scholarly journals Linear Models for the Prediction of Animal Zone Ammonia in a Weaned Piglet Building

Agronomy ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1927
Author(s):  
Tamara Arango ◽  
Roberto Besteiro ◽  
Juan A. Ortega ◽  
Ángel Castro ◽  
Manuel Ramiro Rodríguez ◽  
...  
Keyword(s):  
Linear Models ◽  
Environmental Control ◽  
Ventilation System ◽  
Strong Correlations ◽  
Linear Regression Models ◽  
Weaned Piglet ◽  
Co2 Concentrations ◽  
Positive Correlations ◽  
Ventilation Rates ◽  
Conventional Farm

Measuring ammonia inside livestock buildings poses many challenges that hinder the incorporation of this variable into environmental control systems. The aim of this study was to measure various microclimate variables inside a weaned piglet building and analyse their interactions with NH3 concentrations for setpoint temperatures of 26 and 25 °C, in order to control NH3 concentrations based on other easily measurable variables. The experimental test was conducted on a conventional farm in Northwest Spain. NH3 concentrations in the animal zone were best correlated with CO2 concentrations in the animal zone (R = 0.91 and R = 0.55) and velocity of air extracted through the fan (R = 0.72 and R = 0.65) for setpoint temperatures of 26 and 25 °C, respectively. Similarly, strong correlations were found with relative humidity in the animal zone and temperature of inlet air. Because NH3 concentration in the animal zone is related to the performance of the ventilation system, strong positive correlations were found between NH3 concentration and temperature of inlet air whereas negative correlations were found between NH3 concentration and ventilation rates. Linear regression models based on CO2 concentrations in the animal zone and temperature of inlet air are recommended, because they provide a good fit for both setpoint temperatures using variables that can be readily measured.

scholarly journals Evolution of NH3 Concentrations in Weaner Pig Buildings Based on Setpoint Temperature

Agronomy ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 107 ◽  
Author(s):  
Manuel R. Rodriguez ◽  
Eugenio Losada ◽  
Roberto Besteiro ◽  
Tamara Arango ◽  
Ramon Velo ◽  
...  
Keyword(s):  
Animal Welfare ◽  
Wave Amplitude ◽  
Environmental Control ◽  
Ventilation System ◽  
Mean Square ◽  
Sinusoidal Model ◽  
Livestock Buildings ◽  
Mean Square Errors ◽  
Conventional Farm ◽  
Occupied Zone

Ammonia (NH3) concentration has seldom been used for environmental control of weaner buildings despite its impact on environment, animal welfare, and workers’ health. This paper aims to determine the effects of setpoint temperature (ST) on the daily evolution of NH3 concentration in the animal-occupied zone. An experimental test was conducted on a conventional farm, with ST between 23 °C and 26 °C. NH3 concentrations in the animal-occupied zone were dependent on ST insofar as ST controlled the operation of the ventilation system, which effectively removed NH3 from the building. The highest NH3 concentrations occurred at night and the lowest concentrations occurred during the daytime. Data were fitted to a sinusoidal model using the least squares setting (LSS) and fast Fourier transform (FFT), which provided R2 values between 0.71 and 0.93. FFT provided a better fit than LSS, with root mean square errors (RMSEs) between 0.09 ppm for an ST of 23 °C and 0.55 ppm for an ST of 25 °C. A decrease in ST caused a delay in the wave and a decrease in wave amplitude. The proposed equations can be used for modeling NH3 concentrations and implemented in conventional controllers for real-time environmental control of livestock buildings to improve animal welfare and productivity.

338 Nitrogen Use Efficiency Is Proportionally More Improved When Young Bulls Are Ranked on Residual Body Gain Rather Than on Residual Feed Intake

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 187-188
Author(s):  
Pablo Guarnido Lopez ◽  
Isabelle Ortigues Marty ◽  
Cantalapiedra-Hijar Gonzalo
Keyword(s):  
Nitrogen Use Efficiency ◽  
Feed Intake ◽  
Linear Models ◽  
Residual Feed Intake ◽  
Residual Body ◽  
Nitrogen Use ◽  
N Metabolism ◽  
Use Efficiency ◽  
Δ 15N ◽  
Positive Correlations

