• 한국경영과학회지
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• 제20권1호
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• pp.159-177
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• 1995

The objective of this paper is to propose a knowledge-based fuzzy post adjustment so that unstructured problems can be solved more realistically by expert systems. Major part of this mechanism forcuses on fuzzily assessing the influence of various external factors and accordingly improving the solutions of unstructured problem being concerned. For this purpose, three kinds of knowledge are used : user knowledge, expert knowledge, and machine knowledge. User knowledge is required for evaluating the external factors as well as operating the expert systems. Machine knowledge is automatically derived from historical instances of a target problem domain by using machine learning techniques, and used as a major knowledge source for inference. Expert knowledge is incorporate dinto fuzzy membership functions for external factors which seem to significantly affect the target problems. We applied this mechanism to a prototyoe expert system whose major objective is to provide expert guidance for stock market timing such as sell, buty, or wait. Experiments showed that our proposed mechanism can improve the solution quality of expert systems operating in turbulent decision-making environments.

• 유공압시스템학회논문집
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• 제8권1호
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• pp.1-9
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• 2011

The main design factors which effect on operating speed of linear actuator for valve operation are mass of plunger, electromagnetic motive force, inductance, and return spring, and these factors are not independent but related with each other in view point of design and electromagnetic theory. It is impossible to increase the operating speed by only change the value of any one design factor. The change of any one value results in change of any value related it in various design factors. This paper presents a speed increasing method of linear actuator using a solenoid design method by some governing equations which are composed of electromagnetic theory and empirical knowledge and permanent magnets as assistant material, and proved the propriety by experiments.

• 건축역사연구
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• 제6권2호
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• pp.65-77
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• 1997

The Hwasong City Wall was built for three years(1794-1796), but the real construction term was taken only 28 months. The wall and the buildings on the wall were built simultaneously, and the esttimated construction cost was highly restricted. These conditions were main factors for considering the high efficiency of construction productivity. This study examines these factors that are reflected in the operating system of the architectural standard scale of length, the architectural composition system in the Hwasong City Wall to reduce the construction cost. Through the study, following factors are found. 1.The rule of multiple proportion is found in the relationship between the partition distance, that is, span and the height of the girder which is related to the productivity of ready-made building members. 2.The ruling grade system of scale in the component members is found in the chang-bang(창방, penetration members)

• 지역사회간호학회지
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• 제9권1호
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• pp.213-222
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• 1998

The prevalence rate of low back pain in nurses is higher than that of other jobs, because there are many more risk factors(for example, standing postures, lifting and carrying heavy loads, transfering patients, changing a patient's position etc.). This investigation is to provide basic data for prevention of low back pain by analyzing the prevalence rate and related factors of low back pain in nurses(esp. operating room staff) in general hospitals. A self-reported questionaire survey was carried out on three hundred and five nurses of three general hospitals in Seoul from June, 1996 to August, 1996. Subjects of the survey were divided into a low back pain group(LBP) and a cotrol group to investigate the association between low back pain and the general characteristics and work related factors of each group. The results were as follows: 1. In the subjects of the survey, the prevalence rate of low back pain was 60.0% for the last year. 2. 73.6% of operating room(OR) staff complained of low back pain. 3. Standing for a long time and working in twisting postures were associated with low back pain, and so were the shift, the type of work, and the frequency of transfering patients. 4. The weight loads which nurses frequently carried were, under 5kg, 5-10kg, 15-20kg, 15-20kg, over 20kg, and all, except for 10-15kg, were associated with LBP. 5. 76.9% of the LBP experienced low back pain within 3 years after starting nursing jobs. 6. Concerning the degrees of low back pain: 75.8% was limited to waist; 18.8% reached the knees; 4.2% reached ankles. In conclusion, the prevalence rate of low back pain in general hospital nurses was associated with the works in operating room and other work related factors, therefore it is necessary to develop on educational program for the prevention of low back pain as well as and to improve working environments.

• 품질경영학회지
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• 제48권1호
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• pp.51-68
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• 2020

Purpose: The primary objective of this research is to develop the optimal operating conditions as well as their associated design spaces for a Cryogenic Submerged Arc Welding(SAW) process by improving its quality and productivity simultaneously. Methods: In order to investigate functional relationships among quality characteristics and their associated control factors of an SAW process, a stepwise design of experiment(DoE) method is proposed in this paper. Based on the DoE results, not only a multi-dimensional design space but also a safe operating space and normal acceptable range(NAR) by integrating statistical confidence intervals were demonstrated. In addition, the optimal operating conditions within the proposed NAR can be obtained by a robust optimal design method. Results: This study provides a customized stepwise DoE method (i.e., a sequential set of DoE such as a factorial design and a central composite design) for Cryogenic SAW process and its statistical analysis results. DoE results can then provide both the main and interaction effects of input control factors and the functional relationships between the input factors and their associated output responses. Maximizing both the product quality with high impact strength and the productivity with minimum processing times simultaneously in a case study, we proposed a design space which can provide both acceptable productivity and quality levels and NARs of input control factors. In order to confirm the optimal factor settings and the proposed NARs, validation experiments were performed. Conclusion: This research may provide significant contributions and applications to many SAW problems by preparing a standardization of the functional relationship between the input factors and their associated output response. Moreover, the proposed design space based on DoE and NAR methods can simultaneously consider a number of quality characteristics including tradeoff between productivity and quality levels.

