gebhart/patrepeval huggingface dataset:
Cayley differential unitary space-time codes (2002)

One method for communicating with multiple antennas is to encode the transmitted data differentially using unitary matrices at the transmitter, and to decode differentially without knowing the channel coefficients at the receiver. Since channel knowledge is not required at the receiver, differential schemes are ideal for use on wireless links where channel tracking is undesirable or infeasible, either because of rapid changes in the channel characteristics or because of limited system resources. Although this basic principle is well understood, it is not known how to generate good-performing constellations of unitary matrices, for any number of transmit and receive antennas and for any rate. This is especially true at high rates where the constellations must be rapidly encoded and decoded. We propose a class of Cayley codes that works with any number of antennas, and has efficient encoding and decoding at any rate. The codes are named for their use of the Cayley transform, which maps the highly nonlinear Stiefel manifold of unitary matrices to the linear space of skew-Hermitian matrices. This transformation leads to a simple linear constellation structure in the Cayley transform domain and to an information-theoretic design criterion based on emulating a Cauchy random matrix. Moreover, the resulting Cayley codes allow polynomial-time near-maximum-likelihood (ML) decoding based on either successive nulling/canceling or sphere decoding. Simulations show that the Cayley codes allow efficient and effective high-rate data transmission in multiantenna communication systems without knowing the channel.
A Nanoparticle Catalyst for Heterogeneous Phase Para‐Hydrogen‐Induced Polarization in Water (2015)

Abstract Para‐hydrogen‐induced polarization (PHIP) is a technique capable of producing spin polarization at a magnitude far greater than state‐of‐the‐art magnets. A significant application of PHIP is to generate contrast agents for biomedical imaging. Clinically viable and effective contrast agents not only require high levels of polarization but heterogeneous catalysts that can be used in water to eliminate the toxicity impact. Herein, we demonstrate the use of Pt nanoparticles capped with glutathione to induce heterogeneous PHIP in water. The ligand‐inhibited surface diffusion on the nanoparticles resulted in a 1 H polarization of P =0.25 % for hydroxyethyl propionate, a known contrast agent for magnetic resonance angiography. Transferring the 1 H polarization to a 13 C nucleus using a para‐hydrogen polarizer yielded a polarization of 0.013 %. The nuclear‐spin polarizations achieved in these experiments are the first reported to date involving heterogeneous reactions in water.
Time stretch enhanced recording oscilloscope (2009)

Recording analog signals using photonic time-stretch technique in a mode which combines advantages of continuous signal capture, as in real-time analog-to-digital converters (ADCs), and very high bandwidth capability of (equivalent-time) sampling oscilloscopes, is proposed. It is shown that the eye diagrams of high speed serial data can be acquired at least 100 times faster than the fastest capture rates today. Unlike conventional sampling scopes, this technique can capture ultrafast dynamics of repetitive signals, nonrepetitive signals, and rare events. Experimentally, 45 Gbit/s data eye diagram measurement is demonstrated.
Fast, Accurate and Shift-Varying Line Projections for Iterative Reconstruction Using the GPU (2008)

List-mode processing provides an efficient way to deal with sparse projections in iterative image reconstruction for emission tomography. An issue often reported is the tremendous amount of computation required by such algorithm. Each recorded event requires several back- and forward line projections. We investigated the use of the programmable graphics processing unit (GPU) to accelerate the line-projection operations and implement fully-3D list-mode ordered-subsets expectation-maximization for positron emission tomography (PET). We designed a reconstruction approach that incorporates resolution kernels, which model the spatially-varying physical processes associated with photon emission, transport and detection. Our development is particularly suitable for applications where the projection data is sparse, such as high-resolution, dynamic, and time-of-flight PET reconstruction. The GPU approach runs more than 50 times faster than an equivalent CPU implementation while image quality and accuracy are virtually identical. This paper describes in details how the GPU can be used to accelerate the line projection operations, even when the lines-of-response have arbitrary endpoint locations and shift-varying resolution kernels are used. A quantitative evaluation is included to validate the correctness of this new approach.
Adaptive downlink power control for HSDPA femtocells (2011)

