision to pursue a career in the public sector, specifically within category C positions, presents a distinct opportunity for service, growth, and impact on the community. This essaywill delve into the multifaceted aspects of this career path, examining both its advantages and potential drawbacks, while offering insights into factors to be considered when making a well-informed decision.One of the primary advantages of a career in category C positions within the public sector is the opportunity to serve the community directly. Individuals in these rolesplay a crucial role in implementing policies, delivering essential services, and ensuring the well-being of citizens. Whether it is providing healthcare, education,infrastructure maintenance, or social welfare support, category C employees make tangible contributions to their communities. The intrinsic satisfaction derived from making a positive impact on society through one's daily work canbe a powerful motivating force for many.Furthermore, the public sector often offers stability and job security, which can be highly valued by those seeking a predictable career path. Government agencies typically provide competitive salaries, benefits, and opportunities for career advancement. With a clearhierarchy and established promotion criteria, individuals can plan their professional growth within a structured framework. The absence of performance-based layoffs or downsizing associated with private sector employment can provide peace of mind and allow for long-term planning.Additionally, the public sector can provideopportunities for professional development and specializedtraining. Many government agencies invest in their employees' education and training, ensuring that they possess the skills and knowledge necessary to excel intheir roles. This continuous learning and growth can contribute to both career advancement and personal satisfaction.However, it is important to acknowledge that a career in category C positions within the public sector also has its drawbacks. One potential limitation is the bureaucratic nature of government agencies. Decision-making processes can be slow and complex, involving multiple layers of approval and consultation. Individuals who thrive in fast-paced, entrepreneurial environments may find the bureaucracy frustrating and restrictive.Moreover, the public sector is often subject to budget constraints and political influences. Funding for programs and services can fluctuate, and changes in government policies or priorities can have a direct impact on job security or opportunities for advancement. Individuals who prefer a stable and predictable work environment may findthe uncertainty of public sector employment challenging.Another consideration is the potential for limited upward mobility within category C positions. While opportunities for career advancement exist, they may be more limited compared to certain private sector industries. Individuals with ambitious career goals may find themselves desiring a more challenging and rewarding career path.Ultimately, the decision of whether to pursue a career in category C positions within the public sector is ahighly personal one. It requires careful introspection and consideration of one's unique aspirations, values, and circumstances. Those who are motivated by a desire to serve their communities, value stability and job security, and prioritize professional development within a structured environment may find this career path fulfilling. However, individuals who prefer fast-paced, entrepreneurial environments, have ambitious career goals, or are uncomfortable with bureaucratic processes may find themselves better suited to other career paths.中文回答:在人生这幅错综复杂的画卷中,抱负、挑战和机遇的线交织在一起,每个人都面临着无数的选择,这些选择将塑造他们的职业生涯。
德国技工培训计划英语The German technical apprenticeship system is a combination of classroom instruction and on-the-job training. The system is highly structured, with specific requirements for the duration and content of the training, and it is overseen by government agencies and industry associations. Apprentices in the technical trades typically spend three to four years in the program, and they receive a combination of theoretical and practical training, with a focus on the specific skills and knowledge needed for their chosen trade.In recent years, the German government has been promoting the apprenticeship system as a model for other countries to follow. The German Technical Cooperation Agency (GTZ) has been working with other countries to help them develop their own technical apprenticeship programs, and has been providing technical assistance and financial support to help them get started.The German technical apprenticeship system is based on a few key principles:1. Dual system: The German Technical apprenticeship system is based on a dual system of training, in which apprentices receive both classroom instruction and on-the-job training. This combination of theoretical and practical learning helps to ensure that apprentices develop the skills and knowledge they need to succeed in their chosen trade.2. Cooperation between schools and industry: In the German apprenticeship system, there is close cooperation between vocational schools and employers in the industry. This helps to ensure that the training provided to apprentices is up-to-date and relevant to the needs of the industry, and that apprentices are able to develop the skills and knowledge that will be most useful to them in their future careers.3. High-quality standards: The German technical apprenticeship system is highly regulated, with strict standards for the content and quality of the training. This helps to ensure that apprentices receive a high-quality education and that the skills they develop are of a high standard.4. Recognition of qualifications: In Germany, the qualifications received through the apprenticeship system are highly respected and recognised by employers. This helps to ensure that apprentices are able to find good jobs and build successful careers in their chosen trades.The German technical apprenticeship system covers a wide range of trades, including construction, manufacturing, automotive, engineering, and more. Each trade has its own specific training program, with a focus on the skills and knowledge that are most relevant to that particular trade.In recent years, there has been growing interest in the German apprenticeship model from other countries. Many countries are facing challenges in developing a skilled workforce, and are looking to the German system as a model for how to train workers in the technicaltrades. In response to this interest, the German government has been working to promote the apprenticeship system internationally, and to support other countries in developing their own technical apprenticeship programs.A key aspect of the German government's efforts to promote the apprenticeship system is the provision of technical assistance and financial support to other countries. The German Technical Cooperation Agency (GTZ) has been working with other countries to help