nils-herrmann/clean_scirepeval huggingface dataset:
The development of an integrated decision support system for a textile company: A systems engineering approach

This paper describes the development of an Integrated Decision Support System, IDES, for the Planning and Control of ATMA, a Portuguese Textile Company. The methodology used in the process is an interdisciplinary effort, deeply rooted in Systems Engineering, in which the consideration of the Portuguese industrial context was one of the driving factors leading to its synthesis. The paper presents the overall development process emphasising the methodological framework and the main results achieved. Concepts and techniques from Control Systems, Dynamic Optimization, Software Engineering, Enterprise Modelling and Anthropocentric Systems were used.
A multilayered shielded microwave circuit design method based on genetic algorithms and neural networks

In this work we propose the use of genetic algorithms combined with neural networks to design shielded printed microwave filters. Optimization based on genetic algorithm techniques (GA) is usually very time consuming. By using neural networks, the GA can be applied to the design of multilayered shielded circuits in reasonable time. The neural networks approximates the Green's functions employed in the integral equation (IE) approach. Fast analysis of the printed circuits inside the shielded structure can be done, therefore limiting the total execution time of the GA. A new specific fitness function specially well suited for the design of microwave filters has also been derived. Results show good performance of the CAD developed for the design of practical printed shielded microwave filters
Numerical evaluation of the Green's functions for cylindrical enclosures by a new spatial images method

A spatial images technique is used to efficiently calculate the mixed potential Green's functions associated to magnetic sources when they are placed inside a circular cylindrical cavity. The technique places magnetic dipole images and charges outside the cylindrical region. Their strength and orientation are then calculated by imposing the appropriate boundary conditions for the fields at discrete points of the metallic wall. In this paper, the basic technique is combined with spatial domain multilayered Green's functions formulated with Sommerfeld integrals. This allows the analysis of practical multilayered circuits shielded in circular cavities. Convergence results are shown to demonstrate the usefulness of the technique. Two practical microwave circuits are also analyzed to show the validity of the formulation.
Influence of Saturation on the Airgap Induction Waveform of Five-Phase Induction Machines

The third harmonic of the airgap induction plays a more important role in high-phase machines than in conventional three-phase machines, because it can be used to optimize the airgap waveform and produce useful torque. The paper assesses the influence of saturation on the production of an optimized induction waveform in the airgap of five-phase induction machines through the third harmonic induction component. It is shown that teeth and core saturation have opposite effects in what concerns the production of optimized airgap induction. The paper also shows that, different from three-phase machines, a third harmonic airgap field can exist even when the five-phase machine is connected in delta or connected in star with neutral conductor. Analytical expressions to approximate the airgap induction including saturation effects are presented and the joint effect of stator current and saturation is discussed. Experimental results obtained from a prototype machine are presented and compared to theoretical values.
A robust discrete-time observer for induction motors

This paper proposes a convex approach to the design of robust discrete-time observers to the state estimation of induction machines subject to rotor resistance variation and load disturbance. The observer gain is designed in order to minimize these effects on the state estimation in an ℋ∞ sense, while guaranteeing the error dynamics stability. The proposed conditions are cast in terms of state-dependent linear matrix inequalities. Simulation results demonstrates the performance of the approach.
A dynamically configurable architecture for the control of autonomous underwater vehicles

This paper presents a control architecture for autonomous underwater vehicles AUVs. The proposed architecture has its foundations on a hierarchic structure organized linguistically where parallel operations take place in real-time. this hierarchic structure is composed of three levels: organization, coordination and functional layer, structured according to the principle of increasing precision with decreasing intelligence. The main contribution is the concept of dynamically configurable architecture where the notion of architecture coordinator plays a crucial role. This system dynamically configures the connections among modules of the functional and maintains the state of this configuration so that the most adequate translation of planned actions into execution commands takes place. These coordination features are also used to incorporate the emergence of reactive behaviours in this hierarchic architecture.<<ETX>>
A hybrid systems theory framework for the design of a control architecture for multiple autonomous underwater vehicles

