nils-herrmann/clean_scirepeval huggingface dataset:
Characterization of the rod-pinch diode x-ray source on Cygnus

The rod-pinch diode[1] is a self-magnetically insulated electron beam diode that is capable of producing a very bright source of hard x-rays. As fielded on the Cygnus accelerator[2], the diode operates at an impedance of 50 Ohms and produces short pulse ( ∼50 ns) bremsstrahlung radiation with a 2 MeV photon endpoint energy and dose of 4 rad measured at one meter, with an x-ray spot size ∼ 1mm. The source can be used to image through ∼ 40 g/cm2 of material with spatial resolution of order 300 µm. Recently, a series of experiments on Cygnus have been conducted to better characterize the diode's operation and x-ray output. In particular, the x-ray spectral content, source spot-size, and shot-to-shot reproducibility have been diagnosed. The intent of these experiments is to enable improvements that may extend the diode's radiographic utility. An array of diagnostics have been utilized which include, end-on and side view x-ray pin hole imaging, time resolved and time integrated spot size measurements, step wedges, x-ray p-i-n diodes, and diode/MITL current measurements. High fidelity, PIC/Monte-Carlo simulations have also been conducted to help analyze the data. An overview of these experiments, simulations, and the conclusions from analysis is presented.
Detection and classification of liquid explosives using NMR

In this work, we present a novel method for non-invasive identification of liquids, for instance to allow for the detection of liquid explosives at airports or border controls. The approach is based on a nuclear magnetic resonance technique with an inhomogeneous magnetic field, forming estimates of the liquid's spin-spin relaxation time, T2, and diffusion constant, D, thereby allowing for a unique classification of the liquid. The proposed detectors are evaluated using both simulated and measured data sets.
Adaptive synthesis in progressive retrieval of audio-visual data

With the advent of pervasive computing, a growing diversity of client devices is gaining access to audio-visual content. The increased variability in client device processing power, storage, bandwidth, and server loading require adaptive solutions for image, video and audio retrieval. Progressive retrieval is one prominent mode of access in which views at different resolutions are incrementally retrieved and refined over time. The authors present a framework for adaptively partitioning the synthesis operations in progressive retrieval of audio-visual signals. The framework considers that the server and client cooperate in synthesizing the views in order to best utilize the available processing power and bandwidth. They provide experimental results that demonstrate a significant reduction in latency in the progressive retrieval of images under different conditions of the client, server and network.
Cygnus Diverter Switch Analysis

The Cygnus Dual Beam Radiographic Facility consists of two 2.25-MV, 60-kA, 50-ns X-ray sources fielded in an underground laboratory at the Nevada Test Site. The tests performed in this laboratory invoke study of the dynamic properties of plutonium and are called subcritical experiments, from end-to-end. the Cygnus machines utilize the following components: Marx generator, water-filled pulse-forming line (PFL), water-filled coaxial transmission line, 3-cell inductive voltage adder (IVA), and rod-pinch diode. The upstream coaxial transmission line interface to the PFL is via a radial insulator with coaxial geometry. The downstream coaxial transmission line terminates in a manifold where the center conductor splits into three lines which individually connect to each of the IVA cell inputs. There is an impedance mismatch at this juncture. It is a concern that a reflected pulse due to anomalous behavior in the IVA or diode might initiate breakdown upon arrival at the upstream PFL/coax insulator. Therefore near the beginning of the coaxial transmission line a radial diverter switch is installed to protect the insulator from over voltage and breakdown. The diverter has adjustable gap spacing, and an in-line aqueous-solution (sodium thiosulfate) resistor array for energy dissipation. There are capacitive voltage probes at both ends of the coaxial transmission line and on the diverter switch. These voltage signals will be analyzed to determine diverter performance. Using this analysis the usefulness of the diverter switch is evaluated.
NSLS control monitor and its upgrade

The NSLS Control Monitor is a real-time operating system designed for the microprocessor subsystems that control the machine hardware in the NSLS facility. Its major functions are to control the hardware in response to the commands from the host computers, monitor hardware status and report errors to the alarm handler. The software originally developed for the Multibus micros has been upgraded to run on the VME-based systems. The upgraded monitor provides ethernet communication with the new system and serial link with the old system. The dual link is the key feature for a smooth and nondisruptive transition at all levels of the control system. This paper describes the functions of the various modules of the monitor and future plans.<<ETX>>
Detecting stochastic nuclear quadrupole resonance signals in the presence of strong radio frequency interference