Femtocell is emerging as a key technology to improve both the coverage and the capacity in indoor environments, whilst enabling innovative services. Since co-channel deployment of the femtocell network over the existing macrocell one is the most commercially viable solution, a closed/hybrid access policy may lead to severe co-channel interference problems. Therefore, the femtocells have to be carefully operated to disturb as less as possible the macrocell users whilst offering higher throughput to femtocell consumers. In this paper, we propose a dynamic downlink power control mechanism for femtocells, based on the Channel Quality Indicator (CQI) reports. Our results demonstrate that this provide an effective balance between femto users' throughput and femtocell impact on the macrocell performance without modifying the existing back-haul requirements.
Intracoronary optical coherence tomography: Emerging techniques and clinical application (2004)

There is significant interest in technologies capable of identifying high-risk coronary atherosclerotic plaques. We describe a recent intracoronary optical coherence tomography study conducted in a cohort of 69 patients. Our results demonstrate that certain plaque features, characteristic of high-risk lesions, are more prevalent in patients with acute coronary artery disease.
Synthetic ultra-wideband antenna for high-resolution millimeter-wave imaging (2015)

A synthetic ultra-wideband millimeter-wave antenna with application in high-resolution millimeter-wave imaging systems is presented. The antenna provides a synthetic ultra-wide bandwidth of approximately 100 GHz in the millimeter-wave regime. Our approach consists of dividing the assumed ultra-wide bandwidth (20-120 GHz) into four channels or sub-bands, and designing an antenna array including four antennas (equal to the number of sub-bands). The antennas are substrate integrated waveguide (SIW)-based antipodal Vivaldi antennas covering 20-40 GHz, 40-60 GHz, 60-90 GHz, and 90-120 GHz frequency ranges respectively. The achieved ultra-wide bandwidth (100 GHz) results in a significant improvement in the axial resolution of current millimeter-wave imaging systems.
Low Leakage Techniques for FPGAs (2006)

Reconfigurable architectures are well suited for wireless applications since they provide high performance computation together with the capability to adapt to changing communication protocols. Moving to 90-nm technology and below, FPGAs could suffer from leakage energy consumption due to the large number of inactive transistors. This paper presents an extensive study on the application of different low-leakage techniques to the design of FPGAs. The approaches are compared and mixed to find an implementation of switch blocks and look-up tables which reduces leakage without affecting delay and area. The circuits we propose achieve an 86% stand-by energy saving and 46% active leakage reduction with respect to standard implementations. The FPGA delay is not affected, while area is increased by only 3%
Small Molecule Isotope Resolved Formula Enumeration: a Methodology for Assigning Isotopologues and Metabolites in Fourier Transform Mass Spectra (2019)

Improvements in Fourier Transform Mass Spectrometry (FT-MS) enable increasingly more complex experiments in the field of metabolomics. What is directly detected in FT-MS spectra are spectral features (peaks) that correspond to sets of adducted and charged forms of specific molecules in the sample. The robust assignment of these features is an essential step for MS-based metabolomics experiments, but the sheer complexity of what is detected and a variety of analytically-introduced variance, errors, and artifacts has hindered the systematic analysis of complex patterns of observed peaks with respect to isotope content. We have devel-oped a method called SMIRFE that detects small biomolecules and determines their elemental molecular formula (EMF) using de-tected sets of isotopologue peaks sharing the same EMF. SMIRFE does not use a database of known metabolite formulas, instead a nearly comprehensive search space of all isotopologues within a mass range is constructed and used for assignment. This search space can be tailored for different isotope labeling patterns expected in different stable isotope tracing experiments. Using consumer-level computing equipment, a large search space of 2000 daltons was constructed and assignment performance was evaluated and validated using verified assignments on a pair of peak lists derived from spectra containing unlabeled and 15N-labeled versions of amino acids derivatized using ethylchloroformate. SMIRFE identified 18 of 18 predicted derivatized EMFs and each assignment was evaluated statistically and assigned an e-value representing the probability to occur by chance.
Locating multiple incoherent sound sources in three-dimensional space. (2011)

