• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2008년도 춘계 종합학술대회 논문집
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• pp.842-845
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• 2008

단백질 상호작용 네트워크는 허브(Hub)라 할 수 있는 상호작용 수가 많은 소수의 단백질과 상호작용 수가 적은 다수의 단백질들로 구성된다. 최근 들어 여러 연구들에서 허브 단백질이 비 허브(Non-hub) 단백질보다 상호작용 네트워크에 필수적인 단백질일 가능성이 높다고 설명하고 있다. 이러한 현상을 중심-치명 룰(Centrality-lethality Rule)이라 하는데, 이는 복잡계 네트워크에서 허브단백질의 중요성 및 네트워크 구조의 중요성을 설명하기 위한 방법으로 폭넓게 신뢰받고 있다. 이에 본 논문에서는 중심-치명 룰이 항상 옳게 적용되는지를 확인하기 위해 Uetz, Ito, MIPS, DIP, SGD, BioGRID와 같은 효모에 관한 공개된 모든 단백질 상호작용 데이터베이스들을 분석하였다. 흥미롭게도, 상호작용 데이터가 적은 데이터베이스들(Uetz, Ito, DIP)에서는 중심-치명 룰을 잘 나타냈지만 상호작용 데이터가 대용량인 데이터베이스들(SGD, BioGRID)에서는 중심-치명 룰이 잘 맞지 않음을 확인하였다. 이에 따라 SGD와 BioGRID 데이터베이스로 부터 얻은 상호작용 네트워크의 특징을 분석하고 DIP 데이터베이스의 상호작용 네트워크와 비교해보았다.

• 한국정밀공학회지
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• 제20권11호
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• pp.7-15
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• 2003

• Korea-Australia Rheology Journal
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• 제19권1호
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• pp.7-16
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• 2007

A dynamic Monte Carlo percolation grid simulation is used to predict the cure behaviour of thermoset materials. Molecules are distributed in a fixed grid and a probability of reaction is assigned to each pair of neighbouring units considering both reaction rates and diffusion. The concentration and network characteristics are predicted throughout the whole curing process and compared to experimental data for an epoxy-amine matrix.

• 한국통신학회논문지
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• 제17권5호
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• pp.452-459
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• 1992

본 논문에서는 kalman-filter 방법을 이용하여 향후 수년간의 음성 트래픽 양을 예측하고, 이 값들을 이용하여 격자 구조로 구성된 회선 교환망에서의 성능을 평가하였다. Kalman-filter 방법은 특적 오차와 모델링 오차를 고려해서 시스템의 상태를 예측하기 때문에 다른 예측 방법들보다 정확하게 시스템의 상태를 예측할 수 있다. 격자 구조 회선 교환망은 우회 경로가 존재하므로 노드들이 다른 구조로 구성되어 있는 통신망보다 높은 신뢰도를 가진다. 본 논문에서는 향 후 수 년간의 예측된 음성 통화량을 이용하여, 회선 교환망 성능 평각의 근간이 되는 호차단(call blocking)확률을 구했다.

• 한국멀티미디어학회논문지
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• 제16권5호
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• pp.566-576
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• 2013

In Home Area Network (HAN) of the smart grid, Power Line Communication (PLC) technology and ZigBee communication technology can be used in the communication among the Advanced Metering Infrastructure (AMI) devices. However, according to performance evaluation results of the PLC technology, we find that using the PLC technology is unsuitable for the remote meter reading service. It is worth noting that some parts of the PLC are converted to the ZigBee communication technology in Jeju, Korea. Compared with PLC, ZigBee has no restriction of the place, where the equipments can be freely set up, due to the advantage of radio communication. However, number of usable devices will impact the network performance which is depended on the address assignment. In addition, due to the restriction of transmission range among devices, it is difficult to apply the ZigBee address assignment method to the practical circumstance. In this paper, we examine the previous ZigBee address assignment schemes and the corresponding routing algorithms, and propose a novel address assignment scheme compared with the existing methods, the performance of the proposed one is improved. In particular, evaluation results show that the proposed scheme reduces the average number of hop count, the transfer time and the processing time.

