• 산업공학
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• 제11권3호
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• pp.89-101
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• 1998

The randomness of the input variables in simulation experiments produce output responses which are also realizations of random variables. The random responses make necessary the use of statistical inferences to adequately describe the stochastic nature of the output. The analysis of the simulation output of non-terminating simulations is frequently complicated by the autocorrelation of the output data and the effect of the initial conditions that produces biased estimates. The regenerative method has been developed to deal with some of the problems created by the random nature of the simulation experiments. It provides a simple solution to some tactical problems and can produce valid statistical results. However, not all processes can he modeled using the regenerative method. Other processes modeled as regenerative may not return to a given demarcating state frequently enough to allow for adequate statistical analysis. This paper shows how the state transformation concept was successfully used in a queueing model and a job shop model. Although the first example can be analyzed using the regenerative method. it has the problem of too few recurrences under certain conditions. The second model has the problem of no recurrences. In both cases, the state transformation increase the frequency of the demarcating state. It was shown that time state transformations are regenerative and produce more cycles than the best typical discrete demarcating state in a given run length.

• 한국산업경영시스템학회:학술대회논문집
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• 한국산업경영시스템학회 2002년도 춘계학술대회
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• pp.237-242
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• 2002

The sales activity of most of small manufacturing companies is based on orders of buyers. The process of promotion, receipt and selection of orders of the manufacturers is closely coupled with the load status of the production lines. The decision on whether to accept an order or not, or the selection of optimal order set among excessive orders is entirely dependent on the schedule of production lines. However, in the real world, since the production scheduling activity is mainly performed by human experts, most of small manufacturers are suffer from being unable to meet due dates, lack of rapid decision on the acceptance of new order. To cope with this problem, this paper deals with the development of an agent for selecting an optimal order set automatically. The main engine of selection agent is based on the typical job-shop scheduling model since our target domain is the injection molding company. To solve the problem, we have formulated it as IP (Integer Program) model, and it has been successfully implemented by ILOG and selection agent. And we have suggested an architecture of an agent for tackling web based order selection problems.

• 한국경영과학회지
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• 제23권4호
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• pp.87-96
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• 1998

Using the concept of cellular manufacturing systems(CMS) in job shop manufacturing system is one of the most innovative approaches to improving plant productivity. However. several constraints in machine duplication cost, machining capability, cell space capacity, intercell moves and exceptional elements(EEs) are main problems that prevent achieving the goal of maintaining an ideal CMS environment. Minimizing intercell part traffics and EEs are the main objective of the cell formation problem because it is a critical point that improving production efficiency. Because the intercell moves could be changed according to the sequence of operation, it should be considered in assigning parts and machines to machine ceil. This paper presents a method that eliminates EEs under the constraints of machine duplication cost and ceil space capacity attaining two goals of minimizing machine duplications and minimizing intercell moves simultaneously. Developing an algorithm that calculates the machine duplications by cell-machine incidence matrix and part-machine Incidence matrix, and calculates the exact intercell moves considering the sequence of operation. Based on the number of machine duplications and exact intercell moves, the goal programming model which satisfying minimum machine duplications and minimum intercell moves is developed. A linear programming model is suggested that could calculates more effectively without damaging optimal solution. A numerical example is provided to illustrate these methods.

• 산업공학
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• 제12권1호
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• pp.10-18
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• 1999

Job shop manufacturing environments are using the concept of cellular manufacturing systems(CMS) which has several advantages in reducing production lead times, setup times, work-in-process, etc. Utilizing the similarities between cell-machine, part-machine, and the shape/size of parts, CMS can group machines and parts resulting in improved efficiency of this system. However, when grouping machines and parts in machine cells, there inevitably occurs exceptional elements(EEs), which can not operate in the same machine cell. Minimizing these EEs in CMS is a critical point that improving production efficiency. Constraints in machine duplication cost, machining process technology, machining capability, and factory space limitations are main problems that prevent achiving the goal of maintaining an ideal CMS environment. This paper presents an algorithm that minimizes EEs under the constraints of machine duplication cost and factory space limitation. Developing exceptional operation similarity(EOS) by cell-machine incidence matrix and part-machine incidence matrix, it brings the machine cells that operate the parts or not. A mathematical model to minimize machine duplication is developed by EOS, followed by a heuristic algorithm in order to reflect dynamic situation resulting from minimizing exceptional elements process and the mathematical model. A numerical example is provided to illustrate the algorithm.

