Showing papers in "Mathematical and Computer Modelling of Dynamical Systems in 2009"
TL;DR: In this article, the dynamic effect of eddy currents is taken into account using G. Bertotti's approach and a satisfactory agreement between the measured and the modelled dynamic hysteresis loops as well as the corresponding loss densities is obtained.
Abstract: The article deals with the modelling of dynamic hysteresis loops. The modelling is carried out within the framework proposed by D. Jiles and D. Atherton. The dynamic effect of eddy currents is taken into account using G. Bertotti's approach. A satisfactory agreement between the measured and the modelled dynamic hysteresis loops as well as the corresponding loss densities is obtained.
37 citations
TL;DR: The operational planning of seaport container terminals is considered by defining a suitable integrated framework in which simulation and optimization interact, and two modelling and planning levels about container terminals are considered.
Abstract: In this article the operational planning of seaport container terminals is considered by defining a suitable integrated framework in which simulation and optimization interact. The proposed tool is a simulation environment (implemented by using the Arena software) representing the dynamics of a container terminal. When the system faces some particular conditions (critical events), an optimization procedure integrated in the simulation tool is called. This means that the simulation is paused, an optimization problem is solved and the relative solution is an input for the simulation environment where some system parameters are modified (generally, the handling rates of some resources are changed). For this reason, in the present article we consider two modelling and planning levels about container terminals. The simulation framework, based on an appropriate discrete-event model, represents the dynamic behaviour of the terminal, thus it needs to be quite detailed and it is used as an operational planning too...
33 citations
TL;DR: In this article, a pusher-type reheating furnace is considered, which is characterized by a varying number of slabs with variable geometry being discontinuously moved through the furnace, resulting in a hybrid structure of the mathematical model.
Abstract: The slab reheating process turns out to play a key role in dealing with the steadily increasing demands on the quality of hot rolled steel plates. Improvements both in the throughput of the furnace as well as the accurate realization of reheating paths for the slabs require to incorporate modern model-based control design techniques into the furnace automation. For this, suitable mathematical models with manageable dimension and complexity have to be determined for the furnace and slab dynamics. In this contribution, first principles are applied for the derivation of a physics-based model of the reheating process in a so-called pusher-type reheating furnace. Thereby, a discontinuous mode of furnace operation is considered, which is characterized by a varying number of slabs with variable geometry being discontinuously moved through the furnace. This, in particular, results in a hybrid structure of the mathematical model. The accuracy of the mathematical model is validated by a comparison with experimental...
32 citations
TL;DR: In this article, the effect of the rudder on the turning dynamics of a specific model for ESSO's 190,000-deadweight-ton (dwt) tankers was investigated in 1972 using full-scale trial results.
Abstract: Manoeuvrability is of great importance for large tankers in the marine industry. Manoeuvring, involving yaw rates and drift velocities, which are not small compared with the forward speed, demands a mathematical model of considerable complexity. A great deal of effort has been devoted to the construction of non-linear mathematical models describing the manoeuvrability of large tankers in deep and confined waters. This study is concerned with the effect of the rudder on the turning dynamics of a specific model for ESSO's 190,000-deadweight-ton (dwt) tankers, whose manoeuvrability performance has been investigated in 1972 using full-scale trial results. The turning or heading response of the tanker depends on the turning moment generated by the rudder, which in turn depends on the flow of water over the surface of the rudder. Unfortunately, the classical model used for representing the flow velocity at the rudder causes the rudder to react too quickly and to a greater magnitude (increased turning moment) th...
31 citations
TL;DR: In this article, an extension of the port-based modelling approach (bond graphs) which applies to systems subject to heat and mass transfer is presented, based on the first principle, conservation laws and constitutive closure relations.
Abstract: The goal of this article is to present an extension of the port-based modelling approach (bond graphs) which applies to systems subject to heat and mass transfer. The methodology is based on the first principle, conservation laws and constitutive closure relations. The latter are the phenomenological laws relating fluxes and thermodynamic forces. Then instantaneous power conservation appears naturally as a geometric interconnection structure called Dirac structure. The multi-level case (several macroscopic spatial scales) is investigated with the assumption that the spatial scales are separated and may be considered as two distinct phases. In this case, it is shown that both the interconnection coupling within a phase and the multi-level interconnection coupling are Dirac structures.
