gebhart/patrepeval huggingface dataset:
Automated image quality evaluation of retinal fundus photographs in diabetic retinopathy screening (2012)

This paper presents a system that can automatically determine whether the quality of a retinal image is sufficient for computer-based diabetic retinopathy (DR) screening. The system integrates global histogram features, textural features, and vessel density, as well as a local non-reference perceptual sharpness metric. A partial least square (PLS) classifier is trained to distinguish low quality images from normal quality images. The system was evaluated on a large, representative set of 1884 non-mydriatic retinal images from 412 subjects. An area under the ROC curve of 96% was achieved.
Analyzing 180&#x00B0; turns using an inertial system reveals early signs of progression of parkinson's disease (2009)

Changes in turning are one of the early motor deficiencies in Parkinson's Disease (PD). We have proposed a system based on wearable, inertial sensors and a novel automatic analysis algorithm that can assess 180 degrees turns. Twelve patients in early stages of PD and 14 age-matched healthy subjects were enrolled in this study. Inertial sensors were attached on shanks and sternum. Measurement protocol included walking on a straight pathway, turning 180 degrees and returning back. Subjects were measured 4 times, once every 6 months during an 18 months period. At the baseline, 9 subjects from each group repeated the test twice to assess test-retest reliability. Patients with mild PD had a very low Postural Instability Gait Difficulty (PIGD subscore of UPDRS III) score (average 0.67, min 0, max 3). The analysis showed that the patients had a significantly longer turning duration (2.18+/-0.43 vs. 1.79+/-0.27 seconds, p<0.02) and longer delay in their last step before initiating a turn (0.56+/-0.04 vs. 0.52+/-0.04 seconds, p<0.03). Estimated turning duration and other metrics had a high test-retest reliability (rho>0.85). Turning duration also showed a significant Group *Time interaction (p<0.03) during the longitudinal study highlighting early signs of the progression of the disease.
Multichannel adaptive beamforming and interference mitigation in multiuser CDMA systems (2003)

In CDMA systems, multiple users produce cochannel interference that is only partially mitigated by user-dependent spreading codes. Limitations in any closed-loop transmitter power control can create received power variations at the base station that are potentially large. Multichannel multiuser detectors are data-adaptive receivers that provide interference mitigation as well as spatial and temporal diversity. These receivers are discussed in the context of CDMA applications. A maximum likelihood formulation of multiuser detection with antenna arrays is introduced to provide motivation and intuition. The proposed multiuser receiver incorporates space-time beamforming and time-domain interference cancellation. Performance examples using simulated and experimental data are given along with comparisons with a variety of receiver types.
Generalized Routes to Mesostructured Silicates with High Metal Content (2012)

Abstract Nanostructured materials with high metal content are interesting for a number of applications, including catalysis as well as energy conversion and storage. Here we elaborate an approach that combines the advantages of simple silica sol-gel chemistry with the ability to tailor metal composition and structure by introducing a ligand that connects a silane with an amino acid or hydroxy acid. Reacting this ligand with a metal acetate generates a precursor for a range of metal-silica nanocomposites. Comparing this chemistry with conventional organic ligand-metal complexes that can be physically mixed into sol-gel derived silicates elucidates advantages, e.g. of going to high metal loadings. Resulting nanomaterials are characterized by a combination of small-angle X-ray scattering (SAXS), transmission electron microscopy (TEM), and solid-state nuclear magnetic resonance (NMR) to reveal structural characteristics on multiple lengths scales, i.e. from the microscopic (molecular) level (NMR) all the way to the mesoscale (SAXS) and macroscale (TEM).
Spatial Sigma-Delta Signal Acquisition for Wideband Beamforming Arrays (2016)