• Journal of Information Technology Applications and Management
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• 제18권1호
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• pp.125-141
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• 2011

As the sales volume of online shops increases, the job burden in the back-offices of the online shops also increases. Order picking is the most labor-intensive operation among the jobs in a back-office and mid-size pure click online shops are experiencing the time delay and complexity in order picking nowadays while fulfilling their customers' orders. Those warehouses of the mid-size shops are based on manual systems, and as order pickings are repeated, the warehouses get a mess and lots of products in those warehouses are getting missing, which results in severe delay in order picking. To overcome this kind of problem in online clothing shops, we research a methodology to locate warehousing products. When products arrive at a warehouse, they are packed into a box and located on a rack in the warehouse. At this point, the operator should determine the box to be put in and the location on the rack for the box to be put on. This problem could be formulated as an Integer Programming model, but the branch-and bound algorithm to solve the IP model requires enormous computation, and sometimes it is even impossible to get a solution in a proper time. So, we relaxed the problem, developed a set of heuristics as a methodology to get a semi-optimum in an acceptable time, and proved by an experiment that the solutions by our methodology are satisfactory and acceptable by field managers.

• 경영과정보연구
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• 제33권1호
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• pp.279-298
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• 2014

본 연구는 커피전문점에 종사하는 바리스타의 직무속성이 고객들이 바리스타에 대해 느끼게 되는 러브마크에 어떠한 영향을 미치는지, 그리고 이러한 러브마크가 궁극적으로 브랜드 충성도에 영향을 미칠 수 있는지를 검증하고자 한다. 또한 본 연구는 바리스타의 직무속성이 고객들이 지각하는 바리스타에 대한 러브마크를 향상시켜 결국은 점포나 브랜드에 대한 충성도로 까지 이어질 수 있음을 시사하고, 로컬 및 내셔널 커피전문점에서 이를 비교하여 커피시장에 기여할 수 있는 실무적 시사점을 제시하는 데 그 목적을 두고 있다. 연구결과, 우선, 바리스타 직무속성인 전문성, 상호작용성, 서비스 지향성은 러브마크의 사랑차원 속성인 감각, 신비감, 친밀감에 대부분 유의한 정(+)의 영향을 미치는 것을 확인하였다. 단, 전문성과 서비스 지향성이 친밀감에 미치는 영향과 그에 관한 가설은 기각되었다. 이는 실제 현상적으로 볼 때, 고객의 입장에서 바리스타의 전문성이 높다는 것은 고객과의 동질성이 떨어진다는 것을 의미한다고 해석할 수 있었으며, 단순히 바리스타가 고객에 대해 서비스 지향적으로 대하는 것만으로는 친밀감의 형성이 어려울 수 있다는 것을 확인할 수 있었다. 러브마크의 사랑차원인 감각, 신비감, 친밀감이 러브마크의 존경차원의 일부인 성과에 미치는 영향은 모두 유의한 정(+)의 관계가 있는 것으로 나타났다. 러브마크의 존경차원 변수들 간의 구조적인 관계 역시 모두 유의한 정(+)의 관계가 확인되었다. 마지막으로 러브마크의 존경차원 변수들인 성과, 평판, 신뢰는 브랜드 충성도에 유의한 정(+)의 영향을 미친다는 것을 확인하였다.

• 한국응용과학기술학회지
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• 제40권6호
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• pp.1506-1520
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• 2023

본 연구의 목적은 피부미용 종사자의 그릿이 자기효능감과 직무성과에 미치는 영향을 관계에서 자기관리의 매개효과를 실증적으로 분석하는데 있다. 본 연구의 연구참여자는 서울·경기 스킨케어샵과 병원 종사자 344명을 대상으로 구조화된 설문지를 통하여 자료를 수집하였다. 수집된 자료는 SPSS와 AMOS 26.0 통계 프로그램을 이용하여 기술통계, 확인적 요인분석, 상관관계, 구조방정식모델, bootstrapping기법을 이용한 매개효과 분석을 통하여 자료를 분석하였다. 일련의 연구절차를 통하여 도출된 결론은 다음과 같다. 첫째, 피부미용 종사자의 그릿은 자기관리, 자기효능감, 직무성과에 유의미한 정의(+)영향 관계를 나타내었다. 둘째, 피부미용 종사자의 자기관리는 자기효능감과 직무성과에 유의미한 정의(+) 영향 관계를 나타내었다. 셋째, 피부미용 종사자의 그릿과 직무성과와의 관계에서 자기관는 유의미한 매개효과가 있는 것으로 나타났다. 따라서 뷰티 산업 종사자들의 그릿 함양을 통해 자기관리, 자기효능감 및 직무성과를 높일 수 있는 인적관리와 교육 프로그램의 적용이 절실히 필요하다고 판단된다..

