• Title/Summary/Keyword: random-effect model

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Seismic Fragility Analysis of a Cable-stayed Bridge with Energy Dissipation Devices (에너지 소산장치를 장착한 사장교의 지진 취약도 해석)

  • Park, Won-Suk;Kim, Dong-Seok;Choi, Hyun-Sok;Koh, Hyun-Moo
    • Journal of the Earthquake Engineering Society of Korea
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    • v.10 no.3 s.49
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    • pp.1-11
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    • 2006
  • This paper presents a seismic fragility analysis method for a cable-stayed bridge with energy dissipation devices. Model uncertainties represented by random variables include input ground motions, characteristics of energy dissipation devices and the stiffness of cable-stayed bridge. Using linear regression, we established demand models for the fragility analysis from the relationship between maximum responses and the intensity of input ground motions. For capacity models, we considered the moment and shear force of the main tower, longitudinal displacement of the girder, deviation of the stay cables tension and the local buckling of the main steel tower as the limit states for cable-stayed bridge. As a numerical example, fragility analysis results for the 2nd Jindo bridge are presented. The effect of energy dissipation devices is also briefly discussed.

Boussinesq Modeling of a Rip Current at Haeundae Beach (Boussinesq 방정식 모형을 이용한 해운대 이안류 수치모의)

  • Choi, Jun-Woo;Park, Won-Kyung;Yoon, Sung-Bum
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.23 no.4
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    • pp.276-284
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    • 2011
  • The rip current occurred at Haeundae beach was numerically investigated under directional random wave environment. The numerical simulation was performed using a fully nonlinear Boussinesq equation model, FUNWAVE which is capable of simulating nearshore circulation since it includes the effect of wave-induced momentum flux and horizontal turbulent mixing. The results of numerical simulation show the time-dependent evolution of the wave-induced nearshore circulation system (including rip current) that are caused by nonlinear transformation of directional irregular waves due to unique topography of Haeundae. From the results, it was found that rip current is well generated and developed where relatively lower wave height and relatively deeper water depth along the longshore direction, and sudden and strong events of rip current were observed.

A Study of Probabilistic Groundwater Flow Modeling Considering the Uncertainty of Hydraulic Conductivity (수리전도도의 불확실성을 고려한 확률론적 지하수 유동해석에 관한 연구)

  • Ryu Dong-Woo;Son Bong-Ki;Song Won-Kyong;Joo Kwang-Soo
    • Tunnel and Underground Space
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    • v.15 no.2 s.55
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    • pp.145-156
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    • 2005
  • MODFLOW, 3-D finite difference code, is widely used to model groundwater flow and has been used to assess the effect of excavations on the groundwater system due to construction of subways and mountain tunnels. The results of numerical analysis depend on boundary conditions, initial conditions, conceptual models and hydrogeological properties. Therefore, its accuracy can only be enhanced using more realistic and field oriented input parameters. In this study, SA(simulated annealing) was used to integrate hydraulic conductivities from a few of injection tests with geophysical reference images. The realizations of hydraulic conductivity random field are obtained and then groundwater flows in each geostatistically equivalent media are analyzed with a numerical simulation. This approach can give probabilistic results of groundwater flow modeling considering the uncertainty of hydrogeological medium. In other words, this approach makes it possible to quantify the propagation of uncertainty of hydraulic conductivities into groundwater flow.

Factors Affecting Breast Self-examination Behavior Among Female Healthcare Workers in Iran: The Role of Social Support Theory

  • Bashirian, Saeed;Barati, Majid;Shoar, Leila Moaddab;Mohammadi, Younes;Dogonchi, Mitra
    • Journal of Preventive Medicine and Public Health
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    • v.52 no.4
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    • pp.224-233
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    • 2019
  • Objectives: In women, breast cancer is the most common cancer and the leading cause of cancer death. Screening tests are the basis for early diagnosis. In Iranian women, the mortality rate of breast cancer is high due to insufficient screening examinations and delayed visits for care. Therefore, this study aimed to determine the factors affecting breast self-examinations among Iranian women employed in medical careers. Methods: This cross-sectional study included 501 women working in the medical professions at Hamadan University of Medical Sciences in western Iran in 2018. The subjects were selected by stratified random sampling. Data were collected using a researcher-developed, self-report questionnaire that contained demographic information and questions based on protection motivation theory and social support theory. Descriptive data analysis was conducted using SPSS version 23 and model fitting with PLS version 2. Results: The mean age of the participants was $37.1{\pm}8.3years$, and most of the women (80.4%) were married. Most women had a bachelor's degree (67.5%). The findings of this study showed that the coping appraisal construct was a predictor of protection motivation (${\beta}=0.380$, p<0.05), and protection motivation (${\beta}=0.604$, p<0.05) was a predictor of breast self-examination behavior. Additionally, social support theory (${\beta}=0.202$, p<0.05) had a significant positive effect on breast self-examination behavior. Conclusions: The frequency of practicing self-examinations among women employees in the medical sector was low; considering the influence of social support as a factor promoting screening, it is necessary to pay attention to influential people in women's lives when designing educational interventions.

