• 한국안전학회지
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• 제33권3호
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• pp.77-82
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• 2018

This paper aims to analyze the accident based on changing patterns of traffic culture index. For this purpose, this paper particularly focuses on classifying the traffic culture patterns and developing the traffic accidents using panel count data model. The main results are as follows. First, the traffic culture patterns are divided into 'increasing', 'decreasing' and 'other' patterns. The null hypotheses that the number of accident are the same over patterns are rejected. Second, 4 fixed effect negative binomial models which are all statistically significant are developed. Third, the regions with 'increasing' pattern are analyzed to be mostly the counties, and to demand the traffic law enforcement. Fourth, the regions with 'decreasing' pattern are evaluated to be mainly the districts and to require such the traffic culture as turn signal usage. Finally, the regions with 'other' pattern are analyzed to be mostly the cities and to ask for enhancing the level of traffic culture.

• 대한기계학회논문집A
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• 제25권3호
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• pp.353-361
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• 2001

Recently the boundary element method has been developed swiftly. The boundary element method is an efficient and accurate means for analysis of two dimensional elastic crack problems. This paper is concerned with the evaluation and the prediction of the stress intensity factor(SIF) for the crack emanating from the circular hole using boundary element method-neural network. The SIF of the crack emanating from the hole was calculated by using boundary element method. Neural network is used to evaluate and to predict SIF from the results of boundary element method. The organized neural network system (structure of four processing element) was learned with the accuracy 99%. The learned neural network system could be evaluated and predicted with the accuracy of 83.3% and 71.4% (in cases of SIF and virtual SIF). Thus the proposed boundary element method-neural network is very useful to estimate the SIF.

• 한국보육지원학회지
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• 제14권4호
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• pp.1-24
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• 2018

Objective: The purpose of this study was to investigate the differences in early childhood teachers' perceptions of the importance and institutional performance regarding young children's rights. Methods: 171 early childhood teachers responded to the questionnaires. The data were analyzed by using the paired sample t-test and the IPA graph to identify differences in the teachers' perceptions of the importance and performance of each right. Results: First, the teachers perceived the importance of children's rights to be high but low in institutional performance. The main effect of teaching years on the perception appeared significant only regarding performance of the rights of protection and participation. The main effect of teacher education experiences was significant in all areas except the importance of survival rights. The results from Two-Way ANOVA showed the two variables have no interaction. Second, the second quadrant of the IPA matrix displayed the items regarding initiative and autonomy of young children. Both inexperienced- and highly-experiencedteachers, when they had teacher education, recognized that the items related to participation rights should be further improved. Conclusion/Implications: We discussed the various ways in which children's rights should be improved and ways of improving teacher education according to teacher variables in order to promote young children's rights.

• 대한영양사협회학술지
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• 제7권4호
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• pp.397-409
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• 2001

The purposes of this study were to identify customer expectation, perception and satisfaction of foodservice quality to analyze the influencing factors on foodservice quality and finally to provide basic information for the improvement of foodservice quality. A survey of 4 factory foodservices was undertaken and detailed information was collected from 675 respondents. Statistical data analysis was completed using the SPSS package program for descriptive analysis, t-test and one-way ANOVA. Male had higher scores than female in perceptions of foods and services, and the differences were statistically significant. As analysis of expectation, perception and satisfaction result of age, expectation and perception were statistically significant, and mostly expectation and perception increased according as age increased. Expectation and perception showed statistical differences by marital status. Married people had higher scores in expectation and perception of food and service than single. According to family type, respondents living alone showed lower scores in expectation and perception of food and service than those living with family or relatives. Conversely, living alone had high expectation on service. As analysis of work type, office workers showed higher scores of service expectation, food and service perception than production workers. As education level increased, food and service expectation and perception increased mostly. As analysis of work post, food and service expectation and perception increased as work post raised. Meanwhile, married people had higher scores in service quality of satisfaction than single. Result of the study can be summarized as follows the analysis of expectation, perception and satisfaction of foodservice quality, the Quadrant of food and service quality expectation and perception according to demographic variables. Expectation, perception and satisfaction scores of foodservice attributes according to work type. The distribution of attributes with satisfyingly significant difference in grid.

