• Steel and Composite Structures
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• 제46권2호
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• pp.253-261
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• 2023

The goal of this paper is to investigate dynamic responses of simply-supported laminated micro beams under moving load. In the considered micro-scale problem, the modified coupled stress theory which includes the length scale parameter is used. The governing equations of problem are derived by using the Lagrange procedure. In the solution of the problem the Ritz method is used and algebraic polynomials are used with the trivial functions for the Ritz method. In the solution of the moving load problem, the Newmark average acceleration method is used in the time history. In the numerical examples, the effects of stacking sequence of laminas, fibre orientation angles and the length scale parameter on the dynamic responses of laminated micro beams are examined and discussed.

• 가정간호학회지
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• 제27권2호
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• pp.169-178
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• 2020

Purpose: This study examined the mediating effects of nursing professionalism on the relationship between the stress of clinical practice and compassion competence in nursing students. Methods: A correlational research design was used in this study. The participants were 120 nursing students recruited from three universities in South Korea. Data were collected using the self-reporting scales of stress of clinical practice, nursing professionalism, and compassion competence. Baron and Kenny's regression method and the Sobel test were used to analyze the mediating effects of nursing professionalism on the association between the stress of clinical practice and compassion competence. Results: The mean score for compassion competence was above average. Of the compassion competence domains, sensitivity and insights had the highest and lowest scores, respectively; there were significant mean differences in compassion competence scores according to their grade and level of satisfaction with nursing major. Compassion competence correlated negatively with the stress of clinical practice, whereas it correlated positively with nursing professionalism. In addition, nursing professionalism exerted full mediating effects on the relationship between the stress of clinical practice and compassion competence. Conclusion: The results suggested that enhancing nursing professionalism could help promote compassion competence among nursing students who experience stress in clinical practice.

• 간호행정학회지
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• 제17권3호
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• pp.349-356
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• 2011

Purpose: In this study, differences and relationship between teaching style, personality, job stress, and job satisfaction among preceptors were examined. Method: The participants were 121 preceptors. Data were collected in November and December 2010 and analyzed using descriptive statistics, ANOVA, Scheffe's test, and Pearson correlation coefficients. Results: The most frequent teaching style was judgement-initiative, and personality scores were highest for conscientiousness. Job stress was average (3.05${\pm}$.59), and job satisfaction was below the mid-point level (2.76${\pm}$.39). Job stress and job satisfaction were significantly different according to teaching style. Significant correlations were found between personality and job stress, and personality and job satisfaction. Conclusion: These findings indicate that changes in perceived teaching style, and personality may be necessary to decrease job stress, and to promote job satisfaction among preceptors. The results of this study should be considered in the development of effective preceptor training programs.

• 한국식품영양학회지
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• 제32권3호
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• pp.267-274
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• 2019

This study was performed to provide fundamental data on the dietary habits and food purchase types according to the stress patterns. The subject was 312 Chinese students in Gyeonggi region through a self-administered questionnaire. According to the results of the reliability analysis, the stress items showed an average of 2.91 and 0.846 for Cronbach alpha coefficient. The results of ANOVA analysis on the difference of dietary habits according to stress are as follows; There were significant differences for the meal frequency per day according to schoolwork, economic, general living, and dietary habits (p<0.05). Also, the general living pattern showed significant differences for the meal outside frequency and Chinese food intake (p<0.05). The results of ANOVA analysis on the difference of food purchase type according to stress are as follows; There was significant differences in degree of use of convenience foods according to interpersonal relationship, cooking method of convenience foods according to economics, the selection criteria of convenience foods according to schoolwork (p<0.05). The correlation coefficient of dietary habits and convenience food intake are 0.223, -0.147 in stress degree and dietary habits. In conclusion, I would like to provide the basic data necessary for the right choice of Chinese students' dietary habits and food purchases.

