About
119
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Introduction
Additional affiliations
January 2006 - present
Censornet.dk
Position
- External examiner
Description
- Member of the corps of external examiners for the engineering programmes in Denmark
February 1984 - October 1986
SIM-CORP
Position
- Software systems developer
Description
- Software development for agriculture, banks, and insurance companies in the APL language.
Education
September 1979 - September 1982
February 1974 - July 1979
Publications
Publications (119)
The emerging concept of integrated community energy systems (ICESs) proves its suitability for improving the operation of local grids—increasing self-consumption from local generation, enhancing the load factor, and reducing energy cost. In Ballen marina—located on the Danish island of Samsø—the battery energy storage system (BESS)’s action can be...
Implementation of alternative energy supply solutions requires the broad involvement of local communities. Hence, smart energy solutions are primarily investigated on a local scale, resulting in integrated community energy systems (ICESs). Within this framework, the distributed generation can be optimally utilised, matching it with the local load v...
This paper focuses on the Model Predictive Control (MPC) based energy scheduling of a smart microgrid equipped with non-controllable (i.e., with fixed power profile) and controllable (i.e., with flexible and programmable operation) electrical appliances, as well as photovoltaic (PV) panels, and a battery energy storage system (BESS). The proposed c...
This chapter is a typical example of usage of Computational Intelligence Techniques-CI-Techniques (Machine Learning-Artificial Intelligence) in medical data analysis problems, such as optimizing the Pap-Smear or Pap-Test diagnosis. Pap-Smear or Pap-Test is a method for diagnosing Cervical Cancer (4th leading cause of female cancer and 2nd common fe...
Fossil fuel-based cogeneration of heat and power plants have a long history of supplying district heating in Denmark, however small-scale systems are progressively switching to biomass boilers for economic reasons. Biomass, however, should be reserved for other purposes where a storable fuel is pertinent. This paper investigates the transition of a...
This case study analyses an ongoing practical transition to a smart energy system. The Danish island of Samso, with 3700 inhabitants, aims for a fossil fuel free energy system in the year 2030. Owing to natural limitations, it is necessary to exploit the available energy sources in a manner, which requires careful planning. Furthermore, civic engag...
Our study concerns smart energy with respect to three target groups of end-users: farmers, shop owners, and households. We found cattle farmers that can shift their energy demand in time. Shops are willing to save energy during the night and on days when they are closed, and we found 11% savings on average with little or no investments at all. Hous...
This article introduces an approach to PID tuning based solely on a physically meaningful performance specification: settling time. The approach leads to extremely simple tuning procedures which avoid potentially excessive excitation of the process. Provided that the closed loop system meets two necessary conditions, supplemented by a third conditi...
We assess the risk inherent in wind turbine investments that rely on a power market in order to determine the selling price of generated power. Using scenario analysis, we calculate various indexes that attempt to highlight different aspects of the market risk to which the energy producer is exposed. Using as a benchmark a wind turbine in Denmark t...
For savings on heating or cooling, our approach is based on temperature measurements in the household, and we have defined saving factors that estimate the potential savings as a fraction of the observed energy consumption. The approach considers local climate data, to make the saving advices more relevant to the visited households. We have found e...
The goal of the design phase is to meet performance specifications, that is, constraints associated with the closed-loop system response. The constraints specify the speed of response and the relative stability of the closed-loop system. This chapter investigates how to meet specifications on overshoot, dominant time constant, and settling time. Mo...
Foundations of Fuzzy Control: A Practical Approach, 2nd Edition has been significantly revised and updated, with two new chapters on Gain Scheduling Control and Neurofuzzy Modelling. It focuses on the PID (Proportional, Integral, Derivative) type controller which is the most widely used in industry and systematically analyses several fuzzy PID cont...
Nonlinear systems are difficult to analyse, and, as an alternative, standard nonlinear elements have been developed for simulation, including: dead zone, saturation, and quantizer. By analogy, this chapter develops a set of standard control surfaces: the dead zone surface, the saturation surface, and the quantizer surface. The standard surfaces are...
We assess the risk inherent in wind turbine investments that rely on a power market in order to determine the selling price of generated power. Using scenario analysis, we calculate various indexes that attempt to highlight different aspects of the market risk to which the energy producer is exposed. Using as a benchmark a wind turbine in Denmark t...
