• 한국콘텐츠학회논문지
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• 제17권1호
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• pp.50-57
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• 2017

본 논문은 대전도시철도 개통 이후 내부자료 통계분석을 통해 열차지연 원인과 문제점을 살펴보고 고위험군의 위험도를 평가하여 위험도 지수 심각도와 위험도를 측정하였다. 측정방법으로는 위험도 관리방법인 risk matrix($5{\times}5$)를 적용하여 위험도 등급을 산정하였으며, 결과에 따른 안전수준과 허용수준 범위를 분석하였다. 그 결과 차량분야가 가장 위험도가 심각하고, 다음으로 기계설비분야가 위험도를 내재하고 있는 것으로 나타났다. 특히 차량의 출입문장치결함으로 인한 출입문고장과 열차신호 및 제어장치는 심각도도 높지만, 빈도수가 매우 잦아 추가적인 사고 잠재성을 보이고 있다. 기계설비 분야의 PSD결함도 PSD의 안전문 개폐불량이 가장 위험한 것으로 나타났으며, PSD의 오취급 및 PSD의 유리파손 등도 위험도를 내포하고 있는 것으로 나타났다. 본 연구는 이러한 위험도를 내재하고 있는 사고의 빈도수를 경감하고, 심각도를 낮춰서 위험도를 예방할 수 있는 방안을 예측하여 미리 선제적으로 대비할 수 있는 분석결과를 제시함으로써 안전한 도시철도운영으로 이용자의 교통편익에 기여할 것으로 기대된다.

• 한국산학기술학회논문지
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• 제19권8호
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• pp.246-253
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• 2018

본 2018년 충청북도의 주력산업은 스마트 IT 부품, 바이오 헬스, 수송기계 소재부품 산업이다. 수송기계 소재부품 산업은 기계 분야에서 미래형 수송 수단 관련 친환경 및 지능형 핵심 원천기술에 해당한다. 이 산업을 육성하기 위하여 기업지원 사업이 진행되고 있다. 본 연구에서는 기업지원 중 기술지원 사업의 대상과 방향을 설정하기 위하여 충북지역의 해당 기업의 업체 수, 종업원 수, 출하액, 부가가치 액을 수송기계 소재부품 산업의 전방 산업과 후방 산업으로 구분하여 분석하였다. 특히 50인 미만의 중소기업체에 대하여 기업의 창설이후 업력에 따른 업체 당 부가가치 변화를 분석하여 지원 대상 기업군을 설정하였다. 후방 산업의 경우, 창업 3년 이내의 업체의 부가가치 액은 연도 별로 점점 낮아지고 있어 창업 초기에 기술지원이 필요하다. 5~9년 사이의 업체는 연도 별로 극심한 변화 추세를 보이고 있어 사업 다각화 또는 신규 아이템 발굴을 위한 지원이 필요한 것으로 판단된다.

• Journal of Biosystems Engineering
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• 제40권1호
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• pp.19-27
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• 2015

Purpose: A system to measure the visibility of agricultural tractor operators was designed and evaluated according to ISO standards, and a blind area diagram around the tested tractor was created based on the manual method recommended by the National Institute for Occupational Safety and Health (NIOSH). Methods: A visibility measurement system was designed and evaluated based on the ISO 5006 and ISO 5721-1 standards. Two bulbs used to simulate the operator's eyes were mounted on a bar with a supporting frame. A wooden frame was used to determine the seat index point position. The 12-m visibility test circle was divided into six sectors of vision, and the test tractor was placed at the center of the circle. Artificial light was supplied in the darkened environment, and shadow or masking effects were measured manually around the 12-m circle. Results: When the bulbs were placed at the operator's eye level, front visibility was good; no masking was found in the "A" vision sector, but larger masking widths were found in the "B" and "C" vision sectors. Since the masking width exceeded 700 mm, additional tests, such as movement of the light sources to both sides of the operator's eye level, were performed. Less than six masking effects were found in the semi-circle of vision to the front, and more than one masking was found in the "B" and "C" visual fields. The minimum distance between the centers of two masking effects exceeded 2500 mm when measured as a chord on the semi-circle of vision. A blind area diagram was created to define the exact nature of the blind spots and mirror visibility. Conclusions: Visibility evaluation is an effective way to enable proper and safe operation for agricultural tractor operators. Inclusion of this visibility evaluation test in the general testing process might aid tractor manufacturers.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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• pp.1013-1025
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• 1993