• Geomechanics and Engineering
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• 제6권2호
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• pp.173-194
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• 2014

Laboratory and field data showed that deep mixed (DM) columns accelerated the rate of consolidation of the soft foundations. Most analyses of consolidation of DM column-improved foundations so far have been based on the elastic theory. In reality, the DM columns may yield due to the stress concentration from the soft soil and its limited strength. The influence of column yielding on the degree of consolidation of the soft foundation improved by DM columns has not been well investigated. A three-dimensional mechanically and hydraulically-coupled numerical method was adopted in this study to investigate the degree of consolidation of the DM column foundation considering column yielding. A unit cell model was used, in which the soil was modeled as a linearly elastic material. For a comparison purpose, the DM column was modeled as an elastic or elastic-plastic material. This study examined the aspects of stress transfer, settlement, and degree of consolidation of the foundations without or with the consideration of the yielding of the DM column. A parametric study was conducted to investigate the influence of the column yielding on the stress concentration ratio, settlement, and average degree of consolidation of the DM column foundation. The stress concentration ratio increased and then decreased to reach a constant value with the increase of the column modulus and time. A simplified method was proposed to calculate the maximum stress concentration ratios under undrained and drained conditions considering the column yielding. The simplified method based on a composite foundation concept could conservatively estimate the consolidation settlement. An increase of the column modulus, area replacement ratio, and/or column permeability increased the rate of consolidation.

• 터널과지하공간
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• 제30권3호
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• pp.256-269
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• 2020

본 연구의 목적은 KURT 화강암 시료의 포화유무에 따른 균열손상 기준과 파괴인성의 변화를 측정하는 것이다. 이를 위하여 일축압축시험을 이용한 소성체적변형률을 통해 KURT 화강암의 균열손상 기준을 도출하였다. 또한 암석의 파괴인성을 보다 신뢰성 있게 측정하기 위해 암석의 비선형적 변형에 대한 보정(Level II Method; ISRM, 1988) 을 통해 포화유무에 따른 KURT 화강암의 수정 파괴인성(corrected fracture toughness)을 측정하였다. 시험결과 건조시료의 평균 균열개시 응력(σ_ci)과 균열손상 응력(σ_cd)은 91.1 MPa과 128.7 MPa이었으며, 포화시료의 평균 균열개시 응력(σ_ci)과 균열손상 응력(σ_cd)은 58.2 MPa과 68.2 MPa이었다. 건조시료에 비해 포화시료의 균열개시 응력은 36% 감소하였으며 균열손상 응력은 건조시료 대비 47%나 감소되는 결과를 나타내었다. 균열손상 응력(σ_cd)이 상대적으로 더욱 감소하였음을 감안할 때 시료의 포화로 인해 더 낮은 응력조건에서 구조물에 대한 손상이 쉽게 발생할 수 있음을 알 수 있다. KURT 화강암의 비선형성을 고려한 수정 파괴인성은 0.811 MPa·m^0.5이었으며 포화시료의 수정 파괴인성은 0.620 MPa·m^0.5이었다. 즉 암석의 비선형성을 고려함으로써 파괴인성의 증가를 확인할 수 있었으며, 암석의 포화시 수정 파괴인성은 24% 감소하였다. 따라서 지하수 포화로 인해 암석 내 균열의 생성과 진전에 대한 저항성이 감소함을 알 수 있다.

• 한국전산구조공학회논문집
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• 제16권1호
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• pp.1-8
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• 2003

위상최적설계는 개념설계에 적합하며, 제품의 설계에서 사용되어지고 있다. 전통적인 위상최적화는 균질화법과 최적조건법을 사용해 왔다. 균질화법은 구멍으로 구성된 구조물과 강성행렬사이의 관계를 연결해주는데 사용되며, 최적조건법은 부피분율을 유지하며 설계변수의 개선에 사용되어진다. 전통적인 위상최적설계는 수렴성이 좋은 장점은 있지만 수렴시간이 많이 걸린다는 단점이 있었다. 이 문제를 해결하는 하나의 방법으로 평균 응력량을 기준으로 요소를 제거하는 요소제거법을 제시하였다. 예제에서 수렴속도가 향상됨을 알 수 있었다.

