• 제목/요약/키워드: coefficient of variance

검색결과 1,091건 처리시간 0.038초

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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    • 제56권4호
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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.

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

  • 김영옥
    • 한국식품영양과학회지
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    • 제24권6호
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    • pp.892-900
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    • 1995
  • 본 연구대상자들은 열량공급 영양소인 탄수화물 : 단백질 : 지방으로 부터 각각 전체 열량의 63% : 14% : 24%를 공급받아 한국인의 권장비인 65 : 15 : 20에 근사한 값을 보여주고 있다. 이러한 이상적인 섭취양상은 sucrose/starch ratio나 P/S ratio cholesterol 등에서도 바람직한 섭취수준을 보여주고 있어 본 조사대상자는 식이를 통한 고혈압 위험인자를 비교적 적게 갖고 있는 것으로 나타났다. 단, 섭취량이 위험수준 이상 보다 높을 것으로 기대되는 나트륨의 섭취량은 조리과정에서 첨가되는 식염의 양을 측정하지 못하여 그 위함의 심각성을 도출하지 못했다. 영양소 섭취의 식품공급원의 순위와 개인간의 변이식품의 순위는 일반적으로 모든 영양소(열량, 단백질, 지방, 나트륨, 칼륨)에서 크게 다른 것으로 나타나 영양소의 주된 공급식품을 중심으로 빈도조사법의 설문지를 작성할 경우 개인간의 섭취량의 차이를 찾아내는데 크게 실패할 가능성을 보여주고 있다. 단, cholesterol의 경우는 제한된 식품에 의존해서 공급받는 것으로 나타나 공급식품과 변이식품의 순위가 크게 차이 나지않아 빈도조사법 설문지 개발시 주된 공급식품의 섭취빈도 조사만으로도 개인간의 변이를 충분히 반영할 수 있는 것으로 나타났다. 그러므로 질병과의 관련성을 규명하기 위해 식이조사에서 식품섭취 빈도법을 이용하여 설문지를 개발할 경우 주된 급원식품만을 포함시킨다면 개인간의 섭취량의 차이를 도출해 낼 수 없으나, 포함되는 식품항목의 금원식품 뿐 아니라 변이식품도 포함시키는 것이 개인간의 영양소 섭취의 차이를 찾아낼 수 있는 좋은 방법임을 본 연구결과는 시사하고 있다. 본 연구는 고혈압의 식이성 위험인자가 되는 영양소를 중심으로 개인간의 섭취량의 차이를 규명하기 위한 식이조사를 한다는 전제하에 조사에 사용될 식품섭취 빈도법의 설문지 개발시 포함시켜야 할 식품항목의 타당성을 공급식품과 변이식품의 순위 분석을 통해 관찰해 봄으로써 조사표 작성의 기초자료를 제공하고자 하였다. 앞으로 고혈압 이오의 다른 질병인 경우에도 이와같은 연구가 진행되어 각각의 질병연구에 적절한 조사표 작성의 기초자료들이 제공되어야 역학연구에서 식이조사의 효율성을 기대할 수 있을 것이다.

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

  • 김명수;정현경
    • 성인간호학회지
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    • 제26권4호
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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.

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

  • 김문정;정재원
    • 여성건강간호학회지
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    • 제14권1호
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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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    • 제2권3호
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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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의수제어를 위한 인체학습시스템에 관한 연구 (A Study on Human Training System for Prosthetic Arm Control)

  • 장영건;홍승홍
    • 대한의용생체공학회:의공학회지
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    • 제15권4호
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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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직교배열법에 의한 선삭가공시 표면거칠기 평가 (Surface roughness evaluation in turning by an orthogonal array method)

  • 배병중;박태준;양승한;이영문;김희술
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2000년도 추계학술대회 논문집
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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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편마비 노인과 편마비 청장년의 장애수용과 관련요인 (Acceptance of Disability and Related Factors of Hemiplegic Elderly and Non-Elderly)

  • 김미희
    • 성인간호학회지
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    • 제21권5호
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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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간호서비스 질, 만족 및 병원 재이용 의도에 관한 소비자와 제공자간의 지각차이 비교 (A Comparative Study of Consumers and Providers on Nursing Service Quality, Satisfaction, and Hospital Revisiting Intent)

  • 이미애;염영희
    • 간호행정학회지
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    • 제11권4호
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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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    • 제18권2E호
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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.