• 소성∙가공
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• 제9권6호
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• pp.598-603
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• 2000

In order to improve trial-and-error based conventional practices for optimizing forming processes, a direct design method to guide iterative design practices, called the ideal forming theory, has been previously developed. In the theory, material elements are required to deform following the minimum Plastic work Path. The theory can be used to determine the ideal initial blank shape needed to best achieve a specified final shape while resulting in optimum strain distributions. In this work, the direct design method based on the ideal forming theory was applied to design initial design shape for VCR deck chassis. Based on the solution of the ideal forming theory, FEM analysis was utilized to evaluate an optimum blank shape to be formed without tearing. Simulation results are in good agreement with experimental data. It was shown that the proposed sequential design procedure based on direct design method and FEM can be successfully applied to optimize the die design Procedure of sheet metal forming processes.

• 한국컴퓨터정보학회논문지
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• 제25권12호
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• pp.145-153
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• 2020

최근 소셜 빅데이터를 대상으로 한 키워드 분석은 고객 관점의 의견이나 불만 사항을 추출하기 위한 목적으로 광범위하게 활용되고 있다. 이와 관련하여, 이전 연구에서는 키워드 분석의 정확도를 높이기 위해 응집도 점수를 활용한 방법을 제안하였으나, 리뷰의 수가 적을 경우 오류율이 증가하는 문제가 있었다. 본 논문에서는 응집도 점수 기반 알고리즘으로부터 추출된 키워드에 대해 간소화된 형태소 분석 단계를 후처리 형태로 적용함으로써 키워드 추출의 정확도를 개선하고자 하였다. 제안 방법은 입력 데이터가 주어질 때마다 필요한 형태소 분석 규칙을 점증적으로 추가할 수 있도록 지원함으로써, 사전의 크기를 최소화하고 분석의 효율을 높이고자 하였다. 또한 대화형 규칙 입력 시스템을 제공하여 분석 규칙 추가에 드는 노력을 최소화하고자 하였다. 제안 방법을 검증하기 위해 온라인에서 수집된 실제 리뷰를 대상으로 실험을 수행하였으며, 제안 방법을 적용할 경우 오류율이 기존 10%에서 1%로 개선되는 동시에, 5,000개의 리뷰 처리에 450ms가 소요되어 실시간 처리가 가능한 수준임을 확인하였다.

• 한국건설관리학회논문집
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• 제10권1호
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• pp.91-101
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• 2009

철골구조의 확산과 보편화에 따른 건설산업의 대형화, 복합화 추세에 따라 건설 프로젝트의 수행 과정 중 수반되는 작업지연과 같은 불확실성 리스크 요소는 프로젝트의 공기증가, 비용상승, 품질저하로 이어지며 프로젝트의 성패에 영향을 미치는 중요한 관리요소로 간주되고 있다. 이에 전체 프로젝트의 완성도에 영향을 미치는 불확실성 요소에 관한 체계적인 관리방안이 요구되고 있으며, 건설 프로젝트 수행시 발생가능한 작업지연요인을 분석하고 이를 관리하는 것은 건설사업의 확실성을 높일 뿐만 아니라 경쟁력을 높이는 방법이라 할 수 있다. 이러한 측면에서 작업지연요인의 효율적인 관리를 위해서는 각 항목간 정량적 분석방법에 의한 우선순위를 산정하여 해당 공정별로 중점 관리하는 노력이 필요하다. 따라서 본 연구에서는 철골공사를 대상으로 공정별 작업지연요인을 파악하고, FMEA를 활용한 작업지연요인별 중요도의 정량적 수치화를 통하여 작업지연요인을 효과적으로 제거하고 관리할 수 있도록 공정별 코드화한 중점관리항목을 제시함으로써 효과적 관리 및 작업 지연 예방을 위한 기초적 자료를 제공하고자 하였다.

• 한국안전학회지
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• 제10권4호
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• pp.81-86
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• 1995

In order to apply to analysis methods of mechanism and cross tabulation methods for the influence factors by the accident types to the object of accidents which occurred in R.C and P.C methods among the accidents in construction work sites, the latent hazards in P.C method are evaluated from the data of accidents in H Company from Jan. 1, 1993 to Dec. 31, 1993. The relationship between accident types and unsafe acts, unsafe conditions are recognized and the hazards of R.C method and P.C method are compared from the data acquired by the analysis of causes for a kind of occurrence mechanism. In conclusions, the items such as causes of accidents, accidents types, occurrence time, and the characteristics, are concentrated on one side in the P.C method, which is quite different from R.C method. Therefore the control method for the accident causes is easily established with a lot of effective advantages. The frequency and severity of accidents in P.C method are so low in comparison with R.C method.

• 한국의류산업학회지
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• 제20권6호
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• pp.704-712
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• 2018

This study analyzed working postures using the Ovako Working Posture Analysis System (OWAS) to improve work clothes for construction workers. A video taken at a construction work site was stopped at regular intervals and the postures of relevant body parts proposed by OWAS was recorded. Additionally, based on analysis of the working postures code, the level of work action for each postures was classified from stage I to IV. General workers frequently straightened or bent forward at the waist, and used their legs to stand, bend, or walk. Wood workers moved extensively from the waist, keeping their legs relatively straight and their arms held below their shoulders, repeatedly tapping with a hammer weighing less than 10.0kg. Rebar bending workers mainly bent forward at the waist, with both legs bent or standing with one leg bent. Rebar transport and fixing workers walked with the waist straight, and occasionally one or both hands held above the shoulders. Their work also involved holding a hook, which weigh less than 10.0kg, in their hands, and the difficult task of lifting and placing long rebars, which weigh from 10.0 to 20.0kg or more. Concrete pouring workers bent or twisted their back to the side. Therefore, this study suggests that design goals should be different when developing workwear for each type of worker.

