Earticle

Queueing models are good models for fragments of communication systems and networks, so their investigation is interesting for theory and applications. Theses queues may play an important role for the validation of different decomposition algorithms designed for investigating more general queueing networks. So, in this paper we illustrate that the batch size distribution affects the loss probability, which is the main performance measure of a finite buffer queues.

With the proliferation of mobile terminals, use of the Internet in mobile environments is becoming more common. To support mobility in these terminals, Mobile IPv4 is proposed and represents the standard in IPv4 environments. Authentication should be mandatory, because mobile terminals can utilize Internet services in any foreign domain. Mobile IPv4 provides symmetric key based authentication using the default HMAC-MD5. However, symmetric key based authentication creates a key distribution problem. To solve this problem, public key based authentication mechanisms have been proposed. In this paper, the performance of each of these mechanisms is evaluated. The results present that, among these mechanisms, partial certificate based authentication has superior performance, and certificate based authentication has the worst performance. Although current public key based authentication mechanisms have lower performance than symmetric key based authentication, this paper presents the possibility that public key based authentication mechanisms may be used for future mobile terminal authentication.

Kerberos is system that offer authorization in internet and authentication service. Can speak that put each server between client and user in distributed environment and is security system of symmetry height encryption base that offer authentication base mutually. Kerberos authentication is based entirely on the knowledge of passwords that are stored on the Kerberos Server. A user proves her identity to the Kerberos Server by demonstrating Knowledge of the key. The fact that the Kerberos Server has access to the user's decrypted password is a rwsult of the fact that Kerberos does not use public key cryptogrphy. It is a serious disadvantage of the Kerbercs System. The Server must be physically secure to prevent an attacker from stealing the Kerberos Server and learning all of the user passwords. Kerberos was designend so that the server can be stateless. The Kerberos Server simply answers requests from users and issues tickets. This study focused on designing a SIP procy for interworking with AAA server with respect to user authentication and Kerberos System. Kerberos is security system of encryption base that offer certification function mutually between client application element and server application element in distributed network environment. Kerberos provides service necessary to control whether is going to approve also so that certain client may access to certain server. This paper does Credit-Control Server's function in AAA system of Diameter base so that can include Accounting information that is connected to Rating inside certification information message in Rating process with Kerberos system.

We propose a novel programmable miniature vision module based on a custom designed analog VLSI (aVLSI) chip. The vision module consists of the optical flow vision sensor embedded with commercial off-the-shelves digital hardware; in our case is the Intel XScale PXA270 processor enforced with a programmable gate array device. The aVLSI sensor provides gray-scale imager data as well as smooth optical flow estimates, thus each pixel gives a triplet of information that can be continuously read out as three independent images. The particular computational architecture of the custom designed sensor, which is fully parallel and also analog, allows for efficient real-time estimations of the smooth optical flow. The Intel XScale PXA270 controls the sensor read-out and furthermore allows, together with the programmable gate array, for additional higher level processing of the intensity image and optical flow data. It also provides the necessary standard interface such that the module can be easily programmed and integrated into different vision systems, or even form a complete stand-alone vision system itself. The low power consumption, small size and flexible interface of the proposed vision module suggests that it could be particularly well suited as a vision system in an autonomous robotics platform and especially well suited for educational projects in the robotic sciences.

In this paper, we introduce the backward solution of nonlinear wave equation for denoising. The PDE method is approved about 4 PSNR value compare with any convolution method. In neuro images, denoising process using proposed PDE is good about 0.2% increased Voxel Region.

This study applies the Analytic Hierarchy Process (AHP) to evaluate service quality of Third-Party Logistics (3PL) service providers. For this, we first conceptualize five dimensions of 3PL service quality (i.e. tangibles, reliability, responsiveness, assurance and empathy). We then apply the AHP method to determining the relative weights of five service quality dimensions and eventually selecting the best 3PL service provider. To implement this idea in practice, we conduct an empirical study on four companies providing 3PL services in Korea.

Especially, system security is very important in the ubiquitous environment. This paper proposes a protecting scheme for security policies in Firewall and intrusion detection system (IDS). The one-way hash function and the symmetric cryptosystem are used to make the protected rules for Firewalls and IDSs. The proposed scheme could be applied in diverse kind of defense systems which use rules.

Most of the small and medium industries rather focus on immediate problems and how to properly maintain organizational matters and existing system than the strategic and operational use of Information Technology when they deal with applications and operation of Information System. This study found out that there were few studies on IT outsourcing for small and medium companies in Korea compared to large enterprises' IT outsourcing. Most preceding studies researched the problems of partnership and technical, managerial, and economical success factors for big companies. Small and medium companies have the problems of financial difficulty, organizational scale (40.3%), shortage of manpower for system operation (24.1%), and lack of practical use of managers (8.9%). SMB firms have required support of government for their Informationalization but, we found out amount of companies (41%) not be informed or don't account on government's supporting IT of SMB programs. In addition, Range and Contents of outsourcing, Reputation of Outsourcing vendor, Reliability of maintaining were selected as CSFs of SMB IT outsourcing. While large corporation staff more considered CEO's willing and inner facts of their companies.