them develop their own apprenticeship programs, providing assistance in the form of curriculum development, teacher training, and other forms of support. GTZ has also been providing financial assistance to help countries get their apprenticeship programs up and running. The German government has also been working to promote the apprenticeship system through international partnerships and collaborations. For example, Germany has been working with other countries to develop joint training programs in the technical trades, in which apprentices from different countries can receive training together and learn from each other's experiences. This type of international collaboration can help to promote the apprenticeship system and to spread best practices in the training of skilled workers.In addition to its work with other countries, the German government has also been promoting the apprenticeship system through its support for international organisations and initiatives that promote the training of skilled workers. For example, Germany has been a strong supporter of the International Labour Organization's (ILO) efforts to promote the training of skilled workers, and has been working to promote the apprenticeship system through its support for the ILO's work.The German government's efforts to promote the apprenticeship system internationally are part of a broader commitment to promoting the training of skilled workers as a key factor in economic development. Germany has long recognised the importance of a skilled workforce in driving economic growth, and has invested in the development of high-quality training programs in the technical trades. The promotion of the apprenticeship system internationally is part of Germany's broader efforts to promote the importance of vocational education and to support other countries in developing their own training programs.The promotion of the apprenticeship system internationally is also seen as a way for Germany to promote its own economic interests. As a leading exporter of engineering and manufacturing products, Germany has a strong interest in promoting the training of skilled workers in the technical trades. By promoting the apprenticeship system internationally, Germany can help to ensure that there is a strong global market for its products, and that there are skilled workers available to meet the needs of the global economy.Overall, the German technical apprenticeship system is a highly successful model for the training of skilled workers in the technical trades. The system is based on a few key principles, including a dual system of training, cooperation between schools and industry, high-quality standards, and the recognition of qualifications. The German government has been working to promote the apprenticeship system internationally, providing technicalassistance and financial support to other countries, and collaborating with international organisations and initiatives that promote the training of skilled workers. This promotion of the apprenticeship system reflects Germany's long-standing commitment to vocational education and its recognition of the importance of a skilled workforce in driving economic growth.。
考试的好处英语作文In the academic world, examinations are a pivotal element of the learning process. They serve multiple purposes that contribute to the overall development of a student. Here are some of the key benefits of examinations:1. Assessment of Knowledge: Examinations are the primary means by which educators evaluate a student's understanding of the subject matter. They provide a quantifiable measure of what a student has learned.2. Motivation for Study: The pressure of an upcoming exam can be a powerful motivator for students to study and prepare. It encourages them to review their notes and engage with the material more deeply.3. Development of Time Management Skills: Exams often require students to work within a set time frame, which helps them develop the ability to manage their time effectively.4. Identification of Weak Areas: By analyzing exam results, students can identify areas where they struggle and focus their efforts on improving those skills.5. Preparation for Real-World Challenges: Exams simulatehigh-pressure situations that students may encounter in their future careers. They help students learn to perform under pressure.6. Encouragement of Self-Discipline: Preparing for an exam requires a level of self-discipline and commitment that is beneficial in many aspects of life.7. Enhancement of Memory: The process of studying for and taking exams can strengthen memory and improve the retentionof information.8. Recognition of Achievement: For many students, achieving good grades on exams is a source of pride and a validation of their hard work.9. Facilitation of Learning: Exams can help students to consolidate their learning by forcing them to recall andapply information in a structured way.10. Promotion of Fairness: When exams are well-designed, they provide a fair and objective measure of a student's abilities, ensuring that everyone is assessed on the same criteria.In conclusion, while examinations can be stressful, they play a crucial role in education by providing a structured way to assess, motivate, and develop students' skills and knowledge.中文翻译:在学术界,考试是学习过程中的核心要素。
英国议会制辩论基本知识英文回答:Understanding the Basics of Parliamentary Debate in the UK。
Parliamentary debate in the UK is a highly structured and adversarial form of argumentation that takes place in the House of Commons and the House of Lords. The basic principles of parliamentary debate are as follows:1. Roles and Responsibilities:The participants in a parliamentary debate are divided into two teams: the government and the opposition. The government is led by the Prime Minister, while the opposition is led by the Leader of the Opposition. The Speaker of the House presides over the debate and ensures that the rules are followed.2. Motions and Amendments:A debate is typically initiated by a motion, which is a proposal that is put forward for discussion and voting. Amendments can be proposed to modify or change the motion.3. Speeches:Each speaker has a limited amount of time to speak, and they must address the motion or amendment that is being debated. Speeches are typically divided into three parts:an opening statement, a body, and a conclusion.4. Points of Order:Speakers may raise points of order to seekclarification or to challenge the conduct of the debate.The Speaker will rule on points of order and may interveneto ensure that the debate is conducted in an orderly manner.5. Interruptions:Interruptions are permitted, but they must be brief and relevant to the topic being debated. Speakers may yield the floor to allow another speaker to intervene.6. Voting:At the end of the debate, members of Parliament vote on the motion or amendment. The result of the vote is determined by a majority of votes.7. Language and Style:Parliamentary debate is conducted in a formal and respectful manner. Speakers are expected to use appropriate language and to avoid personal attacks. The use of wit and humor is sometimes permitted, but it should be used sparingly.Example:In a recent parliamentary debate on the issue of climate change, the Prime Minister opened the debate with amotion calling for the government to commit to a net-zero emissions target by 2050. The Leader of the Opposition proposed an amendment calling for the target to be met by 2030. Several MPs spoke in favor of the motion, arguing that it was necessary to take urgent action to address the climate crisis. Others spoke in favor of the amendment, arguing that the government needed to be more ambitious in its climate commitments. After a lengthy debate, the amendment was defeated and the motion was passed.中文回答:英国议会制辩论基础知识。
