• 대한인간공학회지
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• 제24권3호
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• pp.11-27
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• 2005

The objectives of this study are to analyze representative wrist postures while using hand tools and parts at general assembly processes, to evaluate perceived discomfort on the wrist when external loads are present, and to suggest an evaluation and prediction model of perceived discomfort. Sixteen subjects participated in an experiment to appraise perceived discomfort. Three types of the wrist postures with five levels of non-neutralities were analyzed when five levels of external load were applied to each posture. The ANOVA results showed that the perceived discomfort of wrist postures was significantly affected by both the wrist posture and external load (p$<$0.001). It was also shown that some of the interactions between external loads and the wrist postures(Flexion/$Extension^*$Load, Flexion/$Extension^*$supination/pronation, ulnar/radial $deviation^*$supination/pronation) were significant(p$<$0.001). The result implies that a new posture classification scheme for workload assessment methods may be needed to reflect such effects of external load and wrist posture. A regression model of perceived discomfort was developed with respect to wrist posture and external load from the experimental data. A subsequent experiment revealed that the correlation coefficient between the predicted values of perceived discomfort from the model and the actual values obtained from the experiment was about 0.98. It is expected that the results help to properly estimate the body stress resulting from worker's postures and external loads and can be used as a valuable design guideline to analyze potential hazard of musculoskeletal diseases in industry.

• 한국재난정보학회 논문집
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• 제16권2호
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• pp.383-391
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• 2020

연구목적 : 에너지 저장실의 외부 화염에 의한 내부자기 점화 및 점화를 식별하고, 과열로 인한 점화와 외부 열원에 의한 점화의 차이를 분석하는 것이다. 연구방법 : 분리막 녹는점 측정, 배터리 외부 수열 실험, 배터리 과충전 실험, 과충전과 외부수열에 의한 연소 시 전극 판 비교분석, 과충전 연소 특징, 외부수열 화재 연소특징, 3.4(전극판 비교)/ 3.5(과충전)/ 3.6(외부수열) 분석 실험을 하였다. 연구결과: 화재 발생 시까지 센서의 위치에 따른 온도 차이가 극심했음으로 기존처럼 한 모듈 당 온도 센서 두 개로는 측정값이 부족해 온도제어를 통한 화재를 사전에 방지할 수 없다고 판단한다. 결론: 단락이 점화원으로 작용하여 혼합가스에 착화돼 가스폭발이 발생하고, 폭발 압력에 의해 전극이 잘게 파손되며, 가루형태의 리튬산화물이 불꽃반응에 의해 폭죽과 유사한 불꽃이 분출되었다.

• 콘크리트학회논문집
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• 제16권5호
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• pp.677-686
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• 2004

본 연구는 외부 프리스트레싱으로 보강된 내부 프리스트레스트 콘크리트 보에 관한 문헌연구와 프리스트레싱 강재의 극한응력 예측식의 개발, 극한응력에 영향을 미치는 변수들에 대한 실험 등이다. 본 논문에서는 내부 및 외부 프리스트레싱 강재의 극한응력에 대한 새로운 합리적 예측식을 제안하고 있는데, 프리스트레싱 강재와 중립축 깊이비의 함수로 표현하여 내부 및 외부 프리스트레싱 강재의 영향을 고려하고 있다. 실험연구에서는 내부 및 외부 프리스트레싱 강재의 극한응력에 가장 큰 영향을 미치는 실험변수를 가지고 외부 프리스트레싱으로 보강된 프리스트레스트 콘크리트 보를 제작하여 실험하였다. 실험연구에서 채택한 영향인자들은 내부 프리스트레싱 강재량, 외부 프리스트레싱 강재량, 지간과 프리스트레싱 강재 높이비 등이다. 실험결과는 분석되어 내부 및 외부 프리스트레싱 강재의 극한응력 예측 제안식의 합리성 적용성을 확인하였다. 본 연구는 제안된 응력 예측식이 실험에서 얻은 실측값들과 잘 일치함을 보여주고 있다.

