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The mobile computing paradigm is becoming a reality due to the advent of mobile devices such as, PDA and Smart Phones having wireless interface to WWW. As a result, the high-end applications related to mobile multimedia and distributed digital contents have gained much attention. However, the existing distributed and mobile file systems are not adequately suitable to support such applications handling the challenges offered by mobile computing systems. In this paper, the concept, design architecture and consistency model of Virtual memory based Mobile Distributed File System (VMDFS) are proposed based on thin-mobileclient/ fat-server model. VMDFS creates the migrate-able virtual memory based mobile file system on top of the disk file systems of remote servers employing dynamic frame-lock to reduce network latency and to attain high-performance. An abstract mathematical model of VMDFS is constructed and associated properties are evaluated. The kernel-level implementation framework of VMDFS is illustrated based on Linux 2.4.22. The network paging latencies for LAN, Wireless VPN and 2.5G GPRS are measured experimentally. The results indicate that VMDFS is realizable.

Multimedia provisioning over Wi-Fi networks is a complex task that should consider also novel issues stemming from the specific behavior of IEEE 802.11 protocols. In particular, we claim the need for visibility of context data about the IEEE 802.11 performance anomaly, i.e., the situation where even a single node located at the borders of the coverage area of a Wi-Fi access point produces a relevant degradation in the connectivity quality of all other nodes in the area. The paper proposes a novel application-level middleware that counteracts IEEE 802.11 anomaly without imposing any modification in standard Wi-Fi protocols, thus permitting to maintain the current wide base of installed equipment. Our middleware portably detects anomaly situations via decentralized standard mechanisms available at clients; anomaly awareness is used to promptly react with application-level management operations (flow quality downscaling and traffic shaping) that both preserve the goodput at nodes in well-covered areas and minimize quality degradations at clients generating the anomaly. The reported experimental results point out the feasibility of application-level middleware approaches also in the challenging multimedia area.

It is the requirement of the next generation communication systems that devices should provide all existing and future communication services in integral way. A novel distributed wireless VoIP infrastructure based on SIP protocol, WiFi, and smart devices is proposed in this paper. The proposed architecture of the infrastructure is simple, manageable, stable, and extendable. The prototype test bed is an Infrastructure of distributed wireless VoIP Server based SIP, which provides text, voice and video communication to both wired and wireless devices. One of the main characteristic of this model is roaming and mobility. User authentication is centralized, and SIP server uses remote centralized AAA server for user authentication . Thus mobile users don’t need to worry about roaming and changing the Server. The whole architecture is modular, and the reason for isolating the core modules from the extended modules is flexibility and extendibility. At the end of the paper, detailed test approaches ,test results and result analysis of the prototype system are presented. Test results show that the prototype system reach the design goal of this research work..

The particle swarm optimization (PSO) is a new swarm intelligence technique inspired by social behavior of bird flocking. In this paper, the optimal multi-objective particle swarm optimization (OMOPSO) is presented. Since the parameters determine the optimization performance of the algorithm, the uniform design is introduced to obtain the optimal combination of the parameters. Additionally, a new crowding operator is used to improve the distribution of nondominated solutions, and ε-dominance is used to fix the size of the set of final solutions. OMOPSO is applied to optimize the parameters of blind color image fusion. First the model of blind color image fusion in YUV color space is established, and then the proper evaluation metrics without the reference image are given, in which a new metrics of conditional mutual information is proposed. Experimental results indicate that the method of blind color image fusion based on OMOPSO realizes the Pareto optimal blind color image fusion.

In this paper, we describe an automatic people-counting system based on a wireless sensor network at a mountain area. Several people-counting systems have been proposed separately. However, these systems are not suitable to a place such as the mountain area because of a few problems. In this paper, we develop a system which can count the number of visiting people and sense environment information to protect an ecosystem of the mountain area. For people-counting in the mountain area, our system uses two photo-beam sensors, a big rechargeable power and a solar power. Our people-counting method can automatically count the number of incoming and outgoing people at a special point in real time. Moreover, the environment sensors measure environment information at the mountain area, and constitute the wireless sensor network with photo-beam sensors. To establish this system in Korea mountain, we did tests on the wireless communications range and the reliability of peoplecounting. By the testing results, we found that the developed system is suitable within 200 meters for effective wireless communications in Korea mountain. When the width of a path up a mountain is within 1.5m, the reliability of people-counting in our system is over 90%. The number of visiting people and the measured environment information are used to manage and control the mountain.

