• 시스템엔지니어링학술지
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• 제2권1호
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• pp.37-41
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• 2006

The KSLV-I satellite launch vehicle will be launched in a space center currently under construction. The Space Center which is an advance post base of space development of Korea is located on Oenaro island in Kohung, South Cholla Province. A Ground Complex of the Space Center consists of an AC(Assembly Complex), a LC(Launch Complex), and a MCC(Mission Control Center). Assembly and test facilities are located in the AC in which stage assembly, integrated assembly, check-up, certification test, and pre-launch test are made effectively. A launch pad, fuel supply facilities, a launch control center and associated supporting facilities are located in the LC, and the MCC has control over the space center. These ground complex facilities have diverse forms of an interface with mechanical device, electric device, and etc. These should also provide optimum condition and performance during launch operation processes of the launch vehicle. This paper introduces the result of R&D for the AC of the ground complex performed during system design period.

• 산업경영시스템학회지
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• 제20권43호
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• pp.1-16
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• 1997

This paper improves the autonomy for supplier's schedule and the flexibility of the final assembly line. The final assembly line is a single work station and each product taking different assembly time is considered. In the assembly schedule, the heuristic method based on the goal chasing method is used. Consequently, suppliers can independently determine their output rates and thus, change their workload pattern according to their needs and priorities. Moreover, this flexibility can help to avoid expensive final-assembly-line stoppages in case of sudden part supply disruptions. The sequencing method can be easily implemented into an existing just-in-time system. In addition, the mathematical model was formulated and the algorithm was explained through the flow chart. The numerical example was given and the efficiency of this method is shown through the analysis of computational results of that example.

• 산업경영시스템학회지
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• 제14권23호
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• pp.47-55
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• 1991

In automated assembly line, an automatic guided vehicle system(AGVS) represents a mire versatile means of moving materials automatically. In this paper, the vehicles not only provide the transportation medium between workstations but also as mobile workstations. The objective for the developed model is the determination of the appropriate time to control AGV based assembly line in order to minimize production makespan while maximizing the efficient use of vehicles. In this paper, we consider the finished goods of two types which are produced in assembly line. The assembly line is considered with and without queue. Because no buffer are present in case 1. this model seeks to determine the point in time at which vehicles should be launched in the assembly line without experiencing a delay. The case 2 model also seek to determine the vehicle launch times while minimizing production makespan. The assumption in this model is that the maximum queue size cannot exceed 1 at any time.

• 한국염색가공학회지
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• 제20권5호
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• pp.23-27
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• 2008

In this work, poly(diallyldimethylammoniumchloride) (PDDAC) and meso-tetrakis(4-carboxyphenyl)porphyrin were considered to produce the self-assembly fabrication films. This method is based on the layer-by-layer (LbL) deposition produced by the electrostatic attraction between positively charged PDDAC and negatively charged porphyrin ions. The result of multilayer fabrication was discussed with the level of color strength (K/S). K/S spectra of the fabricated multilayer films showed gradual increase behaviors. In addition, the color photo images of the fabricated multilayer films showed that PDDAC and porphyrin were successfully attracted by electrostatic self-assembly forces.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.241-245
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• 2003

In this paper, a microassembly system based on hybrid manipulation schemes is proposed and applied to the assembly of a photonic component. In order to achieve both high precision and dexterity in microassembly, we propose a hybrid microassembly system with sensory feedbacks of vision and force. This system consists of the distributed 6-DOF micromanipulation units, the stereo microscope, and haptic interface for the force feedback-based microassembly. A hybrid assembly method, which combines the vision-based microassembly and the scaled teleoperated microassembly with force feedback, is proposed. The feasibility of the proposed method is investigated via experimental studies for assembling micro opto-electrical components. Experimental results show that the hybrid microassembly system is feasible for applications to the assembly of photonic components in the commercial market with better flexibility and efficiency.

• International Journal of Precision Engineering and Manufacturing
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• 제9권3호
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• pp.7-12
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• 2008

Today, manufacturers are forced to acknowledge that the life cycles of products are becoming shorter. In the case of the door trim assembly field, the highly frequent introduction of new products and the continuous increase in product varieties leads to the demand for redesigning assembly systems more often. Modular manufacturing systems can be an important issue in helping to overcome these problems. This paper presents the development of a modular assembly system for the door trim, and because it takes the change drives into consideration, this system is highly flexible in adapting to changes in the environment.