We consider spatial and spatio-temporal sigma-delta modulation structures for wideband signal acquisition with dense sensor arrays. Using closely arranged sensors, the array oversamples the signal in space and applies coarse quantization to each sensor output. A sigma-delta structure propagates quantization noise between sensors to shape the noise in space, just as a time-domain sigma-delta converter shapes noise in frequency. The spatially shaped noise is then filtered by a delayand-sum beamformer. In this work, we also introduce higherorder sigma-delta structures and hybrid space-time architectures that can achieve greater noise shaping in both space and time. The coarsely quantized sigma-delta structure can be used to build high-resolution arrays with lower power and complexity.
Electrical Characterization of Nonvolatile Phase-Change Memory Devices Using Sb-Rich Ge–Sb–Te Alloy Films (2007)

We modified the composition of Ge–Sb–Te alloys for phase-change-type nonvolatile memory devices to realize more reliable memory operations. It is expected that the stability of the low-resistance crystalline phase of the Ge–Sb–Te alloy can be improved when an appropriate amount of excess Sb is added to conventional stoichiometric Ge2Sb2Te5 (GST), because a phase transition directly occurs from the amorphous phase to the more conductive hcp phase without the formation of the less conductive metastable fcc phase. Phase-change memory devices using Sb-rich Ge–Sb–Te alloys were fabricated, where the Sb atomic ratio was controlled to be from 31 to 47%. The effect of Sb addition to GST on the phase-change switching characteristics was investigated in terms of the electrical behaviors of the fabricated memory devices. For the set operations, the threshold voltage (Vth) for electronic switching and the required current for set were observed to decrease with increasing Sb composition. The data endurance of memory devices under repetitive operations was measured to be in the range from 1×105 to 2×106 cycles. From the investigations using energy dispersive X-ray spectroscopy (EDS), it was clearly shown that there was no phase separation and/or marked compositional change of the device experiencing 2×106 successive operations, when the Sb atomic ratio in the Ge–Sb–Te alloy was 39%.
Blast-induced traumatic brain injury research at Lawrence Livermore National Laboratory. (2010)

Our blast-induced TBI research has computational and experimental components. Our numerical hydro-structural simulations show that non-lethal blasts can induce sufficient flexure of the skull to generate potentially damaging loads in the brain, even if no impact occurs. The possibility that this mechanism may contribute to TBI has implications for the diagnosis of soldiers and the design of protective equipment such as helmets. Our experimental work involves designing and testing blast dosimeters, which are needed to quantify the blast environment around the soldier, independent of the mechanism(s) causing TBI. One system that uses MEMS sensors incorporated into the helmet and suspension would record peak pressure, positive-phase duration, blast direction, loads directly on the skull, and accelerations. Another system uses less sophisticated, inexpensive, small, lightweight, disposable, unpowered sensors that act as “yes-no” gauges that indicate the blast magnitude by visual inspection of the gauge. This system is a trade-off between quantity and quality of data, which may be viable, based on current DoD needs. [This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.]
232. Transplantation of Human Embryonic Stem Cell Derived Oligodendroglial Progenitors for the Treatment of Spinal Cord Injury (2004)

Human embryonic stem cells (hESCs) can replicate indefinitely in culture yet upon appropriate cues differentiate into elements of all three embryonic germ layers. Because of these proliferative and differentiative capabilities, hESCs could serve as as the source material for transplantable cells for tissue restorative therapies. To this end, we have developed protocols to direct the differentiation of hESCs into candidate target cell populations for therapeutic activity. Using combinations of extracellular matrix factors, growth factors, and select media components, we have produced cardiomyocytes, neural progenitors, neurons, oligodendroglial progenitors, hematopoietic cells, osteoblasts, and hepatocytes from hES cells. In all cases, the differentiated cells display both a panel of markers and appropriate function characteristic of the target cell. For all of these differentiated cell populations, a thorough cell compositional analysis has been completed or is underway.
Modelling of composite neutron scintillators (2005)

Composite neutron scintillators consisting of neutron-insensitive fluorescent dopant particles (e.g. ZnS:Ag) embedded in a matrix material containing isotopes with high neutron cross sections that emit energetic charged particles (e.g. 6Li) are a popular method for neutron detection in a variety of applications. The size and volume doping fraction of the fluorescent dopant particles and the densities of both dopant particles and the matrix material determine the characteristics of the pulse-height spectrum of emitted light and the probability that capture of a neutron will result in scintillation. In this work, we characterise the effects of these parameters for ZnS:Ag particles in a lithiated glass matrix using a Monte Carlo simulation of composite neutron detectors that we have constructed.
Induction of the transcription factor IRF-1 and interferon-beta mRNAs by cytokines and activators of second-messenger pathways. (1989)

