• Journal of Korea Society of Digital Industry and Information Management
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• v.4 no.4
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• pp.103-111
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• 2008

While the demand for ASP(Application Service Provider) focused on small and medium enterprises who are fully aware of needs of ICT readiness has been increasing, those who consider to adopt ASP are wondering whether their performance would be actually successful if they did. These concerns can be an important standard of judgement, when introducing new information systems, by analyzing ROI(Return on Investment) on the current enterprises. Therefore, to review the feasibility of investing IT and measuring the performance, this study suggests a framework for ROI analysis which estimates IT investment performance, through multi-criteria approach on both financial performance index and non-financial one. We applied methodology on ASP-based IT investment performance evaluation to sample manufacturing companies under 50 employees and deduced the main implications to be considered when introducing the system.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.7
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• pp.123-130
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• 1995

This study presents model synthesis and performance investigation of a new brake system using electro-rheological(ER) fluids. Field-dependent Bingham properties characterized by non-zero yield stresses of the ER fluids are experimentally distilled. These properties are then incorporated with the governing equation of the proposed brake system which features design simplicity, fast response and salient controllability. After analyzing system performance with respect to design parameters such as electrode gap and length, an appropriate size of the brake is designed and fabricated. Both simulation and experimental works are undertaken in order to determine the feasibility and efficiency of the proposed brake system. The system performances are justified by evaluating field-dependent braking torques as well as braking times.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.1
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• pp.135-141
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• 1999

Recently, advance signal analysis which is called "Time-Frequency Analysis" has been developed. Wavelet and Wigner Distribution are used to the method. Wavelet transform(WT) is applied to time-frequency analysis of waveforms obtained by an ultrasonic pulse-echo technique. The Gabor function is adopted as the analyzing wavelet. Wavelet analysis method is an attractive technique for evolution of material characterization evoluation. In this paper, the feasibility of suppression of ultrasonic background noise signal using WT has been presented. These results suggest that ultrasonic background noise ginal can be suppressed and enhanced even for SNR of 20.8 dB. This property of the WT is extremely useful for the detecting flaw echos embedded in background noise.und noise.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.1
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• pp.22-28
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• 2018

In case of developing a combined system by a number of distributed resources with storage device, a number of application suggests a huge capacity can derive operational flexibility both power supply issues or when unexpected situation imposed. However, it is important to determine a resonable energy capacity because the device have many controversial cost issues in current power system industry. An ESS application which focusing essentially required points can induce appropriate storage capacity that required in economic operation. In this paper, a curtailment supporting algorithm based on storage device is introduced, and applied in the capacity calculation method. The main algorithm pursues handling minor exceeding quantities which can cause mechanical load at blade; This paper tries to include it for configuring hybrid algorithm with pitch control. Several fluctuating conditions are utilized in simulation to reflect critical situation. The analyzing process focuses on the control feasibility with applied capacity and control method.

• Proceedings of the Korea Association of Information Systems Conference
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• 2000.11a
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• pp.12-15
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• 2000

An SADT-based methodology is presented for systematically analyzing the container working process in container terminal, as well as an object-oriented design method for an integrated information system for container terminal resource planning and management. Our design architecture is composed of four levels, activity interface, activity PDCA control, human resource management, and facility resource management. Especially, the consideration of the human resource management level makes it possible to support cooperative tasks, to make the authority and responsibility on a task clear, and to extremely promote the balance between human and facility resources. Finally, The system architecture is suggested for Virtual Container Terminal, in which a planned container working process is simulated for previous feasibility check, work orders are transferred to control real devices, and to manage the entire process and related data.

• Journal of Information Technology Applications and Management
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• v.14 no.3
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• pp.1-14
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• 2007

Recently. interests in IT Service Management (ITSM) are increasing internationally as well as domestically. In order to realize the benefits from ITSM, it is necessary to institutionalize it as a culture of the organization through effective change management. One of the most promising approach of effective change management is a Six Sigma technique. In this study, we analyze a success case in which 6 Sigma was applied to Service Desk function which is one of the most important functions of ITSM. Through the analyses, this study aims to propose a feasible and specific approach to institutionalize ITSM. To accomplish the objective. the study analyzed specific methods of application of 6 Sigma to ITSM. performance of the project and future directions based on interview and project document/deliverable review. This study could not provide detailed performance measures due to lack of previous research on this topic and difficulty of obtaining quantitative data. However. this study has contributed to proposing a direction to institutionalize ITSM in organizations by analyzing a feasibility of 6 Sigma in implementing ITSM.

• Journal of Electrical Engineering and Technology
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• v.9 no.5
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• pp.1569-1576
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• 2014

This paper mainly proposes a direct torque control strategy to minimize torque ripple in brushless DC (BLDC) motor. BLDC motor has large current and torque ripple when one voltage vector applied in one cycle due to its low inductance. Hence, this paper proposed a hysteresis torque control with PWM mode to control the resultant torque. Moreover, when the direct torque control system is operating during the two-phase half-bridge $120^{\circ}$ conduction mode, large torque ripple in commutation area appears every 120 electrical degree. Based on analyzing the root of torque ripple in detail, lookup tables of switching devices states for new half-bridge modulation mode in the positive and negative reference torque put forwarded. Finally, simulations by MATLAB software and experiment results from DSP are presented to verify the feasibility and effectiveness of the proposed strategy operating in four-quadrant operation.

• Nuclear Engineering and Technology
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• v.46 no.1
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• pp.81-92
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• 2014

This study suggests 5 evaluation criteria (safety and technology, environmental impact, economic feasibility, social factors, and institutional factors) and 24 evaluation indicators for a NFC (nuclear fuel cycle) derived using factor analysis. To do so, a survey using 1 on 1 interview was given to nuclear energy experts and local residents who live near nuclear power plants. In addition, by conducting a factor analysis, homogeneous evaluation indicators were grouped with the same evaluation criteria, and unnecessary evaluation criteria and evaluation indicators were dropped out. As a result of analyzing the weight of evaluation criteria with the sample of nuclear power experts and the general public, both sides recognized safety as the most important evaluation criterion, and the social factors such as public acceptance appeared to be ranked as more important evaluation criteria by the nuclear energy experts than the general public.

• International Journal of Aeronautical and Space Sciences
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• v.16 no.2
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• pp.137-147
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• 2015

Hypersonic vehicles exhibit distinct dynamic and static characteristics, such as unstable dynamics, strict altitude angle limitation, large control bandwidth, and unconventional system sensitivity. In this study, compromise relations between the dynamic features and static performances for hypersonic vehicles are investigated. A compromise optimal design for hypersonic vehicles is discussed. A parametric model for analyzing the dynamic and static characteristics is established, and then the optimal performance indices are provided according to the different design goals. A compromise optimization method to balance the dynamic and static characteristics is also discussed. The feasibility of this method for hypersonic vehicles is demonstrated.

• Health Policy and Management
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• v.1 no.1
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• pp.42-53
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• 1991

Analysis of health care utilization is very important for health care policy development. Traditional studies of health care utilization were focused on measuring the level of health care utilization and on analyzing the determinants of health care utilization in the defined areas and populations. But there were some limitations in comparing the health care utilizations rates in traditional studies because so many factors were to be considered. Small area analysis is a method used to demonstrate substantial variations in health care utilization with popualtion-base use rates among similar geographic areas. This review discusses the methods, magnitude and trend of geographic variations, factors influencing small area variations, and makes suggestions for further study. Finally, the article discusses the necessity and feasibility of small area analysis in Korea.