• 한국정보통신학회논문지
• /
• 제13권7호
• /
• pp.1453-1458
• /
• 2009

센서 네트워크는 인간이 접근하기 어려운 험난한 지역이나 광범위한 지역의 감시 및 경계 등의 임무를 수행하기 위한 목적으로 그 활용도는 상당히 크다. 본 논문에서는 감시정찰 센서네트워크에서 발생되는 가상의 데이터를 기반으로 네트워크 내의 중요 노드를 파악하고자 한다. 센서 노드로부터 전송되는 데이터는 센서의 측정 범위 내에서 임의로 정하였고, 이를 대상으로 주성분 분석 기법으로 중요한 노드들을 선정하였다. 중요 노드가 파악되면 해당 센서노드들에 대해 물리적으로 관리가 용이하게 되고, 문제 발생 시 보안 대책을 수립할 수 있다. 이것은 센서 네트 워크망에 대한 효용 및 수명과도 직결되며 비용 측면에서도 효과적이다.

• 한국정보과학회논문지:시스템및이론
• /
• 제30권7_8호
• /
• pp.331-340
• /
• 2003

가격대비 성능이 좋은 저가의 상업용 SMP가 클러스터 시스템의 노드로 많이 사용되고 있다. 본 논문에서는 이러한 SMP 클러스터 상에서 KDSM을 확장해 소프트웨어 분산공유메모리를 구현하고 성능을 평가하였다. 본 논문의 SDSM 시스템은 HLRC 메모리 모델을 제공한다. 또한 같은 SMP 노드내에서 실행되는 프로세스 간에는 메모리 공유를 통해 페이지 획득 및 메시지 전달을 줄여 성능을 향상시켰다. 100Mbps Fast Ethernet으로 연결된 8노드의 2-way 펜티엄-III SMP 클러스터 상에서 구현되었고 통신계층은 TCP/IP를 사용한다. 8개의 응용프로그램을 실행시켜 얻은 성능 평가에서는 기존의 단일프로세스 프로토콜과 비교해 최대 33%의 성능 향상과 13%-52%의 페이지 획득 감소가 나타났다.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2000년도 하계종합학술대회 논문집(3)
• /
• pp.31-34
• /
• 2000

Genetic Algorithm is well known as the efficient algorithm which can solve a difficult optimization problem. Recently, there has been increasing interest in applying genetic algorithm to problem related to network design. In this paper, we propose a two-step genetic algorithm for designing a optimum virtual path network(VPN) for a given physical network and traffic demand. The first step is a routing step in which a route is found between every node pair in the network. In the second step, paths are assigned as VPs so as to minimize the total number of VPs configured, the number of VPs carried by a link, and the VP hopcount. We study the performance of the propose algorithm through simulation. The result shows that the VPN generated by the proposed algorithm is good in minimizing the number of VPs configured, the load on a link, and the VP hopcount.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 A
• /
• pp.139-142
• /
• 2003

Location information of individual nodes is useful for routing and some other functions in wireless sensor networks. Each node can use GPS to know its position. However, the GPS service can not be practical to use due to cost efficiency, power, and computing capability. This paper proposes the localization method to make nodes know their location in case of a few nodes knows their position information. The proposed method is named as VALT (Virtual Anchor based Localization using Triangulation method). It uses the virtual anchor concept and calculates the location of individual nodes by means of the triangulation method. This method helps all nodes to determine their position with low cost and high scalability.

