• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.4
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• pp.83-88
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• 2013

Recently, PCCI (premixed charge compression ignition) combustion is studied to reduce both NOx and PM because of homogeneous mixture formation and lower combustion temperature. It has also merit of increasing thermal efficiency owing to better air-fuel mixure. However, it is well known that PCCI combustion has a weakness in fuel economy because PCCI combustion tends to start before TDC. Therefore, it is necessary to find an optimal conditions for PCCI combustion which maintains reduction of NOx, PM and increase of thermal efficiency. In this study, pPCCI combustion was realized by adding early injection strategy to a conventional diesel engine. In addition, the characteristics of pPCCI combustion was analized by comparing conventional diesel injection strategy. The results show that NOx and PM per power in pPCCI combution were reduced compared to a conventional diesel combustion.

• Journal of Korean Elementary Science Education
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• v.33 no.4
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• pp.700-709
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• 2014

The purpose of this study was to examine the effects of question-generating strategy on science academic achievement, scientific attitude in elementary science class. To examine the effects of question-generating strategy this learning materials were applied to elementary science curriculum, and an experimental group and a control group were selected from $5^{th}$ graders at H elementary school located in Gyeonggi-do. Students were taught for 6 weeks. Control group take traditional lessons and solve questions presented textbook. Question generated group generate questions, solve them and feed back by themselves. The results of this study were found statistically significant difference in the pupil's enhancement of the science academic achievement, scientific attitude (p<.05). Thus question-generating strategy for elementary science inquiry instruction that has a positive effect on interests in class is useful and better be widely applied to science education.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.4
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• pp.202-211
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• 2014

Pairs trading is a type of arbitrage investment strategy that buys an underpriced security and simultaneously sells an overpriced security. Since the 1980s, investors have recognized pairs trading as a promising arbitrage strategy that pursues absolute returns rather than relative profits. Thus, individual and institutional traders, as well as hedge fund traders in the financial markets, have an interest in developing a pairs trading strategy. This study proposes pairs trading rules (PTRs) created from a price ratio between securities (i.e., stock index futures) using rough set analysis. The price ratio involves calculating the closing price of one security and dividing it by the closing price of another security and generating Buy or Sell signals according to whether the ratio is increasing or decreasing. In this empirical study, we generate PTRs through rough set analysis applied to various technical indicators derived from the price ratio between KOSPI 200 and S&P 500 index futures. The proposed trading rules for pairs trading indicate high profits in the futures market.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.6
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• pp.603-606
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• 2005

Ralstonia eutropha NCIMB 11599 and ATCC 17699 were grown, and their productions of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] compared. In flask cultures of R. eutropha NCIMB 11599, cell concentration, P(3HB-co-4HB) concentration and polymer content decreased considerably with increases in the ${\gamma}-butyrolactone$ concentration, and the 4HB fraction was also very low (maximum 1.74 mol%). In fed-batch cultures of R. eutropha NCIMB 11599, glucose and ${\gamma}-butyrolactone$ were fed as the carbon sources, under a phosphate limitation strategy. When glucose was fed as the sole carbon source, with its concentration controlled using an on-line glucose analyzer, 86% of the P(3HB) homopolymer was obtained from 201g/L of cells. In a two-stage fed-batch culture, where the cell concentration was increased to 104g/L, with glucose fed in the first step and constant feeding of ${\gamma}-butyrolactone$, at 6g/h, in the second, final cell concentration at 67h was 106g/L, with a polymer content of 82%, while the 4HB fraction was only 0.7mol%. When the same feeding strategy was applied to the fedbatch culture of R. eutropha ATCC 17699, where the cell concentration was increased to 42 g/L, by feeding fructose in the first step and ${\gamma}-butyrolactone$ (1.5g/h) in the second, the final cell concentration, polymer content and 4HB fraction at 74h were 51g/L, 35% and 32 mol%, respectively. In summary, R. eutropha ATCC 17699 was better than R. eutropha NCIMB 11599 in terms of P(3HB-co-4HB) production with various 4HB fractions.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.67 no.4
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• pp.208-213
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• 2018

In this paper, we studied the control strategy of applying STATCOM(static synchronous compensator) to mitigate the FIDVR(fault induced delayed voltage recovery) phenomenon. The proportion of motor loads is gradually increasing which might affect power system stability. Excessive reactive power consumption by the stall of the motor loads causes FIDVR phenomenon. In addition, the low inertia of the small HVAC(heating, ventilation and air conditioner) unit will not separate itself in the event of a contingency, causing system instability. For this reason, we have developed a control strategy that utilizes STATCOM efficiently through static and dynamic analysis. Case studies on a Korean power system have validated the performance of the proposed scheme under severe contingency scenarios. The results have verified that the proposed strategy can effectively mitigate FIDVR and improve the stability and reliability of the system.

• The Journal of the Convergence on Culture Technology
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• v.7 no.4
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• pp.27-34
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• 2021

This study is a descriptive research study to understand the effects of successful aging and SOC coping strategy on quality of life in middle-aged women. The study subjects were middle-aged women (40~65years old) across the country, and data were collected using a structured questionnaire. The collected data were analyzed by descriptive statistics, Independent t-test, one-way ANOVA, Pearson's correlation, and stepwise multiple regression using SPSS WIN/PC 24.0 statistics program. The study found that successful aging of middle-aged women, SOC alternative strategies and quality of life were statically correlated, and statistical significance was identified in order of successful aging(β=.41, p<.001) and SCO coping strategies(β=.17, p=.047) as variables describing quality of life. In this study, the explanatory power by the two variables was 24.7%. Therefore, in order to improve the quality of life of middle aged women, it is necessary to study and program programs to enhance the SOC coping strategy of successful aging.

