nils-herrmann/clean_scirepeval huggingface dataset:
Epipolar Geometry-Based Side Information Creation for Multiview Wyner–Ziv Video Coding

The side information (SI) quality significantly influences the rate-distortion (RD) performance of both monoview and multiview Wyner-Ziv (WZ) video coding. Efficient multiview WZ video coding schemes typically exploit both temporal and inter-view correlation during the SI creation process targeting to achieve high SI quality and, thus, high RD performance. In this context, the overall SI creation process typically involves fusing a temporally created SI with an inter-view created SI. Consequently, the final SI quality does not only depend on the temporal and inter-view SI creation techniques but also on the fusion process. Thus, the main objective of this paper is to propose an efficient SI creation solution for multiview WZ video coding by simultaneously tackling the two main issues aforementioned with the following technical novelty: 1) a disparity-based view synthesis technique accounting for the scene geometry to create high quality inter-view SI and 2) a time-view driven fusion technique efficiently selecting, on a pixel basis, the temporal or inter-view SI depending on which one is estimated to be closer the original WZ data. Experimental results show considerable RD performance improvements, notably gains up to 2 dB or more, regarding the best performing state-of-the-art multiview WZ video coding solutions available.
Feature-based video coding: Designing an RD efficient and search friendly framework

To provide more powerful video enabled applications, e.g. in video surveillance environments, it is increasingly more critical not only to have access to the decoded video but also to, e.g. efficiently search for similar videos. In this context, this paper proposes a feature-based video coding solution adopting a hybrid approach where both pixels and local visual features are exploited for coding. In this novel solution, part of the frames are coded using a set of key point matches, thus allowing not only to decode the usual frames for visualization but also valuable key point information extracted from uncompressed frames which is instrumental for searching. Experimental results for video surveillance like sequences and conditions show bitrate savings regarding the state-of-the-art HEVC standard while additionally facilitating more accurate searching.
Shape refreshment need metric for object-based resilient video coding

Although there are several techniques that video encoders may use to improve error resilience, it is largely recognized that intra coding refreshment plays a major role. This technique is especially useful for video encoders that rely on predictive (inter) coding to remove temporal redundancy because, in these conditions, the decoded quality can decay very rapidly due to error propagation if errors occur in the transmission or storage of the coded streams. Therefore, in order to avoid error propagation for too long a time, the encoder can use a coding refreshment scheme to refresh the decoding process and stop (spatial and temporal) error propagation. In the context of object-based video coding, the video encoder can apply intra coding refreshment to both the shape and the texture data. A shape refreshment need metric is proposed which can be used by object-based video encoders, notably MPEG-4 video encoders, to determine when the shape of a given video object should be refreshed in order to improve the decoded video quality.
An alternative complexity model for the MPEG-4 video verifier mechanism

MPEG-4 is the first object-based audiovisual coding standard. To control the minimum decoding complexity resources required at the decoder, the MPEG-4 visual standard defines the so-called video complexity verifier (VCV). This paper proposes an alternative VCV model, based on a set of relative macroblock (MB) complexity weights assigned to the various MB coding types used in MPEG-4 video coding. The new VCV model allows a more efficient use of the available decoding resources by preventing the over-evaluation of the decoding complexity of certain MB types and thus making possible to encode scenes (for the same profile@level decoding resources) which otherwise would be considered too demanding.
Compact implementation of transmission zeros using the zero shifting property

In this contribution we propose a structure for the implementation of transmission zeros using the zero shifting property. In previous implementations, two open loop resonators operating at different resonances were employed. In the configuration, one of the open loop resonators is substituted by a short-circuited transmission line, thus resulting into a more compact structure. Also, the new configuration is able to support larger bandwidth than traditional designs. This is due to an improved capability to increase the coupling between the input and output lines to the new short-circuited transmission line. For this purpose a new cross-shaped coupling structure is proposed. A manufactured prototype has been successfully tested. The results show the usefulness and validity of the new structure.
Motor current signature analysis and fuzzy logic applied to the diagnosis of short-circuit faults in induction motors

The paper presents the development and the practical implementation of a system for detection and diagnosis of interturn short-circuits in the stator windings of induction motors. Motor current signature analysis (MCSA) and fuzzy logic techniques are utilized in order to achieve that. After a brief description of the MCSA, the causes of short circuits are discussed and characterized with frequency relationships and frequency spectra. Subsequently, failure diagnosis techniques based on fuzzy logic are presented. Afterwards, the results of the practical implementation of fault detection and diagnosis system are shown and commented. MATLAB 6.0 and built-in toolboxes (DSP blockset, fuzzy logic and real-time workshop) are used as a development tool. The implemented and tested method showed efficiency as the practical results corresponded to the predicted with the developed system. The results obtained present a great degree of reliability, which enables them to be used as a monitoring tool for similar motors.
Analysis of finite microstrip structures using an efficient implementation of the integral equation technique

