• Title/Summary/Keyword: Long-term effect

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Temperature effect analysis of a long-span cable-stayed bridge based on extreme strain estimation

  • Yang, Xia;Zhang, Jing;Ren, Wei-Xin
    • Smart Structures and Systems
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    • v.20 no.1
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    • pp.11-22
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    • 2017
  • The long-term effect of ambient temperature on bridge strain is an important and challenging problem. To investigate this issue, one year data of strain and ambient temperature of a long-span cable-stayed bridge is studied in this paper. The measured strain-time history is decomposed into two parts to obtain the strains due to vehicle load and temperature alone. A linear regression model between the temperature and the strain due to temperature is established. It is shown that for every $1^{\circ}C$ increase in temperature, the stress is increased by 0.148 MPa. Furthmore, the extreme value distributions of the strains due to vehicle load, temperature and the combination effect of them during the remaining service period are estimated by the average conditional exceedance rate approach. This approach avoids the problem of declustering of data to ensure independence. The estimated results demonstrate that the 95% quantile of the extreme strain distribution due to temperature is up to $1.488{\times}10^{-4}$ which is 2.38 times larger than that due to vehicle load. The study also indicates that the estimated extreme strain can reflect the long-term effect of temperature on bridge strain state, which has reference significance for the reliability estimation and safety assessment.

Efficiency, Ignorance, and Environmental Effect - long-run Relationship between Asbestos Consumption and the Incidence of Mesothelioma - (효율성과 무지, 그리고 환경피해 - 석면 사용과 악성중피종 발생의 장기관계 -)

  • Son, Donghee;Jeon, Yongil
    • Environmental and Resource Economics Review
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    • v.26 no.3
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    • pp.287-317
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    • 2017
  • Asbestos has been actively used for various places. Since it was designated as the first grade carcinogen in the 1970s, strict regulations on using asbestos has been implemented globally. Considering long-term latent periods between asbestos exposure and environmental diseases, we analyze the time lag between asbestos consumption and the incidence of mesothelioma in Korea and estimate the long-run relationship. In addition, we conduct a comparative analysis on the effectiveness of asbestos regulations in the United Kingdom and the United States, which have accumulated long-term time-series observations. The latent period analysis indicates that the consumption of asbestos and the incidence of the disease are highly correlated in all three countries, being long-term lags of more than 30 years. Also, we find a long-run equilibrium relationship between asbestos consumption and the incidence of mesothelioma in the presence of long-term lags between the variables in all three countries. Furthermore, using a distributed lag model, asbestos consumption has statistically significant positive effects on mesothelioma with a long-term lag.

Hydrogen Evolution Ability of Selected Pure Metals and Galvanic Corrosion Behavior between the Metals and Magnesium

  • Luo, Zhen;Song, Kaili;Li, Guijuan;Yang, Lei
    • Journal of Electrochemical Science and Technology
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    • v.11 no.4
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    • pp.323-329
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    • 2020
  • The cathodic hydrogen evolution ability of different pure metals and their long term galvanic corrosion behavior with pure Mg were investigated. The hydrogen evolution ability of pure Ti, Al, Sn and Zr is weak, while that of Fe, W, Cr, and Co is very strong. Initial polarization test could not completely reveal the cathodic behavior of the tested metals during long term corrosion. The cathodic hydrogen evolution ability may vary significantly in the long term galvanic tests for different metals, especially for Al whose cathodic current density reduced to 1/50 of the initial value. The anodic polarization shows that Al and Sn as alloying elements are supposed to provide relatively good passive effect for Mg alloy, while Ag can provide a slight passive effect and Zn has little passive effect.

The Effect of Capital Structure on Financial Performance of Vietnamese Listing Pharmaceutical Enterprises

  • DINH, Hung The;PHAM, Cuong Duc
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.9
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    • pp.329-340
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    • 2020
  • This study investigates the effect of capital structure on the financial performance of pharmaceutical enterprises which are listing on Vietnam's stock market. The study builds the regression using ROE as dependent variable and four independent variables, including self-financing, financial leverage, long-term asset and debt to assets ratios. In addition, we use other variables as controlling ones, such as firm size, fixed asset rate and growth. We collect data for the period from 2015 to 2019 of all 30 pharmaceutical enterprises which are currently listing on Vietnam's stock market. The least square regression (OLS) is used to test the effect of capital structure to the firms' financial performance. The analysis results show that the financial leverage ratio (LR), long-term asset ratio (LAR) and debt-to-assets ratio (DR) have positive relationship with firm performance, meanwhile the self-financing (E/C) affects negatively to the return on equity (ROE). Upon the findings we suggest that the Vietnamese government should focus on stabilizing macro environment to create favorable environment for enterprises. And the pharmaceutical enterprises should build more reasonable capital structure with higher debt proportion than equity, diversifying loan mobilization channels such as issuing long-term bonds. Additionally, the firms should expand the scale appropriately to maintain development and ability to pay debts.

