nils-herrmann/clean_scirepeval huggingface dataset:
Motion-based shape error concealment for object-based video

In this paper, an original motion-based shape error concealment technique, especially useful for object-based video applications in error-prone environments such as mobile networks, is proposed. It is assumed that the shape of the corrupted object at hand is in the form of a binary alpha plane and some of the shape data is missing due to channel errors. To conceal the corrupted shape, the decoder starts by assuming that the alpha plane changes in consecutive time instants can be described by a global motion model. This way, based on locally estimated global motion parameters, the decoder tries to conceal the corrupted alpha plane by global motion compensating the shape data from the previous time instant. Then, since not all alpha plane changes can be perfectly described by global motion, an additional local motion refinement is applied to deal with areas of the object that have significant motion.
New problems of optimal path coordination for multi-vehicle systems

New problems of optimal path coordination for multiple vehicles are introduced, formulated and solved in the framework of dynamic optimization. The novelty of these problems arises in several ways. The cost function and the dynamics include non-trivial dependencies, modeled through existential quantification over groups of vehicles - this leads to non-Lipschitz behavior and to non-standard optimal control problems. There are consumable resources, modeled with the help of integral constraints - the structure of the constraints suggested new strategies for optimal cooperation which outperform the results obtained with standard formulations with state-constraints. Our formulation uses the structure of the problem to decouple the overall optimization into simpler coupled problems in lower-dimensional spaces. This is expressed in the form of the solution, which is encoded as the composition of value functions in lower-dimensional spaces.
Efficient Analysis of Inductive Multiport Waveguide Circuits using a Surface Integral Equation Formulation

This paper presents a simple and alternative approach for the analysis of inductive multiport waveguide microwave components. The technique uses a surface integral equation formulation to treat both metallic and dielectric objects inside the component structure. In order to avoid the relative convergence problem of other techniques based on mode matching, a novel port treatment is used. The technique is based on the application of the extinction theorem using the spatial representation of the Green's functions and image theory. Different complex H-plane structures are analyzed, including microwave bandpass filters with elliptic transfer functions and waveguide bends with dielectric posts. Results show the high accuracy and versatility of the new technique derived.
Evaluation of a new strategy for controlling induction motors without using speed sensors

This paper presents an alternative approach to determining the speed of induction motors without using speed sensors. The approach is based on reconstructing the rotor flux derivative signal, which is used to calculate the induction motor's mechanical speed analytically. The simplicity of the idea, the results obtained and the ease with which it can be implemented are considered to be the main features of the proposed approach. The effectiveness of the scheme for reconstructing the motor's mechanical speed is demonstrated by comparing the results of simulations using the new method with results, also obtained by simulation, evaluated under the same test conditions, using the strategy for speed reconstruction by Luenberger observers.
An alternative architecture to validate navigation and control strategies for autonomous vehicles

Describes the design and construction of an autonomous vehicle having the important characteristics of versatility, portability and low cost. Additionally, the vehicle's mechanical and electronic features permit rapid prototyping and validation of new control and navigation algorithms. In this context, all information processing is based on a personal computer, using the parallel communication interface to acquire and export real time data. In general, such an interface enables different kinds of actuators and transducers to be managed without additional electronic hardware.
Monte Carlo uncertainty maps-based for mobile robot autonomous SLAM navigation

This paper presents an uncertainty maps construction method of an environment by a mobile robot when executing a SLAM (Simultaneous Localization and Mapping) algorithm. The SLAM algorithm is implemented on a Extended Kalman Filter (EKF) and extracts corners (convex and concave) and lines (associated with walls) from the surrounding environment. A navigation approach directs the robot motion to the regions of the environment with the higher uncertainty. The uncertainty of a region is specified by a probability characterization computed at the corresponding representative points. These points are obtained by a Monte Carlo experiment and their probability is estimated by the sum of Gaussians method, avoiding the timeconsuming map-gridding procedure. The mobile robot has a contour-following controller implemented on it to drive the robot to the uncertainty points. SLAM real time experiments within real environments are also included in this work.
A systems engineering approach to the design of an integrated decision support system for a textile company

This paper describes a systems engineering approach to the design of an integrated decision support system, IDES, for the planning and control of ATMA, a Portuguese textile company. The paper presents the overall process emphasizing the methodological framework and the main results. Systems engineering methods were crucial in the development of a methodological framework adapted to the specificities of the Portuguese industry. This framework proved invaluable in the process of mapping a conceptual planning and control architecture based on dynamical optimization onto the design of the IDES according to the recommendations of the strategic plan of ATMA. Concepts and techniques from control systems, dynamic optimization, software engineering, enterprise modeling and anthropocentric systems were used in this process.
Proposal of an instrument for measuring situational motivation with potential applications in educational contexts

