nils-herrmann/clean_scirepeval huggingface dataset:
Efficient path aggregation and error control for video streaming

This paper presents an efficient multiplexing and error control system to improve streaming video performance over path aggregates. While providing the application with increased aggregate bandwidth, the scheme reduces performance degradation due to high path latencies and loss rates. The reduction in effective loss and delay is achieved by smart multiplexing and exploiting the high latency paths to the user's advantage. A novel out-of-order transmission algorithm utilizes the higher latency paths to transfer suitable frames from within the transmit buffer. We present an FEC strategy for our scheme that decouples the transmission of error correction frames from the associated data. This provides protection against correlated losses. Our scheme, while not completely optimized, can provide close to optimal performance at a considerably lower complexity. We verify the performance of our scheme using the ns-2 simulator.
Hierarchical approach to image estimation

In general, images are inhomogeneous and no single model can accurately represent all the N×N data points of an image. Thus the linear space-invariant (LSI) filter can not produce the best estimates, especially at the lower SNR's. In fact, LSI filters tend to smooth the edges excessively when estimating undistorted images corrupted by additive white Gaussian noise. If we transform the original image space to a more appropriate space, and then process images in the new space, we may obtain better visual quality and lower numeric error also. Investigating such a transformation is the main concept of this paper.
Register locking in an asynchronous microprocessor

A high-performance register bank is a central component of a RISC processor. A novel register bank design has been developed, as an integral part of a self-timed implementation of a commercial RISC microprocessor, to address the problem of register interlocking in an asynchronous micropipelined execution unit. The problem in an asynchronous design is to maintain coherent register operation while allowing concurrent read and write accesses with arbitrary timing. The solution presented here includes a novel arbiter-free locking mechanism which enables efficient read operations in the presence of multiple pending write operations.<<ETX>>
Improvements to the MC-EZBC scalable video coder

MC-EZBC is a fully scalable video coder using a motion-compensated 3-D subband/wavelet decomposition. Temporal filtering is performed along estimated motion trajectories to remove temporal redundancy. To get greatly increased motion compensation (MC) accuracy and increased coding efficiency, we use the lifting filter implementation. Additionally, we introduce unconnected blocks and spatial lowpass transition filtering (SLTF). This results in improved lower frame rate data for the scalable MC-EZBC coder. Finally, an optimized quantization strategy is introduced to compensate for variations in synthesis filtering for connected and unconnected pixels.
Partial discharges in HV machines; initial considerations for a PD specification

Partial discharge (PD) specifications exist for all types of electrical equipment except motors and generators. Whereas specifications essentially require that the equipment is discharge-free the stator conductor bar insulation of the motors and generators under consideration is micaceous and has excellent PD resistance. Consequently, the intention in a specification would be to permit a certain level of PD. It is therefore particularly important that the problem of overcoming the attenuation between the PD site and the measurement equipment at the winding terminals be solved. Within the general context of examining the feasibility of a PD specification, the problem of PD signal attenuation is addressed. The approach adopted was to seek a region of low attenuation by examining the whole of the possible range of PD measurement frequencies. The investigations described consist of experiments on a full-size 500 MW endwinding model and on two large high-voltage motor windings. Careful screening to reduce radiative pick-up from the calibration generator simulating a PD source and a direct earthing scheme enabled the essential elements of PD pulse transfer through a winding to be determined. The frequencies investigated ranged from kHz to GHz. Pulse transmission and frequency spectrum measurements were made. It is concluded that the PD pulse transmits essentially as a travelling wave, the high-frequency components being highly attenuated. No significant crosscoupling was apparent through the end-winding region. The windings acted as a low-pass filter, the cut-off frequency being dependent on the winding length, and being below 1 MHz. Consequently, it is concluded that it should be possible to measure PD, using equipment with a passband below the low-frequency cut-off, with low attentuation.
Integrated end-to-end buffer management and congestion control for scalable video communications

In this paper we present a video communication system that integrates end-to-end buffer management and congestion control at the source with the playout adjustment mechanism at the receiver. While each component of the system has been considered independently in the literature, our focus in this work is their integration. The proposed system exploits the fact that when congestion control is implemented at the source, most of the loss occurs at the source and not within the network. Based on this observation, we design the buffer management to trade off random loss for controlled loss of visually less important data. Frame rate is adjusted at the receiver to maximize the visual quality of the displayed video based on the overall loss. We tested our system with both H.26L and a subband/wavelet video coder, and found that it significantly improves the received video quality in both cases.
Device modeling for III-V semiconductors - an overview

