• Journal of Korean Society of Forest Science
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• v.80 no.4
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• pp.379-382
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• 1991

Tree height at age 10 was used to estimate the statistical efficiencies of sampling size in the progeny test of Pinus koraiensis S. et Z. Experimental design was RCB design which consists of 25 half-sib families in each of three blocks. The number of families and blocks were fixed, therefore, the number of trees sampled per plot was the only factor that influences the environmental portion of the family mean height. Coefficient of variation, the estimate of the standard error of the family mean height, decreased with increase of sampling plot size, and became stable from 4-tree plot sampling (6.97%). The experimental error was significant from 7-tree sampling plot size. Nonlinear relationship (${\hat{Y}}=10.425e-^{0.073x}$ ; $R^2$=0.840) was found between the sampling plot size and the standard error of family mean height.

• Journal of Korea Water Resources Association
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• v.53 no.10
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• pp.917-928
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• 2020

The purpose of this study is to find the appropriate probability distribution representing the size distribution of suspended cohesive sediment. Based on goodness-of-fit test for a significance level of 5% using the Kolmogorov-Smirnov test, it is found that the floc size distributions measured in laboratory experiment and field study show different results. In the case of sample data collected from field experiments, the Gamma distribution is the best fitting form. In the case of laboratory experiment results, the sample data shows the positively-skewed distribution and the GEV distribution is the best fitted. The lognormal distribution, which is generally assumed to be a floc size distribution, is not suitable for both field and laboratory results. By using 3-parameter lognormal distribution, it is shown that similar size distribution with floc size distribution can be simulated.

• The KIPS Transactions:PartA
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• v.16A no.4
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• pp.245-254
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• 2009

With the increasing adoption of embedded processors, the need of developing compilers for the embedded processors with timely manner is also growing. Retargeting has been adopted as a viable approach to constructing new compilers by modifying the back-end of an existing compiler. This paper proposes a test suite generation system for testing retargetable C compilers. The proposed system generates the test suite using the grammar coverage concept. Generally, the size of the test suite satisfying the grammar coverage of the source language is very large. Hence, the proposed system also provides the facility to reduce the size of the test suite. According to the experimental result, the reduced test suite can detect 75% of the compiler faults detected by the original test suite though the size of the reduced test suite is only 10% of that of the original test suite in average. This result indicates that the reduction technique proposed in this paper can be effectively used in the prior phase of the development procedure of the embedded compilers.

• Journal of The Korean Society of Integrative Medicine
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• v.8 no.2
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• pp.169-185
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• 2020

Purpose : This study aimed to conduct a comprehensive meta-analysis to evaluate the effect size for pulmonary function and gait capacity of treadmill exercise in stroke patients. In addition, we aimed to examine the current status of treadmill interventions and compare the effect sizes of treadmill training to provide evidence-based practice for future development and application. Methods : The meta-analysis study was conducted using research articles that applied treadmill exercise to stroke patients and were published between January 2005 and February 2020. For a systematic meta-analysis, we conducted a search using the PICOS framework and selected 25 domestic stroke- and treadmill-related studies. The Comprehensive Meta-Analysis program was used to calculate the effect sizes for lung function and gait capacity (6-minute walk test and 10 m walk test). As Cohen's d has a tendency to overestimate the effect size, we used Hedge's g to increase the accuracy in computing the effect size. Results : Based on the results of the meta-analysis, the total effect size of treadmill exercise was 0.535, which was statistically significant, with a medium effect size (p<0.05). The effects of treadmill exercise in stroke patients were divided into dependent variables, namely pulmonary function (0.372) and gait capacity (0.584). In addition, for gait capacity, the effect sizes were evaluated for both the 6-minute walk test (0.756) and the 10 m walk test (0.514). Conclusion : This study provides objective evidence of the effectiveness of treadmill-based gait training programs. We hope that the results of this study will help support the development and implementation of treadmill-based gait training in stroke patients. Treadmill training is expected to improve not only pulmonary function, but also the gait capacity of stroke patients. Long-term investigations on the effects of treadmill training in stroke patients are necessary.

• International Journal of Railway
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• v.5 no.4
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• pp.152-155
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• 2012

The essential element of brake device for railway vehicle is in demand for higher performance along side the trend of railway vehicle size and speed. Essential element of brake device for high speed train is composed of metallic friction material and brake disc. Thus, brake distance, duration and brake stability shall be determined due to friction materials and friction characteristics. Also friction characteristics are influenced by metallic friction material's properties of matter, manufacturing process and component parts. Various materials and configurations of metallic friction materials are currently being implemented to railway vehicles, For this reason study of friction characteristics in accordance with materials is necessary, but study of these important elements are not actively being accomplished. Therefore, in this study, wished to study the graphite's friction characteristic comprised in friction material in accordance with particle size and amount of volume through lab-scale test.

