gebhart/patrepeval huggingface dataset:
Symmetric and antisymmetric resonances in a pair of metal-dielectric nanoshells: tunability and closed-form formulas (2010)

Resonances of symmetric and antisymmetric polarization states in tightly coupled nanoshell particles made of either a metallic core and a dielectric shell or, vice versa, a dielectric core and a metallic shell were analyzed at optical frequencies. The investigation was performed by using the single dipole approximation (SDA) with all the dynamical retarded field terms included. Furthermore, analytic formulas for the four possible resonances were derived for the first time by retaining only the static (non-retarded) term in the dipolar field expression. The image principle was used to distinguish a priori between symmetric and antisymmetric modes and for full-wave simulations performed to confirm the identification of resonances achieved by the SDA. It was observed that the resonance frequencies of a pair of nanoshells can be tuned over a wide range of wavelength/frequencies by varying the relative dimensions of the core and shell. This makes this kind of particle pairs suited very well to be adopted either as constituents of metamaterials or to enhance local fields when operating frequencies range from the visible to the infrared spectral regions.
Empirical and substantive models, the Bayesian paradigm, and meta-analysis in functional brain imaging (1997)

Functional neuroimaging research is currently rediscovering and adapting established statistical methods for its use, including design of experiments, the general linear model, contrasts, random field theory, longitudinal models, Fourier analysis, and general signal and image processing methods. This brief paper gives an example of comparative performance of five different statistical models applied to the same set of data generated in an fMRI study of motor cortex. These methods include a two-sample t-statistic, a Kolmogorov-Smirnov statistic, a principal component/canonical variates approach, a pruned feed-forward artificial neural network with one hidden layer, and a frequency domain regression convolution model allowing for spatially varying hemodynamic responses. Produced by essentially empirical statistical models, there appear to be more similarities than differences in these spatial activation patterns, yet all lack explicit incorporation of substantive prior information. Distinctions are drawn between exploratory models for hypothesis generation and confirmatory models for hypothesis testing. In addition, the Bayesian paradigm helps to combine empirical and substantive models, and meta-analysis provides a rational means by which to combine information over a range of similar results affected minimally by publication bias.
Evil primes and superspecial moduli (2006)

For a quartic non-biquadratic CM field K, we say that a rational prime p is evil forK if at least one of the principally polarized abelian varieties with CM by K reduces modulo a prime ideal p|p to a product of supersingular elliptic curves with the product polarization. We showed that for fixed K, such primes are bounded by a quantity related to the discriminant of K. We show that evil primes are ubiquitous in the sense that for any rational prime p, there are an infinite number of such CM fields K for which p is evil. (Assuming a standard conjecture, the result holds for a finite set of primes simultaneously.) The proof consists of two parts: (1) showing the surjectivity of the principally polarized abelian varieties with CM by K, for K satisfying some conditions, onto the superspecial points of the reduction modulo p of the Hilbert modular variety associated to the intermediate real quadratic field of K, and (2) showing the surjectivity of the superspecial points of the reduction modulo p of the Hilbert modular variety associated to a real quadratic field with large enough discriminant onto the superspecial points on the reduction modulo p of the Siegel moduli space parameterizing abelian surfaces with principal polarization.
Terminated LDPC convolutional codes over GF(2<sup>p</sup>) (2010)

In this paper, we present a construction method of terminated non-binary low-density parity-check (LDPC) convolutional codes. Our construction method is an expansion of Felstrom and Zigangirov construction [1] for non-binary LDPC convolutional codes. The rate-compatibility of the non-binary LDPC convolutional codes is also discussed. The proposed rate-compatible code is designed from one single mother (2,4)-regular non-binary LDPC convolutional code of rate 1/2. Higher-rate codes are produced by puncturing the mother code and lower-rate codes are produced by multiplicatively repeating the mother code. For moderate values of the syndrome former memory, simulation results show that mother non-binary LDPC convolutional code outperform binary LDPC convolutional codes with comparable constraint bit length. And the derived low-rate and high-rate non-binary LDPC convolutional codes exhibit good decoding performance without loss of large gap to the Shannon limits.
THz generation with photoconductive emitters with a low-noise GHz repetition rate laser (2022)