• 한국방재학회 논문집
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• 제11권2호
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• pp.137-146
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• 2011

본 연구에서는 이변량 극치분포를 이용하여 연최대치 호우사상을 평가하였다. 이를 위해 특정 재현기간을 가지는 호우사상의 강우량을 비동시결합 재현기간, 동시결합 재현기간 그리고 구간조건부 결합재현기간의 세 가지를 이용하여 산정하였다. 이때, 결합재현기간별 호우사상의 값의 크기가 서로 다르게 산정되는 이유를 이변량 분포의 확률특성을 보여주는 사분면을 이용하여 설명하였다. 호우지속기간 24시간인 경우에 동시결합재현기간을 이용하여 산정한 확률강우량은 전통적인 방법으로 얻어진 강우지속기간 24시간의 확률강우량과 유사하게 나타났다. 이러한 결과는 전통적인 강우빈도해석의 제약사항을 극복하는데 도움이 될 것으로 보여진다. 이변량 빈도해석으로 얻어진 확률호우사상은 저류시설물의 계획시 통계적으로 보다 유용하면서도 간단한 설계 호우사상을 제공할 수 있을 것으로 보여진다.

• Journal of Power Electronics
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• 제18권5호
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• pp.1336-1346
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• 2018

Wide band gap semiconductor devices such as SiC MOSFETs are becoming the preferred devices for high frequency and high power density converters due to their excellent performances. However, the proportion of the switching loss that accounts for the whole inverter loss is growing along with an increase of the switching frequency. In view of the third quadrant working characteristics of a SiC MOSFET, synchronous rectification discontinuous pulse-width modulation is proposed (SRDPWM) to further reduce system losses. The SRDPWM has been analyzed in detail. Based on a frequency domain mathematical model, a quantitative mathematical analysis of the harmonic characteristic is conducted by double Fourier transform. Meanwhile, a switching loss model and a conduction loss model of inverter for SRDPWM have been built. Simulation and experimental results verify the result of the harmonic analysis of the double Fourier analysis and the accuracy of the loss models. The efficiencies of the SRDPWM and the SVPWM are compared. The result indicates that the SRDPWM has fewer losses and a higher efficiency than the SVPWM under high switching frequency and light load conditions as a result of the reduced number of switching transitions. In addition, the SRDPWM is more suitable for SiC MOSFET converters.

• 재활간호학회지
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• 제19권1호
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• pp.43-54
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• 2016

Purpose: This study attempted to understand patients' and nurses' perspectives on the priority of rehabilitation nursing services using Importance-Performance Analysis (IPA). Methods: This study used descriptive research design. Data were collected from 121 patients and 144 nurses using self-reported questionnaires. Statistical analysis included an independent t-test, analysis of variance (ANOVA), and IPA conducted using SPSS/WIN 21.0 version. Results: There were no statistical differences between the patients' and nurses' mean scores on perceptions of the importance (t=-0.83, p=.409) and performance (t=-0.32, p=.751) of rehabilitation nursing services. The IPA matrix showed a difference between patients and nurses in terms of their perceived priority of nursing services. Regarding the perception of patients, "helping a patient to continue to practice bedside physiotherapy and occupational therapy", "providing information on the proper care agency and community resources", and "providing education for the prevention of complications" fell in the "concetrate here" area (2nd quadrant). Conclusion: The results showed that the priorities of patients and nurses did not match in terms of some of the rehabilitation nursing services. Thus, rehabilitation nursing services need to be provided based on the patients' needs. Allocation of resources for the service items that fell in the "concentrate here" area of the IPA need be reconsidered for the quality in nursing care.

