• Management Science and Financial Engineering
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• 제11권2호
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• pp.19-43
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• 2005

This paper considers a variation of the customer order scheduling problem, and the variation is the case where the machine-job assignment is fixed. We examine the parallel machine environment, and the objective is to minimize the sum of the completion times of the batches. While a machine can process only one job at a time, different machines can simultaneously process different jobs in a batch. The recognition version of this problem is known to be NP-complete in the strong sense even if there exist only two parallel machines. When there are an arbitrary number of parallel machines, we establish three lower bounds and develop a dynamic programming (DP) algorithm which runs in exponential time on the number of batches. We present two simple but intuitive heuristics, SB and GR, and find some special cases where SB and GR generate an optimal schedule. We also find worst case upper bounds on the relative error. For the case of the two parallel machines, we show that GR generates an optimal schedule when processing times of all batches are equal. Finally, the heuristics and the lower bounds are empirically evaluated.

• 산업경영시스템학회지
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• 제40권4호
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• pp.211-220
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• 2017

The application of the theoretical model to real assembly lines has been one of the biggest challenges for researchers and industrial engineers. There should be some realistic approach to achieve the conflicting objectives on real systems. Therefore, in this paper, a model is developed to synchronize a real system (A discrete event simulation model) with a theoretical model (An optimization model). This synchronization will enable the realistic optimization of systems. A job assignment model of the assembly line is formulated for the evaluation of proposed realistic optimization to achieve multiple conflicting objectives. The objectives, fluctuation in cycle time, throughput, labor cost, energy cost, teamwork and deviation in the skill level of operators have been modeled mathematically. To solve the formulated mathematical model, a multi-objective simulation integrated hybrid genetic algorithm (MO-SHGA) is proposed. In MO-SHGA each individual in each population acts as an input scenario of simulation. Also, it is very difficult to assign weights to the objective function in the traditional multi-objective GA because of pareto fronts. Therefore, we have proposed a probabilistic based linearization and multi-objective to single objective conversion method at population evolution phase. The performance of MO-SHGA is evaluated with the standard multi-objective genetic algorithm (MO-GA) with both deterministic and stochastic data settings. A case study of the goalkeeping gloves assembly line is also presented as a numerical example which is solved using MO-SHGA and MO-GA. The proposed research is useful for the development of synchronized human based assembly lines for real time monitoring, optimization, and control.

• 대한조선학회논문집
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• 제50권5호
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• pp.334-342
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• 2013

In this paper, we analyze the procedure of the design manager for the enhancement of the hull production design process by use of the simulation method. Normally, design manager assigns design jobs according to various methods and estimates the corresponding results. When the construction drawing which is the output of the detail design where a design is dealt by zones, the design manager identifies blocks and analyzes their work difficulties, and assigns jobs to design engineers who are different in capabilities. These processes including the design engineer who can be modeled with man-hours evaluation model are represented in detail as a simulation model. As the high-level modeling for the discrete-event system, we use Event Graph model. And we implemented the simulation using Simkit which is open simulation engine for the discrete-event system. We made the simulation scenario to be written by a user in the scenario generator which is separated from the simulation model, and made the simulation result to be visualized in the form of Gantt chart in a Web. In the scenario of the irregular issuance for various construction drawings which contain different numbers of blocks, we performed the Monte-Carlo simulation according to various assignment methods to find the assignment result that satisfies the mid-term schedule.

• 대한산업공학회지
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• 제17권2호
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• pp.51-61
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• 1991

This paper presents a heuristic method for the Assembly Line Balancing(ALB) of the large-sized product. In the ALB problem of the large-sized product such as bus and truck, the assignments of the Related Task Groups(RTG), the same side tasks, and team tasks should be considered. In this paper, a new concept of the RTG and two kinds of assignment rules are proposed to resolve the above considerations. The first assignment rule allots the RTG with the constraint of the same side tasks to the station while the second allots the RTG to the station, relaxing the above constraint to increase the applicability of the method. An assignment rule for team tasks is also presented. The benefits of the method are to improve work methods, to give more job satisfaction to workers, and to allow greater flexibility in the design of assembly lines.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 1998년도 추계학술대회 논문집
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• pp.216-219
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• 1998

This study proposes JPT(Job-Pair Tardiness) that choose operation to be expected to generate better schedule consequence in comparing schedulable operation sets in pair to minimize total tardiness evaluation function in performing scheduling. In result of comparison with existing assignment rules. JPT generates better solution than most other rules in all kinds of problems. So it is anticipated that this is used for initial solution of heuristic and is used for finding more improved solution.

