A Recursive Optimal Relevance Feedback Scheme for Content Based Image Retrieval
feedback and concerns into consideration -回复
feedback and concerns into consideration -回复如何将反馈和关注纳入考虑。
第一步：认识反馈和关注的重要性（200字）在任何领域，反馈和关注都是实现个人和组织成长的关键因素。
无论是在个人生活中还是在工作环境中，接受反馈可以帮助我们认识自己的优点和改进的方面。
而关注是建立良好关系和增强合作的基础。
因此，我们需要学会认识和接受反馈，并重视他人的关注。
第二步：利用反馈改进个人能力（400字）首先，我们应该积极主动地寻求反馈。
我们可以向领导、同事、家人和朋友寻求反馈。
从不同的角度听取意见有助于我们从多个角度认识自己。
然后，我们需要正确对待反馈。
不论是正面的还是负面的反馈，我们应该以开放的心态接受，并从中寻找改进的机会。
而不是对反馈做出过度反应或忽视它们。
接下来，我们应该将反馈转化为行动。
通过提出具体的行动计划来改进自己的不足之处，并定期检查进展。
最后，我们应该对反馈保持持续的关注。
反馈并不只有一次性的作用，我们需要将其融入到日常生活和工作中，不断改进和增长。
第三步：关注他人的需求和反馈（400字）一个关注他人需求的人往往能建立稳固的人际关系，并在合作中取得更大的成功。
首先，我们要学会倾听别人的反馈和请求。
无论是在工作还是个人生活中，我们都会遇到不同的需求和反馈。
我们应该积极倾听，并从中理解对方的期望。
然后，我们需要及时回应他人的需求。
在工作中，回应和解决同事和领导的需求是建立信任和合作的重要一环。
在个人生活中，我们也应该关注家人和朋友的需求，并尽力提供帮助和支持。
最后，我们应该持续关注他人的反馈，并根据需要作出调整和改进。
只有通过关注他人的反馈，我们才能建立起积极的双向沟通，并改善我们的人际关系。
第四步：将反馈和关注纳入决策过程（500字）在做出决策时，我们应该将反馈和关注纳入考虑。
首先，我们可以收集和分析相关的反馈和关注。
这可以通过调查问卷、面对面交流或观察来实现。
U校园新视野大学英语3参考答案
U校园新视野大学英语3参考答案本参考答案旨在帮助学生更好地理解和掌握《U校园新视野大学英语3》的知识点，提高英语水平。
以下是部分单元的参考答案，供学生参考。
Unit 1: The Power of WordsSection A: Vocabulary and Structure1. The correct answer for the first vocabulary exercise is:- (1). C: articulate- (2). A: eloquence- (3). B: rhetoric2. The sentence structure exercise should be completed as follows:- (1). The speech was so powerful that it moved the audience to tears.- (2). Despite his lack of formal education, he was ableto express his thoughts eloquently.Section B: Reading Comprehension1. The main idea of the passage is:- A: The impact of language on human behavior and emotions.2. According to the passage, which of the following is true?- B: Positive affirmations can enhance self-esteem.1. In the conversation, the two speakers discuss:- B: The importance of choosing the right words whengiving feedback.Unit 2: Technology and SocietySection A: Vocabulary and Structure1. Fill in the blanks with the correct form of the word given: - (1). The rapid advancement of technology has revolutionized the way we communicate.- (2). The company's innovation in software developmenthas set a new standard in the industry.2. Choose the best word to complete the sentence:- (1). B: integrate- (2). A: obsoleteSection B: Reading Comprehension1. The author's purpose in writing the passage is to:- C: Discuss the benefits and drawbacks of technological advancements.2. What is the author's view on the impact of technology on employment?- B: Technology creates new job opportunities while eliminating others.1. The main topic of the lecture is:- A: The role of technology in shaping modern society.Unit 3: Environmental AwarenessSection A: Vocabulary and Structure1. Match the words with their definitions:- (1). A: conservation- (2). C: pollution- (3). B: sustainability2. Rewrite the sentences using the passive voice:- (1). The new policy will be implemented by the government to reduce carbon emissions.- (2). Recycling programs are encouraged in many communities to preserve natural resources.Section B: Reading Comprehension1. The passage suggests that:- A: Individual actions can contribute to environmental protection.2. What is the author's opinion on the effectiveness of recycling programs?- C: They are effective when properly managed and supported by the public.1. The speakers in the interview discuss:- B: The challenges and opportunities in promoting environmental sustainability.Unit 4: Cultural DiversitySection A: Vocabulary and Structure1. Fill in the blanks with the appropriate prepositions:- (1). The festival is celebrated in honor of the cultural heritage.- (2). Despite their cultural differences, the two communities coexist peacefully.2. Choose the correct sentence:- A: Cultural diversity enriches our understanding of the world.Section B: Reading Comprehension1. The main theme of the article is:- B: The importance of respecting and embracing cultural diversity.2. According to the article, what is the impact of globalization on culture?