gebhart/patrepeval huggingface dataset:
Designing Time-Hopping Ultrawide Bandwidth Receivers for Multiuser Interference Environments (2009)

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> The multiple-user interference (MUI) in time-hopped impulse-radio ultrawide bandwidth (UWB) systems is impulse-like and poorly approximated by a Gaussian distribution. Therefore, conventional matched filter receiver designs, which are optimal for Gaussian noise, are not fully efficient for UWB applications. Several alternative distributions for approximating the MUI process and the MUI-plus-noise process in UWB systems are motivated and compared. These distributions have in common that they are more impulsive than the Gaussian approximation, with a greater area in the tails of the probability density function (pdf) compared to a Gaussian pdf. The improved MUI and MUI-plus-noise models are utilized to derive new receiver designs for UWB applications, which are shown to be superior to the conventional matched filter receiver. Multipath propagation is abundant in UWB channels and is exploited by a Rake receiver. A Rake receiver uses multiple fingers to comb the multipath rays with a conventional matched filter implemented in each finger. Rake structures utilizing the new receiver designs that are suitable for reception of UWB signals in multipath fading channels are provided. An optimal performance benchmark, based on an accurate theoretical model for the interference that fully explains the features of the MUI pdf, is also presented. Analysis and simulation results are shown for the novel receivers, which demonstrate that the new designs have superior performance compared to the conventional linear receiver when MUI is significant. Several adaptive receivers are shown to always match or exceed the performance of the conventional linear receiver in all MUI-plus-noise environments. Parameter estimation for the new receivers also is discussed. </para>
<i>XModeScore</i>: a novel method for accurate protonation/tautomer-state determination using quantum-mechanically driven macromolecular X-ray crystallographic refinement (2016)

Gaining an understanding of the protein-ligand complex structure along with the proper protonation and explicit solvent effects can be important in obtaining meaningful results in structure-guided drug discovery and structure-based drug discovery. Unfortunately, protonation and tautomerism are difficult to establish with conventional methods because of difficulties in the experimental detection of H atoms owing to the well known limitations of X-ray crystallography. In the present work, it is demonstrated that semiempirical, quantum-mechanics-based macromolecular crystallographic refinement is sensitive to the choice of a protonation-state/tautomer form of ligands and residues, and can therefore be used to explore potential states. A novel scoring method, called XModeScore, is described which enumerates the possible protomeric/tautomeric modes, refines each mode against X-ray diffraction data with the semiempirical quantum-mechanics (PM6) Hamiltonian and scores each mode using a combination of energetic strain (or ligand strain) and rigorous statistical analysis of the difference electron-density distribution. It is shown that using XModeScore it is possible to consistently distinguish the correct bound protomeric/tautomeric modes based on routine X-ray data, even at lower resolutions of around 3 Å. These X-ray results are compared with the results obtained from much more expensive and laborious neutron diffraction studies for three different examples: tautomerism in the acetazolamide ligand of human carbonic anhydrase II (PDB entries 3hs4 and 4k0s), tautomerism in the 8HX ligand of urate oxidase (PDB entries 4n9s and 4n9m) and the protonation states of the catalytic aspartic acid found within the active site of an aspartic protease (PDB entry 2jjj). In each case, XModeScore applied to the X-ray diffraction data is able to determine the correct protonation state as defined by the neutron diffraction data. The impact of QM-based refinement versus conventional refinement on XModeScore is also discussed.
Novel 3alpha-diphenylmethoxytropane analogs: selective dopamine uptake inhibitors with behavioral effects distinct from those of cocaine. (1999)

