gebhart/patrepeval huggingface dataset:
Helicopter individual-blade-control and its applications (1984)

A new, advanced type of active control for helicopters and its applications are described. The system, based on previously developed M.I.T. Individual-Blade-Control hardware, employs blade-mounted accelerometers to sense blade motion and feeds back information to control blade pitch in such a manner as to reduce the response of selected blade modes. A linear model of the blade and control system dynamics is used to give guidance in the design process as well as to aid in analysis of experimental results. System performance in wind tunnel tests is described, and evidence is given of the system's ability to provide substantial reduction in blade modal responses, including blade bending vibration.
Power-Efficient Design Techniques for mm-Wave Hybrid/Digital FDD/Full-Duplex MIMO Transceivers (2020)

This article describes system and circuit design techniques to enhance power efficiency and incorporate new features in millimeter-wave multi-input-multi-output (MIMO) transceivers. The higher peak-to-average power ratio (PAPR) of the signal transmitted from a digital beamformer (DBF) or a fully connected hybrid beamforming (FC-HBF) transmitter compared with the conventional partially connected hybrid beamforming (PC-HBF) transmitter is identified for the first time. It is then shown that when a power amplifier (PA) with better back-off efficiency than Class-A PA is used, the overall power efficiency of the FC-HBF is superior to the PC-HBF for a given antenna geometry. Second, a new mechanism for built-in dual-band, per-element self-interference cancellation (SIC) is introduced to enable multi-antenna frequency-division-duplex (FDD) and full-duplex (FD) operation. Such SIC can only be supported in the proposed FC-HBF architecture. Several innovative circuit concepts are introduced, including low-loss wideband antenna interface design, dual-band power combining PA, dual-band RF-SIC design, and bidirectional MIMO signal path design. To demonstrate these techniques, a 28-/37-/39-GHz bidirectional two-stream front-end single-element prototype is designed in the 65-nm CMOS. The prototype can be configured as a transmit (TX) or receive (RX) element in DBFs or FC-HBFs which can in turn be configured to support TDD, FDD, or FD operation. The front-end achieves 16-/11-dB RX gain, 6.2-/7-dB NF, 15.8-/16.8-dBm saturated PA output power, and 20%/21.6% peak PA efficiency in the 28-/37-GHz bands. Extensive characterization results are presented to compare the energy efficiencies of the PC-HBF and FC-HBF architectures. The prototype is also characterized in the FDD/FD mode and achieves 36-dB peak RF-domain SIC and better than 26-dB RF-domain SIC across 0.5-GHz modulation bandwidth.
Fair co-existence of Licensed Assisted Access LTE (LAA-LTE) and Wi-Fi in unlicensed spectrum (2015)

Continued growth in wireless data demands has driven the need for more spectrum. Both licensed and unlicensed spectrum solutions are being deployed and viewed as complementary in dealing with the wireless traffic explosion. For example, Wi-Fi is being used successfully to assist in offloading the more spectrally constrained licensed band systems. At the heart of Wi-Fi's success is the premise of fair co-existence so that multiple Wi-Fi system owners can deploy Wi-Fi access points in the same unlicensed spectrum in an unmanaged fashion. Given Wi-Fi's success, the idea of leveraging unlicensed spectrum with LTE is being proposed through a feature called Licensed Assisted Access (LAA-LTE). This paper reports our findings in designing LBT mechanisms for LAA-LTE to ensure that it operates at least as fairly as Wi-Fi in unlicensed spectrum. These findings are based on our simulation results of co-existence performance between LAA-LTE and Wi-Fi for different candidate LBT schemes as reported in this paper. It concludes that for fair co-existence LBT is essential for LAA-LTE, but also that the choice of LBT scheme and settings of that scheme matter, with those proposed in current European regulations likely to result in Wi-Fi being disadvantaged.
Atomic topical segments detection for instructional videos (2006)

