• Title/Summary/Keyword: Principal Components Regression

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Factors Influencing on Prehospital Emergency Nurses' Activities and Procedures in the Field (병원 전 응급간호사의 응급 처치 수행 능력과 영향 요인)

  • Kim, Bog-Ja;Kang, Kyung-Hee;Lim, Yong-Su
    • Journal of Korean Academy of Nursing Administration
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    • v.15 no.1
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    • pp.64-71
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    • 2009
  • Purpose: This study shows the prehospital emergency nursing practices, and analyzes them associated with their individual characteristics and job conditions. Method: Based on a survey of the National Emergency Medical Center in Korea(2008), principal components were extracted from 7 prehospital emergency nursing practices by factor analysis, and some regression analyses of principal components(CPR-AED and V/S-I.V.) were executed on individual characteristics and job conditions. Results: The PENs gave themselves higher order ratings for vital sign check, airway management for loss of consciousness patients, CPR for suspicious cardiac arrest, keeping vein open for shock patients, AED for abnormal pulse rate, AED for suspicious cardiac arrest, and AED for loss of consciousness. Age and duty periods were statistically significant influential factors on the CPR-AED component. Conclusion: The results indicate that the PENs were competent in overall prehospital emergency activities and procedures even some weak self-evaluations, and that the standard curriculum and practice standard for prehospital nursing should be developed in order to increase nursing leadership in prehospital emergency settings.

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Comparison of Principal Component Regression and Nonparametric Multivariate Trend Test for Multivariate Linkage (다변량 형질의 유전연관성에 대한 주성분을 이용한 회귀방법와 다변량 비모수 추세검정법의 비교)

  • Kim, Su-Young;Song, Hae-Hiang
    • The Korean Journal of Applied Statistics
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    • v.21 no.1
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    • pp.19-33
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    • 2008
  • Linear regression method, proposed by Haseman and Elston(1972), for detecting linkage to a quantitative trait of sib pairs is a linkage testing method for a single locus and a single trait. However, multivariate methods for detecting linkage are needed, when information from each of several traits that are affected by the same major gene are available on each individual. Amos et al. (1990) extended the regression method of Haseman and Elston(1972) to incorporate observations of two or more traits by estimating the principal component linear function that results in the strongest correlation between the squared pair differences in the trait measurements and identity by descent at a marker locus. But, it is impossible to control the probability of type I errors with this method at present, since the exact distribution of the statistic that they use is yet unknown. In this paper, we propose a multivariate nonparametric trend test for detecting linkage to multiple traits. We compared with a simulation study the efficiencies of multivariate nonparametric trend test with those of the method developed by Amos et al. (1990) for quantitative traits data. For multivariate nonparametric trend test, the results of the simulation study reveal that the Type I error rates are close to the predetermined significance levels, and have in general high powers.

Taste Characteristics of Kanjang Made with Barley Bran (보리등겨로 제조한 간장의 맛성분 특성)

  • Son, Dong-Hwa;Kwon, O-Jun;Choi, Ung-Kyu;Kwon, O-Jin;Lee, Suk-Il;Im, Moo-Hyeg;Kwon, Kwang-Il;Kim, Sung-Hong;Chung, Yung-Gun
    • Applied Biological Chemistry
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    • v.45 no.1
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    • pp.18-24
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    • 2002
  • This study was conducted to find out optimum conditions for kanjang fermented with barley bran. The correlation between taste components and sensory evaluation score was analyzed with stepwise multiple regression analysis. It was revealed that the taste of kanjang was explained with the mix of free amino acids, free sugars and organic acids. The highest multiple correlation coefficient was obtained from absolute value transformed with logarithm. Thus, stepwise multiple regression analysis was conducted with absolute value transformed with logarithm, for which F-value was highest and standard error of estimation was lowest among the multiple regression models transformed with six variables. The stepwise multiple regression analysis showed that the taste components which most contribute to the quality of taste of kanjang fermented with barley bran was salty taste component followed by palatable taste component, and bitter taste component.

Functional regression approach to traffic analysis (함수회귀분석을 통한 교통량 예측)

  • Lee, Injoo;Lee, Young K.
    • The Korean Journal of Applied Statistics
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    • v.34 no.5
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    • pp.773-794
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    • 2021
  • Prediction of vehicle traffic volume is very important in planning municipal administration. It may help promote social and economic interests and also prevent traffic congestion costs. Traffic volume as a time-varying trajectory is considered as functional data. In this paper we study three functional regression models that can be used to predict an unseen trajectory of traffic volume based on already observed trajectories. We apply the methods to highway tollgate traffic volume data collected at some tollgates in Seoul, Chuncheon and Gangneung. We compare the prediction errors of the three models to find the best one for each of the three tollgate traffic volumes.

