nils-herrmann/clean_scirepeval huggingface dataset:
A Comparison of Virtualization Technologies for HPC

Virtualization is a common strategy for improving the utilization of existing computing resources, particularly within data centers. However, its use for high performance computing (HPC) applications is currently limited despite its potential for both improving resource utilization as well as providing resource guarantees to its users. This paper systematically evaluates various VMs for computationally intensive HPC applications using various standard benchmarks. Using VMWare Server, xen, and OpenVZ we examine the suitability of full virtualization, paravirtualization, and operating system-level virtualization in terms of network utilization SMP performance, file system performance, and MPI scalability. We show that the operating system-level virtualization provided by OpenVZ provides the best overall performance, particularly for MPI scalability.
A non-resampling sequential monte carlo detector for coded OFDM systems based on periodic termination of differential phase trellis

Sequential Monte Carlo (SMC) is a group of methods that use Monte Carlo simulation to solve online estimation problems in dynamic systems. SMC methods are traditionally built on the techniques of sequential importance sampling (SIS) and resampling. In this paper, we apply the SMC methodology to the problem of symbol detection in a differentially encoded orthogonal frequency division multiplexing (OFDM) system over a frequency selective fading channel. We first propose the periodical termination of differential phase trellis at predetermined indices. It is seen that accelerated weight degeneracy and impoverished trajectory diversity - problems that are encountered in traditional SMC methods - are mitigated. Using these observations, a novel SMC framework that circumvents resampling is then developed. The effect of varying termination periods on the performance of the non-resampling detector is investigated. We also present results which show that periodic termination helps to retard weight degeneracy. The performance of traditional and non-resampling SMC detectors for a convolutional-coded OFDM system is compared and simulation results suggest that the non-resampling detector performs better than its traditional counterpart. We also consider a low-density parity check (LDPC)-coded OFDM system and simulation results suggest the near bound performance of the proposed non-resampling SMC detector
Application of Adaptive VAr Compensator for Transmission System Flicker Correction

This paper reviews the application of an adaptive var compensator to reduce voltage flicker associated with the stalling of large motors. The ease considered involves the sequential starting of two 1000 hp motors in an across-the-line mode. The motors are served by a 44 kV-4.16 kV dedicated substation. The 44 kV transmission line also serves over 2000 residential and commercial customers through two widely separated 44 kV-12.5 kV substations. Several methods of reducing flicker were considered. Customer complaints associated with voltage excursions during motor starting were successfully resolved
Copper Via Plating in Three Dimensional Interconnects

This paper describes the development of deep via plating in silicon substrates. Straight walled and tapered vias were plated through photoresist openings usually with bumps plated on top of via. In the second section similar vias were completely or partly filled, in process called "barrel" plating, in the absence of photoresist. The latter process turned out to be more challenging as flat wafer surface strongly competes with vias for current. Tapered vias are flared at the top, making it easier to sputter a base metal and plate with copper without creating seam or pinch off effects. In straight vias, the copper fill was more difficult and overcoming pinch off effect more challenging. Different current waveforms were used for each via shape shown. The changing geometry of gradually filled vias also required multiple steps during each plating process. Three current modes were applied including straight DC, pulse DC, and periodic reverse pulse current.
Analysis of coupling characteristics of coplanar waveguides and microstrip lines to multi-layer dielectric media

The spectral domain technique is used to analyze the coupling characteristics of coplanar waveguide and microstrip lines to highly lossy multilayer dielectric media. The possibility of exciting surface waves and hence generating and coupling nontransverse electric field components is also investigated. It is shown that surface waves will not be excited in the substrate when a high-dielectric lossy media is placed on top of the coplanar structure. In the presence of a superstrate between a high-dielectric lossy medium and the coplanar waveguide, however, the quasi-static TEM and TM/sub 0/ modes may be excited. An axial electric field component can then be coupled to the loss medium. The developed solution was also utilized to optimize the coupling performance of these structures to lossy dielectric media. It is shown that to enhance the EM coupling, higher frequencies should be used, the dielectric constant of the substrate should be small, and the width of the center conductor and the air gaps in a coplanar waveguide should be as large as possible.<<ETX>>
Design challenges in the high volume manufacturing of millimeter-wave transceivers

