• Journal of the Institute of Convergence Signal Processing
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• v.11 no.1
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• pp.53-62
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• 2010

Recently, various industrial embedded systems including vehicles controlled electronically are evolving to distributed multi-micro controller system. Accordingly, there is a need for standard CAN(Controller Area Network) protocol that ensures high stability and reliability of communication and is simple to construct object-oriented system with high control efficiency. CAN communication interface used general-purpose processor doesn't have many limitations in various application development because of fixed hardware architecture. This paper design and implement a CAN communication interface system based on FPGA. It is verified function and performance of system through monitoring communication with existing AT90CAN128 controller. Implemented CAN communication interface can be reused in development of application systems based on FPGA. And it provides low-cost, small-size and low-power design advantages.

• The Journal of the Korea Contents Association
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• v.5 no.1
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• pp.101-108
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• 2005

In this paper, we propose a design methodology of RESTful SOAP-based web services which try to solve extensibility problem of SOAP-based Web service by adopting REST concept into SOAP. And, we apply the proposed RESTful SOAP-based web services design methodology in constructing slip data processing web services, compare it with simple SOAP-based slip data web services, and try to propose a model for building Web Services in the future. REST is a model about architecture type of web distributed computing , the biggest distributed application in the world. In REST, identification of resources are made by URI, states(resources) are represented by document described by XML and transferred through HTTP our proposed RESTful SOAP-based web services are expected to contribute to constructing useful world wide web services which are essential in building E-Commerce society.

• Journal of KIISE:Software and Applications
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• v.26 no.9
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• pp.1105-1113
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• 1999

객체 지향 소프트웨어의 확장과 더불어 소프트웨어의 재사용성의 중요도가 부각되면서 소프트웨어를 콤포넌트 단위로 구현하는 추세이다. 따라서 콤포넌트 기반의 소프트웨어 개발에서의 통합 테스트가 중요한 이슈로 떠오르고 있다. 그러나 콤포넌트들의 통합 테스트에 대한 연구는 미흡한 상태이다. 본 논문에서는 UML을 기반으로 체계적인 통합 테스트 모형을 제안하고. 나아가 본 논문에서는 "멀티미디어 정보처리 시스템"의 사례를 본 논문의 콤포넌트 통합 테스트 모형에 적용한 결과를 분석하여 기술한다. 콤포넌트 통합 테스트 모형은 UML(Unified Modeling Language)의 순서도(sequence diagram)와 협력도(collaboration diagram)를 이용하여 전체 시스템에서 UML의 사건흐름을 구성하는 콤포넌트들 사이의 인터페이스 영역에 존재하는 오류들을 추출한다. 그리고 UML을 기반으로 통합 테스트를 수행함으로써, 테스트 준비 작업을 줄이고, 기존의 UML 지원 도구들과 연계하여 테스트 자동화 도구의 구현을 앞당길 수 있다. 또한 시스템의 순차적 흐름 뿐 아니라, 동시에 수행되는 흐름에 대한 정보까지 모두 수용하여 테스트함으로써, 콤포넌트 기반의 분산 환경의 특성에 적합하다. Abstract As the object-oriented approach to software development becomes more mature, software development from pre-existing, independently developed components becomes an important aim of software engineering. Therefore, integration testing becomes an important aspect of component-based software development. However, there has been little work done in the area of the component-based integration testing. In this paper, we propose the "component integration test model" which is based on UML. Furthermore, we describe a case study on "Multimedia Information Processing System" conducted to analyse the result from which our model is applied. Our model extracts the faults, which exist in interfaces of components, using sequence diagram and collaboration diagram of UML(Unified Modeling Language). As our model is based on UML, the preparation effort for testing is reduced and its test-tools can be implemented more easily through linking existing UML tool. And our model accepts the information of concurrent flow represented by collaboration diagram as well as sequential flow, so it is more suitable to component-based distributed environment.based distributed environment.

• Journal of the Korea Computer Graphics Society
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• v.3 no.2
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• pp.1-13
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• 1997

Two factors are required for a virtual reality system; realism and immersion. Since realism is determined primarily by the realistic image, objects in a virtual environment should be represented with details by their own characteristics. Also, reflection on light must be considered. On the other hand, immersion is defined as realistic movements and fast interactions. Thus, virtual environment should be rendered as fast as possibl. Regular frame rate should also be kept to make moves as intended by the user. In a complex virtual environment composed of objects with various levels, the appropriate level for individual object should be assigned according to the view point, in other words, the selection of level-of-detail is needed. In this paper, the problem of determining the levels of detail is formalized in terms of error, cost and L -distance. Error is defined as the difference between the current level image and the highest level image, cost as rendering time, and L-distance as the level difference between the previous and the current level. To solve this problem, a new method called the well-distributed adaptive algorithmis proposed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.6C
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• pp.535-543
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• 2002