An Efficiency Assessment for Reflectance Normalization of RapidEye Employing BRD Components of Wide-Swath satellite

  • Kim, Sang-Il;Han, Kyung-Soo;Yeom, Jong-Min
    • Korean Journal of Remote Sensing
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    • v.27 no.3
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    • pp.303-314
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    • 2011
  • Surface albedo is an important parameter of the surface energy budget, and its accurate quantification is of major interest to the global climate modeling community. Therefore, in this paper, we consider the direct solution of kernel based bidirectional reflectance distribution function (BRDF) models for retrieval of normalized reflectance of high resolution satellite. The BRD effects can be seen in satellite data having a wide swath such as SPOT/VGT (VEGETATION) have sufficient angular sampling, but high resolution satellites are impossible to obtain sufficient angular sampling over a pixel during short period because of their narrow swath scanning when applying semi-empirical model. This gives a difficulty to run BRDF model inferring the reflectance normalization of high resolution satellites. The principal purpose of the study is to estimate normalized reflectance of high resolution satellite (RapidEye) through BRDF components from SPOT/VGT. We use semi-empirical BRDF model to estimated BRDF components from SPOT/VGT and reflectance normalization of RapidEye. This study used SPOT/VGT satellite data acquired in the S1 (daily) data, and within this study is the multispectral sensor RapidEye. Isotropic value such as the normalized reflectance was closely related to the BRDF parameters and the kernels. Also, we show scatter plot of the SPOT/VGT and RapidEye isotropic value relationship. The linear relationship between the two linear regression analysis is performed by using the parameters of SPOTNGT like as isotropic value, geometric value and volumetric scattering value, and the kernel values of RapidEye like as geometric and volumetric scattering kernel Because BRDF parameters are difficult to directly calculate from high resolution satellites, we use to BRDF parameter of SPOT/VGT. Also, we make a decision of weighting for geometric value, volumetric scattering value and error through regression models. As a result, the weighting through linear regression analysis produced good agreement. For all sites, the SPOT/VGT isotropic and RapidEye isotropic values had the high correlation (RMSE, bias), and generally are very consistent.

Affecting Factors on the Variation of Atmospheric Concentration of Polycyclic Aromatic Hydrocarbons in Central London

  • Baek, Sung-Ok;Roger Perry
    • Journal of Korean Society for Atmospheric Environment
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    • v.10 no.E
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    • pp.343-356
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    • 1994
  • In this study, a statistical investigation was carried out for the evaluation of any relationship between polycyclic aromatic hydrocarbons (PAHss) associated with ambient aerosols and other air quality parameters under varying meteorological conditions. Daily measurements for PAHs and air quality/meteorological parameters were selected from a data-base constructed by a comprehensive air monitoring in London during 1985-1987. Correlation coefficients were calculated to examine any significant relationship between the PAHs and other individual variables. Statistical analysis was further Performed for the air quality/meteorological data set using a principal component analysis to derive important factors inherent in the interactions among the variables. A total of six components were identified, representing vehicle emission, photochemical activity/volatilization, space heating, atmospheric humidity, atmospheric stability, and wet deposition. It was found from a stepwise multiple regression analysis that the vehicle emission component is overall the most important factor contributing to the variability of PAHs concentrations at the monitoring site. The photochemical activity/volatilzation component appeared to be also an important factor particularly for the lower molecular weight PAHs. In general, the space heating component was found to be next important factor, while the contributions of other three components to the variance of each PAHs did not appear to be as much important as the first three components in most cases. However, a consistency for these components in their negative correlations with PAHs data was found, indicating their roles in the depletion of PAHs concentrations in the urban atmosphere.

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Predicting Soil Chemical Properties with Regression Rules from Visible-near Infrared Reflectance Spectroscopy

  • Hong, Suk Young;Lee, Kyungdo;Minasny, Budiman;Kim, Yihyun;Hyun, Byung Keun
    • Korean Journal of Soil Science and Fertilizer
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    • v.47 no.5
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    • pp.319-323
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    • 2014
  • This study investigates the prediction of soil chemical properties (organic matter (OM), pH, Ca, Mg, K, Na, total acidity, cation exchange capacity (CEC)) on 688 Korean soil samples using the visible-near infrared reflectance (VIS-NIR) spectroscopy. Reflectance from the visible to near-infrared spectrum (350 to 2500 nm) was acquired using the ASD Field Spec Pro. A total of 688 soil samples from 168 soil profiles were collected from 2009 to 2011. The spectra were resampled to 10 nm spacing and converted to the 1st derivative of absorbance (log (1/R)), which was used for predicting soil chemical properties. Principal components analysis (PCA), partial least squares regression (PLSR) and regression rules model (Cubist) were applied to predict soil chemical properties. The regression rules model (Cubist) showed the best results among these, with lower error on the calibration data. For quantitatively determining OM, total acidity, CEC, a VIS-NIR spectroscopy could be used as a routine method if the estimation quality is more improved.

