gebhart/patrepeval huggingface dataset:
Precision Spacecraft Pointing Using Single-Gimbal Control Moment Gyroscopes with Disturbance (2000)

Whereas previous work has shown that gain stabilization methods in the attitude control of spacecraft can mitigate external disturbances of a e xed frequency, recent work in cases where the frequency of the disturbance is time variant is summarized here.Specie cally, theapplication ofgain stabilization in the form of a variableperiodic disturbancerejection e lter is shown to bea viablemethod ofmitigating these disturbances. To usethis e lter forthe time-variant case, the character of the source of the disturbance needs to be known a priori with some accuracy. An implementation for a spacecraft steered by single-gimbal control moment gyroscopes where the disturbance is related to the gimbal rate is demonstrated. In addition, performance of the subject e lter is demonstrated in the presence of estimation error and phase shift.
A stereoselective synthesis of the 24(R),25-dihydroxycholesterol side chain (1976)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA stereoselective synthesis of the 24(R),25-dihydroxycholesterol side chainJohn J. Partridge, Voldemar Toome, and Milan R. UskokovicCite this: J. Am. Chem. Soc. 1976, 98, 12, 3739–3741Publication Date (Print):June 1, 1976Publication History Published online1 May 2002Published inissue 1 June 1976https://pubs.acs.org/doi/10.1021/ja00428a076https://doi.org/10.1021/ja00428a076research-articleACS PublicationsRequest reuse permissionsArticle Views111Altmetric-Citations49LEARN 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-Alertsclose Get e-Alerts
Detecting Trustworthy Real-Time Communications Using a Web-of-Trust (2009)

Voice-over-IP protocols (e.g., SIP) are vulnerable to many types of attacks. One core challenge in preventing VoIP attacks is to assess the trustworthiness of the caller's identity. Further, spoofing attacks must be prevented by verifying that the call has been initiated by the user belonging to the caller's identity. In this paper, we propose to adapt a Web-of-Trust model to real-time communication in order to assess the trustworthiness of incoming VoIP calls based on the social relationships among users. We present the design of a system which is capable of cryptographically verifying trust chains associated with VoIP users in real-time, i.e., with minimal overhead during the regular processing of signaling messages. We highlight the benefits of such a system as well as its limitations, discuss open issues, and finally present an evaluation of the proposed approach based on a prototypical implementation. Our results show that indeed real-time cryptographic verification of trust chains among users is feasible for VoIP communications.
Interpretable Counting for Visual Question Answering (2018)

Questions that require counting a variety of objects in images remain a major challenge in visual question answering (VQA). The most common approaches to VQA involve either classifying answers based on fixed length representations of both the image and question or summing fractional counts estimated from each section of the image. In contrast, we treat counting as a sequential decision process and force our model to make discrete choices of what to count. Specifically, the model sequentially selects from detected objects and learns interactions between objects that influence subsequent selections. A distinction of our approach is its intuitive and interpretable output, as discrete counts are automatically grounded in the image. Furthermore, our method outperforms the state of the art architecture for VQA on multiple metrics that evaluate counting.
Congestion Control for Scalability in Bufferless On-Chip Networks (2011)

In this paper, we present network-on-chip (NoC) design and contrast it to traditional network design, highlighting both similarities and differences between NoCs and traditional networks. As an initial case study, we examine network congestion in bufferless NoCs. We show that congestion manifests itself differently in a NoC than in a traditional network. This both reduces system throughput in congested workloads for smaller NoC sizes (16 and 64 nodes), and limits the scalability of the bufferless NoC in larger configurations (256 to 4096 nodes) even when data is mapped with locality in mind. We propose a source throttling-based congestion control mechanism with application-level awareness. This mechanism improves system performance by up to 28 % (15 % on average in congested workloads) in smaller NoCs, and achieves linear throughput scaling in NoCs up to 4096 cores. Thus, we show an effective application of a network-level concept, congestion control, to a class of networks – bufferless on-chip networks – that has not been studied before by the networking community. 1
Low power VLSI sequential circuit architecture using critical race control (2003)

This paper describes a new architecture for VLSI sequential circuits and a method to control the critical races that appears subsequently in their feedback loops. This architecture reduces the number of gates resulting in lower power consumption and smaller area of implementation without incurring significant speed penalty. The critical races are controlled by introducing a delay difference between the sections of the loop. This is implemented by scaling the transmission gates already present in the circuit. This method which sizes transistors in close proximity is insensitive to variations in internal and external operating conditions. The paper presents low-power implementation of conventional circuits and of new circuits providing a higher level of integration. When used with asynchronous circuits this architecture enables the operation of circuits that are unusable using present techniques.
Finding selfies of users in microblogged photos (2014)

