Sharif Digital Repository

Using mixed method research the current study has analyzed Iranian researchers' information searching behavior on the Web. Based on extracted concepts, the model of their information searching behavior was revealed. Forty-four participants, including academic staff from universities and research centers were recruited for this study selected by purposive sampling. Data were gathered from questionnaires including ten questions and semi-structured interview. Each participant's memos were analyzed using grounded theory methods adapted from Strauss & Corbin (1998). Results showed that the main objectives of subjects were doing a research, writing a paper, studying, doing assignments, downloading... 

By the immense growth of the Web-Based Social Networks (WBSNs), the role of trust in connecting people together through WBSNs is getting more important than ever. In other words, since the probability of malicious behavior in WBSNs is increasing, it is necessary to evaluate the reliability of a person before trying to communicate with. Hence, it is desirable to find out how much a person should trust another one in a network. The approach to answer this question is usually called trust inference. In this paper, we propose a new trust inference algorithm (Called RN-Trust) based on the resistive networks concept. The algorithm, in addition to being simple, resolves some problems of previously... 

So far several methods have been proposed for clustering the web. On the other hand, many algorithms have been developed for clustering the relational data, but their usage for the Web is to be investigated. One main category of such algorithms is density based methods providing high quality results. In this paper first, a new density based algorithm is introduced and then it is compared with other algorithms of this category. The proposed algorithm has some interesting properties and capabilities such as hierarchical clustering and sampling, making it suitable for clustering the web data. © Springer-Verlag Berlin Heidelberg 2007  

Social tagging is a process in which many users add metadata to a shared content. Through the past few years, the popularity of social tagging has grown on the web. In this paper we investigated the use of social tags for web page classification: adding new web pages to an existing web directory. A web directory is a general human-edited directory of web pages. It classifies a collection of pages into a wide range of hierarchical categories. The problem with manual construction and maintenance of web directories is the significant need of time and effort by human experts. Our proposed method is based on applying different automatic approaches of using social tags for extending web... 

Internet banking is a tool to achieve competitive advantage and its usage has been spreading rapidly in recent years. This paper strives to identify a comprehensive study of the major internet banking quality measurements, which covers a wide range of literature relevant to international papers and scholars and then evaluate them through using a precise method, Shannon entropy. At the last stage the validated criteria were exploited to survey in Iranian banks. The empirical research consists of a quantitative study of internet banking by a sample of employees in two banks of Iran. In this regard, the raised question is about whether or not the internet banking is a strategic information... 

Nowadays web services composition that presents capabilities in response to customers' complex requirements has a special importance in real businesses. However, service choreography as a form of service composition, still faces many challenges. One of the most important challenges of the choreography domain is how to validate the model based on the corresponding requirements. To this end, in this paper processes choreographies are modeled using the interaction view of BPMN 2.0 standard. Then, goal modeling is suggested to extract the requirements. For each requirement all possible valid scenarios are considered and finally using Savara tool, the requirements' scenarios are modeled and the... 

One of the important yet insufficiently studied subjects in fair allocation is the externality effect among agents. For a resource allocation problem, externalities imply that the share allocated to an agent may affect the utilities of other agents. In this paper, we conduct a study of fair allocation of indivisible goods when the externalities are not negligible. Inspired by the models in the context of network diffusion, we present a simple and natural model, namely network externalities, to capture the externalities. To evaluate fairness in the network externalities model, we generalize the idea behind the notion of maximin-share (MMS) to achieve a new criterion, namely,... 

Recommender Systems have become an attractive field within the recent decade because they facilitate users' selection process within limited time. Conventional recommender systems have proposed numerous methods focusing on recommendations to individual users. Recently, due to a significant increase in the number of users, studies in this field have shifted to properly identify groups of people with similar preferences and provide a list of recommendations for each group. Offering a recommendations list to each individual requires significant computational cost and it is therefore often not efficient. So far, most of the studies impose four restrictive assumptions: (1) limited number of... 

In real-world networks, nodes might have more than one type of relationship. Signed networks are an important class of such networks consisting of two types of relations: positive and negative. Recently, embedding signed networks has attracted increasing attention and is more challenging than classic networks since nodes are connected by paths with multi-types of links. Existing works capture the complex relationships by relying on social theories. However, this approach has major drawbacks, including the incompleteness/inaccurateness of such theories. Thus, we propose network transformation based embedding to address these shortcomings. The core idea is that rather than directly finding the... 

Context awareness in Web services is gaining momentum. Since it is not a trivial task, it suffers from lack of a general solution. In this paper, we introduce a novel approach for context-aware Semantic Web Services which is applicable for any environment. It is established based on composition of context provider Web Services and other context-aware Semantic Web Services. In addition, an extended version of the Semantic Web Service Ontology Language for Semantic Web services is introduced, in order to make it possible to find appropriate context-aware Semantic Web services based on available context information. So as to make it applicable for any environment, the solution does not hold any... 

