• Safety and Health at Work
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• 제10권2호
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• pp.205-212
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• 2019

Background: Workforce health is one of the primary and most challenging issues, particularly in industrialized countries. This article aims at modeling the major factors affecting accidents in the workplace, including general health, work-family conflict, effort-reward imbalance, and internal and external locus of control. Methods: A cross-sectional study was conducted in Esfahan Steel Company in Iran. A total of 450 participants were divided into two groups-control and case-and the questionnaires were distributed among them. Data were collected through a 7-part questionnaire. Finally, the results were analyzed using SPSS 22.0 and Amos software. Results: All the studied variables had a significant relationship with the accident proneness. In the case group, general health with a coefficient of -0.37, worke-family conflict with 0.10, effort-reward imbalance with 0.10, internal locus of control with -0.07, and external locus of control with 0.40 had a direct effect on occupational stress. Occupational stress also had a positive direct effect on accident proneness with a coefficient of 0.47. In addition, fitness indices of control group showed general health (-0.35), worke-family conflict (0.36), effort-reward imbalance (0.13), internal locus of control (-0.15), and external locus of control (0.12) have a direct effect on occupational stress. Besides, occupational stress with a coefficient of 0.09 had a direct effect on accident proneness. Conclusion: It can be concluded that although previous studies and the present study showed the effect of stress on accident and accident proneness, some hidden and external factors such as work-family conflict, effort-reward imbalance, and external locus of control that affect stress should also be considered. It helps industries face less occupational stress and, consequently, less occurrence rates of accidents.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.145-153
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• 2011

In the system necessary for safety such as the train control system, to make train control information be sent correctly is very important to enable organic movement between trains. In the case of the system such as RF-CBTC (Radio Frequency Communication Based Train Control) the control related information is sent through wireless transmission between on-board system of a train and wayside transmitter. The wayside transmitter collects the running information such as location, velocity from the on-board system and operates the optimizing control by sending the control information such as the target, limited velocity to the on-board system. But, when the communication disconnect or train failure, the critical hazard such as train collision or derailment may be possible because the RF-CBTC depends on the information through wireless communication. This paper discribes of performing Fall-Back system to detect train position in the case of rail break or communication failure to avoid train accident and allows train to be operated safely. It can be implemented with ATP function through track circuits using active-type transformers and axle counters, and allows train to be operated manually in emergency status.

• 전자공학회논문지SC
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• 제39권2호
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• pp.85-94
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• 2002

본 논문에서는 CITE를 포함한 2차 반복 학습제어 방법이 수렴 성능의 향상과 외란에 대한 강인성 향상에 덧붙여 초기 오차가 있음에도 불구하고 이를 극복할 뿐만 아니라 기존의 알고리즘보다 더 빠른 수렴 능력이 있음을 확인한다. 또한 불안정한 결과를 낳는 높은 학습 게인의 경우에도 CITE를 추가한 본 학습제어 방법에 의해 안정화됨으로써, 빠른 수렴 특성과 강인성 향상을 가져올 수 있음을 보인다. 그리고 본 알고리즘을 선형 시변 시스템에 대해 적용한 시뮬레이션 결과를 통해 초기 오차의 극복 능력이 뛰어남을 확인하고, 아울러 각 학습 게인들이 수렴 속도와 안정성에 미치는 영향을 상세히 분석한다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1107-1114
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• 2005

The running condition of multi-system air conditioner is prone to vary largely as it is designed for individual conditioning in each space of middle and small sized buildings. This leads to overcooling in case of partial load run, while the lack of capacity happens in case of full load run. Besides these, there exist such problems as instabilities due to the uneven refrigerant distribution caused by fluctuation of load and the change in piping line. Based upon the basic study on the function characteristics found in parts needed for maximized system working design in order to troubleshoot, the system functioning pattern should be identified through the different tests with various operating circumstances and the analysis models should be developed. With this ground, the control logic has to be made to have a control over capacity and make possible the efficient distribution of refrigerant.

• 전기학회논문지P
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• 제56권3호
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• pp.129-135
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• 2007

This paper deals with speed-sensorless control of DC servo motor using Neuro-Fuzzy Observer. DC servo motor has very low rotor inertia and excellent response characteristic and it is very useful to control torque and speed. It is easy to detect the voltage and current and resolver or encoder is used to measure a rotor speed. But it has a limit as a driving speed to detect speed precisely. So it is problem to improve the performance of the driving system. To solve this problem, it is studied to detect a speed of DC servo motor without sensor. In particular, study on the method to estimate the speed using the observer is performed a lot. In this paper, the gain of the observer is properly set up using the Neuro-Fuzzy control and Neuro-Fuzzy Observer that have a superior transient characteristic and is easy to implement compared the existing method is designed. It calculates the differentiation of the rotor current directly using the rotor current measured in the DC servo motor and estimates the speed of the rotor using the differentiation. Proposed speed sensorless control method is performed using the estimated speed. Also, it is proved feasibility of the proposed observer from the comparison tested a case with a speed sensor and a case without a speed sensor which used a highly efficient drive and 200[w] DC servo motor starting system.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2004년도 춘계학술대회 학술발표 논문집 제14권 제1호
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• pp.153-156
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• 2004

This Paper deals with speed control of DC servo motor using a Fuzzy-Sliding observer. Speed sensor detect a speed of rotor continuously. But It have a limit as a driving speed to detect speed precisely. So it is problem to improve the performance of the driving system To solve the problem, it is studied to detect a speed of DC motor without sensor In particular, study on the method to estimate the speed using the observer is performed a lot. In this parer, the gain of the observer is properly set up using the fuzzy control and sliding observer that have a superior transient characteristic and is easy to implement compared the exist ing method is designed. It estimate the derivative of the armature current directly using the armature current measured in the DC motor. It estimate the speed of the rotor using the differentiation. It is Proposed speed sensor less control method using the estimated speed. Optimal gain of Luenberger observer is set up using the fuzzy control and adapted speed control of DC servo motor. It is proved excellence and feasibility of the presented observer from the comparison tested a case with a speed sensor and a case without a speed sensor which used a highly efficient drive and 200W DC servo motor start ing system.

