2,498 research outputs found

    EgoFace: Egocentric Face Performance Capture and Videorealistic Reenactment

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    Face performance capture and reenactment techniques use multiple cameras and sensors, positioned at a distance from the face or mounted on heavy wearable devices. This limits their applications in mobile and outdoor environments. We present EgoFace, a radically new lightweight setup for face performance capture and front-view videorealistic reenactment using a single egocentric RGB camera. Our lightweight setup allows operations in uncontrolled environments, and lends itself to telepresence applications such as video-conferencing from dynamic environments. The input image is projected into a low dimensional latent space of the facial expression parameters. Through careful adversarial training of the parameter-space synthetic rendering, a videorealistic animation is produced. Our problem is challenging as the human visual system is sensitive to the smallest face irregularities that could occur in the final results. This sensitivity is even stronger for video results. Our solution is trained in a pre-processing stage, through a supervised manner without manual annotations. EgoFace captures a wide variety of facial expressions, including mouth movements and asymmetrical expressions. It works under varying illuminations, background, movements, handles people from different ethnicities and can operate in real time

    Tunable nonlinearity in atomic response to a bichromatic field

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    Atomic response to a probe beam can be tailored, by creating coherences between atomic levels with help of another beam. Changing parameters of the control beam will change the nature of coherences and hence the nature of atomic response as well. Such change can depend upon intensity of both probe and control beams, in a nonlinear fashion. We present a situation where this nonlinearity in dependence can be precisely controlled, as to obtain different variations as desired. We also present a detailed analysis of how this nonlinear dependency arises and show that this is an interesting effect of several Coherent Population Trap(CPT) states that exist and a competition among them to trap atomic population in them.Comment: 16 pages and 6 figure

    px+ipyp_{x}+ip_{y} superfluid from s-wave interactions of fermionic cold atoms

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    Two-dimensional (px+ipyp_{x}+ip_{y}) superfluids/superconductors offer a playground for studying intriguing physics such as quantum teleportation, non-Abelian statistics, and topological quantum computation. Creating such a superfluid in cold fermionic atom optical traps using p-wave Feshbach resonance is turning out to be challenging. Here we propose a method to create a px+ipyp_{x}+ip_{y} superfluid directly from an s-wave interaction making use of a topological Berry phase, which can be artificially generated. We discuss ways to detect the spontaneous Hall mass current, which acts as a diagnostic for the chiral p-wave superfluid.Comment: 4 pages, 1 figur

    Discomfort, Pressure Distribution and Safety in Operator's Seat-A Critical Review

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    Rosana G. Moreira, Editor-in-Chief; Texas A&M UniversityThis is an Invited Paper from International Commission of Agricultural Engineering (CIGR, Commission Internationale du Genie Rural) E-Journal Volume 5 (2003): H. Dhingra, V. Tewari, and S. Singh. Discomfort, Pressure Distribution and Safety in Operator's Seat-A Critical Review. Vol. V. July 2003

    Liquid Scintillator Time Projection Chamber Concept

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    Results are presented from a small-scale experiment to investigate the use of room temperature organic liquid scintillators as the active medium for a time projection chamber (TPC). The optical properties of liquid scintillators have long been known, but their ability to transport charge has remained, until now, largely untested. The idea of using room temperature liquids as an active medium for an ionisation chamber was first presented in \cite{EnglerTMS}. Since then the range of liquid scintillators available has been greatly developed. We present successful transport of ionization charges in a selection of both, pure organic liquid solvents and liquid scintillator cocktails over 20 \,mm using a variety of electric drift field strengths. The target of this research is to offer a cost effective alternative to liquid noble gas detectors in neutrino physics.Comment: 6 pages, 5 figures, submitted to Proceedings 12th Pisa Meeting on Advanced Detectors, La Biodola, Isola d'Elba, Ital

