• 한국환경보건학회지
• /
• 제32권4호
• /
• pp.304-315
• /
• 2006

This study is performed to reexamine the association between ambient air pollution and daily mortality in seven major cities of Korea using a method of meta-analysis with the data filed for the period 1998-2001. These cities account for half of the Korean population (about 23 million). The observed concentrations of carbon monoxide (CO, mean=1.08 ppm), ozone ($O_3$, mean=33.97 ppb), particulate matter less than 10 ${\mu}m$ ($PM_{10},\;mean=57.11\;{\mu}g/m^3$), nitrogen dioxide ($NO_2$, mean=25.09 ppb), and sulfur dioxide ($SO_2$, mean=9.14 ppb) during the study period were at levels below Korea's current ambient air quality standards. Generalized additive models were applied to allow for the highly flexible fitting of seasonal and long-term time trends in air pollution as well as nonlinear associations with weather variables, such as air temperature and relative humidity. Also, we calculated a weighted mean as a meta-analysis summary of the estimates and its standard error. In city-specific analyses, an increase of $41.17{\mu}g/m^3(IQR)\;of\;PM_{10}$ corresponded to $1{\sim}12%$ more deaths, given constant weather conditions. Like most of air pollution epidemiologic studies, this meta-analysis cannot avoid fleeing from measurement misclassification since no personal measurement was taken. However, we can expect that a measurement bias be reduced in district-specific estimate since a monitoring station is better representative of air quality of the matched district. Significant heterogeneity was found for the effect of all pollutants. The estimated relative risks from meta-like analysis increased compared to those relative risks from pooled analysis. The similar results to those from the previous studies indicated existence of health effect of air pollution at current levels in many industrialized countries, including Korea.

• 동아시아식생활학회지
• /
• 제26권5호
• /
• pp.400-406
• /
• 2016

This study used K-mean cluster analysis to evaluate the preference and satisfaction according to consumption behavior of naturally fermented bread products among customers residing in the Seoul area. Naturally fermented bread products were best recognized as "great nutrients for good health" ($3.91{\pm}0.87$). The preference for naturally fermented bread products was due to "good taste and flavor" ($3.39{\pm}0.95$), and customers with "intention to purchase" showed a mean of $3.21{\pm}0.94$. The overall satisfaction for naturally fermented bread products was $3.26{\pm}0.75$. Among the specific categories that contributed to this overall satisfaction, "quality" showed the highest satisfaction with $3.43{\pm}0.77$, whereas "price" ($2.77{\pm}0.76$) and "variety" ($2.77{\pm}0.75$) exhibited the lowest. Among the items to modify for naturally fermented bread products, "variety" was the most important item (21.8%), followed by "lower price" and "convenience of purchase" at 19.7% and 17.9%, respectively. In K-mean cluster analysis, customers who frequently visited the bakery and purchased naturally fermented bread products (cluster 1) expressed strong preference, satisfaction, and consumption behavior. Furthermore, these customers expressed high satisfaction in "quality", "convenience of purchase", and "variety" of naturally fermented bread products.

• 지역사회간호학회지
• /
• 제8권1호
• /
• pp.74-88
• /
• 1997

The purpose of this study was to identify the relationship between perceived social support and the quality of life of cancer patients receiving gene therapy. The subjects for this study were 50 cancer patients receiving gene therapy at two general hospital in Seoul. The data were collected during the period from October 14, 1996 to November 11, 1996. The perceived social support was measured by the family support scale made by Hyun Sook Kang, by the medical support of life scale developed by Ok Soo Kim. The quality of life scale developed by Bang-Whal-Ran was used, among the questionnaire, physical factors was developed by U.S.A National Conference on Cancer Nursing. The data was analysed by the SAS statistical program. Percentile, means and standard deviations, t -test, ANOVA, Scheffe test, Pearson correlation were utilized for analysis. The results of this study were as follows. 1. The mean score of the perceived social support of the subjects was 83.66, the item score was 3.8. 1) The mean score of the perceived family support of the subjects was 44.96, the item mean score was 4.5. 2) The mean score of the perceived professional medical support of the subjects was 38.70, the item mean score was 3.2. 2. The mean score of quality of life of the subjects was 120.38, the item mean score was 3.17. For each factor in quality of life scale, the mean score was follows: for attitude toward life, 3.95, for familial relationship and financial status, 3.53, for social activity 3.24, for emotional status, 3.08, for healthy perceptive, 2.90, for physical symptom, 2.80. 3. The result of the analysis of the relationship between perceived social support and quality of life showed a positive correlation(r=.4853, p=.0004). Therefore, the higher the perceived social support of the patients, the higher the quality of life. 1) The result of the analysis of the relationship between perceived family support and quality of life showed significant correlation(r=. 3566, p=.0110). Therefore the higher the perceived family support of the patients, the higher the quality of life. 2) The result of the analysis of the relationship between perceived professional medical support and quality of life showed significant correlation (r=.4477, p=.0011). Therefore, the higher the perceived professional medical support of the patients the higher the quality of life. 4. There was a significant difference in perceived social support according to sex(F=2.1437, p= .0371), others coping non-family (F=2.4863, p=.0164) and duration of treatment (F=4.16, p=.0218). 5. There was a significant differance in quality of life according to sex(F=2.6932, p=.0097), degree of education(F=2.3610, p=.0223), others coping non-family(F=2.0502, p=.0458). In conclusion, this study revealed that social support is an important factor that associated with the quality of life in cancer patients receiving gene therapy.

