nils-herrmann/clean_scirepeval huggingface dataset:
Reliable 50Gb/s silicon photonics platform for next-generation data center optical interconnects

The next generations of data centers require a scalable optical transceiver technology. In this paper we present a silicon photonics platform supporting single-channel data rates of 50Gb/s and above. Advanced process options include 50GHz GeSi electro-absorption modulators, high efficiency thermo-optic phase shifters with Pπ <5mW and silicon carrier depletion-based phase-shifters supporting Mach-Zehnder and micro-ring modulators. The performance and reliability of the key library components such as modulators, detectors, fiber couplers and heaters is described.
Integrating optical receiver transplanted by epitaxial lift off

A GaAs integrating optical receiver has been designed and realized using a commercial foundry process. The receiver was then transplanted by epitaxial lift off (ELO) onto an InP substrate. This technology allows the monolithical integration of previously incompatible materials onto one chip. To our knowledge the chip described is the most complex chip that has been transplanted by ELO. The integrating receiver described here presents a novel circuit topology to integrate optical input power.
The metamorphic algorithm: a speaker mapping approach to data augmentation

Large vocabulary speaker-dependent speech recognition systems adjust to the acoustic peculiarities of each new speaker based on some enrolment data provided by this speaker. As the amount of data required increases with the sophistication of the underlying acoustic models, the enrolment may get lengthy. To streamline it, it is therefore desirable to make use of previously acquired speech data. The authors describe a data augmentation strategy based on a piecewise linear mapping between the feature space of a new speaker and that of a reference speaker. This speaker-normalizing mapping is used to transform the previously acquired data of the reference speaker onto the space of the new speaker. The performance of the resulting procedure, dubbed the metamorphic algorithm, is illustrated on an isolated utterance speech recognition task with a vocabulary of 20000 words. Results show that the metamorphic algorithm can substantially reduce the word error rate when only a limited amount of enrolment data is available. Alternatively, it leads to a level of performance comparable to that obtained when a much greater amount of enrolment data is required from the new speaker. In addition, it can also be used for tracking spectral evolution over time, thus providing a possible means for robust speaker self-adaptation.
New flexible motion estimation technique for scalable MPEG encoding using display frame order and multi-temporal references

The applicability of MPEG video coding can be improved by scaling both the algorithmic complexity and resource usage appropriately for the intended device and application. For this purpose, we present a new technique for motion estimation, based on a scalable three-stage process including frame processing in display order, approximation of motion vector fields using multiple references and optional quality refinements. Experiments show that the computational effort is scalable with a factor of 14, resulting in a global variation of 7 dB SNR in picture quality. At full processing, our technique slightly outperforms a 32/spl times/32 full search motion estimation. The technique forms a valuable contribution to mobile MPEG coding applications, following the scalability concepts introduced by Mietens, de With and Hentschel (see  2001), vol.3, p.462-465, Oct. 2001).
AMC Low Profile Wideband Reference Antenna for GPS and GALILEO Systems

Satellite positioning systems, like GPS and Galileo, require ground reference antennas with high quality radiation performance. The use of a radiator integrated with an artificial magnetic conductor (AMC) appears attractive in order to obtain an antenna with low back radiation and good axial ratio performance near the horizon, which is essential for the considered applications. The presented crossed-dipole antenna integrated on a wideband AMC has a simple feed network consisting mainly of a self balanced feed. It also has a low mechanical profile and is simple to manufacture as a multilayer printed circuit board. Detailed numerical analyses and measurements are presented which clearly demonstrate its potential as a ground reference antenna.
LPC distance measures and statistical tests with particular reference to the likelihood ratio

Several LPC distance measures and statistical tests have been proposed for use in speech processing, the most popular of which is Itakura's log likelihood ratio statistic, and some simple variants thereof. In this paper it is shown that these statistics share some undesirable properties. It is argued that there are more tractable and more sensitive measures available including other relevant likelihood ratio statistics. It is also shown that when Itakura's measure is used to compare two estimated LPC vectors, it is not the log likelihood ratio at all, and the true likelihood ratio for these conditions is derived.
Region-based all-in-focus light field rendering

Light field rendering is an approach to synthesize virtual views of a scene from a set of original images. When minimizing the number of images for rendering, the light field may become under-sampled, leading to aliasing artifacts. To render an under-sampled light field in high quality and without aliasing artifacts is a challenge. We present a light field rendering algorithm with region-based focus to create all-in-focus virtual views. Our algorithm was compared to: (a) ground truth images and (b) a state-of-the-art technique for rendering under-sampled light fields. Extensive rendering experiments confirm that our algorithm provides visible quality improvement, quantified as about 10% RMSE reduction. However, the subjective improvement is larger and it produces images comparable to the ground truth. This algorithm contributes to practical applications of light field rendering, such as image generation in stereoscopic displays and Free-Viewpoint Video (FVV).
A software-based high-quality MPEG-2 encoder employing scene change detection and adaptive quantization

