• Journal of the Korea Safety Management & Science
• /
• v.18 no.1
• /
• pp.131-140
• /
• 2016

This present study tested whether job stress mediates the relationship between workload and safety behavior of members in organization. In addition, we hypothesized trust in leader/coworkers functions as moderator between not only the workload-job stress link, but also the job stress-safety behavior link. In order to investigate the hypotheses, 841 employees in various fields of companies were sampled. Using structural equation modeling(SEM), we conducted moderated mediation model analysis which elaborately investigated the significance of our hypotheses. The results indicated that job stress mediated the link between workload and safety behavior of members. In addition, the relationship between workload and job stress was moderated by trust in leader/coworkers. Moreover trust in leader/coworkers moderated the job stress-safety behavior linkage. The implications and limitations of our study and suggestions for future research were discussed.

• Journal of the Korea Society of Computer and Information
• /
• v.21 no.1
• /
• pp.125-129
• /
• 2016

In this paper, we propose an efficient dynamic workload balancing strategy which improves the performance of high-performance computing system. The key idea of this dynamic workload balancing strategy is to minimize execution time of each job and to maximize the system throughput by effectively using system resource such as CPU, memory. Also, this strategy dynamically allocates job by considering demanded memory size of executing job and workload status of each node. If an overload node occurs due to allocated job, the proposed scheme migrates job, executing in overload nodes, to another free nodes and reduces the waiting time and execution time of job by balancing workload of each node. Through simulation, we show that the proposed dynamic workload balancing strategy based on CPU, memory improves the performance of high-performance computing system compared to previous strategies.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.67 no.4
• /
• pp.200-207
• /
• 2018

In recent, KEPCO (Korea Electric Power Corporation) faced difficulties of the DCC (distribution control center) due to the increase of field equipment and operational cost, and aging of operating staffs. In response to these changes in the DCC, KEPCO is trying to change the organization and system of the DCC. In this paper, we present a new attempt to change organization and structure of distribution control center, which was implemented by KEPCO recently. This paper is divided into three major parts. First, to examine the adequacy of the divided basis of current DCCs based on the quantity of installed electrical equipment, we analyzed the correlation between the operational history of the DCCs and the number of equipment. Through the analysis, we confirmed that there is little relationship between the number of equipment and actual workload. Second, we conducted visits and questionnaire surveys of all the DCCs to identify factors affecting the actual workload of distribution operators and then summarized the results. Third, based on this survey, a general formula for analyzing the workload of a DCC was derived, and each DCC's average annual total workload, day/night workload, and required number of personnel were calculated. Through this study, we proposed a more realistic management method of DCCs that can overcome the division criteria based on equipment quantity.

• Journal of the Korea Society for Simulation
• /
• v.12 no.4
• /
• pp.103-111
• /
• 2003

A distributed sewer cluster system is a cost-effective system to provide a service application for clients with reliable, scalable, available, and fault-tolerant features. In order to provide high quality services, it is necessary to evaluate service performances, tune the server system, and analyze performances. In this paper, we propose a simulator to generate workloads based on statistic configuration according to estimated application traffics, apply workload scheduling algorithms, and evaluate the simulation results. We introduce the simulator design modelling and architecture. By using flexible parameters, the simulator is able to generate various patterns of workloads with different statistics, and configure system environments such as the number of server nodes, system resources considered, and their capacities. With this simulator, we introduce two scenarios: one is to find appropriate thresholds for the best performance of cluster system, and the other is to find the suitable scheduling algorithm for workload characteristics of service applications.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.24 no.69
• /
• pp.51-64
• /
• 2001

A laboratory experiment was conducted to investigate the effects of working posture. work/rest ration, and task type on the physical workload in automobile assembly jobs. Ten healthy male university students participated as subjects in the experiment. East subject performed 18 experimental session with combination of 3 working posture 3 work/rest ratio and 2 task types. To examine the effect of various working conditions on workload, DMG analysis was performed on 4 different muscles in the neck an arm area, Also RPE scale and heart rate were taken as response variables. The result showed that all working conditions considered in the experiment had significant effects on the workload concluding that labor intensity in auto assembly jobs should be adjusted with respect to different levels of working posture, work/rest ratio, and task type. Detailed analysis are presented in the paper.