The classification problem consists of using some known objects, usually described by a large vector of features, to induce a model that classifies others into known classes. Feature selection is widely used as the first stage of the classification task to reduce the dimension of the problem, decrease noise and improve speed by the elimination of i...
ilt in MATLAB for a course on the Internet [Jantzen, 1996, Jantzen & Dotoli, 19981. The simulator is based on a linearised model of the system, i=Ax+Bu y = ex (1) The model is a linear state-space model, where x is a vector of state variables, i is the vector time derivative, u is a vector of inputs to the system, and y is a vector of output variab...
The term pap-smear refers to samples of human cells stained by the so-called Papanicolaou method. The purpose of the Papanicolaou method is to diagnose pre-cancerous cell changes before they progress to invasive carcinoma. In this paper a metaheuristic algorithm is proposed in order to classify the cells. Two databases are used, constructed in diff...
Fuzzy logic is key to the efficient working of many consumer, industrial and financial applications. Providing a brief history of the subject as well as analysing the system architecture of a fuzzy controller, this book gives a full and clearly set out introduction to the topic. As an essential guide to this subject for many engineering disciplines...
Laboratory RigMathematical ModelStep 1: Design a Crisp PID ControllerStep 2: Replace It with a Linear FuzzyStep 3: Make It NonlinearStep 4: Fine-tune ItFurther State-Space Analysis*SummaryNotes and References
Describing FunctionsFuzzy PD ControllerFuzzy PD+I ControllerThe Nyquist Criterion for StabilityClosed-Loop Simulation ExamplesAnalytical Derivation of the Describing Function*SummaryNotes and References
Phase Plane AnalysisFuzzy PD ControlFuzzy PD+I ControlFine-tuningHigher-Order SystemsPractical ConsiderationsSummaryNotes and References
Model Reference Adaptive SystemsThe Original SOCA Linear Performance MeasureExample with a Long DeadtimeTuning and Time LockAnalytical Derivation of the Adaptation Law*SummaryNotes and References
Controller ComponentsRule-Based ControllersTable-Based ControllerLinear ControllerAnalytical Simplification of the Inference*SummaryNotes and References
Fuzzy P ControllerFuzzy PD ControllerFuzzy PD+I ControllerFuzzy Incremental ControllerTuningScalingSimulation Study: Higher-Order ProcessPractical Considerations*SummaryNotes and References
Fuzzy SetsFuzzy Set OperationsFuzzy LogicFuzzy ImplicationRules of InferenceGeneralized Modus PonensTriangular NormsFormal Derivation of the Mamdani Inference*SummaryNotes and References
In this study the performance of various intelligent methodologies is compared in the task of pap-smear diagnosis. The selected intelligent methodologies are briefly described and explained, and then, the acquired results are presented and discussed for their comprehensibility and usefulness to medical staff, either for fault diagnosis tasks, or fo...
The pap-smear benchmark database provides data for comparing classification methods. The data con- sists of 917 images of pap-smear cells, classified carefully by cyto-technicians and doctors. The classes are difficult to separate, since class membership is not clearly defined. A basic data analysis provides numerical measures indicating how well t...
This case study provides data and a baseline for comparing classification methods. The data consists of 917 images of Pap-smear cells, classified carefully by cyto-technicians and doctors. Each cell is described by 20 numerical features, and the cells fall into 7 classes. A basic data analysis includes scatter plots and linear classification result...
To demonstrate and compare the application of different genetic programming (GP) based intelligent methodologies for the construction of rule-based systems in two medical domains: the diagnosis of aphasia's subtypes and the classification of pap-smear examinations.
Past data representing (a) successful diagnosis of aphasia's subtypes from collabora...
This tutorial paper provides an interpretation of the membership assignment in the fuzzy clustering algorithm fuzzy c-means. The membership of a data point to several clusters is shown to be analogous to the gravitational forces between bodies of mass. This provides an alternative way to explain the algorithm to students. The analogy suggests a pos...
In this paper we make use of two highly efficient second order neural network training algorithms, namely the LMAM (Levenberg-Marquardt
with Adaptive Momentum) and OLMAM (OptimizedLevenberg-Marquardt with Adaptive Momentum), for the construction of an efficient
pap-smear test classifier. The algorithms are methodologically similar, and are based on...
