• Title/Summary/Keyword: T-검정 분석

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EMG Power Spectrum Analysis of the Medial Gastrocnemius and the Soleus Under the Fatigued Condition (피로조건하에서의 내측 장딴지근과 가자미근의 근전도 스펙트럼 분석)

  • Cynn, Heonseock
    • Physical Therapy Korea
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    • v.5 no.4
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    • pp.9-19
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    • 1998
  • 연구목적 이 연구의 목적은 피로유발수축후 장딴지근과 가자미근의 근전도 power spectrum 중앙경항치를 비교 검사하는 것이다. 실험대상 열 여섯명의 자원자(남자 10, 여자 6)를 대상으로 하였다. 남자 대상자의 연령범위는 25세에서 33세(평균 $28.6{\pm}2.5$)였고 여자 대상자의 연령범위는 26세에서 31세($27.8{\pm}1.9$)였다. 실험방법 실험대상자는 피로유발수축전후 50% 최대등척성근수축을 수행하였다. 자료수집과 분석을 위해 LabVIEW 소프트웨어를 사용하였다. 결과 t-검정결과 내측 장딴지근에서는 피로유발수축후 주파수의 중위값과 평균이 통계적으로 유의하게 감소하였으나 가자미근에서는 통계적으로 유의한 차이가 없었다. t-검정결과 두 근육간 주파수 감소의 차이는 통계적으로 유의한 차이가 있었다. 토의 및 결론 이 결과들은 피로유발수축후 근전도 power spectrum 중앙경향치가 저주파대역으로 감소함을 나타내었다. 이 연구는 중앙주파수와 평균주파수가 피로지수로서의 신뢰도와 타당도가 뛰어나며 객관적 측정과 훈련효과 평가로 사용할수 있음을 보였다.

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An Analysis of Satisfaction and Utilization from the Parents' Perspective on the Application of Early Childhood Education Institutions (유아교육기관의 어플리케이션 사용에 대한 학부모 관점에서의 만족도 및 활용도 분석)

  • Rim, Jeng-Hee;Han, Sang-Kil
    • The Journal of the Korea Contents Association
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    • v.20 no.5
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    • pp.140-152
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    • 2020
  • This study analyzed the satisfaction and utilization of the institutional applications used by child-education institutions from a parent's perspective. The research target is a parent who enlisted their children in private kindergarten institution located in Gyeong-gi province and final research outcomes are 443 in total. The difference in satisfaction and utilization have been identified with demographic descriptive statistics, students t-test, and F-test statistics analysis method. First, the result of T-test on the difference in satisfaction and utilization based on parents' employment status shows that statistically significant difference was found in convenience from overall satisfaction, communication from overall utilization and child-parent relationship. Second, the F-test of differences in satisfaction and utilization showed a statistically significant difference in education utilization variables, with all variables in educational background and motivation. In terms of utilization, parents' educational background and overall utilization, and children's age were confirmed to have significant differences in communication, children's relationship, and motivation in basic life. Third, the result of multiple regression analysis shows that all predictors, including ease of use, communication, and satisfaction with educational activities, have a statistically significant impact on utilization standard variables, relative contributions showed the highest level of communication satisfaction. Therefore this paper implicates that institutional applications can maximize educational effectiveness by checking the applicability of active communication and educational activities with parents and actively communicating with parents in early childhood through various educational content applications.

A Robust Test for Location Parameters in Multivariate Data (다변량 자료에서 위치모수에 대한 로버스트 검정)

  • So, Sun-Ha;Lee, Dong-Hee;Jung, Byoung-Cheo
    • The Korean Journal of Applied Statistics
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    • v.22 no.6
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    • pp.1355-1364
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    • 2009
  • This work propose a robust test for location parameters in multivariate data based on MVE and MCD with the affine equivariance and the high-breakdown properties. We consider the hypothesis testing satisfying high efficiency and high test power simultaneously to bring in the one-step reweighting procedure upon high-breakdown estimators, which generally suffer from the low efficiency and, as a result, usually used only in the exploratory analysis. Monte Carlo study shows that the suggested method retains nominal significance levels and higher testing power without regard to various population distributions than a Hotelling's $T^2$ test. In an example, a data set containing known outliers does not make an influence toward our proposal, while it renders a Hotelling's $T^2$ useless.

