• 제목/요약/키워드: Correlated Random Effect

검색결과 49건 처리시간 0.032초

중고등학생의 건강위험지각이 건강위험행위에 미치는 영향 (The impact of Health Risk Perception on Health Risk Behavior in Middle and High School Students)

  • 김미정
    • 한국학교보건학회지
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    • 제12권1호
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    • pp.45-56
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    • 1999
  • Adolescence is vulnerable to various Health Risk Behaviors (HRB). These behaviors can affect his remaining life as well as adolescence, thus prevention of HRB is a critical issue in health education. This study is aimed to provide basic information for prevention of HRB. Thus, this study was conducted to analyze the impact of peer group's health risk behaviors on health risk perception (HRP) and that of health risk perception on health risk behaviors based on 832 respondents. The 852 subjects were selected in six middle and high schools in Seoul through random sampling. Data were collected from September, 18-October, 21, 1998, and the 832 data were analyzed after excluding the 20 incomplete and inaccurate data. Questionnaire items and measures are based on an instrument to measure Perceived Health Risk Perception, which Hodge B.C. developed in 1992. Cronbach alpha is used to test the reliability. The reliability of HRP and HRB is 0.9473, 0.8768 in this study, Statistical analysis divided into four phases. First, the impact of socio-demographic characteristics on HRP is analyzed by oneway ANOV A. Male students have lower HRP than female students. As grade goes up, HRP is getting lower. Perceived higher concern of parents and HRP are correlated. And the experience of school health education and HRP are correlated. Second, the impact of peer group's HRB on the HRP is analyzed by linear regression. Peer group's HRB and HRP are negatively correlated, Third, the impact of HRP on HRB is analyzed by linear regression. There is a correlation between high HRP and low HRB. Fourth, Powerful impact factors on HRB are analyzed by stepwise multiple regression. Grade, gender, peer group's HRB, and related HRP is entered as independent variables. Because of correlation between entered variables, three interaction variables between grade, gender, peer group's HRB and related HRP also entered, In general, peer group's HRB is the most accountable factor to HRB. And Interaction variable between HRP and peer group's HRB and HRB are negatively correlated. These results indicate that HRP may reduce the impact of peer group's HRB on HRB. Some recommendations are as follows: First, health educational programs suitable for gender and grade are required. Second, a systematic cooperation between school and home is necessary for effective prevention of HRB. Third, the educational effect for decreasing HRB by increasing HRP is statistically assisted. However, peer group has much stronger impact on HRB than subjective HRP, thus special consideration and management are necessary for peer group which does HRB more frequently.

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임상간호사의 직무 스트레스와 자기효능감이 우울에 미치는 영향 (The Effect of Job-stress and Self-efficacy on Depression of Clinical Nurses)

  • 김정희;박은옥
    • 한국직업건강간호학회지
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    • 제21권2호
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    • pp.134-144
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    • 2012
  • Purpose: The purpose was to investigate the relations among job-stress, self-efficacy, and depression of nurses. Methods: The data were collected from a random sample of 213 nurses working in two general hospitals of a local area. A self-reported questionnaire was used to assess the level of job-stress, self-efficacy, and depression. Results: The mean score of job-stress was 49.1 and the score of job demand was the highest. The mean score of self-efficacy was 3.4, and depression was 18.2. The prevalence of depression was very high. The job-stress and depression were negatively correlated with self-efficacy. Hierarchial multiple regression showed that the self-efficacy and the high job demand, lack of reward, and organizational injustice of job-stress explained 53% of the variance for the nurses' depression. Conclusion: The findings indicated that the self-efficacy and job stress, especially job demand, organizational injustice, and lack of reward contributed to the depression. In order to prevent and decrease the depression, the developing programs to improve self-efficacy are needed.

