• Journal of Korean Institute of Industrial Engineers
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• v.30 no.2
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• pp.107-119
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• 2004

A study on the following parallel machine problem is addressed in this research. An order is completed only when a given number of processes (cycle) are repeated. Anew cycle is possible only upon the completion of the previous cycle. Orders are classified into job group according to product feature. For a machine to switch to a different job group from the currently processing one a major setup is required while a minor setup time is inserted in between two jobs of the same job group. The objective of the study is to find a schedule that minimizes total weighted tardiness. An initial solution is obtained by the RATCS(Restricted Apparent Tardiness Cost with Setup) rule, and a Tabu search is applied to improve the solution. Numerical examples are also presented.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.29 no.1
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• pp.1-8
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• 2006

This paper proposes a real-time resource allocation algorithm for minimizing the completion time of overall workflow process. The jobs in a workflow process are interrelated through the precedence graph including Sequence, AND, OR and Loop control structure. A resource should be allocated for the processing of each job, and the required processing time of the job can be varied by the resource allocation decision. Each resource has several inherent restrictions such as the functional, geographical, positional and other operational characteristics. The algorithm suggested in this paper selects an effective resource for each job by considering the precedence constraint and the resource characteristics such as processing time and the inherent restrictions. To investigate the performance of the proposed algorithm, several numerical tests are performed for four different workflow graphs including standard, parallel and two series-parallel structures. In the tests, the solutions by the proposed algorithm are compared with random and optimal solutions which are obtained by a random selection rule and a full enumeration method respectively.

• Journal of the Korean Data and Information Science Society
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• v.21 no.6
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• pp.1191-1201
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• 2010

In this paper, we analyze the impact on quitting one's first job based on "Graduates Occupational Mobility Survey" data given by Korea Employment Information Service. According to the survey, there are a large number of questionnaires on quitting one's first job and so it is not easy to choose among them. We will investigate model selection criteria and apply the procedure proposed by Shtatland et al. (2003) to identify the final model.

• Journal of Navigation and Port Research
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• v.28 no.8
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• pp.721-726
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• 2004

This study was performed to analyze the operation system of transfer crane to improve the reality of yard operation rules in container terminal and present the applicable method of operation rules to apply the operation priority. And we derived the procedure to estimate the maximum number of waiting truck based on the waiting of truck and the occupancy of driving lane in yard, and analyzed the constraint state of space. To solve the space constraint, we provided a multi-job principle to define the space resource and described the solution and sequence diagram for the principle.

• The Journal of Information Systems
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• v.25 no.1
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• pp.159-182
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• 2016

Purpose This paper aims to develop a novel tabu search algorithm for solving the sequencing problems with precedence constraints. Due to constraints, the traditional meta heuristic methods can generate infeasible solutions during search procedure, which must be carefully dealt with. On the contrary, the candidate order based tabu search (COTS) is based on a novel neighborhood structure that guarantees the feasibility of solutions, and can dealt with a wide range of sequencing problems in flexible manner. Design/methodology/approach Candidate order scheme is a strategy for constructing a feasible sequence by iteratively appending an item at a time, and it has been successfully applied to genetic algorithm. The primary benefit of the candidate order scheme is that it can effectively deal with the additional constraints of sequencing problems and always generates the feasible solutions. In this paper, the candidate order scheme is used to design the neighborhood structure, tabu list and diversification operation of tabu search. Findings The COTS has been applied to the single machine job sequencing problems, and we can see that COTS can find the good solutions whether additional constraints exist or not. Especially, the experiment results reveal that the COTS is a promising approach for solving the sequencing problems with precedence constraints. In addition, the operations of COTS are intuitive and easy to understand, and it is expected that this paper will provide useful insights into the sequencing problems to the practitioners.

