• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제4권6호
• /
• pp.1152-1168
• /
• 2010

Recently, due to the prevalence of various mobile devices and wireless broadband networks, there has been a significant increase in interest and demand for multimedia streaming services such as the mobile IPTV. In such a wireless broadband network, transmitting a continuous stream of multimedia data is difficult to achieve due to mobile stations (MSs) movement. Providing Quality of Service (QoS) for multimedia video streaming applications requires the server and/or client to be network-aware and adaptive. Therefore, in order to deploy a mobile IPTV service in wireless broadband networks, offering users efficient wireless resource utilization and seamlessly offering user perceived QoS are important issues. In this paper, we propose a new adaptive streaming scheme, called MARC (Mobile-aware Adaptive Rate Control), which adjusts the quality of bit-stream and transmission rate of video streaming based on the wireless channel status and network status. The proposed scheme can control the rate of multimedia streaming to be suitable for the wireless channel status by using awareness information of the wireless channel quality and the mobile station location. The proposed scheme can provide a seamless multimedia playback service in wireless broadband networks in addition to improving the QoS of multimedia streaming services. The proposed MARC scheme alleviates the discontinuity of multimedia playback and allocates a suitable client buffer to the wireless broadband network. The simulation results demonstrate the effectiveness of our proposed scheme.

• 디지털융복합연구
• /
• 제10권4호
• /
• pp.199-206
• /
• 2012

최근에 무선 모바일 네트워크상에서 모바일 클라이언트 요청증가로 인하여 스트리밍 미디어 객체를 관리하고 서비스하기 위한 새로운 기법이 제안되고 있다. 본 논문에서는 무선 모바일 네트워크상에서 스트리밍 미디어 서비스의 성능을 향상시키기 위한 새로운 객체 세그먼트 그룹화 방법을 제안한다. 제안된 기법은 분할된 객체 세그먼트들에 대해서 유사성 척도를 수행하며, 유사성 척도를 위해 disjunction, conjunction, 그리고 filtering연산을 수행한다. 이들 연산 척도에 따라 분할된 세그먼트들의 그룹화가 결정되며, 스트리밍 미디어 서비스 성능이 결정된다. 시뮬레이션 결과 제안된 기법은 처리율, 평균 시작지연, 그리고 캐시 히트율의 성능이 우수함을 보였다.

• Journal of information and communication convergence engineering
• /
• 제3권2호
• /
• pp.80-83
• /
• 2005

At present, GML becomes the global standard for the XML encoding of geographic information and is the foundation for the Geo-Web. GML is being applied to a wide range of geographic applications including GIS and location-based services, telematics and intelligent transportation systems. In this paper, we propose the tourism information system for supporting the location based service application. We made an effort to design and implement a GIS computing environment by thin client for mobile web mapping service. We are interested in the GML applications that include traditional GIS system for navigation service and location finder for points of interest (POI) services. This paper summarizes the Tourism information system for location based service of a small area (Han-Ok Village with the Korean traditional houses in Jeonju-city), in which moving travelers can obtain proper information services at the current location associated with traditional monuments, cultural products, food, and conveniences. In the paper, we report on the design of the thin client/server system for a mobile environment. This paper is divided into three parts. First, we give a general overview of the organization of the system and of the important concerns of our design. Second we focus on our system supports for location and POI determination, and design concerns. Finally, we show the graphic user interface of PDA, the procedures involved in the service, and the executed results.

• 한국전자거래학회:학술대회논문집
• /
• 한국전자거래학회 1999년도 학술대회지 vol.2
• /
• pp.587-596
• /
• 1999

In this paper, we introduce the design and development of a web-based workflow management system. The goal of the developed system is to manage business processes occurring in the CITIS (Contractor Integrated Technical Information Services) environment. The system is composed of three main modules: Process Designer, Workflow Engine, and Client modules. The Process Designer is a module that provides the environment for the build-time function, which generates the specifications of processes. The module presents the capability of defining nested process models, which is powerful in particular for designing complex processes. Since the other two modules are implemented using pure Java technology, the Workflow Engine can be implemented on any platform and the Client programs can be accessed via the WWW interface. This indicates that there is no need to install any client programs at the client-sides. Users who has a connection to the internet with web browsers, such as Internet Explorer and Netscape Navigator, and has a proper right of access can utilize the normal client, monitoring client, and system administration client programs. Communications between the workflow engine and the clients are implemented using the java servlet mechanism. The workflow system can serve as the underlying platform of process management tool in CALS and CITIS environments. An example scenario of using the system is presented.

• 산업경영시스템학회지
• /
• 제28권2호
• /
• pp.53-59
• /
• 2005

The environment of If is, currently, on its developing process to the period of Web Service, Ubiquitous, and Telemetics which not only enable computer and internet to be utilized like the water or the air, but also be a new motivating force for its advance. In the respect of various interactions and User Interface, however, it is requiring more demands from its users, and additional functions which cannot be provided by the Web Browser. It is required a new model for supplementary of the limitation of Web_based according to their customers' requirement, to enrich the good aspects of Client-Server System, and accept such various intricate requirements. It is X-Internet, which has born with these requirements. In this study, therefore, it will be suggested a productive development framework and a method to perform the project on Rich-Thin Client Platform of X-Internet Based.