28 citations
TL;DR: In this paper, an analysis of trolley impact on the dynamic behaviour of the flexible structure of the mega quayside container crane (QCC) boom, identified as the most relevant structural part, is presented.
Abstract: This article deals with the analysis of trolley impact on the dynamic behaviour of the flexible structure of the mega quayside container crane (QCC) boom, identified as the most relevant structural part. It develops a modelling method for the dynamic response of the large flexible structure of the QCC boom under a moving trolley. By using FEM the original structure of the whole crane structure is reduced to an equivalent model of the boom. The boom is in this way modelled as a system with distributed parameters, comprising reduced stiffnesses and lumped masses from other parts of the upper structure. The article looks at the moving mass approach to achieve the desired performance of the QCC. Differential equations of the mathematical model are obtained by using Lagrange's equations and the assumed mode method. The continuum is discretized by a finite number of admissible functions. Deterministic simulation gives the dynamic response of the boom for quay-to-ship container transfer. Results are obtained for...
24 citations
TL;DR: In pulp and paper the modelling and simulation of the pulp production processes was the first major application as mentioned in this paper, and it is now for the paper industry to learn from these industries what can be done with the help of computers to control or optimise processes or to design new grades.
Abstract: In pulp and paper the modelling and simulation of the pulp production processes was the first major application. Since then several other applications have been realised though papermaking has never been on the lead concerning the use of computer-based modelling and simulation. The complex nature of the materials is one of the most demanding challenges and the biggest hurdle for any electronic description of the papermaking process or paper itself. So other industries took the lead and it is now for the paper industry to learn from these industries what can be done with the help of computers to control or optimise processes or to design new grades. The application of results gained with the use of modelling and simulation techniques in pulp and paper manufacturing processes has helped the industry to, for example, reduce emissions and increase the productivity and cost-efficiency of the processes. Still there are many important tasks open. A better understanding of the mechanisms of the processes and thei...
23 citations
TL;DR: This study incorporates random machine breakdown and failure in rework factors into the imperfect EMQ model examined by the aforementioned paper, and mathematical modelling and cost analysis are employed and the renewal reward theorem is used to deal with variable cycle length.
Abstract: This article studies the optimal replenishment policy for an economic manufacturing quantity (EMQ) model with failure in rework, backlogging and random breakdown. A recent article [P.A. Hayek and M.K. Salameh, Prod. Plann. Control 2001;12:584–590] investigated the optimal lot size problem on an imperfect quality EMQ model. However, in most real-life manufacturing systems random breakdown is another inevitable reliability factor. To cope with the stochastic machine failures, the production planners need to calculate the mean time between failures and establish a robust plan accordingly, so that the overall production-inventory costs for such an unreliable system can be minimized. This study incorporates random machine breakdown and failure in rework factors into the imperfect EMQ model examined by the aforementioned paper. Mathematical modelling and cost analysis are employed and the renewal reward theorem is used to deal with variable cycle length. Convexity of the long-run average cost function is proved...
21 citations
TL;DR: In this paper, the authors considered the mathematical modelling of the spring force of three interconnected rolling diaphragm type air springs used on a 40-ton tri-axle semi-trailer.
Abstract: This article considers the mathematical modelling of the spring force of three interconnected rolling diaphragm type air springs used on a 40-ton tri-axle semi-trailer. The aim of the air spring model is to obtain a validated mathematical model that can be used in full vehicle multi-body dynamic simulations. The model considers the flow effects in the pipes connecting the three air springs as well as the mass transfer between them. Comparisons with experimental results show that the proposed mathematical model of the interconnected air springs is indeed able to accurately predict the pressures and forces of the air springs.
19 citations
TL;DR: A method for autonomous rendezvous with and capturing of a non-cooperative object in space is proposed and a modelling and simulation system to verify the corresponding algorithms are developed.
Abstract: Space robotic systems are expected to play an increasingly important role in the future. The applications include repairing, refuelling or the de-orbiting of a satellite, or removal of space debris. Such objects are generally non-cooperative, i.e. neither any artificial patterns used for the measurement nor grappling fixtures applied for the capture are mounted on the targets. In this article, we propose a method for autonomous rendezvous with and capturing of a non-cooperative object in space and develop a modelling and simulation system to verify the corresponding algorithms. The system, realized in VC® (Microsoft Visual C++) environment, is composed of seven modules: Image Processing and 3D Reconstruction, the Planning and Control of the Chaser, the Target Controller, the Dynamic Model, the Geometry Model, the Binocular Cameras Model and the Stereo Calibration Module. With the system, the closed-loop simulations, including image grabbing, image processing, pose measurement, chaser guidance, navigation ...