This paper presents a software-only MPEG encoder implementation which uses adaptive quantization and scene change detection to enhance the picture quality. Scene change detection is also used to assign picture coding types allowing easy, lossless cutting at scene change positions in a later editing process. Although our current implementation concentrates on MPEG-2, all concepts can also be directly applied to MPEG-4 encoders.
Measurements of low gain antennas at VHF frequencies for space-based AIS applications

Measurement of the radiation properties of low gain antennas at VHF frequency is in many cases a challenging task. Measurements performed in shielded anechoic chambers are usually preferred to outdoor ranges because they are not subject to the electromagnetic pollution and less affected by the scattering of the environment. However, different source of errors, such as truncation of the scanning surface and the presence of echoes caused by a poor reflectivity of the anechoic chamber, could affect the measurement results. In such cases, advanced post-processing techniques must be involved. In this paper, the results of two Engineering Models of a low gain VHF space antenna are reported. The first one has been tested in a multi-probe automotive hemispherical range and applying an advanced processing, in order to mitigate the truncation errors. The second has been measured in a spherical multi-probe system with smaller truncated area applying the standard data processing.
Advances in integrated 2D MEMS-based solutions for optical network applications

Reduction of installation and operational costs are currently the driving force behind the implementation of optical networks. 2D MEMS technology plays an important role in the development of these network systems with several applications, including optical cross-connects, protection switching, optical add-drop multiplexing and wavelength switching. The optical design and packaging technology that has been developed for 2D MEMS has resulted in a flexible platform that can be used to manufacture highly integrated fiber optic devices.
A statistical approach to the design of an adaptive self-normalizing silence detector

Silence detection is an important aspect of automatic speech recognition. In this paper a silence detector is described which classifies each frame of an utterance as being silent or nonsilent. No attempt is made to determine the endpoints of words. The silence detector is based upon a statistical test and has the properties that it is adaptive, self-normalizing, speaker independent, and script independent. No training sets are required, although it is assumed that the first part of a signal is silent. An experiment is described in which the silence detector was successfully applied to more than 2 h of isolated-word speech using a frame length of 1 cs.
Coupling Reduction Between Dipole Antenna Elements by Using a Planar Meta-Surface

The mutual coupling between dipole antenna array elements using a planar meta-surface as superstrate is experimentally investigated. The meta-surface is based on grids of short metal strips and continuous wires. A comparison between the mutual coupling when the dipoles are radiating in free space and in presence of the superstrate is presented. On average, between 3 to 14 dB reduction of the mutual coupling is achieved when the superstrate is used. The effect of the mutual coupling on the radiation performance of the array is studied by spherical near-field measurements of the radiation pattern when one driven dipole is fed and the others are matched with 50 Omega loads. The back-projected field on the aperture and on the E-plane is shown.
Improving satellite antenna temperature estimation by high-resolution emission model of the Earth

This paper describes the results of a study aimed at accurately determining the antenna noise temperature used to calculate the uplink G/T for satellite-borne receivers. The antenna noise temperature is calculated from a brightness temperature database of the Earth which, for each surface pixel (1/spl deg//spl times/1/spl deg/), includes the effects of the season, observation angle and frequency. Good correlation has been found by comparison with in-orbit test (IOT) measurements.
Analysis of uniplanar electromagnetic band-gap (EBG) structures by the MoM/BI-RME method

This paper presents a novel method for the characterization of uniplanar electromagnetic band-gap structures. Their characterization requires the calculation of the dispersion diagram of the guided modes and the phase of the reflection coefficient under plane-wave illumination. The reflection coefficient is determined by using the MoM/BI-RME method. The same method is adopted in conjunction with a new technique for the efficient calculation of the dispersion diagram. This technique is based on the tracking of the eigenvalue path in the complex plane, and proved more reliable than the method based on the searching of the determinant zeros. The method is applied to the analysis of the classical Uniplanar Compact Electromagnetic Band-Gap structure, and some results show the accuracy of the method, its efficiency, and its convergence properties.
Combined generation of road marking and road sign databases applied to consistency checking of pedestrian crossings

Combined road marking and traffic sign databases are beneficial for both road maintenance and for usage within navigation devices and autonomous driving vehicles. The combination of both markings and signs completely provides all instructions and legislation for drivers. This paper presents a conceptual system for the automated creation of such combined databases and investigates the benefit of this combination for the specific case of pedestrian crossings. Evaluations on 62 km of road have shown that individual detection of road signs and markings indicating pedestrian crossings is very accurate (≥ 95%), enabling selective safety analysis towards these specific locations. Combining both approaches enables very accurate identification of crosswalks and additionally leads to the retrieval of crossings with undetectable markings or signs, such that maintenance can be directed specifically towards these potentially dangerous crosswalks.
Polarisation Independent Submillimetre Wave Annular Slot Frequency Selective Surface

