• Title/Summary/Keyword: variance structure

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The Reliability and Validity Test of Psychosocial Well-being Index(PWI) (사회심리적 건강 측정 도구의 신뢰도 및 타당도 검정)

  • 김정희
    • Journal of Korean Academy of Nursing
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    • v.29 no.2
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    • pp.304-313
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    • 1999
  • The purpose of this study is to test the reliability and validity test of PWI to utility of PWI. this newly developed by Sejin Jang which measures stress. The subject were 186 workers in service area. Cronbach's a and Guttman split-half coefficient is used to test the reliability of PWI. Factor analysis and the correlation of the GHQ-60. GHQ-30, GHQ-28, GHQ-20, and GHQ-12 with the PWI is used to convergent validity and discriminant validity. The important results of this study are as follows : Cronbach's $\alpha$ coefficient of data was 0.894 and Guttman split-half coefficient was 0.7097. The PWI was classified as 13 principle component (eigenvalue>1.0). After exploring 4 factor structure according to previous study result, 4 factors was explained 40.5% out of the total variance. The factor 1 was explained 15.9% and then the rest three factor was 24.6%. Factor 2 and 4 showed good agreement but factor 1 and 3 did not. Depression-related items were classified two factors. Anxiety and depression-related items were loaded unifactor. It was not clear that the PWI was consist of 4 concepts(factors). The correlation of the GHQ-60, GHQ-30, GHQ-28, GHQ-20, and GHQ-12 with the PWI were 0.744~0.905. According to findings of this study. the PWI showed a high degree of validity and reliability. Thus it is recommended to use the PWI in general setting for screening for stress. In addition, it is necessary to clarify the concept of depression and anxiety. In the further study. it my be considered to the factor structure of PWI and studied to two or unidimensional factor structure.

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Development of Abnormal Behavior Monitoring of Structure using HHT (HHT를 이용한 이상거동 시점 추정 기법 개발)

  • Kim, Tae-Heon;Park, Ki-Tae
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.19 no.2
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    • pp.92-98
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    • 2015
  • Recently, buildings tend to be large size, complex shape and functional. As the size of buildings is becoming massive, the need for structural health monitoring (SHM) technique is increasing. Various SHM techniques have been studied for buildings which have different dynamic characteristics and influenced by various external loads. "Abnormal behavior point" is a moment when the structure starts vibrating abnormally and this can be detected by comparing between before and after abnormal behavior point. In other words, anomalous behavior is a sign of damage on structures and estimating the abnormal behavior point can be directly related to the safety of structure. Abnormal behavior causes damage on structures and this leads to enormous economic damage as well as damage for humans. This study proposes an estimating technique to find abnormal behavior point using Hilber-Huang Transform which is a time-frequency signal analysis technique and the proposed algorithm has been examined through laboratory tests with a bridge model using a shaking table.

Stochastic FE Analysis of Plate Structure (평판구조의 추계론적 유한요소해석)

  • 최창근;노혁천
    • Computational Structural Engineering
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    • v.8 no.1
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    • pp.127-136
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    • 1995
  • In this paper the stochastic FE analysis considering the material and geometrical property of the plate structure is performed by the weighted integral method. To consider the stochasity of the material and geometrical property, the stochastic field is assumed respectively. The mean value of the stochastic field is 0 and the value of variance is assumed as 0.1. The characteristics of the assumed stochastic field is represented by auto-correlation function. This auto-correlation function is used in evaluating the response variability of the plate structure. In this study a new auto-correlation function is derived to concern the uncertainty of the plate thickness. The newly derived auto-correlation function is a function of auto-correlation function and coefficient of variation of the assumed stochastic field. The two results, obtained by proposed Weighted Integral method and Monte Carlo Simulation method, are coincided with each other and these results are almost equal to the theoretical result that is derived in this study. In the case of considering the variability of plate thickness, the obtained result is well coincide with those of Lawrence and Monte Carlo simulation.

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Variability of the Coastal Current off Uljin in Summer 2006 (2006년 하계 울진 연안 해류의 변동성)