17 citations
TL;DR: A new topic diffusion mechanism incorporating Markov model based on topic activity transition is employed in the model, and the time-dependent spreading of topics in directed scale-free networks is explored.
Abstract: Because of the booming of the Internet, content security is becoming more intractable, because of the emergence of complex contents and the diversity in human activity on the Internet. The article proposes a model for the dynamics of topic propagation over the Internet. Topics on the Internet are considered as clusters of contents on websites, which describe various kinds of events. The model accounts for the behaviours of websites, such as anti-infection ability, recovery ability, spreading ability and effective propagation rate. A new topic diffusion mechanism incorporating Markov model based on topic activity transition is employed in the model. By means of simulations, we explore the time-dependent spreading of topics in directed scale-free networks, in which nodes are considered as websites and directed links represent the source dependencies between websites. The simulation results accord with the actual observation very well.
TL;DR: In this paper, an energy management system for a hybrid electric vehicle is developed, which is based on the fuzzy logic approach, and its results show considerable improvement in the efficiency of the internal combustion engine and, consequently, fuel consumption and acceleration performances.
Abstract: With the stricter limitations on both fuel consumption and air pollution, the advantages of a hybrid electric vehicle are becoming more evident than ever. In the present study, an energy management system for a hybrid electric vehicle is developed. Because the plant under consideration is nonlinear, multi-domain, time-varying, has multiple uncertainties and, in addition, the designed control strategy must be able to obey the driver's commands and achieve the par-internship for a new generation of vehicle regulations, the fuzzy logic approach is chosen. A feed-forward hybrid vehicle simulation model is used to demonstrate the validity and the convenience of the current approach and its results have been compared with the other parallel hybrid electric vehicle control strategies. Simulation results show considerable improvement in the efficiency of the internal combustion engine and, consequently, fuel consumption and acceleration performances.
TL;DR: In this article, a fuzzy agent with dynamic personality is modelled based on a five-factor personality model and implemented in a Java environment and then it is extended with a fuzzy emotion component.
Abstract: Personality and emotions are effective factors in human decision-making processes. Thus, when an agent has to emulate human behaviour, not only should this agent think and reason but also should have emotions and personality. In this article a fuzzy agent with dynamic personality is modelled based on a five-factor personality model and implemented in a Java environment. Then it is extended with a fuzzy emotion component. This emotion component uses calculated personality factors and some related parameters and then determines the degree of anger. The proposed personality and emotion model provides a proper framework for human-like agent decision-making tasks.
TL;DR: In this paper, the Stodola-Green model was used to derive the equations of motion for a general rotor with an imbalance to include most rotordynamic phenomena including gyroscopic effects, and the implementation into the bond graph models using both multibond and scalar bonds was discussed.
Abstract: Basic rotordynamic models such as for the Jeffcott [H. H. Jeffcott, Lateral vibration of laded shafts in the neighborhood of a whirling speed–Thee ffect of want of imbalance, Philos.Mag. 37, 1919, pp. 304–314] and Stodola–Green [A. Stodola, Dampf-und Gasturbinen, Springer-Verlag, Berlin, 1924, R.Green, Gyroscopic effects of the critical speeds of flexible rotors, J Appl Mech, 15 (1948), pp. 369–376] rotors are developed in a bond graph formalism. The equations of motion for a general rotor with an imbalance are derived from Lagrange's equations to include most rotordynamic phenomena including gyroscopic effects. The implementation into the bond graph models using both multibond and scalar bonds is given and discussed. An example of bond graph models for the classical Jeffcott rotor is included and the derivation of the complete state equations from the scalar bond graph is shown in detail. A more complex bond graph-modelling example using the Stodola–Green model mounted on a stiff shaft with bearing elast...
TL;DR: In the last decade, some significant changes occurred in the bio-medical area with the introduction of systemic view, and mathematical modelling, as one of the principal tools of control engineering, is now becoming a necessary tool in the analysis of biological systems.
