nils-herrmann/clean_scirepeval huggingface dataset:
A comparison of two-tone intermodulation experiments with CHRISTINE 1D helix TWT code simulations

CHRISTINE is a 1D nonlinear parametric helix TWT code that can accept multiple-carrier inputs and can accurately simulate the performance of the TWT including the effects of harmonic interaction and intermodulation distortion. To test the multi-frequency capabilities of the code and the accuracy of an improved tape helix model, a series of two-tone experiments was carried out with a Hughes 8537B TWT, a periodic permanent magnet (PPM) focused helix TWT designed to produce a nominal 80-W of saturated output power over a frequency range of 1.530 to 1.548 GHz. The CHRISTINE simulations were also compared with an empirical multi-frequency model based power series fit to a single-carrier gain transfer curve.
Defining optical injector parameters for optimal acceleration bunches

This paper presents a methodology for defining an optimal initial electron energy distribution, in conjunction with the details of the LWFA to be used, in order to provided a specified accelerated electron bunch distribution. For instance, for a given laser power and accelerating plasma density a specific approximate Hamiltonian function can be identified. Given this Hamiltonian and a desired distribution for the energy spread and phase for the accelerated electrons, an initial energy distribution and phase for the electrons can be identified. These initial conditions can be used to deduce an optimal effective temperature and bunch length for the optical injection beam. Results of both analytic analysis and simulations will be presented and implications for planned LWFA experiments and NRL will be discussed.
Distribution automation leading to a smarter grid

In the delivery of electricity from the generating station to the consumers, Power Distribution System (PDS) plays a major role. Electric power utilities worldwide are adopting the computer aided monitoring, control and management of PDS to provide better services to the consumers. Recent advances in Information Technology and data communication system are being utilized to automate the electric PDS. The next-generation electricity grid, which is the smart grid, is addressing the major shortcomings of the existing grid. In essence, the smart grid envisages providing utility companies with full visibility and control over their assets and services. This paper presents a review of automation of the Power systems with special emphasis on distribution automation, leading to a smarter grid. The distribution automation and distribution management system functions are discussed in detail and the emergence of a smart grid. The wide area monitoring and control implementation in the transmission sector is also touched upon. The paper also provides some insight into the expansion of laboratory facilities for smart grid implementation and research.
Adaptive neighbor connection for PRMs: A natural fit for heterogeneous environments and parallelism

Probabilistic Roadmap Methods (PRMs) are widely used motion planning methods that sample robot configurations (nodes) and connect them to form a graph (roadmap) containing feasible trajectories. Many PRM variants propose different strategies for each of the steps and choosing among them is problem dependent. Planning in heterogeneous environments and/or on parallel machines necessitates dividing the problem into regions where these choices have to be made for each one. Hand-selecting the best method for each region becomes infeasible. In particular, there are many ways to select connection candidates, and choosing the appropriate strategy is input dependent. In this paper, we present a general connection framework that adaptively selects a neighbor finding strategy from a candidate set of options. Our framework learns which strategy to use by examining their success rates and costs. It frees the user of the burden of selecting the best strategy and allows the selection to change over time. We perform experiments on rigid bodies of varying geometry and articulated linkages up to 37 degrees of freedom. Our results show that strategy performance is indeed problem/region dependent, and our adaptive method harnesses their strengths. Over all problems studied, our method differs the least from manual selection of the best method, and if one were to manually select a single method across all problems, the performance can be quite poor. Our method is able to adapt to changing sampling density and learns different strategies for each region when the problem is partitioned for parallelism.
Coding of Multilevel Graphics

In this paper we consider the digitization and coding of graphics, specifically typewritten letters, and make two contributions. The first contribution concerns the tradeoff between resolution and number of gray levels. We carried out subjective tests which showed that, in order to get better image quality at a given bit rate, for good-quality originals, one should use only two levels/sample and higher resolution; while for poor-quality originals, one should use more levels/sample. Second, we estimated the bit rates achievable when bit-plane run length coding is applied to the multilevel images.
A low power 72.8 GHz static frequency divider implemented in AlInAs/InGaAs HBT IC technology

We report a 72.8 GHz fully static frequency divider in AlInAs/InGaAs HBT IC technology. The CML divider operates with a 350 mV logic swing at less than 0 dBm input power up to a maximum clock rate of 63 GHz and requires 86 dBm of input power at the minimum clock rate of 72.8 GHz. Power dissipation per flip-flop is 55 mW with a 3.1 V power supply. To our knowledge this is the highest frequency of operation for a static divider in any technology. The power-delay product of 94 fJ/gate is also the lowest power-delay product for a circuit operating above 50 GHz in any technology. A low power divider on the same substrate operates at 36 GHz with 6.9 mW of dissipated power per flip-flop with a 3.1 V supply. The power delay of 24 fJ/gate is, to our knowledge, the lowest power delay product for a static divider operating above 30 GHz in any technology.
Cluster-based analysis of 3D MIMO channel measurement in an urban environment

