• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.5
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• pp.339-357
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• 2021

As the construction of trans infrastructure using the underground tunnel have been rapidly increased, various nearby excavation of existed underground facility including subway structure has been occurred in urban tunnelling. The concern and worry relating to the safety and stability of the existed facility by nearby excavation is becoming the key issues in urban tunnelling. In this study, it was conducted for existed the subway station structure at Seoul subway line which was closely located in the new Dongbuk urban metro railway to determine the behavior characteristics of station structure according to adjacent tunnel construction. Also, it was reviewed the evaluation of the safety zone and excavation method for subway structure. And after a review of damage evaluation, track irregularities and structural calculation by using a numerical analysis, stability of the subway structure according to nearby tunnel excavation was evaluated to be secured. This study is expected to be applied as useful reference in advance if you need to review the effects of existed structure according to nearby construction in complex urban tunnelling.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.06a
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• pp.512-514
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• 2013

대형선이 입출항하기 위한 항만 및 부두의 건설은 이미 포화상태에 이르러 중소규모의 조선단지 및 발전소 운영을 위한 선박통항 수요가 발생하고 있다. 접안시설 건설비용을 절감하기 위하여 선박의 조종성능을 우수하게 건조하여 투입하여 기존의 안전성 평가에 대한 대책과는 다른 대책을 수립하여야 안전성을 향상할 수 있다. 이 연구에서는 부두 및 방파제가 미리 건설된 상황에서 통항예정 선박을 한정하여 안전성 평가를 수행하고 도출된 문제점에 대한 해결방안을 제시하였다.

• Electronics and Telecommunications Trends
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• v.25 no.5
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• pp.84-96
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• 2010

국내 휴대폰 시장은 최근 급격한 변화의 시기를 맞고 있다. 음성정보 송 수신과 단순한 개인정보관리, 또는 멀티미디어 데이터 처리에 주력하던 피처폰 시장은 고사양의 운영체제, HD급 비디오, 수십만 가지의 앱(App.; Application), 고성능 디스플레이로 대표되는 스마트폰 시장으로 급격히 전환되고 있다. 이러한 스마트폰의 고사양화는 모바일프로세서, 베이스밴드 칩, 다양한 센서를 포함하는 스마트폰 하드웨어와 데스크톱 수준에 근접하는 고사양의 운영체제가 견인하고 있다. 특히, 모바일 프로세서는 스마트폰 기술 발전을 견인하는 핵심 부품으로서 다수의 프로세서와 외부인터페이스 장치를 포함하는 고성능, 저전력의 시스템온칩(SoC)이며 모바일프로세서의 동작속도, 전력소모량 등은 스마트폰의 성능을 가늠하는 척도로 인식되고 있다. 최근, 모바일프로세서는 스마트폰 시장을 넘어서 넷북, MID, 스마트 TV 등 다양한 산업영역에서 채용되고 있으며 2018년에 100억 개의 제품이 생산될 것으로 전망되어 모바일 시장의 폭발적인 성장을 견인하는 핵심 부품이다.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.34 no.2
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• pp.49-59
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• 2011

지속적으로 강화되고 있는 국제 환경규제로, 해운사들은 선박의 온실가스 배출량을 줄이기 위한 노력을 해야 하는 상황에 직면해 있다. 본 연구에서는 총 온실가스 배출량에 대한 제약이 있는 상황에서 복수개의 항로를 운영하는 해운사에서 일 평균 선박 운영비용의 총합을 최소화하는 항로별 최적 선박대수와 운항속도를 결정하는 문제를 다룬다. 이 문제를 풀기위해 라그랑지안 휴리스틱 알고리즘을 개발하고 라그랑지안 쌍대문제를 풀어 최적해에 대한 하한값을 구한다. 제시한 알고리즘의 성능을 평가하기 위해 비용인자들의 값을 달리하면서 랜덤하게 테스트 문제들을 생성하였으며, 실험결과 제시한 알고리즘이 짧은 시간에 최적해에 매우 근접한 좋은 해를 찾음을 알 수 있었다.

• Journal of the Korea Organic Resources Recycling Association
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• v.26 no.1
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• pp.13-19
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• 2018

25 local districts in Seoul have been running Waste Transfer Stations(WTSs) to secure regional collection bases, to connect between collection systems and waste treatment systems, and to commit various pre-screening of mixed wastes. There were, however, few previous researches to define how much WTSs are beneficial to waste collection system at least in Korea. So this study analyzed costs of waste collection systems with varied haul distances from waste sources(WSs) to WTS or building types of WTSs. Major results showed that the closer WTS is to WS or the cheaper the construction cost of WTS is, the lower the cost of waste collection system is. There was an additional result that WTS system with more than 15 km of total haul distance might be useful in Seoul and encapsulation of WTS in building or underground will make effective total haul distances longer up to 35km.