The pharmacological effects were assessed for a series of 3alpha-diphenylmethoxy-1alphaH,5alphaH-tropane analogs which have structural similarities to cocaine. Like cocaine, these compounds displaced [3H]WIN 35,428 binding from rat caudate and had affinities ranging from approximately 10-fold greater than cocaine (Ki=11.8 nM) to relatively low affinity (Ki=2000 nM). The compounds also inhibited dopamine uptake with potencies corresponding to their affinities for WIN 35,428 binding sites. Like the parent compound, benztropine, the 3alpha-(diphenylmethoxy)tropane analogs displaced [3H]pirenzepine from muscarinic M1 receptors with affinities ranging from 2 to 120 nM. Cocaine produced dose-related increases in locomotor activity (horizontal ambulation) in Swiss Webster mice, whereas the 3alpha-(diphenylmethoxy)tropane analogs generally had lower efficacy than cocaine. Compounds with fluoro-substituents in the phenyl rings generally were among those with efficacy approaching that of cocaine; those with chloro- and bromo-substituents were markedly less efficacious, despite having binding affinities comparable to those of the corresponding fluoro-substituted compounds. The 3alpha-(diphenylmethoxy)tropane analogs were also examined in rats trained to discriminate saline from cocaine (10 mg/kg, i.p.). Cocaine produced a dose-related increase in responding on the cocaine-appropriate lever, reaching 100% at 10 mg/kg. Only the 4',4"-difluoro-substituted analog produced effects similar to those of cocaine; the other compounds showed markedly reduced efficacy compared to cocaine. Drug interaction studies showed that the antimuscarinics, atropine and scopolamine, potentiated rather than attenuated the locomotor stimulant and cocaine-like discriminative-stimulus effects of cocaine, indicating that the antimuscarinic effects of the 3alpha-diphenylmethoxytropane analogs did not contribute to their diminished cocaine-like activity. Studies of the time course of selected compounds indicated that their reduced cocaine-like efficacy was likely not due to behavioral observations being conducted at an inopportune time period. Because none of the 3alpha-diphenylmethoxytropane analogs studied showed evidence that they were binding to more than one site, and because the structure activity relationships among these drugs are distinctly different from those obtained with cocaine, these data suggest that the 3alpha-diphenylmethoxytropane analogs are accessing a different binding domain than that accessed by cocaine. Binding to this domain may produce a behavioral profile that is distinct from that of the cocaine-like dopamine uptake inhibitors.
Development of a Lean Direct Fuel Injector for Low Emission Aero Gas Turbines (2002)

CFD Research Corporation has developed a promising lean direct fuel injector for application to all sizes of aero gas turbine engines. The patented injector design utilizes a bifurcated flow pattern structure that produces low NOx emissions at full power conditions and low CO, UHC and smoke emissions at low power. The design consists of three swirlers and two fuel circuits, and a flow splitter that divides the airflow into two airstreams. Two concentric fuel circuits fuel the two airstreams, producing two distinct flames: a pilot flame and a main flame. This unique flame structure allows separate control of two flame regions, but still allows them to interact. A large percent of combustor airflow enters through the injector. At low power (idle and approach), only the pilot circuit is fueled. The pilot fuel flows into the pilot airstream, and a flame is anchored in the bifurcated recirculation zone. Lean blowouts at idle conditions as low as an injector equivalence ratio of 0.04 have been realized. Low CO, UHC and smoke emissions have been demonstrated at these conditions. For power settings above approach, the fuel flow through the pilot is reduced, and the main is fueled. At cruise to max power conditions, only 10% of the fuel goes through the pilot and 90% goes through the main to achieve both low NOx and good stability. At max power conditions, the injector equivalence ratio is approximately 0.60–0.65, and the flame is blue and non-luminous, resulting in reduced heat loads to the liner. NOx emission levels have been measured in single-injector tests that show this injector has the potential to reduce the Landing/Takeoff (LTO) NOx levels by 60–70% compared with 1996 ICAO standards. This paper presents an overview of how the fuel injector works and how overall performance was achieved. The most difficult aspect of injector performance, i.e. achieving low lean blowout (LBO) fuel-air ratio, is described at the end of the paper, including LBO data for a range of configurations.
Exceptionally High CO<sub>2</sub> Adsorption at 273 K by Microporous Carbons from Phenolic Aerogels: The Role of Heteroatoms in Comparison with Carbons from Polybenzoxazine and Other Organic Aerogels (2018)

