• Proceedings of the Korean Operations and Management Science Society Conference
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• 2002.05a
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• pp.371-377
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• 2002

근래 정보 시스템의 흐름은 생산 분야의 관리뿐만 아니라, 고객과의 관계를 중시하는 CRM(Costumer Relation Management)과 공급업체와의 협업 관계를 유지하는 eProcurement시스템에 초점을 맞추고 있다. 즉, 기존에는 단위 생산 시스템의 관리에 중점을 두었지만 최근에는 그 외부 요소들에 대한 관리의 중요성을 인식하게 되었고 이를 통징하여 공급망 관리(SCM Supply Chain Management)라고 한다. 본 논문에서는 공급망 관리에서 필요한 생산 계획수립 문제에 대해서 살펴본다. 특히 고객과의 관계에서 중요한 기능인 납기 회답을 지원하는 생산 계획 수립의 실행 주기에 대해서 살펴본다. 첫째, 단위 생산 시스템에서 사용하는 작업지시(Work Order)와 구매 지시(Purchase Order)를 생성하는 정규계획 모델에 대해서 설명한다. 정규계획 모델에서 필요로 하는 정적 정보와 동적 정보의 수집 및 계획의 실행을 담당하는 ERP 시스템과의 관계에 대해서 정의하고 정규계획 모델의 운영 주기를 정의한다. 둘째, 정규계획 모델과 상호 협조하면서 납기 회답을 지원하는 납기회답 모델의 설계에 대해서 살펴본다. 정규계획 모델과 달라지는 입력 부분의 정의와 정규계획 모델과의 상호 관계를 정의한다. 다음으로, 정해진 납기를 지키기 위해서 정규계획 모델에서 고려래야 하는 요소에 대해서 알아본다. 가장 중요한 것으로 작업 부하와 생산 용량을 고려한 계획 일자(PST)와 고객 납기와 제조 공정 LT를 고려한 계획 일자(LPST)중 최소값을 원자재의 납기 일자로 사용하는 것을 제안한다. 동시에 신규 구매 지시 계획을 생성하기보다는 기존에 발생된 구매 지시의 우선적 사용과 기존 구매 지시의 납기 일자를 고객 납기에 가장 잘 맞출 수 있도록 변경하는 방안을 제시한다. 이렇게 함으로써 최대한 고객 납기를 만족하도록 계획을 수립할 수 있게 된다. 본 논문에서 제시하는 계획 모델을 사용함으로써 고객 주문에 대한 대응력을 높일 수 있고, 계획의 투명성으로 인한 전체 공급망의Bullwhip effect를 감소시킬 수 있는 장점이 있다. 동시에 이것은 향후 e-Business 시스템 구축을 위한 기본 인프라 역할을 수행할 수 있게 된다.

• Journal of the Korea Society for Simulation
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• v.32 no.3
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• pp.93-108
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• 2023

In manufacturing productivity analysis, understanding the intricate interplay among factors like facility performance, layout design, and workforce allocation within the production line is imperative. This paper introduces a simulation-based methodology tailored to food manufacturing, progressively expanding scenarios to analyze production enhancement. The target system is a food processing plant, encompassing production processes, including warehousing, processing, subdivision, packaging, inspection, loading, and storage. First, we analyze the target system and design a simulation model according to the actual layout arrangement of equipment and workers. Then, we validate the developed model reflecting the real data obtained from the target system, such as the workers' working time and the equipment's processing time. The proposed model aims to identify optimal factor values for productivity gains through incremental scenario comparisons. To this end, three stages of simulation experiments were conducted by extending the equipment and worker models of the subdivision and packaging processes. The simulation experiments have shown that productivity depends on the placement of skilled workers and the performance of the packaging machine. The proposed method in this study will offer combinations of factors for the specific production requirements and support optimal decision-making in the real-world field.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.4
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• pp.37-42
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• 2006

The effect of arc like streamer discharge is investigated on the hydrogen generation using the multineedle-plate electrode geometry plasma realtor(MPER) and the needle-plate electrode geometry plasma reactor(NPER). In order to restrict waves at the water surface when the high voltage applied, two kinds of the insulator such as the rectangular mesh or the hole mesh type are installed under the water surface. The discharge assistant of the two type(the saw type and the $TiO_2$ pellet type) was placed under the water surface to investigate the effect of the water surface conditions. The experimental results are compared in case of the reactor with and without the discharge assistant on the water surface.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.12
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• pp.6324-6329
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• 2013

The aim of this study was to prepare and evaluate tablets containing liquid choline alphoscerate, which is capable of being formulated as a solid dosage form by the adsorption of magnesium aluminum silicate. The tablets were prepared with various absorbent to choine alphoscerate ratios. The physical properties and the dissolution rate were investigated. Considering the tabletting and dissolution rate, the formula scontaining 50-75% absorbent were adequate in the tested formulations. The 62.5% absorbent formula showed superior results with the tests of hardness, friability, disintegration time, and the ratio of dissolution area under the curve. Overall, magnesium aluminum silicate can be an alternative additive to a liquid drug.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.3
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• pp.157-163
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• 2016

Green vehicles include electric vehicles, natural gas vehicles, fuel cell vehicles (FCV), and vehicles running on fuel such as a biodiesel or an ethanol blend. An FCV is equipped with a cylinder valve installed in an ultra-high pressure vessel to control the hydrogen flow. For this purpose, an optimum design of the solenoid actuator is necessary to ensure reliability when driving an FCV. In this study, an electromagnetic field analysis for ensuring reliable operation of the solenoid actuator was conducted by using Maxwell V15. The electromagnetic field analysis was performed by magnetostatic technique, according to the distance between magnetic poles in order to predict the attraction force. Finally, the attraction force was validated through comparison between the Maxwell results and measurement results. From the results, the error of attraction force ranged from 4.53 % to 9.05 % at testing conditions.

