nils-herrmann/clean_scirepeval huggingface dataset:
A linear 250 watt Doherty power amplifier based on two-stage power ICs for 1.8 GHz single and multi-carrier GSM applications

In this paper we describe the design and measured performance of a Doherty power amplifier constructed using two-stage power amplifier IC building blocks. The Doherty PA was designed for single- and multi-carrier GSM applications in the 1800 MHz band. The 3-dB compression point of the amplifier is 54 dBm, and the PA displays excellent raw linearity for use in single-carrier GSM applications. Using a commercial digital predistortion system, the amplifier provides power output of 47 dBm at −70 dBc correction with a two-carrier GSM signal, and 45.5 dBm at −60 dBc correction with a four-carrier GSM signal.
Scalable Motion Vector Coding Based on CABAC for MC-EZBC

In the scalable video coder MC-EZBC, the motion-vector (MV) bitstream was not scalable in bitrate or resolution. In this short paper, we enhance MC-EZBC with a new scalable MV coder based on context adaptive binary arithmetic coding. Alphabet general partition of MV symbols is proposed to achieve accuracy or quality scalability of MVs. A selective layered structure is used to reduce the number of MVs transmitted when appropriate, mainly needed for resolution scalability. With these two additions, we have a layered temporal, SNR, and resolution scalability for the MV bitstream. Experimentally, we find that this gives significant visual and objective improvement for low bitrates and/or resolutions with only very slight PSNR loss and unnoticeable visual loss at high bitrates
Systematic waveform engineering enabling high efficiency modes of operation in Si LDMOS at both L-band and S-band frequencies

This paper demonstrates that by robust waveform engineering it is possible for high power Si LDMOS to achieve very high efficiency at frequencies up to 2.1GHz. Class F amplifier operation was realized in a 5W LDMOS device by the successful application of robust waveform engineering procedures; undertaken at the current generator plane. The peak power added efficiency was found to be 78% at 0.9GHz and 77% at 2.1GHz. In both cases the RF waveforms were optimized in terms of the gate voltage, fundamental and harmonic impedances. The main difference at 2.1GHz was the change in fundamental impedance to a more reactive impedance to compensate for the dynamic device output capacitance. To the authors’ knowledge this is the highest efficiencies reported in the literature for Si LDMOS devices at 2.1GHz.
Error Concealment for Scalable Motion-Compensated Subband/Wavelet Video Coders

In this paper, we present two error-concealment algorithms developed for scalable motion-compensated subband/wavelet video coders. These algorithms exploit the properties of motion-compensated temporal filtering to recover lost video data by motion compensation from correctly received previous and future video frames. Our experiments indicate that backward motion-compensated prediction outperforms replacement from neighboring correctly received frames by up to 3 dB in terms of PSNR. In addition, a bidirectional algorithm tops the unidirectional one by up to 1 dB. Also, visual improvements are often higher that PSNR improvements would suggest
Rate constrained multiresolution transmission of video

Multiresolution transmission of compressed video is performed using subbands. Multistage quantization is necessary for efficient embedded video transmission on rate constrained channels. This paper investigates the performance of a number of multistage scalar quantization techniques: concatenated coding, conditional entropy coding and conditional quantization. Intraframe as well as interframe coding approaches are investigated with these multistage quantization techniques on high definition and standard definition source material.
Image Identification And Restoration In The Subband Domain

Recently Lagendijk et al. [l] have presented the application of the Expectation-Maximization (EM) method to the image restoration problem. In this paper we extend their method to include a subband decomposition on the input data. This is then followed by EM model identification and simultaneous restoration on each subband. Finally the estimates from the subbands are recombined to produce the output image, which constitutes a full-band estimate of the original unblured image.
A multiple model algorithm for the adaptive restoration of images

We present a multiple model image restoration technique with on-line edge detection over noisy and blurred images. Four edge models corresponding to major correlation directions and an isotropic model are used to represent the image. Unlike previous results, a decision-directed approach is used to adaptively estimate the edge orientation which then defines the appropriate deconvolution model. The overall effect is space-variant deconvolution implemented by efficient reduced update filters. Processed images are shown as examples.
Peak Class F and Inverse Class F Drain Efficiencies Using Si LDMOS in a Limited Bandwidth Design