Photoconductive emitters and receivers are widely accepted as the best combination for applications requiring broadband and high dynamic range and are nowadays deployed in most commercially available systems. Novel laser sources with higher repetition rate and power levels are a promising route towards further improvements in this area. We present our first steps in this direction by combining state-of-the-art emitters and receivers with an ultra-stable commercial fs laser (MENHIR-1550 SERIES) at 1 GHz repetition rate as the optical source. The output of the laser is amplified and compressed by a commercial fiber amplifier setup. In this experiment, we use 17 mW as the probe beam and 30 mW as the pump beam with a pulse duration of 150 fs, as these are the best operation points for the emitter and receiver available. The emitter is based on iron doped InGaAs in a strip line geometry with an active region of 50 μm x 50 μm while a fiber coupled dipole antenna with a 10 μm gap is used as the receiver. We demonstrate a 1 GHz repetition rate terahertz time-domain spectroscopy (THz-TDS) system with a dynamic range of 73 dB and a bandwidth of 3.5 THz using state-of-the-art THz photoconductive emitter and receiver with a measurement time of 60 s. This result is part of a larger effort to understand the compromises to be realized in terms of repetition rate and average power to take photoconductive emitters and receivers to the next step in dynamic range enhancement.
Maximum Likelihood Estimation of Nominal Direction of Arrival and Angular Spread Using and Array of Sensors (1994)

Maximum Likelihood Estimation of Nominal Direction of Arrival and Angular Spread Using and Array of Sensors
Comparison of the Effects of Calcitonin Gene-Related Peptide and Amylin on Osteoblasts (1999)

Calcitonin gene-related peptide (CGRP) and amylin are homologous 37-amino-acid peptides which have been demonstrated to have anabolic effects on bone. It is not clear whether these effects are mediated by a common receptor, nor is it known which ligand is the more potent. These questions are addressed in the present study using cultures of fetal rat osteoblasts. CGRP increased cell number when present in a concentration >/=10-9 M, but 10-8 M CGRP was required to stimulate thymidine and phenylalanine incorporation. Amylin was effective on these indices at 100-fold lower concentrations, and its maximal effects were about twice as great as those of CGRP. ED50's for the effects of amylin and CGRP on cell number were 10-12 M and 10-10 M, respectively. There was no additivity between maximal doses of the peptides on these indices. The effects of specific receptor blockers on the maximal stimulation of cell number by these peptides were also studied. The CGRP receptor-blocker, CGRP-(8-37), completely blocked the effect of CGRP at blocker concentrations >/=10-9 M. In contrast, the amylin receptor blocker, amylin-(8-37), completely blocked the effects of CGRP when the blocker was present in concentrations as low as 10-11 M. The KI of CGRP-(8-37) was 2 x 10-10 M and that of amylin-(8-37) was 7 x 10-12 M. In converse experiments studying the blockade of maximal doses of amylin, amylin-(8-37) 10-10 M was effective (KI 1 x 10-10 M), whereas a 100-fold greater concentration of CGRP-(8-37) was necessary to achieve the same effect (KI 6 x 10-9 M). It is concluded that amylin and CGRP probably act through a common receptor to stimulate osteoblast growth, and that this receptor has a higher affinity for amylin than for CGRP.
A constant-directivity beamforming microphone array (1994)

The quality of audio teleconferencing in large rooms and noisy environments can be increased with the use of steerable directional microphone arrays. A minimum bandwidth of 4 oct is required to faithfully transmit the speech signal. In a typical teleconferencing arrangement, only discrete angular directions are of interest and therefore the microphone steering directions are quantized. A standard delay-sum beamformer can result in noticeable frequency response changes as the talker moves between these steering locations. In an effort to mitigate this problem, a broadband constant-directivity beamformer has been designed and constructed. A few of the algorithms developed in this work will be discussed and compared to existing techniques. Basically, the solution revolves around the design of FIR filters that are inserted in the delay-sum beamformer after each element. A constant-beamwidth 4 oct steerable linear array microphone using directional elements will be described. A real-time implementation utilizing multiple AT&amp;T DSP3210 digital signal processors is also described.
Too Sharp for its Own Good – Tool Edge Deformation Mechanisms in the Initial Stages of Metal Cutting (2017)

Metal cutting simulations have become an important part of cutting tool design and the research in the field in general. One of the most important aspects of modeling is the accuracy of the tool geometry. 3D microscopy is used for measuring the tool edge radius with good accuracy. However, especially with sharp tools, i.e. small tool edge radii, the measurements, no matter how accurate, are not much of a use, since the initial wear, or deformation is so fast in the first 1-30 seconds into the cutting, that the tool geometry is significantly different than the one measured from the new tool. The average tool life is often set to 15 minutes. Therefore, the cutting simulations that only predict the tool behavior in the first seconds of its lifetime are not very useful in predicting the process variables throughout the tool life. Simulations with creep and elastic-plastic material model however, can predict the initial deformation of the tool. This tool shape can be then used in rigid tool model to predict the process variables in the steady wear region of the tool life. This paper presents simulation model for predicting the initial tool edge deformation for WC-10%Co tool while machining AISI 304 stainless steel. The novelty in this approach is the simultaneous coupled calculation of contact surface temperature and stress and change of the tool shape.
A Systems Approach to Predict Oncometabolites via Context-Specific Genome-Scale Metabolic Networks (2014)