Nuclear quadrupole resonance (NQR) is a radio frequency (RF) spectroscopic technique, allowing the detection of many high explosives and narcotics. In practice, NQR is restricted by the low signal-to-noise ratio of the observed signals, a problem further exacerbated by the presence of strong RF interference (RFI). The current literature focuses on the use of conventional, multiple-pulsed NQR (cNQR) to obtain signals. Here, we investigate an alternative method called stochastic NQR (sNQR), having many advantages over cNQR, one of which is the availability of signal-of-interest free samples. We exploit these samples forming a matched subspace-type detector, able to efficiently reduce the influence of RFI. Further, many of the ideas already developed for cNQR, including providing robustness to uncertainties in the assumed complex amplitudes and exploiting the temperature dependencies of the NQR spectral components, are recast for sNQR. The presented detector is evaluated on both simulated and measured trinitrotoluene (TNT) data.
Measurement of cardiovascular state using attractor reconstruction analysis

Attractor reconstruction (AR) analysis has been used previously to quantify the variability in arterial blood pressure (ABP) signals. Since ABP signals are only available in a minority of clinical scenarios, we sought to determine whether AR could also be performed on more widely available pho-toplethysmogram (PPG) signals. AR analysis was performed on simultaneous ABP and PPG signals before, during and after a change in cardiovascular state. A novel quality metric was used to eliminate windows of low quality AR. A high level of agreement was found between the detected periodicity of each signal. The remaining cardiovascular parameters derived using AR analysis exhibited similar trends between the two signals in response to the change in state, although there was poor agreement between their absolute values. This demonstrates the feasibility of applying AR to the PPG signal, increasing the range of patients in whom cardiovascular state can be measured using AR analysis.
Operation of subsea electrical submersible pumps supplied over extended length cable systems

The special circumstances are considered of an induction motor driven submersible pump supplied from a variable frequency converter which is remote from the pump location, necessitating subsea cables which may be considerably longer than in normal practice. The principal objective of the series of practical tests is to investigate the performance of such systems to evaluate a complete electromechanical system model for use in the prediction of the current and torque requirements of the drive, and to assess the effect of converter switching patterns on the voltage profile of the transmission section. Results of computer studies are presented which are validated by comparison with measurements taken on an ESP system during precommissioning tests. The factors affecting the in-service operational characteristics of the drive are discussed and recommendations made.
Time-current characteristic of miniature zinc-element electric fuses for automotive applications

A theoretical analysis is outlined to determine, for a specified direct current, the pre-arcing opening duration of miniature zinc-element electric fuses used extensively in the automotive industry. The effects of ohmic heating and natural convective cooling are treated using analytical methods. A closed-form solution for the opening duration, as a function of the applied current, is derived. Moreover, an approximation for the high overcurrent condition is determined. The results are compared with published data, derived from experimentation, to show that the model is an accurate representation of the devices under consideration.
Engineering design of cryocondensation pumps for the DIII-D radiative divertor program

A new double-null, slotted divertor configuration will be installed for the DIII-D Radiative Divertor Program at General Atomics in late 1996. Four cryocondensation pumps, three new and one existing, will be part of this new divertor. The purpose of the pumps is to provide plasma density control and to limit the impurities entering the plasma core by providing pumping at each divertor strike point. The three new pumps are based on the design of the existing pump, installed in 1992 as part of the Advanced Divertor Program. The pump continues to operate successfully. The toroidally continuous pumps vary in lengths from approximately 7 to 12 m depending upon their locations within the vessel. Each pump is independently operated and offers on average 0.7 m/sup 2/ of liquid helium-cooled pumping surface. The tubular pumping surface is surrounded concentrically by nitrogen shields and a particle shield of larger diameters. The nitrogen-cooled shields limit the heat flux on the helium surface. The particle shield limits energetic particles from impacting the helium and nitrogen cooled surfaces, preventing the condensed gases on the pump, primarily water, from being released. The new pumps require geometry modifications to the original design. Therefore, extensive modal and dynamic analyses were performed to determine the behavior of these pumps and their helium and nitrogen feed lines during disruption events. Thermal and fluid analyses were also performed to characterize the helium two-phase flow regime in the pumps and their feedlines. A flow testing program was completed to test the change in geometry of the pump feed lines with respect to helium flow stability. The results were compared to the helium thermal and fluid analyses to verify predicted flow regimes and flow stability.
Multimodal information fusion for video concept detection

Video media carries multimodal information including visual, audio, textual data. Considerable research has been focused on utilizing multimodal features for better understanding of video content. However, many problems remain such as how to combine multimodal features and what are the effects of different combinations. In this paper, we propose to find the optimal combination of multimodal information in order to improve the performance of video concept detection using two methods, one is gradient-descent-optimization linear fusion and the other is super-kernel nonlinear fusion. Gradient-descent-optimization linear fusion learns an optimal weighted linear combination of single modalities based on fusing individual kernel matrices with gradient descent techniques. Super-kernel nonlinear fusion trains separate classifiers for single modalities as the first step. Once individual models have been designed, super-kernel nonlinear fusion learns an optimal nonlinear combination of individual models by fusing single-modality classifiers. Our experiments show that both methods improve performance significantly on TREC-Video 2003 benchmarks.
Power supply control and monitoring for the SNS ring and transport system

