• Title/Summary/Keyword: statistical assessment

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The Quantitative Assessment of Renal Function and Size by Differences of Acquisition Counts in $^{99m}Tc$-DMSA Renal Scan ($^{99m}Tc$-DMSA 신장검사에서 획득 계수의 차이에 따른 기능 및 형태 평가)

  • Shim, Dong-Oh;Kim, Ho-Sung;Chung, Eun-Mi
    • The Korean Journal of Nuclear Medicine Technology
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    • v.14 no.2
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    • pp.117-121
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    • 2010
  • Purpose: In nuclear medicine study, there are two methods, preset count method and preset time method, to acquire static images. We usually use preset count method for static image in $^{99m}Tc$-DMSA renal scan, but occasionally use preset time method. In case of using preset count method, we always acquire same counts but it causes a difference of scan time. In case of using preset time method, it takes same scan time to acquire images but it causes different counts. Therefore, the purpose of this study is to investigate any differences of function and formal information in both kidney by acquisition counts Materials and Methods: From January 11, 2010 to March 31, 2010, we analyzed the 30 patients (M: 11, W: 19). who were examined by $^{99m}Tc$-DMSA scan and have one side of functioning kidney relatively between 40~60%. And the patients who have cold and hot region in image were analyzed but we did not accept images of patients when it was hard to divide kidney into cortex. There was no division between subjects and age of subjects is $14.83{\pm}22.07$ old. We used the BrightView gamma camera from PHILIPS. To analyze function and formal of kidney, we used JET stream release 3.0 version from PHILIPS. Using SPSS 12.0 program, we compared descriptive statistics and paired T-test. Images were acquired sequentially in the same parameters, but there are three methods which different from acquisition time and scan time, 100 kcounts, 300 kcounts and 7 minutes method (exceed 300 kcounts). To assess function and formal information of kidney, we measured renal relative function, geometric mean and size of kidney and analyzed each difference. Results: In case of renal relative function in both kidney, 100 kcounts method was $50.52{\pm}3.64%$. 300 kcounts method was $50.38{\pm}3.66%$ and 7 minutes method was $49.91{\pm}3.40%$ and there were no statistical significant differences between each method. In case of geometric mean, 100 kcounts method was $50.08{\pm}3.25%$. 300 kcounts method was $49.89{\pm}3.40%$ and 7 minutes method was $49.91{\pm}3.24%$. And also, there were no statistical significant differences. When comparing size of kidney, 100 kcounts method was $8.23{\pm}1.96$ cm. 300 kcounts method was $8.12{\pm}1.90$ cm and 7 minutes method was $8.35{\pm}1.97$ cm. In case of right kidney, 100 kcounts method was $7.91{\pm}1.88$ cm. 300 kcounts method was $8.12{\pm}1.90$ cm and 7 minutes method was $8.25{\pm}1.96$ cm. From those values, we recognized that there were significant differences each method (p<0.05). Conclusion: From results of this study, there were no statistical differences in renal relative function and geometric mean by acquisition counts. However, in shape of kidney, the more acquisition counts are increasing, the more size of kidney is getting big. And there were statistical significant differences. Therefore, to perform reliable quantitative result, preset count method is more desirable than preset time method. Especially, in case of a follow-up test, if we use preset time method, it will cause differences of formal results in kidney due to acquisition counts each time we examine patients.

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High Incidence of Hiatal Hernia in Esophageal Atresia and Its Etiologic Factors (선천성 식도폐쇄 수술 후 열공탈장의 호발과 그 유발인자)

  • Son, Hai-Young;Chang, Eun-Young;Chang, Hye-Kyung;Oh, Jung-Tak;Han, Seok-Joo
    • Advances in pediatric surgery
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    • v.17 no.2
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    • pp.170-178
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    • 2011
  • Hiatal hernia is a very rare disease in the pediatric population. However information from our esophageal atresia postoperative follow-up program has hypotheses; "Hiatal hernia may more frequently occur in postoperative esophageal atresia patients (EA group) than in the general pediatric population (GP group)" and "The tension on the esophagus after esophageal anastomosis may be an important etiologic factor of hiatal hernia in EA group". To prove the first hypotheses, we compared the incidence of hiatal hernia in the GP group with the incidence in the EA group. The Incidence in the GP group was obtained from national statistic data from Statistics Korea and Health Insurance Review and Assessment Service of Korea. The incidence in the EA group was obtained from the medical record and the imaging studies of our esophageal atresia postoperative follow-up program. To prove the second hypothesis, the presumptive risk factors for the development of hiatal hernia in EA group, such as the type of esophageal atresia, degree of esophageal gap, the stage operation and the redo-operation with resection and re-anastomosis of esophagus were analyzed statistically. The total number of patients in the EA group was ninety-nine and there were 5 hiatus hernias. The incidence of EA group (5 %) is significantly higher than incidence of GP group (0.024 %). (p=0.0001) The statistical analysis of the presumptive risk factors for hiatal hernia development in EA group failed to show any evidence of correlation between postoperative esophageal tension and the hiatal hernia. This study shows that the postoperative patients with esophageal atresia have high occurrence of hiatal hernia and should be followed up carefully to detect hiatal hernia.

