• Journal of Positioning, Navigation, and Timing
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• v.10 no.2
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• pp.103-111
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• 2021

A series of experiments have been carried out by using National Geographic Information Institute(NGII)'s Continuously Operating Reference Station (CORS) data with various strategies to analyze the impact of multi-GNSS measurements on baseline processing. The results of baseline processing were compared in terms of ambiguity fixing rate, precision, and hypothesis tests were conducted to confirm the statistical difference. The combination of multi-GNSS measurements has helped to improve ambiguity fixing rate, especially under harsh positioning environments. Combination of GPS, Galileo, BeiDou could get better precision than that of GPS, GLONASS, Galileo, and adding QZSS made the baseline solution's vertical component more precisely. The hypothesis tests have statistically confirmed that the inclusion of the multi-GNSS in the baseline processing enables not only to reduce field observation time length but also to enhance the solution's precision. However, it is of interest to notice that results of the baseline solution are dependent upon the software used. Hence, comprehensive studies should be performed shortly to derive the best practice to select the appropriate software.

• Asia-Pacific Journal of Business
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• v.11 no.1
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• pp.61-75
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• 2020

Purpose - The purpose of this study was to examine the efficiency of the foreign exchange markets in Korea, Japan and China. Design/methodology/approach - This study collected 1327 observations each of the daily closing exchange rates of the three currencies against the US dollar for the sample period from January 1, 2015 to January 31, 2020, based on the tests for autocorrelation, unit root tests and GARCH-M(1,1) model estimation. Findings - We have found that the autocorrelation test indicates the lack of autocorrelation and unit root test confirms the existence of unit roots in all times series of the three currencies, respectively. The GARCH-M(1,1) test results, however, suggest that the exchange rates do not follow a random walk process. In conclusion, the recent spot foreign exchange markets in Korea, Japan and China are believed to be informationally inefficient. Research implications or Originality - These findings have practical implications for both individual and institutional investors to be able to obtain excess returns on their investments in the foreign exchange markets in three countries by using appropriate risk management, portfolio strategy, technical analysis, etc. This study provides the first empirical examination on the foreign exchange market efficiency in the three biggest economies in Asia including China, which has been excluded from research due to its exchange rate regime.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.1
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• pp.23-36
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• 2021

The study explores the nexus between foreign direct investment (FDI), financial innovation, and exchange rate volatility in selected South Asian countries for 1980 to 2017. The study applies the unit root test, Autoregressive Distributed Lagged, nonlinear ARDL, and causality test following Toda-Yamamoto. Unit root tests ascertain that variables are integrated in a mixed order; few variables are stationary at a level and few after the first difference. Empirical model estimation with ARDL, Long-run cointegration revealed with the tests of FPSS, WPSS, and tBDM by rejecting the null hypothesis of "no cointegration." This finding suggests that, in the long-run financial innovation, FDI inflows, and exchange rate volatility move together. Moreover, study findings established adverse effects running from FDI inflows and financial innovation to exchange rate volatility in the long run. These findings suggest that continual FDI inflows and innovativeness in the financial system assist in lessening the volatility in the foreign exchange market. Furthermore, nonlinear ARDL confirms the presence of asymmetric cointegration in the model. The standard Wald test established asymmetric effects running from FDI inflows and financial innovation to exchange rate volatility, both in the long and short run. Directional causality unveils feedback hypothesis holds for explaining causality between FDI, financial innovation, and exchange rate volatility.

• The Korean Journal of Applied Statistics
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• v.22 no.6
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• pp.1249-1263
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• 2009

The power function in sample size determination has to be characterized by an appropriate statistical test for the hypothesis of interest. Nonparametric tests are suitable in the analysis of ordinal data or frequency data with ordered categories which appear frequently in the biomedical research literature. In this paper, we study sample size calculation methods for the Wilcoxon-Mann-Whitney test for one- and two-dimensional ordinal outcomes. While the sample size formula for the univariate outcome which is based on the variances of the test statistic under both null and alternative hypothesis perform well, this formula requires additional information on probability estimates that appear in the variance of the test statistic under alternative hypothesis, and the values of these probabilities are generally unknown. We study the advantages and disadvantages of different sample size formulas with simulations. Sample sizes are calculated for the two-dimensional ordinal outcomes of efficacy and safety, for which bivariate Wilcoxon-Mann-Whitney test is appropriate than the multivariate parametric test.

