The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
Tania Pencheva - One of the best experts on this subject based on the ideXlab platform.
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Functional State Modelling of Saccharomyces cerevisiae Cultivations
2020Co-Authors: Tania Pencheva, Iasen Hristozov, Stoyan Tzonkov, Bernd HitzmannAbstract:The implementation of Functional State approach for modelling of yeast cultivation is considered in this paper. This concept helps in monitoring and control of complex processes such as bioprocesses. Using of Functional State modelling approach for fermentation processes aims to overcome the main disadvantage of using global process model, namely complex model structure and big number of model parameters. The main advantage of Functional State modelling is that the parameters of each local model can be separately estimated from other local models parameters. The results achieved from batch, as well as from fed-batch, cultivations are presented.
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Functional State modelling approach for batch cultivation of Saccharomyces cerevisiae
Chemical and Biochemical Engineering Quarterly, 2020Co-Authors: Iasen Hristozov, Tania Pencheva, Tzonkov, Bernd HitzmannAbstract:An application of Functional State modelling approach for aerobic batch baker's yeast cultivation is presented in this paper. The Functional State approach is appropriate for description, monitoring and control of complexprocesses such as bioprocesses. The main idea is to divide the process into macroStates, called Functional States, according to behavioural equivalence. In each Functional State the process is described by a conventional type of model, called a local model, which is valid in this Functional State only. Functional State modelling approach is more convenient than using of a global model when parameter estimation should be made. The main advantage of Functional State modelling approach is that the parameters of each local model can be separately estimated from the parameters of the other local models. The concept of Functional State modelling approach is applied for real aerobic batch baker's yeast cultivation.
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IMPLEMENTATION OF Functional State APPROACH FOR MODELLING OF ESCHERICHIA COLI FED-BATCH CULTIVATION
Biotechnology & Biotechnological Equipment, 2020Co-Authors: Olympia Roeva, Tania Pencheva, Bernd Hitzmann, Y. Georgieva, Stoyan TzonkovAbstract:ABSTRACTThis paper presents the implementation of Functional State approach to modelling of Escherichia coli fed-batch cultivation. Due to the complex metabolic pathways of microorganisms, the accurate modelling of bioprocesses is rather difficult. The Functional State approach of a process is an alternative concept which helps in modelling and control of complex processes. The approach main idea is developing of models based on multiple submodels for each Functional States (operating regime). In each Functional State the process is described by a conventional type of model, called the local model, which is valid in this State. For parameter identification of the model the genetic algorithms are used. Genetic algorithms are directed random search techniques, applying the mechanics of natural selection and natural genetics, which can find the global optimal solution in complex multidimensional search spaces. Based on the available experimental data and simulations of E. coli fed-batch cultivation it is sho...
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Functional State modelling approach validation for yeast and bacteria cultivations
Biotechnology & Biotechnological Equipment, 2014Co-Authors: Olympia Roeva, Tania PenchevaAbstract:In this paper, the Functional State modelling approach is validated for modelling of the cultivation of two different microorganisms: yeast (Saccharomyces cerevisiae) and bacteria (Escherichia coli). Based on the available experimental data for these fed-batch cultivation processes, three different Functional States are distinguished, namely primary product synthesis State, mixed oxidative State and secondary product synthesis State. Parameter identification procedures for different local models are performed using genetic algorithms. The simulation results show high degree of adequacy of the models describing these Functional States for both S. cerevisiae and E. coli cultivations. Thus, the local models are validated for the cultivation of both microorganisms. This fact is a strong structure model verification of the Functional State modelling theory not only for a set of yeast cultivations, but also for bacteria cultivation. As such, the obtained results demonstrate the efficiency and efficacy of the Functional State modelling approach.
Bernd Hitzmann - One of the best experts on this subject based on the ideXlab platform.
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Functional State Modelling of Saccharomyces cerevisiae Cultivations
2020Co-Authors: Tania Pencheva, Iasen Hristozov, Stoyan Tzonkov, Bernd HitzmannAbstract:The implementation of Functional State approach for modelling of yeast cultivation is considered in this paper. This concept helps in monitoring and control of complex processes such as bioprocesses. Using of Functional State modelling approach for fermentation processes aims to overcome the main disadvantage of using global process model, namely complex model structure and big number of model parameters. The main advantage of Functional State modelling is that the parameters of each local model can be separately estimated from other local models parameters. The results achieved from batch, as well as from fed-batch, cultivations are presented.
