• Title/Summary/Keyword: Shape Regression

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Ultrasound Score to Select Subcentimeter-sized Thyroid Nodules Requiring Ultrasound-guided Fine Needle Aspiration Biopsy in Eastern China

  • Cheng, Pu;Chen, En-Dong;Zheng, Hua-Min;He, Qiu-Xiang;Li, Quan
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.8
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    • pp.4689-4692
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    • 2013
  • Ultrasound-guided fine needle aspiration biopsy (FNAB) is a costly diagnostic item with a low yield in identifying the tiny proportion of nodules that actually represent malignant disease. Our aim through this study was to obtain an ultrasound (US) score for selecting subcentimeter-sized thyroid nodules requiring FNAB in eastern China. Some 248 patients for a total of 270 thyroid nodules less than 1 cm in diameter underwent FNAB and subsequent surgery from January 2006 to March 2012 at our hospital. The clinicopathological and US data from all the nodules were analyzed retrospectively. An US score was developed on the basis of independent predictive factors for malignancy. Irregular shape, hypoechogenicity, no well-defined margin, presence of calcifications and ratio between antero-posterior and transversal diameters (AP/TR) ${\geq}1$ were independent predictive factors for malignancy on logistic regression analysis. US score were statistically significant, with ${\leq}2$ favoring benignancy with an 80.3% sensitivity and a 72.7% specificity. US score is useful for differentiating between malignant and benign subcentimeter-sized thyroid nodules. We suggest FNAB for nodules when the US score is higher than 2.

Estimation of Synthetic Unit Hydrograph by Cluster Analysis Using Geomorphic Characteristics of Mid-size Watershed (지형학적 인자에 따라 군집화된 중소규모유역의 합성단위도법 제시)

  • Kim, Jin Gyeom;Kim, Jong min;Kang, Boosik
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.36 no.3
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    • pp.439-449
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    • 2016
  • The methodology of synthetic unit hydrograph using geomorphic characteristics was suggested. Six geomorphic components over 19 watersheds were used to estimate synthetic unit hydrograph and the test watersheds were classified into two groups on the basis of the area of $200km^2$. The regression formulas between standardized geomorphic characteristics for each group and peak quantities of specific streamflow and time of representative unit hydrograph were suggested and the Nash and the Clark unit hydrographs were derived. For verifying the derived unit hydrographs, the resulting hydrographs were compared with the ones using the existing Clark unit hydrographs based on the empirical parameter estimation for the 145 storm events during 2010 to 2011 for the additional six watersheds. The results showed the relatively higher performance over the existing synthetic unit hydrograph methods, which could be a contribution to the hydrologic estimation in ungauged watersheds.

An Estimation of Discharge Coefficient Considering the Geometrical Shape of Broad Crested Side Weir (광정횡월류위어의 기하학적 형상을 고려한 유량계수 산정)

  • Cho, Hong-Je;Kang, Ho-Seon
    • Journal of Korea Water Resources Association
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    • v.44 no.12
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    • pp.955-965
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    • 2011
  • The flow characteristics of rectangular and 1 : 1 and 1 : 2 trapezoidal weirs were investigated through hydraulic experiments in order calculate the exact overflow discharge of the broad-crested side weir. The flow was found to be most stable in trapezoidal shapes with the lowest incline. The 1 : 1 and 1 : 2 trapezoidal weirs had 5.67% and 8.57% increases, respectively, compared to the rectangular weir in terms of overflow amount, which suggests that they are more effective in preventing flood. An integrated discharge coefficient equation taking into account the discharge coefficient equation and shapes was proposed through a multiple linear regression analysis with an addition of a new parameter for the side wear, $L/L_H$, to the conventional discharge coefficient equation. Also, the applicability of the newly proposed discharge coefficient equation was reviewed by comparing the measured and calculated overflow amounts based on the experimental data of preceding researches and existing researchers and the research data of this study.

