• 건축역사연구
• /
• 제17권6호
• /
• pp.29-44
• /
• 2008

This paper analyses the railroad trunk line constructed in the Korea since the end of the 19th century. The analysis consists of the following problematics. 1) The process of the decision of the railroad route 2) The relationship of the location of Eupchi and the stations By clarifying the above, the purpose of this paper is to clarify how the morphology of the city in Korea has been affected by the change in the relationship with Korea and Japan. The Empire of Japan has been reconnoitering the Korea since way before the formal contract for the railroad construction was signed. Therefore, the Empire of Japan had a very good understanding of the actual transportation system when it started the construction of the railroad. The railroad construction was used by the Empire of Japan to empower the control over the Korea. For this reason, the new railroad system was constructed as a different system from the former transportation system and the urban system was also affected. Also the relationship of the western powers and Japan around the turn of the 20th century defined the characteristic of the railway system as a pathway through the Korean peninsular to link Japan to the continent. Moreover, being apprehensive about the friction with the western, Japan located the railway stations to avoid the missionary land properties. This made it clear that the restraint relationship between Japan and the western affected the urban special structure.

• 한국철도학회논문집
• /
• 제12권5호
• /
• pp.778-787
• /
• 2009

본 논문은 우리나라에서 철도가 가져온 사회경제적 변화에 대해 분석하였다. 우리나라 철도는 1899년 개통된 이후 금년으로 110주년이 되었는데 철도는 그동안 교통뿐만 아니라 국토의 공간구조, 새로운 도시의 형성 등 사회경제적으로 큰 영향을 미쳤다. 대전은 좋은 예의 하나이다. 본 논문에서는 철도가 가져온 변화를 구체적인 사례를 통해 통행시간의 변화, 도시발전과 인구변화, 산업의 변화, 문화와 관광의 변화 등을 분석하였다. 향후 이러한 연구는 다른나라와의 비교연구를 통해 철도가 가진 보편적인 기능과 한국철도의 독특성을 파악하는데 도움을 줄 것이다.

• 소성∙가공
• /
• 제27권1호
• /
• pp.12-17
• /
• 2018

This paper outlines the research findings on the microstructure and mechanical properties of AZ31 Mg alloy fabricated by differential speed rolling (DSR) with respect to processing variables such as temperature, roll speed ratio (RSR), and deformation route. The resultant microstructure of the sample, deformed by 2-pass DSRs at 473 K, comprised finer grains with more uniform distribution than those at 573 and 623 K. This was due to active recrystallization, which was expected to appear during DSR at temperatures higher than 573 K. When the sample was deformed via DSR with RSR of 1:4 for the upper and lower rolls at 453 K, the values of yield and ultimate tensile strength were observed to be higher than their counterpart with RSR of 1:1. The application of sample rotation around the longitudinal axis would give rise to an excellent combination of tension strength (~330 MPa) and ductility (~20 %) at ambient temperatures. This is discussed based on its uniform fine grained structure and the softening of basal texture.

• 한국화재소방학회논문지
• /
• 제29권2호
• /
• pp.8-12
• /
• 2015

성능위주소방설계 초기단계로서 피난안전성평가에 있어서 Available safe egress time (ASET)과 Required safe egress time (RSET)를 계산하여 단순비교하고 있다. 본 논문에서는 FDS를 이용하여 열, 연기, 독성가스 등에 대한 위험정보값을 추출하였다. 또한 피난시뮬레이션 프로그램인 Artisoc를 이용하여 FDS에서 추출한 위험정보값을 적용하였다. 건축물의 구조는 가로 60 m, 세로 65 m로 구성하였으며, 출입구는 2곳에 설치하였으며 재실자는 50명을 랜덤하게 배치하였다. 시뮬레이션은 case1~case20 까지 총 20회에 걸쳐 진행하여, 피난 경로별 위치에 따른 재실자의 위험도를 분석하였다. 이를 통해 위험정보값을 적용하여 기존의 단순비교 하던 피난안전성평가의 신뢰도를 높이기 위한 위험정보값 전달기반의 평가기법을 제시하였다.

• 한국농공학회지
• /
• 제33권2호
• /
• pp.104-111
• /
• 1991

In Korea, small-scale reclaimed areas have been suffering from many problems because of the lack of comprehensive developing strategy although considerable investments have been inputed by the public sector since 1970's. For 3 reclaimed sites in Chonnam Province choser as case study areas, the analysis, the second attempt of widely-spanned studies on areal conditions, concentrated on their farming and economic conditions. Its results were as follows ; 1. Although farming pattern has been transferred to the full4ime rice cropping type by the creation of reclaimed paddy field, farming size in the areas has not been increased more than that in existing agricultural areas. This means that agricultural planning should be included in the initial stage of reclamation projects, especially with reference to the substantial enlargement of farming size. 2. Block parcelling of severely fragmented holdings in new and old lands should be carried out, which can make farming activities efficient and farming route shortened. In large-scale reclaimed areas, new village planning could be considered in its central zone for efficent farming. 3. Because soil in the areas contains much more salt and water than that in other areas, new design methodology should be introduced for the efficient use of agricultural machines in reclaimed areas. 4. There are deep-seated economic problems in reclaimed area, which have been caused by very poor level and agriculturally dominated structure of household income. These problems should motivate farmers to give up positive action for qualitative and quantitative improvement in farming.

