scholarly journals Application of Mixed Linear Models in the Analysis of Road Surface Features

2015 ◽  
Vol 54 (1) ◽  
pp. 101-109 ◽  
Author(s):  
Jurgita Židanavičiūtė ◽  
Audrius Vaitkus
Keyword(s):  
Linear Models ◽  
Road Surface ◽  
Linear Regression Models ◽  
Mixed Linear Models ◽  
Time Intervals ◽  
Surface Strength ◽  
The Road ◽  
Unequally Spaced ◽  
Units Of Analysis ◽  
The Impact

The data were collected by researchers at the Road Research Institute, in a study investigating the impact of differentfactors on road surface strength. In this statistical analysis, we apply linear mixed models (LMMs) to clustered longitudinal data, inwhich the units of analysis (points in the road) are nested within clusters (sample of four different road segments), and repeatedmeasures of road strength in these different points are collected over time with unequally spaced time intervals. The data arebalanced – each cluster has the same number of units, which are measured at the same number of time points. Because of correlateddata and different clusters in which data could be correlated, linear regression models are not appropriate here, and therefore linearmixed models are applied.

scholarly journals Laboratory experiment on the nano-TiO2 photocatalytic degradation effect of road surface oil pollution

2020 ◽  
Vol 9 (1) ◽  
pp. 922-933
Author(s):  
Qing’e Wang ◽  
Kai Zheng ◽  
Huanan Yu ◽  
Luwei Zhao ◽  
Xuan Zhu ◽  
...  
Keyword(s):  
Photocatalytic Degradation ◽  
Oil Pollution ◽  
Road Surface ◽  
Test Method ◽  
Driving Safety ◽  
The Road ◽  
Road Surfaces ◽  
The Many ◽  
The Impact ◽  
Degradation Effect

AbstractOil leak from vehicles is one of the most common pollution types of the road. The spilled oil could be retained on the surface and spread in the air voids of the road, which results in a decrease in the friction coefficient of the road, affects driving safety, and causes damage to pavement materials over time. Photocatalytic degradation through nano-TiO2 is a safe, long-lasting, and sustainable technology among the many methods for treating oil contamination on road surfaces. In this study, the nano-TiO2 photocatalytic degradation effect of road surface oil pollution was evaluated through the lab experiment. First, a glass dish was used as a substrate to determine the basic working condition of the test; then, a test method considering the impact of different oil erosion degrees was proposed to eliminate the effect of oil erosion on asphalt pavement and leakage on cement pavement, which led to the development of a lab test method for the nano-TiO2 photocatalytic degradation effect of oil pollution on different road surfaces.

scholarly journals Stool and ruminal microbiome components associated with methane emission and feed efficiency in Nelore beef cattle.

2021 ◽  
Author(s):  
Bruno G.N. Andrade ◽  
Haithem Afli ◽  
Flavia A. Bressani ◽  
Rafael R. C. Cuadrat ◽  
Priscila S. N. de Oliveira ◽  
...  
Keyword(s):  
Methane Emission ◽  
Feed Efficiency ◽  
Linear Models ◽  
Anthropogenic Activities ◽  
Mixed Linear Models ◽  
Human Welfare ◽  
Feed Composition ◽  
Fecal Microbiome ◽  
Treatment Groups ◽  
The Impact

Abstract Background: The impact of extreme changes in weather patterns in the economy and human welfare are some of the biggest challenges that our civilization is facing. From the anthropogenic activities that contribute to climate change, reducing the impact of farming activities is a priority, since it is responsible for up to 18% of greenhouse gases linked to such activities. To this end, we tested if the ruminal and fecal microbiome components of 52 Brazilian Nelore bulls, belonging to two treatment groups based on the feed intervention, conventional and by-products based diet, could be used in the future as biomarkers for methane emission and feed efficiency in bovine.Results: We identified a total of 5,693 Amplicon Sequence Variants (ASVs) in the Nelore bulls microbiomes. Differential abundance (DA) analysis with the ANCOM approach identified 30 bacterial and 15 archaea ASVs as DA among treatment groups. Association analysis using Maaslin2 and Mixed Linear Models indicated that bacterial ASVs are linked to the residual methane emission (RCH4) and Residual Feed Intake (RFI) phenotypes, contributing to the host’s phenotypic variation, suggesting their potential as targets for interventions and/or biomarkers.Conclusion: Feed composition induced significant differences in abundance and richness of ruminal and fecal microbial populations. The diet based on industrial byproducts applied to our treatment groups influenced the microbiome diversity of bacteria and archaea, but not of protozoa. Different ASVs were associated with RCH4 emission and RFI in both ruminal and fecal microbiomes. While ruminal ASVs are expected to directly influence RCH4 emission and RFI, the relation of fecal taxa, such as Alistipes and Rikenellaceae (gut group RC9), with these traits might also be associated with host health due to their link to anti-inflammatory compounds, and these have the potential to be used as accessible biomarkers for these complex phenotypes.