Millimeter-wave transceivers are the critical component needed for the today's expanding fixed wireless multipoint applications. The design and fabrication, in high volume, of these transceiver units presents many challenges. Procurement of thousands of units demands a very robust, low cost design that can simultaneously meet the system requirements. The digital modulation format of modern communication systems demands better transmitter and receiver performance in the areas of linearity, phase noise, spurious emissions and amplitude flatness. Design parameters such as linearity and spurious responses are second or third order effects that are difficult to predict and control. Production of large quantities of units will result in a wide Gaussian distribution of performance which demands large margins relative to the specifications to maintain high test yields. Individual tuning of each unit would be time consuming and uneconomical. Potential design solutions to these issues are discussed along with the cost tradeoffs inherent in the different designs.
A first generation Mutually-Immersive Mobile Telepresence surrogate with automatic backtracking

Mutually-immersive mobile telepresence uses a teleoperated robotic surrogate to visit remote locations as a substitute for physical travel. Our goal is to recreate to the greatest extent practical, both for the user and the people at the remote location, the sensory experience relevant for business interactions of the user actually being in the remote location. The system includes multi-channel bidirectional video and audio on a mobile platform as well as haptic feedback. The user-controlled surrogate can autonomously backtrack along the path it has previously been driven if it loses wireless connectivity.
Bregman distance to L1 regularized logistic regression

In this work we investigate the relationship between Bregman distances and regularized logistic regression model. We convert L1-regularized logistic regression (LR) into more general Bregman divergence framework and propose a primal-dual method based algorithm for learning the parameters of the model. The proposed method utilizes L1 regularization to incorporate parameter sparsity into the divergence minimization scheme. We perform tests on public domain data sets and produce results which are amongst the best reported.
Array measurement of the double-directional mobile radio channel

We describe a novel technique to measure the double-directional mobile radio channel. The channel is called double-directional since it includes directional spreading at both link ends, namely the base station and the mobile station. We use a double-array multiplexing technique consisting of a switched linear array at the receiver and a virtual array at the transmitter site. The measured microcellular scenarios are an open and a closed courtyard with different transmitter positions. The data are evaluated with an alternating estimation and beamforming technique that relies on (Unitary) ESPRIT estimation of positional parameters and subsequent beamforming for complex weight extraction. Usage of a two-axis crossed array at the transmitter site avoids forward-backward ambiguity. The presented exemplary results show a good agreement of the extracted directional information with the physical environment and give an indication of its scattering properties.
Combined audio and video watermarking using mel-frequency cepstra

Digital watermarking is a promising technique to help protect the data security and intellectual property right. In this paper a combined audio and video watermarking technique is proposed. Content-dependent information is extracted from the audio signal. The extraction uses a well-known feature set for audio, the melfrequency cepstra. The information is encoded and embedded into the video. The algorithm can be applied to the content authentication of audiovisual data in journalism, commerce and law.
Electromagnetic properties of corrugated and smooth waveguides filled with radially inhomogeneous plasma

The creation and diagnosis of plasma in high power microwave devices remains one of the primary challenges of plasma microwave electronics. In the present work we deal with (a) diagnostics techniques for characterization of radially nonuniform plasma columns suitable for use in high power microwave sources and (b) the effects of such plasmas on the electromagnetic properties of finite length, spatially periodic slow wave structures. Experimental studies were performed both for a strong and weak guiding magnetic field. A single Langmuir probe technique cannot be used alone for precise characterization of magnetized plasma columns, especially for measurements of the electron plasma density. However, using a combination of a novel cylindrical resonant cavity technique supported by accurate numerical calculations of the plasma influence on cavity resonances of a long, thin plasma, column we were able to characterize pulsed plasma columns. The peak density (higher than 10/sup 12/ cm/sup -3/) and the spatial distributions (transverse and axial) of the plasma was measured as a function of the applied magnetic field (2 to 10 KG) and the plasma gun operating conditions. By applying a combined probe-microwave resonator (X band) technique to plasma-filled, open, corrugated cavities we were able to measure in situ for the first time the complete dispersion curve of the TM/sub 01n/ modes of a plasma-loaded, finite length, corrugated cavities immersed in guiding magnetic field.
A Dynamic Slew Correction Circuit for Low Noise Silicon Detector Pre-amplifiers

This manuscript introduces a transistor level technique that results in simultaneous improved slew rate and noise performance for applications where only the final settled output voltage over a predefined time frame is important - such as silicon detector read out charge-to-voltage reset amplifiers. For large signal swings, slew limitation is detected and compensated dynamically. For non-slew limiting situations the amplifier operates normally in a low noise mode. To verify correct operation of the dynamic slew correction circuit, a single-ended, pulse-reset charge amplifier was fabricated in IBM 130 nm 6M/2P technology. The test amplifier achieved a slew rate of 1V/120 ns with a 50 pF load and a total of ~ 23μVrms noise over 100 kHz-20 MHz. The reported amplifier also serves as the basis for the high performance front-end amplifier in the LPD detector system for the European XFEL.
A Drifting-proof Framework for Tracking and Online Appearance Learning

