• Title/Summary/Keyword: Coefficient of Variance

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Postoperative Flat Back : Contribution of Posterior Accessed Lumbar Interbody Fusion and Spinopelvic Parameters

  • Kim, Jin Kwon;Moon, Byung Gwan;Kim, Deok Ryeng;Kim, Joo Seung
    • Journal of Korean Neurosurgical Society
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    • v.56 no.4
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    • pp.315-322
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    • 2014
  • Objective : Posterior accessed lumbar interbody fusion (PALIF) has a clear objective to restore disc height and spinal alignment but surgeons may occasionally face the converse situation and lose lumbar lordosis. We analyzed retrospective data for factors contributing to a postoperative flat back. Methods : A total of 105 patients who underwent PALIF for spondylolisthesis and stenosis were enrolled. The patients were divided according to surgical type [posterior lumbar inter body fusion (PLIF) vs. unilateral transforaminal lumbar interbody fusion (TLIF)], number of levels (single vs. multiple), and diagnosis (spondylolisthesis vs. stenosis). We measured perioperative index level lordosis, lumbar lordosis, pelvic tilt, sacral slope, pelvic incidence, and disc height in standing lateral radiographs. The change and variance in each parameter and comparative group were analyzed with the paired and Student t-test (p<0.05), correlation coefficient, and regression analysis. Results : A significant perioperative reduction was observed in index-level lordosis following TLIF at the single level and in patients with spondylolisthesis (p=0.002, p=0.005). Pelvic tilt and sacral slope were significantly restored following PLIF multilevel surgery (p=0.009, p=0.003). Sacral slope variance was highly sensitive to perioperative variance of index level lordosis in high sacral sloped pelvis. Perioperative variance of index level lordosis was positively correlated with disc height variance ($R^2=0.286$, p=0.0005). Conclusion : Unilateral TLIF has the potential to cause postoperative flat back. PLIF is more reliable than unilateral TLIF to restore spinopelvic parameters following multilevel surgery and spondylolisthesis. A high sacral sloped pelvis is more vulnerable to PALIF in terms of a postoperative flat back.

Studies of Specific Foods to Absolute Intake and Between-Person-Variance in Various Nutrients Intake (농촌거주 청소년의 식이조사에서 나타난 영양소의 주된 공급식품과 변이식품의 양상)

  • 김영옥
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.24 no.6
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    • pp.892-900
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    • 1995
  • Dietary data of 538 middle school students have been analysed to identify the contribution of specific foods to absolute intake and between-person-variance in nutrient consumption. The 24-hour-dietary-recall method had been used to collect the data required. Contribution of specific foods, in terms of ranking order for both absolute intake and between-person-variance have been observed. Ranking order of food for absolute intake was given based on the percen of contribution whereas the ranking order of foods for between-person-variance was given based on the percent of contribution whereas the ranking order of foods for between-person-variance was given based on a coefficient fo variation. As a result, for most of the nutrients(except cholesterol), the ranking order of foods for the between-person-variance was quite different from that of absolute intake. The results indicate that to identify between-person-variance of nutrient intake in an epidemiology study, foods with a high ranking in between-person-variance should be included in developing the food frequency questionnaires rather than foods which showed a high ranking in absolute intake.

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Validity of Korean Version of Clinical Decision Making Short Form Scale (한국어판 임상적 의사결정 (clinical decision making) 축약도구의 타당성 검정)

  • Kim, Myoung Soo;Jung, Hyun Kyeong
    • Korean Journal of Adult Nursing
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    • v.26 no.4
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    • pp.403-412
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    • 2014
  • Purpose: The purpose of this study was to validate the Korean version of shortened Nursing Decision-Making Instrument developed by Lauri & $Salanter{\ddot{a}}$(2002). Methods: The subjects were 247 nurses working in eight hospitals of Korea. Data were collected by questionnaires from June to July, 2012 and were analyzed by Principal Component Analysis for construct validity and Cronbach's ${\alpha}$ coefficient for reliability. Results: Factor loadings of the four subscales ranged from .32 to .73. The explained variance from the four factors was 48.54% of the total variance. The factors were named 'implementation of plan, monitoring and evaluation', 'plans of action', 'data collection', and 'data processing and identification'. The first factor consisted of 6 items which explained 13.21% of the total variance and the second factor contained 8 items. The Cronbach's ${\alpha}$ coefficients of the four subscales were from .64 to .81. Conclusion: The Korean version of the shortened Nursing Decision-Making Instrument has satisfactory construct validity and reliability. However, that the scores of the analytic items weren't reversed unlike the analysis method of the original tools is the biggest limitation of this study. In addition, based on the fact that there were several discrepancies for item interpretation of Korean comparing to the findings of the instrument development study, repetitive researches would be suggested.

