Linear parameter estimation of rational biokenetic functions (2009)
For rational biokinetic functions such as the Michaelis¿Menten equation, in general, a nonlinear least-squares method is a good estimator. However, a major drawback of a nonlinear least-squares...
Generally, system parameters that are nonlinear in the model output are estimated by nonlinear least-squares (NLS) optimization algorithms. As an alternative, for nonlinear discrete-time models with...
Associated plant and animal diversity provides ecosystem services within crop production systems. The importance of the maintenance or restoration of diversity is therefore increasingly acknowledged....
The double exponential settling model is the widely accepted model for wastewater secondary settling tanks. However, this model does not estimate accurately solids concentrations in the settler...
Linear parameter estimation of rational biokinetic functions (2009)
For rational biokinetic functions such as the Michaelis-Menten equation, in general, a nonlinear least-squares method is a good estimator. However, a major drawback of a nonlinear least-squares...
Selective precipitation of Cu from Zn in a pS controlled continuously stirred tank reactor (2009)
Martinho Sampaio, R.M., Timmers, R.A., Xu, Y., Keesman, K.J., Lens, P.N.L.
Copper was continuously and selectively precipitated with Na2S to concentrations below 0.3 ppb from water containing around 600 ppm of both Cu and Zn in a Continuously Stirred Tank Reactor. The pH...
For chemical reactors with non-linear fluid dynamics, a linear model realisation is proposed. The inputs are the ingoing concentration of a certain component in the fluid, and the reaction rate. The...
Monitoring ZnS Precipitation: Estimation, Error Analysis and Experiment Design (2009)
Martinho Sampaio, R.M., Keesman, K.J., Lens, P.N.L.
A mass balance model of total soluble sulfide and free zinc with a second-order reaction term is theoretically able to reconstruct the zinc effluent concentration and the kinetic parameter (k)....
System Identification in Production Ecology: from theory to agroforestry practice (2009)
Keesman, K.J., Graves, A., Burgess, P.
This paper introduces a system identification approach to agricultural ecosystems. In particular, the identification of an agroforestry system, combining trees with crops, is subject of study....
Van Mourik, S., Zwart, H.J., Keesman, K.J.
For chemical reactors with non-linear fluid dynamics, a linear model realisation is proposed. The inputs are the ingoing concentration of a certain component in the fluid, and the reaction rate. The...
Abstract. In this paper a novel approach to estimate parameters in an LTI continuous-time statespace model is proposed. Essentially, the approach is based on a so-called pqR-decomposition of the...
Integrated open loop control and design of a food storage room (2009)
Usually, control design in a food storage room takes place after the plant has been designed. However, the performance of the plant connected to the controller might be improved by simultaneous...
Uncertainty analysis of a storage facility under optimal control (2008)
Model reduction, linearisation and discretisation are standard techniques in systems theory to simplify nonlinear models. In this paper, these techniques are used on a nonlinear model of a storage...
Boundary observer synthesis: static and dynamic structure design (2008)
Vries, D., Keesman, K.J., Zwart, H.
We design and analyze a static boundary and a dynamic boundary observer for a typical Convection-Diffusion-Reaction system. The system is a model of a UV disinfection process, which is used in water...
Grootscholten, T.I.M., Keesman, K.J., Lens, P.N.L.
In this paper a method is presented to estimate the reaction term of zinc sulphide precipitation and the zinc concentration in a CSTR, using the read-out signal of a sulphide selective electrode. The...
Modelling and on-line estimation of zinc sulphide precipitation in (2008)
Grootscholten, T.I.M., Keesman, K.J., Lens, P.N.L.
In this paper the ZnS precipitation in a continuously stirred tank reactor (CSTR) is modelled using mass balances. The dynamics analysis of the model reveals that the ZnS precipitation shows a two...
Palma, J. H. N., Graves, Anil R., Burgess, Paul J., Keesman, K. J., Van Keulen, H., Mayus, M., ...
Silvoarable agroforestry, the deliberate combined use of trees and arable crops on the same area of land, has been proposed in order to improve the environmental performance of agricultural systems...
Modeling environmental benefits of silvoarable agroforestry in Europe. (2007)
Palma, J. H. N., Graves, Anil R., Bunce, R. G. H., Burgess, Paul J., De Filippi, R., Keesman, K. J., ...
Increased adoption of silvoarable agroforestry (SAF) systems in Europe, by integrating trees and arable crops on the same land, could offer a range of environmental benefits compared with...