Abstract: In the last decade, some significant changes occurred in the bio-medical area with the introduction of systemic view. In neurology and pharmacokinetics, the systemic paradigm was already well accepted, whereas other areas of bio-medicine were more or less accepting the reductionism paradigm where systems were studied through the analysis of its isolated sub-systems. The genome project showed that it is not possible to explain the diversity of life only with combinations of genes, which resulted in a new science called systems biology. Mathematical modelling, as one of the principal tools of control engineering, is now becoming a necessary tool in the analysis of biological systems. Interdisciplinary research has the already showed significant advantages over single-disciplinary research; however, the communication barrier between scientists of different backgrounds is still a major problem. Therefore, mathematical modelling is not as widely used in life sciences as would be expected with the potential ben...
TL;DR: The theoretical background of an implemented FEM–MBS interface (MORPACK) is presented allowing the application of any kind of reduction method for FE-modelled structures and furthermore their import into SIMPACK via the SID file generation.
Abstract: Various research areas in the field of vehicle modelling, structural mechanics, engine dynamics, microelectromechanical systems (MEMS), etc. require the utilization of both multibody system formalism (MBS) and finite element method (FEM) in order to sufficiently capture the model's dynamics. The FEM–MBS coupling is accomplished by reducing the dimension of the FE-modelled part and then importing it into an MBS-code for further simulation. When using commercial FEM (Nastran, ANSYS, etc.) as well as MBS (SIMPACK) software packages the necessary standard input data (SID) file is needed for the coupling procedure (FEMBS interface). A problem arises by the restriction that both commercial FEM and MBS codes support only two condensation methods (Guyan reduction and component mode synthesis (CMS)), thus disabling the direct application of any other reduction approach (e.g. from the field of control theory) that actually could be better. In this article, the theoretical background of an implemented FEM–MBS interf...
TL;DR: The FE multi-reference-plane model is extended to fuzzy randomness and dynamic loads and a suitable discretization strategy enables the repeated processing of FE algorithms as deterministic fundamental solution.
Abstract: In many engineering problems the dynamical reactions of structures depend on uncertain data. For considering this uncertainty, fuzzy random processes are applied. An enhanced dynamic analysis method called fuzzy stochastic finite element method (FSFEM) has been developed in order to consider the fuzzy random processes within the dynamic analysis of structures. A suitable discretization strategy enables the repeated processing of FE algorithms as deterministic fundamental solution. In this paper the FE multi-reference-plane model is extended to fuzzy randomness and dynamic loads. The numerical solution is based on the fuzzy stochastic sampling (FSS). FSS and FSFEM are applied for the numerical simulation of the load-bearing capacity of a strengthened RC plate under static and dynamic loads.
TL;DR: In this paper, the accuracy of different types of models are discussed, which are called black box mod-el models and are based on process data and/or observations from lab measurements.
Abstract: This paper discusses the accuracy of different types of models. Statistical models are based on process data and/or observations from lab measurements. This class of models are called black box mod ...
TL;DR: In this paper, a free surface problem arising in the Czochralski (CZ) crystal growth process is considered, and a mathematical model accounting for the interaction of the molten material with applied and induced magnetic fields, temperature-induced convection, rotating boundaries and the free surface is given.
Abstract: A free surface problem arising in the Czochralski (CZ) crystal growth process is considered. A mathematical model accounting for the interaction of the molten material with applied and induced magnetic fields, temperature-induced convection, rotating boundaries and a free surface is given. The model described avoids some common simplifying assumptions and allows for more general geometries, and non-axisymmetric (fully three-dimensional) and time-dependent flow fields. It accounts for the induced magnetic field and avoids non-realistic idealized boundary conditions on the magnetic field. The use and limitations of the model in optimization of crystal growth are also discussed.
TL;DR: It is found that BMCS containing only one control input are completely controllable, whereas BMCS displaying more than one input variable are harder to control.
Abstract: In this article, we study a class of non-linear control systems called Boolean (i.e. over the finite field F 2) monomial control systems (BMCS) defined as mappings such that every component gi is a monomial function in n state variables and in m input variables. These represent a particular class of finite state automata. We successfully apply the theory of Boolean dynamical systems [Colon-Reyes et al., Ann. Comb 8 (2004), pp. 425–439, Delgado-Eckert (2008), Ph.D thesis, http://mediatum2.ub.tum.de/doc/645326/document.pdf], in particular, the graph theoretical notion of ‘loop number’ to investigate controllability issues for BMCS. We found that BMCS containing only one control input are completely controllable, whereas BMCS displaying more than one input variable are harder to control. Additionally, we introduce the principle of loop number assignment, which is in some sense analogous to the well known ‘pole placement’ method for state continuous linear systems. Moreover, we present an algorithm that synth...
