Relevant bibliographies by topics / Backward stepwise / Journal articles

To see the other types of publications on this topic, follow the link: Backward stepwise.

Journal articles on the topic 'Backward stepwise'

Author: Grafiati

Published: 4 June 2021

Last updated: 6 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'Backward stepwise.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

Ribon, Adriana Aparecida, João Tavares Filho, Kathleen Lourenço Fernandes, and Victor Talles Lourenceti Hermógenes. "SELEÇÃO DE MÉTODO ESTATÍSTICO PARA MODELOS DE ESTIMATIVA DA QUALIDADE FÍSICA DE SOLOS ARGILOSOS." BRAZILIAN JOURNAL OF AGRICULTURE - Revista de Agricultura 89, no. 1 (2014): 29. http://dx.doi.org/10.37856/bja.v89i1.100.

Full text

Abstract:

Foram selecionados três métodos estatísticos (“Stepwise, Backward” e “Forward”) para a escolha do melhor na obtenção de modelos para estimativa da qualidade física de um Latossolo Vermelho Eutroférrico sob cultura perene e um Latossolo Vermelho Distroférrico sob plantio direto. O método “Stepwise” foi o mais adequado na obtenção dos modelos finais para estimativa da qualidade física do Latossolo Vermelho Eutroférrico sob cultura perene. Os três procedimentos (“Stepwise, Forward” e “Backward”) foram adequados na obtenção dos modelos finais para a estimativa da qualidade física do Latossolo Vermelho Distroférrico sob plantio direto.

APA, Harvard, Vancouver, ISO, and other styles

Afiqah Muhamad Jamil, Siti, Mohd Asrul Affendi Abdullah, Kek Sie Long, Nur Fazilla Mohd Jupri, and Mustafa Mamat. "A Stepwise Logistic Regression Analysis: An application toward Poultry Farm Data in Johor." International Journal of Engineering & Technology 7, no. 3.28 (2018): 68. http://dx.doi.org/10.14419/ijet.v7i3.28.20968.

Full text

Abstract:

The aims of this study are to fit a logistic regression model towards the fly problem in a farm and to identify the variables that are associated with the fly problem in a poultry farm. By using SPSS software, this study used ‘FORWARD STEPWISE’ and ‘BACKWARD STEPWISE’ methods to perform the analysis. Compared to linear regression analysis, logistic regression does not require rigorous assumptions to be met. This study used Likelihood Ratio test, Omnibus test and Hosmer and Lemeshow test to validate and to test the fit of poultry farm data. Akaike Information Criterion (AIC) is calculated to observe the difference between the methods of stepwise used by SPSS software in this study. As a result, logistic regression is fit towards poultry farm data by a stepwise procedure. BACKWARD STEPWISE seems to be more suitable for conducting the stepwise method of analysis. Besides, variables that influence the problem of fly in a poultry are the wasps, distance and number of flies.

APA, Harvard, Vancouver, ISO, and other styles

Chang, T. H., and S. H. Chen. "Stepwise frequency tuning of a gyrotron backward-wave oscillator." Physics of Plasmas 12, no. 1 (2005): 013104. http://dx.doi.org/10.1063/1.1827217.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Fang, Chunsheng, Jialu Gao, Dali Wang, Diansheng Wang, and Ju Wang. "Optimization of stepwise clustering algorithm in backward trajectory analysis." Neural Computing and Applications 32, no. 1 (2018): 109–15. http://dx.doi.org/10.1007/s00521-018-3782-9.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Trong, Dang Duc, Dinh Nguyen Duy Hai, and Nguyen Dang Minh. "Stepwise regularization method for a nonlinear Riesz–Feller space-fractional backward diffusion problem." Journal of Inverse and Ill-posed Problems 27, no. 6 (2019): 759–75. http://dx.doi.org/10.1515/jiip-2018-0033.

Full text

Abstract:

Abstract In this paper, we consider the backward diffusion problem for a space-fractional diffusion equation (SFDE) with a nonlinear source, that is, to determine the initial data from a noisy final data. Very recently, some papers propose new modified regularization solutions to solve this problem. To get a convergence estimate, they required some strongly smooth conditions on the exact solution. In this paper, we shall release the strongly smooth conditions and introduce a stepwise regularization method to solve the backward diffusion problem. A numerical example is presented to illustrate our theoretical result.

APA, Harvard, Vancouver, ISO, and other styles

Henderson, Douglas A., and Daniel R. Denison. "Stepwise Regression in Social and Psychological Research." Psychological Reports 64, no. 1 (1989): 251–57. http://dx.doi.org/10.2466/pr0.1989.64.1.251.

Full text

Abstract:

Researchers often invoke stepwise ordinary least squares regression to explain, predict or classify practical problems or theoretical constructs in psychological and social research. Unfortunately, this statistical technique is used without proper consideration for its inherent theoretical and practical limitations, a problem expected to grow even more serious with the proliferation of statistical packages for use on personal computers. Use of stepwise regression in social and psychological research is reconsidered here. Explanations of forward selection, backward elimination and combination stepwise procedures are provided; limitations of the technique, statistical and practical, are then addressed. Analysis shows that most of the current applications of stepwise regression should be rejected, or at least tempered with strong qualification to inference.

APA, Harvard, Vancouver, ISO, and other styles

Wojszel, Zyta Beata. "Impending Low Intake Dehydration at Admission to A Geriatric Ward- Prevalence and Correlates in a Cross-Sectional Study." Nutrients 12, no. 2 (2020): 398. http://dx.doi.org/10.3390/nu12020398.

Full text

Abstract:

Dehydration risk increases with frailty and functional dependency, but a limited number of studies have evaluated this association in hospitalized geriatric patients. This cross-sectional study aimed to assess the prevalence and determinants of dehydration in patients admitted to the geriatric ward. Dehydration was diagnosed when calculated osmolarity was above 295 mMol/L. Logistic regression analyses (direct and stepwise backward) were used to assess determinants of impending dehydration. 358 of 416 hospitalized patients (86.1%) were included: 274 (76.5%) women, and 309 (86.4%) 75+ year-old. Dehydration was diagnosed in 209 (58.4%) cases. Significantly higher odds for impending dehydration were observed only for chronic kidney disease with trends for diabetes and procognitive medication when controlling for several health, biochemical, and nutritional parameters and medications. After adjusting for “dementia” the negative effect of “taking procognitive medications” became a significant one. Chronic kidney disease, diabetes, taking procognitive medications and hypertension were the main variables for the outcome prediction according to the stepwise backward regression analysis. This may indicate an additional benefit of reducing the risk of dehydration when using procognitive drugs in older patients with dementia.

APA, Harvard, Vancouver, ISO, and other styles

Quyen, Nguyen The, Michel D. Jouan, Nguyen Quy Dao, Edouard Da Silva, and Duong Ai Phuong. "New Raman Spectrometer Using a Digital Micromirror Device and a Photomultiplier Tube Detector for Rapid On-Line Industrial Analysis. Part II: Choice of Analytical Methods." Applied Spectroscopy 62, no. 3 (2008): 279–84. http://dx.doi.org/10.1366/000370208783759713.

Full text

Abstract:

In this paper, the performances of four improved analytical methods (backward stepwise selection of peak intensities, sum of characteristic peaks of a component, moving window partial least squares, and genetic algorithms) using wavelength selection for the analysis of xylene mixtures by Raman spectroscopy are tested for further use on the new “digital micromirror device associated with a photomultiplier tube” Raman spectrometer. It is shown that the errors of prediction using only a few selected points (from 4 to 49 depending on the method) are almost the same as when using the whole spectral range (1050 points). Compared to the last two methods, the “backward stepwise selection of peak intensities” and “sum of characteristic peaks of a component” methods are robust under industrial conditions and appear to be well suited for chemical quantitative analysis with the new Raman spectrometer, which allows the measurements of the total intensity to be made simultaneously for a number of pre-selected frequencies. Results show that the errors of prediction can be near to or even lower than 2%.

APA, Harvard, Vancouver, ISO, and other styles

Laborda, Juan, and Seyong Ryoo. "Feature Selection in a Credit Scoring Model." Mathematics 9, no. 7 (2021): 746. http://dx.doi.org/10.3390/math9070746.