• Journal of Korean Society of Archives and Records Management
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• v.20 no.3
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• pp.23-37
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• 2020

This paper aims to elaborate on the reality of Gagakgo (架閣庫) by looking into its staff and abolition, given how Gagakgo was originally where diverse archives in Joseon were preserved. This study on Gagakgo, therefore, could be used as a basic reference to grasp the reality of the Joseon's Records Centers and Archives. This institution was changed as a labor organization following changes in the political environment. As a result, the status and operational aspects of the institution also changed. Gagakgo was abolished once during King Sejo (世祖)'s reign and then restored during the period between King Hyojong (孝宗)'s and YoungJo (英祖)'s reign. This restored institution also performed the same role as before. This paper serves as reference to better understand the system of Gagakgo and the archival preservation system in Joseon.

• Proceedings of the KIPE Conference
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• 2004.07b
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• pp.733-737
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• 2004

오랫동안 연구되어 오던 전력선 통신 기술은 1990 년대 중반에 이르러, 모뎀 기술을 응용한 10kbps급의 저속 전력선통신 기술이 개발되어 상용화 수준에 근접한 제품이 등장하기 시작했다. 반면 고속 전력선통신 기술 분야는 관심을 갖기 시작한 시기가 저속 분야에 비해 상대적으로 늦지만, 국내외 여러업체에서 고속 전력선통신 솔루션을 개발, 상용화에 근접한 칩셋 및 제품들을 선보이고 있다. 국내에서는 산업자원부의 중기거점 사업으로 수행중인 "50Mbps급 고속 전력선 통신망 개발사업"과 관련하여 고속 전력선 통신망 장치를 실용화 할 수 있도록 집단주택과 단독주택 형태의 인터넷 시범사업에 관한 연구가 활발히 수행중이다. 본 연구에서는 실제 수용가 환경인 단독주택 약 20세대에서 수행한 인터넷 시범사업을 통하여 개발된 전력선 통신 모뎀과 시스템에 대한 성능 측정을 수행한다. 이를 토대로 현 단계에서의 기술을 분석하고, 전력선 통신망에 대한 운영상의 적정 노드 및 가입자망 전송 섹터범위 등의 종합적인 평가에 대한 내용 등 실증시험망 구축 및 운용에 대한 결과와 향후 활용방안에 대해서 기술하고자 한다.

• Journal of Korean Tunnelling and Underground Space Association
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• v.8 no.4
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• pp.307-324
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• 2006

Effects of new tunnel construction on an existing tunnel are investigated in this paper. A parametric study was conducted on a number of conditions in terms of relative location of the new tunnel to the existing tunnel using 2D and 3D finite element models. The results indicated that the new tunnel construction imposes most severe effect on the existing tunnel's lining when located below the existing tunnel's springline for cases in which the new tunnel is constructed parallel to the existing tunnel. It is also revealed that the effect to the new tunnel construction is larger when the new tunnel is constructed under the existing tunnel than above for cases in which the new tunnel is crossed with the existing tunnel. Practical implications of the finding are discussed.

• Tunnel and Underground Space
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• v.17 no.2 s.67
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• pp.152-164
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• 2007

Recently as increasing the amounts of cargoes and passengers, it is necessary to improving railway capacity and speed. So the constructions of improving the existing railway line have been advanced. Sometimes the new railway tunnel is built to adjacent the existing railway line. Furthermore the new tunnel might be built near the existing facility within the tunnel width. In this case, it should be analyzed the influence of existing tunnel and if it is necessary, it should be taken the appropriate counterplan. The major analysis contents are follows. One is the influence on the existing tunnel by a blasting and train vibration and the other is stability problem of the existing tunnel by excavation of new tunnel. Therefore, we peformed the following analysis. Refer to a domestic and foreign standard and paper, the permitting level of blasting vibration is decided and the excavation plan of the new tunnel are designed. The numerical analysis is performed about the stability of the existing tunnel and new tunnel. The influence of the train vibration on tunnel is analyzed by the empirical equation.

• Journal of Space Technology and Applications
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• v.2 no.1
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• pp.30-40
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• 2022

This paper illustrates the trajectory design of drift distance recovery after initial launch and proximity operation when verifying rendezvous/docking technology using nanosatellites. The rendezvous/docking is a technology that is the basis of on-orbit servicing technology and is a preemptive process essential for approaching a target object. In particular, since it is difficult to verify in space, nanosatellites have recently been used to reduce the risk and cost of the development stage. Therefore, this paper not only introduces the configuration and specifications of thrusters for nanosatellites but also designs relative trajectories that can take into account the thrust limitations which come from the small size and low power of nanosatellites. In addition, we intend to be helpful in later designing scenarios according to the improvement of available thruster performance through comparison of trajectories and thrust usage with cases without thrust limitations.