nils-herrmann/clean_scirepeval huggingface dataset:
Multiple feature instance detection with density based clustering

This paper describes an approach to local feature instance detection by treating this as a clustering problem. We use a density based clustering algorithm and a local feature detection algorithm. The paper also provides an approach to validating the results. Confidences are calculated for each cluster using core distances and intra-cluster distances to determine how valid the each cluster is for a particular value of the clustering algorithm parameter minPts. We used the statistical values of kurtosis and skewness to validate the choice of minPts and describe a way of using these values to make an informed choice of the proper value of minPts.
Effect of Seed Layers on Polycrystalline ${\rm Co}_{2}{\rm FeSi}$ Thin Films

We report on the control of grain development and its effect on magnetic properties in polycrystalline Co2FeSi thin films through use of Ag layers. Thin film polycrystalline samples consisting of a 20 nm Co2FeSi layer deposited onto a 6 nm Ag seed layer have been fabricated using high target utilization sputtering. After thermal annealing at 300°C for 6 hours these films have median grain diameters of between 30 and 40 nm which are constrained by island like growth of the Ag Seed layer. This constraint of grain growth results in films with coercivities of no greater than 40 Oe and values of saturation magnetization exceeding 80% of the theoretical bulk value. The use of Ag seed layers is thus shown to reduce coercivities by almost 90% compared with previously reported similar materials making them much more suitable for device applications.
Maximum-likelihood parameter estimation of discrete homogeneous random fields with mixed spectral distributions

This paper presents a maximum-likelihood solution to the general problem of fitting a parametric model to observations from a single realization of a real valued, 2-D, homogeneous random field with mixed spectral distribution. On the basis of a 2-D Wold-like decomposition, the field is represented as a sum of mutually orthogonal components of three types: purely indeterministic, harmonic, and evanescent. The proposed algorithm provides a complete solution to the joint estimation problem of the random field components. By introducing appropriate parameter transformations, the highly nonlinear least-squares problem that results from the maximization of the likelihood function is transformed into a separable least-squares problem. In this new problem, the solution for the unknown spectral supports of the harmonic and evanescent components reduces the problem of solving for the transformed parameters of the field to linear least squares. Solution of the transformation equations provides a complete solution of the field model parameter estimation problem.
Deterioration of slot stress control materials on generator stator conductors by non-mechanical mechanisms

Long-term aging experiments conducted to examine mechanisms which could degrade a stator conductor slot stress control system are described. Models consisting of two conductor bars in a short length of core, single conductor bars, and other arrangements were used to investigate the development of slot discharge and compare the performances of various materials. Damage was found to start in the junction region between the slot stress control and endwinding stress control layer. Removal of the low-conductivity paint at the junction region led to surface discharge, which caused the consequent further erosion of the paint and led to complete removal of the slot stress control layer. The cause of the initial removal of paint is thought to be the action of ozone on the binding resin used in the paint. The ozone arose from discharge on bars in the test vessel or on an endwinding stress control layer. An improved version of the paint was shown to perform well, but the best results have been obtained with a low-conductivity molded tape layer. Such damage did not appear to develop in a hydrogen atmosphere.<<ETX>>
Investigation of X-parameters measurements on a 100 W Doherty power amplifier

In this article we describe a high-power reflectometer set-up specifically designed for large-signal nVNA measurements for the extraction of X-parameters. The heart of the measurement set-up is an Agilent N5242A PNA-X in nVNA mode. We have measured a Doherty amplifier constructed from a 2-stage, dual-path RF power amplifier IC. This power amplifier can deliver in excess of 100 W in Doherty mode, and these measurements represent the highest power X-parameter extraction reported to date.
The effects of material interfaces on thermal resistance values for high-power microwave transistors

