Earticle

In a dynamic database where the new transaction are inserted into the database, keeping patterns up-to-date and discovering new pattern are challenging problems of great practical importance. This may introduce new association rules and some existing association rules would become invalid. Thus, the maintenance of association rules for dynamic database is an important problem. In this paper, false positive itemset algorithm, which is an incremental algorithm, is proposed to deal with this problem. The proposed algorithm uses maximum support count of 1-itemsets obtained from previous mining to estimate infrequent itemsets, called false positive itemsets, of an original database. False positive itemsets will capable of being frequent itemsets when new transactions are inserted into an original database. This can reduce a number of times to scan an original database. This paper also proposes a new updating and pruning algorithm that guarantee to find all frequent itemsets of an updated database efficiently. The simulation results show that the proposed algorithm has a good performance.

Though security is nothing new, the way that security has become a part of our daily lives today is unprecedented. Today, steganography is most often associated with the high-tech variety, where data is hidden within other data in an electronic file. Steganography is hidden writing, whether it consists of invisible ink on paper or copyright information hidden in an audio or video file. This work has as purpose to expand the field of applicability of the steganography from the classical informatics to the quantum one.

Natural language watermarking (NLW) is a kind of digital rights management (DRM) techniques specially designed for natural language documents. Watermarking algorithms based on synonym substitution are the most popular kind, they embeds watermark into documents in linguistic meaning-preserving ways. A lot of work has been done on embedding, but only a little on steganalysis such as detecting, destroying, and extracting the watermark. In this paper, we try to distinguish between watermarked articles and unwatermarked articles using context information. We evaluate the suitability of words for their context, and then the suitability sequence of words leads to the final judgment made by a SVM (support vector machine) classifier. IDF (inverse document frequency) is used to weight words’ suitability in order to balance common words and rare ones. This scheme is evaluated on internet instead of in a specific corpus, with the help of Google. Experimental results show that classification accuracy achieves 90.0%. And further analysis of several influencing factors affecting detection effects is also presented.

Over the past few years, several backoff algorithms such as Exponential Increase Exponential Decrease (EIED) and Adaptive Enhanced Distributed Coordination Function (AEDCF)) have been proposed for wireless local area networks to improve channel access. We propose a new backoff technique that monitors the number of backoff counter pauses experienced and modifies the contention window accordingly. We evaluate and compare the performance of our proposed approach with EIED and AEDCF channel access techniques. Our simulations results, obtained under different network conditions, show improved performance for metrics such as the fairness index and end-to-end delay.

In order to protect Internet users from various attacks such as worms, viruses and other intrusions, signature-based intrusion detection system (IDS) should be deployed at the critical part of the network with rapid response for updating newly emerged attack signatures and containing the spread of worms or viruses at their early stage. The processing speed of one IDS cannot achieve the throughput requirement in the core networks because of the pattern matching, the key operation for signature-based IDS, is complex and time consuming. In this paper, it argues that if the signature set is shared by multiple IDSs, a packet needs to be checked once and once only by one of the IDSs, so traffic load can be redistributed among the IDSs to avoid local congestion. Packet marking is used to indicate the status of this packet utilized by collaborative IDSs, and a redistribution strategy named inner logical ring (ILR) is built among IDSs to redistribute the traffic load. Meanwhile, caching scheme is used to keep sequence for packets belonging to the same flow. This collaborative distributed IDS is robust with rapid response to various attacks, and the detection throughput is significantly increased from the throughput of the weakest IDS to the summation of all the collaborative IDSs.

The improvement of the communication systems is conducted through communication protocol engineering and optimization process. This paper presents an effort to upgrade the IEEE 802.16 and IEEE 802.16e protocol performance regarding the delay during subscriber network entry or base station handover. Our communication protocol engineering process of WiMax protocol and its optimization resulted in a new UCD-aware initial ranging transmission opportunity slots distribution. Using an analytical and numerical performance evaluation, we prove the relevance of the new algorithm and the increase of the IEEE 802.16-based network performance.

