• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.3
• /
• pp.1233-1239
• /
• 2014

Background: The incidence of brain metastases (BM) varies in patients with non-small cell lung cancer (NSCLC), calls into question the value of prophylactic cranial irradiation (PCI). It is possible that clinicopathologic characteristics are associated with the development of BM, but these have yet to be identified in detail. Thus, we conducted the present meta-analysis on risk factors for BM and the value of PCI in patients with NSCLC. Methods: Eligible data were extracted and the risk factors for BM and the value of PCI in patients with NSCLC were analyzed by calculating the pooled odds ratio (OR). Heterogeneity was detected using Q and I-squared statistics, and publication bias was tested by funnel plots and Egger's test. Results: Six randomized controlled trials with a focus on the value of PCI and 13 eligible studies with a focus on risk factors for BM were included. PCI significantly reduced the incidence of BM in patients with NSCLC (p=0.000, pooled OR=0.34, 95% confidence interval = 0.37-0.59). Compared with non-squamous cell carcinoma, squamous cell carcinoma was associated with a low incidence of BM in patients with NSCLC (p=0.000, pooled OR=0.47, 95% confidence interval =0.34-0.65). The funnel plot and Egger's test suggested that there was no publication bias in the current meta-analysis. Conclusions: This meta-analysis provides statistical evidence that compared with non-squamous cell carcinoma, squamous cell carcinoma can be used as a predictor for BM in patients with NSCLC, and PCI might reduce the incidence of BM in patients with NSCLC, but does not provide a survival benefit.

• Journal of the Korean Professional Engineers Association
• /
• v.20 no.3
• /
• pp.15-25
• /
• 1987

Statistical control charts are useful tools to monitor and control the manufacturing processes and are widely used in most Korean industries. Many Korean companies, however, do not always obtain desired results from the traditional control charts by Shewhart such as the X-chart, X-chart, X-chart, etc. This is partly because the quality charterstics of the process are not distributed normally but are skewed due to the intermittent production, small lot size, etc. In Shewhart X-chart, which is the most widely used one in Korea, such skewed distributions make the plots to be inclined below or above the central line or outside the control limits although no assignable causes can be found. To overcome such shortcomings in nonnormally distributed processes, a distribution-free type of confidence interval can be used, which should be based on order statistics. This thesis is concerned with the design of control chart based on a sample median which is easy to use in practical situation and therefore properties for nonnormal distributions may be easily analyzed. Control limits and central lines are given for tile more famous nonnormal distributions, such as Gamma, Beta, Lognormal, Weibull, Pareto, Truncated-normal distributions. Robustness of the proposed median control chart is compared with that of the X-chart, the former tends to be superior to the latter as the probability distribution of the process becomes more skewed. The average run length to detect the assignable cause is also compared when the process has a Normal or a Gamma distribution for which the properties of X are easy to verify, the proposed chart is slightly worse than the X-chart for the normally distributed product but much better for Gamma-distributed products. Average Run Lengths of the other distributions are also computed. To use the proposed control chart, the probability distribution of the process should be known or estimated. If it is not possible, the results of comparison of the robustness force us to use the proposed median control chart based on a normal distribution. To estimate the distribution of the process, Sturge's formula is used to graph the histogram and the method of probability plotting, $X^2$-goodness of fit test and Kolmogorov-Smirnov test, are discussed with real case examples. A comparison of the propose4 median chart and the X chart was also performed with these examples and the median chart turned out to be superior to the X-chart.

• The Journal of the Korea Contents Association
• /
• v.16 no.5
• /
• pp.399-409
• /
• 2016

Purpose: The purpose of this study was to examine factors influencing health related quality of life(HRQOL) in patients with hypertension. Methods: This study carried out secondary analysis using the data from the $5^{th}$ Korean National Health and Nutrition Examination Survey. Subject samples who were selected are 1,240 hypertension patients. The data were analyzed by using descriptive statistics, traditional classic regression, and quantile regression. Results: Restriction of activity, depressive mood, and subjective health status had only significant effects on HRQOL(p<.001). After quantile regression, depressive mood and subjective health status had only significant at 20%(p<.001), 40%(p<.001), and 60%(p<.01) of HRQOL. Perceived stress(p<.001) and regular exercise(p<.01) had only significant at 20% of HRQOL. Current drinking status had only significant at 20%(p<.001) and 80%(p<.01) of HRQOL. Conclusions: Quantile regression maybe a better statistical tool in understanding the heterogeneous effect of hypertension patient's HRQOL as health outcome. Therefore interventions are needed for patients with hypertension to manage each of the factors affecting the patient's perceived health status by each quantile.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.6
• /
• pp.2484-2490
• /
• 2012