This paper discusses the potential of fuzzy logic methods within medical imaging. Technical advances have produced imaging techniques that can visualize structures and their functions in the living human body. The interpretation of these images plays a prominent role in diagnostic and therapeutic decisions, so physicians must deal with a variety of...
This simulation study provides an analysis of the adaptation mechanism in the self-organising fuzzy controller, SOC. The approach is to apply a traditional adaptive control viewpoint. A simplified performance measure in the SOC controller is used in a loss function, and thus the MIT rule implies an update mechanism similar to the SOC update mechani...
This educational study is based on a course taught over the Internet for seven years. The objective of the study is to evaluate the didactic method, e-mail tutoring. An average of about 45 students complete the course every year. The course evaluation is based on 42 - 51 student responses to a questionnaire, as well other statistics supplemented by...
This educational study is based on a course taught over the Internet for seven years. The objective of the study is to evaluate the didactic method, e-mail tutoring. An average of about 45 students complete the course every year. The course evaluation is based on 42–51 student responses to a questionnaire, as well other statistics supplemented by p...
The paper presents the fuzzy self-organising controller (SOC). The original controller configuration is shown and compared to modern model reference adaptive systems. The paper analyses the original configuration, and a novel approximation to the adaptation mechanism is developed. A simulation study in Simulink demonstrates that the SOC is able to...
This paper demonstrates two methodologies for the construction of rule-based systems in medical decision making. The first approach consists of a method combining genetic programming and heuristic hierarchical rule-base construction. The second model is composed by a strongly-typed genetic programming system for the generation of fuzzy rule-based s...
The language disability aphasia has several sub-diagnoses such as Amnestic, Broca, Global, and Wernicke. Data concerning 265
patients is available in the form of test scores and diagnoses, made by physicians according to the Aachen Aphasia Test. A
neural network model has been built, which is available for consultation on the World Wide Web. The ne...
The paper presents the fuzzy self-organising controller (SOC). The original controller con guration is shown and compared to modern model reference adaptive systems. The paper analyses the original con guration, and a novel approximation to the adaptation mechanism is developed. A simulation study in Simulink demonstrates that the SOC is able to st...
A new neuroanatomic method is described which allows to map the orientation of central nervous fibers in gross histological sections. Polarised light is used to calculate the angle of inclination and direction of the fibers in each pixel. Serial fiber orientation maps (FOMs) can be aligned and 3D reconstructed. This volume allows to identify and se...
The objective of the study was to test the feasibility of teaching
some of the many engineering applications within medicine to medical
students together with engineering students. A summer school was created
in a block-course design that lasted one week. Different teaching
modules were divided into lecture and exercise sessions. Several
engineerin...
In aphasiology many inconsistencies exist in the definition and interpretation of aphasic syndromes. These syndromes are the co-occurrence of a set of symptoms. Thus, ambiguities in these clinical, aphasic categories are suited to be generalized to many problems of classification in medicine. In this paper the aphasia database is launched as a mode...
A clinical syndrome is a set or a cluster of concurrent symptoms which indicate together the presence and the nature of a disease. Looking for concurrent symptoms is therefore one of the main tasks in medical diagnosis. In medicine imprecise conditions are the rule and therefore fuzzy methods are more suitable than crisp ones. We used fuzzy c-means...
A web-based software model was developed as an example for data mining in aphasiology. It is used for educating medical and engineering students. It is based upon a database of 254 aphasic patients which contains the diagnosis of the aphasia type, profiles of an aphasia test battery (Aachen Aphasia Test), and some further clinical information. In a...
A web-based software model (http://fuzzy.iau.dtu.dk/aphasia.nsf) was developed as an example for classification of aphasia using neural networks. Two multilayer perceptrons were used to classify the type of aphasia (Broca, Wernicke, anomic, global) according to the results in some subtests of the Aachen Aphasia Test (AAT). First a coarse classifica...
A clinical syndrome is a set or a cluster of concurrent symptoms which indicate together the presence and the nature of a disease. Looking for concurrent symptoms is therefore one of the main tasks in medical diagnosis. In medicine imprecise conditions are the rule and therefore fuzzy methods are more suitable than crisp ones. We used fuzzy c-means...
Aphasia is a disturbance of formulation and comprehension of language. The Aphasia Diagnoser was developed for educational purposes and is based on a database of 254 aphasic patients. Two different approaches are taken: 1) Classification with neural networks for group studies, 2) nearest neighbour ranking for detailed information about similar, sin...