There are approximately 300 magnet power supplies in the SNS accumulator ring and transport lines. Control and monitoring of the these converters will be primarily accomplished with a new Power Supply Interface and Controller (PSI/PSC) system developed for the SNS project. This PSI/PSC system provides all analog and digital commands and status readbacks in one fiber isolated module. With a maximum rate of 10KHz, the PSI/PSC must be supplimented with higher speed systems for the wide bandwidth pulsed injection supplies, and the even wider bandwidth extraction kickers. This paper describes the implementation of this PSI/PSC system, which was developed through an industry/laboratory collaboration, and the supplimentary equipment used to support the wider bandwidth pulsed supplies.
Cygnus PFL Switch Jitter

The Cygnus Dual Beam Radiographic Facility consists of two identical radiographic sources - Cygnus 1 and Cygnus 2. Each source has the following X-ray output: 1-mm diameter spot size, 4 rad at 1 m, 50-ns Full Width Half Max. The diode pulse has the following electrical specifications: 2.25 MV, 60 kA, 60 ns. This Radiographic Facility is located in an underground tunnel test area at the Nevada Test Site (NTS). The sources were developed to produce high-resolution images on subcritical tests which are performed at NTS. Subcritical tests are single-shot, high-value events. For this application, it is desirable to maintain a high level of reproducibility in source output. The major components of the Cygnus machines are: Marx generator, water-filled pulse- forming line (PFL), water-filled coaxial transmission line, three-cell inductive voltage adder, and rod-pinch diode. A primary source of fluctuation in Cygnus shot-to-shot performance is jitter in breakdown of the main PFL switch, which is a "self-break" switch. The PFL switch breakdown time determines the peak PFL charging voltage, which ultimately affects the diode pulse. Therefore, PFL switch jitter contributes to shot-to-shot variation in source endpoint energy and dose. In this paper we will present PFL switch jitter analysis for both Cygnus machines and give the correlation with diode performance. For this analysis the PFL switch on each machine was maintained at a single gap setting which has been used for the majority of shots at NTS. In addition to this analysis, PFL switch performance for different switch gap settings taken recently will be examined. Lastly, implications of source jitter for radiographic diagnosis of subcritical shots will be discussed.
Application of divertor cryopumping to H-mode density control in DIII-D

In this paper we describe the method and the results of experiments where a unique in-vessel cryopump-baffle system was used to control density of H-mode plasmas. We were able to independently regulate current and density of ELMing H-mode plasmas, each over a range of factor two, end measure the H-mode confinement scaling with plasma density and current. With a modest pumping speed of /spl ap/40 kl/s, particle exhaust rates as high as 2/spl times/10/sup 22/ atom/s/sup -1/ have been observed.
Content transcoding middleware for pervasive geospatial intelligence access

We describe a novel content transcoding middleware for accessing military geospatial intelligence information in real-time. Intelligence information, including maps and location, category and properties of object targets, is adapted for various pervasive devices such as laptop, personal digital assistant (PDA), cellular phone, etc. The middleware is deployed as proxies on the Web using the IBM Websphere Transcoding Publisher (WTP) platform, which facilitates the middleware management. We developed several Java-based plug-ins and Extensible Stylesheet Language (XSL) stylesheets for content transcoding. A prototype has been established and real experiments have demonstrated the effectiveness of this novel middleware.
Complementary energy methods in the computation of electrostatic fields

It is shown how complementary energy methods can be applied to problems involving the calculation of electrostatic fields. The results obtained using such methods provide error bounded solutions to the system energy, and may be compared with those found through application of the conventional finite element method. To illustrate the technique the classical problem of a cylindrical tank, half filled with a charged liquid, is investigated. Comparisons are made on the basis of computer C.P.U. time, and core storage requirements, for a given degree of accuracy in total system energy. The question of local error in primary field quantities is also examined.
Epi-SPIRE: a system for environmental and public health activity monitoring

Health activity monitoring (HAM) has received increasing attention due to the rapid advances of both hardware and software technologies and strong environmental and public health needs. In this paper, we describe the architecture and implementation of the Epi-SPIRE prototype, which is a novel health activity monitoring system that generates alerts from environmental, behavioral, and public health data sources. A model-based approach is used to develop disease and behavior models from multi-modal heterogeneous data sources. Furthermore, a model-based indexing technique has been developed to speed up the data access and retrieval. This system has been successfully applied to various genuine and simulated diseases outbreaks scenarios'.
An Experimental and Computational Study of Electrostatic Fields Arising During the Pumping of Powder into Small Metal and Plastic Containers