• 한국정보처리학회논문지
• /
• 제2권3호
• /
• pp.417-424
• /
• 1995

본 논문에서는 정량화(Quantification) 문제를 MFT(Mean Field Theroy)를 통해서 해결하는 기법을 제안한다. 통계학에서 중요한 문제의 하나인 정량화 문제는 주어진 공간에서 대상들간의 유사성에 따라서 최적의 상태를 갖도록 하는 문제이다. 평균장 접근 방법에 기초한 한개의 변수로 표현되는 확률적 시뮬레이티드 아닐링을 제안하고 정량화 문제를 패널티(penalty) 파라메타 항을 첨가한 비한정된 최적화 문제로 변형하 여 MFT를 적용하였다. 또한 연속변수를 갖는 신경회로망에서 실제 값을 계산하는 것 보다 평균장 접근방법으로 계산하는것이 더 빠르게 계산될 수 있음을 확인하였다. 본 논문에서 제안한 방법이 실험결과 해석적인 방법보다 좋은 정량적 결과를 보였다.

• 대한토목학회논문집
• /
• 제31권1B호
• /
• pp.21-27
• /
• 2011

유출예측량을 모의할 때 과거와 현재의 수문자료를 이용한다는 측면에서 미래 예측결과의 불확실성을 완전히 제거할 수는 없겠지만, 다양한 기법별 분석에 의하여 불확실성을 감소시킬 수 있다. 본 연구에서는 유출예측의 정확성 향상을 위해 다양한 유출예측 기법을 적용 및 평가하였으며 확률론적 예측을 가능하게 하는 예측기법인 ESP와 관측 시계열 자료를 이용한 통계기법으로 공주지점의 유출예측을 수행하였다. 각 기법에 따른 유출예측 결과의 신뢰성 평가는 MAE(Mean Absolute Error), RMSE(Root Mean Squared Error), RRMSE(Relative Root Mean Squared Error), Mean Absolute Percentage Error (MAPE), TIC(Theil Inequality Coefficient)를 이용하였다. ESP 확률을 이용하여 예측한 유출결과와 통계적 시계열 분석에 의해 예측된 유출결과를 MAE, RMSE, RRMSE, MAPE, TIC를 이용하여 비교 분석하였으며 유출예측의 개선효과를 확인해본 결과, ESP 확률을 이용한 예측이 MAE(10.6), RMSE(15.14), RRMSE(0.244), MAPE(22.74%), TIC(0.13)으로 평가되었으며 MAE(23.2), RMSE(37.13), RRMSE(0.596), MAPE(26.69%), TIC(0.30)으로 평가된 ARMA와 MAE(26.4), RMSE(34.44), RRMSE(0.563), MAPE(47.38%), TIC(0.25)으로 평가된 Winters 에 비해 신뢰성이 높게 나타났다.

• 전기학회논문지
• /
• 제66권7호
• /
• pp.1072-1077
• /
• 2017

Mean-reverting analysis refers to a way of estimating the underlining tendency after new data has evoked the variation in the equilibrium state. In this paper, we propose a new method to interpret the specular portraits of Premature Ventricular Contraction(PVC) arrhythmia by applying K-means unsupervised learning algorithm on electrocardiogram(ECG) data. Aiming at this purpose, we applied a mean-reverting model to analyse Heart Rate Variability(HRV) in terms of the modified poincare plot by considering PVC rhythm as the component of disrupting the homeostasis state. Based on our experimental tests on MIT-BIH ECG database, we can find the fact that the specular patterns portraited by K-means clustering on mean-reverting HRV data can be more clearly visible and the Euclidean metric can be used to identify the discrepancy between the normal sinus rhythm and PVC beats by the relative distance among cluster-centroids.

• 품질경영학회지
• /
• 제22권4호
• /
• pp.1-12
• /
• 1994

각각의 설계인자들의 실험조건에서 얻어지는 특성치들의 분산은 평균에 영향을 받는다. 많은 경우에 평균이 커짐에 따라서 분산이 커지는 경향이 있다. 다구찌가 산포제어인자를 찾기 위해서 제시한 SN 비인 $(SN)_i$ = 10 log ($\bar{y}_{i}^{2}/s_{i}^{2}$) 은 분산이 평균의 제곱에 비례하여 커지는 경우이다. 그런데 분산이 평균의 제곱보다 더 느리게 또는 더 빠르게 커질 수도 있기 때문에 이 논문에서는 간단한 자료분석적 기법에 의해서 그 관계를 추측하여, 합당한 SN 비를 사용할 것을 제시하였고, 평균조정인자를 찾기위한 통계량인 감도 $(S)_i$ 의 통계적 성질들을 논의하였다.