In order to overcome disadvantages of existing centralized network management systems that use simple objects, dynamic object platforms are proposed as alternative systems. So the distributed network management systems are implemented using various distributed platform such as CORBA and Java-RMI. Subsequently mobile agent-based platforms are proposed. The mobile agent-based platform can additionally provide flexibility and scalability to network management system that CORBA or Java-RMI based platforms do not support. In this paper, we address an architecture to solve the problem of the occurrence of additional traffic by using mobile agent and to save resources of network element. Our proposal in this paper is an efficient network management architecture using motile agents. And we make use of mobile agents for minimizing of traffic that can happen when mobile agents moves. Also we design agents using information architecture of TMN for efficient resource management of network element and improvement of operation performance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.2
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• pp.383-393
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• 2010

DVC (Distributed Video Coding) allows us to explore the video statistics at the decoder side, resulting in a less complex encoder and more complex decoder. In this approach, it is important to generate a good prediction to the current Wyner-Ziv frame, called side information, which plays a crucial role in the overall performance of a DVC system. Conventional MCFI (motion compensated frame interpolation) techniques, which explore temporal correlations between neighbor frames of the current frame, preform the block-based or object-based motion estimation, but, they do not include the basis frame for the Wyner-Ziv frame. This paper proposes an efficient way to get better side information, by finding the average frame between neighbor frames and by comparing adaptively the candidate blocks. Through computer simulations, it is shown that the proposed method can improve the performance up to 0.4dB and provide better subjective and objective visual qualities in Wyner-Ziv CODEC.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06d
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• pp.235-237
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• 2006

최근 분산 해쉬 테이블(Distributed Hash Table)을 이용한 구조적 P2P(peer-to-peer) 시스템에서 로드 밸런싱에 관한 연구가 활발하게 진행되고 있다. 일반적으로 P2P 시스템에서의 피어들은 빈번하게 참여하는 동시에 탈퇴하기도 하기 때문에 로드의 불균형이 심화되는 문제점이 있다. 본 논문에서는 구조적 P2P 시스템에서 피어의 참여와 탈퇴 시 발생하는 가상서버의 이동을 효과적으로 관리하는 기법인 PALB(Peer Activity-aware Load Balancing)를 제안한다. 제안하는 PALB는 피어의 참여, 탈퇴 시에 발생하는 로드 불균형을 해결하기 위하여 적절한 수의 가상서버를 가장 적합한 피어에게 분산시킨다. 또한 이전 연구에서 제안한 OLAB(Object Lifetime-aware Load Balancing)와 함께 사용하여 로드 밸런싱 성능을 향상시킬 수 있다. PALB의 성능 평가를 위하여 동적 P2P 시스템 환경을 구성하였고, 피어와 오브젝트의 랜덤 데이터 셋을 이용하여 시뮬레이션을 수행하였다. 시뮬레이션 결과 PALB가 기존의 시스템에 비하여 더 적은 비용으로 더 나은 로드 밸런싱을 수행함을 확인하였다. 또한 OLAB와 동시에 사용하였을 경우, 매우 뛰어난 성능을 보임을 확인하였다.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.3
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• pp.67-78
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• 2013

In this paper, We proposed an development method of application framework for using the precision time protocol(PTP) based on physical layer devices to synchronize clocks across a network with IEEE1588 capable devices. The algorithm was not designed as a complete solution across all conditions, but is intended to show the feasibility of such a for the PTP(Precision Time Protocol) based on time synchronization of heterogeneous network between devices that support in IEEE 1588 Standard application framework. With synchronization messages per second, the system was able to accurately synchronize across a single heavily loaded switch. we describes a method of synchronization that provides much more accurate synchronization in systems with larger networks. In this paper, using the IEEE 1588 PTP support for object-oriented modeling techniques through the 'application framework development Development(AFDM)' is proposed. The method described attempts to detect minimum delays, or precision packet probe and packet metrics. The method also takes advantage of the Tablet PC(Primary to Secondary) clock control mechanism to separately control clock rate and time corrections, minimizing overshoot or wild swings in the accuracy of the clock. We verifying the performance of PTP Systems through experiments that proposed method.

• KSCI Review
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• v.14 no.2
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• pp.199-204
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• 2006

The sensor network is a wireless network of the sensor nodes which sensing, computation and communication ability. Each sensor nodes create the data items by sensor nodes above one. Like this feature, the sensor network is similar to distributed data base system. The sensor node of the sensor network is restricted from the power and the memory resources is the biggest weak point and is becoming the important research object. In this paper, We try to see efficient sensor data stream management method and efficient query processing method under the restricted sensor network environment.

• The Transactions of the Korea Information Processing Society
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• v.3 no.5
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• pp.1027-1036
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• 1996

X.500 Directory is an application level protocol in the Open Systems Interconnection(OSI) 7 layer's reference model adopted by the international Standards Organization (ISO). It manages effectively needed information for the communication service, and is a service to support the functions that the user can approach conveniently. Tourist information is distribution on several locations. The access of distributed information is similar to X.500 directory service. Therefore, we design of Tourist Information System(TIS) and directory schema using X.500 directory services. To define tourist information, we also propose Directory Information Tree(DIT) of locality architecture and several new object classes, such as museum, mountain, sea, hotel, etc.