• 전기전자학회논문지
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• 제24권4호
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• pp.1104-1108
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• 2020

본 논문에서는 3상 영구자석 동기전동기의 속도리플 저감을 위한 가변형 비례공진 전향보상 알고리즘을 제안한다. 일반적인 토크 맥동의 원인은 전류측정오차 및 데드타임으로 인한 전기적 맥동과 회전자 편심과 편심 부하로 인해 발생될 수 있다. 이러한 토크 맥동은 전동기의 속도 맥동을 야기하고 전동기 구동 시스템의 운전 성능을 저하시킬 수 있다. 이를 위한 본 논문에서는 속도 맥동의 원인을 분석하고 속도 맥동을 저감하기 위한 알고리즘을 제안하였다. 제안한 알고리즘은 속도 맥동에 포함된 특정 운전 주파수를 저감하기 위해 가변형 비례 공진 제어기를 적용하였고, 전향보상 제어기 구조를 이용하여 보상동작이 수행되도록 하였다. 제안한 알고리즘은 다양한 실험을 통하여 타당성과 효용성을 검증하였다.

• 한국수자원학회논문집
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• 제51권10호
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• pp.875-886
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• 2018

본 연구에서는 표준강수지수를 이용하여 가뭄사상을 정의하고, 가뭄심도와 부족 강수량을 대상으로 이변량 가뭄빈도해석을 수행하였다. 부족강수량은 표준강수지수의 가뭄기준인 -1에 해당하는 강수량을 기준으로 산정하였다. 지금까지 연구에서 가뭄지수의 심도와 지속기간 이용한 빈도해석을 통한 가뭄의 평가가 주를 이루었다. 하지만 이 두 변량은 선형적인 관계가 매우 높아 각 변량에 대한 단변량 빈도해석과 비교하여 정보의 확장성은 크지 않다. 2015년 가뭄의 경우, 서울, 양평, 충주지점의 '가뭄심도-부족 강수량'량의 재현기간은 모두 300년 이상의 극심한 가뭄을 나타내고 있지만, '가뭄심도-지속기간'에서는 재현기간을 약 10년, 50년, 50년으로 평가하여 큰 차이를 나타냈다. 우기를 포함한 가뭄은 강수량 부족이 심각할지라도 가뭄심도는 가뭄을 상대적으로 낮게 평가할 수 있어 실제 가뭄의 심각성을 나타내는데 한계가 있었다. '가뭄심도-부족 강수량' 빈도해석 결과는 강수량의 절대적인 부족량 정보를 함께 포함하고 있어, 가뭄에 대응하기 위한 지표로 활용성이 높을 것으로 판단된다.

• 한국지진공학회논문집
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• 제9권5호
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• pp.41-52
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• 2005

지진응답제어를 위한 효율적 방법으로 제시된 퍼지관리제어기법은 퍼지에 기반한 의사결정과정을 통하여 가변 제어이득행렬을 구현함으로써 하나의 제어이득만으로 표현되는 선형제어기법보다 개선된 제어성능을 발휘할 수 있다. 이 논문에서는 퍼지관리제어기법의 효율성을 하중 및 교량모델의 불확실성에 대한 제어성능의 강인성 측면에서 평가하였다. 강인성 평가에 있어서는 Dyke등이 제시한 벤치마크 교량에 대하여, 최적설계된 LQG기법과 제어성능을 비교하는 방법을 사용하였다. 불확실성을 주는 요인으로는 주파수 특성이 다른 여러 지진가속도의 규모 및 교량의 강성변화를 가정하였다. 최적설계된 LQG 제어기와 제어효과를 비교한 결과, FSC시스템이 지진의 종류와 규모에 따라 보다 작은 전력을 사용하면서도 개선된 제어성능을 발휘하였다. 특히, LQG 제어시스템이 강성변화에 대하여 불안정한 제어성능을 보인 반면, FSC 시스템은 매우 안정적인 응답제어효과를 보이면서도 제어시스템에 소요되는 전력량과 제어장치의 스트로크에 있어서도 큰 변화를 보이지 않음으로써 매우 탁월한 강인성을 보장할 수 있는 것으로 나타났다.