A new technology for locating incoherent sound sources in three-dimensional space is developed. The underlying principle of this technology is a model based approach that assumes acoustic radiation from a point source in free space, together with triangulations and signal pre-processing to enhance the signal to noise ratio. A prototype developed for this technology consists of six microphones, multi-channel high-accuracy data acquisition module, and a web camera. This device allows for capturing and visualizing target sources in three ways: (1) through the camera viewing angle that shows the actual sources and their Cartesian coordinates directly, (2) through projection of the source positions on a horizontal plane and their traces as they move in space, or (3) automatically switching between the camera and top view displays, depending on whether the target falls inside the viewing angle of the camera or outside. To ensure a real-time display of the results, four microphones are used. The disadvantage of using four microphones is that the accuracy in source localization may be reduced when the input data are contaminated by interfering and background signals. Under this condition, redundancy checks using six microphones can be used to enhance the accuracy and spatial resolution of source localization.
Vidrios sintéticos homogéneos para lodos cementantes = Homogenous synthetic mud-to-cement cementing glasses (2008)

Una familia de vidrios sintéticos en el campo de la fase\n cuaternaria de CaO-SiO2-Al2O3-MgO (CSAM) con\n propiedades hidráulicas y puzolánicas para usar en\n diferentes aplicaciones en el área cementante de pozos de\n gas y petróleo. Un método para fabricar una pasta de lodo\n cementante (MTC) y un método para tratar pozos de\n petróleo y gas con la pasta MTC que contiene vidrio amorfo\n sintético formado por una mezcla de materiales inorgánicos\n seleccionados de un grupo que consiste en CSAM, en la\n que los vidrios cementantes con la mezcla de materiales\n inorgánicos se encuentran en una fase amorfa de 100% con\n grado cero de cristalización.\nA synthetic glass family in the quaternary phase field of CaO-SiO2-Al2O3-MgO (CSAM) with hydraulic and pozzolanic properties for use in differing applications in the gas and oil well cementing area. A method of making a mud-to-cement (MTC) slurry and a method for treating oil and gas wells with the MTC slurry containing a homogenous amorphous synthetic glass made from a mixture of inorganic materials selected from the group consisting of CSAM, wherein the cementing glasses with the mixture of inorganic materials are in a 100% amorphous phase with a degree of crystallization of zero.
Damping of mechanical vibration by superconducting <i>Y</i> <i>B</i> <i>a</i> <b>2</b> <i>C</i> <i>u</i> <b>3</b> <i>O</i> <b>7−</b> <i>x</i> in a magnetic field (1995)

As the load capacity of magnetic bearings using high-Tc superconductors increases, the inherent damping decreases. Damping of externally generated vibration is an important unsolved problem. A proposal is made for an active damping system, based upon the strong temperature dependence of the magnetic flux dissipation in a high-Tc superconductor in the region of the phase transformation a few degrees below the transition temperature. The damping system would be distinct from the levitated system. The strong temperature dependence of the dissipation is demonstrated with a single crystal of yttrium barium copper oxide, but a melt-processed ceramic sample would behave in the same way.
Two Chemical Repellents for Control of German (Orthoptera: Blattellidae) and American Cockroaches (Orthoptera: Blattidae) (1987)

Two experimental repellents, N, N-diethylcyclohexaneacetamide (DECA) and N, N-diethylcyclohexanepropanamide (DCP), and a standard, 3-isopropyl-l-methylcyclopentanecarboxylic acid (fencholic acid), effectively repelled both the German cockroach, Blattella germanica (L.), and the American cockroach, Periplaneta americana (L.). DCP and DECA were more effective against German than American cockroaches, with residual activity of ca. 3 wk. Fencholic acid was more effective against American than German cockroaches, with residual activity of ca. 2 wk. These synthetic chemical repellents may be useful parts of an integrated cockroach management program.
BindingDB Entry 50018740: Dual serotonin transporter/histamine H3 ligands: Optimization of the H3 pharmacophore. (2009)

