articles+ search results
195 articles+ results
1 - 20
Next
Number of results to display per page
-
L.M.M TIJSKENS, R.E. SCHOUTEN, T. UNUK, and Marjan SIMČIČ
- Acta Agriculturae Slovenica, Vol 105, Iss 1, Pp 157-164 (2015)
- Subjects
-
biological properties, biological differences, biodiversity, data analysis, data processing, measurement, apples, tomatoes, statistical methods, mathematics, and Agriculture
- Abstract
-
Biological variation is omnipresent in nature. It contains useful information that is neglected by the usually applied statistical procedures. To extract this information special procedures have to be applied. Biological variation is seen in properties (e.g. size, colour, firmness), but the underlying issue is almost always to the variation in development or maturity in a batch of individuals generated by small scale environmental differences. The principles of assessing biological variation in batches of individuals are explained without putting emphasis on mathematical details. Obtained explained parts increase from about 60 to 80 % for the usual approach to 95 when the biological variation is taken into account. When technical variation or measuring error is small even 99 % can be achieved. The benefit of the presented technology is highlighted based on a number of already published studies covering the colour of apples during growth and storage and the firmness of cut tomatoes during storage
- Full text View record in DOAJ
-
Borges, Uirassu, Laborde, Sylvain, and Raab, Markus
- PLoS ONE, Vol 14, Iss 10, p e0223848 (2019)
- Subjects
-
Research Article, Anatomy, Mathematics, Prefrontal Cortex, Engineering and Technology, Mathematical and Statistical Techniques, Measurement, Head, Functional Electrical Stimulation, Physical Sciences, Psychology, Analysis of Variance, Sensory Perception, Heart Rate, Surgical and Invasive Medical Procedures, Biology and Life Sciences, Cognition, Neuroscience, Research and Analysis Methods, Medicine, Brain, Cardiology, Ears, Time Measurement, Social Sciences, Science, Medicine and Health Sciences, Statistical Methods, Cognitive Science, and Statistics
- Abstract
-
The present study investigated the effects of transcutaneous vagus nerve stimulation on cardiac vagal activity, the activity of the vagus nerve regulating cardiac functioning. We applied stimulation on the left cymba conchae and tested the effects of different stimulation intensities on a vagally-mediated heart rate variability pagerameter (i.e., the root mean square of successive differences) as well as on subjective ratings of strength of perceived stimulation intensity and unpleasantness due to the stimulation. Three experiments (within-subject designs, M = 61 healthy participants each) were carried out: In Experiment 1, to choose one fixed stimulation intensity for the subsequent studies, we compared three preset stimulation intensities (i.e., 0.5, 1.0 and 1.5 mA) with each other. In Experiment 2, we compared the set stimulation method with the free stimulation method, in which the participants were instructed to freely choose an intensity. In Experiment 3, to control for placebo effects, we compared both methods (i.e., set stimulation vs. free stimulation) with their respective sham stimulations. In the three experiments, an increase of cardiac vagal activity was found from resting to the stimulation phases. However, this increase in cardiac vagal activity was not dependent on stimulation intensity (Experiment 1), the method used to stimulate (i.e., set vs. free; Experiment 2), or whether stimulation was active or sham (Experiment 3). This pattern of results was solidly supported by Bayesian estimations. On the subjective level, higher stimulation intensities were perceived as significantly stronger and a stronger stimulation was generally also perceived as more unpleasant. The results suggest that cardiac vagal activity may be similarly influenced by afferent vagal stimuli triggered by active and sham stimulation with different stimulation intensities. Potential explanations for these findings and its implications for future research with tVNS are discussed.
- Full text
View/download PDF
-
Kang, Daekook and Lee, Sanghoon
- PLoS ONE, Vol 14, Iss 8, p e0219739 (2019)
- Subjects
-
Research Article, Cognitive Psychology, Computing Methods, Mathematics, Thermodynamics, Geographical Locations, Engineering and Technology, Mathematical and Statistical Techniques, Measurement, Physical Sciences, Entropy, Psychology, Distance Measurement, People and Places, Physics, Biology and Life Sciences, Cognition, Computer and Information Sciences, Neuroscience, Fuzzy Logic, Asia, Research and Analysis Methods, Equipment, Medicine, Factor Analysis, Korea, Social Sciences, Decision Making, Science, Statistical Methods, Cognitive Science, Number Theory, and Statistics
- Abstract
-
As the airline industry has become ever-more competitive and profitability more tenuous, airline service quality management has grown more important to airlines. Although many studies have focused on the evaluation of airline service quality, some common limitations need to be noted. First, traditional fuzzy logics were utilized to present linguistic variables as fuzzy numbers. However, precise quantification of lower and upper bounds with a single number is often difficult; thus, interval-valued fuzzy sets that represent the lower and upper bounds in the fuzzy number as an interval form should be applied instead. Second, while some studies have applied various multiple-criteria decision-making method [MCDM] and the service quality (SERVQUAL) method for evaluation of airline service quality, few have utilized grey relational analysis (GRA, a simple and data-driven MCDM method applicable to environments with incomplete information) and the service performance (SERVPERF), a performance-based measure that can resolve the ambiguity issue of the expectations construct in SERVQUAL. Third, extant studies dealing with the issue of weighting criteria in the evaluation of airline service quality have focused only on either subjective or objective weights, though weighting criteria based on a combined objective/subjective approach would be much better than those just considering the subjective approach. The present study endeavored to fill these literature gaps by developing, for evaluation of airline service quality, interval-valued fuzzy GRA with SERVPERF based on both subjective and objective weights. It contributes to the field by incorporating the 22 criteria from SERVPERF to effectively account for the various characteristics of airline service. Additionally, it is the first study to utilize interval-valued fuzzy GRA together with a novel technique that combines a subjective/objective weighting method for integration of objective decision-matrix-derived information with subjective decision-maker preferences. The supplemental empirical case study of airline service evaluation, further, provides researchers and practitioners with a means of better understanding the proposed approach in the practical perspectives.