Full text

Abstract:

This paper proposes different classification algorithms—logistic regression, support vector machine, K-nearest neighbors, and random forest—in order to identify which candidates are likely to default for a credit scoring model. Three different feature selection methods are used in order to mitigate the overfitting in the curse of dimensionality of these classification algorithms: one filter method (Chi-squared test and correlation coefficients) and two wrapper methods (forward stepwise selection and backward stepwise selection). The performances of these three methods are discussed using two measures, the mean absolute error and the number of selected features. The methodology is applied for a valuable database of Taiwan. The results suggest that forward stepwise selection yields superior performance in each one of the classification algorithms used. The conclusions obtained are related to those in the literature, and their managerial implications are analyzed.

APA, Harvard, Vancouver, ISO, and other styles

Wang, Qinggang, John J. Koval, Catherine A. Mills, and Kang-In David Lee. "Determination of the Selection Statistics and Best Significance Level in Backward Stepwise Logistic Regression." Communications in Statistics - Simulation and Computation 37, no. 1 (2007): 62–72. http://dx.doi.org/10.1080/03610910701723625.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Hsu, Fang-Chen, Chien-Nan Chen, and Meng-Dar Shieh. "Using stepwise backward elimination to specify terms related to tactile sense for product design." Advanced Engineering Informatics 46 (October 2020): 101193. http://dx.doi.org/10.1016/j.aei.2020.101193.

Full text

APA, Harvard, Vancouver, ISO, and other styles

A., Ademuyiwa J., and Adetunji A. A. "Impact of Some Economic Variables on the Real Gross Domestic Product of Nigeria." Budapest International Research and Critics Institute (BIRCI-Journal) : Humanities and Social Sciences 2, no. 4 (2019): 12–19. http://dx.doi.org/10.33258/birci.v2i4.563.

Full text

Abstract:

The influences of External Debt Service (EDS), External Debt Stock (EDSt), Government Expenditure (GE), Inflation Rate (InfR), Interest Rate (IntR) and Exchange Rate (ExR) of Nigeria on the Real Gross Domestic Product (RGDP) are examined. Results of the analysis using Stepwise Regression (Backward Elimination and Forward Selection) reveals that GE, EDS, and IntR have positive significant contributions to the RGDP of the country compared to other variables considered.

APA, Harvard, Vancouver, ISO, and other styles

Hasan, M. N. "Factors Associated with Attrition of Girls Students from School in Bangladesh." Journal of Scientific Research 12, no. 1 (2020): 29–38. http://dx.doi.org/10.3329/jsr.v12i1.41579.

Full text

Abstract:

Many girls who enrolled in a school but didn’t complete elementary or secondary education, have become a serious problem in the last few decades in Bangladesh. Several studies have been conducted to identify the determinants of school dropout by constructing bivariate and multiple logistic regression (MLR) model. Bangladesh multiple indicator cluster surveys (MICS) 2012 data were selected in this investigation. This study was based on girls aged between 15 and 17 years since all these girls should have been in school or have completed primary education. The backward stepwise method was used for model selection and fitting to the dataset. From 4800 girls, 29.1% were out of school and 70.9% were attending school. Backward stepwise method confirmed that girl’s marital status, area, division, wealth index, religion, mothers and father’s aliveness and household education were the major reasons of girl’s dropout and these covariates are only considered in the analysis. The MLR analysis showed that married girls were significantly (OR 11.06; 95% CI 9.05–13.56) more likely to attrition compared to unmarried girls. School-based programs aimed at preventing child marriage should target girls from the fifth grade because of their escalated risk, and they need to prioritize girls from disadvantaged groups.

APA, Harvard, Vancouver, ISO, and other styles

Carasso, Alfred S. "Stabilized Richardson leapfrog scheme in explicit stepwise computation of forward or backward nonlinear parabolic equations." Inverse Problems in Science and Engineering 25, no. 12 (2017): 1719–42. http://dx.doi.org/10.1080/17415977.2017.1281270.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Derksen, Shelley, and H. J. Keselman. "Backward, forward and stepwise automated subset selection algorithms: Frequency of obtaining authentic and noise variables." British Journal of Mathematical and Statistical Psychology 45, no. 2 (1992): 265–82. http://dx.doi.org/10.1111/j.2044-8317.1992.tb00992.x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Cultrera, Loredana, and Bauweraerts Jonathan. "Exploring Corporate Bankruptcy in Belgian Private Firms." International Journal of Economics and Finance 9, no. 3 (2017): 108. http://dx.doi.org/10.5539/ijef.v9n3p108.

Full text

Abstract:

The main purpose of this paper is to identify the financial antecedents of corporate bankruptcy by employing a robust variable selection procedure. Based on a sample of 1,338 Belgian private firms, a backward stepwise logistic regression technique is employed. The findings indicate that the likelihood of corporate bankruptcy is higher at lower levels of solvency, liquidity and profitability. Furthermore, our results reveal that corporate bankruptcy is more likely in older and larger firms.

APA, Harvard, Vancouver, ISO, and other styles

Rahman, Md Siddiqur, and Jafar A. Khan. "Building a Robust Linear Model with Backward Elimination Procedure." Dhaka University Journal of Science 62, no. 2 (2015): 87–93. http://dx.doi.org/10.3329/dujs.v62i2.21971.

Full text

Abstract:

For building a linear prediction model, Backward Elimination (BE) is a computationally suitable stepwise procedure for sequencing the candidate predictors. This method yields poor results when data contain outliers and other contaminations. Robust model selection procedures, on the other hand, are not computationally efficient or scalable to large dimensions, because they require the fitting of a large number of submodels. Robust version of BE is proposed in this study, which is computationally very suitable and scalable to large high-dimensional data sets. Since BE can be expressed in terms of sample correlations, simple robustifications are obtained by replacing these correlations by their robust counterparts. A pairwise approach is used to construct the robust correlation matrix -- not only because of its computational advantages over the d-dimensional approach, but also because the pairwise approach is more consistent with the idea of step-by-step algorithms. The performance of the proposed robust method is much better than standard BE. DOI: http://dx.doi.org/10.3329/dujs.v62i2.21971 Dhaka Univ. J. Sci. 62(2): 87-93, 2014 (July)

APA, Harvard, Vancouver, ISO, and other styles

Li, Jijun, Xiaomin Fang, Chunhui Song, Baotian Pan, Yuzhen Ma, and Maodu Yan. "Late Miocene–Quaternary rapid stepwise uplift of the NE Tibetan Plateau and its effects on climatic and environmental changes." Quaternary Research 81, no. 3 (2014): 400–423. http://dx.doi.org/10.1016/j.yqres.2014.01.002.

Full text

Abstract:

AbstractThe way in which the NE Tibetan Plateau uplifted and its impact on climatic change are crucial to understanding the evolution of the Tibetan Plateau and the development of the present geomorphology and climate of Central and East Asia. This paper is not a comprehensive review of current thinking but instead synthesises our past decades of work together with a number of new findings. The dating of Late Cenozoic basin sediments and the tectonic geomorphology of the NE Tibetan Plateau demonstrates that the rapid persistent rise of this plateau began ~8 ± 1 Ma followed by stepwise accelerated rise at ~3.6 Ma, 2.6 Ma, 1.8–1.7 Ma, 1.2–0.6 Ma and 0.15 Ma. The Yellow River basin developed at ~1.7 Ma and evolved to its present pattern through stepwise backward-expansion toward its source area in response to the stepwise uplift of the plateau. High-resolution multi-climatic proxy records from the basins and terrace sediments indicate a persistent stepwise accelerated enhancement of the East Asian winter monsoon and drying of the Asian interior coupled with the episodic tectonic uplift since ~8 Ma and later also with the global cooling since ~3.2 Ma, suggesting a major role for tectonic forcing of the cooling.

APA, Harvard, Vancouver, ISO, and other styles

Williams, Valerie J., Takashi Nagai, Timothy C. Sell, et al. "Prediction of Dynamic Postural Stability During Single-Leg Jump Landings by Ankle and Knee Flexibility and Strength." Journal of Sport Rehabilitation 25, no. 3 (2016): 266–72. http://dx.doi.org/10.1123/jsr.2015-0001.