An efficient numerical implementation of the integral equation technique (IE) has been developed for the analysis of the electrical characteristics of finite microstrip structures. The technique formulates a volume version of the IE for the finite dielectric objects. The numerical implementation combines rooftop basis and testing functions for the conducting metallic areas, and two different choices for the dielectric objects. The first is based on a classical approach, combining pulse basis functions and deltas for testing. The second is a novel full Galerkin approach which employs rooftop functions defined on brick cells inside the dielectrics. The input impedances of two microstrip antennas have been computed with the new technique, showing good agreement with respect measurements. Also the radiation patterns of the antennas have been evaluated, showing again good agreement with respect to measurements. The practical value of the approach is that microstrip circuits can be designed minimizing the volume and size of the dielectric substrates. In addition, it is possible to accurately predict the backward radiation of practical microstrip radiators.
A WDM-PON implementation employing spectrum sliced ASE source, dispersion management and PIN receivers

In this work we propose a novel wavelength division multiplexing passive optical network (WDM-PON) configuration. The system is based on a colorless optical source employing the injection of amplified spontaneous emission (ASE) into a reflective SOA (R-SOA). In addition, optical detection at the ONTs is carried out by PIN based receivers, without decision threshold level adjustment (DTLA). We investigated the system performance for four directly modulated 1.25 Gb/s channels at the C-band in the presence of chromatic dispersion and experimentally demonstrated error free operation for downstream traffic in a 20 km reach, with 1.0 dB penalty.
Analysis and design of periodic leaky-wave antennas for the millimeter waveband in hybrid waveguide-planar technology

This work presents a full-wave integral equation approach specifically conceived for the analysis and design of laterally-shielded rectangular dielectric waveguides, periodically loaded with planar perturbations of rectangular shape. This type of open periodic waveguide supports the propagation of leaky-wave modes, which can be used to build leaky-wave antennas which exhibit many desirable features for millimeter waveband applications. The particularities of the leaky-mode analysis theory are described in this paper, and comparisons with other methods are presented for validation purposes. Using this leaky-mode analysis method, a novel periodic leaky-wave antenna is presented and designed. This novel antenna shows some important improvements with respect to the features of previously proposed antennas. The results of the designed radiation patterns are validated with three-dimensional electromagnetic analysis using commercial software.
Model-checking framework for embedded systems controllers development using IOPT Petri nets

This paper presents a new model-checking framework for embedded systems controllers development using IOPT Petri nets. The new tools, comprehending a state-space generator, a query system and a new automatic code generator, were added to an existing tool framework which already had tools to import and edit controller models, automatic code generators and automatic hardware synthesis tools. The new tools permit the automatic analysis of system properties and the fast detection of errors during early design stages, considerably reducing debug and validation time. All tools share the same Web based user interface, publicly available on the research group Web page (http://gres.uninova.pt).
Necessary conditions of optimality for state constrained infinite horizon differential inclusions

This article presents and discusses necessary conditions of optimality for infinite horizon dynamic optimization problems with inequality state constraints and set inclusion constraints at both endpoints of the trajectory. The cost functional depends on the state variable at the final time, and the dynamics are given by a differential inclusion. Moreover, the optimization is carried out over asymptotically convergent state trajectories. The novelty of the proposed optimality conditions for this class of problems is that the boundary condition of the adjoint variable is given as a weak directional inclusion at infinity. This improves on the currently available necessary conditions of optimality for infinite horizon problems.
An approach for the efficient optimization-oriented design of high-order 3-D filters

This paper describes a design tool of high-order three dimensional (3-D) filters by means of 2-D and 3-D electromagnetic (EM) softwares and two space mappings. The first space mapping aligns the 3-D EM response with the 2-D EM response of a low-order 3-D filter. The second mapping performs a calibration of the first mapping. The high-order filter is optimized using the fast 2-D EM software. The design parameters of the high-order 3-D filter are directly obtained by means of the calibration equations. This design tool is applied to 3-D bandpass filters with increasing order in evanescent rectangular waveguide.
Light Field-Based Face Presentation Attack Detection: Reviewing, Benchmarking and One Step Further