• Journal of the Korean Society of Clothing and Textiles
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• v.26 no.1
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• pp.62-73
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• 2002

The purpose of this study was to develop men's formal jacket pattern for the Korean males of age 25 to 34 age with an average physique. Through the survey on seven industries of the ready-made men's wear, we investigated size systems and jacket patters presently practiced. From the fitting test of four patterns (three for ready-made jacket patterns, one for educational pattern) the moat favorable and comfortable pattern was selected. New experimented jacket pattern was based on it. The findings were as followed. 1) Survey of the domestic ready-made garment industries showed that each company classified its own manufactured goods according to its own size systems. 2) Anthropometric measurments of forty males for the subjects of lilting test were agreed to the survey of National Anthropometric of Korean(1997). These were also compatible to the standard size (100-88-175) of investigated industries. 3) Experimental jacket pattern was completed through the three times rectification and it gained higher ratings.

• Geomechanics and Engineering
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• v.22 no.2
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• pp.165-171
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• 2020

Laboratory determination of strength and deformation behavior of clean sands and gravels has always been challenging due to the difficulty in obtaining their undisturbed samples. An alternative solution to this problem is to develop correlations between mechanical properties of cohesionless soils and their gradation characteristics. This study presents database of 3 natural sands with 11 varying particle size gradation curves to allow investigating relationships between mean particle size, maximum and minimum void ratio, relative density and shear strength of the test soils. Direct shear tests were performed at relative densities of 50, 75 and 95% to explore the effects of gradation and density on the angle of internal friction of the modeled sand samples. It is found that the mean grain size D₅₀ bears good correlations with void ratio range (e_max - e_min) and peak angle of internal friction 𝜙'_peak. The generated regression models are in good agreement with published literature and can be considered as reliable for natural sands in Pakistan. These empirical correlations can save considerable time and efforts involved in laboratory and field testing.

• Communications for Statistical Applications and Methods
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• v.25 no.5
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• pp.545-557
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• 2018

The inclusion of covariates in the model often affects not only the estimates of meaningful variables of interest but also its statistical significance. Such gap between statistical and subject-matter significance is a critical issue in huge sample studies. A popular huge sample study, the sample cohort data from Korean National Health Insurance Service, showed such gap of significance in the inference for the effect of obesity on cause of mortality, requiring careful consideration. In this regard, this paper proposes a sample size calibration method based on a Monte Carlo t (or z)-test approach without Monte Carlo simulation, and also proposes a test procedure for subject-matter significance using this calibration method in order to complement the deflated p-value in the huge sample size. Our calibration method shows no subject-matter significance of the obesity paradox regardless of race, sex, and age groups, unlike traditional statistical suggestions based on p-values.

• Journal of The Korean Society of Agricultural Engineers
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• v.47 no.4
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• pp.43-52
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• 2005

It is known in some literatures that the B value is not equal to unity in saturated soil when effective stress is given, in which the B Value is the ratio of measured excess pore water pressure and isometric loading pressure. In this study the B value was measured on various effective stresses and on various incremental loading stresses in various grain size of specimens with saturated sand. The test results showed that the B value was affected largely by grain size of sand in specimen and the amount of effective stress. There was the semi-logarithmic relationship between B value and effective stress, and also there was the linear relationship between the gradient of the former semi-logarithmic relationship and grain size of specimen.

• Korean Journal of Human Ecology
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• v.11 no.3
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• pp.301-306
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• 2002

The purpose of this research is to provide basic data by which more suitable hats manufacturing can be possible. The method for this research was to ask male and female college students what their favorite design and size are by the questionnaire. Data were collected from 383 college students in Seoul, Iksan. Statistical tests such as descriptive analysis, Crosstabs, F-test, Duncan test, were used to analyze the data. The conclusion which gotten through this process is that, first of all, their favorite design is Apollo cap, and there is no difference between male and female college students. Then, It also appeared that most of them didn't know their own hat size, but responded that their hats are suitable for their heads, it means that they are contented with their hats. Yet, those positive responses are, in some part, due to the insufficiency of the questions that can point out negative responses.