• 한국기록관리학회지
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• 제8권1호
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• pp.235-255
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• 2008

정부기관에 근무하는 기록연구사들의 근무실태와 직무만족, 제도운영의 개선방안을 파악하기 위해 설문조사와 면접조사를 실시하였다. 직무특성은 Hackman과 Oldham의 직무특성요인을 포함하여 전문성, 역할갈등, 스트레스, 이직의사의 9가지 항목으로 조사하였다. 직무환경은 의사소통, 참여, 인간관계, 상급자, 교육훈련의 5개 항목으로 구분하여 조사하였다. 직무만족은 일반적 만족도, 보람, 소명감의 3가지 항목으로 측정하였는데 모든 항목에서 매우 긍정적인 인식을 보여주었다. 제도운영의 개선을 위한 과제로는 조직편제, 업무분장, 인사관리, 중앙기록물관리기관과 기록관의 협력을 중심으로 의견을 분석하였다. 이상의 분석을 통해 시사점과 개선책을 제시하였다.

• 산업경영시스템학회지
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• 제35권2호
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• pp.21-29
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• 2012

Person characteristics and the perception of organization climate affect on the performances associated with causes of job stress, and may induce various types of human errors. For incidence, a person's adaptation to organizational traits can influence on a person's performance with tasks assigned as well as job satisfaction, a change of occupation, etc. There are several evaluation methods such as an aptitude test to evaluate the suitability of department allocation. However, only person's traits such as an aptitude has been associated with department allocation and job assignment for the personnel management. This paper shows not only an evaluation result on the job-stress of the workers in nuclear power plants (NPPs), but also the relationships between the job-stress and the coincidences of group-personal, team-personal traits. Then, we systematically deduct a basic information on the factors to be considered to manage the organizational traits and job stress. We expect this result can contribute to enhance the organizational management against to the human errors as well as for the promotion of safety and efficiency of NPPs.

• 산업공학
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• 제11권3호
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• pp.65-75
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• 1998

This research considers the problem of scheduling jobs on parallel machines with non-common due dates and additional resource constraints. The objective is to minimize the total absolute deviation of job completion times about the due dates. Job processing times are assumed to be the same. This problem is motivated by restrictions that occur in the handling and processing of jobs in certain phases of semiconductor manufacturing and other production systems. We examine two problems. For the first of these, the number of different types of additional: resources and resource requirements per job are arbitrary. The problem is formulated as a zero-one integer linear programming and the Lagrangian relaxation approach is used. For the second case, there exists one single type of additional resource and the resource requirements per job are zero or one. We show how to formulate the problem as an assignment problem.

• Industrial Engineering and Management Systems
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• 제7권2호
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• pp.171-181
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• 2008

Home care, known also as domiciliary care, is part of the community care service that is a responsibility of the local government authorities in the UK as well as many other countries around the world. The aim is to provide the care and support needed to assist people, particularly older people, people with physical or learning disabilities and people who need assistance due to illness to live as independently as possible in their own homes. It is performed primarily by care workers visiting clients' homes where they provide help with daily activities. This paper is concerned with the dispatching of care workers to clients in an efficient manner. The optimized routine for each care worker determines a schedule to achieve the minimum total cost (in terms of distance traveled) without violating the capacity and time window constraints. A collaborative population-based meta-heuristic called Particle Swarm Optimization (PSO) is applied to solve the problem. A particle is defined as a multi-dimensional point in space which represents the corresponding schedule for care workers and their clients. Each dimension of a particle represents a care activity and the corresponding, allocated care worker. The continuous position value of each dimension determines the care worker to be assigned and also the assignment priority. A heuristic assignment scheme is specially designed to transform the continuous position value to the discrete job schedule. This job schedule represents the potential feasible solution to the problem. The Earliest Start Time Priority with Minimum Distance Assignment (ESTPMDA) technique is developed for generating an initial solution which guides the search direction of the particle. Local improvement procedures (LIP), insertion and swap, are embedded in the PSO algorithm in order to further improve the quality of the solution. The proposed methodology is implemented, tested, and compared with existing solutions for some 'real' problem instances.

• 간호행정학회지
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• 제21권4호
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• pp.386-392
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• 2015

Purpose: The purpose of this study was to identify the job of emergency room (ER) nurses working in small and medium sized hospitals and to explore factors affecting their job. Methods: The survey data were collected between January 2014 and May 2014 and participants were 159 nurses working in Seoul, Kyunggi, Incheon, and Chungnam in hospitals of less than 500 beds. Results: The score for nurses job was 2.12/4.0, and emergency treatment (1.87/4.0) followed basic nursing (3.51/4.0) and counseling (2.32/4.0). The nursing job was significantly different depending on the age, education level, position, resident doctor(emergency medicine specialty or other) and grade of ER (regional ER or local ER). In the multiple regression, education level (${\beta}=.18$), position (${\beta}=.24$), hospital size (${\beta}=.20$), and grade of ER (${\beta}=.21$) explained 17.0% of variance in ER nurses' job in small and medium sized hospitals. Conclusion: The findings indicate that ER nurses in vulnerable areas do more nursing practice including emergency treatment as well as the usual independent nursing practice. Accordingly, a systematic assignment of nursing professionals is needed to reduce loading of ER nurses in small and medium sized hospitals.