- C: It leads to both the spread and the potential loss of cultural identities.1. The interviewee talks about:- A: The benefits of cultural exchange programs for fostering understanding between different cultures.Unit 5: Personal DevelopmentSection A: Vocabulary and Structure1. Use the correct form of the word to complete the sentence: - (1). The key to success is perseverance and hard work. - (2). The seminar aims to enhance participants' leadership skills.2. Choose the sentence that best expresses the idea:- B: Setting realistic goals is crucial for personal development.Section B: Reading Comprehension1. The author believes that:- A: Self-improvement is a continuous process.2. What does the passage suggest about the role of failure in personal growth?- C: It can provide valuable lessons and motivate further efforts.Section C: Listening1. The main points discussed in the lecture include:- A: Strategies for effective time management.- B: The importance of maintaining a healthy work-life balance.ConclusionThese are just a few examples of the types of exercises and questions you might。
初中英语教资的affective strategy
初中英语教资的affective strategy1. Fostering a positive learning environment: Creating a positive learning atmosphere that encourages participation, risk-taking, and mutual respect among learners.2. Developing rapport with students: Building rapport with students, knowing their interests, strengths, and learning styles, and showing interest in their lives.3. Encouraging self-reflection: Encouraging students to reflect on their learning, emotions, and experiences, and providing them with opportunities for self-expression.4. Providing feedback: Providing frequent and constructive feedback to learners to help them improve their performance and build their confidence.5. Promoting learner autonomy: Encouraging learners to take responsibility for their own learning, setting goals, and monitoring their progress.6. Using humor: Using humor to lighten the mood, create a relaxed atmosphere, and engage learners.7. Encouraging collaboration: Encouraging learners to interact and collaborate with each other to achieve common goals.8. Catering to individual differences: Catering to individual differences by providing differentiated instruction, and adapting teaching strategies to meet the needs of diverse learners.9. Providing a sense of accomplishment: Providing opportunities for learners to experience success and a sense of accomplishment, which can contribute to their motivation.10. Promoting cultural awareness: Promoting cultural awareness and respect for diversity by recognizing and valuing learners' cultural backgrounds and experiences.。
人文英语4形考作业及答案
最新国家开放大学电大《人文英语4》网络核心课形考网考作业及答案考试说明：2018 年秋期电大把《人文英语4》网络核心课纳入到“国开平台”进行考核，它共有八个形考任务(单元自测)。
针对该门课程，本人汇总了该科所有的题，形成一个完整的标准题库，并且以后会不断更新，对考生的复习、作业和考试起着非常重要的作用，会给您节省大量的时间。
做考题时，利用本文档中的查找工具，把考题中的关键字输到查找工具的查找内容框内，就可迅速查找到该题答案。
本文库还有其他网核及教学考一体化答案，敬请查看。
本课程考核采用形成性考核与终结性考试相结合的方式。
形成性考核占课程综合成绩的50%，终结性考试占课程综合成绩的50%。
课程考核成绩统一采用百分制，即形成性考核、终结性考试、课程综合成绩均采用百分制。
课程综合成绩达到60 分及以上（及格），可获得本课程相应学分。
单元自测1一、选择填空，从A、B、 C 三个选项中选出一个能填入空白处的最佳选项。
（每题10 分）题目1– Thank you for your invitation. _______________A. I'll appreciate it.B. It's a pleasure.C. It doesn't matter.题目2– Good afternoon. Can I help you? ______________A. Yes, I think so, too.B. I need to buy a birthday present for my son.C. I don't think I need any of your help.题目3On average, a successful lawyer has to talk to several________ a day.A. customersB. clientsC. guests题目4Both the kids and their parents __________English, I think. I know it from their accent.A. beenB. areC. is题目5John's father _________ mathematics in this school ever since he graduated from Harvard University.A. taughtB. has taughtC. teaches题目1– Do you think I can borrow your bike for a few hours?________A. I'm sorry, but I really need it this afternoon.B. I don't think so.C. I am afraid you can.题目2– Excuse me, could you tell the time? _________A. You'd better buy a watch.B. Can you see the clock?C. It's three thirty by my watch.题目3Professor Smith promised to look ________ my paper, that is, to read it carefully before the defence.A. overB. afterC. onNever before _________ see such a terrible car accident on the road!A. have IB. I haveC. did I题目5Both the kids and their parents __________English, I think. I know it from their accent.A. beenB. isC. are题目1– Do you think I can borrow your bike for a few hours?