• Journal of Korean Society of Transportation
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• v.25 no.1 s.94
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• pp.73-79
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• 2007

This study deals with traffic accidents at the ramps of trumpet interchanges. The purpose of the study is to analyze the relations between tke turning direction of ramps (and combinations with other factors) and traffic accidents. In Pursuing this analysis, this study gives particular attention to the combination of turning direction and grade and the combination of turning direction and radius of curvature in the case of the trumpet interchange ramps. The null hypothesis tests show that the average accident number and average accident rate ate rejected at the 90% and 95% significance level respectively Also. the null hypothesis tests show that the combinations or turning direction and Evade as well as turning direction and radius are all rejected at the 95% significance level. In summary, right turn movements ate more dangerous than left turns on the trumpet interchange vamps. Also, ramps with a right turn and up grade or with a left turn and radius more than 200m have more traffic accident Potential than other types of ramps.

• Journal of Korean Academy of Nursing
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• v.23 no.2
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• pp.170-186
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• 1993

This study evaluated the effect of diabetic group teaching programs in one university hospital in Seoul to predict when re-education would be needed. This study examined the patients’ knowledge at four points (before, directly after, three months and six months after the teaching program) and self-care performance related to diabetes twice (three months and six months after the teaching program). The subjects of the study were 24 admitted diabetic patients who participated in four-day teaching programs. Data were gathered from January to October, 1992 by means of an instrument developed from two diabetic knowledge tests which were equivalent in item differentiation and item discrimination coefficients. Collected data were analyzed by paired t-test, Pearson correlation, t and F tests. The results of study were as follows. 1. The analysis of the effect of the diabetic group teaching program and the duration of the effect of teaching. 1) The first hypothesis, that the diabetes knowledge score directly after the teaching program would be higher than before, was rejected (t=-1.40 ; p=.172). 2) The second hypothesis, that the diabetes knowledge score directly after teaching would be higher than three months later, was rejected(t= -4.27 ; p=.000). 3) The third hypothesis, that the diabetes knowledge score three months after teaching would be higher than six months later, was supported(t=2.43 : p=.020). 2. The relation of knowledge and self-care performance 1) The forth hypothesis, that the level of self-care performance related to diabetes three months later would be higher than six months later, was rejected( t=1.49 ; p=.146). 2) The fifth hypothesis, that the higher the diabetes knowledge, the higher the level of self-care performance, was rejected(r=.2086 ; p=.118). 3. The relation of diabetes knowledge and self-care performance according to demographic variables and structural variables of diabetes. 1) Diabetic knowledge scores varied according to the educational levels of the clients directly after the teaching. Three months after the teaching program higher educational levels and higher economic status were related to higher diabetic knowledge scores and men had higher knowledge scores than women. 2) Self-care performance scores of men were higher than those of women at three months and six months after the teaching program. 3) Before the diabetes teaching, the diabetic knowledge scores of subjects who had a diabetic patient in the family were higher than those who did not have patient in their family. Six months after the teaching, the diabetic knowledge scores of subjects who read the distributed books about diabetes were higher than those who did not read them. 4) No significance differences were found be-ween self-care performance and structural variables of dialetes. The results of this study indicated that the levels of diabetes knowledge and self-care performance incense of three months after the teaching program but decrease of six months. Reeducation would be needed between three and sir months. The investigator thinks that a study of the content and teaching methodology is needed to increase the education effect. The subjects want to hear patient histories of diabetic management. Group discussion would be helped after the teaching sessions.

• Journal of Korean Academy of Nursing
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• v.30 no.2
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• pp.380-390
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• 2000

This study was performed to evaluate the effectiveness of music therapy as one of the psychiatric nursing intervention tools, with addtional information in relieving anxiety during the procedure. Data were collected through nonequivalent pre-and post tests from July 1, 1998 to September 30 1998 in 90 patients (test group A: 28 patients, test group B: 27 patients, control group: 33 patients) who were hospitalized in DongSan Medical Center in order to have cardiac catheterization. The Subjects were informed by educational videos, which were modified according to the sensory information of the 10 study patients. They were based on the informative booklet by Kim keum-soon (1989). The procedural information was also modified according to the hospital`s customs. Provided the music for patients suitable to their tastes, and measured their blood pressure, heart rate, the degree of anxiety using the Spielberger`s measurement device of anxiety, and behavioral response of Finesilver`s. The statistical significance was analyzed using chi-square test and ANOVA. The results of this study were as follows : Hypothesis 1 : There are significant differences in the degree of anxiety among test group A, Test group A was provided only information, Test group B was provided information and the control group was provided neither. Hypothesis 2 : There are significant differences in systolic blood pressure among test group A, test group B, and control group.: non-significant. Hypothesis 3 : There are significant differences in diastolic blood pressure among test group A, test group B, and control group.: significant(F=1.31, p=.27, interaction; F=3.80, p=.00). Hypothesis 4 : There are significant differences in heart rate among test group A, test group B, and control group.: non-significant. Hypothesis 5 : There are significant differences in behavioral responses among test group A, test group B, and control group.: significant(F=10.05, p=.00). Further validation study is required with other subjects and other settings.

