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1.
Theory Biosci ; 142(3): 221-234, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37421497

ABSTRACT

For this research, the properties of the logistic growth model for independent and coexisting species were used to set definitions for the possible regulation of one or two growth variables through their coupling parameters. The present analysis is done for the single-species Verhulst model without coupling, the single-species Verhulst model coupled with an exogenous signal, and the two-species Verhulst coexistence growth model which represents six different ecological regimes of interaction. The models' parameters, such as the intrinsic growth rate and the coupling, are defined. Finally, the control results are expressed as lemmas for regulation, and they are shown using a simulation example of a fish population growing independent of human interaction (no harvesting, no fishing) and the simulation of the regulation of said population when the coupling of fish and humans is involved (harvesting, fishing).


Subject(s)
Models, Biological , Population Growth , Animals , Humans , Population Dynamics , Computer Simulation
2.
ISA Trans ; 100: 358-372, 2020 May.
Article in English | MEDLINE | ID: mdl-31733892

ABSTRACT

In this research, fault detection and diagnosis (FDD) scheme for isolating the damaged injector of an internal combustion engine is formulated and experimentally applied. The FDD scheme is based on a temporal analysis (statistical methods), as well as in a frequency analysis (fast Fourier transform) of the fuel rail pressure. The arrangement of the scheme consists of three coupled artificial neural networks (ANNs) to classify the faulty injector correctly. The ANNs were trained considering five different scenarios, one scenario without fault in the injection system, and the other four scenarios represent a fault per injector (1 to 4). The Levenberg-Marquardt (LM), BFGS quasi-Newton, gradient descent (GD), and extreme learning machine (ELM) algorithms were tested to select the best training algorithm to classify the faults. Experimental results obtained from the implementation in a VW four-cylinder CBU 2.5L vehicle in idle operating conditions (800 rpm) show the effectiveness of the proposed FDD scheme.

3.
Pediatr Obes ; 14(3): e12476, 2019 03.
Article in English | MEDLINE | ID: mdl-30362284

ABSTRACT

BACKGROUND: The sequence of prenatal growth restraint and postnatal catch-up growth leads to a thicker intima-media and more pre-peritoneal fat by age 3-6 years. OBJECTIVES: To study whether carotid intima-media thickness (cIMT) and pre-peritoneal fat differ already between catch-up small-for-gestational-age (SGA) infants and appropriate-for-gestational-age (AGA) controls in late infancy (ages 1 and 2 years) and whether such differences - if any - are accompanied by differences in cardiac morphology and function. METHODS: Longitudinal assessments included body height and weight; fasting glucose, insulin, Insulin-like growth factor (IGF-I), high-molecular-weight adiponectin; body composition (by absorptiometry); cIMT, aortic IMT, pre-peritoneal fat partitioning (by ultrasound); cardiac morphometry and function (by echocardiography) in AGA and SGA infants at birth, at age 1 year (N = 87), and again at age 2 years (N = 68). RESULTS: Catch-up SGA infants had already a thicker cIMT than AGA controls at ages 1 and 2 years, and more pre-peritoneal fat by age 2 years (all p values between <0.01 and <0.0001); all cardiac and endocrine-metabolic results were similar in AGA and SGA infants at ages 1 and 2 years. CONCLUSIONS: From late infancy onwards, catch-up SGA infants have a thicker cIMT and more pre-peritoneal fat than AGA controls, but their cardiac morphology and function remain reassuringly similar.


Subject(s)
Abdominal Fat/physiology , Carotid Intima-Media Thickness/statistics & numerical data , Child Development/physiology , Heart/physiology , Infant, Small for Gestational Age/physiology , Adiponectin/blood , Blood Glucose/physiology , Body Composition/physiology , Body Height , Body Weight , Child, Preschool , Echocardiography/methods , Female , Humans , Infant , Infant, Newborn , Insulin/blood , Insulin-Like Growth Factor I/analysis , Longitudinal Studies , Male , Pregnancy , Prospective Studies
4.
Int J Obes (Lond) ; 42(4): 915-918, 2018 04.
Article in English | MEDLINE | ID: mdl-29089613

ABSTRACT

Low birth weight followed by rapid postnatal weight gain is associated with increased risks for obesity and diabetes in adulthood. Modulation of glucagon-like-peptide 1 (GLP-1) secretion by (epi)genetic mechanisms or nutrition may, in part, influence this risk. Formula-fed infants born small-for-gestational-age (SGA) have higher circulating GLP-1 at age 4 months than breastfed SGA or appropriate-for-gestational-age (AGA) infants. Here we assessed GLP-1 concentrations in healthy AGA (n=149) and SGA (n=107) subjects at age 12 months and their association with endocrine-metabolic and body composition parameters and GLP-1 receptor (GLP-1R) rs6923761 and rs3765467 polymorphisms. At birth, cord GLP-1 concentrations were comparable in AGA and SGA infants. At age 12 months, insulin-like growth factor I (IGF-I) and GLP-1 levels were higher than at birth; SGA infants displayed higher IGF-I and GLP-1 concentrations than AGA infants (both P<0.001) that were unrelated to neonatal nutrition or GLP-1R genotype and that were paralleled by a significant increase in weight Z-score (P<0.001 vs AGA). In conclusion, SGA infants have augmented IGF-I and prefeeding GLP-1 concentrations in late infancy. Increased GLP-1 levels may impair hypothalamic and/or peripheral GLP-1R signaling, exert long-term negative effects on the hypothalamic nuclei regulating energy homeostasis and increase the risks for obesity and diabetes.


Subject(s)
Glucagon-Like Peptide 1/blood , Glucagon-Like Peptide-1 Receptor/genetics , Infant, Low Birth Weight/metabolism , Insulin-Like Growth Factor I/analysis , Nutritional Status/physiology , Adult , Breast Feeding , Female , Humans , Infant , Infant, Low Birth Weight/blood , Infant, Newborn , Longitudinal Studies , Male , Polymorphism, Single Nucleotide/genetics
5.
ISA Trans ; 68: 433-449, 2017 May.
Article in English | MEDLINE | ID: mdl-28209426

ABSTRACT

This paper presents the problem of safe and fast transportation of packages by an Unmanned Aerial Vehicle (UAV) kind quadrotor. A mathematical model and a control strategy for a special class of underactuated mechanical systems, composed of a quadrotor transporting a cable-suspended payload, are proposed. The Euler-Lagrange formulation is used to obtain the dynamic model of the system, where the integrated dynamics of the quadrotor, cable and payload are considered. An Interconnection and Damping Assignment-Passivity Based Control (IDA-PBC) is chosen because of its inherent robustness against parametric uncertainty and unmodeled dynamics. Two cases are considered to obtain two different control laws, in the first case, the designed control law depends on the swing angle of the payload, in the second case the control law does not depend on it. The control objective is to transport the payload from point to point, with swing reduction along trajectory. Experimental results using monocular vision based navigation are shown to evaluate the proposed control law.

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