The Application of Stepwise Regression in Analyzing Pavement Friction Data

Abstract It is proposed that tire-pavement friction is controlled by thermal rather than by hysteresis and viscoelastic effects. A numerical model of heating effects in sliding is described in which the friction coefficient emerges as a dependent variable. The overall results of the model can be expressed in a closed form using Blok's flash temperature theory. This allows the factors controlling rubber friction to be recognized directly. The model can be applied in quantitative form to metal-polymer-ice contacts. Several examples of correlation are given. The difficulties of characterizing the contact conditions in tire-pavement friction reduce the model to qualitative form. Each of the governing parameters is examined in detail. The attainment of higher friction by small, discrete particles of aluminum filler is discussed.

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A closer look at the locked-wheel pavement friction data in the ltpp database for selected states

Cogent Engineering ◽

10.1080/23311916.2019.1690214 ◽

2019 ◽

Vol 6 (1) ◽

pp. 1690214

Author(s):

Maher M. Murad ◽

Khaled A. Abaza ◽

Filippo G. Pratico

Keyword(s):

Pavement Friction

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Effect of aggregate properties on asphalt pavement friction based on random forest analysis

Construction and Building Materials ◽

10.1016/j.conbuildmat.2021.123467 ◽

2021 ◽

Vol 292 ◽

pp. 123467

Author(s):

You Zhan ◽

Joshua Qiang Li ◽

Cheng Liu ◽

Kelvin C.P. Wang ◽

Dominique M. Pittenger ◽

...

Keyword(s):

Random Forest ◽

Asphalt Pavement ◽

Random Forest Analysis ◽

Aggregate Properties ◽

Pavement Friction

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Tire/Road Rolling Resistance Modeling: Discussing the Surface Macrotexture Effect

Coatings ◽

10.3390/coatings11050538 ◽

2021 ◽

Vol 11 (5) ◽

pp. 538

Author(s):

Malal Kane ◽

Ebrahim Riahi ◽

Minh-Tan Do

Keyword(s):

Slip Rate ◽

Rolling Resistance ◽

Friction Model ◽

Slip Rates ◽

Wide Range ◽

Road Surfaces ◽

Profile Depth ◽

Experimental Rolling ◽

Resistance Modeling ◽

Pavement Friction

This paper deals with the modeling of rolling resistance and the analysis of the effect of pavement texture. The Rolling Resistance Model (RRM) is a simplification of the no-slip rate of the Dynamic Friction Model (DFM) based on modeling tire/road contact and is intended to predict the tire/pavement friction at all slip rates. The experimental validation of this approach was performed using a machine simulating tires rolling on road surfaces. The tested pavement surfaces have a wide range of textures from smooth to macro-micro-rough, thus covering all the surfaces likely to be encountered on the roads. A comparison between the experimental rolling resistances and those predicted by the model shows a good correlation, with an R2 exceeding 0.8. A good correlation between the MPD (mean profile depth) of the surfaces and the rolling resistance is also shown. It is also noticed that a random distribution and pointed shape of the summits may also be an inconvenience concerning rolling resistance, thus leading to the conclusion that beyond the macrotexture, the positivity of the texture should also be taken into account. A possible simplification of the model by neglecting the damping part in the constitutive model of the rubber is also noted.

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Evaluating the Robustness of Biomarkers of Dairy Food Intake in a Free-Living Population Using Single- and Multi-Marker Approaches

Metabolites ◽

10.3390/metabo11060395 ◽

2021 ◽

Vol 11 (6) ◽

pp. 395

Author(s):

Katherine J. Li ◽

Kathryn J. Burton-Pimentel ◽

Elske M. Brouwer-Brolsma ◽

Edith J. M. Feskens ◽

Carola Blaser ◽

...

