• Journal of Korean Library and Information Science Society
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• v.43 no.4
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• pp.403-425
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• 2012

This research aims to present a development plan on the Korean diaspora information resource management in a viewpoint document information and archives. This study consists of two aspects : a document investigation based on Korean diaspora and information resource and in a practical examine based on a spot of life, settlement, and movement of overseas. A lot of Korea Diaspora have immigrated to Japan, China and Russia mostly with other people in the political and economic dominant cause. They are produced a various of document information and was formed information resource management and archives in a library, a newspaper office and a publishing company. The result of this research was looked forward to help to R&D of information resource management in values and competencies for Korean diaspora.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.1
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• pp.92-97
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• 2012

This paper suggests a data gathering scheme using dynamic branch tree in wireless sensor networks. A mobile sink gathers data from each sensor node using a dynamic data gathering tree rooted at the mobile sink node. As the sink moves, a tree that has multiple branch is formed and changed dynamically as with the position of the sink node. A hop-based scope filter and a restricted flooding scheme of the tree are also suggested. Simulation results show that the proposed data gathering scheme has better results in data arrival rate, the end-to-end delay and energy saving characteristics compared with the previous scheme.

• The KIPS Transactions:PartC
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• v.10C no.3
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• pp.367-376
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• 2003

This study deals with the DCMST (Delay constrained Capacitated Minimum Spanning Tree) problem applied in the topological design of local networks or finding several communication paths from root node. While the traditional CMST problem has only the traffic capacity constraint served by a port of root node, the DCMST problem has the additional mean delay constraint of network. The DCMST problem consists of finding a set of spanning trees to link end-nodes to the root node satisfying the traffic requirements at end-nodes and the required mean delay of network. The objective function of problem is to minimize the total link cost. This paper presents two-phased heuristic algorithm, which consists of node exchange, and node shift algorithm based on the trade-off criterions, and mean delay algorithm. Actual computational experience and performance analysis show that the proposed algorithm can produce better solution than the existing algorithm for the CMST problem to consider the mean delay constraint in terms of cost.

• Explosives and Blasting
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• v.41 no.4
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• pp.1-8
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• 2023

On August 4, 2020, 2750 tons of ammonium nitrate stored in a storage warehouse at the Port of Beirut exploded. This explosion is said to be the largest ammonium nitrate explosion ever. By applying the TNT equivalency method, TNT equivalent amount corresponding to the explosion energy of 2750 tons of ammonium nitrate was calculated, and it is found to be 856 tons. Overpressure and impulse were calculated in a range up to 3600 m from the blast using the Kingery-Bulmash explosion parameter calculator tool. As the distance from the explosion center increases, the overpressure and impulse decrease exponentially, but the overpressure decreases more significantly, showing that overpressure is more affected by distance than the impact. As a result of applying the damage criteria to evaluate the effects of overpressure and impulse on the structure, the critical distances at which partial collapse, major damage, and minor damage to the structure occur are found to be approximately 500, 800, and 2200 m from the center of the explosion, respectively. The probit function was applied to evaluate the probability of damage to structures and human body. The points where the probability of collapse, major damage, minor damage, and breakage of window-panes to structures are greater than 50% are found to be approximately 500, 810, 2200, and 3200 m, respectively. For people within 200 m from the center of the explosion, the probability of death due to lung damage is more than 99%, and the 50% probability of eardrum rupture is approximately 300 m. The points with a 100% probability of death due to skull rupture and whole body impact due to whole body displacement are evaluated to be 300 and 100 m, respectively.

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.2
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• pp.99-110
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• 2009

This study is to establish urban green network on the urbanized area using characteristics of fragmented and ornamental green area distribution. To do this, the survey for the green area characteristics was carried out in Changwon City. In order to analyze network, a virtual network in whole city sky for bird's movement, which is consisted with 30m grid lines was prepared. To analyze which network routes depend on the direction, we estimated bird's movement between 8-direction and 16-direction's outskirt forest's source point and inner city's fragmented green area. In the analysis of two types different direction models, the results of green network routes are mostly matched. So green network plan by this results is more reasonable for enhancing bird's movement to inner city. Based on the these findings, this green network planning will be providing for inner city to influx outside forest's birds and maximize the ecological connectivity.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.2
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• pp.186-190
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• 2008