A Fusion Navigation of Double Laser Radar for Intelligent Vehicle

2011 ◽  
Vol 346 ◽  
pp. 711-718 ◽  
Author(s):  
Li Xia Meng ◽  
Fu Chun Sun ◽  
Hua Ping Liu ◽  
Tao Chu
Keyword(s):  
Field Method ◽  
Road Surface ◽  
Laser Radar ◽  
Intelligent Vehicle ◽  
Height Difference ◽  
The Road ◽  
Potential Field Method ◽  
Regular Shape ◽  
The Impact ◽  
Navigation Method

A navigation method is presented for intelligent vehicle based on fusion of double laser radar. Given laser radar model and road curb model, road curbs are detected by one laser radar tilt-mounted on the intelligent vehicle, and they restrict the vehicle to travel inside the road surface. First, obstacle information from two laser radar are unified to same reference frame and fused, then they are implemented using angle potential field method, the best navigation angle is computed under the road curb restriction. Experiments show the algorithm works well in spite of road-boundary has regular shape or not, and is free from the impact of height difference of the road curb and road surface.

scholarly journals The Impact of Different Competitive Environments on Pacing and Performance

2018 ◽  
Vol 13 (6) ◽  
pp. 701-708 ◽  
Author(s):  
Marco J. Konings ◽  
Florentina J. Hettinga
Keyword(s):  
Fixed Effects ◽  
Linear Models ◽  
Real Life ◽  
Energy Resources ◽  
Mixed Linear Models ◽  
Start Position ◽  
Available Energy ◽  
Competitive Environments ◽  
And Performance ◽  
The Impact

Purpose: In real-life competitive situations, athletes are required to continuously make decisions about how and when to invest their available energy resources. This study attempted to identify how different competitive environments invite elite short-track speed skaters to modify their pacing behavior during head-to-head competition. Methods: Lap times of elite 500-, 1000- and 1500-m short-track speed skating competitions between 2011 and 2016 (N = 34,095 races) were collected. Log-transformed lap and finishing times were analyzed with mixed linear models. The fixed effects in the model were sex, season, stage of competition, start position, competition importance, event number per tournament, number of competitors per race, altitude, and time qualification. The random effects of the model were athlete identity and the residual (within-athlete race-to-race variation). Separate analyses were performed for each event. Results: Several competitive environments, such as the number of competitors in a race (a higher number of competitors evoked most likely a faster initial pace; coefficient of variation [CV] = 1.9–9.3%), the stage of competition (likely to most likely, a slower initial pace was demonstrated in finals; CV = −1.4% to 2.0%), the possibility of time qualification (most likely a faster initial pace; CV = 2.6–5.0%), and competition importance (most likely faster races at the Olympics; CV = 1.3–3.5%), altered the pacing decisions of elite skaters in 1000- and 1500-m events. Stage of competition and start position affected 500-m pacing behavior. Conclusions: As demonstrated in this study, different competitive environments evoked modifications in pacing behavior, in particular in the initial phase of the race, emphasizing the importance of athlete–environment interactions, especially during head-to-head competitions.

The Carbon Emission Quantification of the Low Carbon Road Maintenance Technology in China

2012 ◽  
Vol 260-261 ◽  
pp. 833-840 ◽  
Author(s):  
Ke Zhou ◽  
Yim Wong ◽  
Xi Juan Xu ◽  
Cha Ren Ce Chiang ◽  
Hui Cong Zhang
Keyword(s):  
Surface Quality ◽  
Carbon Emission ◽  
Transportation Policy ◽  
Road Surface ◽  
Road Maintenance ◽  
Low Carbon ◽  
The Road ◽  
The Right ◽  
The Impact ◽  
Maintenance Process

Low carbon road maintenance( hereinafter referred to as LCRM) technology is an important and essential part of the overall low carbon transportation policy in China. The large amount of carbon emission resulting from road maintenance needs to be determined with definitive methods and data to form a basis of measurement of the carbon emission of the road maintenance process. Various road surface maintenance technologies have different environmental impacts and dissimilar levels of carbon emission. When comparing the merits and drawbacks of the various maintenance technologies, not only factors such as the maintenance outcome, road surface quality, serviceable lifespan, costs and the impact on traffic and environment should be evaluated, but also other factors, such as carbon emission of the material used for the maintenance process, carbon emission of the machinery deployed and other amounts released during construction, have to be assessed and measured. This paper will allow for a comprehensive analysis that will help to choose the right road surface maintenance technology that produces the best road surface quality, the optimal economic benefit and the most favourable social and environmental outcome. LCRM protocol should be regulated and promoted by government legislation and through which adoption of the best practices would be encouraged.

