• Communications for Statistical Applications and Methods
• /
• v.4 no.2
• /
• pp.581-588
• /
• 1997

Univariate F test is based on the multisample sphericity assumption. Robustness for tests of a main effect of the within-subjects factor was investigated when the assumptions of the onmibus F tests are violated in a split-plot design with one between-subjects factor using untrimmed data and trimmed data. The results indicate that when sample sizes are unbalanced and dispersion matrices are heterogeneous, the CIGA and the $CIGA_T$ tests better control Type I error rates than do the $F_T$test and the$\widetilde{\xi_T}$test.

• Journal of the Korea Society of Computer and Information
• /
• v.28 no.5
• /
• pp.179-187
• /
• 2023

In this paper, we studied the impact of outliers on the power of the significance tests for Cronbach alpha reliability coefficient. Four variables were varied: sample size, the number of items, the number of outliers and population Cronbach Alpha levels. We simulated data using multivariate normal distribution and used outliers sampled from uniform distribution. To test the significance of Cronbach Alpha Reliability, parametric approach(F statistic) and permutation method were used. Consequently, we observed that the powers of permutation test are equal to or greater than those of F test under all conditions, and also both F test and permutation test lose the power as the number of outliers increases, and that these effects of outliers on the power are enhanced for increasing population alpha levels.

• Korean Journal of Social Welfare
• /
• v.56 no.3
• /
• pp.37-59
• /
• 2004

Short Michigan Alcoholism Screening Test for Fathers(F-SMAST) and Mothers(M-SMAST) is to measure the presence of an alcohol use disorder in one's father and/or mother. The purpose of this study is to evaluate the Korean version of the F-SMAST and M-SMAST. A total of 241 college students, who resided in Seoul and two other cities, participated in this study. The internal consistency of the Korean version of the F-SMAST and M-SMAST was assessed using alpha coefficient. The alpha coefficient of both the F-SMAST and the M-SMAST was 0.82. Standard Errors of Measurement(SEM) were also computed. SEMs of the F-SMAST and the M-SMAST were quite low. With a cut-off score of 3, the F-SMAST correctly identified 91 percent of respondents who were presumed to be children of alcoholics and correctly identified 81 percent of respondents who were presumed not to be children of alcoholics. Sensitivity and specificity of the M-SMAST with a cut-off score of 1 are 0.33 and 0.81, respectively. Several variables were examined in relation to the F-SMAST and the M-SMAST to examine convergent and discriminant validity. It was found that the F-SMAST and the M-SMAST were significantly correlated with most of convergent variables(average amount of drinking per day, AUDIT, distress) and had not statistically significant relationships with discriminant variables(demographic variables). This study suggests that the Korean version of the F-SMAST and the M-SMAST be repeatedly assessed across different sample in order to confirm the findings of this study.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2009.05a
• /
• pp.255-256
• /
• 2009

This purpose of this study was to evaluate the controlling effect of alkali-aggregate reactivity using mineral admixtures for aggregates in Korea according to test methods: chemical test by KS F 2545; mortar bar test by KS F 2546; accelerated mortar bat test by ASTM C 1260.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2018.11a
• /
• pp.187-188
• /
• 2018

In this study, wind pressure resistance test was carried out among the nine test items of KS F 2622 using five types of water-tight material. After comparing the results with the performance range of the current KS F 2622 wind pressure resistance test, it is recommended to check the adequacy of the addition of the combined series.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.33 no.1
• /
• pp.62-68
• /
• 2005

An injector for fuel rich gas generator was designed and experimentally investigated. Five variations of F-O-F triplet impinging type injector were tested to evaluate spray characteristics with kerosene/water simulant propellant. Test was focused to find the effect of design variables of impinging angle, and impinging distance, on the atomization performance. A mixing efficiency is used to compare droplet distribution and local O/F ratio of each injector in the range of momentum ratio of 0.2~1.3. Test results shows the max value of mixing efficiency locates about the 0.8 in momentum ratio. And the injector with an impinging angle of 45 degree and impinging distance of 6mm shows the very good performance result suitable for fuel rich gas generator. A combustion test will be also conducted with selected injector to verify the spray pattern and mixing efficiency.

