• 대한전기학회논문지:시스템및제어부문D
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• 제54권9호
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• pp.539-546
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• 2005

This paper describes a method of building the probability grid map for an autonomous mobile robot using the ultrasonic DAF(data association filter). The DAF, which evaluates the association of each data with the rest and removes the data affected by the specular reflection effect, can improve the reliability of the data for the Probability grid map. This method is based on the evaluation of possibility that the acquired data are all from the same object. Namely, the data from specular reflection have very few possibilities of detecting the same object, so that they are excluded from the data cluster during the process of the DAF. Therefore, the uncertain data corrupted by the specular reflection and/or multi-path effect, are not used to update the probability map, and hence building a good quality of a grid map is possible even in a specular environment. In order to verify the effectiveness of the DAF, it was applied to the Bayesian model and the orientation probability model which are the typical ones of a grid map. We demonstrate the experimental results using a real mobile robot in the real world.

• 한국정보통신학회논문지
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• 제14권11호
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• pp.2497-2506
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• 2010

최근 진행되고 있는 제주 스마트그리드 실증에서 스마트 파워 그리드는 특히 기존의 전력 IT 기술의 통합을 통한 전력 계통 운영의 개선을 목표로 하고 있다. 스마트 파워 그리드의 구축을 위해서는 전력망의 실시간 양방향 통신과 상호 연동성이 필수적이다. 그러나, 스마트그리드의 도입으로 인한 무선 센서 수와 통신망의 외부 노출기회의 증가는 전력망의 보안취약점을 증가시킨다. 또한, 통신망의 데이터 도청 및 위변조 공격을 통한 해커의 공격은 전력 계통 시스템에 대한 혼란을 야기 시킬 수 있다. 스마트 파워 그리드는 스마트그리드의 추진을 위해 가장 핵심이 되는 시스템의 하나로 문제의 발생시 스마트그리드의 존립을 위협하게 되므로 체계적인 보안설계가 필수적이다. 본 논문에서는 국내외 스마트 그리드 보안 표준 및 전력 계통 시스템의 보안 취약점 및 요구사항 분석을 기반으로 스마트 파워 그리드 실증을 위한 2단계 보안 서비스 모델을 제안하였다.

• 전기학회논문지
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• 제59권11호
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• pp.1964-1970
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• 2010

A new intelligent power network (Smart Grid) that grafts some new technologies, such as the extension of the new and reproducible energy, electric motors, and electric storages, onto the regulation of green house gases according to the recent convention on climate changes has been actively promoted. As establishing such an intelligent power network, it is possible to implement a real-time rate system according to the change from the conventional single directional information transmission to the bidirectional information transmission. Such a real-time rate system can provide power during the chip rate hour by avoiding the high rate hour although customers use the same level of power through providing such real-time rate information including power generation costs. In this study, the establishment of an operating system that makes an effective use of the real-time rate system and its operation method are to be proposed.

• Journal of Electrical Engineering and Technology
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• 제8권1호
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• pp.20-30
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• 2013

An intelligent grid computing architecture is proposed and developed for transient stability constrained total transfer capability evaluation of future smart grid. In the proposed intelligent grid computing architecture, a model of generalized compute nodes with 'able person should do more work' feature is presented and implemented to make full use of each node. A timeout handling strategy called conditional resource preemption is designed to improve the whole system computing performance further. The architecture can intelligently and effectively integrate heterogeneous distributed computing resources around Intranet/Internet and implement the dynamic load balancing. Furthermore, the robustness of the architecture is analyzed and developed as well. The case studies have been carried out on the IEEE New England 39-bus system and a real-sized Chinese power system, and results demonstrate the practicability and effectiveness of the intelligent grid computing architecture.

• 대한기계학회논문집B
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• 제28권5호
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• pp.604-611
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• 2004

Simulation of three-dimensional turbulent flow with LES and DNS lakes much time and expense with currently available computing resources and requires big computing resources especially for high Reynolds number. The emerging alternative to provide the required computing power and working environment is the Grid computing technology. We developed the CFD code which carries out the parallel computing under the Grid environment. We constructed the Grid environment by connecting different PC-cluster systems located at two different institutes of Pusan National University in Busan and KISTI in Daejeon. The specification of PC-cluster located at two different institutes is not uniform. We run our parallelized computer code under the Grid environment and compared its performance with that obtained using the homogeneous computing environment. When we run our code under the Grid environment, the communication time between different computer nodes takes much larger time than the real computation time. Thus the Grid computing requires the highly fast network speed.

