nils-herrmann/clean_scirepeval huggingface dataset:
Real-time free-viewpoint DIBR on GPUs for large base-line multi-view 3DTV videos

GPUs are ample utilized for their parallel processing capabilities and are also interesting in the area of 3D image processing where computational demanding tasks are essential. We concentrate particularly on free-view 3DTV applications, based on image warping to the new view and image artifact reduction techniques. In this paper, we report on the implementation of an efficient free-viewpoint DIBR algorithm with an off-the-shelf GPU, which can be readily integrated into future 3DTV systems. For exploiting maximal parallelism, we have mapped the processing of each pixel to a separate thread and grouped multiple threads to larger blocks as much as possible. Using a combination of the highly parallel programming architecture CUDA and a graphics API, we have achieved a real-time performance operating on 1080p HD multi-view video with a rendering quality that is comparable to the software implementation.
Measurements of the Radiation Performance of a Planar Meta-Surface based on Dipoles and Wires

The radiation performance of a planar meta-surface based on dipoles and wires are experimentally investigated. Transmission and reflection coefficients are presented for normally incident plane wave excitation. A dipole antenna closely placed to the meta-surface is also used as a feeding source of the meta-surface in order to enhance its radiation performance. Due to the uniform illumination of the superstrate, an enhancement of the gain up to 6.8 dBi is obtained being the thickness of the whole system 0.135 λ0 and the aperture efficiency 82%. (5 pages)
Effect of internal reflections on the radiation properties and input admittance of integrated lens antennas

This paper begins with the modeling of the reflected waves within integrated lens antennas, which consist of a dielectric lens on which a planar antenna is mounted. It is demonstrated that if the relative dielectric constant of the lens is small (/spl epsi//sub r//spl les/4), the single- and double-reflected waves are sufficient to analyze the effect of the internal reflections. For small angles around boresight, these unwanted reflected fields mainly affect the cross-polar far-field pattern, while for large observation angles, both the co-polar and cross-polar patterns are significantly disturbed. It appears that by neglecting the internally reflected field contributions, the beam efficiency may be overestimated more than 10%. In this paper, two types of matching layers are analyzed in order to reduce these unwanted reflections. It is demonstrated that the radiation performances of the integrated lens antennas with optimum-thickness and quarter-wavelength matching layer are almost equal. Even for low dielectric-constant lenses, the beam efficiency can be increased by over 10%. Finally, it is demonstrated that the internal reflections may also have a strong effect on the antenna admittance, which can only be reduced partly by the use of a matching layer.
Reuse of Motion Processing for Camera Stabilization and Video Coding

The low bit rate of existing video encoders relies heavily on the accuracy of estimating actual motion in the input video sequence. In this paper, we propose a video stabilization and encoding (ViSE) system to achieve a higher coding efficiency through a preceding motion processing stage (to the compression), of which the stabilization part should compensate for vibrating camera motion. The improved motion prediction is obtained by differentiating between the temporal coherent motion and a more noisy motion component which is orthogonal to the coherent one. The system compensates the latter undesirable motion, so that it is eliminated prior to video encoding. To reduce the computational complexity of integrating a digital stabilization algorithm with video encoding, we propose a system that reuses the already evaluated motion vector from the stabilization stage in the compression. As compared to H.264, our system shows a 14% reduction in bit rate yet obtaining an increase of about 0.5 dB in SNR
Adaptive Tone-Mapping Transfer Functions for High Dynamic Range Video Cameras

For real-time imaging with digital video cameras, good tonal rendition of video is important to ensure high visual comfort for the user. Except local contrast improvements, high dynamic range (HDR) scenes require adaptive gradation correction (tone-mapping curve) that should enable good visualization of details at lower brightness. We discuss how to construct and control optimal tone mapping curves, which enhance visibility of image details in the dark regions while not excessively compressing the image in the bright image parts. The result of this method is a 21 dB expansion of the dynamic range. The new algorithm was successfully evaluated in HW and is suited for any video system performing HDR video compression.
DECT technology for radio in the local loop

There is increasing interest in radio in the local loop (RLL) applications due to technology advancements and the liberalisation of the telecommunications markets. The paper describes the properties of DECT RLL applications. DECT offers toll quality digital speech, voice band transparency and ISDN services. All user information is encrypted. The DECT continuous dynamic channel selection procedures provide efficient utilisation of the spectrum and avoid the need for traditional frequency planning. The maximum range for a line of sight fixed RLL subscriber unit is much larger than for a non line of sight mobile RLL pocket unit. The DECT repeater concept makes it possible to combine the longer range of fixed RLL with mobility, which gives added value to a DECT RLL solution. The rapid advent of other private and public DECT services provide a platform both for service integration and for economy of scale. Estimates on traffic capacity and ranges has been supported by simulations and field trails.<<ETX>>
Coupled defects in photonic crystals