Full text

Abstract:

Context:Dynamic postural stability is important for injury prevention, but little is known about how lower-extremity musculoskeletal characteristics (range of motion [ROM] and strength) contribute to dynamic postural stability. Knowing which modifiable physical characteristics predict dynamic postural stability can help direct rehabilitation and injury-prevention programs.Objective:To determine if trunk, hip, knee, and ankle flexibility and strength variables are significant predictors of dynamic postural stability during single-leg jump landings.Design:Cross-sectional study.Setting:Laboratory.Participants:94 male soldiers (age 28.2 ± 6.2 y, height 176.5 ± 2.6 cm, weight 83.7 ± 26.0 kg).Intervention:None.Main Outcome Measures:Ankle-dorsiflexion and plantar-flexion ROM were assessed with a goniometer. Trunk, hip, knee, and ankle strength were assessed with an isokinetic dynamometer or handheld dynamometer. The Dynamic Postural Stability Index (DPSI) was used to quantify postural stability. Simple linear and backward stepwise-regression analyses were used to identify which physical characteristic variables were significant predictors of DPSI.Results:Simple linear-regression analysis revealed that individually, no variables were significant predictors of the DPSI. Stepwise backward-regression analysis revealed that ankle-dorsiflexion flexibility, ankle-inversion and -eversion strength, and knee-flexion and -extension strength were significant predictors of the DPSI (R2 = .19, P = .0016, adjusted R2 = .15).Conclusion:Ankle-dorsiflexion ROM, ankle-inversion and -eversion strength, and knee-flexion and -extension strength were identified as significant predictors of dynamic postural stability, explaining a small amount of the variance in the DPSI.

APA, Harvard, Vancouver, ISO, and other styles

Matsumoto, Ryo, Shinkichi Sawa, and Hiroshi Utsunomiya. "Cold Backward Extrusion of Titanium Billet with Pulsating Lubricant Supply on Servo Press." Key Engineering Materials 504-506 (February 2012): 381–86. http://dx.doi.org/10.4028/www.scientific.net/kem.504-506.381.

Full text

Abstract:

To prevent seizure in backward extrusion of holes for lightweight structural components, an extrusion method utilizing a punch having an internal channel for supplying liquid lubricant to the punch nose was applied to forming of pure titanium billet using a servo press. On the servo press, the punch was pushed into the billet in a manner combining pulsed and stepwise modes. The sufficient amount of the liquid lubricant was pulsating supplied to the cavity formed at the bottom of the hole. Appropriate punch ram motion and forming limit for preventing seizure are determined from the surface observation of the formed hole and the punch.

APA, Harvard, Vancouver, ISO, and other styles

Joseph, Shijo, K. Anitha, V. K. Srivastava, Ch Sudhakar Reddy, A. P. Thomas, and M. S. R. Murthy. "Rainfall and Elevation Influence the Local-Scale Distribution of Tree Community in the Southern Region of Western Ghats Biodiversity Hotspot (India)." International Journal of Forestry Research 2012 (2012): 1–10. http://dx.doi.org/10.1155/2012/576502.

Full text

Abstract:

The present study characterises the tree communities with respect to topographic and climatic variables and identifies the most important environmental correlate of species richness in the southern region of Western Ghats Biodiversity Hotspot, India. Digitally derived environmental variables in combination with tree species richness information were analysed using Canonical Correspondence Analysis (CCA) to characterise the communities. Multiple regression technique based on stepwise backward elimination was used to identify the most important environment correlate of species richness. Canonical correspondence analysis results in six major tree communities along the first and second axes. Rainfall is the dominant environmental gradient influencing vegetation patterns on the first CCA axis while elevation showed the highest correlation with the second CCA axis. Backward elimination regression technique yielded rainfall as the most important environmental correlate of species richness. Results were in agreement with the observations in the Neotropics that rainier areas maintain high species diversity.

APA, Harvard, Vancouver, ISO, and other styles

Brenning, A. "Spatial prediction models for landslide hazards: review, comparison and evaluation." Natural Hazards and Earth System Sciences 5, no. 6 (2005): 853–62. http://dx.doi.org/10.5194/nhess-5-853-2005.

Full text

Abstract:

Abstract. The predictive power of logistic regression, support vector machines and bootstrap-aggregated classification trees (bagging, double-bagging) is compared using misclassification error rates on independent test data sets. Based on a resampling approach that takes into account spatial autocorrelation, error rates for predicting "present" and "future" landslides are estimated within and outside the training area. In a case study from the Ecuadorian Andes, logistic regression with stepwise backward variable selection yields lowest error rates and demonstrates the best generalization capabilities. The evaluation outside the training area reveals that tree-based methods tend to overfit the data.

APA, Harvard, Vancouver, ISO, and other styles

Dantas, Régis Façanha, and Sérgio Aquino DeSouza. "Modelo de risco e decisão de crédito baseado em estrutura de capital com informação assimétrica." Pesquisa Operacional 28, no. 2 (2008): 263–84. http://dx.doi.org/10.1590/s0101-74382008000200006.

Full text

Abstract:

A partir de uma amostra 241 empresas da Indústria Manufatureira brasileira, concluímos que parâmetros que definem a estrutura de capital das empresas são bons sinalizadores para discriminar as empresas quanto ao seu risco de crédito em um ambiente de informação assimétrica. Para chegar a tal resultado, usamos uma equação regressão do tipo Logit, cujas variáveis explicativas são oriundas da análise fatorial e da regressão discriminante através do método stepwise backward. Outro ponto importante é a incorporação de um modelo de decisão de crédito com o uso de programação Linear Inteira como o desenvolvido por Gehrlein & Wagner (1997).

APA, Harvard, Vancouver, ISO, and other styles

Hasan, Muhammad, Dumilah Ayuningtyas, and Misnaniarti Misnaniarti. "Good Corporate Governance Implementation and Performance of Civil Servant." Kesmas: National Public Health Journal 11, no. 1 (2016): 20. http://dx.doi.org/10.21109/kesmas.v11i1.855.

Full text

Abstract:

In order to achieve the vision and mission, every hospital must implement Good Corporate Governance (GCG). Its implementation aims to optimally improve performance of employees that will finally improve organizational performance. This study aimed to analyze the relation between principles of GCG and performance of civil servants of the Natuna Field Hospital in Anambas Islands District. This analytical descriptive study using cross sectional design involved 56 civil servants as samples. Data was collected in 2012 using a structured questionnaire. This study used chi square and logistic regression tests. Multivariate model was simplified by eliminating the confounding variables using backward stepwise method. This study found two variables significantly related to performance of civil servants, namely implementation of fairness and transperancy principles. Both were the most related variables to the performance of civil servants.AbstrakDalam rangka mencapai visi dan misi, setiap rumah sakit harus menjalankan tata kelola perusahaan yang baik (Good Corporate Governance/GCG). Penerapan GCG sendiri bertujuan untuk meningkatkan kinerja pegawai secara optimal, yang akhirnya akan meningkatkan kinerja organisasi. Penelitian ini bertujuan untuk menganalisis hubungan penerapan prinsip-prinsip GCG terhadap kinerja pegawai negeri sipil (PNS) Rumah Sakit Umum Lapangan Natuna Kabupaten Kepulauan Anambas. Jenis penelitian ini adalah deskriptif analitik dengan desain potong lintang pada 56 PNS. Pengumpulan data dilakukan pada tahun 2012 dengan kuesioner terstruktur. Digunakan analisis dengan uji kai kuadrat dan regresi logistik, dan untuk penyederhanaan model dilakukan eliminasi terhadap faktor perancu dengan menggunakan metode backward stepwise. Penelitian ini menemukan dua variabel yang signifikan berhubungan dengan kinerja PNS, yaitu penerapan prinsip fairness dan penerapan prinsip transparancy. Keduanya merupakan variabel yang paling berhubungan dengan kinerja pegawai negeri sipil.

