• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.131-134
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• 2005

This paper describes the efficient peer-to-peer migration method of Grid service agent on the mobile agent based P-Grid. The migration mechanism for transmitting service agent upon the service request is based on the peer's logic network topology. The network topologies that this system uses are organized as star topology, ring topology and tree topology, and agents are migrated by the master/slave method and serial/parallel method. The migration method of services is chosen based on the execution range and characteristic of the requested service. Also, the entire execution time of service is affected by the performance of peer that is a part of network topology, and the migration order, Therefore, the system monitors the performance of peers, and determines the migration priority based on analyzing and learning history. The system can reduce service execution time efficiently with decisions of migration method for service agent and priority of peers.

• Journal of Korea Society of Industrial Information Systems
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• v.17 no.5
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• pp.19-28
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• 2012

Recently a grid and cloud computing collaboration have become a social issue. These collaborative network system, the P2P system based on this system. Distingui shed from the client/server systems, P2P systems in order to exchange information, its purpose and functions are divided according to the morphological Category. In accordance with the purposes and functions of information and data retrieval, remote program control and integration services for the offers. Most P2P systems client/server scalability, and management takes the form, but to overcome the disadvantages in terms of applying the mixed-mode system is increasing. And recently the distributed computing aspects of the service to users in order to provide suitable to accommodate the diverse needs of various types of mobile agent technology is needed. In this paper, as required by the mobile agent access to a remote resource access control and agent for the execution and management capabilities and improve the reliability of the mobile agent system designed to suggest.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06a
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• pp.433-435
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• 2006

P2P 그리드 컴퓨팅 환경에서 자원제공자가 수행한 연산 결과의 정확성을 보장하는 것은 중요한 고려사항이다. 기존의 연산 결과 검사에 대한 연구들은 중앙 서버가 연산 결과를 관리하는 중앙집중형 환경에서 이루어졌다. 그러나 중앙집중형 환경에서 중앙 서버의 부하로 인한 확장성 문제로 최근에는 분산형 환경에서 많은 연구가 진행 중이나 연산 결과 검사에 대한 연구는 없는 실정이다. 게다가 분산형 환경은 연산 결과를 관리하는 중앙 서버의 부재로 연산 결과를 신뢰하기 어렵고, 또한 검사하기도 어렵다. 이에 본 논문에서는 분산형 P2P 그리드 컴퓨팅 환경에서 자원제공자의 평판도 기반연산 결과 검사 기법을 제안한다. 제안 기법은 자원제공자의 가용성과 평판도를 기반으로 작업 트리를 구성한 후, 트리의 단계별 특징에 따라 차별화 된 연산 결과 검사와 스케줄링을 수행하여, 기존 연산 결과 검사 기법을 분산형 환경에 그대로 적용할 때보다 연산 결과의 정확성은 보장하면서 연산 결과 검사로 인한 부하는 감소시킨다.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10d
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• pp.112-117
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• 2006

그리드 환경은 원격의 이질적인 자원들을 서로 공유하며 상호 접근이 가능하도록 하여 사용자의 작업을 처리할 수 있는 메커니즘을 제공한다. 이때 그리드에 참여하는 각 노드들은 그리드에 자유롭게 참여 및 탈퇴가 가능하다는 점에서 P2P(Peer-to-Peer) 네트워크 구조와 유사하다. 또한 그리드 정보 서비스의 배치(deployment)와 특정한 자원 검색 서비스의 측면을 고려할 때 P2P 구조는 그리드 환경에서 유용하게 활용 될 수 있다. 따라서 그리드를 설계함에 있어 기존의 방법과는 달리 P2P 형식으로 그리드를 구성하는 것은 시스템의 확장성과 이에 따른 효율성을 개선하는 중요한 요소가 된다. 본 논문에서는 P2P 형식의 그리드를 구성하는데 필요한 계층형 Ring 기반의 멤버쉽 프로토콜을 제안한다. 계층형 Ring 기반의 멤버쉽 프로토콜은 제한된 네트워크 연결만을 가지게 되므로 멤버쉽을 위한 통신 비용을 감소 시킬 수 있게 되며, 각 노드에서 유지해야 하는 멤버쉽 정보들이 지역적인 정보들만을 대상으로 하기 때문에 멤버쉽 정보 유지에 따른 관리 비용 또한 감소하게 되는 장점을 갖게 된다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.3
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• pp.653-661
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• 1994

In this paper the CSCM type upwind flux difference splitting Navier-Stokes method has been applied to study the ARL-SL19 supersonic/transonic compressor cascade flow. H-type grid was chosen for its simplicity in applying cyclic tridiagonal matrix algorithm along with conventional slip/no-slip boundary conditions. The thin-layer algebraic model of Baldwin-Lomax was employed for the calculation of turbulent flows. The test case inlet Mach No. was 1.612 and inlet/exit pressure ratio($P_2/P_1$) was 2.15. The results were compared with experimental results from current method were compared well in suction surface with the experiments and other computational results; however, not well in pressure surface. It might be due to the complex flowfields such as shock/boundary layer interaction, turbulence, and flow separation, etc. In the future, a proper turbulence modelling and adaptive grid system will be studied to improve the solution quality.