Keyword(s):

Food Intake ◽

Generalized Linear Model ◽

Stepwise Regression ◽

Intervention Studies ◽

Gas Chromatography Mass Spectrometry ◽

Targeted Metabolomics ◽

Free Living ◽

Dairy Food ◽

Dairy Foods ◽

Single Marker

Studies examining associations between self-reported dairy intake and health are inconclusive, but biomarkers hold promise for elucidating such relationships by offering objective measures of dietary intake. Previous human intervention studies identified several biomarkers for dairy foods in blood and urine using non-targeted metabolomics. We evaluated the robustness of these biomarkers in a free-living cohort in the Netherlands using both single- and multi-marker approaches. Plasma and urine from 246 participants (54 ± 13 years) who completed a food frequency questionnaire were analyzed using liquid and gas chromatography-mass spectrometry. The targeted metabolite panel included 37 previously-identified candidate biomarkers of milk, cheese, and/or yoghurt consumption. Associations between biomarkers and energy-adjusted dairy food intakes were assessed by a ‘single-marker’ generalized linear model, and stepwise regression was used to select the best ‘multi-marker’ panel. Multi-marker models that also accounted for common covariates better captured the subtle differences for milk (urinary galactose, galactitol; sex, body mass index, age) and cheese (plasma pentadecanoic acid, isoleucine, glutamic acid) over single-marker models. No significant associations were observed for yogurt. Further examination of other facets of validity of these biomarkers may improve estimates of dairy food intake in conjunction with self-reported methods, and help reach a clearer consensus on their health impacts.

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Determinants of In-Hospital Mortality in Elderly Patients Aged 80 Years or above with Acute Heart Failure: A Retrospective Cohort Study at a Single Rural Hospital

Journal of Clinical Medicine ◽

10.3390/jcm10071468 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1468

Author(s):

Yusuke Watanabe ◽

Kazuko Tajiri ◽

Hiroyuki Nagata ◽

Masayuki Kojima

Keyword(s):

Heart Failure ◽

Regression Analysis ◽

Elderly Patients ◽

Hospital Mortality ◽

Acute Heart Failure ◽

Stepwise Regression ◽

Stepwise Regression Analysis ◽

Antibiotic Administration ◽

Very Elderly ◽

Survivor Group

Heart failure is one of the leading causes of mortality worldwide. Several predictive risk scores and factors associated with in-hospital mortality have been reported for acute heart failure. However, only a few studies have examined the predictors in elderly patients. This study investigated determinants of in-hospital mortality in elderly patients with acute heart failure, aged 80 years or above, by evaluating the serum sodium, blood urea nitrogen, age and serum albumin, systolic blood pressure and natriuretic peptide levels (SOB-ASAP) score. We reviewed the medical records of 106 consecutive patients retrospectively and classified them into the survivor group (n = 83) and the non-survivor group (n = 23) based on the in-hospital mortality. Patient characteristics at admission and during hospitalization were compared between the two groups. Multivariate stepwise regression analysis was used to evaluate the in-hospital mortality. The SOB-ASAP score was significantly better in the survivor group than in the non-survivor group. Multivariate stepwise regression analysis revealed that a poor SOB-ASAP score, oral phosphodiesterase 3 inhibitor use, and requirement of early intravenous antibiotic administration were associated with in-hospital mortality in very elderly patients with acute heart failure. Severe clinical status might predict outcomes in very elderly patients.

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Effectiveness of Green Warning Lights with Different Flashing Patterns for Winter Maintenance Operations

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/03611981211008187 ◽

2021 ◽

pp. 036119812110081

Author(s):

Fatemeh Fakhrmoosavi ◽

Ramin Saedi ◽

Farish Jazlan ◽

Ali Zockaie ◽

Mehrnaz Ghamami ◽

...

Keyword(s):

Human Subjects ◽

Test Results ◽

Night Time ◽

Winter Maintenance ◽

Warning Light ◽

Rigorous Study ◽

Static Versus Dynamic ◽

Color Combinations ◽

Warning Lights ◽

Pavement Friction

Snow removal activities are performed by roadway agencies to enhance winter mobility and safety. Slower travel speeds during these operations, combined with low visibility and reduced pavement friction, mean that safety and collision avoidance remain a persistent concern. Many studies have implemented signing and lighting technologies to improve the visibility of snowplows. Although a few studies have evaluated the use of different colors on snowplows, there is no rigorous study that evaluates the potential impacts of using green warning lights for winter maintenance operations. This study, therefore, investigates the impacts of various warning light configurations on the visibility of snowplows, with the focus on green lights. To this end, 37 warning light configurations are designed using various color combinations (green and amber), and flashing patterns (single and quad) on the back (LED), the top (beacon), or both, of snowplows. These configurations are evaluated to identify the most effective configurations. Three sets of experiments are designed and implemented: static, dynamic, and weather to evaluate the visibility effectiveness in different contexts: day versus night, clear versus snowy weather, and static versus dynamic scenarios. Human subjects are employed to conduct the experiments and the test results are evaluated using statistical analyses. The conspicuity during the day time and glare during the night time are statistically different among various configurations. In addition, adding green lights with a single flash pattern to amber warning lights improves the conspicuity, while keeping the glare at an acceptable level relative to configurations using only amber.