Nuclear protein IRF-1 (interferon regulatory factor 1) was earlier shown to bind to cis-acting regulatory elements present on interferon (IFN)-alpha/beta genes and some IFN-inducible genes. Here we show that in both human FS-4 and murine L929 cells, steady-state levels of IRF-1 mRNA were increased by treatment with tumor necrosis factor (TNF), interleukin 1 (IL-1), poly(I).poly(C), or IFN-beta. IRF-1 mRNA induction was also demonstrated in cells treated with calcium ionophore A23187 or with phorbol 12-myristate 13-acetate, but not with epidermal growth factor, dibutyryl-cAMP, or the adenylate cyclase activator forskolin. To determine whether stimulation of IRF-1 mRNA levels correlates with IFN-beta induction, we compared IRF-1 and IFN-beta mRNA levels in cells exposed to various stimuli. In L929 cells, treatment with poly(I).poly(C) under conditions that failed to induce significant levels of IFN-beta mRNA led to a very low induction of IRF-1 mRNA, but "priming" cells with IFN prior to the addition of poly(I).poly(C) greatly increased both IRF-1 and IFN-beta mRNAs. In FS-4 cells an increase in IFN-beta mRNA (examined by the polymerase chain reaction) was seen after treatment with TNF, IL-1, A23187, or poly(I).poly(C), but not with IFN-beta, epidermal growth factor, dibutyryl-cAMP, or forskolin. Thus, all treatments that increased steady-state levels of IFN-beta mRNA also enhanced IRF-1 mRNA levels. However, treatment with IFN-beta, which caused a marked stimulation in IRF-1 mRNA, failed to produce a detectable increase in IFN-beta mRNA. It appears that IRF-1 may be necessary but not sufficient for IFN-beta induction. The ability of TNF and IL-1 to increase both IRF-1 and IFN-beta mRNAs may be responsible for some similarities in the actions of TNF, IL-1, and the IFNs.
On phase noise of self-injection locked semiconductor lasers (2014)

We discuss our recent progress in iimproving the phase noise of a semiconductor laser using self-injection locking of to a mode of a high-Q whispering gallery mode resonator. Locking efficiency is analyzed for semiconductor distributed feedback (DFB) as well as Fabry-Perot (FP) lasers operating at 690 nm, 1060 nm, 1550 nm, and 2 μm. Instantaneous linewidth below 300 Hz is realized with telecom DFB lasers. Tunability of the lasers is demonstrated. Commercially available packaged ”plug-and-play” devices are manufactured.
New Elastomers by Reactive Processing. Part II. Dynamic Vulcanization of Blends by Trans-Esterification (1992)

Abstract The dynamic vulcanization of a rubbery acrylate copolymer (ACR) (the dispersed phase) during its mixing with NBR (the continuous phase) can produce a millable specialty elastomer alloy. The ACR polymer can be crosslinked even without having special molecular sites for vulcanization such as those of the conventional acrylate rubbers (ACM). This is possible because, under the conditions for dynamic vulcanization, the acrylate-derived ester groups themselves can be made to act as sites for vulcanization by using tin-catalyzed ester-interchange chemistry. The millable dynamic vulcanizate containing the crosslinked dispersed phase can be later mixed with curatives for the continuous phase, fillers, antidegradants, etc. and then be vulcanized ( e.g. , in a heated mold). Since the ACR can be completely vulcanized during the dynamic vulcanization stage of the mixing process, the usual postcuring associated with acrylate rubber (ACM) technology is not necessary. Excellent performance characteristics can be produced by using this technology.
Terahertz Generation and Detection Using Frequency Conversion (2009)

