nils-herrmann/clean_scirepeval huggingface dataset:
Objective evaluation of video segmentation quality

Video segmentation assumes a major role in the context of object-based coding and description applications. Evaluating the adequacy of a segmentation result for a given application is a requisite both to allow the appropriate selection of segmentation algorithms as well as to adjust their parameters for optimal performance. Subjective testing, the current practice for the evaluation of video segmentation quality, is an expensive and time-consuming process. Objective segmentation quality evaluation techniques can alternatively be used; however, it is recognized that, so far, much less research effort has been devoted to this subject than to the development of segmentation algorithms. This paper discusses the problem of video segmentation quality evaluation, proposing evaluation methodologies and objective segmentation quality metrics for individual objects as well as for complete segmentation partitions. Both stand alone and relative evaluation metrics are developed to cover the cases for which a reference segmentation is missing or available for comparison.
Trajectory generation for a remotely operated vehicle

This paper addresses the problem of trajectory generation for a remotely operated vehicle (ROV). The ROV is a nonholonomic vehicle and has limited actuator capabilities. This means that the task of trajectory generation for the inspection of underwater structures is not a trivial one, and that it cannot be done without computer aided design tools. The approach is based on techniques developed for differential flat systems. The ROV model is presented and it is shown that it satisfies the differential flatness property. The paper details the architecture of the computer aided trajectory generation tool.
MPEG-4 video subjective test procedures and results

In the recent years, the technical developments in the area of audio-visual communications, notably in video coding, encouraged the emergence of new services which are already changing our everyday life. The convergence of the telecommunications, computer, and TV/film technologies is leading to the intermixture of elements formerly characteristic of each one of these fields, creating new needs and new requirements. Among the most important trends is the need to increase the interaction capabilities between the user and the audio-visual information, notably by considering the scene as a composition of objects-the content-according to a script that describes their spatial and temporal behavior and not just a set of pixels. MPEG-4 is a new audio-visual standard aiming to establish a universal, efficient coding of different forms of audio-visual data, called audio-visual objects. To reach this target, MPEG-4 has called for proposals on techniques that may be instrumental to efficiently represent visual information, allowing simultaneously high degrees of content-based interactivity and error resilience. This paper addresses the conditions under which the proposals to the MPEG-4 first round of video subjective tests have been evaluated. Moreover, the most significative results of these tests are also presented.
Data and Instruction Uniformity in Minimal Multi-threading

Simultaneous Multi-Threading (SMT) is a hardware model in which different threads share the same instruction fetching unit. This model is a compromise between high parallelism and low hardware cost. Minimal Multi-Threading (MMT) is a technique recently proposed to share instructions and execution between threads in a SMT machine. In this paper we propose new ways to explore redundancies in the MMT execution model. First, we propose and evaluate a new thread reconvergence heuristics that handles function calls better than previous approaches. Second, we demonstrate the existence of substantial regularity in inter-thread memory access patterns. We validate our results on the four data-parallel applications present in the PARSEC benchmark suite. The new thread reconvergence heuristics is, on the average, 82% more efficient than MMT's original reconvergence method. Furthermore, about 69% to 87% of all the memory addresses are either the same for all the threads, or are affine expressions of the thread identifier. This observation motivates the design of newly proposed hardware that benefits from regularity in inter-thread memory accesses.
Coordination strategies between UAV and AUVs for ocean exploration

Autonomous underwater vehicles (AUVs) have limited and low bandwidth communication capabilities. In order to communicate a host, they need to surface. To increase the operational period of the AUVs and decrease the surfacing time, we deploy a single Unmanned aerial vehicle (UAV) that cooperates with AUVs in performing an ocean exploration mission efficiently. A team of AUVs are deployed in the ocean and surface when their mission leg is completed. The UAV flies over the AUVs, acquires the information, and provides a new mission plan to the AUVs. The UAV has to meet all the AUVs and reach the base station within a prescribed sortie time. However, the AUVs may not complete the assigned task and may surface anywhere along the mission plan. Hence, the UAV has to take the uncertainty of AUV surfacing into account while generating the next mission plan to the AUV. We develop a robust route planning algorithm for the UAV and path generation algorithm for the AUV such that the UAV always reaches the base station within the sortie time limit. Theoretical results are presented to show the robustness of the algorithms. Simulations are carried out to show how the mission is accomplished.
Impulsive observation and control strategies in minimax problems