- Full text
View/download PDF
-
Escalona-Marfil, Carles, Puig-Diví, Albert, Padullés-Riu, Josep Maria, Busquets, Albert, Padullés-Chando, Xavier, and Marcos-Ruiz, Daniel
- PLoS ONE, Vol 14, Iss 6, p e0216448 (2019)
- Subjects
-
Research Article, Mathematics, Anatomy, Classical Mechanics, Engineering and Technology, Mathematical and Statistical Techniques, Measurement, Physical Sciences, Distance Measurement, Analysis of Variance, Research Assessment, Physics, Software Engineering, Software Tools, Instrumentation, Biology and Life Sciences, Computer and Information Sciences, Research and Analysis Methods, Musculoskeletal System, Computer Software, Kinematics, Medicine, Research Validity, Science, Medicine and Health Sciences, Statistical Methods, and Statistics
- Abstract
-
An objective analysis of the human movement can help both clinical assessment and sports performance. Kinovea is a free 2D motion analysis software that can be used to measure kinematic parameters. This low-cost technology has been used in sports sciences, as well as in the clinical and research fields. One interesting tool is that it can measure an object (or person) passing in front of the camera, taking into account the perspective between the camera and the recorded object. Although it has been validated as a tool to assess time-related variables, few studies assessed its validity compared to a Gold Standard; furthermore, its reliability in different perspectives has not been previously assessed. The main objective of this study is to determine the validity of the Kinovea software compared to AutoCAD, and its intra and inter-rater reliability in obtaining coordinates data; a second objective is to compare their results at 4 different perspectives (90°, 75°, 60° and 45°) and to assess the inter and intra rater reliability at each perspective. For this purpose, a wire structure figure in the shape of a human lower limb was designed and measured in AutoCAD; it was then recorded during a pendular motion with a video-camera placed at distance of 5 m and analyzed with Kinovea in the 4 perspectives (90°, 75°, 60° and 45°). Each frame was examined by three observers who made two attempts. A multiple approach was applied involving the analysis of the systematic error, with a two-way ANOVA 2x4; the relative reliability with Intraclass Correlation Coefficient (ICC) and the Coefficient of Variance (CV) (95% confidence interval); and the absolute reliability with the Standard Error (SE). The results indicate that the Kinovea software is a valid and reliable tool that is able to measure accurately at distances up to 5 m from the object and at an angle range of 90°–45°. Nevertheless, for optimum results an angle of 90° is suggested.
- Full text
View/download PDF
-
Sprysl,, M., Czech University of Life Sciences, Prague (Czech Republic). Faculty of Agrobiology, Food and Natural Resources, Stupka, R., Czech University of Life Sciences, Prague (Czech Republic). Faculty of Agrobiology, Food and Natural Resources, and Citek, J., Czech University of Life Sciences, Prague (Czech Republic). Faculty of Agrobiology, Food and Natural Resources
- Research in Pig Breeding (Czech Republic), Nov 2013, v. 7(1) p. 5-8.
- Subjects
-
Animal husbandry, THICKNESS, INSTRUMENT DE MESURE, COMPOSICION DE LA CANAL, TEJIDO ADIPOSO, MEASURING INSTRUMENTS, TECHNIQUE DE PREVISION, MUSCLES, LEAN BODY MASS, FORECASTING, MAIN D'OEUVRE, INSTRUMENTOS DE MEDICION, ESPESOR, COMPUTER SOFTWARE, MATHEMATICS, EVALUACION, METHODS, MASSE MAIGRE DE L'ORGANISME, CERDO, APTITUD CARNICA, METODOS, METHODE, MASA CORPORAL DELGADA, CARCASS COMPOSITION, MUSCULOS, EPAISSEUR, METHODE STATISTIQUE, MEASUREMENT, LARD DORSAL, EQUIPO, METODOS ESTADISTICOS, EQUIPMENT, APTITUDE POUR LA VIANDE, STATISTICAL METHODS, MANPOWER, MATHEMATIQUE, PROFONDEUR, PROFUNDIDAD, ADIPOSE TISSUE, DEPTH, CLASSIFICATION, MEAT PERFORMANCE, TOCINO DORSAL, MATEMATICAS, BACKFAT, COMPOSITION DE LA CARCASSE, PORCIN, MEDICION, MESURE, TECNICAS DE PREDICCION, MANO DE OBRA, MUSCLE, PROGRAMAS DE ORDENADOR, LOGICIEL, TISSU ADIPEUX, CLASIFICACION, SWINE, EVALUATION, and MATERIEL
- Abstract
-
The aim of the study was to determine the repeatability and operator variability, which estimate the backfat thicknes (S-FOM), muscle depth (M-FOM) and lean meat share (LMP) measured twice in one pig with one instrument (FOM). The observed LMP-FOM estimations was also compared with the ZP method. 180 total hybrid pigs of common genotypes, using in the Czech Republic was measured at the abbatoir. For the lean meat share prediction and its comparison the FOM and ZP equations were used. Calculation and the results comparison was performed by mathematical-statistical program SAS Propriety Software Release 6.04. Significance of differences was tested by analysis of variance. The results showed that: - there are minimal differences in the LMP estimation between FOM and ZP, - ZP method, compared to FOM, LMP estimate overstates, - considerable differences between LMP estimates of operators are caused by punctures in the wrong place, - repeatability S and M for the first and repeated injection is high, the accuracy of the estimate LMP-FOM/LMP-ZP are 0.98351/0.838, - accuracy of M-FOM determination is affected by operator, - repeatability accuracy of LMP estimates is for all operators practically identical.