Altered metabolism in cancer cells has been viewed as a passive response required for a malignant transformation. However, this view has changed through the recently described metabolic oncogenic factors: mutated isocitrate dehydrogenases (IDH), succinate dehydrogenase (SDH), and fumarate hydratase (FH) that produce oncometabolites that competitively inhibit epigenetic regulation. In this study, we demonstrate in silico predictions of oncometabolites that have the potential to dysregulate epigenetic controls in nine types of cancer by incorporating massive scale genetic mutation information (collected from more than 1,700 cancer genomes), expression profiling data, and deploying Recon 2 to reconstruct context-specific genome-scale metabolic models. Our analysis predicted 15 compounds and 24 substructures of potential oncometabolites that could result from the loss-of-function and gain-of-function mutations of metabolic enzymes, respectively. These results suggest a substantial potential for discovering unidentified oncometabolites in various forms of cancers.
The inner workings of phase change memory: Lessons from prototype PCM devices (2010)

We describe observations into the inner workings of phase change memory devices, obtained by fabrication, electrical characterization, failure analysis, and modeling of prototype phase change memory devices over the past few years. Experiments involving the RESET and SET operations, the speed of SET operations, the impact of voltage polarity, and the drift of RESET resistances after programming have been performed. Our prototype devices include PCM “pore” devices down to 20 nm in actual diameter, PCM “bridge” devices down to 20 nm in width, and novel “parallel cell” devices designed to trade off resistance contrast for lower resistance drift. Simple resistors integrated in series with these devices allow programming with pulses down to <;10ns pulse-widths. Highly accurate current measurements can be triggered as soon as 1 millisecond after programming, so that even five-minute-long measurements can capture drift over five orders of magnitude in time. A customized finite-difference PCM simulator is capable of handling large and arbitrary 3-D structures, and can be matched against fast electrical SET and RESET experiments, slow thin-film crystallization experiments, or optical pulse experiments. Our results suggest that many of the idiosyncrasies of real PCM devices - “telegraph”-like noise, the dependence of SET resistance on pulse duration, and the variability of both repeated programming events and drift measurements even on the same device - can be traced to the important yet under-appreciated role of poly-crystalline grains and grain boundaries within the PCM device.
Mechanistic analysis of the reactions of (pentafluorophenyl)nitrene in alkanes (1991)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMechanistic analysis of the reactions of (pentafluorophenyl)nitrene in alkanesMary J. T. Young and Matthew S. PlatzCite this: J. Org. Chem. 1991, 56, 22, 6403–6406Publication Date (Print):October 1, 1991Publication History Published online1 May 2002Published inissue 1 October 1991https://pubs.acs.org/doi/10.1021/jo00022a036https://doi.org/10.1021/jo00022a036research-articleACS PublicationsRequest reuse permissionsArticle Views502Altmetric-Citations45LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-AlertscloseSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts
Thermal Processing of Diblock Copolymer Melts Mimics Metallurgy (2016)

Small-angle x-ray scattering experiments conducted with compositionally asymmetric low molar mass poly(isoprene)-b-poly(lactide) diblock copolymers reveal an extraordinary thermal history dependence. The development of distinct periodic crystalline or aperiodic quasicrystalline states depends on how specimens are cooled from the disordered state to temperatures below the order-disorder transition temperature. Whereas direct cooling leads to the formation of documented morphologies, rapidly quenched samples that are then heated from low temperature form the hexagonal C14 and cubic C15 Laves phases commonly found in metal alloys. Self-consistent mean-field theory calculations show that these, and other associated Frank-Kasper phases, have nearly degenerate free energies, suggesting that processing history drives the material into long-lived metastable states defined by self-assembled particles with discrete populations of volumes and polyhedral shapes.
Experimental observation of superscattering (2018)

Superscattering, induced by degenerate resonances, breaks the fundamental single-channel limit of scattering cross section of subwavelength structures; in principle, an arbitrarily large total cross section can be achieved via superscattering. It thus provides a unique way to strengthen the light-matter interaction at the subwavelength scale, and has many potential applications in sensing, energy harvesting, bio-imaging (such as magnetic resonance imaging), communication and optoelectronics. However, the experimental demonstration of superscattering remains an open challenge due to its vulnerability to structural imperfections and intrinsic material losses. Here we report the first experimental evidence for superscattering, by demonstrating the superscattering simultaneously in two different frequency regimes through both the far-field and near-field measurements. The underlying mechanism for the observed superscattering is the degenerate resonances of confined surface waves, by utilizing a subwavelength metasurface-based multilayer structure. Our work paves the way towards practical applications based on superscattering.
THE ROLE OF INSTITUTIONS IN THE REVIVAL OF TRADE: THE LAW MERCHANT, PRIVATE JUDGES, AND THE CHAMPAGNE FAIRS (1990)