• ETRI Journal
• /
• 제18권4호
• /
• pp.229-244
• /
• 1997

Realization of the economical, reliable, and efficient ATM interface block becomes an important key to development of the ATM switching system when we consider new issues raised recently. In this paper, we summarize requirements for the ATM interface block and present the UNI (User Network Interface)/NNI (Network Node Interface) architecture to meet these requirements. We also evaluate the performance of the multiplexer adopting the various multiplexing schemes and service disciplines. For ATM UNI/NNI interface technologies, we have developed a new policing device using the priority encoding scheme. It can reduce the decision time for policing significantly. We have also designed a new spacer that can space out the clumped cell stream almost perfectly. This algorithm guarantees more than 99 % conformance to the negotiated peak cell rate. Finally, we propose the interface architecture for accommodation of the ABR (Available Bit Rate) transfer capability. The proposed structure that performs virtual source and virtual destination functions as well as a switch algorithm can efficiently accommodate the ABR service.

• 산업기술연구
• /
• 제21권A호
• /
• pp.117-122
• /
• 2001

Currently, the VHE (suggested for global roaming user to provide personal service environment) implementation scenario is being proposed to realize 3G network requirements. However, developing VHE scenarios are focused on signal flow between node and network, and network and network. this case may result in weakness to protect subscriber's privacy in 3G network which commonly uses visited network. In this paper, we reanalyze a several VHE implementation scenarios for user profile protection, indicate a problem concerning user privacy, and finally, design a procedure to cope with vulnerability in VHE implementation scenario.

• 제어로봇시스템학회논문지
• /
• 제14권1호
• /
• pp.13-20
• /
• 2008

Sensor network consists of a large number of sensor node distributed in the environment being sensed and controlled. The resource-constrained sensor nodes tend to have various and heterogeneous architecture. Thus, it is important to make its software environment platform-independent and reprogrammable. In this paper, we present BeeVM, a Java operating system designed for sensor networks. BeeVM offers a platform-independent Java programming environment with its efficiently executable file format and a set of class APIs for basic operating functions, sensing and wireless networking. BeeVM's high-level native interface and layered network subsystem allow complex program for sensor network to be short and readable. Our platform has been ported on two currently popular hardware platforms and we show its effectiveness through the evaluation of a simple application.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2003년도 컴퓨터소사이어티 추계학술대회논문집
• /
• pp.107-110
• /
• 2003

In this paper, we propose sharing 3D media between multisite using enhanced Access Grid (e-AG) which is a composition of 3D display and Access Grld (AG) Conventional AG and other collaborative systems have a limitation to share immersive 3D media Thus, proposed system supports sharing 3D media contents in a AG meeting section. Real object can be shared by acquiring stereo image with pre-calibrated stereo camera and by delivering, and virtual object can be shared by transmitting state information after downloading 3D model. And also, real video scene acquired by stereo camera and virtual object from 3D model can be displayed on the 3D display system of each node adaptively. The characteristics of proposed sharing method are sharing 3D media, displaying 3D media on a system adaptively, supporting real-time interaction. The proposed sharing method will be used remote lecture, remote collaboration with 3D media.

• 한국컴퓨터산업교육학회:학술대회논문집
• /
• 한국컴퓨터산업교육학회 2003년도 제4회 종합학술대회 논문집
• /
• pp.119-126
• /
• 2003

Computer simulation has used to a area of military training from about several years ago. War game model(or computer simulation) endow a military man with field training such as combat experience without operating combat strength or capabilities. To samely construct simulation environment against actual combat environment is to well construct DB to operate war game model, associate among federates on network. Thus, we construct virtual combat environment enabling to efficiently manage network traffic among federates(or active nodes) on active network that construct virtual military training space such as urgent combat field needed to rapidly transfer combat information including image and video.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2007년도 하계종합학술대회 논문집
• /
• pp.11-12
• /
• 2007

OVPN(Optical Virtual Private Network) based on DWDM(Dense Wavelength Division Multiplexing) backbone framework is considered as a promising approach for the future VPN. This paper proposes a new routing algorithm, called PMIPMR (Priority-based Minium Interference Path Multicast Routing) algorithm which finds an alternate route considering node priorities when the congestion is occurred in a network. The PMIPMR algorithm tries to improve blocking probability and wavelength utilization by avoiding congested path for potential future connection requests.