Modeling environmental benefits of silvoarable agroforestry in Europe (2007)
Palma, J.H.N., Graves, A.R., Bunce, R.G.H., Burgess, P.J., Keesman, K.J., ...
Increased adoption of silvoarable agroforestry (SAF) systems in Europe, by integrating trees and arable crops on the same land, could offer a range of environmental benefits compared with...
Keesman, K.J., Burgess, P.J., Graves, A.R., Pilbeam, D., Incoll, L.D., ...
1. Silvoarable agroforestry (SAF) is the cultivation of trees and arable crops on the same parcel of land. SAF may contribute to modern diversified land use objectives in Europe, such as enhanced...
Graves, A.R., Burgess, P.J., Palma, J.H.N., Herzog, F., Moreno, G., Bertomeu, M., ...
Silvoarable agroforestry could promote use of trees on farms in Europe, but its likely effect on production, farm profitability, and environmental services is poorly understood. Hence, from 2001 to...
Palma, J.H.N., Graves, A.R., Burgess, P.J., Keesman, K.J., Mayus, M., ...
Silvoarable agroforestry, the deliberate combined use of trees and arable crops on the same area of land, has been proposed in order to improve the environmental performance of agricultural systems...
Keesman, K.J., Burgess, P.J., Graves, A.R., Pilbeam, D., Incoll, L.D., ...
1.Silvoarable agroforestry (SAF) is the cultivation of trees and arable crops on the same parcel of land. SAF may contribute to modern diversified land use objectives in Europe, such as enhanced...
Keesman, K.J., Burgess, P., Graves, A., Pilbeam, D., Incoll, L.D., ...
1. Silvoarable agroforestry (SAF) is the cultivation of trees and arable crops on the same parcel of land. SAF may contribute to modern diversified land use objectives in Europe, such as enhanced...
Palma, J.H.N., Graves, A.R., Burgess, P.J., Keesman, K.J., Mayus, M.M., ...
Silvoarable agroforestry, the deliberate combined use of trees and arable crops on the same area of land, has been proposed in order to improve the environmental performance of agricultural systems...
Mathemetical performance analysis of a temperature controlled bulk storage room (2007)
Ploegaert, J.P.M., Zwart, H., Keesman, K.J.
Usually, control design takes place after the plant has been designed. However, the performance of the plant connected to the controller might be improved by simultaneous design of the plant and the...
In this paper, the yield and the land equivalent ratio (LER) of a silvo-arable agroforestry (SAF) system, containing one tree and one crop species, is analyzed analytically using a minimal...
In this paper, the yield and the land equivalent ratio (LER) of a silvo-arable agroforestry (SAF) system, containing one tree and one crop species, is analyzed analytically using a minimal...
Modeling and control of water disinfection process in annular photoreactors (2007)
Keesman, K.J., Vries, D., Zwart, H.
Abstract¿ As an alternative or addition to complex physical modeling, in this paper transfer function models of the disinfection process in annular photoreactors under different flow conditions are...
Switching control for post-harvest food storage (2007)
Abstract: Harvested products inside a storage room are kept cool by a fan that blows air through a heat exchanger. The air and product temperature are regulated by switching the fan on and off. The...
On-line estimation of the dissolved zinc concentration during ZnS precipitation in a CSTR (2007)
Grootscholten, T.I.M., Keesman, K.J., Lens, P.N.L.
Abstract In this paper a method is presented to estimate the reaction term of zinc sulphide precipitation and the zinc concentration in a CSTR, using the read-out signal of a sulphide selective...
A Luenberger observer for an infinite dimensional bilinear system: a uv disinfection example (2007)
Vries, D., Keesman, K.J., Zwart, H.
Abstract: Inspired by the UV disinfection processes in food and water treatment industry, we design a Luenberger observer which works at the boundary of the infinite dimensional bilinear system....
An H alpha observer at the boundary of an infinite-dimensional system (2007)
Vries, D., Keesman, K.J., Zwart, H.
We design and analyze an H_\$\infty\$ observer which works at the boundary of an infinite dimensional system with scalar disturbances. The system is a model of a UV disinfection process, which is...
Process Modelling of Ultrafiltration Units: An RSM Approach (2007)
M.O. Daramola, K.J. Keesman, F. Spenkelink
This study reports a study on the process modelling of ultrafiltration (UF) units with a focus on the development of backwashing models based on properly designed experiments under pilot scale...
Modeling and control of water disinfection process in annular photoreactors (2007)
Keesman, K.J., Vries, D., Van Mourik, S., Zwart, H.J.
