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Inferences on Growth in Biological Populations Via distributed parameters

IFAC Proceedings Volumes 1988年第1期21卷 281-286页

作者： K.L. Q. Read P.J. B. Berry Department of Mathematical Statistics and Operational Research University of Exeter Exeter UK Pfizer Central Research Sandwich Kent UK

A flexible system of nonlinear statistical models based on Gamma distributions of integer order has been developed to describe aspects of animal growth and development in quantitative terms, Models from this system have been applied to data concerning the generation and growth of ovarian follicles in infant Wistar rats and shown to fit for a range of animals aged 8–24 days. The problem discussed here is how to combine the data from different animals to provide inferences on the parameters describing the population from which the experimental animals are assumed to be a random sample. This work is of methodological interest, since the information matrices of the estimates specific to individual animals vary depending on age and/or biological development. However, insofar as the underlying form of model is deemed adequate, the specific parameters may be regarded as randomly distributed about global population values which are fixed throughout time. On the standard asymptotic theory, estimates of parameters for individual animals are taken as Normally distributed, with dispersion matrices estimated in the usual way, and animals are considered to be independent. It is natural to assume that the animal-specific parameters are themselves Normal, and the main work of this paper is to discuss the estimation of this global distribution. The effects of parametric redundancies and other computational issues are assessed in the context of the results obtained for the Wistar rat data. Clearly, the theory discussed here is applicable generally to the estimation of population or reference values for developmental or growth parameters in humans or other animals.

关键词： Statistics Biology Models Maximum Likelihood distributed parameters

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The Calculation Method Research on the distributed parameters of the Transmission Line in Lossy Semi-infinite Medium

The Calculation Method Research on the Distributed Parameter...

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2014 International Conference on Electrical and Electronic Engineering(EEE 2014)

作者： Zi-wen MAO Cheng GAO Hai-lin CHEN Wan-yang ZHOU Feng NI National Key Laboratory on Electromagnetic Environment Effects and Electro-optical Engineering PLA University of Science and Technology PLA 73698 Troops

To obtain the distributed parameters and the characteristic impedance of the transmission line in lossy semi-infinite medium,the electric vector potential of the horizontal electric dipole in lossy semi-infinite medium is ***,the electric vector potential of the horizontal electric dipole in lossy semi-infinite medium is calculated by using the method of images,static electric and magnetic field theories and so *** distributed inductance of the transmission line is obtained by the numerical integration of the electric vector ***,the characteristic impedance of the transmission line is given.

关键词： Lossy semi-infinite medium Horizontal electric dipole Electric vector potential Method of images distributed parameters

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Spectral Problems in the Monitoring of distributed Safety parameters of Objects in the Technosphere

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MEASUREMENT TECHNIQUES 2016年第5期59卷 505-511页

作者： Khlystunov, M. S. Poduval'tsev, V. V. Mogilyuk, Zh. G. Moscow State Construct Univ Moscow Russia Bauman Moscow State Tech Univ Moscow Russia Natl Res Nucl Univ MEPhI Moscow Engn Phys Inst Moscow Russia

Metrological aspects of the monitoring of distributed safety parameters of objects in the technosphere are discussed. Amplitude and phase frequency characteristics of the spectra of the spatial distribution of monitored parameters are presented for various sensor positioning schemes. A comparative analysis is made of the effect of the density and uniformity of sensor positioning schemes on the error of monitoring systems. A set of tasks is formulated for eliminating error in monitoring systems for multidimensional processes.

关键词： technosphere safety distributed parameters monitoring schemes spectrum monitoring system error

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Modelling bagpipes: numerical simulation exercise for distributed parameter system

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EUROPEAN JOURNAL OF PHYSICS 2025年第2期46卷 025001-025001页

作者： Tuzil, Josef Slegr, Jan Univ Hradec Kralove Rokitanskeho 62 Hradec Kralove Czech Republic

Bagpipes are an ancient folk musical instrument, used as far back as ancient Greece. To this day, they are part of folk music in many countries and cultures. This paper deals with the modelling of the reed and melodic pipe (chanter) for bagpipes, focusing on tuning of the instrument. We present a theoretical model in the Geogebra software, which allows for qualitative simulating and visualizing the interaction between the reed blade and the air column of the pipe.

