• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.632-634
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• 1996

In modern train systems, the high-speed and the high-density of train operation have been required. Effective train control systems need various information interchanged between the ground-site and on-board devices. So the systems are essential to the digital systems to admit lots of information and to raise the accuracy of transmission. In this paper, it is dealt with n bi-directional transmission of digital information between on-board devices and ground-site. Especially, this paper shows the experiment of bi-directional transmission of mass information by using transponder.

• Journal of Information Technology Applications and Management
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• v.11 no.3
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• pp.77-87
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• 2004

The importance of information systems(IS) operations and maintenance is increasing as the costs of IS operations and maintenance take larger share of total IS costs and organization's dependency on IS is increasing. However, this area has received relatively little attention from scholars and practitioners despite of its significance. The main objectives of this study are to provide practical guidelines for improving IS operations and maintenance practices, and to propose a research framework for this area. To accomplish this objectives, the following three issues are investigated. First, IS operations and maintenance practices of a case company are analyzed. Second, the current practices are compared with best practices. Finally, suggestions are made based on the analyses to improve the IS operations and maintenance practices.

• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.349-351
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• 1997

In modern train systems, the high-speed and the high-density of train operation have been required. Effective train control systems need various information interchanged between the ground-site and on-board devices. So the systems are essential to the digital systems to admit lots of information and to raise the accuracy of transmission. In this paper, it is dealt with a transmission of digital information between on-board and ground. Especially, this paper shows the experiment of data transmission and realize the system for information transmission in railway system.

• Journal of Korean Institute of Industrial Engineers
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• v.21 no.1
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• pp.85-101
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• 1995

Automated Guided Vehicles(AGVs) are widely used in computer integrated manufacturing(CIM) systems for material handling purposes. Although automated guided vehicles provide higher levels of flexibility and computer integrability, the installations are limited in number and one of the critical reasons lies in the complexity involved in the operation. The main objective of this research is to alleviate this problem by proposing efficient integrated operational control methods for AGV-based CIM systems. Particularly, this research is concerned with the mixed problem of dispatching automated guided vehicles and scheduling machines operation. The proposed dynamic heuristic algorithm uses various priority schemes and relevant information concerning the load of the system, the status of queues, and the position of AGVs in the scheduling process. The scheduling decision process is hierarchical in the sense that different decision criteria are applied sequentially to identify the most appropriate part to be served. This algorithm consists of two sections, the section of part selection by AGVs for the next service whenever an AGV completes the current assignment, and the section of part selection by machines for next service whenever a machine completes the current operation. The proposed algorithm has been compared with other scheduling schemes using the performance measure of mean flow-time and mean tardiness. Simulation results indicate that the proposed algorithm can reduce the mean flow-time and mean tardiness significantly.

• International journal of advanced smart convergence
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• v.13 no.2
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• pp.235-248
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• 2024

The performance of informatization differs depending on its utilization, investment and construction methods. This study analyzed the key factors affecting the performance of informatization based on a public survey on the information system operation of small and medium-sized companies in Korea. Through structural equation modeling and one-way ANOVA, the study identified the pathways leading to performance. As a result of the analysis, it was confirmed that higher levels of top management support are associated with increased information system use and performance. Similarly, higher levels of information system use are correlated with better performance of information systems. This research is significant as it investigates and reveals how top management support and information system usage work in the cases of SMEs in South Korea, which is a leading country in manufacturing. The findings of this study will provide valuable insights for SMEs, whether they have already developed an information system or plan to do so, in their efforts to enhance corporate competitiveness.

• International Journal of Safety
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• v.6 no.1
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• pp.1-6
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• 2007

Operation of human-centered robot, in general, facilitates the creation of new process that may potentially harm the human operators. Design of safety-guaranteed operation of human-centered robots is, therefore, important since it determines the ultimate outcomes of operations involving safety of human operators. This study discusses the application of geometric tolerance and head injury criteria to safety assessment of human-centered robotic operations. Examples show that extending "Work Area" has more significant effect on the uncertainty in safety than extending the system range in the presence of velocity control.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1225-1228
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• 1996

This paper describes the application area of the multimedia conference system for the electric power system operation. A variety of multimedia systems which are to be installed in the existing information communication network of KEPCO are introduced.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.583-588
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• 1989

In this paper, a modelling methodology for a robotic workcell is proposed and compared with the conventional Petri nets model. Also, a method for managing the cell operation is described through the knowledge base. The knowledge bases for state transition and assembly job information are obtained from the state transition map(STM) and the assembly job tree(AJT), respectively. Using the knowledge base, the system structure is discussed in both managing the cell operation and evaluating the various performance. Finally, a simulation algorithm is presented with the simulation results to show the effectiveness of the proposed modelling approach.

• Journal of Communications and Networks
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• v.10 no.1
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• pp.1-4
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• 2008

This paper reports the design of a multiwavelength fiber laser source that utilizes a linear cavity of hybrid Brillouin/Erbium fiber laser (BEFL). The output power, threshold power and free running cavity modes were investigated against the pump powers. The structure exhibited low threshold operation of 4 mW at 2.3 mW injected Brillouin pump power. The optimization of Brillouin pump wavelength, power and Erbium gain led to a maximum possible number of channels generated. Simultaneous and stable operation of 21 channels with 10.88 GHz channels spacing were obtained from this architecture at 1 mW injected Brillouin pump power and 90 m W Erbium doped fiber pump power in the 1555 nm region.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.67.2-67
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• 2002

$\textbullet$ Contents 1. Introduction $\textbullet$ Contents 2. Mathematical Modeling $\textbullet$ Contents 3. PID Parameter Application $\textbullet$ Contents 4. Simulations and Experiments $\textbullet$ Contents 5. Conclusions