• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 B
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• pp.979-981
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• 2003

A novel single-stage power factor corrected (PFC) drive for switched reluctance motor (SRM) is presented to achieve sinusoidal, near unity power factor input current. The proposed PFC SRM drive has no additional active switch. And a single-stage approach, which combines a DC link capacitor used as do source and a drive used for driving the motor into one power stage, has a simple structure and low cost. The characteristics and validity of the proposed circuit will be discussed in depth through the experimental results.

• 대한조선학회논문집
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• 제53권3호
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• pp.237-248
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• 2016

As OPB and IPB moment-induced fatigue damage on mooring chain links were reported for a offloading buoy, verification of OPB and IPB fatigue has been a key engineering item in offshore structure mooring design. Mathematical and physical features of the conventional approach which was mainly explained in BV guideline are reviewed and disadvantages of the conventional approach are addressed in terms of stress proportionality and nonlinearity of OPB and IPB moments. In order to eradicate these disadvantages, a novel approach is newly proposed which is able to dispel apprehension on stress proportionality and is not dependent of nonlinearities of OPB and IPB moments. Significant differences between two approaches are suggested by comparing relations of OPB moment versus OPB interlink angle and IPB moment versus IPB interlink angle. For periodic OPB tension angle processes having three different OPB angle ranges with a simple irregular tension process, fatigue damage calculation reveals that OPB moment-induced fatigue damage has dominant portion to total fatigue damage. Comparative studies between two approaches also show that the conventional approach based on BV guideline predicts fatigue damage far conservatively since it assume unrealistic high stress concentration factor for tension load. Meanwhile IPB moment-induced fatigue damage is negligible compared to tension-induced fatigue damage.

• 한국멀티미디어학회논문지
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• 제19권3호
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• pp.603-611
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• 2016

Educational games offer an opportunity to engage and inspire students to take an interest in every subject material in school. The "fun" obtain when playing games become a trigger for the use of games in learning. However, there are doubts whether the players actually learn while they are having fun. Vidyanusa is an Online Mathematics Education Game being developed by Crayonpedia Education Ecosystem in Indonesia. The learning goal of Vidyanusa is to engage junior high school students in learning mathematics. In this paper, we design the Vidyanusa game material Functions and Relations by using Balanced Design Approach. This approach has three models in succession; the Content Model outlines the purpose of the game, the Task Model maps out the mission, and the Evidence Model outlines student measurement. This paper will then discusses the quality of games produced in term of Usability factor for effective results and objective. The measurement of the game was carried out based on International Standard ISO/IEC 9126-1 FDIS about Software Quality Product.

• 여성건강간호학회지
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• 제9권3호
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• pp.287-298
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• 2003

Purpose: To explain the concept of postpartum weight retention and to analyze factor effect on it. Method: A total of 20 studies related postpartum weight retention were selected in the year of 1988-2001 and analysis was done. Result: A demographic factor like parity, age, social and economic level and life style such as exercise, diet, breast feeding are influential factor on postpartum retention weight. But parts of them don't agree the same results. Meanwhile, in some studies, psychological factor like women's self esteem related to postpartum retention weight, body image change, depressing is found to be very related. As a result, postpartum overweight gain could be a bad factor of physical and mental health. In Korea, we have few studies related to them. Conclusion: It is required to do many-sided and deep studies about aspects of postpartum retention weight and the factor that effect on it. Postpartum retention weight should be approached by controling weight from the period of pregnancy. And it would rather be researched through individual approach considered women's various demographic, social-cultural and physical level than be required standardized level of weight gain.

• Geomechanics and Engineering
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• 제5권5호
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• pp.485-497
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• 2013

The factor of safety is the most common measure of the safety margin for slopes. When the traditionally defined factor is used in kinematic approach of limit analysis, calculations can become elaborate, and iterative methods have to be used. To avoid this inconvenience, the safety factor was defined in terms of the work rates that are part of the work balance equation used in limit analysis. It was demonstrated for two simple slopes that the safety factors calculated according to the new definition fall close to those calculated using the traditional definition. Statistical analysis was carried out to find out whether, given normal distribution of the strength parameters, the distribution of the safety factor can be approximated with a well-defined probability density function. Knowing this function would make it convenient to calculate the probability of failure. The results indicated that the normal distribution could be used for low internal friction angle (up to about $16^{\circ}$) and the Johnson distribution could be used for larger angles ${\phi}$. The data limited to two simple slopes, however, does not allow assuming these distributions a priori for other slopes.

• Journal of Mechanical Science and Technology
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• 제15권1호
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• pp.44-51
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• 2001

One of the recent issues in design of the spot-welded structure such as the automobile body is to develop an economical prediction method of the fatigue design criterion without additional fatigue test. In this paper, as one of basic investigation for developing such methods, fracture mechanical approach was investigated. First, the Model I, Mode II and Mode III, stress intensity factors were analyzed. Second, strain energy density factor (S) synthetically including them was calculated. And finally, in order to decide the systematic fatigue design criterion by using this strain energy density factor, fatigue data of the ΔP-N(sub)f obtained on the various in-plane bending type spot-welded lap joints were systematically re-arranged in the ΔS-N(sub)f relation. And its utility and reliability were verified by the theory of Weibull probability distribution function. The reliability of the proposed fatigue life prediction value at 10(sup)7 cycles by the strain energy density factor was estimated by 85%. Therefore, it is possible to decide the fatigue design criterion of spot-welded lap joint instead of the ΔP-N(sub)f relation.