APA, Harvard, Vancouver, ISO, and other styles

Wittens, Mandy Melissa Jane, Diana Maria Sima, Ruben Houbrechts, et al. "Diagnostic Performance of Automated MRI Volumetry by icobrain dm for Alzheimer’s Disease in a Clinical Setting: A REMEMBER Study." Journal of Alzheimer's Disease 83, no. 2 (2021): 623–39. http://dx.doi.org/10.3233/jad-210450.

Full text

Abstract:

Background: Magnetic resonance imaging (MRI) has become important in the diagnostic work-up of neurodegenerative diseases. icobrain dm, a CE-labeled and FDA-cleared automated brain volumetry software, has shown potential in differentiating cognitively healthy controls (HC) from Alzheimer’s disease (AD) dementia (ADD) patients in selected research cohorts. Objective: This study examines the diagnostic value of icobrain dm for AD in routine clinical practice, including a comparison to the widely used FreeSurfer software, and investigates if combined brain volumes contribute to establish an AD diagnosis. Methods: The study population included HC (n = 90), subjective cognitive decline (SCD, n = 93), mild cognitive impairment (MCI, n = 357), and ADD (n = 280) patients. Through automated volumetric analyses of global, cortical, and subcortical brain structures on clinical brain MRI T1w (n = 820) images from a retrospective, multi-center study (REMEMBER), icobrain dm’s (v.4.4.0) ability to differentiate disease stages via ROC analysis was compared to FreeSurfer (v.6.0). Stepwise backward regression models were constructed to investigate if combined brain volumes can differentiate between AD stages. Results: icobrain dm outperformed FreeSurfer in processing time (15–30 min versus 9–32 h), robustness (0 versus 67 failures), and diagnostic performance for whole brain, hippocampal volumes, and lateral ventricles between HC and ADD patients. Stepwise backward regression showed improved diagnostic accuracy for pairwise group differentiations, with highest performance obtained for distinguishing HC from ADD (AUC = 0.914; Specificity 83.0%; Sensitivity 86.3%). Conclusion: Automated volumetry has a diagnostic value for ADD diagnosis in routine clinical practice. Our findings indicate that combined brain volumes improve diagnostic accuracy, using real-world imaging data from a clinical setting.

APA, Harvard, Vancouver, ISO, and other styles

Badshah, Waqar, and Mehmet Bulut. "Model Selection Procedures in Bounds Test of Cointegration: Theoretical Comparison and Empirical Evidence." Economies 8, no. 2 (2020): 49. http://dx.doi.org/10.3390/economies8020049.

Full text

Abstract:

Only unstructured single-path model selection techniques, i.e., Information Criteria, are used by Bounds test of cointegration for model selection. The aim of this paper was twofold; one was to evaluate the performance of these five routinely used information criteria {Akaike Information Criterion (AIC), Akaike Information Criterion Corrected (AICC), Schwarz/Bayesian Information Criterion (SIC/BIC), Schwarz/Bayesian Information Criterion Corrected (SICC/BICC), and Hannan and Quinn Information Criterion (HQC)} and three structured approaches (Forward Selection, Backward Elimination, and Stepwise) by assessing their size and power properties at different sample sizes based on Monte Carlo simulations, and second was the assessment of the same based on real economic data. The second aim was achieved by the evaluation of the long-run relationship between three pairs of macroeconomic variables, i.e., Energy Consumption and GDP, Oil Price and GDP, and Broad Money and GDP for BRICS (Brazil, Russia, India, China and South Africa) countries using Bounds cointegration test. It was found that information criteria and structured procedures have the same powers for a sample size of 50 or greater. However, BICC and Stepwise are better at small sample sizes. In the light of simulation and real data results, a modified Bounds test with Stepwise model selection procedure may be used as it is strongly theoretically supported and avoids noise in the model selection process.

APA, Harvard, Vancouver, ISO, and other styles

TENGKU IBRAHIM, TENGKU NILAM BAIZURA, FARIDAH OTHMAN, NOOR ZALINA MAHMOOD, and TAHER ABUNAMA. "Seasonal Effects on Spatial Variations of Surface Water Quality in a Tropical River Receiving Anthropogenic Influences." Sains Malaysiana 50, no. 3 (2021): 571–93. http://dx.doi.org/10.17576/jsm-2021-5003-02.

Full text

Abstract:

This study investigates the seasonal and spatial water quality patterns along a tropical river that continuously receives various pollution sources. Multivariate analysis was used to study the spatial and temporal variations of the water quality parameters and to determine the origin of the pollution sources. Three regions (low, moderate, and high pollution levels) were determined based on cluster analysis. The stepwise DA mode proposed six parameters (pH, EC, COD, NO3, TC, and Fe) with 75% correct assignations as the most significant water quality parameters to present the spatial variations. In the temporal discrimination, forward stepwise mode analysis showed eight parameters (EC, TUR, BOD,COD, AN, NO3, Cu, and Cr) with 92% correct assignations, while five parameters (EC, AN, Al, Cu, and Cr) affording 89% correct assignations in backward stepwise mode analysis. Principal component analysis and factor analysis were used to investigate the origins of each water quality parameter based on the three clustered regions and successfully yielded eight latent factors loadings for each period that significantly identified the pollution sources and types along the river. The pollution sources for moderate and high pollution level areas are anthropogenic sources (landfill, industrial activities, and sewage discharge). Agricultural runoff is the main pollution source for the low pollution level areas. This study has shown classifications of river water quality based on seasonal and spatial criteria.

APA, Harvard, Vancouver, ISO, and other styles

Yan, Yongquan, and Ping Guo. "Predicting Software Abnormal State by using Classification Algorithm." Journal of Database Management 27, no. 2 (2016): 49–65. http://dx.doi.org/10.4018/jdm.2016040103.

Full text

Abstract:

Software aging, also called smooth degradation or chronics, has been observed in a long running software application, accompanied by performance degradation, hang/crash failures or both. The key for software aging problem is how to fast and accurately detect software aging occurrence, which is a hard work due to the long delay before aging appearance. In this paper, two problems about software aging prediction are solved, which are how to accurately find proper running software system variables to represent system state and how to predict software aging state in a running software system with a minor error rate. Firstly, the authors use proposed stepwise forward selection algorithm and stepwise backward selection algorithm to find a proper subset of variables set. Secondly, a classification algorithm is used to model software aging process. Lastly, t-test with k-fold cross validation is used to compare performance of two classification algorithms. In the experiments, the authors find that their proposed method is an efficient way to forecast software aging problems in advance.

APA, Harvard, Vancouver, ISO, and other styles

Adamczewska, Katarzyna, Marzena Wiernicka, Ewa Kamińska, Joanna Małecka, Agata Dąbrowska, and Ewa Malchrowicz-Mośko. "Annual Observation of Changes in the Angle of Trunk Rotation. Trunk Asymmetry Predictors. A Study from a Scoliosis Screening in School Adolescents." International Journal of Environmental Research and Public Health 17, no. 6 (2020): 1899. http://dx.doi.org/10.3390/ijerph17061899.

Full text

Abstract:

Adolescent forms of idiopathic scoliosis are commonly encountered deformities of the thoracic and lumbar spine. They affect a significant number of adolescents, yet their cause is still unknown. The presented research is a cross-sectional analysis of 3933 volunteers (2131 girls and 1802 boys). The participants were primary school students aged 9 to 13 years old. This study determined a relationship between predictors such as: body mass, body height and body mass index (BMI) (independent variables) and angle of trunk rotation (ATR) value (dependent variable). Moreover, a stepwise multiple regression with backward selection was conducted to determine to what extent the dependent variable is explained by body mass, body height and BMI. In the group of 11,12,13-year-old girls, the analyzed results of multiple stepwise regression were statistically significant. Among the all studied predictors, it has been shown that body mass in the 11-year-old girls and body height in 12- and 13-year-old girls are major correlates of a 1-year ATR increase in proximal and main thoracic spine levels.