• Current Optics and Photonics
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• 제3권5호
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• pp.429-437
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• 2019

Temperature adaptability is an important metric for evaluating the performance of an optical system. The temperature characteristics of the optical system are closely related to the material and shape of its lens. In this paper, we establish a mathematical model relating the temperature characteristics to the shape and material of the lens. Then a novel assembly structure that can solve the lens constraint and positioning problem is proposed. From those basics, the correctness of the theoretical model and the effectiveness of the assembly structure are verified through simulated analysis of the imaging quality of the optical system, whose operating temperature range is $-60{\sim}100^{\circ}C$.

• 대한기계학회논문집
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• 제19권7호
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• pp.1604-1618
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• 1995

In the process of mechanical assembly design, assembly modeling systems have been used mainly for the design verification before manufacturing by enabling to check the interference and/ or the dynamic and kinematic performance. However, the conventional assembly modeling systems have a shortcoming that they can not be used in the initial design stage but can be used only after the design is fully completed. In other words conventional assembly modeling systems provide bottom-up modeling which means that the detailed modeling of components must precede the definition of relationships between them. To resolve this problem, an assembly modeling system is proposed to provide a top-down modeling environment in which components and assembly can be modeled simultaneously. To this end, an assembly data structure suitable for top-down assembly modeling has been established. Feature positioning Module(FPM) using geometric constraints has been also developed. The Sekective Solving Method proposed for FPM is based on the priority between the constraint equations and enables the designer's intent expressed by geometric constraints to be maintained throughout the whole modeling process. Finally, the feature based modeling technique using two-level features has been developed. Two-level features include an abstract model and a detailed model in a merged form in non-manifold data frame.

• 한국산학기술학회논문지
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• 제10권12호
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• pp.3863-3869
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• 2009

최근 자동차산업에서의 시장의 세계화와 증가하는 고객의 까다로운 욕구는 다양한 제품의 증가와 제조업체가 공급해야 하는 생산라인의 다양한 방식의 증가로 이어지게 되었다. 또한, 자동차 생산시스템의 모듈화는 자동차부품 공급업체들의 생산시스템에도 많은 영향을 미치고 있다. 이러한 변화는 혼합형 모델 조립라인이라 불리는 비용 효율적이고 유연한 생산시스템의 구현을 요구하고 있다. 본 논문에서는 이러한 혼합형 모델 조립에서 발생하는 여러 문제점들과 이러한 조립오류를 방지할 수 있는 기술에 대해 살펴보고, 혼합형 모델 자동차부품 조립라인에서 RFID를 이용한 오류방지 모니터링시스템을 개발하였다. 특히, 자동차부품 조립현장에서 일어나는 부품의 잘못된 설치와 누락과 같은 문제점들을 최소화하기 위하여 RFID를 이용한 모니터링시스템을 개발함으로써 문제점을 해결하고 조립오류를 예방하여 기존의 시스템을 보완하고자 하였다.

• 한국산학기술학회논문지
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• 제20권8호
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• pp.657-661
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• 2019

자동차 산업은 전 세계적으로 매출액이 1조 달러가 넘고 1천만 명 이상을 고용하고 있는 세계최대 제조업으로서, 약 2만 여개의 부품으로 완성되는 복합적 성격의 대표적인 산업이며 자동차 조립공정은 도장된 차체에 약 3천여 종의 내장, 계기판, 시트, 유리, 엔진, 트랜스미션, 차축 등의 유닛(Unit)을 조립하는 노동집약적 공정으로, 타 공정에 비해 자동화 비율이 가장 낮은 특징을 가지고 있다. 또한, 현재의 자동차 조립공정은 작업자의 조립작업에 대한 실시간 모니터링이 이루어지고 있지 못한 실정으로, 작업자의 작업 공구위치 측정시스템의 도입을 통해 공구의 위치를 실시간으로 파악하고 분석하여 일관된 작업 순서를 지시하면서 작업의 누락 및 가감을 체크한다면, 자동차 제조공정에서 발생할 수 있는 불량을 사전에 차단하여 조립공정의 생산성 및 품질향상을 이룰 수 있다. 따라서 본 논문에서는 작업자의 작업공구 위치 측정 시스템의 도입을 통해 일관된 작업 순서를 지시하면서 작업의 누락 및 가감을 체크하고, 제조공정에서 발생할 수 있는 조립불량을 사전에 차단하여 조립공정의 생산성 및 품질향상을 이룰 수 있는 실시간 공구 위치추적 시스템의 구성을 위하여 UWB(Ultra Wide Band) 무선측위를 활용한 공구의 실시간 위치추적시스템을 개발하고 그 효용성을 증명하고자 한다.