Kullback-Leibler Information-Based Tests of Fit for Inverse Gaussian Distribution (역가우스분포에 대한 쿨백-라이블러 정보 기반 적합도 검정)

  • Choi, Byung-Jin
    • The Korean Journal of Applied Statistics
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    • v.24 no.6
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    • pp.1271-1284
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    • 2011
  • The entropy-based test of fit for the inverse Gaussian distribution presented by Mudholkar and Tian(2002) can only be applied to the composite hypothesis that a sample is drawn from an inverse Gaussian distribution with both the location and scale parameters unknown. In application, however, a researcher may want a test of fit either for an inverse Gaussian distribution with one parameter known or for an inverse Gaussian distribution with both the two partameters known. In this paper, we introduce tests of fit for the inverse Gaussian distribution based on the Kullback-Leibler information as an extension of the entropy-based test. A window size should be chosen to implement the proposed tests. By means of Monte Carlo simulations, window sizes are determined for a wide range of sample sizes and the corresponding critical values of the test statistics are estimated. The results of power analysis for various alternatives report that the Kullback-Leibler information-based goodness-of-fit tests have good power.

A study on the effects of a 12-week compound exercise program on obese middle school girls' leptin and insulin levels (12주 복합운동이 비만 여중생의 렙틴과 인슐린에 미치는 영향)

  • Lee, Seon-Ik;Cho, Young-Seuk;Yang, Jeong-Ok
    • Journal of the Korean Data and Information Science Society
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    • v.23 no.5
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    • pp.895-904
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    • 2012
  • This study aims to examine the effects of a 12-week compound exercise program (aerobic exercise+weight training) on obese middle school girls' leptin and insulin before and after the exercise. This is achieved by dividing obese middle school girls whose body fat percentage is over 30% into a compound exercise group (n=20) and a control group (n=20) and conducting comparative analysis on them.After the Shapiro-Wilk normality test of the variables, a two-sample t-test was performed to see if the variables have the same mean between the compound exercise and control groups. A paired t-test was also performed to see if the changes in the variables before and after the compound exercise program were statistically significant. For all the statistical analysis, the significance level was set at ${\alpha}=0.05$. The results of this study showed the leptin and insulin levels in the combined exercise group had been significantly decreased. The regular 12 weeks of combined exercise is considered to have a positive impact on leptin and insulin levels in obese schoolgirls.

주식시장(株式市場)의 경기선행성(景氣先行性)에 관한 연구(硏究)

  • Ji, Ho-Jun
    • The Korean Journal of Financial Management
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    • v.9 no.1
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    • pp.207-222
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    • 1992
  • 본(本) 연구(硏究)는 주식시장의 변화가 경기변동에 대하여 갖는 선행성(先行性)의 유무(有無)와 선행기간(先行期間) 및 선행패턴을 검정하였다. 기존의 경기 정점(peak)과 저점(trough)에 따른 선행시차분석(先行時差分析)이나 주식시장과 경기변동간의 단순회귀모형에 의한 ${\beta}$계수 측정 방법과는 달리, 교차상관관계(交叉相關關係)에 의한 선행 결합여부를 검정하고 Granger 정의에 입각한 인과관계검정(因果關係檢定)을 시도하였다. 1975년부터 1991년까지의 월별자료를 이용하여 교차상관계수(交叉相關係數)에 의한 Ljung-Box Q-통계량 검정을 실시한 결과 주식수익률과 경기동행지수 순환변동치는 선행결합(先行結合)하고 있음을 알 수 있었으며, t-7기의 주식수익률과 t기의 경기동행지수 순환변동치간의 계수가 가장 크게 나타났다. 또한 주식수익률의 lead 1에서 3기까지 보다는 lead 4기 이후에 크게 나타났으며 업종별(業種別)로는 제조업(製造業) 관련분야에서 유의적으로 나타났다. Granger 정의에 의한 인과관계(因果關係) 검정(檢定)을 실시한 결과, 12개월 내지 9개월 전부터 1개월 전까지의 주식수익률을 이용하는 것이 경기동행지수 순환변동치의 과거 정보만을 이용하는 것보다 예측오차를 줄일 수 있는 것으로 나타나 주식수익률이 경기동행지수 순환변동치의 원인변수라 할 수 있을 것이다. 업종별(業種別) Granger 검정결과는 교차상관계수(交叉相關係數)에 의한 Ljung-Box Q-통계량 검정결과와 유사하게 나타났는데 이는 검정결과의 신뢰성을 높여주었다.

