• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.10a
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• pp.251-252
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• 2015

Recently, as warehouses became automated, workers are trying to maximize storage efficiency as well as work efficiency. So, using mobile-rack which has wheels or rails at the bottom and minimizes dead space by removing extra passages between racks is rapidly rising as a notable technology. So, this paper seeks how to manage optimally cryogenic warehouse using mobile-rack. At first, routes of mobile-rack and operation vehicle will be synchronized and storage location will be decided with seasonal demand. After that, it will be simulated considering additional factors.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2016.05a
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• pp.211-212
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• 2016

It is important to adopt an operation system to operate the Automated warehouses using limited resources such as space, mobile racks, and forklift. The main purpose from the operation system is to reduce the length of moving and time for both mobile racks and forklift. The complexity of the warehouse will be higher because the racks and vehicles are moving at the same time. This complexity influences badly so the operation system has to control it well. Not only layout or receipt or issue, but also conflict between mobile racks and vehicles give more complexity to the warehouse. This paper aims to fine the proper operation method related to the layout and the cargo assignment.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2016.05a
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• pp.209-210
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• 2016

Depending on the progress of globalization is increasing the expectations for logistics services. The introduction of logistics equipment to promote the efficiency of the logistics center has emerged as a key factor influencing the competitiveness of the logistics center. Most of the logistics equipment introduced in the logistics center is expensive imported products. The development of logistics equipment is needed....

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.6
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• pp.527-534
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• 2016

The non-rail mobile rack, which is used for cargo storage, can improve the storage capacities of logistics centers. Furthermore, it has the advantage that it can be used in traditional logistics centers without making any changes or renovation, such as installing rails. However, when the rack is operated by separated drive actuators mounted on the left and the right wheels, precise position control of the wheels is necessary even if the unbalanced cargo weight on the rack would affect the control. Therefore, internal synchronization control for position tracking between the left and right wheels on the non-rail mobile rack is necessary in this study. In addition, external synchronization control for realizing the same straight movements between mobile racks is necessary. For the internal and the external synchronization control, we propose a synchronization control algorithm based on the repetitive control theory. An internal synchronization control algorithm with repetitive control theory requires the application of the robust servo control method owing to parameter variations. In this case, we can set up the gains for the robust servo control system by considering the cargo variations on the mobile rack. Furthermore, for developing the external synchronization control algorithm, we use a double repetitive control system to perform synchronization control between mobile racks. The efficiency of the proposed control algorithm will be verified by simulation and experimental results. The proposed algorithm can be easily applied in the industry.

• Journal of Korean Institute of Industrial Engineers
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• v.21 no.2
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• pp.195-206
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• 1995

Higher utilization of warehouse space can be achieved by using automated mobile racking systems. Therefore, those systems may be employed for factories or distribution centers as a good option of increasing the storage capacity. In this paper, travel-time models are developed to estimate the average performance of the system assuming randomized storage. Expected travel times are determined for both single- and dual-command cycles. Two extreme input/output-point locations are considered. Some numerical results obtained from the models are given.

• Proceedings of the Korea Society for Simulation Conference
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• 1998.10a
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• pp.213-216
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• 1998

수원시에 소재한 T 물류센터는 제품의 종류를 고려하여 랜덤 불출정책에 의해 운영되고 있는 단위적재 형 out-of-aisle in-process 자동창고 형태이다. 랜덤불출의 결과 팔렛에 잔량의 제품이 발생할 수 있으며, 잔량의 제품 팔렛은 저장경로를 통해서 랙으로 재저장이 이루어진다. 현재 T 물류센터에서는 상당한 양의 재저장이 발생되고 있으며, 이로 인하여 저장공간이 비효율적으로 이용되고 있으며, 운송기계(S/R 기계)의 이동시간 및 이동거리의 증가, throughput의 감소, 대기시간의 증가 등이 심각한 문제로 나타나고 있다. 본 연구는 시뮬레이션 기법을 활용하여 이 물류센터에서 사용할 수 있는 4가지 불출정책 대안을 비교·분석하여 최적의 불출정책을 도출하는 것을 목적으로 하고 있다. 시뮬레이션 기법을 통해 결정된 최적의 불출정책을 도입함으로써 T 물류센터에서는 저장공간 이용률의 최소화, 운송기계의 이동시간 및 이동거리 최소화, 재저장 횟수의 최소화를 통해 효율적인 불출작업과 저장공간의 활용도를 증가시키는 효과를 기대할 수 있을 것이다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1994.10a
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• pp.62-66
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• 1994

본 연구에서는 실제 사용되고 있는 TDX-10 교환기의 subrack과 보드에 대한 진동 특성과 이 보드가 subrack에 실장되었을 때 진동 특성을 연구하였으며, subrack이 rack에 실장되는 조건을 갖는 진동 시험용 jig를 제작하여 보드와 subrack을 실장한 후 강제 진동시의 진동 전달 특성을 알아보았다. 본 연구의 결과는 내진동 특성이 우수한 전자통신 시스템 설계와 CDMA 이동통신 시스템의 HINA subrack 구조설계와 같은 개발장비 환경시험의 기초 자료로 활용될 수 있을 것이다.

• Electronics and Telecommunications Trends
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• v.8 no.3
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• pp.21-32
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• 1993

SMX/CMP는 통신망기술연구실에서 개발한 대용량 stand-alone 신호중계교환기 SMX-1을 이용하여 지능망 또는 이동통신망의 노드에 CCS No.7 접속이 가능하도록 설계된 CCS No.7 프로토콜 처리장치이다. 기존의 SMX/CMP는 2대의 대형 랙으로 구성되었으며, CCS No.7 프로토콜 처리 장치로서는 너무 크기 때문에 소형으로 되어야 한다는 요구가 있었다. 상호연결시스팀인 HSCU-8채널의 설계와 물리적인 재구성으로 SMX/CMP을 소형화 하였다.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.76-77
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• 2015

In construction industry, management of construction factors such as cost, schedule, quality and safety is the most important key for delivering successful projects. According to the Smart Market Report, a magazine specialized in construction industry, recently said 'Off-site Prefabrication' is a significant trend related with construction productivity in global construction industry. It is a kind of practice shift from On-site to Off-site. A lot of general contractors in oversea have been using 'Multi-trade MEP Ceiling Rack Prefabrication' method for getting benefits such as decreased cost & schedule and increased labor productivity. Thus, in this paper, critical management factors at each phase from design to installation was derived by researching case studies. Forwardly, it can be a basic guideline for applying Multi-trade MEP Ceiling Rack Prefabrication in Korea construction industry.

• IE interfaces
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• v.18 no.3
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• pp.297-307
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• 2005

PCB assembly is a complicated and difficult process to optimize due to the necessity of simultaneous consideration of component’s rack assignment and board mounting sequencing. An efficient PCB assembly method is developed by using neighboring positioned identical components information as well as quantity and size of the components. It is found that same type of components are located closely each other by checking real PCBs and interviewing with PCB designers in practice. Better performance of the developed procedure is obtained along with more number of total components and more number of neighboring positioned identical components cases. Simulation models are developed using Visual C++ for performance evaluation purposes of the suggested heuristic.