• Journal of Electrical Engineering and Technology
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• 제12권2호
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• pp.495-501
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• 2017

The introduction of smart grid, which is an innovative application of digital processing and communications to the power grid, might lead to more and more cyber threats originated from IT systems. In other words, The Energy Management System (EMS) and other communication networks interact with the power system on a real time basis, so it is important to understand the interaction between two layers to protect the power system from potential cyber threats. This paper aims to identify and clarify the cyber security risks and their interaction with the power system in Smart Grid. In this study, the optimal power flow (OPF) and Power Flow Tracing are used to assess the interaction between the EMS and the power system. Through OPF and Power Flow Tracing based analysis, the physical and economic impacts from potential cyber threats are assessed, and thereby the quantitative risks are measured in a monetary unit.

• Journal of the Korean Data and Information Science Society
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• 제17권2호
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• pp.569-579
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• 2006

Recently, the amount of genome sequence is increasing rapidly due to advanced computational techniques and experimental tools in the biological area. Sequence comparisons are very useful operations to predict the functions of the genes or proteins. However, it takes too much time to compare long sequence data and there are many research results for fast sequence comparisons. In this paper, we propose a hybrid grid system to improve the performance of the sequence comparisons based on the LanLinux system. Compared with conventional approaches, hybrid grid is easy to construct, maintain, and manage because there is no need to install SWs for every node. As a real experiment, we constructed an orthologous database for 89 prokaryotes just in a week under hybrid grid; note that it requires 33 weeks on a single computer.

• 한국정밀공학회지
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• 제17권4호
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• pp.85-96
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• 2000

An Eggcrate assembly is an important part to hold and support 16,000 tubes containing hot and contaminated water in the steam generator of nuclear power plant. As a great number of tubes should be inserted into the eggcrate assembly, the dimensions of each eggcrate grid are one of the critical factors to determine the availability of tube insertion. in this paper. we propose a machine vision algorithm for measuring the inner-circle diameter of each eggcrate grid whose shape is not exact quadrangular. The overall procedure of the algorithm is composed of camera calibration, eggcrate image preprocessing, grid height adjustment, and inner-circle diameter estimation. The algorithm is tested on real specimens and the results show that the algorithm works fairly well.

• 한국위성정보통신학회논문지
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• 제10권1호
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• pp.44-48
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• 2015

스마트그리드는 전력망에 정보기술을 접목하여, 전력공급자와 소비자가 양방향으로 실시간 정보를 교환, 에너지효율을 최적화하며 새로운 부가가치를 창출하는 차세대 전력망이다. 본 논문에서는 스마트그리드 환경 하에서 수요반응 통신시스템에 사용되는 프로토콜을 알아보고 수용반응 프로토콜을 이용한 수요반응 시스템을 구현하고 에어컨 제어를 통한 전력감소를 하는 수요반응 시나리오를 실험하였다.

• 한국생물정보학회:학술대회논문집
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• 한국생물정보시스템생물학회 2004년도 The 3rd Annual Conference for The Korean Society for Bioinformatics Association of Asian Societies for Bioinformatics 2004 Symposium
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• pp.13-20
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• 2004

Grid system has the potential to resolve the current need of bioinformatics for super-computing environment inexpensively. There are already several Grid applications of bioinformatics tools. To solve the real-world bioinformatics problems, however, the various integration of each tool is necessary in addition to the implementation of more basic tools. Workflow based problem solving environment can be the efficient solution for this type of software development. There are still heavy overhead, however, to develop and implement workflow model on current Grid system. He re we propose a model of simple problem solving environment that enables component based workflow design of integrated bioinformatics applications on Grid environment by using Condor functionalities. We realized this model for practical bioinformatics solutions of a genome sequence analysis and a comparative genome analysis. We implemented necessary bioinformatics tools and interfacing tools as the components, and combine them in the workflow model of each solution by using the tools presented in Condor.