We present a theoretical and numerical description of coupled defects in photonic-bandgap crystals, expandable to cover a wide range of applications. Based on a weak interaction approach, explicit expressions are derived for defect interaction. The basis is formed by a system of coupled ordinary differential equations for the field amplitudes for individual defects. The actual configuration of the defects (chain, lattice, bend, or anything else) enters the equations as a linear coupling between neighboring defects. The strength of this method is that many solutions of this system are known analytically; the band structure as well as the transmission response of a defect chain, or of a defect lattice, can be determined. The results for the superlattice of defects are compared with widely accepted numerical methods, the transfer matrix method, and finite-difference time domain method.
Real-time facial feature extraction using statistical shape model and Haar-wavelet based feature search

We propose a fast facial feature extraction technique for an embedded face recognition system. The novel key element is a combination of a statistical shape model and the application of a Haar-wavelet based feature matching. Our statistical face model is based on the active shape model (ASM). However ASM lacks robustness to illumination changes and it has a limited convergence area. Instead of a 1D profile analysis, we propose a 2D texture pattern search-and-fitting scheme, which provides more robustness and faster convergence than conventional ASM. Furthermore, we employ Haar-wavelets to model local-facial textures, which yields two improvements: faster processing and more robustness with respect to low-quality images. Our proposed approach shows good results dealing with test face images, which are quite dissimilar with the faces used for statistical training. The convergence area of our proposed method almost quadruples compared to ASM, and the extraction accuracy is also improved. The total processing requires 30 - 70 ms, which is comparable to ASM, but faster than the active appearance model (AAM)
Efficient body of revolution finite-difference time-domain modeling of integrated lens antennas

An efficient body of revolution finite-difference time-domain (BOR-FDTD) method for the analysis of the radiation properties of integrated lens antennas is presented in this paper. By neglecting most of the reactive power of the planar feed and by expanding the filtered source currents into azimuthal modes, lenses with both rotationally and nonrotationally symmetric planar feeds can be handled. It appears that three to four azimuthal modes are sufficient to adequately model the magnetic currents of a double-slot feed. Therefore, compared to a full three-dimensional (3-D) numerical method, the implementation of the proposed method is very time and memory efficient. If only the radiation properties are required, the model described here can also be applied efficiently to other axially symmetric geometries with an asymmetric feeding structure.
Shape-induced anisotropy in antidot arrays from self-assembled templates

Using self-assembly of polystyrene spheres, well-ordered templates have been prepared on glass and silicon substrates. Strong guiding of self-assembly is obtained on photolithographically structured silicon substrates. Magnetic antidot arrays with three-dimensional architecture have been prepared by electrodeposition in the pores of these templates. The shape anisotropy demonstrates a crucial impact on magnetization reversal processes.
A generic 2D sharpness enhancement algorithm for luminance signals

In this paper we attempt to generalize a sharpness enhancement technique for TV applications. Basically, the enhancement is accomplished by adding overshoot to luminance edges. However, the optimal amount of overshoot added for a high image quality depends on the local image statistics. For this purpose, four properties of the video signal are analysed locally by separate units and depending on this analysis, we regulate the amount of sharpness enhancement to be provided. Due to these additional controls, the system is robust with respect to varying image statistics and yields a high performance.
Low Mass Calibration Target for MM-Wave Remote Sensing Instruments

The reliability of millimeter and sub-millimeter wave radiometer measurements is dependent on the accuracy of the loads they employ as calibration targets. In the recent past on-board calibration loads have been developed for a variety of satellite remote sensing instruments. Unfortunately some of these have suffered from calibration inaccuracies which had poor thermal performance of the calibration target as the root cause. Stringent performance parameters of the calibration target such as low reflectivity, high temperature uniformity, low mass and low power consumption combined with low volumetric requirements remain a challenge for the space instrument developer. In this paper we present a novel multi-layer absorber concept for a calibration load which offers an excellent compromise between very good radiometric performance and temperature uniformity and the mass and volumetric constraints required by space-borne calibration targets.
Resource prediction and quality control for parallel execution of heterogeneous medical imaging tasks

We have established a novel control system for combining the parallel execution of deterministic and non-deterministic medical imaging applications on a single platform, sharing the same constrained resources. The control system aims at avoiding resource overload and ensuring throughput and latency of critical applications, by means of accurate resource-usage prediction. Our approach is based on modeling the required computation tasks, by employing a combination of weighted moving-average filtering and scenario-based Markov chains to predict the execution. Experimental validation on medical image processing shows an accuracy of 97%. As a result, the latency variation within non-deterministic analysis applications is reduced by 70% by adaptively splitting/merging of tasks. Furthermore, the parallel execution of a deterministic live-viewing application features constant throughput and latency by dynamically switching between quality modes. Interestingly, our solution can successfully be reused for alternative applications with several parallel streams, like in surveillance.
Problems of antenna measurement in the terahertz frequency range