An Analysis of the Economic Effects of R&D Investment in the IT Industry (IT산업 연구개발 투자의 경제적 효과 분석)

  • Hong, Jae-Pyo;Choi, Na-Lin;Kim, Pang-Ryong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37B no.9
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    • pp.837-848
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    • 2012
  • This study has conducted the economic effects of R&D investment in the IT industry using multi-regression analysis with three independent variables; capital stock, labor input and R&D stock. In this study, the IT industry has been categorized into three sub-industries; broadcasting communication appliances, information appliances and electronic components industry. Our analysis has found that auto-correlation shows considerable levels whereas figures of t-value and R-square show significant levels among all the IT sub-industries. Meanwhile, the values of R&D stock in the information appliances industry and that of labor input coefficients in the electronic components industry were minus, thus multi-collinearity was suspected. We have solved the problems regarding auto-correlation and multi-collinearity through Cochrane-Orcutt estimation and principal components analysis. This paper has derived the implications that R&D investment in the broadcasting communication industry is much more influential than any other IT sub-industry.

Assessment through Statistical Methods of Water Quality Parameters(WQPs) in the Han River in Korea

  • Kim, Jae Hyoun
    • Journal of Environmental Health Sciences
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    • v.41 no.2
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    • pp.90-101
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    • 2015
  • Objective: This study was conducted to develop a chemical oxygen demand (COD) regression model using water quality monitoring data (January, 2014) obtained from the Han River auto-monitoring stations. Methods: Surface water quality data at 198 sampling stations along the six major areas were assembled and analyzed to determine the spatial distribution and clustering of monitoring stations based on 18 WQPs and regression modeling using selected parameters. Statistical techniques, including combined genetic algorithm-multiple linear regression (GA-MLR), cluster analysis (CA) and principal component analysis (PCA) were used to build a COD model using water quality data. Results: A best GA-MLR model facilitated computing the WQPs for a 5-descriptor COD model with satisfactory statistical results ($r^2=92.64$,$Q{^2}_{LOO}=91.45$,$Q{^2}_{Ext}=88.17$). This approach includes variable selection of the WQPs in order to find the most important factors affecting water quality. Additionally, ordination techniques like PCA and CA were used to classify monitoring stations. The biplot based on the first two principal components (PCs) of the PCA model identified three distinct groups of stations, but also differs with respect to the correlation with WQPs, which enables better interpretation of the water quality characteristics at particular stations as of January 2014. Conclusion: This data analysis procedure appears to provide an efficient means of modelling water quality by interpreting and defining its most essential variables, such as TOC and BOD. The water parameters selected in a COD model as most important in contributing to environmental health and water pollution can be utilized for the application of water quality management strategies. At present, the river is under threat of anthropogenic disturbances during festival periods, especially at upstream areas.

A Study on the Prediction of Fuel Consumption of a Ship Using the Principal Component Analysis (주성분 분석기법을 이용한 선박의 연료소비 예측에 관한 연구)

  • Kim, Young-Rong;Kim, Gujong;Park, Jun-Bum
    • Journal of Navigation and Port Research
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    • v.43 no.6
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    • pp.335-343
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    • 2019
  • As the regulations of ship exhaust gas have been strengthened recently, many measures are under consideration to reduce fuel consumption. Among them, research has been performed actively to develop a machine-learning model that predicts fuel consumption by using data collected from ships. However, many studies have not considered the methodology of the main parameter selection for the model or the processing of the collected data sufficiently, and the reckless use of data may cause problems such as multicollinearity between variables. In this study, we propose a method to predict the fuel consumption of the ship by using the principal component analysis to solve these problems. The principal component analysis was performed on the operational data of the 13K TEU container ship and the fuel consumption prediction model was implemented by regression analysis with extracted components. As the R-squared value of the model for the test data was 82.99%, this model would be expected to support the decision-making of operators in the voyage planning and contribute to the monitoring of energy-efficient operation of ships during voyages.