Development of a "Grandmothering Stress Index" for Korean Day-care Grandmothers (손자녀 양육 스트레스 측정도구 개발 - 주간양육 할머니를 중심으로 -)

  • Kim, Moon-Jeong;Chung, Chae-Weon
    • Women's Health Nursing
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    • v.14 no.1
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    • pp.56-65
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    • 2008
  • Purpose: The study was to develop an instrument to measure grandmothering stress for Korean day-care grandmothers and to test the validity and reliability of the instrument Method: The items of the instrument were based on a literature review and secondary data, After content validity tests and a pilot test, 20 items were developed. In order to test the reliability and validity of the scale, data were collected from 126 grandmothers. Result: After a factor analysis, five factors and 15 items were selected. These explained 67.2% of the total variance. The first domain was termed 'Health problems', and explained 18.1 % of the total variance, and the second domain of 'Possibility of role substitution' explained 13.8%. The third and the fourth domains were 'Relations with adult children' and 'Grandchildren's characteristics' explaining 12.5% and 12.1 %, respectively. The last domain explained 10.8% of the total variance with the theme 'Restriction of social life' After accomplishing the reliability analysis, Cronbach's alpha coefficient was determined to be .75. Conclusions : This initial step in the development of a Grandmothering Stress Index is valuable to reflect the subject of Grandmothering stress in senior citizens in Korea. Future study should to refine the constitution of the instrument.

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The Evaluation of Evenness of Nonwovens Using Image Analysis Method

  • Jeong, Sung-Hoon;Kim, Si-Hwan;Hong, Cheol-Jae
    • Fibers and Polymers
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    • v.2 no.3
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    • pp.164-170
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    • 2001
  • Authors studied on the applicability of image analysis technique using a scanner with a CCD (charged coupled deviced) to the evaluation of evenness of nonwovens because it has distinctive features to considerably save time and labor in the analysis compared with other classical methods. As specimens fur the experiment, two different types that are unpatterned and patterned ones were prepared. For the unpatterned specimen, webs were chemically bonded, while for the patterned specimen, webs being thermally calendered with engraved roller. Several webs having various areal densities were prepared and bonded. Coefficient of variation (CV%) was used as a parameter to evaluate the evenness. Scanning conditions could be suitably set up through comparing the total variance to the between-group variance and to the within-group variance, respectively, on the images scanned at the different conditions. The 2D convolution method with smoothing filter kernel was introduced to further filter the noises on the scanned images. After the filtering process, the increase of web areal densities gave an uniform decrease of the CV%. This showed that the scanned image analysis with proper filtering process could be successfully applicable to the evaluation of evenness in nonwovens.

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A Study on Human Training System for Prosthetic Arm Control (의수제어를 위한 인체학습시스템에 관한 연구)

  • 장영건;홍승홍
    • Journal of Biomedical Engineering Research
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    • v.15 no.4
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    • pp.465-474
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    • 1994
  • This study is concerned with a method which helps human to generate EMG signals accurately and consistently to make reliable design samples of function discriminator for prosthetic arm control. We intend to ensure a signal accuracy and consistency by training human as a signal generation source. For the purposes, we construct a human training system using a digital computer, which generates visual graphes to compare real target motion trajectory with the desired one, to observe EMG signals and their features. To evaluate the effect which affects a feature variance and a feature separability between motion classes by the human training system, we select 4 features such as integral absolute value, zero crossing counts, AR coefficients and LPC cepstrum coefficients. We perform a experiment four times during 2 months. The experimental results show that the hu- man training system is effective for accurate and consistent EMG signal generation and reduction of a feature variance, but is not correlated for a feature separability, The cepstrum coefficient is the most preferable among the used features for reduction of variance, class separability and robustness to a time varing property of EMG signals.