This paper describes the modeling, design and implementation of the generalized vehicle (GV) architecture for the coordinated control of multiple autonomous underwater vehicles in the framework of the hybrid systems theory. A generalized vehicle is a group of vehicles whose spatial and logic organization is controlled in such a way that the group behaves as a single entity. The hybrid systems formalism provides the most adequate framework for incorporating the discrete event and continuous dynamics that arise in the concurrent coordinated operation of multiple vehicles and fully encompasses the modeling, analysis, design and implementation cycle of the GV architecture. A micro-simulation environment of the coordinated operation of multiple AUVs was developed in SHIFT, a new specification language for describing networks of hybrid automata. The DIADEM software environment for implementing on-line, real-time automated management and control systems, is discussed in the context of the implementation of the GV concept.
Laboratory Tests in a prototype of a Self-Monitored Current Transformer for monitoring electrical measurement systems

CEPEL (Centro de Pesquisas de Energia Elétrica) has developed and patented a solution for monitoring measurement systems based on intelligent instrument transformers, called Self-Monitored Current Transformers (TCAMs)1 and Self-Monitored Potential Transformers (TPAMs)2, in order to reduce non-technical losses and monitor the electrical measurement system. This paper presents the main features of the proposed monitoring solution, based on an electronic circuit that is embedded into conventional instrument transformers. Accuracy test results obtained in the laboratory using the prototype of TCAM developed in CEPEL are also presented.
Impulsive robust control with peak gain constraints using LMIS

This article addresses the problem of controlling a continuous linear system subject to a continuous perturbation by a series of impulses. The approach follows a H∞ setting based on state feedback. A second observation of the state is further considered to designate state variables for which the system is sensitive to peak values. A constraint is introduced in the form of a maximum admissible initial state to peak value gain. The problem is address using semidefinite programming.
Direct vector control for a servopositioner using an alternative rotor flux estimation algorithm

This paper presents a direct vector control scheme used for the positioning of servomotors. As is well known, direct vector control requires accurate information about rotor flux. To provide such information, the authors propose a new estimation algorithm that combines the recursive prediction error method-RPEM-with a linear Kalman filter. The RPEM algorithm makes the rotor resistance estimation and calculates the gains of the Kalman filter which makes the rotor flux estimation. The authors present digital simulations using the proposed scheme that highlight the effectiveness of vector control.
A dynamically configurable architecture for the control of an autonomous underwater vehicle

This paper presents a tri-level hierarchic control architecture for autonomous underwater vehicles (AUVs). This hierarchic structure is composed of three levels: organization, coordination and functional, structured according to the principle of increasing precision with decreasing intelligence. These levels are organized linguistically. The main contribution is the concept of dynamically configurable architecture where the notion of architecture coordinator plays a crucial role. This system dynamically configures the connections among modules of the functional layer and maintains the state of this configuration so that the most adequate translation of planned actions into execution commands takes place. These coordination features are also used to incorporate the emergence of reactive behaviors in this hierarchic architecture. The architecture structure has provisions to support multi-modal operator interfaces and for integration in complex operational systems governing the operation of multiple AUVs, divers and other sensors and actuators.
Video compression: Discussing the next steps

Video compression has been intensively evolving for more than 20 years. Until recently, around 50% compression gains every 5 years were obtained, resulting in the current set of video coding standards. More recently, after the development of the very successful H.264/AVC standard, compression gains have been short and more difficult to reach than usual. In this context, this talk will discuss the future of video compression considering the emerging industry needs, notably in terms of promising technological novelties, and recent standardization initiatives targeting 3D video and further video compression efficiency.
An Efficient Encoder Rate Control Solution for Transform Domain Wyner–Ziv Video Coding

Most Wyner-Ziv (WZ) video coding solutions in the literature use a feedback channel (FC) based decoder rate control (DRC) strategy to adjust the bitrate to correct the side information (SI) errors. More recently, some encoder rate control (ERC) strategies have been proposed to address application scenarios where a FC is not available. The ERC based WZ video coding RD performance depends not only on the (encoder) parity rate estimator (PRE) accuracy but also on the decoder “intelligence” in dealing with the residual errors due to parity rate underestimation. In this context, the main objective of this paper is to propose a more efficient and powerful ERC solution for transform domain WZ (TDWZ) video coding by simultaneously tackling the two issues aforementioned with the following technical novelty: 1) integration in an ERC context of Gray mapping for the quantized DCT coefficients to enhance the correlation between WZ and SI data; 2) more accurate PRE to better estimate the needed parity rate to avoid undesired parity rate underestimations and overestimations; 3) novel soft reconstruction function to reduce the impact of the residual bitplane errors in the decoded WZ frame quality; and 4) weighted overlapped block motion compensation technique to refine the SI used in an iterative WZ decoding framework with the correlation noise model parameters dynamically updated. Experimental results show a considerable RD performance improvement with a reduction of up to about 2 dB of the gap between the ERC and DRC based approaches in TDWZ video coding solutions, thus making this ERC based WZ codec the most efficient available and competitive regarding DRC based WZ video coding solutions.
E‐plane radiation pattern analysis of rectangular horn antennas with V‐shaped corrugations by UTD‐PO formulation

