• Title/Summary/Keyword: College Based Stress

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An extended finite element method for modeling elastoplastic FGM plate-shell type structures

  • Jrad, Hanen;Mars, Jamel;Wali, Mondher;Dammak, Fakhreddine
    • Structural Engineering and Mechanics
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    • v.68 no.3
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    • pp.299-312
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    • 2018
  • In this paper, an extended finite element method is proposed to analyze both geometric and material non-linear behavior of general Functionally Graded Material (FGM) plate-shell type structures. A user defined subroutine (UMAT) is developed and implemented in Abaqus/Standard to study the elastoplastic behavior of the ceramic particle-reinforced metal-matrix FGM plates-shells. The standard quadrilateral 4-nodes shell element with three rotational and three translational degrees of freedom per node, S4, is extended in the present study, to deal with elasto-plastic analysis of geometrically non-linear FGM plate-shell structures. The elastoplastic material properties are assumed to vary smoothly through the thickness of the plate-shell type structures. The nonlinear approach is based on Mori-Tanaka model to underline micromechanics and locally determine the effective FGM properties and self-consistent method of Suquet for the homogenization of the stress-field. The elasto-plastic behavior of the ceramic/metal FGM is assumed to follow Ludwik hardening law. An incremental formulation of the elasto-plastic constitutive relation is developed to predict the tangent operator. In order to to highlight the effectiveness and the accuracy of the present finite element procedure, numerical examples of geometrically non-linear elastoplastic functionally graded plates and shells are presented. The effects of the geometrical parameters and the volume fraction index on nonlinear responses are performed.

Status of Antepartum Depression and Its Influencing Factors in Pregnant Women (임신 여성의 산전우울 실태 및 영향요인)

  • Lee, Eun-Joo;Park, Jeong-Sook
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.8
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    • pp.3897-3906
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    • 2013
  • The purpose of this study was to identify the rate and influencing factors on antepartum depression in pregnant women. A self-administered questionnaire-based study was performed in 160 pregnant women who visited outpatient clinics or attended special lectures of the general hospital in D metropolitan city. All participants were interviewed using the Korean version of Edinburgh Postnatal Depression Scale(EPDS). The data were analyzed using descriptive statistics, t-test, ANOVA, Pearson's correlation coefficients, and stepwise multiple regression. On the results, the mean score of antepartum depression was $7.80{\pm}4.86$ scores(0-30 scores). The percentage of all participants for EPDS scale were 56.3% with normal level, 20.6% with a boundary line and 23.1% with serious level. Influencing factors on antepartum depression were accounted for 36.7% of the total variance which consisted of perceived health status, pregnancy stress and self esteem. The results indicate that these variables should be considered in preventing depression of pregnant women.

Association between Awareness of Nutrition Labels and Menstrual Cycle Irregularity in Korean Women: The Fifth Korea National Health and Nutrition Examination Survey (2010~2012)

  • Yoo, Hae Young;Ryu, Eunjung;Kim, Ji-Su;Han, Kyung-do
    • Journal of Korean Academy of Nursing
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    • v.47 no.1
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    • pp.133-141
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    • 2017
  • Purpose: The aim of this study was to identify the relationship between awareness of nutrition labeling and menstrual cycle irregularity in women from a nationally representative sample of the Korean population. Methods: A cross-sectional analysis was performed using hierarchical multi-variable logistic regression analysis models. A total of 4,324 women aged 19~54 years from the 2010~2012 Korean National Health and Nutrition Examination Survey participated in the study. The participants were classified into three groups based on self-report responses to a questionnaire about their awareness of nutrition labels: Reading, Not-Reading, and Not-Knowing Groups. Results: The Reading, Not-Reading, and Not-Knowing Groups comprised 46.4%, 44.9%, and 8.7% of the participants, respectively, and 53.6% of the participants had never used nutrition labels. In the Not-Knowing Group, irregular menstrual cycles for more than 3 months were significantly more common than women with irregular menstrual cycles for up to 3 months and women with regular menstrual cycles. Women in the Not-Knowing Group were more likely to exhibit menstrual cycle irregularity (adjusted odds ratio: 1.63, 95% confidence interval: 1.10~2.41) compared to women in the Reading Group after adjusting for age, body mass index, smoking status, alcohol intake, exercise regularity, stress, depression, suicidal ideation, metabolic syndrome, age at menarche, parity, and use of oral contraceptives. Conclusion: No awareness of nutrition labeling appears to be associated with a higher prevalence of menstrual cycle irregularity in a nationally representative group of Korean women.