Massive MIMO (multiple - input - multiple - output) and full-dimensional MIMO systems in next-generation cellular communications systems as well as high-data-rate military systems have garnered considerable attention recently. For the assessment of their performance, knowledge of the 3D propagation channel characteristics, i.e., azimuth and elevation of the multipath components (MPCs) is essential. In this paper, we present first results of a 3D outdoor propagation channel measurement campaign performed in an urban macro-cellular environment. The measurements were performed with a 20 MHz wideband polarimetric MIMO channel sounder centered at 2.53 GHz. At each measurement location, parameters of all MPCs observed were extracted with RIMAX, an iterative maximum likelihood high-resolution algorithm. It was observed that MPCs naturally grouped into clusters. We then present a cluster-based analysis of the propagation channel providing some results of the intra and inter cluster parameters and their relevant statistics. Correlation between all extracted cluster parameters are also provided. Parameters such as elevation and azimuth spread (at the base-station) in this work have been used as input to recent international channel model standardization.
Database integration and visualization of maps of the human genome using the GnomeView interface

GnomeView is a graphical user interface to information generated by the Human Genome Project. Its central data organization and conceptual themes are pictorial representations of genomic maps. The methods used to preserve pictorial representations and achieve database integration are presented here. The current version of GnomeView is a database browser and integration tool for two major genomic databases: GDB (Genome Data Base), which provides chromosome data, and GenBank, which provides DNA sequence data. GnomeView is presently undergoing extended beta testing.<<ETX>>
Discriminative local binary patterns for human detection in personal album

In recent years, local pattern based object detection and recognition have attracted increasing interest in computer vision research community. However, to our best knowledge no previous work has focused on utilizing local patterns for the task of human detection. In this paper we develop a novel human detection system in personal albums based on LBP (local binary pattern) descriptor. Firstly we review the existing gradient based local features widely used in human detection, analyze their limitations and argue that LBP is more discriminative. Secondly, original LBP descriptor does not suit the human detecting problem well due to its high complexity and lack of semantic consistency, thus we propose two variants of LBP: Semantic-LBP and Fourier-LBP. Carefully designed experiments demonstrate the superiority of LBP over other traditional features for human detection. Especially we adopt a random ensemble algorithm for better comparison between different descriptors. All experiments are conducted on INRIA human database.
Design and implementation of a fuzzy controller based automatic voltage regulator for a synchronous generator

Fuzzy controllers are increasingly being accepted by engineers and scientists alike as a viable alternative for classical controllers. The processes involved in fuzzy controllers closely imitate human control processes. Human responses to stimuli are not governed by transfer functions and neither are those from fuzzy controllers. This study involves the design and application of fuzzy control to the problem of automatic voltage regulation of a synchronous generator. The method explored deals with the use of binary input-output fuzzy associative memories for control. Error and rate of change of voltage are used to maintain a constant output voltage. Software routines were written in the 'C' language and were fast enough for real time computer control. The fuzzy controller was implemented in an IBM compatible personal computer to control an industrial size 5 kVA synchronous machine.
Automatic temporal pattern extraction and association

This paper proposes an approach for automatic temporal pattern extraction from a temporal sequence, whose signal samples suffer from noise and non-linear temporal warping. The patterns are recurrent signal segments in the original temporal sequence with respect to some criteria defined by the user. We use Threshold hidden Markov model (THMM) to model the signal sequence. A variance of the Segmental K-means algorithm is used to train the THMM The trained THMM can be used to detect the pattern in the temporal sequence. We apply the proposed approach to automatically analyze multiple synchronized temporal sequences from several input modalities. The timing information of the extracted patterns is used to learn the correlation across multiple modalities, which leads to automatic concept learning.
A 2.4GHz ambient RF energy harvesting system with −20dBm minimum input power and NiMH battery storage

We describe a radio frequency (RF) energy harvester and power management circuit that trickle charges a battery from incident power levels as low as -20dBm. We designed the harvester for the 2.4 GHz RF band to leverage the ubiquity of energy that is produced by Wi-Fi, Bluetooth, and other devices. This paper reports on the design and current status of the harvester and compares our performance to other published results. In this incident power regime, rectified voltages are low, so power management circuit operation in the 100mV regime is critical. This paper describes a novel rectenna design, boost converter, and battery charger for RF energy harvesting specifically tuned to this low-power regime. At -20dBm RF input power, the harvesting system (rectenna, boost converter, and battery charger) sources 5.8μJ into a rechargeable battery after 1 hour.
A simulation study on space-time equalization for mobile broadband communication in an industrial indoor environment