We examine the use of clustering to identify selfies in a social media user's photos. Faces are first detected within a user's photos followed by clustering using visual similarity. We define a cluster scoring scheme that uses a combination of within-cluster visual similarity and average face size in a cluster to rank potential selfie-clusters. Finally, we evaluate this ranking approach over a collection of Twitter users and discuss methods that can be used for improving performance in the future. An application of user selfies is estimating demographic information such as age, gender, and race in a more robust fashion.
Vector field animation with texture maps (1995)

Vector fields can represent magnetic, electrical, fluid, and gas velocity fields in engineering applications, as well as various displacement and strain fields. They implicitly contain a large amount of data not directly or easily observable. Computer graphics has several techniques to assist scientists and engineers in understanding the phenomena behind the analyzed data. The paper discusses a technique that uses time-dependent textures to animate vector data in 2D and 3D spaces. It can visualize large data sets when conventional methods are too slow or generate too cluttered a display.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
A New Power Gating Circuit Design Approach Using Double-Gate FDSOI (2016)

Power gating circuits are utilized to manage power consumption and thermal stress in microprocessors and other high-performance integrated circuits. Most of the power gating techniques utilize sleep transistors in different configurations to reduce the subthreshold leakage current, which is the primary source of the standby power. These sleep transistors, which are added between the supply lines and the circuits as header and footer switches, impose additional area, delay, power, and other overheads and complexities. This brief introduces the concept of combining the functionality of the sleep transistors with the logic devices by utilizing fully depleted silicon-on-insulator (FDSOI) device. This FDSOI transistor-based power gating circuit design approach will eliminate the requirement of employing a separate set of sleep transistors to place the circuit in the sleep or idle mode. This will reduce the overall complexity and overheads of integrated circuits and simplify power gating techniques. In addition, it improves the overall power efficiency and lower thermal effects. SOI devices are becoming critically important for various very-large-scale integration applications, because SOI devices provide higher performance and reliability, and options to design circuits with multiple-threshold voltages to ensure faster switching and lower power consumption. In the proposed circuit design approach, the flexibility to control the threshold voltage of a double-gate FDSOI device via back gate has been exploited to eliminate the need for using a separate set of sleep transistors. The presented sleep transistor design is verified via HSPICE simulation using the Leti-UTSOI model from CEA-Leti.
A 32&#x00D7;32 integrated CMUT array for volumetric ultrasound imaging (2013)

Real-time 3D volumetric ultrasound imaging systems require transmit and receive circuitry to generate the ultrasound beam and process the received echo signals. Since a 2D array is required for 3D imaging, the complexity of building such a system is significantly higher, e.g., front-end electronics need to be interfaced to the transducer, a large number of elements need to be interfaced to the backend system and a large dataset needs to be processed. In this work, we present a 3D imaging system using capacitive micromachined ultrasonic transducer (CMUT) technology that addresses many of the challenges in building such a system. The transducer is a 5-MHz CMUT array with an 8 mm × 8 mm aperture size. The aperture consists of 1024 elements (32×32) with an element pitch of 250 µm. An integrated circuit (IC) is integrated very close to the CMUT array. It consists of a transmit beamformer and receive circuitry to improve the noise performance of the overall system. Simultaneous multi-beam transmit is also incorporated in the IC to improve the imaging frame rate. The CMUT is flip-chip bonded to the IC and the final assembly measured 9.2 mm × 9.2 mm. The assembly was then interfaced with an FPGA and a backend system (comprising of a data acquisition system and PC). The FPGA provided the digital I/O signals for the IC and the backend system was used to process the received RF echo data (from the IC) and reconstruct the volume image using a phased array imaging approach. Imaging experiments were performed using wire phantoms. Real-time volumetric images were captured at 5 volumes per second and are presented in this paper.
Metal&ndash;Organic Framework Membranes: From Fabrica-Tion to Application in Gas Separation (2018)