A new method for the calculation of the radiation pattern of corrugated E‐plane rectangular horn antennas based on a hybrid uniform theory of diffraction‐physical optics (UTD‐PO) formulation is presented. The method, which allows for the analysis of horns in which V‐shaped corrugations have been considered, has been validated with numerical data obtained through the application of both an electric field integral equation (EFIE) solved by the method of moments (MoM) and the finite element method (FEM)‐based full‐wave electromagnetic analysis software, HFSS. In this sense, the proposed solution is mathematically less complex and computationally more efficient than existing techniques.
First and second order necessary conditions of optimality for impulsive control problems

We present first and second order necessary conditions of optimality for a general class of nonlinear measure driven dynamic control systems subject to both equality and inequality endpoint state constraints. An important feature of our result is that the conditions remain informative even for abnormal control processes. Our result is obtained by decoding the necessary conditions of optimality for an abstract minimization problem with equality and inequality type constraints and constraints given by convex cone.
Repetitive controller with low-pass filter compensation applied to Uninterruptible Power Supplies (UPS)

In this paper is proposed a method to improve the tracking performance of repetitive controllers in Uninterruptible Power Supplies (UPS). The main idea is to simultaneously compensate the gain reduction and frequency shift caused by the introduction of a low-pass filter in series with the delay element. Also, an optimization problem based on LMI constraints is presented to determine controller gains that guarantee stability and performance of the closed loop system. Simulation results based on the output stage of 3.5kVA UPS demonstrate the effectiveness of the proposed method.
Optimal power consumption motion control of a fish-like vehicle in a vortices vector fiele

This article concerns the formalization of a control framework for the fish-like motion control in a fluid due to a vector field generated by point vortices so that the overall power consumption required to travel between the departure and the arrival points is minimized. The control action is synthesized by specifying the time, location and circulation of at least one vortex and the extent to which this vortex, together one or more other vortices will propel the mobile platform considered as a point particle. Given the complexity of the general problem, we consider two simplifying assumptions: (i) only two vortices are active at each time interval, and (ii) the motion takes place in R2. Necessary conditions of optimality in the form of a Maximum Principle of Pontryagin are stated, and the features ensuring that they constitute a solid basis for the synthesis of the optimal control strategy are discussed.
Real-time application of simulation tools and implementation of control techniques for induction machines in Matlab/Simulink/spl reg/ environment

The main contribution of this work is the development of a Matlab/Simulink-based software environment that allows the integrated simulation, validation and fast prototyping of real-time control algorithms for induction machines. The transition from the simulation phase to the real-time prototyping is straightforward. A single modification by the user is required to perform the substitution of simulation tools by real-time tools. The algorithm developed is kept in the environment during the whole design process. Real-time tools will read sensors signals and send control signals for the drivers. Practical results were obtained and are hereby presented in order to illustrate the use and the characteristics of the platform. The use of flux estimators and current control was also exemplified in simulation and real-time implementation in such way that all the potentiality of the developed platform could be demonstrated.
An IOPT-net state-space generator tool

This paper presents the IOPT2SS tool, used to automatically generate state-space graphs associated with IOPT (Input-Output Place-Transition) Petri nets models. The new tool accounts with the non autonomous nature of the IOPT Petri net class, where transition firing is constrained by external input events and input signals (expressed in transition guards); on the other hand, transitions can trigger the occurrence of output signal events and place marking can activate output signals. To achieve the performance level necessary for the fast generation of complex state-spaces during reasonable time, the tool employs a compilation strategy, starting with the automatic creation of an optimized C program. When executed, the program will create an hierarchical XML file containing the state-space graph. The output XML file can subsequently be used for model checking and property analysis, applying standard XML query languages. Finally, the output file can be converted to SVG (Scalable Vector Graphics), enabling the graphical visualization of small to medium size state-space graphs. The new tool was implemented using a set of XSL transformations and can be used as a standalone tool or as a building block in higher level frameworks, with easy integration in Web applications and graphical integrated development environments.
Mission planning and specification in the Neptus framework