APA, Harvard, Vancouver, ISO, and other styles

Shanmuganathan Dhameeth, Gehan. "Predictive Modeling of the Brand Equity: Analysis Based on Multiple Logistic Regression and Backward Stepwise Model Selection Methods." International Journal of Data Science and Analysis 5, no. 4 (2019): 67. http://dx.doi.org/10.11648/j.ijdsa.20190504.13.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Andrade, Fernanda Helena Nascimento, Ceres Duarte Guedes Cabral de Almeida, Brivaldo Gomes de Almeida, João Audifax Cézar Albuquerque Filho, Bruno Campos Mantovanelli, and José Coelho Araújo Filho. "ATRIBUTOS FÍSICO-HÍDRICOS DO SOLO VIA FUNÇÕES DE PEDOTRANSFERÊNCIA EM SOLOS DOS TABULEIROS COSTEIROS DE PERNAMBUCO." IRRIGA 25, no. 1 (2020): 69–86. http://dx.doi.org/10.15809/irriga.2020v25n1p69-86.

Full text

Abstract:

ATRIBUTOS FÍSICO-HÍDRICOS DO SOLO VIA FUNÇÕES DE PEDOTRANSFERÊNCIA EM SOLOS DOS TABULEIROS COSTEIROS DE PERNAMBUCO  FERNANDA HELENA NASCIMENTO DE ANDRADE1; CERES DUARTE GUEDES CABRAL DE ALMEIDA2; BRIVALDO GOMES DE ALMEIDA3; JOSÉ AUDIFAX CÉZAR DE ALBUQUERQUE FILHO1; BRUNO CAMPOS MANTOVANELLI4 E JOSÉ COELHO DE ARAÚJO FILHO5  1 Departamento de Engenharia Agrícola, Programa de Pós-Graduação em Engenharia Agrícola da Universidade Federal Rural de Pernambuco - UFRPE, Rua Dom Manuel de Medeiros, S/N, Dois Irmãos, CEP: 52171-900, Recife, PE, Brasil, fernanda_andrade89@hotmail.com, jaudifax@deagri.ufrpe.br 2 Colégio Agrícola Dom Agostinho Ikas, Programa de Pós-Graduação em Engenharia Agrícola da Universidade Federal Rural de Pernambuco - UFRPE, Rua Dom Manuel de Medeiros, S/N, Dois Irmãos, CEP: 52171-900, Recife, PE, Brasil, ceres.codai.ufrpe@gmail.com. 3 Departamento de Agronomia, Programa de Pós-Graduação em Ciência do Solo da Universidade Federal Rural de Pernambuco - UFRPE, Rua Dom Manuel de Medeiros, S/N, Dois Irmãos, CEP: 52171-900, Recife, PE, Brasil, brivaldoalmeida@gmail.com. 4 Departamento de Ciências Rurais, Programa de Pós-Graduação em Ciência do Solo da Universidade Federal de Santa Maria - UFSM, Avenida Roraima, n° 1000, Camobi, CEP: 97105-900, Santa Maria, RS, Brasil, brunomantovanelli21@gmail.com. 5 Empresa Brasileira de Pesquisa Agropecuária, EMBRAPA Solos - UEP Recife, Rua Antônio Falcão, n° 402, Boa Viagem, CEP: 51020-240, Recife, PE, Brasil, jose.coelho@embrapa.br.   1 RESUMO  Objetivou-se gerar funções de pedotransferência (FPT) com base em dados das frações granulométricas, distribuição do tamanho de poros, densidade do solo e de partículas para estimar a umidade do solo equivalente à capacidade de campo (CC), ponto de murcha permanente (PMP) e a capacidade de armazenamento de água disponível (CAD) em Argissolos Amarelos representativos dos tabuleiros costeiros na zona da mata norte de Pernambuco. Para isso, foram coletadas amostras deformadas e indeformadas na camada 0,00 - 0,20 m de profundidade. As FPTs foram geradas a partir do método de regressão linear múltipla aplicando a técnica de stepwise backward. Este método eliminou alguns atributos físico-hídricos do solo baseado nos valores de R2 e no Teste t. Os coeficientes de regressão do modelo proposto para predição de CAD, CC e o PMP apresentaram significância de 1% de probabilidade para as variáveis independentes selecionadas para cada modelo, indicando que esses parâmetros podem ser preditos, com ótima precisão, a partir do conteúdo de areia, argila, mesoporosidade, microporosidade e densidade do solo, as quais são fáceis de serem determinadas e obtidas, pré-requisito básico para construção das FPTs.  Palavras-chave: manejo de irrigação, stepwise backward, índices estatísticos.   ANDRADE, F. H. N.; ALMEIDA, C. D. G. C.; ALMEIDA, B. G.; ALBUQUERQUE FILHO, J. A. C.; MANTOVANELLI, B. C.; ARAÚJO FILHO, J. C. SOIL PHYSICAL-HYDRIC PROPERTIES BY PEDOTRANSFER FUNCTION IN SOILS OF COASTAL PLAINS OF PERNAMBUCO  2 ABSTRACT  Aimed to generate pedotransfer functions (PTF) based on particle size, pore size distribution, soil and particle density to estimate the field capacity (CC), permanent wilting point (PMP) and available water capacity (CAD) in Ultisol Typic Fragiaquults in coastal plains of Pernambuco. Thus, deformed and undeformed samples were collected at 0.00 - 0.20m depth. PTFs were generated from multiple linear regression method by stepwise backward technique. This method eliminated some hydro-physical soil attributes, based on the values of R2 and t test. CAD, CC and PMP estimated values showed a significant correlation of 1% probability for independent variables selected for each model. Thus, available water capacity, field capacity and permanent wilting point can be predicted with great precision by sand, clay content, mesoporosity, microporosity and soil density, which are easy to determine and obtain, basic prerequisite for construction of PTFs.  Keywords: irrigation management, stepwise backward, statistical indexes.

APA, Harvard, Vancouver, ISO, and other styles

Haque, Sanjida, Mohammad Khursheed Alam, and Mohd Fadhli Khamis. "Factors Responsible for Unfavorable Dental Arch Relationship in non Syndromic Unilateral Cleft Lip and Palate Children." Journal of Clinical Pediatric Dentistry 41, no. 3 (2017): 236–42. http://dx.doi.org/10.17796/1053-4628-41.3.236.

Full text

Abstract:

Objectives: Multiple factors are whispered to be crucial cause of unfavourable dental arch relationship in cleft lip and palate (CLP).This study aims to evaluate the dental arch relationship of Bangladeshi children with non syndromic unilateral cleft lip and palate (UCLP) following cheiloplasty and palatoplasty. Also to explore the various congenital (UCLP type, UCLP side, family history of cleft, family history of class III) and environmental (cheiloplasty, palatoplasty) factors that affects dental arch relationship of UCLP patients. Study design: This was a retrospective study where 84 dental models were taken before orthodontic treatment and alveolar bone grafting. The mean age was 7.69± 2.46 (mean± SD). The dental arch relationship was assessed by GOSLON (Great Ormond Street, London and Oslo) Yardstick. According to GOSLON Yardstick, five categories are rated; named- 1: excellent; 2: good; 3: fair; 4: poor; 5: very poor. Also the groups have been dichotomized into favorable (category ratings 1–3) and unfavorable (category ratings 4 and 5) groups. Kappa statistics was used to evaluate the intra- and inter-examiner agreements and logistic regression analysis was used to explore the responsible factors that affect dental arch relationship. Results: Total 37 subjects (44% of all subjects) were categorized into unfavourable group (category rating 4 and 5) using GOSLON yardstick. Intra- and inter-examiner agreements were very good. The mean GOSLON score was 3.238. Using crude and stepwise backward regression analysis, significant association was found between family history of skeletal class III malocclusion (p = 0.015 and p = 0.014 respectively) and unfavourable dental arch relationship. Complete UCLP (p = 0.054) and left sided UCLP (p = 0.053) also seemed to be correlated but not significant with unfavourable dental arch relationship using crude and stepwise backward regression analysis respectively. Conclusion: This analysis suggested that family history of skeletal class III was significantly correlated with unfavourable dental arch relationship of Bangladeshi UCLP children.

APA, Harvard, Vancouver, ISO, and other styles

Thanaviratananich, Sikawat, Hao Cheng, Naricha Chirakalwasan, and Sirimon Reutrakul. "477 Association between Nocturnal Hypoxemic Burden and Glucose Metabolism." Sleep 44, Supplement_2 (2021): A188. http://dx.doi.org/10.1093/sleep/zsab072.476.

