114 research outputs found
Self-Supervised Continual Learning for Interaction-Aware Pedestrian Prediction Models
No full textLearning human motion prediction models online is key for autonomous navigation in unknown dynamic scenarios. Previous works focus solely on improving prediction network architectures, whilst training them offline. This paper introduces a self-supervised continual learning framework that continuously improves data-driven pedestrian trajectory prediction models online across various environments. We propose to use online streams of pedestrian data, normally available from detection and tracking pipelines. Examples are autonomously extracted from this data stream and aggregated in temporally bounded episodes, where the data of each episode is discarded as soon as the model has been adapted to it. Our framework overcomes the problem of catastrophic forgetting across episodes by selectively slowing down learning of important neurons and by rehearsing a small set of examples of constant length. Our approach is shown to significantly improve prediction performance in new and unseen environments compared standard gradient descent approaches. Finally, we present qualitative experimental results in simulation and in real environments
Pseudo-state theory of surface ion neutralization
No full textThe theory of resonant charge transfer is refined to deal with the overlap between the ion orbital and substrate orbitals, to introduce new numerical methods for estimating the interaction and most significantly to construct pseudo-states to model realistic densities of states for substrates.PT: J; CR: ADURU S, 1988, SURF SCI, V205, P269 AMOS AT, 1989, ADV CHEM PHYS, V76, P335 AMOS AT, 1989, SOLID STATE COMMUN, V71, P449 BLOSS W, 1978, SURF SCI, V72, P277 BRAKO R, 1981, SURF SCI, V108, P253 BURROWS BL, 1984, Q APPL MATH, V42, P73 BURROWS BL, 1990, J PHYS A-MATH GEN, V23, P1101 CHADI DJ, 1975, PHYS STATUS SOLIDI B, V68, P405 HERMAN F, 1963, ATOMIC STRUCTURE CAL HOFFMAN AJ, 1953, DUKE MATH J, V20, P37 IHM J, 1980, PHYS REV B, V21, P4592 MUDA Y, 1980, SURF SCI, V97, P283 MUDA Y, 1988, NUCL INSTRUM METH B, V33, P388 MUDA Y, 1988, PHYS REV B, V37, P7048 MURRELL JN, 1985, CHEM BOND SULSTON KW, 1988, CHEM PHYS, V124, P411 SULSTON KW, 1988, PHYS REV B, V37, P9121 SULSTON KW, 1988, SURF SCI, V197, P555 WEAKLIEM PC, 1990, SURF SCI, V232, L219 WEISENDANGER R, 1990, SURF SCI, V232, P1 WILKINSON JH, 1965, ALGEBRAIC EIGENVALUE; NR: 21; TC: 5; J9: SURFACE SCI; PG: 10; GA: GB311Source type: Electronic(1
cDNA sequence of the horse (Equus caballus) LAMA3 gene and characterization of two intronic SNP markers.
No full textInternational audienceLaminins are large heterotrimeric basement membrane glycoproteins composed of alpha, beta and gamma chains. The Laminin 5 isoform has an alpha3beta3gamma2 composition and is essential for the adhesion of basal keratinocytes to the underlying epithelial basement membrane where it is mainly located. Mutations in the genes coding for the 3 chains have been associated with a severe skin blistering disease, Herlitz's junctional epidermolysis bullosa (JEB), observed in different species as man, dog, cat and horse. In this study, we report the sequence of the 5.2 kb horse laminin alpha 3 cDNA (LAMA3) as well as the detection of two intronic SNPs. These data will be useful to further identify causal mutations for the disease in this gene
Power line communications under Rayleigh fading and Nakagami noise: novel insights on the MIMO and multi‐hop techniques
