• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.21 no.46
• /
• pp.241-251
• /
• 1998

There are two methods of load balancing for detail scheduling : One method is to generate an initial schedule and obtain an improved final schedule by load balancing only during a specific period. The other method is to generate an initial schedule and obtain an improved schedule by load balancing from current date(TIMENOW) to unlimited time with the whole manufacturing processes. This paper proposes an algorithm for detail scheduling which can be a practical solution in job shop production or project job type by applying the former method.

• Korean Management Science Review
• /
• v.21 no.2
• /
• pp.79-91
• /
• 2004

In industrial production settings, scheduling problems for detailed day-to-day operations are often ordeals to production practitioners. For those who have scheduling experiences with the Gantt Chart, the job oriented heuristic scheduling has illustrated its merits in solving practically large scale scheduling problems. It schedules all operations of a job within a finite capacity before considering the next job. In this paper, we Introduce the LSB (load smoothing backward) scheduling algorithm for the job oriented heuristic scheduling. Through a computer experiment in a hypothetical setting, we make a performance comparison of LSB scheduling algorithm with existing algorithms and also suggest a guideline for selecting the suitable algorithm for certain industrial settings.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.11 no.1
• /
• pp.237-252
• /
• 2017

In recent years, data centers have become the core infrastructure to deal with big data processing. For these big data applications, network transmission has become one of the most important factors affecting the performance. In order to improve network utilization and reduce job completion time, in this paper, by real-time monitoring from the application layer, we propose job-aware priority scheduling. Our approach takes the correlations of flows in the same job into account, and flows in the same job are assigned the same priority. Therefore, we expect that flows in the same job finish their transmissions at about the same time, avoiding lagging flows. To achieve load balancing, two approaches (Flow-based and Spray) using ECMP (Equal-Cost multi-path routing) are presented. We implemented our scheme using NS-2 simulator. In our evaluations, we emulate real network environment by setting background traffic, scheduling delay and link failures. The experimental results show that our approach can enhance the Hadoop job execution efficiency of the shuffle stage, significantly reduce the network transmission time of the highest priority job.

• The Journal of the Korea Contents Association
• /
• v.8 no.10
• /
• pp.361-372
• /
• 2008

The purpose of this study was to verify the relationship between perfectionism and job stress of archery trainers. Participants of this study were 113 archery trainers who worked at the middle and high school's archery teams. Some of the archery trainers who participated in korea archery championship for junior in 2007 were selected using the purposive sampling method. The questionnaire was Multidimensional Perfectionism Scale developed by Hewitt and Flett(1991) which was revised by Lim(2005) into Korean and The Job Stress Scale developed by Jo(1998). Responses were made on 5-point and 7-point scale. The statistical methods for the analysis of this study were Pearson's correlation and multiple regression analysis. The results of this study were as follows. First, there was self perfectionism, person perfectionism, social perfectionism highly on the perfectionism of archery trainers and job condition stress, game stress, job load stress, support system stress, interpersonal relation stress highly on the job stress. Second, there was statistical significant relation between the job condition stress, game stress, job load stress and self perfectionism, between the game stress, job load stress and person perfectionism. Third, self perfectionism affect on job condition stress and self and person perfectionism affect on game stress, job load stress.

• Research in Community and Public Health Nursing
• /
• v.15 no.2
• /
• pp.289-297
• /
• 2004

Purpose: This study was conducted to determine factors affecting workers' physiological somatic complain using the Job Stress Model proposed by the National Institute for Occupational Safety and Health (NIOSH). Method: Data were collected from the 1st to the 30th of December 1999. The subjects were 2.123 workers employed at 155 work sites. Collected date were analyzed through SAS/PC program. Result: According to individual characteristics, younger and women groups showed significantly higher physiological somatic complaint than elder men groups. By work condition, groups with higher physiological somatic complaint included workers of irregular shift work. Dark lighting, improper temperature in winter, improper ventilation, inappropriate humidity, unpleasant work environment and crowded work place were significantly related with physiological somatic complaint. By work-related factor, physiological somatic complaint was high in those with higher variance in work load, quantitative work load, role conflict, job burden, role ambiguity and future ambiguity. On the other hand, physiological somatic complaint was low in those with little underutilization of ability. As for the relationships between physiological somatic complaint and non-work related factors, physiological somatic complaint was high in workers who had a side job, were bringing up infants alone, cleaned the house alone, cared for the elderly and disabled persons, were studying, were volunteering at another organization, and were spending 5-10 hours in religious activities per week. Physiological somatic complain was in significantly negative correlations with overall social support, supervisory support and family support, but in significantly positive correlations with co-worker support. Conclusion: The main predictors of physiological somatic complain were gender, shift work pattern, overtime work, ventilation, role ambiguity, role conflict, future ambiguity, job control, variance in work load, overall social support, worker with side job, worker who cleans the house alone, worker who is studying. These predictors explained 19.10% of the total variance of physiological somatic complain.

