• Cement
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• s.67
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• pp.25-41
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• 1977

미$\cdot$일에서 기 개발 운영되고 있는 대형 노천광산 및 광산장비 제작 공장에 대한 전반적인 실태 파악을 통하여 향후 대형화로 국제규모화될 당사 석회석 광산의 운영 및 기술적인 방향을 모색코자 함이 금번 출장의 목적이었다. 이에 당사 광산분야 기술자 6명으로 팀을 구성, 76년 하반기에 약 1개월은 미국에서, 약 1개월은 일본에서 양국 굴지의 10여 open pit mine 및 3개 장비 메이커를 방문 견학하였다. 금번 방문 결과 다음과 같은 점을 확인할 수 있었다. 첫째 금번 당사의 560만톤 증설은 사실상 미$\cdot$일을 앞지르고 국제적으로 굴지의 규모임을 확인할 수 있었고, 둘째 deposit(광상)의 지리적 여건비교에서는 미국의 것에는 뒤지나 일본의 조건에 비해서는 우리의 것이 결코 악조건이 아니며, 세째 특히 일본 석회석 광산업계가 안고 있는 제반문제점의 심각성(광구 경계 인접에 따른 분쟁, 시가지 인접에 따른 공해문제, 개발 여건의 불량 등)에 비추어 볼 때 국내 광산 기술자들의 노력 여하에 따라 일본은 충분한 경쟁대상이 될 수 있으며 국내시멘트업계 광산의 지리적, 지질적 여건상 일본광산보다 더욱 우수한 광산을 만들 수 있다는 자신감을 얻었다. 그러나 (1) long term 한 측면에서의 광산개발의 결여 (2) dyke와 폐토 처리 및 quarry QC의 불가피성 (3) 사회적 요소의 낙후(M.S 뇌관부재, 메이커 출장에 의한 장비의 수리, 화약류의 산원 혼합사용 등)등은 두드러진 우리의 결함이라고 느꼈으며 이들 결함의 시정, 보완을 위해서 사내외적으로 기존질서의 재검토가 이루어져야 할 것으로 사료된다. 미$\cdot$일 광산에서 일반화되어 있는 radio(walkie-talkie) system 및 electric shovel 주우 Cement Co., 산구사업소에서 시도된 belt 반전장치, 인력의 확대관리 등은 조기도입하여 실용화할수 있는 대상이라 생각하며 일철의 조형산 개발(72년 생산 개시, 광산 개발비 200억원, 연산 능력 800만톤)은 괄목할만한 것이었다. 또한 앞으로 국내업계 여건이 허락하는 한 광산 기술자의 해외파견 회수를 증가시켜 더 많은 사람들이 직접 보고 느끼어 우리의 것을 개선 창조해 나갈 수 있는 기회를 많이 가져 국내는 물론 국제 경쟁에 대처할 수 있는 업계 직원의 자질 향상을 바란다.

• Journal of the Korea Convergence Society
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• v.10 no.10
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• pp.173-183
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• 2019

The purpose of research is to explore the direction of building a collaborative supply chain, which may enhance the competitiveness of firms and their project-based supply chain. Large-scale plants or large-scale buildings construction is referred to as a EPC project. To identify a collaboration mechanism in the project-based supply chain, the empirical research was conducted on the interrelationship between the absorption capacity of firms participating in the EPC project, the incentive norms, the goal congruence with supply chain, and the ability of respond to changes of the task of supply chain. PLS-SEM was used as an analysis method to verify the research model. It is expected that the results will help inform the need for SCM, the importance of the incentive norms and the goal congruence in the supply chain of EPC project.

• Journal of the Korean Institute of Gas
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• v.1 no.1
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• pp.27-32
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• 1997