• 한국간호교육학회지
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• 제5권2호
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• pp.315-331
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• 1999

This study was done to describe health promoting lifestyle and to identify the factors affecting the performance in health promoting lifestyle among the climacteric women. The subjects of this study were 240 women(40 to 60 years old) The sample data were collected using a purposive sampling method, and collected from August 23 to September 6, 1999. The instruments for his study were a health promoting lifestyle scale, a health locus of control scale, a self-esteem scale and a perceived health status questionnaire. Frequency, percentage, t-test, ANOVA, Pearson's correlation and stepwise multiple regression technique with SPSS program were used to analyze the data. The results of the study were as follows ; 1) The average score of performance in the health-promoting lifestyle variables was 166.40. The variable with the highest degree of performance was the sanitary environment , whereas the one with the lowest degree was the professional health maintenance. 2) Performance in the health-promoting lifestyle was positively related to self-esteem, internal health locus of control and negatively related to accidental health locus of control and perceived health status. 3) A significant difference between educational level and health-promoting lifestyle were found. 4) Self-esteem and perceived health status explained 21.0% of the variance for the total health promoting lifestyle. The results of this study show that self-esteem, perceived health status predicted the health promoting lifestyle of the climacteric women. Therefore, health promoting programs that increase self-esteem and perceived health status should be developed to promote a healthy lifestyle of the climacteric women, especially those who have a low level of education.

• Nuclear Engineering and Technology
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• 제54권8호
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• pp.2852-2858
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• 2022

A proton therapy facility is under development at Huazhong University of Science and Technology (HUST). To meet the need for fast energy changes during treatments, a beamline control system (BCS) has been designed and implemented. The BCS coordinates and controls various beamline devices by adopting a distributed architecture divided into three layers: the client, server, and device layers. Among these, the design of the server layer is the key to realize fast energy changes. The server layer adopts the submodule programming paradigm and optimizes the data interface among modules, allowing the main workflow to be separated from the device workflow and data. Furthermore, this layer uses asynchronous, multithreaded, and thread-locking methods to improve the system's ability to operation efficiently and securely. Notably, to evaluate the changing energy status over time, a dynamic node update method is adopted, which can dynamically adjust the update frequency of variable nodes. This method not only meets the demand for fast updates on energy changes but also reduces the server's communication load in the steady state. This method is tested on a virtual platform, and the results are as expected.

• 보존과학연구
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• 통권25호
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• pp.47-74
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• 2004

We investigated the nucleotide substitution and insertion polymorphism of the hypervariable region Ⅰ and Ⅱ in mt DNA by sequencing ancient DNA from 51 ancient bones and teeth excavated at Nuk-do and Yimdang-dong in Korea. It revealed 35 sequence types from the ancient Korean. Of these, different sequences were 34 sequences. There were 19 and 38 base substitutions in HVI and HVⅡ, respectively. Some substitutions were characteristic of East Asian populations as compared with data reported on Caucacianpopulations,16051, 16150, 16172, 16223 in region I and 73, 263 in region II were noted as polymorphic sites, respectively. These were distributed evenly along the control region, though the frequency of each site was variable. Nucleotide substitution rather than insertion and deletion was the prevalent pattern of variation. Insertion of cytosine between312 and 315 in region HVⅡ were detected up to 98% in 51 ancient bone samples. This sequence data represents a phylogenetic tree using NTI DNA Suite computer program. The phylogenetic tree showed that mt DNA sequences of Nuk-do bones were relative to west Siberian and Indonesian. The usefulness of mt DNA sequencing in ancient Korean population excavated atarchaeological sites is based on biological and historical evidence for origin and migration of ancient Korean.