_________________A. I don't think so.B. I am afraid you can.C. I'm sorry, but I really need it this afternoon.题目2– Thank you for your invitation. _________A. I'll appreciate it.B. It doesn't matter.C. It's a pleasure.题目3As the bus came round the corner, it ran ________ a big tree by the roadside.A. overB. intoC. on题目4Never before _________ see such a terrible car accident on the road!B. I haveC. did I题目5Did you notice the guy _________head looked like a big potato?A. whoB. whoseC. which二、阅读理解：选择题（每题10 分）Graffiti painting is traditionally a daredevil pursuit.Teenagers dodge security guards to put their names on trains and buses. But over the past decade, graffiti has all but disappeared from Britain's cities. Between 2007 and 2012 the number of incidents of graffiti recorded by the British Transport Police fell by 63%. A survey by the Environment Ministry shows that fewer places are blighted by tags than ever. Graffiti are increasingly confined to sanctioned walls, such as the Stockwell ball courts. In time the practice may die out entirely.The most obvious reason for the decline in tagging and train-painting is better policing. Numerous CCTV cameras mean it is harder to get away with painting illegally. And punishments are more severe. A generational shift is apparent, too. Fewer teenagers are getting into painting walls. They prefer to play with iPads and video games. Some have gone to art school and want to make money from their paintings. The Internet means that painters can win far more attention by posting pictures online than they can by breaking into a railway yard.Taggers and graffiti artists mostly grew up in the 1980s and 1990s. Those men—and almost all are men—are now older and less willing to take risks. Graffiti may eventually disappear. But for now the hobby is almost respectable. The former graffiti artists paint abandoned warehouses at the weekend. It has become something to do on a Sunday afternoon—a slightlyhealthier alternative to sitting and watching football.1.Teenagers are not afraid of being caught by security guards when they put their names on trains and buses. F2.Less tags can be found in public places nowadays. T3.Because of better policing graffiti decreases. T4.Some teenagers go to art school in order to learn to paint walls. F5.Taggers and graffiti artists are still willing to take risks.F选择题（每题10 分）Jim Thorpe was a Native American. He was born in 1888 in an Indian Territory(印第安人保护区)that is now Oklahoma. Like most Native American children then, he liked to fish, hunt, swim, and play games outdoors. He was healthy and strong, but he had very little formal education. In 1950, Jim Thorpe was named the greatest American football player. He was also an Olympic gold medal winner. But Thorpe had many tragedies in his life.Jim had a twin brother who died when he was nine years old. By the time he was 16, his mother and father were also dead, Jim then went to a special school in Pennsylvania for Native American children. There, he learned to read and write and also began to play sports. Jim was poor, so he left school for two years to earn some money. During this time, he played on a baseball team. The team paid him only $15 a week. Soon he returned to school to complete his education. Jim was a star athlete (运动员) in several sports, including baseball, running, and football. He won many awards for his athletic ability, mainly for football. In many games, he scored all or most of the points for his team.In 1912, when Jim Thorpe was 24 years old, he became part of the U.S Olympic team. He competed in two very difficult events: the pentathlon and the decathlon. Both require great ability and strength. The pentathlon has five track and field events, including the long jump and the 1500-meter race. The decathlon has ten track and field events, with running, jumpingand throwing contests.People thought it was impossible for an athlete to compete in both the pentathlon and the decathlon. So everyone was surprised when Thorpe won gold medals in both events. When the King of Sweden presented Thorpe with his two gold medals, he said, “Sir, you are the greatest