gebhart/patrepeval huggingface dataset:
DyERNIE: Dynamic Evolution of Riemannian Manifold Embeddings for Temporal Knowledge Graph Completion (2020)

There has recently been increasing interest in learning representations of temporal knowledge graphs (KGs), which record the dynamic relationships between entities over time. Temporal KGs often exhibit multiple simultaneous non-Euclidean structures, such as hierarchical and cyclic structures. However, existing embedding approaches for temporal KGs typically learn entity representations and their dynamic evolution in the Euclidean space, which might not capture such intrinsic structures very well. To this end, we propose Dy- ERNIE, a non-Euclidean embedding approach that learns evolving entity representations in a product of Riemannian manifolds, where the composed spaces are estimated from the sectional curvatures of underlying data. Product manifolds enable our approach to better reflect a wide variety of geometric structures on temporal KGs. Besides, to capture the evolutionary dynamics of temporal KGs, we let the entity representations evolve according to a velocity vector defined in the tangent space at each timestamp. We analyze in detail the contribution of geometric spaces to representation learning of temporal KGs and evaluate our model on temporal knowledge graph completion tasks. Extensive experiments on three real-world datasets demonstrate significantly improved performance, indicating that the dynamics of multi-relational graph data can be more properly modeled by the evolution of embeddings on Riemannian manifolds.
Functional connectivity of fMRI using differential covariance predicts structural connectivity and behavioral reaction times (2022)

Abstract Recordings from resting-state functional magnetic resonance imaging (rs-fMRI) reflect the influence of pathways between brain areas. A wide range of methods have been proposed to measure this functional connectivity (FC), but the lack of “ground truth” has made it difficult to systematically validate them. Most measures of FC produce connectivity estimates that are symmetrical between brain areas. Differential covariance (dCov) is an algorithm for analyzing FC with directed graph edges. When we applied dCov to rs-fMRI recordings from the human connectome project (HCP) and anesthetized mice, dCov-FC accurately identified strong cortical connections from diffusion magnetic resonance imaging (dMRI) in individual humans and viral tract tracing in mice. In addition, those HCP subjects whose dCov-FCs were more integrated, as assessed by a graph-theoretic measure, tended to have shorter reaction times in several behavioral tests. Thus, dCov-FC was able to identify anatomically verified connectivity that yielded measures of brain integration significantly correlated with behavior.
Multi-User Detection Performance Demonstrator for Realistic High Throughput Satellite Systems (2018)

Multi-beam satellite systems gain capacity from frequency reuse in the forward link, but they suffer from inter-system interference problems. Multi-user detection (MUD) is an advanced interference mitigation technique applied at the user terminal to cope with co-channel interferences. This paper complements theoretical studies on the efficiency of MUD by the development of a system performance demonstrator allowing the analysis of MUD performance limits under realistic channel conditions. A two-color system is assumed and compared to a traditional four-color application, which is to be used as a benchmark. By the application of MUD, a performance gain in peak and system throughput can be observed, while requiring higher complexity at the user terminal.
The location-dependent nature of perceptually salient features of the human head-related transfer functions (1994)

The human head-related transfer function (HRTF) has been recorded binaurally from eight subjects using an "in-ear" recording system, for 343 stimulus locations around the head. There are a number of systematic changes in the HRTF as a function of horizontal location and elevation, on and off the median plane, that could be used as cues to sound location. To identify which components of the HRTF might provide perceptually salient cues to sound location, the HRTFs were transformed using an auditory filter model which accounts for the frequency dependence of auditory sensitivity and the frequency and level-dependent characteristics of the auditory filters. These transformations indicated a systematic variation in the frequency of the peak excitation as a function of the horizontal location of a broad band stimulus. Furthermore, there were differences in the frequency range over which elevation-dependent changes in the excitation patterns varied as a function of the vertical meridian. Interaural level differences were also estimated using the excitation patterns. The across frequency pattern of ILDs were roughly symmetrical about the interaural axis, although there were substantial differences between each ear in the magnitude of the ILDs generated for ipsilateral sounds locations.
Reverberation Chamber Modeling Based on Image Theory: Investigation in the Pulse Regime (2010)