A series of tetrahydroisoquinolines acting as dual histamine H3/serotonin transporter ligands is described. A highly regio-selective synthesis of the tetrahydroisoquinoline core involving acid mediated ring-closure of an acetophenone intermediate followed by reduction with NaCNBH3 was developed. In vitro and in vivo data are discussed.
<title>Near-field acoustic microscopy (Invited Paper)</title> (1992)

We have integrated silicon micromachining techniques with piezoelectric thin film deposition to make a near-field acoustic microscope. A piezoelectric zinc oxide (ZnO) transducer is deposited on a substrate of 7740 glass. A sharp tip is formed in a silicon wafer which is anodically bonded to the glass substrate. A sample is attached to substrate of glass with a receiving ZnO transducer. The transducer on the tip excites an ultrasonic beam which passes from the tip to the sample and is detected by the receiving transducer. A feedback signal is generated to keep the transmitted amplitude constant as a sample is raster scanned. The feedback signal is applied to a tube scanner and is also used to modulate the intensity of a display monitor. We find that the instrument has a vertical height sensitivity of about 20 angstroms, and a lateral resolution of better than 800 angstroms.
Results from the microminiature thermionic converter demonstration testing program (1999)

Research is in progress to develop microminiature thermionic converters (MTCs) with high energy conversion efficiencies and variable operating temperatures using semiconductor integrated circuit (IC) fabrication methods. The use of IC techniques allows the fabrication of MTCs with cathode to anode spacing of several microns or less and with anode and cathode materials that will have work functions ranging from 1 eV to 3 eV. The small cathode to anode spacing and variable electrode work functions should allow the conversion of heat energy to relatively large current densities (up to tens of Amps/cm2) at relatively high conversion efficiencies (15–25%).
New Materials by Atom Transfer Radical Polymerization (2004)

Fundamentals of atom transfer radical polymerization(ATRP)and other controlled/living radical polymerizations are discussed. Several new polymer materials with controlled topology, composition, and functionality prepared by ATRP are presented.
Polymeric Inverse Micelles as Selective Peptide Extraction Agents for MALDI-MS Analysis (2007)

Analyses of peptides in complex mixtures are significant challenges in proteomics applications. Here, we report an amphiphilic polymer-based nanoassembly that is capable of selectively extracting peptides, on the basis of their isoelectric points, into an immiscible organic phase from an aqueous solution. The isoelectric point (pI) cutoff in these extractions depends on the pH of the aqueous solution, and thus, sequential fractionation of peptide mixtures based on pI can be accomplished by varying the pH of the aqueous solution. Additionally, we observe an unexpected enhancement in the MALDI-MS signal for extracted peptides ionized in the presence of the polymer, which allows us to obtain reproducible ion signals for some peptides at concentrations as low as 10 pM.
Pervasive Diagnosis: Integration of Active Diagnosis into Production Plans (2008)

In model-based control, a planner uses a system descrip-tion to create a plan that achieves production goals. The same model can be used by model-based diagnosis to indirectly infer the condition of components in a sys-tem from partially informative sensors. Existing work has demonstrated that diagnosis can be used to adapt the control of a system to changes in its components, however diagnosis must either make inferences from passive observations of production plans, or production must be halted to take specific diagnostic actions. In this paper, we observe that the declarative nature of model-based control allows the planner to achieve pro-duction goals in multiple ways. We show that this flex-ibility can be exploited by a novel paradigm we call pervasive diagnosis which produces diagnostic produc-tion plans that simultaneously achieve production goals while generating additional information about compo-nent conditions. We derive an efficient heuristic search for these diagnostic production plans and show through experiments on a model of an industrial digital printing press that the theoretical increase in information can be realized on practical real-time systems and used to obtain higher long-run productivity than a decoupled combination of planning and diagnosis. 1
Optimal single image capture for motion deblurring (2009)