No full textThis work targets a comprehensive understanding of the impact of the serial-relaying and multiple-input-multiple-output (MIMO) fading mitigation techniques on the performance of indoor power line communication (PLC) systems. While these techniques were studied extensively under additive Gaussian noise, we aim at highlighting the implications of Nakagami-like noise on the achievable performance levels. The author derive approximate closed-form expressions for the bit error rate (BER) under Rayleigh fading and Nakagami-m background noise where the obtained approximations are very close to the exact BERs. The derived expressions are useful for evaluating the achievable diversity orders and for relating the BER to the main parameters of the PLC system in a direct and intuitive way. In this context, we analytically prove that MIMO doubles the diversity order with different combining schemes while the diversity order of a system under Nakagami-like noise is only half the diversity order that would have been obtained under Gaussian noise. The author also shows that multi-hop relaying does not enhance the diversity order.PublishedN/
A Nonlinear ϕ0-Convexity Result for the Bilateral Minimal Time Function
No full textFor a nonlinear control system, we derive a ϕ0-convexity result for the epigraph of the bilateral minimal time function. This extends the main result in a previous publication of the second author [Proximal subdifferential of the bilateral minimal time function and some regularity applications, J. Convex Analysis 20 (2013) 1095--1112], which discussed the linear case.Publishe
Many-electron theory of resonant charge transfer: Role of surface states in He and He+ scattering off Si(100)
No full textA many-electron theory of resonant charge transfer, originally formulated for the scattering of an atom with an empty valence orbital from a surface, is extended to treat the case where the valence orbital is initially occupied by one or two electrons. The scattering of He and He+ from the Si(001) surface is investigated. The interaction is assumed to be with the narrow band of surface states, and not the much wider bulk band. As a result, considerable oscillations are found in the ionization and/or neutralization probabilities as a function of the incident energy.PT: J; CR: AMOS AT, 1989, ADV CHEM PHYS, V76, P335 AMOS AT, 1989, SOLID STATE COMMUN, V71, P449 BLOSS W, 1978, SURF SCI, V72, P277 BRAKO R, 1981, SURF SCI, V108, P253 BURROWS BL, 1984, Q APPL MATH, V42, P73 BURROWS BL, 1990, J PHYS A-MATH GEN, V23, P1101 BURROWS BL, 1991, SURF SCI, V253, P365 CHADI DJ, 1975, PHYS STATUS SOLIDI B, V68, P405 HAGSTRUM HD, 1954, PHYS REV, V96, P336 HAGSTRUM HD, 1961, PHYS REV, V122, P83 HERMAN F, 1963, ATOMIC STRUCTURE CAL IHM J, 1980, PHYS REV B, V21, P4592 MUDA Y, 1980, SURF SCI, V97, P283 MUDA Y, 1988, NUCL INSTRUM METH B, V33, P388 MUDA Y, 1988, PHYS REV B, V37, P7048 PAULING L, 1935, INTRO QUANTUM MECHAN ROBERTS N, 1990, SURF SCI, V236, P112 SOUDA R, 1985, SURF SCI, V150, L59 SOUDA R, 1986, NUCL INSTRUM METH B, V15, P114 SOUDA R, 1986, NUCL INSTRUM METH B, V15, P138 SOUDA R, 1986, SURF SCI, V176, P657 SULSTON KW, 1988, PHYS REV B, V37, P9121 SULSTON KW, 1988, SURF SCI, V197, P555 SULSTON KW, 1989, SURF SCI, V244, P543 WEAKLIEM PC, 1990, SURF SCI, V232, L219 WEISENDANGER R, 1990, SURF SCI, V232, P1; NR: 26; TC: 4; J9: PHYS REV B; PG: 11; GA: HZ245Source type: Electronic(1
Ligilactobacillus salivarius CNCM I-4866, a potential probiotic candidate, shows anti-inflammatory properties in vitro and in vivo
No full textIntroductionThe aim of this work was to characterize a new strain of Ligilactobacillus salivarius (CNCM I-4866) (CNCM I-4866) to address its potential as probiotic with a special focus on intestinal inflammation. Potential anti-inflammatory abilities of this strain were evaluated through in vivo and in vitro experiments.MethodsFirstly, the strain was tested in a murine acute inflammation colitis model induced by DNBS. In vitro characterization was then performed with diverse tests: modulation capability of intestinal permeability; study of the impact on immunity profile through cytokines dosage; capacity to inhibit pathogens and adhere to intestinal cells lines. Production of metabolites, antibiotic resistance