A new generation of scientific instruments is under consideration at millimetre and submillimetre wavelengths which include both earth observation and scientific missions. In the current generation of earth observation studies, there are millimetre and submillimetre limbsounding instruments (for example, MASTER and SOPRANO). Astronomy missions are also projected in which the frequency range may extend to above 3 THz. Because of the high gain and high frequency of these instruments, testing and proving the antennas and their associated feed systems present problems which require special attention. A study funded by ESTEC is currently under way to examine possible measurement techniques and to recommend a cost-effective solution. This paper sets out the measurement requirements and highlights the accuracy required of any facility finally implemented. The problem areas identified to date are listed.
A 40-Gb/s QSFP Optoelectronic Transceiver in a 0.13μm CMOS Silicon-on-Insulator Technology

We have demonstrated a 40-Gb/s optoelectronic transceiver in a quad small form-factor pluggable (QSFP) module. Each module includes a 4xlO-Gb/s, 0.13 μm CMOS silicon-on-insulator integrated optoelectronic transceiver chip co-packaged with a single, externally modulated CW laser.
Predicting real-time properties of component assemblies: a scenario-simulation approach

This work addresses the problem of predicting timing properties of multitasking component assemblies during the design phase. For real-time applications, it is of vital importance to guarantee that the timing requirements of an assembly are met. We propose a simulation-based approach for predicting the real-time behaviour of an assembly based on models of its constituent components. Our approach extends the scenario-based method in [J. Muskens et al. (2004)] by offering a system model that is tailored to the domain of real-time applications. Contributions of This work include the possibility to handle the following features: mutual exclusion, combinations of aperiodic and periodic tasks and synchronization constraints. The analytical approach we used in previous work cannot handle these features. Therefore, we introduce the simulation-based approach. Our simulator provides data about dynamic resource consumption and real-time properties like response time, blocking time and number of missed deadlines per task. We have validated our approach using a video-decoder application.
Leaky wave enhanced feeds for multi-beam reflector systems

This paper discusses the use of dielectric superlayers to shape the radiation pattern of focal plane feeds of a multi-beam reflector system. The shaping of the pattern is obtained by exciting a pair (TE/TM) of leaky waves that radiate incrementally as they propagate between the ground plane and the super-layer. Using the super-layers, it is possible to reduce the spillover from the reflectors without increasing the dimension of each aperture. This effect is achieved with an inter-element distance between the feeds of 2.4 wavelengths, which can be considered typical for satellite based multi beam telecommunication links. Thanks to the adoption of a x4 reuse scheme, based on frequency and polarization orthogonal channels, the measured edge of coverage gain has improved, with respect to a standard technology case, by 2 dB over an operational bandwidth of 2%.
Blue Sky Detection for Content-based Television Picture Quality Enhancement

Using high-resolution flat panel displays for TV systems, the visibility of signal impairments has grown. As a solution, content-based image processing can be used for obtaining higher levels of picture-quality improvement, thereby outperforming traditional TV image-enhancement methods. This paper presents a new algorithm and feature model for blue sky detection, which enables content-adaptive enhancement of TV video sequences. The algorithm analyzes the image, creates adaptive position and color models, and classifies the sky areas of the image using a pixel-accurate soft segmentation. Such a probabilistic measure matches well with the requirements of typical video enhancement functions in TVs. We have evaluated the proposal for typical and critical natural scenes, and obtained a clear improvement over state-of-the-art techniques.
A method for the construction of acoustic Markov models for words

A technique for constructing Markov models for the acoustic representation of words is described. Word models are constructed from models of subword units called fenones. Fenones represent very short speech events and are obtained automatically through the use of a vector quantizer. The fenonic baseform for a word-i.e., the sequence of fenones used to represent the word-is derived automatically from one or more utterances of that word. Since the word models are all composed from a small inventory of subword models, training for large-vocabulary speech recognition systems can be accomplished with a small training script. A method for combining phonetic and fenonic models is presented. Results of experiments with speaker-dependent and speaker-independent models on several isolated-word recognition tasks are reported. The results are compared with those for phonetics-based Markov models and template-based dynamic programming (DP) matching.
Necrosis evolution during high-temperature hyperthermia through implanted heat sources

