• 한국지하수토양환경학회지:지하수토양환경
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• 제16권6호
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• pp.10-18
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• 2011

This study presents a state of the art in evaluation on naturally occurring asbestos (NOA) areas and effective strategies for investigation and management of NOA areas in Korea. First of all, we defined and classified the NOA area as compiling various countries' regulations, then discussed the best methods for evaluation and management of NOA for reducing exposure of asbestos in the vicinity of NOA areas. According to the literature survey, a three-steps management strategy was suggested in this study. The first step is a confirmation stage of asbestos contamination possibility and the second step is an assessment stage of asbestos contamination using investigation, analysis, evaluation and reclamation. The final step is a following-up control stage. These three management steps for NOA area will give the maximum effectiveness of NOA control in Korea.

• International Journal of Contents
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• 제13권4호
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• pp.1-11
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• 2017

This paper studies the effect of flipping the classroom in undergraduate physics classes using English as the medium of instruction (EMI). Data on student use of learning strategies, course satisfaction level and perceptions of the flipped classes were collected through a survey including close-ended and open-ended questions. The sample size was 71 students in flipped classes, with 60 students in non-flipped classes used as a control group (total N=131). It was found that students in the flipped classes showed greater intrinsic goal orientation (p<.05), control of learning beliefs (p<.05), and use of critical thinking (p<.01) than those in the non-flipped classes. While the survey highlighted problems of student engagement with the pre-class activities, students who had previous experience with online classes committed more time to pre-class, suggesting that engagement may improve with exposure to blended learning. It is concluded that the flipped classroom helps students develop their identities as self-directed learners, but that more support is necessary for weaker students in the EMI context. Implications are drawn for the content design of flipped EMI classrooms.

• 한국잡초학회지
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• 제12권1호
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• pp.86-87
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• 1992

• 한국산학기술학회논문지
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• 제16권10호
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• pp.6759-6765
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• 2015

본 연구에서는 자연외기를 활용하여 건물의 중앙냉방시스템에 대한 에너지를 절약하기 위한 제어방법으로서 외기온도 조건을 고려한 나이트 퍼지제어의 적용방안에 대해 시뮬레이션 연구가 수행되었다. 외기온도의 변화특성 및 건물의 축냉성능 등이 고려되었으며, 나이트 퍼지제어를 위한 운전시작시간과 제어설정온도의 선정방안이 연구되었다. 본 연구를 위하여 TRNSYS 프로그램을 활용하여 시스템 해석 모델링을 수행하였으며, 기존 제어방식 대비 제안된 제어방법의 에너지 절약성능을 비교 분석하였다. 연구결과로 외기온도 변화에 따라 나이트 퍼지제어를 위한 운전조건을 선정한 제안된 제어방법이 기존의 나이트 퍼지제어 제어방식과 비교하였을 때는 최대 16.8%, 나이트 퍼지제어를 적용하지 않은 경우에 비해서는 최대 28.6%의 에너지 절감이 가능함을 알 수 있었다.

• 농업과학연구
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• 제29권2호
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• pp.109-121
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• 2002

In the near future information technology will make more extensive applications to agricultural marketing system through e-commerce system. This paper is to investigate the current trends of e-commerce in agricultural marketing and suggest strategies for increasing agricultural product sales at the farm level as follows ; 1) price and quality control for attracting customers 2) increasing brand power for marketing promotion, and 3) devising more convenient website for internet users.

• 가족자원경영과 정책
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• 제1권1호
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• pp.17-26
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• 1997

The purpose of this study was to investigate the effects of two variable groups(socio-demographic factors and psychological factors) on money management strategies and financial satisfaction. The major findings of this study are as follows : Household income, level of education of wives, and locus of control had significant effect on the level of financial satisfaction. After the effect of socio - demographic variables and psychological variables was controlled, Especially evaluating strategy was found to be the most powerful variable in explaining financial satisfaction.

• 유통과학연구
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• 제12권8호
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• pp.43-54
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• 2014