- Full text View record at AGRIS
7. A unified framework for unconstrained and constrained ordination of microbiome read count data [2019]
-
Hawinkel, Stijn, Bijnens, Luc, Kerckhof, Frederiek-Maarten, and Thas, Olivier
- PLoS ONE, Vol 14, Iss 2, p e0205474 (2019)
- Subjects
-
MULTIVARIATE ANALYSES, Applied Mathematics, Algorithms, Probability Theory, Research Article, Mathematics, Statistical Dispersion, Ecology and Environmental Sciences, Engineering and Technology, Mathematical and statistical techniques, Microbial Ecology, Statistical Distributions, Measurement, Simulation and Modeling, Monte Carlo method, Ecology, Genetics, Physical sciences, Mathematics and Statistics, Distance Measurement, Genomics, LATENT VARIABLE MODELS, Data Visualization, Biology and Life Sciences, Computer and Information Sciences, Research and analysis methods, Microbiology, Medicine, Microbiome, Microbial Genomics, Medical Microbiology, Science, Statistical methods, and Statistics
- Abstract
-
Explorative visualization techniques provide a first summary of microbiome read count datasets through dimension reduction. A plethora of dimension reduction methods exists, but many of them focus primarily on sample ordination, failing to elucidate the role of the bacterial species. Moreover, implicit but often unrealistic assumptions underlying these methods fail to account for overdispersion and differences in sequencing depth, which are two typical characteristics of sequencing data. We combine log-linear models with a dispersion estimation algorithm and flexible response function modelling into a framework for unconstrained and constrained ordination. The method is able to cope with differences in dispersion between taxa and varying sequencing depths, to yield meaningful biological patterns. Moreover, it can correct for observed technical confounders, whereas other methods are adversely affected by these artefacts. Unlike distance-based ordination methods, the assumptions underlying our method are stated explicitly and can be verified using simple diagnostics. The combination of unconstrained and constrained ordination in the same framework is unique in the field and facilitates microbiome data exploration. We illustrate the advantages of our method on simulated and real datasets, while pointing out flaws in existing methods. The algorithms for fitting and plotting are available in the R-package RCM.
- Full text
View/download PDF
-
David, L., Institute of Animal Science, Prague (Czech Republic). Dept. of Pig Breeding, Pulkrabek, J., Institute of Animal Science, Prague (Czech Republic). Dept. of Pig Breeding, and Valis, L., Institute of Animal Science, Prague (Czech Republic). Dept. of Pig Breeding
- Research in Pig Breeding (Czech Republic), Dec 2014, v. 8(2) p. 1-3.
- Subjects
-
Animal husbandry, THICKNESS, REPUBLIQUE TCHEQUE, COMPOSICION DE LA CANAL, SYSTEMES DE CLASSIFICATION, TEJIDO ADIPOSO, LEAN BODY MASS, PESADA, POIDS A L'ABATTAGE, PESO DE LA CANAL, ESPESOR, BACK, MATHEMATICS, EVALUACION, CZECH REPUBLIC, CLASSIFICATION SYSTEMS, MASSE MAIGRE DE L'ORGANISME, CERDO, CLASSEMENT, MASA CORPORAL DELGADA, PESEE, CARCASS COMPOSITION, DOS, TEMPERATURA, EPAISSEUR, TEMPERATURE, METHODE STATISTIQUE, MEASUREMENT, DORSO, SLAUGHTER WEIGHT, METODOS ESTADISTICOS, CLASIFICACION DE PRODUCTOS, STATISTICAL METHODS, CARCASSES, MATHEMATIQUE, ADIPOSE TISSUE, CLASSIFICATION, GRADING, MATEMATICAS, CARCASSE, COMPOSITION DE LA CARCASSE, PORCIN, MEDICION, MESURE, CANAL ANIMAL, TISSU ADIPEUX, CLASIFICACION, REPUBLICA CHECA, SISTEMA DE CLASIFICACION, EVALUATION, SWINE, and WEIGHING
- Abstract
-
The study was focused on the selected parameters of carcass value used within the SEUROP grading system. There were 1591 pig carcasses put in the test. The lean meat content was determined using the new predicting formula Y(%)=70.28164 - 0.75376 S + 0.00270 M. The average lean meat content reached the value of 59.62 +/- 0.069% and the average carcass value was 91.67 +/- 0.259 kg. Comparing to the old regression formula there was an increasing tendency of the lean meat content of two percentage points. The results of the test according to the grading classes show a very similar share of the two best classes S and E. In the class S were 741 carcasses (46.57%) and in the class E were 739 carcasses (46.45%). Into these two classes were ranked more than 93% of all carcasses put in the test. In the class U were 107 carcasses, which made 6.73% of the sample. In the class R were only 4 carcasses (0.25%) and the classes O and P were not represented. For the use in practice is then necessary to put the subclasses in the range of 1% in the SEUROP grading system - every class is divided into 5 subclasses. In the Czech republic, the carcasses with the carcass weight between 80 and 100 kg are preferred. In this weight interval were 65% of the carcasses. The highest lean meat content (62.14%) was within the weight category 60-70 kg compared to the category of 110-120 kg where the lean meat content was only 56.11%.
