scholarly journals Brief history and future of animal simulation models for science and application

2014 ◽  
Vol 54 (12) ◽  
pp. 1883 ◽  
Author(s):  
J. L. Black

Mathematical equations have been used to add quantitative rigour to the description of animal systems for the last 100 years. Initially, simple equations were used to describe the growth of animals or their parts and to predict nutrient requirements for different livestock species. The advent of computers led to development of complex multi-equation, dynamic models of animal metabolism and of the interaction between animals and their environment. An understanding was developed about how animal systems could be integrated in models to obtain the most realistic prediction of observations and allow accurate predictions of as yet unobserved events. Animal models have been used to illustrate how well animal systems are understood and to identify areas requiring further research. Many animal models have been developed with the aim of evaluating alternative management strategies within animal enterprises. Several important gaps in current animal models requiring further development are identified: including a more mechanistic representation of the control of feed intake; inclusion of methyl-donor requirements and simulation of the methionine cycle; plus a more mechanistic representation of disease and the impact of microbial loads under production environments. Reasons are identified why few animal models have been used for day-to-day decision making on farm. In the future, animal simulation models are envisaged to function as real-time control of systems within animal enterprises to optimise animal productivity, carcass quality, health, welfare and to maximise profit. Further development will be required for the integration of models that run real time in enterprise management systems adopting precision livestock farming technologies.

Parasitology ◽  
2016 ◽  
Vol 143 (7) ◽  
pp. 805-820 ◽  
Author(s):  
HAMISH McCALLUM

SUMMARYModelling wildlife disease poses some unique challenges. Wildlife disease systems are data poor in comparison with human or livestock disease systems, and the impact of disease on population size is often the key question of interest. This review concentrates specifically on the application of dynamic models to evaluate and guide management strategies. Models have proved useful particularly in two areas. They have been widely used to evaluate vaccination strategies, both for protecting endangered species and for preventing spillover from wildlife to humans or livestock. They have also been extensively used to evaluate culling strategies, again both for diseases in species of conservation interest and to prevent spillover. In addition, models are important to evaluate the potential of parasites and pathogens as biological control agents. The review concludes by identifying some key research gaps, which are further development of models of macroparasites, deciding on appropriate levels of complexity, modelling genetic management and connecting models to data.


1997 ◽  
Vol 36 (8-9) ◽  
pp. 19-24 ◽  
Author(s):  
Richard Norreys ◽  
Ian Cluckie

Conventional UDS models are mechanistic which though appropriate for design purposes are less well suited to real-time control because they are slow running, difficult to calibrate, difficult to re-calibrate in real time and have trouble handling noisy data. At Salford University a novel hybrid of dynamic and empirical modelling has been developed, to combine the speed of the empirical model with the ability to simulate complex and non-linear systems of the mechanistic/dynamic models. This paper details the ‘knowledge acquisition module’ software and how it has been applied to construct a model of a large urban drainage system. The paper goes on to detail how the model has been linked with real-time radar data inputs from the MARS c-band radar.


1998 ◽  
Vol 37 (1) ◽  
pp. 347-354 ◽  
Author(s):  
Ole Mark ◽  
Claes Hernebring ◽  
Peter Magnusson

The present paper describes the Helsingborg Pilot Project, a part of the Technology Validation Project: “Integrated Wastewater” (TVP) under the EU Innovation Programme. The objective of the Helsingborg Pilot Project is to demonstrate implementation of integrated tools for the simulation of the sewer system and the wastewater treatment plant (WWTP), both in the analyses and the operational phases. The paper deals with the programme for investigating the impact of real time control (RTC) on the performance of the sewer system and wastewater treatment plant. As the project still is in a very early phase, this paper focuses on the modelling of the transport of pollutants and the evaluation of the effect on the sediment deposition pattern from the implementation of real time control in the sewer system.