    Convection during Thermally Unstable Solidification of Pb-Sn in a Magnetic Field

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    Convection and macrosegregation in directionally solidified hypoeutectic Pb-38 wt pct Sn and hypereutectic Pb-64.5 wt pct Sn have been examined during upward and downward growth. Temperature fluctuations are observed along the length of the melt column during downward growth. With increasing Rayleigh number, these fluctuations change from none, to cyclic, to time periodic having multiple harmonics, and finally to random. At the higher convective driving force of 350 K temperature inversion, the transverse magnetic field decreased convective levels, strong random temperature fluctuations (flows) becoming smaller and periodic. The maximum field of 0.45 T was unable to completely eliminate convection. For the lower convective driving force of 150 K temperature inversion, the 0.05 T magnetic field decreased flows, and at 0.15 T, the field caused a dramatic decrease in the characteristic frequency of the temperature fluctuations, indicating a change in the nature of the flow, the waveform of the temperature fluctuations changing from sinusoidal to a pulsed wave. Temperature fluctuations and time delays between thermocouples were used to estimate flow velocities. Irrespective of the convection in the bulk melt (ahead of the mushy zone), longitudinal macrosegregation occurs only if the interdendritic melt mixes with the bulk melt

    Roles of Government and Community Support, Flood Experience, and Flood Education in Livelihood Resilience

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    Flooding is a perennial problem in the state of Bihar, India with devastating impact on the livelihood of people. In spite of the government\u27s measures of flood mitigation, households continue to live with suffering on account of severe damage to their material and non-material assets. In this background, the objectives of the study are: (1) to explore the differential role of the community and government support in livelihood resilience; (2) to assess the impact of flood experience and flood education in livelihood resilience; and (3) to explore the impact of level of education, reflected in average years of schooling of the male-headed households in livelihood resilience. The primary data were collected from 472 households by using a multi-stage random sampling technique over seven blocks in river basins of Ganga and Kosi in the district of Bhagalpur, Bihar. To analyze the data, descriptive statistics and structural equation modeling were used. The findings of the study show that prompt and spontaneous community action was more effective than government help. Flood experience also plays a crucial role in the revamping of livelihood. Flood education is not found to exist in the area; people learn the skills of survival during and after floods from their elders. Moreover, difference in education among the male-headed households creates difference in the attitudes and awareness surrounding livelihood resilience

    Underground Cordon by Microorganisms-Part-III Role of Soil Inhabiting Actinomycetes

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    Certain strains of soil inhabiting actinomycetes were found to substantially corrode aluminium alloy (54-S) which has bscn found tobe more resistant to bacterial or fungal corrosion in our earlier studies.These strains did not produce any corrosion on the mild steel and galvanised iron panels which were heavily corroded by bacteria and fungi. The corrosive isolates have been partialiy characterised after their isolation and purification. The extent of corrosion caused by eachstrain has been determined

    Sharp signature of DDW quantum critical point in the Hall coefficient of the cuprates

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    We study the behavior of the Hall coefficient, RHR_H, in a system exhibiting dx2−y2d_{{x^2}-{y^2}} density-wave (DDW) order in a regime in which the carrier concentration, xx, is tuned to approach a quantum critical point at which the order is destroyed. At the mean-field level, we find that nHall=1/RHn_{\rm Hall}=1/R_H evinces a sharp signature of the transition. There is a kink in nHalln_{\rm Hall} at the critical value of the carrier concentration, xcx_c; as the critical point is approached from the ordered side, the slope of nHalln_{\rm Hall} diverges. Hall transport experiments in the cuprates, at high magnetic fields sufficient to destroy superconductivity, should reveal this effect.Comment: 5 pages, 2 eps figure

    Proposal to stabilize and detect half-quantum vortices in strontium ruthenate thin films: Non-Abelian braiding statistics of vortex matter in a px+ipy{p_x}+i{p_y} superconductor

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    We propose a simple way to stabilize half-quantum vortices in superconducting strontium ruthenate, assuming the order parameter is of chiral px+ipyp_x + ip_y symmetry, as is suggested by recent experiments. The method, first given by Salomaa and Volovik in the context of Helium-3, is very naturally suited for strontium ruthenate, which has a layered, quasi-two-dimensional, perovskite crystal structure. We propose possible experiments to detect their non abelian-braiding statistics. These experiments are of potential importance for topological quantum computation
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