athlete in the world.”Thorpe was a simple and honest man. He just answered, “Thanks, King.”1. From the passage we learn that Jim Thorpe was born in CA. IndiaB. PennsylvaniaC. Oklahoma2. According to the passage, most American Indian children loved all the following EXCEPT BA. fishingB. singingC. swimming3. Jim Thorpe started to play sports BA. before he was 9 years oldB. when he was 16 years oldC. when he was 24 years old4. The word decathlon in paragraph 3 probably means CA. jumpingB. five track and field eventsC. ten track and field events5. Which of the following is NOT TRUE? AA. In 1912, Thorpe went back to finish his college education.B. Thorpe won two gold medals in the 1912 Olympic Games.C. Thorpe once played on a baseball team for money.选择题（每题10 分）排序题A. Does it cost the same for every household?B. You can pay right here, on the Internet!C. Just go ahead.D. We do for the live Cable TV programs.E. Exactly, even digital boxes.Liu Hui: Gordon, may I ask you a question?Gordon: Hi, Liu Hui. CLiu Hui: Do I need to pay for a TV license if I only watch TV online in the UK?Gordon: Yes, indeed. You need to be covered by a TV license if you watch or record programs as they're being shown on TV or live on an online TV service.Liu Hui: Including watching TV on computers and mobile phones? Gordon: EIt is the law.Liu Hui: I see. How much is the license fee?Gordon: It costs £145.50 for a color TV license and £49.00 for a black and white TV license.Liu Hui: That's a lot of money for a year. AGordon: It costs the same for all applicants under 75. When you reach the age of 75, you may apply for a free Over 75 TV License.Liu Hui: I see.Gordon: Do you need such a license in China?Liu Hui: DGordon: Oh, it sounds similar. But for BBC, the license fee is the main source of income. There is no advertising on the BBC channels.Liu Hui: By the way, where should I go to pay for mylicense?Gordon: BLiu Hui: Well, sure! Thank you!单元自测2一、选择填空，从A、B、 C 三个选项中选出一个能填入空白处的最佳选项。
1390国开电大本科《人文英语4》历年期末考试(第三大题阅读判断题)题库(分学期版)
1390国开电大本科《人文英语4》历年期末考试(第三大题阅读判断题)题库(分学期版)2021年7月试题及答案26-30题：请根据短文内容判断给出的语句是否正确，正确的写“T”，错误的写“F”。
Passage 2All communication begins with the sender and ends with the receiver.The sender is responsible for successful conveyance.The sender's personality，beliefs，cultural and educational background all influence the message and it is important for the sender to be aware of this as he or she is encoding the message.Simply put，encoding is translating information into symbols that represent the ideas or concepts of the message that needs sending.These symbols are usually words in written or spoken form.To ensure successful communication，the sender should know as much about his or her audience-the receiver-as possible in order to focus and support the encoding process.In addition to this awareness of self and encoding，the sender must choose the proper channel for conveying the ing the wrong channel may result in miscommunication.Like the sender，receivers are influenced by internal factors：theirpersonality，their receptivity to the message or their relationship to the sender.Additionally，their current feelings，mood，or state of mind can affect a message.Once the message moves through the channel，the receiver then decodes it.The receiver uses his or her own experience and the context of the message to interpret its meaning.Feedback is the return message from the receiver to the sender.It is feedback that enables the sender to know whether the message was received successfully or not.Therefore it is essential to the communication process.This process，though very common，is fraught with potential breakdown at every turn.Spoken or written language is inherently easy to misinterpret.In conclusion，effective and successful Communication takes place when the message is successfully received and the receiver provides the sender with desirable feedback.26.The sender's gender also influences the message.[答案]F27.Encoding is a process that translating information into symbols which serve as the ideas or concepts of the message that will be sent later.[答案]T28.These symbols are usually words and sentences in written form.[答案]F29.Channel is not crucial for conveying the message.[答案]F30.Feed backs enable the sender to know whether the receiver has received the message successfully or not.[答案]T附：所有的沟通都始于发送者，结束于接收者。
