• Geomechanics and Engineering
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• 제18권3호
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• pp.247-258
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• 2019

Soil strength and failure surface geometry directly influence magnitudes of passive earth thrust acting on geotechnical retaining structures. Accordingly, it is expected that as long as the shape of the failure surface geometry and strength parameters of the backfill are known, magnitudes of computed passive earth thrusts should be highly accurate. Building on this premise, this study adopts conventional method of slices for calculating passive earth thrust and combines it with equations for estimating failure surface geometries based on in-situ stress state and density. Accuracy of the proposed method is checked using the results obtained from small-scale physical retaining wall model tests. In these model tests, backfill was prepared using either air pluviation or compaction and different backfill relative densities were used in each test. When the calculated passive earth thrust magnitudes were compared with the measured values, it was noticed that the results were highly compatible for the tests with pluviated backfills. On the other hand, calculated thrust magnitudes significantly underestimated the measured thrust magnitudes for those tests with compacted backfills. Based on this observation, a new approach for the calculation of passive earth pressures is developed. The proposed approach calculates the magnitude and considers the influence of locked-in stresses that are the by-products of the backfill preparation method in the computation of lateral earth forces. Finally, recommendations are given for any geotechnical application involving the compaction of granular bodies that are equally applicable to physical modelling studies and field construction problems.

• 한국전문물리치료학회지
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• 제27권2호
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• pp.140-148
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• 2020

Background: Scapular winging (SW) could be caused by tightness or weakness of the periscapular muscles. Although data mining techniques are useful in classifying or predicting risk of musculoskeletal disorder, predictive models for risk of musculoskeletal disorder using the results of clinical test or quantitative data are scarce. Objects: This study aimed to (1) investigate the difference between young women with and without SW, (2) establish a predictive model for presence of SW, and (3) determine the cutoff value of each variable for predicting the risk of SW using the decision tree method. Methods: Fifty young female subjects participated in this study. To classify the presence of SW as the outcome variable, scapular protractor strength, elbow flexor strength, shoulder internal rotation, and whether the scapula is in the dominant or nondominant side were determined. Results: The classification tree selected scapular protractor strength, shoulder internal rotation range of motion, and whether the scapula is in the dominant or nondominant side as predictor variables. The classification tree model correctly classified 78.79% (p = 0.02) of the training data set. The accuracy obtained by the classification tree on the test data set was 82.35% (p = 0.04). Conclusion: The classification tree showed acceptable accuracy (82.35%) and high specificity (95.65%) but low sensitivity (54.55%). Based on the predictive model in this study, we suggested that 20% of body weight in scapular protractor strength is a meaningful cutoff value for presence of SW.

• The Journal of Korean Physical Therapy
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• 제18권3호
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• pp.59-70
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• 2006

Purpose: This study is intended to examine the aquatic exercise on the improvement of muscle atrophy and motor function in an ischemic stroke model induced by middle cerebral artery occlusion. Methods: We used 60 Sprague-Dawely rats which were divided into 4 groups; the subjects were divided into group of 5 rats. Group I was a group of high dose aquatic exercise after inducing ischemic stroke; Group II was a group of low dose aquatic exercise after inducing ischemic stroke; Group III was a control group, Group IV was a sham group without ischemic stroke. Results: Muscle weight of gastrocnemius muscle was significantly difference in Group II compared to Group III on 8 weeks(p<0.05). For the changes in relative muscle weight of gastrocnemius muscle, there was significant increase in Group II compared to Group III on 8 weeks(p<0.05). For neurologic exercise behavior test, Group II generally had the highest score, compared to other groups. The results of behavior test that Group II improved in degeneration and inflammation of muscle fiber and decreased in destruction of nerve cells and cerebral infarction, indicating a similar state of muscle fiber and brain to Group III. Conclusion: Based on these results, aquatic exercise may improve muscle atrophy and contribute to the improvement of motor function.