Full text

Abstract:

Abstract Introduction To evaluate the association between a novel integrated event-based and hypoxemia-based parameter of polysomnography (PSG), hypoxemic load or HL100, and fasting blood glucose (FBG) and hemoglobin A1c (HbA1c) levels. Methods Adult patients, who underwent an in-lab PSG at University of Iowa Hospitals and Clinics with FBG or HbA1c levels were included. Event-based parameter and hypoxemia-based parameter data were derived. HL100, defined as an integrated area of desaturation under 100% oxygen saturation curve during the total sleep time divided by the total sleep time, was calculated by Python software version 3.8.5. Demographic data and glycemic parameters within 1 year prior to PSG(FBG and HbA1c) were retrieved from chart review Spearman correlation analysis and stepwise backward regression analysis were performed to determine independent predictors of FBG and HbA1c levels. Results Of the 467 patients underwent an in-lab PSG, 385 had FBG levels and 239 had HbA1c levels. All event-based and hypoxemia-based parameter; including HL100, were significantly correlated to FBG and HbA1c levels. Stepwise backward regression analyses, adjusting for age, sex, body mass index and diabetes status, revealed that log HL100 was significantly related to FBG (B=20.8, p=0.015), and log oxygen desaturation index was found related to HbA1c levels (B=0.273, p=0.037). Other parameters (e.g. apnea hypopnea index, minimum oxygen saturation) were not independently associated with glycemic parameters. Conclusion HL100 showed a significant positive correlation with FBG and HbA1c levels and only log HL100 was an independent predictor for FBG levels. This might imply that any degree of desaturation below 100% could result in adverse glucose metabolism. HL100 might be useful for interpretation of sleep studies, risk stratification and patient management purposes in the future. Support (if any):

APA, Harvard, Vancouver, ISO, and other styles

Gavril, Mihaela, Peter V. Hodson, and Jim McLellan. "Decoloration of Amaranth by the white-rot fungusTrametes versicolor. Part I. Statistical analysis." Canadian Journal of Microbiology 53, no. 2 (2007): 313–26. http://dx.doi.org/10.1139/w06-123.

Full text

Abstract:

The white-rot fungus Trametes versicolor decolorized the mono-azo-substituted naphthalenic dye Amaranth. The relationship between the amount of enzymes present in the system and the efficiency of the decoloration process was investigated. The two responses used to quantify the process of decoloration (i.e., initial decoloration rate, v0, and the percent concentration of dye decolorized in 1 h, %c) were correlated with the amount of three enzymes considered for the study (lignin peroxidase, manganese peroxidase, and laccase) and analyzed through stepwise regression analysis (forward, backward, and mixed). The results of the correlation analysis and those of the regression analysis indicated that lignin peroxidase is the enzyme having the greatest influence on the two responses.

APA, Harvard, Vancouver, ISO, and other styles

Zainal, S. S. N., M. J. Masnan, A. Ahmed, and N. A. M. Amin. "A Study on Significant Predictors for Prediction of Undiagnosed T2DM Using Binary Logistic Regression Model." International Journal of Engineering & Technology 7, no. 4.30 (2018): 355. http://dx.doi.org/10.14419/ijet.v7i4.30.22309.

Full text

Abstract:

Type 2 Diabetes Mellitus (T2DM) is a chronic disease that can cause premature deaths worldwide. Malaysia is one of the many countries that facing this serious epidemic. The World Health Organization (WHO) has also estimated that Malaysia would have 2.8 million people having T2DM disease in 2030. This study aims to identify significant predictors for prediction of undiagnosed T2DM patients in one of the highest prevalence states of T2DM. Binary logistic regression model proposed to predict the presence of T2DM among undiagnosed respondents. The selection of significant predictors using univariate, multivariate and backward stepwise selection was implemented in this study. The study concludes that four predictors were found significant for prediction of undiagnosed T2DM patients.

APA, Harvard, Vancouver, ISO, and other styles

Jürimäe, Jaak, Kaja Haljaste, Antonio Cicchella, et al. "Analysis of Swimming Performance from Physical, Physiological, and Biomechanical Parameters in Young Swimmers." Pediatric Exercise Science 19, no. 1 (2007): 70–81. http://dx.doi.org/10.1123/pes.19.1.70.

Full text

Abstract:

The purpose of this study was to examine the influence of the energy cost of swimming, body composition, and technical parameters on swimming performance in young swimmers. Twenty-nine swimmers, 15 prepubertal (11.9 ± 0.3 years; Tanner Stages 1−2) and 14 pubertal (14.3 ± 1.4 years; Tanner Stages 3−4) boys participated in the study. The energy cost of swimming (Cs) and stroking parameters were assessed over maximal 400-m front-crawl swimming in a 25m swimming pool. The backward extrapolation technique was used to evaluate peak oxygen consumption (VO2peak). A stroke index (SI; m2 · s−1 · cycles−1) was calculated by multiplying the swimming speed by the stroke length. VO2peak results were compared with VO2peak test in the laboratory (bicycle, 2.86 ± 0.74 L/min, vs. in water, 2.53 ± 0.50 L/min; R2 = .713; p = .0001). Stepwise-regression analyses revealed that SI (R2 = .898), in-water VO2peak (R2 = .358), and arm span (R2 = .454) were the best predictors of swimming performance. The backward-extrapolation method could be used to assess VO2peak in young swimmers. SI, arm span, and VO2peak appear to be the major determinants of front-crawl swimming performance in young swimmers.

APA, Harvard, Vancouver, ISO, and other styles

Pedrinolla, Anna, Massimo Venturelli, Stefano Tamburin та ін. "Non-Aβ-Dependent Factors Associated with Global Cognitive and Physical Function in Alzheimer’s Disease: A Pilot Multivariate Analysis". Journal of Clinical Medicine 8, № 2 (2019): 224. http://dx.doi.org/10.3390/jcm8020224.

Full text

Abstract:

Recent literature highlights the importance of identifying factors associated with mild cognitive impairment (MCI) and Alzheimer’s Disease (AD). Actual validated biomarkers include neuroimaging and cerebrospinal fluid assessments; however, we investigated non-Aβ-dependent factors associated with dementia in 12 MCI and 30 AD patients. Patients were assessed for global cognitive function (Mini-Mental state examination—MMSE), physical function (Physical Performance Test—PPT), exercise capacity (6-min walking test—6MWT), maximal oxygen uptake (VO2max), brain volume, vascular function (flow-mediated dilation—FMD), inflammatory status (tumor necrosis factor—α ,TNF- α, interleukin-6, -10 and -15) and neurotrophin receptors (p75NTR and Tropomyosin receptor kinase A -TrkA). Baseline multifactorial information was submitted to two separate backward stepwise regression analyses to identify the variables associated with cognitive and physical decline in demented patients. A multivariate regression was then applied to verify the stepwise regression. The results indicated that the combination of 6MWT and VO2max was associated with both global cognitive and physical function (MMSE = 11.384 + (0.00599 × 6MWT) − (0.235 × VO2max)); (PPT = 1.848 + (0.0264 × 6MWT) + (19.693 × VO2max)). These results may offer important information that might help to identify specific targets for therapeutic strategies (NIH Clinical trial identification number NCT03034746).

APA, Harvard, Vancouver, ISO, and other styles

M. Zolkipli, H., H. Juahir, G. Adiana, et al. "Spatial Variation and Possible Sources Assessment at Federal Territory of Kuala Lumpur Water Treatment Plan Using Chemometric Technique." International Journal of Engineering & Technology 7, no. 4.34 (2018): 70. http://dx.doi.org/10.14419/ijet.v7i4.34.23583.

Full text

Abstract:

This study aims to identify the possible sources in drinking water parameters heavy metal and organic parameters (HMOPs) and spatial variation between untreated water and treated water at Federal Territory of Kuala Lumpur water treatment plant. The indicator HMOPs in drinking water in Kuala Lumpur were selected as parameters to discriminate the possible source of water treatment plants (WTPs) pollutant. Chemometric technique such as principal component analysis (PCA) and discriminant analysis (DA) was identified based on the five years’ availability data starting from 2012 to 2016. PCA were used to identify the most significant parameters which are highlighted eleven strong factors loading of parameter respectively out of sixteen for PCs and classified as possible sources in WTPs. Continue with DA analysis that is successful distinguish two categories region in WTP using the forward stepwise and backward stepwise with significant amount is 98.46%. From this study, we can conclude that this chemometric is the best technique of analysis to get a lot of information such as identify possible sources of pollutant and discriminant of two station sampling categories that will give novelty to Malaysian Ministry of Health (MOH) and collaboration agency in National Drinking Water Quality Surveillances Program (NDWQSP).