走路上学英语观后感Walking to school every day was a valuable experience that taught me a great deal about learning English. As a non-native English speaker, I found that the daily commute provided numerous opportunities to immerse myself in the language and improve my fluency. From observing conversations to picking up on common expressions, the journey to and from school became an integral part of my language learning journey.One of the most significant benefits of walking to school was the exposure to authentic English conversations. Rather than learning from textbooks or classroom settings, I was able to listen to how native speakers actually used the language in real-life situations. Whether it was overhearing discussions between friends, eavesdropping on phone calls, or catching snippets of conversations between strangers, these natural interactions allowed me to contextualize the vocabulary and grammar I had been studying.Moreover, the act of walking itself created a more relaxed and informal environment that encouraged me to engage with thelanguage in a less structured way. As I strolled through the neighborhood, I would find myself mulling over the words and phrases I had heard, trying to piece together their meanings and applications. This casual, immersive approach helped me to develop a more intuitive understanding of the language, rather than simply memorizing rigid rules and definitions.Another valuable aspect of my walking commute was the opportunity to observe nonverbal communication. While textbooks and classroom lessons often focus on the mechanics of language, such as vocabulary and grammar, walking to school allowed me to witness the subtle nuances of body language, facial expressions, and tone that are integral to effective communication. Watching how native speakers used these nonverbal cues to convey meaning and emotion was incredibly insightful and helped me to better understand the social and cultural context of the language.Furthermore, the act of walking itself proved to be a powerful tool for language learning. As I traversed the familiar route to and from school, I found that my mind naturally wandered, allowing me to ponder and process the language I had encountered throughout the day. The rhythmic motion of walking seemed to facilitate a state of relaxed focus, enabling me to make connections and draw insights that I might have missed in a more sedentary setting.Additionally, the physical act of walking provided a sense of freedom and independence that I believe enhanced my language learning experience. Rather than being confined to a classroom or relying on others for transportation, I was able to take ownership of my own learning journey. The autonomy and sense of exploration that came with walking to school fostered a greater sense of investment and motivation, which in turn, helped to accelerate my progress in English.Of course, the walking commute was not without its challenges. There were times when I felt overwhelmed by the sheer volume of new vocabulary and expressions I was encountering, or when I struggled to comprehend the rapid-fire exchanges I overheard. However, these difficulties actually became valuable learning opportunities, as they forced me to develop strategies for coping with ambiguity and actively seeking out clarification.For example, I learned to pay close attention to context clues, such as body language and facial expressions, to help me decipher the meaning of unfamiliar words and phrases. I also became adept at using my smartphone to quickly look up definitions and translations, allowing me to maintain the flow of conversation and continue improving my understanding.Additionally, the act of walking provided me with a chance to reflecton my language learning progress and identify areas for improvement. As I traversed the familiar route, I would often catch myself stumbling over certain words or phrases, prompting me to make a mental note to focus on those particular aspects of the language during my next study session.In this way, the walking commute became an integral part of a holistic language learning approach, where the informal, immersive experience complemented the more structured classroom instruction and independent study. By seamlessly integrating language learning into my daily routine, I was able to make steady and sustainable progress, developing a deeper understanding and appreciation for the English language.Looking back, I can confidently say that my walking commute was a transformative experience that had a profound impact on my language learning journey. The exposure to authentic conversations, the opportunity to observe nonverbal communication, and the sense of freedom and independence all contributed to my growth as an English language learner.Moreover, the physical act of walking itself seemed to facilitate a state of relaxed focus and introspection that further enhanced my learning process. By embracing the challenges and capitalizing on the opportunities presented by my daily commute, I was able todevelop a more well-rounded and effective approach to mastering the English language.In conclusion, the experience of walking to school to learn English was a valuable and multifaceted one that I would highly recommend to any language learner. Whether you are a student or an adult learner, incorporating a walking commute into your language learning routine can provide a wealth of benefits, from exposure to authentic language use to the development of crucial communication skills. So, the next time you find yourself on the way to school or work, embrace the journey as a valuable opportunity to immerse yourself in the language and continue your path towards fluency.。
