• International Journal of Precision Engineering and Manufacturing
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• 제2권1호
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• pp.33-42
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• 2001

In switched reluctance motor(SRM) deives, the turn-on and turn-off angles of each phase switch should be accurately controlled for accuracy and efficiency. The accuracy of the switching angles is mainly dependent upon the resolution of the encoder and the sampling period of the microprocessor, that are used to provide the information of the rotor position and to implement a control algorithm of the SRM, respectively. Thus, the higher the speed of the SRM is increased, the larger the amount of the switching angle deviations are from preset turn-on and turn-off angles. Consequently, the motor can not be driven stably high speed region. There fore, a simples and low cost encoder suitable for the practical and stable SRM drive is proposed and the control algorithm to provide the switching signals using a simple digital logic circuit is also presented for a wide speed range operation.

• 한국경영과학회지
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• 제26권4호
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• pp.133-141
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• 2001

Rapid development in computer and network technology these days has created in environment in which decisions for manufacturing companies can be made in a much broader perspective. Especially, better decisions on production and distribution planning(PDP) problems can be made laking advantage of real time information from all the parties concerned. However, since the PDP problem-a core part of the supply chain management- is known to be the so-called NP-hard problem, so heuristic methods are dominantly used to find out solutions in a reasonable time. As one of those heuristic techniques, many previous studios considered genetic a1gorithms. A standard genetic a1gorithm applies rules of reproduction, gene crossover, and mutation to the pseudo-organisms so the organisms can pass along beneficial and survival-enhancing trails to a new generation. When it comes to representing a chromosome on the problem, it is hard to guarantee an evolution of solutions through classic a1gorithm operations alone, for there exists a strong epitasis among genes. To resolve this problem, we propose a hybrid genetic a1gorithm based on Silver-Meal heuristic. Using IMS-TB(Intelligent Manufacturing System Test-bed) problem sets. the good performance of the proposed a1gorithm is demonstrated.

• 한국생산제조학회지
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• 제23권4호
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• pp.374-379
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• 2014

Mobile robots with omni-directional wheels can generate instant omni-directional motion without requiring extra space to change the direction of the body. Therefore, they are capable of moving in an arbitrary direction under any orientation even in narrow aisles or tight areas. In this research, an omni-directional mobile robot based on Mecanum wheels was developed to achieve omni-directionality. A CompactRIO embedded real-time controller and C series motion and I/O modules were employed in the control system design. Ultrasonic sensors installed on the front and lateral sides were utilized to measure the distance between the mobile robot and the side wall of a workspace. Through intensive experiments, a performance evaluation of the mobile robot was conducted to confirm its feasibility for industrial purposes. Mobility, omni-directionality, climbing capacity, and tracking performance of a squared trajectory were selected as performance indices to assess the omni-directional mobile robot.

• 한국기계가공학회지
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• 제16권4호
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• pp.113-118
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• 2017

As the demand for industrial robots and Automated Guided Vehicles (AGVs) increases, higher performance is also required from them. Fuzzy controllers, as part of an intelligent control system, are a direct control method that leverages human knowledge and experience to easily control highly nonlinear, uncertain, and complex systems. This paper uses a $LabVIEW^{(R)}-based$ fuzzy controller with gain scheduling to demonstrate better performance than one could obtain with a fuzzy controller alone. First, the work area was set based on forward kinematics and inverse kinematics programs. Next, $LabVIEW^{(R)}$ was used to configure the fuzzy controller and perform the gain scheduling. Finally, the proposed fuzzy gain scheduling controller was compared with to controllers without gain scheduling.

• 한국기계가공학회지
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• 제11권6호
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• pp.175-182
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• 2012

Light characteristics of the monochromatic red(R), blue(B), green(G) and white(W) and the mixed LED (B-R LED) were investigated by light control a Spectrometer-MMS1 and an illuminometer. The power consumption of each LED was 1W and R LED has five wavelength bands(600nm, 640nm, 660nm, 680nm, 750nm). The light intensity of each LED was changed in a range 10~100%. As a results, the wavelength and the spectrum distribution of R LED increase with increasing light intensity but the wavelength of B, G, W LED decreases. It was found that illumination of each mononochromatic and B-R LED increases linearly with increasing light intensity. It was confirmed that the illumination intensity of R-B light has greater values than those obtained by monochromatic light at the same conditions.

• 한국기계가공학회지
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• 제21권3호
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• pp.70-76
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• 2022

Recently, the demand for ultra-precision processing has increased owing to the increase in the demand for high-performance ultra-precision optical parts in the fields of information technology (IT), bio, healthcare, aerospace, and future automobiles. In this study, a performance improvement of a multi-stage pump was achieved by improving the pump casing structure rather than using the existing performance improvement method. To verify the performance improvement, the CFD analysis reliability of the existing pump, Pump A, was verified using the FLUENT app in the analysis software ANSYS, and the pump casing was improved through the verified CFD analysis of Pump B. Therefore, we want to analyze the performance improvement.