In this paper, we examine the effects that the thermal interface between materials has on the thermal resistance extracted from electrical measurements. We also examine the consequent degradation in electrical performance. We present the characterization of the transistor under various thermal environments: mounted in packages, using various die attachments, and on-wafer. A wide range of thermal resistances are extracted and we demonstrate the importance of proper characterization during on-wafer thermal measurements. Finite-element simulations show that we can account for various thermal interfaces by changing the coefficient of thermal transfer from the semiconductor device to the material beneath it. Simulations are shown to be in good agreement with measured results.
Rapid Transport of Suspended Payloads

The topic of composing inputs for systems with mechanical flexibility has received attention for many years. Two popular methods are (1) shaping a nominal trajectory by convolution with an impulse sequence which itself cancels the flexibility, and (2) trajectory parameter optimization using structured basis functions, e.g. bang-coast-bang. However, each of these methods deteriorates in a different way when the motion is rapid compared to the natural period of the flexibility. Motions synthesized using dynamic programming offer clear advantages in these situations: (1) the resulting motions are smoother than those using impulse-convolution, and (2) dynamic programming is deterministic and does not rely on a convex objective function like gradient-based parameter optimization. Examples of the shortcomings of impulse-convolution and parameter-optimization will be shown; then we present both simulation and experimental evaluation of rapid transport of a suspended object using a robot manipulator and a minimum-energy trajectory obtained by dynamic programming.
Low temperature reactive ion etching of silicon with SF/sub 6//O/sub 2/ plasmas

An investigation of low temperature reactive ion etching of silicon to produce ultra small structures is presented. Plasmas containing SF/sub 6//O/sub 2/ were used to etch silicon samples in the temperature range +25/spl deg/C to -140/spl deg/C. At low flow rates and temperatures the etching produces nearly anisotropic etching in agreement with predictions of the reactive spot model. At higher flow rates etching produced facetted features indicating higher chemical reactivity of the plasma with the silicon.
Performance evaluation of MANET routing protocols in a maritime environment

DSDV (Destination-Sequenced Distance Vector), AODV (Ad hoc On-Demand Distance Vector), AOMDV (Ad hoc On-Demand Multipath Distance Vector) and DSR (Dynamic Source Routing) are among the most widely used routing protocols in Mobile Ad-hoc Networks (MANET) due to their compatibility with multi hop routing environments and scalability towards increased traffic and mobility. On the other hand due to the differences in the routing schemes where DSDV is a table driven routing scheme and AODV, AOMDV and DSR are on-demand routing schemes, each routing protocol has its advantages and disadvantages. In this paper we investigate the performance of these routing protocols in Ship Ad-hoc Networks (SANET) in a maritime environment where ships communicate using Very High Frequency (VHF) as the physical layer. A mobile ad-hoc network is achieved so that ships can use it to share data networking facilities or to send particular sensor data such as sea depth, temperature, wind speed and direction, etc. to a central server to produce a public information map.
Total Dose Susceptibility of the SBP 9989 Microprocessor

The SBP9989NJ (16 bit) microprocessor is a candidate device for use in synchronous-orbit satellite systems. It has recently been evaluated for its susceptibility to electron radiation and found to be vulnerable to dose levels significantly below the objective of 1 MRad (Si). Based on this evaluation, a decision has been made to use the functionally similar SBP9900ANJ devices instead.
A perspective on compact transistor modeling for future microwave and millimeter-wave GaN power amplifier design

In this paper we present an approach for the development of a compact nonlinear model for use in the design of discrete and MMIC GaN power amplifiers for microwave and millimeter-wave applications. We propose that the compact model use current and charge state functions modeled with continuously-differentiable functions, be fully charge conservative, cover the complete current-voltage and charge-voltage space, include dynamical models for thermal effects and trapping, and provide size scalability. Speed of simulation and convergence are vitally important concerns; these aspects need to be addressed in the detailed formulation of the algebraic functions used in the model. A parameter-extraction procedure is also outlined.
Motion compensated multiresolution transmission of high definition video