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Functional State modelling approach for batch cultivation of Saccharomyces cerevisiae
Chemical and Biochemical Engineering Quarterly, 2020Co-Authors: Iasen Hristozov, Tania Pencheva, Tzonkov, Bernd HitzmannAbstract:An application of Functional State modelling approach for aerobic batch baker's yeast cultivation is presented in this paper. The Functional State approach is appropriate for description, monitoring and control of complexprocesses such as bioprocesses. The main idea is to divide the process into macroStates, called Functional States, according to behavioural equivalence. In each Functional State the process is described by a conventional type of model, called a local model, which is valid in this Functional State only. Functional State modelling approach is more convenient than using of a global model when parameter estimation should be made. The main advantage of Functional State modelling approach is that the parameters of each local model can be separately estimated from the parameters of the other local models. The concept of Functional State modelling approach is applied for real aerobic batch baker's yeast cultivation.
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IMPLEMENTATION OF Functional State APPROACH FOR MODELLING OF ESCHERICHIA COLI FED-BATCH CULTIVATION
Biotechnology & Biotechnological Equipment, 2020Co-Authors: Olympia Roeva, Tania Pencheva, Bernd Hitzmann, Y. Georgieva, Stoyan TzonkovAbstract:ABSTRACTThis paper presents the implementation of Functional State approach to modelling of Escherichia coli fed-batch cultivation. Due to the complex metabolic pathways of microorganisms, the accurate modelling of bioprocesses is rather difficult. The Functional State approach of a process is an alternative concept which helps in modelling and control of complex processes. The approach main idea is developing of models based on multiple submodels for each Functional States (operating regime). In each Functional State the process is described by a conventional type of model, called the local model, which is valid in this State. For parameter identification of the model the genetic algorithms are used. Genetic algorithms are directed random search techniques, applying the mechanics of natural selection and natural genetics, which can find the global optimal solution in complex multidimensional search spaces. Based on the available experimental data and simulations of E. coli fed-batch cultivation it is sho...
Jan Treur - One of the best experts on this subject based on the ideXlab platform.
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DESIGN AND VALIDATION OF A MODEL FOR A HUMAN'S Functional State AND PERFORMANCE
International Journal of Modeling Simulation and Scientific Computing, 2020Co-Authors: Tibor Bosse, Mark Hoogendoorn, Fiemke Both, Syed Waqar Jaffry, R.m. Van Lambalgen, Rogier Oorburg, Alexei Sharpanskykh, Jan TreurAbstract:This paper presents a computational model of the dynamics of a human's Functional State in relation to task performance and environment. It can be used in intelligent systems that support humans in demanding circumstances. The model takes task demand and situational aspects as input and calculates internal factors related to human functioning, such as the experienced pressure, exhaustion, and motivation, and how they affect performance. Simulation experiments under different parameter settings pointed out that the model is able to produce realistic behavior of humans with different types of personalities. Moreover, by a mathematical analysis the equilibria of the model have been determined, and by automated checking a number of expected properties of the model have been confirmed. In addition to this "internal" validation of the model, an experiment has been designed for the purpose of external validation, addressing the estimation of aspects of the human process that are relevant for its practical application. Output from the experiment, like information about personality characteristics and performance quality, has been used to perform estimation of the parameters of the model. By the parameter estimation, a set of parameter values has been identified by which an adequate representation of a person's Functional State when performing a task is achieved.
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IEA/AIE - An integrated agent model for attention and Functional State
Advanced Research in Applied Artificial Intelligence, 2012Co-Authors: Tibor Bosse, Rianne Van Lambalgen, Peter-paul Van Maanen, Jan TreurAbstract:To provide personalized intelligent ambient support for persons performing demanding tasks, it is important to have insight in their State of attention. Existing models for attention have difficulties in distinguishing between stressed and relaxed States. To solve this problem, this paper proposes to extend an existing model for attention with a model for ‘Functional State'. In this integrated agent model, output of a Functional State model (experienced pressure) serves as input for the attention model; the overall amount of attention is dependent on the amount of experienced pressure. An experiment was conducted to test the validity of the integrated agent model against the validity of an earlier model based on attention only. Results pointed out that the integrated model had a higher validity than the earlier model and was more successful in predicting attention.
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PRIMA - An integrated agent model addressing situation awareness and Functional State in decision making
Lecture Notes in Computer Science, 2011Co-Authors: Mark Hoogendoorn, Rianne Van Lambalgen, Jan TreurAbstract:In this paper, an integrated agent model is introduced addressing mutually interacting Situation Awareness and Functional State dynamics in decision making. This shows how a human's Functional State, more specific a human's exhaustion and power, can influence a human's situation awareness, and in turn the decision making. The model is illustrated by a number of simulation scenarios.