MIMO Capacity, Level Crossing Rates and Fades: The Impact of Spatial/Temporal Channel Correlation

  • Giorgetti, Andrea;Smith, Peter J.;Shafi, Mansoor;Chiani, Marco
    • Journal of Communications and Networks
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    • 제5권2호
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    • pp.104-115
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    • 2003
  • It is well known that Multiple Input Multiple Output (MIMO) systems offer the promise of achieving very high spectrum efficiencies (many tens of bit/s/Hz) in a mobile environment. The gains in MIMO capacity are sensitive to the presence of spatial and temporal correlation introduced by the radio environment. In this paper, we examine how MIMO capacity is influenced by a number of factors e.g., a) temporal correlation b) various combinations of low/high spatial correlations at either end, c) combined spatial and temporal correlations. In all cases, we compare the channel capacity that would be achievable under independent fading. We investigate the behaviour of "capacity fades," examine how often the capacity experiences the fades, develop a method to determine level crossing rates and average fade durations and relate these to antenna numbers. We also evaluate the influence of channel correlation on the capacity autocorrelation and assess the fit of a Gaussian random process to the temporal capacity sequence. Finally we note that the particular spatial correlation structure of the MIMO channel is influenced by a large number of factors. For simplicity, it is desirable to use a single overall correlation measure which parameterizes the effect of correlation on capacity. We verify this single parameter concept by simulating a large number of different spatially correlated channels.

Audit Quality and Stock Return Co-Movement: Evidence from Vietnam

  • PHAM, Chi Bich Thi;VU, Thu Minh Thi;NGUYEN, Linh Ha;NGUYEN, Dung Duc
    • The Journal of Asian Finance, Economics and Business
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    • 제7권7호
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    • pp.139-147
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    • 2020
  • This paper aims to explore the relationship between the quality of the audit and the level of stock return co-movement in the context of the Vietnamese emerging market. The empirical study is designed based on the quatitative method and deductive approach. The panel dataset includes 256 listed firms from different industries,with 1115 firm-year observations on Ho Chi Minh City Stock Exchange for the period from 2014 to 2018. In the research, we built the econometric regression model, using stock return synchronicity and audit quality as the dependent and independent variable, respectively. Some control variables are also added to the econometric regression models as they are well-documented in prior research to have an effect on stock price synchronicity. To improve the accuracy of the regression coefficients, beside the Ordinary Least Squares, we employ the Random Effects Model and the Fixed Effects Model for better statistical analysis of panel data set. The results show that the quality of the audit is positively correlated to stock price synchronicity. This finding suggests that stock returns of companies with higher quality of the audit are more synchronous with the market. Results for other control variables also support our reasoning for the main findings.

삼요소시비량과 수도생육상태가 백엽고병(벼, 흰빛잎마름병) 발병에 미치는 영향 (Effects of N,P,K fertilizer levels and growth condition on the development of Bacterial leaf blight in rice plants)

  • 김정화;조용섭
    • 한국응용곤충학회지
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    • 제9권1호
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    • pp.7-13
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    • 1970
  • 1. 본 병에 강한 감수성품종인 금남풍을 사용하였고, Xanthomonas oyzae 6526 균주를 반합성감자배양기에 이식, $28^{\circ}C$에 3일간 사면배양한 뒤 균부유액을 만들어 상엽 상단부에 단침접종하고 14일 뒤에 확대된 병반길이를 조사하였다. 시험구설정은 3요소를 각각 무비$\cdot$표준비$\cdot$배비의 3개 수준으로 시비하여 총 27개구를 설정하고 3반복 임의배치하였다. 2. 질소질비료는 인산$\cdot$가리의 시용량에 크게 좌우되지 않았고 증시할 수록 발병이 심하였다. 3. 인산은 표준량시용하였을 때만 다소 발병억제효과의 경향이 있었으나 배비하게 되면 오히려 무비구보다도 터 발병이 촉진되었다. 4. 가리를 표준양시용하였을에 발병이 현저히 줄어들으나 시용량과 비례하지 않았고 배비하면 인산에서 처럼 다시 발병이 촉진되었다. 5. 출수시기가 늦어질 수록, 그리고 수수가 많을수록 발병이 심하였다. 6. 삼요소를 다같이 표준량시용하였을 때가 가장 발병이 적었는데, 작물의 영양조성은 비료의 종류, 시용량, 시용방법에 따라 좌우되며 발병도 기주식물의 조성과 밀접한 관계가 있으므로 시비법을 적절히 조절하면 본 병의 피해를 많이 감소시킬 수 있을 것으로 기대된다.