TL;DR: In this paper, Artificial Neural Networks (ANNs) were used to predict newsprint paper properties from wet-end parameters, and the results showed that formation and strength proper were not affected.
Abstract: Papermaking is an industrial process that is becoming more competitive nowadays. In this process there are numerous techniques and measurements to indicate paper quality. To increase competitiveness a good control of paper quality is needed through paper properties predictions from different process measurements. However, complex physico-chemical processes take place during papermaking, and thus, paper property predictions are not easy to obtain, especially in the wet-end area. In the wet end flocculation takes place, which will determine the floc properties during the formation of the sheet, and therefore, it will influence retention, drainage and formation. These strongly affect the runnability of the machine and the properties of the final product, and thus, using wet-end measurements for the predictions implies advanced data treatment. Artificial neural networks have been used in this article to predict newsprint paper properties from wet-end parameters. Results show that formation and strength proper...
TL;DR: In this article, a wavelet transform is used to obtain dynamical models describing the behavior of fluid flow in a local spatial region of interest, where the flow is then expanded onto a set of basis vectors that are constructed from the wavelet function.
Abstract: In this paper, we utilize wavelet transform to obtain dynamical models describing the behaviour of fluid flow in a local spatial region of interest. First, snapshots of the flow are obtained from experiments or from computational fluid dynamics (CFD) simulations of the governing equations. A wavelet family and decomposition level is selected by assessing the reconstruction success under the resulting inverse transform. The flow is then expanded onto a set of basis vectors that are constructed from the wavelet function. The wavelet coefficients associated with the basis vectors capture the time variation of the flow within the spatial region covered by the support of the basis vectors. A dynamical model is established for these coefficients by using subspace identification methods. The approach developed is applied to a sample flow configuration on a square domain where the input affects the system through the boundary conditions. It is observed that there is good agreement between CFD simulation results a...
TL;DR: In this paper, a detailed dynamic model of the polymerization reaction of vinyl acetate in a real-life industrial reactor is presented, with the recipe and the operating procedures observed in the factory as inputs, with reasonable accuracy the final conversion, the average particle diameter, the solid content and the viscosity.
Abstract: A detailed dynamic model of the polymerization reaction of vinyl acetate in a real-life industrial reactor is presented. With the recipe and the operating procedures observed in the factory as inputs, the model predicts with reasonable accuracy the final conversion, the average particle diameter, the solid content and the viscosity. The manual and semi-manual operations, and the decision process followed by the operator, are also modelled in order to replicate closely the process carried out in the factory. The model provides further insight into the reaction kinetics and allows us to make knowledge-based decisions. The model is intended to be used for the optimization of the policy of adding monomer in order to reduce the batch time.
TL;DR: A three-dimensional cellular automaton model performing the growth simulation of normal and cancerous cells is presented and an extension of the model to simulate angiogenic processes is possible.
Abstract: Cellular automaton theory has previously been used to study cell growth. In this study, we present a three-dimensional cellular automaton model performing the growth simulation of normal and cancerous cells. The necessary nutrient supply is provided by an artificial arterial tree which is generated by constrained constructive optimization. Spatial oxygen diffusion is approximated again by a cellular automaton model. All results could be illustrated dynamically by three-dimensional volume visualization. Because of the chosen modelling approach, an extension of the model to simulate angiogenic processes is possible.
TL;DR: In this paper, a complete study of two apple quality attributes, the soluble solids content and the firmness, is carried out, where the system of differential equations is linear and the state variables and the parameters are represented as random variables with their statistical properties known at the initial time.
Abstract: Recently, the basic dynamics of fruit characteristics have been modelled using a stochastic approach. The time evolution of apple quality attributes was represented by means of a system of differential equations in which the initial conditions and model parameters are both random. In this work, a complete study of two apple quality attributes, the soluble solids content and the firmness, is carried out. For each of these characteristics, the system of differential equations is linear and the state variables and the parameters are represented as random variables with their statistical properties (mean values, variances, covariances, joint probability density function) known at the initial time. The dynamic behaviour of these statistical properties is analysed. The variance propagation algorithm is used to obtain an analytical expression of the dynamic behaviour of the mean value, the variance, the covariance and the probability density function. A Monte Carlo method and the Latin hypercube method were deve...
