• 제목/요약/키워드: t3 statistic

검색결과 151건 처리시간 0.024초

T-Commerce 요인에 따른 사용의도 판별에 관한 연구 (A Study on the Discrimination of Use Intention by Critical T-Commerce Factors)

  • 김주안
    • 통상정보연구
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    • 제8권3호
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    • pp.71-95
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    • 2006
  • In recent, T-commerce is widely dispersed as alternative type of commerce. It is forecasted that t-commerce system is used more than e-commerce system. Therefore more and more t-commerce-related industries are also recognizing that t-commerce is a critical business model. It is needed to understand the concept of t-commerce and develop the t-commerce marketing strategy. CEO analyses consumer's behaviors according to the data about buyers and applies the advantage of t-commerce to the communication with customers. This t-commerce system plays an important role in maximizing customer satisfaction and affecting their intention to reuse it. Therefore this paper attempts to identify T-commerce critical success factors and divide between use-intention group and unuse-intention group by taking out a discriminant function by the discriminant analysis. This lays a foundation in developing T-commerce strategy. According to the discriminant function extracted, convenience factor, amusement factor, system quality factor, product perception factor are significant in the sequence of influential degree. However, usefulness factor and speedy connection factor are not significant. In result, the target hitting rate is 77.9% in the first unuse-intention group and it is 95.2% in the second use-intention group. The total discriminant target hitting rate is computed to higher value, 86.55%. The statistic package, SPSS 12.0, is used to survey and analyse data and test the hypothesis. The validity and reliability of variables are verified by both reliability analysis and factor analysis. The discriminant analysis is used to tell the difference between use-intention group and unuse-intention group.

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Goodenss of Fit Test on Density Estimation

  • Kim, J.T.;Yoon, Y.H.;Moon, G.A.
    • Communications for Statistical Applications and Methods
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    • 제4권3호
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    • pp.891-901
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    • 1997
  • The objective of this research is to investigate the problem of goodness of fit testing based on nonparametric density estimation with a data-driven smoothing parameter. The small and large smaple properties of the proposed test statistic $Z_{mn}$ are investigated with the minimizer $\widehat{m}$ of the estimated mean integrated squared error by the Diggle and Hall (1986) method.

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온요법이 여고생의 월경곤란증 경감에 미치는 효과 (The Effect of Thermotherapy on High School Girls' Dysmenorrhea)

  • 강인선;조결자
    • 지역사회간호학회지
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    • 제12권3호
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    • pp.773-784
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    • 2001
  • The study was conducted to test the effectiveness of thermotherapy for high school girls who suffered from disruption in school activities through dysmenorrhea, and to study the extent of its availability in school infirmaries as one of the nursing methods. The test for the study was designed to make a contrast between half of the subjects (20) who did not receive the thermotherapy, and the rest (20) who did during the period from February 15th to April 14th, 2001. Measurements were taken of the subjects who complained of painful menstruation by a set of variables. The variables that were established and complemented by Hur, Mung-heang (1985) consist of 29 items that assess the dysmenorrhea and vitality through the symptoms of primary menstruation visually. Spsswin was used to analyze the data. The Cronbach-${\alpha}$ method was used for statistic confidence, and the test effect of both the subjects and the contrary ones was analyzed by way of T-test. The conclusions are as follow. (1) The hypothesis 1 states that the subjects with themotherapy have a lower degree of dysmenorrhea rather than the contrary ones without it. By the above assessment, there was a quantitative difference between the subjects at 39.40, and the contrary ones at 22.0. After the themotherapy, the degree of dysmenorrhea in the subjects was low indicating that there is a still 5% chance of statistic meaningful difference (t= 2.651. P= .012). As a result, the first hypothesis was accepted. (2) The hypothesis 2 states that the subjects with themotherapy have a different primary menstruation than those without. Data indicate that there was a difference of -5.95 and -4.80. The subjects showed low degrees. Since it was statistically insignificant (t=-1.398, P=.170), the second hypothesis was rejected. (3) The hypothesis 3 states that the subjects with themotherapy have a different vitality. The vitality was measured in three aspects. (1) pulse rate (/min) The hypothesis 3' states that the subjects with themotherapy have the different pulse rate from those without. Data indicate that there was no statistically meaningful difference between the two groups (t=.237, P=. 814). Therefore, the third 1st hypothesis was rejected. (2) Respiration rate The hypothesis 3' states that the subjects with themotherapy have a different respiration rate between pre-thermotherapy and post-thermotherapy. in contrast with the ones without it. The data show that there was no statistically meaningful difference (t=.133. P=.895). A little respiration rate difference was shown between pre-and post-. Likewise. the third 2nd hypothesis was rejected. (3) Blood pressure In the 3rd sub-hypothesis that there would be a difference between experimental and controlled groups was also rejected. because there was no statistically significant difference between the contracting blood pressure and the relaxing blood pressure. In terms of vitality. the pulse rate, respiration rate and blood pressure have no statistical meaning but the first two ones show the decreasing in the rate. In short, though exclusive studies focused on thermo therapy have not been conducted and the comparison can not be made, this study shows not only that the thermotherapy is very effective to dysmenorrhea, but also that it can be available in school infirmaries as one of the nursing methods.