Abstract Phenolic aerogels containing oxygen and other polymeric aerogels containing both oxygen and nitrogen (polybenzoxazine and a polyamide‐polyimide‐polyurea co‐polymer) are converted to carbon aerogels (800 °C/Ar), and are etched with CO 2 (1000 °C). Etching opens closed pores and increases micropore volumes and size. Heteroatoms are retained in the etched samples. All carbon aerogels are evaluated as CO 2 absorbers in terms of their capacity and selectivity toward CH 4 , H 2 , and N 2 . CO 2 adsorption capacity is linked to microporosity. In most cases, monolayer coverage of micropore walls is enough to explain CO 2 uptake quantitatively. The interaction of CO 2 with micropore walls is evaluated via isosteric heats of adsorption, and is stronger with carbons containing only oxygen heteroatoms. The adsorption capacity of those carbons (5–6 mmol g −1 ) is on par with the best carbon and polymeric CO 2 adsorbers known in the literature, with one exception however: etched carbon aerogels from low‐density resorcinol‐formaldehyde aerogels show a very high CO 2 uptake (14.8 ± 3.9 mmol g −1 at 273 K, 1 bar) attributed to a pore‐filling process that proceeds beyond monolayer coverage, whereas surface phenoxides engage in a thermally neutral carbonate forming reaction (surface‐O – + CO 2 → surface‐O–(CO)–O – ) that continues until micropores are filled.
Gallium nitride junction field effect transistors for high-temperature operation (1996)

GaN is an attractive material for use in high-temperature or high-power electronic devices due to its high bandgap (3.39 eV), high breakdown field ({approximately}5 {times} 10{sup 6} V/cm), high saturation drift velocity (2.7 {times} 10{sup 7} cm/s), and chemical inertness. To this end, Metal Semiconductor FETs (MESFETs), High Electron Mobility Transistors (HEMTs), Heterostructure FETs (HFETs), and Metal Insulator Semiconductor FETs (MISFETs) have all been reported based on epitaxial AlN/GaN structures (Khan 1993a,b; Binari 1994 and 1995). GaN Junction Field Effect Transistors (JFETs), however, had not been reported until recently (Zolper 1996b). JFETs are attractive for high-temperature operation due to the inherently higher thermal stability of the p/n junction gate of a JFET as compared to the Schottky barrier gate of a MESFET or HFET. In this paper the authors present the first results for elevated temperature performance of a GaN JFET. Although the forward gate properties are well behaved at higher temperatures, the reverse characteristics show increased leakage at elevated temperature. However, the increased date leakage alone does not explain the observed increase in drain current with temperature. Therefore, they believe this first device is limited by temperature activated substrate conduction.
Analog Electrical Phase Noise Compensation for Coherent Optical Receivers (2012)

The applicability of optical phase noise compensation in the analog electrical domain is presented and experimentally investigated. Frequency noise power density can be reduced two orders of magnitude, enabling the use of low-cost DFB lasers for advanced modulation formats like 16-QAM.
ChemInform Abstract: POLARIZATION BEHAVIOR AND STRUCTURE OF LITHIUM‐ALUMINUM‐MAGNESIUM ALLOY ELECTRODES (1979)

Abstract Der Einbau von Mg in die LiA1‐Elektrode (zu einem Niveau von 5‐19 Atom‐% an MgAl im Ausgangsmaterial) führt zu steigender Polarisation sowie zu einer bemerkenswerten morphologischen Veränderung, die eine verbesserte Strukturstabilität während cyclischer Lade‐Entlade‐Vorgänge bewirkt.
Identification of Exogenous Forms of Human-Tropic Porcine Endogenous Retrovirus in Miniature Swine (2004)

