• Title/Summary/Keyword: Random Effects Model

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Effects of Transcranial Direct Current Stimulation on Lower Extremity Function of Stroke Patients : A meta-analysis of domastic research (뇌졸중 환자의 다리 기능에 대한 경두개직류자극의 효과: 국내 연구의 메타분석)

  • Lee, Jeong-Woo;Lim, Ji-Sun
    • Journal of The Korean Society of Integrative Medicine
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    • v.9 no.3
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    • pp.87-97
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    • 2021
  • Purpose : The purpose of this meta-analysis was to evaluate the effects of transcranial direct current stimulation on the lower extremity function of stroke patients. Methods : Domestic data were gathered from studies that conducted clinical trials associated with transcranial direct current stimulation and its impact on lower extremity function of stroke patients. A total of 592 studies published between 2012 and 2020 were identified, with 7 studies satisfying the inclusion data. The studies consisted of patient, intervention, comparison, and outcome (PICO) data. The search outcomes were items associated with muscle activity, balance, muscle strength and walking ability. Cochrane risk of bias (ROB) was used to evaluate the quality of 3 randomized control trials. The quality of 4 non-randomized control trials was evaluated using risk of bias assessment tool for non-randomized studies (RoBANS). Effect sizes in this study were computed as the corrected standard mean difference (SMD). A random-effect model was used to analyze the effect size because of the high heterogeneity among the studies. Egger's regression and 'trim-and-fill' tests were carried out to analyze the publishing bias. Results : The following factors had a large total effect size (Hedges's g=2.10, 95 %CI=1.54~2.66) involving transcranial direct current stimulation on stroke patients: muscle activity (Hedges's g=2.38, 95 %CI=1.08~3.68), balance (Hedges's g4=2.41, 95 %CI=1.33~3.60), walking ability (Hedges's g=1.54, 95 %CI=0.49~2.59), and muscle strength (Hedges's g=2.45, 95 % CI: 0.85~4.05). Egger's regression test showed that the publishing bias had statistically significant differences but 'trim-and-fill' test showed that there was still statistical difference. Conclusion : This study provides evidence for the effectiveness of transcranial direct current stimulation on the lower extremity in terms of muscle activity, balance, walking ability, and muscle strength in stroke patients. However, due to the low quality of studies and high heterogeneity factors, the results of our study should be interpreted cautiously.

The Effect of a Physical Touch Play Program in Children: A Systematic Review and Meta-analysis (아동의 신체접촉놀이 프로그램에 대한 효과 : 체계적 문헌고찰 및 메타분석)

  • Yoon, Jeong Ah
    • Journal of Life Science
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    • v.32 no.10
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    • pp.821-831
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    • 2022
  • This study evaluated the effects of physical touch play programs in children through a systematic literature review and meta-analysis. A literature search for journal articles published before August 2022 was conducted using KERIS, KISS, DBpia, and ScienceON. The keywords used for the search were 'child', 'infant', 'physical touch', 'physical touch play', 'physical touch activities' and 'physical touch play program'. For the study's purpose, seven studies were selected through a systematic process of using several databases and were used to estimate the effect size of physical touch play programs. A meta-analysis was performed using a random effects model, and the effect size on cognitive function was calculated. Hedges' g of the physical touch play program was 6.20 (95% CI: 3.74-8.66), indicating a large effect size. To determine heterogeneity (I2= 95.4%, Q = 417.30, p<0.001), moderator analysis was performed using the total number of times and intervention duration. The total number of times was statistically significant; the other moderators did not differ significantly. This study systematically analyzed the results of physical touch play programs on children in Korea. It also provides insights that can be applied to the design of physical touch play programs for children. To present more evidence that supports the effectiveness of physical touch programs, further research is warranted.