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대한물리의학회지(2006-2012)의 연구동향 (The Trend of Research in Journal of the Korean Society of Physical Medicine)

  • 노정석
    • 대한물리의학회지
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    • 제8권3호
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    • pp.457-466
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    • 2013
  • PURPOSE: The purpose of this study was to investigate the trend of research in Journal of the Korean Society of Physical Medicine (JKSPM). METHODS: A total of 897 articles of JKSPM from Vol.1, No.1, 2006 to Vol.7, No.4, 2012 were reviewed in regard to research type, research level, subjects, research topic, statistic method, and researcher. RESULTS: The most common research type was experimental study(65%). The most common research level was level 2(randomized controlled trials; RCT)(55%). The most common age group of subject was age 11-30 group(55%). The most common diagnosis of subjects was stroke(49%). The main research topic of articles was therapeutic exercise(13.2%). Independent t-test was the most used statistic method. A professor was the most common researcher. The Daegu and Busan were the most common provinces that researcher works. CONCLUSION: This study showed the trend of research in JKSPM and helped readers to understand the trends of research in fields of physical therapy of Korea. In further studies, it is necessary to review systematically and intensively other journals in field of physical therapy.

Bearing fault detection through multiscale wavelet scalogram-based SPC

  • Jung, Uk;Koh, Bong-Hwan
    • Smart Structures and Systems
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    • 제14권3호
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    • pp.377-395
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    • 2014
  • Vibration-based fault detection and condition monitoring of rotating machinery, using statistical process control (SPC) combined with statistical pattern recognition methodology, has been widely investigated by many researchers. In particular, the discrete wavelet transform (DWT) is considered as a powerful tool for feature extraction in detecting fault on rotating machinery. Although DWT significantly reduces the dimensionality of the data, the number of retained wavelet features can still be significantly large. Then, the use of standard multivariate SPC techniques is not advised, because the sample covariance matrix is likely to be singular, so that the common multivariate statistics cannot be calculated. Even though many feature-based SPC methods have been introduced to tackle this deficiency, most methods require a parametric distributional assumption that restricts their feasibility to specific problems of process control, and thus limit their application. This study proposes a nonparametric multivariate control chart method, based on multiscale wavelet scalogram (MWS) features, that overcomes the limitation posed by the parametric assumption in existing SPC methods. The presented approach takes advantage of multi-resolution analysis using DWT, and obtains MWS features with significantly low dimensionality. We calculate Hotelling's $T^2$-type monitoring statistic using MWS, which has enough damage-discrimination ability. A bootstrap approach is used to determine the upper control limit of the monitoring statistic, without any distributional assumption. Numerical simulations demonstrate the performance of the proposed control charting method, under various damage-level scenarios for a bearing system.

