• The Transactions of the Korea Information Processing Society
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• v.7 no.3
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• pp.1021-1024
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• 2000

In this paper we describe a nonparametric Wilcoxon test and a parametric Z test based on statistical hypothesis testing for the detection of edges. We use the threshold determined by specifying significance level $\alpha$, while Bovik, Huang and Munson[4] consider the range of possible values of test statistics for the threshold. From the experimental results of edge detection, the Z method performs sensitively to the noisy image, while the Wilcoxon method is robust over both noisy nd noise-free images. Comparison with our statistical tests and Sobel operator shows that our tests perform more effectively in both noisy and noise-free images.

• The Korean Journal of Applied Statistics
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• v.24 no.6
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• pp.1149-1160
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• 2011

Model selection and hypothesis testing problems in Bayesian inference are still debated between scholars. Bayesian factors traditionally used as a criterion in Bayesian hypothesis testing and model selection, are easy to understand but sometimes hard to compute. In addition, there are other model selection criterions such as DIC(Deviance Information Criterion) by Spiegelhalter et al. (2002) and Bayesian P-values for testing. In this paper, we briefly introduce the Bayesian hypothesis testing and model selection procedure. In addition we have applied a Bayesian inference to Swiss banknote data by a fitting logistic regression model and computing several test statistics to see if they provide consistent results.

• The Korean Journal of Applied Statistics
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• v.23 no.6
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• pp.1115-1124
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• 2010

Normal approximation methods under the null hypothesis of no difference are frequently used to test the two independent proportions in non-inferiority trials. However, these tests are not appropriate under the null hypothesis of non-zero difference. We review the likelihood score methods proposed by Miettinen and Nurminen, Farrington and Manning, and Gart and Nam and compare the performance of these tests. The simulation study shows that the likelihood score tests under the null hypothesis of non-zero difference have better performance at a Type I error and power than usual normal approximation methods.

• The Korean Journal of Applied Statistics
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• v.26 no.4
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• pp.595-610
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• 2013

Testing of order-restricted alternative hypothesis in $2{\times}k$ contingency tables can be applied to various fields of medicine, sociology, and business administration. Most testing methods have been developed based on a large sample theory. In the case of a small sample size or unbalanced sample size, the Type I error rate of the testing method (based on a large sample theory) is very different from the target point of 5%. In this paper, the exact testing method is introduced in regards to the testing of an order-restricted alternative hypothesis in categorical data (particularly if a small sample size or extreme unbalanced data). Power and exact p-value are calculated, respectively.

• Journal of Distribution Science
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• v.16 no.1
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• pp.17-27
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• 2018

Purpose - The purpose of this study is to practically analyze the effect of the brand equity of Korean food companies in Vietnam on the brand attitude and purchase intention of Vietnamese consumers. Research design, data, and methodology - In total, 240 subjects were examined in this study. The collected data were analyzed using statistical programs SPSS 21 and AMOS 21. The credibility of the variables was examined using the exploratory factor analysis, and confirmatory factor analysis. The hypothesis was examined through the structural equation model analysis. Results - It is proven that brand image and perceived quality are accepted, and the brand awareness is rejected from the hypothesis that "the brand equity has a positive effect on the brand attitude". However, the brand image and brand awareness are accepted, and the perceived quality is rejected from the hypothesis that "the brand equity has a positive effect on the purchase intention". Conclusions - The following are the conclusions of the study. First, among the components of brand equity, the brand image is confirmed to positively affect both brand attitude and purchase intention. Second, high brand awareness does not necessarily lead to positive brand attitudes of the consumers. Third, The brand image appears to positively affect the brand attitude and purchase intention. However, the awareness of consumers of a brand does not directly lead to positive consumer attitudes.

• Journal of Korean Clinical Nursing Research
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• v.14 no.1
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• pp.33-44
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• 2008

Purpose: This study was performed to determine the effects of foot reflexology on pain and quality of sleep in patients with terminal cancer. Method: Quai-experimental research design was used. The subjects of this study were consisted of 19 for experimental group and 18 for control group. Visualue Scale(VAS) was used as the measurement tool of pain in this study, Verra & Snyder-Halpern Sleep Scale(VSH) and Visual Analogue Scale(VAS) were used as the measurement tool of perceived quality of sleep. Data were analyzed using statistical methods such as frequency, percent, $x^2$-test, t-test using SPSS WIN 12.0 program. Results: The hypothesis 1 that the experimental group with reflexology has less degree of pain than the control group without reflexology was supported (t=5.41, p<.001). The hypothesis 2 that the experimental group with reflexology has higher degree of VSH Scale than the control group without reflexology was supported(t=2.37, p=.02). The hypothesis 3 that the experimental group with reflexology has the difference among the mean of sleep VAS Scale during the 12 measurement periods was not supported(F=1.63, p=.08), and no significant interactions between group and time. Conclusion: It is considered that reflexology is effective for reducing cancer pain and improving quality of sleep in patients with terminal cancer.