This paper presents our latest work on structuring instructional videos into units of atomic topical segment so as to facilitate topic-based video browsing and offer efficient video authoring. Specifically, we developed a comprehensive text analysis component to first extract informative text cues such as keyword synonym set and sentence boundary information, from a video's transcript. These text cues are then applied with various audiovisual cues such as silence/music break and speech similarity, to identify topical segments. Early experiments carried out on collections of real data from targeted user communities have yielded good results, and the user feedback on using the generated topical segment information is very encouraging.
Autocorrection in MR Imaging: Adaptive Motion Correction without Navigator Echoes (2000)

A technique for automatic retrospective correction of motion artifacts on magnetic resonance (MR) images was developed that uses only the raw (complex) data from the MR imager and requires no knowledge of patient motion during the acquisition. The algorithm was tested on coronal images of the rotator cuff in a series of 144 patients, and the improvements in image quality were similar to those achieved with navigator echoes. The results demonstrate that autocorrection can significantly reduce motion artifacts in a technically demanding MR imaging application.
Computerized hand diagnostic/rehabilitation system using a force feedback glove. (1997)

This paper describes recent results of a unified computerized system for hand diagnosis and rehabilitation. Automatic diagnosis data collection and Virtual Reality rehabilitation exercises are the main characteristics of the system. The diagnosis subsystem includes a tactile sensing glove in addition to standard devices such as electronic dynamometer, pinchmeter and goniometer. Three standard rehabilitation exercises were simulated in a Virtual Reality environment, using the WorldToolKit graphics library. The first two exercises (ball squeezing and DigiKey) allow measurement of finger forces exerted during the rehabilitation routine. The third exercise (Peg board) involves the patient's visual-motor coordination. The rehabilitation subsystem uses a VPL DataGlove retrofitted with Rutgers Master (RM-I) and its interface. The exercises involve manipulation of objects with different stiffnesses and geometry. Grasping forces were modeled and fed back using the Rutgers Master worn on patient's hand. Data is gathered in real time from both diagnosis and rehabilitation subsystems. Finger specific forces recorded during rehabilitation exercises allow better diagnosis of the patient impairment. An ORACLE database is used to store and manipulate patients' records. Proof of concept trials were performed in a clinical environment. Some results of patient records analysis are presented in this paper. A new version of the system using an RM II haptic interface is presently under consideration.
Distributed feedback quantum cascade lasers on silicon (2016)

We demonstrate distributed feedback (DFB) quantum cascade lasers (QCLs) that are heterogeneously integrated on silicon. The lasers emit up to 210 mW of pulsed power at room temperature, and operate up to 100 °C.
A highly efficient receiver for satellite-based Automatic Identification System signal detection (2014)

An innovative receiver architecture for the satellite-based Automatic Identification System (AIS) has been recently proposed. In this paper, we describe a few modifications that can be introduced on the algorithms for synchronization and detection, that provide an impressive performance improvement with respect to the previous system. The receiver architecture has been designed for an on-board implementation, and for this reason all algorithms have been realized keeping the complexity as low as possible. A prototype for the proposed receiver has been implemented by the University of Parma and CGS S.p.A. Compagnia Generale per lo Spazio under the ESA project FENICE.
Proteomic approaches to studying protein tyrosine phosphatases (2007)

Protein tyrosine phosphatases (PTPs) constitute a large family of enzymes that play key roles in cell signaling. Deregulation of PTP activity results in aberrant tyrosine phosphorylation, which has been linked to the etiology of several human diseases, including cancer. Since phosphate removal by the PTPs can both enhance and antagonize cellular signaling, it is essential to elucidate the physiological context in which PTPs operate. Two powerful proteomic approaches have been developed to rapidly establish the exact functional roles for every PTP, both in normal cellular physiology and in pathogenic conditions. In the first, an affinity-based substrate-trapping approach has been employed for PTP substrate identification. Identification and characterization of specific PTP-substrate interactions will associate functions with PTP as well as implicate PTP to specific signaling pathways. In the second, a number of activity-based PTP probes have been developed that can provide a direct readout of the functional state of the PTPs in complex proteomes. The ability to profile the entire PTP family on the basis of changes in their activity is expected to yield new functional insights into pathways regulated by the PTPs and contribute to the discovery of PTPs as novel therapeutic targets. Effective application of these proteomic techniques will accelerate the functional characterization of PTPs, thereby facilitating our understanding of PTPs in cell signaling and in diseases.
Studying the impact of hardware prefetching and bandwidth partitioning in chip-multiprocessors (2011)