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Influence of Anticipation on Landing Patterns during Side-Cutting Maneuver in Female Collegiate Soccer Players

  • Park, Eun-Jung;Lee, Jung-Ho;Ryue, Jae-Jin;Sohn, Ji-Hoon;Lee, Ki-Kwang
    • 한국운동역학회지
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    • 제21권4호
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    • pp.391-395
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    • 2011
  • To investigate the anticipatory effect on landing patterns during side-cutting maneuver, thirteen healthy female elite college soccer players participated in this study. Three-dimensional knee kinematics, effective mass and correlation between both these were measured and analyzed using a motion analysis and force plates. Each testing session included anticipated tasks, $45^{\circ}$ side-cutting tasks (AC), followed by a set of unexpected side-cutting (UC) in a random order. Knee flexion/extension, valgus/varus and internal/external rotation angles and effect mass were compared by using paired t-test. Also, correlation analysis was performed to identify the relationship between knee angles and effective mass. Effective mass during UC was greater than that during AC. Effective mass and maximum knee flexion angle were positively correlated during AC and not during UC. Based on the relationship between effective mass and knee flexion angle in AC, shock absorption can be controlled by knee joint flexion in pre-predicted movement condition. However, effective mass can not be controlled by knee flexion in UC condition. The unexpected load affects were more irregular on the knee joint, which may be one of the injury mechanisms of anterior cruciate ligament (ACL) in female soccer players.

Large eddy simulation of wind loads on a long-span spatial lattice roof

  • Li, Chao;Li, Q.S.;Huang, S.H.;Fu, J.Y.;Xiao, Y.Q.
    • Wind and Structures
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    • 제13권1호
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    • pp.57-82
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    • 2010
  • The 486m-long roof of Shenzhen Citizens Centre is one of the world's longest spatial lattice roof structures. A comprehensive numerical study of wind effects on the long-span structure is presented in this paper. The discretizing and synthesizing of random flow generation technique (DSRFG) recently proposed by two of the authors (Huang and Li 2008) was adopted to produce a spatially correlated turbulent inflow field for the simulation study. The distributions and characteristics of wind loads on the roof were numerically evaluated by Computational Fluid Dynamics (CFD) methods, in which Large Eddy Simulation (LES) and Reynolds Averaged Navier-Stokes Equations (RANS) Model were employed. The main objective of this study is to explore a useful approach for estimations of wind effects on complex curved roof by CFD techniques. In parallel with the numerical investigation, simultaneous pressure measurements on the entire roof were made in a boundary layer wind tunnel to determine mean, fluctuating and peak pressure coefficient distributions, and spectra, spatial correlation coefficients and probability characteristics of pressure fluctuations. Numerical results were then compared with these experimentally determined data for validating the numerical methods. The comparative study demonstrated that the LES integrated with the DSRFG technique could provide satisfactory prediction of wind effects on the long-span roof with complex shape, especially on separation zones along leading eaves where the worst negative wind-induced pressures commonly occur. The recommended LES and inflow turbulence generation technique as well as associated numerical treatments are useful for structural engineers to assess wind effects on a long-span roof at its design stage.

Ki-67/MIB-1 as a Prognostic Marker in Cervical Cancer - a Systematic Review with Meta-Analysis

  • Piri, Reza;Ghaffari, Alireza;Gholami, Nasrin;Azami-Aghdash, Saber;PourAli-Akbar, Yasmin;Saleh, Parviz;Naghavi-Behzad, Mohammad
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권16호
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    • pp.6997-7002
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    • 2015
  • Background: In cervical cancer patients it has been reported that there in a significant Ki-67/MIB-1 expression is correlated with survival in cervical cancer patients. However, the prognostic value is still not well understood. Materials and Methods: In the present meta-analysis the prognostic value of Ki-67/MIB-1 with regard to overall survival (OS) and disease-free survival (DFS) in cervical cancer was investigated. The databases of PubMed, ISI Web of Science, Cochrane Central Register of Controlled Trials, EMBASE, Science Direct and Wiley Online Library were used to identify appropriate literature. Results: In order to explore the relationship between Ki-67/MIB-1 and cervical cancer, we have included 13 studies covering 894 patients in the current meta-analysis. The effect of Ki-67/MIB-1 on OS for pooled random effects HR estimate was 1.63 (95%confidence interval (CI) 1.09-2.45; P<0.05). The pooled HR for DFS was 1.26 (95%CI 0.58-2.73; P>0.05) and the subgroup analysis indicated Ki-67/MIB1 was associated with DFS (HR=3.67, 95%CI 2.65-5.09) in Asians. Conclusions: According to this meta-analysis, Ki-67/MIB-1 has prognostic value for OS in patients suffering from cervical cancer. For better evaluation of the prognostic role of Ki-67/MIB-1 on DFS, studies with larger numbers of patients are needed to validate present findings in the future.