• Journal of Families and Better Life
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• v.2 no.1
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• pp.1-11
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• 1984

The purpose of the study is to inquire how the family environmental variables are to influence on the behavior, time of laundering and laundering facilities in the urban households. Independent variables are limited to the number of family members, the are of the youngest child, the age of the home maker, and her educational level, family income , and the type of housing in which the family lives. The total of 222 samples were thus selected. The data was analyzed on the basis of statistical method such as percentage, mean ,standard deviation, chi-square, and F-test. The major findings are as follows; 1) Hypothesis 1 is rejected, because the behavior of laundering management is not influenced by six family environmental variables. 2) The facilities for laundering management are affected by the home maker's age(p<.05), her educational level(p<.001), family income (p<.001), the housing of the family (p<.01) among six family environmental variables ; there fore, Hypothesis 2 is partially proved; 3) the time for laundering management is affected by the number of family members(p<.01), the age of the youngest child(p<.05), the home maker's educational level(p<.001) among six family environmental variables; therefore, Hypothesis 3 is partially proved.

• Journal of Communications and Networks
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• v.14 no.5
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• pp.481-486
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• 2012

Accurate and efficient estimation of the number of sources is critical for providing the parameter of targets in problems of array signal processing and blind source separation among other such problems. When conventional estimators work in unfavorable scenarios, e.g., at low signal-to-noise ratio (SNR), with a small number of snapshots, or for sources with a different strength, it is challenging to maintain good performance. In this paper, the detection limit of the minimum description length (MDL) estimator and the signal strength required for reliable detection are first discussed. Though a comparison, we analyze the reason that performances of classical estimators deteriorate completely in unfavorable scenarios. After discussing the limiting distribution of eigenvalues of the sample covariance matrix, we propose a new approach for estimating the number of sources which is based on a sequential hypothesis test. The new estimator performs better in unfavorable scenarios and is consistent in the traditional asymptotic sense. Finally, numerical evaluations indicate that the proposed estimator performs well when compared with other traditional estimators at low SNR and in the finite sample size case, especially when weak signals are superimposed on the strong signals.

• International Journal of Highway Engineering
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• v.16 no.3
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• pp.119-129
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• 2014

PURPOSES : This investigational survey is to observe a proper spatial aggregation method for path travel time estimation using the hi-pass DSRC system. METHODS : The links which connect the nodes of section detectors location are used for path travel time estimation traditionally. It makes some problem such as increasing accumulation errors and processing times. In this background, the new links composition methods for spatial aggregation are considered by using some types of nodes as IC, JC, RSE combination. Path travel times estimated by new aggregation methods are compared with PBM travel times by MAE, MAPE and statistical hypothesis tests. RESULTS : The results of minimum sample size and missing rate for 5 minutes aggregation interval are satisfied except for JC link path travel time in Seoul TG~Kuemho JC. Thus, it was additionally observed for minimum sample size satisfaction. In 15, 30 minutes and 1 hour aggregation intervals, all conditions are satisfied by the minimum sample size criteria. For accuracy test and statistical hypothesis test, it has been proved that RSE, Conzone, IC, JC links have equivalent errors and statistical characteristics. CONCLUSIONS : There are some errors between the PBM and the LBM methods that come from dropping vehicles by rest areas. Consequently, this survey result means each of links compositions are available for the estimation of path travel time when PBM vehicles are missed.

• Journal of Distribution Science
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• v.15 no.7
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• pp.61-71
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• 2017

Purpose - This study empirically analyzed the effect of the customer orientation in Insurance Salespersons on the perceived referral risk and referral intention. In the empirical study, we try to provide suggestions for reducing the perceived referral risk of customer oriented selling activities and improving the referral intentions according to customers' tendencies. Research design, data, and methodology - Data collection was conducted through the convenience sampling method for customers who had insurance coverage for about two months from March to May 2015. A total of 700 copies were distributed and 670 copies (95.7% recovery) were collected. Finally, 661 copies were used for final analysis. With the IBM PASW 22.0 statistical program. The interaction effect for the hypothesis test was generated by multiplying the average centralized independent variable and the control variable, and the average centralization variable was used to minimize the multi-collinearity problem of the interaction effect between the independent variable and the control variables. Results - Hypothesis 1 was adopted because the effect of customer-oriented selling activities on perceived referral risk were significantly negative. The effect of customer orientation on perceived referral risk is affected by innovative tendency, risk-taking tendency, and interpersonal tendency Interaction effect was observed. Therefore, Hypothesis 2-2, Hypothesis 2-3, Hypothesis 2-4 were adopted. The effect of customer-oriented selling activities on referral intention was significantly positive, and Hypothesis 3 was adopted. The effect of customer orientation was influenced by the interaction effect of innovative tendency. Therefore, only Hypothesis 4-2 was adopted. Finally, the effect of perceived referral risk on referral intention was significantly negative and hypothesis 5 was adopted. Conclusions - This study suggests that it is important for the salespeople to grasp the customers' propensity in consideration of the perceived referral risk and referral intention according to the moderating effect of customer orientation. In this study, we showed that customer-oriented selling activities positively influence referral intention by inducing perceived referral risk in customers with stronger risk-taking tendencies. It is thought that it will be an important basic data in designing a customer's selling strategy or conducting selling activities.