• The Magazine of the IEIE
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• v.22 no.8
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• pp.86-97
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• 1995

Computer simulation is a powerful tool for the design and evaluation of manufacturing systems. This paper consists of two major parts. First, it presents a brief survey of simulation languages oriented towards the analysis of manufacturing systems, with their important properties. Second, it introduces a simple case of simulation application to a flexible manufacturing system(FMS).

• IE interfaces
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• v.10 no.2
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• pp.91-97
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• 1997

A mass production system was implemented to reduce a manufacturing cost in a way of copying with a strong world market competition. However customer's demands are changing so rapidly and the mass production system is no longer competitive to meet the demands. FMS(Flexible Manufacturing System) has been introduced as a replacement for the mass production system, but it still does not meet system's requirements. A new manufacturing system, called a holonic manufacturing system (HMS), is emerging. This paper is giving a first approach of a HMS for a multirobot cooperative process.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.512-515
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• 1996

A mass production system was implemented to reduce a manufacturing cost in a way of copying with a strong world market competition. However customer's demands are changing so rapidly and the mass production system is nolonger competitive to meet the demands. FMS (Flexible Manufacturing System) has been introduced as a replacement for the mass production system, but it still does not meet system's requirements. A new manufacturing system, called a holonic manufacturing system(HMS), is emerging. In this paper it is introduced an autonomous cooperative system under the concept of HMS.

• Journal of the Korea Fashion and Costume Design Association
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• v.13 no.2
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• pp.163-173
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• 2011

The objective of this study is to examine the current status of manufacturing formal knit jackets for middle-aged women. Fifteen manufacturers specializing in formal knitwear brands were chosen as the study subjects, and interviews and questionnaires were used with patterners and designers. The questionnaire was composed of 27 items and began with general questions, such as how the jackets were manufactured. Specific questions, such as materials and sewing method, were also considered further on. The results are as follows: First, as for the structure of the knit jacket manufacturer, seven out of fifteen manufacturers directly manufactured knit jackets in their own factory, while the manufacturing was comprised of 20% woven jackets and 80% knit jackets for all manufactures. Second, as for the type of yarn mostly used in knitting the fabric for the jackets, satin yarn and wool were used mostly for F/W with Plain and Half Milano rib stitches as the type of knit with a gauge of 12G and 7G. Third, as for the margin between the product size of the target brand and the size of the body at the time of designing a knit jacket pattern, the investigation of the actual state of manufacturing showed that the margin at the bust was B+4.8cm, the waist was W+6.9cm, and the hip girth was H+5cm. Therefore, the bust and hip girth of the knit jackets were designed to be smaller than those of the bust and hip girth lines of non-flexible woven jackets. On the contrary, the waist measurement of non-flexible woven jacket was designed to be smaller than the knit jacket. It was found that the side line of the knit jacket was expressed with greater give as compared to that of the non-flexible woven jacket.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.9
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• pp.3232-3238
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• 2010

As flexible manufacturing systems (FMSs) are highly automated and required flexibility to satisfy market need, dispatching rules are constrained by specific environments of manufacturing systems such as mechanical failures, absence of employees, and lack of spare parts. In this paper, an ontology-based knowledge approach is proposed to improve efficiency of system through adapting suitable dispatching rules, considering context in a FMS shop floor, which consists multiple manufacturing cells. the multi-agents monitor manufacturing system status and job so that it figures out a dispatching rule considering context. To demonstrate the proposed approach, a proof-of-concept prototype system has been implemented in the $JADE^{TM}$ platform and Protege to make OWL DL ontology.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.1
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• pp.87-92
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• 2011

This article proposes a new technique of the dynamic model using multi-body dynamic analysis tool for a flexible main spindle rotor system with a novel phase adjusting control technique for the purpose of an active control of rotor vibration. The dynamic model is used as a plant model. Also in order to make control system, a component parameters and phase controller is composed and simulated by SIMULINK. The vibration is reduced to 50%. Therefore the ADAMS dynamic model for the flexible main spindle rotor and the phase adjusting control techniques may be effective for the suppressing the vibration and helpful for the future active control for rotor vibration.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.05a
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• pp.425-428
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• 2004

Flexible assembly line (FAL) is a production system that assembles various parts in unidirectional flow line with many constraints and manufacturing flexibilities. In this research we deal with a FAL balancing problem with the objective of minimizing the maximum workload allocated to the stations. However, almost all the existing researches do not appropriately consider various constraints due to the problem complexity. Therefore, this thesis addresses a balancing problem of FAL with many constraints and manufacturing flexibilities, unlike the previous researches. To solve this problem we use a genetic algorithm (GA). To apply GA to FAL, we suggest a genetic representation suitable for FAL balancing and devise evaluation method for individual's fitness and genetic operators specific to the problem, including efficient repair method for preserving solution feasibility. The experimental results are reported.

• Journal of the Korean Operations Research and Management Science Society
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• v.24 no.2
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• pp.1-15
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• 1999

This research involves the development and evaluation of a work flow control model for a type of flexible manufacturing system(FMS) called a flexible flow line(FFL). The control model can be considered as a kind of hybrid intelligent model in that it utilizes both computer simulation and neural network technique. Training data sets were obtained using computer simulation of typical FFL states. And these data sets were used to train the neural network model. The model can easily incorporate particular aspects of a specific FFL such as limited buffer capacity and dispatching rules used. It also dynamically adapts to system uncertainty caused by such factors as machine breakdowns. Performance of the control model is shown to be superior to the random releasing method and the Minimal Part Set(MPS) heuristic in terms of machine utilization and work-in-process inventory level.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.1
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• pp.81-87
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• 2000

A variable cutting speed control model was developed to be implemented for the flexible disk grinding process Control algorithm was based on the error referred by the discrepancy between current disk angle and intended one that are pro-posed to produce desired resulting depth of cut. Controller was implemented in two different aspect One was to initiate the control law from the beginning while the other was to activate as soon as the disk start to produce ground surface i.e. The beginning of the between edges stage. Several performance analysis were conducted comparing various process parameters such as cutting force disk angle depth of cut and disk speed with respect to process transition time Tentative results revealed that controller implemented from the earlier stages of the process showed better performance than the other revealed that controller implemented from the earlier stages of the process showed better performance that the other.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.1250-1255
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• 1990

This paper discusses an optimal cyclic scheduling problem for a FMC (Flexible Manufacturing Cell) modeled by a two-machine flowshop with two machining centers with APC's (Automated Pallet Changers), an AGV (Automated Guided Vehicle) and loading and unloading stations. Cyclic production in which similar patterns of production is repeated can significantly reduce the production lead-time and WIP (Work-In-Process) in such flexible, automated system. Thus we want to find an optimal cyclic schedule that minimizes the cycle time in each cycle. However, the existence of APC's as buffer storage for WIP makes the problem intractable (i.e., NP-complete). We propose an practical approximation algorithm that minimizes, instead of each cycle time, its upper bound. Performances of this algorithm are validated by the way of computer simulations.