- Full text View record at AGRIS
9. Geo-spatial analysis of individual-level needle and syringe coverage in Melbourne, Australia [2018]
-
O’Keefe, Daniel, Wilkinson, Anna, Aitken, Campbell, and Dietze, Paul
- PLoS ONE, Vol 13, Iss 12, p e0209280 (2018)
- Subjects
-
Research Article, Mathematics, Sociology, Regression Analysis, Professions, Geographical Locations, Engineering and Technology, Mathematical and Statistical Techniques, Measurement, Population Groupings, Physical Sciences, Distance Measurement, People and Places, Labor Economics, Oceania, Pharmacology, Heroin, Criminology, Research and Analysis Methods, Equipment, Medicine, Australia, Employment, Behavioral Pharmacology, Economics, Police, Social Sciences, Science, Recreational Drug Use, Medicine and Health Sciences, Linear Regression Analysis, Statistical Methods, and Statistics
- Abstract
-
Distance to health services is known to be negatively associated with usage and needle and syringe programs (NSPs) for people who inject drugs (PWID) are no different. Australia has a mixture of NSP modalities (primary or secondary fixed-site NSPs), which may present unique barriers to access. In this study, we explore 1) the effect of distance to NSPs on individual-level needle and syringe coverage, and 2) differences in coverage dependent on NSP modality. Using data from 219 PWID in an ongoing cohort study in Melbourne, Australia, we measured the straight-line distance from participants' residence to their nearest primary or secondary fixed-site NSP. We analysed the relationship between geographical distance and coverage via regression analysis. The median distance to any type of NSP was 1872 metres. Regardless of service type, 52% of participants lived within 2 kms of a fixed-site NSP and 87% lived within 5 kms. We found no association between distance to NSPs and syringe coverage or a significant difference in coverage by nearest service type. Our findings suggest that the number and distribution of NSPs in Melbourne, Australia caters adequately for the population of PWID.
- Full text
View/download PDF
-
Al-bashiri, Hael, Abdulgabber, Mansoor Abdullateef, Romli, Awanis, and Kahtan, Hasan
- PLoS ONE, Vol 13, Iss 10, p e0204434 (2018)
- Subjects
-
Applied Mathematics, Algorithms, Research Article, Memory, Cognitive Psychology, Mathematics, Engineering and Technology, Mathematical and Statistical Techniques, Measurement, Simulation and Modeling, Physical Sciences, Psychology, Distance Measurement, Memory Recall, Biology and Life Sciences, Cognition, Computer and Information Sciences, Neuroscience, Computer Networks, Forecasting, Research and Analysis Methods, Medicine, Similarity Measures, Learning and Memory, Social Sciences, Science, Decision Making, Computing Systems, Internet, Statistical Methods, Cognitive Science, and Statistics
- Abstract
-
This paper describes an approach for improving the accuracy of memory-based collaborative filtering, based on the technique for order of preference by similarity to ideal solution (TOPSIS) method. Recommender systems are used to filter the huge amount of data available online based on user-defined preferences. Collaborative filtering (CF) is a commonly used recommendation approach that generates recommendations based on correlations among user preferences. Although several enhancements have increased the accuracy of memory-based CF through the development of improved similarity measures for finding successful neighbors, there has been less investigation into prediction score methods, in which rating/preference scores are assigned to items that have not yet been selected by a user. A TOPSIS solution for evaluating multiple alternatives based on more than one criterion is proposed as an alternative to prediction score methods for evaluating and ranking items based on the results from similar users. The recommendation accuracy of the proposed TOPSIS technique is evaluated by applying it to various common CF baseline methods, which are then used to analyze the MovieLens 100K and 1M benchmark datasets. The results show that CF based on the TOPSIS method is more accurate than baseline CF methods across a number of common evaluation metrics.