社团英语作文篇 1When I first stepped into the campus, I was immediately attracted by the various clubs. I joined the calligraphy club with great enthusiasm. At the beginning, my calligraphy skills were rather clumsy, and I often felt frustrated when my strokes didn't look right. However, with the patient guidance of the club instructor and my continuous practice, I gradually improved. Day after day, I spent countless hours honing my skills. Eventually, my efforts paid off when I won a prize in a calligraphy competition. The joy and sense of achievement I felt at that moment were indescribable.Another unforgettable experience was in the music club. We got together to rehearse programs, sharing the joy that music brought us. Every note, every rhythm, seemed to be a language that connected our hearts. We worked hard together, supporting and encouraging each other. During the process, I not only enhanced my musical skills but also forged deep friendships with my fellow club members. These experiences in the clubs have not only enriched my campus life but also helped me grow and become a better version of myself.篇 2I have been a member of various clubs during my school years, and each one has left me with precious memories and deep friendships. One of the most unforgettable experiences was in the photography club. We often went on outings to capture the beauty of nature and the hustle and bustle of the city. There was Jack, who had a unique perspective on framing a scene, and Mary, whose talent in post-processing always amazed us. We shared our techniques and insights, encouraging and learning from each other. Those moments spent discussing how tocapture the perfect light or the most touching expression were truly wonderful.Another remarkable experience was in the sports club. I was part of a basketball team, and together with my teammates, we strived for the glory of our team. We practiced hard, sweated on the court, and supported each other through every win and loss. The bond we formed was not just about the game but about the shared determination and the spirit of never giving up.These friendships and times spent in the clubs have become an integral part of my life. They have taught me the value of companionship, the power of shared interests, and the importance of working towards a common goal. I truly cherish these friendships and the memories we created together.篇 3I joined the debating club last year. One of the most memorable experiences was when we were pitted against a highly experienced and formidable opponent. The topic of the debate was incredibly complex and challenging.I was filled with anxiety and self-doubt. However, instead of giving in to fear, our team decided to face it head-on. We spent countless hours researching, preparing arguments, and practicing our delivery.During the actual debate, our opponents presented strong points that initially put us on the back foot. But we remained calm and composed. We listened attentively, identified the flaws in their reasoning, and presented our well-prepared counter-arguments with confidence and clarity.In the end, through our hard work, teamwork, and perseverance, we emerged victorious. This experience taught me the power of preparation, the importance of working together as a team, and the ability to stay calm under pressure. It was a significant step in my growth and development.篇 4I have had an incredibly enriching experience being a part of various clubs in my school. One of the most remarkable ones was the Science and Technology Club. In this club, I was exposed to a plethora of advanced concepts and cutting-edge technologies that I had never encountered before. I learned how to assemble simple electronic circuits, program basic algorithms, and even participated in a robotics competition. Through these activities, not only did I acquire practical skills but also broadened my horizons, realizing the boundless possibilities that science and technology can bring to our lives.Another club that had a profound impact on me was the Literature Club. Here, I was immersed in the world of words and imagination. I engaged in intense discussions about classic literary works, analyzed the writing styles of renowned authors, and constantly practiced writing my own stories and essays. This process significantly enhanced my writing ability and cultivated my literary appreciation. I began to understand the power of language in expressing emotions and ideas, and the importance of a well-structured narrative.In conclusion, being part of these clubs has been a transformative journey for me. They have provided me with valuable knowledge and skills, as well as opportunities to explore my interests and passions. Clubs truly play an indispensable role in an individual's growth and development.篇 5Joining various clubs in campus has been an integral part of my college life. The experiences I've gained through these clubs have had a profound and positive impact on me.Take the drama club for instance. I participated in the rehearsal of classic plays, which not only enhanced my acting skills but also allowed me to deeply understandand inherit the essence of drama culture. Through our performances, we brought the charm of classic works to more people, making them appreciate the beauty and depth of drama.Another example is the traditional culture club. In this club, I delved into the research and promotion of outstanding Chinese traditional culture. We organized activities such as calligraphy exhibitions and folk art demonstrations. This not only made me prouder of our own culture but also spread the wisdom and charm of traditional culture to more classmates, strengthening our cultural confidence.In conclusion, club activities have enriched our campus life, broadened our horizons, and helped us grow into more comprehensive individuals. They have truly become an indispensable part of our colorful campus memories.。
Servo System ControllerMELSEC iQ-R Series Motion Module Basics(RD78G(H)/Startup)This course is for participants who will establish amotion control system using the MELSEC iQ-Rseries motion module for the first time.Click the Forward button at the upper right of thescreen to proceed to the next page.L(NA)00238ENG-AThis course requires the basic knowledge of MELSEC iQ-R series PLCs, AC servos, and the positioningThis course requires the basic knowledge of MELSEC iQ-R series PLCs, AC servos, and the positioningThis course requires the basic knowledge of MELSEC iQ-R series PLCs, AC servos, and the positioningThis course requires the basic knowledge of MELSEC iQ-R series PLCs, AC servos, and the positioningIntroductionHow to Use This e-Learning ToolGo to the next page.Back to the previous page."Table of Contents" will be displayed, enabling you to navigate to the desired page.Exit the learning. Window such as "Contents" screen and the learning will be closed.IntroductionThe icon indicates the reference manual.The contents of the manuals described in this course are those of the following versions.Chapter 1 1.11.21.3Format of the STMELSEC iQ-R Structured Text (ST) Programming Guide BookCommands that can be used in the STMELSEC iQ-R Programming Manual (CPU Module Instructions, Standard Functions/Function Blocks) MELSEC iQ-R Programming Manual (Motion Module Instructions, Standard Functions/Function Blocks) Labels and structuresMELSEC iQ-R CPU Module User's Manual (Application)MELSEC iQ-R Programming Manual (Motion Control Function Blocks)which is a courseMELSEC iQ-R Programming Manual (Motion Control Function Blocks)4.2 Motion Module Program Creation1.61.7Summary of This ChapterIn this chapter, you have learned:PLCopen® Motion Control FBProgramming Using STLabel, arrangement, and structureProgram