The moderate effects of father's attachment between self-esteem and adolescents' internalizing problem behavior -Focusing on the male students- (자아존중감과 청소년 외현화 문제행동 간의 영향과 아버지애착의 조절효과 연구-남학생을 중심으로-)

  • Kim, Min Joo;Ji, Eun Gu;Jo, mi jeong
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.6 no.8
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    • pp.63-72
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    • 2016
  • The main purpose of this study was to empirically validate whether a factor in reducing youth externalizing problem behaviors impact analysis and affection between father and youth self-esteem externalizing problem behavior through effective regulation. The survey was conducted by the researcher who visits the school to collect the sample data by random sampling method on 336 male students at D area. After delating the 38 insincere questionnaires, final 298 data were analyzed. Using SPSS 21.0, the simple correlational analysis was conducted to decide the relationship among the variables and in order to know the reciprocal model, hierarchical multiple regression analysis was implemented. The results showed the esteem and the affection his father on a statistically significant effect on youth externalizing problem behavior, father attachment had the effect of regulating the relationship between self-esteem and externalizing problem behavior. Through these results through the self-esteem Improvement Plan of the Father and the love of young people and to promote a proposal for reducing externalizing problem behavior.

Factors Related to Depression of Children and Adolescents in South Korea: A Meta-Analysis (메타분석을 통한 국내 아동·청소년의 우울 관련 변인 탐색)

  • Sunmee Kim ;Hayoung Ko ;Soohyun Park ;Eunjoo Yang
    • Korean Journal of Culture and Social Issue
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    • v.18 no.4
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    • pp.533-555
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    • 2012
  • This study investigated the relationship of self-esteem, academic stress, social support, and parenting attitudes with depression of Korean children and adolescents using a meta-analysis. A total of 86 studies, both published and unpublished manuscripts, were included. The results showed that depression of children and adolescents were positively associated with self-esteem, social support, and functional parenting attitudes, and negatively related to academic stress. The largest effect size was found in the relationship with self-esteem, followed by the relationships with academic stress, social support, and functional parenting attitudes, all in the range between moderate and large effect size. As the analysis indicated the heterogeneity of the results, subsequent analyses were performed to test the moderating effects of instrument and age. The significant moderators were the types of instruments used to measure self-esteem, academic stress, parenting attitudes, and depression. Age was also a significant moderator.

Postmenopausal Hormone Therapy is Associated with in Situ Breast Cancer Risk

  • Ni, Xiao-Jian;Xia, Tian-Song;Zhao, Ying-Chun;Ma, Jing-Jing;Zhao, Jie;Liu, Xiao-An;Ding, Qiang;Zha, Xiao-Ming;Wang, Shui
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.8
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    • pp.3917-3925
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    • 2012
  • Background: The relationship between postmenopausal hormone therapy (HT) and invasive breast cancer has been extensively investigated, but that with breast carcinoma in situ (BCIS) has received relatively little attention. The aim of our present study was to review and summarize the evidence provided by longitudinal studies on the association between postmenopausal HT use and BCIS risk. Methods: A comprehensive literature search for articles published up to May 2012 was performed. Prior to performing a meta-analysis, the studies were evaluated for publication bias and heterogeneity. Relative risk (RR) or odds ratio (OR) values were calculated using 14 reports (8 case-control studies and 6 cohort studies), published between 1986 and 2012. Results: There was evidence of an association between ever postmenopausal estrogen use and BCIS based on a random-effects model (RR = 1.25, 95% confidence interval (CI) = 1.01, 1.55). However, we found no strong evidence of an association between ever postmenopausal estrogen combined with progesterone use and BCIS using a randomeffects model (RR = 1.55, 95% CI = 0.95, 2.51). Furthermore, our analysis showed a strong association between "> 5 years duration" of estrogen or estrogen combined with progesterone use and BCIS. Furthermore, current use of any HT is associated with increased risk of BCIS in cohort studies. Additional well-designed large studies are now required to validate this association in different populations.

