• Journal of Institute of Control, Robotics and Systems
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• v.2 no.3
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• pp.200-208
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• 1996

This paper describes the mechanism, guidance, sensor system, and navigation algorithm of METRO, a free ranging mobile robot. METRO is designed for use in structured surroundings or factory environments rather than unstructured natural environments. An overview of the physical configuration of the mobile robot is presented as well as a description of its sensor system, an omnidirectional laser range finder. Except for the global path planning algorithm, a guidance and a navigation algorithm with a local path planning algorithm are used to navigate the mobile robot. In METRO the computer support is divided into a supervisor with image processing and local path planning and a slave with motor control. The free ranging mobile robot is self-controlled and all processing being performed on board.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.4
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• pp.369-376
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• 2005

In recent years, AGVs(Automated Guided Vehicles) have received growing attention as a subsystem of the integrated container operating system which enables unmanned control. improvement of job reliability, accuracy and productivity. Therefore, a number of works have been done to enhance the performance AGVs. In this paper. job deployment and a dynamic routing control system composed of supervisor, traffic controller. motion controller and routing table are discussed. A simple job deployment scheme and an efficient dynamic routing algorithm incorporating with the deadlock prediction and avoidance algorithm are investigated.

• Transactions on Control, Automation and Systems Engineering
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• v.3 no.1
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• pp.1-9
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• 2001

The promise of improved productivity and quality has lead to numerous research investigations in machining process monitoring and control. Recent studies have demonstrated that careful attention must be paid to the regulation of multiple process modules within a single operation such that each module performs its function properly and adverse interactions between modules do not occur. This had lead to the development of supervisory control; particularly to the development of methodologies to systemati-cally construct and implement these controllers. However, no research study has investigated the effect of the production environ-ment on the design of supervisor controllers. In this paper, the design of supervisory controllers for various production environ-ment is studied. The design approach given in Landers and Ulsoy(1998) is applied to construct two supervisory machining control-lers that are experimentally implemented in a face milling operation. Comparisons with an experimental implementation without process control illustrate the benefits of utilizing process controllers that are coordinated properly. The results also show that the given design approach may be used to construct supervisory controllers for different types of production environments.

• Korea Journal of Hospital Management
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• v.11 no.2
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• pp.32-60
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• 2006

Based on the Job Demand-Control model which was proposed by R. A. Karasek, this study was designed to investigate the relationships among job demand, job control, and job burnout of nurses. In addition, the other aim of the present study was to test the moderating or buffering role of social supports in the relationship between the job demand and job burnout. The analysis based on data collected from 239 nurses who are working in two general hospitals has produced the following results. We found that job demand was primarily related to the exhaustion component of burnout, whereas (lack of) job control was related to the disengagement dimension of burnout. And social supports from the supervisor attenuated the disengagement, whereas social supports from the colleague diminished the exhaustion. But, we found no interaction effects that were expected in the hypotheses. Specifically, social supports didn't buffer the negative effects of job demand on burnout, while job control had the moderating effect which was in opposite direction. The implications of these analyses and limitations of the study were then discussed.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.525-526
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• 2016

전기자동차 (EV)에서 구동용 모터의 토크 제어를 위한 인버터에는 제어 연산 및 고장 진단 기능을 수행하기 위한 MCU가 있으며, MCU는 상위 제어기 차량 제어 유닛 (VCU)에게 현재 모터 및 인버터의 상태를 주기적으로 전달하고, 현재 차량 주행에 적합한 토크 지령을 받아 토크 제어를 수행하게 된다. 이를 위해 MCU는 전류, 전압 및 위치 센서의 값을 읽어 제어를 수행하게 되며, 제어의 결과 값으로 pulse width modulation (PWM)을 생성하여 이를 통해 모터에 전압을 공급하게 된다. 즉 차량의 구동에 있어 PWM 신호는 가장 중요한 부분이다. 하지만 생산 불량 또는 진동에 의한 납땜 불량 또는 MCU 전원 고장 등으로 MCU에 고장이 발생하게 되면 이상 PWM을 생성하게 되고 정상적인 토크 제어가 불가능해진다. 이때 안전하게 EV를 정지 시키는 알고리즘이 필요하게 되며, 이를 수행 할 supervisor control unit (SCU)가 인버터 컨트롤 보드에 추가되어야 한다. 본 논문에서는 고속으로 주행하던 차량에서 메인 MCU가 고장 날 경우에 안전하게 EV를 정차시키는 방법에 대해 다루었다.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.9
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• pp.791-796
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• 2013