Deblurring images of moving objects captured from a traditional camera is an ill-posed problem due to the loss of high spatial frequencies in the captured images. Techniques have attempted to engineer the motion point spread function (PSF) by either making it invertible using coded exposure, or invariant to motion by moving the camera in a specific fashion. We address the problem of optimal single image capture strategy for best deblurring performance. We formulate the problem of optimal capture as maximizing the signal to noise ratio (SNR) of the deconvolved image given a scene light level. As the exposure time increases, the sensor integrates more light, thereby increasing the SNR of the captured signal. However, for moving objects, larger exposure time also results in more blur and hence more deconvolution noise. We compare the following three single image capture strategies: (a) traditional camera, (b) coded exposure camera, and (c) motion invariant photography, as well as the best exposure time for capture by analyzing the rate of increase of deconvolution noise with exposure time. We analyze which strategy is optimal for known/unknown motion direction and speed and investigate how the performance degrades for other cases. We present real experimental results by simulating the above capture strategies using a high speed video camera.
Development and Characterization of an Aircraft Aerosol Time-of-Flight Mass Spectrometer (2009)

Vertical and horizontal profiles of atmospheric aerosols are necessary for understanding the impact of air pollution on regional and global climate. To gain further insight into the size-resolved chemistry of individual atmospheric particles, a smaller aerosol time-of-flight mass spectrometer (ATOFMS) with increased data acquisition capabilities was developed for aircraft-based studies. Compared to previous ATOFMS systems, the new instrument has a faster data acquisition rate with improved ion transmission and mass resolution, as well as reduced physical size and power consumption, all required advances for use in aircraft studies. In addition, real-time source apportionment software allows the immediate identification and classification of individual particles to guide sampling decisions while in the field. The aircraft (A)-ATOFMS was field-tested on the ground during the Study of Organic Aerosols in Riverside, CA (SOAR) and aboard an aircraft during the Ice in Clouds Experiment-Layer Clouds (ICE-L). Initial results from ICE-L represent the first reported aircraft-based single-particle dual-polarity mass spectrometry measurements and provide an increased understanding of particle mixing state as a function of altitude. Improved ion transmission allows for the first single-particle detection of species out to approximately m/z 2000, an important mass range for the detection of biological aerosols and oligomeric species. In addition, high time resolution measurements of single-particle mixing state are demonstrated and shown to be important for airborne studies where particle concentrations and chemistry vary rapidly.
Improved Broadband Liner Optimization Applied to the Advanced Noise Control Fan (2014)

The broadband component of fan noise has grown in relevance with the utilization of increased bypass ratio and advanced fan designs. Thus, while the attenuation of fan tones remains paramount, the ability to simultaneously reduce broadband fan noise levels has become more desirable. This paper describes improvements to a previously established broadband acoustic liner optimization process using the Advanced Noise Control Fan rig as a demonstrator. Specifically, in-duct attenuation predictions with a statistical source model are used to obtain optimum impedance spectra over the conditions of interest. The predicted optimum impedance information is then used with acoustic liner modeling tools to design liners aimed at producing impedance spectra that most closely match the predicted optimum values. Design selection is based on an acceptance criterion that provides the ability to apply increased weighting to specific frequencies and/or operating conditions. Constant-depth, double-degree of freedom and variable-depth, multi-degree of freedom designs are carried through design, fabrication, and testing to validate the efficacy of the design process. Results illustrate the value of the design process in concurrently evaluating the relative costs/benefits of these liner designs. This study also provides an application for demonstrating the integrated use of duct acoustic propagation/radiation and liner modeling tools in the design and evaluation of novel broadband liner concepts for complex engine configurations.