and survival to gastro-intestinal tract conditions were also tested.ResultsIn vitro assay has shown a reduction of colonic damage and markers of inflammation after treatment with CNCM I-4866. Transcriptomic analysis performed on colons showed the capacity of the strain to down-regulate pro-inflammatory cytokines. L. salivarius CNCM I-4866 exerted anti-inflammatory profile by reducing IL-8 production by TNF-α stimulated cell and modulated cytokines profile on peripheral blood mononuclear cells (PBMC). It protected intestinal integrity by increasing trans-epithelial electrical resistance (TEER) on Caco-2 TNF-α inflamed cells. Additionally, L. salivarius CNCM I-4866 displayed inhibition capacity on several intestinal pathogens and adhered to eukaryotic cells. Regarding safety and technical concerns, CNCM I-4866 was highly resistant to 0.3% of bile salts and produced mainly L-lactate. Finally, strain genomic characterization allowed us to confirm safety aspect of our strain, with no antibiotic gene resistance found.DiscussionTaken together, these results indicate that L. salivarius CNCM I-4866 could be a good probiotic candidate for intestinal inflammation, especially with its steady anti-inflammatory profile
Electronic structure of the arsenic-passivated Si(111) surface
No full textAn empirical tight-binding (ETB) approach combined with a Green's-function (GF) method has been employed to investigate the electronic structure of the Si(111) and arsenic-passivated Si(111) surfaces. An accurate silicon band structure has first been developed keeping up to second-nearest-neighbor terms in the Hamiltonian. The ETB-GF approach has allowed the calculation of the local density of states (LDOS) at various atomic layers of the semi-infinite samples. It has also been possible to calculate the contribution of the individual atomic orbitals to the LDOS. The results obtained for the arsenic-passivated Si surface provide the position and strength of localized surface states as well as the density of the bulk states in the valence band, the band gap, and the conduction band. The calculated localized states reproduce the existing experimental data and other partial calculations. Furthermore, this calculation predicts a localized state in the conduction band, which has so far not been studied experimentally.PT: J; CR: APPELBAUM JA, 1973, PHYS REV LETT, V31, P106 BECHSTEDT F, 1988, SEMICONDUCTOR SURFAC, P122 BECKER RS, 1988, PHYS REV LETT, V60, P116 CHADI DJ, 1975, PHYS STATUS SOLIDI B, V68, P405 CHELIKOWSKY JR, 1976, PHYS REV B, V14, P556 ECONOMOU EN, 1983, SPRINGER SERIES SOLI, V7, CH5 HARRISON WA, 1989, ELECTRONIC STRUCTURE HEADRICK RL, 1988, PHYS REV B, V37, P1051 KALKSTEIN D, 1971, SURF SCI, V26, P85 OLMSTEAD MA, 1986, PHYS REV B, V34, P6041 PANDEY KC, 1974, PHYS REV LETT, V32, P1433 SCHICK JT, 1989, PHYS REV B, V40, P7825 SLATER JC, 1954, PHYS REV, V94, P1498 UHRBERG RIG, 1987, PHYS REV B, V35, P3945; NR: 14; TC: 1; J9: PHYS REV B; PG: 6; GA: PP124Source type: Electronic(1
A Green function theory of the electronic structure of metal disilicide surfaces and their interfaces with silicon
No full textA theoretical study of the electronic structure of the (111) surfaces of CoSi2 and NiSi2 and their interfaces with Si has been carried out with particular attention paid to the existence of localized states. A Green function method has been used within the empirical tight-binding approximation to calculate the bulk, surface and interface densities of states of these samples. The (111) surface electronic structures of bot the Si-terminated disilicides are qualitatively similar, each possessing a pair of localized states. One of these states is associated with the dangling bond at the surface (Si) layer and the other with that at the first subsurface (Co or Ni) layer. Formation of an interface with Si(111) gives rise to two localized resonance states below the Fermi level