• Journal of Institute of Control, Robotics and Systems
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• v.7 no.4
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• pp.319-325
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• 2001

Recently. AGV systems are used to serve the raw material to each work stations automatically. There exists a trade-off between the adequate service supply and the number of purchased AGVs. Also, to reduce the overall production cost, the amount of inventory hold on the shop floor should be considered. In this paper, we present a heuristic technique for determining the number of AGVs which includes the net present fixed costs of each station, each purchased AGV, delivering cost, stock inventory cost, and safety stock inventory cost. Secondly, by using a genetic algorithm, the optimal number of AGVs and the optimal reorder quantity at each station are decided. Lastly, to verify then heuristic algorithm, we have done a computer simulation with different GA parameters.

• Health Policy and Management
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• v.30 no.1
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• pp.4-14
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• 2020

Since the government is fully aware of the specificity and importance of the healthcare field, it operates bureaucracy and affiliated organizations composed of many government ministries and experts and is also handling the related bureaus. However, recent incidents of humidifier disinfectant not only make these government activities unreliable but also cause disappointment to many people. Why did not the government take active measures to ensure product safety? But why was the Korea Centers for Disease Control and Prevention (KCDC) able to speed up the identification of the cause and the recovery of the product? The purpose of this study is to clarify the behavioral mechanisms of government intervention by comparing the behaviors of the Ministry of Trade, Industry and Energy and the KCDC. Then, we will discuss the desirable government structure.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2457-2459
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• 2002

In this paper, we describe the way how to create a curvature trajectory where the dynamics of a mobile robot is considered. Synchro-drive motor is used in a mobile robot. And translational and rotational speeds are controlled independently. Using these two speeds, a mobile robot traces a smooth curvature trajectory that consists of circle trajectories to a target point. While trying to avoid obstacles, the robot can be goal-directed using curvature trajectory. Also, while the robot can navigate the trajectory, the maximum speed is controlled to trade off speed and safely.

• Proceedings of KOSOMES biannual meeting
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• 2001.05a
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• pp.105-133
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• 2001

World trade has been increasing continuously in total volume, on the other hand, environmental protection on sea and conservation of fishery resources has been rising up the major issue. All of the world are pushing their efforts two major purposes to the full, one is taking competitive place in marine transportation throughout the world and another Is environment protection. Pusan Port as world leading Port put its all effort in bring more ocean going vessels and securing their traffic route by providing them more information related marine traffics through PTMS in port. During two years of operation, statistics of marine traffic accidents showed that many dynamic casualties such as collisions, groundings, and rammings has been decreased. However, due to increasing cargo volume, limited water area and unpredictable weather condition, potential risks still exist high. In this paper, in order to maximize the efficiency of PTMS and reduce various risks in the future, we examine risk factors over operational results and experience, and propose reasonable operational methods of PTMS.

• Structural Engineering and Mechanics
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• v.36 no.6
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• pp.729-744
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• 2010

There is world wide concern for safety of nuclear power installations after the terrorist attack on World Trade Center in 2001 and several other civilian structures in the last decade. The nuclear containment structure in many countries is a double shell structure (outer shell a RCC and inner a prestressed concrete). The outer reinforced concrete shell protects the inner shell and is designed for external loading like impact and blast. A comparative study of non-linear response of reinforced concrete nuclear containment cylindrical shell subjected to impact of an aircraft (Phantom) and explosion of different amounts of blast charges have been presented here. A material model which takes into account the strain rate sensitivity in dynamic loading situations, plastic and visco-plastic behavior in three dimensional stress state and cracking in tension has been developed earlier and implemented into a finite element code which has been validated with published literature. The analysis has been made using the developed software. Significant conclusions have been drawn for dissimilarity in response (deflections, stresses, cracks etc.) of the shell for impact and blast loading.

• Journal of Information Technology Applications and Management
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• v.25 no.2
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• pp.117-132
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• 2018

This study examines the reason why consumers try to use the online shopping cart more, and especially analyzes the influence of personal psychological factor such as regulatory focus. Hypotheses are tested with a two-way ANOVA model using experimental data collected from 210 undergraduate students at a business school in South Korea. We found that prevention focused consumers try to use online shopping cart more than promotion focused consumers. It is possible that prevention focused consumers try to consider as many alternatives as possible to ensure safety as they focus on negative results or losses during shopping online. However, we also found out when the buying purpose is utilitarian, promotion focused consumers are not different from the promotion in terms of the usage intention of online shopping carts. Marketing managers can provide different messages customized for their consumers by leading them to use the online shopping cart in a more effective way.

• Journal of Korean Society for Quality Management
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• v.22 no.3
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• pp.16-33
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• 1994

This paper developes a multiple-item scale instrument (called SHIPQUAL which is designed to measure the quality of shipping industry. The procedures of developing instrument were followed by recommendations on the developing measures of marketing constructs. We divided shipping service quality into 4 demensions (reliability, conformability, timely/completness, safety) by empirical study. These demensions and scales were varified through the assessment of reliability and validity. Finally, we suggested potential applications of the scale into the shipping industry.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.265-267
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• 2013

Tire labeling is an important issue to reduce $CO_2$ and to secure the safety of tire/vehicle on wet road. A basic study on the effects of tire basic stiffness design on tire labeling performance has been done through experimental test. The pass-by noise is affected by tire structural design. The tire with lower side part stiffness and lower tread part stiffness has the lowest PBN level and the best wet grip. And the tire with higher tread part stiffness and higher side part stiffness has the better RR performance. Also it is observed that the trade-off between RR and wet grip exists for various tire stiffness design.

• Journal of Hydrogen and New Energy
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• v.33 no.4
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• pp.301-308
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• 2022

The Hydrogen Economy Promotion and Hydrogen Safety Management Act (hereinafter referred to as the "Hydrogen Economy Act") stipulates matters related to certification and cancellation of clean hydrogen by grade, and requires those who produce, import, or sell clean hydrogen to report to the Minister of Trade, Industry and Energy. In order for this system to operate smoothly, the clean hydrogen Certification system must be designed to meet international standards, and the institution operating the System must have appropriate capabilities and foundations. The clean hydrogen certification system should serve as an opportunity for Korea's domestic energy industry to take a leap forward.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.2
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• pp.69-76
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• 2010

Recently, the natural environment changes drastically and the frequency of occurrence for lightning has gradually been increased. Such lightning delivers high volume of energy along the power line and communication line to the equipment in use. The high volume of energy arising from the lightning surge develops in fast velocity to destroy the facilities in power source and many other facilities in operation in sequential destruction with vast energy. This paper examines the characteristics of ZnO varistor to prevent from thermal runaway. We carry out performance evaluation of electrical characteristics on ZnO varistor. we will develop ZnO varistor Prevented from thermal explosion using test result of this paper.