• 대한소아치과학회지
• /
• 제23권2호
• /
• pp.503-524
• /
• 1996

A series of 31 patients with primary oral squamous cell carcinoma (SCC) who were treated at Chonbuk National University Hospital during the years 1991-1995, were evaluated by dual parameter analysis in flow cytometric DNA measurement, Bryne's malignancy grading system, and the TNM classification. The aims of the present study were to discover that previously undetected aneuploid clones could be detected by dual parameter analysis and to determine the prognostic value of the above parameters. 1. Using dual parameter analysis of cytokeratin and DNA on disintegrated paraffin-embedded samples, aneuploid clones which were undetected by regular single parameter DNA analysis could be found among the cytokeratin-selected cells. DNA aneuploidy from paraffin-embedded samples were 15 cases compared with 10 cases using conventional DNA analysis. 2. The portion of aneuploid tumors showed slightly higher clinical stage and tumor size than the portion of diploid tumors, but the difference was not significant. The portion of DNA aneuploid tumors showed significantly higher mean mitosis and total malignancy scores than the portion of DNA diploid tumors. 3. The majority of the patients presented with clinical stage III and IV lesions showed significantly higher mean total malignancy score as compared to those with clinical stage I and II. 4. Histopathologic mean total malignancy score of the 31 cases was 12.7. Among the histologic parameters, mean mitosis score was correlated to the status of DNA ploidy and total malignancy score were correlated to the DNA ploidy and clinical staging.

• 대한치과보철학회지
• /
• 제38권1호
• /
• pp.12-25
• /
• 2000

To demonstrate possible influences of general bone density on the mandible, histomorphometric analysis was carried out in mandibles and iliac bones and the correlation of the two bone densities was tested. Comparison of bony density in women and men over 60 years in the mandible was carried out too. Quantitative computed tomography(QCT) was taken in cross-section of mandibles at the same site where histomorphometric analysis was peformed to evaluate the reliability of QCT. The analysis included 40 cadavers with no known diseases affecting the bones. The subjects consisted of 15 females and 25 males with a mean age of 60.3 years. Spearman correlation analysis and Wilcoxon rank sum test was performed. The results were as follows. 1. There was statistically no correlation between the mandible and iliac bone in the values of corrected cortical width(CCW), cortical porosity(POR) in cortex, and total bone volume(TBV), mean trabecular plate thickness(MTPT), mean trabecular plate density(MTPD), and mean trabecular plate separation(MTPS) in trabecular bone. 2. Comparison of women and men over 60 years, men had statistically higher bone density than women except fir POR of buccal and lingual cortex, and WTPD of alveolar trabeculae in mandible. 3. There was statistically significant correlation between TBV of trabecular bone and CT No., but not between POR and CT No. in mandible. According to the results above, there was no correlation between mandible and iliac bone density and between mandibular bony density and age. Further studies are required to support the results. A more noninvasive method to be able to measure the bone density of mandible should be developed and it is necessary to accumulate data on the normal values of bone density of mandible according to age and sex. Further study should be carried out about QCT to measure mandibular bony density using QCT.

• Annals of Clinical Neurophysiology
• /
• 제5권2호
• /
• pp.197-201
• /
• 2003

Background: The aim of this study is to present the basic reference data of kinematic gait analysis of normal Korean adults with 3 dimensional electrogoniometer, $Domotion^{(R)}$. Method: The basic kinematic gait parameters of hip, knee and ankle joints on the sagittal plane were obtained from 10 healthy adults with 5 repetition for each. Three-dimensional gait analysis was performed with $Domotion^{(R)}$ electrogoniometer in 10 meters long flat floor. Each data collected was processed with IBM PC equipped with gait analysis program. Results: Mean maximal hip flexion was $23.05^{\circ}{\pm}4.62^{\circ}$and mean maximal hip extension was $6.46^{\circ}{\pm}1.30^{\circ}$. Knee flexion was observed with two peak values. The first peak knee flexion was $6.50^{\circ}{\pm}2.07^{\circ}$ at 20.4% of gait cycle and the second peak flexion was $50.34^{\circ}{\pm}2.23^{\circ}$ at 75.8% of gait cycle. Mean maximum ankle dorsiflexion was $5.57^{\circ}{\pm}1.19^{\circ}$ at 44% of gait cycle and mean maximum ankle plantar flexion was $15.51^{\circ}{\pm}1.73^{\circ}$ at 68.5% of gait cycle. Conclusion: We concluded three dimensional gait analysis with electrogoniometer $Domotion^{(R)}$ offers a valid and reliable kinematic data and the application of this tools for clinical gait evaluation will be helpful in management of pathological gait.