In this paper, we propose a straightforward 3-D time-domain model of a reverberation chamber (RC) based on image theory. This model allows one to describe the earliest moments of an arbitrary waveform in an RC. Time domain and frequency domain results from this model are analyzed and compared with measurements conducted in a RC.
Clock-driven on-chip testing for superconductor logic circuits (1999)

We have developed and demonstrated a clock-driven on-chip testing (CDOT) method for high-speed testing of superconductor logic circuits. This testing method uses an on-chip signal-pattern generator (SPG) driven by a clock signal. The SPG is based on a feedback shift register, in which a complement output of the last-stage D-flip-flop is fed back to the first-stage D-flip-flop. Thus, SPG generates a periodic signal-pattern when a clock signal is applied to it. The advantages of this testing method are that: (a) no external control signal is needed; (b) a simple SPG that consists of only D-flip-flops is used; (c) it is easy to extend to multi-bit testing. This greatly simplifies high-speed testing and design of test circuits. We have applied this method to the high-speed testing of the ring interface (RIF) circuit, which is an elemental circuit in our superconducting ring-network system. We have designed a test circuit, consisting of the RIF circuit and a 12-bit on-chip test-pattern generator, with resistor-coupled Josephson logic (RCJL). The test circuit includes about 1,400 Josephson-junctions. It has been fabricated using Nb/AlO/sub x//Nb Josephson-junction technology. As the result of the high-speed testing, full operation of the RIF circuit at 1-GHz clock frequency and proper operation of a sending part of the RIF circuit at 2-GHz clock frequency have been successfully verified.
Antibodies with Weakly Basic Isoelectric Points Minimize Trade-offs between Formulation and Physiological Colloidal Properties (2022)

The widespread interest in antibody therapeutics has led to much focus on identifying antibody candidates with favorable developability properties. In particular, there is broad interest in identifying antibody candidates with highly repulsive self-interactions in standard formulations (e.g., low ionic strength buffers at pH 5–6) for high solubility and low viscosity. Likewise, there is also broad interest in identifying antibody candidates with low levels of non-specific interactions in physiological solution conditions (PBS, pH 7.4) to promote favorable pharmacokinetic properties. To what extent antibodies that possess both highly repulsive self-interactions in standard formulations and weak non-specific interactions in physiological solution conditions can be systematically identified remains unclear and is a potential impediment to successful therapeutic drug development. Here, we evaluate these two properties for 42 IgG1 variants based on the variable fragments (Fvs) from four clinical-stage antibodies and complementarity-determining regions from 10 clinical-stage antibodies. Interestingly, we find that antibodies with the strongest repulsive self-interactions in a standard formulation (pH 6 and 10 mM histidine) display the strongest non-specific interactions in physiological solution conditions. Conversely, antibodies with the weakest non-specific interactions under physiological conditions display the least repulsive self-interactions in standard formulations. This behavior can be largely explained by the antibody isoelectric point, as highly basic antibodies that are highly positively charged under standard formulation conditions (pH 5–6) promote repulsive self-interactions that mediate high colloidal stability but also mediate strong non-specific interactions with negatively charged biomolecules at physiological pH and vice versa for antibodies with negatively charged Fv regions. Therefore, IgG1s with weakly basic isoelectric points between 8 and 8.5 and Fv isoelectric points between 7.5 and 9 typically display the best combinations of strong repulsive self-interactions and weak non-specific interactions. We expect that these findings will improve the identification and engineering of antibody candidates with drug-like biophysical properties.
Dynamic Measurement System for Contact Pressure Distribution in Human Joints Utilizing Pressure-Sensitive Conductive Rubber. (1992)