Several methods to perform multiresolution transmission of HDTV through subband coding are compared. The first is simple intraframe encoding of the spatial subbands of the video. The authors have used the subband decomposition for both hierarchical estimation of the motion as well as encoding of the compensated error function. They have used block matching for motion estimation on both 2D lowpass and bandpass (QMF) pyramids. They found that the motion estimation on the lowpass QMF pyramid performs better than the motion estimation on the bandpass QMF pyramid. They achieved approximately the same quality reconstructed video with either backward or forward motion compensated schemes. For multiresolution transmission, by simulating a test sequence, they have obtained a PSNR of 35 dB at the bit rate of 0.44 bits per pixel with adaptive PCM and at a bit rate of 0.53 bits pet pixel with PCM. Such a result would require 0.75 bits per pixel for the intraframe scheme. The complexity of the motion compensated multiresolution coding scheme is comparable to that of a single resolution method.
Two-Dimensional Delta-Mod Facsimile Coding

A new facsimile source coding algorithm, called twodimensional (2-D) delta-mod (Δmod), is presented. The algorithm is based on conventional run length coding. Additional compression is achieved by vertically delta-modulating the horizontal run lengths. The delta-modulation introduces a distortion into the image which can be traded-off versus the rate of transmission. Cumulative error is prevented, as in conventional Δ mod, by including the (run length) quantizer in the feedback loop. Some parametric results are presented
Bidirectional MC-EZBC with lifting implementation

In conventional motion-compensated three-dimensional subband/wavelet coding, where the motion compensation is unidirectional, incorrect classification of connected and unconnected pixels caused by incorrect motion vectors (MVs) has resulted in some coding inefficiency and visual artifacts in the embedded low-frame-rate video. In this paper, we introduce bidirectional motion compensated temporal filtering with unconnected pixel detection and I blocks. We also incorporate a recently suggested lifting implementation of the subband/wavelet filter for improved MV accuracy in an MC-EZBC coder. Simulation results compare PSNR performance of this new version of MC-EZBC versus H.26L under the constraint of equal groups of pictures size, and show a general parity with this state-of-the-art nonscalable coder on several test clips.
Subband finite state scalar quantization

A novel image coding algorithm that exploits the relationship between various subbands of an image is presented. This algorithm has been simulated on the monochrome 'Lena' image and an MIT high-definition (HD) video. Uniform-threshold quantizers (UTQs) and differential pulse code modulation (DPCM) are used in the implementation of the algorithm. Using local variance for classification, a 15% reduction in quantization noise has been achieved compared with other published techniques for 'Lena' at an average bit rate of 1.0 bit/pixel. For the MIT HD video, this reduction was 29.1%.<<ETX>>
Resource Allocation Scheme Based on Online QoE Estimation of Mobile H.264 Video Streaming

Demand on multimedia content by consumers' handheld devices over wireless channels is on the increase. In view of the accelerated trend towards consumption of high quality video, power utilization by mobile devices is expected to excessively increase. This paper presents a power and bandwidth efficient resource allocation scheme considering the end user's Quality of Experience (QoE) in the context of mobile video streaming. QoE has become the prime performance criterion for media delivery technologies. The QoE is estimated by an objective online estimation model based on adaptive Fuzzy Inference Systems (FIS). We simulate a mobile video transmission through which we identify the correlation between receiver's signal-to-noise ratio and QoE. Compared to QoS-based techniques, the proposed QoE-based scheme enables to save up to 33.13% in power and grant up to 50% more data bits for transmission.
Binary Partition Tree for Semantic Object Extraction and Image Segmentation

In this work, we demonstrate a systematic way to analyze a binary partition tree representation of natural images for the purposes of archiving and segmentation. Within the tree structure, these problems are transformed into locating prevalent tree branches. With a user interface these points can be found manually by browsing branches. However, tree visualization is difficult due to the high node density. A simpler version of the tree is desired which facilitates subsequent retrieval whilst maintaining as much semantic detail as possible. By studying the evolution of region statistics, our method highlights nodes which represent the boundary between salient detail and provide a set of tree levels from which simplifications and segmentations can be derived. A series of subjective tests are performed to demonstrate the effectiveness of using the simplified trees for object extraction. Segmentation results are compared to ground truths showing semantic content is maintained
100 MHz and 100 Mbit Recording and Readout Instrumentation Systems for Electromagnetic Field Perturbations