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Estimation of Personal Exposure to Air Pollutants for Workers Using Time Activity Pattern and Air Concentration of Microenvironments (시간활동 양상과 국소환경 농도를 이용한 근로자의 유해 공기오염물질 노출 예측)

  • Lee, Hyunsoo;Lee, Seokyong;Lee, Byoungjun;Heo, Jung;Kim, Sunshin;Yang, Wonho
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.24 no.4
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    • pp.436-445
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    • 2014
  • Objectives: Time-activity studies have become an integral part of comprehensive exposure assessment and personal exposure modeling. The aims of this study were to estimate exposure levels to nitrogen dioxide($NO_2$) and volatile organic compounds(VOCs), and to compare estimated exposures by using time-activity patterns and indoor air concentrations. Methods: The major microenvironments for office workers were selected using the Time-Use Survey conducted by the National Statistical Office in Korea in 2009. A total of 9,194 and 6,130 workers were recruited for weekdays and weekends, respectively, from the Time-Use Survey. It appears that workers were spending about 50% of their time in the house and about 30% of their time in other indoor areas during the weekdays. In addition, we analyzed the time-activity patterns of 20 office workers and indoor air concentrations in Daegu using a questionnaire and time-activity diary. Estimated exposures were compared with measured concentrations using the time-weighted average analysis of air pollutants. Conclusions: According to the time-activity pattern for the office workers, time spent in the residence indoors during the summer and winter have been shown as $11.12{\pm}2.20$ hours and $12.48{\pm}1.77$ hours, respectively, which indicates higher hours in the winter. Time spent in the office in the summer has been shown to be 1.5 hours higher than in the winter. The target pollutants demonstrate a positive correlation ($R^2=0.076{\sim}0.553$)in the personal exposure results derived from direct measurement and estimated personal exposure concentrations by applying the time activity pattern, as well as measured concentration of the partial environment to the TWA model. However, these correlations were not statistically significant. This may be explained by the difference being caused by other indoor environments, such as a bar, cafe, or diner.

A Study on the Marine Traffic Risk Assessment by using Ship Handling Simulator (선박조종 시뮬레이터를 이용한 해상교통 위험도 평가에 관한 연구)

  • Park, Young-Soo;Kim, Jong-Sung;Kim, Chol-Seong;Yong, Jeong-Jae;Lee, Hyong-Ki;Jeong, Eun-Seok
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.19 no.2
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    • pp.138-144
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    • 2013
  • Large and small marine accidents which are related to vessel's navigation are happening continuously and these maritime accidents have caused loss of lives and properties, and serious maritime environmental pollution damage. It is also true that maritime pollution damage is increasing due to these accidents, probability of growth of seaborne volume and complicated maritime traffic environment. Korea, recently, is developing an evaluation index which can assess sea risk through the evaluation of maritime traffic environment and provide danger and general information with relation to maritime traffic environment on target sea area to evaluate maritime traffic safety. In this paper, we intend to confirm the validity of maritime traffic safety on the basis of vessel navigator's risk consciousness and various sailing conditions by using the ship handling simulator. To confirm the validity of sailing vessel's maritime traffic safety, we use analysis of variance. By using analysis of variance, we analyze vessel navigator's characteristics, distance, speed and encounter type between vessels. Through multiple comparison of each factor's risk difference, we can confirm the change of numerical value of risk difference in statistical aspect.