Modern high performance microprocessors widely employ hardware prefetching technique to hide long memory access latency. While very useful, hardware prefetching tends to aggravate the bandwidth wall, a problem where system performance is increasingly limited by the availability of the off-chip pin bandwidth in Chip Multi-Processors (CMPs).
Test Generation for Timing-Critical Transition Faults (2007)

Timing-aware ATPG [1] has been shown to be an effective method for generating high-quality test sets that detect small delay defects through the longest paths. However, this method usually results in a much higher test pattern count than the traditional transition fault test generation. In this paper, we propose a new criterion that identifies a subset of transition faults to be targeted by the timing-aware ATPG in order to reduce test pattern count while minimizing the impact on the overall delay test quality. The new criterion utilizes the minimal static slack to classify certain transition faults as timing-critical. The test pattern count reduction is achieved by restricting the timing-aware ATPG to targeting the timing-critical transition faults while using traditional transition fault test generation for the remaining transition faults. The experimental results for the industrial circuits show the effectiveness of the proposed method.
Automatic quantification of local and global articular cartilage surface curvature: Biomarkers for osteoarthritis? (2008)

The objective of this study was to quantitatively assess the surface curvature of the articular cartilage from low-field magnetic resonance imaging (MRI) data, and to investigate its role in populations with varying radiographic signs of osteoarthritis (OA), cross-sectionally and longitudinally. The curvature of the articular surface of the medial tibial compartment was estimated both on fine and coarse scales using two different automatic methods which are both developed from an automatic 3D segmentation algorithm. Cross-sectionally (n=288), the surface curvature for both the fine- and coarse-scale estimates were significantly higher in the OA population compared with the healthy population, with P<0.001 and P<<0.001, respectively. For the longitudinal study (n=245), there was a significant increase in fine-scale curvature for healthy and borderline OA populations (P<0.001), and in coarse-scale curvature for severe OA populations (P<0.05). Fine-scale curvature could predict progressors using the estimates of those healthy at baseline (P<0.001). The inter-scan precision was 2.2 and 6.5 (mean CV) for the fine- and coarse scale curvature measures, respectively. The results showed that quantitative curvature estimates from low-field MRI at different scales could potentially become biomarkers targeted at different stages of OA.
Subband Decomposition for High-Resolution Color in HEVC and AVC 4:2:0 Video Coding Systems (2014)

Summary form only given. High-resolution color video (in 4:4:4 format) is becoming increasingly important for screen content and graphics. We have developed a frame packing arrangement (FPA) scheme that enables transmission of 4:4:4 luma-chroma (YUV or YCoCg) content through conventional subsampled chroma (4:2:0) codecs as an approach for low-cost support of 4:4:4 content. We focus on the "band separation" method initially discussed in [1] and evaluate new scenarios with the 4:4:4 and 4:2:0 versions at similar compression levels. We use the HEVC HM12.0 reference software for evaluating the FPA scheme. We vary the luma QP for the main 4:2:0 representation from 10 to 34, keeping the QP for the main frame's chroma and auxiliary frame's luma and chroma (containing three-fourths of the 4:4:4 chroma data) at the same value as the luma QP. We then compare the final 4:4:4 chroma rate-distortion performance of band separation, direct frame packing, and native HM 4:4:4 encoding. We also show preliminary results for lifting-based band separation (with clipping), which eliminates the inherent rounding errors of other band separation filters and provides better rate-distortion performance. Fig. 1 provides an example for a typical case of the new results showing that both the "band separation" and "lifting-based band separation" approaches have much better performance than previously reported, and are significantly better than the earlier-developed "direct" frame packing approach. Although the rate-distortion performance is inferior to that of native HM 4:4:4 coding, the FPA scheme enables the use of existing 4:2:0 decoding hardware, thus allowing for considerable battery power savings in mobile devices. A more complete discussion and evaluation is available in [2].
Natural Network Coding in Multi-Hop Wireless Networks (2008)