The requirement for a wideband recording capability for instrumenting electromagnetic fields with nanosecond rise time perturbations and long duration reactions lead to the development of a modulated laser beam analog recorder. The original concept of the recorder yielded 100 MHz bandwidth records of ±40 db dynamic range of approximately 25 ?sec duration but required synchronization of the event to the rotating mirror camera of the recorder. Normalization of data required digital computer processing of densitometer conversion of film density data to analog electrical signal. An improvement of the original system, which permits continuous recording up to several minutes at 100 Mbit digital writing solves the major shortcomings of the analog recorder. Using techniques of signal conditioning and laser beam splitting and modulation of the previous system, the data stream is split into four channels recorded simultaneously and continuously on moving 70 mm film in a four-to-one interlace pattern. Each channel is organized into discrete blocks with data synchronizing words to provide block and timing identification. The physical arrangement of the recorder is such that film readout is effected on the same transport deck. Simultaneously scanned data tracks generate a parallel serial data train which is buffered, multiplexed, and recombined to produce the serial data stream.
Side information generation in Distributed Video Coding using selective DC coefficients

The quality of Side Information determines the performance of the DVC coder. The technique of generating Side Information using only available decoded key frames at decoder offers acceptable result for video sequences with low and medium level of motion. However, for complex and high motion sequences, sending some additional “hint” information from encoder for selective blocks is necessary. This paper proposes a new framework for Distributed Video Coding using selective DC information at the encoder to assist the side information generation at the decoder. This scheme offers higher rate distortion performance for sequences with complex and high motion without adding significant complexity to the encoder.
Envelope-domain time series (ET) behavioral model of a Doherty RF power amplifier for system design

In this paper, we present an envelope-domain behavioral model of a high-power RF amplifier. In this modeling approach, we use the signal envelope information, and the behavioral model is generated using an established nonlinear time-series approach to create a time-domain model that operates in the envelope or signal domain. We have generated a model of a 200-W Doherty amplifier from measured IQ data taken using a wideband code-division multiple-access excitation; the amplifier was driven from the linear regime into saturation. The time-series model was created using a time-delay embedding identified from auto-mutual information analysis, and an artificial neural network was used to fit the multivariate transfer function. The model has been validated using measured and simulated data, and it has been used in the development of a system-level design of a digital pre-distorter
Building Novel VHF-Based Wireless Sensor Networks for the Internet of Marine Things

Traditional marine monitoring systems such as oceanographic and hydrographic research vessels use either wireless sensor networks with a limited coverage, or expensive satellite communication that is not suitable for small and mid-sized vessels. This paper proposes a novel Internet of Marine Things data acquisition and cartography system in the marine environment using Very High Frequency (VHF) available on the majority of ships. The proposed system is equipped with many sensors such as sea depth, temperature, wind speed and direction, and the collected data is sent to 5G edge cloudlets connected to sink/base station nodes on shore. The sensory data is ultimately aggregated at a central cloud on the internet to produce up to date cartography systems. Several observations and obstacles unique to the marine environment have been discussed and feed into the solutions presented. The impact of marine sparsity on the network is examined and a novel hybrid Mobile Ad-hoc/Delay Tolerant routing protocol is proposed to switch automatically between Mobile Ad-hoc Network and Delay Tolerant Network routing according to the network connectivity. The low rate data transmission offered by VHF radio has been investigated in terms of the network bottlenecks and the data collection rate achievable near the sinks. A data synchronization and transmission approach has also been proposed at the 5G network core using Information Centric Networks.
Use Of Noninvasive Bioelectric Impedance To Predict Cardiac Output After Open Heart Surgery