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Surface roughness evaluation in turning by an orthogonal array method (직교배열법에 의한 선삭가공시 표면거칠기 평가)

  • 배병중;박태준;양승한;이영문;김희술
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.11a
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    • pp.862-865
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    • 2000
  • The object of this paper is to evaluate the surface roughness using the experimental equation of surface roughness, which is developed in turning by an orthogonal array method. $L_9{3^4}$ orthogonal array method, one of fractional factorial design has been used to study effects of main cutting parameters such as cutting speed, feed rate and depth of cut, on the surface roughness. And the analysis of variance (ANOVA)-test has been used to check the significance of cutting parameters. Using the result of ANOVA-test, the experimental equation of surface roughness, which consists of only significant cutting parameter - feed rate, has been developed. The coefficient of determination of this equation is 0.962.

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Acceptance of Disability and Related Factors of Hemiplegic Elderly and Non-Elderly (편마비 노인과 편마비 청장년의 장애수용과 관련요인)

  • Kim, Mi-Hee
    • Korean Journal of Adult Nursing
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    • v.21 no.5
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    • pp.547-558
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    • 2009
  • Purpose: This study was conducted to study the acceptance of disability and influential factors between hemiplegic elderly and non-elderly after stroke. Methods: Data were collected with questionnaires from 104 elderly and 134 non-elderly with hemiplegia. Data were analyzed by $x^2$-test, t-test, ANOVA, ANCOVA, Pearson correlation coefficient, and multiple regression. Results: Significant predictors of acceptance of disability were family support, activities of daily living, and age, and these factors accounted for 24.2% of variance in acceptance of disability in the hemiplegic elderly. On the other hand, the significant predictors were family support and employment, and these factors accounted for 32.3% of variance in acceptance of disability in the non-elderly. Family support was the most influential variable in both the elderly and the non-elderly. Conclusion: An acceptance of disability program for the hemiplegic elderly should be designed differently from that for the non-elderly.

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A Comparative Study of Consumers and Providers on Nursing Service Quality, Satisfaction, and Hospital Revisiting Intent (간호서비스 질, 만족 및 병원 재이용 의도에 관한 소비자와 제공자간의 지각차이 비교)

  • Lee, Mi-Aie;Yom, Young-Hee
    • Journal of Korean Academy of Nursing Administration
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    • v.11 no.4
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    • pp.425-437
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    • 2005
  • Purpose: The purposes of this study were to compare the nursing service quality, gap, overall nursing service satisfaction, overall medical service satisfaction and intent to revisit the hospital perceived by consumers and providers. Methods: Data were collected with self-administered questionnaire and analyzed using frequency, %, mean, standard deviation, t-test, Pearson correlation coefficient, and multiple regression analysis. Result: Nursing service gap perceived by consumers was smaller than that of providers. Consumer's overall satisfaction with nursing and medical service was higher than that of nurses. In consumers, nursing service satisfaction alone accounted for 62.9% of the variance in their intent to revisit the hospital, while explained 3% of the variance in providers. Conclusion: There are definitely perception gap between consumers and providers. Therefore nursing and hospital managers must recognize it, and carry out the internal marketing strategies for nurses.

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Uncertainty Analysis of Concrete Structures Using Modified Latin Hypercube Sampling Method

  • Yang, In-Hwan
    • International Journal of Concrete Structures and Materials
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    • v.18 no.2E
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    • pp.89-95
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    • 2006
  • This paper proposes a modified method of Latin Hypercube sampling to reduce the variance of statistical parameters in uncertainty analysis of concrete structures. The proposed method is a modification of Latin Hypercube sampling method. This analysis method uses specifically modified tables of random permutations of ranked numbers. In addition, the Spearman coefficient is used to make modified tables. Numerical analysis is carried out to predict the uncertainty of axial shortening in prestressed concrete bridge. Statistical parameters obtained from modified Latin Hypercube sampling method and conventional Latin Hypercube sampling method are compared and evaluated by a numeric analysis. The results show that the proposed method results in a decrease in the variance of statistical parameters. This indicates the method is efficient and effective in the uncertainty analysis of complex structural system such as prestressed concrete bridges.