A nonstationary model for high-temperature hyperthermic treatments is developed. The aim of this model is to describe the thermal propagation within a living tissue and to quantify its clinical effects as it regards the physiological status (necrosis) of a neoplastic body. Particular attention is turned to the description of the necrotic transition induced by heating. This leads to the introduction of a necrosis field and to an effective-medium approximation for the corresponding physiological status (vascularization, necrosis, etc.) of the exposed tissue. The resulting nonlinear, nonstationary model is applied to a multilayered spherical structure with a temperature-regulated implant, and to a clinical case of a solid liver tumor. Clinical data on the spatial extent of the necrotized region are in good agreement with model predictions.
Terahertz space applications and technology

Research has been carried out in the THz region for several decades. Until fairly recently, the main drive came from applications such as radio astronomy, later followed by planetary, cometary and atmospheric science. Arguably, without these driving influences it is unlikely that many of the recent technological breakthroughs would have occurred. This paper presents an overview of space related applications and technologies, divided into three main areas: terrestrial science, astronomy and planetary/cometary science. The more traditional and some most likely future space applications will be treated.
A fast match for continuous speech recognition using allophonic models

In a large vocabulary real-time speech recognition system, there is a need for a fast method for selecting a list of candidate words from the vocabulary that match well with a given acoustic input. The authors describe a highly accurate fast acoustic match for continuous speech recognition. The algorithm uses allophonic models and efficient search techniques to select a set of candidate words. The allophonic models are derived by constructing decision trees that query the context in which each phone occurs to arrive at an allophone in a given context. The models for all the words in the vocabulary are arranged in a tree structure and efficient tree search algorithms are used to select a list of candidate words using these models. Using this method, the authors are able to obtain over 99% accuracy in the fast match for a continuous speech recognition task which has a vocabulary of 5000 words.<<ETX>>
Fast segmentation using level set curves of complex wavelet surfaces

Active contour methods are a powerful approach to image segmentation. The first approaches were based on the direct evolution of a contour but recently level set methods have been found to give more robust solutions. These methods are based on the iterative deformation of a surface and their main drawback is the large number of iterations required. We propose a new energy formulation for which it is possible to obtain a good estimate for the optimum step size in a gradient descent algorithm and which therefore produces much faster convergence. This is made possible by representing the surface with the coefficients of a complex wavelet transform. The energy function has one term that is minimised for smooth contours, and one term that is minimised for contours close to edges in an image. We explain how the complex wavelet transform can efficiently represent both these terms and show experimental results on real and synthetic images confirming that the method gives good results within a few iterations.
Electro-Magnetic Band-Gap feed overlapping apertures for multi-beam antennas on communication satellites

An `EBG antenna (Electro-Magnetic Band Gap)' is built with a semi-reflective screen over a set of horns feeding a reflector. A clever application of the partial spreading of the electro-magnetic field in such a structure is to provide `overlapped radiating apertures', which generate `overlapped beams' when feeding a reflector. This is a unique single-antenna solution, fitting with multi-beams missions from satellite which require low gain ripple over a regional coverage, e.g. for high data-rate communication in Ka-band. A prototype has been optimised and built, as a co-operation between Thales Alenia Space France & XLIM/Antenna Lab, supported by space agencies ESA & CNES. Adding a very light meanderline polariser (honeycomb based) transforms the alternated orthogonal linear polarisations into orthogonal circular ones, coping with most recent missions.
Manufacturing Tolerance Analysis, Fabrication, and Characterization of 3-D Submillimeter-Wave Electromagnetic-Bandgap Crystals

The sensitivity of the characteristic band edge frequencies of three different 500-GHz electromagnetic-bandgap crystals to systematic variations in unit cell dimensions has been analyzed. The structures studied were square bar woodpiles made with dielectric having epsiv rap12 and epsivr=37.5 and two wide bandgap epsivr=37.5 crystals designs proposed by Fan and Johnson and Joannopoulos. These epsivr values correspond to high-resistivity silicon and a zirconium-tin-titanate ceramic, respectively. For the woodpiles, the fractional frequency bandgap varied very little for dimensional deviations of up to plusmn5% from the optimum. The bandgaps of the Fan and Johnson and Joannopoulos structures were affected to a greater extent by dimensional variations, particular sensitivity being exhibited to the air-hole radius. For all crystals, the effect of increasing the amount of dielectric in the unit cell was to shift the bandgap edges to lower frequencies. Both silicon and ceramic woodpiles, along with a ceramic Fan structure, were fabricated and dimensionally characterized. Mechanical processing with a semiconductor dicing saw was used to form the woodpiles, while the Fan structure required both dicing and UV laser drilling of circular thru-holes. Good agreement with predicted normal incidence transmissions were found on the low-frequency side of the bandgap in all cases, but transmission values above the upper band edge were lower than expected in the ceramic structures