Intelligent appliances with multimedia capability have been emerging into our daily life, thanks to the fast advance of computing technology and the wide use of the Interne. Smart home is one of the most prominent areas of intelligent appliances. Kitchen is one of the places where such intelligent appliances have been used. Since modern life style is driving people spending less time on cooking healthy food at home, an enjoyable and healthy life style can be assisted with an intelligent kitchenware such as a smart fridge. In this paper we introduce a novel idea of the smart fridge which can enable better nutrition and enhance health. It is designed for managing items stored in it and advising its users with cooking methods depending on what kind of food is stored. More importantly, it can perform other actions such as dietary control, nutrition monitoring, eating habit analysis, etc. The characteristics, functions and design details of the smart fridge are presented in details. We are confident that such a smart fridge will be an important component in future smart home.

With the widespread penetration of broadband accesses, many multimedia applications, such as video surveillance, on-demand video streaming, IPTV and news broadcast are emerging. Since video streaming applications on the Internet generally have very high bandwidth requirements and yet are often unresponsive to network congestion. In order to avoid congestion collapse and improve video quality, these applications need to respond to congestion in the network by deploying adaptive control mechanisms. In this paper, we present a receiver-based, bandwidth estimation rate control mechanism with content-aware probability retransmission to limit the burden on the congested network. Like the TCP Friendly Rate Control (TFRC) protocol, we compute the sending rate as a function of the loss event rate and round-trip time. Considering the different importance of three distinct types of frames in Standard MPEG encoders, we divide data packets into three grades coarsely and adopt adaptive probability retransmission strategy to assure video playback quality. It is an extension of TCP friendly congestion control. This paper describes the smooth rate algorithm and probability retransmission mechanism. The result of experiments with competing TFRC specification demonstrates the proposed approach reaches a higher throughput and higher PSNR than TFRC congestion control algorithms especially on the bottleneck links.

We have presented an 2()Om time algorithm for locating the g-centroid for Ptolemaic graphs, where n is the number of edges and m is the number of vertices of the graph under consideration [6]. If the graph is sparse (i.e. =()mOn) then the algorithm presented will output the g-centroid in quadratic time. However, for several practical applications, the graph under consideration will be dense (i.e. 2()mOn) and the algorithm presented will output g-centroid in 4()On time. In this paper, we present an efficient 3()On time algorithm to locate the g-centroid for dense Ptolemaic graphs.

Medium access control protocols for wireless sensor networks are almost always designed to be energy efficient. One mechanism used to reduce energy expenditure is to periodically turn off the radio receivers of the sensor nodes in a coordinated manner. The nodes with radio receivers turned off are said to be in the sleep mode. Nodes form virtual clusters based on common sleep schedules. However, protocols like the widely used S-MAC may require some nodes to follow multiple sleep schedules causing them to wake up more often than the other nodes. This paper demonstrates in some wireless sensor networks using S-MAC, a significant proportion of the nodes may have to stay awake much longer than envisaged. A modification of the protocol is then proposed to eliminate the need for some nodes to stay awake longer than the other nodes. The modified version improves the energy efficiency and increases the life span of a wireless sensor network. The paper concludes with the result of simulation studies which indicate that the use of the proposed protocol is expected to increase the life time of wireless sensor networks significantly.

Ubiquitous multimedia computing becomes a major focus in scientific research due to recent flourishing of wireless communication infrastructures such as 3G, WiMax and RFID. There have been many surveys were written based on various ubiquitous multimedia computing related topics. If we can find a way to dash out the latest development in this particular science and technology field, it would be valuable to scientist and researchers. However, it is a challenging task to promptly and efficiently penetrate information for elevating scholastic research efficiency in large volume of information. The goal of this paper is to help us comprehend the scope and major themes of ubiquitous multimedia computing research. Different perspectives and methods were introduced to analyze leading research theme in particular in ubiquitous computing field is proposed. Factor analysis, pathfinder network and context-based ontology techniques are presented to display research directions by clustering scientific papers taken from the ISI web (CiteSeer papers). The results obtained show that recent popular research towards to pursue ubiquitous applications in particular in m-health. The beneficiary of the proposed methods could be for someone new to a specific domain in research study, who wishes to analyze and understand current development status of intended research study field.

