• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.414-414
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• 2011

우리나라 뿐만 아니라 전 세계적으로 기후변화로 인한 집중호우, 폭설 등이 빈번하게 일어나고 있으며 수공구조물 설계에 필요한 확률강우량도 증가하고 있다. 확률강우량을 산정하는 빈도해석의 경우 지점빈도해석의 문제점을 보완한 지역빈도해석에 대한 연구가 꾸준히 진행되고 있다. 지역빈도해석을 적용하기 위해서는 수문학적 동질성을 가지는 지역 구분이 무엇보다 중요하다. 군집 분석은 개체들이 지니고 있는 다양한 속성의 유사성을 동질적인 집단으로 군집화하는 방법을 말한다. 군집분석의 기본원리는 분석하고자 하는 여러 특성등을 유사성(similaruty) 거리(distance)로 환산하고 거리가 상대적으로 가까운 개체들을 동질적으로 군집화하는 것이다. 군집분석을 적용하기 위해서는 기상학적 인자와 지형학적 인자를 이용하여 군집분석을 실시한다. 군집분석을 실시할 때 가장 중요한 것은 입력변수의 선택으로 입력 변수의 적절한 선택이 결과값에 큰 영향을 준다. 상호정보량(Mutual Information, MI) 기법은 두 무작위 변수간의 관련성을 측정하는 방법이며 (Cover and Tomas, 2006), 두 변수간의 독립성 구조에 관한 가정이 없고 데이터 변형이나 잡음(noise)에 대한 영향이 적어 다른 기법보다 신뢰도가 높다고 알려져 있다(Peng et al., 2005). 본 연구에서는 상호정보량 기법을 이용하여 군집된 지점들의 종속성과 독립성의 관계를 정량적으로 산정하여 비교하고자 한다.

• Proceedings of the KIEE Conference
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• 2004.11b
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• pp.75-77
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• 2004

상정사고 해석의 경우 수많은 상정사고를 실시간에 해석하기 위하여 전력조류계산 결과로 얻어진 Jacobian의 역행렬이 포함하고 있는 민감도 정보를 이용하는 경우가 많다. 이 경우 각종 상정사고 후의 각 모선전압과 전압의 위상각과 같은 상태변수를 선형적으로 신속히 계산할 수 있는 장점이 있는 반면에 송전선로 고장과 같이 계통구성이 변하는 상정사고의 경우에는 계산결과 얻어지는 상태변수 값들의 오차가 커져 상정사고 해석 결과가 부정확해지는 문제점이 있다. 이때 보다 정확한 상태변수 값들을 계산하기 위해서는 탈락한 송전선로를 반영하여 Jacobian을 재구성하고 그 역행렬을 계산하여야한다. 본 논문에서는 특히 민감도를 이용한 상태변수 값의 선형 계산에서 오차가 커지는 문제점이 있는 송전선로 고장의 경우 계통의 구조 변화를 반영한 Jacobian의 역행렬을 별도로 계산하지 않고 기본 케이스 Jacobian의 역행렬을 그대로 이용하여 간단히 구하는 방법을 제시함으로서 보다 빠르고 정확한 상정사고 해석을 할 수 있는 기법에 대해 제안하였다. 제안한 방법은 뉴잉글랜드 39 모선 계통에 적용하여 그 효과를 입증하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.45-45
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• 2015