Development of MLS Difference Method for Material Nonlinear Problem (MLS차분법을 이용한 재료비선형 문제 해석)

  • Yoon, Young-Cheol
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.29 no.3
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    • pp.237-244
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    • 2016
  • This paper presents a nonlinear Moving Least Squares(MLS) difference method for material nonlinearity problem. The MLS difference method, which employs strong formulation involving the fast derivative approximation, discretizes governing partial differential equation based on a node model. However, the conventional MLS difference method cannot explicitly handle constitutive equation since it solves solid mechanics problems by using the Navier's equation that unifies unknowns into one variable, displacement. In this study, a double derivative approximation is devised to treat the constitutive equation of inelastic material in the framework of strong formulation; in fact, it manipulates the first order derivative approximation two times. The equilibrium equation described by the divergence of stress tensor is directly discretized and is linearized by the Newton method; as a result, an iterative procedure is developed to find convergent solution. Stresses and internal variables are calculated and updated by the return mapping algorithm. Effectiveness and stability of the iterative procedure is improved by using algorithmic tangent modulus. The consistency of the double derivative approximation was shown by the reproducing property test. Also, accuracy and stability of the procedure were verified by analyzing inelastic beam under incremental tensile loading.

A Study of the Trends in Korean Nursing Research on Critical Care in the Last 10 Years (2008-2017) Using Integrated Review and Key Word Analysis (통합적 고찰과 키워드 분석을 이용한 최근 10년(2008-2017) 동안의 국내 중환자간호 연구 동향 분석)

  • Kang, Jiyeon;Kim, Soo Gyeong;Cho, Young Shin;Ko, Hyunyoung;Back, Ji Hyun;Lee, Su Jin
    • Journal of Korean Critical Care Nursing
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    • v.11 no.2
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    • pp.75-85
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    • 2018
  • Purpose : The purpose of this study was to examine the possible direction of critical care nursing research in the future by analyzing the trends of recent Korean studies. Method : Using a database search, we selected 263 articles on critical care nursing that were published in Korean journals between 2008 and 2017. Then, we conducted an integrative review of the contents of the selected articles and analyzed the English abstracts using the relevant packages and functions of the R program. Results : The number of studies concerning critical care nursing has increased over the 10-year period, and the specific topic of each study has diversified according to the time at which it was conducted. In terms of quality, the majority of the research was published in high-level academic journals. The key words regularly studied over the past decade were: knowledge, delirium, education, restraint, stress, and infection. Studies related to vancomycin-resistant enterococci infection, compliance, and standards have decreased, while studies related to death, communication, and safety have increased. Conclusion : Randomized controlled trials and protocol research for evidence-based critical care need to be conducted, as does research on family involvement. The key word analysis of unstructured text used in this study is a relatively new method; it is suggested that this method be applied to various critical care nursing research and develop it methodologically.

Current Status and Future Perspective of Nuclear Cardiology (심장핵의학의 현황과 전망)

  • Chung, June-Key
    • Nuclear Medicine and Molecular Imaging
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    • v.43 no.3
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    • pp.159-164
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    • 2009
  • Coronary artery disease is on the rise over the world. Myocardial perfusion SPECT is a well established technique to detect coronary artery disease and to assess left ventricular function. In addition, it has the unique ability to predict the prognosis of the patients. Moreover, the application of ECC-gated images provided the quantitatve data and improved the accuracy. This approach has been proved to be cost-effective and suitable for the emerging economies as well as developed countries. However, the utilization of nuclear cardiology procedures vary widely considering the different countries and region of the world. Korea exits 2-3 times less utilization than Japan, and 20 times than the United States. Recently, with the emerging of new technology, namely cardiac CT, cardiac MR and stress echocardiography, the clinical usefulness of nuclear cardiology has been called in question and its role has been redefined. For the proper promotion of nuclear cardiology, special educations should be conducted since the nuclear cardiology has the contact points between nuclear medicine and cardiology. Several innovations are in horizon which will impact the diagnostic accuracy as well as imaging time and cost savings. Development of new tracers, gamma camera technology and hybrid systems will open the new avenue in cardiac imaging. The future of nuclear cardiology based on molecular imaging is very exciting. The newly defined biologic targets involving atherosclerosis and vascular vulnerability will allow the answers for the key clinical questions. Hybrid techniques including SPECT/CT indicate the direction in which clinical nuclear cardiology may be headed in the immediate future. To what extent nuclear cardiology will be passively absorbed by other modalities, or will actively incorporate other modalities, is up to the present and next generation of nuclear cardiologists.

Water-extract of Helianthus annuus Seed Exhibits Potent Anti-asthma Activity In Vitro and In Vivo (해바라기씨 추출물의 천식 완화 효과)

  • Heo Jin-Chul;Park Ja-Young;Woo Sang-Uk;Chung Shin-Kyo;Jeong Kyu-Shick;Lee Jin-Man;Ma Jin-Yeol;Lee Sang-Han
    • Food Science and Preservation
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    • v.13 no.4
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    • pp.495-500
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    • 2006
  • In order to investigate whether antioxidant biomaterials inhibits IL-4 and/or IL-13 expression in vitro and in vivo, we carried out antioxidant assays by enzyme or cell-based assays with Helianthus annuus extract. Antioxidant assays include DPPH, FRAP, hydroxyl radical assays. Helianthus annuus extract exhibited SOD scavenging activity, and had different patterns by each solvent extracted reaction. DW extract inhibited oxidative stress by $H_2O_2$ that induced apoptosis. We measured $CD4^+$ cell and IL-/13 cytokine expression in a classical mouse animal model. The result show that Helianthus annuus extract showed strung inhibition of immune response in the lung. These result suggest that Helianthus annuus extract can reduce inflammation induced by n mouse asthma model.

