• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.406-408
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• 2000

Recently, Korea's electric industry is in the midst of a period of profound changes in the structure and function, including the introduction of market competition in the generation sector. Therefore, it is difficult to promote long-term capacity planning and new generating capacity construction which have been driven by KEPCO so far, after the introduction of market competition, so new generating capacity construction and security of reserve margin is needed through self·regulation plan of private generation producers by market mechanism. According to the competition in the generation sector, a new paradigm is necessary to the long-term capacity planning driven by the Government. This paper analyzes the plan and the incentive level able to guide the new generation capacity construction considering the uncertainty risk in a period of introduction of competition. In addition, this paper analyzes the plan able to guide the new capacity construction by market function at the stage which market become established and Government's role to solve the anxiety about the capacity supply and demand.

• Journal of Engineering Education Research
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• v.20 no.5
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• pp.23-33
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• 2017

It is examined that how flipped learning and mind-wandering affect an idea generation task. For the purpose, the participants in the idea generation task are divided into two groups to learn SIT(Systematic Inventive Thinking) and BCC(Business Creativity Codes) as idea generating tools in advance. One group learned the tools in a classroom, and the other group through an online education program. The creativity level of an idea is evaluated in the dimensions of originality, practicality, and realizability. The creativity levels of the ideas from the two groups are not statistically different in all the three creativity dimensions. To examine the effect of mind-wandering, another group generated ideas two hours a day in four days instead of eight hours in one day. The creativity levels of the ideas from the third group are higher in the dimensions of originality and practicality. This shows that the effectiveness of flipped learning is not so different from the face-to-face learning in a classroom, and mind-wandering has a positive effect in the learning.

• Journal of Distribution Science
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• v.12 no.3
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• pp.55-63
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• 2014

Purpose - This study aims to examine differences in donation behavior as surrogates of prosocial consumption behavior among three generation types. Further, it attempts to examine the moderator roles that affect donation behavior influenced by the difference in generations. Research design, data, and methodology - This study used the statistical ANOVA technique to examine generational difference. Surveys were structured differently by ages, as 20th, 30th, 40th, 50th, 60th, and 70th to classify generations into each group. A survey to measure the psychological distance was performed to identify whether the respondents intended to donate to a domestic or overseas target. Results - First, subjective judgment of psychological distance has no effect on objective donation behavior. Second, though the result of the relationship with moral identity is not statistically significant, it provides evidence that a higher moral identity level possesses more donation behavior. Further, groups with higher symbolization tend to donate more than the others. This was especially evident among the young and baby boomer generation. Conclusion - This empirical study suggests that marketers need to differentiate the market segment of the baby-boomer generation with high purchasing power of prosocial consumption.

• Environmental and Resource Economics Review
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• v.19 no.1
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• pp.3-21
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• 2010

By the significant structural change in 1999, a partial privatization has occurred in Korean fossil-fuel power generation sector. Under the current price scheme wholesale electricity price is dependent on output size, and hence, may not satisfy the assumption of price-taking producers. The purpose of our study is constructing the productivity change measurements of Korean power generation sector taking into account possibly imperfect competition and variable returns to scale. Our approach based on Harrison (1994) and Levinsohn (1993) derives the plant-level productivity measurements of the period between 2001 and 2007, as well as the measurements of mark-ups and returns to scale. It is shown that the mark-up size is dependent on the plants' fuel type and is decreasing over time. Allowing for imperfect competition and variable returns to scale adjusts the productivity measurements substantially.

• Toxicological Research
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• v.22 no.4
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• pp.397-402
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• 2006

Lipid mediator such as lysophosphatidic acid (LPA) plays an important role in inflammation and wound heating, has been recently reported to induce influx of extracellular calcium into erythrocytes. This elevation in intracellular calcium level may cause destruction of membrane asymmetry and procoagulant microvesicle formation. Thus, we investigated if the lipid mediator could induce microvesicle formation as a result of extracellular calcium influx in human erythrocytes. Treatment with lipid mediator to erythrocytes resulted in microvesicle generation In a concentration-, time-dependent manner. Microvesicles formed expressed procoagulant phosphatidylserine (PS) on their surface membrane significantly as well. LPA did not affect the band 3 phosphorylation which is involved in morphological change in erythrocytes. Pretreatment with suramin did not inhibit LPA-induced microvesicle generation, suggesting microvesicle generation was not receptor-dependent pathway. Depletion of intracellular ATP levels in erythrocytes was suggested to be one of the mechanism for these events.