Recently, many organizations in various industries have introduced e-businesses for the purpose of adding value to their businesses. However, due to no comparable business models to e-business in the past, there are no reliable yardsticks to predict the performance of an e-business. This paper considers an environmental change analysis as a means to resolve this difficulty. System Dynamics (SD) could be a useful tool to generate effective results by examining the e-business model. SD model is developed to analyze the effects of an e-sales channel which was appended to the existing sales channels in the steel manufacturing industry. The results show an increase in average price and sales volume through the use of an auction process on the e-marketplace. Stocking expenses are reduced as well by the increase of the sales turnover. A possible scenario was adopted to the developed simulation model and investigated strategic issues to draw desirable strategies with market changes.

Supply chain optimization is one of the most important components in the optimization of a company's value chain. This paper considers the problem of designing the supply chain for a product that is represented as an assembly bill of material (BOM). In this problem we are required to identify the locations at which different components of the product arc are produced/assembled. The objective is to minimize the overall cost, which comprises production, inventory holding and transportation costs. We assume that production locations are known and that the inventory policy is a base stock policy. We first formulate the problem as a 0-1 nonlinear integer programming model and show that it can be reformulated as a 0-1 linear integer programming model with an exponential number of decision variables.

Lots of researches have been focusing on ubiquitous computing which means wherever, whenever, whatever the required information must be accessible. In ubiquitous computing environment, ubiquitous sensor network (USN) is the basis technology for gathering and transferring the required information. However sensor network characteristically has more severe vulnerability than the existing networks do. The paper presents operation of secure protocols for delivering information in secure in ubiquitous computing environment and show improvement of the secure transferring protocol.

digitalized. To make it worse, the development of various contents that be illegally copied and plagiarized are resulting in the increasing infringement on and the plagiarism of the intellectual property. This dissertation tries to put forth the method and the theory to effectively detect any plagiarism of the source code of programs realized in various languages. This dissertation analyzes the advantage and disadvantage of the plagiarism test software, and especially, presents a method to detect possible plagiarism by using the Pattern Matching to overcome its disadvantage. And it also intends to introduce more developed automatic detection system by overcoming the problems with the method of Pattern Matching.

Vast amount of information is generated and shared in this active digital As the digital informatization is vividly going on now, most of documents are in digitalized forms, and this kind of information is on the increase. It is no exaggeration to say that this kind of newly created information and knowledge would affect the competitiveness and the future of our nation. In addition to that, a lot of investment is being made in information and knowledge based industries at national level and in reality, a lot of efforts are intensively made for research and development of human resources. It becomes easier in digital era to create and share the information as there are various tools that have been developed to create documents along with the internet, and as a result, the share of dual information is increasing day in and day out. At present, a lot of information that is provided online is actually being plagiarized or illegally copied. Specifically, it is very tricky to identify some plagiarism from tremendous amount of information because the original sentences can be simply restructured or replaced with similar words, which would make them look different from original sentences. This means that managing and protecting the knowledge start to be regarded as important, though it is important to create the knowledge through the investment and efforts. This dissertation tries to suggest new method and theory that would be instrumental in effectively detecting any infringement on and plagiarism of intellectual property of others. DICOM(Dynamic Incremental Comparison Method), a method which was developed by this research to detect plagiarism of document, focuses on realizing a system that can detect plagiarized documents and parts efficiently, accurately and immediately by creating positive and various detectors.

This paper suggests the Ethernet aggregation to XGMII framing procedure (EAXFP) mechanism to economically combine the traffic adaptation technology with the link aggregation method in designing 10 Gigabit Ethernet (10 GbE) interfaces. This design sidesteps the data-loss issues that can result from designing an interface with only one link. The most critical issue in relation to the link aggregation interface is the algorithm used to control frame distribution between the ten ports. The proposed EAXFP mechanism offers an efficient link aggregation method as well as an efficient frame distribution algorithm, which maximize the throughout of the 10 GbE interface. In the experiment and analysis of the proposed mechanism, it was also discovered that the 10 GbE interface that uses the proposed EAXFP mechanism significantly reduced the packet loss rate. When there will be heavy traffic loads come about in the future, the proposed EAXFP mechanism assures an efficient and economical transmission performance on the router system.

medicine system. The mobile medicine system contains (i) blood pressure and body temperature measurement value, (ii) ECG medical signals measured by the electrocardiogram device, (iii) mobile patient's history, (iv) G.729 audio signal, MPEG-4 CCD sensor video signal, and JPEG2000 medical image. By the help of the multi-code CDMA spread spectrum communication system with downlink power control scheme and unequal error protection strategy, it is possible to transmit mobile medicine media and meet the quality of service. Numerical analysis and simulation results show that the system is a well transmission platform in mobile medicine.

