• Title/Summary/Keyword: Curve Estimation Regression

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Study on the Optimum Range of Weight-Age Data for Estimation of Growth Curve Parameters of Hanwoo (한우의 체중 성장곡선 모수 추정을 위한 체중 측정 자료의 최적 범위에 관한 연구)

  • Cho, Y.M.;Yoon, H.B.;Park, B.H.;Ahn, B.S.;Jeon, B.S.;Park, Y.I.
    • Journal of Animal Science and Technology
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    • v.44 no.2
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    • pp.165-170
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    • 2002
  • Mature weight (A) and rate of maturing (k) estimated by nonlinear regression were studied to determine the optimum age range over which the estimate of growth curve parameters can be estimated. The weight-age data from 1,133 Hanwoo bulls at Hanwoo Improvement Center of N.A.C.F. were used to fit the growth curve using Gompertz model. All available weight data from birth to the specific age of months were used for the estimation of parameters: the six specific ages used were 12, 14, 16, 18, 20 22 and 24 months of age. The mean estimates of mature weight (A) were 966.5, 1,255.9, 1,126.2, 916.5, 842.2, 780.9 and 767.0kg for ages 12 through 24 months, respectively. The mean estimates of mature weight (A) to 22 and 24 months of age were not different from each other. However, they were different from the estimates based on the data to other ages. Mean estimates of rate of maturing (k) were 3.362, 3.595, 3.536, 3.421, 3.403, 3.409 and 3.411 for ages 12 through 24 months, respectively. The mean estimates of maturing rate (k) for ages 18 through 24 months of age were not significantly different from each other. However, they were different from the estimates based on the data to other ages. Correlations among estimates of A at various ages showed the highest value of 0.93 between 22 and 24 months. Correlations among estimates of k at various ages were highest ranging from 0.91 to 0.99 among 18 to 24 months. The correlations between A and k were positive and tended to decrease with the increase of the age from 0.84 for the age of 12 months to 0.10 for the age of 24 months. Thus, the estimates of growth curve parameters, A and k, suitable for genetic studies can be derived from accumulated Hanwoo bulls after 22 months of age.

Estimation of Ultimate Bearing Capacity of Gravel Compaction Piles Using Nonlinear Regression Analysis (비선형 회귀분석을 이용한 쇄석다짐말뚝의 극한지지력 예측)

  • Park, Joon Mo;Han, Yong Bae;Jang, Yeon Soo
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.25 no.2
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    • pp.112-121
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    • 2013
  • The calibration of resistance factor in reliability theory for limit state design of gravel compaction piles (GCP) requires a reliable estimate of ultimate bearing capacity. The static load test is commonly used in geotechnical engineering practice to predict the ultimate bearing capacity. Many graphical methods are specified in the design standard to define the ultimate bearing capacity based on the load-settlement curve. However, it has some disadvantages to ensure reliability to obtain an uniform ultimate load depend on engineering judgement. In this study, a well-fitting nonlinear regression model is proposed to estimate the ultimate bearing capacity, for which a nonlinear regression analysis is applied to estimate the ultimate bearing capacity of GCP and the results are compared with those calculated using previous graphical method. Affect the resistance factor of the estimate method were analyzed. To provide a database in the development of limit state design, the load test conditions for predicting the ultimate bearing capacity from static load test are examined.

A Study on the Prediction of Discharge by Estimating Optimum Parameter of Mean Velocity Equation (평균유속공식의 최적매개변수 산정에 의한 유량예측에 관한 연구)

  • Choo, Tai Ho;Chae, Soo Kwon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.11
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    • pp.5578-5586
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    • 2012
  • The accurate estimation of discharge is very essential as the important factor of river design for the utilization and flood control, hydraulic construction design. The present discharge production is using the stage-discharge relationship curve in the river. The rating curve uses the method by predicting the discharge based on regression analysis using the measured stage and discharge data in a flood season. The method is comparatively convenient and has especially advantages in that it can predict the discharge having the difficulty of observation in a flood season. However, this method has basically room for improvement because the method only uses the relationship between stage and discharge, and doesn't reflect the hydraulic parameters such as hydraulic radius, energy slope, roughness, topography, etc.. Therefore, in this study, discharge was predicted using the convenient calculation method with empirical parameters of the Manning and Chezy equations, which were proposed by Choo et at (2011) in KSCE as a new methodology for estimating discharge in open channel. The proposed method can conveniently estimate empirical parameters in both of Manning and Chezy equations and the discharge is estimated in the open channels. There are proved by using data measured in meandering lab. channel and India canal and the accuracies show about determination coefficient 0.8. Accordingly, this method will be used in actual field if this study is continuously conducted.