Abstract Animals with superior feed efficiency (FE) may also have an improved nitrogen use efficiency (NUE), which would be beneficial to economic profitability while reducing environmental impacts. When genetically selecting animals on FE, it is preferable to use residual traits [e.g. residual feed intake (RFI) or residual body gain (RG)] rather than ratios because of their predictable genetic outcomes. We studied the relationship of RFI and RG with NUE, estimated from the validated 15N abundance in plasma, across two contrasted diets based on corn or grass silages. We evaluated FE of 588 (half by diet) Charolais bulls (545 ± 57 kg BW) from 12 experimental cohorts (different farms and periods) over 200 days. Before the end of the FE test, plasma was sampled and analyzed for δ 15N. NUE was related to FE through simple-linear models with variables previously corrected for the cohort and diet effects. The models’ slopes were standardized according to FE deviation in order to compare the response of NUE to FE between indices. Higher NUE was related to higher FE (P < 0.001), showing positive correlations with RG (r=-0.40) and negative with RFI (r=0.29). However, the standardized slope of NUE to RG was significantly higher (+28%; P < 0.05) than that of NUE to RFI. This stronger NUE relation to RG compared to RFI could reflect a higher potential of RG animals to deposit N as compared to a more conservational N metabolism in RFI individuals. Regarding diets, and despite the correction of NUE and FE for this effect, the slopes of NUE to FE were numerically (P > 0.05) higher (-16% and +36%; for RG and RFI) in corn-based diets, which agrees with superior NUE observed in corn-vs-grass diets. Results suggested that superior RG animals may present proportionally higher NUE than superior RFI animals, with even better results in corn-vs-grass diets.

scholarly journals Relationship Between Carcass Weight, Muscle, Fat, and Predicted Lean Yield for Commercial Pigs in Ontario

2019 ◽  
Vol 3 (2) ◽  
Author(s):  
R. S. Barducci ◽  
Z. Zhou ◽  
D. Tulpan ◽  
B. M. Bohrer
Keyword(s):  
Negative Correlation ◽  
Correlation Coefficients ◽  
Carcass Weight ◽  
Linear Regression Models ◽  
Strong Negative Correlation ◽  
Statistical Software ◽  
Carcass Parameters ◽  
Scatter Plots ◽  
Positive Correlations ◽  
Meaningful Relationships

ObjectivesGreater knowledge of variance and relationships of pork carcass parameters could be used to improve performance, efficiency, and profitability of the pork industry. Previous research has investigated the correlation between pork carcass parameters; however, there are still many misunderstandings, particularly in commercially representative pigs. Thus, the purpose of this study was to examine the correlation and variance of carcass weight, fat depth, muscle depth, and predicted lean yield in commercial pigs.Materials and MethodsThe second largest commercial pig slaughter facility in Ontario slaughtered approximately 1.5 million pigs in 2018. Carcass data (hot carcass weight, fat depth, muscle depth, and predicted lean yield) from 1025,572 pigs was used for this study with pigs slaughtered on each production day of 2018 (between January 2, 2018 and December 31, 2018). Hot carcass weight was reported immediately following slaughter as a head-on weight, and fat depth and muscle depth were measured with a Destron PG-100 probe (International Destron Technologies, Markham, Ontario). The equation used for predicted lean yield was the Canadian Lean Yield equation (CLY (%) = 68.1863– (0.7833 × fat depth) + (0.0689 × muscle depth) + (0.0080 × fat depth2) – (0.0002 × muscle depth2) + (0.0006 × fat depth × muscle depth). Pearson product moment correlation coefficients were calculated among all parameters using RStudio version 1.1.456 and R version 3.5.1 statistical software. Correlation coefficients were considered significantly different from 0 at P < 0.05. Correlations were considered weak (in absolute value) for r < 0.35, moderate for 0.36 ≤ r ≤ 0.67, and strong for r ≥ 0.68. Linear regression models were created between parameters that had meaningful relationships using the RStudio statistical software. Gnuplot version 5.2 was used to create scatter plots to allow for better visualization of the correlation between meaningful parameters.ResultsThe mean ± standard deviation for fat depth, muscle depth, hot carcass weight, and predicted lean yield were 18.27 ± 4.12 mm, 65.69 ± 9.06 mm, 105.93 ± 8.39 kg, and 61.03 ± 1.91%, respectively. We observed weak positive correlations between fat depth and hot carcass weight (r = 0.27; P < 0.0001), and between muscle depth and hot carcass weight (r = 0.17; P < 0.0001). We obtained a weak negative correlation between predicted lean yield and hot carcass weight (r = –0.21; P < 0.0001). The predicted lean yield equation used for this set of pigs included measurements for fat depth and muscle depth, so strong correlation between these parameters was expected. We obtained a moderate positive correlation between muscle depth and predicted lean yield (r = 0.39; P < 0.0001) and a strong negative correlation between fat depth and predicted lean yield (r = –0.96; P < 0.0001).ConclusionResults from this dataset revealed that hot carcass weight was generally not correlated with fat depth, muscle depth, or predicted lean yield. The conclusion of this study based on the current dataset is that pigs do not reach a weight threshold where they consistently become fatter or heavier muscled.