We developed a dynamic measurement system for contact pressure distribution in human joints using a thin carbon-particle-impregnated rubber pressure sensor particularly designed for this application together with a simple circuit. The electric resistance in the thin rubber correlates well with the amount of pressure applied. The sensors are flexible and have the ability to adapt to concave surfaces, sufficiently low hysteresis, high test-retest reliability and sufficient endurability. The indentation tests of a thick elastic layer by cylindrical and spherical punches were carried out to make a comparison of the contact pressure distributions measured with those due to a three-dimensional theory of elasticity and to estimate reliability of the sensing system. This system was applied to the patellofemoral joint of human cadaver knees in order to study kinematics of the joint. The results obtained show that the mean pressure on the patella with any flexion angles and the tension in the quadriceps are constant.
Visual, tactile and visuo-tactile motion discrimination (2010)

We investigated visual and tactile motion perception by measuring velocity discrimination thresholds over a wide range of base velocities and spatial frequencies (0, 3.3, 5 & 10 c/deg). The stimuli used were physical wheels etched with a sinewave profile that could be seen and felt. Two similar wheels were simultaneously driven at specific velocities (either congruent or in conflict, in the same or opposite directions) by two independent, computer controlled, motors. Subject was presented with two separate intervals and required to discriminate in 2AFC interval contained the faster movement, using only visual, only tactile or bimodal information (viewing distance was maintained constant at 57 cm). Both bimodal and unimodal visual and tactile thresholds showed a characteristic “dipper function”, with the minimum at a given “pedestal duration”. The “dip” (indicating facilitation) occurred over the same velocity range (0.05 - 0.2 cm/sec) at all spatial frequencies and conditions. At detection levels we found no direction-specific facilitation for visual-tactile motion, but an overall improvement (about root two) in the bimodal detection and discrimination thresholds, that were well predicted by the maximum likelihood estimation model. Our results suggest that visual and tactile systems analyze motion with similar sensitivities, and information between them is integrated in an optimal manner.
A urban vehicle with very low fuel consumption: realization, analysis and optimization (2014)

The problem of energy saving is, at present, more and more important and the reduction of the consumption of the vehicles is a target that a lot of countries and car manufacturers are searching for. In this scenario Shell organizes a competition called Shell Eco Marathon; the winner of this race is the team that realize the vehicle capable of covering a fixed distance with the lowest fuel consumption. At the Politecnico di Milano a vehicle to participate to this competition has been realized. A high performance aerodynamic shape has been developed starting from the “Morelli's shape” which has been further optimized to reduce the aerodynamic drag. A CFD analysis has been completed to refine the vehicle shape and to reach the final body geometry. To reduce the frontal area the wheels have been connected to the main body by using CFRP wing beams and both suspension system and powertrain, have been integrated into the wheels. A highly efficient powertrain has been developed and an electronic differential has been implemented. All the subsystems have been optimized both to reduce the motion resistance of the vehicle and to maximize the efficiency. A numerical model of the vehicle has been developed in order to aid the design and to simulate the race strategy on different competition tracks. The model has been validated by considering data acquired during the race.
Compile-time memory reuse in logic programming languages through update in place (1999)

Standard implementation techniques for single-assignment languages modify a data structure without destroying the original, which may subsequently be accessed. Instead a variant structure is created by using newly allocated cells to represent the changed portion and to replace any cell that references a newly allocated cell. The rest of the original structure is shared by the variant. The effort required to leave the original uncorrupted is unnecessary when the program will never reference the original again. This effort includes allocating and initializing new cells, as well as garbage collecting replaced cells. This article specifies a transformation system that introduces update-in-place operations, making Prolog programs update recursive data structures much as an imperative program would. The article introduces the notion of a reuse map, which formalizes reallocation decisions. Because optimal memory reuse is intractable, a heuristical method is presented that performs well in practice. Small Prolog programs that manipulate recursive data structures have their speed increased up to about five times (naive recurse), not counting any speedup obtained by avoiding garbage collection. Quicksort is about three times as fast, merge-sort about one and a half, matrix transposition about twice, and Gaussian elimination is about 1.2 times as fast.
Internal structure of the temporomandibular joint and the circumferential bone: comparison between dentulous and edentulous specimens. (1997)