Long-term Effect of a Fermented Milk Product on the Level of Blood Cholesterol in Korean (유산균발효유 장기음용시 혈중 콜레스테롤에 미치는 영향)

  • 이용욱;김종규;노우섭;김판기;나승식
    • Journal of Food Hygiene and Safety
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    • v.14 no.1
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    • pp.122-128
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    • 1999
  • The cholesterol-lowering effect of a fermented milk was studied for long-term period (56 weeks) in 206 Korean adults (106 normal cholesterol group and 100 hypercholesterol group) 300 $m\ell$ of the fermented milk was taken daily to all subjects for 10 weeks. 24 subjects drinking the fermented milk for 56 weeks and 42 subjects no-drinking for 40 weeks and then re-drinking from 50 th week for 6 weeks were followed up. Paired t-test, Duncan's multiple range test, and GLM repeated measure were used for statistical analysis. The level of total blood cholesterol and LDL after drinking the fermented milk for 10 weeks were decreased significantly in both group and affected by total cholesterol level at baseline, BMI, smoking and drinking. there is no significant change in triglyceride, HDL, and LDL/HDL ratio by drinking the fermented milk. The fermented milk intake for long-term period (56 weeks) did not show any more effect after 10 week on the level of TC, TG, HDL, LDL.

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An Analysis of the Research on Effect of Smoking Cessation Intervention (국내학술지에 발표된 금연중재논문(1980-2007) 분석)

  • Hyun, Hye-Jin;Ahn, Hye-Young
    • Research in Community and Public Health Nursing
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    • v.19 no.3
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    • pp.469-479
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    • 2008
  • Purpose: We reviewed all the articles on effect of smoking cessation intervention to find out the way of improvement of it. Method: 48 researches were published in Korean journals from 1980 to 2007. The research were analyzed according to: major of first author, subjects, application of theoretical framework, contents of intervention, a term of intervention, the time of evaluation on effect of interventions, research design, dependant variables, and effect of interventions. Results: Research on effect of smoking cessation intervention increased rapidly in the 2000's. At this time. 72.9% of research was published. Most of research subject were students. Theoretical framework were applied in 20.8% of articles. The most common intervention was education(39.4%). The effect of combined program on outcome variable was found to be stronger than only education program. Experimental design was used in 29.2% and quasi-experimental design was adapted in 43.8% of articles. 1- 6months intervention was in 35.4%. The long term intervention more than 1month was found to be effective. Health behavior related index was measured as a dependant variable in 62.3%. conclusion: Accordingly, long term program to apply to various subject is needed.

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A study on the evaluation of policy elements for a solution of long-term unexecuted urban parks (장기 미집행 도시공원 해소를 위한 정책구성요인 평가 연구)

  • Hong, Ji Wook;Shim, Jae Heon;Lee, Sung-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.6
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    • pp.3907-3915
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    • 2014
  • This paper provides a solution for long-term unexecuted urban parks and its implication by evaluating the policy elements using an analytic hierarchy process approach. The policy elements evaluation was carried out for a group of experts related to long-term unexecuted urban planning facilities or parks. The evaluation process consisted of the following three steps: the selection of policy elements, the weights assessment, and an analysis of the evaluation results. The empirical findings show that experts place a high value on policy elements, such as government subsidies (0.183), the linkage between a municipal fiscal plan and an executive plan (0.165), a reconsideration of the current long-term unexecuted urban parks (0.154), and a grant or long-term lease of state-owned land (0.110). A wide range of in-depth discussion is strongly needed ahead of the sunset regulation on urban parks, which will take effect in 2015.

