• 산업경영시스템학회지
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• 제20권43호
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• pp.277-285
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• 1997

In this paper, the definition to flexibility is examined through the literature and re-classified to set up an evaluation model. Flexibility is classified into three categories to find the flexibility types for evaluation. The flexibility type called as manufacturing flexibility is defined and a model is developed to make the performance evaluation possible, The manufacturing flexibility has a heavy relationship to the machine flexibility; and 5 flexibility types out of 8 have relationship to the machine flexibility. This indicates that it is possible to have a pretty good evaluation measure if the machine flexibility related types could be evaluated using a model. There are four different inter-arrival times in the model. A big time saving is observed if the processing time is set equal to 72 second. This indicates that a flexibility affects the system a lot if the inter-arrival time is close to the processing time. The model used in this paper includes multi-processes in a production line with machine failure. However, development of realistic models with buffer between processes and some of the flexibility types not included in this model are remained for further research.

• 산업경영시스템학회지
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• 제20권43호
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• pp.127-137
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• 1997

This paper proposes a heuristic method for job shop scheduling with alternative machines. Our heuristic suggests two machine-selecting rules and two priority dispatching rules for modifying existent ones considering alternative machines, and then it extends existing nondelay/active job shop schedule generation. This heuristic provides good criteria(rules) in the selection of a proper machine among those performing a specific operation and for the dispatch of an operation to a selected machine and thus these rules permit the efficient job shop scheduling with alternative machines. The performances of our two machine-selecting rules in addition to the two priority dispatching rules, applied together with the existing 17 rules, are experimented and evaluated, respectively.

• 대한산업공학회지
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• 제24권4호
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• pp.601-611
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• 1998

The machining accuracy of CNC machine tools will decrease the production lead time because the coordinate compensation of the tool path will be unnecessary to meet design specifications. Improving the accuracy of machined parts enhances the reliability and functionality of the assembly as well as the life of the product. Among various factors affecting the accuracy of machined parts, the ambient temperature is the major factor that refers to the temperature surrounding the machine and workpiece. In this study, an experiment was conducted to confirm the dimensional variations caused by changes in the ambient temperature. The ambient temperature resulted in overcutting when it increased. A developed pre-processor converts the CNC program to compensate the dimensional variations caused by temperature changes. This methodology can be used to determine the machining accuracy and improve the positioning accuracy of a machine tool.

• 한국산학기술학회논문지
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• 제5권4호
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• pp.326-330
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• 2004

본 논문에서는 레그 익스텐션 기구의 안정성을 평가하기 위하여 3차원 유한요소 해석 코드인 ANSYS를 활용하여 구조해석을 실시하였다. 레그 익스텐션 기구를 제작함에 있어서 기존의 기구를 보완하고 운동효과의 향상, 안정성을 고려하여 설계하였다. 또한 레그 익스텐션 기구의 회전봉의 각도를 0°-360°까지 회전 가능하게 설계하여 운동하는 사람의 운동 강도를 조절할 수 있는 새로운 기구를 설계하였다.

• 대한산업공학회지
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• 제18권1호
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• pp.91-104
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• 1992

Flowshop scheduling problem is known to be NP-complete. Since the optimization apporach like branch-and-bound is limited by exponentially growing computation time, many heuristic methods have been developed. Total tardiness is one of the criteria that the researchers have recently considered in flowshop scheduling. There, however, are few literatures which studied the general (m machine)-flowshop scheduling under the total tardiness criterion. In this paper, a heuristic scheduling method to minimize total tardiness at the (m machine, n job)-flowshop is presented. A heuristic value function is proposed to be used as a dispatching criterion in initial schedule generation. And the schedule improving procedure, by pairwise interchange of tardy job with the job right ahead of it, is introduced. Illustrative examles and simulated results are presented.

