• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3202-3203
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• 1999

In this paper we show an integrated system of crane maneuvering, crane productivity, terminal operating system, and material handling system, so that the terminal users can have a unified database which enables them to improve the productivity, convenience for users and offer a wide variety of choices resulting in sharing information between terminal operating companies and efficient management of national key harbor industries.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2495-2497
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• 2003

본 논문에서는 다수의 AGV를 이용한 물류자동화 시뮬레이션에 대해 연구하였다. 각각의 AGV가 독립적으로 명령을 수행하도록 가상의 AGV를 제안하고 이미 연구된 AGV의 주행경로 표현방법, 경로망 구성방법을 이용하였다. 작업요구시 주어진 작업을 가장 빨리 수행 할 수 있는 AGV를 선정하고 최적 경로 계획을 수행하였다. 그리고 작업을 수행 중인 AGV는 경로 합류점에서의 교착상태(dead lock)와 충돌이 발생할 수 있는데 이를 방지하기 위한 통제구역을 정의하고 교통제어를 수행하였다.

• IE interfaces
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• v.13 no.2
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• pp.266-272
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• 2000

This paper deals with a computer-aided product arrangement system in the plant industry. The arrangement schedule may be performed manually. But this is inadaptable to change and difficult to store the results, which eventually requires time consuming and ineffective works. Using computerbased scheduling system, problems mentioned above can be resolved. In the system, the products can be arranged in a workarea with an automatic algorithm as well as manual operation using mouse dragging. In the automatic scheduling algorithm, the position of a product is determined by considering the existing products and material handling costs. Then the scheduled results are stored in DB and can be manipulated at any time.

• Journal of Korean Institute of Industrial Engineers
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• v.17 no.1
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• pp.109-115
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• 1991

In automated manufacturing systems, Automated Guided Vehicle(AGV) Systems are increasingly important in material handling and manufacturing operations. A considerably flexible AGV system needs to be operated with maximum effectiveness. This paper develops an algorithm for the determination of the entering point and the number of AGVs required in the Flow Shop Type FMS. We consider an AGV used as a carrier and mobile workstation. For the limited number of AGV, the entering point of an AGV on a simple loop is determined in order to maximize the utilization of AGVs. For the unlimited number of AGVs, the number of AGVs required in the FMS is determined on the basis of the entering point of AGVs. The result by the algorithm may be used as a criterion on the control of material flow and the assignment of AGVs in the FMS. A numerical example is given to illustrate the algorithm.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2000.04a
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• pp.5-8
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• 2000

Vehicle travel time (empty travel time pius loaded travel time) is a key parameter for designing AGV-based material handling systems. Especially, the determination of empty vehicle travel time is difficult because of the stochastic nature of the empty vehicle locations. This paper presents a method to estimate vehicle travel times for AGV-based material transport systems. The model considers probabilistic aspects for the travel time and vehicle location under random vehicle selection rule and nearest vehicle selection rule. The estimation of empty travel time is of major effort. Simulation experiments are used to verify the proposed travel time model, and the simulation results show that the presented model provides reasonable travel time estimations.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.3
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• pp.265-272
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• 2023

Objectives: Since the material safety data sheets(MSDS) submission and non-disclosure review system was introduced in January 2021, the implementation status of MSDS for chemical manufacturing and importing workplaces being supervised for the first time. Methods: A supervisory team consisting of two labor inspectors and one from the Korea Occupational Safety and Health Agency directly visited the selected workplaces to check compliance with the MSDS system as a whole. Results: As a result of supervising 214 chemical substance manufacturing/importing workplaces, a total of 241 violations of the law were found in 121 workplaces, or 57% of them. In response, the Ministry of Employment and Labor took legal action on 8 cases in 6 locations, imposed a fines totaling of 249.69 million won on 120 chemical handling workplaces, and took action to correct the violations immediately. Conclusions: Major violations were in the order of non-request for warning signs, non-submission of MSDS, non-execution of MSDS training, and non-posting of MSDS. This shows the reality that employers who handle chemical substances are sufficiently communicating chemical information to workers. In the future, the government will actively implement preparation and submission support and system guidance for the implementation of the MSDS system, while making efforts to ensure that the MSDS system works well in the field through thorough on-site supervision in the future.