• Asian Pacific Journal of Cancer Prevention
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• 제13권12호
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• pp.6203-6206
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• 2012

The aim of this study was to evaluate the outcomes of women with high-grade squamous intraepithelial lesion (HSIL) smears who had undergone the "see and treat" approach compared to those who underwent a conventional approach. The records of women with HSIL smears undergoing colposcopy at Srinagarind Hospital were reviewed. In those undergoing the conventional approach, the final histological diagnosis was made on the most severe histological results obtained after initial colposcopy. In the "see and treat" group, the final histological diagnosis was made on the examination of LEEP specimens obtained after initial colposcopy. Overtreatment in the see and treat group was defined as the LEEP specimens containing cervical intraepithelial neoplasia (CIN) 1 or less. During the study period, 302 women with HSIL underwent colposcopy. Twenty (6.6%) were nulliparous. One hundred and ninety-four (64.2%) underwent conventional management while the remaining 108 (35.8%) received the see and treat management. The prevalence of underlying high-grade lesions in women undergoing the conventional approach was significantly higher than that observed among women undergoing the see and treat approach (89.2% and 47.2%, respectively, P<0.001). The overtreatment rate in the see and treat group was 52.8%. Multivariate analysis revealed that only parity status was a statistically significant factor for predicting the overtreatment after undergoing the see and treat approach. In conclusion, the overtreatment rate among women undergoing see and treat in this study is notably high and therefore this approach should not be routinely practiced.

• Earthquakes and Structures
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• 제8권2호
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• pp.443-462
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• 2015

Some model building codes stipulate that the design displacement of a building can be computed using the elastic static analysis results multiplied by the deflection amplification factor, $C_d$. This approach for estimating the design displacement is essential and appealing in structural engineering practice when nonlinear response history analysis (NRHA) is not required. Furthermore, building codes stipulate the consideration of accidental torsion effects using accidental eccentricity, whether the buildings are symmetric-plan, or asymmetric-plan. In some model building codes, the accidental eccentricity is further amplified by the torsional amplification factor $A_x$ in order to minimize the discrepancy between statically and dynamically estimated responses. Therefore, this warrants exploration of the reliability of statically estimated design displacements in accordance with the building code requirements. This study uses the discrepancy curves as a way of assessing the reliability of the design displacement estimates resulting from the factors $C_d$ and $A_x$. The discrepancy curves show the exceedance probabilities of the differences between the statically estimated design displacements and NRHA results. The discrepancy curves of 3-story, 9-story, and 20-story example buildings are investigated in this study. The example buildings are steel special moment frames with frequency ratios equal to 0.7, 1.0, 1.3, and 1.6, as well as existing eccentricity ratios ranging from 0% to 30%.

• International Journal of Contents
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• 제12권4호
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• pp.31-44
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• 2016

Knowledge creation and management are regarded as critical success factors for an organization's survival in the knowledge era. As a process of knowledge acquisition and sharing, organizational learning mechanisms (OLMs) guide the learning function of organizations represented by its different learning activities. We examined a variety of learning processes that constitute OLMs. In this study, we aimed to capture the process and framework of OLMs and knowledge sharing and acquisition. Factors facilitating OLMs were investigated at three levels: individual, group, and organizational. The concept of an OLM has received some attention in the field of organizational learning, however, the relationship among the factors generating OLMs has not been empirically tested. As part of the ongoing discussion, we attempted a systemic approach for OLMs. OLMs can be represented by factors that are inherent to the organization's system; therefore, prior to empirically testing the OLM generating factor(s), evaluation of its organizational integration is required to determine effective treatment of each factor. Thus, we developed a framework to manage knowledge and proposed a method to numerically evaluate factors influencing the OLMs. Specifically, composite importance (CI) of the Decision-Making Trial and Evaluation Laboratory (DEMATEL) method was applied to explore the interaction effect of these factors based on systemic approach. The augmented matrix thus generated is expected to serve as a stochastic matrix of an absorbing Markov chain.

• 대한안전경영과학회지
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• 제9권5호
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• pp.103-110
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• 2007

To build a most efficient and competitive warehouse, need to reflect tenants various opinions in advance such as location, rentable size, leasing terms, rental, configuration of the building, building structure, traffic flow and amenities. Thus a survey for major tenants which are logistics, retailers and manufactures should be done to figure out potential demand and marketing strategy to lead to be a competitive warehouse. However above survey is time consuming work and requires high cost involvement thus to avoid such an inefficient process and to facilitate investors prompt and right decision making, there should be a tool which helps to make a decision process easier with simple key factors. In other word, we have used above mentioned 'Demand Approach' so far but here I am introducing 'Factors Comparison' which reflects location factors and facility factors. I derived Kwang-myung logistics park's proper rental rate through 'Demand Approach' which analyzed Seoul Metropolitan area's rental warehouse status and rents, and also defined a size of potential demand area and rental. And this report compared the result with an outcome of 'Factors Comparison' then compared each methods and drew a conclusion of 'Factors Comparion's better convenience and efficiency.