• Journal of the Korean Data and Information Science Society
• /
• v.23 no.4
• /
• pp.677-682
• /
• 2012

There are lots of sampling design which is determined for sample survey in various fields. Especially, it is important problem for clinical data because basic characteristic variables by group which consist of experiment group and control group in population should be reflect to sample. Therefore, frequencies, center scales and dispersion scales of variables by group in population should be similar in sample. But usual sampling design is very complicate so it is difficult to use in practice for researcher. In this paper, we consider the sampling method using simulation. We applied the proposed method to colon cancer data from a hospital. We compare basic characteristic variables between population and sample with mean, frequency and statistic hypothesis test.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.56 no.4
• /
• pp.21-28
• /
• 2014

In this study, evaluated ware the strength and durability of the vegetated water purification channel concrete to which recycled aggregates, hawang-toh and jute were applied. Box-Behnken method of response surface analysis in statistics was applied to the experimental design. Experimental variables are as follows, recycled coarse aggregates, hawang-toh, blast-furnace slag and jute fiber. In the experiment, conducted were the tests of compressive strength, chloride ion penetration, abrasion resistance and impact resistance the replacement rate effects of the recycled aggregates, blast-furnace slag and hwang-toh on the performance of vegetated water purification channel concrete were analyzed by using the response surface analysis method on the basis of the experimental results. In addition, an optimum mixing ratio of vegetated water purification channel concrete was determined by using the experimental results. The optimum mixing ratio was determined to be in 10.0% recycled coarse aggregates, 60.0% blast-furnace slag, 10.1% hwang-toh and 0.16% jute fiber. The compressive strength, chloride ion penetration, abrasion rate, and impact number of fracture test results of the optimum mixing ratio were 24.1 MPa, 999 coulombs, 10.30 g/mm3, and 20 number, respectively.

• The Journal of the Korea Contents Association
• /
• v.8 no.7
• /
• pp.103-111
• /
• 2008

There have been a few mathematic education programs that based on operating activity considering cognitive development level of elementary student, although we can find a variety of computer-aided mathematic teaching methods for elementary school. The purpose of this paper was to examine the effect of mathematical program based on operating activity developed as teaching materials in plain figures. As results of the post-achievement test and attitude test, it was found that the math program has been improved the achievement positively. By a result that inspects mathematical learning attitude of the experiment group, it was found that variable factors such as interest, confidence, self-learning were changed significantly more important in statistics.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.13 no.2
• /
• pp.362-368
• /
• 2009

The SA filters encompass a large class of filters based on order statistics as well as linear FIR filters. The class of SA filters is defined as a multi-stage filters whose output is linear combination of nonlinear(minimum, maximum, exclusive-OR) sub-filter outputs. According to the lust stage nonlinear sub-filters, SA filters are called SAMAX, SAMIN, and SAXOR filters. In this paper, optimal SAMAX and SAMED filters are designed for images corrupted by biased noise. The performance analysis of this experiment shows that SAMAX filters outperforms SAMED filters for biased noise. In the case of un-biased noise, the SAMAX and SAMED filters give the same performance. This result leads us to a new guideline in the application of SA filters.

• Journal of Korean Academy of Fundamentals of Nursing
• /
• v.17 no.3
• /
• pp.304-313
• /
• 2010

Purpose: The purpose of this study was to examine preventive effects of water drinking on postprandial fall of blood pressure in the elderly. Method: Participants were 25 elders who had experienced postprandial fall of systolic blood pressure of more than 15mmHg in a previous study. Within subject repeated measures design using random order allocation was used to control extraneous variables among participants. During the experiment, each participant had to drink 400mL water before lunch, whereas when in the control, they only had their lunch. Blood pressure and heart rate were measured for both times before lunch and at 15 minutes intervals up to 90 minutes after lunch. Data were analyzed using descriptive statistics, repeated measures of ANOVA, paired t-test and Bonferroni adjustment as Post-hoc analysis. Results: Water drinking before lunch elicited significant pressor effects by increasing systolic and diastolic pressure $13.9{\pm}4.7/5.2{\pm}2.2mmHg$ compared blood pressure during the control p<.005, p<.022. Heart rate, however, did not change significantly at either time. Conclusion: Drinking water before meal is recommended for elders who experience postprandial hypotension. However, the appropriate volume of water to prevent postprandial fall in blood pressure should be further studied.