Effective Sample Sizes for the Test of Mean Differences Based on Homogeneity Test

  • Heo, Sunyeong
    • 통합자연과학논문집
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    • 제12권3호
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    • pp.91-99
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    • 2019
  • Many researchers in various study fields use the two sample t-test to confirm their treatment effects. The two sample t-test is generally used for small samples, and assumes that two independent random samples are selected from normal populations, and the population variances are unknown. Researchers often conduct F-test, the test of equality of variances, before testing the treatment effects, and the test statistic or confidence interval for the two sample t-test has two formats according to whether the variances are equal or not. Researchers using the two sample t-test often want to know how large sample sizes they need to get reliable test results. This research gives some guidelines for sample sizes to them through simulation works. The simulation had run for normal populations with the different ratios of two variances for different sample sizes (${\leq}30$). The simulation results are as follows. First, if one has no idea equality of variances but he/she can assume the difference is moderate, it is safe to use sample size at least 20 in terms of the nominal level of significance. Second, the power of F-test for the equality of variances is very low when the sample sizes are small (<30) even though the ratio of two variances is equal to 2. Third, the sample sizes at least 10 for the two sample t-test are recommendable in terms of the nominal level of significance and the error limit.

기능적 전기자극 치료가 편마비 환자의 균형에 미치는 영향 (Effects of Functional Electrical Stimulation on the Balance of Hemiplegic Patients)

  • 김용철;이석민;송창호
    • The Journal of Korean Physical Therapy
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    • 제16권3호
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    • pp.97-111
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    • 2004
  • This study, adopting the pretest-post test experimental study, is designed to find out how the functional electrical stimulation makes effect on the balance of a patient with spasticity of the ankle plantarflexor muscle caused by hemiplegic after stroke. The 46 subjects for this study were randomly sampled out of the patients who were hospitalized from September 1, 2003 to November 30, 2003 in H sanitarium in Yangpyung. The patients were with spasticity of the ankle plantarflexor muscle caused by hemiplegic after stroke and able to walk without supporting implements. The purpose of the study is firstly to analyze the change of ROM, FRTof a patient with spasticity of the ankle plantarflexor muscle when the functional electrical stimulation is applied and secondly to find out how the sex, age, height, weight, part of the diagnosis, duration of pain, experience of relapse and getting hurt from a fall of a patient make effect on the change. The experimental group for the study is divided into two to compare the differences of the effect. The exercising treatment only was performed for the conrtol group, and the functional electrical stimulation to the ankle dorsiflexor muscle as well as the exercising treatment was applied to the experimental group. The ROM test was performed to check the range of motion of the ankle with a double armed universal goniometer. The test was done 3 times to take an average. FRT were performed to check the balance. The statistical test was conducted using the SPSS 10.0/PC program by means of the following methods: χ2-test and t-test for testing homogeneity between the groups; paired t-test, independent sample t-test, F-test, and two-way ANOVA for analyzing the changes before and after the treatment. The levels of statistical significance of all the data were maintained at p<.05. According to the test, ROM has more decreased in experimental group than in control group when the functional electrical stimulation was applied only to the experimental group. However, the significant statistic difference was not shown (p=.059). FRT showed remarkable differences in the experimental group compared to the control group, showing the significant statistic difference (p=.000). On the one hand, the change of ROM, FRT related with the sex, age, height, weight, part of the diagnosis, and experience relapse was a meaningless minimum value. The change of ROM related to the duration of pain and the experience of falling down was also meaningless. However, FRT showed significant statistic difference (p<.05). According to the test above, the application of functional electrical stimulation to a patient with spasticity of the ankle dorsiflexor muscle caused by hemiplegic after stroke makes significant effect on the balance of a patient, but the result has nothing with the sex, age, height, weight, part of the diagnosis, duration of pain, experience of relapse and getting hurt from a fall of a patient. However, it is regarded to give contribution to the balance improvement of a patient. Therefore, this study expects to be a valuable clinical material for a patient with spasticity.

