• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.2075-2076
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• 2008

복잡 다기능화 사회를 효율적으로 운영하기 위한 각종 관련 산업이 발전하면서 초초고층빌딩의 건설이 확대될 예정이다. 일반적으로 1,000 ft를 넘는 빌딩을 '초초고층 빌딩'이라 하며, 고부가가치 시설인 초초고층빌딩 전기설비의 국내 기술수준은 기본설계 자료 외국 의존, 기본 성능보증을 위한 여건 미흡, 초초고층빌딩 건설 관련 전기설비시공 경험의 부족 등으로 인하여 선진국의 의존도가 높다. 따라서, 초초고층 빌딩 전기설비 성능 중심의 시공기술 개발 등이 절실하게 필요하다. 본 연구에서는 국내 외 초초고층 빌딩의 전기설비 성능 중심 기준 현황, 시공기술의 로드맵 작성을 위한 기술동향 및 환경을 조사, 분석하였으며, 또한 전기설비공사 성능 중심 로드맵 작성 및 요소기술을 도출하였다. 향후 국내의 성능관련 법규 및 기준을 마련할 필요성이 있으며, 기법 개발과 더불어 실용 시스템에 구축하는 연구가 필요할 것으로 사료된다.

• Journal of the Institute of Convergence Signal Processing
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• v.6 no.2
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• pp.95-99
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• 2005

This paper presents an accurate recovery method of the reference clock which is needed for network synchronization in two-way satellite multimedia systems compliant with DVB-RCS specification and which use closed loop method for burst synchronization. In these systems, the remote station transmits TDMA burst via return link. For burst synchronization, it obtains reference clock from program clock reference (PCR) defined by MPEG-2 system specification. The PCR is generated periodically at the hub system by sampling system clock which runs at 27MHz $\pm$ 30ppm. Since the reference clock is recovered by means of digital PLL(DPLL) using imprecise PCR values due to variable random jitter, the recovered clock frequency of remote station doesn't exactly match reference clock of hub station. We propose a robust recovery method of reference clock against random delay jitter The simulation results show that the recovery error is remarkably decreased from 5 clocks to 1 clock of 27MHz relative to the general DPLL recovery method.

• Journal of the Korea Concrete Institute
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• v.23 no.3
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• pp.365-376
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• 2011

The current Concrete Structural Design Code (2007) prescribe the equivalent rectangular stress block of the ACI 318 Building Code as concrete compressive stress distribution for design of concrete structures. The rectangular stress block may be enough for flexural strength calculation, but realistic stress-strain relationship is required for performance verification at selected limit state in performance-based design. Moreover, the ACI rectangular stress block provides non-conservative flexural strength for high strength concrete columns. Therefore a new stress distribution model is required for development of performance-based design code. This paper proposes a concrete compressive stress-strain distribution model for design and performance verification. The proposed model has a parabolic-rectangular shape, which is adopted by Eurocode 2 and Japanese Code (JSCE). It was developed by investigation of experimental test results conducted by the authors and other researchers. The test results cover high strength concrete as well as normal strength concrete. The stress distribution parameters of the proposed models are compared to those of the ACI 318 Building Code, Eurocode 2, Japanese Code (JSCE) and Canadian Code (CSA) as well as the test results.

• KIPS Transactions on Computer and Communication Systems
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• v.8 no.8
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• pp.191-200
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• 2019

In an Ad-hoc network, a method of time synchronizing all the nodes in a network centering on one reference node can be used. A representative algorithm based on a reference node is Flooding Time Synchronization Protocol (FTSP). In the process of sending and receiving messages, predictable and unpredictable delays occur, which should be removed because it hinders accurate time synchronization. In multi-hop communications, hop delays occur when a packet traverses a number of hops. These hop delays significantly degrade the synchronization performance among nodes. Therefore, we need to find a method to reduce these hop delays and increase synchronization performance. In the FTSP scheme, hop delays can be greatly increased depending on the position of a reference node. In addition, in FTSP, a node with the smallest node ID is elected as a reference node, hence, the position of a reference node is actually arbitrarily determined. In this paper, we propose an optimal reference node election algorithm to reduce hop delays, and compare the performance of the proposed scheme with FTSP using the network simulator OPNET. In addition, we verify that the proposed scheme has an improved synchronization performance, which is robust to topology changes.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.921-924
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• 2006

현재 국내에서는 기존에 사용되었던 안정성 위주인 사양중심의 설계(prescriptive code)에서 구조물의 성능을 고려하여, 인명피해 뿐 아니라 구조물의 기능도 설계의 감안요소로 하는 성능 기반 설계기준(Performance-based design)이 도입되고 있는 추세이다. 본 연구에서는 일본 토목학회(JSCE), 캘리포니아 도로연방국(Caltrans), 유럽코드(Eurocode 8), 뉴질랜드 교량설계(NZ code)에서 어떤 식으로 성능기반 설계기준을 제시하고 있으며, 각 국가 간의 성능(performance)과 레벨(performance level)에 대한 접근 방식을 비교하고 국내의 성능기반 설계 도입의 필요성에 대해 논하는데 그 목적이 있다.