The rapid growth in the size of databases and the advances made in Query Languages has resulted in increased SQL query complexity submitted by users, which in turn slows down the speed of information retrieval from the database. The future of high performance database systems lies in parallelism. Commercial vendors’ database systems have introduced solutions but these have proved to be extremely expensive. This paper invistagete how networked resources such as workstations can be utilised by using Parallel Virtual Machine (PVM) to Optimise Database Query Execution. An investigation and experiments of the scalability of the PVM are conducted. PVM is used to implement parallelism in two separate ways: (i) Remove the work load for deriving and maintaining rules from the data server for Semantic Query Optimisation, therefore clears the way for more widespread use of SQO in databases [1,2]. (ii) Answer users queries by a proposed Parallel Query Algorithm PQA which works over a network of workstations, coupled with a sequential Database Management System DBMS called PostgreSql on the prototype called Expandable Server Architecture ESA [1,2,3,4]. Experiments have been conducted to tackle the problems of Parallel and Distributed systems such as task scheduling, load balance and fault tolerance.

For more than a decade now, multimedia developers have usually “ride the waves”, so to speak, with the coming of each generation of microprocessors, which allows their applications, designs and programs to usually running more proficiently, efficiently and effectively. This so-called ‘free’ ride seems to be coming to an end, with results of increases clock speeds, the widening of the gap in processor and memory performance, and the tradeoffs that are needed to meet the former two points, with the new multi-core systems. In this paper, we build upon our previous work within multi-core systems, by proposing a ubiquitous multi-core (UM) design. The goal of such a framework is help researchers to plan and implement their multimedia applications so they can take advantage of speed up computations of multi-core systems and allow real-time multimedia. As our experiments show, our UM system increases performance speeds at an average of 100%, with the average execution cost of 1.4ms, showing that multimedia can use multi-core resources efficiently and effectively.

Nowadays, an increasing number of users get high-speed broadband access to the Internet. These broadband connections make new multimedia applications possible. However, such applications also introduce new Quality of Service (QoS) requirements to the network. Particularly, they require an assured bandwidth even in the case of network overload. The network itself has to provide such bandwidth assurances. This article introduces our concept of a novel network QoS device being located in network edge nodes. It provides a solution for relaxed QoS guarantees to certain flows on a congested link by focussing packet discard on selected flows. However, unlike for IntServ solutions like RSVP, our approach only requires minimal signalling and therefore provides both efficiency and scalability. We furthermore provide a quantitative performance evaluation of our QoS device by using simulations.

Sensors have a function to gather environmental data in sensor networks. They operate by limited, small-size battery depending on applications. Thus there are several kinds of research efforts to make better use of local energy. In this paper, we propose multi-attribute query processing algorithm (Section Bit based scheme (SB)). In the initial setup, routing path is determined based on parent-child relationship by two phases and some partial information (section bits) about the sensing data of their descendant nodes are delivered to the parent in second phase (parent selection phase); that is, an attribute is divided into the same, small size, N sections and one bit is used to each section. By using a small volume of local information, it is possible to protect nodes from propagating messages who does not become the help during query processing. Finally, we measure energy efficiency by counting the number of messages. Experimental results show the improved energy efficiency of the proposed algorithm.

Textual data in electronic documents today around the world have no doubt brought forward all the information one could need and as data banks build up worldwide, and access gets easier through technology, it has become easier to overlook vital facts and figures that could bring about groundbreaking discoveries. This research paper discusses in detail an implementation of Information Extraction and Categorization in the text mining application that we have implemented. To extract terms from the document we have used modified version of Porter’s Algorithm for inflectional stemming. For calculating term frequencies for categorization, we have used a domain dictionary for ‘Computer Science’ domain.

We propose in this paper a formal methodology that makes it possible to check whether a multimedia presentation could behave consistently when it is processed in a resource-limited environment. The approach uses the TSPN model to specify the resource constraints of the environment as well as the time and the synchronization requirements of the presentation. A graph is then built from this specification to check over its consistency. Hence it becomes possible to manage more efficiently the resource availability, and to adapt the content of the presentation so that the latter can be performed consistently under the given environment constraints.