• IE interfaces
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• v.16 no.spc
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• pp.93-98
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• 2003

This paper addresses an AGV dispatching problem in semiconductor clean-room bays where AGVs move cassettes of wafers between machines or machines and a central buffer. Since each machine in a bay has a local buffer of limited capacity, material flow should be controlled in a careful way to maintain high system performance. It is regarded that two most important performance measures in a semiconductor bay are throughput rate and lead-time. The throughput rate is determined by a bottleneck resource and the lead-time depends on smooth material flow in the system. This paper presents an AGV dispatching procedure based on the concept of theory of constraints (TOC), by which dispatching decisions are made to utilize the bottleneck resource at the maximum level and to smooth the flow of material. The new dispatching procedure is compared with existing dispatching rules through simulation experiments.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.22 no.50
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• pp.75-90
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• 1999

이 논문은 전자 부품 조립산업에서의 통합 물류 시스템의 효율적인 선택과 최적의 설계를 위해 객체지향형 전문가 시스템과 해석적 모델을 결합한 방법론을 제시한다. 물류시스템의 선택과 설계 (마이크로로드 AS/)RS 선정)를 위해 지능형 물류시스템 (IMHSS:Intelligent Material Handling and Storage System)을 개발하여, 그 결과를 시뮬레이션 결과와 비교함으로써 지능형 물류시스템 모델의 적합성을 나타내고자 한다.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.15 no.26
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• pp.1-11
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• 1992

Material Handling equipments such as hoists, cranes, storage and retrieval machines, gantry robots and conveyors are carrying out more important tasks in material flow automation field. This paper is concerned with the characteristic and the position of this industry, and presents the status of the business world scale, supply and demmand. import and export transition, and directing posts of the profits. Also it gives productivity security and activity.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.602-607
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• 1990

Spent nuclear fuel is very dangerous substance emitting strong ionizing radiation which is harmful to human body. The remote handling of spent nuclear fuel is essential because people cannot access this substance without protecting radiation. To handle highly radioactive material or nuclear waste, many kinds of teleoperators such as master slave manipulator, electro mechanical manipulator, servo manipulator, mobile robot was developed. The distance and dimension of target object cannot be measured easily when highly radioactive material is handled by teleoperator because one should use lead glass or TV camera and monitor to protect radiation and see target object. During experiments on the remote handling of spent nuclear fuel by electro mechanical manipulator, we often felt that a distance and dimension measurement system is necessary to handle the objects which is in the highly radioactive environment, so we developed a system which is appropriate for this purpose.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.22 no.50
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• pp.65-73
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• 1999

Most psychophysical studies in manual material handling (MMH) have paid more attention to two-handed MMH activities than to one-handed MMH activities. Also, studies are involved only with single MMH activities - lifting, lowering, carrying, holding, pushing or pulling. Very few studies are reported on the determination of workers' capacities for combinations of one-handed MMH activities (lifting a box, then carrying the box, and lowering the box). The objective of this study was to find the psychophysical and physiological responses of human subjects from a simulated industrial task involving one-handed and two-handed combined tasks. The capacities that were determined as the maximum acceptable weight workloads for 1 hr work period for one-handed and two-handed combined tasks - lifting a box from floor to knuckle height, carrying the box for 4.3 m, and lowering the box from knuckle to floor height - were determined psychophysically under three frequencies: six handlings per minute, one handling per minute and one handling per five minutes. In addition to maximum acceptable weight, heart rate and RPE values on wholebody, back, and arm were also measured as responses.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.45 no.3
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• pp.40-48
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• 2022

An automated material handling system (AMHS) has been emerging as an important factor in the semiconductor wafer manufacturing industry. In general, an automated guided vehicle (AGV) in the Fab's AMHS travels hundreds of miles on guided paths to transport a lot through hundreds of operations. The AMHS aims to transfer wafers while ensuring a short delivery time and high operational reliability. Many linear and analytic approaches have evaluated and improved the performance of the AMHS under a deterministic environment. However, the analytic approaches cannot consider a non-linear, non-convex, and black-box performance measurement of the AMHS owing to the AMHS's complexity and uncertainty. Unexpected vehicle congestion increases the delivery time and deteriorates the Fab's production efficiency. In this study, we propose a Q-Learning based dynamic routing algorithm considering vehicle congestion to reduce the delivery time. The proposed algorithm captures time-variant vehicle traffic and decreases vehicle congestion. Through simulation experiments, we confirm that the proposed algorithm finds an efficient path for the vehicles compared to benchmark algorithms with a reduced mean and decreased standard deviation of the delivery time in the Fab's AMHS.

• Journal of the Korea Society for Simulation
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• v.10 no.3
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• pp.71-82
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• 2001

Considering material handling delay which occurs between storage and processing stations, we propose an algorithm to estimate the required storage capacity, i.e., number of aisles and number of openings in vertical and horizontal directions in each aisle, of an automated storage/retrieval(AS/R) system. Due to the random nature of storage and retrieval requests, proportion of single and dual commands is not known in advance. Two design criteria, maximum permissible overflow probability and maximum allowable storage/retrieval(S/R) machine utilization, are used to compute the storage capacity. Most of studies assume that storage capacity of AS/R systems is given, although it is a very important decision variable in the design phase. Therefore, the proposed model can be effectively used in the design phase of new AS/R systems.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.33
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• pp.45-53
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• 1995

The Purpose of this paper is to describe and demonstrate a quantitative procedure for evaluating alternative material handling systems that are being considered for possible purchase. The procedure considers both quantitative factors(i.e. costs) and qualitative factors(i.e. equipment productivity) that should be considered in the evaluation process. Since these factors are not always quantifiable it is necessary that the procedure be able to quantify all factors in commensurable units. This is accomplished via a modification of the Brown and Gibson model for facility site location and selection. The model was demonstrated via a case example that encompassed the derivation of performance measures for three material handling systems.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.5
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• pp.524-530
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• 2012

In this study, it is performed that the assessment of feasibility of developed material processing facilities using tele-operation manipulator system for the pyroprocessing. To evaluate the performance of developed facilities using tele-operation system, several performance indices are considered as remote visibility, remote reachability and remote manipulability. These are applied to RHEM (Remote Handling Evaluation Mock-up) and digital mock-up system respectively. Through this approaches, several requirements for the system improvement are deduced and preliminary inspection for real system application is fully performed. Additionally, assembly and disassembly tasks for the repair of remote handling system are also examined remotely in RHEM and evaluated those performances.

• Journal of Korean Institute of Industrial Engineers
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• v.19 no.2
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• pp.23-34
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• 1993

Although there are numerous studies that address the problem of optimal machine grouping and part family classification for cellular manufacturing, little research has been reported that studies the conditions where cellular manufacturing is appropriate. This paper, in order to evaluate and compare the job shop with the GT cellular shop, the performance of those shops were simulated by using SIMAN. We tested the effect of independent variables including changes of product demands, intercell flow level, group setup time, processing time variability, variety of material handling systems, and job properties (ratio of processing time and material handling time). And also performance measures (dependent variables), such as machine utilization, mean flow time, average waiting time, and throughput rate, are discussed. Job shop model and GT cellular shop written in SIMAN simulation language were used in this study. These systems have sixteen machines which are aggregated as five machine stations using the macro feature of SIMAN. The results of this research help to better understand the effect of production factors on the performance of cellular manufacturing systems and to identify some of the necessary conditions required to make these systems perform better than traditional job shops. Therefore, this research represents one more step towards the characterization of shops which may benefit from cellular manufacturing.