Continual monitoring of abnormal operating conditions i a key issue in maintaining high product quality and safe operation, since the undetected process abnormality may lead to the undesirable operations, finally producing low quality products, or breakdown of equipment. The statistical projection method recently highlighted has the advantage of easily building reference model with the historical measurement data in the statistically in-control state and not requiring any detailed mathematical model or knowledge-base of process. As the complexity of process increases, however, we have more measurement variables and recycle streams. This situation may not only result in the frequent occurrence of process Perturbation, but make it difficult to pinpoint trouble-making causes or at most assignable source unit due to the confusing candidates. Consequently, an ad hoc skill to monitor and diagnose in plat-wide scale is needed. In this paper, we propose a hierarchical plant-wide monitoring methodology based on hierarchical decomposition and principal component analysis for handling the complexity and interactions among process units. This have the effect of preventing special events in a specific sub-block from propagating to other sub-blocks or at least delaying the transfer of undesired state, and so make it possible to quickly detect and diagnose the process malfunctions. To prove the performance of the proposed methodology, we simulate the Tennessee Eastman benchmark process which is operated continuously with 41 measurement variables of five major units. Simulation results have shown that the proposed methodology offers a fast and reliable monitoring and diagnosis for a large scale chemical plant.

• Journal of Biosystems Engineering
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• v.6 no.2
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• pp.65-76
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• 1982

This survey was conducted to investigate the status of repair and maintenance of 4 wheel tractor for a basic reference to the improvement of quality and proper utilization of tractors. Thirty two counties from eight provinces, except Jeju, were covered in this study in order to investigate annual break-down and repair of tractor in 1980. The analyzed results are summarized as follows; 1. The average number of break-down of large size tractors(47ps) was 5.0 times in a year and it was about twice of that of small size tractors(19-23ps). The break-down frequency per 100 hours of use was 1.11 times in the large size and 0.65 times in the small size tractors. 2. 75.6 percent of total break-down was occured in main body of tractor and 24.4 percent in attachments. In particular, the break-down of plow and rotavator was more than 80 percent of total break-down of the small size tractor attachments. 3. The large size tractors which were occured more than one times of break-down a year was 75 percent and its rate of the small size tractor was 62 percent. But 9 percent of tractor surveyed had more than ten times of break-down in a year 4. The frequency of break-down had a peak in May, and it was directly proportional to the hours of use. 5. The causes of break-down were poor maintenance and operation by 29.8 precent, old parts by 30.2 percent, poor quality of parts by 20.6 percent, poor field condition by 16.3 percent and others by 3.1 percent. 6. Annual number of repair was 5.5 times and among them 55.6 percent was done by shop and 44.4 percent by operator. 7. Total required repair time was 30.6 hours a year in the large size tractor and 19.9 hours in the small size tractor. Average repair time was 3.62 hours a time. 8. Annual repair cost was 278 thousand won in the large size tractor and 70 thousand won in the small size tractor. The repair cost per hour of use was 621 won in the large size and 198 won in the small size tractor. 9. The repair cost rate of tractor(Y) was regulated with tractor age (X) as follow; Y=0.752X In case of the service life of tractor was 10 years, the total repair cost rate was 64 percent.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.9
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• pp.85-92
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• 2020

In this study, the automatic processing of the wing ribs of large aircraft was simulated. Specifically, in the simulation for the automatic processing of the fly ribs, the process of the automated loading device with a robot was examined, along with the wing rib processing and manufacturing automation processes. Moreover, the process time, corresponding to all the stages in the wing rib processing, was calculated. The results pertaining to the machining and manufacturing times of 34 wing ribs (Nos. 1-17), as obtained through the proposed simulation approach, indicated that the total machining time for the left and right wing ribs and rib guns was 537.7 h. The production time was calculated as 1,117.4 h. It is considered that the processing of the wing ribs of large aircraft can be automated in a factory, based on the results of the proposed simulation process.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.2122-2123
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• 2011

대규모 발전단지의 계통연계 및 지역간 전력 융통과 대도시지역의 전력공급원 역할을 담당하기 위해 현재 전국적으로 67개의 345kV 이상 초고압변전소가 운전되고 있고, 향후에도 지속적으로 변전설비가 확충될 예정이다. 초고압 변전소에 필수적으로 설치되는 주변압기, 리액터는 그 용량에 따라 대형 중량물(345kV 변압기 66톤, 리액터 88톤 등)로 제작됨으로써 특수 운반차량을 통해서만 공장에서 현장까지 운반되고 있다. 현행 국내 도로법에서는 운반차량의 축하중이 10톤을 초과하거나 적재물 중량을 포함한 총 중량이 40톤을 초과할 경우 도로(교량)관리청의 허가를 득한 후 운반토록 규정하고 있고, 허가 조건을 맞추기 위해서는 교량보강 등의 공사를 통해 교량에 가해지는 중량을 분산시키거나 별도 우회도로를 설치하고 있다. 교량보강 공사는 교량의 종류에 따라 하부지보, 상부가교, 우회가교, 우회가도 등의 개별공법 또는 복합공사를 시행하고 있으나, 엄청난 토목공사비와 시간이 소요되고 있는 실정이다. 따라서 본 논문에서는 중량물 교량통과를 위해 대규모 토목공사 없이 운반할 수 있는 신기술 장비인 'Crossing Bridge System'에 대한 이론적 내용과 더불어 해당 기술의 특징 및 활용계획에 대해 기술하고자 한다.

