gebhart/patrepeval huggingface dataset:
A real-time implementation of a stereophonic acoustic echo canceler (2001)

Teleconferencing systems employ acoustic echo cancelers to reduce echoes that result from the coupling between loudspeaker and microphone. To enhance the sound realism, two-channel audio is necessary. However, stereophonic acoustic echo cancellation (SAEC) is more difficult to solve because of the necessity to uniquely identify two acoustic paths, which becomes problematic since the two excitation signals are highly correlated. In this paper, a wideband stereophonic acoustic echo canceler is presented. The fundamental difficulty of stereophonic acoustic echo cancellation is described and an echo canceler based on a fast recursive least squares (FRLS) algorithm in a subband structure, with equidistant frequency bands, is proposed. The structure has been used in a real-time implementation, with which experiments have been performed. In this paper, simulation results of this implementation on real life recordings, with 8 kHz bandwidth, are studied. The results clearly verify that the theoretic fundamental problem of SAEC also applies in real-life situations. They also show that more sophisticated adaptive algorithms are needed in the lower frequency regions than in the higher regions.
Sub-surface imaging by scanning thermal microscopy (1996)

Scanning probe thermal microscopy has been used to achieve sub-surface imaging of metallic particles embedded in a polymer matrix, using a probe which can act as both ohmic heater and thermometer. A lateral resolution of the order of a micron and a depth detection of a few microns were achieved. Together with the description of the technique and the experimental results obtained, a basic theoretical framework is presented which describes heat flow and temperature distributions within a sample consisting of inclusions buried within a bulk material. Computer models have been developed to give theoretical heat flows and temperature profiles: these are compared here with the experimental data. The theoretical lateral resolution was found to be in good agreement with the experimental observation. We show that theoretical modelling can be used to calibrate the instrument for specific investigations. For example, the technique could be used quantitatively to determine and map thermal conductivity variations across heterogeneous samples, or to determine the depth at which inclusions are located in the case where the thermal conductivities of both the inclusions and the enclosing material are known as well as the geometry of the inclusions.
Chiral Amplification Based on Enantioselective Dual-Phase Distribution of a Scalemic Bisoxazolidine Catalyst (2007)

A readily available bisoxazolidine ligand was found to catalyze the asymmetric alkylation of aldehydes with Et(2)Zn and less reactive Me(2)Zn, providing high yields and ee's in both reactions. The bisoxazolidine-catalyzed alkylations and alkynylation of benzaldehyde show a positive nonlinear effect that cannot be accounted for by Kagan's ML(n) model. The chiral amplification originates from selective phase distribution favoring enrichment of the major enantiomer of the scalemic catalyst in solution.
Microgyroscope with Vibrating Post as Rotation Transducer (2003)

The figure depicts a micromachined silicon vibratory gyroscope that senses rotation about its z axis. The rotation-sensitive vibratory element is a post oriented (when at equilibrium) along the z axis and suspended at its base by thin, flexible silicon bands oriented along the x and y axes, respectively. Unlike in the vibratory microgyroscopes described in the immediately preceding article ["Cloverleaf Vibratory Microgyroscope With Integrated Post" (NPO-20688)] and other previous articles in NASA Tech Briefs, the rotation-sensitive vibratory element does not include a cloverleaf-shaped structure that lies (when at equilibrium) in the x-y plane. As in the cases of the previously reported vibratory microgyroscopes, vibrations of the rotation-sensitive vibratory element are excited electrostatically, the vibrations are measured by use of capacitive proximity sensors, and the rate of rotation along the axis of sensitivity is deduced from the effect of the Coriolis force upon the vibrations. To create electrodes for electrostatic excitation and capacitive sensing of vibrations, portions of the facing surfaces of the post and of the four stationary members that surround the post are rendered electrically conductive; this can be accomplished by either depositing metal films or else doping the silicon in the affected areas.
Conversion of Enkephalin and Dermorphin into δ‐Selective Opioid Antagonists by Single‐Residue Substitution (1994)