Relationship Between Prevalence of Allergic Diseases and Recognition of Food Nutrition Labeling (알레르기 질환 진단 경험과 식품 영양표시 인지의 관련성)

  • Han, Yun-su;Jung, Woo-young;Hwang, Yun-tae;Kim, Ji-yeon;Lee, Yejin;Kwon, Ohwi;Noh, Jin-won
    • The Journal of the Korea Contents Association
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    • v.19 no.11
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    • pp.434-444
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    • 2019
  • Prevalence of allergic diseases is influenced by environment and dietary life. It is key to improve daily food life to relieve them. Food nutrition labeling is useful to do it by offering nutrition information. The purpose of the study is to find relationship between experience of diagnosis of allergic diseases and recognition of food nutrition labeling. The data of 4,928 people with experience on diagnosis allergic rhinitis, asthma, atopic dermatitis of 2016 Korea National Health and Nutrition Survey was used. According to the result of binary logistic regression analysis, those who had experience in being diagnosed with an allergy showed high awareness in food labels. There were differences between allergy diagnosis groups and allergy non-diagnosis in affecting factors of residence, income level, subjective health status and body-shape perception. Support measures are needed to enhance access and convenience to nutrition education and nutrition labeling to support nutrition labeling utilization.

Analysis of Bird Species Diversity Response to Structural Conditions of Urban Park - Focused on 26 Urban Parks in Cheonan City - (도시공원 구조 및 식생 조건에 따른 조류 종다양성 분석 - 천안시 26개 도시공원을 대상으로 -)

  • Song, Wonkyong
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.18 no.3
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    • pp.65-77
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    • 2015
  • The urban park has important functions as a habitat for wildlife as well as open space of rest and community for people. This study was carried out to find what factors of structure and vegetation of urban parks could affect forest bird species diversity in Cheonan city. The study surveyed bird and vegetation species in 26 urban parks, Cheonan city. A correlation analysis and multiple linear regressions were performed to test whether habitat structure and vegetation were the major correlate with species diversity. The results showed the Dujeong park was the most high bird species diversity (H' = 2.13), and the Dujeong-8 park (H' = 2.02) and the Cheongsa park (H' = 1.73) were considerably higher than the other urban parks. The variables that were strongly correlated with bird species diversity were park area, number of subtree species, canopy of shrub, number of shrub species, shape index, canopy of subtree, canopy of tree, and impervious surface ratio. The regression of bird species diversity against the environmental variables showed that 3 variables of park area, canopy of subtree, and canopy of tree were included in the best model. Model variable selection was broadly similar for the 5 optimal models. It means park area and multi-layer vegetation were the most consistent and significant predictor of bird species diversity, because urban parks were isolated by built-up areas. Especially the subtree coverage that provides shelter and food for forest birds was an important variable. Therefore, to make parks circular-shaped and abundant multi-layer vegetation, which could be a buffer to external disturbances and improve the quality of habitats, may be used to enhance species diversity in creation and management of urban parks.

A Study on the Optimization for a V-groove GMA Welding Process Using a Dual Response Method (듀얼 반응표면법을 이용한 V-그루브 GMA 용접공정 최적화에 관한 연구)

  • Park, Hyoung-Jin;Ahn, Seung-Ho;Kang, Mun-Jin;Rhee, Se-Hun
    • Journal of Welding and Joining
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    • v.26 no.2
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    • pp.85-91
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    • 2008
  • In general, the quality of a welding process tends to vary with depending on the work environment or external disturbances. Hence, in order to achieve the desirable quality of welding, we should have the optimal welding condition that is not significantly affected by these changes in the environment or external disturbances. In this study, we used a dual response surface method in consideration of both the mean output variables and the standard deviation in order to optimize the V-groove arc welding process. The input variables for GMA welding process with the dual response surface are welding voltage, welding current and welding speed. The output variables are the welding quality function using the shape factor of bead geometry. First, we performed welding experiment on the interested area according to the central composite design. From the results obtained, we derived the regression model on the mean and standard deviation between the input and output variables of the welding process and then obtained the dual response surface. Finally, using the grid search method, we obtained the input variables that minimize the object function which led to the optimal V-groove arc welding process.