A Bayesian GLM Model Based Regional Frequency Analysis Using Scaling Properties of Extreme Rainfalls (극치자료계열의 Scaling 특성과 Bayesian GLM Model을 이용한 지역빈도해석)

  • Kim, Jin-Young;Kwon, Hyun-Han;Lee, Byung-Suk
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.37 no.1
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    • pp.29-41
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    • 2017
  • Design rainfalls are one of the most important hydrologic data for river management, hydraulic structure design and risk analysis. The design rainfalls are first estimated by a point frequency analysis and the IDF (intensity-duration-frequency) curve is then constructed by a nonlinear regression to either interpolate or extrapolate the design rainfalls for other durations which are not used in the frequency analysis. It has been widely recognised that the more reliable approaches are required to better account for uncertainties associated with the model parameters under circumstances where limited hydrologic data are available for the watershed of interest. For these reasons, this study developed a hierarchical Bayesian based GLM (generalized linear model) for a regional frequency analysis in conjunction with a scaling function of the parameters in probability distribution. The proposed model provided a reliable estimation of a set of parameters for each individual station, as well as offered a regional estimate of the parameters, which allow us to have a regional IDF curve. Overall, we expected the proposed model can be used for different aspects of water resources planning at various stages and in addition for the ungaged basin.

An Estimation of Flood Quantiles at Ungauged Locations by Index Flood Frequency Curves (지표홍수 빈도곡선의 개발에 의한 미 계측지점의 확률 홍수량 추정)

  • Yoon, Yong-Nam;Shin, Chang-Kun;Jang, Su-Hyung
    • Journal of Korea Water Resources Association
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    • v.38 no.1
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    • pp.1-9
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    • 2005
  • The study shows the possible use of the index flood frequency curves for an estimation of flood quantiles at ungauged locations. Flood frequency analysis were made for the annual maximum flood data series at 9 available stations in the Han river basin. From the flood frquency curve at each station the mean annual flood of 2.33-year return period was determined and the ratios of the flood magnitude of various return period to the mean annual flood at each station were averaged throughout the Han river basin, resulting mean flood ratios of different return periods. A correlation analysis was made between the mean annual flood and physiographic parameters of the watersheds i.e, the watershed area and mean river channel slope, resulting an empirical multiple linear regression equation over the whole Han river basin. For unguaged watershed the flood of a specified return period could be estimated by multiplying the mead flood ratio corresponding the return period with the mean annual flood computed by the empirical formula developed in terms of the watershed area and river channel slope. To verify the applicability of the methodology developed in the present study the floods of various return periods determined for the watershed in the river channel improvement plan formulation by the Ministry of Construction and Transportation(MOCT) were compared with those estimated by the present method. The result proved a resonable agreement up to the watershed area of approximately 2,000k $m^2$. It is suggested that the practice of design flood estimation based on the rainfall-runoff analysis might have to be reevaluated because it involves too much uncertainties in the hydrologic data and rainfall-runoff model calibration.

Liver Cancer Mortality Characteristics and Trends in China from 1991 to 2012

  • Fang, Jia-Ying;Wu, Ku-Sheng;Zeng, Yang;Tang, Wen-Rui;Du, Pei-Ling;Xu, Zhen-Xi;Xu, Xiao-Ling;Luo, Jia-Yi;Lin, Kun
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.5
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    • pp.1959-1964
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    • 2015
  • Purpose: To investigate the distribution of liver cancer mortality as well as its developing trend from 1991 to 2012, forecast the future five-year trend, and provide a basis for the comprehensive prevention and management. Materials and Methods: Mortality data for liver cancer in China from 1991 to 2012 were used to describe characteristics and distribution of liver cancer mortality. Trend surface analysis was used to study the geographical distribution of liver cancer mortality. Curve estimation, time series modeling, gray modeling (GM) and joinpoint regression were used to predict and forecast future trends. Results: The mortality rate of liver cancer has constantly increased in China since 1991. Rates in rural areas are higher than in urban areas, and in males are higher than in females. In addition, our data predicted that the trend will continue to increase in the next 5 years. The age-specific mortality of liver cancer increases with age and peaks in the group of 80-84 years old. Geographical analysis showed the liver mortality rate was higher in the southeast provinces, such as Jiangsu, Zhejiang and Guangdong, and southwest regions like Guangxi Province. Conclusions: The standardized mortality rate of liver cancer in China has consistently increased from 1991 to 2012, and the upward trend is predicted to continue in the future. Much better prevention and management of liver cancer is needed in high mortality areas (the southwestern and southeastern parts of China) and high mortality age groups (80- to 84-year-olds), especially in rural areas.

Study on the Catchment Area of Child Care Center by Means of Transportation Mode (어린이집의 통행수단별 이용권 분석)

  • Kim, Yong-Jin;Kim, Seong-Hee
    • The Journal of the Korea Contents Association
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    • v.17 no.8
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    • pp.483-489
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    • 2017
  • The purpose of this study is to analyze the catchment area of child care centers, which are becoming increasingly important due to social changes such as nuclear family and women's participation in society. In this study, we surveyed 2,174 children in 32 municipal child care centers in Suwon city. As a result, most of infants(0~2years old) were coming to daycare facilities by cars, and its catchment area for 90%ile were about 3km. Next, the catchment area of the children who walk to child care centers is about 500m. When using the car, the catchment area was 1.3km. This study provides the following suggestions. Considering the infant car use area, it is necessary to install more than one child care center per living area. In particular, there is a need to urgently expand daycare centers that provide child care services for infant care. Next, a nursing center-based pedestrian environment improvement project is needed.