APA, Harvard, Vancouver, ISO, and other styles

Al-Qerem, Walid, Anan S. Jarab, Mohammad Badinjki, Dana Hyassat, and Raghda Qarqaz. "Exploring variables associated with medication non-adherence in patients with type 2 diabetes mellitus." PLOS ONE 16, no. 8 (2021): e0256666. http://dx.doi.org/10.1371/journal.pone.0256666.

Full text

Abstract:

Objective This study aims to assess medication adherence and explore its predictors in outpatients with type 2 diabetes. Method This cross-sectional study collected socio-demographics, disease-related information, and different biomedical variables for type 2 diabetes patients attending a Jordanian Diabetes center. The four-item medication adherence scale (4-IMAS) and the beliefs about medications questionnaire (BMQ) which includes necessity and concerns were used. Stepwise backward quartile regression models were conducted to evaluate variables associated with the Necessity and Concerns scores. Stepwise ordinal regression was conducted to evaluate variables associated with adherence. Results 287 diabetic patients participated in the study. Almost half of the participants (46.5%) reported moderate adherence and 12.2% reported low adherence. Significant predictors of the adherence were necessity score (OR = 14.86, p <0.01), concern score (OR = 0.36, p <0.05), and frequency of medication administration (OR = 0.88, p- <0.01). Education was a significant predictor of Necessity and Concerns scores (β = 0.48, -0.2, respectively). Conclusion Simplifying the medication regimen, emphasizing medication necessity and overcoming medication concerns should be targeted in future diabetes intervention programs to improve medication adherence and hence glycemic control among diabetic patients.

APA, Harvard, Vancouver, ISO, and other styles

GU, W., A. R. VIEIRA, R. M. HOEKSTRA, P. M. GRIFFIN, and D. COLE. "Use of random forest to estimate population attributable fractions from a case-control study of Salmonella enterica serotype Enteritidis infections." Epidemiology and Infection 143, no. 13 (2015): 2786–94. http://dx.doi.org/10.1017/s095026881500014x.

Full text

Abstract:

SUMMARYTo design effective food safety programmes we need to estimate how many sporadic foodborne illnesses are caused by specific food sources based on case-control studies. Logistic regression has substantive limitations for analysing structured questionnaire data with numerous exposures and missing values. We adapted random forest to analyse data of a case-control study of Salmonella enterica serotype Enteritidis illness for source attribution. For estimation of summary population attributable fractions (PAFs) of exposures grouped into transmission routes, we devised a counterfactual estimator to predict reductions in illness associated with removing grouped exposures. For the purpose of comparison, we fitted the data using logistic regression models with stepwise forward and backward variable selection. Our results show that the forward and backward variable selection of logistic regression models were not consistent for parameter estimation, with different significant exposures identified. By contrast, the random forest model produced estimated PAFs of grouped exposures consistent in rank order with results obtained from outbreak data, with egg-related exposures having the highest estimated PAF (22·1%, 95% confidence interval 8·5–31·8). Random forest might be structurally more coherent and efficient than logistic regression models for attributing Salmonella illnesses to sources involving many causal pathways.

APA, Harvard, Vancouver, ISO, and other styles

Giungato, P., E. Laiola, and V. Nicolardi. "Evaluation of Industrial Roasting Degree of Coffee Beans by Using an Electronic Nose and a Stepwise Backward Selection of Predictors." Food Analytical Methods 10, no. 10 (2017): 3424–33. http://dx.doi.org/10.1007/s12161-017-0909-z.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Tang, Yongfu, Lin Meng, Hailong Li, Ling Zheng, Bin Wang, and Feina Zhang. "Design of a high-efficiency dual-band coaxial relativistic backward wave oscillator with variable coupling impedance and phase velocity." Laser and Particle Beams 31, no. 1 (2012): 55–62. http://dx.doi.org/10.1017/s0263034612000882.

Full text

Abstract:

AbstractA dual-band high-efficiency coaxial relativistic backward wave oscillator (CRBWO) with asymmetric resonant reflector is designed and presented in this paper. Improved sectioned coaxial slow wave structure (SWS) with stepwise variation of coupling impedance and phase velocity is employed, and the performance of the dual-band CRBWO is investigated by use of a 2.5-D particle-in-cell (PIC) simulation code. When the diode voltage is 510 kV and beam current is 9.03 kA, an average microwave power of 1.0 GW with power conversion efficiency of 21.7% is obtained. Synchronously radiating dual-band frequencies of 8.1 GHz and 9.9 GHz are obtained, corresponding to C-band and X-band, respectively. A more clear and stable beating radiation microwave power with beating frequency of 1.8 GHz is acquired.

APA, Harvard, Vancouver, ISO, and other styles

Juahir, Hafizan, Adiana Ghazali, Azimah Ismail, et al. "Spatial and Temporal Assessment of Titiwangsa Lake Water Quality Using Chemometrics Analysis." International Journal of Engineering & Technology 7, no. 3.14 (2018): 20. http://dx.doi.org/10.14419/ijet.v7i3.14.16856.

Full text

Abstract:

Titiwangsa Lake is a renowned recreational lake in Kuala Lumpur, Malaysia. The present study was purposely to define the current status of Titiwangsa Lake water quality and propose a water quality monitoring program to conserve and sustain the health of this lake. Samples were collected in January 2017 during the day and night-time periods. Spatial classification using hierarchical agglomerative cluster analysis (HACA) has clustered the sampling stations into low, medium and high contaminated areas. Temporal classification of discriminant analysis (DA) forward stepwise mode has highlighted DO, chlorophyll-a and E-coli are the significant variables. They showed a lower range of data during the day-time period compared to night-time period. DA backward stepwise model showed significant variables of total suspended solid (TSS) and total phosphate (TP) were higher in concentration during the day-time period as compared to night-time period. The significant of varimax factors (VFs) in the principal component analysis (PCA) might contribute by the landscaping, small-scale domestic wastewater, urban stormwater and land erosion. In a nutshell, based on HACA classification, samples can be collected at only three stations represent each cluster during the next water quality monitoring activities as this could reduce the time and cost of sampling and sample analysis.

APA, Harvard, Vancouver, ISO, and other styles

Yu, Jin. "Efficient fidelity control by stepwise nucleotide selection in polymerase elongation Abstract: Polymerases select nucleotides." Computational and Mathematical Biophysics 2, no. 1 (2014): 141–60. http://dx.doi.org/10.2478/mlbmb-2014-0010.

Full text

Abstract:

Abstract Polymerases select nucleotides according to a template before incorporating them for chemical synthesis during gene replication or transcription. Efficient selection to achieve sufficiently high fidelity and speed is essential for polymerase function. Due to multiple kinetic steps detected in a polymerase elongation cycle, there exist multiple selection checkpoints to allow different strategies of fidelity control. In our current work, we examined step-by-step selections in an elongation cycle that have conformational transition rates tuned one at a time, with a controlled differentiation free energy between the right and wrong nucleotides at each checkpoint. The elongation is sustained at non-equilibrium steady state with constant free energy input and heat dissipation. It is found that a selection checkpoint in the later stage of a reaction path has less capability for error reduction. Hence, early selection is essential to achieve an efficient fidelity control. In particular, for an intermediate state, the selection through the forward transition inhibition has the same capacity for error reduction as the selection through the backward rejection. As with respect to the elongation speed, an initial screening is indispensible for maintaining high speed, as the wrong nucleotides can be removed quickly and replaced by the right ones at the entry. Overall, the elongation error rate can be repeatedly reduced through multiple selection checkpoints. This study provides a theoretical framework to guide more detailed structural dynamics studies, and to support rational redesign of related enzymes and devices.