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MRI Findings Suggestive of Metastatic Axillary Lymph Nodes in Patients with Invasive Breast Cancer (유방암 환자에서 액와부 림프절 전이를 시사하는 자기공명영상 소견)

  • Ka Eun Kim;Shin Young Kim;Eun Young Ko
    • Journal of the Korean Society of Radiology
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    • v.83 no.3
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    • pp.620-631
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    • 2022
  • Purpose This study aimed to investigate the diagnostic performance of features suggestive of nodal metastasis on preoperative MRI in patients with invasive breast cancer. Materials and Methods We retrospectively reviewed the preoperative breast MRI of 192 consecutive patients with surgically proven invasive breast cancer. We analyzed MRI findings of axillary lymph nodes with regard to the size, long/short ratio, cortical thickness, shape and margin of the cortex, loss of hilum, asymmetry, signal intensity (SI) on T2-weighted images (T2WI), degree of enhancement in the early phase, and enhancement kinetics. Receiver operating characteristic (ROC) analysis, chi-square test, t test, and McNemar's test were used for statistical analysis. Results Increased shorter diameter, uneven cortical shape, increased cortical thickness, loss of hilum, asymmetry, irregular cortical margin, and low SI on T2WI were significantly suggestive of metastasis. ROC analysis revealed the cutoff value for the shorter diameter and cortical thickness as 8.05 mm and 2.75 mm, respectively. Increased cortical thickness (> 2.75 mm) and uneven cortical shape showed significantly higher sensitivity than other findings in McNemar's test. Irregular cortical margins showed the highest specificity (100%). Conclusion Cortical thickness > 2.75 mm and uneven cortical shape are more sensitive parameters than other findings, and an irregular cortical margin is the most specific parameter for predicting axillary metastasis in patients with invasive breast cancer.

Efficient Edge Detection in Noisy Images using Robust Rank-Order Test (잡음영상에서 로버스트 순위-순서 검정을 이용한 효과적인 에지검출)

  • Lim, Dong-Hoon
    • The Korean Journal of Applied Statistics
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    • v.20 no.1
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    • pp.147-157
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    • 2007
  • Edge detection has been widely used in computer vision and image processing. We describe a new edge detector based on the robust rank-order test which is a useful alternative to Wilcoxon test. Our method is based on detecting pixel intensity changes between two neighborhoods with a $r{\times}r$ window using an edge-height model to perform effectively on noisy images. Some experiments of our robust rank-order detector with several existing edge detectors are carried out on both synthetic images and real images with and without noise.

A Quality Assessment Method of Biometrics for Estimating Authentication Result in User Authentication System (사용자 인증시스템의 인증결과 예측을 위한 바이오정보의 품질평가기법)

  • Kim, Ae-Young;Lee, Sang-Ho
    • Journal of KIISE:Computing Practices and Letters
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    • v.16 no.2
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    • pp.242-246
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    • 2010
  • In this paper, we propose a quality assessment method of biometrics for estimating an authentication result in an user authentication system. The proposed quality assessment method is designed to compute a quality score called CIMR (Confidence Interval Matching Ratio) as a result by small-sample analysis like T-test. We use the C/MR-based quality assessment method for testing how to well draw a distinction between various biometrics in a multimodal biometric system. We also test a predictability for authentication results of obtained biometrics using the mean $\bar{X}$ and the variance $s^2$ in T-test-based CIMR. As a result, we achieved the maximum 88% accuracy for estimation of user authentication results.

Development and Application of Person-Centered Nursing Educational Program for Clinical Nurses (임상간호사를 위한 인간중심간호 교육프로그램 개발 및 적용)

  • Yoo, Eun-Young
    • Journal of Digital Convergence
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    • v.18 no.11
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    • pp.365-375
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    • 2020
  • This study aims to develop and apply Person-Centered Nursing educational program for clinical nurses. This study followed the ADDIE instructional design model to develop the Person-Centered Nursing educational program for clinical nurses. To investigate the effect of application, a non-equivalent control group posttest-pretest design was used to evaluate the clinical nurse's self-awareness, interpersonal relationship competency, self-esteem, co-worker support, and nursing job satisfaction. The results of the study showed that the self-awareness, interpersonal relationship competency, co-worker support and nursing job satisfaction scores of the control and experimental groups were significantly different between the groups based on time of measurement. Person-Centered Nursing competency was identified as a crucial element in addition to the knowledge, skills, and attitude essential to a clinical nurses.