A Study on the Extraction of a River from the RapidEye Image Using ISODATA Algorithm (ISODATA 기법을 이용한 RapidEye 영상으로부터 하천의 추출에 관한 연구)

  • Jo, Myung-Hee
    • Journal of the Korean Association of Geographic Information Studies
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    • v.15 no.4
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    • pp.1-14
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    • 2012
  • A river is defined as the watercourse flowing through its channel, and the mapping tasks of a river plays an important role for the research on the topographic changes in the riparian zones and the research on the monitoring of flooding in its floodplain. However, the utilization of the ground surveying technologies is not efficient for the mapping tasks of a river due to the irregular surfaces of the riparian zones and the dynamic changes of water level of a river. Recently, the spatial information data sets are widely used for the coastal mapping tasks due to the acquisition of the topographic information without human accessibility. In this research, we tried to extract a river from the RapidEye imagery by using the ISODATA(Iterative Self_Organizing Data Analysis) classification algorithm with the two different parameters(NIR (Near Infra-Red) band and NDVI(Normalized Difference Vegetation Index)). First, the two different images(the NIR band image and the NDVI image) were generated from the RapidEye imagery. Second, the ISODATA algorithm were applied to each image and each river was generated in each image through the post-processing steps. River boundaries were also extracted from each classified image using the Sobel edge detection algorithm. Ground truths determined by the experienced expert are used for the assessment of the accuracy of an each generated river. Statistical results show that the extracted river using the NIR band has higher accuracies than the extracted river using the NDVI.

Assessment of the Relationship between Air Temperature and TOA Brightness Temperature in Different Seasons Using Landsat-8 TIRS (Landsat-8 위성의 열적외 센서를 활용한 대기온도와 밝기온도의 계절별 상관관계 분석)

  • CHOUNG, Yun-Jae;CHUNG, Youn-In;CHOI, Soo-Young
    • Journal of the Korean Association of Geographic Information Studies
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    • v.21 no.2
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    • pp.68-79
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    • 2018
  • In general, Top Of Atmosphere(TOA) brightness temperature is closely related to air temperature. Brightness temperature can be derived from the Thermal Infra-Red Sensors (TIRS) of the earth observation satellites such as the Landsat series. The TIRS instrument of the Landsat-8 satellite collects the two spectral bands (Bands 10 and 11) that measure brightness temperature. In this research, the relationship between the air temperature data measured by the weather stations in Seoul, South Korea and the brightness temperature data separately derived from Bands 10 and 11 of the Landsat-8 satellite were assessed in the different seasons through the correlation analysis. The statistical results led to the following conclusions. First, brightness temperature is closely related to air temperature in order of Spring, Autumn, Winter and Summer. Second, when air temperature increases, brightness temperature also increases in Spring, Autumn and Winter but decreases in Summer. Third, Band 10 has a closer relationship to air temperature than Band 11.

Safety Assessment of Ovarian Cryopreservation and Transplantation in Nude Mice Bearing Human Epithelial Ovarian Cancer

  • Zhu, Gen-Hai;Wang, Sheng-Tan;Yang, Zhao-Xin;Cai, Jun-Hong;Chen, Chun-Ying;Yao, Mao-Zhong;Hong, Lan;He, Guo-Li;Yang, Shu-Ying
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.9
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    • pp.4669-4675
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    • 2012
  • Objective: Nude mice with orthotopic transplantation of human ovarian epithelial cancer were used to investigate screening criteria for paraneoplastic normal ovarian tissue and the security of the freezing and thawing for ovarian tissue transplantation. Methods: Expression of CK-7, CA125, P53, survivin, MMP-2/TIMP-2 in paraneoplastic normal ovarian tissues were detected by RT-PCR as well as immunohistochemistry. The tissues of the groups with all negative indicators of RT-PCR, all negative indicators of immunohistochemistry, negative expression of CK-7, CA125 and survivin, positive expression of CK-7, CA125 and survivin, cancer tissues and normal ovarian tissues of nude mice were used for freezing and thawing transplantation, to analyze overt and occult carcinogenesis rates after transplantation. Results: When all indicators or the main indicators, CK-7, CA125 and survivin, were negative, tumorigenesis did not occur after transplantation. In addition the occult carcinogenesis rate was lower than in the group with positive expression of CK-7, CA125 and survivin (P<0.01). After subcutaneous and orthotopic transplantation of ovarian tissues, rates did not change (P>0.05). There was no statistical significance among rates after transplantation of ovarian tissues which were obtained under different severity conditions (P>0.05). Conclusion: Negative expression of CK-7, CA125 and survivin can be treated as screening criteria for security of ovarian tissues for transplantation. Immunohistochemical methods can be used as the primary detection approach. Both subcutaneous and orthotopic transplantation are safe. The initial severity does not affect the carcinogenesis rate after tissue transplantation. Freezing and thawing ovarian tissue transplantation in nude mice with human epithelial ovarian carcinoma is feasible and safe.