scholarly journals Implicit Learning of the Time Interval Sequence

2021 ◽  
Vol 14 (1) ◽  
pp. 108-121
Author(s):  
A.Y. Agafonov ◽  
A.D. Fomicheva ◽  
G. A. Starostin ◽  
A.P. Kryukova
Keyword(s):  
Implicit Learning ◽  
Experimental Approach ◽  
Linear Models ◽  
Time Interval ◽  
Mixed Linear Models ◽  
Motor Sequence ◽  
Time Intervals ◽  
Interval Sequence ◽  
Temporal Sequences ◽  
Special Case

The article considers the studies performed in the «Sequence Learning» paradigm. A special case of this experimental approach is the method of temporal sequences memorization. The elements of such sequences are time intervals instead of stimulus or their spatial localization. The item of the conducted and described study was implicit learning of the time interval sequence. The goal of the experiment was to check the possibility of unconscious acquisition of the temporal sequences, not related to the sequences of another type of organization. To process the obtained results, mixed linear models were used. It was found that the learning of time interval sequences can occur regardless of the presence of regularity in the reaction order (motor sequence) and without rules in stimuli organization (structural sequence) or in the order of their localization (spatial sequence).

scholarly journals Fecal and Ruminal Microbiome Components Associated With Methane Emission in Beef Cattle.

2020 ◽  
Author(s):  
Bruno G.N. Andrade ◽  
Haithem Afli ◽  
Flavia A. Bressani ◽  
Rafael R. C. Cuadrat ◽  
Priscila S. N. de Oliveira ◽  
...  
Keyword(s):  
Treatment Group ◽  
Linear Models ◽  
Anthropogenic Activities ◽  
Dietary Treatment ◽  
Mixed Linear Models ◽  
Feed Composition ◽  
Treatment Groups ◽  
Weather Patterns ◽  
Group B ◽  
The Impact

Abstract Background: The impact of extreme changes in weather patterns in the economy and humanity welfare are some of the biggest challenges that our civilization is facing. From the anthropogenic activities that contribute to climate change, reducing the impact of farming activities is a priority, since its responsible for up to 18% of greenhouse gases linked to such activities. To this end, we tested if the ruminal and fecal microbiomes components of 52 Brazilian Nelore bulls, belonging to two experimental groups based on the feed intervention, conventional (A) and byproducts based diet (B), could be used as biomarkers for methane (CH4) emission.Results: We identified a total of 5,693 Amplicon Sequence Variants (ASVs) in the Nelore bulls microbiomes from the experimental group B. Statistical analysis showed that the microbiome populations were significantly different among treatment groups. Differential abundance (DA) analysis with the ANCOM approach identified 30 bacterial and 15 archaea ASVs as DA among treatment groups. Random forest models, using either bacteria or archaea ASVs as predictors, were able to predict the treatment group with high accuracy (r2>0.85). Association analysis using Mixed Linear Models indicate that bacterial and archaea ASVs are linked to the CH4 emission phenotype, of which the most prominent were the ruminal ASV 40 and fecal ASV 35. These ASVs contributed to a 9.7% increase and 7.3% decrease of the variation in CH4 emission, respectively, which indicated their potential as targets for feed interventions and/or biomarkers.Conclusion: The feed composition induced significant differences in abundance and richness of ruminal and fecal microbial populations. The dietary treatment based on industrial byproducts applied had an impact on the microbiome diversity of bacteria and archaea, but not on protozoa. Microbiome components (ASVs) of bacteria and archaea can be successfully used to predict the treatment group, thus giving support to the hypothesis that the feed intervention modulate microbiome abundance and diversity. Microbiome components were associated with CH4 emission in both microbiomes. Therefore, both ruminal and fecal ASVs can be used as biomarkers for methane production and emission.