• 동아시아식생활학회지
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• 제17권4호
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• pp.589-596
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• 2007

The level of hygiene practices varies depending on a variety of factors. The purpose of this study was to evaluate the level of hygiene practices performed in the contract foodservice establishments based on several variables, and to also determine the possible effects of each variable on the performance level of hygiene practices. We surveyed 215 contract foodservice establishments, excluding school facilities, managed by a large-scale contract foodservice company. The survey used a formulated sanitary checklist to evaluate the level of hygiene practices performed in the foodservice establishments. The sanitary checklist consisted of a total of 52 items in all 6 categories including personal sanitation and process control. The collected data underwent a series of analyses such as frequency analysis, ANOVA, and correspondence analysis of means using SPSS. from the results, we found significant differences among groups in categories such as the existence of a person in charge and types of business. A higher foodstuff cost had a tendency to correlate with a higher performance level for sanitary maintenance, but there was no significance on a statistical level.

• Journal of Korean Biological Nursing Science
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• 제19권3호
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• pp.151-157
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• 2017

Purpose: The purpose of this study was to identify the effects of hand and foot baths on sleep and body temperature of the elderly. Methods: The research was designed for a nonequivalent control group before and after the test design. The subjects of this study totaled 43, aged 65 and over (23 people in hand bath group and 20 people in a foot bath group), who received a written voluntary consent to participate in experimental treatment and are in the W care center, S Nursing Home, and H care center in Seoul. Data were collected with questionnaires and observations, and were analyzed on the basis of frequency, percentage, mean, standard deviation, ${\chi}^2-test$, Fisher exact test, t-test and paired t-test. Results: There are no significant differences in homogeneity test of a dependent variable between groups (hand bath, foot bath). The differences between 2 groups on the sleep quality score and systolic blood pressure, diastolic blood pressure temperature were not significant statistically except on the pulse. Conclusion: Based on the results of this study, hand bath is as efficient as foot bath. Therefore, a hand bath can be a nursing intervention in order to enrich sleep quality for the elderly because a hand bath is more convenient than foot bath.

• 한국보육지원학회지
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• 제12권6호
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• pp.169-188
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• 2016

The purpose of this study was to examine the influence of religious maturity of Christian teachers in child care centers on teacher-infant interaction, emotional labor and emotional intelligence. The survey was conducted on 173 Christian teachers of early-child classes who work in child care centers in Gyeonggi-do province. For the research analysis, frequency and Cronbach's ${\alpha}$ coefficient were calculated and regression analysis were conducted. The results are as follows. First, the affective and volitional factors from religious maturity of Christian teachers in child care centers have had a positive influence on the overall teacher-infant interaction. Second, the affective factor from religious maturity of Christian teachers in child care centers have had a negative influence on outward behavior, which is the lower variable of emotional work, and a positive influence on inner behavior. Third, the volitional factor from religious maturity of Christian teachers in child care centers have had a positive influence on perception of self-emotions, perception of others' emotion, emotional application, emotional control, and emotional intelligence overall.

• 전력전자학회논문지
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• 제22권1호
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• pp.36-43
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• 2017

This paper describes a hybrid multi-output three-level DC/DC converter suitable for a wide, high-input voltage range of an auxiliary power supply for a high-power photovoltaic generating system. In a high-power photovoltaic generating system, the solar panel output voltage depends on solar radiation quantity and varies from 450Vdc to 1100Vdc. The proposed hybrid multi-output three-level DC/DC converter, which is an auxiliary power supply, would be used as power source for control printed circuit boards and relay and cooling fans in a high-power photovoltaic generating system. The proposed multi-output ($24V_{DC}/30A$, $230V_{DC}/5A$) hybrid three-level boost converter, which uses an energy recovery snubber, is controlled by variable-frequency and phase-shifted modulations and can achieve zero-voltage switching with all operating conditions of input voltage and load range. Experimental results of a 2kW prototype are evaluated and implemented to verify the performance of the proposed converter.