In aphasiology many inconsistencies exist in the definition and interpretation of aphasic syndromes. These syndromes are the co-occurrence of a set of symptoms. Thus, ambiguities in these clinical, aphasic categories are suited to be generalized to many problems of classification in medicine. In this paper the aphasia database is launched as a mode...
In a cart-ball balancer the control objective is to balance a ball on a curved track. This simulation study in Simulink tries to stabilise the system with a nonlinear adaptive controller. A simplified adjustment mechanism is implemented, and test results show that the adjustment mechanism works, if it is applied to the cart controller, but fails to...
In a cart-ball balancer the control objective is to balance a ball on a curved track. This simulation study in Simulink tries to stabilise the system with a nonlinear adaptive controller. A simplified adjustment mechanism is implemented, and test results show that the adjustment mechanism works, if it is applied to the cart controller, but fails to...
A ball-balancer, basically an inverted pendulum problem, is stabilised by a linear controller. With certain design choices, a fuzzy controller is equivalent to a summation; thus it can replace the linear controller. It can be claimed, that the fuzzy controller performs at least as well as the linear controller, since the linear controller is contai...
The Training and Education Committee (TED) is a committee under ERUDIT, a Network of Excellence for fuzzy technology and uncertainty in Europe. The main objective of TED is to improve the training and educational possibilities for the nodes of ERUDIT. Since early 1999, TED has set up the TED server, an educational server that serves as a learning c...
Control problems in the process industry are dominated by non-linear and time-varying behaviour, many inner loops, and much interaction between the control loops. Fuzzy controllers have in some cases nevertheless mimicked the control actions of a human operator. Simple fuzzy controllers can be designed starting from PID controllers, and in more com...
Næsten alle kvinder i Danmark deltager i vaginalcytologiske screeningsprogrammer dvs. regelmæssige undersø gelser af celler (smear) fra livmoderhalsen. Smearscreening er i dag hovedsagelig en manuel procedure. Formålet med vores projekt er at udvikle et computerstyret system til automatisk screening for livmoderhalskræft med samme eller bedre diagn...
The tutorial concerns automatic control of an inverted pendulum, especially rule based control by means of fuzzy logic. A ball balancer, implemented in a software simulator in Matlab, is used as a practical case study. The objectives of the tutorial are to teach the basics of fuzzy control, and to show how to apply fuzzy logic in automatic control....
EVWUDFW An engineer about to design a fuzzy controller is faced with many design choices. The objective of this tutorial paper is to identify and describe the choices based on an interna-tional standard which is underway. The paper can be used as an introduction to commercial software packages for fuzzy controller design.
EVWUDFW The ball-balancer, or cart-ball system, demonstrates some basic concepts in control be-ing nonlinear, multivariable, and non-minimum phase. It is basically an inverted pendulum problem, which is a much used benchmark problem. The objective here is to provide an analysis of the system, which can be the basis for designing different kinds of...
A course in fuzzy logic control has been offered on the Internet (http://www.iau.dtu.dk/~jj/learn) since late 1995. Now that about 100 students have taken the course it is possible to report some results and experiences. The course concerns fuzzy logic for automatic control. The objectives are to teach the basics of fuzzy logic, to show how to use...
This simulation study investigates how di¤erent types of rule bases a¤ect the control of di¤erent types of plant In Simulink three nonlinear control surfaces have been tested and compared to a linear surface It is recommended to be aware of the shape of the control surface, and carefully select a type that matches the type of plant to be controlled
In this paper we consider the structural decoupling and disturbance rejection of a distillation column. The considered approach is general and makes use of a digraph representation of the system. The analysis of the associated digraph allows both to answer the question of existence of a solution to a control problem and to get, where the problem is...
The paper investigates the unit commitment problem of Swedish
power company Sydkraft as a constraint satisfaction problem. The power
system is a simplified system with nuclear, thermal, and hydro
generators as well as power interchange. In this paper we focus on soft
constraints, for instance `approximately equal', `much larger than', and
`a little...
In order to "see" the signal flow in a multivariable system it is easy to map state space equations into a directed graph (digraph). The paper introduces some programs that can provide a control engineer with qualitative information with regard to decomposition, controllability, pole placement, disturbance rejection, input-output decoupling, and mo...