Purpose - This study was based on a theoretical consideration of the structural relationship between the support and control of the franchisor and the satisfaction and strategic response (voice, loyalty, exit, neglect) of the franchisee. First, based on the preceding research, this study systematically organized the type of support and control of the franchisor. Second, the study examined the effects of a franchisor's support and control on the expectancy disconfirmation between affiliated franchisees' expectations before a franchise agreement and performance after operating an affiliated store. Third, the study looked into the effects of expectancy disconfirmation relating to a franchisor's support and control on an affiliated franchisees' general satisfaction. Fourth, this study examined the influence of the general satisfaction of a franchisee on affiliated franchisees' response strategies. Research design, data, and methodology - In this study, the population comprised the nation's franchisors, and the sample comprised franchisees conducting business in Seoul and Gyeonggi-do. A self-administered questionnaire was used; the author and examiner explained the study's parameters to the interviewees in advance, to lessen the rate of rejection of the answers and to maintain reliability. The author distributed 350 copies of the questionnaire and collected 327 copies (93.4%). The author removed 54 copies of the sample, as these copies belonged to franchisees that were not registered by the Fair Trade Commission and/or were thought to have either defects or inadequate answers. The author selected an effective sample of 273 copies to enter data and to do the statistical analysis. Results - Both a reliability analysis and a confirmatory factor analysis were performed to measure reliability and validity, and a structural equation model was used to conduct the hypothesis test and investigate the models. The hypothesis was tested (Table 5). The models had a suitable fit, for instance, χ² = 447.663(df = 212, p = .000), χ²/df = 2.112, GFI = .881, AGFI = .858, RMR = .083, RMSEA = .067, NFI = .932, and CFI = .961. The hypothesis test results were as follows. Hypothesis 1 was accepted (C.R. = -2.339, p = .019). Hypothesis 2 was accepted (C.R. = 15.213, p = .000). Hypothesis 3 was accepted (C.R. = -2.631, p = .006). Hypothesis 4 was accepted (C.R. = 16.271, p = .000). Hypothesis 5 was accepted (C.R. = 2.391, p = .017). Hypothesis 6 was accepted (C.R. = 5.777, p = .000). Hypothesis 7 was accepted (C.R. = 17.153, p = .000). Hypothesis 8 was accepted (C.R. = 24.746, p = .000). Hypothesis 9 was accepted (C.R. = -10.150, p = .000). Hypothesis 10 was accepted (C.R. = -12.124, p = .000). Conclusions - The research results showed that expectations for a franchisor's support and control had a significant influence on expectation disconfirmation in a negative way, whereas the performance of support and control were found to have a significant influence on expectation disconfirmation in a positive way. In addition, the expectation disconfirmation of support and control was found to have a significant influence on satisfaction of franchisees in a positive way. Generally, regarding the research on control, control is found to have a negative influence on the satisfaction of franchisees, but this study proves that control is found to affect it in a positive way through conformity.

• Wind and Structures
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• 제18권2호
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• pp.195-213
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• 2014

Recently, the horizontal axis rotor performance optimizer (HARP_Opt) tool was developed in the National Renewable Energy Laboratory, USA. This innovative tool is becoming more popular in the wind turbine industry and in the field of academic research. HARP_Optwas developed on the basis of two fundamental modules, namely, WT_Perf, a performance evaluator computer code using the blade element momentum theory; and a genetic algorithm module, which is used as an optimizer. A pattern search algorithm was more recently incorporated to enhance the optimization capability, especially the calculation time and consistency of the solutions. The blade optimization is an aspect that is highly dependent on experience and requires significant consideration on rotor control strategies, wind data, and generator type. In this study, the effects of rotor control strategies including fixed speed and fixed pitch, variable speed and fixed pitch, fixed speed and variable pitch, and variable speed and variable pitch algorithms on optimal blade shapes and rotor performance are investigated using optimized blade designs. The effects of environmental wind data and the objective functions used for optimization are also quantitatively evaluated using the HARP_Opt tool. Performance indices such as annual energy production, thrust, torque, and roof-flap moment forces are compared.

• Journal of Power Electronics
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• 제17권2호
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• pp.334-345
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• 2017

In order to meet the increasing needs of the hybrid energy source system for electric vehicles, which demand bidirectional power flow capability with a wide-voltage-conversion range, a bidirectional three-level DC-DC converter and some control strategies for hybrid energy source electric vehicles are proposed. The proposed topology is synthesized from Buck and Boost three-level DC-DC topologies with a high voltage-gain and non-extreme duty cycles, and the bidirectional operation principle is analyzed. In addition, the inductor current ripple can be effectively reduced within the permitted duty cycle range by the coordinated control between the current fluctuation reduction and the non-extreme duty cycles. Furthermore, benefitting from duty cycle disturbance control, series-connected capacitor voltages can also be well balanced, even with the discrepant rise and fall time of power switches and the somewhat unequal capacitances of series-connected capacitors. Finally, experiment results of the bidirectional operations are given to verify the validity and feasibility of the proposed converter and control strategies. It is shown to be suitable for hybrid energy source electric vehicles.

• Smart Structures and Systems
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• 제15권4호
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• pp.931-947
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• 2015

This paper focuses on the design of an intelligent control system. The used techniques are based on Neuro Fuzzy approaches applied to a magnetorheological damper in order to reduce the vibrations over footbridges; it has been applied to the Science Museum Footbridge of Valladolid, particularly. A model of the footbridge and of the damper has been built using different simulation tools, and a successful comparison with the real footbridge and the real damper has been carried out. This simulated model has allowed the reproduction of the behaviour of the footbridge and damper when a pedestrian walks across the footbridge. Once it is determined that the simulation results are similar to real data, the control system is introduced into the model. In this sense, different strategies based on Neuro Fuzzy systems have been studied. In fact, an ANFIS (Artificial Neuro Fuzzy Inference System) method has also been used, in addition to an alternative Neuro Fuzzy approach. Several trials have been carried out, using both techniques, obtaining satisfactory results after using these techniques.