• 산업경영시스템학회지
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• 제17권30호
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• pp.167-175
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• 1994

Generally, queueing networks, networks, chains and simulation techniques are among the most widely used evaluation tools to study computer systems, manufacturing systems etc. But, these tools have some assumptions and difficulties. So, this thesis presents a method for manufacturing system using Petri nets. Petri nets are a graphical and mathmatical modeling tool and are promising tool for describing and studying systems that are characterized as being concurrent asychronous, dynamic, distributed and parrallel. It designs Petri net model for processing time of manufacturing system And it applied to a job shop system composed of 8 machines and 4 different job types.

• Journal of Ship and Ocean Technology
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• 제8권4호
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• pp.45-55
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• 2004

How to achieve engineering collaboration among diverse engineering activities is one of the key topics in manufacturing fields nowadays. The infrastructure for collaborative engineering is essential, and it can be realized by information technologies and intelligent engineering applications in digital environments. Digital Manufacturing is a technology to facilitate effective product developments and agile productions by computer models representing the physical and logical schema and the behavior of real manufacturing systems including products, processes and factories. A digital factory as a well-designed and integrated digital environment is incorporated in it. In this paper, digital manufacturing is recommended as a good strategy for collaborative engineering, especially in product developments and productions. By business process analysis and some case studies, we suggested sophisticated digital models are very useful to concurrent and collaborative engineering. It is expected that digital manufacturing is a very good strategy for achieving dramatic time and cost savings in many engineering activities of many manufacturing industries, including machinery, automotive and shipbuilding.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2000년도 춘계공동학술대회 논문집
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• pp.135-138
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• 2000

This paper is intended to propose what manufacturing configuration (manufacturing planning and shop floor control) is suitable for the tire industry. Basically tire-manufacturing process is mixed-products, parallel-disconnected-flow-shop. Both throughput time and cycle tine are very short, the variety of tires is very high, the setup time is long, shop floor data reporting requirements is high, and there are many equipments and people working. And with no exception, tire industry also now confronts increasing requirements of delivery conformance with the above peculiar characteristics of tire manufacturing and changing market environments, this paper suggests, weekly master scheduling with no MRP is desirable and traditional kanban is right selection for shop floor control/scheduling. This paper describes why this configuration should be, using the manufacturing engineering principles and some new insights like four primitives of parallel flow shop. Generally known that shop with high parallel-product-mix and long setup time isn't good candidate for kanban. The four primitives of parallel flow shop explain why kanban is also useful scheduling technique in that environment.

• Journal of Power Electronics
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• 제15권3호
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• pp.849-859
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• 2015

This paper proposes a novel compound-type hybrid energy storage system (HESS) that inherits the unique advantages of both battery/supercapacitor (SC) and the SC/battery HESSs for electric vehicles (EVs). Eight operation modes are designed to match this system. A mode control strategy is developed for this HESS on the basis of these modes, and five classes of operation modes are established to simplify this strategy. The mode control strategy focuses on high operating efficiency and high power output. Furthermore, the compound-type HESS is designed such that the SC is the main priority in braking energy absorption. Thus, this HESS can operate efficiently and extend battery life. Simulation results also show that the compound-type HESS can not only supply adequate power to the motor inverter but can also determine suitable operation modes in corresponding conditions. Experimental results demonstrate that this HESS can extend battery life as well. The overall efficiency of the compound-type HESS is higher than those of the battery/SC and the SC/battery HESSs.

• 한국광학회지
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• 제18권6호
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• pp.395-400
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• 2007

본 연구는 지문 인식 시스템 중에서 프리즘을 이용한 광학계의 설계에 대한 것이다. 이는 프리즘, 렌즈, 그리고 CMOS 이미지 센서(혹은 CCD) 등으로 구성되어 있는 광학계이다. 종래의 프리즘을 이용한 지문인식 광학계에서는 지문에 물이 묻어 있는 경우에 영상의 품질이 현저히 저하되는 문제점이 있다. 이 경우에 프리즘의 굴절률을 높임으로써 영상의 품질을 충분히 높일 수 있었다. 또한 프리즘과 렌즈를 사용함으로 인하여 발생하는 비대칭 축소 왜곡(anamorphic distortion)과 상면의 지를 최소화되는 프리즘 꼭지각 $\alpha$를 제안한다.