• 응용통계연구
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• 제22권2호
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• pp.297-307
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• 2009

최근 금융위기의 요인이 되고 있는 가계부채에 대하여 가계구성원이 느끼는 부담감, 즉, 가계부채에 대한 체감도에 가계구성원의 속성들(주택점유형태, 가구주 학력, 가구주 연령, 월소득, 거주지역)이 미치는 영향을 2004년도 국민은행이 조사한 실제자료를 가지고 분석하였다. 체감도를 부채에 대한 부담감이 낮음과 높음의 이항자료로 구분하여 가계구성원의 속성들을 설명변수로 갖는 로지스틱 회귀분석을 수행하였다. 적합도에 대한 우도비 통계량을 이용한 후진제거법을 사용하여 간단하면서도 자료를 잘 적합시키는 모형을 선택한 결과 2개의 2차 교호작용을 갖는 모형이 선택되었다. 선택된 모형에 대한 계수 추정치를 통하여 각 속성이 부채 체감도에 대하여 미치는 영향을 분석하였다. 또한 가계부채의 유무에 대하여 가계구성원의 속성들이 미치는 영향을 로지스틱 회귀모형을 통하여 유사한 방법으로 분석하였다 자가주택일수록, 월소득이 증가할수록, 가구주 학력이 낮을수록 그리고 가구주 연령이 낮아질수록 부채에 대한 체감도가 낮아짐을 알 수 있었다.

• 보건교육건강증진학회지
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• 제25권3호
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• pp.153-165
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• 2008

Objectives: The purpose of this study was to understand health-promotion behaviors and to find factors associated with the behaviors among Korean-Chinese workers who live in Korea. Methods: The number of Korean-Chinese workers participated in this study was 187, and the sample was chosen using a convenient sampling method. To understand general characteristics, frequencies and percentages were utilized. To examine the seven categories of health-promotion behavior, their average scores were calculated. To explore factors related to health-promotion behaviors, a multiple stepwise regression analysis was performed. Independent variables used for the analysis were self-concept, social support, stress, perceived health status, and demographics. Results: The average score of the seven health-promotion behaviors was 2.35. Of the seven subcategories of health-promotion behaviors, the scores of rest/sleep and self-actualization were relatively higher; the scores of exercise and stress management were relatively lower. Of demographics and four factors of main interest (i.e., self-concept, social support, stress, perceived health status), education level, types of residence, social support, and perceived health status remained statistically significant. Among the four factors, social support had the greatest impact on health-promotion behaviors. Conclusions: This study has two suggestions. First, it is needed to develop strategies, which can help Korean-Chinese workers enhance levels of health-promotion behaviors regarding stress management and exercise. Second, considering the greatest effect of social support on health-promotion behavior, it is necessary to strengthen social support among Korean-Chinese workers.

• 대한전기학회논문지:시스템및제어부문D
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• 제50권6호
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• pp.302-308
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• 2001

SVD(Singular Value Decomposition) filter for the suppression of EMG in multi-lead stress ECG is studied. SVD filter consists of two parts. In the first part, the basis vectors were chosen from the averaged singular vectors obtained from the decomposed noise-free ECG. The singular vector is computed from the stress ECG and is compared itself with basis vectors to know whether the noise exist in stress ECG. In the second part, the existing elimination method is used, when one(or two) channels is(or are) contaminated by noise. But the proposed enhanced SVD filter is used in case of having the noise in the many channels. During signal decomposition and reconstruction, the noise-free channel or the least noisy channel have the weight of 1, the next less noisy channel has the weight of 0.8. In this way, every channel was weighted by decreased of 0.2 in proportion to the amount of the added noise. For the evaluation of the proposed enhanced SVD filter, we compared the SNR computed by the enhanced SVD filter with the standard average filter for the noise-free signal added with artificial noise and the patient data. The proposed SVD filter showed better in the SNR than the standard average filter. In conclusion, we could find that the enhanced SVD filter is more proper in processing multi-lead stress ECG.