• 한국융합학회논문지
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• 제11권2호
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• pp.127-137
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• 2020

본 연구는 2019년 국립중앙박물관 중 디지털기술을 이용한 특별기획전을 중심으로 연구하였으며 그 연구목적은 향후의 전시에 있어 더욱 합리적이고 효과적으로 디지털기술을 응용하여 관람객의 전체적인 체험효과를 제고하기 위한 것이다. 연구과정에서 문헌조사를 통해 관람객의 기대, 체험 및 만족도 간의 관계에 대해 분석하고 최종적으로 4개 측면에서의 디지털 체험 차원을 종합하였으며 이를 기초로 설문지 내용을 작성하였다. IPA분석법(Importance-Performance Analysis)에 근거하여 디지털기술에 대한 체험 만족도에 대해 평가하고 중점적으로 개선해야 할 내용에 대해 알아보았다. IPA분석 원리에 근거하여 제IV사분면의 내용에 대해 중점적으로 분석하고 거시적 측면, 미시적 측면 및 관람객의 내심적 측면에서 개선해야 할 내용에 대해 건의하였으며 최종적인 연구결과는 현 단계 문제점을 개선하는 실행가능성에 대한 참고적인 기초자료로 활용할 수 있다. 본 연구의 선도성과 시효성을 보장하기 위해 향후 디지털 기술의 변화와 발전에 의한 연구를 지속적으로 진행할 것이다.

• 한국방재학회 논문집
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• 제9권5호
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• pp.87-92
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• 2009

현재까지의 치수대책이나 복구대책은 대부분 당해 연도의 지역별 피해액만을 기준으로 이루어지고 있다. 그러나 지역의 홍수 발생빈도와 홍수피해액 관계를 분석하면 지역의 홍수피해특성을 고려한 보다 합리적인 치수대책을 마련할 수 있다. 본 연구에서는 점빈도 분석을 이용하여 과거 38년('70~'07)간의 전국 시군구별 홍수피해자료를 이용하여 무차원 홍수피해 발생빈도와 피해액간의 상관관계를 분석하였다. 분석결과를 바탕으로 사분면적 해석방법을 도입하여 전국 시군구의 홍수피해 유형을 다빈도-대피해 지역, 다빈도-소피해 지역, 소빈도-대피해 지역, 소빈도-소피해 지역이라는 네 가지 유형으로 구분하였다. 본 연구의 분석결과를 활용하면 시군구별로 홍수피해액별 발생빈도와 발생빈도별 홍수피해액을 손쉽게 비교할 수 있기 때문에 지역의 치수방어년을 설정하는 데에도 많은 도움이 될 수 있다. 또한, 발생빈도별 홍수피해액을 산정할 수 있기 때문에 치수사업의 효과를 분석하거나 예측하기 위한 기초자료로도 충분히 활용할 수 있을 것이다.

• 디지털융복합연구
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• 제17권10호
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• pp.169-176
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• 2019

최근 한국경제는 일본의 경제보복조치와 미국과 중국 간 무역전쟁, 한국은행의 0.25% 기준금리 인하, 한국의 경제성장률 전망치 수정으로 혼잡한 상황이다. 본 연구의 목적은 한국종합주가지수와 소비자물가지수, 국고채(3년) 금리, 전산업의 매출실적을 분석하여 각 지수별로 종합주가지수에 미치는 영향을 살펴보는데 있다. 분석기간은 2003년 1월부터 2019년 6월까지이고, 각 지수별로 종합주가지수에 미치는 정도를 분석하였다. 본 연구는 수치분석에서 상관계수와 회귀분석을, 모형분석에서 분포도, 사분위도, Scatter, Box-Plot, Impulse Response를 살펴보았다. 이를 통해 각 지수별 변동성과 동행성을 찾아보았다. 분석결과 종합주가지수는 매출실적과 국고채금리 순으로 높은 동행성과 변동률을 보인 반면 소비자물가지수와는 매우 낮은 상관관계를 보여 주었다. 앞으로 종합주가지수는 매출실적과 금리의 영향을 받을 것으로 보여 꾸준한 관심이 필요해 보인다.