This work presents an overview of several key technical considerations required for state-of-the-art nonlinear circuit simulation models of III-V HBT and FET devices. A unified large-signal modeling framework that incorporates the voltage and current dependence of nonlinear transit time and depletion capacitances in III-V HBTs, as well as the multiple voltage dependence of nonlinear capacitances in FETs is presented. Considerations for modeling thermal and electro-thermal interactions in III-V HBTs and FETs are reviewed and contrasted. Trends in advanced characterization techniques and their benefits for modeling are highlighted. Finally, selected recent advances in mathematical CAD techniques are reviewed with particular relevance for advanced circuit modeling of III-V devices.
Texture discrimination using doubly stochastic Gaussian random fields

The authors propose a compound random field for texture discrimination called the doubly stochastic Gaussian (DSG) random field, to reduce isolated errors. Two major advantages of the DSG model are that it is easy to extract the features (the autoregressive parameters) and the a priori information can be incorporated into the model through the probability function of the lower level field. Experimental results on synthetic and natural images are presented. The results are quite good for the cases of both supervised and unsupervised models obtained from the simulated annealing algorithm and the HCF (highest confidence first) algorithm.<<ETX>>
Linear pre/post filters for transform and subband/wavelet coding

We propose a novel method for designing linear pre/post filters for transform and subband/wavelet coders. We use a linear gain-plus-additive noise model to describe the effects of a class of point distribution function-optimized quantizers. Using this quantizer model, we provide an explicit expression for the power spectral density of the reconstruction error in an improved transform coding system that includes linear pre/post filters. This expression allows us to design pre/post filters that minimize the overall mean square error at a given target rate, by improving the frequency domain behavior of the overall system. For a 1-D Gauss-Markov source, we show that pre/post filters help DCT-based coders to match the performance of subband coders. We also describe an a posteriori method of designing postfilters for a JPEG coder, that uses the actual image data and maximizes the PSNR performance of the system. The postfilter coefficients are designed at the transmitter, and are sent to the receiver as part of the coded data.
A symmetric and thermally de-embedded nonlinear FET model for wireless and microwave applications

This paper describes the development of a new large-signal nonlinear FET model. The raison d'etre for this model is the design of modern wireless RFICs which places new demands on the predictions of linearity and efficiency of the circuit. The model is a hybrid, comprising an advanced development of the Chalmers University (a.k.a. 'Angelov') (Angelov et al., 1992) drain current model to include dynamic electro-thermal behavior, and a table-based HPFET (Root et al., 1991) 2-dimensional gate current and charge model. Both components are enhanced to include symmetry, even though the model is extracted from measurements made only on the half-space V/sub ds/ /spl ges/ 0. The model has been validated in class B amplifier, power amplifier and mixer RFIC applications.
The Detection and Identification of Overheated Insulation in Turbogenerators

The principle of an instrument being developed to identify particles emitted from overheated turbogenerator insulation is described. The continuous reading instrument may be used in conjunction with a generator condition monitor to validate an indication. Particles carried in the gas stream, some of which are normally passed through a condition monitor, are collected on a fine mesh filter incorporated in the new instrument. An ultraviolet source irradiates the material which fluoresces, giving off a characteristic visible emission spectrum. This characteristic is used to identify directly the source of the particles.
Video Post-Production with Compressed Images

This article presents new methods for performing two video post-production practices directly on subband compressed images, i.e., without decoding them first. The first post-production operation is composition of two images, i.e., realizing picture-in-picture. If one simply composes the coded subbands of two images, ringing and blurring occur because of the spatially rapid switch from one image to the other. To solve this problem, adaptive box borders are introduced that greatly reduce the ringing. The second post-production operation is overlaying text directly into a subband coded image. Here, only a small section of the image is decoded where the text is to be located, the text is overlaid into this small ima ge fragment, subbands of the fragment are obtained and seamed into the original subbands, and the modified fragment is quantized
Wavelet-denoising of complex magnetic resonance images

Wavelet and wavelet packets may be used to "denoise" magnetic resonance images by finding image basis functions that preferentially concentrate signal relative to background Gaussian noise. At very low SNR (<5), however, standard magnitude MRI images have skewed Rician noise statistics which degrade denoising performance. The authors hypothesized that wavelet-packet denoising techniques would yield better edge preservation if performed on the raw real and imaginary images prior to rectification. To test this hypothesis, synthetic, phantom, and volunteer cardiac images were denoised either in the complex or magnitude domains. The techniques were compared with regard to signal-to-noise, signal-to-background, contrast-to-noise and edge blurring. While magnitude and complex denoising both significantly improved SNR, SBR, and CNR, complex denoising yielded sharper edge resolution and feature extraction. Wavelet packet denoising of MRI images should be performed prior to signal rectification in very low SNR applications.
Advanced intelligent mechanical sensors (AIMS)