TL;DR: In this paper, the authors present a short summary of decision making under uncertainty and then suggest that the mathematical structure of stochastic optimization serves as a model for the architecture of future operational decision support systems.
Abstract: Operational decisions are influenced not only by the data and models available to the decision maker but also by the uncertainty in the data and in model-based predictions about the impacts of decision makers' actions. In non-linear systems the potential actions may have widely differing uncertainty associated with them. Then the decision maker must take an attitude towards risk and balance that against the expectation value of performance. In stochastic optimization, methods to deal with uncertainty have been developed. However, these methods have not been widely used in decision making about operating industrial processes. In this article, we first present a short summary of decision making under uncertainty and then suggest that the mathematical structure of stochastic optimization serves as a model for the architecture of future operational decision support systems. We demonstrate this framework by analysing four idealized operational decision cases, which are closely related to practical daily decisi...
TL;DR: It is proved that this problem of detecting dead transitions is decidable for TAPNs with natural times, and an algorithm is presented that can be used to find dead transitions in the particular case of 1-safe T APNs.
Abstract: Timed-arc Petri nets (TAPNs) are a timed extension of Petri nets where tokens are assigned an age indicating the time elapsed from its creation, and PT-arcs (place to transition arcs) are labelled with time intervals that are used to restrict the age of the tokens that can be used to fire the adjacent transition. This is a rather pathological model, as reachability is undecidable, whereas some other known properties of Petri nets, like boundedness, coverability and even termination, are decidable. This article focuses on the problem of detecting dead transitions, i.e. transitions that can be removed from the model since they can never become enabled. We prove that this problem is decidable for TAPNs with natural times, and we present an algorithm that can be used to find dead transitions in the particular case of 1-safe TAPNs.
TL;DR: Deterministic and statistical descriptions of parametric model uncertainties are discussed and illustrated with a case study from the paper industry, and how closed loop operation can reduce the prediction sensitivity due to parameter uncertainties.
Abstract: Deterministic and statistical descriptions of parametric model uncertainties are discussed and illustrated with a case study from the paper industry. Prediction uncertainties under open loop and closed loop operation are then studied. The results illustrate the importance of a realistic description of parametric uncertainties, and also how closed loop operation can reduce the prediction sensitivity due to parameter uncertainties.
TL;DR: In this article, an explicit governing equation of motion describing nonlinear dynamics of a particle conveyed by a propagating surface wave is deduced and a dynamic equilibrium is constructed at the contact point of the particle and the surface.
Abstract: An explicit governing equation of motion describing nonlinear dynamics of a particle conveyed by a propagating surface wave is deduced. A dynamic equilibrium is constructed at the contact point of the particle and the surface. The mathematical model of the system is constructed in such a way that it involves dynamically shifted coordinates around the contact point. Such an approach yields an explicit nonlinear differential equation. Coexisting attractors and their basin boundaries can be analysed in the general case. Special computational techniques are developed for numerical integration of such differential equations with dynamically shifted coordinates. Attractor control strategy based on small external impulses is proposed when stable equilibrium points and a limit cycle coexist. Such control strategies can dramatically increase the effectiveness of operation and can be applicable in different areas of engineering where positioning or conveyance is performed by means of propagating surface waves.
TL;DR: The biosystem model representations described here demonstrate to varying degrees the power of more microscopic methods for discriminating between alternative mechanistic hypotheses of biocontrol system connectivity and dynamics.
Abstract: Dynamical biological systems can be modelled mathematically at many levels, from relatively macroscopic, i.e. aggregating many processes or components into subsystem blocks and associated equations characterizing overall behaviour, to microscopic, i.e. focusing on physical mechanisms at the level of individual molecules and associated unit-process equations reflecting such couplings. Here we examine some representative examples within this spectrum of approaches, illustrating the ways in which various investigators handle data-driven modelling problems associated with drug effects–from mostly blood-borne data; switch-like responses in cell signalling subsystems–from molecular biochemistry data; gene network regulation–from pharmacogenomics data; and tumour-suppressor protein regulation mechanisms–also from molecular biochemistry data. Special attention is given to the latter, as modelling of the potential mechanisms involved in this system is an ongoing investigation in our lab. The biosystem model repres...