The study of the motivational aspect and its relevance to the comprehension of the efficacy of learning has been the subject matter of several researches. According to the Self-determination Theory (SDT) there is a relation between the context, the motivation, and the performance of individuals in a given task. Thus, a continuum is defined between intrinsic, extrinsic, and lack of motivation; so individuals intrinsically motivated would perform optimally. In order to adequate the communication module of the system Sapiens for the learning of efficient energy consumption, this work has proposed to develop an instrument to evaluate the level of situational motivation of individuals, and to design persuasive messages to increase the engagement on the task, based on the motivation profiles described by SDT. For this, a methodology was defined comprising the following stages: (i) bibliographic research of the state-of-art scales to assess motivation; (ii) design of a data collection instrument in the form of a structured questionnaire; (iii) evaluation of the instrument considering an heterogeneous sample of 589 college, high-school, technical, master, and doctoral students, aged between 14 and 80 years, at three different situations (the library, the classroom, and leisure); (iv) design of the persuasive messages to enhance the user engagement on the task. The resulting instrument was named Ubiquitous Situational Motivation Scale (USMS), consisted in 18 questions presented as a 7-points Likert Scale, that measures four motivational factors with Cronbach alpha coefficients ranging from 0.61 to 0.86. Our study revealed that subjects' motivation profile varied according to the context, so leisure activities were respectively more related to intrinsic motivation than the library and the classroom activities, and suggests that classroom activities are probably more related to external regulation. The results were also consistent with the continuum hypothesis of SDT. The evaluation with potential users showed that the persuasive messages designed based on the motivational profiles were positively rated. From these results the persuasive module will integrated to the Sapiens platform so the performance of the users can be studied.
Proposal for an integrated video analysis framework

The analysis of video data targeting the identification of relevant objects and the extraction of associated descriptive characteristics will be the enabling factor for a number of multimedia applications. This process has intrinsic difficulties, and since semantic criteria are difficult to express, usually only a part of the desired analysis results can be automatically achieved. For many applications, the automatic tools can be complemented with user guidance to improve performance. This paper proposes an integrated framework for video analysis, addressing the video segmentation and feature extraction problems. The framework includes a set of modules that can be combined following specific application needs. It includes both automatic (more objective) and user interaction (more semantic) analysis modules. The paper also proposes a specific segmentation solution to one of the most relevant application scenarios considered-off-line applications requiring precise segmentation.
Performance Improvement of Tomographic Image Reconstruction Based on DSP Processors

This paper presents the use of a multiprocessor architecture for the performance improvement of tomographic image reconstruction. Image reconstruction in computed tomography (CT) is an intensive task for single-processor systems. We investigate the filtered image reconstruction suitability based on DSPs organized for parallel processing and its comparison with the Message Passing Interface (MPI) library. The experimental results show that the speedups observed for both platforms were increased in the same direction of the image resolution. In addition, the execution time to communication time ratios (Rt/Rc) as a function of the sample size have shown a narrow variation for the DSP platform in comparison with the MPI platform, which indicates its better performance for parallel image reconstruction.
General Model of a Five-Phase Induction Machine Allowing for Harmonics in the Air Gap Field

This paper presents a general mathematical model of a five-phase induction machine including the effects of higher space and time harmonics in the air gap field. These harmonic waves play a decisive role in the behavior of machines with more than three phases. Mathematical expressions for the calculation of the self and mutual inductances are presented, and results are compared with values obtained by finite element analysis and measurements. Based on the air gap field distribution produced by the stator and rotor, all the field harmonics are included in a direct and simple way in the self-inductances. The mutual inductances are obtained from a Fourier series description of the air gap field, resulting in a different inductance for each harmonic field. The machine equations are then simplified using coordinate transformations, which result in equivalent d-q models and equivalent circuits for given harmonic groups. In their final form, the equations are appropriated for the simulation of the machine behavior and developing new control strategies including higher space and time harmonics. Finally, practical results of a prototype machine are compared with simulations demonstrating the accuracy of the model
An Improved Decoding Algorithm for DVC Over Multipath Error Prone Wireless Channels