An optimization problem for systems that are subject to perturbations and have both controlled discrete state observations and impulsive control actions is here addressed. The dynamics equation is given by a differential inclusion x(t) ∊ F(t, x(t)) and the optimal strategy is the minimizer of the worst viable perturbation process (minimax). Such formulation is appropriate when noise is barely known but limited and when observing the system, similarly to changing its state, has a positive cost that is not negligible. Since observation and control actions occur at stopping times relative to the σ-algebra generated by the state values at previous observation times (which are the only known state values), this formulation has a discrete time analogue, which is exploited. An algorithm based on sufficient conditions for optimality is presented.
The language LinF for fractal specification

We present the language LinF for L-System specification. L-Systems are formal string rewriting systems introduced in 1968 by the botanist Aristid Lindenmayer that are used to model fractal images. LinF allows the definition of three-dimensional fractals and stochastic fractals. Together with the LinF definition we present the implementation of cFLC, an OpenGL-based system that generates fractal images from LinF specifications. Results obtained through the LinF formalism show the ease of use and generality of the developed tools with respect to the existing literature.
Wavelet-like based efficient analysis of dielectric and magnetic scatterers using the equivalence principle

Lossy dielectric and magnetic obstacles are typically present in many high-frequency scattering applications. We study this problem using the equivalence principle and the method of moments (MoM). When the structure is complex and high accuracy is required; the number of unknowns in the numerical solution naturally grows. Therefore, we propose the use of wavelet-like bases to improve the numerical efficiency and memory requirements. For verification purposes, the results provided by the new technique are successfully compared with those obtained with the conventional MoM approach. The new technique has been applied to characterize the scattering behavior of large square and elliptical obstacles which are composed of lossy dielectric and magnetic media.
Dynamic programming based feedback control for systems with switching costs

This paper is concerned with the synthesis of optimal feedback controllers for nonlinear continuous-time systems with switching costs. The design approach is based on dynamic programming techniques. Robustness with respect to model uncertainty and bounded disturbances is encompassed by considering an adversarial input. The problem is solved in the framework of zero-sum differential games. Controller specifications include state and input constraints. A numerical algorithm for the synthesis of the controller is described.
A neural-network method for the analysis of multilayered shielded microwave circuits

In this paper, a neural-network-based method for the analysis of practical multilayered shielded microwave circuits is presented. Using this idea, a radial basis function neural network (RBFNN) is trained to approximate the space-domain multilayered media boxed Green's functions used in the integral-equation (IE) method. Once the RBFNN has been trained, the outputs of the neural network (NN) replace the exact Green's functions, during the numerical solution of the IE. The computation of the RBFNN output values is very fast in comparison with the numerical methods used to calculate the exact Green's functions. This paper describes two novel strategies for efficiently training the RBFNN. In the first strategy, the input space of the RBFNN is divided into several spatial and frequency regions. The spatial subdivision is extended for the first time to both observation and source regions. In addition, the subdivision of the observation points regions is applied in a novel manner to the whole cross section of the metallic box. The second strategy combines the above region subdivision with an adaptive selection of the neurons variances in each region. The accuracy and the computational gain achieved with the NN method proposed makes possible the implementation of computer-aided-design tools that can be used for the analysis and design of integrated shielded microwave circuits (e.g., monolithic microwave integrated circuit devices) on a real-time basis
Investigation of second-order optimality conditions for impulsive control problems under the Frobenius condition

In this work impulsive control problems are investigated in that case in which matrix G that appears in the dynamics multiplying vector-valued control measure μ depends on the state variable, that is, G = G(x, t). The solution concept and the extension procedure in this non-linear case are not as trivial as in the case G = G (t). The key-point is to ensure robustness of the impulsive control system w.r.t. the control measure and regarding the approximations in the weak-∗ topology (“w.r.t.” stands for “with respect to” here and further). Note that such approximations are required by applications. But this type of robustness is generally lost unless some extra assumptions on the matrix G w.r.t. the x-variable are imposed. It turns out that the weakest possible assumption, that still meets the robustness property, is the so-called Frobenius condition presented and discussed below. Under the Frobenius condition and without a priori regularity assumptions, we derive second-order necessary optimality conditions in a new form. This form and relations with previous results are discussed.
Dynamic optimization in the coordination and control of autonomous underwater vehicles

The coordination and control problems arising in team composition and tasking of autonomous underwater vehicles are discussed in the framework of dynamic optimization. Team composition and tasking are specified in terms of sets and relations among the elements of these sets. Results from dynamic optimization and non-smooth analysis are used to show that these coordination and control problems can be phrased in terms of concepts such as invariance, solvability, monotonicity, and switchings among value functions.
Neptus - a framework to support multiple vehicle operation