• 한국산학기술학회논문지
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• 제11권11호
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• pp.4075-4079
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• 2010

본 논문의 목적은 현재 도기가스, 상하수도 및 화학배관 파이프 등의 플라스틱 배관 공사에서 사용되는 파이프 융착기를 3차원 설계하고 융착 시 발생하는 문제점을 해결하기 위하여 구조해석에 의한 검증작업을 거쳐 구조를 개선한다. 현장에서 파이프 융착 작업 시 융착기 크램프에 크랙이 발생하므로 이를 개선하기 위하여 융착기의 구조를 변경하는 설계치를 제시함으로서 작업의 효율성을 높이고 기술경쟁력을 향상시킨다.

• 대한안전경영과학회지
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• 제18권1호
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• pp.35-43
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• 2016

The past five years, industrial accidents due to food processing machinery have been occurred 725 cases, injury by the food cutter occurred 390 cases in its. On this study, to prevent food cutter injury, an attempt is made to present the improved documentation of fundamental safety of the food cutter workplace through the injury analysis of food cutter injury and surveys on band saw machine business field. Analyzing the result of 390 cases on food cutter injury, amputation, cut, puncture occupied 75.1 percent (293 cases), compressed occupied 23.3% (91 cases), also it showed constant component without reference to gender, age, scale of work place, service period. In the survey, lack of concentration for workers have been pointed out as the biggest factor in the cause of band saw machine injury. Meanwhile, such as the EU and Japan, whereas presents safety standards about band saw machines that are tailored to each country, on the other hand, South Korea doesn't provide the standards. To prevent the food cutter injury, safety standards need to be established in consideration of amputation, cut, puncture, compressed injury and financial support is required to procure protective equipment at each place of business.

• 산업경영시스템학회지
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• 제28권1호
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• pp.121-128
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• 2005

This paper proposes the heuristic approach for the generalized GT(Group Technology) problem to consider the restrictions which are given the number of cell, maximum number of machines and minimum number of machines. This approach is classified into two stages. In the first stage, we use the similarity coefficient method which is proposed and calculate the similarity values about each pair of all machines and align these values in descending order. If two machines which is selected is possible to link the each other on the edge of machine cell and they don't have zero similarity value, then we assign the machines to the machine cell. In the second stage, it is the course to form part families using proposed grouping efficacy. Finally, machine-part incidence matrix is realigned to block diagonal structure. The results of using the proposed approach are compared to the Modified p-median model.

• 한국산학기술학회논문지
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• 제11권11호
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• pp.4145-4150
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• 2010

본 논문에서는 자동차 핵심부품 중 하나인 알터네이터 수풀의 육안검사를 대체하기 위한 머신비전시스템을 설계하는 데 목적이 있다. 플라스틱 사출물인 알터네이터 스풀의 경우 일반적으로 미성형, 찍힘, 뜯김, 크랙 등의 불량 유형이 발생한다. 스풀을 고속으로 전수검사하기 위하여 설계의 실패 사례를 예로 들었고, 이를 통해 최적의 고속 자동화 머신비전 시스템을 설계하고 2차 협력 업체인 중소기업을 위해 저비용 검사 시스템에 초점을 맞추고자 한다. 3차원 설계 소프트웨어인 Pro-Engineer와 CATIA가 사용되었다. 개발 제작 될 시스템은 산업현장에 적용하여 절대적 판정의 안정성을 도모하고, 생산성 향상을 위한 사이클 타임을 충족하는 데 기여할 수 있다.

• 대한안전경영과학회지
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• 제25권2호
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• pp.159-165
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• 2023

The entire industry is increasing the use of big data analysis using artificial intelligence technology due to the Fourth Industrial Revolution. The value of big data is increasing, and the same is true of the production technology. However, small and medium -sized manufacturers with small size are difficult to use for work due to lack of data management ability, and it is difficult to enter smart factories. Therefore, to help small and medium -sized manufacturing companies use big data, we will predict the gross production time through machine learning. In previous studies, machine learning was conducted as a time and quantity factor for production, and the excellence of the ExtraTree Algorithm was confirmed by predicting gross product time. In this study, the worker's proficiency factors were added to the time and quantity factors necessary for production, and the prediction rate of LightGBM Algorithm knowing was the highest. The results of the study will help to enhance the company's competitiveness and enhance the competitiveness of the company by identifying the possibility of data utilization of the MES system and supporting systematic production schedule management.