In this paper we use numerical predictions to show that a freestanding frequency selective surface (FSS) can be designed to separate the two channels 316.5- 325.5 GHz and 349.5 - 358.5 GHz with an insertion loss 20 dB and crosspolar levels < 21 dB in both the TE and TM planes at 45° incidence. The structure consists of two closely spaced identical metal screens which are perforated with an array of nested shorted annular slots. The magnetic current mode which is supported by the periodic screens at resonance is determined by the diameter and the orientation of the asymmetrical slots. This design feature is used to tune independently the spectral responses of the FSS in the two planes of incidence. The periodic structures have been fabricated using a precision micromachining technique. Quasi-optical swept frequency measurements in the range 295 - 359 GHz yield results that are in close agreement with the computed copolar and crosspolar values.
Label-free biosensors on silicon-on-insulator optical chips based on microring cavities and surface plasmon interferometry

To come up to the demand for extremely sensitive biosensors for parallel real-time bioanalyses, we present two configurations of label-free biosensors on silicon-on-insulator optical chips. We discuss results on microring resonators and the design and fabrication of an integrated surface plasmon resonance interferometer. The high refractive index contrast material offers submicron-size features with high quality for dense integration, high sensitivity and detection with very low analyte volumes. Fabrication with deep UV lithography allows for mass production of cheap disposable biochips.
Video-object segmentation using multi-sprite background subtraction

The background subtraction algorithm is a frequently-used object segmentation technique because of its algorithmic simplicity. However, we show that, for general rotational camera-motion, it is impractical, or even impossible, to use a single background image. As a solution, we propose to use multi-sprite backgrounds which enables processing of arbitrary rotational camera-motion. The paper describes a complete video-object segmentation system employing multi-sprites. The system generates object masks and background sprites that are compatible with MPEG-4 object-oriented video-coding tools. Good segmentation results are also obtained for sequences which cannot be processed with ordinary background images.
Broadband Radar Cross-Section Reduction Using AMC Technology

This paper presents the design, fabrication, and characterization of a planar broadband chessboard structure to reduce the radar cross-section (RCS) of an object. The chessboard -like configuration is formed by combining two artificial magnetic conductor (AMC) cells. The bandwidth limitations intrinsic to AMC structures are overcome in this work by properly selecting the phase slope versus frequency of both AMC structures. A 180 ° phase difference has been obtained over more than 40% frequency bandwidth with a RCS reduction larger than 10 dB. The influence of the incidence angle in the working bandwidth has been performed. A good agreement between simulations and measurements is achieved.
Incorporating Depth-Image Based View-Prediction into H.264 for Multiview-Image Coding

We investigate the coding of multiview images obtained from a set of multiple cameras. To exploit the inter-view correlation, two view-prediction tools have been implemented and used in parallel: a block-based motion compensation scheme and a depth image based rendering technique (DIBR). Whereas DIBR relies on an accurate depth image, the block-based motion-compensation scheme can be performed without any geometry information. Our encoder adaptively selects the most appropriate prediction scheme using a rate-distortion criterion for an optimal prediction-mode selection. The attractiveness of the algorithm is that the compression algorithm is robust against inaccurately estimated depth images and requires only one single reference camera for fast random-access to different views. We present experimental results for several multiview sequences, that result in a quality improvement of up to 1.4 dB as compared to H.264 compression.
Magnetization reversal in micron-sized stripes of epitaxial (110)YFe2 films

In this paper, YFe2(110) single crystal films with Laves phase structure were grown on sapphire substrates by molecular beam epitaxy, and its magenization reversal was investigated by magneto-optical Kerr effect measurements. Results show that the film's magnetic behavior is governed by the combined effect of induced shape anisotropy and intrinsic four-fold magneto-crystalline anisotropy. A dominant uniaxial in-plane anisotropy can be created by geometrical effects.
Performance-efficient architecture for free-viewpoint 3DTV receiver

This paper presents algorithmic and architectural solutions for a free-viewpoint 3DTV receiver system. We describe our rendering algorithm and evaluate performance-related challenges in mapping of the algorithm on a receiver board of which the architecture is outlined. It is found that the required processing load exceeds the provisioning of dual Virtex5 FPGAs. We develop several mapping optimizations to fit the rendering algorithm into a platform.
Full-wave and multi-GTD analysis of the ice cloud imager for MetOp-SG

