• Magazine of the Korean Society of Agricultural Engineers
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• v.37 no.E
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• pp.1-9
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• 1995

It is shown that two step power transformation is more efficient for the normalization of frequency distribution with the coefficient of skewness of zero in comparison with others including SMEMAX and power transformations. It is confirmed that the design low flows calculated using power and two step power transformations used in this study are generally nearer to the observed data as compared with those of SMEMAX transformation at all return periods in the applied watersheds of the Kum, Naktong and Yongsan rivers in Korea.

• Journal of Power Electronics
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• v.11 no.5
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• pp.734-742
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• 2011

In this paper a robust method is presented for the combined design of STATCOM and Power System Stabilizer (PSS) controllers in order to enhance the damping of the low frequency oscillations in power systems. The combined design problems among PSS and STATCOM internal ac and dc voltage controllers has been taken into consideration. The equations that describe the proposed system have been linearized and a Fuzzy Logic Controller (FLC) has been designed for the PSS. Then, the Particle Swarm Optimization technique (PSO) which has a strong ability to find the most optimistic results is employed to search for the optimal STATCOM controller parameters. The proposed controllers are evaluated on a single machine infinite bus power system with the STATCOM installed in the midpoint of the transmission line. The results analysis reveals that the combined design has an excellent capability in damping a power system's low frequency oscillations, and that it greatly enhances the dynamic stability of power systems. Moreover, a system performance analysis under different operating conditions and some performance indices studies show the effectiveness of the combined design.

• Nuclear Engineering and Technology
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• v.55 no.5
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• pp.1901-1910
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• 2023

The safety-class (1E) digital control system (DCS) of nuclear power plant characterized structural multiple redundancies, therefore, it is important to quantitatively evaluate the reliability of DCS in different degree of backup loss. In this paper, a reliability evaluation model based on T-S fuzzy fault tree (FT) is proposed for 1E DCS of nuclear power plant, in which the connection relationship between components is described by T-S fuzzy gates. Specifically, an output rejection control system is chosen as an example, based on the T-S fuzzy FT model, the key indicators such as probabilistic importance are calculated, and for a further discussion, the T-S fuzzy FT model is transformed into Bayesian Network(BN) equivalently, and the fault diagnosis based on probabilistic analysis is accomplished. Combined with the analysis of actual objects, the effectiveness of proposed method is proved.

• Journal of Energy Engineering
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• v.25 no.1
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• pp.108-112
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• 2016

This study is established the data-centric design concept, which is the latest design technique, by analyzing existing study literature for its application on the nuclear power plant industry in Korea. This study investigated the data-centric design cases in the advanced companies and suggests a data-centric design integrated system framework by analyzing the major functions of the commercial 3D CAD system, which is globally used in the plant architect engineering. In order to apply the data-centric design integrated system framework to the nuclear power plant industry in Korea, the main functions of a nuclear power plant design information integrated system framework, which can manage the design products of each EPC step and the related information in integrated way, is suggested by analyzing the supplier design, field design process and field design drawings, which have close relation with the plant Architect Engineering (A/E). It is expected that the result of this study would contribute in the dramatic enhancement in the job efficiency of nuclear power plant design process in Korea.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.480-484
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• 2000

The pole placement technique for control design of the current mode controlled DC-DC switchmode power converter is proposed. It is compared with conventional transfer function analysis. Using the pole placement technique control design automation algorithm, by computer-based tool is presented. Control design example with large signal simulation is shown.

• Journal of Aerospace System Engineering
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• v.8 no.1
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• pp.42-47
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• 2014

The role of Electrical Power Subsystem (EPS) is to generate a power and distribute it to the electrical devices for the system operation. For on-orbit operation of cube satellite, it is also necessary to supply power to on-board mission devices as commercial satellite does. Recently, commercial EPS products dedicated for the cube satellite application has been developed and widely used for the power subsystem design. In this paper, a permanent magnet attitude stabilization method without external power has been introduced because it has advantage from power consumption point of view and the EPS design of cube satellite by applying the commercial EPS products has been introduced and investigated. This paper also deals with the specification of the commercial EPS products for the beginner of the cube satellite design.

• 한국연소학회:학술대회논문집
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• 2013.06a
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• pp.15-17
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• 2013

In the design of combined cycle power plants, the design parameters considered mainly could be changed and added for performance evaluation with change on the design objective and method. Therefore, the design criteria considering the different objectives and type of power plant were needed. Thermodynamic and economic analyses of various types of gas turbine combined cycle power plants with demand on generation of power and heat and carbon capture system from high pressure flue gas have been performed to establish criteria for optimization of power plants.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1756-1758
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• 2005

This paper deals with the power conversion and design of permanent magnet generator for wind power applications. This paper derives analytical solutions for open-circuit field, armature reaction field, torque, back-emf, inductance and resistance of permanent magnet generators for wind power applications. And then, by presenting the variation of torque according to design parameters and by applying restrict conditions to it, we determine proper design parameter appropriate to rated power and speed. Finally, this paper also presents power conversion system resonable in wind power applications.

• KEPCO Journal on Electric Power and Energy
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• v.5 no.3
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• pp.181-188
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• 2019

In this study, the Heat & Mass balance design optimization tool has developed by linking the design input/output variables with the Heat & Mass balance calculation solver and optimization algorithm and also automating the iterative calculation process. As a result of testing this optimization tool for 10 kinds of power plant, it was expected to improve the NPV and IRR compared with general design methods.

• Journal of Biosystems Engineering
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• v.22 no.2
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• pp.105-116
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• 1997

Using the design variables and conditions reported in the rut part of this paper, an analysis and optimum design of the tractor-rotary power driveline were carried out. The optimum design method involved 1 variable, 2 variable and multiple variable analysis performed as requested in the design process. In order to evaluate the effects of the design variables on the power transmission performance a sensitivity analysis were also conducted. the results indicated that the length and link point of the upper link, the upper hitch point of the implement master and the location of the implement input connection affect most significantly the driveline performance. The optimum design improved the performance of an exampled tractor-rotary driveline by 93% in terms of cosine ratio.