Linear space-time equalization is shown to be effective in coping with the complicated propagation conditions for wireless broadband communication in an industrial indoor environment. This is demonstrated by realistic simulations that use real channel measurement data obtained from a vector channel sounder for modeling the influence of the radio channel. The system parameters are similar to the HIPERLAN/1 standard of the ETSI with a data rate of about 24 Msym/s and a carrier frequency of 5.2 GHz.
A Three-Phase High-Frequency Semicontrolled Rectifier for PM WECS

This paper proposes the use of a three-phase high-frequency semicontrolled rectifier for wind energy conversion systems based on permanent magnet generators. The main advantages of the topology are: simplicity, since all active switches are connected to a common point, robustness, as short-circuit through a leg is not possible, and high efficiency due to reduced number of elements. As a disadvantage, higher but acceptable total harmonic distortion of the generator currents results. The complete operation of the converter and theoretical analysis are presented. Additionally, a single-phase pulsewidth modulation inverter is also employed in the grid connection. Experimental results on 5-kW prototype are presented and discussed.
A fused hidden Markov model with application to bimodal speech processing

This paper presents a novel fused hidden Markov model (fused HMM) for integrating tightly coupled time series, such as audio and visual features of speech. In this model, the time series are first modeled by two conventional HMMs separately. The resulting HMMs are then fused together using a probabilistic fusion model, which is optimal according to the maximum entropy principle and a maximum mutual information criterion. Simulations and bimodal speaker verification experiments show that the proposed model can significantly reduce the recognition errors in noiseless or noisy environments.
Accurate Head Pose Tracking in Low Resolution Video

Estimating 3D head poses accurately in low resolution video is a challenging vision task because it is difficult to find continuous one-to-one mapping from person-independent low resolution visual representation to head pose parameters. We propose to track head poses by modeling the shape-free facial textures acquired from the video with subspace learning techniques. In particular, we propose to model the facial appearance variations online by incremental weighted PCA subspace with forgetting mechanism, and we do the tracking in an annealed particle filtering framework. Experiments show that, the tracking accuracy of our approach outperforms past visual face tracking algorithms especially in low resolution videos
Coherent Synchrotron Radiation from an Electron Beam in a Curved Waveguide

The radiation emitted by a pulsed electron beam as it travels on a circular trajectory inside a waveguide is calculated using a 3D simulation. Forward-propagating wave equations for the fields in the waveguide are calculated by a perturbation of the Maxwell equations where the radius of curvature is large compared to the dimensions of the waveguide. These are integrated self-consistently with the distribution of charge in the beam to provide the complete fields (electric and magnetic) for all times during the passage of the beam through the waveguide and therefore are applicable to sections of any length or combinations thereof. The distribution of electrons and their momentum are also modified self-consistently so that the results may be used to estimate the effect of the radiation on the beam quality (emittance and energy spread).
Commercial and industrial applications getting ready for direct-current power distribution

This paper describes design trends in several classes of power-electronic appliances that will increase the appeal for distributing DC power in buildings. In the commercial sector information technology (IT) power conversion architectures are moving from multi to single-voltage supplies, initially 12 Vdc and evolving toward 48 Vdc. These changes apply to both data processing and Internet server equipment. For motor loads, adjustable speed drives (ASDs) are increasingly common in industrial settings as well as modern commercial buildings. Since these motor drives operate with a 200 to 700 V dc-link they are good candidates for direct DC power. In fact, drives are also beginning to appear in single-phase residential appliances and offer opportunities for direct integration with DC from photovoltaic systems or fuel cells. This paper reviews basic design considerations and energy savings potential for operating these appliances directly from DC distribution.
Design of VR headset using augmented reality

Our intention is to develop an android application that gives the users a virtual environment with the help of VR headset. With this application, it allows users to generate an object which doesn't exist in real environment. In Augmented Reality (AR), the interfaces comprises of merging both real and virtual objects. In this project we examine existing gaming styles that are played in the real world or on computers. With the help of advanced AR technology the information about the real world that surrounds the user becomes interactive and digitally manipulable. Artificial information about the environment and its objects can thus be overlaid on the real world. A key distinction to VR purists is the fact that the user is completely immersed in the computer simulation. All our senses are focused on visiting this new place. It provides the following features i.e. Full field of vision display, usually produced by the wearing of a Head Mounted Display, tracking of the location and attitude of the contributor's body, computer tracking of the participant's movements and actions along with some negligible delay in updating the display with feedback from the body's movements and actions. This enables users to visualize what if an object an object actually exists there without its actual existence.
Ergonomics in control centre design for power system

