• 한국산업보건학회지
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• 제16권3호
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• pp.276-283
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• 2006

Work-related musculoskeletal disorders (WMSDs) were a major source of disability and lost work time after 'Foreign Currency Crisis(1998-2000)' in Korea. There is considerable evidence documenting the association between psychosocial risk factors and work disability due to WMSDs. But, there is not much in Korea. The present study aimed to explore the predictive association between the changed working conditions and WMSDs after 'Foreign Currency Crisis' in Korea. A study sample of 8,670 automobile assembly workers were recruited for this study. A structured-questionnaire was used to assess general characteristics, working conditions, and information concerning medical treatment of WMSDs. After adjustment for sociodemographic factors, increased overtime work(OR=1.22), daily work time(OR=1.20), work speed (OR=1.32), number of workers(OR=0.83), supervisory control(OR=1.39), physical load(OR=1.39), and mental load (OR=1.25) were all founded to be significantly associated with WMSDs. This study has shown the importance of changed working conditions in the occurrence of WMSDs. Therefore, it will be necessary to reduce WMSDs with controlling both physical and psychosocial factors.

• Journal of Mechanical Science and Technology
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• 제20권9호
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• pp.1514-1524
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• 2006

This work presents the three-dimensional analysis of flow and heat transfer performed for a wire-wrapped fuel assembly of liquid metal reactor using Reynolds-averaged Wavier-Stokes analysis in conjunction with 557 model as a turbulence closure. The whole fuel assembly has been analyzed for one period of the wire-spacer using periodic boundary conditions at inlet and outlet of the calculation domain. Three different assemblies, two 7-pin wire-spacer fuel assemblies and one bare rod bundle, apart from the pressure drop calculations for a 19-pin case, have been analyzed. Individual as well as a comparative analysis of the flow field and heat transfer have been discussed. Also, discussed is the position of hot spots observed in the wire-spacer fuel assembly. The flow field in the subchannels of a bare rod bundle and a wire-spacer fuel assembly is found to be different. A directional temperature gradient is found to exist in the subchannels of a wire-spacer fuel assembly Local Nusselt number in the subchannels of wire-spacer fuel assemblies is found to vary according to the wire-wrap position while in case of bare rod bundle, it's found to be constant.

• 한국CDE학회논문집
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• 제17권1호
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• pp.35-44
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• 2012

Many automobile manufacturers are doing experiment on manufacturing environments by using an augmented reality technology. However, system layout and process simulation by using the virtual reality technology have been performed actively more than by using the augmented reality technology in practical use so far. Existing automobile assembly by using the augmented reality requires the precise calibrating work after setting the robot because the existing augmented reality system for the automobile assembly system configuration does not include the end tip deflection and the robot joints deflection due to the heavy weight of product and gripper. Because the robot is used mostly at the automobile assembly, the deflection problem of the robot joint and the product in the existing augmented reality system need to be improved. Moreover camera lens calibration has to be performed precisely to use augmented reality. In order to improve this problem, this paper introduces a method of the software based calibration to apply the augmented reality effectively to the automobile assembly system. On the other hand, the camera lens calibration module and the direct compensation module of the virtual object displacement for the augmented reality were designed and implemented. Furthermore, the developed automobile assembly system oriented AR-system was verified by the practical test.

• 한국기록관리학회지
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• 제19권3호
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• pp.97-121
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• 2019

본 연구는 국회 기록물관리 제도를 분석하여, 기록관리상의 문제점을 파악하고 그 대안을 제시하는 데 목적을 두었다. 연구 방법으로는 국회 조직 및 업무 분석을 바탕으로 국회의정활동 기록물의 개념을 정의하였고, 국회기록보존소와 헌정기념관의 국회기록물 관리현황을 분석하여 국회기록물 관리제도의 구조적 문제점을 도출하였다. 이에 "공공기록물 관리에 관한 법률" (이하 '공공기록물법')의 특별법으로서 국회기록물관리에관한법률(안)을 제시하였고 나아가 국회에 유한보존 기록물을 전담하는 중간기록물 관리기관 설치 및 헌정기념관의 수집기능을 국회기록보존소로 이관하여 의정활동 기록물의 통합 관리를 목표하였다. 이를 통해 모든 의정활동 기록물이 국회기록물 관리 체제 내에서 체계적으로 관리될 수 있는 방안에 대해 제안하였다.

• 한국산학기술학회논문지
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• 제22권1호
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• pp.24-30
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• 2021

본 연구에서는 자동차 밸브 바디 (valve body) 나사의 조립 상태를 검지하고 조립 작업을 보조하기 위한 증강현실 (AR) 앱을 개발하고 테스트를 통해 유효성을 보인다. 조립할 나사의 조립 위치와 순서 및 조립 상황들을 표시하는 컨텐츠들을 생성한 후 스마트 폰 화면의 밸브 바디 영상 위에 정합하여, 조립 도중에 작업자에게 보여준다. 이를 위해, 밸브 바디의 2차원 이미지로부터 특징 데이터를 추출하고 밸브 바디의 포즈를 알아낸다. 밸브 바디 위의 각 나사들이 조립될 영역의 영상을 추출하고 주기적으로 해당 영역의 휘도를 판별하며, 밸브 바디 위의 정해진 위치에 순서에 따라 각 나사들이 조립되고 있는 지를 확인한다. 미조립 또는 조립 순서 오류 등 조립 에러가 검지되면 경고 음이 발생되어, 작업자가 스마트 폰 화면에서 즉시 조립 상태를 확인하고 에러를 처리할 수 있다. 테스트를 통해 5개 나사의 조립 상태를 검지하는데 약 65ms가 걸리고 1시간 동안 오류 없이 조립 상태가 검지되는 것을 확인했다.

