• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.5
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• pp.415-422
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• 2009

This paper describes the UIPV(Utility Interactived Photovoltaic) system which can improve the peak-cut effect by adding energy storage device of batteries to the power converter. The proposed system has three possible operation modes depending on relative condition of PV output, which can have the power shaping function covering the peak power for 3 hours. A new power circuit and application algorithm has been applied to UIPV system which is based on working PV system during 3-hour peak time. The energy relationship by the proposed system is analyzed theoretically and experimentally. Also the proposed system is evaluated at the viewpoint of cost and total spacing, which enables the proposed UIPV system to have the reduction of the peak power demand and hence to improve.

• Journal of Electrical Engineering and Technology
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• v.13 no.3
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• pp.1060-1068
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• 2018

Droop control schemes have been widely employed in the control strategies for Multi-Terminal Direct Current (MTDC) system for its high reliability. Under the conventional DC voltage-active power droop control, the droop slope applies a proportional relationship between DC voltage error and active power error for power sharing. Due to the existence of DC network impedance and renewable resource fluctuation, there is inevitably a DC voltage deviation from the droop characteristic, which in turn results in inaccurate control of converter's power. To tackle this issue, a piecewise droop control with DC voltage dead band or active power dead band is implemented into controller design. Besides, an advanced droop control scheme with versatile function is proposed, which enables the converter to regulate DC voltage and AC voltage, control active and reactive power, get participated into frequency control, and feed passive network. The effectiveness of the proposed control method has been verified by simulation results.

• Nuclear Engineering and Technology
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• v.53 no.5
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• pp.1658-1663
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• 2021

Research on climate change and global warming on the power generation systems are rapidly increasing because of the Importance of the sustainable energy supply, thus the electricity supply since its growing share, in the end, uses energy supply. However, some researchers conducted this field, but many research gaps are not mentioned and filled in this field's literature since the lack of general statements and the quantitative models and formulation of the issue. In this research, an exergy-based model is implemented to model a set of six power generation technologies (combined cycle, gas turbine, nuclear plant, solar PV, and wind turbine) and use this model to simulate each technology's responses to climate change impacts. Finally, using these responses to define and calculate a formulation for the relationship between the system's energy performance in different environmental situations and a dimensionless index to quantize each power technology's reliability against the climate change impacts called the Pahlev reliability index (P-index) of the power technology. The results have shown that solar and nuclear technologies are the most, and wind turbines are the least reliable power generation technologies.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.5
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• pp.541-552
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• 2022

This research examines the effects of organizational learning and network involvement, as well as many contextual factors, on power generation businesses' innovation capability and operational success in Vietnam. This research also aims to attest to the moderating roles of top management support and company age, and firm possession type in the power generation industry. This study applied the exploratory factor analysis (EFA) and PLS-SEM approach for data analysis. In this research, we have tested hypotheses with data collected from 132 top managers and other key personnel from power generation companies in Vietnam. The results also attest to the moderating role of top management support on the two relationships between organizational learning - innovation capability and network involvement - innovation capability. Another important finding is that the company age has a negative impact on operational performance but shows a positive moderating role in the relationship between innovation capability and operational performance. This study highlights the central roles of organizational learning and innovation capability in impacting the organizational performance of power generation companies. These companies play a key role in supporting the development of industries in practice. This research also emphasizes the moderating roles of top management support and company age and possession type in practice.

• 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.

• Korean Journal of Social Welfare
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• v.37
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• pp.327-355
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• 1999

This study analyzes the relationship between NGOs and government assisting defecting North Korean residents and seeks a desirable model of a linkage between the two sectors. The factors used in this study for an analysis of the relationship between NGOs and government are frequency and direction of interaction between NGOs and government, government's acceptance or resistance of institutional pluralism. the degree of formality of the relationship, and the relative power balance in the relationship. Also, Coston's typology(l998) of NGO-government relationships is applied for the analysis. Results of the analysis indicates that, in resettlement assistance for defecting North Korean residents, Korean NGOs and government have a cooperative relationship at minimal level, which means that there is a low linkage, informal relationship, and asymmetrical power-relationship between the two sectors. Also, government's acceptance of institutional pluralism seems to be superficial and a tendency of one-way direction of interaction is identified. Based on the findings, this study suggests a more collaborative relationship or partnership between NGOs and the government to arrange more effective assistance programs and activities. Discussion of some controversial issues related to achieving the collaboration and suggestion of a possible model of linking government to the NGOs are followed in conclusion.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.4 no.2
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• pp.25-30
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• 1995

The shifting and steering performance of the tracked vehicle with the hydromechanical continuous variable transmission is analyzed. The simulation results are closely similar to both the vehicle test result, As a result of hydromechanical transmission simulation, power circulation in 2nd and 3rd range is maximum 142% And power flow of mechanical part has the relationship with the effeciency of the vehicle and transmission.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.1-2
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• 2011

This paper presents an educational program realized through by LabVIEW, which can explore the dependancy of the characteristics of DC-DC converters on their parameter changes By using the proposed LabVIEW program it is easy to understand the operationing principle of DC-DC converter and relationship between variables.

• Journal of the Korean Home Economics Association
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• v.25 no.1
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• pp.121-127
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• 1987

The purpose of this study was to investigate the importance of mental capacity and to see whether it can be a barometer to predict childrne's cognitive development. The instruments used were Pictoral Test of Intelligence to select homogeneous samples, Cucui Scale for their M-power and Conservation Test. The results showed that M-power develops as age increases, and it can be a strong variable to predict their cognitive development. It has been demonstrated that capacity increases developmentally but whether this reflects changes in capacity perse, or in the efficient use of that capacity is a debatable issue. More study needs to be repeated for this matter.

• Journal of the Korea Society of Computer and Information
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• v.25 no.9
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• pp.133-141
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• 2020

This study was conducted to investigate the relationship between sexual consciousness, marriage consciousness, birth consciousness and pre-parent role of college students.,The subjects of this study were college students attending B,K University located in B city and the significance level(α) 0.05, power(1-) 0.8, effect size(fz) was verified in ANOVA using G-POWER 3.1.9.2 program.,The results of the study showed that the average score of sexual consciousness was 2.91±0.43, the marriage consciousness was 3.27±0.40, the birth consciousness was 3.32±0.43, and the pre-parent role was 3.35±0.35. When examining the relationship between sexual consciousness, marriage consciousness, birth consciousness, and pre-parent role according to the general characteristics of the subjects, sexual consciousness showed significant differences according to gender (t=6.910, p<.001), age (F=3.032 p=.030), major (F=5.402, p=.005), and parental orientation (F=2.801, p=.027).,The marriage consciousness of college students showed significant difference according to family members, and the birth consciousness showed significant difference according to grade and family members, and the role of pre-parents was significant according to grade and family members.,The role of pre-parents of college students showed significant correlations in sexual consciousness, marriage consciousness, and birth consciousness.,Repeated studies on the role of pre-parents based on parent-child relationship are needed, and studies are required to identify the relationship between sexual consciousness, marriage consciousness, birth consciousness, and pre-parent role.