Ten stable male non-ventilated coronary artery bypass patients (mean age 59 f 12 years) were comparatively studied with thermodilution (T.D.) and bioelectric impedance (Z) 24-48 hrs. post surgery, in the Open Heart Recovery (OHR) Unit. Cardiac outputs (CO) were compared, after blinded measurements were obtained in three sequential positions (supine, 45 degree head-up tilt and supine). (Z) cardiac outputs were compared to (T.D.) using the actual value for resistivity @) of blood (sampled at the time of the study) and assumed values of 135.5 ohm-an and 150 ohm-an. The results indicate high correlations (range = .W to 99) in the initial supine position for all resistivity conditions followed by a progressive dedine when body position is changed to 45 degrees and supine (range = .74 to 30). The highest overall correlations and closest mean CO values were obtained when (p) was measured. Signifcant (p<.02) mean differences between 2 and T.D. were observed when (p) was assumed to be 150 ohm-cm. In this spedic group of patients, impedance CO is highly correlated to T.D. CO with mean values not significantly different when (p) is measured or assumed to be 135.5 ohm-cm, yet absolute mean values are closest when (p) is not assumed.
Experimental comparison of reduced update Kalman filters and Wiener filters for two-dimensional LMMSE estimation

This paper compares the steady-state reduced update Kalman filter to the unrealizable Wiener filter for the two-dimensional LMMSE estimation of imaqes and random fields. The comparison is composed of three parts: experimental MSE performance, subjective quality of the estimates, and computational complexity. The performance comparison is conducted on both real and synthetic image data. The Wiener filters are designed using both estimated power density spectra and the AR models necessary for the Kalman filter. These AR models are determined using 2-D linear prediction techniques on real image data. The computational comparison considers both multiplies and adds as well as amount and type of required memory.
Stability of DPCM Coders for Television

In digital pulse-code modulation (DPCM) transmission of pictures, often a two-dimensional (2-D) predictor is considered for use in the feedback loop. This paper considers the problem of stability of this 2-D recursive filter. It is assumed the predictor is designed to minimize the mean-square error over the space of all linear predictors. For positive definite correlation arrays it is shown that the first-order recursive filter which uses the previous element in the same row and column can be unstable. It is also shown that the bilinear recursive filter which uses the three nearest neighbors to the left and above may be unstable. When the correlation function of the data is isotropic, it is shown that stability follows for these two classes of filters.
An experimental investigation of labeling efficiency for pseudo-continuous arterial spin labeling

Cerebral blood flow (CBF) is an important physiological metric of neurovascular health that can be measured non-invasively using Arterial Spin Labeling (ASL) MRI. Labeling efficiency (LE) refers to the percentage of the blood spins recruited for the flow estimation and is a crucial parameter for ASL quantification. Traditionally, a labeling efficiency of 0.85 is assumed based on Bloch simulations of spins moving across the labeling plane at laminar, constant physiological velocities. In practice, however, LE is highly dependent on blood velocities, which vary across the cardiac cycle and across the vessel. Here, Bloch simulations for LE estimation were performed using time-varying velocities (TVV). The agreement between ASL and phase contrast (PC) CBF estimates were compared under three conditions: a) an assumed LE of 0.85, b) LE calculated using the average velocity in the vessel, and c) LE calculated using TVV profiles. Using an assumed labeling efficiency, ASL underestimated PC by 15.6±4.4 ml/100g/min, p<0.003. This bias was eliminated by both velocity correction techniques. The use of TVV yielded systemically higher flows than the average velocity correction (−3.6±3.1 ml/100g/min, p<0.276) as well as the lowest bias with respect to PC (−0.9 ± 3.01 ml/100g/min, p=0.777). Velocity correction is an important procedure in ASL quantification, particularly in populations such as children and anemic subjects where blood flow velocity is highly variable.