- Full text
View/download PDF
-
Khamis, Heba, Liu, Yingying, and Sowmya, Arcot
- PLoS ONE, Vol 13, Iss 4, p e0195600 (2018)
- Subjects
-
Research Article, Mathematics, Anatomy, Anthropometry, Regression Analysis, Engineering and Technology, Mathematical and Statistical Techniques, Optical Equipment, Measurement, Cameras, Physical Sciences, Distance Measurement, Statistics (Mathematics), Biology and Life Sciences, Research and Analysis Methods, Musculoskeletal System, Equipment, Medicine, Ellipses, Malnutrition, Nutrition, Science, Geometry, Arms, Linear Regression Analysis, Medicine and Health Sciences, Limbs (Anatomy), and Statistical Methods
- Abstract
-
Background Manually measured anthropometric quantities are used in many applications including human malnutrition assessment. Training is required to collect anthropometric measurements manually, which is not ideal in resource-constrained environments. Photogrammetric methods have been gaining attention in recent years, due to the availability and affordability of digital cameras. Objective The primary goal is to demonstrate that height and mid-upper arm circumference (MUAC)–indicators of malnutrition–can be accurately estimated by applying linear regression to distance measurements from photographs of participants taken from five views, and determine the optimal view combinations. A secondary goal is to observe the effect on estimate error of two approaches which reduce complexity of the setup, computational requirements and the expertise required of the observer. Methods Thirty-one participants (11 female, 20 male; 18–37 years) were photographed from five views. Distances were computed using both camera calibration and reference object techniques from manually annotated photos. To estimate height, linear regression was applied to the distances between the top of the participants head and the floor, as well as the height of a bounding box enclosing the participant’s silhouette which eliminates the need to identify the floor. To estimate MUAC, linear regression was applied to the mid-upper arm width. Estimates were computed for all view combinations and performance was compared to other photogrammetric methods from the literature—linear distance method for height, and shape models for MUAC. Results The mean absolute difference (MAD) between the linear regression estimates and manual measurements were smaller compared to other methods. For the optimal view combinations (smallest MAD), the technical error of measurement and coefficient of reliability also indicate the linear regression methods are more reliable. The optimal view combination was the front and side views. When estimating height by linear regression of the distance from the head to the floor, the mean MAD was 10.51 mm ± 6.52 mm SD, and when estimating height from the bounding box using the reference object, the mean MAD per participant was 11.53 mm ± 6.43 mm SD. When estimating MUAC from the mid-upper arm radius using the reference object, the mean MAD was 7.24 mm ± 4.79 mm SD. The mean MAD for all methods when using camera calibration was 2–3 mm smaller. Conclusions Applying linear regression to distance measurements from photos of adults taken from multiple view angles has been shown to accurately estimate height and MUAC to within the accuracy required for nutrition assessment. Future work will focus on automating the landmark detection, and validating the methods on populations that include undernourished adults and children of all nutrition statuses. These future works will improve the practicality of this method as a potential tool for nutrition assessment by novice users.
- Full text
View/download PDF
-
Marshall, Julia, Gollwitzer, Anton, and Santos, Laurie R.
- PLoS ONE, Vol 13, Iss 3, p e0194101 (2018)
- Subjects
-
Research Errors, Research Article, Cognitive Psychology, Theory of Mind, Mathematics, Anatomy, Sociology, Engineering and Technology, Mathematical and Statistical Techniques, Eyes, Measurement, Pervasive Developmental Disorders, Head, Physical Sciences, Psychology, Analysis of Variance, Developmental Psychology, Research Assessment, Autism Spectrum Disorder, Statistics (Mathematics), Biology and Life Sciences, Social Research, Neuroscience, Research and Analysis Methods, Medicine, Ocular System, Social Sciences, Time Measurement, Science, Attention, Medicine and Health Sciences, Statistical Methods, and Cognitive Science
- Abstract
-
Considerable debate has focused on whether adults possess an implicit system for representing others’ mental states. Some argue that people automatically represent the perspective of others using evidence from altercentric interference—cases in which another agent’s perspective affects the speed with which one can report one’s own perspective. Others have argued that altercentric interference is not always specific to social stimuli and thus may represent a simpler process such as submentalizing. To distinguish between these positions, Study 1 developed a novel measure of altercentric interference—a “sandbox” measure—that allowed us to more sensitively assess altercentric interference across social and non-social conditions. We replicated previous findings showing that participants experience both egocentric and altercentric interference, but we found that these effects emerge equally in social and non-social conditions. To further test whether altercentric interference emerges in social perspective-taking situations, Study 2 conducted a conceptual replication of a study which used a novel “goggle” paradigm to assess whether individuals implicitly represent others’ perspectives. Although we failed to find evidence of altercentric interference in response times, participants’ accuracy reflected the possibility of interference from others’ perspectives. We argue that these findings provide support for the idea that altercentric interference in response to social stimuli (an avatar) is driven by perspective-taking mechanisms, while such interference in response to non-social stimuli (an arrow) is driven by attention-cuing mechanisms.
- Full text
View/download PDF
-
de Azevedo Peixoto, Leonardo, de Oliveira, Tássia Boeno, Teodoro, Paulo Eduardo, de Alvarenga, Amauri Alves, Bhering, Leonardo Lopes, Campo, Clara Beatriz Hoffmann, and UFV; UFV; UFV; UFLA; UFV; CLARA BEATRIZ HOFFMANN CAMPO, CNPSO.