Epidemiological Characteristics and Prediction of Esophageal Cancer Mortality in China from 1991 to 2012

  • Tang, Wen-Rui;Fang, Jia-Ying;Wu, Ku-Sheng;Shi, Xiao-Jun;Luo, Jia-Yi;Lin, Kun
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.16
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    • pp.6929-6934
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    • 2014
  • Background: To analyze the mortality distribution of esophageal cancer in China from 1991 to 2012, to forecast the mortality in the future five years, and to provide evidence for prevention and treatment of esophageal cancer. Materials and Methods: Mortality data for esophageal cancer in China from 1991 to 2012 were used to describe its epidemiological characteristics, such as the change of the standardized mortality rate, urban-rural differences, sex and age differences. Trend-surface analysis was used to study the geographical distribution of the mortality. Curve estimation, time series, gray modeling, and joinpoint regression were used to predict the mortality for the next five years in the future. Results: In China, the incidence rate of esophageal cancer from 2007 and the mortality rate of esophageal cancer from 2008 increased yearly, with males at $8.72/10^5$ being higher than females, and the countryside at $15.5/10^5$ being higher than in the city. The mortality rate increased from age 45. Geographical analysis showed the mortality rate increased from southern to eastern China, and from northeast to central China. Conclusions: The incidence rate and the standardized mortality rate of esophageal cancer are rising. The regional disease control for esophageal cancer should be focused on eastern, central and northern regions China, and the key targets for prevention and treatment are rural men more than 45 years old. The mortality of esophageal cancer will rise in the next five years.

Risk Factors for Appendiceal Metastasis with Epithelial Ovarian Cancer

  • Kokanali, Mahmut Kuntay;Guzel, Ali Irfan;Erkilinc, Selcuk;Tokmak, Aytekin;Topcu, Hasan Onur;Gungor, Tayfun
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.6
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    • pp.2689-2692
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    • 2014
  • Purpose: To investigate the risk factors for appendiceal metastasis of epithelial ovarian cancer and compare findings with the previous studies. Materials and Methods: One hundred and thirty-four patients with epithelial ovarian cancer were assessed in this study. All of them had undergone a surgical procedure including appendectomy. Of these, 21 (15.7%) patients who had appendiceal metastasis were analyzed as the case group and the patients with no metastasis were the controls, compared according to stage, grade, histology of tumor, preoperative Ca125 levels, presence of ascites, peritoneal cytology, diameter and site of tumor considered as risk factors. Results: We found statistically significant differences between the groups in terms of stage, grade, right-sided tumor location, presence of ascites, diameter of tumor${\geq}10cm$ and positive peritoneal cytology (p<0.05). In the logistic regression model, stage, grade, presence of ascites, right-sided location and diameter of tumor were independent risk factors. ROC curve analysis showed that stage, grade and diameter of the tumor were discriminative factors for appendiceal metastasis. Conclusions: In epithelial ovarian cancer, stage, grade, presence of ascites, right-sided location and large tumor size have importance for estimation of risk of appendiceal metastasis. As we compare our findings with previous studies, there is no definite recommendation for the risk factors of appendiceal metastasis in epithelial ovarian cancer and more studies are needed.

Mortality Characteristics and Prediction of Female Breast Cancer in China from 1991 to 2011

  • Shi, Xiao-Jun;Au, William W.;Wu, Ku-Sheng;Chen, Lin-Xiang;Lin, Kun
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.6
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    • pp.2785-2791
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    • 2014
  • Aims: To analyze time-dependent changes in female breast cancer (BC) mortality in China, forecast the trend in the ensuing 5 years, and provide recommendations for prevention and management. Materials and Methods: Mortality data of breast cancer in China from 1991 to 2011 was used to describe characteristics and distribution, such as the changes of the standardized mortality rate, urban-rural differences and age differences. Trend-surface analysis was used to study the geographical distribution of mortality. In addition, curve estimation, time series modeling, Gray modeling (GM) and joinpoint regression were performed to estimate and predict future trends. Results: In China, the mortality rate of breast cancer has increased yearly since 1991. In addition, our data predicted that the trend will continue to increase in the ensuing 5 years. Rates in urban areas are higher than those in rural areas. Over the past decade, all peak ages for death by breast cancer have been delayed, with the first death peak occurring at 55 to 65 years of age in urban and rural areas. Geographical analysis indicated that mortality rates increased from Southwest to Northeast and from West to East. Conclusions: The standardized mortality rate of breast cancer in China is rising and the upward trend is predicted to continue for the next 5 years. Since this can cause an enormous health impact in China, much better prevention and management of breast cancer is needed. Consequently, disease control centers in China should place more focus on the northeastern, eastern and southeastern parts of China for breast cancer prevention and management, and the key population should be among women between ages 55 to 65, especially those in urban communities.