We report an RF study at 50 GHz of the Ice Cloud Imager, consisting of a parabolic reflector inside a semi-closed sun shield, as obtained with full-wave method of moments (MoM) and the asymptotic high-frequency multi-geometrical theory of diffraction (Multi-GTD) method. The Multi-GTD results accurately reproduce details of the main beam and sidelobes originating from focusing, but fail to predict other parts of the pattern that are due to a large number of scattering events inside the semi-closed sun shield. MoM results at the half and double frequency (25 and 100 GHz) show that the parts of the pattern that are not well described by Multi-GTD, but still within the dynamic MoM range, remain at the same overall level as the frequency is varied. Thus, when analyzing at higher frequencies of interest (≥ 183 GHz), a complementary MoM and Multi-GTD approach can be adopted to predict the radiation pattern.
Linearly and circularly polarized slot antennas integrating solar cells

A new way to integrate antennas and solar cells of the amorphous silicon type (a-Si:H) is presented. In previous published designs, solar cells are glued on and around microstrip patches. It has been shown that only a reduced space around the radiating edges of the patches should not be covered by the cells. In this more integrated solution, called "fully-integrated" design, the solar cells are glued or even directly grown on the ground plane of a printed slot antenna. This solution results in an high level integration of the solar cells and antenna functions while allowing circular polarisation operation, beam scanning and minimizing the RF effects of the solar cells collector network. Examples of operational designs are given and their performances are discussed. The final prototypes represent a large gain in surface coverage, volume, weight and electric performance with respect to the simple juxtaposition of antennas and solar cells.
A validation study of stroke volume measurement by means of electrical impedance tomography

ECG-gated electrical impedance tomography (EIT) has been developed to monitor blood volume changes. The aim of this study was to compare stroke volume measurements by EIT with established methods of thermodilution and magnetic resonance imaging (MRI). After right cardiac catheterization, EIT measurements were performed in 26 patients. Regression analysis was used to analyze the relation between the EIT results and stroke volume. From the regression line an equation was derived to estimate stroke volume (in ml) by EIT. In a group of eleven healthy subjects this equation was validated to MRI. A strong correlation was found between EIT and stroke volume measured by the thermodilution method (r=0.86). The reproducibility coefficient for EIT measurements was 0.98. The average standard deviation between stroke volume measured by EIT and MRI is 5.4 ml, the mean difference between both methods is 0.7 ml and the coefficient of variation is 8.4%. We conclude that EIT is a valid and reproducible method for the assessment of stroke volume in healthy controls and cardiological patients.
Modelling and Analysis of Composite Antenna Superstrates Based on Grids of Dipoles and Wires

A new planar superstrate, proposed for the gain enhancement of dipole antennas, is modelled and analyzed. The superstrate consists of two closely located parallel grids of short dipoles and one grid of continuous wires in between the dipole grids. Also the situation when the wire grid is absent is studied. An analytical model based on the local field approach has been derived in order to extract the transmission and reflection responses of the superstrates. The responses have been compared with the results predicted by Ansoft-HFSS. A finite size superstrate has been designed for a dipole antenna, and the simulations show that a significant gain enhancement can be achieved with the proposed design
Shape induced anisotropy in hybrid anti-dot arrays from guided self-assembly templates

Ordered templates are used for electro-deposition of different magnetic materials. This technique offers new opportunities, which are not easily realized by standard lithographic methods, and which allows creation of magnetic nanostructures with 3D architectures on broad range of length scale. To address limitations of self-assembly, hybrid techniques using well established Si technology to guide and confine self-assembly templates is employed. Magnetic measurements are performed using superconducting quantum interference device (SQUID), a vibrating sample magnetometer and a magneto-optical Kerr effect rig. Electrical properties are studied using a four-point probe configuration. Magnetic structures have been imaged using magnetic force microscopy (MFM). Obtained results are analysed using micromagnetic simulations and simple analytical models of domain wall pinning and magnetization curling behavior.
Improved skin segmentation for TV image enhancement, using color and texture features

Maintaining natural appearance for human face and skin areas is essential in TV image enhancement. High-end TV video processing chips include skin detectors for this purpose. This paper presents a technique for improved skin detection, using a trainable color feature and a multi-scale texture feature. Evaluation on a database of 173 manually annotated natural images shows that at a true positive rate of 90%, the proposed technique yields a false positive rate of 12%, as compared to 19% and 20% of two color-only skin detectors.
An optimal stochastic control approach to maintenance campaign scheduling

Presents an optimal stochastic control approach to scheduling of preventive maintenance activities for offshore installations. The author introduces a Markov decision problem with a cost structure that is based on manpower requirements for corrective and preventive maintenance activities. The objective is to determine a preventive maintenance strategy that minimizes the total cost, taking into account the inaccessibility of the installation during winter months. The authors show how the dynamic programming algorithm, used to solve the problem, can be implemented efficiently on a small computer.<<ETX>>