- Repositório Institucional da EMBRAPA
PLoS ONE, Vol 13, Iss 2, p e0192189 (2018)
Universidade Federal de Viçosa
Repositório Institucional da UFV
- Subjects
-
Phenols, Probability Theory, Research Article, Medição, Mathematics, Covariance, Plant Breeding, Crops, Mathematical and Statistical Techniques, Phakopsora, Multivariate Analysis, Chemical Compounds, Measurement, Soybeans, Agriculture, Plant Physiology, Physical Sciences, Analysis of Variance, Leaves, Plants, Crop Science, Plant Science, Agronomy, Soybean, Chemistry, Statistics (Mathematics), Biology and Life Sciences, Soja, Research and Analysis Methods, Random Variables, Plant Anatomy, Physiology, Medicine, Ferrugem, Effects, Atividade Enzimática, Science, Soybean rust, Statistical Methods, and Principal Component Analysis
- Abstract
-
Submitted by Marcilene Souza (marcilenesouza86@yahoo.com.br) on 2018-04-16T17:44:43Z No. of bitstreams: 1 artigo.pdf: 3077866 bytes, checksum: 6b325a61b3f8865c33688416ce5a7e71 (MD5) Approved for entry into archive by Nathália Faria da Silva (nathaliafsilva.ufv@gmail.com) on 2018-04-18T12:09:46Z (GMT) No. of bitstreams: 1 artigo.pdf: 3077866 bytes, checksum: 6b325a61b3f8865c33688416ce5a7e71 (MD5) Made available in DSpace on 2018-04-18T12:09:46Z (GMT). No. of bitstreams: 1 artigo.pdf: 3077866 bytes, checksum: 6b325a61b3f8865c33688416ce5a7e71 (MD5) Previous issue date: 2018-01-19 Asian rust affects the physiology of soybean plants and causes losses in yield. Repeatability coefficients may help breeders to know how many measurements are needed to obtain a suitable reliability for a target trait. Therefore, the objectives of this study were to determine the repeatability coefficients of 14 traits in soybean plants inoculated with Phakopsora pachyrhizi and to establish the minimum number of measurements needed to predict the breeding value with high accuracy. Experiments were performed in a 3x2 factorial arrange- ment with three treatments and two inoculations in a random block design. Repeatability coefficients, coefficients of determination and number of measurements needed to obtain a certain reliability were estimated using ANOVA, principal component analysis based on the covariance matrix and the correlation matrix, structural analysis and mixed model. It was observed that the principal component analysis based on the covariance matrix out-per- formed other methods for almost all traits. Significant differences were observed for all traits except internal CO2 concentration for the treatment effects. For the measurement effects, all traits were significantly different. In addition, significant differences were found for all Treatment x Measurement interaction traits except coumestrol, chitinase and chlorophyll content. Six measurements were suitable to obtain a coefficient of determination higher than 0.7 for all traits based on principal component analysis. The information obtained from this research will help breeders and physiologists determine exactly how many measure- ments are needed to evaluate each trait in soybean plants infected by P. pachyrhizi with a desirable reliability.
- Full text
View/download PDF
-
Golacki, K., Grabos, A., and Stropek, Z.
- Inzynieria Rolnicza (Poland), 1999, (no.1) p. 111-117.
- Subjects
-
Mathematical and statistical methods, Research methods, Plant structure, PLANT PRODUCTS, MECHANICAL PROPERTIES, ELASTICITY, STRENGTH, MEASUREMENT, MEASURING INSTRUMENTS, METHODS, MATHEMATICAL MODELS, MATHEMATICS, STATISTICAL METHODS, PRODUIT VEGETAL, PROPRIETE MECANIQUE, ELASTICITE, RESISTANCE MECANIQUE, MESURE, INSTRUMENT DE MESURE, METHODE, MODELE MATHEMATIQUE, MATHEMATIQUE, METHODE STATISTIQUE, PRODUCTOS DE ORIGEN VEGETAL, PROPIEDADES MECANICAS, ELASTICIDAD, RESISTENCIA MECANICA, MEDICION, INSTRUMENTOS DE MEDICION, METODOS, MODELOS MATEMATICOS, MATEMATICAS, and METODOS ESTADISTICOS
- Abstract
-
Summaries (En, Pl)
1 fig., 1 table; 5 ref.
Plant materials of high moisture content and viscoelastic behaviour may be described by generalized Maxwell model. Using this model and making relaxation test consisted in axial squeezing of cylindrical samples at determined speed and deformation extent, the viscoelastic qualities of plant material may be determined. An experimental stand was developed and equipped with force sensor and software for gathering and analysis of measurement data. Actual sample deformation was used for calculation that in the experiment was smaller by the bend of force sensor and constituted a systematic measurement error. Instantaneous sensor bend was determined from force applied and linear sensor characteristics. As a result of numerical computations corrected models' parameters were obtained at 2% systematic error
- Full text View record at AGRIS
-
Clausnitzer, V., Hopmans, J.W., and Starr, J.L.
- Soil Science Society of America (USA), Nov-Dec 1998, v. 62(6) p. 1477-1487.