A system of integrated, intelligent mechanical transducers, based on the microelectromechanical systems (MEMS) approach, is being developed. The FET-based detectors coexist in the silicon chip with other circuit elements which can amplify, digitize, and multiplex signals produced by detector/emitter interactions. Two transducer types being developed are used as examples: the rotary displacement transducer (RDT) and the uniaxial strain transducer (UAST). By appropriate arrangement of emitter and detector arrays, transducers are being designed to achieve desired tradeoffs between resolution, dynamic range, bandwidth, sensor population size, and other features. With detector and associated circuitry on the same chip, transducers are being designed to implement local intelligence necessary for functions such as self-calibration, correction for subsystems failure, and interaction with adjacent sensors.<<ETX>>
Sectioned implementation of two-dimensional symmetric half-plane recursive filters

This paper concerns sectioning approaches for the implementation of two-dimensional recursive filters with symmetric half-plane support. Two new algorithms are presented and compared to the direct implementation as regards computational requirements. Procedures for choosing optimal sectioning parameters for both infinite and finite size rows are provided. This method has been implemented on a scientific minicomputer (Prime 750) and examples are given to illustrate the computational requirements. The method is also suitable for microprocessor implementation with an associated signal processing chip to perform the section FFT's.
Identification of image and blur parameters for the restoration of noncausal blurs

An optimal statistical parameter estimation technique is presented for the identification of unknown image and blur model parameters. The development leads to an autoregressive moving average (ARMA) model identification problem, where the image model coefficients define the AR part, and the blur parameters define the MA part. Conditional maximum-likelihood estimates of the unknown parameters are derived both in the absence and in the presence of observation noise. The proposed algorithms constitute a generalization of previous work on blur identification in that they are able to locate the zero loci of the blurred image spectrum on the entire z 1 - z 2 plane. Simulation results, as well as photographically blurred images processed with the proposed algorithms, are shown as examples.
Timing-Driven Physical Design for VLSI Circuits Using Resonant Rotary Clocking

Resonant clocking technologies are next-generation clocking technologies that provide low or controllable-skew, low-jitter and multi-gigahertz frequency clock signals with low power consumption. This paper describes a collection of circuit partitioning, placement and synchronization methodologies that enables the implementation of high speed, low power circuits synchronized with the resonant rotary clocking technology. Resonant rotary clocking technology inherently supports (and requires) non-zero clock skew operation, which permits further improved circuit performances. The proposed physical design flow entails integrated circuit partitioning and placement methodologies that permit the hierarchical application of non-zero clock skew system timing. This design flow is shown to be a computationally efficient implementation method.
Domain-based multiple description coding of images and video

In this paper, we present a method of creating domain-based multiple descriptions of images and video. These descriptions are created by partitioning the transform domain of the signal into sets whose points are maximally separated from each other. This property enables simple error concealment methods to produce good estimates of lost signal samples. We present the approach in the context of Internet transmission of subband/wavelet-coded images and scalable motion compensated three-dimensional (3D) subband/wavelet-coded video, but applications are not limited to these scenarios. The results indicate that the proposed methods offer improvements over similar competing methods by up to 1 dB for images, and several decibels for video. Visual quality is also improved.
Invertible temporal subband/wavelet filter banks with half-pixel-accurate motion compensation

Three-dimensional (3-D) subband/wavelet coding with motion compensation has been demonstrated to be an efficient technique for video coding applications in some recent research works. When motion compensation is performed with half-pixel accuracy, images need to be interpolated in both temporal subband analysis and synthesis stages. The resulting subband filter banks developed in these former algorithms were not invertible due to image interpolation. In this paper, an invertible temporal analysis/synthesis system with half-pixel-accurate motion compensation is presented. We look at temporal decomposition of image sequences as a kind of down-conversion of the sampling lattices. The earlier motion-compensated (MC) interlaced/progressive scan conversion scheme is extended for temporal subband analysis/synthesis. The proposed subband/wavelet filter banks allow perfect reconstruction of the decomposed video signal while retaining high energy compaction of subband transforms. The invertible filter banks are then utilized in our 3-D subband video coder. This video coding system does not contain the temporal DPCM loop employed in the conventional hybrid coder and the earlier MC 3-D subband coders. The experimental results show a significant PSNR improvement by the proposed method. The generalization of our algorithm for MC temporal filtering at arbitrary subpixel accuracy is also discussed.
Rotary traveling-wave oscillator arrays: a new clock technology