In order to avoid the notorious drifting problem for tracking system, a new integrated appearance learning framework is proposed in this paper. Previous tracking frameworks with appearance learning ability (Black, et al., 1998) either require supervised offline training or will fail inevitably if the tracker locks on the background. While in our framework, no offline training is required. Given the location of the object in the first frame of the video sequence, we model the foreground (the image patch containing the object)/background difference as the transition cost in our tracking objective function. A tracker based on dynamic programming (DP) and template prediction (Toyama, et al., 2001) is carried out on the pixels with high foreground-likelihood. The typical views (i.e. appearance model) proposed by the tracker are used to initialize the states of a hidden Markov model (HMM). With the learned HMM, the tracking results and the appearance model can be further refined until the video sequence and all of these estimated parameters/hidden variables can be well explained by the HMM. Through this iterative procedure, typical views of the object, transition probabilities between the typical views, and location of the object are simultaneously estimated with strong confidence. The experiments show that the proposed framework achieves fairly satisfied results for several challenging video sequences and therefore has many potential applications for video analysis
A Methodology for Non-Invasive 3-D Surveillance of Arteriovenous Fistulae Using Freehand Ultrasound

Surveillance techniques for arteriovenous fistulae are required to maintain functional vascular access, with two-dimensional duplex ultrasound the most widely used imaging modality. This paper presents a surveillance method for an arteriovenous fistula using a freehand three-dimensional (3-D) ultrasound system. A patient-case study highlights the applicability in a clinical environment.  The freehand ultrasound system uses optical tracking to determine the vascular probe location, and as the probe is swept down a patient's arm, each B-mode slice is spatially arranged to be post-processed as a volume. The volume is segmented to obtain the 3-D vasculature for high detail analysis.  The results follow a patient with stenosis, undergoing surgery to have a stent placement. A surveillance scan was taken pre-surgery, postsurgery, and at a two-month follow-up. Vasculature changes are quantified using detailed analysis, and the benefits of using 3-D imaging are shown through 3-D printing and visualization. D surveillance of arteriovenous fistulae is possible, and a patient-specific geometry was created using ultrasound and optical tracking. Access to this non-invasive 3-D surveillance technique will enable future studies to determine patient-specific remodeling behavior, in terms of geometry and hemodynamics over time.
Conformational defects in high-strain, electrostrictive polymers

Alternative methodologies are sought whereby high-strain electrostrictive polymer can be generated without the need of electron-beam irradiation, which is expensive and difficult to reproduce. One of these alternative approaches has been the use of chlorinated P(VDF-TrFE) copolymers, which in the present paper are subsequently referred to as "terpolymers". To be converted into high-strain electrostrictive films, terpolymers do not need to be irradiated, a significant advantage. Like P(VDF-TrFE), the terpolymers retain considerable polarization due to the existence of polar crystalline regions, but these ferroelectric regions are short-range due to the presence of the chlorine atoms, which disrupt the long-range ferroelectric regions. In this paper, we present Fourier transform infrared spectroscopic evidence and computational results that strongly indicate that the chlorine atom does indeed favor formation of disordered crystalline regions.
Active Learning Based on Locally Linear Reconstruction

We consider the active learning problem, which aims to select the most representative points. Out of many existing active learning techniques, optimum experimental design (OED) has received considerable attention recently. The typical OED criteria minimize the variance of the parameter estimates or predicted value. However, these methods see only global euclidean structure, while the local manifold structure is ignored. For example, I-optimal design selects those data points such that other data points can be best approximated by linear combinations of all the selected points. In this paper, we propose a novel active learning algorithm which takes into account the local structure of the data space. That is, each data point should be approximated by the linear combination of only its neighbors. Given the local reconstruction coefficients for every data point and the coordinates of the selected points, a transductive learning algorithm called Locally Linear Reconstruction (LLR) is proposed to reconstruct every other point. The most representative points are thus defined as those whose coordinates can be used to best reconstruct the whole data set. The sequential and convex optimization schemes are also introduced to solve the optimization problem. The experimental results have demonstrated the effectiveness of our proposed method.
Estimation of the Radio Channel Parameters from a Circular Array with Directional Antennas