• 지역사회간호학회지
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• 제25권3호
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• pp.159-169
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• 2014

Purpose: The purpose of this study was to evaluate the effectiveness of case management for patients with hypertension on their health status and medical service utilization. Methods: This study was a secondary analysis of data collected for a larger study of chronic disease management in 2008 using the National Health Insurance Corporation database. A total of 12,944 patients who received case management for hypertension were included in this analysis. The subjects of case management were classified into subgroups, namely, over-use, under-use, and non-use groups according to the amount of medical service utilization. To compare the medical service utilization, a control group was selected randomly. The data were analyzed through descriptive statistics, McNemar test, and ANOVA. Results: All the subgroups displayed significant differences in blood pressure, self-management, social support, and their characteristics of medical service utilization. The total medical expense of the under-use and non-use groups increased after case management. However, there was no decrease in the medical expense of the over-use group. Conclusion: This finding suggests that there is a need to re-examine why patients overuse medical services and to supplement specific strategies for encouraging appropriate medical service utilization, and enhancing case management efforts for the over-use group.

• 한국간호교육학회지
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• 제27권2호
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• pp.107-116
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• 2021

Purpose: The purpose of this study was to identify the effects of case-based learning based on flipped learning in a pathophysiology course for nursing students. Methods: Participants were sophomore nursing students enrolled in a pathophysiology course. The experimental group (n=42) received the case-based learning in class after similar case-based learning in a pre-class based on flipped learning, while the control group (n=39) received the usual flipped learning. Data were analyzed by χ²-test, independent t-test, and ANCOVA using SPSS WIN 21.0. Results: There were significant differences in self-directed learning ability (F=10.93, p=.001), self-efficacy (F=5.45, p=.022), problem-solving ability (F=6.11, p=.016), and critical thinking disposition (F=6.76, p=.011) between the experimental group and the control group. Conclusion: The application of case-based learning based on flipped learning in a pathophysiology course for nursing students was effective in improving problem-solving and self-directed learning abilities, self-efficacy, and the critical thinking disposition of sophomore nursing students.

• 한국멀티미디어학회논문지
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• 제3권1호
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• pp.63-76
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• 2000

기존의 CSCW (Computer Supported Collaborative Work) 시스템은 단순히 문서나 메시지를 구성하고 전달하는 기능만을 지원할 뿐 협동 작업자들간의 조직구성, 업무분할 및 통합, 작업흐름 제어와 같은 인지학적 기능등은 효과적으로 반영하지 못하고 있다. 본 연구는 협동작업환경에서의 CAD(Computer Aided Design)/CASE(Computer Aided Software Engineering)와 같은 공학 디자인 프로세스를 인지학적으로 지원하기 위한 CSCW 시스템을 개발하는 데 그 목적이 있다. 제안된 DCWA (Distributed Collaborative Writing Aid) 시스템은 CAD/CASE 및 시뮬레이션 기능을 하나의 시스템으로 통합함으로써 조직구성, 업무분할, 작업흐름제어가 이들 기능에 통일적으로 적용될 수 잇도록 하였다. 특히 CAD 도구에서는 다중 사용자들 소유의 그림객체 간의 바인딩, 어태치먼트, 스케일링 기능들은 제공하여 결합 형태 및 정도를 나타내는 관계성 표현이 가능하도록 함으로써 업무분할 및 병합이 CAD 도구에서도 명확히 드러나도록 하였고, CASE 도구에서는 소프트웨어 시뮬레이션 기능과 연계하여 작업흐름 제어가 용이하도록 하였다. 이는 또한 제품을 생산하기 전에 미리 모형을 시뮬레이션 해봄으로써 제품 개발의 시간과 비용을 단축할 수 있는 효과를 가져다 준다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권1호
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• pp.183-188
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• 2013

Background: Breast cancer (BC), the most common female cancer in Pakistan, is associated with a very high mortality. However, the roles of individual risk factors for BC among Pakistani women are still controversial. To assess potential risk factors for BC, a matched case-control study was conducted in two tertiary care hospitals of Karachi, Pakistan. Materials and Methods: The study population included 297 pathologically confirmed incident cases of BC patients diagnosed between January 2009 and December 2010. 586 controls without any history of BC were matched on hospital and ${\pm}5$ years of ages. Results: Positive family history of BC (MOR=1.72; 95%CI: 1.10, 2.80 for first degree vs. none), single marital status (MOR=1.55; 95%CI: 1.10, 2.39 for single/divorced/widowed women vs. married women), older age at menopause (MOR=3.92; 95%CI: 2.52, 6.18 for menopausal women aged below 45 years, MOR=6.42; 95%CI: 3.47, 11.98 for menopausal women above 45 years of age compared with premenopausal women) conferred an increased risk of BC for women. Increasing parity decreased the risk of BC (MOR=0.90; 95%CI: 0.85, 0.97 for each live birth). Intake of Vitamin D supplements (MOR=0.30; 95%CI: 0.12, 0.81 for ${\leq}3$ years and MOR=0.27; 95%CI: 0.13, 0.56 for >3 years) was protective compared to non-users of Vitamin D. Conclusions: This study confirmed only few of the recognized risk factors in Pakistani women. The protective effect of Vitamin D is important from public health perspective and needs to be further explored through a randomized controlled trial.