This letter presents an improved decoding algorithm for distributed video coding (DVC) for enhanced performance over error prone wireless channels with multipath fading. The effects of the channel errors on both Wyner-Ziv and key frame bit streams are considered and novel noise models are proposed together with the associated modifications to the decoding algorithm. Simulations are performed using a W-CDMA wireless channel and the results are analyzed to determine the effect of each individual modification. State-of-the-art H.264/AVC is also considered under similar conditions for the comparison. The simulation results show that the proposed modifications provide a significant improvement in the DVC codec performance under unfavorable channel conditions.
Measurement of zero-dispersion wavelength using a novel method based on cw four-wave mixing

The performance of long-haul high-capacity optical transmission systems based on WDM requires knowledge of the zero-dispersion wavelength, /spl lambda//sub 0/, in order to reduce power penalties due to nonlinearities. In dispersion-shifted fibers, it is necessary to allocate high-power wavelength channels away from the /spl lambda//sub 0/s over the nonlinear length. Considering the amount of dispersion-shifted fiber deployed in both terrestrial and festoon links, it is of critical importance to be able to measure the /spl lambda//sub 0/s using a simple and direct method, which should require access to only one end of the fiber. We propose a nondestructive technique to measure directly all the /spl lambda//sub 0/s within the nonlinear length. This technique uses cw light, requires access to only one end of the fiber, and is based on the effect that causes the penalty in the system. The experimental method developed was used in a field measurement to characterize the Brazilian fiber festoon cable. The technique proposed is based on the measurement of the four-wave mixing efficiency.
Experimental analysis of system performance in an EDFA with pump driven in PWM mode

This paper presents the analysis of the system performance of an EDFA (Erbium Doped Fiber Amplifier) with pump laser operating in a PWM (Pulse Width Modulation) mode, when compared to the typical linear operation mode (Continuous Wave — CW). Besides the fact that PWM driving mode significantly reduces the heat dissipation in the driver devices , it also avoids the use of big heat sinks and reduces the area occupied by the electronic circuit. We verified that it increases both the operation range and the efficiency of the laser in the low pump power region. To validate the EDFA performance in PWM mode, penalty parameters (such as bit error rates), gain control and transient suppression were analyzed in an experimental setup and compared to results obtained in CW mode. Measurements showed that the performance is not compromised when the PWM technique is implemented, suggesting that it can be used to reduce the high power consumption of the equipment.
Advanced H.264/AVC-Based Perceptual Video Coding: Architecture, Tools, and Assessment

The characteristics of the human visual system may be further exploited in lossy video coding to improve the video compression efficiency beyond the state-of-the-art H.264/AVC standard. Although the literature is rich in solutions to model the human visual system characteristics, the performance and real benefits brought by these models have not been fully integrated and assessed yet. Moreover, the rate-distortion (RD) performance is usually measured by means of methodologies that do not account for the implicit variability of the observers when rating the video quality. In this context, the novelty brought by this paper is threefold: first, it proposes novel perceptual video coding tools, notably decoder side just noticeable distortion (JND) model estimation to perceptually allocate the available rate with the finest level of granularity while avoiding the extra rate associated to coding the varying quantization steps. Second, it proposes an integrated, powerful H.264/AVC-based perceptual video coding architecture embedding a state-of-the-art JND model based on spatio-temporal human visual system masking mechanisms; this model is exploited for both the aforementioned rate allocation as well as to perceptually weight the distortion used in the motion estimation and RD optimization. Finally, it proposes a relative assessment methodology to measure the RD performance of a perceptual video codec (PVC) with respect to another codec taken as reference. The methodology considers the implicit observers variability when rating video quality which leads to a nonlinear sensitivity of the objective metrics used for quality assessment. The obtained RD performance, measured according to this methodology, shows an average bitrate reduction of up to 30% when the proposed PVC is compared with the H.264/AVC High profile at the same objective quality level. Moreover, the proposed perceptual codec outperforms an alternative perceptual codec recently published in the literature.
Error sensitivity of the modified Huffman code

The authors evaluate the error sensitivity of the modified Huffman code by computer simulation. The quantitative analysis uses the error sensitivity factor and the incorrect image ratio as a function of the image resolution, minimum scan line time, and bit error rate for two error distributions, uniform and burst. The qualitative analysis is based on a comparison between the original CCIT test images and the same images after contamination by errors. The integration of the facsimile devices in asynchronous transfer mode networks, which has become of general interest for the implementation of future broadband networks, is briefly discussed.<<ETX>>
A versatile acoustic beacon for navigation and remote tracking of multiple underwater vehicles