As an alternative or addition to complex physical modeling, in this paper transfer function models of the disinfection process in annular photoreactors under different flow conditions are derived....
Van Mourik, S., Zwart, H.J., Keesman, K.J.
For a class of scalar nonlinear systems with switching input a controller is designed using design theory for linear systems. A stability criterion is derived that contains all the physical system...
Analytic control law for a food storage room (2007)
Van Mourik, S., Zwart, H.J., Keesman, K.J.
A storage room contains a bulk of potatoes that produce heat due to respiration. A ventilator blows cooled air around to keep the potatoes cool and prevent spoilage. The aim is to design a control...
Vries, D., Keesman, K.J., Zwart, H.
Abstract In input-output relations of (compartmental) diffusive systems, physical parameters appear non-linearly, resulting in the use of (constrained) non-linear parameter estimation techniques with...
Automatic detection of exogenous respiration end-point using artificial neural network (2006)
Bisschops, I.A.E., Keesman, K.J.
When aerobic bacteria receive a biodegradable material such as wastewater, then respiration changes from endogenous to exogenous. The reverse occurs when biodegradation is complete. When using...
Climate control of a bulk storage room for foodstuffs (2006)
A storage room contains a bulk of agricultural products, such as potatoes, onions, fruits, etcetera. The products produce heat due to respiration, see for example [1, 2]. A ventilator blows cooled...
Parameter estimation and prediction of nonlinear biological systems: some examples (2006)
Rearranging and reparameterizing a discrete-time nonlinear model with polynomial quotient structure in input, output and parameters (xk = f(Z, p)) leads to a model linear in its (new) parameters. As...
In this short paper for the panel discussion on ¿Experience and challenges in identification of non-linear systems¿ some major issues with respect to identification of non-linear biochemical and...
Projective Modeling and System Change: Reservoir Management Examples (2006)
In this paper a projective modeling approach for ecological/ environmental systems is introduced. The basic idea behind projective modeling is to define (possible) future output behavior and to use...
Dynamic Modelling and process control of ZnS precipitation (2006)
König, J., Keesman, K.J., Veeken, A., Lens, P.N.L.
This paper presents the dynamic modelling and design of a control strategy for the ZnS precipitation process. During lab¿scale experiments, the sulfide concentration in a precipitator was controlled...
On adaptive optimal input design: A bioreactor case study (2006)
Stigter, J.D., Vries, D., Keesman, K.J.
The problem of optimal input design (OID) for a fed-batch bioreactor case study is solved recursively. Here an adaptive receding horizon optimal control problem, involving the so-called E-criterion,...
Modelling environmental benefits of silvoarable agroforestry in Europe (2006)
Palma, J.H.N., Graves, A.R., Bunce, R.G.H., Burgess, P.J., Keesman, K.J., ...
Modelling of water disinfection process in annular photoreactors (2006)
Keesman, K.J., Parasoglou, M., Vries, D.
As an alternative or addition to complex physical modelling, in this paper transfer function models of the disinfection process in annular photoreactors under different flow conditions are derived....
Dynamic modelling and process control of ZnS precipitation (2006)
König, J., Keesman, K.J., Veeken, A.H.M., Lens, P.N.L.
This paper presents the dynamic modelling and design of a control strategy for the ZnS precipitation process. During lab¿scale experiments, the sulfide concentration in a precipitator was controlled...
Vries, D., Keesman, K.J., Zwart, H.J.
In input-output relations of (compartmental) diffusive systems, physical parameters appear non-linearly, resulting in the use of (constrained) non-linear parameter estimation techniques with its...
Climate control of a bulk storage room for foodstuffs (2006)
Van Mourik, S., Zwart, H.J., Keesman, K.J.
A storage room contains a bulk of potatoes that produce heat due to respiration. A ventilator blows cooled air around to keep the potatoes cool and prevent spoilage. The aim is to design a control...
Improving Local Weather Forecasts for Agricultural Applications (2005)
For controlling agricultural systems, weather forecasts can be of substantial importance. Studies have shown that forecast errors can be reduced in terms of bias and standard deviation using...
Adaptive Weather Forecasting using Local Meteorological Information (2005)
In general, meteorological parameters such as temperature, rain and global radiation are important for agricultural systems. Anticipating on future conditions is most often needed in these systems....
Parameter Estimation and Prediction of a Nonlinear Storage Model: an algebraic approach (2005)
Generally, parameters that are nonlinear in system models are estimated by nonlinear least-squares optimization algorithms. In this paper, if a nonlinear discrete-time model with a polynomial...