The Effects of Balloon-Guide Catheters on Outcomes after Mechanical Thrombectomy in Acute Ischemic Strokes : A Meta-Analysis

  • Ahn, Jun Hyong;Cho, Steve S.;Kim, Sung-Eun;Kim, Heung Cheol;Jeon, Jin Pyeong
    • Journal of Korean Neurosurgical Society
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    • v.62 no.4
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    • pp.389-397
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    • 2019
  • Objective : Mechanical thrombectomies with balloon-guide catheters (BGC) are thought to improve successful recanalization rates and to decrease the incidence of distal emboli compared to thrombectomies without BGC. We aimed to assess the effects of BGC on the outcomes of mechanical thrombectomy in acute ischemic strokes. Methods : Studies from PubMed, EMBASE, and the Cochrane library database from January 2010 to February 2018 were reviewed. Random effect model for meta-analysis was used. Analyses such as meta-regression and the "trim-and-fill" method were additionally carried out. Results : A total of seven articles involving 2223 patients were analyzed. Mechanical thrombectomy with BGC was associated with higher rates of successful recanalization (odds ratio [OR], 1.632; 95% confidence interval [CI], 1.293-2.059). BGC did not significantly decrease distal emboli, both before (OR, 0.404; 95% CI, 0.108-1.505) and after correcting for bias (adjusted OR, 1.165; 95% CI, 0.310-4.382). Good outcomes were observed more frequently in the BGC group (OR, 1.886; 95% CI, 1.564-2.273). Symptomatic intracranial hemorrhage and mortality did not differ significantly with BGC use. Conclusion : Our meta-analysis demonstrates that BGC enhance recanalization rates. However, BGC use did not decrease distal emboli after mechanical thrombectomies. This should be interpreted with caution due to possible publication bias and heterogeneity. Additional meta-analyses based on individual patient data are needed to clarify the role of BGC in mechanical thrombectomies.

The Effect of Mind Awareness Records on Awareness of Imaginations, Decentering, Parenting stress and Subjective Well-bing: With a Focus on Parents of Adolescents (마음알아차리기 기록이 공상자각, 탈중심화, 양육스트레스 및 주관적 안녕감에 미치는 영향 : 청소년기 자녀를 둔 부모를 중심으로)

  • Jung, Hyun Gi;Sung, Seoung Yun
    • Journal of Family Relations
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    • v.20 no.4
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    • pp.73-103
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    • 2016
  • Objectives: The purpose of this study is to examine the effects of reading mind recording on awareness of imaginations, Method: Decentering, parenting stress and subjective well-being through comparing expressive writing. random assignment was performed on each 13 persons of a recording group (experimental group) and an expressive writing group (comparison group) for reading mind from 26 parents having adolescents. The experimental group conducted the reading of reading mind and the comparison group performed expressive writing twice a week for eight weeks, twenty minutes per time, and responded to four questions on thought arrangement after writing. The researcher participated in the groups once per week and an assignment was suggested once per week. Repeated Measurement Two-way Repeated Measures ANOVA was conducted to confirm the differences according to periods and groups for the data analysis method. In order to examine the changes according to periods, t-test was conducted on the pre- and post-test. Results: The findings are as follows: First, regarding awareness of imaginations and decentering, the reading mind recording group showed a significant result in repeated measurement. Second, the reading mind recording group showed a significant decrease in the pre- and post-t-test about parenting stress. Third, all the reading mind recording group and expressive writing group showed significant results about subjective well-being. Conclusions: This study is significant in that it verified the effectiveness of reading mind recording on awareness of imaginations, decentering and parenting stress, and proved the possibility as an oriental counseling model that considers the characteristics of our culture.

The Role of Customer Values in Increasing Tourist Satisfaction in Gianyar Regency, Bali, Indonesia

  • CEMPENA, Ida Bagus;BRAHMAYANTI, Ida Ayu Sri;ASTAWINETU, Erwin Dyah;PANJAITAN, Feliks Anggia B.K.;KARTINI, Ida Ayu Nuh;PANJAITAN, Hotman
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.8
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    • pp.553-563
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    • 2021
  • Customer value has long been believed to be a direct trigger for increased tourist satisfaction, but as a mediating variable, it still needs to be proven further. This paper aims to examine the causal relationship between research variables, as well as to examine the role of customer value as a mediating variable in the relationship between service quality, brand quality, tourism products, customer value, and tourist satisfaction with tourists' objects. The population is tourists who visit tourist sites/destinations in the Gianyar Regency on the island of Bali, Indonesia, and the sample size is 270 respondents, selected through random sampling. Structural equation modeling (SEM), a multivariate statistical analysis technique, is used to analyze the causal relationships between variables. The results show that the model is accepted, and customer value is proven to be a positive mediating variable. The results also show that service quality, brand quality, and tourism products have an effect on customer value. This provides insight into the practical implications for tourism managers to increase the brand quality of tourist attractions as well as increase the professionalism and quality of tour guide services. This, in turn, will increase customer value and increase tourist satisfaction.