The replication of porcine endogenous retrovirus subgroup A (PERV-A) and PERV-B in certain human cell lines indicates that PERV may pose an infectious risk in clinical xenotransplantation. We have previously reported that human-tropic PERVs isolated from infected human cells following cocultivation with miniature swine peripheral blood mononuclear cells (PBMC) are recombinants of PERV-A with PERV-C. Here, we report that these recombinants are exogenous viruses in miniature swine; i.e., they are not present in the germ line DNA. These viruses were invariably present in miniature swine that transmitted PERV to human cells and were also identified in some miniature swine that lacked this ability. These data, together with the demonstration of the absence of both replication-competent PERV-A and recombinant PERV-A/C loci in the genome of miniature swine (L. Scobie, S. Taylor, J. C. Wood, K. M. Suling, G. Quinn, C. Patience, H.-J. Schuurman, and D. E. Onions, J. Virol. 78:2502-2509, 2004), indicate that exogenous PERV is the principal source of human-tropic virus in these animals. Interestingly, strong expression of PERV-C in PBMC correlated with an ability of the PBMC to transmit PERV-A/C recombinants in vitro, indicating that PERV-C may be an important factor affecting the production of human-tropic PERV. In light of these observations, the safety of clinical xenotransplantation from miniature swine will be most enhanced by the utilization of source animals that do not transmit PERV to either human or porcine cells. Such animals were identified within the miniature swine herd and may further enhance the safety of clinical xenotransplantation.
Development of a video-based slurry sensor for on-line ash analysis. Second quarterly technical progress report, January 1, 1995--March 31, 1995 (1995)

Automatic control of fine coal cleaning circuits has traditionally been limited by the lack of sensors for on-line ash analysis. Although several nuclear-based analyzers are available, none have seen widespread acceptance. This is largely due to the fact that nuclear sensors are expensive and tend to be influenced by changes in seam type and pyrite content. Recently, researchers at VPI&SU have developed an optical sensor for phosphate analysis. The sensor uses image processing technology to analyze video images of phosphate ore. It is currently being used by Texasgulf for off-line analysis of dry flotation concentrates. The primary advantages of optical sensors over nuclear sensors are that they are significantly cheaper, are not subject to measurement variations due to changes in high atomic number minerals, are inherently safer and require no special radiation permitting. Purpose of this work is to apply the knowledge gained in the development of an optical phosphate analyzer to the development of an on-line ash analyzer for fine coal slurries. During the past quarter, tests were performed on two prototype sample presentation systems for the optical analyzer. Preliminary results indicate that the flow of slurry past the camera lens is too consistent to provide reliable results. A third option for sampel presentation is being explored.
Luminescent solar concentrators 1: Theory of operation and techniques for performance evaluation (1979)

Techniques and calculations are presented that give explicit expressions for the over-all performance of a luminescent solar concentrator (LSC) in terms of the intrinsic spectral response and quantum efficiency of its constituents. We examine the single dye (or inorganic ion) LSC with emphasis on the planar geometry. Preliminary data on the degradation of candidate LSC dyes under severe weathering conditions are also given. Armed with our experimental results and analysis of solar absorption, self-absorption, and solar cell efficiency, we present a new genre of solar concentrator with a theory of operation for the device.
Low-barrier-height epitaxial Ge-GaAs mixer diodes (1979)

Using a thin Ge-GaAs structure, barrier height lowering of 0.2–0.3 eV has been attained. These X-band diodes have a noise figure of 6.0–6.5 dB at 0.75–1.0 mW of local-oscillator power. The diodes have superior power-handling capability with Pt-Ti-Mo-Au metallisation.
ProtoSteer: Steering Deep Sequence Model with Prototypes (2019)

Recently we have witnessed growing adoption of deep sequence models (e.g. LSTMs) in many application domains, including predictive health care, natural language processing, and log analysis. However, the intricate working mechanism of these models confines their accessibility to the domain experts. Their black-box nature also makes it a challenging task to incorporate domain-specific knowledge of the experts into the model. In ProtoSteer (Prototype Steering), we tackle the challenge of directly involving the domain experts to steer a deep sequence model without relying on model developers as intermediaries. Our approach originates in case-based reasoning, which imitates the common human problem-solving process of consulting past experiences to solve new problems. We utilize ProSeNet (Prototype Sequence Network), which learns a small set of exemplar cases (i.e., prototypes) from historical data. In ProtoSteer they serve both as an efficient visual summary of the original data and explanations of model decisions. With ProtoSteer the domain experts can inspect, critique, and revise the prototypes interactively. The system then incorporates user-specified prototypes and incrementally updates the model. We conduct extensive case studies and expert interviews in application domains including sentiment analysis on texts and predictive diagnostics based on vehicle fault logs. The results demonstrate that involvements of domain users can help obtain more interpretable models with concise prototypes while retaining similar accuracy.
Globally optimized least-squares post-filtering for microphone array speech enhancement (2016)