关键词： modelling bagpipes numerical simulation distributed parameters

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Drying of guaco leaves: experimental and modeling kinetic, equilibrium isotherms and heat of desorption

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JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY 2022年第13期147卷 7411-7420页

作者： Martins, Marina Roberto Johann, Gracielle Palu, Fernando da Silva, Edson Antonio Western State Univ Parana Chem Engn Course Rua Fac 645 BR-85903000 Toledo PR Brazil Fed Technol Univ Parana Bioprocesss Engn & Biotechnol Course Estr Boa EsperancaKm 04 BR-85660000 Curitiba PR Brazil

Due to the huge variety of therapeutic properties found in plant leaves, many of these are widely used in traditional medicine. Among these plants, guaco, which has a rich in chlorogenic acids composition, is considered exotic in Brazil, being, therefore, an environmental problem. In this context, this study obtained the drying kinetics and the experimental equilibrium isotherms of guaco leaves, in the 40 to 70 degrees C range. Oswin's empirical model described 96% of the equilibrium data. The phenomenological mathematical model of distributed parameters, solved with the employment of thermo-physical properties, obtained from the centesimal composition, described 99% of the thin layer drying kinetics of guaco leaves. The heat of desorption, obtained by the Othmer method, ranged from 2375 to 3858 kJ kg(-1), for the moisture in the range of 0.05 and 0.35 (d.b.). With the obtained results, it is possible to estimate both the drying time and the amount of energy needed to reach the final moisture which is safe for the storage of guaco leaves.

关键词： Medicinal plant Safe storage Thermo-physical properties Energy consumption distributed parameters

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On Modelling of Co-current Rotary Dryers

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REVISTA IBEROAMERICANA DE AUTOMATICA E INFORMATICA INDUSTRIAL 2009年第4期6卷 32-+页

作者： Castano, F. Rubio, F. R. Ortega, M. G. Univ Seville Dept Ingn Sistemas & Automat Seville 41092 Spain

This paper presents a methodology for the modelling Of co-current rotary dryers. The model is based in parametric differential equations and in the use of some correlations that allow simplifying the processing. In the work, which aspects of modelling are common to most installations are distinguished, and which ones are particular of each one depending on its configuration or drying material. It is also shown the tests to which the material has to be subjected to for,the determination of some analytical expressions that are essential in the model. Likewise, the application of the modelling to an experimental rotary dryer of sand is presented. Copyright (C) 2009 CEA.

关键词： Rotary dryer Modelling Differencial equations distributed parameters Correlation coefficients

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A study of a water desalination station using the SMCEC technique: production optimisation

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RENEWABLE ENERGY 2000年第3-4期21卷 523-536页

作者： Ben Bacha, H Bouzguenda, M Damak, T Abid, MS Maalej, AY Ecole Natl Ingenieurs Sfax Dept Mech Engn LADS Sfax Tunisia

Following the detailed study of the three modules of the Solar Multiple Condensation Evaporation Cycle (SMCEC)-based desalination unit located in Sfax, Tunisia, it was found necessary to couple the three modules, to simulate the desalination unit operation in an environment close to that of the real process and to develop a regulation scheme that would optimise the desalination production. The developed models were then reduced using the orthogonal collocation method. Based on the reduced models, several cases of numerical simulation of the unit operation have been conducted to monitor the evolution of the unit operation as a function of its command parameters and external perturbations. In this study and for the sake of optimising the desalination unit operation, a global model is developed based on which a regulation algorithm is designed. (C) 2000 Elsevier Science Ltd. All rights reserved.