• 토지주택연구
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• 제10권3호
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• pp.77-87
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• 2019

In Korea, the modular construction method was applied to the construction of facilities such as military barracks and school dormitories, beginning with the pilot project of Seoul New Elementary School in 2003. In 2017, public modular houses were supplied to Busan(Yongho-dong) and Seoul(Gayang-dong), and modular housing is expected to continue to be supplied in the future. However, there is no clear construction standard for the modular housing construction yet, and there are few cases where the infill modular system is applied. Therefore, this study established the work breakdown structure and proposed a standard process focusing on the infill modular system applied to the construction of Dujeong-dong modular house in Cheonan. Level 1 of the work breakdown structure by construction stage of Infill modular was defined as modular manufacturing, assembly, and finishing process. Level 2 was defined as preparation, modular production, modular infill, modular fixing, floor plastering, building finishing, and other site finishing. Level 3 is defined as 57 detailed unit work of infill modular construction. The standard process of infill modular is proposed for the assembly stage that is commonly applicable to infill modular housing construction. The results of this study can be used for the process plan, transportation plan, lifting plan of modular housing construction.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1998년도 춘계학술대회논문집
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• pp.31-35
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• 1998

Many reaearchers have reproted that poor body postures are associated with pains or symptoms of musculoskeletal dissoders. Therefore, the ergonomic evaluation of postural stresses as well as biomechanical stresses is important when a job such as automobile assembly tasks involves highly repetitive and/or prolonged poor body postures. A macropostural classification shema was developed to characterise various body postures occurring in automobile assembly tasks in the study. To specify a postural code and stress level to each body posture, perceived joint discomforts were subjectively evaluated in the lab experiments for the full range of motion in five human body joints. Based on the reaults, a postural classification scheme was developed where the full range of motion in each body joint was classified into several codes repressenting different stress levels. The automobile tasks were clustered into 12 types based on the result walk-in-surveillance and the possible posture codes for each task type are defined. I was exposed that the poor postural problems in automobile assembly tasks were concerned in most part with arms, trunk and neck. Application of te developed schema to seven operations in automobile assembly tasks showed that the schema can be used as a tool to identify the operations and tasks involving highly stressful body postures. The schema can also be utilised as a basis to prioritise the candidate assembly operations for redesign of work methods.

• 한국멀티미디어학회논문지
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• 제18권5호
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• pp.583-598
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• 2015

We need many assembly lines to produce industrial product such as automobiles that require a lot of composited parts. Big portion of such assembly line are still operated by manual works of human. Such manual works sometimes cause critical error that may produce artifacts. Also, once the assembly is completed, it is really hard to verify whether of not the product has some error. In this paper, for monitoring behaviors of manual human work in an assembly line automatically, we proposes a realtime hybrid monitoring system that combines 2D vision sensor tracking technique with 3D motion recognition sensors.

• 산업공학
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• 제7권2호
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• pp.75-85
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• 1994

This paper presents a production scheduling model in a block assembly shop in shipbuilding industry. In a block assembly shop, the most important performance criterion is load leveling, which balances manpower and work area utilization through the planning horizon. The problem is formulated as a mixed-integer nonlinear programming(MINLP) problem of which objective function is to optimize load leveling. The developed MINLP problem can not be solvable due to computational complexity. The MINLP problem is decomposed into two stage mixed-integer linear programming (MILP) problems to obtain a good solution, but the decomposed MILP problems are still computationally intractable because of combinatorial complexity. Therfore, a heuristic method using linear programming is proposed to solve two stage MILP problems sequentially. The proposed heuristic generates a good production schedule within a reasonable computation time, and it is easily applicable for establishing the production schedule in a block assembly shop in shipbuilding industry.

• 한국염색가공학회지
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• 제20권5호
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• pp.23-27
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• 2008

In this work, poly(diallyldimethylammoniumchloride) (PDDAC) and meso-tetrakis(4-carboxyphenyl)porphyrin were considered to produce the self-assembly fabrication films. This method is based on the layer-by-layer (LbL) deposition produced by the electrostatic attraction between positively charged PDDAC and negatively charged porphyrin ions. The result of multilayer fabrication was discussed with the level of color strength (K/S). K/S spectra of the fabricated multilayer films showed gradual increase behaviors. In addition, the color photo images of the fabricated multilayer films showed that PDDAC and porphyrin were successfully attracted by electrostatic self-assembly forces.