In order to support ultrawide-band signal generation for low rate WPAN, several types of signal generation mechanisms are suggested such as Chaos, Impluse, and Chirp signals by the activity of IEEE 802.15.4a. The communication system applied chaos theory may have ultrawide-band characteristics with spread spectrum and immunity from multipath effect. In order to use the advantage of chaotic signal generation, we introduce the system implementation of communication and networking systems with the chaos UWB signal. This system may be composed of mainly three parts in hardware architecture : RF transmission with chaotic signal generation, signal receiver using amplifiers and filters, and 8051 & FPGA unit. The most difficult part is to implement the chaotic signal generator and build transceiver with it. The implementation of the system is devidced into two parts i.e. RF blocks and digital blocks with amplifiers, filters, ADC, 8051 processor, and FPGA. In this paper, we introduce the system block diagram for chaotic communications. Mainly the RF block is important for the system to have good performance based on the chaotic signal generator. And the main control board functions for controlling RF blocks, processing Tx and Rx data, and networking in MAC layer.

It will not be impossible to develop an Information Systems and Information Technologies (IS/IT) program and a curriculum that represents the true needs of the IS/IT industry until IS/IT educator, reduce the gap perception and IS/IT practitioner's perception of IS/IT knowledge and technical skills that the industry might need. This paper represents and analysis of perceptions about IS/IT knowledge and skills that IS/IT practitioners might consider important. This study is based in Korean. The findings give us a very important lesson for IS/IT academicians that their understanding about the required knowledge and skills for the IS/IT career is not in line with that of IS/IT industry. Classifies the critical knowledge/skill set according to content or domain of knowledge by means of a survey. This is conducted in accordance with what IS/IT practitioners and educators can easily relate. The survey uses this approach and includes four broad categories of critical information Systems and Information technologies (IS/IT) knowledge/skills: IS/IT technology knowledge/skills, organizational and societal knowledge/skills, interpersonal knowledge/skills, and personal trait knowledge/skills.

A loop RFID tag antenna and a dipole RFID antenna with a T-matching method have been designed. The characteristic of loop and dipole with T-matching antenna structures of RFID tag antennas have been studied. The impedance of different sizes of loop and dipole antenna structures are found. This paper shows parametric research of loop RFID antenna structure and RFID dipole antenna with T-matching method to match the impedance of commercially available RFID chips.

Domestic enterprises are surveyed and analyzed to find the empirical relationship between environmental characteristics and electronic commerce(EC) performance. Dynamism, hostility and heterogeneity are selected as environmental characteristics. EC performance is articulated as EC utilization, EC satisfaction and EC usefulness. Empirical test presents that dynamism has a statistically significant relationship with EC performance except EC usefulness, but hostility and heterogeneity have no statistically significant relationship with EC performance. The impact of industry type on environmental characteristics and EC performance is also tested.

Recently, many companies and consumers are using Internet to sell and buy goods and manage their businesses. And for most companies, they have Electronic Commerce system and Enterprise Resource Planning (ERP) system. But the two systems manage separately and the data are not integrative. So it is hard to mangement the system alike and the costs may be higher than the system which has intergrated information. ebXML-based Electronic Catalog (e-Catalog) can provide intergrated information. In this paper, we took a manufacturing industry company for example. We planned to construct the e-Catalog System, analyze the products of the company as well as design e-Catalog system using ebXML to connect EC with ERPs.

While the goal of new IT adoption in small and medium sized firms is to choose an optimal system to fit with their own environments and conditions, that of IT post-adoption usage is to fully implement new IT and maximize their benefits from it. Therefore, the decision-making environments of new IT adoption is definitely different from those of post-adoption. Also, The direct experience of IT usage can provide some learning effect and the change of users' beliefs on new IT. From this point of view, this study attempts to figure out the differences of influencing factors on IOS usage intention between adopters and non-adopters. The results show that there are clear differences of influencing factors between two groups. Non-adopter group shows that perceived financial cost and ability of use have significant influences on IOS usage intention, while relative advantage and perceived risk in adopter group have statistically significant influences on post-adoption usage of IOS.

Virtual Communities are many and varied have been around for a number of years now. Cyworld has all the makings of a successful website, with its unique and profitable business model. Our purpose in studying Cyworld is two fold ; we want to know the motivations people have for using the service and why they are willing to pay to use it. This study is based on motivation theory and flow theory to enhance our understanding of Cyworld user's behavior.

Recently, the area of ubiquitous computing has gained a great attention both in academics and in industry. However, previous research on this area attempts the categorization in part of context and the critical success factors (CSFs) and services of ubiquitous computing unsuccessfully. The purpose of this paper is to propose a framework on ubiquitous computing, including its context, roadmap, CSFs, and services.