Terahertz is nonlinearly upconverted to telecommunication wavelengths, resulting in detection with 4.5 pW/Hz1/2 noise equivalent power and nanosecond temporal resolution. Optical frequencies from an ultrashort pulse mix, generating 3 mW of broadband terahertz.
Characterization and formation mechanism of nano-structured hydroxyapatite coatings deposited by the liquid precursor plasma spraying process (2010)

Nano-structured hydroxyapatite (HA) coatings were deposited on the Ti-6Al-4V alloy substrate by the liquid precursor plasma spraying (LPPS) process. The thermal behavior of the HA liquid precursor was analyzed to interpret the phase change and structure transformation during the formation process of the nano-structured HA coatings. The phase composition, structure and morphology of the nano-structured HA coatings were characterized by x-ray diffraction (XRD), scanning electron microscope (SEM) and Fourier transform infrared (FTIR) spectroscopy. The XRD spectra showed that the coatings deposited by the LPPS process mainly consisted of the HA phase and the crystallite size was measured to be 56 nm. The SEM observation showed that the as-deposited LPPS coatings had small splat size, and nano-scale HA particles were found in certain regions of the coating surface. The FTIR spectroscopy showed the strong presence of the OH(-) group in the as-deposited LPPS coatings, indicating a superior structural integrity. In addition, the coatings deposited by the LPPS process were also carbonated HA coatings. The results indicate that the LPPS process is a promising plasma spraying technique for depositing nano-structured HA coatings with unique microstructural features that are desirable for improving the biological performance of the HA coatings.
Bootstrapping Language Models for Spoken Dialog Systems From The World Wide Web (2006)

In this paper, we describe our approach for bootstrapping statistical language models for spoken dialog systems using indomain Web data and utterances collected from previous applications. The approach is based on the idea of stitching conversational templates with the predicate and arguments extracted from the Web pages using semantic role labeling, to generate conversational style utterances. The conversational templates represent the task-independent portions of user utterances and can be built by hand, or learned from utterances collected from other domain applications. Experiments have shown that, stitching with both types of conversational templates have resulted in significantly better ASR word accuracy. Furthermore, the new language model bootstrapping approach can be combined with unsupervised and active learning to improve word accuracy even with very little in-domain transcribed data
High Sensitivity Long-Wavelength Infrared QWIP Focal Plane Array Based Instrument for Remote Sensing of Icy Satellites (2003)

GaAs based Quantum Well Infrared Photodetector (QWIP) technology has shown remarkable success in advancing low cost, highly uniform, high-operability, large format multi-color focal plane arrays. QWIPs afford greater flexibility than the usual extrinsically doped semiconductor IR detectors. The wavelength of the peak response and cutoff can be continuously tailored over a range wide enough to enable light detection at any wavelength range between 6 and 20 micron. The spectral band-width of these detectors can be tuned from narrow (Deltalambda/lambda is approximately 10%) to wide (Deltalambda/lambda is approximately 40%) allowing various applications. Furthermore, QWIPs offer low cost per pixel and highly uniform large format focal plane arrays due to mature GaAs/AlGaAs growth and processing technologies. The other advantages of GaAs/AlGaAs based QWIPS are higher yield, lower l/f noise and radiation hardness (1.5 Mrad). In this presentation, we will discuss our recent demonstrations of 640x512 pixel narrow-band, broad-band, multi-band focal plane arrays, and the current status of the development of 1024x1024 pixel long-wavelength infrared QWIP focal plane arrays.
Analysis of Ultrafiltration and Mass Transfer in a Bioartificial Pancreas (1988)

A bioartificial pancreas is an implantable device which contains insulin secreting cells (Langerhans islets), separated from the circulating blood by a semi-permeable membrane to avoid rejection. This paper describes the operation of such a device and evaluates the respective contributions of diffusion and ultrafiltration to the glucose and insulin mass transfer. It is shown that the pressure drop along the blood channel produces across the first half of the channel an ultrafiltration flux toward the islet compartment followed in the second half by an equal flux in reverse direction from islets to blood. The mass transfer analysis is carried out for an optimal geometry in which a U-shaped blood channel surrounds closely a very thin islet compartment formed by a folded flat membrane. A complete model of insulin release by this device is developed and is compared with in vitro data obtained with rats islets. Satisfactory kinetics is achieved with a polyacrylonitrile membrane used in hemodialysis. But the model shows that the membrane hydraulic permeability should be increased by a factor of 10 to significantly improve the performance.
Jackknife (2017)