2023年全国高考英语二卷语法填空题
2023年全国高考英语二卷语法填空题第二节(共5小题;每小题2.5分,满分12.5分)阅读下面短文,从短文后的选项中选出可以填入空白处的最佳选项。
选项中有两项为多余选项。
As an artist who shares her journey on social media,I’m often asked by curious followers how to begin an art journey.Unfortunately,there is no magic list I can offer.I do remember, though,what it was like to be a complete beginner.So I’ve put together some good tips for starting an art journey.·Start small.I suggest using a sketchbook(素描本)for small studies.These small studies provide inspiration and may be a springboard for more complex works in the future.___36___ You’ll want to look back on your journey to see how far you’ve come.·Paint often and paint from life.There’s no better way to improve than to put in those brush miles.Whether you paint still lifes,portraits,or landscapes,paint from life as much as possible. ___37___·Continually challenge yourself to try something new.___38___Artistic growth can be a bit painful.Welcome to the club；we’ve all been there.I love taking on challenges.I once took up a challenge to create a painting every day for a month and post the works online.·___39___Seeking and accepting constructive feedback(反馈)is crucial to growth.I post my work on social media and,in turn,have met some of the kindest people.They make me feel valued and respected,no matter my level of artistic ability.The journey you’re on won’t follow a straight path.___40___Push through,give it time and put in the effort.You will harvest the rewards of an artistic life.A.Get out of your comfort zone.B.Make career plans and set goals.C.Don’t throw away your beginner art.D.Share your work if you feel comfortable doing so.E.You’ll hit roadblocks,and you’ll feel discouraged at times.F.Evaluate your performance and,if needed,redefine your role.G.You’ll develop that painting muscle memory that only comes with repetition.第三部分语言运用(共两节,满分30分)第一节(共15小题;每小题1分,满分15分)阅读下面短文,从每题所给的A、B、C、D四个选项中选出可以填入空白处的最佳选项。
Ellis-Corrective-Feedback
T tries to elicit correct pronunciation and the corrects
S: alib[ai]
S fails again
T: okay, listen, listen, alb[ay] T models correct pronunciation
SS: alib(ay)
Theoretical perspectives
1. The Interaction Hypothesis (Long 1996) 2. The Output Hypothesis (Swain 1985;
1995) 3. The Noticing Hypothesis (Schmidt
1994; 2001) 4. Focus on form (Long 1991)
2. In the course of this, they produce errors. 3. They receive feedback that they recognize as
corrective. 4. The feedback causes them to notice the errors they
first row. (uptake)
The complexity of corrective feedback
Corrective feedback (CF) occurs frequently in instructional settings (but much less frequently in naturalistic settings)
Commentary
Initial focus on meaning Student perceives the feedback as corrective
2024版高考英语二轮总复习第2部分阅读能力突破篇专题2阅读七选五第1讲根据设题位置解题课件
技法点拨
1．利用主题句或总结句确定答案 主题句或总结句通常是结论性、概括性的语句。分析与前文是转折 还是对比关系，在选项中查找表示转折、对比的关联词，同时注意选项 中所讲内容是否与前文在同一主题上形成对立、对比关系，表示结果、 结 论 、 总 结 等 的 信 息 词 有 ： therefore ， as a result ， thus ， hence ， in short，to sum up，to conclude，in a word等，选项中也可能发现前文的同 义词或句。
考点3 段尾题类
辨明题类
段尾句通常是结论性、概括性语句，但也有可能是段落间的过渡 句。一般而言，当段尾句是段落间的过渡句时，该段尾句通常出现在短 文的第一段。
如果缺的是结论性、概括性的语句，考生应快速浏览七个备选项， 注 意 选 项 中 是 否 出 现 表 示 结 果 、 结 论 、 总 结 等 的 信 息 词 ， 如 so ， therefore，as a result，in short，in a word，all in all等词或短语，快速缩 小选择范围，再根据段落主题一致性原则，从而确定正确选项。假如所 缺的是段落间的过渡句，首先可以关注表示逻辑关系的衔接词，再结合 词汇复现等原则进行答案的选择。
【解题示范】 段首题。根据上段中“Emoji can help communication feel friendlier(表情符号有助于使交流让人觉得更友好)”和后句“and emoji can contribute directly to that positive outcome(并且表情符号可以直接促成 这种积极的结果)”可知，这里陈述表达友好的表情符号能给工作场所带 来的好处。所以选项“Studies show that friendlier communication leads to a happier workplace(研究表明，更友好的沟通会带来更快乐的工作场所)” 承上启下，符合语境。故选F。
初中英语学习自我培养计划
03
Improving listening, speaking, reading, and writing skills
Listening training methods and techniques
Regular listening practice
Listen to English audio materials such as news broadcasts, podcasts, and movies to improve listening comprehension
Engage in creative writing activities, such as journaling or short story writing, to practice using a variety of presence structures and express yourself more fluently in English
