• Communications for Statistical Applications and Methods
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• v.9 no.2
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• pp.389-399
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• 2002

In order to examine whether the difference between two point estimates of population proportions is statistically significant, data analysts use two techniques. The first is to explore the overlap between two associated confidence intervals. Second method is to test the significance which is introduced at most statistical textbooks under the common assumptions of consistency, asymptotic normality, and asymptotic independence of the estimates. Under the null hypothesis which is two population proportions are equal, the pooled estimator of population proportion is preferred as a point estimator since two independent random samples are considered to be collected from one population. Hence as an alternative method, we could obtain another confidence interval of the difference of the population proportions with using the pooled estimate. We conclude that, among three methods, the overlapped method is under-estimated, and the difference of the population proportions method is over-estimated on the basis of the proposed method.

• The Korean Journal of Applied Statistics
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• v.26 no.4
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• pp.611-622
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• 2013

Mudholkar and Tian (2002) proposed an entropy-based test of fit for the inverse Gaussian distribution; however, the test can be applied to only the composite hypothesis of the inverse Gaussian distribution with an unknown location parameter. In this paper, we propose an entropy-based goodness-of-fit test for an inverse Gaussian distribution that can be applied to the composite hypothesis of the inverse Gaussian distribution as well as the simple hypothesis of the inverse Gaussian distribution with a specified location parameter. The proposed test is based on the probability integration transformation. The critical values of the test statistic estimated by simulations are presented in a tabular form. A simulation study is performed to compare the proposed test under some selected alternatives with Mudholkar and Tian (2002)'s test in terms of power. The results show that the proposed test has better power than the previous entropy-based test.

• Journal of Acupuncture Research
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• v.26 no.5
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• pp.137-149
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• 2009

Objectives : This study was designed to analyze whether General Coordinative Manipulation(GCM) Intervention could have effects on the balanced restoration of asymmetrical posture. Methods : Sixty eight(68) healthy volunteers(1st hypothesis: 46, 2nd hypothesis 22) participated in two GCM interventions, which have been performed 2 times a week for 3 weeks. The Global Postural System(GPS) Unit was used to measure the posture, and measurements were performed before and after the application of each intervention group. A paired t-test and wilcoxon test were used to determine the statistical significance. Results : The outcome of examining the hypothesis is as follows: 1. The 1st hypothesis: It has been proved that GCM Intervention, which coordinates the flexion type of upper extremity and the extension type of lower extremity, excluding self-care, shows the efficiency in treatment on more than two aspects of 3 parts: anterior, posterior and lateral postures, and the effects on more than 3 of 4 body types. 2. The 2nd hypothesis: It has been proved that GCM Intervention, which coordinates the flexion type of lower extremity and the extension type of upper extremity, excluding self-care, shows the treatment in efficiency on more than two aspects of 3 parts: anterior, posterior and lateral postures, and the effects on more than 2 of 3 body types. Conclusions : GCM intervention programs on the two hypothesis groups have an affect on the balanced restoration of the postural control system.

• The Korean Journal of Applied Statistics
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• v.14 no.2
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• pp.449-462
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• 2001

베이지안 다중 검정방법(multiple hypothesis test)은 여러 통계모형에서 성공적인 결과를 주는 것으로 알려져있다. 일반적으로, 베이지안 가설검정은 고려중인 모형에 대한 사후확률을 계산하여 가장 높은 확률은 갖는 모형을 선택하기 때문에 귀무가설의 기각여부에만 관심을 가지는 고전적인 분산분석 검정과는 달리 좀 더 구체적인 모형을 선택할 수 있는 장점이 있다. 이 논문에서는 독립이면서 로그정규분포를 따르는 K($\geq$3)개 모집단의 모수에 대한 가설 검정방법으로 O’Hagan(1995)이 제안한 부분 베이즈 요인을 이용한 베이지안 방법을 제안한다. 이 때 모수에 대한 사전분포로는 무정보적 사전분포를 사용한다. 제안한 검정 방법의 유용성을 알아보기 위하여 실제 자료의 분석과 모의 실험을 이용하여 고전적인 검정방법과 그 결과를 비교한다.