This paper analyzes previous work on publish/subscribe in mobile ad-hoc networks with respect to collaboration methods among distributed event brokers. Our experiments suggest that approaches building event delivery structures are suitable for a scenario where there are events of various types each of which is consumed by a few subscribers. However, these approaches based on independent periodic exchange of network topology information may fail to reflect the up-to-date information when building event delivery paths. For this reason they do not correctly recover a broken path caused by node mobility, which results in lower event delivery rates. This paper proposes a scheme for building and maintaining event delivery paths based on advertisements initiated by and hence propagated from the root node. This guarantees correct recovery of event delivery paths within each period. Our experiments show that, our proposed scheme gives a better event delivery ratio with lower overhead.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.60.1-60.1
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• 2011

본 연구에서는 풍력 터빈 블레이드의 다분야 통합 최적 설계를 위하여, 진동하는 비정상 공력하중에 의한 작동 수명을 고려한 최적화 과정을 수행하였다. 최적화 대상으로는 NREL의 1.5MW 급 풍력터빈을 baseline 으로 하였고, NREL의 FAST 프로그램을 이용하여 발전기의 정격 출력 및 블레이드에 작용하는 비정상 공력 하중 특성을 분석하였다. 최적화 수행 시 블레이드 형상의 효율적인 구현을 위해 형상모델링 함수를 이용하여 코드 길이와 트위스트 분포를 모델링하였다. 그리고 상용 MDO Framework 인 Piano를 이용하여 블레이드 루트부의 비정상 공력하중 조건을 완화시키는 최적화 설계를 수행하였다. 정격출력을 유지하면서도 Out of Plain 방향의 하중 조건을 개선하여 보다 긴 작동 수명을 기대할 수 있는 블레이드 형상을 설계하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2007.10d
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• pp.281-285
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• 2007

일반 공학용계산기를 모델로 WIPI를 이용한 어플리케이션인 모바일 공학용계산기를 개발하였다. 모바일 공학용계산기는 사용빈도가 높은 함수연산(삼각함수, log, $\surd$(루트), $\Pi$(파이), !(팩토리얼), 제곱 등)을 지원하며 식의 저장(Save), 불러오기(Load) 기능으로 이용의 편리함을 더하였다. 입력받은 문자열을 숫자로 변환하여 한자리씩 계산한 후 문자열로 재결합하는 구조로 결과값의 길이에 대한 제한 없이 출력이 가능하다. 성능은 PC나 일반 공학용계산기의 처리속도와 결과의 정확도면에서 뒤떨어지지 않는다. 모바일 공학용계산기는 휴대폰에 탑재되어 이동성이 탁월하며 언제어디서나 사용가능하고, 한번의 다운로드로 수명이 영구적이다. 또한 소프트웨어 업그레이드로 프로그램의 확장성이 특징이다.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.11a
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• pp.1319-1322
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• 2005

복호 후 전달 협력 통신 프로토콜(DFP: Decode-and-Forward Cooperative Communication Protocol)은 물리적인 안테나의 증가 없이 다중 안테나 시스템의 장점을 가지는 통신 방법이다. 지금까지는 신호 대 잡음 비율(SNR: Signal to Noise Ratio)이나 경로이득 크기의 루트를 취한 값들을 이용하여 중계 노드에서 복호한 데이터를 전달 여부를 결정하여 중계 노드에서 부정확한 검파가 되지 않도록 방지하였다. 본 논문에서는 기존의 DFP 에서 사용되던 SNR 을 대체할 수 있는 LLR(Log-Likelihood Ratio)를 이용하는 방법을 제안하였다. 레일리 페이딩 환경과 AWGN 환경에서 기준값이나 중계 노드의 위치에 상관없이 LLR 기반의 DFP 가 SNR 기반의 DFP 보다 높은 성능을 보이는 것을 확인하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.06a
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• pp.182-184
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• 2013

가속되는 지구온난화로 인해 인류는 과거엔 경험해 보지 못한 북극항로 개척이라는 새로운 상황에 직면하게 되었다. 북극항로가 새로운 물류이동 루트로 떠오르면 지리적 이점으로 인해 우리나라는 큰 이득을 얻을 수 있으며 그 중심에 부산항이 있다. 글로벌 물류중심 국가로의 도약을 이루기 위해 북극해 관련 국가 전담조직 신설, 국가종합계획 및 전략 수립, 해양 플랜트 R&D 센터 건립, 관련 전문가 육성, 북극해 연안항로 개발, 해운서비스 비즈니스 모델 개발, 북극관련 해양관광 기반을 마련해야 한다. 또한, 국가간 군사협력기구 또는 협력체제를 구성, 통항 선박 보호 및 구조 문제의 해결이 요구된다. 이를 위해 다목적 함, 통항 위협요소를 실시간으로 파악하기 위한 극지 작전가능형 초계기 등의 전력과 운용 인력을 육성해야 한다.