The properties of di- and tri-peptides containing 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (Tic) in second position suggest that the message domain of opioid peptides can be composed of only two residues [Temussi, P. A., Salvadori, S., Amodeo, P., Guerrini, R., Tomatis, R., Lazarus, L. H., Picone, D. & Tancredi, T. (1994) Biochem. Biophys. Res. Commun. 198, 933-939]. As a crucial test of the possibility that the Tyr-Tic segment be a message domain in longer peptide sequences, we have inserted it in the sequences of two typical opioid peptides: [Leu]enkephalin, a non-selective agonist, and dermorphin, a selective mu agonist. Here we report the synthesis and biological activity of [L-Tic2]enkephalin, [L-Tic2]dermorphin, [L-Tic2]dermorphin carboxylic acid and [D-Tic2]dermorphin: all [L-Tic2]peptides were converted from agonists to delta-selective antagonists. The NMR conformational study in a dimethylsulfoxide/water cryoprotective mixture at low temperature shows diagnostic side-chain--side-chain NOEs in the spectra of all [L-Tic2]peptides and hints that the 90 degrees arrangement of the the two aromatic rings found in the cis-Tyr-L-Tic moiety, typical of N-methyl naltrindole and other delta-selective opiate antagonists, is responsible for the antagonist activity of all these peptides.
Competitive Metagenomic DNA Hybridization Identifies Host-Specific Microbial Genetic Markers in Cow Fecal Samples (2006)

Several PCR methods have recently been developed to identify fecal contamination in surface waters. In all cases, researchers have relied on one gene or one microorganism for selection of host-specific markers. Here we describe the application of a genome fragment enrichment (GFE) method to identify host-specific genetic markers from fecal microbial community DNA. As a proof of concept, bovine fecal DNA was challenged against a porcine fecal DNA background to select for bovine-specific DNA sequences. Bioinformatic analyses of 380 bovine enriched metagenomic sequences indicated a preponderance of Bacteroidales-like regions predicted to encode membrane-associated and secreted proteins. Oligonucleotide primers capable of annealing to select Bacteroidales-like bovine GFE sequences exhibited extremely high specificity (>99%) in PCR assays with total fecal DNAs from 279 different animal sources. These primers also demonstrated a broad distribution of corresponding genetic markers (81% positive) among 148 different bovine sources. These data demonstrate that direct metagenomic DNA analysis by the competitive solution hybridization approach described is an efficient method for identifying potentially useful fecal genetic markers and for characterizing differences between environmental microbial communities.
Ex Vivo Growth of Bioengineered Ligaments and Other Tissues (2005)

A method of growing bioengineered tissues for use in surgical replacement of damaged anterior cruciate ligaments has been invented. An anterior cruciate ligament is one of two ligaments (the other being the posterior cruciate ligament) that cross in the middle of a knee joint and act to prevent the bones in the knee from sliding forward and backward relative to each other. Anterior cruciate ligaments are frequently torn in sports injuries and traffic accidents, resulting in pain and severe limitations on mobility. By making it possible to grow replacement anterior cruciate ligaments that structurally and functionally resemble natural ones more closely than do totally synthetic replacements, the method could create new opportunities for full or nearly full restoration of functionality in injured knees. The method is also adaptable to the growth of bioengineered replacements for other ligaments (e.g., other knee ligaments as well as those in the hands, wrists, and elbows) and to the production of tissues other than ligaments, including cartilage, bones, muscles, and blood vessels. The method is based on the finding that the histomorphological properties of a bioengineered tissue grown in vitro from pluripotent cells within a matrix are affected by the direct application of mechanical force to the matrix during growth generation. This finding provides important new insights into the relationships among mechanical stress, biochemical and cell-immobilization methods, and cell differentiation, and is applicable to the production of the variety of tissues mentioned above. Moreover, this finding can be generalized to nonmechanical (e.g., chemical and electromagnetic) stimuli that are experienced in vivo by tissues of interest and, hence, the method can be modified to incorporate such stimuli in the ex vivo growth of replacements for the various tissues mentioned above. In this method, a three-dimensional matrix made of a suitable material is seeded with pluripotent stem cells. The patient s bone-marrow stromal cells are preferably used as the pluripotent cells in this method. Suitable matrix materials are materials to which cells can adhere for example, collagen type I. The seeded matrix is attached to anchors at opposite ends and then the cells in the matrix are cultured under conditions appropriate for the growth and regeneration of cells. Suitable anchor materials are materials to which the matrix can attach; examples include demineralized bone and Goinopra coral that has been treated to convert its calcium carbonate to calcium phosphate.
Surface control system for the 15 meter hoop-column antenna (1986)

The 15-meter hoop-column antenna fabricated by the Harris Corporation under contract to the NASA Langley Research Center is described. The antenna is a deployable and restowable structure consisting of a central telescoping column, a 15-meter-diameter folding hoop, and a mesh reflector surface. The hoop is supported and positioned by 48 quartz cords attached to the column above the hoop, and by 24 graphite cords from the base of the antenna column. The RF reflective surface is a gold plated molybdenum wire mesh supported on a graphite cord truss structure which is attached between the hoop and the column. The surface contour is controlled by 96 graphite cords from the antenna base to the rear of the truss assembly. The antenna is actually a quadaperture reflector with each quadrant of the surface mesh shaped to produce an offset parabolic reflector. Results of near-field and structural tests are given. Controls structures and electromagnetics interaction, surface control system requirements, mesh control adjustment, surface control system actuator assembly, surface control system electronics, the system interface unit, and control stations are discussed.
SynTF (2018)