• 한국터널지하공간학회 논문집
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• 제9권3호
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• pp.263-273
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• 2007

일반적으로 고심도에 건설되는 암반구조물의 경우 높은 현지응력과 공동의 굴착에 따른 유도응력으로 인하여 공동 경계면에서 스폴링(spatting)이나 슬래빙(slabbing)과 같은 취성파괴가 발생할 수 있다. Hoek-Brown과 Mohr-Coulomb 파괴기준과 같은 전통적인 파괴기준을 적용한 결과 취성파괴현상과 파괴심도 등을 예측할 수 없는 것으로 나타나 취성파괴를 예측하기 위한 여러 모델이 제안되었으며, 그 중 CWFS 모델이 적합한 것으로 알려져 있다. 본 연구에서는 모형실험에서 얻어진 원형공동주변의 취성파괴현상을 모델링하기위하여 CWFS 모델을 적용하였으며, 입력자료의 산정을 위해 암석의 손상정도와 손상에 따른 물성의 변화를 측정하는 손상제어시험을 수행하였다. CWFS 모델에 의해 예측된 파괴양상을 전통적인 파괴기준에 의한 해석결과 및 모형실험결과와 비교하여 취성파괴모델링의 적용성을 평가하였다.

• Tuberculosis and Respiratory Diseases
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• 제82권4호
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• pp.311-318
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• 2019

Background: Although physical activity is known to be beneficial to lung function, few studies have been conducted to investigate the correlation between physical activity and lung function in dusty areas. Therefore, the purpose of this study is to investigate the correlation between physical activity and lung function in a Korean cohort including normal and COPD-diagnosed participants. Methods: Data obtained from the COPD in dusty areas (CODA) cohort was analyzed for the following factors: lung function, symptoms, and information about physical activity. Information on physical activity was valuated using questionnaires, and participants were categorized into two groups: active and inactive. The evaluation of the mean lung function, modified Medical Research Council dyspnea grade scores, and COPD assessment test scores was done based on the participant physical activity using a general linear model after adjusting for age, sex, smoking status, pack-years, height, and weight. In addition, a stratification analysis was performed based on the smoking status and COPD. Results: Physical activity had a correlation with high forced expiratory volume in 1 second ($FEV_1$) among CODA cohort (p=0.03). While the active group exhibited significantly higher $FEV_1$ compared to one exhibited by the inactive group among past smokers (p=0.02), no such correlation existed among current smokers. There was no significant difference observed in lung function after it was stratified by COPD. Conclusion: This study established a positive correlation between regular physical activity in dusty areas and lung function in participants.

• 한국농공학회논문집
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• 제66권1호
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• pp.15-24
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• 2024

Unlike artificially created homogeneous materials, the process of calculating the elastic modulus of natural soil involves the possibility of errors. Because the stress-strain behavior of soil is nonlinear, the secant modulus of elasticity is often used based on 1/2 of the stress at failure. Since soil has the property of changing its elastic modulus depending on the confining pressure, numerical analysis models that analyze its behavior inevitably include complex elements. The hyperbolic model, which relatively accurately simulates the behavior immediately after loading in soft ground, assumes that the stress-strain curve of the consolidated undrained triaxial test is hyperbolic and requires the slope of the tangent line at the starting point. However, the slope of the initial tangent in the stress-strain curve obtained from an actual triaxial test is difficult to have regularity according to changes in confining pressure. Additionally, due to the characteristics of a hyperbola, even small changes in related factors cause large changes in the hyperbola. Therefore, there is a lot of randomness in the process of calculating model parameters from the triaxial test results, which causes large differences in the results. Therefore, the method of calculating the initial elastic modulus by the consolidation test presented in this study is also used to verify the method by the triaxial test. It can be applied. However, since this study was applied to only one sample showing typical consolidation characteristics, it is necessary to check samples with various physical properties in the future.

• 한국산학기술학회논문지
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• 제17권5호
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• pp.260-268
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• 2016

본 연구는 만성질환자 노인의 피로, 우울 및 신체활동의 정도와 그 관계를 밝히고, 우울 및 신체활동이 피로에 미치는 영향을 파악하기 위한 서술적 조사 연구이다. 연구 대상자는 경북지역의 3곳의 의료기관 외래를 방문한 500명의 만성질환 노인이었으며, 자료는 일반적 특성, 피로, 우울과 신체활동에 관한 설문지를 통해 수집되었다. 수집된 자료는 ANOVA, t-test, sheffe test, pearson's correlation coefficient와 hierarchial regression으로 분석하였다. 연구결과 만성질환자의 피로는 우울과는 음의 상관관계를, 신체활동 정도와는 양의 상관관계를 보였고, 일반적 특성과의 차이비교에서는 연령과 성별, 학력에서 차이가 있었다. 또한 피로와 차이를 보인 연령, 성별 및 학력을 통제하기 위해 위계적 회귀분석을 실시한 결과 1단계 모형에서 연령, 성별 및 학력은 피로에 6%의 영향력을 가지고 있었고, 2단계 모형에서는 우울과 신체활동은 만성질환 노인의 피로에 16%의 영향력을 갖는 것으로 나타났다. 결론적으로 만성질환자 노인의 피로는 우울 및 신체활동에 영향을 받으므로 우울의 중재와 신체활동 향상를 위한 노력은 피로를 감소시키는 데에 도움이 될 수 있다. 따라서 만성질환을 가진 노인에 대한 피로 중재에는 우울을 감소시키기 위한 방안과 신체활동을 증가시킬 수 있는 전략이 함께 포함되어야 할 것이다. 본 연구 결과는 만성질환 노인의 피로 정도를 감소시키기 위한 전략을 개발하는 데에 기초자료로 활용할 수 있다.