Rotary traveling-wave oscillators (RTWOs) represent a new transmission-line approach to gigahertz-rate clock generation. Using the inherently stable LC characteristics of on-chip VLSI interconnect, the clock distribution network becomes a low-impedance distributed oscillator. The RTWO operates by creating a rotating traveling wave within a closed-loop differential transmission line. Distributed CMOS inverters serve as both transmission-line amplifiers and latches to power the oscillation and ensure rotational lock. Load capacitance is absorbed into the transmission-line constants whereby energy is recirculated giving an adiabatic quality. Unusually for an LC oscillator, multiphase (360/spl deg/) square waves are produced directly. RTWO structures are compact and can be wired together to form rotary oscillator arrays (ROAs) to distribute a phase-locked clock over a large chip. The principle is scalable to very high clock frequencies. Issues related to interconnect and field coupling dominate the design process for RTWOs. Taking precautions to avoid unwanted signal couplings, the rise and fall times of 20 ps, suggested by simulation, may be realized at low power consumption. Experimental results of the 0.25-/spl mu/m CMOS test chip with 950-MHz and 3.4-GHz rings are presented, indicating 5,5-ps jitter and 34-dB power supply rejection ratio (PSRR). Design errors in the test chip precluded meaningful rise and fall time measurements.
Behavioral modeling of high power RF amplifiers using pruned Volterra scheme with IIR basis functions

This paper proposes a new behavioral PA modeling scheme which combines existing pruned Volterra (PV) model with infinite impulse response (IIR) basis functions. These IIR basis functions are inherently composed of a parallel structure of single-pole IIR filters, summed at the output. Performance of this new IIR-PV model is found to be significantly better than existing memory polynomial (MP) and pruned Volterra only (PV) PA models. For the validation, characterization results of 80W Class-AB PA and 240W Asymmetric Doherty PA are presented. Excellent results are obtained, where error between model prediction and measurements is better than -41.7dBc (Class-AB PA) and -42.1dBc (Doherty PA).
AMULET3i-an asynchronous system-on-chip

AMULET3i is the third generation asynchronous ARM-compatible microprocessor subsystem developed at the University of Manchester. It is internally modular being based around the MARBLE asynchronous on-chip bus, and is also extensible through the addition of conventional clocked synthesizable peripherals via an on-chip synchronous peripheral bus. As such it is capable of forming the core of a wide range of system-on-chip applications, bringing asynchronous design into commercial use in a flexible and easy-to-use configuration. Its performance and area are comparable with clocked equivalents, and its low-power and electromagnetic emission characteristics give it unique capabilities in appropriate applications.
Inhomogeneous Gaussian image models for estimation and restoration

Two inhomogeneous Gaussian-image models are presented for estimation and restoration. By incorporating the local statistics of an image, a homogeneous autoregressive (AR) random field can be extended to an inhomogeneous AR field. This inhomogeneous random field can provide a better description of the image than the homogeneous one. As a consequence of this improved modeling, a minimum-mean-square-error estimator (MMSE), based on the inhomogeneous Gaussian model, can produce good results in both subjective and objective criteria. Two image models are proposed for use in image estimation and restoration: a residual image model (original image minus the space-variant mean) and a normalized image model (residual image divided by space-variant standard variation). The novel aspect of these models is the use of an autoregressive dynamical model for residual and normalized images. Some aspects of parameter estimation are discussed and simulation results are presented.
An adaptive coverage control algorithm for deployment of nonholonomic mobile sensors

We show the Lyapunov stability and convergence of an adaptive and decentralized coverage control for a team of mobile sensors. This new approach assumes nonholonomic sensors rather than the usual holonomic sensors found in the literature. The kinematics of the unicycle model and a nonlinear control law in polar coordinates are used in order to prove the stability of the controller applied over a team of mobile sensors. The convergence and feasibility of the coverage control algorithm are verified through simulations in Matlab. Furthermore, some experiments are carried out using a team of four Pioneer 3-AT robots sensing a piecewise constant light distribution function.
Spatiotemporal subband/wavelet coding of video with object-based motion information

We present a novel object-based spatiotemporal (3-D) subband/wavelet coding scheme for very low bit-rate video compression. First, the image sequence is segmented into objects based on motion and color. The objects are then independently decomposed by subband/wavelet analysis, both in the temporal and spatial domain. The temporal analysis is greatly facilitated over existing methods by the object-based representation. Each object's subband/wavelet coefficients are then quantized according to a bit allocation scheme based on the generalised BFOS algorithm. Simulations at very low bit-rates indicate competitive performance to classical motion-compensated predictive (MCP) coding schemes, while allowing the flexibility of frame-rate scalability.
Process-orientated physics-based modeling of microwave power transistors: Small- and large-signal characterization

The coupling between charge transport, heat and energy flow required to model high frequency power devices is developed in the context of a computationally efficient physics-based model, which has been successfully applied to microwave laterally diffused MOS transistors. The accurate prediction of small- and large-signal microwave characteristics, and the physical insight gained, can be used in the process-orientated optimization and process sensitivity analysis of LDMOS power FETs. The charge-based model is well-suited to non-linear CAD implementation for applications such as power amplifier design.