This study reports on the development and performance verification of cell simulation boards of simulator and the embedded program for board control of the battery management system (BMS) of electric vehicle (EV) cars, which manages the next-generation automotive lithium-ion battery pack. Here, we have improved the speed of the simulator by using operational (OP) amplifier and transistors that were connected in series. In addition, using a digital analog converter (DAC) in each channel, we have improved the performance by channel-to-channel isolation (isolation) as compared to the traditional methods. Furthermore, by constructing a current-limiting protection circuit, one can be protected from disturbance and, by utilizing a precision shunt resistor for the current sensor, we have increased the precision of the current control. In order to verify the performance of the developed simulator, we have performed the experiment 10 times, with values ranging from 0.5 V to 5 V, and a voltage drop step of 0.5 V. Significance analysis of experimental data, and repeatability tests were performed, showing an average standard deviation of 0.001~0.004 V, indicating high repeatability and high statistical significance of the current method and system.

• Journal of Korean Society of Steel Construction
• /
• v.13 no.5
• /
• pp.567-575
• /
• 2001

In order to consider statistical properties of probability variables used in the structural analysis the conventional approach using the safety factor based on past experience usually estimated the safety of a structure Also the real structures could only be analyzed with the error in estimation of loads material characters and the dimensions of the members. But the errors should be considered systematically in the structural analysis Safety of structure could not precisely be appraised by the traditional structural design concept Recently new aproach based on the probability concept has been applied to the assessment of structural safety using the reliability concept Thus the computer program by the Probabilitstic FEM is developed by incorporating the probabilistic concept into the conventional FEM method. This paper estimated for the reliability of a plane stress structure by Advanced First-Order Second Moment method using von Mises, Tresca and Mohr-Coulomb failure criterions. Verification of the reliability index and failure probability of attained by the Monte Carlo Simulation method with the von Mises criterion were same as PFEM, but the Monte Carlo Simulation were very time-consuming. The variance of member thickness and load could influence the reliability and failure probability most sensitively among the design variables from the results of the parameter analysis. The proper failure criterion according to characteristic of materials must be used for safe design.

• Korea journal of population studies
• /
• v.33 no.1
• /
• pp.75-101
• /
• 2010

One of the reasons for low fertility rate in Korea is related to the delayed marriage among the population belong to marriage cohorts. The major goal of this study is to analyze how the economic resources such as level of education, whether employed or not, and occupation have affected one's marriage opportunity and how it is differed by gender. Meanwhile, the changes in the influence of economic resources and the changes in the marriage norms were also studied by analyzing 2% Census data in 1995, 2000 and 2005. Total number of 1.1 million men and women in their ages between 20 to 44 are included in data and binary-logistic analysis is used for statistical research. This study supports a traditional hypothesis that the influence of economic resources on probability of marriage is different by gender. More important academic contribution of this study is the quality of economic resources is becoming more important for men since Asian economic crisis and that the negative effect of it on women is declining since 2000. It is analyzed that the effect of marriage norm has recently decreased on the part of women. These findings suggest that there is a tendency of polarization of marriage market in Korea affected by economic polarization since Asian economic crisis.

• Korean Journal of Food Science and Technology
• /
• v.32 no.4
• /
• pp.851-859
• /
• 2000

In the present study, changes in physicochemical and sensory properties, and microflora and enzyme activities, by addition of pumpkin (1, 2 and 5% pumpkin on the weight basis), of Sunchang sikhe kochujang, the most famous traditional kochujang, were investigated. Moisture content appeared to be reduced during fermentation, possibly due to exposure to the sun. Patterns of pH changes were rather complicated. pH of control kochujang was gradually reduced from the begining of fermentation up to 60 days of fermentation. Thereafter, it tended to be increased but again reduced after 90 days of fermentation. On the other hand, titratable acidity increased with fermentation reaching at the highest level at 90 day of fermentation and then slowly decreased. The addition of pumpkin induced a reduction in pH and an increase in titratable acidity, but this was due to organic acid contained in pumpkin itself. Contents of reducing sugar and amino nitrogen were increased by the addition of pumpkin in relation to the level of addition. Ethanol content was highly increased by the addition of pumpkin. Bacterial and yeast count, and activities of amylase and protease were not affected by the addition of pumpkin. Sensory evaluation test revealed that the addition of pumpkin improved sweet and savory taste, but color turned to be undesirable. However, none of tested parameters except color showed statistical significance.