Experimental Investigation of Tire Slap Noise

2018 ◽  
Vol 46 (1) ◽  
pp. 38-52
Author(s):  
Rui Cao ◽  
J. Stuart Bolton
Keyword(s):  
High Frequency ◽  
Sound Intensity ◽  
Road Surface ◽  
Structural Vibration ◽  
Vehicle Interior ◽  
Tire Noise ◽  
The Road ◽  
On The Road ◽  
The Impact ◽  
Surface Noise

ABSTRACT Tire noise is an important issue both in the vehicle interior and to the vehicle exterior, since it affects passenger comfort and environmental noise levels, respectively. Such noise is increased when a tire encounters discontinuities on the road surface, the discontinuity being either a gap or a bump. The relatively high frequency (e.g., approximately 1 kHz and above) airborne tire noise generated by such discontinuities is defined as tire slap noise in this study. Most previous research on noise generated by surface discontinuities has been focused on lower frequency tire noise, typically below 600 Hz, and, in particular, on structural-borne noise transmitted from the tire into the vehicle associated with the acoustic modes of the tire interior. Here, instead, the focus is on higher frequency airborne transmission. Further, the study here is conducted from the perspective of tire structural vibration, which concerns the vibration of and sound radiation from the tire treadband structure, rather than tire pattern noise, for example. The high frequency tire slap noise was investigated in a laboratory environment. The measurements were conducted by using the Ray W. Herrick Laboratories' Tire Pavement Test Apparatus (TPTA), on which a loaded tire can be run on realistic road surfaces at speeds up to 50 km/h; the resulting tire noise was measured using the On-Board Sound Intensity (OBSI) method. A gap between two different concrete surfaces was chosen as the road discontinuity, and both narrow band and one-third-octave band spectra were recorded over the gap and over the adjacent smooth road surface segments. Several tires were tested on the TPTA, and their slap noise was recorded. Surface noise and slap noise were compared up to 1600 Hz to show the impact of the discontinuity on the tire noise radiation. Generally, slap noise is of a higher level than the surface noise, especially between 800 and 1400 Hz, but some tires showed distinct differences between the noise response on the surface and over the gap, while other tires radiated similar noise on both the surface and over the gap. Moreover, static tire mobility measurements were performed to investigate the wave type responsible for the different responses on the gap and the surface.

A Computerized Method for Dynamic Response of Vehicle-Bridge Interaction System under Various Conditions

2013 ◽  
Vol 639-640 ◽  
pp. 1214-1219
Author(s):  
Yao Xiao ◽  
Zheng Qing Chen ◽  
Xu Gang Hua
Keyword(s):  
Surface Roughness ◽  
Dynamic Effect ◽  
Integrated System ◽  
Road Surface ◽  
Dynamic Responses ◽  
Superposition Method ◽  
The Road ◽  
Computerized Method ◽  
Road Surface Roughness ◽  
The Impact

A computerized method is presented for computing the dynamic responses of bridges under moving vehicles. The bridge and vehicle are treated as integrated system and modal superposition method is applied to transfer the equation of motion into modal coordinate system. The road roughness/unevenness is also considered. The effects of different vehicle models, vehicle passing speed and road surface roughness on bridge dynamic responses are studied. The impact factor representing the dynamic effect of passing vehicle is calculated for different road surface roughness

scholarly journals Rill Erosion in Unpaved and Rock-Paved Roads after Wildfire in a Mediterranean Forest

Geosciences ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 79
Author(s):  
Manuel Esteban Lucas-Borja ◽  
Demetrio Antonio Zema
Keyword(s):  
Linear Models ◽  
Bare Soil ◽  
Road Surface ◽  
Rill Erosion ◽  
Forest Roads ◽  
Unpaved Roads ◽  
The Road ◽  
Burned Areas ◽  
La Mancha ◽  
Input Variables

Forest roads are often subject to intense runoff and erosion, and the rates can be increased by other disturbance factors, such as wildfires. Since scarce literature exists on the effects of wildfires on rill erosion of forest roads, this study presents the first results of a wider research, evaluating rill erosion in four different types of roads on a forest in Hellìn (Castilla-La Mancha, Central-Eastern Spain): unpaved roads made of native materials (soil found at the study site) and rock-paved roads, both built in unburned areas as well as unpaved and rock-paved roads, in fire-affected areas. In general, the unpaved roads are more subject to rill erosion compared to the rock-paved roads. In particular, the road of burned areas shows an erodibility that is higher by more than 200% compared to the unpaved and unburned roads, and even by about 400% compared to rock-paved roads (in both burned and unburned areas). A modeling approach based on distance linear models and distance-based redundancy analysis has identified the slope of road surface and upstream hillslope as well as the percent bare soil over the road surface as important input variables to predict rill erosion in future modeling experiences. All these variables may be easily measured by quick field surveys. Although the analytical approach of this study is limited to the geometric characteristics of erosion features, the results and the methods developed are useful to support the activity of land managers to better understand the magnitude of road erosion and to develop efficient measures for its control and mitigation.

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