In this paper, we present a low-cost versatile device developed to support the navigation of autonomous underwater vehicles. Unlike the usual transponders extensively used for long baseline acoustic navigation of a single vehicle, this device allows the navigation of multiple vehicles and the remote tracking of their positions, without any extra acoustic signals being transmitted. The navigation beacon has a radio buoy connected to an underwater reconfigurable multifrequency transponder. A remote tracking station receives data from the buoy and monitors the position of the vehicles in real time. We describe the mechanical, electronic and software modules involved, as well as the tracking algorithm, and we also present experimental data from an operational mission.
Novel Microwave Network for the Leaky-Wave Analysis of Evanescent Fields in Stub-Loaded Structures

In this paper, a new transverse equivalent network for the modal analysis of stub-loaded leaky-wave antennas is developed. The derived network is useful for the study of the radiation of evanescent fields that occurs when they reach the top aperture of the parallel-plate stub. This transverse network is based, for the first time, on a nonhybrid formulation of the constituent parallel-plates modes of order 1 (TE<sub>1</sub> <sup>Z</sup> and TE<sub>1</sub> <sup>Z</sup> ). The obtained network is an alternative to the one based on hybrid TE<sub>1</sub> <sup>V</sup>and TE<sub>1</sub> <sup>V</sup> modes, and leads to a simpler transverse resonance equation. The new equivalent network is validated by obtaining leaky-mode dispersion curves for a previously studied leaky-wave antenna in non- radiative dielectric guide technology.
On the feedback control of impulsive dynamic systems

An Euler solution concept and weak invariance conditions are presented for impulsive control systems. In this paper, we model impulsive systems by measure driven differential inclusions. The Euler solution is defined in the original time frame and does not require any reparameterization technique. As a consequence, we present a constructive result giving conditions for weak invariance. The proof of this result will provide a control synthesis in feedback form, which, in turn, will permit its implementation on-line.
Integrating a spatial just noticeable distortion model in the under development HEVC codec

Although great achievements have been obtained in the past, recent developments towards ultra high definition video have been asking for further compression efficiency gains regarding the H.264/AVC state-of-the-art. As an answer to these needs, ITU-T and MPEG started a new standardization project called High Efficiency Video Coding. This paper extends and integrates a perceptual visual model in the High Efficiency Video Coding experimental codec to improve its RD performance. The designed extensions are related to the new Integer Discrete Cosine Transform block sizes as well as the new Mode Dependent Directional Transform. Moreover, an estimation mechanism for the perceptual model at the decoder side is also integrated to avoid the rate burden of sending to the decoder the model parameters. The RD performance is assessed using a methodology taking into account the variability of subjective scores which is reflected into a nonlinear sensitivity of the subjective quality metric. The RD performance obtained for the perceptually driven codec shows a bitrate reduction of up to 43% regarding the non-perceptual video codec.
UTD-PO Radiation Pattern Analysis of Rectangular Horn Antennas With Cylindrical Corrugations

The calculation of the E-plane radiation pattern of corrugated E-plane rectangular horn antennas in which the corrugations have a cylindrical shape is hereby performed through a method based on a hybrid uniform theory of diffraction-physical optics (UTD-PO) formulation. The proposed method is successfully validated through comparison with the application of an electric field integral equation (EFIE) solved by the method of moments (MoM), with the UTD-PO analysis showing more computational efficiency than the EFIE and other numerical techniques based on the full discretization of the geometry. On the other hand, the use of cylindrical corrugations instead of the traditional rectangular-shaped corrugations is analyzed and, in view of the results, the former may offer a series of advantages in comparison to the latter, such as narrower main lobes as well as better fabrication-related aspects.
Underwater plume tracing with an AUV cooperative navigation scheme based on the simplex algorithm

This article concerns an approach for cooperative plume tracing in an underwater environment characterized by very strict communication constraints such as delays, low reliability and limited bandwidth, as well as by the absence of natural features which would help localization and navigation. Localization is of utmost importance for plume tracing and remains a challenging area for AUVs in such a difficult environment. The adopted approach requires only relative localization which is satisfactorily achieved by using a SLAM-like scheme based on Extended Kalman Filter that takes into account the communications constraints. In this scheme, for any given AUV, the other elements of the team play the role of “environmental" features of a dynamic nature. The vehicles share data - relative localization as well as plume samples data - in order to improve localization estimates and generate motion waypoints according to the well known simplex algorithm. Since in this case the vertices are given by vehicle position estimates, they will have some associated uncertainty. We analyse under what conditions the simplex with uncertain vertices reduces to the regular simplex, and simulations reveal that the uncertainty of the adopted cooperative localization method suffices to ensure that the simplex algorithm “converges” to an estimate of the plume source.