• 한국지능정보시스템학회:학술대회논문집
• /
• 한국지능정보시스템학회 2000년도 춘계정기학술대회 e-Business를 위한 지능형 정보기술 / 한국지능정보시스템학회
• /
• pp.175-184
• /
• 2000

Recently Venture business in the area of information and communication industry is booming. Though Technology classification chart helps the potential entrepreneur through Survey paper and Internet Web Page, its service does not meet the customer demand. Hence Technology Classification system, which is proposed in this paper, will solve this problem by using virtual network among venture, technology experts and potential entrepreneurs. This system supports potential entrepreneurs' decision making for choice of venture business items by using dual client technology, and provides better services than existing systems by linking expert client and customer client, .

• 한국컴퓨터정보학회논문지
• /
• 제7권4호
• /
• pp.16-23
• /
• 2002

최근 컴퓨터의 대용량화 및 고성능화에 따라 GIS에 근거한 다양한 형태의 연구 및 응용 시스템이 개발되고 있다. 또한, 점차적으로 PDA, HPC 등과 같은 Mobile 장치와 GPS와 같은 위치 추적 기술이 발전함에 따라 개인의 위치에 근거한 다양한 서비스가 제공되어지고 있다 이러한 Mobile GIS에서는 처리 능력이 낮은 Mobile 장치의 특성을 고려한 Mobile GIS를 위한 클라이언트의 개발이 필요하다. 이를 위하여, 본 연구에서는 Mobile GIS를 위한 클라이언트 인터페이스를 설계 및 구현하였다.

• 반도체디스플레이기술학회지
• /
• 제3권4호
• /
• pp.13-17
• /
• 2004

As the usage of wireless LAN becomes common in working environment, the number of database systems that support both wired and wireless users increases rapidly. The characteristics of wireless LAN that its speed is slow relatively comparing to wired network and the users in its environment connects to different communication points as they moves creates another challenge to be resolved in database systems. In the environment of hybrid communication systems, wired and wireless for voluminous data amount and a number of users, the two layer architecture of the conventional client-server database systems has limitation in the system performance. This is due to that server is the only point of data service in client-server database systems. In this paper, we discuss a new extended database system architecture that data services are distributed among servers and clients based on user database access patterns in order to improve system performance. We analyze the expected system performance by using simulation technique and prove the practical utilization of the system by demonstrating experimental results.

• 한국조명전기설비학회:학술대회논문집
• /
• 한국조명전기설비학회 2009년도 춘계학술대회 논문집
• /
• pp.259-262
• /
• 2009

IEC 61850 based substation automation system mainly consists of human machine interface and a various of IEDs in charge of protective and control functions of the substation. Both of them should require the performance verification of IEC 61850 communication services because their communication relation is the same as client and server throughout the digital network. This paper shows a research result on the testing method of basic communication interface of the IEC 61850 based client, which was implemented by the analysis of real communication between HMI and IED of IEC 61850 based substation automation system and refereed to IED IEC 61850 conformance test procedures.

• 인터넷정보학회논문지
• /
• 제6권6호
• /
• pp.71-83
• /
• 2005

본 논문에서는 분산시스템 상의 클라이언트로부터 요청되는 객체 자원들에 대한 그룹관리 및 동적 바인딩을 지원하는 분산객체그룹 프레임워크 기반에서 편리하게 분산응용 프로그램을 작성할 수 있는 분산 프로그래밍 도구(Distributed Programming Developing Tool: DPDT)를 개발했다. 분산객체그룹 프레임워크는 서버객체에 대한 그룹등록/철회, 접근권한, 이름과 속성서비스 등의 그룹관리 서비스와 동적 바인딩, 중복객체 지원, 부하 균형화 및 분산응용 간의 연동 등의 분산응용 지원 서비스를 제공한다. 분산응용의 개발 시 본 툴을 이용하여, 서버 프로그램 개발자는 해당 서버시스템 상에서 객체들을 구현하고 객체그룹에 서비스 제공에 필요한 속성정보를 등록하며, 클라이언트 프로그램 개발자도 이들 객체 또는 객체그룹에 대한 접근권한을 받아 허가된 객체들의 속성정보를 사용하여 클라이언트 프로그램을 작성할 수 있다. 이를 위해 본 논문에서는 객체그룹에 대한 정의와 본 툴이 지원하는 분산객체그룹 프레임워크의 구조와 기능들을 살펴보고, 분산객체그룹 프레임워크와 분산응용 간의 편리한 인터페이스를 제공할 수 있도록 구현한 DPDT의 3개의 GUI 환경들에 대해 기술하였다. 마지막으로 DPDT를 사용하여, 서버 프로그램으로 구현된 객체들의 그룹등록/철회, 접근권한 부여 및 클라이언트 프로그램의 작성과정과 개발된 분산응용의 수행결과를 보였다.