Cooperative communication has been intensively studied in recent years. In cooperative communication, cooperative users are grouped into clusters to form virtual MIMO channels. However, existing work mainly aims at achieving diversity gain, while generally overlooks the spatial multiplexing property of MIMO channels. In this paper, we address spatial multiplexing by introducing natural network coding protocol (NNC). In a user cooperative scenario, NNC takes advantage of the natural randomness of wireless channels. Simulation experiments show that NNC greatly reduces bit error probability and achieves about 70% throughput gain over time sharing transmission protocols.
Synthesis, X-ray Crystallography, and Pharmacokinetics of Novel Azomethine Prodrugs of (R)-.alpha.-Methylhistamine: Highly Potent and Selective Histamine H3 Receptor Agonists (1995)

Since various neuroregulatory functions of the histamine H3 receptor have been proved during the last few years, the H3 receptor is of current interest. Azomethine derivatives of the highly potent histamine H3 receptor agonist (R)-alpha-methylhistamine (1) were prepared as lipophilic prodrugs to improve the bioavailability of the hydrophilic drug, particularly its entry into the brain. Additionally, azomethine derivatization provides protection against histamine methyltransferase, the major metabolizing enzyme in man, and thus efficiently enhances the bioavailability of 1. The molecular conformations of (R)-2(-)[[N(-)[1-(1H-imidazol-4-yl)-2-propyl]- imino]phenylmethyl]phenol (9a) and (R)-4-fluoro-2(-)[[N(-)[1-(1H-imidazol-4-yl)-2-propyl[imino]- (4-chlorophenyl)methyl]phenol (9p) were determined by X-ray structure analysis. An intramolecular hydrogen bond which is essential for the stability of these azomethines was thereby confirmed. Moreover, the pharmacokinetic parameters of the prodrugs were investigated in vitro as well as in vivo. The halogenated azomethines have an effect following peroral administration in mice, and some of them seem to be highly potent for the central nervous system (CNS) delivery of 1. At present the most potent prodrug of 1 is (R)-4-chloro-2(-)[[N(-)[1-(1H-imidazol-4-yl)-2-propyl]imino](4- chlorophenyl)methyl]phenol (9q), reaching by far the highest CNS level of 1 (Cmax = 71 ng/g). Prodrugs of this type are not only valuable pharmacological tools but may also become H3 histaminergic drugs for therapeutic use.
Luminescence spot test for screening of PCBs (1994)

There is a critical demand to have a rapid and simple technique for screening polychlorinated biphenyls (PCBs) under field conditions. The use of field screening analysis allows rapid decisions in a cleanup operation and reduces the need for either return visits to a site by a cleanup crew or extensive and costly laboratory analysts of samples that contain no detectable levels of PCBs. Field screening techniques also reduce the cost of remedial actions by preventing unnecessary excavation of uncontaminated soil. This paper describes a new method based on enhanced photoactivated luminescence (EPL) for rapid detection of polychlorinated biphenyls (PCBs). The EPL method described here is a unique procedure combining several processes including (1) photoactivation by UV irradiation, (2) excitation of the photoproduct complex, and (3) fluorescence detection of the product. The EPL procedure is simple and rapid and can be performed as a spot test method under field conditions. The methodology for determination of total chlorine content of complex PCB mixtures is described.
Antioxidant and Antiinflammatory Activities of Anthocyanins and Their Aglycon, Cyanidin, from Tart Cherries (1999)

The anthocyanins (1-3) and cyanidin isolated from tart cherries exhibited in vitro antioxidant and antiinflammatory activities comparable to commercial products. The inhibition of lipid peroxidation of anthocyanins 1-3 and their aglycon, cyanidin, were 39, 70, 75, and 57%, respectively, at 2-mM concentrations. The antioxidant activities of 1-3 and cyanidin were comparable to the antioxidant activities of tert-butylhydroquinone and butylated hydroxytoluene and superior to vitamin E at 2-mM concentrations. In the antiinflammatory assay, cyanidin gave IC50 values of 90 and 60 mM, respectively, for prostaglandin H endoperoxide synthase-1 and prostaglandin H endoperoxide synthase-2 enzymes.
Optomechanical Design of a Hard X-ray Nanoprobe Instrument with Nanometer-Scale Active Vibration Control (2007)