This paper describes the development of a C3I (communications, command, control and intelligence/information) infrastructure, taking place at the Underwater Systems and Technology Laboratory (LSTS) of FEUP. This infrastructure, the Neptus framework, goal is to support the coordinated operation of heterogeneous teams, which include autonomous and remotely operated underwater, surface, land, and air vehicles and people. People perform a fundamental role, not only in the case of remotely operated vehicles, but also with autonomous vehicles where mix-initiative operation is a requirement. The operational scenarios for these teams are mainly environmental monitoring missions but could also include environmental disaster scenarios, rescue missions, etc. The Neptus distributed architecture is service oriented, which enables high degrees of interoperability between applications, of scalability (number of nodes), and of reconfiguration (number and type of nodes).
Automatic detection of TV commercial blocks: A new approach based on digital on-screen graphics classification

In this paper, a simple, yet effective method for TV commercials detection is proposed, that exploits the presence or absence, in the screen, of the broadcaster logo (or TV channel logo). The approach is based on a digital on-screen graphics (DoG) detection and classification mechanism, targeting to detect and distinguish TV channel logos from other types of DoGs. No pre-built database is required, as the proposed solution is able to gather its own collection of DoGs from the broadcasted videos. A continuous update and control of the DoGs database is performed, thus allowing to conclude about the nature of each DoG and to classify each video segment as Regular Program or Commercial Block. For the used test video dataset, corresponding to recordings from three Portuguese TV channels, a minimum accuracy of 93,9% on commercials detection was achieved; furthermore, the measured processing time suggests that the proposed solution should enable real-time (i.e., while recording) detection of commercial blocks.
A new attachment model for the study of wire-plate junction antennas

In this contribution, a simple but effective attachment mode for the analysis of wire to plate junction structures is presented. The wire elements are connected to the surface metallic areas through the center of a relevant mesh cell. Up to four half roof-top functions are defined on the sides of this cell to correctly model the current flowing from the wire, and spreading through out the plate. Results are presented for various monopole antennas excited over finite metallic plates or cubes. In spite of being simple, the results obtained show that the attachment mode indeed works well even for wire antennas closed to edge corners.
Application of the high-gain substrate-superstrate configuration to dielectric leaky-wave antennas

The high-gain substrate-superstrate configuration, which was proposed to increase the gain in printed circuit antennas, is applied to dielectric leaky-wave antennas (LWAs) to improve its frequency response. Analysis of a slitted suspended dielectric rectangular waveguide is carried out using a full-wave method. It is proved that the minimum values of the leakage constant of the leaky-wave mode for the suspended configuration are related to the high-gain resonance conditions. Moreover, it is found that the suspended LWA exhibits very small beamwidth variations in a large frequency bandwidth. It is well-known that inhomogeneous filled LWAs suffer from variation of beamwidth as the angle of maximum radiation is scanned with frequency. The proposed topology can be adjusted so that a flat response of the beamwidth can be obtained in a large frequency band, while maintaining the frequency-scanning behavior of the LWA.
Multi-technology RF fingerprinting with leaky-feeder in underground tunnels

Techniques using RSS fingerprinting for localization have been studied over a number of different technologies in many different scenarios. In the case of underground tunnels localization can be quite challenging, yet it is extremely important for safety reasons. In the specific case of the CERN tunnels, accurate and automatized localization methods would additionally allow the workflow of some activities to become substantially faster. In a radiation area this would also have the added benefit of reducing the exposure time of personnel conducting so called radiation surveys which have to be carried out before access can be granted. In this paper Fingerprinting techniques for GSM and Wireless LAN are studied and enhanced to take advantage of both network technologies simultaneously as well as the channels RSS differential and an observed effect in the radiated power in the leaky-feeder cables. Besides the higher accuracy achieved for a single technology, this methodology looks promising for scenarios where several types of wireless networks are available or expected to be installed at a later stage.
Multifunctional Controller Architecture for Solid-State Marx Modulator Based on FPGA

This paper proposes a multifunctional architecture to implement field-programmable gate array (FPGA) controllers for power converters and presents a prototype for a pulsed power generator based on a solid-state Marx topology. The massively parallel nature of reconfigurable hardware platforms provides very high processing power and fast response times allowing the implementation of many subsystems in the same device. The prototype includes the controller, a failure detection system, an interface with a safety/emergency subsystem, a graphical user interface, and a virtual oscilloscope to visualize the generated pulse waveforms, using a single FPGA. The proposed architecture employs a modular design that can be easily adapted to other power converter topologies.
Web based IOPT Petri net Editor with an extensible plugin architecture to support generic net operations