Author(s):  
Weiwei Yang ◽  
Jiejunyi Liang ◽  
Jue Yang ◽  
Nong Zhang

Considering the energy consumption and specific performance requirements of mining trucks, a novel uninterrupted multi-speed transmission is proposed in this paper, which is composed of a power-split device, and a three-speed lay-shaft transmission with a traction motor. The power-split device is adapted to enhance the efficiency of the engine by adjusting the gear ratio continuously. The three-speed lay-shaft transmission is designed based on the efficiency map of traction motor to guarantee the drivability. The combination of the power-split device and three-speed lay-shaft transmission can realize uninterrupted gear shifting with the proposed shift strategy, which benefits from the proposed adjunct function by adequately compensating the torque hole. The detailed dynamic models of the system are built to verify the effectiveness of the proposed shift strategy. To evaluate the maximum fuel efficiency that the proposed uninterrupted multi-speed transmission could achieve, dynamic programming is implemented as the baseline. Due to the “dimension curse” of dynamic programming, a real-time control strategy is designed, which can significantly improve the computing efficiency. The simulation results demonstrate that the proposed uninterrupted multi-speed transmission with dynamic programming and real-time control strategy can improve fuel efficiency by 11.63% and 8.51% compared with conventional automated manual transmission system, respectively.


Author(s):  
V. P. Lysenko ◽  
I. S. Chernova

Annotation Purpose. Improving the efficiency of entomophages production by developing innovative approaches for it management. Methods. System approach, intelligent information technologies. Results. Innovative approaches for it management of entomophages production have been developed, which consist of: determining and ranking the factors that have the greatest impact on the quality of entomological products, and factors that lead to substandard products; the creation of structural and parametric complexes for assessing product quality; real-time assessment of the intensity of entomocultures development processes; automation of management abiotic parameters stepwise development of insects (temperature and relative humidity of the box for growing of insects) in real time; determining the quality of entomological products in conditions of incomplete information, taking into account the impact of a combination of abiotic and biotic production parameters; calculation of optimal values of production parameters in conditions of uncertainty; systematization of knowledge about the interaction of heterogeneous parameters in the production of entomophages. Conclusions. The proposed innovative approaches to manage the production of entomophages can increase its efficiency by forming optimal management strategies, using the technological experience of specialists and modern intelligent information technologies in particular, SCADA-systems, fuzzy logic theory and cognitive analysis. Keywords: innovative approaches, production of entomophages, intelligent information technologies.


2002 ◽  
Vol 45 (3) ◽  
pp. 229-237 ◽  
Author(s):  
T. Frehmann ◽  
A. Niemann ◽  
P. Ustohal ◽  
W.F. Geiger

Four individual mathematical submodels simulating different subsystems of urban drainage were intercoupled to an integral model. The submodels (for surface runoff, flow in sewer system, wastewater treatment plant and receiving water) were calibrated on the basis of field data measured in an existing urban catchment investigation. Three different strategies for controlling the discharge in the sewer network were defined and implemented in the integral model. The impact of these control measures was quantified by representative immission state-parameters of the receiving water. The results reveal that the effect of a control measure may be ambivalent, depending on the referred component of a complex drainage system. Furthermore, it is demonstrated that the drainage system in the catchment investigation can be considerably optimised towards environmental protection and operation efficiency if an appropriate real time control on the integral scale is applied.


2020 ◽  
Author(s):  
Sara König ◽  
Ulrich Weller ◽  
Birgit Lang ◽  
Mareike Ließ ◽  
Stefanie Mayer ◽  
...  