  • Lee, Jae Chul;Chang, Kyung-Il
    • Ocean and Polar Research
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    • v.36 no.2
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    • pp.165-177
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    • 2014
  • In an effort to investigate the structure and variability of the coastal current in the East Sea, a moored ADCP observation was conducted off Uljin from late May to mid-October 2006. Owing to the transition of season from summer to autumn, the features of the current and wind can be divided into two parts. Until mid-August (Part-I), a southward flow is dominant at all depths with a mean alongshore velocity of 4.2~8.9 cm/s but northward winds are not strong enough to reverse the near-surface current. During Part-II, a strong northward current occurs frequently in the upper layer but winds are predominantly southward including two typhoons that have deep-reaching influence. Profile of mean velocity has three layers with a northward velocity embedded at 12~28 m depth. The near-surface current of Part-II significantly coheres with winds at 4-8 day periods with a phase lag of about 12 hours. The modal structure of the current obtained by EOF analysis is: (1) Mode-1, having 83.6% of total variance, represents the current in the same direction at all depths corresponding to the southward North Korean Cold Current (NKCC). (2) Mode-2 (11.7%) reveals a two-layer structure that can be explained by the northward East Korean Warm Current (EKWC) in the upper layer and NKCC in the lower. (3) Mode-3 (2.6%) has three layers, in which the EKWC is reversed near the surface by opposing winds. This mode is particularly similar to the mean velocity profile of Part-II.

Factor Structure on the Korean Version of Tellegen Absorption Scale (한국판 텔레겐몰입척도의 요인구조)

  • Lee, Jun-Seok;Lee, Jang-Han;Kim, Bo-Ra;Sim, Jong-Onn
    • Korean Journal of Psychosomatic Medicine
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    • v.15 no.2
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    • pp.88-92
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    • 2007
  • Objective : Tellegen Absorption Scale(TAS) is an instrument intended to assess hypnotizability and designed to sample absorbing and self-altering experiences, including dissociative experiences. The present study attempted to identify the internal structure of TAS. Methods : One hundred and thirty nine undergraduates completed the Korean version of Tellegen Absorption Scale(TAS-K). Cronbach's alpha was calculated and factor analyses were done. Results : An exploratory principal-components analysis yielded three factors accounting for 31.06% of variance. Factor 1 included dissociative(dissociation-like) experiences, factor 2 tapped imaginative involvements, and factor 3 had to do with perceptual sensitivity. Conclusion : TAS-K may include absorbing and self-altering experiences.

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Arthropod Diversity and Community Structure in Fields of Non-genetically Modified (GM) and Herbicide-tolerant GM Rice (PPO 저해 제초제 내성 유전자변형 벼가 절지동물군집에 미치는 영향)

  • Kim, Young-Joong;Lee, Joon-Ho;Back, Kyoungwhan;Kim, Chang-Gi
    • Korean journal of applied entomology
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    • v.54 no.4
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    • pp.335-343
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    • 2015
  • One of the primary concerns about the environmental risks of genetically modified (GM) crops is that they may have adverse effects on the local arthropod communities. In this study, we investigated whether the arthropod diversity and community structure in fields of GM rice tolerant to protoporphyrinogen oxidase (PPO)-inhibiting herbicides differ from those in non-GM (control) rice fields. The aim of this study was to assess the potential adverse effects of GM rice on the local arthropod communities. During the growing seasons in the study period, we collected arthropods from both fields by using yellow sticky traps and compared the diversity and community structure of arthropods from the two sites. Overall, the GM rice had no significant effect on the diversity of the local arthropod communities. In addition, multivariate analyses (permutational multivariate analysis of variance and nonmetric multidimensional scaling) showed that the structures of arthropod communities were not affected by the rice genotype (GM vs. non-GM), although these comparisons were made using data obtained at different sampling dates.

Biopsychological Structure of the Sasang Personality Questionnaire in Elementary School Students (초등학생에 있어서의 사상성격검사 타당화 연구)

  • LEE, Soo Jin;CHOI, Mi Hwa;CHAE, Han
    • The Journal of Pediatrics of Korean Medicine
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    • v.31 no.1
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    • pp.12-24
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    • 2017
  • Objectives The purpose of this study was to validate the biopsychological structure of Sasang Personality Questionnaire (SPQ) measuring Yin-Yang temperament with Junior version of Temperament and Character Inventory (JTCI) for temperament and Body Mass Index (BMI) and Pondera Index (PI) for physical constitution in elementary school students. Methods 903 Korean elementary school students (430 boys and 473 girls) completed SPQ, JTCI, and height and weight measures. Then they were analyzed by their genders and age groups. The correlation between SPQ and JTCI subscales were examined. The differences found in the SPQ and JTCI subscales, BMI and PI among high (30%), middle (40%), and low (30%) SPQ groups were investigated by analysis of variance. The profile analysis was also performed to compare JTCI subscale profiles of three SPQ total score groups. Results The SPQ score was significantly (p<0.001), and positively correlated with the JTCI Novelty-Seeking and negatively with the JTCI Harm-Avoidance. The JTCI Novelty-Seeking score of high SPQ group was significantly (p<0.001) higher than that of low SPQ group, and the JTCI Harm-Avoidance score of low SPQ group was significantly higher than that of high SPQ group. The JTCI subscale profiles for three SPQ groups were significantly (p<0.001) different for boys and girls. Significant correlations between BMI and SPQ were not found. PI and BMI of high and low SPQ groups were not significantly different. Conclusions The SPQ was shown to have robust biopsychological structure in elementary school students. It would be useful clinical measures for Sasang typology in pediatric patients.