TypeImportant points® Motion Control FB PLCopen®, a third-party organization, develops the standard FB specifications that are independent of thevendor.The motion control is defined as Motion Control FB.Programming Using ST All statements end with ";"(semicolon).The assignment statement is represented by <variable> := <expression>;.The input variable of the FB is indicated by ":=",and the output variable is indicated by "=>"Label, Arrangement, and Structure The label types include the local label, global label, module label, system label, and slave label.Arrangement is a collection of labels with the same variable type.Structure is a collection of labels with different variable types.Program Type The program execution types include the initial execution type, scan execution type/normal execution type,fixed scan execution type, event execution type, standby execution type, and no executiontype/unregistered program.Chapter 2 2.12.22.3 2.3.1Item Applicable cable size Tightening torque(Note) In this course, the STO function is not used. Thus, do not disconnect the short-circuit connector supplied with the servoUse the alternate operation switch only for Servo-on (X0), and use the momentary operation switch for other signals.2.4Turn on the DIP switch (SW3-1) of the servo amplifier.Connect the servo amplifier and a personal computer with a USB cable or Ethernet cable. (Note) Turn on the servo amplifier. "TST" is displayed on the display.Start MR Configurator2 and perform the test operation (JOG operation).Check the rotation direction and machine operation.(7)After the test operation is completed, turn off the servo amplifier, and turn off the DIP switch (SW3-1). (Note) When using a Ethernet cable, change the project of MR Configurator2 to a multi-axis project.TipsWhen using multiple servo amplifiers, the connection with Ethernet can eliminate the necessity of replacing cables.2.5Summary of This ChapterIn this chapter, you have learned:Device ConfigurationSystem ConfigurationWiringTest OperationImportant pointsDevice Configuration Use a one-axis ball screw in the sample system.System Configuration Connect the remote input module NZ2GN2S1-32D and servo amplifier MR-J5-G to the motion moduleRD78G4.Wiring Use a one-cable type option cable for the servo motor.Set the fourth octet of the IP addresses of the remote input module and servo amplifier with the rotaryswitches.Connect the proximity dog signal, limit switches, and forced stop switch to the servo amplifier.Connect operation command switches to the remote input module.Test Operation Change the DIP switch of the servo amplifier, and connect it to a personal computer.Check the rotation direction of the motor and machine operation using the test operation function of MRConfigurator2.Chapter 3When the following window appears, set whether to use the module label and sample comment.following window appears, click the [OK] button.When the Module Configuration screen is opened, drag and drop a module to be used (base module, power supply module, as the one shown in Section 2.2.After creating the module configuration diagram, right-click the screen, and select [Parameter] → [Fix].When the following precautions appear, click the [Yes] button.When the following window appears, check that the sample comment is set to [Use].M E L S O FT GX W o rk§.3Add a mo du l e.M o d u l e S e tti叩(Mo d ule N年)直)78G4 [S ta r t 1/0 No,] 0000Sa m pl e Co mm e nt:U史口�Not S ho w tti i s D i al o g A g a i n しSe tti心Ch a n ge_J^v I·OK3.23.3 3.3.1Module parameter (Network)Double-click [Parameter] → [Module Information] → [0000:RD78G4] → [Module Parameter (Network)] in the project tree. In this section, configure the settings for devices to be connected to the network and a link refresh.Network configuration setting(1)Select [Basic Settings] in the setting item list, and double-click<Detailed Setting>in Network Configuration Settings.* If NZ2GN2S1-32D or MR-J5-G is not displayed in the module list on the right side of the screen, download the profile data (CSP+ file) from here, and register it to GX Works3.* If NZ2GN2S1-32D or MR-J5-G is not displayed in the module list on the right side of the screen, download the profile data (CSP+ file) from here, and register it to GX Works3.* If NZ2GN2S1-32D or MR-J5-G is not displayed in the module list on the right side of the screen, download the profile data (CSP+ file) from here, and register it to GX Works3.* If NZ2GN2S1-32D or MR-J5-G is not displayed in the module list on the right side of the screen, download the profile data (CSP+ file) from here, and register it to GX Works3.* If NZ2GN2S1-32D or MR-J5-G is not displayed in the module list on the right side of the screen, download the profile data (CSP+ file) from here, and register it to GX Works3.* If NZ2GN2S1-32D or MR-J5-G is not displayed in the module list on the right side of the screen, download the profile data (CSP+ file) from here, and register it to GX Works3.* If NZ2GN2S1-32D or MR-J5-G is not displayed in the module list on the right side of the screen, download the profile data (CSP+ file) from here, and register it to GX Works3.* If NZ2GN2S1-32D or MR-J5-G is not displayed in the module list on the right side of the screen, download the profile data (CSP+ file) from here, and register it to GX Works3.* If NZ2GN2S1-32D or MR-J5-G is not displayed in the module list on the right side of the screen, download the profile data (CSP+ file) from here, and register it to GX Works3.。
ACCV2002:The5th Asian Conference on Computer Vision,23–25January2002,Melbourne,Australia.Learning A Highly Structured Motion Model for3D Human TrackingTao Zhao Tianshu Wang Heung-Yeung Shum University of Southern California Artificial Intelligence and Robotics Lab Microsoft Research,China Los Angeles,CA90089Xi’an Jiaotong University Beijing10080,Chinataozhao@ tswang@ hshum@AbstractThis paper presents our work on learning high level struc-ture from human motion sequences,and its applications in humanfigure tracking.We use a structured representation (“primitives”and their transitions)of complex motion and propose a two-step unsupervised learning approach to re-cover the natural“primitives”from unsegmented3D-motion captured sequences of complex human motion.The struc-ture recovery is done under the MDL(minimum description length)paradigm.Then the learnt dynamic model of human motion is used in the CONDENSATION framework to suc-cessfully track human motion in a video sequence.Experi-mental results of ballet dancing sequences demonstrate that our approach works well.The learnt structure is also used to synthesize new video sequences.1IntroductionHuman motion tracking and understanding have been ac-tive research topics in computer vision for a long time be-cause of their wide applications in recognition,animation and human-computer interaction.Good survey on visual analy-sis of human motion and vision-based motion-capture can be found in[7],[13].However,3D human tracking from a2D video sequence remains largely unsolved.In3D human tracking,a kinematics model is generally used and the problem is