To clarify changes in the trabecular structure due to loss of the teeth, the author compared soft X-ray images and morphological measurement values of the mandibular condyle and articular eminence between dentulous and edentulous specimens. The center of the skull base containing the temporomandibular joint was removed along the Frankfort horizontal and median sagittal planes. A block in the center of the cranial base was rejected using the Frankfort horizontal plane and median sagittal plane as references. The specimens were embedded in polyester resin by the routine method. The hardened specimens were horizontally cut into 500 microns sections and photographed using soft X-ray films. Soft X-ray of each section was taken for observation by naked eye and morphometry by computer. Observation of the compact bone in the articular eminence showed thinner compact bone on the posterior slope of the articular eminence, which is a functional plane, than on the anterior slope of the articular eminence. There was a trabecular bone group on the lateral area running from the compact bone on the posterior surface of the articular eminence into the zygomatic arch and a thick trabecular bone group in a network pattern on the medial area. In the central area of the mandibular condyle, spongy bone was surrounded by oval compact bone, and the internal trabecular bone ran anteromedially in nearly the same pattern as the arrangement of the lateral pterygoid muscle. At all sites, the density, width, extent, and index indicating the complexity of the trabecular bone had higher values in dentulous specimens than in edentulous specimens.
Enabling passive measurement of zoom performance in production networks (2022)

Video-conferencing applications impose high loads and stringent performance requirements on the network. To better understand and manage these applications, we need effective ways to measure performance in the wild. For example, these measurements would help network operators in capacity planning, troubleshooting, and setting QoS policies. Unfortunately, large-scale measurements of production networks cannot rely on end-host cooperation, and an in-depth analysis of packet traces requires knowledge of the header formats. Zoom is one of the most sophisticated and popular applications, but it uses a proprietary network protocol. In this paper, we demystify how Zoom works at the packet level, and design techniques for analyzing Zoom performance from packet traces. We conduct systematic controlled experiments to discover the relevant unencrypted fields in Zoom packets, as well as how to group streams into meetings and how to identify peer-to-peer meetings. We show how to use the header fields to compute metrics like media bit rates, frame sizes and rates, and latency and jitter, and demonstrate the value of these fine-grained metrics on a 12-hour trace of Zoom traffic on our campus network.
Microscopie non-linéaire vibrationnelle CARS affranchie de bruit non-résonant aux interfaces (2010)