This paper compares two popular high power, high efficiency modes of operation, class F and inverse class F, and assesses the peak obtainable drain efficiencies when using Si LDMOS devices in a limited bandwidth design. Optimum class F and inverse class F conditions are presented using active harmonic load-pull measurements, and it was found that a higher drain efficiency was achieved in the class F configuration. This result is due to the limitations imposed by the soft voltage breakdown occurring due to the extended voltage swings inherent to inverse class F, as a consequence generating unwanted current content during the off cycle. This significantly reduces the peak measured efficiency using Si LDMOS devices when implementing an inverse class F design with a drain bias of 28 V. By reducing the drain bias to 18 V, to accommodate the voltage extension of inverse class F, it became possible to achieve peak measured efficiencies much closer to what theory predicted.
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. Maximum likelihood estimates of the unknown parameters are derived both in the absence and in the presence of observation noise. The proposed algorithms are able to locate the zeros of the observed image spectrum on the entire Z1-Z2plane and therefore, unlike previous algorithms, are not restricted to the Fourier domain. Images restored with the proposed algorithms are shown as examples.
Motion-Compensated Temporal Filtering and Motion Vector Coding Using Biorthogonal Filters

This paper investigates 3-D subband coding via motion-compensated temporal filtering (MCTF) using biorthogonal filters. While nonoverlapping Haar filter-based MCTF has a fixed size group of pictures (GOP) structure, for longer filters we need to use extensions at the GOP ends resulting in coding efficiency loss and/or significant peak signal-to-noise (PSNR) variation. We solve this problem by introducing a "sliding window" approach to MCTF. While we find the longer filters have higher coding gain and significant PSNR improvement at high bit rates, a necessary doubling of the number of motion vectors (MVs) causes a drop in PSNR at lower bit rates. The paper then concentrates on improving the efficiency of both the MV estimation and compression. We employ the MV estimate at higher temporal resolutions as the starting point for local MV refinement at the present temporal resolution thereby reducing the complexity of motion search and obtaining a more uniform motion field. We improve MV coding performance by adapting the context-based binary arithmetic coder (CABAC) from H.264. Instead of encoding MV residuals along a quadtree scanning path, we reduce the MV bit rate by prediction from both neighboring MV blocks and blocks in the previous or the next lower temporal level. Our proposed motion estimation and coding schemes can reduce the MV bit rate by 10%-20% for Haar and 15%-30% for 5/3 MCTF
Binary Partition Tree Analysis Based on Region Evolution and Its Application to Tree Simplification

Pyramid image representations via tree structures are recognized methods for region-based image analysis. Binary partition trees can be applied which document the merging process with small details found at the bottom levels and larger ones close to the root. Hindsight of the merging process is stored within the tree structure and provides the change histories of an image property from the leaf to the root node. In this work, the change histories are modelled by evolvement functions and their second order statistics are analyzed by using a knee function. Knee values show the reluctancy of each merge. We have systematically formulated these findings to provide a novel framework for binary partition tree analysis, where tree simplification is demonstrated. Based on an evolvement function, for each upward path in a tree, the tree node associated with the first reluctant merge is considered as a pruning candidate. The result is a simplified version providing a reduced solution space and still complying with the definition of a binary tree. The experiments show that image details are preserved whilst the number of nodes is dramatically reduced. An image filtering tool also results which preserves object boundaries and has applications for segmentation
The wobble motor: an electrostatic, planetary-armature, microactuator

A variety of micromotor concepts has been evaluated, with the wobble motor (WM) approach being one of those selected for extensive study. Various WM configurations have been analytically evaluated using finite-element methods and closed-form solutions. Important performance characteristics have been estimated such as stall torque and free speed, and alternate strategies for motor control have been examined. Five motor configurations and a variety of silicon-based and non-silicon-based fabrication techniques have been examined in detail. In exploratory exercises, motors have been fabricated using direct mechanical assembly, electro-discharge machining (EDM), cylindrical photolithographic etching, and coextrusion of metal and plastic. The EDM approach was selected as the motor alternative which could function as an experimental testbed. Fifteen EDM WMs have been constructed and utilized for experimental purposes. Experiments aimed at generating simple preliminary data have been conducted, and results compare reasonably to analytical studies.<<ETX>>
Towards a new partial discharge calibration strategy based on the transfer function of machine stator windings

Individual partial discharge (PD) detection and measurement is well recognised as a methodology for providing data on which assessments of the insulation integrity of high power plant can be made. It relies, as a technique, on the accurate acquisition of PD pulse data, including pulse magnitudes. Unfortunately, due to calibration difficulties with partial discharge detectors in static or rotating machine applications, pulse magnitude measurements may be erroneous. Calibration difficulties arise when the PD pulse is not simulated by the calibration pulse. This occurs when the PD pulse is 'distorted' as it propagates from its site of origin to the machine/detector terminals. To aid in the development of a new calibration strategy, the paper reports the results of two techniques. In the first, the transfer functions of different sections of stator winding are investigated to determine whether a frequency band exists in which a PD pulse would suffer minimal distortion as a function of location, in its propagation from site of origin to detector. Such a frequency band would indicate the appropriate bandwidth to which a detector could be tuned to avoid errors which were location dependent. This work builds on previously reported investigations. In the second, a technique of detected PD pulse reconstruction is investigated. The distorted, detected pulse postpropagation is reconstructed to its original magnitude via transfer function techniques. Given that the transfer functions from different locations in a winding are known and the location of the discharge can be identified or inferred, the technique offers an empirical approach to minimise calibration errors.
QoE-enabled transport optimisation scheme for real-time SVC video delivery