• Journal of Pharmaceutical Investigation
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• v.32 no.1
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• pp.41-45
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• 2002

The purpose of this study is to microencapsulate a highly hygroscopic drug, pyridostigmine bromide (PB), with a waterproof wall material, in order to increase the flowability of the drug particles. Polyvinylacetaldiethylaminoacetate (AEA), Eugragit E and Eugragit RS were examined as the wall materials. Microcapsules containing PB were prepared by the evaporation technique in an acetone/liquid paraffin system using aluminum tristearate as a core material, and evaluated for drug encapsulation efficiency, surface morphology, particle size and drug dissolution. The encapsulation of PB in the wall material was almost complete. Among the wall materials examined, AEA exhibited the most excellency in shape, surface texture, flowability, size distribution of microcapsules. Above results suggest that AEA would be a potential wall material for microcapsulation of highly hygroscopic drugs, such as PB. Through microencapsulation with AEA, inconvenience of handling of PB powders encountered in the process of weighing and packing the powders to tableting die or capsule body could be greatly improved.

• Journal of Korean Institute of Industrial Engineers
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• v.21 no.1
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• pp.137-151
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• 1995

A difficult problem in operating Flexible Manufacturing Systems (FMS) is to control the system in real-time by coordinating heterogeneous machines and integrating distributed information. The objective of the paper is to present the models and methodologies useful to resolve the difficult problem. The detailed objectives can be described in three folds. First, a hierarchical Colored and Timed Petri-Net (CTPN) is designed to control an FMS in real-time. The concerned FMS consists of a loading station, several machining cells, a material handling system, and an unloading station. Timed-transitions are used to represent the timed-events such as AGV movements between stations and cells, part machining activities in the cells. Signal places are also used to represent communication status between the host and the cell controllers. To resolve the event conflicts and scheduling problems, dispatching rules are introduced and applied. Second, an implementation methodology used to monitor and diagnose the errors occurring on the machines during system operation is proposed. Third, a Petri-Net simulator is developed to experiment with the designed control logic.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.294-296
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• 1996

JIT(just-in-time) 생산시스템은 제조라인의 재공품 재고량을 최소화하고, 필요한 품목을 적시에 필요한 양만큼만 생산하여 공급하는 것을 목적으로 한다. 이러한 시스템은 사용하는 칸반의 수에 따라 single-card kanban system과 two-card kanban system으로 구별할 수 있다. 또한 각 공정이 입력버퍼(input buffer)와 출력버퍼(output buffer)를 갖는 경우와 공정간에 하나의 버퍼를 갖는 경우로 나누어 볼 수 있다. 본 연구는 기계간의 물류(material handling)가 필요한 시점에 즉시 이루어진다는 가정하에 기계간 버퍼가 하나이고, 그 버퍼의 용량이 1인 경우의 single-card kanban의 효율적인 운용방안을 개발하였다. 본 연구의 목적은 생산지시칸반의 회수시기를 적절히 조절하여 생산라인의 이용효율(utilization)을 극대화하고자 하는 것이다. 칸반회수시기 결정을 위한 상황분석의 범위를 10대의 기계로 제한하여 시뮬레이션에 의해 분석하였다. 기존의 칸반운영방식과 생산라인에서의 재고를 최소화하는 운영 알고리듬, 그리고 생산기계의 효율을 최대화할 수 있는 운영 알고리듬을 개발하여 비교.분석하였다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.6
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• pp.66-72
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• 2012

The main sources of energy consumption in warehouses are MHE(Material Handling Equipment), HVAC(Heating, Ventilating and Air Conditioning) and Lighting. Warehouses in advanced countries raise energy efficiencies with energy consumption diagnosis, technology development and systematic management and improvements for MHE, HVAC and Illuminating, etc. They have managed illuminating system, air conditioning, motor driven system, air circulation method, dock facility, layout, AS/RS, conveyor system and battery management, etc. Ansong Pyeongtaek area investigation resulted that 43.9[%] of enterprises are managing partly energy consumption source. But the data resulted with not substantial management of energy consumption but passive management for only electric bill curtailment. Therefore through survey research & visiting interviews of some companies in Ansong Pyeongtaek area, we understood the status of energy consumption source management and proposed energy efficiency methods on the basis of that results.