to recover the joint angles from the image sequence.Many factors contribute to the difficulty of 3D humanfigure tracking:kinematics has singular poses;camera projection loses depth,and introduces an obser-vation singularity and reflective symmetry;large number of DOFs(20+for full body);complex human dynamics;various image noises including complex background, non-rigid motion of body and clothing,change of illu-mination,etc.This work was done while thefirst two authors were visiting Microsoft Research,China.Some of the difficulties can be alleviated by introducing an appropriate dynamic model(i.e.,how the object moves) which serves as a prior.For complex human motion,such as dancing,gymnastics and Kung Fu,which are made up of a number of basic moves or“buildingblocks”,a single dynamic model is in general insufficient,instead,a structured dynamic model is preferred.Much previous work has been done in modeling complex human motion model and they can be largely categoried into two classes.Thefirst class is by supervised learning.Mixture motion model is used for tracking in[9].But the primitives are pre-defined and segmented manually for training.The second class of approach,unsupervised or semi-unsupervised human motion modeling,avoids such tedious and error prone process of manual segmentation.In[3], HMM(hidden Markov model)is learnt for human locomotion (walking,running).But the topology of the HMM is given and it is difficult to extend it to more complex motion.In [1],each primitive follows a different dynamic law(acceler-ation)which can be used to differentiate each other.V ariable length Markov models(VLMM)[6]were learnt to model hu-man behavior.However,simple heuristics such as low veloc-ity points at the boundary of two primitives was employed for segmentation.SLDS(switching linear dynamic systems)are learnt in[14]for classifying human motion.[2]also learned HMMs for complex motion such as dancing.It employed a very complicated optimization process and the high level structure is still hidden in the HMM.In this paper,we adopt the unsupervised approach and aim to recover the original primitives in a systemetic way.Mini-mum description length(MDL)criterion is used for structure recovery and an explicit two-step coarse tofine method is pro-posed.In both steps,MDL guarantees the conciseness of the recovery,thus leading to original or nearly original primitives. Once learnt,the structured representation can then be used in tracking and synthesis.An overview of our system is shown in Fig.1.It is worth mentioning the ballet dancing data we use in our experiments.To learn the motion model,we use10sequences of captured3D motion of a ballet tutorial,4428frames(about 3min)in total.We try to model the arm movements(4DOFsfor each arm).By assuming symmetry between the left arm and the right arm,we effectively double the amount of train-ing data.All the sequences for tracking are captured by a reg-ular videocamera.Figure 1:The overall system diagram.2Learning Structured ModelOur objective is to recover the original “building blocks”or primitives of the motion sequences and segment the se-quences accordingly.Fig.4shows a motion sequence (four joint angle trajectories of a ballet dance)and the segmented result.The problem is analogue to the language problem in which the vocabulary of an un-separated (i.e.,no space,etc)text is to be found.If we think of the language problem,there are a large num-ber of solutions since every sub-string can potentially be a word and there seems to be no way to know which set of vo-cabulary is the original one.But the real vocabulary has the property that it provides a concise coding of the text.And this coding conciseness can be well described by MDL,which is widely used in unsupervised learning and is known to give hu-man interpretable results.Under the paradigm of MDL,the language problem is es-sentially an un-separated text compression problem.Some works have been done including [18][12][11].In these works,various heuristics (frequency,descriptive length gain)were applied and approximating results were found.The approximating results are good for compression of a huge dataset (natural language or DNA sequences)but they are not sufficient for understanding.Motion primitive finding introduces extra difficulty com-pared to the language problem in that there are possible vari-ations in different instances of one primitive.In the motion we study below,the velocity may be different.Besides,the motion signals are always corrupted by noise.In ballet,the arms of the dancer have 4standard poses:,,,and .The arms stay in these poses as well as moving between them.In the four poses,the arms are drooped naturally in front of the body,raised in front of the chest,stretched to the left and right,and stretched above the head respectively.We propose a two-step coarse to fine approach to find the MDL efficiently.First we solve the language problem with the quantized discrete data.The quantization and the repeated symbol removal reduce the problem scale greatly so that asearch is applicable.And then the segmentation points are re-fined in the motion domain.2.1Clustering poses to symbolsIn order to transform the multi-dimensional continuous-valued poses into a discrete domain,vector quantization (VQ)is needed.We used the fuzzy C-mean algorithm to cluster the poses.And then the close-by clusters were merged to achieve a relatively uniform resolution.This resulted in 21clusters,which we label with letter from a to u .Each frame is replaced by the label of the cluster which it belongs to.And adjacent frames having the same label are merged.Therefore,the 20motion sequences are transformed into 20sentences,the one corresponding to the motion se-quence in Fig.4is shown in Fig.2.(a)as example.2.2Structure recovery in discrete series2.2.1MDL criterionWe code the sentences in a dictionary-based approach.The total description length is the sum of the description length of the dictionary and that of the text expressed by the in-dices of the dictionary.Assume the vocabulary contains words ,...,whose lengths and counts are ,...,and ,...,respectively.The text has a total word count of.The dictionary is not compressed while the text is compressed with Huffman coding.The description length is then computed as:The minimum DL criterion satisfies the general require-ments for a good structured representation:the number of words should be small;their repeating rate should be high;and the words should be long (i.e.,the compressed article should be short).2.2.2Finding the MDL by searchWe find the set of vocabulary that gives the MDL of the text by search.The search procedure tries all possible combinations of the word candidates to see if they can be used to construct the text.And it finds the one that gives the minimum value of .Since the complexity of the search is exponential,we propose the following techniques to cut down the computa-tion.First,we assume that no word is a sub-string of any other word in the vocabulary.It enables us to search in vocabulary space instead of segmentation space,making