• Journal of Animal Environmental Science
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• v.21 no.3
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• pp.93-98
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• 2015

The objective of this study was to review application of next-generation sequencing (NGS) to investigate microbiome in the livestock sector. Since the 16S rRNA gene is used as a phylogenetic marker, unculturable members of microbiome in nature or managed environments have been investigated using the NGS technique based on 16S rRNA genes. However, few NGS studies have been conducted to investigate microbiome in the livestock sector. The 16S rRNA gene sequences obtained from NGS are classified to microbial taxa against the 16S rRNA gene reference database such as RDP, Greengenes and Silva databases. The sequences also are clustered into species-level OTUs at 97% sequence similarity. Microbiome similarity among treatment groups is visualized using principal coordinates analysis, while microbiome shared among treatment groups is visualized using a venn diagram. The use of the NGS technique will contribute to elucidating roles of microbiome in the livestock sector.

• Journal of Korean Elementary Science Education
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• v.33 no.3
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• pp.566-578
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• 2014

The purpose of this study is to develop a program for elementary school students' scientific experimental design knowledge generation. This study also investigated the effects of their experimental design ability, as well as the change in the type and elaborateness of their experimental design by applying the program. The subjects of this study was 4 classes in 6th grade of an elementary school located in Seoul, KOREA. The classes were divided into experimental and comparative groups. While the treatment was applied to the experimental group, the comparative group was taught using conventional methods. The pre-test and post-test for students' capability of building scientific experimental design knowledge were conducted to compare the ability of experimental design, the change in the type and elaborateness of experimental design. The findings in this study are as follows: First, the program appeared to be effective in improving experimental design ability. Furthermore, the program appeared to be more effective in generating a higher level of the experimental design type and elaborateness. Therefore, in order to improve experimental design knowledge generation ability, the program can be utilized as effective learning model in elementary school.

• Journal of Electrical Engineering and Technology
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• v.13 no.2
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• pp.540-549
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• 2018

This paper proposes the method of active distribution network expansion planning considering distributed generation integration and distribution network reconfiguration. The distribution network reconfiguration is taken as the expansion planning alternative with zero investment cost of the branches. During the process of the reconfiguration in expansion planning, all the branches are taken as the alternative branches. The objective is to minimize the total costs of the distribution network in the planning period. The expansion alternatives such as active management, new lines, new substations, substation expansion and Distributed Generation (DG) installation are considered. Distribution network reconfiguration is a complex mixed-integer nonlinear programming problem, with integration of DGs and active managements, the active distribution network expansion planning considering distribution network reconfiguration becomes much more complex. This paper converts the dual-level expansion model to Second-Order Cone Programming (SOCP) model, which can be solved with commercial solver GUROBI. The proposed model and method are tested on the modified IEEE 33-bus system and Portugal 54-bus system.

• Journal of the Korean Solar Energy Society
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• v.31 no.6
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• pp.49-56
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• 2011

In this study a novel cogeneration system driven by low-temperature sources at a temperature level below $190^{\circ}C$ is investigated by first and second laws of thermodynamics. The system consists of Organic Rankine Cycle(ORC) and an additional heat generation as a parallel circuit. Seven working fluids of R143a, R22, R134a, R152a, $iC_4H_{10}$(isobutane), $C_4H_{10}$(butane), and R123a are considered in this work. Maximum mass flow rate of a working fluid relative to that of the source fluid and optimum turbine inlet pressure are considered to extract maximum power from the source. Results show that due to a combined heat and power generation, both the efficiencies by first and second laws can be significantly increased in comparison to a power generation, however, the second law efficiency is more resonable in the investigation of cogeneration systems. Results also show that the working fluid for the maximum system efficiency depends on the source temperature.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.3
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• pp.513-521
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• 2017

Robust optimal operation of a microgrid is required since the increase of the penetration level of renewable generators in the microgrid raises uncertainty due to their intermittent power output. In this paper, an application of probabilistic optimization method to economical operation of a microgrid is studied. To simplify the treatment of the uncertainties of renewable generations and load, the new 'band of virtual equivalent load variation' is introduced considering their uncertainties. A simplified robust optimization methodology to generate the scenarios within the band of virtual equivalent load variation and to obtain the optimal solution for the worst scenario is presented based on Monte Carlo method. The microgrid to be studied here is composed of distributed generation system(DGs), battery systems and loads. The distributed generation systems include combined heat and power(CHP) and small generators such as diesel generators and the renewable energy generators such as photovoltaic(PV) systems and wind power systems. The modeling of the objective function for considering interruption cost by the penalty function is presented. Through the case study for a microgrid with uncertainties, the validity of proposed robust optimization methodology is evaluated.