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부분 방전 전하와 음향 방출 펄스의 동시 측정에 의한 트리잉 파괴 진단 (The Diagnosis of Treeing Breakdown Using Simultaneous Detection of Electrical Charge and Acoustic Emission Pulse of Partial Discharge)

  • 김성홍;박재준;김재환
    • E2M - 전기 전자와 첨단 소재
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    • 제10권3호
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    • pp.247-254
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    • 1997
  • Internal voids in insulators give rise to partial discharge, which causes a local breakdown and even entire insulation breakdown. Recently, the necessity of establishing the way to diagnose the aging of insulation materials and to predict of insulation breakdown become important. The purpose of our work are to investigate the treeing phenomena with an artificial needle shaped void by the charge of discharge and acoustic emission pulse in each phase angle area at the same time. We analyzed the .PHI.-QA-t pattern and .PHI.-AEA-t pattern using statistic operators such as pulse magnitude, pulse number, skewness, kurtosis. Therefore, the relation between the charge of discharge and acoustic emission pulse will be helpful to predict the breakdown just before the breakdown occur.

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태권도 수련에 따른 신체적 자기개념 인식 변화 (Change of Physical Self-concept according to Taekwondo Discipline)

  • 임태희;김동현
    • 한국콘텐츠학회논문지
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    • 제12권9호
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    • pp.408-421
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    • 2012
  • 이 연구는 태권도 수련집단과 비수련집단의 신체적 자기개념 인식에 대한 변화차이를 규명하는 것에 목적이 있었다. 이러한 연구목적을 달성하기 위하여 연구대상은 S시에서 1개 초등학교를 연구자가 임의로 선정하였다. 그리고 ACSM(2000) 운동 가이드라인 기준에 따라 태권도 참여집단 30명, 비참여집단 40명을 선정한 후 12주 간격으로 3차례에 걸쳐 반복측정을 통한 이원혼합설계를 활용하여 연구를 수행하였다. 이것의 통계처리방법은 SPSS 12.0 for Windows를 활용한 기술통계, 이원변량분석, 대응 t검정과 독립 t검정이었다. 이러한 과정을 토대로 연구를 수행한 결과에 기초하여 다음과 같은 결론에 도달하였다. 첫째, 태권도 수련집단과 비수련집단은 측정시점에 따라 신체적 자기개념의 변화패턴에는 전반적으로 차이가 있다. 둘째, 태권도 수련집단과 비수련집단의 신체적 자기개념 점수는 1차보다 2차가 그리고 1차보다 3차가 높게 나타났다. 셋째, 태권도 수련집단과 비수련집단 간에 신체적 자기개념에서는 2차와 3차 측정에서 집단 간에 차이가 있다. 즉, 두 집단은 태권도 수련에 따른 신체적 자기개념의 변화패턴에는 전반적으로 차이가 있다. 결론적으로 태권도 수련은 유소년의 신체적 자기개념 변화에 효과가 있다.

비만환자의 위장조영술에 있어 복와위 압박법의 적용에 관한 연구 (A study on the Application of Prone Compression Study for Obese Patients in Upper Gastrointestinal Series)

  • 손순룡;정홍량
    • 대한방사선기술학회지:방사선기술과학
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    • 제22권2호
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    • pp.9-15
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    • 1999
  • The aim of this study is to measure the application of prone compression study using compression paddle for obese patients in upper gastrointestinal series. Prone compression study using compression paddle was performed in fifty patients, who were not examined completely erect compression study for obesity. The radiographs of stomach were classified into the lower, middle, and high body and then we gave five points included 'very poor', 'poor', 'suspicious', 'good', and 'complete' according to level of detection for area gastrica and mucosal fold. Statistic analysis was performed using T-test and ANOVA, and confidence rate was fixed in 95%(P<0.05) for the significance. The results were as follows : 1. The compression marks on high body was 'poor' grades in erect and prone compression study. The points were 1.64 and 1.86, respectively. 2. The compression marks on middle body was 1.68 in erect compression study, and 'suspicious' in prone compression study. 3. The compression marks on lower body was 'poor' in erect compression study, and 'good' in prone compression study. 4. There was a high statistic signification between the two study on middle and lower body except for high body(P<0.01). 5. The average abdominal thickness of subjects was 23.98 centimeter. There was no statistic signification between the difference of average marks by the abdominal thickness(P>0.05). As these results, the prone compression study in upper gastrointestinal serie seem to be an useful study for obese patients, because it decreases pain and the feeling of uneasiness, and improve compression efficiency remarkably.

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