Agriculture in Swaziland is the most important sector of the economy from the stand point of export earning, rural employment and dependency for family food. But, inspite of 65.5 percent of the household being busy in food production for family consumption in Swaziland, the import bill of food and live animals is rising from E119.7268 million in 1987/90 (An.St.Bul.1988) . A typical farm size, based on holding's growing crops, is only 1.93 ha which may prohibit owning a four wheel tractor for farm operations. The traditional hand tools are just not efficient and comfortable to operate in order to exploit full potential of the land. There are over 120.000 draught animals which have potential to be utilized in farming. The two wheel-tractor is another energy source which can be used for many farm-operations.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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• pp.114-115
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• 2018

Since the introduction of the C.M(Construction Management)system in the Basic Law of the Construction Industry in 1997, the recent arrangement of construction management engineers in public sector buildings has generally been based on architecture·civilengineering·machinery·landscaping, electricity, telecommunication, fire fighting by the number of M/M(Man and Month). In the field of engineers arrangement in each field, the arrangement of M/M according to the workload of architecture.civilengineering.machinery.landscaping and electricity is inadequate causing conflicts and C.M among construction management engineers. Therefore, this study aims at basic research that is used to identify the problems through the questionnaire and to prepare future improvement plans.

• 기술혁신학회지
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• 제16권2호
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• pp.391-407
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• 2013

본 연구에서는 산업연관표를 통해서 특정연도(1990년) 기술의 진부화 정도를 측정하고, 노동생산성과의 연관성을 밝힘으로써 체화가설(embodiment hypothesis)을 검증한다. 이는 기술에 강한 경제적 의미를 부여한 Salter(1969)의 주장에 근거한 것으로, 경제적 잉여율의 감소를 기술진부화 정도로 보았다. 분석대상은 우리나라 제조업에 속한 주요 업종인 음식료, 섬유의복, 화학, 비금속광물, 철강, 금속제품, 일반기계, 전기전자, 정밀기기, 수송기계 등이다. 연구결과, 우리나라 제조업 전체에 대해서 일률적으로 체화가설의 성립여부를 판단하기는 어려웠다. 그러나 제조업 주요 업종 중 섬유의복, 화학, 비금속광물, 금속제품, 전기전자, 수송기계 등의 산업에서는 체화가설이 성립함을 확인하였다. 즉 이들 6개 산업에서는 기존 자본설비에 현대적인 새로운 자본설비가 연속적으로 도입됨에 따라 특정시점에서 자본설비에 체화되어 도입된 기술은 진부화 하지만, 시현되는 노동생산성은 증가하는 것으로 분석되었다. 따라서 개별기업들은 설비투자에 대한 의사결정 시에 관련설비에 체화된 기술진보에 관한 정보를 적극 고려해야 하며, 정부는 R&D지원 일변도의 정책에서 벗어나 체화기술진보 효과가 큰 산업에 대해서는 설비투자를 지원하는 정책도 고려해야 한다.