A good reputation can be an effective bond for honest behavior in a community of traders if members of the community know how others have behaved in the past – even if any particular pair of traders meets only infrequently. In a large community, it would be impossibly costly for traders to be perfectly informed about each other's behavior, but there exist institutions that can restore the effectiveness of a reputation system using much less extensive information. The system of judges used to enforce commercial law before the rise of the state was such an institution, and it successfully encouraged merchants (1) to behave honestly, (2) to impose sanctions on violators, (3) to become adequately informed about how others had behaved, (4) to provide evidence against violators of the code, and (5) to pay any judgments assessed against them, even though each of these behaviors might be personally costly.
Method for Commercial Aircraft Nitric Oxide Emission Measurements (1999)

Worldwide increases in commercial air traffic have raised concerns about the effects of aircraft emissions on the atmosphere. The purpose of this study was to demonstrate the capability of a remote sensor, developed for the measurement of automobile emissions, in measuring nitric oxide emission indices from in-use aircraft on the ground without interfering with their normal operation. In two days of sampling at London Heathrow Airport, a total of 122 measurements were made of 90 different aircraft in a mix of idle, taxi-out, and takeoff modes. Aircraft measured at idle exhibited little nitric oxide emission. Emission indices measured from aircraft at higher thrust levels were not inconsistent with values from the ICAO Engine Exhaust Emissions Databank.
Laser ablation plume of FeSi 2 alloy target studied by TOF mass and optical emission spectroscopies (2003)

Time-of-flight (TOF) mass and optical emission spectroscopies have been performed on the ablation plume from &#945;-FeSi<sub>2</sub> alloy target under KrF excimer laser irradiation at a fluence of 0.35-2.5J/cm<sup>2</sup> to characterize the mass, kinetic energies and excited states of the ejected species. According to the TOF mass measurements in vacuum, the most prominent species were Si and Fe atoms and ions over the entire fluence range, in addition to Si dimer. At 0.4-0.7 J/cm<sup>2</sup>, only neutrals of Si, Fe and Si<sub>2</sub> with the kinetic energy of around 0.2eV were observed. At the fluences above 0.7J/cm<sup>2</sup>, doubly and singly charged Si and Fe ions appeared abruptly increased their number density and kinetic energies from 6 eV at 0.7 J/cm<sup>2</sup> to over 100 eV at 2.5 J/cm<sup>2</sup>. Consistent with the TOF mass spectra, the optical emission lines stemmed from the monatomic Si and Fe as well as Si dimer in the wavelength range of 240-800 nm in vacuum. On the other hand, we confirmed some luminescent lines appeared only in helium atmosphere of 10 Torr, suggesting the cluster formation such as FeSi.
Protection of Video Packets over a Wireless Rayleigh Fading Link: FEC versus ARQ (2008)

Video content can be provided to an end user by transmitting video data as a sequence of internet protocol (IP) packets over the network. When the network contains a wireless link, packet erasures occur because of occasional deep fades. In order to maintain a sufficient video quality at the end user, video packets must be protected against erasures by means of a suitable form of error control. In this contribution, we investigate two types of error control: (1) forward error correction (FEC), which involves the transmission of parity packets that enables recovery of a limited number of erased video packets, and (2) the use of an automatic repeat request (ARQ) protocol, where the receiver requests the retransmission of video packets that have been erased. We point out that FEC and ARQ considerably reduce the probability of unrecoverable packet loss, because both error control techniques provide a diversity gain, as compared to the case where no protection against erasures is applied. We derive a simple analytical expression for the diversity gain resulting from FEC or ARQ, in terms of the channel coherence time, the allowable latency, and (for FEC) the allowable overhead or (for ARQ) the time interval between (re)transmissions of copies of a same packet. In the case of HDTV transmission over a 60 GHz indoor wireless link, ARQ happens to outperform FEC.
SEAGLE: Sparsity-Driven Image Reconstruction under Multiple Scattering (2017)

Multiple scattering of an electromagnetic wave as it passes through an object is a fundamental problem that limits the performance of current imaging systems. In this paper, we describe a new technique-called Series Expansion with Accelerated Gradient Descent on Lippmann-Schwinger Equation (SEAGLE)-for robust imaging under multiple scattering based on a combination of a new nonlinear forward model and a total variation (TV) regularizer. The proposed forward model can account for multiple scattering, which makes it advantageous in applications where linear models are inaccurate. Specifically, it corresponds to a series expansion of the scattered wave with an accelerated-gradient method. This expansion guarantees the convergence even for strongly scattering objects. One of our key insights is that it is possible to obtain an explicit formula for computing the gradient of our nonlinear forward model with respect to the unknown object, thus enabling fast image reconstruction with the state-of-the-art fast iterative shrinkage/thresholding algorithm (FISTA). The proposed method is validated on both simulated and experimentally measured data.