• 한방재활의학과학회지
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• 제24권3호
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• pp.87-98
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• 2014

Objectives The present study aimed to investigate the effects of acupuncture and herbal external preparation on wound healing procedure in a deep partial thickness burn model in rats. Methods A total of 40 male Sprague-Dawley rats were allocated into four groups with an equal number in each group: acupuncture treatment group, herbal external perparation group, Silver sulfadiazine dressing group and control group. We describe the effect of acupuncture and herbal external preparation on morphologic and histologic changes, epithelial growth factor (EGF), hematological value of the deep partial thickness burn wound in rats. Results At 21th day after wounding the wound size in acupuncture treat group and herbal external preparation group were decreased more significantly compared to control group. In addition, epidermal regeneration on acupuncture treatment was than other treatment and control group in histological finding. Hematological findings revealed that acupuncture treatment group and herbal external prepartion group was more effective than control group in reducing inflammation response induced by burn. In acupuncture treated group, neutrophil and leukocyte level were significantly decreased compared to other treatment group. Also, this study showed that EGF was obviously expressed in nascent tissue when wounds were treated with the acupuncture and herbal external preparation after injury. In particular, acupuncture treatment group had a significant increase of EGF expression in burn wound healing area when compared with the other treatment groups. Conclusions These findings suggest that acupuncture and herbal external prepration may improve burn wound healing through decreasing inflammatory reaction, increasing tissue regeneration and expression of EGF. Moreover, acupuncture treatment could be more effective in comparison with Silver sulfadiazine dressing.

• 산업경영시스템학회지
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• 제40권1호
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• pp.144-149
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• 2017

This study empirically analyzes the effect of IT SME ventures' external information network diversity on their production period reduction and productivity improvement generated from technology development. This research constructs a mediating model based on the open innovation perspective and tests it with the 138 samples of South Korean IT SME ventures based on the ordinary least squares regression. This research is expected to make a good contribution by shedding a new light on the following three points about the critical role of IT SME ventures' external information network diversity in increasing their production period reduction and productivity improvement generated from technology development which has scarcely been illuminated in the extant studies in the field of the management of technology for SMEs. First, IT SME ventures' external information network diversity positively influences their production period reduction. Second, the external information network diversity positively influences IT SMEs' ventures' productivity improvement. Third, IT SME ventures' production period reduction partially mediates the influence of IT SME ventures' external network diversity on their productivity improvement. These three fresh points are expected to provide useful theoretical and practical implications. Related to the theoretical implication, this research provides a fresh implication that IT SME ventures' external information network diversity positively influences not only their production period reduction but also productivity improvement generated from technology development. Concerning the practical implication, this study suggests that the CEOs in IT SME ventures make strategic efforts to use more diverse external information sources in order to increase their production period reduction and productivity improvement generated from technology development.

• 대한가정학회지
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• 제35권5호
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• pp.163-175
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• 1997

This study investigated the relationship between mother's verbal control modes and children's social competency, the relationship between mother's verbal control modes and children's internal-external control, and the relationship between children's internal-external control and children's social competency. The subjects of this study were 157 boys and 144 girls attending elementary schools and their mothers in Busan. Lee's(1993) questionnaire on mother's verbal control modes, the modified version of Nowicki and Strickland's CN-SIE on internal-external control and Choi's(1992) questionnaire on social competence were used. The results were as follows: 1) The mothers control their children mostly by position-oriented mode. And mother's imperative mode for boys differed significantly from that for girls. Boys perceived mother's verbal control mode as more imperative. 2) There were significant negative correlations between mother's imperative mode and boy's social competency, between mother's imperative mode and boy's anxiety, and between mother's imperative mode and boy's internal-external control and boy's social competency, and between boy's internal-external control and boy's leadership. There were significant correlations between mother's position-oriented mode and girl's leadership, between mother's position-oriented mode and girl's, affection on parents, between mother's position-oriented mode and girl's internal-external control. There were significant negative correlations between girl's internal-external control and girl's anxiety. 3) Children's internal-external control was the predictor variable influencing on children' social competency, children's leadership. Children's sex was the predictor variable influencing on children' anxiety. And the mother's imperative mode and the mother's position-oriented mode were the predictor variables influencing on children' affection on parents.

• 한국지능시스템학회논문지
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• 제23권5호
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• pp.379-384
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• 2013

해상교통관제센터(Vessel Traffic Service, VTS)에서 항해중인 선박의 효과적인 관리를 위해 선박에 영향을 주는 외력에 대한 평가가 필요하다. 해상교통 빅데이터는 크게 선박 제원 및 통항정보 등 선박에 의하여 수집되는 정보가 있으며, 다른 하나는 해역에 관련된 바람, 파고, 조류흐름의 외력정보가 있다. 본 연구에서는 이러한 해상교통 빅데이터를 활용하여 선박에 영향을 주는 외력영향을 평가하는 방법에 대해 제안한다. 해상교통 빅데이터를 활용하기 위하여 바람, 파도, 조류 정보, 대수속력(Speed Over Water, SOW)에 대한 정보로 구성되는 해역외력코드(Waterway External Force Code)를 사용하였다. 해역외력코드를 데이터베이스로 하여 그 결과로서 선박에 작용하는 외력영향을 추정하였다.