The purpose of this study is to find the relationships between personal demographic attributes and long distance travel mode choices based on the Artificial Intelligence technique-rough set theory. Rough set theory can learn and refine decision rules or hidden facts from the incomplete observed data without the constraints of statistical assumptions. Also the induced decision rules are expressed in natural language, which can help policymakers in the decision making process. In the study, we conducted a survey to collect the peoples’ most preferred travel mode choices for the given destination and people’s demographic information. We analyzed the observed data based the rough set theory, calculated and discussed the approximation, core, reduct and rules of the data. The results of validation test were very promising, which showed that the induced decision rules could represent the relationships between data with the accuracy of 74.59%.

The paper presents an advanced system for railway and road traffic noise monitoring in metropolitan areas. This system is a functional part of a more complex solution designed for environmental monitoring in cities utilizing analyses of sound, vision and air pollution, based on a ubiquitous computing approach. The system consists of many autonomous, universal measuring units and a multimedia server, which gathers, processes and presents data obtained from the distributed measuring units. The results are visualized on numerical maps. The paper contains a functional and technical description of the monitoring system. It describes also the algorithm for moving vehicle detection in video sequences based on a pixel-level difference among the image frames and a continually updated background model utilizing mixtures of Gaussians. The experiments carried out involve the implemented algorithm to the detection of vehicles in the recorded video sequences. The results obtained are illustrated with some examples and discussed.

One of the principal motivations to use the grids computing and data grids comes from the applications using of large sets from data, for example, in High-Energy physics or Life Science to improve the total output of the software environments used to carry these applications on the grids, data replication are deposited on various selected sites. In the field of the grids the majority of the strategies of replication of the data and scheduling of the jobs were tested by simulation. Several simulators of grids were born. One of the most simulators interesting for our study is the OptorSim tool. In this paper, we present an extension of the OptorSim simulator by a consistency management module of the replicas in the Data Grids. This extension corresponds to a hybrid approach of consistency, it inspired by the pessimistic and optimistic approaches of consistency. This suggested approach has two vocations, in the first time, it makes it possible to reduce the response times compared with the completely pessimistic approach, in the second time, it gives a good quality of service compared with the optimistic approach.

For H.264/SVC, different layers or frames have different order of precedence according to their importance on video quality and the decoding process. Network should provide more protection for high priority layers or frames when SVC stream is transmitted over IP network. This paper proposes an active queue management algorithm based on priority dropping and PID algorithm, called PID_PD, which first drops the least important packets when network congestion arises. PID_PD implements differentiated service in IP layer to provide high quality video for end user. In addition, PID_PD does not create a side effect for the performance of control system. In this paper, we use BCC (Binomial Congestion Control) as source rate control protocol. BCC and PID_PD form a close-loop control system. By using a classic control theoretic approach to analyze the stability of the close-loop system, we present a method to decide the PID_PD parameters. Simulation shows PID_PD can protect important video data well, lower the disturbance of background flow, and decrease the packet loss rate of SVC flow.

POS system is a supply net administration system for customer management. It becomes an essential element in distribution industry to construct database, and uses XML-Encryption to complement PKI techniques and standards for security. POS system has four advantages. First, it does not have to be certificated and transmit data every time because there is no server. Second, it can integrate database by using XML and improve portability of program itself. Third, transmitted data is safe because of XML-Encryption. Fourth, processing speed will be faster because it gathers data from data transmission. All systems should be designed by considering security level to reduce non-necessary burdens. The concept of security level management was developed by Dr. Tai-hoon Kim a few months ago, and this paper used this idea. In this paper, Security Level 1st environment was considered to design POS systems.