This paper proposes a fuzzy logic gain scheduling method for depth controller of the AUV (Autonomous Underwater Vehicle). Gains of depth controller are calculated by using multi-loop root locus technique. Fuzzy logic based gain scheduling approach is used to modify multi-loop gains as control condition. It is illustrated by simulations that the proposed fuzzy logic gain scheduling method yields smaller rising time and overshoot compared to the fixed-gain controller. Finally, being implemented on real hardwares, all the proposed algorithms are validated with integrations of hardware and software altogether by HILS.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.216-224
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• 2018

The purpose of this study was to measure the depressive symptoms and to determine their relationship with job stress content and social support of manufacturing male workers. A total of 428 male workers were surveyed from July 1 to August 31, 2017 using self-administered questionnaires. For the results, the rate of the depression group was 25.1%. In terms of the CES-D scores by job stress contents, CES-D scores were higher in the high job demand group than in the low group and higher in the low job control group than in the high group. In terms of CES-D scores by social support, CES-D scores were higher in the low supervisor support and coworker support group than in the high group. CES-D scores showed a significant positive correlation with job demand but a negative correlation with job control, supervisor support, and coworker support. In terms of hierarchical multiple regression analysis, higher job demand was associated with lower job control, and lower support of supervisors and coworkers gave high depression scores. Explanatory power for depression score significantly increased by 18.4% according to job demand and added job controls. Explanatory power increased by 14.1% with the support of supervisors and coworkers. The above results suggest that the level of depressive symptoms is highly correlated with job demand, job control, and support of supervisors and coworkers.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.735-737
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• 2015

In this paper, SaaS (Software as a Service) based transport and construction process safety management systems by utilizing the construction work process management and safety management and schedule, and results for various types of construction process, achieved through high-speed wireless Internet access by applying to ensure a systematic means for safety and can quickly and accurately manage all made within the process control system. The operator should be indicated by using a smart phone to work as a supervisor report the current status and results of the operation. Also be reported to the supervisor immediately in an emergency situation and there is no vibration occurs over a period of time the smartphone is to check the danger to the operator. If the commissioner is directed to specific business processes that establish and verify the results obtained and the result is satisfied by presenting the part down the measures insufficient command of the field workers risk situations. In the case of software (server) to store all the data relating to the operation member in charge of management and security.

• Korea Journal of Hospital Management
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• v.18 no.4
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• pp.54-77
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• 2013

This paper is a comparison study about leadership training transfer factors between physicians working in large scale hospitals and managers working in firms. To fulfill this purpose, this study conducted a regression analysis on 101 managers and 59 physicians who had attended similar leadership training programs more than 16 hours recently in order to identify the differences on the learning transfer factors. 6 factors such as Learner readiness, Performance self-efficacy, (so far as Trainee Characteristics group), Organization Culture, Supervisor's tangible incentives and Supervisor's intangible support, (so far as Work environment group), Content Validity & Transfer Design (so far Training Design group) were used as independent variables while the personal Managerial Capability Increase and Leadership Capability Increase were used as dependent variables. And also we used 5 factors as control variables ; Job style (Manager or Physician), Age, Gender, Working years and Organization size. Here are the summary of major findings ; first, there were statistically significant differences between the learning transfer factors in leadership training programs for managers and those of physicians. Second, there were also statistically significant differences among trainees' working years and their organization size factors while age and gender do not affect the learning transfer factors. Third, for the physician's leadership training the practitioners should focus on two factors ; Organization Culture and Learner readiness.

• Safety and Health at Work
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• v.5 no.1
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• pp.7-12
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• 2014

Background: In Japan, more than 60% of employees are reported to suffer from anxiety and stress. Consequently, Japanese society has begun to address such important issues as psychogenic disability and job-related suicide. Furthermore, given the aging of society and the surge in the number of elderly people requiring care, it is necessary to adequately and proactively support employees who care for their elderly relatives. The purpose of the present study was to investigate caregiver burden in caring for elderly relatives and work-related stress factors associated with mental health among employees. Methods: We studied 722 men and women aged 18-83 years in a cross-sectional study. The K10 questionnaire was used to examine mental health status. Results: The proportion of participants with a high K10 score was 15% (n = 106). Having little conversation with their supervisor and/or coworkers significantly increased the risk of depression [odds ratio (OR) 1.8], as did high job overload (OR 2.7) and job dissatisfaction (OR 3.8), compared with employees who frequently conversed with their supervisor and/or coworkers. Caring for elderly relatives as a prominent characteristic of an employee was a significant risk factor for depression (OR 2.1). Conclusion: The present study demonstrated that employees who were caring for elderly relatives were significantly associated with an increased risk of depression. To prevent depressive disorders, it may be important to focus on reducing the work-caregiving role conflict, as well as enhancing employees' job control and better rewarding their efforts in the workplace.