• Journal of Korea Technology Innovation Society
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• v.16 no.2
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• pp.391-407
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• 2013

The paper tests the embodiment hypothesis by measuring the technological obsolescence of a specific year (1990)'s technology and investigating the relationship between labor productivity and technological obsolescence. This approach is based on Salter (1969) that emphasizes the economic aspect of technology. We use the rate of economic surplus as the proxy of technological obsolescence for 10 main industries, including food processing, textiles, chemicals, non-steel metals, steels, metal products, machinery, electronics, precision machinery, and transportation equipments. The result shows that the embodiment hypothesis is not accepted for the overall manufacturing sector. However, we found the vintage effect - a positive relationship between technological obsolescence and labor productivity over time - in textiles, chemicals, non-steel metals, metal products, electronics, and transportation equipments. Therefore, the government should support R&D investment as well as capital equipments investment for the industries with large vintage effect.

• Journal of Korean Academy of Nursing
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• v.28 no.4
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• pp.941-957
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• 1998

The purpose of this study was to use meta-analysis to analyze result of 17 studies which investigated the effects of integrated programs, and 11 studies which examined the effects of exercise programs on pain, depression, and disability. The 28 studies analyzed in this work were selected from the following sources. MEDLINE Search, bibliographies of related studies, main academic journals of nursing in Korea, and journals on arthritis issues. For the analysis of the data, homogeniety of effect sizes which were calculated based on data in the 28 studies was tested and its average effect size was computed by using meta analysis software package which was developed by Song(1992, 1998). The results can be summarized as follows : 1) Homogeneity tests were conducted on integrated programs on pain. In the prelimiary homogeneity tests on effect size of all 17 studies, no homogeneity was found. When homogeneity tests on the effect size of the remaining 15 studies were performed, excluding two studies which had extremely larger effect size compared to other studies, the 15 studies were found to be homogeneous(Q=16.38, p=.23). The obtained average effect size, D(Mean Standardized Difference Between Means), was .25. When homogeneity tests on effect size on pain was conducted for the excercise programs, effect size for all nine studies were found to be homogeneous (Q=7.42, p=.49) and the average effect size D=.30. Therefore, Hypothesis 1 was rejected from the results, that an average effect size of the integrated programs on pain was not significantely different from that of the exercise programs on pain. 2) Since only two studies investigated the effect of exercise programs on depression, comparison between the average effect size of integrated programs and that of exercise programs on depression could not be conducted, and hypothesis 2 could not be tested. Thereby, only the average effect size of integrated programs on depression was obtained. Eight studies were tested to be positive on the homogeneity of effect sizes(Q=18.31, p=.02) at $\alpha$<.01 and its average effect size was D=.11. 3) For the analysis of integrated program on disability, 13 studies, except for four which had an extremely large effect size compared to the others were found to be homogeneous at $\alpha$<.01 (Q=22.30, p=.04) and the average effect size on disability was D=.16. For analysis of the exercize programs on disability, eight studies, except for one which had an extremely large effect size compared to others, were found to be homo geneous(Q=7.87, p=.34) and the average effect size on disability was D=.60. Therefore, Hypothesis 3 was accepted from the results that an average effect size of exercise programs on disability was significantly larger than that of integrated programs on disability.

• Journal of The Korean Digital Architecture Interior Association
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• v.12 no.1
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• pp.71-79
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• 2012

This study aims at finding relationships between the competitiveness of cities and the size or distance of them, based on some premises; (1) the competitiveness can be measured on the interval-ratio level, that is, factor scores, (2) a hypothesis that the spatial interaction model is valid for the relationships can be generally accepted. Based on the general recognition a research hypothesis that the more is the population or the nearer is the distance from a central city the higher is the competitiveness score is constructed. According to the premises 5-factor scores and composite score are calculated by means of regression method, and the scores are regressed on cities' populations and distances from Seoul city. Using bootstrapping method for the tests of significance is effective due to small sample of 21 cities. Results of the analyses show that most aspects of the hypothesis should be rejected or adjusted. Scores on Health-welfare factor, public service factor, and commercial vitality factor have no relation to the cities' sizes or distances. But the results also find the facts that the strong (negative) relationships exist between (1) educational base factor score and population, (2) density factor score and distance. Although this study improves systematic and analytic understanding of spatial interaction patterns, the understanding should be invalid for the general context because it has used the data on 21 cities in the capital region at the time of 2009.