APA, Harvard, Vancouver, ISO, and other styles

Oliveira, Margareth Da Silva, Fernanda Cerutti, Fernanda De Almeida Ribeiro, and Irani Iracema de Lima Argimon. "Internalizing and externalizing symptoms of crack-cocaine users." Psychologica 59, no. 1 (2017): 43–53. http://dx.doi.org/10.14195/1647-8606_59-1_3.

Full text

Abstract:

The present study aimed to analyse the psychopathological functioning of crack-cocaine users compared to the general population. It is a quantitative cross-sectional study. A sample of 971 adults, aged from 18 to 59 years, was divided in two groups: crack-cocaine users and general population, selected by convenience sampling. Results: Statistical analysis, using Pearson’s chi-square test, showed a significant association between crack-cocaine users and a greater severity in internalizing and externalizing symptoms. Binary logistic regression analysis using the conditional stepwise backward method showed a severity model for the use of crack-cocaine adjusted to the gender, age, schooling, and anxiety/depression symptoms variables. Conclusions: Based on the results, the comorbidities associated with crack-cocaine use should be investigated to ensure an appropriate treatment for these users.

APA, Harvard, Vancouver, ISO, and other styles

Hrynkiewicz, Monika, Anna Iwaniak, Justyna Bucholska, Piotr Minkiewicz, and Małgorzata Darewicz. "Structure–Activity Prediction of ACE Inhibitory/Bitter Dipeptides—A Chemometric Approach Based on Stepwise Regression." Molecules 24, no. 5 (2019): 950. http://dx.doi.org/10.3390/molecules24050950.

Full text

Abstract:

Forward and backward stepwise regression (FR and BR, respectively) was applied for the structure–bioactivity prediction of angiotensin converting enzyme (ACE)-inhibitory/bitter-tasting dipeptides. The datasets used in this study consisted of 28 sequences and numerical variables reflecting dipeptides’ physicochemical nature. The data were acquired from the BIOPEP-UWM, Biological Magnetic Resonance Databank, ProtScale, and AAindex databases. The calculations were computed using STATISTICA®13.1. FR/BR models differed in R2 (0.91/0.76, respectively). The impact of C-atC(−) and N-Molw(+) on the dual function of dipeptides was observed. Positive (+) and negative (−) correlations with log IC50 are presented in parens. Moreover, C-Bur(+), N-atH(+), and N-Pol(−) were also found to be important in the FR model. The additional statistical significance of N-bul(−), N-Bur(−), and N-Hdr(+) was reported in the BR model. These attributes reflected the composition of the dipeptides. We report that the “ideal” bitter ACE inhibitor should be composed of P, Y, F (C-end) and G, V, I, L (N-end). Functions: log Rcaf. = f (observed log IC50) and log Rcaf. = f (predicted log IC50) revealed no direct relationships between ACE inhibition and the bitterness of the dipeptides. It probably resulted from some structural discrepancies between the ACE inhibitory/bitter peptides and/or the measure of activity describing one of the two bioactivities. Our protocol can be applicable for the structure–bioactivity prediction of other bioactivities peptides.

APA, Harvard, Vancouver, ISO, and other styles

Delisle-Houde, Patrick, Nathan A. Chiarlitti, Ryan E. R. Reid, and Ross E. Andersen. "Predicting On-Ice Skating Using Laboratory- and Field-Based Assessments in College Ice Hockey Players." International Journal of Sports Physiology and Performance 14, no. 9 (2019): 1184–89. http://dx.doi.org/10.1123/ijspp.2018-0708.

Full text

Abstract:

Purpose: To determine the predictability of common laboratory/field and novel laboratory tests for skating characteristics in Canadian college ice hockey players. Methods: A total of 18 male hockey players from the university’s varsity hockey team age 20–25 y (height 180.7 [6.4] cm, weight 87.1 [6.7] kg, and body fat 16.2% [4.0%]) completed common laboratory-/field-based testing (ie, standing long jump, vertical jump, off-ice proagility, , Wingate), novel laboratory-based testing (ie, Biodex dynamometer, dual-energy X-ray absorptiometry scan), and on-ice testing (ie, 30-m forward sprint, 30-m backward sprint, on-ice proagility). Results: Pearson correlations and stepwise regression revealed relationships between on-ice forward sprint and 4 off-ice tests (Wingate relative peak power [r = −.62, P < .01], standing long jump [r = −.45, P < .05], off-ice proagility left [r = .51, P < .05], and vertical jump impulse [r = .60, P < .01]). On-ice proagility left was correlated with off-ice proagility left (r = .47, P < .05), Wingate relative peak power (r = −.55, P < .01), and vertical jump impulse (r = −.53, P < .05). The 30-m backward skating test and the on-ice proagility right were not correlated with any off-ice test. Conclusion: Commonly used laboratory/field tests are effective in predicting 2 important primary abilities in ice hockey.

APA, Harvard, Vancouver, ISO, and other styles

Matsumoto, Ryo, Hiroshi Utsunomiya, and Shinya Ishigai. "Lubrication in Hot Forging with Pulsed Ram Motion." Key Engineering Materials 767 (April 2018): 149–56. http://dx.doi.org/10.4028/www.scientific.net/kem.767.149.

Full text

Abstract:

The effect of pulsed (oscillating) ram motion control on lubrication was investigated in hot forging of stainless steel workpiece with oxide glass lubricant. During the retreat in the pulsed ram motion, the workpiece was re-lubricated by flow of lubricant through the gap between the workpiece and the die. A hot spike-type forging test on a servo press with pulsed ram motions was carried out to investigate the lubrication performance of the oxide glass. In the test, the workpiece with a temperature of 1223 K was extruded into the hollow part of the upper die together with oxide glass in a manner that combined pulsed and stepwise ram operations. The re-lubrication of the workpiece with oxide glass was confirmed by the test results showing 5–10% reduction in the forging load and 5% longer length of the backward extruded part of the workpiece under an appropriate pulsed ram motion.

APA, Harvard, Vancouver, ISO, and other styles

Chowdhury, Mohammad Ziaul Islam, and Tanvir C. Turin. "Variable selection strategies and its importance in clinical prediction modelling." Family Medicine and Community Health 8, no. 1 (2020): e000262. http://dx.doi.org/10.1136/fmch-2019-000262.

Full text

Abstract:

Clinical prediction models are used frequently in clinical practice to identify patients who are at risk of developing an adverse outcome so that preventive measures can be initiated. A prediction model can be developed in a number of ways; however, an appropriate variable selection strategy needs to be followed in all cases. Our purpose is to introduce readers to the concept of variable selection in prediction modelling, including the importance of variable selection and variable reduction strategies. We will discuss the various variable selection techniques that can be applied during prediction model building (backward elimination, forward selection, stepwise selection and all possible subset selection), and the stopping rule/selection criteria in variable selection (p values, Akaike information criterion, Bayesian information criterion and Mallows’ Cp statistic). This paper focuses on the importance of including appropriate variables, following the proper steps, and adopting the proper methods when selecting variables for prediction models.

APA, Harvard, Vancouver, ISO, and other styles

Ready, A. Elizabeth, Suzanne L. Boreskie, Susan A. Law, and Robert Russell. "Fitness and Lifestyle Parameters Fail to Predict Back Injuries in Nurses." Canadian Journal of Applied Physiology 18, no. 1 (1993): 80–90. http://dx.doi.org/10.1139/h93-008.

Full text

Abstract:

Performance on fitness and back related isometric strength tests, as well as the response to a lifestyle questionnaire, were related to the subsequent occurrence of back injuires in 119 nurses. In all, 22% of subjects sustained injuries during the 18-month study. Injured nurses were more likely to be from high-risk wards and to have received worker's compensation pay for past back injuries. Fitness and lifestyle characteristics did not differ significantly between injured and not-injured groups. Using backward stepwise logistic regression, a model was developed that accounted for 41% of the variability between groups and predicted 67% of those injured. Prior compensation pay, smoking status, and job satisfaction were the most useful discriminators. It was concluded, however, that the fitness and lifestyle parameters measured did not effectively predict back injury in nurses. Key words: fitness assessment, isometric strength, job satisfaction, job selection criteria, smoking status

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!