• Korean Management Science Review
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• v.11 no.1
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• pp.23-37
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• 1994

This paper discusses the methodology for the operational performance of unit-load automated guided vehicles(AGVs) in a flow-shop-type flexible machining and assembly systems (FM/AS). Throughout the paper, AGVs are working as a carrier and mobile workstation. For a double-loop FM/AS, in which one loop is dedicated to machining and the other to assembly, three AGV operating strategies are proposed. Considering the entering interval and travel time of AGVs between workcenters, the strategies are developed to determine the best job sequence which minimizes the makespan and vehicle idle time. Entering times of AGVs and the required minimum number of AGVs are obtained on the basis of the best job sequence. When the number of AGVs are limited, entering times of AGVs are adjusted to maximize the utilization of AGVs.

• Korean Management Science Review
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• v.33 no.2
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• pp.1-10
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• 2016

We treats a job scheduling in a 2-machine flow-shop problem with outsourcing strategy allowed. Jobs in the first machine are processed in-house or outsourced to the other companies. In this paper, all the considered jobs are determined to be in-house processed or outsourced. When a job is outsourced, then the firm should pay an outsourcing cost additionally. We want to minimize the sum of the outsourcing costs and the total completion times of finished jobs. In this paper, some solution properties are characterized, and then some heuristic algorithms and a branch-and-bound solution algorithm are derived. This paper evaluates finally the performance of the proposed algorithms during the numerical tests.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.22 no.51
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• pp.41-52
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• 1999

In this paper, a load balancing problem among operators is considered, when one or more machines can be assigned to an operator. The machines are grouped into two types and there are more than one machines in each group. The type of machine in which a job can be processed, is determined. However, an operator can handle both types of machine. The elementary operations of a job are classified into three classes : machine-controlled elements, operator-controlled elements and machine/operator- controlled elements. The objective is to balance the workloads among operators under the constraints of available machine-time and operator-time. A heuristic solution procedure is suggested for allocating jobs to machines and allocating machines to operators. The performance of the algorithm is evaluated with various data set.

• 대한공업교육학회지
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• v.30 no.2
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• pp.33-44
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• 2005

The purpose of this study is to suggest plans to improve the industrial high school through the inquiry of Competency-Based Education(CBE). The suggestions are as followings: (1) Selection and organization of the educational contents of industrial high school must be based on job analysis. (2) Instructional objectives must be defined as a performance objective and enabling objectives. (3) Instruction must be individualized in method, the instructional contents must be organized in the unit of module. (4) Evaluation system must be not knowledge based but performance-based. (5) Physical Environment of work shop must be organized based on facilities, equipments and machines abstracted by job analysis. (6) Competency-Based Teacher Education(CBTE) program is required to train competent teachers in practice.

• IE interfaces
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• v.5 no.1
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• pp.35-46
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• 1992

This paper deals with analysis of material handling system efficiency of a heat-exchanger manufacturing line. This line is a typical flow shop type assembly line which consists of 10 steps of assembly stations. Each station have one or two workers who assemble and move components for the job, and no special transporters for component's movement. Therfore, all the workers are involoved in unnecessary moving activities which decrease overall production efficiencies of the line. To improve productivities, production outputs and worker's job performances for this assembly line, the several alternatives are considered such as installing new conveyor lines and automatic guided vehicle(AGV) system. Analyzing economic feasibilities and responses of the system alternatives, an experimental simulation model is built suing SIMAN Ver. 3. 5 simulation language with CINEMA package for animation of the process flow. Through this animation process a vivid picturial analysis could performed on the process flow.

• Journal of Korean Institute of Industrial Engineers
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• v.21 no.2
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• pp.207-216
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• 1995

Constructing a distributed management system has its own advantages in addressing the issue of implementing a quick responsive management system in dynamically changing environment of enterprise. We suggest a basic scheduling methodology applicable to a distributed production management system. A new concept of "flexible schedule" is introduced as a tool to accommodate dynamically changing situations of job shops. Then a search technique (referred to as CSP-CBA search) is presented to obtain such a schedule for the job shop scheduling problem, which is converted into a constraint satisfaction problem(CSP), by using the constraint based analysis(CBA). This approach is tested on more than 100 test problems. The results show that the suggested approach required shorter CPU time and solved more problems in given time than another fixed schedule method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8585-8595
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• 2015

This study was implemented to amass and analyze the data from 500 Seoul district beauty shop workers, which came from the use of the SPSS18.0. The statistical analysis was conducted through frequency for demographic characteristics, validity for factors analysis by using Varimax rotation, and reliability for Cronbach's alpha coefficient.. Also, the analysis was once again analyzed through the Pearson correlation coefficient, where our hypothesis was proven through regression analysis. Our research results have shown that, first, job satisfaction and job performance differed over matters like gender, age, education level, employment conditions, job category, overall work experience, daily work hours, and monthly income. Second, job satisfaction was shown to have a significant influence on job performance, where higher job satisfaction levels led to higher job performance. Thus, job satisfaction was a great factor to increase job performance by fulfilling their needs level. Also, they would act more positive and future-oriented when they have special needs like motivate achievement, wage, promotion, and reward. Therefore, managerial staff should continually develop any programs in order to upgrade beautician's job performance through their job satisfaction.

• The Transactions of the Korea Information Processing Society
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• v.6 no.4
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• pp.959-968
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• 1999

several papers have reported that parallel heuristics or hybrid approaches combining several heuristics can get better results. However, the parallelization and hybridization of any search methods on the single CPU type computer need enormous computation time. that case, we need more elegant combination method. For this purpose, we propose Fast Model of Parallel Heuristics(FMPH). FMPH is based on the island model of parallel genetic algorithms and takes local search to the elite solution obtained form each island(sub group). In this paper we introduce how can we adapt FMPH to the job-shop scheduling problem notorious as the most difficult NP-hard problem and report the excellent results of several famous benchmark problems.

• Journal of Korea Multimedia Society
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• v.3 no.4
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• pp.407-415
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• 2000

The ultimate goal of flow control in the semiconductor fabrication process, one of the most equipment-intensive and complex manufacturing process, is to reduce lead time and work in process. In this paper, we propose stand alone layout in the form of job shop using group technology to improve the Productivity and eliminate the inefficiency in FMS (flexible manufacture system). The performance of stand alone layout and in-line layout are analyzed and compared while varying number of device variable chanties. The analysis of in-line layout is obtained by examining its adoption in the memory products of semiconductor factory. The comparison is performed through simulation using ProSys; a window 95 based discrete system simulation software, as a tool for comparing performance of two proposed layouts. The comparison demonstrates that when the number of device variable change is small, in-line layout is more efficient in terms of production Quantity. However, as the number of device variable change is more than 14 times, stand alone layout prevails over in-line layout.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.8
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• pp.1415-1421
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• 2016

There are considerable concern on the methods for the efficient utilization of the test-resources as increasing of the number of the tests for functionality and performance verification of weapon systems. Furthermore, with an increase in the complexity of the resource assignment the decision support is required. Test resource allocation is basically the same problems as conventional NP-hard FJSP(Flexible Job Shop Problem), therefore empirical test resource allocation method that has been used in many decades is limited in the time performance. Although research has been conducted applying the genetic algorithm to the FJSP, it is limited in the test resource allocation domain in which more than one machine is necessary for a single operation. In this paper, a variable group genetic algorithm is proposed. The algorithm is expected to improve the test plan efficiency by automating and optimizing the existing manual based allocation. The simulation result shows that the algorithm could be applicable to the test plan.