• Journal of Family Resource Management and Policy Review
• /
• v.10 no.1
• /
• pp.83-105
• /
• 2006

The purposes of this study were to classify types of consumption values and to examine 5 types of art appreciation of university students in Seoul. Five types of art appreciation included fine art exhibition(including photographs, architects, calligraphy works), classical and opera performance, traditional Korean music performance, drama and musical performance, dance performance. The sample for this study consisted of 422 university students of five universities in Seoul. The data were collected using the structured questionnaires. The statistical methods used for the analysis were descriptive statistics, chi-square, factor analysis, and cluster analysis. The major findings are as follows. 1. The result of factors for consumption values of students emerged four factors. These were called as 'materialism', 'honor centered', 'family centered', 'hedonism' value. 2. The cluster analysis was conducted based on these four factors. The result showed 3 groups of consumption value which were called as 'material' honor value group', 'family value group', 'hedonic value group'. 3. The consumption value of university students did not significantly differ according to their demographic variables. 4. The behavior of art appreciation of university students significantly differed by their demographic characteristics and consumption value. The material' honor valued group showed the least chances to make decisions on art appreciation for one's own, which reflected that this group appreciate art to satisfy their honors rather than to enjoy art itself. They also showed the most chances to consider the renownedness of the art work or artists among three groups. And they showed the least chances to pay for the tickets for art appreciation, all of those meant that they appreciate arts unvoluntarily in situational condition. The family valued group showed the most chances to pay for the tickets when they appreciate arts. And therefore they were most susceptible for the prices. The hedonic valued group showed the most interests in art. They decided to appreciate art for their own, and they considered the contents and the highness in the level of the art the most when they appreciate art. And they show the most intention of participation in drama/musical performances, which reflect their interests in hedonic values. Based on these results of this study concluded that the consumption values of university students affected their behavior of art appreciation. Thus, university students' behavior on art appreciation can be effectively developed by education according to their consumption values.

• THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
• /
• v.6 no.1
• /
• pp.1-18
• /
• 2000

The present study was performed in order to evaluate the effects of the gamihyangsayukgunjatang on radioprotection and apoptosis in small intestines of mice after whole body irradiation. Two hundred forty mice were divided into 40 groups according to the radiation dose and the gamihyangsayukgunjatang treatment. The extracts of the herbal medicines were orally administered to each group differently before and/or after irradiation. The gamihyangsayukgunjatang treated groups were divided into 3 groups. Sample Ⅰ was the group treated with the gamihyangsayukgunjatang for 3 days before the radiation, sample Ⅱ was the group treated with the gamihyangsayukgunjatang for 3 days after the radiation. Sample Ⅲ was the group treated with the gamihyangsayukgunjatang for both 3 days before and after the radiation. To analyze the crypt survival, the micradony survival assay was used according to the Withers and Elind's method. To analyze the apptosis, the TUNEL assay was done. The results obtained are a follows : 1. From the microcolony survival assay, the gamihyangsayukgunjatang treated groups showed the radioprotective effect with a statistical significance(p<0.05), as compared to the control group. Comparing the radioprotective effect among the 3 groups, sample III was statistically more significant than sample I and II (p<0.05). Sample I showed no effect. In accordance with the research mentioned above, it is suggested that the radioprotective effect of the gamihyangsayukgunjatang is more useful for the treatment of the radiation injury rather that the prevention. 2. The results of the TUNEL assay showed that the apoptotic index in the gamihyangsayukgunjatang treated group was slightly decreased with no effectiveness, as compared to the control group. According to the above results, it could be suggested that the gamihyangsayukgujatang has a prominent protective effect in mice intestines against the radiation damage. However, the radioprotective effect does not seem to be related to inhibition of the apoptosis.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.31 no.1B
• /
• pp.29-36
• /
• 2011

Evapotranspiration (ET) from the various surfaces needs to be understood because it is a crucial hydrological factor to grasp interaction between the land surface and the atmosphere. A traditional way of estimating it, which is calculating it empirically using lysimeter and pan evaporation observations, has a limitation that the measurements represent only point values. However, these measurements cannot describe ET because it is easily affected by outer circumstances. Thus, remote sensing technology was applied to estimate spatial distribution of ET. In this study, we estimated major components of energy balance method (i.e. net radiation flux, soil heat flux, sensible heat flux, and latent heat flux) and ET as a map using Mapping Evapo-Transpiration with Internalized Calibration (METRIC) satellite-based image processing model. This model was run using Landsat imagery of Gyeongan watershed in Korea on Feb 1, 2003 and Sep 13, 2006. Basic statistical analyses were also conducted. The estimated mean daily ETs had respectively 22% and 11% of errors with pan evaporation data acquired from the Suwon Weather Station. This result represented similar distribution compared with previous studies and confirmed that the METRIC algorithm had high reliability in the watershed. In addition, ET distribution of each land use type was separately examined. As a result, it was identified that vegetation density had dominant impacts on distribution of ET. Seasonally, ET in a growing season represented significantly higher than in a dormant season due to more active transpiration. The ET maps will be useful to analyze how ET behaves along with the circumstantial conditions; land cover classification, vegetation density, elevation, topography.