Loss of Expression of PTEN is Associated with Worse Prognosis in Patients with Cancer

  • Qiu, Zhi-Xin;Zhao, Shuang;Li, Lei;Li, Wei-Min
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권11호
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    • pp.4691-4698
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    • 2015
  • Background: The tumor suppressor phosphatase and tensin homolog (PTEN) is an important negative regulator of cell-survival signaling. However, available results for the prognostic value of PTEN expression in patients with cancer remain controversial. Therefore, a meta-analysis of published studies investigating this issue was performed. Materials and Methods: A literature search via PubMed and EMBASE databases was conducted. Statistical analysis was performed by using the STATA 12.0 (STATA Corp., College, TX). Data from eligible studies were extracted and included into the meta-analysis using a random effects model. Results: A total of 3,810 patients from 27 studies were included in the meta-analysis, 22 investigating the relationship between PTEN expression and overall survival (OS) using univariate analysis, and nine with multivariate analysis. The pooled hazard ratio (HR) for OS was 1.64 (95% confidence interval (CI): 1.32-2.05) by univariate analysis and 1.56 (95% CI: 1.20-2.03) by multivariate analysis. In addition, eight papers including two disease-free-survival analyses (DFSs), four relapse-free-survival analyses (RFSs), three progression-free-survival analyses (PFSs) and one metastasis-free-survival analysis (MFS) reported the effect of PTEN on survival. The results showed that loss of PTEN expression was significant correlated with poor prognosis, with a combined HR of 1.74 (95% CI: 1.24-2.44). Furthermore, in the stratified analysis by the year of publication, ethnicity, cancer type, method, cut-off value, median follow-up time and neoadjuvant therapy in which the study was conducted, we found that the ethnicity, cancer type, method, median follow-up time and neoadjuvant therapy are associated with prognosis. Conclusions: Our study shows that negative or loss of expression of PTEN is associated with worse prognosis in patients with cancer. However, adequately designed prospective studies need to be performed for confirmation.

Genetic Models for Carcass Traits with Different Slaughter Endpoints in Selected Hanwoo Herds I. Linear Covariance Models

  • Choy, Y.H.;Lee, C.W.;Kim, H.C.;Choi, S.B.;Choi, J.G.;Hwang, J.M.
    • Asian-Australasian Journal of Animal Sciences
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    • 제21권9호
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    • pp.1227-1232
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    • 2008
  • Carcass characteristics data of Hanwoo (N = 1,084) were collected from two stations of the National Livestock Institute of Animal Science (NIAS), Korea and records from thirteen individual cow-calf operators were analyzed to estimate variance and covariance components and the effect of different slaughter endpoints. Carcass traits analyzed were cold carcass weight (CWT, kg), REA (rib eye area, cm2), back fat thickness (mm) and marbling score (1-7). Four different models were examined. All models included sex and contemporary group as fixed effects and the animal's direct genetic potential and environment as random effects. The first model fitted a linear covariate of age at slaughter. The second model fitted both linear and quadratic covariates of age at slaughter. The third model fitted a linear covariate of body weight at slaughter. The fourth model fitted both linear covariates of age at slaughter and body weight at slaughter. Variance components were estimated using the REML procedure with Gibb's sampler. Heritability estimate of CWT was in the range of 0.08-0.11 depending on the model applied. Heritability estimates of BF, REA and MS were in the ranges of 0.23-0.28, 0.19-0.26, and 0.44-0.45, respectively. Genetic correlations between CWT and BF, between CWT and REA, and between CWT and MS were in the ranges of -0.33 - -0.14, 0.73-0.84, and -0.01- 0.11, respectively. Genetic correlations between REA and BF, between MS and BF and between REA and MS were in the ranges of -0.82 ~ -0.72, 0.04~0.28 and -0.08 ~ -0.02, respectively. Variance and covariance components estimated varied by model with different slaughter endpoints. Body weight endpoint was more effective for direct selection in favor of yield traits and body weight endpoints affected more of the correlated response to selection for the traits of yield and quality of edible portion of beef.