• Journal of the Korean Institute of Gas
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• v.17 no.1
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• pp.49-55
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• 2013

Large scale systems, the facilities for the production of power, gas and chemical, have the complex structures. Most systems require the high reliability for the improvement of process efficiency, but it is difficult to analyze the reliability of processes with complex structures. In this study, we investigated reliability path of chemical process with k-out-of-n system by reliability block diagram(RBD) and calculated the reliability of process through the failure enumeration method of reliability path. This method should help in analyzing the reliability of k-out-of-n system.

• 월간 기계설비
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• no.4 s.201
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• pp.30-36
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• 2007

ESCO란 에너지 절약회사(Energy Saving Company) 또는 에너지 서비스 회사(Energy Service Company)를 뜻하는 용어로 지난 1992년 정부에서 에너지 절약을 촉진하기 위해 정책자금을 도입하면서 등장했다. 이들 기업은 정부에서 정책자금을 빌려 공장이나 아파트 등 에너지 사용자에게 에너지 절약시설을 지어주고 에너지를 줄인양만큼 투자비를 회수해 간다. 고유가가 계속되면서 에너지절약 전문기업인 ESCO 단위 사업규모가 점차 대형화되고 있다. ESCO 투자실적은 1998년 이후 에너지절약 시설 개체 사업의 급속한 증가에 힘입어 매년 급격히 성장하고 있다. 최근에는 2천억원대의 시장규모를 가지고 2005년에는 건당 평균 9.1억원이 지원된 것으로 나타났다. 에너지관리공단 자금지원팀의 자료에 의하면 ESCO투자사업 자금지원은 1993~1998년 197건에 480억원이 지원됐으나 2005년에는 202건에 1,829억원이 지원된 것으로 나타났다. 지난 2006년 9월 말 현재 ESCO투자사업 자금지원은 106건에 1,020억원이 대출 은행에 추천된 것으로 알려졌다. 또한 에스코 사업분야가 조명기기·보일러 등 단순설비 교체에서 열병합발전소·냉난방설비, 공정개선 및 폐열회수 등 복합설비 쪽으로 확대되고 있는 것으로 나타났다. 따라서 에너지 소비가 큰 화학 철강 제지 등 산업체, 대형병원, 산업단지 등이 새 에너지 절감 시스템을 도입하면 에너지 효율성 개선에 효과적인 사업이다. 본지는 지난호에 ESCO사업 현황과 투자사례를 게재하고, 이번호에는 ESCO사업 지원시책과 외국의 ESCO활동 현황 및 국내의 ESCO 투자사례를 게재할 계획이다.

• Korean Journal of Construction Engineering and Management
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• v.9 no.6
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• pp.164-174
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• 2008

As buildings become larger, higher and more complex in most construction sites, construction projects have to deal with transportation of more materials, labor and equipment, necessitating more use of construction equipment. Notably, in the high-rise building and plant construction projects mobile cranes are adopted more frequently among different types of construction machinery, which also results in serious industrial accidents relating to the use of crane. To reduce serious industrial accidents involving cranes, researches on its stability is in need. The research herein aims to study how to select sling and lug of mobile crane and review its stability. The research outcomes herein will make considerable contributions to selecting mobile cranes efficiently and ensuring their stability.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.539-542
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• 2004

Nowadays, High-rise building becomes higher and bigger than ever. As a result, lots of construction materials are needed at the same times. Because of divided diverse process of construction, several different Processes concur simultaneously with complexity of procurement. So, effective construction material supply and lift-up are essential part of the spot. Especially, when ending part of construction, there are much conflict between finishing and equipment materials also problems of folding lift-up. The Purpose of this paper is suggesting better effective lift-up system through analysis of loading factors.