There are many websites on the Internet which are for adult users and we want to restrict access to them for adults only. Adult content filtering programs on client computers are the current available solutions. But if we can identify the child users at server side, we can protect the children more. In this paper, we try to answer the question that whether it is possible to identify child users or not? © 2008 SICE  

Nowadays the Internet users are from different ages and groups. The disabled people also use the Internet. Some websites are especially created for disabled people. Many Internet sites offers services for human users, but unfortunately some computer programs are designed to abuse these services. To solve this problem, some systems named CAPTCHA (Completely Automated Public Turing test to tell Computers and Human Apart) have been introduced to distinguish between human users and computer programs. CAPTCHA methods are mainly based on the weaknesses of OCR systems while using them is undesirable for human users, especially for disabled people. Therefore some CAPTCHA methods are designed... 

As web contents grow, the importance of search engines became more critical and at the same time user satisfaction decreased. Query recommendation is a new approach to improve search results in web. In this paper we represent a method to help search engine users in attaining required information. Such facility could be provided by offering some queries associated with queries submitted by users in order to direct them toward their target. At first, all previous query contained in a query log should be clustered, therefore, all queries that are semantically similar will be detected. Then all queries that are similar to user's queries are ranked according to a relevance criterion. The method... 

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 these people. One group of the disabled people are deaf persons. They have a special talking language which is named sign language. Here we present a method to encourage them, esp. children, to learn the sign language. In this method, when a deaf person wants to enter a website which is created for deaf persons, a word is shown as a movie using a sign language. The user should recognize the word and select it from a list. If the user understands the sign language and recognizes the word, he/she can enter the website. This project has been... 

Question Answering systems are one of the hot topics in context of information retrieval. In this paper, we develop an open-domain Question Answering system for spatial queries. We use Google for gathering raw data from the Web and then in a few iterations density of potential answers will be increased, finally based on a couple of evaluators the best answers are selected to be returned to user. Our proposed algorithm uses fuzzy methods to be more precise. Some experiments have been designed in order to evaluate the performance of our algorithm and results are totally promising. We will describe that how this algorithm can be applied to other type of questions as well  

Ontology Aligning is an answer to the problem of handling heterogenous information on different domains. After application of some measures, one reaches a set of similarity values. The final goal is to extract mappings. Our contribution is to introduce a new genetic algorithm (GA) based extraction method. The GA, employs a structured based weighting model, named "coincidence based model", as its fitness function. In the first part of the paper, some preliminaries and notations are given and then we introduce the coincidence based weighting. In the second part the paper discusses the details of the devised GA with the evaluation results for a sample dataset  

Motivated by the problem of automatically composing network accessible services, such as those on the World Wide Web, this paper proposes an approach to exploit all semantic information available for semantic web services to complete this task. For semantic web services, we propose a prioritized and limited list of other web services, with composability measure value based on feasibility of being succeeding service in a composition to fulfill the request. Due to the fact that in semantic web services, semantic information- all description and signatures- is defined by ontology language, we use some of the mapping rules to estimate a correlation between services for composability. Then we... 

Recent years have witnessed an explosion in the availability of news articles on the World Wide Web. In addition, organizing the results of a news search facilitates the user(s) in overviewing the returned news. In this work, we have focused on the label-based clustering approaches for news meta-search engines, and which clusters news articles based on their topics. Furthermore, our engine for NEws meta-Search REsult Clustering (NeSReC) is implemented along. NeSReC takes queries from the users and collect the snippets of news which are retrieved by The Altavista News Search Engine for the queries. Afterwards, it performs the hierarchical clustering and labeling based on news snippets in a... 

A web attack is an attack against a web server through the HTTP Protocol. By analyzing known web attacks, we find out that each one has its own behavior. Vestiges of their behavior could be detected in non-body parts of the HTTP Protocol. Such information can be used to verify web alerts generated by Web Application Firewalls (WAFs) and Web Intrusion Detection Systems (Web IDSs). In this paper, we propose a method to verify web alerts generated by mentioned sensors. The goal of the alert verification component is to eliminate or tag alerts that do not represent successful attacks. Our approach is based on analyzing HTTP Transaction metadata, including Request method, Request Headers, Status... 

Many real-world systems and applications such as World Wide Web, and social interactions can be modeled as networks of interacting nodes. However, in many cases, one encounters the situation where the pattern of the node-to-node interactions (i.e., edges) or the structure of a network is unknown. We address this issue by studying the Network Reconstruction Problem: Given a network with missing edges, how is it possible to uncover the network structure based on certain observable quantities extracted from partial measurements? We propose a novel framework called CS-NetRec based on a newly emerged paradigm in sparse signal recovery called Compressive Sensing (CS). The results demonstrate that...