• 대한인간공학회지
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• 제26권2호
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• pp.45-59
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• 2007

The operating tasks of overhead crane have caused undue stress to the operators from physical, mental, and environmental workload. Existing workload assessment models for musculoskeletal disorders such as OWAS, RULA, and QEC have limited applicability to the crane operating tasks because they focus mainly on physical factors and do not consider the relative importance of each factor. The present study was to develop a workload assessment model customized to overhead crane operation, following a systematic process: (1) analyzing task characteristics, (2) selecting workload factors, (3) developing assessment methods, (4) establishing action levels, and (5) computerizing the assessment model. Based on literature review, worksite survey, and focus group interview, 4 physical factors (awkward posture, static posture, repetitive motion, and excessive force), 6 mental factors (visual demand, auditory demand, task complexity and difficulty, time urgency, work schedule related stress, and safety related stress), and 4 environmental factors (noise, vibration, dust, and temperature) were selected and their rating scales and relative weights were determined. Then, based on the workload assessment results of 8 overhead cranes operated at different workplaces, the action levels of each factor category were established. Finally, the crane operation assessment model was computerized for effective analysis and report preparation. The present approach is applicable to develop a customized workload assessment model for an operating task under consideration.

• 한국산학기술학회논문지
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• 제15권12호
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• pp.7118-7133
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• 2014

창업보육센터의 효율적인 운영시스템을 도출하기 위해 창업보육센터 운영시스템에 따른 운영성과 및 보육매니저의 역할에 따른 운영성과에 대해서 고찰하였다. 설문 대상은 창업보육센터에 입주한 기업체로 하고, 분석은 SPSS 19 Ver 프로그램을 활용하여 요인분석, 신뢰도분석, 상관관계분석, 회귀분석 및 매개변수에 의한 회귀분석을 실시하였다. 그 결과 창업보육센터 운영시스템은 창업보육센터 성과에 영향을 미치는 중요한 요인임을 확인하였으며, 이 중 H/W시스템과 S/W시스템 모두가 유의적인 영향을 미치는 요인임을 확인하였다. 그러나 매니저 특성이 창업보육센터 지원시스템과 성과와의 관계를 매개하는 변수인지에 대해서는 가설이 기각되어 반드시 매니저의 특성 요인이 상호간에 영향력을 미치지는 않는 것으로 보인다. 운영성과는 센터에 대한 성과와 입주기업에 대한 성과로 나누어 분석한 결과 매니저 특성은 입주기업 성과에 유의적인 영향을 미치는 것으로 분석되었다.

• 한국컴퓨터정보학회논문지
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• 제26권7호
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• pp.91-102
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• 2021

정보화의 효과는 투자와 구축뿐만 아니라 정보시스템의 운영 수준에 따라 다를 수 있다. 본 연구는 국내 중소 제조기업의 정보시스템 운영 환경과 품질 수준을 조사 분석하고, 기업의 성과 지표에 어떤 영향을 미치는지 알아보고자 한다. 정보시스템 운영환경 요인이 정보시스템 품질수준을 매개로 생산성 성과와 재무성과에 미치는 영향을 구조 모형을 통해 분석하였다. 분석 결과로, 정보시스템 운영환경 요인들의 수준이 높을수록 품질수준은 높아지고, 품질수준이 높을수록 생산성 성과는 높아지며, 생산성 성과가 높을수록 재무성과는 높아진다고 할 수 있다. 정보화의 효과는 정보시스템 구축 후 운영 환경과 품질 수준에 달려 있다고 판단된다.

• 한국직업건강간호학회지
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• 제28권4호
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• pp.197-207
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• 2019

Purpose: This study aimed to examine the relationship between organizational health (OH), safety climate (SC), the nursing working environment (NWE), and engagement in patient safety management activities (PSMA) among operating room nurses and identify the factors that predict engagement in PSMA. Methods: From August 10th to 25th, 2018, 176 operating room nurses who were working in tertiary and general hospitals responded to a structured questionnaire. Using SPSS/WIN 25.0, the collected data were subjected to independent-samples t-test, one-way analysis of variance, Scheffe?test, and Pearson's correlational and multiple stepwise regression analyses. Results: OH and SC were significantly correlated with engagement in PSMA. The factors that predicted engagement in PSMA were OH, NWE, participation in accreditation, years of work experience, and hospital size; together, they explained 17% of the variance in engagement in PSMA. Conclusion: This study revealed that OH has a significant influence on engagement in PSMA among operating room nurses. Therefore, hospitals should aim to create healthy working environments to promote engagement in PSMA among operating room nurses, actively delegate responsibilities to increase their level of participation in accreditation, and implement strategies that maintain high levels of nurse retention.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.2467-2471
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• 2008

Railway accident analysis results show that accidents cased by human factors are not decreasing, whereas H/W related accidents are steadily decreasing. For the efficient management of human factors, many expertise on design, conditions, safety culture and staffing are required. But current safety management activities on safety critical works are focused on training, due to the limited resource and information. In order to establish railway human factors management requirements, human factors management status on all train operating companies are analysed in this study.