We are developing a new hard x‐ray nanoprobe instrument that is one of the centerpieces of the characterization facilities of the Center for Nanoscale Materials being constructed at Argonne National Laboratory. This new probe will cover an energy range of 3–30 keV with 30‐nm spacial resolution. The system is designed to accommodate x‐ray optics with a resolution limit of 10 nm, therefore, it requires staging of x‐ray optics and specimens with a mechanical repeatability of better than 5 nm. Fast feedback for differential vibration control between the zone‐plate x‐ray optics and the sample holder has been implemented in the design using a digital‐signal‐processor‐based real‐time closed‐loop feedback technique. A specially designed, custom‐built laser Doppler displacement meter system provides two‐dimensional differential displacement measurements with subnanometer resolution between the zone‐plate x‐ray optics and the sample holder. The optomechanical design of the instrument positioning stage system with nanometer‐scale active vibration control is presented in this paper.
A Digital Predistortion System With Extended Correction Bandwidth With Application to LTE-A Nonlinear Power Amplifiers (2014)

This article presents a bandwidth extended digital predistortion system suitable for LTE-advanced applications. The proposed predistortion system uses a two-box architecture based on the cascade of a memory polynomial followed by a memoryless predistortion function. The memoryless predistorter is identified offline and used to perform a coarse linearization which cancels out most of the static nonlinearity of the device under test allowing for a reduced observation bandwidth for the synthesis of the memory polynomial predistortion sub-function. The proposed predistorter was experimentally validated and its performance benchmarked against a predistorter having the same structure but identified using the conventional approach. The measurement results demonstrate that the proposed predistorter requires 30% less sampling speed for the analog to digital converter of the feedback path.
Shorted Bowtie Patch Antenna With Less Susceptibility to Surface Condition (2015)

An antenna with less susceptible to surface condition is proposed in this communication. By adding a pair of parasitic shorted patches at the side of a shorted bowtie patch antenna, very low back radiation can be achieved within entire operating bandwidth. Frontto-back ratio, impedance bandwidth and peak gain are over 30 dB, 12.23% and 6.5 dB, respectively, and confirmed by measurement. The proposed antenna has thickness and projection area of only 0.08 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> and 0.77 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> × 0.77 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> . A prototype for 5.8-GHz ISM band application (5.725-5.875 GHz) is also designed. Experimental results confirmed that the reflection coefficient, gain, and radiation pattern have been less affected by mounting on different types of surfaces like human wrist, phantom hand, phantom head, or large metal sheet. Its potential applications include 5.8G Wi-Fi, on-body communication, biometric applications, wearable healthcare, and biomedical devices.
Complexation of basic fibroblast growth factor with gelatin (1998)

Polyion complexation between basic fibroblast growth factor (bFGF) and gelatin was studied by the turbidity change of mixed solution, heparin high performance liquid affinity chromatography (HPLAC), and isoelectric electrophoresis. When an aqueous solution of acidic gelatin with an isoelectric point (IEP) of 5.0 was mixed with that of bFGF, the turbidity of the mixed solution increased with time, whereas basic gelatin with and IEP of 9.0 did not cause any solution turbidity. A maximum turbidity of the mixed bFGF and acidic gelatin solution was observed around a bFGF/gelatin molar ratio of 1.0, irrespective of the gelatin concentration and solution temperature. The solution turbidity decreased with an increase in the ionic strength of the mixed solution. Complexation of bFGF with acidic gelatin was slower than that with poly(acrylic acid) probably because of the lower density of gelatin negative charge than that of poly(acrylic acid). HPLAC study revealed that complexation of bFGF with the acidic gelatin reduced the affinity of bFGF for heparin, in contrast to the basic gelatin, although the extent became smaller with the increasing ionic strength of the solution. An electrophoretic experiment showed that the IEP of bFGF shifted to a lower value after its gelatin complexation. These findings indicate that an electrostatic interaction is the main driving force for the complexation between acidic gelatin and basic bFGF.