The C3I (command, control, communication and information) Neptus framework which is being developed at the Underwater Systems and Technology Laboratory (USTL/LSTS) is presented. Neptus is a modular mixed initiative framework (human operators in the control loop) for the operation of heterogeneous teams of vehicles such as autonomous and remotely operated underwater, surface, land, and air vehicles. Neptus is composed of mission and vehicle planning, supervision, and post-mission analysis modules which are provided as services across a network. This paper focus mainly on the mission definition module with the presentation of MDL - a XML based language for mission definition
Necessary conditions of optimality for impulsive differential inclusions

In this paper, we address a class of optimal control problems with dynamic constraints are specified by a differential inclusion, the control variables are in the space of positive Borel measures and the state trajectories are considered to be in the space of /spl Rscr//sup n/-valued functions of bounded variation. A concept of robust solution to a measure differential inclusion is introduced that takes into account the interaction between the control measure and state variables during the jumps. Necessary conditions of optimality are obtained as a limit of the same type of conditions for a sequence of an appropriate class of conventional dynamic optimization problems.
Integral equation analysis of capacitive waveguide circuits

This contribution presents a formulation based on the integral equation technique for the analysis of waveguide circuits containing capacitive obstacles, and including material bodies, such as dielectric or magnetic posts. The formulation is very efficient, since it reduces the 3D structure to a 2D problem by using a mixed spatial and spectral formulation. Results show high accuracy and efficiency in the analysis of lowpass filters in waveguide technology. Using the software tool, several new applications in the area of waveguide lowpass filters are introduced. This includes the use of magnetic materials to implement resonant irises, and the use of dielectric materials to reduce multipactor risk in high power applications.
Efficient calculation of the Green's functions for multilayered shielded cavities with right isosceles-triangular cross-section

An efficient calculation of the Green's functions inside multilayered shielded cavities with right isosceles-triangular cross-section is presented. The method is entirely developed in the spatial domain, and it is based on image theory. The idea is to use the spatial-domain Green's functions inside a multilayered shielded square box, in order to accurately obtain the Green's functions for the right isosceles-triangular cavity. Image theory is then used to enforce the boundary conditions along the non-equal side of the triangle. It is shown that the new algorithm is very robust, with limited computational effort. Resonance frequencies and potential patterns of a triangular cavity have been calculated and compared with those obtained by other techniques, showing very good agreement. Finally, a transversal filter inside a multilayered triangular-shaped cavity is designed, manufactured and tested using the developed technique.
MPEG-7: a standard for describing audiovisual information

MPEG-1 and MPEG-2 have been successful standards, and it is expected that MPEG-4 will also set new frontiers in terms of audiovisual representation. Following these projects, MPEG has decided to address the problem of quickly and efficiently identifying various types of multimedia material of interest to the user. For this, a standardized way of describing audiovisual information will be developed in MPEG-7. Since MPEG is a very open environment evolving based on the validity of technical arguments and relevance of application requirements, it is needed, desirable and expected that many experts with useful knowledge in the field of audiovisual description will join this challenging effort.
Using MPEG-7 for Generic Audiovisual Content Automatic Summarization

This paper proposes and evaluates a fully automatic summarization application for generic audiovisual based on MPEG-7 compliant hierarchical summary descriptions, which allows providing flexibility, low complexity, and interoperability. The novelty of this paper regards the exploitation of a three features, low-level arousal model to generate the summary metadata needed to instantiate MPEG-7 compliant summary descriptions with the advantages this brings in terms of interoperability. Moreover, a novel, solid performance evaluation methodology has been proposed and its application has been performed.
Modeling and control of the IES project ROV

This paper describes the modeling and control of a Remotely Operate Vehicle (ROV), as part of the effort performed in the context of the Inspection of Underwater Structures (IES) project. The main objective of IES is the implementation of a ROV-based system for the inspection of underwater structures. The IES project is a 3 yearlong effort funded by the Portuguese R&D program Praxis XXI. After addressing the complete model, including the body model and the thruster model, we present the design of a nonlinear controller based on the Sliding Modes methodology, which allow the vehicle to move according to the application requirements. PID controllers were also used in order to compare both performances.