Promising results from applying an array-based approach to two-valued logic suggests its application to fuzzy logic. The idea is to limit the domain of truth-values to a discrete, finite domain, such that a logical relationship can be evaluated by an exhaustive test of all possible combinations of truth-values. The paper presents a study of the top...
In order to "see" the signal flow in a multivariable system it is easy to map state space equations into a directed graph (digraph). The paper introduces some programs that can provide a control engineer with qualitative information with regard to decomposition, controllability, pole placement, disturbance rejection, input-output decoupling, and mo...
The DIGRAPH TOOLBOX, using MATLAB is a collection of algorithms, expressed in M-files, that implement structural analysis and design of linear control systems. Control systems modelled in state-space form can be mapped into a directed graph (digraph) and system properties can be expressed as properties of the digraph.
A process knowledge based control structuring method for process start-up is presented. The methodology leads to definition of tracking tasks. The tasks contain properties to describe some sub-procedures in the whole start-up procedure. Operational safety aspects are included into the task properties. Thus combining the tasks a complete procedure f...
The problem in this case study can be described as a
multi-dimensional surface fit to a given set of data. The data are sales
figures in MWH/H for a hydro-thermal power generation system. The data
are incomplete and not totally reliable. A model with ten fuzzy rules
fits the data with a total error of 19%; with twenty-six rules the error
would be 0...
A process knowledge based control structuring method for process start-up is presented. The methodology leads to definition of tracking tasks. The tasks contain properties to describe some sub-procedures in the whole start-up procedure. Operational safety aspects are included into the task properties. Thus combining the tasks a complete procedure f...
The digraph approach is a graphical approach to analysis and design of control systems. Its objective is to reveal generic properties of state space models. The approach is based on a mapping of the state space equations into a directed graph and system properties are expressed as properties of the graph. The structural concepts of path, cycle, and...
As a basis for an automated interpretation of magnetic resonance
images, the authors propose a fuzzy segmentation method. The method uses
five standard fuzzy membership functions: small, small medium, medium,
large medium, and large. The method fits these membership functions to
the modes of interest in the image histogram by means of a
piecewise-l...
The digraph approach is a graphical approach to analysis and design of control systems. Its objective is to reveal generic properties of state space models. The approach is based on a mapping of the state space equations into a directed graph, and system properties are expressed as properties of the graph. The structural concepts of path, cycle, an...
The identification of weakly coupled sub-systems often provides the basis for complex multivariable control system design. Such identification is not always easy, and conventional methods of system reduction often make such an approach impossible. An alternative approach to the reduction of system structure is suggested, based on eigenvalue sensiti...
Practical CAD techniques for a structural approach to multivariable control are described. These are based on earlier graph theoretic analysis, as largely developed by one of the authors. Their application to two major control design problems; an IFAC benchmark problem in disturbance rejection and another of noninteractive control, are successfully...
The identification of weakly coupled sub-systems often provides the basis for complex multi-variable control system design. Such identification is not always easy, and conventional methods of system reduction often make such an approach impossible. An alternative approach to the reduction of system structure is suggested, based: on eigenvalue sensi...
Practical CAD techniques for a structural approach to multivariable control are described. These are based on earlier graph theoretic analysis, as largely developed by one of the authors. Their application to two major control design problems; an IFAC benchmark problem in disturbance rejection and another of noninteractive control, are successfully...
Practical CAD techniques for a structural approach to multivariable control are described. These are based on earlier graph theoretic analysis, as largely developed by one of the authors. Their application to two major control design problems; an IFAC benchmark problem in disturbance rejection and another of non-interactive control, are successfull...
A critical computational requirement for many of the decision technologies in the fields of operations research (PERT/CPM, Markov chains, decision trees, Bayesian analysis, MRP, simulation, …), artificial intelligence (evidential reasoning, truth maintenance systems, propositional logic, rule based inference, frames and semantic nets, …), and decis...
To prevent sewage floods during rainstorms, a prototype of a fault diagnosis system has been built. The prototype is written in the Nested Interactive Array Language, Nial. A fuzzy inference method has been implemented by means of array theory. Thus, a rule like Clog: = Big if (Level is High) is directly executable. As a result, a whole rule-base e...
A critical computational requirement for many of the decision technologies in the fields of MS/OR, AI/KBS, and DSS is the development and manipulation of a network describing the relationship between "actors" involved in the application of the decision technology to a specific problem. The manipulation of such networks using Boolean arrays and func...