关键词： solar energy water desalination SMCEC global dynamic model distributed parameters orthogonal collocation numerical simulation dynamic behaviour production control regulation algorithm optimisation

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Using Universal Line Model (ULM) for Representing Electromagnetic Transients in Three-Phase Transmission Lines

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IEEE LATIN AMERICA TRANSACTIONS 2014年第2期12卷 190-196页

作者： de Araujo, A. R. J. da Silva, R. C. Kurokawa, S. Univ Estadual Paulista UNESP Ilha Solteira SP Brazil IFSP Campi Votuporanga Votuporanga SP Brazil

The second-order differential equations that describe the polyphase transmission line are difficult to solve due to the mutual coupling among them and the fact that the parameters are distributed along their length. A method for the analysis of polyphase systems is the technique that decouples their phases. Thus, a system that has n phases coupled can be represented by n decoupled single-phase systems which are mathematically identical to the original system. Once obtained the n-phase circuit, it's possible to calculate the voltages and currents at any point on the line using computational methods. The Universal Line Model (ULM) transforms the differential equations in the time domain to algebraic equations in the frequency domain, solve them and obtain the solution in the frequency domain using the inverse Laplace transform. This work will analyze the method of modal decomposition in a three-phase transmission line for the evaluation of voltages and currents of the line during the energizing process.

关键词： Electromagnetic Transients transmission lines modal decomposition distributed parameters

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High-Voltage Cable Buffer Layer Ablation Fault Identification Based on Artificial Intelligence and Frequency Domain Impedance Spectroscopy

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SENSORS 2024年第10期24卷 3067页

作者： Liu, Jiajun Ma, Mingchao Liu, Xin Xu, Haokun Xian Univ Technol Sch Elect Engn Xian 710054 Peoples R China

In recent years, the occurrence of high-voltage cable buffer layer ablation faults has become frequent, posing a serious threat to the safe and stable operation of cables. Failure to promptly detect and address such faults may lead to cable breakdowns, impacting the normal operation of the power system. To overcome the limitations of existing methods for identifying buffer layer ablation faults in high-voltage cables, a method for identifying buffer layer ablation faults based on frequency domain impedance spectroscopy and artificial intelligence is proposed. Firstly, based on the cable distributed parameter model and frequency domain impedance spectroscopy, a mathematical model of the input impedance of a cable containing buffer layer ablation faults is derived. Through a simulation, the input impedance spectroscopy at the first end of the cables under normal conditions, buffer layer ablation, local aging, and inductive faults is performed, enabling the identification of inductive and capacitive faults through a comparative analysis. Secondly, the frequency domain amplitude spectroscopy of the buffer layer ablation and local aging faults are used as datasets and are input into a neural network model for training and validation to identify buffer layer ablation and local aging faults. Finally, using multiple evaluation metrics to assess the neural network model validates the superiority of the MLP neural network in cable fault identification models and experimentally confirms the effectiveness of the proposed method.

关键词： buffer layer ablation artificial intelligence distributed parameters fault identification

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State estimation for a large-scale wastewater treatment system

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AUTOMATICA 1996年第3期32卷 305-317页

作者： Tenno, R Uronen, P Lab. of Proc. Control and Management Helsinki University of Technology SF-02150 Espoo Kemistintie 1 Finland

A new distributed parameter stochastic model is introduced for modelling a large-scale wastewater treatment system with distributed water feeding, sludge recycling and removal. The state estimation problem is formulated as a biomass and organic matter profile estimation problem for the aeration basin. It is solved by approximation of the original model with a finite-dimensional bilinear model and the filtration distribution with the normal distribution. It is shown that the profile can be estimated online using dissolved oxygen and gas analysis results measured from several points over the aeration basin. The estimation quality is higher in the case of a large-scale aeration basin than in the case of a completely mixed basin. The estimation algorithm is obtained in a computationally effective form. The model and the estimation algorithm are tested in a simulation experiment. It is demonstrated that the sludge and water distribution has a strong effect on treated water quality. The distribution is considered as a new control parameter. It can be used in practice for improvement of treatment process quality.

关键词： biotechnology wastewater treatment modelling distributed parameters partially observable stochastic system state estimation

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