• 지능정보연구
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• 제9권3호
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• pp.1-21
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• 2003

전자상거래의 확산에 따른 환경변화 속에서 다품종소량 생산하는 주문제조업체들이 다양한 고객들의 주문에 대응하고, 동적으로 변화하는 내 외적 기업환경 속에서 경쟁력을 제고시키기 위해 본 연구에서는 멀티에이전트 기반 협상지원시스템을 개발하였다. 이 시스템은 동적으로 변하는 환경과 고객들의 주문에 대응하고, 유연한 시스템구조를 이루는데 있어 새로운 패러다임으로 부각되고 있는 에이전트 기술을 사용하였다. 또한, 에이전트간의 협업을 통해 문제를 해결할 수 있는 멀티에이전트 기술을 사용하였다 본 연구에서 제시한 멀티에이전트 기반 협상지원시스템은 주문제조업체에서 가장 중요한 거래활동인 협상의 자동화를 통해 주문에서부터 생산에 이르는 일련의 모든 거래활동을 자동화하는 것을 목적으로 한다.

• 한국기계가공학회지
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• 제16권2호
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• pp.69-80
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• 2017

In or To use, manage, and preserve sustainable water resources for the current and future generations amid the threat of abnormal climate, it is necessary to establish a smart water grid system, the next-generation intelligent water management system. In this study, sensors, which make use of the five senses to watch, listen, and detect machine vibration, bearing temperature, machine operation sounds, current, voltage, and other symptoms that cannot be verified when the irrigation facilities are running, are used to establish various decision-making criteria appropriate to on-site situations. Based on such criteria, the unmanned conditions in the facilities were verified and analyzed. Existing technologies require on-site workers to check any defects caused by overloading of machines, which is the biggest constraining factor in the application of an unmanned control system for irrigation facilities. The new technology proposed in this study, on the other hand, allows for the unmanned analysis of the existence of machine vibration. This controls the decision-making process of any defect based on the analysis results, and necessary measures are taken automatically, resulting in improved reliability of the unmanned automation.

• 한국지능정보시스템학회:학술대회논문집
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• 한국지능정보시스템학회 2006년도 춘계학술대회
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• pp.288-293
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• 2006

최근 반도체 개발 및 제조부문에서는 급속도로 성장한 Mobile 시장과 Digital Consumer Trend 에 주도적으로 대응하고자 빠른 속도의 기술적 변화를 추진하여 왔으며, 이에 따라 현장에서 발생하는 기술적 문제의 유형 또한 점점 복잡 다양해지고 있다. 기존 Commodity 제품의 경우, 세대 전환이 느리게 진행되어, 이에 수반되는 기술적 문제의 난이도와 그 발생 종류가 현재 대비 상대적으로 단순하였다. 그러나 최근 다품종 주문형 제품비중 확대로, 발생되는 문제점들이 Field Application 과 tight 한 연관성을 지니고 있어, 문제의 발생 경로, 원인 파악과 해결 대책 수립에 상당한 초기대응 시간을 필요하며, 관련 부서와의 실시간 협업 및 Cross-Checking을 통하지 않고서는 문제에 대한 최적 Solution 을 결정하기 힘든 현실이 되었다. 이러한 기술 이슈 해결 과정에 기 발생했던 유사 이슈 처리 과정 및 결과 자료가 문제 해결에 크게 기여할 수 있으나, 종래의 지식관리 시스템 체계로는 이러한 실무 형 지식을 획득하기 어려운 부분이 한계점으로 지적되고 있다. 본 논문에서는 이러한 문제점 개선이 가능한 실무형 지식 관리 (AKM: Actual Knowledge Management) 기반의 기술적 이슈 추적 관리 시스템(TITS: Technical Issue Tracking System) 구축 사례를 제시하고자 한다. TITS 는 1) 기술 이슈의 발의 및 전파 기능과 2) 이슈 해결을 위한 Action Item 부여 및 의견 교환 기능 3) 해결된 이슈의 처리 결과 등록 기능 4) 유사 이슈 사례 검색 기능 등의 크게 4 개 모듈오 구성 되어있다. 이 시스템을 통해 반도체 엔지니어들은 기술적 이슈의 발생 시점부터, 원안분석, 대책 협의 ; Action Item 수립 등 문제 해결 과정과 결과 등록 시점까지 Real time Tracking이 가능해 졌으며, 본 시스템을 통해 처리된 모든 기술적 이슈 정보는 Issue Case Database 에 분류 저장되어, 향후 유사 이슈 발생 시, 이를 활용함으로써, 빠른 초기 대응 및 문제 해결에 직접적인 도움을 받을 수 있게 되었다.

• 대한기계학회논문집
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• 제18권4호
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• pp.805-815
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• 1994

The development of automatic production systems has a trend toward Computer Integrated Manufacturing System(CIMS) in recent years. In hardware configuration, CIMS are composed of intelligent CAD/CAM work stations, multifunction CNC machining centers including material handling systems. The DNC systems present the key element of automation hierarchy in a FMS. A DNC system is one which connects a number of numerically-controlled machines to a common memory in a digital computer for part program storage with provision for on-demand distribution of part program data to machines using communication in hierarchical structure of central computer, control computer and cell controller. This paper describes the development of Behind-the-Tape-Reader(BTR) type DNC system using CYBER 180-830 as a central computer and IBM PC-386 cell control computer and NC lathe with FANUC 5T NC controller. In this system, the connection between central computer and cell control computer is done via RS-232C serial interface board, and the connection between cell control computer and FANUC 5T controller is done via parallel interface board. The software consists of two module, central computer communication module for NC program downloading and status uploading, NC machine running module for NC operating.