• International Commerce and Information Review
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• v.11 no.1
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• pp.67-92
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• 2009

This study investigates the relationship between Culture and online trust in three cultural dimensions: individualism, collectivism and long term orientation. For this purpose, this study proposes the empirical hypothesis to test the implication of the proposed model. The results are as follows. First, the purchase intention is influenced by the online trust in statistical sense. Second, the relationship between Culture and the antecedents of online trust are statistically established in three cultural dimensions: individualism, collectivism and long term orientation. The direction of future research is to develop the more refined hypothesis to test the empirical model in the field of on line trust and culture.

• Journal of Korean Academy of Nursing
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• v.4 no.1
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• pp.38-49
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• 1974

Presently, the performance level of the college student has received a great deal of attention, particularly in the area of professional education. The problem of under achievement, especially in areas dealing with science and technology, has gone through considerable investigation by numerous Psychologists and Educators. Thus for, however, they have not been successful in determining conclusively the non-intellectual factors involved. The maladjustment problem of these students has been a thorn in the side of nursing education for some time. This topic has been discussed among nursing educators without any tangible results. Furthermore, the fact that the number of students who withdraw from nursing education programs before graduation has increased. This represents a major problem for nursing education. This problem area had increased attention drawn to it on October 1957, when Russia successfully launched to first satellite "Sputnik" into space. Various studies seem to indicate that factors related to over achievement and under.achievement can be found in the motivation of the students. This study is aimed at testing 3 hypotheses which hopefully will lead to a better understanding of the learning activities of nursing students and to determine some of their nonintellectually personality traits. Hypothesis I: learning activities in nursing students and persona1ity are correlated, there will be significant differences in personality need structures between 4 classes of nursing collegiate students. Sub-hypothesis: There will also be significant differences in the degree of student satisfaction in her major subject. Hypothesis I: If there is a special personality need structure which is required for the clinical learning activity in general, then there will be significant differences between the personality need structures of under-achievers and overachiever. Hypothesis II : If each clinical nursing subject requires different personality need structures, then there will be differences in personality need structure between the different clinical groups Methodology: 1. Tool: A Korean translation and correction of the Edwards Personal Preference Schedule of U.S.A. was used. 2. Subject and Test Method: Subjects were nursing students at Yonsei University, who enrolled for Fall semester of 1971. The Researcher herself executed the test for the test for the class as a group, and the absent students were tested indidually. Out of 307 students, 293 students (95.4%) were reported. 3. Statistical treatment: The mean and standard deviation for each of the 15 personality need variables were computed and the value of T-test was obtained to determine the differences in the personality need structures between each group. Results: 1, For the first hypothesis, the personality need structures between each of the 4 classes and the reported degree of satisfaction in major subject showed significant differences. Therefore the hypothesis I was accepted. 2. The comparison of personality need structure of under-achievers and over-achievers in clinical fields showed significant differences. Thus hypothesis II was accepted. 3. Personality need structure between clinical subject groups showed significant differences therefore the 3rd hypothesis was accepted.

• Computers and Concrete
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• v.14 no.2
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• pp.145-161
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• 2014

The article presents the statistical method of grouping the results of the compressive strength of concrete in continuous production. It describes the method of dividing the series of compressive strength results into batches of statistically stable strength parameters at specific time intervals, based on the standardized concept of "concrete family". The article presents the examples of calculations made for two series of concrete strength results, from which sets of decreased strength parameters were separated. When assessing the quality of concrete elements and concrete road surfaces, the principal issue is the control of the compressive strength parameters of concrete. Large quantities of concrete mix manufactured in a continuous way should be subject to continuous control. Standardized approach to assessing the concrete strength proves to be insufficient because it does not allow for the detection of subsets of the decreased strength results, which in turn makes it impossible to make adjustments to the concrete manufacturing process and to identify particular product or area on site with decreased concrete strength. In this article two independent methods of grouping the test results of concrete with statistically stable strength parameters were proposed, involving verification of statistical hypothesis based on statistical tests: Student's t-test and Mann - Whitney - U test.