Text mining and information retrieval techniques have been developed to assist us with analyzing, organizing and retrieving documents with the help of computers. In many cases, it is desirable that the authors of such documents remain anonymous: Search logs can reveal sensitive details about a user, critical articles or messages about a company or government might have severe or fatal consequences for a critic, and negative feedback in customer surveys might negatively impact business relations if they are identified. Simply removing personally identifying information from a document is, however, insufficient to protect the writer's identity: Given some reference texts of suspect authors, so-called authorship attribution methods can reidentfy the author from the text itself. One of the most prominent models to represent documents in many common text mining and information retrieval tasks is the vector space model where each document is represented as a vector, typically containing its term frequencies or related quantities. We therefore propose an automated text anonymization approach that produces synthetic term frequency vectors for the input documents that can be used in lieu of the original vectors. We evaluate our method on an exemplary text classification task and demonstrate that it only has a low impact on its accuracy. In contrast, we show that our method strongly affects authorship attribution techniques to the level that they become infeasible with a much stronger decline in accuracy. Other than previous authorship obfuscation methods, our approach is the first that fulfills differential privacy and hence comes with a provable plausible deniability guarantee.
ChemInform Abstract: In situ Preparation of a Highly Active N‐Heterocyclic Carbene‐Coordinated Olefin Metathesis Catalyst. (2001)

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Simultaneous and Synergistic Extraction of Cationic and Anionic Heavy Metallic Species by a Mixed Solvent Extraction System and a Novel Contained Liquid Membrane Device (1996)

Many wastewaters as well as aqueous solutions used for hydrometallurgical extractions have multiple toxic heavy metals: some are present as cations; others are present as anions. This research is directed toward extracting multiple heavy metallic species simultaneously into an appropriate mixed solvent and then recovering and concentrating such heavy metals into appropriate aqueous stripping solutions. Heavy metals of interest are Cu(II), Cr(VI), Zn(II), Hg(II), etc. Such processes have been carried out in a nondispersive fashion in microporous hydrophobic hollow fiber membrane-based devices containing multiple sets of fibers. The results will be presented, and the basis of the observed synergism will be discussed. The advantages of such extraction-stripping processes will be pointed out.
Towards discovery of event correlation rules (2002)

For large installations, event management is critical to ensuring service quality by responding rapidly to exceptional situations. The key to this is having experts encode their knowledge (e.g., in rules, state machines, codebooks) about the relationship between event patterns and actions to take. Unfortunately, doing so is time-consuming and knowledge-intensive. We propose reducing this burden by using offline decision support consisting of visualizing and mining event histories to discover patterns in event data. Our experience with a wide variety of production data has identified several patterns of interest such as, event bursts and partial periodicities. Herein, we use production data to illustrate how to visualize and mine event patterns, and we describe a tool we have developed to aid in pattern discovery.
Lifting Gate Polydimethylsiloxane Microvalves and Pumps for Microfluidic Control (2012)

We describe the development and characterization of pneumatically actuated "lifting gate" microvalves and pumps. A fluidic layer containing the gate structure and a pneumatic layer are fabricated by soft-lithography in PDMS and bonded permanently with an oxygen plasma treatment. The microvalve structures are then reversibly bonded to a featureless glass or plastic substrate to form hybrid glass-PDMS and plastic-PDMS microchannel structures. The break-through pressures of the microvalve increase linearly up to 65 kPa as the closing pressure increases. The pumping capability of these structures ranges from the nanoliter to microliter scale depending on the number of cycles and closing pressure employed. The micropump structures exhibit up to 86.2% pumping efficiency from flow rate measurements. The utility of these structures for integrated sample processing is demonstrated by performing an automated immunoassay. These lifting gate valve and pump structures enable facile integration of complex microfluidic control systems with a wide range of lab-on-a-chip substrates.
Pushing CDN-ISP collaboration to the limit (2013)