writing abilities
Foster a positive attitude towards English learning
and self-development
Develop long term and short term plans
Long term plan
Establish a comprehensive learning plan that covers all aspects of English proficiency, including vocabulary, grammar, listening, speaking, reading, and writing Break down the plan into manageable chunks and set realistic targets for each stage
2023年高考英语2卷阅读第二节
2023年高考英语2卷阅读第二节答题要求：阅读短文，并根据短文内容回答问题。
所给的答案完全正确才能得分。
AArtificial Intelligence (AI) has become an indispensable part of our lives. From virtual assistants like Siri and Alexa to autonomous vehicles, AI is transforming various industries, including education.In recent years, AI has been employed in education to enhance the learning experience and improve academic outcomes. One of the key applications of AI in education is personalized learning. AI algorithms analyze data collected from students and provide tailored learning materials and strategies based on individual strengths and weaknesses. This allows students to learn at their own pace and focus on areas that need improvement.Furthermore, AI is also used to automate administrative tasks, such as grading. By using machine learning algorithms, teachers can save a significant amount of time on repetitive tasks, allowing them to focus more on providing personalized instruction and support to students.However, the integration of AI in education also raises concerns. Some argue that AI may lead to a lack of human interaction in the learning process, as students rely more on digital platforms and virtual teachers. While AI can provide personalized feedback, it cannot fully replace the role of human educators in fostering critical thinking and social skills.Another concern is the potential bias in AI algorithms. AI systems learn from data, and if the data used to train the algorithms is biased, it can perpetuate existing biases in educational systems. For example, if the algorithm is trained on historical data that reflects gender or racial bias, it may unintentionally reinforce those biases in the personalized learning recommendations it provides.In conclusion, AI has great potential in revolutionizing education by providing personalized learning experiences and automating administrative tasks. However, it is important to strike a balance between the benefits of AI and the preservation of human interaction and critical thinking skills in education. Additionally, efforts should be made to ensure the fairness and ethical use of AI algorithms in educational settings.B1. What is one of the key applications of AI in education?Personalized learning is one of the key applications of AI in education. AI algorithms analyze data collected from students and provide tailored learning materials and strategies based on individual strengths and weaknesses.2. How does AI help save time for teachers?AI helps save time for teachers by automating administrative tasks, such as grading. By using machine learning algorithms, teachers can focus more on providing personalized instruction and support to students.3. What concerns are raised regarding the integration of AI in education?Two concerns raised regarding the integration of AI in education are the lack of human interaction in the learning process and the potential bias in AI algorithms.4. How can the potential bias in AI algorithms be addressed?Efforts should be made to ensure the fairness and ethical use of AI algorithms in educational settings. This includes carefully selecting and monitoring the data used to train the algorithms to avoid perpetuating existing biases.5. What is the importance of striking a balance between AI and human interaction in education?While AI can provide personalized feedback, it cannot fully replace the role of human educators in fostering critical thinking and social skills. Striking a balance ensures that students benefit from both the advantages of AI and the essential human aspect of education.。
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Nikolaos Doulamis and Anastasios Doulamis