• 한국결정성장학회지
• /
• 제24권2호
• /
• pp.84-87
• /
• 2014

Separation/recovery of valuable metals such as zinc, nickel or tin from copper alloy dross has recently attracted from the viewpoints of environmental protection and resource recycling. In this study, preliminary investigation on separation of tin (Sn) from copper alloy dross using selective dissolution method was performed. The tin in the copper alloy dross did not dissolve in an aqueous nitric acid solution which could allow the concentration/separation of tin from the copper alloy dross. Precipitation of tin as $H_2SnO_3$ (meta stannic acid)occurred in the solution and transformed to tin dioxide ($SnO_2$) after drying process. The dried sample was heat-treated at low temperature and its crystal structure, surface morphology and chemical composition were investigated.

• 한국세라믹학회지
• /
• 제56권5호
• /
• pp.474-482
• /
• 2019

Chromium-doped zinc ferrite nanoparticles with the general formula Cr_yZnFe_2-yO₄ (y = 0, 0.025, 0.05, 0.075, and 0.1) were synthesized by a surfactant-assisted chemical co-precipitation route using metal nitrate salt precursors. The phase purity and structural parameters were determined by powder X-ray diffraction. The concentration of Cr³⁺ doped into ZnFe₂O₄ (ZF) noticeably affected the crystallite size, which was in the range of 22 nm to 36 nm, and all samples showed a single cubic spinel structure without any secondary phase or impurities. The lattice parameter, X-ray density, and skeletal density increased with an increase in the Cr-doping concentration; on the other hand, a decreasing trend was observed for the particle size and porosity. The influence of Cr³⁺ substitution on ZF magnetic properties were studied under an applied field of 15 kOe. The overall results revealed that the incorporation of a small amount of Cr dopant changed the structural, electrical, and magnetic properties of ZF.

• 정보학연구
• /
• 제7권3호
• /
• pp.127-137
• /
• 2004

본 연구에서는 프로젝트의 계획단계에서 프로젝트 관리자가 수행해야 할 프로젝트에 대하여 규모, 범위, 기간, 성격 등의 측면에서 가장 유사한 과거의 사례를 찾아주고 이를 참조하여 WBS를 설계할 수 있도록 규칙과 사례기반 추론에 근거한 프로젝트 계획수립 지원모듈(PPSM: Project Planning Support Module)개발 방법을 제안한다.

• 대한전기학회논문지:전력기술부문A
• /
• 제48권11호
• /
• pp.1457-1463
• /
• 1999

This paper develops an real-time expert system for the electronic interlocking system. it obtains the higher safety by determining the railway interlocking strategy in order to prevent trains from colliding, and derailing in the viewpoint of veteran expert, considering the situation of station in real-time. The expert system determines the real-time interlocking strategy by confirming the interlocking relationships among signal facilities based on the interlocking knowledge base from input information such as signal, points, and it is implemented as the rule-based system in order to represented accurately and effectively the interlocking relationships. Especially in case of emergency the function which determines the rational route coordinating with IIKBAG on the workstation is designed in order to minimize the spreading effect. It is implemented in C computer language for the purpose of the implementation of the inference engine using the dynamic memory allocation technique, the build and interface of the station structure database. And, the validity of the built expert system is proved by simulating the diversity cases which may occur in the real system for the typical station model.

• 한국세라믹학회지
• /
• 제52권2호
• /
• pp.108-113
• /
• 2015

In an effort to evaluate the practicability of an imprinting technique for amorphous chalcogenide film in Ge-based compositions, we investigate the deformation behavior of the surface of amorphous $GeSe_2$ film deposited via a thermal evaporation route according to varying static loads applied at elevated temperatures. We observe that, under these static loading conditions, crystallization tends to occur on its surface relatively more easily than in As-based $As_2Se_3$ films. As for the present $GeSe_2$ film, higher processing temperatures are required in order to make its surface reflect the given stamp patterns well; however, in this case, its surface becomes partially crystallized in the monoclinic $GeSe_2$ phase. The increased vulnerability of this amorphous $GeSe_2$ film toward surface crystallization under static loading, when compared with the $As_2Se_3$ counterpart, is explained in terms of the topological aspects of its amorphous structure.