• Journal of the Korea Society for Simulation
• /
• v.3 no.1
• /
• pp.89-98
• /
• 1994

In this paper, a criteria for selecting an appropriate load redistribution algorithm is devised so that a fault-tolerance distributed system can operte at its optimal efficience. To present the guideline for selecting redistributing algorithms, simulation models of fault-tolerant system including redistribution algorithms are developed using SLAM II. The job arrival rate, service rate, failure and repair rate of nodes, and communication delay time due to load migration are used as parameters of simulation. The result of simulation shows that the job arrival rate and the failure rate of nodes are not deciding factors in affecting the relative efficiency of algorithms. Algorithm B shows relatively a consistent performance under various environments, although its performance is between those of other algorithms. If the communication delay time is longer than average job processing time, the performance of algorithm B is better than others. If the repair rate is relatively small or communication delay time is longer than service time, algorithm A leads to good performance. But in opposite environments, algorithm C is superior to other algorithms.

• Journal of the Korean Society of Safety
• /
• v.20 no.4 s.72
• /
• pp.122-129
• /
• 2005

With Zohar(1980)'s research on safety climate and industrial safety, occupational safety and health literatures begin to emphasize the influence of organizational context. Based on this research trend, this paper tried to review the relationship between individual/ organizational factors and occupational accidents. Based on the responses from 294 manufacturing workers, this paper reviewed the relationships among safety climates, safety performance, and age. The results of statistical analysis showed that all safety climate factors have affirmative effects on safety participation and safety attitudes negative effect on accident number, and job load affirmative effect on accident number. Job load and management commitment showed interactive effects on accident number with age.

• The Transactions of the Korea Information Processing Society
• /
• v.2 no.5
• /
• pp.768-776
• /
• 1995

In a distributed computer system with star topology, the processing power of central node may be greater than that of peripheral nodes and the job arrival rate of each node may be different. The performance of load balancing may be very different according to the selection of sender criteria and receiver criteria for job transfer. But the optimal decision of sender and receiver criteria is very difficult in heterogeneous distributed computer systems. In this paper we propose effective destination decision policies using dynamic criteria such as mean job response time of a node and estimated response time of a job, instead of fixed threshold for dynamic load balancing.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.7 no.5
• /
• pp.8-13
• /
• 1997

In multi-server environment there are many servers which are able to process job requests. So we bave to design a mechanism that selects appropriate servers for processing each job request while maximizing server throughput and minimizing average response time of requests. Conventional methods ac~ opt the load of each server as criteria of server selection. that is, they select a server whose load is not bigger than the others. In this work we propose an approach that uses the degree of server performance, server load and the estimated service time of requested job as guidelines of server selection. We incorporate fuzzification techniques and expert knowledge in this approach. Comparing the performances c~f our approach to that of conventional one, experiments show that the proposed approach provides better performances.

• Research in Community and Public Health Nursing
• /
• v.18 no.3
• /
• pp.410-419
• /
• 2007

Purpose: This study is a descriptive survey to find out musculoskeletal symptoms in care workers working at medical welfare facilities for elders and factors affecting such symptoms. Methods: Data were collected from 115 care workers selected through convenient sampling from 6 medical welfare facilities in Seoul and Gyeonggi-do during the period from May 15th to May 19th. 2006. The Korean version of Job Content Questionnaire (JCQ) were used. Result: Of the subjects, 81.7% complained of musculoskeletal symptoms in two or more parts of their body. The frequency of body parts with musculoskeletal symptoms was high in order of shoulder, leg/foot, waist, neck/hand/wrist/finger and arm/elbow. The average job insecurity instability in the age group of 50-59 was 9.19, the average degree of regular exercise was 59.68. and the average job demand in those diagnosed with musculoskeletal diseases was 47.06, and the average job demand in those wounded during exercise or by an accident was 47.78, and all these were statistically significant. The heavier physical load in their work was, the higher their complaint of musculoskeletal symptoms was. In the lower social support group, the degree of complaint on musculoskeletal symptoms was remarkably high. Conclusion: The physical load of their duty and social support worked as the factors affecting musculoskeletal symptoms in care workers.