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An Agent Model for a Human's Functional State and Performance
2008 IEEE WIC ACM International Conference on Web Intelligence and Intelligent Agent Technology, 2008Co-Authors: Tibor Bosse, Rianne Van Lambalgen, Fiemke Both, Jan TreurAbstract:This paper presents an agent model of the dynamics of a humanpsilas Functional State in relation to task performance and environment. It can be used in agent systems that support humans in demanding circumstances. Simulation experiments under different parameter settings pointed out that the model is able to produce realistic behaviour of different types of personalities. Moreover, by a mathematical analysis the equilibria of the model have been determined, and by automated checking a number of expected properties of the model have been confirmed.
Naceur Benhadj Braiek - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of a Minimum Functional State Observer Approach for Unperturbed/Perturbed Dynamical Systems
International Journal of Control Automation and Systems, 2018Co-Authors: Ridha Aloui, Naceur Benhadj BraiekAbstract:In this paper, we investigate the synthesis of minimum Functional State observer for unperturbed and perturbed linear time invariant systems. The principal contribution is the design of a minimum Functional State observer, which can estimate directly the State feedback control law. Hence, for the linear time invariant systems, the existence conditions of a minimum Functional State observer are obtained by verification of a special dimension condition on system matrices. As a matter of fact, the exact solution of the proposed approach is determined, and the minimum Functional State observer that has the same dimension as the control vector is derived by solving a set of linear matrix inequality (LMI) constraints. Whereas, for perturbed linear systems, the proposed minimum Functional State observer scheme is developed to ensure the robust quadratic stability of the augmented system. The robustness issue is given via the reconstructed control law designed using an LMI based H∞ method; so that the desired design matrices are derived through the resolution of an optimum LMI system. The effectiveness and usefulness of the proposed approach are validated through a flexible link robot example.
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Minimum Functional State Observer Based Guaranteed Cost Performance for Uncertain Dynamical Systems
2018 15th International Multi-Conference on Systems Signals & Devices (SSD), 2018Co-Authors: Ridha Aloui, Naceur Benhadj BraiekAbstract:The focus of this paper is on the design of an optimal and robust minimum Functional State observer scheme for uncertain dynamical systems composed of linear model and uncertain parameters. Its aim is to study a minimum Functional observer which can estimate, directly, the State feedback control law. Moreover, the minimum Functional State observer which has the same dimension as the control vector is derived by solving a Linear Matrix Inequality (LMI) constraint. The proposed approach is formulated as an optimization problem in terms of LMI constraint to compute the robust gain matrices characterizing the proposed minimum Functional observer. Indeed, a design method is developed to ensure the stability of the closed-loop system with the Lyapunov technique and to minimize the upper bound of a cost function leading to optimal performances. Through an example, characterized by a flexible link robot, it will be illustrated the proposed approach provide the effectiveness and the availability of the developed method.
Jaroslav Zdinak - One of the best experts on this subject based on the ideXlab platform.
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Modular Measuring System for Assesment of the Thyroid Gland Functional State
Advances in Electrical and Electronic Engineering, 2011Co-Authors: Vladimir Rosik, Milan Tysler, Jana Svehlikova, Jaroslav ZdinakAbstract:Distributed modular system BioLab for biophysical examinations enabling assessment of the thyroid gland Functional State is presented in the paper. The BioLab system is based on a standard notebook or desktop PC connected to an Ethernet-based network of two smart sensors. These sensors are programmed and controlled from PC and enable measurement of selected biosignals of the human cardiovascular and neuromuscular system that are influenced by the production of thyroid gland hormones. Recorded biosignals are processed in a PC and peripheral indicators characterizing thyroid gland Functional State are evaluated.
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Modular Measuring System for Assessment of the Thyroid Gland Functional State
2005 IEEE Engineering in Medicine and Biology 27th Annual Conference, 2006Co-Authors: P. Kneppo, Vladimir Rosik, Milan Tysler, Jaroslav ZdinakAbstract:Distributed modular system BioLab for biophysical examinations enabling assessment of the thyroid gland Functional State is presented. Two smart sensors modules measuring 4 different biosignals are connected to an Ethernet based network and enable to obtain peripheral indicators of human cardiovascular and neuromuscular functions. Personal notebook or desktop computer with a network interface controls the sensors and performs processing and evaluation of measured biosignals