the search more efficient.Second,we screen the word candidates (all the sub-strings of the text)based on the following claim.Claim.If string =+and their occurrence count,then and should be removed from theset of word candidates.Obviously,using instead of ,can only decrease the description length.This cuts down the computation a lot mainly because it avoids reaching a lot of solutions made by the combinations of the sub-strings of the MDL vocabu-lary.The techniques make the search efficient and practicalfor problems of larger scale.2.2.3Search resultThe sentences we got from Sec.2.1are fed into the search pro-gram for vocabulary recovery.We obtained the set of vo-cabulary which gives the MDL of the sentences,and at the same time,the sentences are segmented.The 8words cor-respond very well to basic ballet movements (transitions be-tween standard poses)with the exception of gi ,which is the small movement serving as a prefix sometimes before moving from to pose.Fig.3shows how the recovered motion primitives and their transitions correspond to human knowl-edge of ballet.Since we have found the correspondence of our recovered vocabulary with human knowledge,we will use the label in ballet notation in the rest of the paper (i.e.,->instead of mhnc ,->instead of gjrf ,etc,where =)After that,the segmented sentence is as in Fig.2.(d).The search procedure only took 10seconds,compared to over 30minutes without screening of wordcandidates.Figure 2:V ocabulary recovery:The sentences (quantized from mo-tion sequences,only one corresponding to Fig.4shown here)are fed into the search program and the vocabulary and segmentedsentencesare the output.,,,and are the 4standard arm poses of the balletdance.Figure 3:The correspondence of recovered vocabulary (words onedges)and their transitions with domain knowledge (see also foot-note).Figure 4:The final segmentation/labeling result of the first motion sequence in the examples of Fig.2.The labeling and the initial seg-mentation is done in Sec.2.2,and the accurate segmetation is ob-tained in Sec.2.3.2.3Refining segmentation in the motion domainGoing back to the original motion domain,the segmenta-tion points we got from the previous step are coarse and need to be refined to get precise segmentation.Furthermore,there might be a static pose between two primitives that was dis-carded by our repetition removal.We add a static primitive if the boundary symbol lasts more than 0.5second between two adjacent primitives.As a result,we added 4static poses (m ,c ,g ,a ,which correspond to the 4standard poses:,,,,in ballet notation respectively),so we have 12prim-itives in total.We use the segmental K-means algorithm [10]to optimize an object function,again by the MDL criterion.Assume we have N motion primitives (dynamic and static),...,.And the entire motion data are segmented into M seg-ments ,...,with labels ,...respec-tively.The average length of all instances of primitive is .The mean trajectory of primitive is calculated by averag-ing all instances of the primitive after normalizing them in length ().The objective function (1)we will minimize reflects the MDL of the motion data.(1)The first term is the description length of the mean trajec-tories,the second term is the description length of the tem-poral scaling factors and labels,and the third term is a likeli-hood term which is the description length for the residues as-suming they are independent Gaussians [15].and are two constants which are assigned as 1in our implementation.The objective function can be described as favoring the following characteristics:A smaller number of primitives.The homogeneity of segments of the same label after normalization in time.A smaller number of segments.Similarity of the segment and the primitive it belongs to.Items 1and 2reflect the entropy of the model and item 4reflects the cross-entropy of data and the model,which is sim-ilar to the entropy representation in [2].Compared with theof text,the likelihood term is new since it does not exist in the discrete domain.It should be noted that the objective function is a general one with respect to segmentation point number,segmenta-tion point positions and the segment labels.But minimizing it from a random initial condition is very difficult due to the large number of parameters and the complexity of the solution space.In our approach,we have a very good initial solution from the search result,and only optimize on the positions of the segmentation points.The segmental K-means algorithm,which is similar to EM algorithm,consists of two-step loops.In thefirst step,wefind better segmentation point positions by searching in a small region around the original positions in a dynamic program-ming fashion.And in the second step,we update according to the new segments.Since the initial value is al-ready close to the minimum,the algorithm converges after a few iterations.As an example,the result segmentation of the motion sequence corresponding to thefirst sentence in Fig.2 is shown in Fig.4.3Monocular3D Human Figure Tracking 3D humanfigure tracking is generally formulated as to re-cover the value of the joint angles()of a kinematic model from the image sequence().Recently,the CONDENSA TION framework[8]became popular in visual tracking and has also been used in3D human tracking in a number of works(e.g.,[4][17]).It is a sample-represented Bayesian approach that calculates the posterior distribution rather than a single most likely value.Thus it is more robust than Kalmanfilter in case of singularities and discontinuities [5],which are not rare cases in human motion.Therefore,we use the CONDENSATION framework in our tracking task.The main idea of CONDENSATION is as ing Bayesian theory,the posterior for frame is decomposed into a dynamic model(or the prior)of the object being tracked ()and likelihood of the configuration(joint an-gles)measured in the image features()[8]:where is all the configurations up to frame ,and is a normalizing factor.The posterior distribution of each frame is evaluated by propagating a set of samples of the state over time.The details of the algorithm can be found in [8].CONDENSATION only provides a framework in which both the dynamic model and the likelihood measure need to be designed.3.1Mixture dynamic modelOur structured motion representation naturally leads to a mixture dynamic model in which each primitive has its own dynamic model and the primitives transit according to a tran-sition matrix.Since each primitivehas relativelyhomogenous dynamic property,a simple dynamic model will suffice.We use a order dynamic model[8]:where is a vector of independent zero-mean one-standard deviation Gaussian random variables.Each primitive has several instances in the training data. After normalizing these segments in length,thepairs are used to compute the unknowns in,using LMS fitting.And is then estimated using both,and. The transition matrix can be easily computed by counting.Considering different execution speeds we introduced a speed factor,which follows a Normal distribution.This speed factor not only handles different ex-ecution speeds,but also provides support for DTW(dynamic time warping).3.2Computing likelihoodWe treat each limb as a truncated cylinder and project it with a scaled orthographic camera model with the same ap-proximation as in[17].The appearance model we are using is an integration of boundary and texture.Multiple cue inte-gration provides more robust result than single cue in realis-tic images.The two are integrated by simple multiplication assuming they are statisticallyindependent.