• Analytical Science and Technology
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• v.8 no.4
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• pp.1075-1078
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• 1995

This paper describes how industry has responded to the environmental challenge. Benefits include compliance with environmental legislation; genuine reductions to environmental impact; sustainable improvements to profitability in the face of increased competitive pressure. National and international Standards for environmental management offer security and direction for a company wishing to improve environmental performance and coupled with a waste minimisation strategy many financial and environmental benefits can be achieved. Introduction of new technical skills, techniques and worker understanding to aid motivation is an essential component of such a strategy. Monitoring and targeting has a key role to play in the establishment of improved environmental performance.

• Journal of Korean Clinical Health Science
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• v.8 no.2
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• pp.1450-1461
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• 2020

Purpose: The purpose of this study was to understand the degree of nursing professional intuition, major satisfaction, clinical practice satisfaction, self-leadership, and career preparation behavior of nursing college students, and to identify factors that influence career preparation behavior. Method: This study was a descriptive research study to analyze the factors affecting career preparation behavior. The data collection period was from August 03 to 30, 2020 for 4 weeks. The survey conducted an online survey of 220 students in grades 3-4 who were enrolled in 6 nursing departments located in P metropolitan city and G province, and have clinical practice experience. The collected data were analyzed using SPSS Win 20.0 program. Results: Career preparation behavior had a significant positive correlation with nursing professional intuition(r=.455, p<.001) and self-leadership(r=.539, p<.001), and major satisfaction(r=-.337, p<.001) and clinical practice satisfaction(r=-.380, p<.001) had a significant negative correlation. Self-leadership(β=.424, p<.001) was the most significant factor influencing the study subjects' career preparation behavior, nursing professional intuition(β=.170, p=.010), clinical practice Satisfaction(β=.127, p=.047), employment information(β=.122, p=.023), major satisfaction(β=.137, p=.042) in the order, these variables were found in the order of The explanatory power of the factors affecting the subject's career preparation behavior was 40.2%. Conclusion: Therefore, in order to help nursing students' career preparation behavior, a strategy to provide a variety of employment information and a strategy for nursing intervention that can improve self-leadership, clinical practice satisfaction, and major satisfaction is required.

• Journal of Appropriate Technology
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• v.5 no.2
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• pp.97-105
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• 2019

Most of the BoP (Base of the Pyramid) do not have the economic power to eat balanced nutrients. Therefore, the solution is to add essential nutrients to the food you eat. This method can improve nutrition without putting an economic burden on the BoP classes. The aim of the paper is to apply the strategic management process for analysing BoP solutions in nutrition improvement sector. This allows identification of critical aspects in developing BoP solutions. This includes reaching sustainability related objectives. Two cases (Ajinomoto, Grameen Danone) covering both products and services have been researched, allowing a contribution towards the applicability of strategic management in respective situations. In this study, we analyzed the case through the "Appropriate Technology 2.0" framework of Polak and Warwick (2014). In addition, we introduced the strategy of BoP business. Based on the results of this analysis, we analyzed the success factors of appropriate technology business in the emerging markets through the 4A model.

• (The)Study of the Eastern Classic
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• no.73
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• pp.249-279
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• 2018

This paper analyzes the 'strategy' of Sunzi's art of war and verifies the modern application value of it by combining the 'strategy' of the art of war with modern enterprise management. The army adopts 'war strategy' with the aim of minimizing the loss and sacrifice caused by the war and winning in the shortest time. Enterprise aims to maximize profits at the lowest cost and adopt 'business strategy'. Three factors of art of war's strategic, the 'power', 'adaptation', 'trickery', are similar to the 'internal resources analysis', 'external environment analysis' and 'information management' of the modern enterprise's management. In the process of establishing strategic plan, the art of war emphasizes 'strategy of winning' including 'prophet', 'estimates' and 'maneuvering', in the modern enterprise management, 'prophet' is shown as 'competitor analysis' of the '3C analysis' and 'benchmarking learning'. 'Estimates' is shown as 'SWOT analysis' and '4P's analysis'. 'Maneuvering' is shown as 'market positioning strategy' and 'market preemption strategy'. In the stage of implementing the strategy, 'surprise attack strategy', 'strategy of void and actuality' and 'dividing and integrating strategy' of the art of war are shown as follows in modern enterprises ; 'Surprise attack strategy' is shown as 'differentiation strategy' and 'concentration strategy', 'Strategy of void and actuality' is shown as 'information management' and 'rational market positioning strategy'. 'Dividing and integrating strategy' is shown 'diversification strategy', 'concentration strategy', 'change management', 'basic competition strategy', 'synergy effect' and etc. In terms of strategic results, the 'victory of war' of the art or war is shown as 'competitive advantage' and 'maximization of profits' in modern enterprise management strategy. In a word, although there are different names and expressions between the strategy of Sunzi's art of war and modern enterprise, but their connotation is the same. We can see that the art of war which was written in about B.C.500, has left a high utilization value for modern enterprise in rapid environmental change and intense competition.