• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.3
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• pp.64-74
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• 2014

We show how a supplier can peg cost measures to the reliability of his time guarantees via the penalty costs considered in the framework. The framework also enables us to study the connections between the logistics network and the market. In this context, we show that even when the market base increases significantly, the supplier can still use the logistics network designed to satisfy lower demand density, with only a marginal reduction in profit. Finally we show how the framework is useful to evaluate and compare various logistics system improvement strategies. The supplier can then easily choose the improvement strategy that increases his profit with the minimal increase in his logistics costs.

• Journal of Information Technology Applications and Management
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• v.22 no.1
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• pp.109-130
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• 2015

This study aims to provide the results of a case study, based on the action research approach, in which an user-oriented management system for enterprise information systems operational performance is successful developed and applied. This study performs the research and summarizes the results by adopting 5-step approach of action research, i.e., diagnosing, action planning, action taking, evaluating and specifying learning. The most important lessons learned from the study include (1) operation performance measures should be established to be shared by the management and users; (2) evaluation and improvement activities should be performed continually; and (3) formula to calculate the measure should be evolved so that improvement initiatives can be identified. The results of the study are expected to provide the companies intending to develop a management system for enterprise information systems operational performance with the practical and useful information. In addition, it is expected to suggest the research results that can be utilized as a basis for future research in this area.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.567-571
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• 1989

This paper describes the improvement of thermal power plant turbine control system by analyzing nonlinear characteristics. The turbine control depends on the frequency variation and boiler condition. The nonlinearity of turbine control is the result of governor/valve properties, steam condition and boiler thermal unbalance. Nonlinear analysis is divided into two; main steam valve position - turbine output anal governor response. Of course, every analysis must be done on considering plant operating condition. In this paper, after analyzing turbine control nonlinearity by numerical method and actual results, the sensitive operating load which corresponds to frequency is proposed, on guarranteed boiler stability. This idea is implemented at Pyung Tack thermal power plant, and the practical results are showed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.189-193
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• 2001

The performance of printer can be determined by the printing speed, noise level, printing quality which includes the resolution, regularity of printed matter and etc. Among them, printing quality mostly depends on the irregularity of the line spacing and dot size. The irregular line spacing and dot size in laser beam printer are mainly from the jitter which comes from the vibration of Organic Photo Conductive(OPC) drum and the Laser Scanning Unit(LSU). Jitter due to the vibration of LSU appears as high-frequency component which occurs 100-300$\mu\textrm{m}$ interval in printed matter and the causes of it can be estimated as the vibration of polygon motor, case, reflecting mirror and etc. In this paper, vibration characteristics of the LSU under development are investigated and the strategy for improvement of the dynamic characteristics is established and its validity is demonstrated.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2005.03a
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• pp.469-476
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• 2005

To date, many viable smart base isolation systems have been proposed. In this study, a novel friction pendulum system (FPS) and an MR damper are employed as the isolator and supplemental damping device, respectively. A fuzzy logic controller (FLC) is used to modulate the MR damper. A genetic algorithm (GA) is used for optimization of the FLC. The main purpose of employing a GA is to determine appropriate fuzzy control rules as well to adjust parameters of the membership functions. To this end, a GA with a local improvement mechanism is applied. Neuro-fuzzy models are used to represent dynamic behavior of the MR damper and FPS. Effectiveness of the proposed method for optimal design of the FLC is judged based on computed responses to several historical earthquakes. It has been shown that the proposed method can find appropriate fuzzy rules and the GA-optimized FLC outperforms not only a passive control strategy but also a human-designed FLC and a conventional semi-active control algorithm.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.284-286
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• 1995

The most common for starting a single phase induction motor is to install a starting condenser and a centrifugal switch in series with the auxiliary winding. Though this method is simple, life of single phase induction motor is short because of malfunction of a starting condenser and a centrifugal switch and efficiency improvement has limitation. In this paper, the starting characteristics of SPIM is improved by voltage and phase control strategy of auxiliary winding in removing a starting condenser and a centrifugal switch. Finally, the excellent starting performance of SPIM is shown through simulation and experimental results.

• Journal of the Society of Disaster Information
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• v.2 no.1
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• pp.113-127
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• 2006

The suggestions that follow are about the Qualitative Improvement of private security Industrial. First, in legal and institutional policy, new establishment by law for private security and more support from government is asked. Moreover, the restructuring or M&A between petty companies and the pricing for security service should be performed. Second, in the structural aspect of private security industry, the professional education center for private security guards should be established and the terms of payment and welfare should be improved to the level above standard. In addition, it should be achieved to change the public to have a new and correct understanding of private security and develope the specialized parts suited to the characteristic and ability of each companies. Third, the construction of operating system for private security service should be achieved; recruit system for competent security guards, marketing strategy and enforcement system, widely known confidence to client, normal training system for security guards and post management system for client. This is also to be suited to the characteristic of each companies.

• Korean Journal of Organic Agriculture
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• v.17 no.3
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• pp.327-345
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• 2009

Environment-friendly agricultural products market has been experiencing various change through the quantitative growth in Korea. The food safety is considered seriously and the interest of the consumer is increasing about environment-friendly agricultural products and organic agricultural products. Environment-friendly agricultural products is encouraged in the link of the counter-measure which follows in the market opening. This research aims at making shorter the distance between the productive person and the consumer and to improve the income for organic farm and the price competitiveness for Environment-friendly agricultural products through the present condition analysis for organic produce's production, distribution and consumption market. To solve the problems above, the development of strategies for the establishment of distribution system for the organic produce's stable supply and the improvement of price competitiveness, the establishment of the cooperating system on the produce's demand and supply, the improvement of consumer's reliability by reinforcement with connectivity and transparency of the process, and the vitalization of regional economy and the exchange of rural and city area are needed.

• Journal of Korean Society for Atmospheric Environment
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• v.8 no.4
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• pp.262-268
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• 1992

The trend of international concerns on environmental conservation and domestic demand of ambient air quality improvement, specially on sulfur dioxide level has resulted in the establishment of mid-term strategy of environmental improvement and stepwise strengthening of emission regulations in this decade in Korea. Development of flue gas desulfurization(FGD) process is becoming an essential task to be accomplished especially for the power plants and large industrial facilities. This study is an initial stage researc focusing on the mass transfer principles in wet type FGD process and the effects of operating variables of a jet bubbling scrubber utilizing limestone slurry on sulfur dioxide removal efficiency. Experimental results showed this type of scrubbing system has some advantages in terms of mass transfer mechanism and removal efficiency. More rigorous research is needed for the reaction system and the comparison with existing FGD processess for the possible development of a process which is compatative in view of installation cost and treatment of by-products.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.161-164
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• 1988

The purpose of this paper is to propose a simple firmware realization of PCM framing system, which exploits LSI memories for performance improvement and hardware simplification. The proposed system simply consists of a tapped delay line for simultaneous observation of in framing-bits and ROM programmed sequence controller for framing process. Perpormance analyses are made in terms of misframe interval, sync-loss-detection time and reframe time. The proposed strategy proved to be significantly better in reframe time, stability and hardware implementation.