• Proceedings of the Korean Institute of Landscape Architecture Conference
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• 2009.03a
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• pp.95-97
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• 2009

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.449-449
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• 2012

과거 우리나라의 침수피해는 하천의 범람으로 인한 농경지를 중심으로 외수침수가 빈번하게 발생하였다. 하지만 도시지역의 불투수층 면적 증가, 토지의 집약적인 이용과 이상기후로 인한 집중호우의 증가는 내수침수 피해를 가중시키고 있다. 특히 지난 2010년 9월 서울 광화문 등에 발생한 호우와 2011년 7월 중부지방을 중심으로 우리나라에 발생한 집중호우로 인한 도시지역의 침수 피해는 상당부분이 내수침수가 원인으로 작용하고 있다. 이에 소방방재청에서는 동일 배수구역 내 각 시설물이 통합적인 방재성능을 발휘할 수 있도록 방재성능기준을 제시하였다. 따라서, 본 연구에서는 도시지역의 내수침수로 인한 피해를 줄이기 위해서, 우리나라 주요 도시지역에서의 침수피해원조사를 바탕으로, 소방방재청의 방재성능목표에 따른 도시지역 내배수시설의 방재성능 평가절차를 제시하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.421-424
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• 2022

Hough transform is a representative algorithm for detecting straight lines in an edge image. It corresponds the parameters of straight lines that may occur in the edge pixel into a parameter space, and detects valid parameters satisfying a given condition as straight lines. In general Hough transform, the parameters of the line are calculated with the image origin as the reference point. However, in this paper, the Hough transform based on the image center as a reference point is performed and its performance is compared and analyzed with the conventional Hough transform.

• Journal of the Society of Disaster Information
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• v.17 no.3
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• pp.487-499
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• 2021

Purpose:The purpose of the paper is to review the problems of performance enhancement of safety certification standards and to suggest directions for improvement in order to rationalize safety certification standards for future industrial development and environmental changes. Method: The problems and limitations of the safety certification system are summarized through literature review and interview with manager, and the status of safety certification standards is classified into design standards, performance standards, and detailed standards, and the status analysis is performed. In addition, by synthesizing the results of the investigation and analysis, improvements are suggested to improve the performance of the safety certification standards. Result: Through the survey, the problems and limitations of safety certification could be grouped into six categories: government-led certification system operation, standardized certification standards, long time required to improve certification, poor certification standards preparation system, and lack of reflection of industry opinions. And, as a result of analyzing the certification standards by dividing them into performance and design standards, in the case of machinery, equipment, and protection devices, the design standards were high at 69.7% and 64.9%, whereas in the case of protective equipment, the performance standards were high at 61.1%. In order to improve the performance of safety certification standards centered on design standards, it is necessary to determine the possibility of performance enhancement of the certification standards and determine the feasibility of the inspection test method. In order to improve performance, it was reviewed that it was necessary to establish a systemic foundation and infrastructure, such as strengthening the Product Liability Act, systematizing market monitoring, etc., distributing certification test tasks, and participating in the preparation of certification standards by the private sector. Conclusion: Through this study, the problems and limitations of Korea's safety certification system were summarized and the necessity for performance improvement was reviewed. Performance improvement of safety certification standards is a matter that requires preparatory work, such as legislative revision and infrastructure construction, and requires mid-to-long-term promotion. In addition, rather than improving the overall safety certification standards, the performance requirements for each item subject to certification should be reviewed and promoted, and details should be specified through additional research.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1551-1552
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• 2015

현재 태양광인버터의 안전성확보에 대한 기술기준이 IEC로부터 채택하게 됨과 동시에 독일, 일본, 미국 등 선진 각국에서는 안전성 확보용 기술기준을 적용하고 있으며, 강제(Mandatary) 규격으로 적용하고 있는 상태이다. 그러나 국내 태양광인버터분야는 인버터의 성능만 수행하고 있는 상태이며, 안전성분야는 전무한 상태이다. 따라서 본 논문에서는 성능위주의 특성에서 벗어나 사용자의 보호 및 안전성을 중심으로 CE, UL 등의 해외인증에서 요구하는 기준으로 자리를 잡아가고 있는 IEC 62109 표준화에 대한 정확한 기술기준 및 시험방법에 대해 살펴본다.