Video traffic today accounts for 50 percent of all traffic on the network and is set to reach the 70 percent mark in a few years. Bringing in large volumes of video traffic threatens to exceed the network's capacity. As a result, traffic congestion is becoming more frequent, degrading the Quality of Experience (QoE) for video consumers. In this paper, we present a QoE-enabled Transport Optimization Scheme (QETOS) for real-time scalable video stream. The proposed scheme is a crucial design choice that will optimise the video traffic by mapping video quality degradations (that are caused by network) to the QoE without penetrating the video packets. It takes the advantage of the Scalable Video Coding (SVC) partitions that can organize video into layers of different importance, facilitating rate adaptation of video streams. Our approach will help to minimize the side effects on user perceived quality.
Discharge Studies of Epoxy/Mica Turbine Generator Insulation

This paper describes frequency accelerated experiments employed in an investigation into discharge resistance of small samples of epoxy resin bonded mica materials used for turbine generator stator bar insulation. Surface discharge experiments have been performed in nitrogen and helium at NTP, and internal discharge experiments in dry air at NTP and hydrogen at 650C and 310 kN m-2. An acceleration factor of 24, nominal stress 4 kV mm-1, was used for the particular experimental arrangement without any apparent change in the progression of dielectric deterioration. Only one sample failed at the above stress, equivalent service lifetimes in excess of 25 years being recorded at which point experiments were terminated. All mica based materials to some extent delaminated forming natural cavities; within these cavities white dentritic deposits were formed which were determined to be the result of discharge action on mica. Puncture of mica flakes between natural cavities and tracking between mica flakes was also observed. In general the materials made from small mica flakelets appeared to withstand the discharge attack better than large flake materials although all materials had lifetimes of at least 25 years. Samples made from relatively narrow tapes indicated severe damage at tape junctions.
IEEE 802.11ac wireless delivery of 4kUHD video: The impact of packet loss

This paper examines the 4kUHD video quality from streaming over an IEEE 802.11ac wireless channel, given measured levels of packet loss. Findings suggest that there is a strong content dependency to loss impact upon video quality but that, for short-range transmission, the quality is acceptable, making 4kUHD feasible on head-mounted displays.
Generic Object Registration Using Multiple Hypotheses Testing in Partition Trees

Using image processing techniques that partition an image into a number of homogenous regions, the authors' work regards image analysis as a process to be conducted within a binary partition tree without regard to the image processing stage used to generate it. This work recognises through subjective tests that tree-based representations are amenable to segmentation based on simple descriptions. The method considers the novel application of relative topology of constituent regions within the tree representation and applies it to form registrations in the spatial and temporal domains. To achieve this requires the use of graph-matching techniques to circumvent the non-direct mapping between tree conjugates and derived models. Search strategies are successfully applied in the tree using multiple hypotheses testing in a Bayesian formulation framework, facilitating object registration from very simple models.
Estimation and identification of two-dimensional images

Estimation of image pixel density can be performed using a reduced update Kalman filter provided that a mathematical model for the image generating process is available. To this effect various algorithms suitable for identifying the parameters of autoregressive image models are discussed and evaluated in terms of the mean-squared error between the true and filtered images. Algorithms considered include general and bias-compensated least-square procedures, a correlation-based algorithm, and procedures involving the simultaneous estimation of both the image model coefficient vector and pixel estimates. Experiments using two real images and two random fields indicate that bias-compensated least squares and correlation-based procedures might be most useful for image identification and adaptive filtering.
Systematic behavioral modeling of nonlinear microwave/RF circuits in the time domain using techniques from nonlinear dynamical systems