Despite decades of research, there is yet no general rapid prototyping recognizer for dynamic gestures that can be trained with few samples, work with continuous data, and achieve high accuracy that is also modality-agnostic. To begin to solve this problem, we describe a small suite of accessible techniques that we collectively refer to as the Jackknife gesture recognizer. Our dynamic time warping based approach for both segmented and continuous data is designed to be a robust, go-to method for gesture recognition across a variety of modalities using only limited training samples. We evaluate pen and touch, Wii Remote, Kinect, Leap Motion, and sound-sensed gesture datasets as well as conduct tests with continuous data. Across all scenarios we show that our approach is able to achieve high accuracy, suggesting that Jackknife is a capable recognizer and good first choice for many endeavors.
Detection of Antiphospholipid Antibodies by Flow Cytometry: Rapid Detection of Antibody Isotype and Phospholipid Specificity (1993)

Laboratory diagnosis of antiphospholipid antibodies is important in patients with clinical features of the antiphospholipid syndrome, such as thrombosis and fetal loss. We have developed a novel method for the detection of antiphospholipid antibodies using flow cytometry. Anionic phospholipids cardiolipin, phosphatidylserine and phosphatidylinositol are coated onto polystyrene beads of different sizes, allowing detection and semiquantitation of their respective phospholipid antibody isotypes. The results of the flow cytometric method closely correlate those of the standardised anticardiolipin enzyme-linked immunosorbent assay (ELISA), but the method is quicker and is versatile in its ability to detect IgG, IgM and IgA antibody isotypes at the same time. The method promises to be useful in evaluating the significance of phospholipid specificity and antibody isotypes in patients with the antiphospholipid syndrome.
Reed-Solomon decoding algorithms for digital audio broadcasting in the AM band (2001)

Digital audio broadcasting (DAB) systems for the AM band are being developed to provide higher-quality radio broadcasts, broader coverage, and data services. Transmission is typically done by means of multistreaming with QAM/OFDM in the high bits/sec/Hz regime in which Reed-Solomon codes, either alone or in concatenation with inner trellis coded modulation (TCM), are natural choices for error control. For the AM DAB application, Reed-Solomon codes with suboptimal decoders of the bounded-distance type offer error correction important for bringing down the error probability, but also offers error detection important for generating block detected-error flags for use in the error concealment, or error mitigation, algorithm in the audio decoder. For multistream systems, the block detected-error flags can also be used to select the component streams retained by the audio decoder. In this paper, we evaluate the performance of Reed-Solomon codes in terms of both detected (flag) and undetected error rates for DAB applications. We provide simulation results for a variety of decoding algorithms, including hard-decision decoding (HDD), successive-erasure decoding (SED), and fixed-erasure decoding (FED), and discuss the channel environments in which each of these algorithms may be appropriate. Among other results, for example, we address the issue of matching the blocklength of the Reed-Solomon code to the audio decoder with its variable frame structure. From our simulation results for HDD, we conclude that the increased error correction capability of longer Reed-Solomon codes more than compensates for the mismatch in terms of error mitigation in the audio decoder. We also observe that SED provides only small improvements for uniform interference channels, while FED offers considerable improvements for some partial-band interference channels. We describe an appealing two-mode adaptive configuration using HDD and FED for mitigating partial-band interference caused by some second-adjacent AM broadcasts.
Broadband Suspended Plate Antennas Fed by Double L-Shaped Strips (2004)

A broadband suspended plate antenna fed by double L-shaped strips is presented experimentally and validated numerically. The broad impedance bandwidth is achieved because of the electromagnetic coupling between feeding strips and radiating plate. The radiation performances within the bandwidths are enhanced owing to a symmetrical balanced (balance-like) center-fed design. The impedance and radiation characteristics of the proposed antennas with varied heights are studied experimentally.