scholarly journals Robust Statistical Inference in Generalized Linear Models Based on Minimum Renyi’s Pseudodistance Estimators

Entropy ◽  
2022 ◽  
Vol 24 (1) ◽  
pp. 123
Author(s):  
María Jaenada ◽  
Leandro Pardo
Keyword(s):  
Generalized Linear Models ◽  
Influence Function ◽  
Regression Models ◽  
Linear Models ◽  
Asymptotic Properties ◽  
Significant Loss ◽  
Superior Performance ◽  
Test Statistics ◽  
Linear Regression Models ◽  
Type Test

Minimum Renyi’s pseudodistance estimators (MRPEs) enjoy good robustness properties without a significant loss of efficiency in general statistical models, and, in particular, for linear regression models (LRMs). In this line, Castilla et al. considered robust Wald-type test statistics in LRMs based on these MRPEs. In this paper, we extend the theory of MRPEs to Generalized Linear Models (GLMs) using independent and nonidentically distributed observations (INIDO). We derive asymptotic properties of the proposed estimators and analyze their influence function to asses their robustness properties. Additionally, we define robust Wald-type test statistics for testing linear hypothesis and theoretically study their asymptotic distribution, as well as their influence function. The performance of the proposed MRPEs and Wald-type test statistics are empirically examined for the Poisson Regression models through a simulation study, focusing on their robustness properties. We finally test the proposed methods in a real dataset related to the treatment of epilepsy, illustrating the superior performance of the robust MRPEs as well as Wald-type tests.

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 A comparison between tracer gas and tracer particle techniques in evaluating the efficiency of ventilation in operating theatres

1983 ◽  
Vol 91 (3) ◽  
pp. 509-519 ◽  
Author(s):  
Per-Arne Andersson ◽  
Anna Hambraeus ◽  
Ulla Zettersten ◽  
Bengt Ljungqvist ◽  
Kenneth Neikter ◽  
...  
Keyword(s):  
Tracer Particle ◽  
Ventilation System ◽  
Airborne Bacteria ◽  
Tracer Gas ◽  
Operating Theatres ◽  
Ventilation Rates ◽  
Operation Wound

Operating theatres are ventilated for a number of reasons, one of them being to keep numbers of airborne bacteria low at the operation wound. No matter how air is brought into the room, bacteria are removed by dilution rather than by air currents, because of turbulence caused by heat liberated by people and equipment and by movement in the room (Lidwell & Williams, 1960). With ventilation rates up to 20 air changes/hour, the dilution may differ at different sites in the room depending on the design of its ventilation system.

An Interpretable Machine Learning Model Enhanced Integrated CPU-GPU DVFS Governor

2021 ◽  
Vol 20 (6) ◽  
pp. 1-28
Author(s):  
Jurn-Gyu Park ◽  
Nikil Dutt ◽  
Sung-Soo Lim
Keyword(s):  
Machine Learning ◽  
Energy Efficiency ◽  
High Performance ◽  
Linear Models ◽  
Piecewise Linear ◽  
Prediction Errors ◽  
Linear Regression Models ◽  
Mobile Games ◽  
Interpretable Machine Learning ◽  
Mathematical Formulas