• Clean Technology
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• v.23 no.4
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• pp.388-392
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• 2017

In this study, a quantitative environmental impact assessment for the production process of breathable film was conducted employing Life Cycle Assessment (LCA) methodology. Among the various categories, Global Warming (GW) accounted for the highest impact (97%) followed by Human Toxicity (HT). And the key substances of various impact categories included HDPE, PP, and electricity. In the production process, the high impact resulted from mixing process (57%), lamination process (29%), and extruder process (10%). To improve environmental impact, it is necessary to design a new process system that reduces the amount of electricity used and that increases production yields, if raw materials such as HDPE and PP owe excluded.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.3
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• pp.308-313
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• 2015

In this research, a multi-objective optimal design of a scroll compressor lower frame was approximated, and the design parameters of the lower frame were selected. The sensitivity of the design parameters was induced through a parameter analysis, and the thickness was determined to be the most sensitive parameter to stress and deflection. All of the design parameters regarding the mass are sensitive factors. It was formulated for the problem about stress and deflection to be caused by the axial load. The sensitivity of the design variables was determined using an orthogonal array for the parameter analysis. Using the central composite and D-optimal designs, a second polynomial approximation of the objective and constraint functions was formulated and the accuracy was verified through an R-square. These functions were applied to the optimal design program (NSGA-II). Through a CAE analysis, the effectiveness of the central composite and D-optimal designs was determined.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.6
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• pp.954-960
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• 2012

Nowadays, rapidly changing and unstable global economic environments request a lot of roles to engineers. In this situation, product should be designed to make more profit by cost down and to satisfy distinguished performance comparing to other competitive ones. In this research, the optimization design of the industrial robot casting will be done. The weight and deflection have to be reduced as objective functions and stress has to be constrained under some constant value. To reduce time cost, CCD (Central Composite Design) will be used to make experimental design. And RSM (Response Surface Methodology) will be taken to make regression model for objective functions and constraint function. Finally, optimization will be done with Genetic Algorithm. In this problem, the objective functions are multiple, so NSGA-II which is brilliant and efficient for such a problem will be used. For the solution quality check, the diversity between Pareto solutions will be also checked.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.5
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• pp.313-320
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• 2016

The need for high-strength, multi-axis, and multi-functional machine tools has recently increased because of part complexity and workpiece strength. However, most of the machine tool manufacturers rely on experience for a detailed design because of the shortcomings in the existing design technology. This study uses a topology optimization method to more effectively design a large multi-functional machine tool considering static stiffness. The ram, saddle, and column parts are important structures in a machine tool. Hence, they are selected for the finite element method analysis. Based on this analysis, the optimized internal rib structure for those parts is designed for desirable rigidity and weight. This structure could possibly provide the required design technology for machine tool manufacturers.

• Proceedings of the KIPE Conference
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• 2019.11a
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• pp.46-48
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• 2019

본 논문은 Discontinuous Conduction Mode(DCM) 플라이백 컨버터로 생성한 고전압 펄스를 스파크 갭으로 펄스 상승 시간을 줄이는 방법에 관하여 다룬다. 이러한 방법으로 생성된 빠른 상승률 특성을 가지는 고전압 펄스 전원장치는 친환경 가스 처리 분야에 사용할 수 있다. 기존 스태킹 구조의 펄스 전원 장치는 많은 수의 스위치들과 에너지 저장 소자가 필요하므로 부피가 커지고 제조 단가가 증가하는 반면, 분 논문에 제안된 전원 장치는 구조를 단순화하여 전체 시스템의 소형화 및 제조 단가를 낮춘 점을 특징으로 한다. 제안된 설계 토폴로지는 플라이백 변압기 2차 측에 다이오드의 사용 유무에 따라 두 개의 변형된 회로로 응용 가능 하다. 변압기 2차측에 다이오드를 사용하면, 음의 성분 없이 깨끗한 고전압 출력 펄스를 만들 수 있지만 사용한 다이오드의 전압 정격을 고려해야 한다. 다이오드를 사용하지 않는다면, 고전압 출력 펄스에 음의 성분이 발생하지만 비용과 부피를 최대한 줄일 수 있다. PSIM 시뮬레이션을 사용하여 제안하는 전원 장치의 23kV, 0.5 ㎲, 10 ns rising time의 출력 펄스 발생 성능을 검증하고, 다이오드 사용에 따른 출력 펄스의 차이점을 비교하였다.