Catálogo de publicaciones - libros

The crawler engines of today cannot reach most of the information contained in the Web. A great amount of valuable information is “hidden” behind the query forms of online databases, and/or is dynamically generated by technologies such as JavaScript. This portion of the web is usually known as the Deep Web or the Hidden Web. We have built DeepBot, a prototype hidden-web crawler able to access such content. DeepBot receives as input a set of domain definitions, each one describing a specific data-collecting task and automatically identifies and learns to execute queries on the forms relevant to them. In this paper we describe the techniques employed for building DeepBot and report the experimental results obtained when testing it with several real world data collection tasks.

The combining of mobility and quality of service (QoS) is becoming a big issue in mobile IPv6 networks. It is general that the traditional Internet service provides the same level of service to all users. However, new type of services demand better QoS and host mobility according to wireless and Internet technologies have being speedily developed. To satisfy these requirements, we deploy differentiated service (Diffserv) model to provide various demand of new application in mobile IPv6 networks. The operational procedures and cost evaluation schemes for seamless connection during a mobile node (MN) changes its network attachment point are proposed while satisfying its QoS requirement. A Priority Queue is used to manage three types of services and the performances are evaluated.

Tackling the disadvantages associated with remote communication is a challenge in multi-site software development. The challenge includes all these factors: awareness of the work that is being done according to the project plan, the work that is being done to co-operate between teams, the issues that have been currently raised, the issues that have been clarified, and a means of discussing issues and arriving at a solution within a multi-site distributed environment. If everyone working on a certain project is located in the same area, then situational awareness is relatively straightforward, but the overheads in communication can be great when team members need to meet in order to discuss the problems, to raise issues, to make decisions and to find answers in a multi-site distributed environment. In this paper, we present issues, solutions, and challenges in Multi-site Software Development. The solution main idea is to have knowledge and agreement explicitly interpreted by software tools rather than just being implicitly interpreted by human developers. The representation of software engineering concepts, software development tasks, software development models, software development processes, software development issues and development solutions, as well as software development documentation in the digital form, provides intuitive, clear, precise concepts and ideas, knowledge. Sharing knowledge facilitates a common understanding of the knowledge. This enables effective ways of reaching a consensus of understanding which is of benefit to remote team members in a distributed environment. The common knowledge is semantically shared not only among remote team members but also among software systems.

This thesis intends to suggest a way to convert it to VML code to play back diagram in internet browser to generate diagram contents used in production of multimedia title as Internet contents, and play it back. By converting multimedia title including excellent contents to web contents, web contents of high quality is intended to be generated. For this, it is rearranged to maintain spatial synchronization of object used inside title in web page by using the CSS Layer and generating VML code, location of playback of diagram contents and shape of the diagram are played back on web page through generation VML code. Through this research, diagram representation that is a difficult problem in converting multimedia title to web contents becomes possible. And furthermore, by using writing tool, diagram of web page can become designed by operating mouse without complex VML code.

Recommender systems are tools to help users find items that they deem of interest to them. They can be seen as an application of data mining process. In this paper, a new recommender system based on multi-features is introduced. Demographic and psychographic features are used to asses similarities between users. The model is built on a collaborative filtering method and addresses three problems: sparsity, scalability and cold-star. The sparsity problem is tackled by integrating users-documents relevant information within meta-clusters. The scalability and the cold-start problems are considered by using a suitable probability model calculated on meta-cluster information. Moreover, a weight similarity measure is introduced in order to take into account dynamic human being preferences behaviour. A prediction score for generating recommendations is proposed based on the target user previous behaviour and his/her neighbourhood preferences on the target document.

In recent years, wireless sensor networks have many potential applications for both civil and military tasks. However, sensor networks are susceptible to many types of attacks because they are deployed in open and unprotected environment. So it is necessary to use effective mechanisms to protect sensor networks against many types of attacks on routing protocols. Intrusion detection is one of the major and efficient defense methods against attacks in a computer network and system. Because of different characteristics of sensor networks, security solutions have to be designed with limited usage of computation and resources. In this paper, we proposed a hybrid, lightweight intrusion detection system integrated for sensor networks. Our intrusion detection scheme take advantage of cluster-based protocol to build a hierarchical network and provide an intrusion framework based both on anomaly and misuse techniques. Our scheme can prevent most of routing attacks on sensor networks.

Hyperlink, or shortly link, analysis seeks to model the web structures and discover the relations among web sites or Web pages. The extracted models or relations can be used for the web mining applications, including market researches and various online businesses. It is well known that PageRank of Google’s search engine is one of the most successful stories of link analysis. In this paper, we investigate into the link structures among the sites, each of which is the collection of web pages in the same university domain in Korea. However, the PageRank algorithm cannot be directly applied to the ranking of a relatively small number of sites or communities since the transition probabilities from a node with a low out-degree significantly affect the whole rankings among the sites. We modify the original version of the PageRank algorithm in order to make it fit into the site ranking, we propose a site ranking algorithm, which is a modification of the PageRank algorithm. The experimental results show that our approach to the site ranking performs much better than PageRank.

Various complex systems have an underlying architecture governed by shared organizing principles. We model the natural perceptual schema as a complex system by introducing a hidden variable, called negative schema, based on the idea of Minsky’s negative knowledge. We first show that the negative schema is necessary in recognizing a negated concept and that the positive schema is defined only relative to the negative schema. In the paper, we claim that the schema shares the same underlying architecture of complex systems by proving that the positive and the negative schemas inside the system interact with each other simultaneously and in parallel, and that the suppressor controls the interaction for emerging property.

Since the Wibro service realize mobile network on the public, it has been considered that it is not enough to support real time service at vehicular speed. The standard Fast Mobile IPv6 Handover Protocol using HMIPv6 may guarantee seamless service as long as the Mobile Node moves in the same domain MAP however it does not regard fast handover over inter-MAP domain. Thus Macro Mobility Handover in HMIPv6 was proposed to reduce handover latency in inter-MAP domain. But it is still not enough to support real-time service. So we propose an Improved FHMIPv6 over 802.16e network to reduce the overall handover latency. We embedded Layer 3 handover messages of the FHMIPv6 into the Layer 2 handover messages. So the MN is able to finish overall handover procedure earlier in our scheme. The numerical results show the performance of IFHMIPv6 has improved 32% in comparison with FHMIPv6.

In proportion to the increase of a number of various wireless devices and development of wireless access technologies, mobile users desire to access the Internet regardless of their location at anytime. In Hierarchical Mobile IPv6 (HMIPv6) when a mobile node (MN) moves from a MAP domain to another, it can experience disruption of connection as well as packet loss due to a long handover latency. To cope with these problems, we propose an advanced macro mobility scheme to reduce handover latency and packet loss. We adopt the fast handover scheme from FMIPv6 to optimize the performance of the proposed scheme. In this paper, we analyze the handover latency for various protocols and compare to our scheme with analytical model. The results show that the proposed scheme is better approach to handle the mobile node’s movement than the other protocols.