• 한국BIM학회 논문집
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• 제3권3호
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• pp.9-18
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• 2013

In case of applying the BIM method in the civil engineering of irregularly shaped structure, BIM method began to be introduced in the current building engineering area compared with the expected effects of the relatively high construction productivity has been recognized. In this paper, I have developed quantity calculation algorithms applying it to earthwork and bridge construction, tunnel construction, retaining wall construction, culvert construction and implemented BIM based 3D-BIM Modeling quantity calculation. Structure work in which errors occurred in range between -6.28% ~ 5.17%. Especially, understanding of the problem and improvement of the existing 2D-CAD based of quantity calculation through rock type quantity calculation error in range of -14.36% ~ 13.07% of earthwork quantity calculation. It's benefit and applicability of BIM method in civil engineering. In addition, routine method for quantity of earthwork has the same error tolerance negligible for that of structure work. But, rock type's quantity calculated as the error appears significantly to the reliability of 2D-based volume calculation shows that the problem could be. Through the estimating quantity of earthwork based 3D-BIM, proposed method has better reliability than routine method. BIM, as well as the design, construction, maintenance levels of information when you consider the benefits of integration, the introduction of BIM design in civil engineering and the possibility of applying for the effectiveness was confirmed. In addition, as the beginning phase of information integration, quantity document automation program has been developed for activation of BIM. And automatically enter the program code number, linkage and manual volume calculation program, quantity document automation programs, such as the development is now underway, and step-by-step procedures and methods are presented.

• 한국직업건강간호학회지
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• 제13권1호
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• pp.30-39
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• 2004

Purpose: This study was performed to identify the factors of the job stress and to analysis affecting job satisfaction in clinical nurses, using the Job Stress Model by the National Institute for Occupational Safety and Health (NIOSH). Method: Data collection was done from July 21 to July 30, 2003. The study was involved in 203 nurses who work at the hospital. It was examined the self-recording questionnaire about general characteristics, work-related factors, non-work factors, instrument revised by NIOSH Job Stress questionnaire translated by the Korea Occupational Safety & Health Research Institute(1999). Instrument about shift work was the tool developed by Kim and Gu(1984). Result: Job satisfaction of subjects at an average level with $1.96{\pm}0.37$ score on the basis of 3 points. According to general characteristics, job satisfaction was high in those with older age and married group. According to work related general factors, job satisfaction was high with working career, an officer to higher grade. According to work characteristics factors, job satisfaction was low with much role conflict at work and much workload and much interpersonal conflict. As for the relationship between job satisfaction and non-work factor, job satisfaction was did not show statistically significant differences. As a result of Stepwise multiple regression analysis, job satisfaction was influenced by shift work, conflicts of between group and grade of office. Conclusion: Therefore, it suggests that the nurses need stress management related shift work for improvement of job satisfaction.

• 한국산학기술학회논문지
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• 제19권12호
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• pp.416-431
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• 2018

본 연구의 목적은 간호사들의 병원 근무 경험과 경력단절 영향요인을 심층적으로 분석하기 위해 시도되었다. 이를 위해 26-55세 경력단절 간호사 20명을 대상으로 간호사로서의 경험, 간호 일의 특성과 퇴직사유의 내용을 인터뷰하였으며 현상학적 방법 중 꼴라쥐(Colaizzi)의 분석방법을 적용하였다. 분석결과 104개의 주요 진술과 17개의 구성된 의미, 6개의 공통 주제군, 2개의 범주가 도출되었다. 2개의 범주는 간호 업무 특성과 근무 환경 특성이며 간호 업무 특성에서는 '시간 압박', '자율성 부재', '신체 감정 노동', '낮은 임금 상승률'의 4가지 공통 주제군이, 근무 환경 특성에서는 '물리적 환경', '인적 환경'의 2가지 공통 주제군이 각각 도출되었다. 따라서 간호사의 경력단절 현상을 개선하기 위해서는 과도한 업무강도를 완화하고 적정수준의 임금인상과 안전한 근무환경을 제공하려는 노력이 필요하다.

• 한국정밀공학회지
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• 제29권11호
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• pp.1228-1235
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• 2012

A refrigerator has many components which are made from diverse materials such as metal, polymer, plastic, and rubber. So, it generally requires much time and efforts to build up an analysis model in finite element analysis. In this work, to reduce the computational time and efforts a simplified modeling method was proposed for the analysis of a refrigerator. Occasionally, a stick-slip noise occurs in a refrigerator due to relative slip between shelf and inner-case. When we solve the problem by a FE analysis, we should model the structures with detail for considering the contact conditions; by this reason, too many efforts are consumed in the conventional analysis method. Through this work, we shows the concept of simplifying approach and a good agreement with the results of a real model analysis. And also, the evaluation of the proposed method and the application of contact analysis using the simplified model are discussed.

• Structural Engineering and Mechanics
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• 제7권1호
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• pp.111-126
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• 1999

The work presented here focuses on the development of suitable discretised formulations, for large-displacement shape and non-shape design sensitivity analysis (DSA), which enable the straightforward incorporation of structural optimisation into established finite element analysis (FEA) codes. For the generalised displacement-based functional the design sensitivity vector has been expressed in terms of displacement sensitivity. The Total Lagrangian formulation is utilised for modelling of large deformation of truss structures. The variational formulation of the sensitivity analysis procedure is discretised by using "pseudo" - finite elements, Results are presented for the sensitivity analysis and optimisation of standard truss structures. For the purposes of this work, the analysis and optimisation procedures outlined below are incorporated into the FEA code ABAQUS.