• Journal of Digital Convergence
• /
• v.17 no.4
• /
• pp.29-39
• /
• 2019

This paper understands small and medium-sized enterprises(SMEs) with the lenses of 'labors' and 'technology' and analyzes possible alternatives for creating jobs in Korea. Interviews with eighty CEOs, directors, managers are conducted during the summer in 2017. In terms of 'labors,' critical issues were 'low income' and 'income gap from conglomerates.' When it comes to 'technology,' support for R&D was critically presented. This study proposes three policies for creating jobs: 1) National Management for Good Technicians, 2) Technical Bidding System, and 3) Mutual benefit disclosure System. Implications for the employment policy are followed.

• Journal of Korean Institute of Industrial Engineers
• /
• v.25 no.1
• /
• pp.47-55
• /
• 1999

This paper develops an efficient heuristic algorithm for scheduling workforce level that can accommodate all the requested maintenance jobs. Each job has its own release and due dates as well as man-day requirement, and must be scheduled in a non-interrupted time interval, namely, without preemption. Duration of each job is not fixed, but to be determined within given specific range. The objective is to minimize workforce level to complete all the requested maintenance jobs. We show that the problem can be seen as a variant of the two-dimensional bin-packing problem with some additional constraints. A non-linear mixed integer programming model for the problem is developed, and an efficient heuristic algorithm based on bin-packing algorithms is proposed. In order to evaluate goodness of the solution obtained from the proposed algorithm, a scheme for getting a good lower bound for the optimum solution is presented and analyzed. The computational experiment shows that the proposed algorithm performs quite satisfactorily.

• Journal of Computing Science and Engineering
• /
• v.10 no.1
• /
• pp.9-20
• /
• 2016

Several task clustering heuristics are proposed for allocating tasks in heterogeneous systems to achieve a good response time in data intensive jobs. However, one of the challenging problems is the process in task scheduling after task allocation by task clustering. We propose a task scheduling method after task clustering, leveraging worst schedule length (WSL) as an upper bound of the schedule length. In our proposed method, a task in a WSL sequence is scheduled preferentially to make the WSL smaller. Experimental results by simulation show that the response time is improved in several task clustering heuristics. In particular, our proposed scheduling method with the task clustering outperforms conventional list-based task scheduling methods.

• IE interfaces
• /
• v.18 no.3
• /
• pp.350-360
• /
• 2005

This paper considers a strategy for planning of rework in semiconductor monitoring burn-in test process. The equipment error in monitoring burn-in test process generates many defects. These defects are transformed into good products by rework process, i.e. retest. Rework has the advantage of saving production costs. But rework increases holding costs and incurs rework costs. In monitoring burn-in test process, rework depends on operator's experience with no pre-defined specification. In practice, a number of rework activities are performed with respect to the product importance and inventory quantity. Moreover, disregard for order jobs schedule have caused due date penalties. So a strategy for planning of rework by which order jobs schedule are not affected is suggested. Futhermore, production costs, rework costs and inventory costs for planning of rework are considered.

• Journal of Korean Institute of Industrial Engineers
• /
• v.18 no.2
• /
• pp.99-107
• /
• 1992

Both simulation and expert systems are popular ways to solve complex and hard problems. However, the results of the simulation, which include a large amount of valuable information as a good knowledge source, are not used efficiently. Furthermore, the development of the expert systems can fail because there is no expert or an expert is not available. A new Simulation-Based Expert System(SIMBES) paradigm has been constructed to overcome these problems. It consists of simulator, feature extractor, machine learning system, performance evaluator and Knowledge-Based Expert System(KBES). A SIMBES was implemented for an existing schedule-based MRP system in Smalltalk/V to show how this paradigm works and experimented for a large number of jobs. The KBES and the existing system produced better schedules for 72 percent and 28 percent of the jobs, respectively.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.8 no.1
• /
• pp.24-35
• /
• 1998

Cumulative trauma disorders(CTDs) have been a growing problems for US and European industries with higher incidence rate every year. The increase and their associated costs has led companies to form committes and implement programs to address this problem. In our country, we have just started to recognize and to work on the problems in industry. This study conducted an ergonomic analysis for typical jobs of ship building industry which was not usually surveyed for CTD problem. A baseline CTD checklist which was supposed to do a risk assessment was developed and applied in this study. Initially, we considered five major parts in the checklist which consisted of personal, frequency, posture, force, and miscellaneous information. Most jobs in ship building industry were much different from typical assembly work and VDT work that have been major part of the previous CTD studies. Specifically, job characteristics in terms of frequency and posture were quite different. There were relatively long cycle time, awkward postures for whole body (not just for upper extremities). Also, CTD risk scores based on checklist were a lot higher than the scores for VDT jobs which was a case of preceding application of the checklist. Specifically, grinding jobs turned out to be the most risky one in terms of CTDs. In conclusion, usual CTD prevention guidelines are not likely to he effective in this type of industry. An individual job based interventions are strongly suggested to have a good control of CTD problems in ship building industry.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.18 no.34
• /
• pp.99-106
• /
• 1995

Recently, neural network is recognized as a new approach to solve jobshop scheduling problems in manufacturing system. Scheduling problem is known to be a difficult combinational explosive problem with domain-dependence variations in general. In addition, the needs to achieve a good performance in flexible manufacturing system increase the dimensions of decision complexity. Therefore, mathematical approach to solve realistic problems could be failed to find optimal or optimal-trending. In this paper a technique with neural network for jobs grouping by job-attributes and Gaussian machine network for generating to near-optimal sequence is presented.