• The Journal of Korean Academy of Prosthodontics
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• v.32 no.3
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• pp.411-430
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• 1994

The denture may be fractured accidentally by an impact while outside the mouth, or may be cracked or broken while in service in the mouth. The latter is generally a fatigue failure caused by repeated flexure over a period of time. This investigation compared the flexural fatigue resistance, the impact force and the transverse strength of two denture base materials with and without the grid strengthener, the T300, the T800 and the Kevlar fiber to evaluate the fracture resistance. The distribution and behavior of fibers across fracture lines were examined by Hi-Scope Compact Microvision System. Through analyses of the data from this study, the following conclusions were obtained. 1. The flexural fatigue resistance, impact strength and transverse strength of high impact strength resin were higher than those of conventional heat polymerizing resin, but statistically there was no significant difference(p>0.05). 2. All specimens with and without the grid strengthener did not show significant differences in the flexural fatigue, the impact and the transverse strength test(p>0.05). 3. All specimens reinforced with the T300, the T800 and the Kevlar fiber showed significant increase of the fatigue resistance and the impact force(p<0.05). 4. All specimens reinforced with the T800 and the Kevlar fiber showed significant increase of the transverse strength(p<0.05). 5. All specimens reinforced with the T300, the T800 and the Kevlar fiber exhibited greenstick fractures. The fibers tended to remain enveloped in the resin, resisting pull-out.

• Journal of Internet Computing and Services
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• v.7 no.6
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• pp.87-103
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• 2006

Advances in computer and network technology provide new computing environment that were only possible with supercomputers before. In order to provide the environment, a distributed runtime system has to be provided, but most of the conventional distributed runtime systems lack in providing dynamic and flexible system reconfiguration depending on workload variance, due to a static architecture of fixed master node and slave working nodes. This paper proposes and implements a new model for distributed job allocation and management which is a distributed runtime system is P2P environment for flexible and dynamic system reconfiguration. The implemented systems enables job program transfer and management, remote compile and execution among cooperative developers based on P2P standard protocol Jxta platform. Since it makes dynamic and flexible system reconfiguration possible, the proposed method has some advantages in that it can collect and utilize idle computing resources immediately at a needed time for distributed job processing. Moreover, the implemented system's effectiveness and performance increase are shown by applying and processing the crawler jobs, in a distributed way, for collecting a large amount of data needed for internet search.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.45 no.2
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• pp.10-17
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• 2008

In this paper, we propose an efficient data replication strategy based on Peer-to-Peer which improves the performance of Data Grid system. The key idea of this replication strategy is to add the Peer-to-Peer concept for reducing data transmission restriction caused by hierarchical topology. And, it makes the nodes can store data replica to set a critical section at the storage of client level nodes. Therefore, it is possible to transmit the data replica between client level nodes and from client level nodes to upper data replication server. It is more effective to transmit data replica between client level nodes than transmitting data replica 1mm data server or data replication server with respect to minimize the transmission time. This results in improving the performance of Data Grid system. Through simulation, we show that the proposed data replication strategy based on Peer-to-Peer improves the performance of entire Data Grid environment compared to previous strategies.

• Journal of the Korean Institute of Telematics and Electronics
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• v.20 no.1
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• pp.22-26
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• 1983

P+N and P+NN+ solar cells with the area of 3.36 $\textrm{cm}^2$ were fabricated by thermal diffusion. Under the light intensity of 100 mW/$\textrm{cm}^2$, total area(active area) conversion efficiency was 13.4%(14.7%) for P+N cell fabricated by 15 min boron predeposition at 94$0^{\circ}C$ and 20 min annealing at 80$0^{\circ}C$, and 14.3%(15.6%) for P+NN+ cell processed by 15 min boron predeposition at 94$0^{\circ}C$ and 50 min annealing at 80$0^{\circ}C$ after 20 min back phosphorus diffusion at 1,05$0^{\circ}C$. The minority carrier lifetime in bulk of P+NN+ cells was increased about 2~3 times comparing with P+N cells because of guttering and BSF effect due to back phosphorus doping. The methods used for efficiency improvement were AR coating, Ag electroplating, back doping and fine grid pattern as well as the control of front doping profile.

• Journal of Power Electronics
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• v.17 no.2
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• pp.464-475
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• 2017

This study examines a P+multi resonant-based voltage control for voltage harmonics compensation under the islanded mode of a microgrid. In islanded mode, the inverter is defined as a voltage source to supply the full local load demand without the connection to the grid. On the other hand, the output voltage waveform is distorted by the negative and zero sequence components and current harmonics due to the unbalanced and nonlinear loads. In this paper, the P+multi resonant controller is used to compensate for the voltage harmonics. The gain tuning method is assessed by the tendency analysis of the controller as the variation of gain. In addition, this study analyzes the slight voltage magnitude drop due to the practical form of the P+multi resonant and proposes a counter method to solve this problem by adding the PI-based voltage restoration method. The proposed P+multi resonant controller to compensate for the voltage harmonics is verified through the PSIM simulation and experimental results.