A powerful and systematic approach to behavioral modeling of nonlinear microwave/RF circuits in the time domain is presented, integrating several techniques from nonlinear dynamical systems analysis. Algorithms based on information-theoretic principles help determine efficient tradeoffs between model accuracy, speed, and complexity. Models are constructed from large-signal microwave measurements or simulations, and are integrated into a commercial nonlinear circuit simulator. A simulation speedup of more than an order of magnitude has been achieved.
Complexity reduced odd-order memory polynomial pre-distorter for 400-watt multi-carrier Doherty amplifier linearization

this paper expounds on the computation complexity reduction of memory polynomial (MP) digital predistorter (DPD) construction and implementation as needed to linearize power amplifiers (PA) when driven with multi-carrier signals. For that, the even-order terms in the MP branches were first removed. Then, the PA memory effects theory was used to further reduce the number of coefficients of the MP-DPD by decreasing the nonlinearity orders in the different branches individually. These two steps allowed for a reduction of the number of coefficients to almost one-third and the conditioning number by three orders of magnitude while maintaining the same linearization capability. This substantially alleviates the requirements on the digital signal processors and the time needed to construct and implement the MP-DPD in real environment. Experimental validation carried out using a 400Watt Doherty Power Amplifier (DPA), driven with 4-Carrier WCDMA signal, showed excellent linearization capability by achieving an ACPR of better than 50dBcwith a power efficiency of better than 42.4%.
Efficient modelling of spiking neural networks on a scalable chip multiprocessor

We propose a system based on the Izhikevich model running on a scalable chip multiprocessor - SpiNNaker - for large-scale spiking neural network simulation. The design takes into account the requirements for processing, storage, and communication which are essential to the efficient modelling of spiking neural networks. To gain a speedup of the processing as well as saving storage space, the Izhikevich model is implemented in 16-bit fixed-point arithmetic. An approach based on using two scaling factors is developed, making the precision comparable to the original. With the two scaling factors scheme, all of the firing patterns by the original model can be reproduced with a much faster execution speed. To reduce the communication overhead, rather than sending synaptic weights on communicating, we only send out event packets to indicate the neuron firings while holding the synaptic weights in the memory of the post-synaptic neurons, which is so-called event-driven algorithm. The communication based on event packets can be handled efficiently by the multicast system supported by the SpiNNaker machine. We also describe a system level model for spiking neural network simulation based on the schemes above. The model has been functionally verified and experimental results are included. An analysis of the performance of the whole system is presented at the end of the paper.
Subband coding of images

Subband coding has become quite popular for the source encoding of speech. This paper presents a simple yet efficient extension of this concept to the source coding of images. We specify the constraints for a set of two-dimensional quadrature mirror filters (QMF's) for a particular frequency-domain partition, and show that these constraints are satisfied by a separable combination of one-dimensional QMF's. Bits are then optimally allocated among the subbands to minimize the mean-squared error for DPCM coding of the subbands. Also, an adaptive technique is developed to allocate the bits within each subband by means of a local variance mask. Optimum quantization is employed with quantizers matched to the Laplacian distribution. Subband coded images are presented along with their signal-to-noise ratios (SNR's). The SNR performance of the subband coder is compared to that of the adaptive discrete cosine transform (DCT), vector quantization, and differential vector quantization for bit rates of 0.67, 1.0, and 2.0 bits per pixel for 256 × 256 monochrome images. The adaptive subband coder has the best SNR performance.
A Glimpse of the Future

The RF and microwave world has largely been exempt from the rigors of Moore's law, whereas aggressive scaling in the digital world has been the norm for several decades. But now, as CMOS transistors have picosecond switching speeds and transition frequencies in the tens to 100s of GHz, there is an opportunity for the integration of RF and microwave components into a complete system on a single integrated circuit (IC). Single-chip transceivers for wireless local area network (LAN) and femtocell base stations are already a commercial reality. As with complex digital systems, the demand for first-pass design success requires that accurate predictive models are available for the subsystem components of the whole system, enabling the system design to be simulated and any errors or faults remedied before the design is committed to hardware. This will save time and the cost of unnecessary fabrication and test of the complete system.
IEEE MTT-Society Fellows of 2014

In 2014, the IEEE will mark its 50th Fellow class. This represents five decades of honoring IEEE Fellows whose extraordinary accomplishments have changed the world. The IEEE grade of Fellow was born in 1964 out of the merger of the American Institute of Electrical Engineers (AIEE) and the Institute of Radio Engineers (IRE). The emphasis on the elevation was and still is reserved for select IEEE Members who have contributed importantly to the advancement of engineering, science, and technology, bringing the realization of significant value to society.  Fellow is the highest grade of membership and is recognized by the technical community as a prestigious honor and an important career achievement.
Sub-band coding of images

This paper presents an extension of sub-band coding to two-dimensions with particular application to images. We employ a 16 band decomposition using a tree structure of separable quadrature mirror filters and decimators. The sub-bands are encoded using DPCM with bits allocated to approximately minimize the mean-square error. A block-adaptive variant is also presented. A limited SNR comparison shows adaptive sub-band coding to outperform the adaptive discrete cosine transform and two types of vector quantizers.