Modern heterogeneous CPU-GPU-based mobile architectures, which execute intensive mobile gaming/graphics applications, use software governors to achieve high performance with energy-efficiency. However, existing governors typically utilize simple statistical or heuristic models, assuming linear relationships using a small unbalanced dataset of mobile games; and the limitations result in high prediction errors for dynamic and diverse gaming workloads on heterogeneous platforms. To overcome these limitations, we propose an interpretable machine learning (ML) model enhanced integrated CPU-GPU governor: (1) It builds tree-based piecewise linear models (i.e., model trees) offline considering both high accuracy (low error) and interpretable ML models based on mathematical formulas using a simulatability operation counts quantitative metric. And then (2) it deploys the selected models for online estimation into an integrated CPU-GPU Dynamic Voltage Frequency Scaling governor. Our experiments on a test set of 20 mobile games exhibiting diverse characteristics show that our governor achieved significant energy efficiency gains of over 10% (up to 38%) improvements on average in energy-per-frame with a surprising-but-modest 3% improvement in Frames-per-Second performance, compared to a typical state-of-the-art governor that employs simple linear regression models.

scholarly journals Ammonia emissions from a naturally and a mechanically ventilated broiler house in Brazil

2014 ◽  
Vol 18 (11) ◽  
pp. 1179-1185 ◽  
Author(s):  
Luciano B. Mendes ◽  
Ilda F. F. Tinoco ◽  
Nico W. M. Ogink ◽  
Keller S. O. Rocha ◽  
Jairo A. Osorio S. ◽  
...  
Keyword(s):  
Ventilation System ◽  
Stocking Density ◽  
Emission Factors ◽  
Ammonia Emission ◽  
Mechanically Ventilated ◽  
Nh3 Emission ◽  
Modeling Process ◽  
Tropical Conditions ◽  
Ventilation Rates ◽  
Broiler House

This study was conducted with the aim of monitoring NH3 emissions from a mechanically and a naturally ventilated broiler house (MVB and NVB, respectively) and calculate their ammonia emission factors (fNH3). Bird stocking density was 13.5 and 11.1 birds m-2 for the MVB and NVB, respectively. The marketing age was 43 days and bedding consisted of dried coffee husks in its first time of use. Ventilation rates were calculated with the metabolic carbon dioxide mass balance method. Values of fNH3 were 0.32 ± 0.10 and 0.27 ± 0.07 g bird-1 d-1 for the MVB and NVB, respectively, and are in agreement to what was presented in other studies performed under similar conditions. The fNH3 estimated on yearly basis was 58 g bird-place-1 year-1. It was concluded that the different types of ventilation system between the studied broiler barns did not significantly affect emissions in the modeling process. The results obtained help providing reliable methodology for the determination of a solid database on NH3 emission factors for tropical conditions that can be used for future inventories, when performed in a sufficient number of barns that is representative for the Brazilian scenario.

Correlations between Cancer Mortality Rates from Various Italian Regions

1985 ◽  
Vol 71 (5) ◽  
pp. 441-448 ◽  
Author(s):  
Carlo La Vecchia ◽  
Adriano Decarli
Keyword(s):  
Cancer Mortality ◽  
Strong Correlations ◽  
Genetic Determinants ◽  
Death Certification ◽  
Correlation Studies ◽  
Northern Areas ◽  
Italian Regions ◽  
Positive Correlations ◽  
Positive Coefficients ◽  
Indirect Indication

Death certification rates from 17 non-sexual and 4 sexual cancers were used to examine patterns of correlation between various cancers within the 20 Italian regions. A large number of strongly positive correlations emerged, reflecting the geographical distribution of cancer mortality in Italy which shows substantially higher rates for several common sites in northern areas. The most notable findings were the high positive correlations between various tobacco-related cancers in both sexes (however somewhat higher in males), the positive correlations between most intestinal sites and between a well defined group of other cancers including intestines in both sexes, breast and ovary in females and prostate in males, previously described in several widely heterogeneous populations. Various alcohol-related cancers showed high positive coefficients in males but not in females. Several suggestions which emerged from previous correlation studies but which generally lacked convincing biological or epidemiological consistency were not confirmed by the present data. Conversely, a few strong correlations emerged in the present study which are not explainable in terms of available knowledge of the causes of cancer, or obvious confounding. Though probably incidental, the existence of these correlations between cancers with widely heterogeneous or largely undefined etiology is still an indirect indication that these neoplasms are largely avoidable, since it is unlikely that the same genetic determinants are strongly associated with such different malignancies.

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