• Safety and Health at Work
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• 제9권1호
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• pp.115-124
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• 2018

Background: Substantial empirical research has shown conflicting results regarding the influence of organizational external factors on construction risk management, suggesting the necessity to introduce a moderator into the study. The present research confirmed whether rules and regulations matter on the relationships between organizational external factors and construction risk management. Methods: Based on discouragement and organizational control theory, this research examined the effects of organizational external factors and rules and regulations on construction risk management among 238 employees operating in construction companies in Abuja and Lagos, Nigeria. A personally administered questionnaire was used to acquire the data. The data were analyzed using partial least squares structural equation modeling. Results: A significant positive relationship between organizational external factors and construction risk management was asserted. This study also found a significant positive relationship between rules and regulations and construction risk management. As anticipated, rules and regulations were found to moderate the relationship between organizational external factors and construction risk management, with a significant positive result. Similarly, a significant interaction effect was also found between rules and regulations and organizational external factors. Implications of the research from a Nigerian point of view have also been discussed. Conclusion: Political, economy, and technology factors helped the construction companies to reduce the chance of risk occurrence during the construction activities. Rules and regulations also helped to lessen the rate of accidents involving construction workers as well as the duration of the projects. Similarly, the influence of the organizational external factors with rules and regulations on construction risk management has proven that most of the construction companies that implement the aforementioned factors have the chance to deliver their projects within the stipulated time, cost, and qualities, which can be used as a yardstick to measure a good project.

• 한국음향학회지
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• 제38권5호
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• pp.607-613
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• 2019

본 논문은 external knowledge를 사용한 lattice 없는 상호 정보 최대화(Lattice Free Maximum Mutual Information, LF-MMI) 기반 음향 모델링 방법을 제안한다. External knowledge란 음향 모델에서 사용하는 학습 데이터 이외의 문자열 데이터를 말한다. LF-MMI란 심층 신경망(Deep Neural Network, DNN) 학습의 최적화를 위한 목적 함수의 일종으로, 구별 학습에서 높은 성능을 보인다. LF-MMI에는 DNN의 사후 확률을 계산하기 위해 음소의 열을 사전 확률로 갖는다. 본 논문에서는 LF-MMI의 목적식의 사전 확률을 담당하는 음소 모델링에 external knowlege를 사용함으로써 과적합의 가능성을 낮추고, 음향 모델의 성능을 높이는 방법을 제안한다. External memory를 사용하여 사전 확률을 생성한 LF-MMI 모델을 사용했을 때 기존 LF-MMI와 비교하여 14 %의 상대적 성능 개선을 보였다.

• 한국전문물리치료학회지
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• 제26권3호
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• pp.91-98
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• 2019

Background: The bridge exercise targets the gluteus maximus (Gmax) and gluteus medius (Gmed). However, there is also a risk of dominant hamstring (HAM) and erector spinae (ES) muscles. Objects: To analyze the muscle activity the of Gmax, Gmed, HAM and ES during the bridge exercise with and without hip external rotation in different degrees of knee flexion. Methods: Twenty-three subjects were participated. The electormyography (EMG) activity of the Gmax, Gmed, HAM and ES muscles was recorded during the exercise. The subjects performed the bridge exercise under four different conditions: (a) with $90^{\circ}$ knee flexion, without hip external rotation (b) with $90^{\circ}$ knee flexion, with hip external rotation (c) with $135^{\circ}$ knee flexion, without hip external rotation (d) with $135^{\circ}$ knee flexion, with hip external rotation. Results: There was no significant interaction effect between the degree of knee flexion and hip external rotation. There was a significant main effect for degree of knee flexion in Gmax, HAM muscles activity. Gmax muscle activity was significantly greater in the $135^{\circ}$ knee flexion position than in the $90^{\circ}$ knee flexion position (p<.001). While HAM muscle activity was significantly less in $135^{\circ}$ knee flexion position than in the $90^{\circ}$ knee flexion position (p<.001). ES muscle activity was significantly less in the $135^{\circ}$ knee flexion position than in the $90^{\circ}$ knee flexion position (p=.002). The activity of both the Gmax and Gmed muscles was significantly greater with hip external rotation (p<.001 and p=.005, respectively). Conclusion: For patients performing the bridge exercise, positioning the knee in $135^{\circ}$ of flexion with hip external rotation is effective for improving Gmax and Gmed muscle activity while decreasing HAM, and ES muscle activity.