• Journal of the Ergonomics Society of Korea
• /
• v.19 no.2
• /
• pp.15-31
• /
• 2000

The aim was to evaluate the prevailing ergonomic and psychosocial conditions regarding low back injury in an automobile assembly system. This study consisted of two parts. In the first part of the study, analytic biomechanical model and NIOSH guidelines were applied to evaluate risk levels of low back injury for automobile assembly jobs. Total of 246 workers were analysed. There were 20 jobs having greater back compressive forces than 300kg at L5/S1. Also, there were 44 jobs over Action Limit with respect to 1981 NIOSH guidelines. This might in part be explained by the ergonomic conditions of the company analysed generally being good, with a relatively low duration of 'combined' extreme work posture. The relationship between psychosocial factors and low back injury was examined in the second part of the study. It has recently been recognized that overall reaction to working conditions was influenced by a range of factors, some of which were physical and some psychosocial. The psychosocial environment surrounding the work place may contribute to the perception of risk and eventual ill-health. A battery of questionnaires concerning the psychosocial stress based on PWI(Psychosocial Well-being Index) and musculoskeletal pain symptoms at low back was completed by 246 workers at the same plant. Results showed that 207 out 246 workers experienced the symptoms and 27 workers were diagnosed as patients. Two groups(low stressed, high stressed) based on PWI score had no significant relationships with both symptoms and results of diagnosis. However, sensitivities for symptoms and diagnosis by PWI were 91.3% and 92.6% respectively. Finally, relationships between physical work load and psychosocial stress were analysed. Specifically, some postural factors {vertical deviation angle of forearm, horizontal deviation angle of upperarm, vertical deviation angle of thigh, etc) were highly correlated with psychosocial stress. The results illustrated that PWI scores were associated with some physical workloads. However, psychosocial stress levels couldn't be well related with the pain symptom as well as the actual incidence of low back injury since pain or discomfort regarding low back injury were more complex than that of other musculoskeletal disorders.

• International Journal of Safety
• /
• v.3 no.1
• /
• pp.27-31
• /
• 2004

Some of the petroleum products contain benzene which is well known as a confirmed human carcinogen. For example, gasoline products contain benzene ranging up to several percents by weight. High exposures to the benzene and other organic solvents would be likely to occur during intermittent tasks and or processes rather than continuous jobs such as sampling, repair, inspection, and loading/unloading jobs. The work time for these jobs is various. However, most of work time is very short and the representative time interval is 15 minutes. Thus, it is preferable to do exposure assessment for 15 minute time weighted average which is known as a short time exposure level(STEL) by ACGIH rather than for 8-hours TWA. It is particularly significant to the exposure monitoring for benzene since it has been known that the exposure rate plays an important role to provoke the leukemia. Due to the large variations, a number of processes/tasks, the traditional sampling technique for organic solvents with the use of the charcoal and sampling pumps is not appropriate. Limited number of samples can be obtained due to the shortage of sampling pumps. Passive samplers can eliminate these limitations. However, low sampling rates resulted in collection of small amount of the target analysts in the passive samplers. This is originated the nature of passive samplers. Field applications were made with use of passive samplers to compare with the charcoal tube methods for 15 minutes. Gasoline loading processes to the tank lorry trucks at the loading stations in the petroleum products storage area. Good agreements between the results of passive samplers and those of the charcoal tubes were achieved. However, it was found that special cautions were necessary during the analysis at very low concentration levels.

• Korean Institute of Interior Design Journal
• /
• v.21 no.4
• /
• pp.172-180
• /
• 2012

Recently, the definition of work space contains so many meanings. Basically, this means space where handling various information and developing numerous creative activities. Moreover, the work space is important not only for individual itself but also organizational development. This research is studied for suggesting revitalization of advanced work efficiency, deriving motivation as well as creative operation support for harmonious communication. In order to make the better creative work places, "concentration and motivating interests between members of organization", "Necessity of environment for development and operational progress of work", "improvement and creativity of work and importance of the physical environment" and "harmonious communication and development of advanced community" should be considered. This research arranged based on ALCEMIS model and used actual examples on each step for better understanding of creative work spaces. ALCEMIS model is as follows: (1) Opportunity Finding (2) Fact Finding (3) Opportunity Definition (4) Idea Finding (5) Evaluate & Select (6) Plan (7) Acceptance (8)Execution' over the eight-step details to proceed through the 1. Discovert ((1)+(2)) 2. Dream ((3)+(4)) 3. Design((5)+(6)) 4. Destiny((7)+(8))y" It has been understood that many works related to creative jobs make good use of public spaces to progress operational improvement. The place where co-workers share with can create more effective and fulfilling outcome and satisfaction than independent and exclusive places. Especially creative jobs need this kind of spaces for better communication and cooperation.