Effects of Nutrition Knowledge, Dietary Attitude, Dietary Habits and Life Style on the Health of College Students in the Chungnam Area (충남지역 대학생의 영양지식, 식태도, 식습관 및 생활습관이 건강상태에 미치는 영향)

  • 김인숙;유현희;한혜숙
    • Korean Journal of Community Nutrition
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    • v.7 no.1
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    • pp.45-57
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    • 2002
  • The purpose of this research of this research was to survey the health of 181 male and 130 female students at K University in Chunganm from June 1 to June 23, 2001. It analyzed the students’dietary behaviors, life styles and perceived body shapes and the correlation of these factors to the health condition of the students surveyed. The results of the survey are summarized as follows. The average nutrition knowledge score (out of a possible 20 points), dietary attitudes score (out of a possible 50 points) and dietary habits score (out of a possible 30 points) were 8.66, 33.14 and 19.02 for males, and 9.99, 32.64, and 19.05 for females, respectively. The percentages of those who smoked, drank, smoked and drank and exercised regularly were 55.2, 92.8, 54.1, 82.9% for males, and 6.9, 91.5, 6.9, 63.1 for females, respectively. A significantly higher proportion of males smoked, drank, and exercised as compared to females (p<0.001). The percentages of students who were underweight, normal or overweight by BMI were 5.0, 79.0 and 16.0 for males, and 20.0, 78.5 and 1.5 for females, respectively. Fifty percent of females indicated that they felt they were obese, versus only 31.1% of males. Half of the females thought they were fattish, while only 31.1% of males thought that. Seventy-six point nine percent of females and 61.9% of males, more females than males, were dissatisfied with their weights. The health scores (the higher the point, the better the health condition) of the females (44.17) were significantly lower than those of the males (47.17) (p<0.001). A stepwise multiple regression analysis with health scores as the dependent variable and other scores as independent variables, indicated that the health scores of males were highly correlated with satisfaction with his body weight, smoking and drinking, and perceived body shape, whereas the females’health scores were highly correlated with obesity level, satisfaction with her body weight, and smoking and drinking.

Development of a Real-Time Measurement System for Horizontal Soil Strength

  • Cho, Yongjin;Lee, Dong Hoon;Park, Wonyeop;Lee, Kyou Seung
    • Journal of Biosystems Engineering
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    • v.40 no.3
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    • pp.165-177
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    • 2015
  • Purpose: Accurate monitoring of soil strength is a key technology applicable to various precision agricultural practices. Soil strength has been traditionally measured using a cone penetrometer, which is time-consuming and expensive, making it difficult to obtain the spatial data required for precision agriculture. To improve the current, inefficient method of measuring soil strength, our objective was to develop and evaluate an in-situ system that could measure horizontal soil strength in real-time, while moving across a soil bin. Methods: Multiple cone-shape penetrometers were horizontally assembled at the front of a vertical plow blade at intervals of 5 cm. Each penetrometer was directly connected to a load cell, which measured loads of 0-2.54 kN. In order to process the digital signals from every individual transducer concurrently, a microcontroller was embedded into the measurement system. Wireless data communication was used between a data storage device and this real-time horizontal soil strength (RHSS) measurement system travelling at 0.5 m/s through an indoor experimental soil bin. The horizontal soil strength index (HSSI) measured by the developed system was compared with the cone index (CI) measured by a traditional cone penetrometer. Results: The coefficient of determination between the CI and the HSSI at depths of 5 cm and 10 cm ($r^2=0.67$ and 0.88, respectively) were relatively less than those measured below 20 cm ($r^2{\geq}0.93$). Additionally, the measured HSSIs were typically greater than the CIs for a given numbers of compactor operations. For an all-depth regression, the coefficient of determination was 0.94, with a RMSE of 0.23. Conclusions: A HSSI measurement system was evaluated in comparison with the conventional soil strength measurement system, CI. Further study is needed, in the form of field tests, on this real-time measurement and control system, which would be applied to precision agriculture.