- Subjects
-
Soil chemistry and physics, Mathematical and statistical methods, INFILTRATION, SIMULATION MODELS, MATHEMATICAL MODELS, EVALUATION, MEASUREMENT, STATISTICAL METHODS, MATHEMATICS, CLAY SOILS, LOAM SOILS, SANDY SOILS, MODELE DE SIMULATION, MODELE MATHEMATIQUE, MESURE, METHODE STATISTIQUE, MATHEMATIQUE, SOL ARGILEUX, SOL SABLOLIMONEUX, SOL SABLEUX, INFILTRACION, MODELOS DE SIMULACION, MODELOS MATEMATICOS, EVALUACION, MEDICION, METODOS ESTADISTICOS, MATEMATICAS, SUELO ARCILLOSO, SUELO FRANCO, SUELO ARENOSO, ERRORS, and MONTE CARLO METHOD
- Abstract
-
references
Water infiltration is a driving force influencing crop growth, soil erosion, and chemical leaching processes. Knowledge of the relative precision and accuracy of infiltration models is needed for best characterization of the infiltration parameters. The two-parameter Green-Ampt and Philip, three-parameter Horton, Mezencev, Swartzendruber, and Parlange et al., and four-parameter Barry et al. infiltration models were compared for their precision and accuracy of estimated parameter confidence intervals using simulated infiltration reference data. To account for potential levels of uncertainty, three levels of measurement error were included using a Monte Carlo analysis. Reference data were generated for a clay and a sandy loam soil using an adaptive-grid finite-element code. Results show that extending the measurement period provided parameter estimates with higher confidence, a more precise estimate of that confidence, and better defined minima in the objective function. The empirical Horton model resulted in the worst fits due to model bias, which also prevented estimation of parameter uncertainty for this model. The semianalytical Swartzendruber and the physically based Parlange et al. and Barry et al. models provided the best fits. Considering all selected criteria, the Swartzendruber model was a reasonable compromise under the conditions imposed in this study
- Full text View on content provider's site
16. Characterization of cider apple fruits according to their degree of ripening. A chemometric approach [1998]
-
Mangas, J.J., Moreno, J., Picinelli, A., and Blanco, D.
- Journal of agricultural and food chemistry (USA), Oct 1998, v. 46(10) p. 4174-4178.
- Subjects
-
Food composition, Mathematical and statistical methods, Food processing and preservation, APPLES, CIDERS, RIPENING, SUGARS, ORGANIC ACIDS, AMINO ACIDS, POLYPHENOLS, PECTINS, GENETIC MARKERS, MEASUREMENT, MATHEMATICS, STATISTICAL METHODS, POMME, CIDRE, MURISSAGE, SUCRES, ACIDE ORGANIQUE, ACIDE AMINE, POLYPHENOL, PECTINE, MARQUEUR GENETIQUE, MESURE, MATHEMATIQUE, METHODE STATISTIQUE, MANZANA, SIDRA, MADURAMIENTO, AZUCARES, ACIDOS ORGANICOS, AMINOACIDOS, POLIFENOLES, PECTINAS, MARCADORES GENETICOS, MEDICION, MATEMATICAS, METODOS ESTADISTICOS, CIDERMAKING, LINEAR DISCRIMINANT ANALYSIS, RIPENING STAGE, PRINCIPAL COMPONENT ANALYSIS, and DISCRIMINANT ANALYSIS
- Abstract
-
references
A chemometric study was carried out in order to typify cider apples according to their degree of ripening. Several chemical variables (sugars, organic acids, amino acids, polyphenols, and pectins) were analyzed using HPLC and FIA methods. Univariate data treatment was not sufficient to allow the apple varieties to be differentiated according to their stage of ripening. Two linear combinations of original variables, ascertained by principal component analysis (PCA), provided an adequate data structurization. To classify apples by their degree of ripening, a mathematical decision rule was established with a prediction capacity of 85% using a LDA method; the most relevant variables in the canonical function ascertained by LDA were sugars, pectins, malic acid, glycine, serine, valine, and glutamic acid. The use of the PLS-2 algorithm demonstrated the influence of the ripening process on the chemical composition of the fruits (R2: 91.7%) and furthermore allowed authors to differentiate apple varieties according to their degree of ripening
- Full text View on content provider's site
-
Gollop, F.M. and Swindand, G.P.
- American journal of agricultural economics (USA), Aug 1998, v. 80(3) p. 577-583, 591-599.
- Subjects
-
Pollution, Organization, administration and management of agricultural enterprises or farms, Mathematical and statistical methods, USA, GROUNDWATER POLLUTION, PESTICIDES, AGRICULTURAL SECTOR, STATISTICAL METHODS, PRODUCTIVITY, MEASUREMENT, PRODUCTION FUNCTIONS, MATHEMATICS, ETATS UNIS, POLLUTION DE L'EAU SOUTERRAINE, PESTICIDE, SECTEUR AGRICOLE, METHODE STATISTIQUE, PRODUCTIVITE, MESURE, FONCTION DE PRODUCTION, MATHEMATIQUE, EUA, POLUCION DE AGUAS SUBTERRANEAS, PLAGUICIDAS, SECTOR AGRARIO, METODOS ESTADISTICOS, PRODUCTIVIDAD, MEDICION, FUNCIONES DE LA PRODUCCION, MATEMATICAS, FACTOR ANALYSIS, and EQUATIONS
- Abstract
-
references. Paper presented at the ASSA winter meeting held January 3-5, 1998, Chicago, Illinois. Discussions by V.K. Smith, p. 591-594, and R.D. Weaver, p. 595-599
- Full text
View/download PDF
-
Lawrence, K.C., Windham, W.R., and Nelson, S.O.
- Transactions of the ASAE (USA), Jan-Feb 1998, v. 41(1) p. 135-142.
