Sharif Digital Repository

By a great leap, the computer game industry has today reached fame as big as filmmaking industry. Upon introduction of the new generation of game consoles, this industry will witness spectacular progress. One of these next generation consoles is Nintendo console named "Wii". This console has a new game pad which utilizes motion sensors. On the other hand, facilities such as internet connection are added in new consoles and they are not merely for playing. It is observed that placing password for creating usernames by game consoles is difficult. By the use of the specifications of Wii console game pads, a method for user authentication and entering password is proposed in this paper. By using... 

In the modern world, electronic communications play a significant role in national and international electronic transactions. This issue has forced all legal systems to face up to many emerging legal problems in the context of electronic communications, such as the legal status of electronic agents in contracting electronically. Regarding the legal validity of e-contracts made through interactive websites, the legal status of electronic agents which play an important role in this process is questionable to see whether they are akin to real agents in the physical world or they are only a mere tool of communication. The current article tries to analyse this question by criticising a number of... 

Question and answer (Q&A) websites like Stack Overflow are one of the important sources of code examples in which developers can ask their questions and leave their answers about programming issues. Since the number of programmers who use these websites are increasing and a large number of questions and answers are being posted there by them, verifying the quality of all the answers and particularly the code snippets in them is impossible. Consequently, some code snippets might be of low quality and/or with faults. To mitigate this issue, we introduce ExRec (Example Recommender), an Eclipse plugin with which programmers can contribute in improving the quality of code snippets in the answers... 

Shared hosting is a kind of web hosting in which multiple websites reside on one webserver. It is cost-effective and makes the administration easier for websites' owners. However, shared hosting has some performance and security issues. In default shared hosting configuration, all websites' scripts are executed under the webserver's user account regardless of their owners. Therefore, a website is able to access other websites' resources. This security problem arises from lack of proper isolation between different websites hosted on the same webserver. In this survey, we have examined different methods for handling mentioned security issue. Also we evaluated the performance of mentioned... 

A social network is a set of people (or organizations or other social entities) connected by a set of social relationships, such as friendship, co-working or information exchange. Social network analysis focuses on the analysis of patterns of relationships among people, organizations, states and such social entities. Social network analysis provides both a visual and a mathematical analysis of human relationships. Web can also be considered as a social network. Social networks are formed between Web pages by hyperlinking to other Web pages. In this paper a state of the art survey of the works done on social network analysis ranging from pure mathematical analyses in graphs to analyzing the... 

Semantic web search engines are evolving and many prototype systems and some implementation have been developed. However, there are some different views on what a semantic search engine should do. In this paper, a categorization scheme for semantic web search engines are introduced and elaborated. For each category, its components are described according to a proposed general architecture and various approaches employed in these components are discussed. We also propose some factors to evaluate systems in each category. © 2006 IEEE  

Web pages change frequently and thus crawlers have to down-load them often. Various policies have been proposed for refreshing local copies of web pages. In this paper, we introduce a new sampling method that excels over other change detection methods in experiment. Change Frequency (CF) is a method that predicts the change frequency of the pages and, in the long run, achieves an optimal efficiency in comparison with the sampling method. Here, we propose a new hybrid method that is a combination of our new sampling approach and CF and show how our hybrid method improves the efficiency of change detection. © Springer-Verlag Berlin Heidelberg 2005  

Community Question-Answering websites, such as StackOverflow and Quora, expect users to follow specific guidelines in order to maintain content quality. These systems mainly rely on community reports for assessing contents, which has serious problems, such as the slow handling of violations, the loss of normal and experienced users' time, the low quality of some reports, and discouraging feedback to new users. Therefore, with the overall goal of providing solutions for automating moderation actions in QA websites, we aim to provide a model to predict 20 quality or subjective aspects of questions in QA websites. To this end, we used data gathered by the CrowdSource team at Google Research in... 

In recent years, community Q&A websites have attracted many users and have become reliable sources among experts from various fields. These platforms have specific rules to maintain their content quality in addition to general user agreements. Due to the vast expanse of these systems in terms of the number of users and posts, manual checking and verification of new contents by the administrators and official moderators are not feasible, and these systems require scalable solutions. In major Q&A networks, the current strategy is to use crowdsourcing with reliance on reporting systems. This strategy has serious problems, including the slow handling of violations, the loss of new and... 

Ambient Intelligence environments detect and respond to users needs, actions, behaviors and feelings. In the presence of interaction conflicts, user trust plays an important role in accepting Ambient Intelligence environments for living, working, etc. In this paper, we propose a multimedia-supported virtual experiment for online user–system trust studies. We conduct web-based experiments to gather data from a large number of online participants. Subjects experience the environment through an intelligent environment web-based 3D simulator. Our proposed approach can be utilized to measure trust not only in the presence of interaction conflicts, but also in the presence of any other variability... 

Ambient Intelligence environments detect and respond to users needs, actions, behaviors and feelings. In the presence of interaction conflicts, user trust plays an important role in accepting Ambient Intelligence environments for living, working, etc. In this paper, we propose a multimedia-supported virtual experiment for online user–system trust studies. We conduct web-based experiments to gather data from a large number of online participants. Subjects experience the environment through an intelligent environment web-based 3D simulator. Our proposed approach can be utilized to measure trust not only in the presence of interaction conflicts, but also in the presence of any other variability... 

Nowadays the Internet users are from different ages and groups. Disabled people are a group of the Internet users. Some websites are especially created for disabled people and public access to them is undesirable. In this paper, for the first time, a method is introduced for distinguishing between deaf persons and other users using a new HIP (Human Interactive Proofs) system. In this method, the sign language is used. A word is shown as a movie using a sign language. The user should recognize the word and select it from a list. Only deaf persons can understand sign language and recognize the word, therefore other persons and also computer programs cannot enter the website. This project has... 

Nowadays, there are plenty of online websites related to news. Hence, new technologies, tools and special search engines are created for having access to the news on these websites. Online news is a special type of public information which has exclusive characteristics. These characteristics contribute news engines tasks such as discovering, collecting and searching to be different with similar tasks in traditional web search engines. Clustering plays conspicuous role in news engines tasks. In this paper we study various tasks in news engines and also focusing on clustering applications in them. © 2007 Springer  

Following the expansion of Internet, many software were produced that could launch through Internet without prior installation on computers. This included game software and software that deal with financial affairs. These softwares are mainly in Java language and can be found on web pages as Java Applets. Some software owners want that their products only able to execute through their own web pages so that no one could put them on other web pages. In this paper, a new method has been presented to protect Java Applets from copying by using "Steganography in HTML web pages" method. In this method, a special 8-character string is hidden in the HTML page by a secret key. The string and the... 

One important problem proposed recently in the field of web mining is website classification problem. The complexity together with the necessity to have accurate and fast algorithms yield to many attempts in this field, but there is a long way to solve these problems efficiently, yet. The importance of the problem encouraged us to work on a new approach as a solution. We use the content of web pages together with the link structure between them to improve the accuracy of results. In this work we use Naïve-bayes models for each predefined webpage class and an extended version of Hidden Markov Model is used as website class models. A few sample websites are adopted as seeds to calculate... 

Shared Web Hosting service enables hosting multitude of websites on a single powerful server. It is a well-known solution as many people share the overall cost of server maintenance and also, website owners do not need to deal with administration issues is not necessary for website owners. In this paper, we illustrate how shared web hosting service works and demonstrate the security weaknesses rise due to the lack of proper isolation between different websites, hosted on the same server. We exhibit two new server-side attacks against the log file whose objectives are revealing information of other hosted websites which are considered to be private and arranging other complex attacks. In the...