Today a spectrum of solutions are available for istributing content over the Internet, ranging from commercial CDNs to ISP-operated CDNs to content-provider-operated CDNs to peer-to-peer CDNs. Some deploy servers in just a few large data centers while others deploy in thousands of locations or even on millions of desktops. Recently, major CDNs have formed strategic alliances with large ISPs to provide content delivery network solutions. Such alliances show the natural evolution of content delivery today driven by the need to address scalability issues and to take advantage of new technology and business opportunities. In this paper we revisit the design and operating space of CDN-ISP collaboration in light of recent ISP and CDN alliances. We identify two key enablers for supporting collaboration and improving content delivery performance: informed end-user to server assignment and in-network server allocation. We report on the design and evaluation of a prototype system, NetPaaS, that materializes them. Relying on traces from the largest commercial CDN and a large tier-1 ISP, we show that NetPaaS is able to increase CDN capacity on-demand, enable coordination, reduce download time, and achieve multiple traffic engineering goals leading to a win-win situation for both ISP and CDN.
Electrochemical detector for liquid chromatographic determination of carbohydrates (1991)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectrochemical detector for liquid chromatographic determination of carbohydratesJavad M. Zadeii, Juan. Marioli, and Theodore. KuwanaCite this: Anal. Chem. 1991, 63, 6, 649–653Publication Date (Print):March 15, 1991Publication History Published online1 May 2002Published inissue 15 March 1991https://doi.org/10.1021/ac00006a019RIGHTS & PERMISSIONSArticle Views249Altmetric-Citations89LEARN 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 InReddit PDF (650 KB) Get e-Alerts Get e-Alerts
Few-mode multi-core fibre with highest core multiplicity factor (2015)

The highest relative core multiplicity factor of more than 22 is achieved by arranging a 6-mode 12-core fibre in 227-μm cladding. A quadratic double ring core arrangement realizes sufficiently low crosstalk and enables us to use advanced multi-level modulation.
Magnetic scanning tunneling microscopy: theory and experiment (1993)

We have developed magnetic force scanning tunneling microscopy as a powerful tool to analyze magnetic patterns on recording media with sub-micron resolution. The technique employs the interaction of surface magnetic fields with a flexible thin-film magnetic probe. We have made a thorough theoretical analysis of the interaction between the probe and the surface magnetic fields emanating from a typical recorded pattern. Quantitative data about the constituent magnetic fields and the underlying magnetization patterns can then be obtained. We have employed these techniques in studies of two of the most important issues of magnetic recording: data-density and data overwrite. In the course of these studies we have developed new techniques to analyze the magnetic fields of recorded media. These studies are both theoretical and experimental and combined with the use of our magnetic force scanning tunneling microscope should lead to further breakthroughs in the field of magnetic recording.
Theoretical basis and experimental confirmation: why a CMOS imager is superior to a CCD (1999)

Sub-micron CMOS has already enabled the development of IR focal plane array with ultra-low read noise and high sensitivity for many demanding applications. The successful monolithic integration of silicon photo detector with low- noise pixel-based amplifiers in fine pixel pitch via modern CMOS technology now suggests the imminent obsolescence of CCDs and photographic film for consumer uses. Specifically, we report the achievement of < 20 e- read noise at high data rates and video frame rate,s the confirmation of the fundamental superiority of the CMOS imager for visible imaging, and approximately 2X reduction in kTC noise without invoking classical correlated double sampling techniques. These suggest a strong likelihood reduction in kTC noise without invoking classical correlated double sampling techniques. These suggest a strong likelihood that the CCDs long reign is coming to an end.
Using Atom Transfer Radical Polymerization in Environmentally Benign Processes (2002)

Atom Transfer Radical Polymerization (ATRP) is a controlled/"living" radical polymerization system that allows for the synthesis of well-defined polymers with predetermined molecular weights, functionalities, and architectures. The ability to control these parameters enables the preparation of polymeric materials with novel, and heretofore unknown, utility. Materials prepared by ATRP perform more efficiently than comparable polymers, require less material to manufacture, and generate less catalytic waste than conventional processes. This paper describes the latest progress in the development of more efficient catalyst systems for ATRP, the extension to more environmentally friendly media, and some of the advanced materials prepared.
A High Data Rate Communications System Using Long Pulses. (1990)

Abstract : A communications system which decreases noise errors and increases information rate without sacrificing bandwidth is formed by a transmitter and a receiver designed to handle long pulse compression waveforms. An encoder connected to the transmitter converts a voice message into digitized voice words, encodes the digitized voice words into time shifted code sequences, and phase modulates the long pulse compression waveform, producing a M-ary coded signal at the output of the transmitter. The receiver is connected to a decoder which includes at least one convolver for computing the correlation of received digitally coded words with independently generated time shifted code sequences, and a controller for generating a plurality of data values according to the largest correlation values, and a transducer responsive to the data values. (Author)