Channel sounding, channel modeling and their parameter extraction in particular considering MIMO configurations, plays an important role for todays realistic wireless system design and evaluation. The analysis of the gathered channel sounding data has to match the specifics in the measurement system configuration. Within this contribution directional antenna arrays are used at both sides of the measured link. Furthermore, the measurement system applies automatic gain control between subsequent MIMO snapshots and additionally within the MIMO matrix. Both features lead to improved measurement accuracy. A new extension of existing power and delay domain analysis procedures considering the automatic gain control within the MIMO matrix is introduced and evaluated. The results show that delay spread and K-factor are more affected, while shadow fading and cross polarization ratios are almost not.
Emulation of virtual radio environments for realistic end-to-end testing for intelligent traffic systems

We consider two approaches for real-time end-to-end over-the-air testing for intelligent traffic systems using virtual radio environments. One approach is based on coherent wavefield synthesis, while the other aims at emulating the essential features of a realistic radio channel in vehicular ad-hoc networks. Due to finite hardware resources, the former is limited to electrically small systems-under-test, while the latter is suited for typical vehicle-to-vehicle scenarios. Three major aspects of the emulation of radio environments in our facilities in Ilmenau, Germany, are described: 1. Emulation hardware, 2. Channel sounding, modeling, and feature extraction, 3.
Distributed Multi-class Rule Based Classification Using RIPPER

Traditional data mining (DM) has certain challenges viz. Scalability, high dimensionality, distributed data and often it also requires huge amount of computational resources in terms of space and time to extract the hidden patterns in the data. In addition, the data has to be available at one location. But in today's era the data are often inherently distributed in several databases. Hence, due to the limited bandwidth, centralized processing of the data is highly inefficient. Therefore, distributed computing becomes very important for efficient DM, both in terms of space and time. This can be done by developing a mechanism to mine the massive data by applying DM in a non-centralized way that distributes the work load seamlessly among the available sites. Therefore, in this paper, we propose an algorithm distributed multi-class rule based classification (DiRUC) which implements repeated incremental pruning to produce error reduction (RIPPER) at local level and then merges into a global level in a distributed manner. The algorithm first constructs the local rule sets for the distributed data and then at each iteration the local models are sent from one location to other. Finally, the global model is constructed by efficiently merging these local models and is made available at each site for further prediction of the class labels. The performance (accuracy and efficiency) analysis of the algorithm is done for the five data sets with different parameters and the result shows that the proposed approach DiRUC outperforms the normal RIPPER and Ischibuchi et al. island model.
Design and development of a high performance PBGA package for the UltraSPARC-I/sup TM/ processor

This paper describes the development of a 520 terminal Plastic Ball Grid Array (PBGA) package to meet the system level requirements of the UltraSPARC-I/sup TM/ microprocessor. The Printed Circuit Board (PCB) substrate PBGA package developed was designed to handle chip operation above 200 MHz and dissipate 36 watts of power with the assistance of an integral heat sink and airflow. Mechanical stresses, board level reliability, thermal and electrical requirements are outlined. The package enhancements and process refinements executed to meet the design goals and reliability requirements are presented.
Broadband generation of cascaded four-wave mixing products

A new method to efficiently generate broadband cascaded four-wave mixing products is presented. It consists of launching two strong pump waves near the zero-dispersion wavelength of an optical fiber. The obtained bandwidth of Four-Wave Mixing products is width- and wavelength-tunable by adjusting the laser wavelengths and their polarization states. This method has been applied to standard, dispersion-shifted and highly nonlinear fibers (HNLF). The maximum measured bandwidth of 300 nm has been obtained nonlinear fibers by using HNLF.
An analytical model to characterize the input stage of a MOSFET based RF energy harvester for improved impedance matching

RF energy harvesting has been widely investigated as a promising method of providing power to passive wireless devices or recharging the battery used in such systems. The AC input signal which is the ambient RF radiation from the available ISM band is received through the coupled antenna and converted into DC output voltage through the energy harvester chip. The energy harvester, which is a novel resonant boost rectifier circuit, typically consists of multiple stages of voltage doubler stacked in series to achieve a desired output voltage level. In order to achieve maximum rectifier conversion efficiency, it is imperative to have impedance matching between the receiving antenna and the harvester circuit. The input of the harvester is frequently modeled as a resistance in parallel with a capacitance . Therefore, a physical model-based derivation of the equivalent input resistance and capacitance of the rectifier is useful to design an appropriate matching network to resonate out the input capacitance and to match the input resistance to the radiation resistance of the antenna. This paper presents an analytical approach to derive the equivalent input impedance of a multistage voltage doubler circuit designed using short-channel diode-connected MOSFETs.