National Technical University of Athens, Electrical and Computer Engineering Department, 15773, Athens, Greece E-mail: ndoulam@image.ntua.gr
relevant selected images and as far as possible to all irrelevant images. This is addressed in this paper, where an optimal relevance feedback scheme is proposed in contrast to the previous works. In this paper, an efficient optimal relevance feedback mechanism is presented to improve the performance of a content-based image retrieval system. In particular, the algorithm is based on an optimal weight updating strategy, which regulates the importance of each image descriptor to the retrieval response. The weights are updated so that the correlation between the query image and all selected images of high degree of relevance is maximized, while simultaneously the correlation over all selected images of low degree of relevance is minimized. The computational complexity and performance of the proposed weight updating is also low demanded. Two different cases of relevance feedback are examined in this paper. The first assumes that one feedback iteration is sufficient to adapt the response of the CBIR system to the users' query. This case is called single relevance feedback. When more than one feedback iterations are required for the system adaptation, a multiple relevance feedback strategy is accomplished. In the latter case, we propose a recursive estimation of the optimal weight updating in order to increase the system efficiency. In particular, at each new feedback iteration, the weights are adapted based only on the current selected images (relevant, neutral or irrelevant) and the weights estimated at the previous iteration. It should be mentioned that the proposed scheme is not affected on the selected features. Convergence of the weight updating is achieved if the user submits "consistent" relevant or irrelevant images to the system, i.e., images of similar content. This means that the system response adapts its performance to the user's information needs in a stable manner. Experimental results b image databases are presented to indicate all theoretical aspects and verify the good performance of the proposed scheme.
1. INTRODUCTION
No doubt, the performance of a Content-Based Image Retrieval (CBIR) system depends on a) how efficiently the image visual content is represented and b) the degree of importance, which is assigned to each content-descriptor. In the first case, efficient visual representation is achieved, apart from the extraction of appropriate descriptors, through a proper organization of them [1]. The second case faces the problem arising from the subjectivity of humans, which often perceive the same visual content in a different way. This is, for example, the case when a person is interested in color information of an image, while another one, or even the same under different circumstances, in texture or motion information. To overcome the aforementioned difficulty, the human can be considered as a part of the retrieval process resulting in an interactive CBIR scheme [2]. In particular, the retrieval results are evaluated by the user and a degree of relevance is assigned to some selected images so that the system response is adapted according to the user's demands. This interactive framework is usually called relevance feedback, similarly to the definition used in traditional text-based information systems [3]. Towards this direction, some CBIR systems incorporating relevance feedback algorithms have been proposed. In particular, a relevance feedback algorithm based on a probabilistic framework was reported in [4], while a relevance feedback algorithm, which exploits the variation of the feature elements to perform the weight updating, has been investigated in [2] and [5]. Extension of [5] to negative examples has been presented in [6] very recently, while in [7] the extension is performed to the interaction of different feature elements with each other. However, as mentioned in the conclusions of [5], there is a need for an optimal weight updating strategy. In this case, optimality means that the system should be adapted so that its response is as close as possible to all
Abstract