Examination of Consumer Purchase Intention for Foreign Infant Foods in China (중국에서 외국산 유아식품의 구매의도에 관한 연구)

  • Wu, Shi-Yuan;Yoon, Ki-Chang
    • Journal of Distribution Science
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    • v.15 no.3
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    • pp.49-60
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    • 2017
  • Purpose - The aims of this study are follows. We investigated to find out how country image and brand image affect the consumer perceived value, consumer attitude, and purchase intention of foreign infant foods in China. Especially, we focused on investigate for the moderating role of consumer knowledge between national image, brand image and consumer perceived value of foreign infant foods in China. Research design, data, and methodology - This study analyzed the effect of national image and brand image on purchase intention through consumer perceived value and consumer attitude. This study collected data for empirical analysis of Chinese consumers who have been purchase experience infant foods in China. 256 copies of questionnaire data were used for substantial analysis. Before testing the hypothesis, factor analysis was conducted to test the construct validity of measurement items. Hypotheses about effects between variables were verified using structural equation modeling analysis and hierarchical regression analysis. Results - First, the country image had a positive effect on consumer perceived value of foreign infant foods. Second, the brand image had a positive effect on consumer perceived value of foreign infant foods. Third, the consumer perceived value had a positive effect on consumer attitude. Fourth, the consumer attitude had a positive effect on purchase intention. Fifth, the consumer knowledge was moderating roles between brand image and consumer perceived value of foreign infant foods. However, the consumer knowledge did not effect of moderating between country image and perceived value of consumers. Conclusions - First, the impact of country image and brand image on consumer perceived value of foreign infant foods in China can be seen as a universal psychology of consumers who trust pure foreign products such as high quality, technology, etc. Second, consumer perceived value of foreign infant foods has a positive effect on consumer attitude, and this attitude is leading to purchase intention. Third, the consumer knowledge between brand image and perceived value acts as a moderating variable. It means that the consumer's knowledge can shape the perception of the brand image more strongly.

DESIGN OF A LOAD FOLLOWING CONTROLLER FOR APR+ NUCLEAR PLANTS

  • Lee, Sim-Won;Kim, Jae-Hwan;Na, Man-Gyun;Kim, Dong-Su;Yu, Keuk-Jong;Kim, Han-Gon
    • Nuclear Engineering and Technology
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    • v.44 no.4
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    • pp.369-378
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    • 2012
  • A load-following operation in APR+ nuclear plants is necessary to reduce the need to adjust the boric acid concentration and to efficiently control the control rods for flexible operation. In particular, a disproportion in the axial flux distribution, which is normally caused by a load-following operation in a reactor core, causes xenon oscillation because the absorption cross-section of xenon is extremely large and its effects in a reactor are delayed by the iodine precursor. A model predictive control (MPC) method was used to design an automatic load-following controller for the integrated thermal power level and axial shape index (ASI) control for APR+ nuclear plants. Some tracking controllers employ the current tracking command only. On the other hand, the MPC can achieve better tracking performance because it considers future commands in addition to the current tracking command. The basic concept of the MPC is to solve an optimization problem for generating finite future control inputs at the current time and to implement as the current control input only the first control input among the solutions of the finite time steps. At the next time step, the procedure to solve the optimization problem is then repeated. The support vector regression (SVR) model that is used widely for function approximation problems is used to predict the future outputs based on previous inputs and outputs. In addition, a genetic algorithm is employed to minimize the objective function of a MPC control algorithm with multiple constraints. The power level and ASI are controlled by regulating the control banks and part-strength control banks together with an automatic adjustment of the boric acid concentration. The 3-dimensional MASTER code, which models APR+ nuclear plants, is interfaced to the proposed controller to confirm the performance of the controlling reactor power level and ASI. Numerical simulations showed that the proposed controller exhibits very fast tracking responses.