• The Korean Journal of Rehabilitation Nursing
• /
• v.16 no.1
• /
• pp.71-78
• /
• 2013

Purpose: This study was performed to identify the effects of a health management program on health-promoting lifestyle and depression for the elderly living at home. Methods: Study design was a quasi-experiment with one group pre-test and post-test. Twenty-four elderly were participated in this study. The health management program for the elderly consisted of health education, health consultation, and exercise. The program was conducted for 60 minutes, once a week for 10 weeks. Data were analyzed using descriptive statistics and paired t-test with SPSS/WIN 18.0 version. Results: After the health management program, health-promoting lifestyle (t=14.14, p<.001) and depression (t=-4.78, p=.001) in the elderly were significantly improved. Conclusion: The health management program was effective for the elderly. Further research is needed to validate the effects of this program including control groups and a larger sample.

• Journal of the Korean Solar Energy Society
• /
• v.33 no.4
• /
• pp.89-93
• /
• 2013

In recent years, many investigations about photovoltaic power systems have been significantly carried out in the fields of renewable power energy. Such research area generally includes developments of highly efficient solar cells, advanced power conversion systems, and smart monitoring systems. A generic objective of fault detection and diagnosis techniques is to timely recognize unexpected faulty of dynamic systems so that economic demage occurred by such faulty is decreased by means of engineering techniques. This paper presents a novel fault detection approach for photovoltaic power arrays which are electrically connected in series and parallels. In the proposed fault detection scheme, we first measure all of photovoltaic modules located in each array by using electronic sense systems and then compare each measurement in turn to detect location of fault module through statistic computation algorithm. We accomplish real-time experiments to demonstrate our proposed fault detection methodology by using a test-bed system including two 20 watt photovoltaic modules.

• Research in Community and Public Health Nursing
• /
• v.30 no.1
• /
• pp.57-68
• /
• 2019

Purpose: This study was performed to determine effects of a structure-centered cooperative learning safety education program based on blended learning for elementary school students. Methods: The study is developed in nonequivalent control group non-synchronized design. The subjects included 24 sixth grade students in the experimental group and 23 sixth grade students in the control group, respectively. To prevent diffusion of the experiment, it was carried out from May 20th to June 24th in 2015 with the control group and the other from August 26th to September 30th in 2015 with the experimental group. It was performed on experimental group after the structure-centered cooperative learning safety education program based on blended learning once a week for 6weeks. Data were analyzed by using descriptive statistics, paired t-test and independent t-test. Results: After the intervention, the experimental group showed significant increases in the self-directed learning attitudes and safety behavior compared to the control group except for the academic self-efficacy. Conclusion: The results indicate that the structure-centered cooperative learning safety education program based on blended learning program is effective in safety education for 6th graders.

• Korean Journal of Materials Research
• /
• v.13 no.3
• /
• pp.200-204
• /
• 2003

A statistical experiment method was employed to investigate the window of the thermal stability of $TiSi_2$films which are popular for Ti-salicide and ohmic layers. The statistical experimental results showed that the first order term of $TiSi_2$thickness and annealing temperature was acceptable as a function of $\Delta$resistivity by 95% reliability criteria, and R-sq value implying a fit accuracy of the model also showed a high value of 93.80%. We found that $\Delta$resistivity of the $TiSi_2$film annealed at $700^{\circ}C$ for 1 hr changed from 3.35 to $0.379\mu$$\Omega$$\cdot$cm with increasing thickness from 185 to $703\AA$, and TEX>$\Delta$resistivity of the $TiSi_2$film with a fixed thickness of 444 $\AA$ changed from 0.074 to 17.12 $\mu$$\Omega$$\cdot$cm with increasing temperature increase from 600 to $800^{\circ}C$. From these results, we report that the process conditions of$ 692^{\circ}C$-1 hr, $715^{\circ}C$-1 hr, and 73$0^{\circ}C$-1 hr for $TiSi_2$($400 \AA$) are stable by the criteria of 1, 2, and 3 $\mu$$\Omega$$\cdot$cm of $\Delta$resistivity, respectively.

• Journal of Korean Society for Quality Management
• /
• v.39 no.3
• /
• pp.400-411
• /
• 2011

Process variables are factors in an experiment that are not mixture components but could affect the blending properties of the mixture ingredients. For example, the effectiveness of an etching solution which is measured as an etch rate is not only a function of the proportions of the three acids that are combined to form the mixture, but also depends on the temperature of the solution and the agitation rate. Efficient designs for the mixture components-process variables experiments depend on the mixture components-process variables model which is called a combined model. We often use the product model between the canonical polynomial model for the mixture and process variables model as a combined model. In this paper we propose three starting models for the mixture components-process variables experiments. One of the starting model we are considering is the model which includes product terms up to cubic order interactions between mixture effects and the linear & pure quadratic effect of the process variables from the product model. In this paper, we propose a method for finding robust designs and practical designs with respect to D-, G-, and I-optimality for the various starting combined models and then, we find practically efficient and robust designs for estimating the regression coefficients for those models. We find the prediction capability of those recommended designs in the case of three components and three process variables to be good by checking FDS(Fraction of Design Space) plots.