• 대한물리치료과학회지
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• 제8권1호
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• pp.759-770
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• 2001

The purpose of this study is through a analysis between old diagnostic tests of the Internet Addiction Syndrome to make a new test model for the physical disturbance problems for the addiction persons. Suggestion treatment for the Internet Addiction Syndrome are follows: 1. Try to decide in advance how much time you will spend on the Net time a day. 2. Decide how much you want the Internet to be a part of each area of your life and then allocate time accordingly. 3. You may decide that you want to keep the Internet at work, and shut the door on it when you leave for home. 4. To physical exercise regularly. 5. Take frequent breaks. 6. Seek out friends and acquaintances who couldn't care less about the Internet. 7. Interact with people in a non-wired world. 8. Consult a Dr. if you can't solved.

• 문화기술의 융합
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• 제6권4호
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• pp.453-468
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• 2020

본 연구의 목적은 습관형성모델을 기반으로 간호대학 여학생의 신체활동 정도와 신체활동에 미치는 영향요인을 파악하여 간호대학 여학생의 신체활동 증진 및 유지 전략을 개발하는데 기초자료를 제공하기 위함이다. 연구대상은 J시에 소재한 G대학교와 J대학교에 간호학과에 재학중인 여학생 207명이었고, 자료수집 기간은 2020년 8월 31일에서 9월 13일까지였다. 자료 분석은 IBM SPSS Statistics Ver. 22.0 통계프로그램을 사용하여 빈도, 백분율, 평균, 표준편차, ANOVA 및 Scheffĕ test, Pearson's correlation coefficient, Univariate, and Multivariate multinomial logistic regression을 이용하였다. 연구결과 간호대학 여학생의 신체활동 정도는 평균 2506.31±2807.05 MET-min/week이었고 신체활동 분류기준에 따라 세 군으로 분류한 결과 건강증진 신체활동군은 59명(28.5%), 최소한 활동군은 98명(47.3%), 비활동군은 50명(24.2%)으로 나타났다. 다변량 로지스틱 회귀분석에서는 신체활동 습관강도가 간호대학 여학생의 신체활동에 유의한 영향요인으로 규명되었다. 따라서, 간호대학 여학생의 신체활동 증진 및 유지를 위해 습관형성 프로그램을 개발하고 효과를 검증하는 연구가 필요하다.

• 대한간호학회지
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• 제35권3호
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• pp.565-574
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• 2005

Purpose: The purpose of this study was to develop a Dan Jeon Breathing Model and to identify effects of the developed Dan Jeon Breathing Model for maintenance and promotion of health and improvement of health problems in middle-aged women. Method: This study was constructed with two procedures. The first procedure was to develop appropriate movements for middle-aged women, performing a focus group discussion and developing a Dan Jeon Breathing Model in qualitative research. The collected data from focus group discussions was categorized for fitting movements. The second procedure was to verify and conclude a Hypothetic Dan Jeon Breathing Model through a quasi-experimental nonequivalent control group pre-post test design. Result: The developed Dan Jeon Breathing Model was composed of 28 preparation movements to accept Ki comfortably, 10 breathing movements to accumulate Ki for activation of metabolic function in organs and 14 finishing movements to transmit activated Ki to organs. It took 40 minutes to do them. In the Second procedure, the score of physical health (t=4.205, p=.000), psycho-social health(t=3.292, p=.002) and physical strength of the experimental group(t=5.905, p=.000) was higher than that of the control group. Conclusion: The Dan Jeon Breathing Model developed in this study is the correct health promotion model for middle-aged women, their demand, developmental traits and health problems.