Existing post-filtering techniques for microphone array speech enhancement have two common deficiencies. First, they assume that the noise is either white or diffuse and cannot deal with point inter-ferers. Second, they estimate the post-filter coefficients using only two microphones at a time and then perform averaging over all microphone pairs, yielding a suboptimal solution at best. In this paper, we present a novel post-filtering algorithm that alleviates the first limitation by using a more generalized signal model including not only white and diffuse but also point interferers, and overcomes the second deficiency by offering a globally optimized least-squares solution over all microphones. It is shown by simulations that the proposed method outperforms the existing algorithms in many different acoustic scenarios.
Noninvasive Diagnosis of Mesenteric Ischemia Using a SQUID Magnetometer (1995)

A SQUID magnetometer is capable of noninvasively detecting mesenteric ischemia reliably and at an early stage by detecting a significant drop in BER frequency. These positive findings have encouraged the authors to continue development of clinically useful, noninvasive, detection of intestinal magnetic fields using SQUID magnetometers.
Digital audio signal generating apparatus (1992)

Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite Search Site Citation Ken Kutaragi, Makoto Furuhashi; Digital audio signal generating apparatus. J. Acoust. Soc. Am. 1 October 1992; 92 (4): 2287. https://doi.org/10.1121/1.405184 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAcoustical Society of AmericaThe Journal of the Acoustical Society of America Search Advanced Search |Citation Search
Burst Vision Using Single-Photon Cameras (2023)

Single-photon avalanche diodes (SPADs) are novel image sensors that record the arrival of individual photons at extremely high temporal resolution. In the past, they were only available as single pixels or small-format arrays, for various active imaging applications such as LiDAR and microscopy. Recently, high-resolution SPAD arrays up to 3.2 megapixel have been realized, which for the first time may be able to capture sufficient spatial details for general computer vision tasks, purely as a passive sensor. However, existing vision algorithms are not directly applicable on the binary data captured by SPADs. In this paper, we propose developing quanta vision algorithms based on burst processing for extracting scene information from SPAD photon streams. With extensive real-world data, we demonstrate that current SPAD arrays, along with burst processing as an example plug-and-play algorithm, are capable of a wide range of downstream vision tasks in extremely challenging imaging conditions including fast motion, low light (< 5 lux) and high dynamic range. To our knowledge, this is the first attempt to demonstrate the capabilities of SPAD sensors for a wide gamut of real-world computer vision tasks including object detection, pose estimation, SLAM, and text recognition. We hope this work will inspire future research into developing computer vision algorithms in extreme scenarios using single-photon cameras.
Fast Multidimensional Scaling using Vector Extrapolation (2008)

Multidimensional scaling (MDS) is a class of methods used to find a low-dimensional representation of a set of points given a matrix of pairwise distances between them. Problems of this kind arise in various applications, from dimensionality reduction of image manifolds to psychology and statistics. In many of these applications, efficient and accurate solution of an MDS problem is required. In this paper, we propose using vector extrapolation techniques to accelerate the numerical solution of MDS problems. Vector extrapolation is used to accelerate the convergence of fixed-point iterative algorithms. We review the problem of multidimensional scaling and vector extrapolation techniques, and show several examples of our accelerated solver for multidimensional scaling problems in various applications. 1
The Cathode Fall Voltage of Low Current Fluorescent Lamps (1991)

The characteristics of hot cathode fluorescent lamps in low current regions (10-40mA) were investigated by experiments and numerical analysis.A quantitative correlation between the cathode fall voltage and the lifetime was obtained. If the cathode fall voltage is less than or equal to 14 V, arc discharge can be maintained stably during the lifetime, and hence, the life reliability of lamps can be improved. In order to reduce the cathode fall voltage for a given lamp current, it is effective to increase Ar gas pressure, and to decrease the surface area of the coils. The cold spot temperature is not effective to reduce the cathode fall voltage in the range of 10 to 60°C.The relation between the lamp design parameters and the cathode fall voltage was analyzed numerically on the basis of a modified theoretical model. The calculated results support the experimental results.