This paper presents a new Web based Petri net Editor employing AJAX principles to allow the interactive design and edition of Petri net models using standard Web browsers. The editor includes an integrated plug-in architecture to simplify the addition of generic net operations without requiring the manipulation of internal editor data-structures. IOPT-nets are a non-autonomous Petri net class targeting the model-based development of embedded system controllers and combine the well know properties of Petri nets with input and output signals and events to establish the communication of controllers with the external world. The editor is a part of the IOPT-tools Web service that also contains model-checking and automatic code-generation tools, supporting a complete model-based development work-flow, starting from model design to the final controller code generation. All tools are available at the research group Web page (http://gres.uninova.pt).
Design of a linguistic postprocessor using variable memory length Markov models

We describe a linguistic postprocessor for character recognizers. The central module of our system is a trainable variable memory length Markov model (VLMM) that predicts the next character given a variable length window of past characters. The overall system is composed of several finite state automata, including the main VLMM and a proper noun VLMM. The best model reported in the literature (Brown et al., 1992) achieves 1.75 bits per character on the Brown corpus. On that same corpus, our model, trained on 10 times less data, reaches 2.19 bits per character and is 200 times smaller (/spl sime/160,000 parameters). The model was designed for handwriting recognition applications but could also be used for other OCR problems and speech recognition.
A simple simulation of 2D radomes using line source excitation and fast multipole method

Starting from a classical method of moments (MOM) approach for analyzing conducting surfaces coated with two layers of homogeneous media, we have replaced the usual plane wave excitation with line sources. In order to enhance the computational cost of this kind of problem, a decomposition based on the fast multipole method (FMM) has also been proposed. The value of the derived approach is that studies of possible effects of dielectric radomes on antennas can be performed. As a result, some practical effects of radomes on the radiation characteristics of antennas are identified and discussed.
Comparison between the Kummer's transformation and Ewald method for the evaluation of the parallel plate Green's functions

In this paper, we present a convergence and efficiency study of two different acceleration techniques for the evaluation of the parallel plate Green's functions. The first technique is based on the extraction of the asymptotic terms of the spectral representation of the parallel plate Green's functions by applying the Kummer's transformation. The second technique is a straightforward reformulation of the 2-D Green's functions for 1-D periodic structures to the parallel plate case. The PPW Green's functions calculated by the two methods have been successfully applied to the analysis of a practical inductive microwave filter containing metallic and dielectric posts. The filter analysis technique is based on solving a surface integral equation by the MoM. The convenience of using one of the proposed acceleration technique or the other for the evaluation of each Green's function components and its derivatives, necessary to solve the MoM problem, is properly justified
Efficient Analysis of Arbitrarily Shaped Inductive Obstacles in Rectangular Waveguides Using a Surface Integral-Equation Formulation

In this paper, we propose to use the surface integral-equation technique for the analysis of arbitrarily shaped H-plane obstacles in rectangular waveguides, which can contain both metallic and/or dielectric objects. The Green's functions are formulated using both spectral and spatial images series, whose convergence behavior has been improved through several acceleration techniques. Proceeding in this way, the convergence of the series is not attached to the employment of any particular basis or test function, thus consequently increasing the flexibility of the implemented technique. In order to test the accuracy and numerical efficiency of the proposed method, results for practical microwave circuits have been successfully compared with other numerical approaches
Automatic synthesis of VHDL hardware components from IOPT Petri net models

The IOPT Petri net class, designed to implement embedded system controllers, combining the well known properties of Petri nets with input and output functions, provides a set of capabilities suitable to specify digital controller systems. This paper presents an automatic code generation tool used to create VHDL controller implementations of IOPT models and describes the underlying code generation strategies. The new tool is integrated under the Web based IOPT-Tools framework (accessible at http://gres.uninova.pt), containing a complete tool-chain ranging from interactive model design and edition, model checking and simulation tools to automatic code generation, allowing the design of embedded system controllers using only graphical tools and without the need to manually write any hardware description or software code.
Efficient Software Tool for the Analysis of Planar-Based Metamaterial Structures

We present a software tool specialized in the analysis of metamaterial structures based on planar circuits. The tool implements a formulation for open transversal multilayered structures, which reduces the number of unknowns employed in the problem. Besides, the formulation has been efficiently accelerated by means of a Kummer-like decomposition, extracting the singular behaviour of the Green's functions from the frequency analysis. By means of this formulation, several different kinds of metamaterial structures built in coplanar and microstrip technologies are successfully analyzed, obtaining bandpass and stopband filter responses in a fast and accurate way. (7 pages)