Effects of Transformational Leadership on the Organizational Effectiveness of Long-Term Care Facilities : Focusing on the Care Giver's Mediating effect of Empowerment (노인장기요양기관의 변혁적 리더십이 조직효과성에 미치는 영향 : 요양보호사의 임파워먼트 매개효과를 중심으로)

  • Shin, Yongseok;Jung, Eunkyung;Kim, Jungwoo
    • Korean Journal of Social Welfare
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    • v.66 no.3
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    • pp.75-99
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    • 2014
  • The purpose of this study is to examine effects of empowerment on relationship between supervisors transformational leadership recognized by care givers and organizational effectiveness represented as the job satisfaction and the organizational commitment. For the purpose, survey were conducted with care givers working in long-term care facilities in Seoul, Gyeonggi-do and Incheon, and final data were resulted from analysis of 283 examines of those care givers. The findings of this study were as follows: first, transformational leadership of long-term care facilities had a significant influence on the job satisfaction and organizational commitment. Second, the care giver's empowerment had a influence on the job satisfaction and organizational commitment. Third, empowerment worked as mediators between the transformational leadership of long-term care facilities and care giver's job satisfaction and organizational commitment. Based upon these findings, we can propose practices towards improving a long-term care facilities administrator's transformational leadership and implication of program development and provide an institutional strategy aiming to care giver's empowerment improvement.

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Effect of Motor Functions of Ipsilateral Upper Limb Induced by Long-Term Cane Usage in Chronic Stroke Patients (장기간 지팡이의 사용이 뇌졸중 환자의 건측 상지 기능에 미치는 영향)

  • Son, Sung-Min;Choi, Yong-Won;Kim, Chung-Sun
    • The Journal of Korean Physical Therapy
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    • v.24 no.2
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    • pp.151-156
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    • 2012
  • Purpose: The purpose of this study was to investigate the adverse effects of sensorimotor function at the shoulder joint according to long-term cane usage in stroke patients without apraxic behavior, in terms of the presence of shoulder joint pain, accuracy of tracking task, proprioceptive joint position sense, and nine-hole pegboard. Methods: Nineteen stroke patients with long-term cane usage (cane usage group) and nineteen stroke patients without cane usage (non-cane usage group) were recruited. All subjects were tested in pain presence, a tracking task for visuomotor function, joint reposition, and nine-hole pegboard in the shoulder joint regarding the non-affected side. Results: In the accuracy index for tracking task and the nine-hole pegboard test, significant differences were observed between the cane usage group and the non-cane usage group. However, although a higher emergence of shoulder pain and a lower accuracy for joint reposition sense were detected in the cane usage group in comparison to the non-cane usage group, there were no significant differences between the two groups. Conclusion: Our findings suggest that long-term cane usage could induce to decrease in delicate movement and coordination in the non-affected upper arm in stroke patients. In addition, they could experience high frequency of shoulder pain and poor joint reposition sense. Therefore, careful evaluation and observation will be required concerning stroke patients with long-term cane usage.

Influence of post-pouring joint on long-term performance of steel-concrete composite beam

  • Huang, Dunwen;Wei, Jun;Liu, Xiaochun;Zhang, Shizhuo;Chen, Tao
    • Steel and Composite Structures
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    • v.28 no.1
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    • pp.39-49
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    • 2018
  • The concrete bridge decks are usually precast and in-situ assembled with steel girders with post-pouring joint in the construction practice of super-wide steel-concrete composite beam. But the difference of concrete age between the precast slabs and the post-pouring joint has been not yet considered for the long-term performance analysis of this kind composite beam. A simply supported precast-assembled T-shaped beam was taken as an example to analyze the long-term performance of steel-concrete composite beam with post-pouring joint. Based on the deformation coordination conditions of the old-new concrete deck and steel girder, a theoretical model for the long-term behavior of precast-assembled composite beam is proposed in this paper according to age-adjusted effective modulus method. Then, the feasibility of the proposed model is verified by the available test data from the Gilbert's composite beams. Parametric studies were preformed to evaluate the influences of the cross-sectional area ratio of the post-pouring joint to the whole bridge deck, as well as the difference of concrete age between the precast slabs and the post-pouring joint, on the long-term performance of the composite beam. The results indicate that the traditional method without considering the age difference would seriously underestimate the effect of creep and shrinkage of concrete bridge decks. The concrete age difference between the precast slabs and the post-pouring joint should be demonstrated for the life cycle design and long-term performance analysis of precast-assembled steel-concrete composite beams.