Ellipsometric study of Mn-doped $Bi_4Ti_3O_{12}$ thin films

  • Yoon, Jae-Jin;Ghong, Tae-Ho;Jung, Yong-Woo;Kim, Young-Dong;Seong, Tae-Geun;Kang, Lee-Seung;Nahm, Sahn
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.08a
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    • pp.173-173
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    • 2010
  • $Bi_4Ti_3O_{12}$ ($B_4T_3$) is a unique ferroelectric material that has a relatively high dielectric constant, high Curie temperature, high breakdown strength, and large spontaneous polarization. As a result this material has been widely studied for many applications, including nonvolatile ferroelectric random memories, microelectronic mechanical systems, and nonlinear-optical devices. Several reports have appeared on the use of Mn dopants to improve the electrical properties of $B_4T_3$ thin films. Mn ions have frequently been used for this purpose in thin films and multilayer capacitors in situations where intrinsic oxygen vacancies are the major defects. However, no systematic study of the optical properties of $B_4T_3$ films has appeared to date. Here, we report optical data for these films, determined by spectroscopic ellipsometry (SE). We also report the effects of thermal annealing and Mn doping on the optical properties. The SE data were analyzed using a multilayer model that is consistent with the original sample structure, specifically surface roughness/$B_4T_3$ film/Pt/Ti/$SiO_2$/c-Si). The data are well described by the Tauc-Lorentz dispersion function, which can therefore be used to model the optical properties of these materials. Parameters for reconstructing the dielectric functions of these films are also reported. The SE data show that thermal annealing crystallizes $B_4T_3$ films, as confirmed by the appearance of $B_4T_3$ peaks in X-ray diffraction patterns. The bandgap of $B_4T_3$ red-shifts with increasing Mn concentration. We interpret this as evidence of the existence deep levels generated by the Mn transition-metal d states. These results will be useful in a number of contexts, including more detailed studies of the optical properties of these materials for engineering high-speed devices.

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Meta-analysis of Change in Weight and Heart Rate for Phentermine in Obesity (비만환자의 펜터민 복용에 따른 체중과 심박수 변화에 대한 메타분석)

  • Woo, Yeonju;Jeong, Hyomi
    • Journal of health informatics and statistics
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    • v.43 no.4
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    • pp.290-299
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    • 2018
  • Objectives: This study aimed to evaluate the change in weight and heart rate associated with the use of phentermine through meta-analysis based on the published literatures. Methods: Eight electronic databases, PubMed, EMBASE, Cochrane library, and five domestic databases were used to search the literature. Randomized controlled trials that evaluated the change in weight and heart rate with the use of phentermine compared with placebo were included in this study. The fixed-effect model weighted by the Mantel-Haenszel method was used in the meta-analysis, and the random-effects model was used when heterogeneity was present. Results: We included 12 studies comprising 677 patients. The change in weight observed with the use of phentermine (SMD = -1.37, 95% CI: -1.55, -1.19) was statistically significant compared with that observed with placebo. As per the subgroup analysis results, the change in weight by publication year, country, phentermine dosage, follow-up check was not heterogeneous. The change in heart rate observed with the use of phentermine (SMD = 0.64, 95% CI: 0.35, 0.92) was significant compared with that observed with placebo. Conclusions: Weight loss and increased heart rate were confirmed in phentermine compared with placebo.

An Artificial Intelligence Approach to Waterbody Detection of the Agricultural Reservoirs in South Korea Using Sentinel-1 SAR Images (Sentinel-1 SAR 영상과 AI 기법을 이용한 국내 중소규모 농업저수지의 수표면적 산출)