A Statistical Analysis of External Force on Electric Pole due to Meteorological Conditions (기상현상에 의한 전주 외력의 통계적 분석)

  • Park, Chul Young;Shin, Chang Sun;Cho, Yong Yun;Kim, Young Hyun;Park, Jang Woo
    • KIPS Transactions on Computer and Communication Systems
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    • v.6 no.11
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    • pp.437-444
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    • 2017
  • Electric Pole is a supporting beam used for power transmission/distribution which is sensitive to external force change of environmental factors. Therefore, power facilities have many difficulties in terms of maintenance/conservation from external environmental changes and natural disasters that cause a great economic impact. The aerial wire cause elasticity due to the influence of temperature, or factors such as wind speed and wind direction, that weakens the electric pole. The situation may lead to many safety risk in day-to-day life. But, the safety assessment of the pole is carried out at the design stage, and aftermath is not considered. For the safety and maintenance purposes, it is very important to analyze the influence of weather factors on external forces periodically. In this paper, we analyze the acceleration data of the sensor nodes installed in electric pole for maintenance/safety purpose and use Kalman filter as noise compensation method. Fast Fourier Transform (FFT) is performed to analyze the influence of each meteorological factor, along with the meteorological factors on frequency components. The result of the analysis shows that the temperature, humidity, solar radiation, hour of daylight, air pressure, wind direction and wind speed were influential factors. In this paper, the influences of meteorological factors on frequency components are different, and it is thought that it can be an important factor in achieving the purpose of safety and maintenance.

A Epidemiological Study on the Oral Health of 5 years Children in Seongnam City (성남시 5세 어린이의 구강건강실태 조사)

  • Han, Ji-Hyoung;Lee, Young-Soo;Ahn, Yong-Soon;Kim, Mi-Jeong;Hu, Sung-Yoon;Shin, Myung-Mi
    • Journal of dental hygiene science
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    • v.5 no.2
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    • pp.89-95
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    • 2005
  • Dental caries is the most prevalent dental issue of childhood. So it is important to control caries form 5 years children and above all, the study of oral health status have been preceding for preventive dental caries. The purpose of this study was to assess the oral health status of 5 years children in seongnam city. The study population consisted of 1035 kindergraten children which had been selected stratified random sampling. The survey is based on WHO, 2000 oral health assessment, which has been modified. From data dt index, ft index, dft index, dt rate, ft rate, percentage of active caries, percentage of pit and fissure sealant, and so on. The findings were as follows: (1) In 5 years children, the experience of dental caries was 73.0% and the percentage with active caries was 49.4%. Dmf index was 4.13 and this observation shows a statistical singnificance. (2) Average number of 5 years children the experience of dental caries surface index was 3.11 and dfts index was 8.91. (3) The experience of dental caries fo the frist molar was 1.9% and the percentage with active caries was 1.1%. Otherwise the percentage of pit and fissure sealant of the first molar was 6.7%. It is show the low percentage for preventive dental caries. (4) Shows percentage of teeth needing treatment for one surface and above two surface was each 27.3%, 34.0%. And percentage of children required single crown and pulp treatment & single crown and tooth extraction was each 3.8%, 4.7%, 3.3%. (5) Soojung-gu and jungwon-gu were having poor oral hygiene as compared to bundang-gu. So it is necessary to establish community oral health program effectively. And for preventive dental caries and early diagnosis and early treatment consider with community characteristic.

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A Study for Comparison of Consequence Analysis for Buried Pipeline Considering the Depth Factor (깊이 인자를 고려한 매설배관의 사고피해영향 비교 분석에 관한 연구)

  • Han, Seung-Hoon;Seol, Ji-Woo;Yoo, Byong-Tae;Tae, Chan-Ho;Ko, Jae Wook
    • Journal of the Korean Institute of Gas
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    • v.20 no.5
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    • pp.9-16
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    • 2016
  • Buried pipe system is subject to leak or rupture due to internal and external defects with age. Especially, if the pipeline is designed for pressurized gas, the leak can wreak a devastating on its surrounding area. The current method of setting up underground gas pipeline is based on OGP criteria of applying one tenth of the inner pipe pressure. The criteria is applied irrespective of their burial depth or pipe's properties. At times, even the whole safety measures are totally ignored. Considering the magnitude of possible damage from a gas leakage, a precise analytical tool for the risk assessment is urgently needed. The study was conducted to assess possible scenarios of gas accidents and to develop a computer model to minimize the damage. The data from ETA was analyzed intensively, and the model was developed. The model is capable of predicting jet fire influence area with comprehensive input parameters, such as burial depth. The model was calibrated and verified by the historic accident data from Edison Township, New Jersey, the United States. The statistical model was also developed to compare the results of the model in this study and the existing OGP model. They were in good agreement with respect to damage predictions, such as radiation heat coming from 10 meters away from the heat source of gas flame.