• 한국실천공학교육학회논문지
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• 제4권1호
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• pp.80-85
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• 2012

현대 산업 사회에서 창고의 역할은 보관창고의 개념에서 정보시스템의 도입을 통해 구매, 생산, 저장 및 분배 활동을 원활히 하는 유통창고의 개념으로 바뀌어 창고의 중요성은 계속 커지고 있다. 본 연구에서는 자동창고의 효율성을 평가할 수 있는 프로그램이 C#을 이용하여 개발되었다. 저장법, 자동창고의 배치형태 및 명령수행절차의 세 가지 운영조건의 조합으로 8가지의 방안에 대하여 모의실험이 이루어졌고, 프로그램에 동일한 입출고 데이터를 입력하여 스태커 크레인의 이동거리 값을 산출하였으며, 결과 값을 토대로 원인을 분석하고 최적의 운영방안을 제시할 수 있다. 이 프로그램은 모의실험을 통해 프로그램의 효율성과 응용가능성을 보여주었고, 공장설비 관련 교과목에 활용되어질 수 있다.

• 한국경영과학회지
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• 제13권1호
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• pp.39-50
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• 1988

The warehousing of inventories is an enormous expense to industries worldwide, and yet there are few available that can be used to design rack storage systems while considering overall system costs. The primary objective of this paper is the development of an overall ware hous storage system costs model to aid a warehous planner in the design of automated warehouse systems. A simulation model and statistical estimation procedures are used to determine the maximum inventory levels accumulated in the receiving, storage, and shipping areas. The overall cost model is developed to determine the required total land, the initial investment fund, the number of pieces of handling equipment, and the storage rack configuration for the main storage area. A numerical example is then presented to demonstrate the application of the overall system cost model developed in this paper.

• 품질경영학회지
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• 제16권2호
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• pp.99-110
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• 1988

This study is concerned with a design algorithm to minimize the investment as well as maximize the throughput in automated warehouse system. A simulation model is designed and a solution methodology is proposed. The experiment, are conducted for the cases with 100, 90, 80, 70, 60, 50 and 0 % dual command policies in terms of the important factors such as the crane velocity, the height of system and the rack utilization. The results indicate that the throughput is slightly decreased when the ratio of dual command is decreased and the other characteristics however are not affected. The result also shows that the optimal rack should be designed for a crane to take the same amount of travel time for horizontal and vertical movement.

• 한국통신학회논문지
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• 제36권12B호
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• pp.1686-1697
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• 2011

This paper aims to build up a RFID-automated cargo movement system in an air-cargo warehouse. In our research, we do the spectrum measurements compliant with the RFID frequency bands to observe the interferences from legacy systems in the air-cargo warehouse. To overcome the dense-reader mode (DRM) problem, we apply three novel approaches, which are the periodic transmit of a reader, the Visible RFID reader & tag, and the sensor-based RFID system. Moreover, for the tag collision issue, we implement the Adaptive Adjustable Framed Q(AAFQ) algorithm, and the demonstration on RFID tag anti-collision algorithms show that the AAFQ algorithm has highly desirable tag anti-collision performance compared to any other commercially available solutions.

• 한국생산제조학회지
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• 제23권5호
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• pp.505-511
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• 2014

The functional role of warehouses in modern industry is changing from an established concept of storage to a concept of circulation. The target of this study is to improve the stacker crane's efficiency for the internal operations of the Automated Storage and Retrieval System (AS/RS). Eight operating schemes are proposed under the combination of three conditions, namely, the storing method, the layout type, and the sequence of command execution. The moving distance of the stacker crane is calculated using the same gateway data through a simulation based on a C# program. The optimal operating scheme is proposed based on the analyzed simulation results. In conclusion, the combination of conditions of random storage, two-way type warehouse, and dual command execution elicits optimum results in travel efficiency for the stacker crane.

• 대한전자공학회논문지
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• 제24권2호
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• pp.292-300
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• 1987

This paper, realizes the design of the sequential controller of a reinforced warehousing-delivery and unmanned transportation system for automated warehouse system. The system is composed of ware housing delivery adn transportation system using two unmanned vehicles with hierachical structure. It is described by GRAFCET and realized by programmed logic with microprocessor. Being described by GRAFCET, the system is able to divide it into subsystems and to synchronize them. Defining the concept of program module, one can easily program the system with the microprocessor instruction language.

• 산업경영시스템학회지
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• 제16권27호
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• pp.73-82
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• 1993

In this paper, We determine the expected travel time for several forks Storage/Retrieval machine which is allowed multiple stops in aisle. When throughput is increased, We propose adding to fork number of each S/R machine rather than adding to number of S/R machine, We also describe such a model which determines the optimal number of each several forks S/R machine subject to constraints on the hourly throughput and warehouse dimensions. Numerical example is presented to compare warehouse shapes against each single fork, twin forks, triple forks S/R machine for various throughput values.

• 산업경영시스템학회지
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• 제34권1호
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• pp.1-8
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• 2011

Controlling industrial vehicle operated by human in warehouse was not simple since the information transfer for controlling the vehicle was not easy. However, as the technology for the WMS (Warehouse Management System) has been advanced and the PDA (Personal Digital Assistant) has come into wide use in a workplace, the control of man-operated vehicle became less difficult as do to AGVS (Automated Guided Vehicle System). This study examines the ways to improve the efficiency of warehouse operation through introducing rule of task assignment for the vehicles, particularly forklift. This study, basically, refer to AGV operation policy because a great number of studies for AGV dispatching rule have been done and the mechanism for the controlling vehicles is very similar. The workers in field prefer to simple dispatching rules such as Shortest Retrieval Time First (SRTF), Shortest Travel Time First (STTF), and Longest Waiting Time First (LWTF). However, these rules have potential disadvantage. Thus, several rules made up by combining rules mentioned above are introduced and these new rules use threshold value or evaluation formula. The effectiveness of these new rules are tested by simulation and the results are compared. This study proposes favorable dispatching rules for forklift in warehouse for the efficiency of the vehicle operation and stability of service level.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2021년도 추계학술대회
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• pp.101-103
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• 2021

전 세계적으로 수출입 화물이 급격하게 늘어나면서 기업들은 창고의 효율성 증가와 창고 인력 감소로 인해 무인 자동화창고에 대한 관심과 연구개발이 증가하고 있다. 소규모 창고에서는 재고의 흐름을 유동적으로 할 수 있는 셔틀랙 기반의 레이아웃이 빈번하게 존재한다. 그러나 셔틀랙 기반의 물류센터는 비상상황(고장, 정전 등)에서 셔틀이 작동하지 않아 물류센터 효율성과 재고관리에 심각한 영향을 미치고 있다. 이에 셔틀랙 기반의 물류센터에서 다양한 셔틀의 통로와 RTV의 통로를 레이아웃별로 분류하고 특성과 유형을 분석하여 각 레이아웃별로 신뢰성을 도출하였다. 통로의 개수에 따라 적재율도 다르게 도출되어 각 레이아웃별로 신뢰성과 적재율을 비교 분석하였다.

• 한국경영과학회지
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• 제13권2호
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• pp.34-46
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• 1988

This paper deals with design problem of unit load automated storage/retrieval systems (AS/RS). We propose an optimal design model in which the investment and maintenance costs of AS/RS, operating under dual command model is minimized over a time horizon satisfying the warehouse dimensional constraints. The model is formulated as an integer nonlinear program and an algorithm is proposed to find an optimum solution. The valididty of the solution algorithm is illustrated through an example.