• Structural Engineering and Mechanics
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• 제29권2호
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• pp.223-235
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• 2008

This paper focuses on the application of artificial neural networks (ANN) for optimal design of tensegrity grid as light-weight roof structures. A tensegrity grid, 2 m ${\times}$ 2 m in size, is fabricated by integrating four single tensegrity modules based on half-cuboctahedron configuration, using galvanised iron (GI) pipes as struts and high tensile stranded cables as tensile elements. The structure is subjected to destructive load test during which continuous monitoring of the prestress levels, key deflections and strains in the struts and the cables is carried out. The monitored structure is analyzed using finite element method (FEM) and the numerical model verified and updated with the experimental observations. The paper then explores the possibility of applying ANN based on multilayered feed forward back propagation algorithm for designing the tensegrity grid structure. The network is trained using the data generated from a finite element model of the structure validated through the physical test. After training, the network output is compared with the target and reasonable agreement is found between the two. The results demonstrate the feasibility of applying the ANNs for design of the tensegrity structures.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2011년도 춘계학술발표대회
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• pp.572-575
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• 2011

It is well known that spanning tree protocol (STP) is the most commonly used protocol in switching networks for smart grid. STP selectively blocks redundancy links of the network to prevent layer 2 loops in network, and it also has a functionality of backing up links. As with the other protocols, STP has been updated with the continuing development of the network. STP is a broad concept and it does not just refer in particular to defined STP protocol in IEEE 802.1D standards, it refers to updated spanning tree protocol based on STP. Because of uneven distribution of communication traffic in root bridge, STP cannot satisfy fast converge nce while the failure occurs near the root bridge or on the root bridge in tree topologies of STP. In this paper, we propose a novel method --- Hyper Cube Spanning Tree Protocol (HCSTP) to solve uneven distribution of communication traffic. Theoretically, hyper cube in our protocol increases throughput and improves the utilization of communication. The simulation results show that HCSTP can achieve comparative and considerably higher performance than other STP protocols in terms of reconnection.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제10권2호
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• pp.81-88
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• 2006

슈퍼 컴퓨터의 등장으로 기존에는 풀지 못했던 과학적, 학술적인 문제들이 대부분 해결되었지만 슈퍼 컴퓨터 자체의 막대한 비용 문제는 여전히 풀지 못한 숙제로 남아 있다. 이에 일반 사용자의 컴퓨터의 유휴 자원을 통합하여 협업하는 그리드 컴퓨팅이라는 개념이 등장하였다. 한편 분산되어 있는 이기종의 시스템의 자원을 통합하여 관리하기 위해서 연결 지향적인 프로토콜들이 사용되었지만, 다른 프로토콜끼리는 호환성이 없는 등의 문제가 존재한다. 본 논문에서는 플랫폼 독립적인 XML 기반의 SOAP을 사용하는 웹 서비스를 이용하여 그리드 네트워크의 성능 정보를 관리해주는 시스템을 제안한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권4호
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• pp.1359-1375
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• 2015

Energy efficiency is critical for Wireless Sensor Networks (WSNs) since sensor nodes usually have very limited energy supply from battery. Sleep scheduling and nodes cooperation are two of the most efficient methods to achieve energy conservation in WSNs. In this paper, we propose an adaptive energy optimization approach for target tracking applications, called Energy-Efficient Node Coordination (EENC), which is based on the grid structure. EENC provides an unambiguous calculation and analysis for optimal the nodes cooperation theoretically. In EENC, the sleep schedule of sensor nodes is locally synchronized and globally unsynchronized. Locally in each grid, the sleep schedule of all nodes is synchronized by the grid head, while globally the sleep schedule of each grid is independent and is determined by the proposed scheme. For dynamic sleep scheduling in tracking state we propose a multi-level coordination algorithm to find an optimal nodes cooperation of the network to maximize the energy conservation while preserving the tracking performance. Experimental results show that EENC can achieve energy saving of at least 38.2% compared to state-of-the-art approaches.

• 전력전자학회논문지
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• 제19권3호
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• pp.201-210
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• 2014

In this paper, dc-link voltage control of a grid-connected QZSI is presented. Since the input current of the ZSI is discontinuous, a capacity with relatively large capacitance should be connected to the output of the PV array in order to reduce the current ripple. Due to the presence of the impedance network inductor in series with the PV array, the QZSI can achieve continuous input current flow. Several dc-link voltage control methods are compared and the method for power quality improvement is also presented. The performance of the proposed method is verified through both simulation and experimental results.