A procedure for designing a predictor of an infinite dimensional linear system is sketched, while preserving the original physical structure contained in the original PDE. After discretization...
Benchmarking procedure for full-scale activated sludge plants (2004)
To enhance development and acceptance of new control strategies, a standard simulation benchmarking methodology to evaluate the performance of wastewater treatment plants has recently been proposed....
Optimal parametric sensitivity control of a fed-batch reactor (2004)
The paper presents an optimal parametric sensitivity controller for estimation of a set of parameters in an experiment. The method is demonstrated for a fed-batch bioreactor case study for optimal...
Modelling anaerobic biomass growth kinetics with a substrate threshold concentration (2004)
Abstract Many bacteria have been observed to stop growing below a certain substrate threshold concentration. In this study, a modification of the Monod kinetics expression has been proposed to take...
On Adaptive Optimal Input Design (2003)
Stigter, J.D., Vries, D., Keesman, K.J.
The problem of optimal input design (OID) for a fed-batch bioreactor case study is solved recursively. Here an adaptive receding horizon optimal control problem, involving the so-called E-criterion,...
Forward and backward uncertainty propagation: an oxidation ditch modelling example (2003)
In the field of water technology, forward uncertainty propagation is frequently used, whereas backward uncertainty propagation is rarely used. In forward uncertainty analysis, one moves from a given...
State and parameter estimation in biotechnical batch reactors (2002)
In this paper the problem of state and parameter estimation in biotechnical batch reactors is considered. Models describing the biotechnical process behaviour are usually non-linear with time-varying...
In this paper the well-known problem of optimal input design is considered. In particular, the focus is on input design for the estimation of kinetic parameters in bioreactors. The problem is...
Estimation of uncertainties in the performance indices of an oxidation ditch benchmark (2002)
Abusam, A., Keesman, K.J., Spanjers, H., Meinema, K.
Estimation of the influence of different sources of uncertainty is very important in obtaining a thorough evaluation or a fair comparison of the various control strategies proposed for wastewater...
Respirometry-based on-line model parameter estimation at a full-scale WWTP (2002)
Spanjers, H., Patry, G.G., Keesman, K.J.
This paper describes part of a project to develop a systematic approach to knowledge extraction from on-line respirometric measurements in support of wastewater treatment plant control and operation....
On compartmental modelling of mixing phenomena (2002)
In this paper the problem of modelling partial mixing phenomena, mostly relevant in environmental and reactors modelling practice, is considered. The ultimate modelling goal is to find identifiable,...
Abusam, A., Keesman, K.J., Spanjers, H., Meinema, K.
To enhance development and acceptance of new control strategies, a standard simulation benchmarking methodology to evaluate the performance of wastewater treatment plants has recently been proposed....
Abusam, A.A.A., Keesman, K.J., Spanjers, H., Meinema, K.
This paper demonstrates the application of the factorial sensitivity analysis methodology in studying the influence of variations in stoichiometric, kinetic and operating parameters on the...
Optimal parametric sensitivity control for a fed-batch reactor (2001)
The paper presents a method to derive an optimal parametric sensitivity controller for optimal estimation of a set of parameters in an experiment. The method is demonstrated for a fed batch...
State and parameter estimation in biotechnical batch reactors (2000)
In this paper the problem of state and parameter estimation in biotechnical batch reactors is considered. Models describing the biotechnical process behaviour are usually nonlinear with time-varying...
Endogenous model state and parameter estimation from an extensive batch experiment (2000)
In this paper an extensive batch experiment of endogenous process behavior in an aerobic biodegradation process is presented. From these experimental data, comprising measurements of MLVSS (mixed...
Lukasse, L.J.S., Keesman, K.J., Spanjers, H., Bloemen, M.
This paper deals with excitation of respiration chamber dynamics in a continuous-flow respirometer with the objective of extracting additional information from its dissolved oxygen (DO) sensor...
Identifying scale-dependent models : The case of overland flow at the hillslope (2000)
The hydrological problem to correctly partition rainfall at various scales may require scale dependent models. This study introduces a new method to identify scale dependent state space models in a...
Modelling and control of an N-removing activated sludge process (1999)
Keesman, K.J., Lukasse, L.J.S.
In this paper an approach to obtain a control strategy for optimal N-removal in alternatingly aerated, continuously mixed, continuously fed activated sludge processes (ASP's) using adaptive Receding...
Kinetics of fatty acid degradation by psychrophilically grown anaerobic granular sludge (1999)
Rebac, S., Gerbens, S., Lens, P., Stams, A.J.M., Keesman, K.J., ...