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Selected Predictors of the Sense of Intimacy in Relationships of Young Adults

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph16224447 ◽

2019 ◽

Vol 16 (22) ◽

pp. 4447

Author(s):

Dorota Czyżowska ◽

Ewa Gurba ◽

Natalia Czyżowska ◽

Alicja Kalus ◽

Katarzyna Sitnik-Warchulska ◽

...

Keyword(s):

Young Women ◽

Stepwise Regression ◽

Interpersonal Relations ◽

Childhood And Adolescence ◽

Main Research ◽

Identity Style ◽

Identity Commitment ◽

Study Results ◽

Predictive Role

The main research objective of this study was seeking the predictive role of closeness to parents, attachment, identity style, identity commitment, type of relationship, and having children in intimacy among young women and men. Many studies indicate differences in the level of engagement, communication, and satisfaction in relationships. The study group comprised 227 people, including 114 women (M = 29.99; SD = 4.36), and 113 men (M = 30.00; SD = 4.33). A total of 40% of the subjects were married, and the remaining 60% subjects were in informal relationships; 101 people had children and the other individuals were childless. The following instruments were used: The Miller Social Intimacy Scale, questionnaires to assess closeness and attachment, and the Identity Style Inventory. The significance of the differences and the stepwise regression analysis were performed. The results of the study demonstrated a higher level of intimacy in a relationship with a partner among women than men. The nature of a relationship does not matter to the sense of intimacy. However, closeness to parents during childhood and adolescence, the model of interpersonal relations, and the identity style are predictors of intimacy in a relationship. The study results can be used in creating preventive and educational programs focused on family life and satisfied relationships.

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How Do Trade-Offs and Synergies between Ecosystem Services Change in the Long Period? The Case Study of Uxin, Inner Mongolia, China

Sustainability ◽

10.3390/su11216041 ◽

2019 ◽

Vol 11 (21) ◽

pp. 6041 ◽

Cited By ~ 2

Author(s):

Zhang ◽

Li ◽

Buyantuev ◽

Bao ◽

Zhang

Keyword(s):

Ecosystem Services ◽

Inner Mongolia ◽

Stepwise Regression ◽

Driving Forces ◽

Extended Period ◽

Trade Offs ◽

Development And Utilization ◽

Long Term Trends

Ecosystem services management should often expect to deal with non-linearities due to trade-offs and synergies between ecosystem services (ES). Therefore, it is important to analyze long-term trends in ES development and utilization to understand their responses to climate change and intensification of human activities. In this paper, the region of Uxin in Inner Mongolia, China, was chosen as a case study area to describe the spatial distribution and trends of 5 ES indicators. Changes in relationships between ES and driving forces of dynamics of ES relationships were analyzed for the period 1979–2016 using a stepwise regression. We found that: the magnitude and directions in ES relationships changed during this extended period; those changes are influenced by climate factors, land use change, technological progress, and population growth.

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TARGET MODAL SPLIT MODEL

Transport ◽

10.3846/16484142.2011.644044 ◽

2012 ◽

Vol 26 (4) ◽

pp. 418-424 ◽

Cited By ~ 3

Author(s):

Valentina Basarić ◽

Jadranka Jović

Keyword(s):

Public Transport ◽

Stepwise Regression ◽

Statistical Data ◽

Transport Policy ◽

Wide Range ◽

Policy Measures ◽

Novi Sad ◽

The Relationship ◽

The City ◽

Statistical Results

The research presented in this paper is aimed at defining a model that enables the management of the relationship between private vehicles and public transport applying the available instruments of city transport policy such as parking policy and public transport policy measures. Statistical data used for modelling is sourced from the database in a wide range of EU cities. The target model was developed in the form of stepwise regression analysis. Very favourable statistical results were obtained, and the subsequent tests on the city of Novi Sad (250000 inhabitants) led to the conclusion that the obtained results were suitable for implementation in practice. The results of the implemented procedure are of great importance for the enhancement of the existing transport policies in cities, as they enable the development of strategies for finding combinations of instruments that would bring the transport system and urban environment into a desired-viable rather than consequential condition.

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