• Journal of Oriental Neuropsychiatry
• /
• v.11 no.2
• /
• pp.113-122
• /
• 2000

In order to understand the psychological charateristics of Sasang Constitution. the Korean version of 20-item Toronto Alexithymia Scale(TAS-20K) was completed by 59 sixth grade students of oriental medical college of KyungHee university who defined as one of Sasang constitution from June 2000 to August, and the mean scores of Yangin versus Eumin and Sasang constitution on TAS-20K was compared. The results of this study were as follows.1. Comparison between male and female on Means of TAS-20K ScoreMann-Whitney U test detected no significant differences between mean ranks of TAS-20K scores of male and those of female in F1, F2 and Total, but significant difference in F3(Mann-Whitney U test, t=2.493. p=.018)2. Comparison between Yangin and Eumin on Means of TAS-20K ScoreMann-whitney U test detected no significant differences between mean ranks of TAS-20K scores of Yangin and those of Eumin in F1. F3 and Total, but significant difference in F2(Mann-Whitney U test. t=-2.805. p=.008)3. Comparison among Sasang constitution on Means of TAS-20K ScoreAlthough mean of TAS-20K score of Taeyangin. Soyangin and Soeumin, there were no significant differences among Sasang constitution in F1, F2 and F3 as well as Total when mean ranks of TAS-20K scores of Sasang constitution were compaed by one-way ANOVA.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.14 no.4
• /
• pp.269-275
• /
• 1981

The fishing hooks were tested for breaking and unbending due to plastic deformation of the material. Study of tensile test is not complicated, but has not even worked out fully enough, especially when the test specimen is subjected to plastic deformation. The fishing hook is subjected to unbending stress and the critical section is a Point which is furthest from the line of action of the forces. The dynamic force of fish during jerks depends on their speed of movement and body weight, the kinetic energy corresponding to it and also on the rlastic displacement of the rigging which absorb the energy. Six kinds of hook were tested by the dynamometer under tensile speed 290mm/min (subscript s) and 780mm/min (subscript f). According to their results, the breaking load(B: kg) can be induced with the formula $B={\alpha}wd^2+\beta$ where w(mm) is the distance between the barb base and the lower shank and d(mm) is diameter. The coefficients of the formula for the round hooks(R) and the angular hooks(A) are approximately as follows: $$R:\;\alpha_{s}=0.5,\;\beta_{s}=1.6,\;\alpha_{f}=0.4,\;\beta_{f}=1.4$$ $$A:\;\alpha_{s}=1.1,\;\beta_{s}=2.0,\;\alpha_{f}=1.0,\;\beta_{f}=0.9$$ The ratio of $B_{f}\;to\;B_{s}$ is corresponding to 0.8. The ratio of deformation(X) that is moved distance of barb base at break to the distance(H) between head base and barb base is about $50\%$. Further study should be carried out on the subject of impact and fatigue test under the same condition which is exerted force by the hooked fish.

• 한국방재학회:학술대회논문집
• /
• 2008.02a
• /
• pp.497-500
• /
• 2008

The typhoon is provoking huge damage attacking in Korea periodically every year. Therefore, in this study, the analysis of 24 hourly maximum precipitation change related to typhoon events achieved based on Mann-Whitney U test, T test, Modified T test, Sign test, F test, and Modified F test. At the results, the 24 hourly maximum precipitation was expose that average and standard deviation are increasing recently. Therefore, hydorlogical structures have to be prepared of extreme rainfall events by typhoons.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2005.11a
• /
• pp.615-618
• /
• 2005

This study concerns the equation of high strength concrete by schmidt hammer test. There are not only few prediction strength equations of concrete by schmidt hammer test, but also many problems to apply them because of time, cost, easiness, structural damage, reliability and so on. For this study, there performed a series of schmidt hammer test with in existing 1,095days' concrete structures and proposed equations as follows ; Linear: ${\Large f}_{ck}=-45.35+2.44R(r^2=72.7\%)$ Quadratic: ${\Large f}_{ck}=-502.08+24.0R-0.25R^2(r^2=82.4\%)$ here, $f_{ck}$ : Estimated compressive strength of concrete by MPa, R : Rebound index of concrete