Gas membrane-based separation is considered one of the furthermost effective technology to address energy efficiency and large footprint challenges. Various classes of advanced materials including polymers, zeolites, porous carbons and metal&ndash;organic frameworks (MOFs) were attempted as membranes for gas separation. MOFs, among other porous materials, possess uniquely tunable nature, in which the pore size and environment can be controlled by connecting metal ions (or metal ion clusters) with organic linkers with various functionalities. This feature makes them attractive for thin membrane fabrication, as both diffusion and solubility components of permeability can be altered. It is interesting to notice that numerous reports have addressed the synthesis of different MOFs, fabrication of their corresponding thin films and their applications, nonetheless, relatively limited studies addressed their gas separation application as membranes. In this review, we provide a synopsis of the various MOF-based membranes that were fabricated in the last decade. In this review we propose a short introduction touching on the gas separation membrane technology and we shed light on (i) the various techniques developed for the fabrication of MOF as membranes and (ii) challenges and application for MOF thin film membranes in various important gas separation applications.
Recombinant <i>Neisseria meningitidis</i> Transferrin Binding Protein A Protects against Experimental Meningococcal Infection (2001)

To better characterize the vaccine potential of Neisseria meningitidis transferrin binding proteins (Tbps), we have overexpressed TbpA and TbpB from Neisseria meningitidis isolate K454 in Escherichia coli. The ability to bind human transferrin was retained by both recombinant proteins, enabling purification by affinity chromotography. The recombinant Tbps were evaluated individually and in combination in a mouse intraperitoneal-infection model to determine their ability to protect against meningococcal infection and to induce cross-reactive and bactericidal antibodies. For the first time, TbpA was found to afford protection against meningococcal challenge when administered as the sole immunogen. In contrast to the protection conferred by TbpB, this protection extended to a serogroup C isolate and strain B16B6, a serogroup B isolate with a lower-molecular-weight TbpB than that from strain K454. However, serum from a TbpB-immunized rabbit was found to be significantly more bactericidal than that from a TbpA-immunized animal. Our evidence demonstrates that TbpA used as a vaccine antigen may provide protection against a wider range of meningococcal strains than does TbpB alone. This protection appears not to be due to complement-mediated lysis and indicates that serum bactericidal activity may not always be the most appropriate predictor of efficacy for protein-based meningococcal vaccines.
Fundamental-mode cutoff in a photonic crystal fiber with a depressed-index core (2001)

We report a photonic crystal fiber with a depressed-index core doped with fluorine. The effective index of the cladding matches that of the core at an antiguiding wavelength, below which the fiber does not guide light at all.
A Dynamic Bayesian Network for Diagnosing Nuclear Power Plant Accidents (2016)

Abstract not provided.
Re-rendering from a Sparse Set of Images (2005)

We present a method to accomplish photorealistic rendering of real-world objects from their sparsely sampled appearance variation. Using a 3D model and a small set of images of an object, we recover all the necessary photometric information for subsequent rendering from arbitrary viewpoints and under novel lighting conditions. We first extract the diffuse reflection component from the input images as a texture map, and then use the residual images to simultaneously recover the specular reflection parameter and the illumination distribution. The simultaneous estimation of the specular reflection parameter and the illumination distribution is achieved by formulating the specular reflection mechanism as a 2D convolution on the surface of a hemisphere. We then run an iterative algorithm to deconvolve it. Rendering from novel viewpoints and under novel illumination distributions can be accomplished using the estimated three components. Unlike previous approaches, we require less input images and we do not assume anything to be known about the three photometric attributes, namely the diffuse and specular reflection parameters and the lighting condition.
Identification and Analysis of <i>In Vivo</i> VEGF Downstream Markers Link VEGF Pathway Activity with Efficacy of Anti-VEGF Therapies (2013)

In this work, we identified surrogate markers (VDV genes) for in vivo VEGF signaling in tumors and showed clinical data supporting a correlation between pretreatment VEGF bioactivity and the subsequent efficacy of anti-VEGF therapy. We propose that VDV genes are candidate biomarkers with the potential to aid the selection of novel indications as well as patients likely to respond to anti-VEGF therapy. The data presented here define a diagnostic biomarker hypothesis based on translational research that warrants further evaluation in additional retrospective and prospective trials.
Efficient Audio Equalization Using Multirate Processing (2008)

A digital signal processing algorithm for efficient audio equalization is presented. In this approach the original full-band audio signal is first downsampled and separated into two or more subband signals using a multirate filter bank, after which the equalization is performed in the downsampled domains. After the equalization, the signal is upsampled and combined back to a full-band audio signal. Linear-phase FIR filters, designed based on user-controlled parameters, are used to implement the actual equalization. The method presented provides a framework for an audio equalizer design with optimization possibilities between audio quality, computational complexity, and memory requirements of the algorithm, making it suitable for various applications and computing platforms.
Efficient, “one‐pot” synthesis of silylene–acetylene and disilylene–acetylene preceramic polymers from trichloroethylene (1990)