• 한국생산제조학회지
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• 제26권3호
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• pp.272-277
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• 2017

CCTV image processing techniques have been developed for safety management in manufacturing sites. However, CCTV growth has become a social problem for video surveillance with regard to privacy. This study aims to manage the safety system efficiently and protect privacy simultaneously. In this study, the CCTV monitoring system is composed of five steps (accident monitoring, detection, notification, management, restoration). De-identified image is observed when we are in a normal situation. De-identified image changes to identified image when it detects an accident. As soon as it detects an accident, the accident information is sent to the safety administrator. Then the administrator could conduct safety measures. Afterward, accumulated accident data could be used for statistical data that could be utilized as analyzing expecting accident.

• 산업경영시스템학회지
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• 제31권4호
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• pp.168-176
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• 2008

In an environment where manufacturing conditions such as product lines keep changing, manufacturing control systems need to be continually maintained and upgraded according to the change. This requires an effective system implementation methodology. In this paper, a methodology based on the multi-criteria similarity comparison of manufacturing processes is proposed. A newly introduced process is compared with existing ones based on the multi-criteria similarity, and candidates for software reuse are selected from stored modules according to the overall process characteristics. The proposed methodology has been tested for an electronics manufacturing company's manufacturing control system, and the result has been satisfactory in that it can save time and efforts for system implementation.

• 한국정밀공학회지
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• 제30권2호
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• pp.194-205
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• 2013

In recent years, the main concerns of enterprise management activities is how to strengthen the competitiveness to quickly respond to changes and sustain the growth in business environment. In order to achieve competitiveness and sustainability, a large variety of production informatization systems, such as MES (Manufacturing Execution System), ERP (Enterprise Resource Planning), have been introduced to manufacturing companies. However, there have been many problems owing to the reckless introduction of those systems. Therefore, it is necessary to evaluate the informatization level of the manufacturing company before introducing production informatization systems. This paper presents methodology and system to evaluate the informatization level of manufacturing company. The proposed evaluation method, based on the traditional questionnaire approaches, considers the various characteristics of the company. And then, we proposed models for calculation and production informatization level using 450 results of conducting a survey. Finally, a web-based system was developed for the evaluation of informatization level.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.1564-1569
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• 1991

In this paper we describe Flexible Manufacturing Systems (FMS) using Petri nets, since Petri nets provide a powerful tool for modeling dynamical behavior of discrete concurrent processes. We deal with off-Line and on-Line rule-based scheduling of FMS. The role of the rule-base is to generate appropriate priority rule for resolving conflicts, that is, for selecting one of enabled transitions to be fired in a conflict set of the Petri nets. This corresponds to select a part type to be processed in the FMS. Towards developing more Intelligent Manufacturing Systems (IMS) we propose a conceptual framework of a futuristic intelligent scheduling system.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.79-80
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• 2007

Copper has been used as an interconnect material in the fabrication of semiconductor devices, because of its higher electrical conductivity and superior electro-migration resistance. Chemical mechanical polishing (CMP) technique is required to planarize the overburden Cu film in an interconnect process. Various problems such as dishing, erosion, and delamination are caused by the high pressure and chemical effects in the Cu CMP process. But these problems have to be solved for the fabrication of the next generation semiconductor devices. Therefore, new process which is electro-chemical mechanical planarization/polishing (ECMP) or electro-chemical mechanical planarization was introduced to solve the. technical difficulties and problems in CMP process. In the ECMP process, Cu ions are dissolved electrochemically by the applying an anodic potential energy on the Cu surface in an electrolyte. And then, Cu complex layer are mechanically removed by the mechanical effects between pad and abrasive. This paper focuses on the manufacturing of ECMP system and its process. ECMP equipment which has better performance and stability was manufactured for the planarization process.