Vulnerability of face recognition systems to presentation attacks has attracted increasing attention from the biometrics and forensics communities. Moreover, the recent availability of light field cameras is opening new possibilities for designing improved face presentation attack detection solutions. In this context, this paper provides the first review and benchmarking study in the literature on light field-based face presentation attack detection solutions. State-of-the-art solutions are assessed in terms of accuracy, generalization and complexity, using a common, representative evaluation framework. This paper also proposes a novel face presentation attack detection solution, based on a histogram of oriented gradients descriptor, which exploits the disparity information available in light field imaging. The evaluation of the proposed face presentation attack detection solution for different presentation attack types shows a very effective and stable performance, notably performing better than the state-of-the-art alternatives.
Universal multimedia experiences for tomorrow

The previous decade has seen a variety of trends and developments in the area of communications and thus multimedia access. While individual, isolated developments produced small advances on the status quo, their combination and cross-fertilization resulted in today's complex but exciting landscape. In particular, we are beginning to see delivery of all types of data for all types of users in all types of conditions. This article discusses the current status of universal multimedia access (UMA) technologies and investigates future directions in this area. Key developments and trends from the last few years have set the scene for ubiquitous multimedia consumption. In summary, these are: wireless communications and mobility; standardized multimedia content; interactive versus passive consumption; and the Internet and the World Wide Web (WWW).
Some questions about hybrid systems

The exciting research concerning the description, analysis, simulation, controller design, and deployment of hybrid systems is reviewed, and perspectives for future developments are discussed. The review attempts to relate precursors to this research, practical motivations, and actual developments. The discussion follows a similar pattern in an attempt to identify topics for future research. Practical motivations arise from new concepts for engineering design, such as networked vehicle systems. The unique aspects of the operation of networked vehicle systems motivated several research questions: multiple forms of interactions, control of configurations, semantics and control, and control over networks. The conclusion is that the analysis, controller design, and implementation of those systems entails a fundamental shift of the focus of research from single to distributed interacting systems — distributed hybrid systems. Topics of value for this research are discussed.
Multiple UAV teams for multiple tasks

In a search and prosecute mission, multiple heterogeneous unmanned aerial vehicles UAVs that carry different resources need to perform the classify, prosecute and battle damage assessment (BDA) tasks on targets sequentially. Depending on the target resource requirement, it may be necessary to deploy a coalition of UAVs to perform the action. In this paper, we propose coalition formation algorithms that have low computational overhead to determine coalitions for the prosecute and the BDA tasks. We also develop a simultaneous strike mechanism based on Dubins curves for the UAVs to prosecute the target simultaneously. Monte-Carlo simulation results are presented to show how the algorithms work and the effect of increasing the number of BDA tasks on the mission performance.
Light field local binary patterns description for face recognition

Light field cameras are emerging as powerful sensor devices to capture the full spatio-angular visual information in a viewing range. As more information should allow better analysis performance, this paper proposes a simple, yet effective descriptor, named Light Field Local Binary Patterns (LFLBP), able to exploit the richer information available in light field images for face recognition. The LFLBP descriptor combines two main components, the spatial, local LBP and the angular LBP, to capture not only the usual spatial information but also the light field angular information associated to the set of sub-aperture images, corresponding to different viewpoints. Experiments were conducted with the novel IST-EURECOM light field face database. When compared with competing methods, the proposed descriptor has shown superior face recognition performance under varied and challenging acquisition conditions. Moreover, the proposed light field angular LBP descriptor can be flexibly combined with any available spatial descriptor to derive combined descriptors for enhanced light field based face recognition performance.
Fast rate distortion optimization for the emerging HEVC standard

The under development High Efficiency Video Coding (HEVC) standard employs several powerful coding tools to obtain improved compression efficiency regarding the state-of-the-art H.264/AVC standard. To efficiently exploit the temporal and spatial redundancies, HEVC adopts a very flexible quadtree coding structure, allowing the encoder to use a block partition better matching the image features. The best combination of HEVC block partitioning and coding modes is found by means of a rate distortion optimization process. During this minimization, the encoder tests all the possible coding modes and block partitions and keeps those providing the smallest RD cost. Due to the large number of available modes and partitions, the minimization involves extremely high complexity, which may not be suitable for real-time application scenarios. To reduce the complexity, two novel fast RDO techniques are proposed in this paper: Top Skip and Early Termination. The experimental evaluation reveals that the proposed techniques significantly reduce the encoding time, notably up to 45% regarding the high complexity HEVC reference software codec, with a negligible quality loss never larger than 0.1 dB.
Persuasive technology: Applications in education