in both Si/CoSi2 and Si/NiSi2, even though their origins are quite different because of the different atomic geometries at the interfaces.PT: J; CR: BISI O, 1981, J PHYS C SOLID STATE, V14, P5479 BYLANDER DM, 1982, PHYS REV B, V26, P6379 CATANA A, 1989, J PHYS-CONDENS MAT, V1, P3999 CHABAL YJ, 1982, PHYS REV B, V25, P7598 CHADI DJ, 1975, PHYS STATUS SOLIDI B, V68, P405 CHANG YJ, 1982, PHYS REV B, V26, P7031 CHERNS D, 1982, PHILOS MAG A, V46, P849 DAS GP, 1989, PHYS REV LETT, V63, P1168 ENGLE WP, 1991, UNPUB FUJITANI H, 1988, J PHYS SOC JPN, V57, P2253 FUJITANI H, 1989, APPL SURF SCI, V41, P164 FUJITANI H, 1990, PHYS REV B, V42, P1696 GEWINNER G, 1988, PHYS REV B, V38, P1879 HAMANN DR, 1988, PHYS REV LETT, V60, P313 HASS KC, 1983, PHYS REV B, V27, P1088 HASS KC, 1984, PHYS REV B, V29, P3697 KALKSTEIN D, 1971, SURF SCI, V26, P85 LAMBRECHT WRL, 1987, PHYS REV B, V36, P2493 REES NV, 1988, J PHYS C SOLID STATE, V21, L981 REES NV, 1989, SEMICOND SCI TECH, V4, P412 ROBERTSON J, 1985, J PHYS C SOLID STATE, V18, P947 SCHICK JT, 1989, PHYS REV B, V40, P7825 SENGUPTA R, 1986, J PHYS F MET PHYS, V16, P733 SLATER JC, 1954, PHYS REV, V94, P1498 TERSOFF J, 1983, PHYS REV B, V28, P1168 TUNG RT, 1982, THIN SOLID FILMS, V93, P77 TUNG RT, 1984, PHYS REV LETT, V52, P461 TUNG RT, 1985, J VAC SCI TECHNOL A, V3, P987 VANDENHOEK PJ, 1988, PHYS REV LETT, V60, P1743 VANDENHOEK PJ, 1988, SURF SCI, V205, P549 WEAVER JH, 1984, PHYS REV B, V29, P3293 XU YN, 1986, PHYS REV B, V33, P8602; NR: 32; TC: 3; J9: J PHYS-CONDENS MATTER; PG: 11; GA: GH953Source type: Electronic(1
Experimental and numerical investigation of the thermal inertia of sugar-beet-pulp/starch based bricks enhanced with phase change materials
No full textDue to environmental concerns, bio-based materials are being increasingly investigated and used in buildings. In general, the density of these materials, and thus their thermal inertia, is low. Thermal inertia can be beneficial for reducing the energy use of buildings by damping indoor temperature fluctuations or by reducing and delaying incoming (solar) heat through the façade.This study explores the thermal inertia of regular-sized bricks made of a sugar-beet-pulp/starch mixture (BP/S), and with 17 circular holes inside. The holes were filled either with the BP/S mixture, with air, with a stabilised phase change material (PCM) gel or with a salt-hydrate based PCM. The brick was insulated on all sides but one. Two series of experimental measurements were performed: 1.) a heating film placed at the back (insulated) side of the brick heated the brick until steady-state conditions were reached; 2.) the heated brick was then passively cooled down to ambient temperature by cutting the power to the heating film. Numerical simulations of these experimental measurements were also modelled using the COMSOL Multiphysics® software. In addition, simulations were run to study the thermal inertia of a full brick wall made out of 1 layer and of 4 layers of the BP/S brick with and without PCM, exposed to a combination of a sinusoidal outdoor air temperature fluctuation with an imposed radiation flux on the outdoor surface, representing summer conditions.The results show that the brick in which the holes were filled with phase change material had a slower temperature response and thus higher thermal inertia than the bricks in which the holes were filled with BP/S or with air. The salt-hydrate based PCM with the higher latent heat of fusion led to the slowest temperature response and highest thermal inertia. Furthermore, the calculated simulations could accurately reproduce the experimental measurements. Applying PCM in thick walls (40 cm) made of BP/S bricks however hardly affects the temperature amplitude damping and time delay of the complete wall. The addition of PCM therefore is only effective for thinner walls (10 cm)
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