• Journal of Distribution Science
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• v.12 no.8
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• pp.43-54
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• 2014

Purpose - This study was based on a theoretical consideration of the structural relationship between the support and control of the franchisor and the satisfaction and strategic response (voice, loyalty, exit, neglect) of the franchisee. First, based on the preceding research, this study systematically organized the type of support and control of the franchisor. Second, the study examined the effects of a franchisor's support and control on the expectancy disconfirmation between affiliated franchisees' expectations before a franchise agreement and performance after operating an affiliated store. Third, the study looked into the effects of expectancy disconfirmation relating to a franchisor's support and control on an affiliated franchisees' general satisfaction. Fourth, this study examined the influence of the general satisfaction of a franchisee on affiliated franchisees' response strategies. Research design, data, and methodology - In this study, the population comprised the nation's franchisors, and the sample comprised franchisees conducting business in Seoul and Gyeonggi-do. A self-administered questionnaire was used; the author and examiner explained the study's parameters to the interviewees in advance, to lessen the rate of rejection of the answers and to maintain reliability. The author distributed 350 copies of the questionnaire and collected 327 copies (93.4%). The author removed 54 copies of the sample, as these copies belonged to franchisees that were not registered by the Fair Trade Commission and/or were thought to have either defects or inadequate answers. The author selected an effective sample of 273 copies to enter data and to do the statistical analysis. Results - Both a reliability analysis and a confirmatory factor analysis were performed to measure reliability and validity, and a structural equation model was used to conduct the hypothesis test and investigate the models. The hypothesis was tested (Table 5). The models had a suitable fit, for instance, χ² = 447.663(df = 212, p = .000), χ²/df = 2.112, GFI = .881, AGFI = .858, RMR = .083, RMSEA = .067, NFI = .932, and CFI = .961. The hypothesis test results were as follows. Hypothesis 1 was accepted (C.R. = -2.339, p = .019). Hypothesis 2 was accepted (C.R. = 15.213, p = .000). Hypothesis 3 was accepted (C.R. = -2.631, p = .006). Hypothesis 4 was accepted (C.R. = 16.271, p = .000). Hypothesis 5 was accepted (C.R. = 2.391, p = .017). Hypothesis 6 was accepted (C.R. = 5.777, p = .000). Hypothesis 7 was accepted (C.R. = 17.153, p = .000). Hypothesis 8 was accepted (C.R. = 24.746, p = .000). Hypothesis 9 was accepted (C.R. = -10.150, p = .000). Hypothesis 10 was accepted (C.R. = -12.124, p = .000). Conclusions - The research results showed that expectations for a franchisor's support and control had a significant influence on expectation disconfirmation in a negative way, whereas the performance of support and control were found to have a significant influence on expectation disconfirmation in a positive way. In addition, the expectation disconfirmation of support and control was found to have a significant influence on satisfaction of franchisees in a positive way. Generally, regarding the research on control, control is found to have a negative influence on the satisfaction of franchisees, but this study proves that control is found to affect it in a positive way through conformity.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.5 no.7
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• pp.25-27
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• 1982

In most introductory statistics courses and text, the two equal tail test is presented without justification. In the present paper, the two equal tail critical region will be discussed in the light of unbiasedness with some test examples for the mean and the variance based on the random sample $X_1$, $X_2$,....$X_n$ from N($\mu$, $\delta^2$) using only elementary mathematics.

• Communications for Statistical Applications and Methods
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• v.19 no.1
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• pp.177-182
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• 2012

A structural break in the level as well as in the innovation variance has often been exhibited in economic time series. In this paper we propose robust unit root tests based on a sign-type test statistic when a time series has a shift in its level and the corresponding volatility. The proposed tests are robust to a wide class of partially stationary processes with heavy-tailed errors, and have an exact binomial null distribution. Our tests are not affected by the size or location of the break. We set the structural break under the null and the alternative hypotheses to relieve a possible vagueness in interpreting test results in empirical work. The null hypothesis implies a unit root process with level shifts and the alternative connotes a stationary process with level shifts. The Monte Carlo simulation shows that our tests have stable size than the OLSE based tests.