The control centre in a SCADA set up is the place from where the operator/system engineer monitors the health of the power system and issues necessary control instructions. The operator/system engineer at the control centre undergoes a variety of muscular stresses while working for long durations, which degrades the quality of work. The proper design of the control center will ensure ease of functioning for the operator without experiencing stress in vital body parts. Care should be taken to install the different equipment for monitoring and controlling the power system in suitable atmosphere and housing. Hence, the authors in this paper have given emphasis on the various aspects of the ergonomics in designing the control room and housing rooms in the control centre for the power system
A framework for region-based instrumentation of energy consumption of program executions

Energy efficiency has become a key issue in computer science related research and development over the last years. While most approaches focus either on hardware or on software, we propose a solution incorporating both hardware and software enabling the measurement the energy consumption of code segments executed on physical machines. Our novel approach to energy measurement and instrumentation allows for both state-of-the-art offline analysis, and innovative online measurements associated with the code being executed. We present our modular architecture which shields the users from in-depth knowledge of their energy measurement hardware, and allows the development of code for measurement and instrumentation independent of each instruments' proprietary interface. Finally, we propose an efficient method for increasing the accuracy of measurements for low sampling rate measurement devices.
A Dynamic Code Division Multiple Access Algorithm for Time Acquisition of FH-MFSK Satellite Communication Systems

A code division multiple-access (CDMA) algorithm is presented for uplink coarse time acquisition for satellite communication systems which use frequency-hopped M-ary FSK signalling with onboard processing. The algorithm is based on self-probing, and it allows independent acquisition by large numbers of users on a multiple access basis. This new algorithm is extremely fast under light loading conditions when compared to the typical approach. Also, it is very efficient compared to perfect preassignment over the full range of loading conditions from light to very heavy loading. The algorithm requires minimal processing by one user and no coordinated action by other users, and it is highly resistant to degradation by downlink channel errors or fading. The performance is evaluated by analysis and verified through Monte Carlo simulations.
Electrical fault protection for a large photovoltaic power plant inverter

The authors analyze the original protection design and describe changes made to improve fault protection after electrical faults caused fires in the DC wiring of a photovoltaic (PV) power plant. The zone-of-protection was extended, and fault detection and response were improved. The results suggest a need for better coordination between DC and AC fault protection philosophies that are commonly applied independently by designers. Design lessons for PV array fault protection are described to assist electrical designers in eliminating fault vulnerabilities from future PV systems. These take into account the unique electrical characteristics of PV generators, including the dispersed-rather than point-source and the current- rather than voltage-source nature of the PV array.<<ETX>>
60 GHz Ultrawideband Polarimetric MIMO Sensing for Wireless Multi-Gigabit and Radar

Polarimetric radio wave processing becomes of increasing interest for very high-data rate wireless transmission and for short-range radar at millimeter-waves (mm-W). This goes along with the huge bandwidth of 7 to 9 GHz, which is available worldwide in the 60 GHz unlicensed band. In this paper, we propose a 60 GHz ultra-wideband (UWB) polarimetric multiple-input-multiple-output (MIMO) sensing system architecture and polarimetric signal processing for short-range communications and radar. Demonstration measurements were made by using an UWB radar interface. By measurements in multipath rich environments it is demonstrated that tap-wise polarimetric filtering in delay domain can enhance the 60 GHz link budget by filtering some paths and then reducing shadowing due to human activity. Additionally, optimum MIMO polarimetric filtering is proposed to reduce heavy clutter for mm-W radar, increasing by about 30 dB the signal-to-clutter-plus-noise-ratio.
A two-dimensional edge detection scheme for general visual processing

This paper presents a new two-dimensional (2D) edge detection scheme for general visual processing. The scheme constructs a 2D edge detection functional under the guidance of the Laplacian of Gaussian (LOG) zero crossing contours to detect edges. The detection functional is optimal in terms of signal-to-noise ratio (SNR) and edge localization accuracy (ELA) for detecting edges in 2D images; it also preserves the nice scaling property that is held uniquely by the LOG operator in scale space. The scheme also provides: (1) an edge regularization procedure; (2) an adaptive edge thresholding procedure; and (3) a scale space combining procedure. Experimental results on real images are given in the paper.