The first Persuasive Technology (PT) emerged in the 1970s, and was being defined as an interactive computer system used to change human behavior. Research has shown the viability of these technologies in a variety of contexts such as advertising, reducing energy consumption, promoting healthy or well-being behavior and education. This research identifies and systematizes this area of knowledge, from the identification of the main works that relate the use of PTs in education. The methodology used was review of the works published between 2010 and 2017 of the state-of art, in the bases of Google Scholar, Springer, Elsevier, ACM. As a result of the analysis of the articles, we highlight as main focus the use of (i) PTs adapted to different user profiles; (ii) PTs applied in different pedagogical activities; (iii) PTs for different methodologies of educational activities; (iv) PTs developed in different technological languages. The PTs can be applied as learning aid instruments, acting directly and/or indirectly in the areas of Social Assistance, Health, Environment, Research and Development, Education and Advertising. Given this scenario, we observed the need to foster publications that problematize the interfaces of PTs in Education, especially architectures and/or technologies that involve, for example, Cyber-Physical Systems, that can extend the educational (physical) environment to the virtual world, in order to leave the student immersed constantly in a teaching environment.
Design and construction of a low-cost mobile platform for developing and validating control and navigation algorithms

This article describes the design, construction and navigation of an autonomous vehicle addressing such important aspects as versatility, portability and low cost. In addition, the vehicle's mechanical and electronic features allow rapid development and test of new control and navigation algorithms. In this context, all information processing is based on a personal computer using the parallel communication interface to require and export real-time data. In general, such an interface makes it possible to manage different kinds of actuators and transducers without additional electronic hardware.
Optimal Rendezvous Trajectory for Unmanned Aerial-Ground Vehicles

Fixed-wing unmanned aerial vehicles (UAVs) can be an essential tool for low-cost aerial surveillance and mapping applications in remote regions. There is, however, a key limitation, which is the fact that low-cost UAVs have limited fuel capacity and, hence, require periodic refueling to accomplish a mission. Moreover, the usual mechanism of commanding the UAV to return to a stationary base station for refueling can result in the fuel wastage and inefficient mission operation time. Alternatively, one strategy could be the use of an unmanned ground vehicle (UGV) as a mobile refueling unit, where the UAV will rendezvous with the UGV for refueling. In order to accurately perform this task in the presence of wind disturbances, we need to determine an optimal trajectory in three-dimensional taking UAV and UGV dynamics and kinematics into account. In this paper, we propose an optimal control formulation to generate a tunable UAV trajectory for rendezvous on a moving UGV that also addresses the possibility of the presence of wind disturbances. By a suitable choice of the value of an aggressiveness index that we introduce in our problem setting, we are able to control the UAV rendezvous behavior. Several numerical results are presented to illustrate the reliability and effectiveness of our approach.
Tuning Rules for Proportional Resonant Controllers

In this brief, we propose a particular structure for resonant controllers and a tuning method of the Ziegler–Nichols type for their tuning. Performance criteria for resonant controllers are also defined. The effectiveness of the tuning rules is illustrated by their application and corresponding performance assessment in a test batch consisting of four representative classes of processes. The control performance is analyzed in detail for one particular example, shedding light on the virtues and limitations of the control structure and of the tuning method.
Just-in-time value specialization

JavaScript emerges today as one of the most important programming languages for the development of client-side web applications. Therefore, it is essential that browsers be able to execute JavaScript programs efficiently. However, the dynamic nature of this programming language makes it very challenging to achieve this much needed efficiency. In this paper we propose parameter-based value specialization as a way to improve the quality of the code produced by JIT engines. We have empirically observed that almost 60% of the JavaScript functions found in the world's 100 most popular websites are called only once, or are called with the same parameters. Capitalizing on this observation, we adapt a number of classic compiler optimizations to specialize code based on the runtime values of function's actual parameters. We have implemented the techniques proposed in this paper in IonMonkey, an industrial quality JavaScript JIT compiler developed in the Mozilla Foundation. Our experiments, run across three popular JavaScript benchmarks, SunSpider, V8 and Kraken, show that, in spite of its highly speculative nature, our optimization pays for itself. As an example, we have been able to speedup SunSpider by 5.38%, and to reduce the size of its native code by 16.72%.
MPEG-4 facial animation technology: survey, implementation, and results

The emerging MPEG-4 standard specifies an object-based audiovisual representation framework, integrating both natural and synthetic content. Tools supporting three-dimensional facial animation will be standardized for the first time. To support facial animation decoders with different degrees of complexity, MPEG-4 uses a profiling strategy, which foresees the specification of object types, profiles, and levels adequate to the various relevant application classes. This paper first gives an overview of the MPEG-4 facial animation technology. Subsequently, the paper describes the Institute Superior Tecnico implementation of an MPEG-4 facial animation system, then evaluates the performance of the various tools standardized, using the MPEG-4 test material.