Factor Structure of the Beck Depression Inventory in Anxiety Disorder (불안 장애에서 벡우울척도의 요인구조)

  • Yang, Hyun-Joo;Kim, Dae-Ho;Jang, Eun-Young;Han, Chang-Woo;Park, Yong-Chon
    • Anxiety and mood
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    • v.7 no.1
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    • pp.16-21
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    • 2011
  • Objective : Depressive symptoms often coexist with other anxiety disorder symptoms. Furthermore, an anxiety disorder that is comorbid with a depressive disorder results in more severe symptoms and a poorer outcome prognosis. To understand the construct of depressive symptoms in anxiety disorder, this study investigated the factor structure of the Beck Depression Inventory among outpatients with anxiety disorders. Methods : All data were from psychiatric department outpatients at a university-affiliated hospital. We conducted a principal component analysis using data from 194 outpatients with DSM-IV anxiety disorders and calculated goodness-of-fit-indices. Results : Exploratory factor analysis revealed a four factor structure--Cognitive-affective symptoms (Factor 1), Somatic symptoms (Factor 2), Self-reproach (Factor 3), and Hypochondriasis/indecisiveness (Factor 4)--and a 57% total variance. This four-factor model demonstrated an acceptable level of model fit, and it fit better than did a three-factor solution from the literature on depressive disorder. Conclusion : This study's results suggest a difference in the construct of self-reported depressive symptoms in anxiety disorders. These findings also support a dimensional approach to studying anxiety and depression. Further studies may benefit from including comorbid depressive disorder and its influence on anxiety disorders.

An Empirical Study on the Determinants of Ownership Structure of Listed Companies in Korea : Evidence from Panel Data (우리나라 상장기업의 소유구조 결정요인에 관한 실증적 연구 : 패널자료로부터의 근거)

  • Lee, Hae-Young;Lee, Jae-Choon
    • The Korean Journal of Financial Management
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    • v.20 no.2
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    • pp.41-72
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    • 2003
  • The purposes of this paper are to build theoretical and empirically testable model to identify determining factors of ownership structure, and to analyze this model empirically using th Korea Stock Exchange panel data, and to test the impact of opening the stock market on the determinants of ownership structure. The determining factors of ownership structure identified in this paper include debt ratio, dividend, asset characteristics, profitability, growth business risk, size, institutional investors and chaebol-non chaebol dummy variable. Empirical panel estimation test reveals that this model can explain about $9\sim11%$ of the cross sectional variance in the equity ratio of large shareholders. The reasons that this model has too explanatory power are that some variables were measured with errors, and that there were some omitted variables in tested model. The regression results on the model variables ar generally in line with predictions. But the coefficient estimates on size is never significant. And it appears that the exogenous variable which explains opening the stock market has positive effect on the determinants of ownership structure.

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A Basic Study on the Design of the Flexible Keel in the Energy-Storage Prosthetic Foot for the Improvement of the Walking Performance of the Below Knee Amputees (하지 절단환자의 보행 능력 향상을 위한 에너지 저장형 의족의 유연 용골 설계를 위한 기초연구)

  • 장태성;이정주;윤용산;임정옥
    • Journal of Biomedical Engineering Research
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    • v.19 no.5
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    • pp.519-530
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    • 1998
  • In this paper, the basic study on the design of the flexible keel of the energy-storage prosthetic foot was performed in order to Improve the walking performance and Increase the activities of the below knee amputees. Based on the analysis of the anthropometric data and the normal gait on two dimensional sagittal plane available In the literature, we presented a model of the basic structure of the flexible keel of the prosthetic foot. The model of the basic structure was composed of the simple beams, and linear rotational spring and damper. Laminated carbon fiber-reinforced composites were selected as the material of the basic structure model of the flexible keel In order to apply the high strength and light weight materials to the basic structure of the flexible keel of the prosthetic foot. The recoverable strain energy In response to the change of beam shape was calculated bur the finite element analysis and it was suggested that the change of beam shape could be the design variable in flexible keel design. The simulation process was systematically designed by using orthogonal array table in order to design the flexible keel structure which could store the more recoverable strain energy. finite element analysis was carried but according to the design of simulations by using the finite element program ABAQUS and the flexible keel structure of the energy-storage prosthetic foot was obtained from the analysis of variance(ANOVA). The dynamic simulation model of the prosthetic walking using the flexible keel structure was made and the dynamic analysis was carried but during one walk cycle. Based on the above results, an effective design process was presented for the development of the prosthetic fool system.

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