• 경영과학
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• 제16권1호
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• pp.157-171
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• 1999

In a increasingly competitive marketplace, the manufacturing companies have no choice but looking for ways to improve productivity to sustain their competitiveness and survive in the industry. Recently cellular manufacturing has been under discussion as an option to be easily implemented without burdensome capital investment. The objective of cellular manufacturing is to realize many aspects of efficiencies associated with mass production in the less repetitive job-shop production systems. The very first step for cellular manufacturing is to group the sets of parts having similar processing requirements into part families, and the equipment needed to process a particular part family into machine cells. The underlying problem to determine the part and machine assignments to each manufacturing cell is called the cell formation. The purpose of this study is to develop a clustering algorithm based on the neural network approach which overcomes the drawbacks of ART1 algorithm for cell formation problems. In this paper, a generalized learning vector quantization(GLVQ) algorithm was devised in order to transform a 0/1 part-machine assignment matrix into the matrix with diagonal blocks in such a way to increase clustering performance. Furthermore, an assignment problem model and a rearrangement procedure has been embedded to increase efficiency. The performance of the proposed algorithm has been evaluated using data sets adopted by prior studies on cell formation. The proposed algorithm dominates almost all the cell formation reported so far, based on the grouping index($\alpha$ = 0.2). Among 27 cell formation problems investigated, the result by the proposed algorithm was superior in 11, equal 15, and inferior only in 1.

• Industrial Engineering and Management Systems
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• 제11권4호
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• pp.310-330
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• 2012

Scheduling is an important tool for a manufacturing system, where it can have a major impact on the productivity of a production process. In manufacturing systems, the purpose of scheduling is to minimize the production time and costs, by assigning a production facility when to make, with which staff, and on which equipment. Production scheduling aims to maximize the efficiency of the operation and reduce the costs. In order to find an optimal solution to manufacturing scheduling problems, it attempts to solve complex combinatorial optimization problems. Unfortunately, most of them fall into the class of NP-hard combinatorial problems. Genetic algorithm (GA) is one of the generic population-based metaheuristic optimization algorithms and the best one for finding a satisfactory solution in an acceptable time for the NP-hard scheduling problems. GA is the most popular type of evolutionary algorithm. In this survey paper, we address firstly multiobjective hybrid GA combined with adaptive fuzzy logic controller which gives fitness assignment mechanism and performance measures for solving multiple objective optimization problems, and four crucial issues in the manufacturing scheduling including a mathematical model, GA-based solution method and case study in flexible job-shop scheduling problem (fJSP), automatic guided vehicle (AGV) dispatching models in flexible manufacturing system (FMS) combined with priority-based GA, recent advanced planning and scheduling (APS) models and integrated systems for manufacturing.

• 한국유통학회지:유통연구
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• 제13권1호
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• pp.79-96
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• 2008

본 연구는 최근에 마케팅분야에서 주목받고 있는 연구영역인 시장지향성이 판매조직의 성과에 긍정적인 영향을 미치는 이유에 대한 설명을 하기 위하여 기업의 시장지향성이 판매원관련 변수들(고객지향성, 직무만족, 그리고 조직몰입)과 고객관련 변수들(서비스품질, 서비스가치, 고객만족, 그리고 고객충성도)을 매개로 하여 성과로 나타남을 설명할 목적으로 수행되었다. 백화점에서 영업활동을 하는 다양한 매장의 점포관리자들을 대상으로 하여 설문조사를 한 결과, 기업의 시장지향성은 판매직원을 통해 고객에게 전해지며, 기업의 시장지향성을 통해 긍정적으로 증가된 판매원관련 변수들이 고객에게 전해지는 서비스품질, 고객만족, 그리고 고객충성도를 증가시킴으로써 성과를 향상시킴을 밝혔다. 또한, 지금까지 판매원관련 변수들과 고객관련 변수들의 순서나 인과관제에 대한 명확한 모형이 존재하지 않았는데, 본 연구를 통하여 판매원관련 변수들과 고객관련 변수들 내에서의 각각의 관제뿐만 아니라 두 집단변수들 간의 연결고리를 명확하게 제시한 이론적 공헌을 갖는다. 지금까지 선행연구의 결과와 같이 본 연구결과를 통해서도 시장지향성은 성과에 긍정적인 영향을 주는 것이 명확한 것으로 나타났고, 이 과정에서 판매원관련 변수들과 고객관련 변수들이 어떻게 영향을 주는지를 명확하게 밝힌 점을 참고로 하여, 앞으로 기업들은 시장지향성을 더욱 강조하고 이와 관련된 판매원관련 변수들과 고개관련 변수들의 작용을 이해함으로써 더 높은 성과를 얻을 수 있을 것이다.