Analysis on the Transition and Determinants of Long-Term Care Service for the Elderly in the Internet of Things era (융합의 시대에(사물인터넷시대에)한국 노인의 장기요양 서비스 이용 상태 전환과 결정요인 분석)

  • Choi, Jang-Won
    • Journal of Internet of Things and Convergence
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    • v.6 no.4
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    • pp.39-48
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    • 2020
  • This study intends to the estimate the determinants and state dependence of long-term care services in Korea. For this purpose, we analyzed the transition patterns among three states of long-term care service utilization over time by using the Korea Welfare Panel Study data with the random effect multinomial logit model. It is found that the result showed a strong state dependence in long-term care service utilization. Especially, long-term care insurance for the elderly showed a strong state dependence among others. Among the individual demographic characteristics, the higher the age, the higher the probability of using long-term care insurance for the elderly, while the lower the probability when married. The characteristics of the residential region showed that the residents of the urban-rural integrated region had a significantly higher probability of using long-term care insurance than the reference region. The results of this study suggest that the long-term care service users have a strong state dependence, which means that it is important to take into account the increase in the utilization period of existing users in future demand forecasting.

Clinical and Laboratory Features of Pediatric Patients with COVID-19: Systematic Review and Meta-analysis (COVID-19 소아 환자의 임상 양상 및 실험실적 특징: 체계적문헌고찰 및 메타분석)

  • Yoon, Ha Young;Cho, Young Ah;Yee, Jeong;Gwak, Hye Sun;Han, Ji Min
    • Korean Journal of Clinical Pharmacy
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    • v.30 no.4
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    • pp.270-278
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    • 2020
  • Background: Although the identification of clinical and laboratory features in pediatric COVID-19 patients is essential in establishing an appropriate treatment plan, a systematic review and meta-analysis on the topic has yet to be reported. Methods: We searched MEDLINE, Embase, and Web of Science to access clinical and laboratory characteristics as well as clinical outcomes of children with COVID-19 infection. A meta-analysis using random-effect model was performed to estimate pooled prevalence and 95% confidence intervals. Results: Among the 532 studies initially collected, 12 articles were finally included in the meta-analysis. Among the investigated 320 pediatric patients with COVID-19, fever (48.2%) and cough (39.3%) were the most common symptoms. Almost one third of patients (30.4%) were asymptomatic. In laboratory findings, only 11.4% of pediatric patients experienced lymphocytopenia. Increased inflammatory markers including c-reactive protein (18.6%) and procalcitonin (32.4%) were observed. Only a few patients needed mechanical ventilation and intensive care support, and only one death was reported. Conclusion: Pediatric patients with COVID-19 infection exhibited milder symptoms and more favorable outcomes compared to adults. However, considering the high rate of asymptomatic pediatric patients, close monitoring is required to prevent community infection in asymptomatic conditions and hidden disease progression.

Factors of Korea-China Product Trade According to GVC Changes: Focused on FTA

  • Kwak, Su-Young;Choi, Mun-Seong;Kim, Yong-Hwan;Lee, Do-Hyung
    • Journal of Korea Trade
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    • v.24 no.8
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    • pp.133-152
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    • 2020
  • Purpose - The purpose of this study is to analyze the determinants of commodity trade in Korea and China and to examine the implications of China's GVC shift from export to domestic market on its impact on Korea's trade. Design/methodology - This study selected 30 major trading partner countries. The dependent variable is the trade volume, and the independent variables are general economic factors such as gross domestic product (GDP), GDP per capita, distance, and FTA. Findings - The trade pattern of Korea's commodities shows that GDP has a positive relationship with trade, import, and export. Distance has a significant negative relationship with total trade, import, and export. FTA is significant for import but it is not significant for total trade and export. The trade pattern of China's commodities shows that GDP has a significant positive relationship with total trade, import, and export. Distance has a negative relationship with trade, import, and export. GDP per capita is not significant for total trade and import, but it is significant for export. FTA is significant for total trade and export, but it is not significant for import. Originality/value - Existing papers were studied mainly in certain industrial sectors such as agriculture, manufacturing, automobile industry and steel industry. This paper attempts to collects vast amounts of data about the 30 countries of Korea and China respectively and analyzes by Random Effect Model dividing the goods (0 to 9) in units of STIC (Rev. 4). The major contribution is that the decision factors affecting commodity trade can be analyzed in SITC units (0-9) to obtain analysis results that are subdivided by product group and organized by product.