고전전인 천수방정식을 적용한 도시침수 해석모형에서 건물의 영향을 고려한 정확한 해석을 수행하기 위해서는 고해상도 격자가 요구되며 이는 계산시간의 증가가 야기된다. 고전 천수방정식을 적용한 도시침수해석 모형의 이러한 문제점을 극복하기 위해서 본 연구에서는 도시지역에 존재하는 건물 체적에 레이놀즈 이송이론을 적용한 수정 천수방정식을 제안하고, 제안 천수방정식을 이용한 효율적인 2차원 도시침수해석 모형을 개발하였다. 도시지역의 침수 모델링을 위해 고전 천수방정식은 건물을 고려하기 위해 고해상도 격자를 사용하는 것과 달리 수정 천수방정식은 건물의 영향을 매개변수화함으로서 저해상도 격자의 사용에도 고전 천수방정식과 유사한 정확도를 얻을수 있다. 건물의 영향을 매개변수화하기 위해서는 건물로 인한 저류와 흐름방향의 변화를 지배방정식이 고려할 수 있도록 수정하였다. 즉. 수정 천수 방정식은 고전 천수방정식을 기본으로 하여 건물의 저류영향을 고려하기 위해 각 계산격자에 적용되는 체적 매개변수와 건물의 흐름방향을 고려하기 위해 흐름방향과 직각방향에 위치한 선분(격자를 구성하고 있는 경계선)에 적용되는 면적 매개변수가 추가된다. 수정 천수방정식을 검증하기 위해 개발모형을 건물이 균일하게 위치한 실험하도와 비균일하게 위치한 실험하도에 적용하고 그 결과를 고전 천수방정식을 사용한 계산결과 및 계산시간과 비교함으로서 개발모형의 정확성과 효율성을 검증하였다.

• Journal of the Korea Convergence Society
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• v.7 no.1
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• pp.197-203
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• 2016

This study is to constructs the model by the relationship between the most important ones of TPM's step activities which are derived from the result of AHP analysis and the management performance. And it is to analyze whether step activities have impact on corporate performance through the mediating variable from a convergence point. Also it is to choose four step activities - irrational field and loss improvement, preparation and system establishment for the basic conditions of 5S, initial cleaning, loss analysis of facility efficiency - as independent variables, and to analyze the effect of TPM activity level as mediating variable on management performance as dependent variable. According to the analysis, four step activities don't have direct effect on corporate performance but TPM activity level as mediating variable has a full-mediated effect on corporate performance. That is, TPM activity level has been shown to play a role as mediating variable. Therefore, higher recognition of confidence in facility, awareness of self-development and definitive management of individual work shows TPM activity can contribute to corporate performance successfully.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.8
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• pp.1104-1110
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• 2012

The inverted pendulum system is a common, interesting control problem that involves many basic elements of control theory. In the early, controls of stabilization for the inverted pendulum system were used classical methods like PD, PID controller. In recently, however, control methods based on modern and intelligent control theory are widely applied. The fuzzy logic controller which is often used in nonlinear control is a little too hard to design due to increasing fuzzy rules rapidly if the given system like inverted pendulum has many state variables. Also, in case the state variables are divided into two parts, two fuzzy controllers are needed in the control system. In this paper, the authors propose FCSC(Fuzzy Controller based on State variables Combination) that reorganized into two new signals depending on the physical meaning of the four state variables of the inverted pendulum system. The proposed method is applied to the inverted pendulum system and simulations are accomplished to illustrate the control performance.

• Journal of Digital Convergence
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• v.15 no.11
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• pp.361-374
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• 2017

The purpose of this study is to investigate the effect of team-based learning on the practice of nursing practice and the effects of nursing students' meta-cognition, academic achievement, confidence in performance, self-confidence and learning satisfaction. The subjects of this study were 115 students who wanted to participate in the research in the second grade of Nursing Department of G region. The data collection period was from March 6 to June 5, 2017. The data were analyzed independence t-test and one-way ANOVA by using the SPSS 21.0 program and paired t-test for the effects of variables after the experiment, and Pearson's correlation coefficient for the correlation between the variables. The results showed that meta-cognition and the confidence in performance of team-based learning was not only increased but also statistically significant. Academic achievement was moderate, learning satisfaction was high, and meta-cognition was positively correlated with learning satisfaction. Therefore, based on the results of this study, it is necessary to activate the application of self-directed and active learning method in order to improve the nursing practice ability required in nursing field.

• Journal of the Korea Convergence Society
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• v.9 no.8
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• pp.311-318
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• 2018

The purpose of this study was to investigate the correlation between basic self - confidence and CPR - related factors and to investigate factors affecting CPR intention in nursing college students. Data were collected between January to March, 2018. Using SPSS(ver, 24.0), independent t-test, Pearson's correlation and logistic regression were used for the statistical analysis. Among the variables related to cardiopulmonary resuscitation, there was a high correlation (r = .575~.738). In the case of AED use, there was a low correlation with self-confidence of core nursing skills, CPR confidence, proficiency, and self-efficacy (r = .163~.301). A moderate correlation (r = .415~453) was found between the variables related to core nursing skills and CPR related variabls. Logistic regression analysis showed that CPR Self-efficacy (OR=1.22, 95% CI: 1.07~1.38), and AED application Competency (OR=1.72, 95% CI: 1.09~2.75) are effect factors. Since there is a correlation with AED, which is the main tool in CPR, it is necessary to include not only the self - efficacy but also the use of AED which is closely related to CPR in the actual situation as an essential element of education.