(a)(b)(c)Figure5:Computing likelihood.(a)Texture windows overlaid on original image(see text);(b)Straight linesfitted;(c)schematic view of matching line segments.3.2.1Measuring boundary matchThe boundary in the image is computedfirst by the Canny edge detector,then approximated with a straight line segments using LMSfitting with a certain error limit(see Fig.5.b).The straight line segments are matched with the projected limb boundary lines with a virtual spring method(see Fig.5c). We put a spring on each of end of the line segment,and the other end of the spring can move on the projected model line. This results in a force from the spring.The sum of the forces of both ends reflects how far the image line segment is from the projected model line.The larger the force is,the less similarity they have.An exponential decay factor is applied to make line segments far away from model limb boundaries have little effect.3.2.2Measuring texture matchTemplate matching has been used to match appearances (e.g.,[17]),but it provides little generalization in spatial relation-ships,thus sensitive to non-rigid motion and projection ap-proximation distortion.A feature histogram of a region is of-ten used in blob-based tracking systems,but it provides no constraint on spatial distributions.Here use a tradeoff of the two extremes.We divide the objects into a number of small blocks (see Fig.5a),and each block is represented with a his-togram.The color distribution is learnt from the first frame.The learnt distribution and the observed distributionare compared with Kullback-Leibler divergence.Distributions of the different blocks are assumed to be independent.3.3Handling appearance distortionGenerally,appearance models have some distortion from real figures due to the approximation.We observe that this distortion is not uniform in different pose-viewpoint combi-nations due to camera projection.Taking the arm for exam-ple,in most appearance models,the most severe distortionoc-curs when the arm is pointing straight at the camera,i.e.the measured value has the greatest error from its real value,thus should not be heavily relied upon.We introduce a distortionfactor to represent how much distortion is expected.In our appearance model we set(projected length)(max length).We add the dis-tortion factor into CONDENSATION by adjusting the likeli-hood measurement towards the average measurement ()as the following:Its interpretation is that since we know we have a distortedmeasure,we should not have the sample to flourish or go ex-tinct because of this measure;rather,we move its expected survival rate towards 1to keep it for later observation.4Results and Discussion 4.1Tracking resultWe tested our tracking algorithm on real video sequences captured from different viewpoints.We fit the human model to the image in the first frame manually and then the program tracks it automatically.We show two of the sequences here (Fig.7).The most dif-ficult part of the data,which makes it distinctive from most previous works,is that the sequences include the configura-tion in which the arms almost point at the camera (around ,Fig.7.(a)frame074),causing the most severe distortion,and the dancer stays in such configuration for a period of time.Other challenges include:sequences that contain sin-gular configurations (,and poses),motion dis-continuities (at the boundary of two primitives);the arm andThe AVI movies of the tracking and synthesis result are available at/˜taozhao/ballet/result.htmlleftarmright armFigure 6:Likelihood weighted sample number (for a frontal viewsequenceof both arms)belonging to different primitives and the seg-mentation basedon it.Darker means higher likelihood.The horizon-tal axis is the time,and the vertical axis represents the 12primitives (8moves and 4standard poses).the torso have the same color;and the arms and the torso have inter-occlusion especially in the side view sequence.Despite all the difficulties,our tracker can track both the frontal view and side view sequence (388-frame,282-frame respectively)fairly accurately with 512samples.Fig.7shows some of the key frames as well as rendered images with recovered model inother complementary viewpoints.To compare the performance,we also tracked the se-quence using a generic constant velocity model as the dy-namic model.In all trials with the same number of samples,tracking began to drift right after the pose.With more samples,the drift happened slightly later,but it still failed to track the entire sequences.We found that the introduction of the distortion factor played an important role in passing the difficult configura-tions.Without it,it is very likely that the tracker is attracted by some features that do not belong to the limb.At the same time,we obtained the segmentation of the video sequence into the primitives according to the likelihood weighted sample number of each frame.(See Fig.6)The seg-mentation is fairly accurate.Obviously,this technique can also be used for recognition if the primitives have syntacticmeaning.4.2Synthesis of new video sequenceWith the structured representation,and the video segmen-tation (clips)corresponding to the motion primitives (exam-ple in Fig.6),we can generate new video sequence.[16]pre-sented a way to generate a new video sequences of relativelyrandom motion,and we have achieved the same goal for struc-tured motion.First a primitive sequence is generated by ran-dom walk in the transition matrix,and then the primitives are replaced by the video clip of it.Due to limited data,we only generate the motion where two arms have the same motion.5ConclusionWe have presented our work on unsupervised learning of a structured motion model of human motion and its application to 3D human motion tracking and synthesis.Our main con-tribution is the fully automatic recovery of the intrinsic struc-ture(i.e.,motion primitives and their transitions)and precise segmentation of the motion primitives from structured human motion.The recovery is done under the MDL paradigm with a two-step approach which makes the optimization process more explicit and efficient.The structured representation re-vealed the data generating mechanism of the motion,thus is natural for various applications.In the later part of our work,we decomposed the dynam-ics of the underlying complex motion(ballet arm motion)into a mixture of simple dynamics.With this decomposition,we performed tracking on challenging video sequences that are otherwise difficult to track.At the same time,the video se-quences are segmented into video 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