- Subjects
-
Food composition, Feed composition, Mathematical and statistical methods, WHEATS, GRAIN, MOISTURE CONTENT, MEASUREMENT, DIELECTRIC PROPERTIES, DENSITY, RADIATION, SPECTROMETRY, MATHEMATICS, STATISTICAL METHODS, BLE, TENEUR EN EAU, MESURE, PROPRIETE DIELECTRIQUE, DENSITE, SPECTROMETRIE, MATHEMATIQUE, METHODE STATISTIQUE, TRIGO, GRANOS, CONTENIDO DE HUMEDAD, MEDICION, PROPIEDADES DIELECTRICAS, DENSIDAD, RADIACION, ESPECTROMETRIA, MATEMATICAS, METODOS ESTADISTICOS, DENSITY-INDEPENDENT MEASUREMENT, BULK DENSITY, RADIO WAVES, SPECTRAL ANALYSIS, ACCURACY, EQUATIONS, MULTIVARIATE ANALYSIS, and PRINCIPAL COMPONENT ANALYSIS
- Abstract
-
references
A technique is presented for rapidly determining the moisture content of hard red winter wheat, Triticum aestivum L., independent of grain bulk density. Complex admittance measurements from 1 to 110 MHz on bulk wheat samples were collected for predicting moisture contents ranging from about 9% to 20%, wet basis, in samples with densities ranging from 0.620 to 0.790 g/cm3. The data were transformed to density-independent function (DIF) values, and multivariate analysis was used to eliminate spectral and statistical outliers. Principal component analysis was also used to determine the optimum frequencies for predicting moisture content with the DIF values. Partial least-squares regression was then used to develop a calibration based on measurements at three frequencies of about 2, 25, and 80 MHz. Calibration was performed with 47 wheat samples representing six cultivars harvested in 1991 and 1992 with a standard error of cross validation of 0.34% moisture content, and validation was tested on 146 different samples from the same cultivars. Predicted moisture contents compared well with values determined by air oven drying with a standard error of performance of 0.39% moisture content and a bias of +0.03%
- Full text View record at AGRIS
-
Wierzbicki, K., Konopka, S., and Choszcz, D.
- Technical Sciences (Poland) / formerly: Acta Academiae Agriculturae ac Technicae Olstenensis (Poland), 1998, (no.1) p. 49-58.
- Subjects
-
Agricultural machinery and equipment, Handling, transport, storage and protection of plant products, Mathematical and statistical methods, VICIA SATIVA, SEED, RYE, GRAIN, SEED MIXTURES, SEPARATING, SEED CLEANING, PHYSICAL PHENOMENA, SEED CLEANERS, EQUIPMENT PARTS, EQUIPMENT PERFORMANCE, LABORATORY EQUIPMENT, PROCESSING QUALITY, MEASUREMENT, LABORATORY EXPERIMENTATION, MATHEMATICS, STATISTICAL METHODS, SEMENCE, SEIGLE, MELANGE DE SEMENCES, SEPARATION, NETTOYAGE DE GRAINS ET SEMENCES, PHENOMENE PHYSIQUE, NETTOYEUR DE GRAINS ET SEMENCES, ELEMENT DE MATERIEL, PERFORMANCE DU MATERIEL, MATERIEL DE LABORATOIRE, QUALITE TECHNOLOGIQUE, MESURE, EXPERIMENTATION EN LABORATOIRE, MATHEMATIQUE, METHODE STATISTIQUE, SEMILLAS, CENTENO, GRANOS, MEZCLA DE SEMILLAS, SEPARACION, LIMPIEZA DE GRANOS Y SEMILLAS, FENOMENO FISICO, LIMPIADORAS DE GRANOS Y SEMILLAS, ELEMENTOS DE MAQUINARIA, DESEMPENO DE LA MAQUINARIA, EQUIPO DE LABORATORIO, CALIDAD DE PROCESAMIENTO, MEDICION, EXPERIMENTACION EN LABORATORIO, MATEMATICAS, and METODOS ESTADISTICOS
- Abstract
-
Summaries (En, Pl)
5 fig.; 5 ref.
The effects of rotational speed, loading volume and composition of seed mixture on caving filling factor were investigated. Truncated cones, narrowing and broading towards the outlet, were used as separation surfaces. The results were statistically analysed and presented in form of diagrams
- Full text View record at AGRIS
20. New interpretation of the fibrogram [1997]
-
Chu, Y.T. and Riley, C.R. Jr.
- Textile research journal : publication of Textile Research Institute, Inc. and the Textile Foundation (USA), Dec 1997, v. 67(12) p. 897-901.
- Subjects
-
Processing of non-food or non-feed agricultural products, Mathematical and statistical methods, COTTON, FIBRES, LENGTH, MEASUREMENT, STATISTICAL METHODS, MATHEMATICS, COTON, FIBRE, LONGUEUR, MESURE, METHODE STATISTIQUE, MATHEMATIQUE, ALGODON, FIBRAS, LARGURA, MEDICION, METODOS ESTADISTICOS, MATEMATICAS, COTTON FIBER BEARDS, DISTRIBUTION, THEORY, and PROBABILITY
- Abstract
-
references
- Full text View on content provider's site
Catalog
Books, media, physical & digital resources
Guides
Course- and topic-based guides to collections, tools, and services.
1 - 20
Next