• Phonetics and Speech Sciences
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• v.15 no.4
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• pp.53-60
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• 2023

This study compared the absolute error of estimated fundamental frequency (AEF0) using voice - (VRP) and speech range profile (SRP) tasks across various etiological groups with voice disorders. Additionally, we explored the association between AEF0 and related voice parameters within each specific etiological group. The participants included 120 individuals, comprising 30 each from the functional (FUNC), organic (ORGAN), and eurological (NEUR) voice disorder groups, and a normal control group (NC). Each participant performed voice and SRP tasks, and the fundamental frequency of connected speech was measured using electroglottography (EGG). When comparing the AEF0 measures across the etiological groups, there were no differences in Grade and Severity among the patients. However, variations were observed in AEF0_VRP and AEF0_SUM. Specifically, AEF0_VRP was higher in the ORGAN group than in the FUNC and NC groups, whereas AEF0_SUM was higher in the ORGAN group than in the NC group. Furthermore, within FUNC and NEUR, AEF0 showed a positive correlation with Grade, while in ORGAN, it exhibited a positive correlation with the mean closed quotient (CQ). Attention should be paid to the application of AEF0 measures and related voice variables based on the etiological group. This study provides foundational information for the clinical application of AEF0 measures.

• The Journal of the Korea Contents Association
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• v.20 no.5
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• pp.140-152
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• 2020

This study analyzed the satisfaction and utilization of the institutional applications used by child-education institutions from a parent's perspective. The research target is a parent who enlisted their children in private kindergarten institution located in Gyeong-gi province and final research outcomes are 443 in total. The difference in satisfaction and utilization have been identified with demographic descriptive statistics, students t-test, and F-test statistics analysis method. First, the result of T-test on the difference in satisfaction and utilization based on parents' employment status shows that statistically significant difference was found in convenience from overall satisfaction, communication from overall utilization and child-parent relationship. Second, the F-test of differences in satisfaction and utilization showed a statistically significant difference in education utilization variables, with all variables in educational background and motivation. In terms of utilization, parents' educational background and overall utilization, and children's age were confirmed to have significant differences in communication, children's relationship, and motivation in basic life. Third, the result of multiple regression analysis shows that all predictors, including ease of use, communication, and satisfaction with educational activities, have a statistically significant impact on utilization standard variables, relative contributions showed the highest level of communication satisfaction. Therefore this paper implicates that institutional applications can maximize educational effectiveness by checking the applicability of active communication and educational activities with parents and actively communicating with parents in early childhood through various educational content applications.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.7
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• pp.3048-3056
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• 2012

The purpose of this study was to investigate VHI, V-RQOL, and vocal characteristics of a teacher and singer. 56 subjects were participated in this study (20 subjects are a teacher with vocal nodule, 20 subjects are a singer with vocal nodule, and 16 subjects are normal speakers). All subjects completed the VHI, V-RQOL, and vocal characteristics were measured using CSL 4500(Kay Pentax. USA). 21 subjects completed the VHI, V-RQOL, and vocal evaluation using CSL 4500 twice to assess test-retest reliability. A statistical analysis was performed using the Statistical Package for Social Sciences 18.0 (SPSS Inc, Chicago, IL). The VHI and V-RQOL showed that the teacher and singer group were significantly higher than those of the control group in functional, physical and emotional aspects(p<0.05). the acoustic analysis using CSL 4500 showed the teacher and singer group were significantly higher than those of the the control group in fundamental frequency related variables, fundamental perturbation related variables, amplitude perturbation related variables, noise related variable, and tremor related variables(p<0.05). Conclusionally, the teacher and singer group recognized their voice problems as a serious physico-functional aspects.