Health Status, Health Behavior, and Health Promotion Program Needs of Industrial Male Workers according to Shift Work at an Workplace (일개 산업장 남성 근로자의 근무형태별 건강상태와 건강행위 및 건강증진 프로그램 요구도)

  • Hwang, Seung-Sook
    • Research in Community and Public Health Nursing
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    • v.17 no.2
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    • pp.210-222
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    • 2006
  • Purpose: This study was performed to identify the health status, healthy behavior, and health promotion program needs of day time and shift time industrial male workers at an workplace. Method: Relevant data were collected from June 20 to August 18, 2005. Questionaries were distributed to all subjects along with their medical records of 2005 and 151 sets of responses were used for the analysis. Collected data were analyzed using SPSS WIN 10.0. Result: 1. Health Status - day time and shift-time workers had significant differences in obesity ($x^2=8.38$, p<.01) and blood pressure ($x^2=-2.17$, p<.05). 2. Healthy Habits - Full-time and part-time workers had significant differences in regular meals (63.83, p<.01), preferred foods ($x^2=7.10$, p<.05), and sleep time (t=-3.55, p<.01). They also had significant differences in exercising ($x^2=13.11$, p<.01), exercising time (minutes) (t=-2.25, p<.01), and use of fitness centers ($x^2=7.02$, p<.05). 3. They also had significant differences in their needs of health programs ($x^2=8.66$, p<.01). Conclusion: This study revealed that day time and shift-time workers had differences in obesity and blood pressure, as well as differences in eating sleeping, and exercising patterns. Both groups needed 'fitness programs' more than any other types of health programs and picked 'weight loss' and 'stress control' programs for other options. Industrial nurses should be able to create appropriate health programs for each group based on the above results and induce the workers' active participation.

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Verification of Parameters Influencing Bond Strength between Fiber-Reinforced Polymer Laminates and Concrete (연속섬유(FRP)시트와 콘크리트의 부착강도 영향 요인 검증)

  • Ko, Hune-Bum
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.9
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    • pp.414-423
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    • 2020
  • Fiber-reinforced polymer (FRP) laminate sheets, which are lightweight with high strength, are commonly used to reinforce concrete structures. The bonding strength is vital in structural design. Therefore, experiments and analytical studies with differing variables (concrete compressive strength and tensile strength, the elastic modulus of concrete and FRP, thickness of concrete and FRP, width of concrete and FRP, bond length, effective bond length, fracture energy, maximum bond stress, maximum slip) have been conducted to obtain an accurate numerical model of the bond strength between an FRP sheet and concrete. Although many models have been proposed, no validated model has emerged that could be used easily in practice. Therefore, this study analyzed the parameters that influence the bond strength that were used in 23 of the proposed models (Khalifa model, Iso model, Maeda model, Chen model, etc.) and compared them to the test results of 188 specimens via the numerical results of each model. As a result, an easy-to-use practical model with a simple and high degree of expression was proposed based on the Iso model combined with the effective bond length model that was proposed by Holzenkӓmpfer.

A Study on the Knowledge-Based T.P.N. System (1) (지식 구조화 경정맥 완전 영양공급 시스템의 개발에 관한 연구 (I))

  • Jeon, Gye-Rok;Choe, Sam-Gil;Byeon, Geon-Sik
    • Journal of Biomedical Engineering Research
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    • v.11 no.2
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    • pp.305-314
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    • 1990
  • In this paper we have implemented and tested TPN which is system to supply sufficent nutrition to nutritionally deficient patient by means of ES (expert system) a kind of A.1 (artificial intelligence) . This system affords to evaluation of nutritional state of patient which is essential to physi- cian. who performs TPN, decision of performing TPN and management of patient-data & calculation of information needing to making TPN fluid. The features were as follolv 1. we input data, take ideal weight of patient and 24hr's creatlnln In urine according to chart in system compare TSF (triceps skin fold), MAC (mid-arm circumference), AMC (arm muscle circumference) to 5th, 15th, 50th percentile and evaluate the nutritional state of patient. 2. Calculation of protein & nonprotein calorie needing to treament of patient can be made exactly by stress factor, activity factor and body temperature. 3. patient's personal recording needing to management of patient date name of chief doc- tor, name of department of admission, chart number, history can by taken very easily. 4. The way of system operating is pull-down Menu one, It can be processing very efficiently. 5. Date processing in system, we can manage memory volume of computer verlr efficiently using of dynamic allocation variables. 6. We can make it very easy to edit & revise the input data, processed data is saved to diskette in 2 files (TDF, THF) , these are semipermanent preservation.

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