  • Choi, Soyeon;Youn, Youjeong;Kang, Jonggu;Park, Ganghyun;Kim, Geunah;Lee, Seulchan;Choi, Minha;Jeong, Hagyu;Lee, Yangwon
    • Korean Journal of Remote Sensing
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    • v.38 no.5_3
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    • pp.925-938
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    • 2022
  • Agricultural reservoirs are an important water resource nationwide and vulnerable to abnormal climate effects such as drought caused by climate change. Therefore, it is required enhanced management for appropriate operation. Although water-level tracking is necessary through continuous monitoring, it is challenging to measure and observe on-site due to practical problems. This study presents an objective comparison between multiple AI models for water-body extraction using radar images that have the advantages of wide coverage, and frequent revisit time. The proposed methods in this study used Sentinel-1 Synthetic Aperture Radar (SAR) images, and unlike common methods of water extraction based on optical images, they are suitable for long-term monitoring because they are less affected by the weather conditions. We built four AI models such as Support Vector Machine (SVM), Random Forest (RF), Artificial Neural Network (ANN), and Automated Machine Learning (AutoML) using drone images, sentinel-1 SAR and DSM data. There are total of 22 reservoirs of less than 1 million tons for the study, including small and medium-sized reservoirs with an effective storage capacity of less than 300,000 tons. 45 images from 22 reservoirs were used for model training and verification, and the results show that the AutoML model was 0.01 to 0.03 better in the water Intersection over Union (IoU) than the other three models, with Accuracy=0.92 and mIoU=0.81 in a test. As the result, AutoML performed as well as the classical machine learning methods and it is expected that the applicability of the water-body extraction technique by AutoML to monitor reservoirs automatically.

Estimation of Annual Trends and Environmental Effects on the Racing Records of Jeju Horses (제주마 주파기록에 대한 연도별 추세 및 환경효과 분석)

  • Lee, Jongan;Lee, Soo Hyun;Lee, Jae-Gu;Kim, Nam-Young;Choi, Jae-Young;Shin, Sang-Min;Choi, Jung-Woo;Cho, In-Cheol;Yang, Byoung-Chul
    • Journal of Life Science
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    • v.31 no.9
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    • pp.840-848
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    • 2021
  • This study was conducted to estimate annual trends and the environmental effects in the racing records of Jeju horses. The Korean Racing Authority (KRA) collected 48,645 observations for 2,167 Jeju horses from 2002 to 2019. Racing records were preprocessed to eliminate errors that occur during the data collection. Racing times were adjusted for comparison between race distances. A stepwise Akaike information criterion (AIC) variable selection method was applied to select appropriate environment variables affecting racing records. The annual improvement of the race time was -0.242 seconds. The model with the lowest AIC value was established when variables were selected in the following order: year, budam classification, jockey ranking, trainer ranking, track condition, weather, age, and gender. The most suitable model was constructed when the jockey ranking and age variables were considered as random effects. Our findings have potential for application as basic data when building models for evaluating genetic abilities of Jeju horses.

An Empirical Study of Students' Start-Up Activities: Integrated Approach of Student-Focused Cognitive Model and Supportive Activities of University (대학생 창업활동에 대한 실증적 연구 : 대학생 중심의 인지적 모델과 대학지원의 통합적 접근)

  • Chang, Sooduck;Lee, Jaehoon
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.9 no.4
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    • pp.65-76
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    • 2014
  • The basic purpose of this study is to examine the relationship among entrepreneurial intention, university supports for startup, and startup activities of university students. For the study, we identified the influence factors of students' startup intention based on reviewing preceding studies and examined how these factors affect their intention of new venture startup. In addition, this study attempted to examine how these factors that can have a significant impact on entrepreneurial intention affect startup activities and analyzed how entrepreneurial intention would mediate the relationship between these influence factors and startup activities. A total of 769 students who chosen by random were surveyed and all questionnaires were sent by mail to the universities that entrepreneurship education and entrepreneurial programs were selected as the forerunners from the government. As a result, this study revealed that student's psychological traits such as entrepreneurial self-efficacy and risk-taking have significant effect on the intention of startup. And student's exposure to the role models and various entrepreneurial experiences such as entrepreneurship education and entrepreneurial student's club in the university has significantly positive influence on the intention of startup. This study also found that the effects of these explanatory variables of this research on startup activities have been partially mediated by entrepreneurial intention. The entrepreneurial intention was also proven to have a significant effect on startup activities. Finally, the extent to which university supports activities for students' startup moderated the relationship between entrepreneurial intention and university students' startup activities. We believe that these results of this study contribute to the understanding of the entrepreneurship process both theoretical and practical perspectives.

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