• Journal of the Korean Dietetic Association
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• v.7 no.1
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• pp.87-104
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• 2001

This study was conducted as a part of the project developing the standards of national board test for the dietitian's licence. The purpose of this study was to define the job description of dietitians, and to describe the task elements based on the detailed analysis of the dietitians' work. This study team established the research team which was composed of food and nutrition experts, 7 of registered dietitians and 3 of university professors. Draft job description form was made to fully explain the dietitians' task elements, process and sequence by the research team. Final job description form was confirmed after the validity of 576 task elements was reevaluated upon 4 point scale test based on the frequency, importance, and difficulty by 21 field registered dietitian by the study team. It was also confirmed by the university. This form was formated by following DACUM method which analyzed the job description containing duty, task and task elements. It was organized to include every dietitians' work and to describe the every detailed process of work. Duty was defined as the specific and independent work as a dietitian, and was composed of 17 parts, i.e 10 parts in food supply management area and 6 parts in nutritional care service area and self promotion area. Duties were also divided into 99 tasks containing the 576 detailed task elements to describe definite action, steps and decisions. Seventeen parts are following; menu planning, storage and inventory control, food production, meal service, waste management, sanitation, equipment and facility management, human resource management, financial management, nutrition assessment of life cycle, nutritional assessment of several disease, nutritional assessment in specific condition, medical nutrition therapy, nutritional education, public health nutrition and self promotion. If these protocols are properly performed and presented, they can provide the likelihood that dietetics professionals work as a primary contributors in promoting health care and preventing disease nationally.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.305-315
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• 2016

Due to the change from small volume production to small quantity batch production systems, individual companies have been attempting to produce a wide range of operating strategies, maximize their productivity, and minimize their WIP level by operating with the proper cycle time to defend their market share. In particular, using a complex workflow and process sequence in the manufacturing line has some drawbacks when it comes to designing the production strategy by applying analytical models, such as mathematical models and queueing theory. For this purpose, this paper uses three heuristic algorithms to solve the job release problem at the bottleneck workstation, product mix problem in multi-purpose machine(s), and batch size and sequence in batch machine(s). To verify the effectiveness of the proposed methods, a simulation analysis was performed. The experimental results demonstrated that the combined application of the proposed methods showed positive effects on the reduction of the cycle time and WIP level, and improvement of the throughput.

• Journal of Korean Society for Quality Management
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• v.17 no.1
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• pp.35-47
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• 1989

This paper is concerned with a development and evaluation of heuristic algorithms for the n-job, M-stage flowshop with sequence dependent setup times. Three heuristic algorithms, CAIDAN, DANNEN and PETROV, are proposed. The makespan is taken as a performance measure for the algorithms. The experiment for each algorithm is designed for a $4{\times}3{\times}3$ factorial design with 360 observations. The experimental factors are PS (ratio of processing times to setup times), M (number of machines), and N (number of jobs). The makespan of the proposed heuristic algorithms is compared with the optimal makespan obtained by the complete enumeration method. The result of comparision of performance measure is called a relative error. The mean relative errors of CAIDAN, DANNEN and PETROV algorithms are 4.488%. 6.712% and 7.282%, respectively. The computational results are analysed using SPSS. The experimental results show that the three factors are statistically signiticant at 5% level.

• Management Science and Financial Engineering
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• v.13 no.1
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• pp.25-34
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• 2007

This paper is concerned with proving a conjecture that the two stage assembly system is reversible in deterministic makespan scheduling context. The reversibility means that a job sequence in the assembly system has the same makespan as that of its reverse sequence in the disassembly system which is the reversal of the assembly system. The proposed conjecture shows that the reversibility of serial flowshops can be extended to non-serial and synchronized shops.

• IE interfaces
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• v.7 no.3
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• pp.125-135
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• 1994

This thesis reports the development of a Computer-Aided Process Planning system for rotational parts. The developed system ultimately generates process plans for rotational parts through a knowledge-base. The knowledge-base and decision-making algorithms are represented by Pascal computer programming language. We have developed a process planning system which adjusts the sequence of processes by itself to ensure the quality of the parts. This system generates more detailed job sequence and descriptions than other well-known process planning systems. We present realistic and efficient process plans through the integration of process planning and scheduling. This system optimizes flow time of parts by decreasing the number of machine set-ups.