L'effet CARS (acronyme anglais de “coherent anti-Stokes Raman scattering”) est un analogue non-linéaire de l'effet Raman. A ce titre, il donne une information vibrationnelle sur l'échantillon étudié. Utilisé en microscopie, c'est une technique résolue chimiquement et qui permet de s'affranchir de marquage fluorescent. CARS est un processus de mélange à quatre ondes dans lequel deux faisceaux laser décalés en fréquence optique dénotés « pompe » et « Stokes » interagissent avec l'échantillon d'étude pour générer un signal dénoté « anti-Stokes » et décalé vers le bleu. Le signal anti-Stokes est la somme cohérente de deux composantes : une composante vibrationnelle, dite « résonante », générée lorsque la différence des fréquences optiques des lasers pompe et Stokes coïncide avec une fréquence de vibration intramoléculaire de l'échantillon, et une composante électronique, dite « non-résonante », plate spectralement, qui vient bruiter la composante résonante. Il existe de multiples techniques pour extraire la composante « résonante » du signal anti-Stokes et éliminer la composante « non-résonante », la plupart d'entre elles souffrant d'une complexité expérimentale accrue. Nous proposons et démontrons, théoriquement et expérimentalement, des techniques de microscopie CARS affranchies de bruit non-résonant pour mettre en évidence des interfaces « chimiques » entre un milieu « résonant » et un milieu « non-résonant » qui sont simples à mettre en œuvre. Pour ceci, nous tirons partie des propriétés de phase des signaux associés aux composantes résonante et non-résonante du signal anti-Stokes et nous revisitons des expériences d'interférométrie à deux ondes. Ainsi, lorsque l'interface entre les deux milieux non-résonant et résonant est perpendiculaire à l'axe optique (interface transverse), défini comme l'axe de propagation commun des lasers excitateurs pompe et Stokes, nous montrons que l'on obtient un signal anti-Stokes affranchi de bruit non-résonant après soustraction des deux signaux obtenus après renversement des rôles des milieux résonant et non-résonant. Lorsque cette interface est parallèle à l'axe optique (interface axiale), nous revisitons l'expérience des fentes d'Young et montrons que ce signal anti-Stokes affranchi de bruit non-résonant est obtenu après soustraction de deux signaux anti-Stokes générés dans deux directions symétriques. Nous démontrons ces propriétés sur des échantillons tests et des cellules fixées. Les techniques que nous développons sont simples et peuvent être mises en œuvre sur des microscopes CARS commerciaux. Par ailleurs, ces approches ne se limitent pas à l'effet CARS et peuvent être appliquées à tout effet linéaire ou non-linéaire dispersif et cohérent.
Insights into the Electrochemical Oxygen Evolution Reaction with ab Initio Calculations and Microkinetic Modeling: Beyond the Limiting Potential Volcano (2019)

Density functional theory calculations are potentially useful for both understanding the activity of experimentally tested catalysts and screening for new catalyst materials. For electrochemical oxygen evolution reaction (OER) catalysts, these analyses are usually performed considering only the thermodynamics of the reaction path, which typically consists of adsorbed OH*, O*, and OOH*. Scaling relationships between the stability of these intermediates lead to a limiting potential volcano whose optimum is constrained by the roughly constant offset between the binding energies of OH* and OOH*. In this work, we evaluate OER kinetics at rutile IrO₂, RuO₂, RhO₂, and PtO₂ surfaces by computing reaction barriers with an explicit model of the electrochemical interface. We conclude that the kinetics of proton transfer between oxygen atoms at the surface and in the electrolyte is facile and that O–O bond formation is most likely rate-determining in all cases. Combining these results with a microkinetic model and a scaling relationship for the OOH* formation barrier, we construct a new activity volcano whose optimum is similar to that of the limiting potential volcano for typical current densities. This kinetic volcano is also shown to agree reasonably well with experimental observations. Based on this analysis, we propose a more precise requirement for improving OER catalysts beyond the state of the art: the transition state for OOH* formation must be stabilized as opposed to the fully formed OOH* final state as has been previously presumed.
Amplification and directional emission of surface acoustic waves by a two-dimensional electron gas (2015)

Amplification of surface acoustic waves (SAWs) by electron drift in a two-dimensional electron gas (2DEG) is analyzed analytically and confirmed experimentally. Calculations suggest that peak power gain per SAW radian occurs at a more practical carrier density for a 2DEG than for a bulk material. It is also shown that SAW emission with tunable directionality can be achieved by modulating a 2DEG's carrier density (to effect SAW generation) in the presence of an applied DC field that amplifies SAWs propagating in a particular direction while attenuating those propagating in the opposite direction.
Dynamic Supramolecular Chemistry: The Role of Hydrogen Bonding in Controlling the Selectivity of Diels-Alder Reactions in Room-Temperature Ionic Liquids (2002)

The Diels-Alder cycloaddition reaction between methyl acrylate and cyclopentadiene has been investigated in a number of air and moisture stable ionic liquids. The endo/exo ratio of the reaction has been used as a probe of the nature of the solvents. We have demonstrated that hydrogen bonding between the cation of the ionic liquid and the methyl acrylate is the principal interacting controlling the product selectivity.