• Proceedings of the Korea Society for Simulation Conference
• /
• 2003.11a
• /
• pp.27-34
• /
• 2003

A distributed server cluster system is a cost-effective system to provide a service application for clients with reliable, scalable, available, and fault-tolerant features. In order to provide high quality services, it is necessary to evaluate service performances, tune the server system, and analyze performances. In this paper, we propose a simulator to generate workloads based on statistic configuration according to estimated application traffics, apply workload scheduling algorithms, and evaluate the simulation results. We introduce the simulator design modelling and architecture. By using flexible parameters, the simulator is able to generate various patterns of workloads with different statistics, and configure system environments such as the number of server nodes, system resources considered, and their capacities. With this simulator, we introduce two scenarios: one is to find appropriate thresholds for the best performance of cluster system, and the other is to find the suitable scheduling algorithm for workload characteristics of service applications.

• Science of Emotion and Sensibility
• /
• v.4 no.1
• /
• pp.1-5
• /
• 2001

The evaluation of mental workload is measured by subjective ratings, physiological signals. It takes long time to analysis the measured signals and is very tedious and time-consumming work. Therefore, to evaluate the affect of workload effectively, real-time measurement system is required. In this paper, real-time mental workload measurement system using cardiac autonomic indiced which reflect well the mental workload was developed and evaluated. Analyzed indices were HR, IBI, Lorentz plot, CSI, CVI, and LF/HF ratio of heart rate variability. The system was applied to evaluate the affect of arithmetic task and showed good results. This system was consisted of ECG amplifier, A/D converter, and personal computer, and algorithm was implemented using LabVIEW.

• Journal of Korean Institute of Industrial Engineers
• /
• v.28 no.2
• /
• pp.178-186
• /
• 2002

The objective of this study is to evaluate impact of computer-based man-machine interfaces of Korea Next Generation Reactor (KNGR) on the operator mental workload. Empirical experiments were conducted to measure the operator mental workloads of KNGR and Yong-Gwang Unit 3 and 4, respectively. A comparison analysis based on a NASA TLX revealed that Yong-Gwang Unit 3 and 4 were superior to KNGR in terms of the mental workload. Post-hoc analyses showed that the mental workload of senior reactor operators was significantly higher than those of reactor and turbine operators, regardless of plant types. The implications of the findings were discussed in detail.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2017.11a
• /
• pp.241-242
• /
• 2017

미국 해안경비대 및 영국 해양사고조사국에 의하면 해양사고에서 인적과실의 원인중 상당부분 선원 피로에 기인하는 것으로 조사되었으며, 스웨덴에서의 연구 결과 약 73% 정도 선박 당직근무자들이 당직 근무 시간 중 최소 1회 또는 그 이상 졸음에 빠져 있는 것으로 보고하고 있다. 본 연구에서는 국내 연안선 항해당직자들을 대상으로 Workload를 분석하였으며, 효율적으로 Workload를 측정할 수 있는 방안을 제시하였다.

• Journal of the Ergonomics Society of Korea
• /
• v.29 no.4
• /
• pp.445-453
• /
• 2010

It is necessary to quantitatively evaluate the workload of workers in order to improve the level of safety and efficiency as well as to prevent workers from musculoskeletal disorders. The purpose of this study is to introduce biomechanical methods that are largely used to quantitatively evaluate workload. The biomechanical methods use kinematics and kinetics to analyze the movement and force of biomechanical body. Motion analysis, joint angle measurement, ground reaction force, mathematical model, and electromyography (EMG) were introduced as a tool or device for biomechanical evaluation. In this study, the special feature of each method was emphasized and important tips for field measurement were summarized. The information and technique disclosed in this summary can be used to evaluate and design the workplace better by effectively control the workload of field workers.