Abstract An extremely efficient process has been developed for the synthesis of linear silylene‐acetylene and disilylene‐acetylene polymers. Trichloroethylene is quantitatively converted by n ‐butyllithium to dilithioacetylene. Quenching with dialkyl‐or diaryldichlorosilanes affords high yields of the polymers, \documentclass{article}\pagestyle{empty}\begin{document}$ \rlap{--} [{\rm SiR}_{\rm 2} \hbox{---} {\rm C} \equiv {\rm C\rlap{--} ]}_n ,{\rm and }\rlap{--} [{\rm SiMe}_{\rm 2} {\rm SiMe}_{\rm 2} - {\rm C} \equiv {\rm C\rlap{--} ]}_n $\end{document} if ClMe 2 SiSiMe 2 Cl is employed. Molecular weights are much higher with this route than when acetylene is used as the dilithio‐ or dimagnesium acetylide precursor. Some of these polymers can be pulled into continuous fibers, and all can be cast into coherent films and thermally converted into silicon carbide.
Kilometre-scale, kilowatt average power, single-mode laser delivery through hollow core fibre: overcoming nonlinear limits of glass fibre (2021)

Abstract High power laser delivery with near-diffraction-limited beam quality, widely used in industry for precision manufacturing, is typically limited to tens of metres distances by nonlinearity-induced spectral broadening inside the glass-core delivery fibres. Anti-resonant hollow-core fibres offer not only orders-of-magnitude lower non-linearity, but also loss and modal purity comparable to conventional beam-delivery fibres. Using a single-mode hollow-core nested anti-resonant nodeless fibre (NANF) with 0.74-dB/km loss, we demonstrate delivery of 1 kW of near-diffraction-limited continuous wave laser light over an unprecedented 1-km distance, with a total throughput efficiency of ~80%. From simulations, more than one order of magnitude further improvement in transmitted power or length should be possible in such air-filled fibres, and considerably more if the core is evacuated. This paves the way to multi-kilometre, kW-scale power delivery – not only for future manufacturing and subsurface drilling, but also for new scientific possibilities in sensing, particle acceleration and gravitational wave detection.
A Next-Generation Parallel Reservoir Simulator for Giant Reservoirs (2009)

Giant reservoirs of the Middle East are crucial for the supply of oil and gas to the world market. Proper simulation of these giant reservoirs with long history and large amount of static and dynamic data requires efficient parallel simulation technologies, powerful visualization and data processing capabilities. This paper describes GigaPOWERS, a new parallel reservoir simulator capable of simulating hundreds of millions of cells to a billion cells with long production history in practical times. The new simulator uses unstructured grids. A distributed unstructured grid infrastructure has been developed for models using unstructured or complex structured grids. Unconventional wells such as maximum reservoir contact wells and fish-bone wells, as well as faults and fractures are handled by the new gridding system. A new parallel linear solver has been developed to solve the resulting linear system of equations. Load balancing issues are also discussed. A unified compositional formulation has been implemented. The simulator is esigned to handle n-porosity systems. An optimization-based well management system has been developed by using mixed integer nonlinear programming. In addition to the core computational algorithms, the paper will present the pre- and postprocessing software system to handle large amount of data. Visualization techniques for billions of cells are also presented.
Flying User Interface (2016)

This paper describes a special type of drone called "Flying User Interface", comprised of a robotic projector-camera system, an onboard digital computer connected with the Internet, sensors, and a hardware interface capable of sticking to any surface such as wall, ceilings, etc. Computer further consists of other subsystems, devices, and sensors such as accelerometer, compass, gyroscope, flashlight, etc. Drone flies from one place to another, detects a surface, and attaches itself to it. After a successful attachment, the device stops all its rotators; it then projects or augments images, information, and user interfaces on nearby surfaces and walls. User interface may contain applications, information about object being augmented and information from Internet. User can interact with user-interface using commands and gestures such as hand, body, feet, voice, etc.
Crowd flow completion from partial spatial observations using kernel DMD (2017)

In this paper, we address the problem of estimating the total flow of a crowd of pedestrians from spatially limited observations. Our approach relies on identifying a dynamical system regime that characterizes the observed flow in a limited spatial domain by solving for the modes and eigenvalues of the corresponding Koopman operator. We develop a framework where we first approximate the Koopman operator by computing the kernel dynamic mode decomposition (DMD) operator for different flow regimes using fully observed training data. We then pose flow completion as a least squares problem constrained by the one step evolution of the kernel DMD operator. We present numerical experiments with simulated pedestrian flows and demonstrate that the proposed approach succeeds in completing the flow from limited spatial observations.