• 한국기계가공학회지
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• 제20권12호
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• pp.44-53
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• 2021

As environmental issues have emerged worldwide, emission gas regulations have been strengthened. In the construction machinery sector, studies have been actively conducted to utilize the power source of electric motors owing to the increasing demand for zero emissions. In this study, the gear specifications of an electric axle for construction machinery were selected by considering the specifications of the motor, gear tooth contact pattern, and face load factor. The gear strength evaluation was performed at the system level using the simulation model. The bending and contact strength of the spiral bevel gears and the bending strength of the planetary gear set showed a safety factor of 1 or more. However, the contact strength of the planetary gear set showed a safety factor of 0.92. Conservative results were derived by performing the analysis under the rated load condition of the motor. However, the ratio of the equivalent torque to the rated torque of the motor was 45% or less, hence, it was determined that no difficulties should arise regarding the durability of the axle.

• 지역연구
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• 제11권1호
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• pp.1-20
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• 1995

This paper studies the comparative advantage of competitive and specialized regional industries which are manufacturing, wholesale and retail trade, servies in the metropolitan area-Seoul, Inchun, Kyunggi-do of Korea, For the analysis of industries, the coefficient of specialization, the indices of competitiveness of labor and value-added, the growth rate are simultaneously examined under the criteria of the number of workers, value of shipment, value-added, This comperative synthetic analysis is different from the traditional approaches. This paper shows that the perfectly competitive advantage of specialized industries satisfying all of three criteria are 'other business related activities', 'recreational, cultural and sporting activities' in Seoul, 'machinery and outfits, n.e.c', 'retail trade, except of motor vehicles and motorcycles, repair of personal and household goods' in Inchun. We conclude that each should strategically develop the region-oriented specialized industry which has the comparative advantage. It is the reason why the concentration of industry in necessary for the leading of regional industry under the weaken local public finance. Moreover, such an industy should provide the increase of employment and income from the viewpoint of the activation of regional economy. The potential-specialized competitive industry requires the advanced structure of production under the criteria of value-added. For the development of the metropolitan area's economy, the highly advanced technology industry including computer and electronics should be induced through the loosening of metropolitan regulation. Research center(science park) supported by th private-public sector should be built for the increase of technology sector should be built for the increase of technology power of the small and medium enterprises, Also it is necessary that the small and medium enterprises strategically make the cooperative-large group in order to avoid the disadvantage from the size.

• 대한조선학회지
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• 제21권2호
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• pp.9-17
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• 1984

Laminar and turbulent boundary layers on a rotating sector and a helical blade are calculated by differential method. The estimation of three dimensional viscous flows provide quite useful informations for the design of propellers and turbo-machinery. A general method of calculation is presented in this paper. Calculated laminar boundary layer on a sector shows smooth development of flows from Blasius' solution at the leading edge to von Karman's solution of a rotating disk at the down-stream. Eddy viscosity model is adopted for the calculation of turbulent flows. Turbulent flows on a rotating blade show similar characters as laminar flows. But cross-flow angle of turbulent flows are reduced in comparison with laminar boundary layers. Effects of rotation make flow structures significantly different from two-dimensional flows. In the range of Reynolds number of model scale propellers, large portion of the blade are still in the transition region from laminar to turbulent flows. Therefore viscous flow pattern might be quite different on the blade of model propeller. The present method of calculation is to be useful for the research of scale effects, cavitation, and roughness effects of propeller blades.

• 농촌지도와개발
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• 제27권4호
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• pp.159-171
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• 2020

This study aims to examine the needs analysis for agricultural management capabilities and farming practices that were emphasized by focusing to the inflow of farmers and the importance of the smooth succession. Data were collected from 134 farm successors. The Borich demand and the Locus for Focus model were hired for the study. Result were as follows. The competency group that the farm successors showed a high educational needs for was financial management. As for the detailed competencies that farm successors showed high educational needs for, based on Borich demand and the Locus for Focus model, the six detailed competencies of financial measures, financial analysis, financial management, sales planning, machine operation, and pest management were common and were derived as priorities. As for the direction of farming practice education for farm successors, based on these analysis results, education on machinery operation in the production sector should be expanded, and the management sector, more systematic and diverse education should be prepared to strengthen financial management capabilities.