<p>The increasing demand for food and bio-energy gives need to optimize soil productivity, while securing other soil functions such as nutrient cycling and buffer capacity, carbon storage, biological activity, and water filter and storage. Mechanistic simulation models are an essential tool to fully understand and predict the complex interactions between physical, biological and chemical processes of soil with those functions, as well as the feedbacks between these functions.</p><p>We developed a systemic soil model to simulate the impact of different management options and changing climate on the named soil functions by integrating them within a simplified system. The model operates on a 1d soil profile consisting of dynamic nodes, which may represent the different soil horizons, and integrates different processes including dynamic water distribution, soil organic matter turnover, crop growth, nitrogen cycling, and root growth.</p><p>We present the main features of our model by simulating crop growth under various climatic scenarios on different soil types including management strategies affecting the soil structure. We show the relevance of soil structure for the main soil functions and discuss different model outcome variables as possible measures for these functions.</p><p>Further, we discuss ongoing model extensions, especially regarding the integration of biological processes, and possible applications.</p>


1998 ◽  
Vol 25 (5) ◽  
pp. 844-853
Author(s):  
Andrée Bilodeau ◽  
Alain Mailhot ◽  
Jean-Pierre Villeneuve

This paper presents results of a study the goal of which is to evaluate the impact of rainfall forecast errors on real time control (RTC) of combined sewers in the Québec Urban Community (Q.U.C.). Firstly, we analyzed the impact of different levels of uncertainty on the probability to generate overloads in combined sewers and on the optimal overflow volume. The effects of the spatial distribution of errors on overloads and on overflow volumes have also been studied. Secondly, we modified the system management decision criteria in order to reduce the overload probability and to avoid possible backflows. This modification consisted of reducing the maximum allowable flow in the pipes of the sewer network. The results obtained showed that despite the negative impacts of forecast errors on overloads, this simple method preserves the efficiency of predictive integrated management. This ensures a safety margin on the possible backflows due to meteorological forecast errors.Key words: overflow, real time, control, combined sewers, forecast, errors, rain, overloads, backflows.


2021 ◽  
Author(s):  
Robert Seifert ◽  
Johannes Porstmann ◽  
Wilfried Hofmann

Previous works have demonstrated that analytical high-fidelity models of nonlaminated actuators and magnetic thrust bearings cannot just describe the magnetic skin effect inside the solid core, but also be applied directly within the control circuit. By an appropriate rational approximation a digital implementation on a microcontroller becomes possible. However, these approximated models neither considered hysteresis and saturation nor frequency-dependent fringing and leakage fluxes. This article elaborates whether or not these nonlinearities can and should be included in real-time control systems. We present an improved process to map an analytical hysteresis model to a limited measured dataset and discuss the impact of the nonlinear magnetization curve. It leads to a novel fractional-order all-pass filter, modeling the frequency-dependent hysteresis angle for a single load point. Its rational filter form is suitable for implementation in Matlab/Simulink as well as real-time applications. Leakage and fringing fluxes, on the other hand, can be considered with relatively low effort within the original analytical models. The underlying reluctance network is determined by a FE-analysis as well as analytically and reduced to a highly simplified form. Depending on whether the total flux or the force-dependent flux is of interest, the model order may increase significantly and constant correction factors are preferable. <br>


2002 ◽  
Vol 45 (4-5) ◽  
pp. 373-381 ◽  
Author(s):  
J. Meirlaen ◽  
P.A. Vanrolleghem

Real time control is one of the possibilities to minimise the impact of the integrated urban wastewater system (sewer system and treatment plant) on the receiving water quality. Integrated control uses information about the river state to act in the sewer system or in treatment plant. In order to test and tune these integrated controllers, a simplified integrated model is needed. Even with these simplified models, the simulation times may be too long and further model reduction is needed. In this paper, dependency-structure based model reduction is proposed as a technique to further reduce model complexity. Three steps are proposed: relocation of the upstream system boundaries to just upstream of the first control point, relocation of the downstream boundaries to just downstream of the last measurement point, and third, a further model simplification based on an analysis of the sensitivity of the control actions on submodel elimination. The effect of applying the different reduction approaches on the control strategy and on the resulting river water quality is discussed on the basis of a case study of the catchment of Tielt.


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