Some experimental and computational results obtained during the study of the loading of small metal and plastic containers with electrostatically charged high-density polyethylene powder are described. The powder was charged by pneumatic transport along a polyethylene pipe, and loaded into the containers. The containers were enclosed in a Faraday cage, and the electrostatic field which built up was monitored using field mills; the mirror current to the metal container was also monitored. Measurements were taken with the metal container isolated from ground in one set of runs and earthed in another. Powder characteristics such as particle size distribution and charging tendency were also measured. A mathematical model of the experimental situation was set up, and the finite element method was used to solve the appropriate boundary value problem. Experimental and computational results are compared, and the efficacy of applying computational techniques to such problems is discussed.
Genetic algorithms for adaptive motion planning of an autonomous mobile robot

This paper proposes genetic algorithms (GAs) for path planning and trajectory planning of an autonomous mobile robot. Our GA-based approach has an advantage of adaptivity such that the GAs work even if an environment is time-varying or unknown. Therefore, it is suitable for both off-line and online motion planning. We first present a GA for path planning in a 2D terrain. Simulation results on the performance and adaptivity of the GA on randomly generated terrains are presented. Then, we discuss extensions of the GA for solving both path planning and trajectory planning simultaneously.
Micro electro mechanical switch (MEMS) technology applied to electronically scanned arrays for space based radar

Recent developments in Micro Electro Mechanical Switches (MEMS) provide the potential for significant reduction in the cost and mass of Electronically Scanned Arrays (ESAs) for Space Based Radar (SBR) and communications applications. This paper addresses the current and projected status of Radio Frequency (RF) MEMS technology and provides an assessment of MEMS phase shifters for application to large aperture ESAs. A trade study was conducted comparing the system-level impact of MEMS phase shifters and conventional technologies. The study used a nominal SBR array of 150,000 elements and analyzed the effect of several competing ESA technologies on antenna efficiency, weight, and cost. It was found that the MEMS phase shifters had a significant efficiency, cost and weight advantage for large array sizes that are consistent with SBR applications.
Time Resolved Spot Size Measurements of the Cygnus Rod Pinch Flash Radiographic X-ray Source

The Cygnus accelerators, based on a pulsed power Inductive Voltage Adder (IVA) architecture, coupled to a rod pinch source have been used successfully to conduct explosive driven hydrodynamic experiments for DOE laboratories. The rod pinch X-ray source produces a small spot size and is well suited for low energy experiments. Beam plasma interactions, which take place in the ns scale, as well as the material response of the target to the impinging beam dictate the dynamic behavior of the diode. A scintillation based Time Resolved Spot Size Diagnostic (TRSD) has been fielded on various rod pinch configurations, different diameter rods as well as tapered and un-tapered rods were used, on the Cygnus I accelerator. Time integrated spot sizes of 1 to 1.5mm, consistent with rod diameter and previous results were observed. Results of the temporal behavior of the spot size, time integrated spot, beam movement and dose rate are presented here.
Variability analysis of in-car gesture interaction

In this paper we present an analysis of the variability of contactless gestures performed to control secondary functions in a car. In particular, those used to control the music player. We set up a Wizard-of-Oz experiment in a driving simulator where participants performed the gestures they think they would use to control the functions of the music player. The results of the experiment show a high level of variability in the gestures performed by different drivers for the same function. This could lead to driver distraction as well as user acceptance issues if a gesture vocabulary is `enforced' in order to use these systems. Thus, vehicle manufacturers should provide solutions to overcome these issues, such as gesture customization.
VERL: An Ontology Framework for Representing and Annotating Video Events

The notion of "events" is extremely important in characterizing the contents of video. An event is typically triggered by some kind of change of state captured in the video, such as when an object starts moving. The ability to reason with events is a critical step toward video understanding. This article describes the findings of a recent workshop series that has produced an ontology framework for representing video events-called Video Event Representation Language (VERL) -and a companion annotation framework, called Video Event Markup Language (VEML). One of the key concepts in this work is the modeling of events as composable, whereby complex events are constructed from simpler events by operations such as sequencing, iteration, and alternation. The article presents an extensible event and object ontology expressed in VERL and discusses a detailed example of applying VERL and VEML to the description of a "tailgating" event in surveillance video.
Voice and data transmission in a mobile radio channel at 850 MHz

This paper is a review of those properties of a communications channel in the 850 MHz band that have importance to the quality of voice and data transmission for frequency modulated land mobile radio. The presentation is made with emphasis on the simpler aspects and consequences of the propagation environment encountered. The distribution of fading amplitude and rate and the distribution of fade durations are described such that a qualitative impression is gained of the effect of fades on voice transmission, and a quantitative description is obtained of their effect on data transmission.