2,195 research outputs found
Angle-resolved photoemission spectra in the cuprates from the d-density wave theory
Angle-resolved photoemission spectra present two challenges for the d-density
wave (DDW) theory of the pseudogap state of the cuprates: (1) hole pockets near
are not observed, in apparent contradiction with the assumption
of translational symmetry breaking, and (2) there are no well-defined
quasiparticles at the {\it antinodal} points, in contradiction with the
predictions of mean-field theory of this broken symmetry state. Here, we show
how these puzzles can be resolved.Comment: 4 pages, 3 eps figures, RevTex
Study of Different Algorithms for Face Recognition
The importance of utilising biometrics to establish personal authenticity and to detect impostors is growing in the present scenario of global security concern. Development of a biometric system for personal identification, which fulfils the requirements for access control of secured areas and other applications like identity validation for social welfare, crime detection, ATM access, computer security, etc., is felt to be the need of the day [2]. Face recognition has been evolving as a convenient biometric mode for human authentication for more than last two decades. It plays an important role in applications such as video surveillance, human computer interface, and face image database management [1]. A lot of techniques have been applied for different applications. Robustness and reliability becomes more and more important for these applications especially in security systems.
Basically Face Recognition is the process through which a person is identified by his facial image. With the help of this technique it is possible to use the facial image of a person to authenticate him into any secure system. Face recognition approaches for still images can be broadly categorized into holistic methods and feature based methods. Holistic methods use the entire raw face image as an input, whereas feature based methods extract local facial features and use their geometric and appearance properties.
This work studies the different approaches for a Face Recognition System. The different approaches like PCA, DCT and different types of Wavelets have been studied with the help of Euclidean distance as a classifier and Neural Network as a classifier.
The results have been compared for the two database, AMP which contains 975 images of 13 individuals (each person has 75 different images) under various facial expressions and lightning condition with each image being cropped and resized to 64×64 pixels for the simulation and ORL (Olivetti Research Lab) which contains 400 images (each with 112×92 pixels) corresponding to 40 persons in 10 poses each including both male and female. The ORL database image has been resized to 128×128 pixels
Text-based Editing of Talking-head Video
Editing talking-head video to change the speech content or to remove filler words is challenging. We propose a novel method to edit talking-head video based on its transcript to produce a realistic output video in which the dialogue of the speaker has been modified, while maintaining a seamless audio-visual flow (i.e. no jump cuts). Our method automatically annotates an input talking-head video with phonemes, visemes, 3D face pose and geometry, reflectance, expression and scene illumination per frame. To edit a video, the user has to only edit the transcript, and an optimization strategy then chooses segments of the input corpus as base material. The annotated parameters corresponding to the selected segments are seamlessly stitched together and used to produce an intermediate video representation in which the lower half of the face is rendered with a parametric face model. Finally, a recurrent video generation network transforms this representation to a photorealistic video that matches the edited transcript. We demonstrate a large variety of edits, such as the addition, removal, and alteration of words, as well as convincing language translation and full sentence synthesis
Extractive-photometric determination of cobalt(II) in steels using 4-(2-pyridylazo)resorcinol and xylometazoline hydrochloride
Cobalt(II) forms anionic chelates with 4-(2-pyridylazo)resorcinol (PAR) at pH 7.0-8.0, which can be quantitatively extracted into chloroform as an ion-pair with xylometazolonium cation (XMH). The ion-association system has an absorption maximum at 535 nm and obeys Beers law in the range 0-1.6 mu g of Co/ml with a molar absorptivity 42000 dm(3) mol(-1) cm(-1). The Job's method of continuous variations indicated a composition of 1 : 2 : 2 for cobalt : PAR : XMH for the extracting species. Based on this extraction, a highly sensitive and selective spectrophotometric method for the determination of cobalt in various steels, after prior separation of iron, is described
Microstructure and Interfacial Reactions During Vacuum Brazing of Stainless Steel to Titanium Using Ag-28 pct Cu Alloy
Microstructural evolution and interfacial reactions during vacuum brazing of grade-2 Ti and 304L-type stainless steel (SS) using eutectic alloy Ag-28 wt pct Cu were investigated. A thin Ni-depleted zone of α -Fe(Cr, Ni) solid solution formed on the SS-side of the braze zone (BZ). Cu from the braze alloy, in combination with the dissolved Fe and Ti from the base materials, formed a layer of ternary compound τ2, adjacent to Ti in the BZ. In addition, four binary intermetallic compounds, Cu3Ti2, Cu4Ti3, CuTi and CuTi2 formed as parallel contiguous layers in the BZ. The unreacted Ag solidified as islands within the layers of Cu3Ti2 and Cu4Ti3. Formation of an amorphous phase at certain locations in the BZ could be revealed. The β -Ti(Cu) layer, formed due to diffusion of Cu into Ti-based material, transformed to an α -Ti + CuTi2eutectoid with lamellar morphology. Tensile test showed that the brazed joints had strength of 112 MPa and failed at the BZ. The possible sequence of events that led to the final microstructure and the mode of failure of these joints were delineated
Advanced stage of breast cancer hoist alkaline phosphatase activity: risk factor for females in India
Breast cancer is the most common neoplasm affecting women in the western world with an average frequency of 1 in 11, developing the malignancy and it is second most common cancer in India. Variations in serum levels of biochemical parameters especially alkaline phosphatase (ALP) changes may be of great help in diagnosis of breast carcinoma. Serum ALP activity was assayed in 388 histopathologically proven breast cancer patients using spectrophotometric methods and monitored association with cancer stages. Breast cancer is a female-biased disease and our study was conducted in a group of female patients with mean age of 48.67 ± 8.32 years. A significant increase in levels of ALP (809.65 ± 145.97 IU/L) was observed in stage IV of the disease. The logistic regression study gave a significant result (P < 0.001) when we compared the group of ALP level (>500 IU/L) with metastatic presentation. The present study besides being cost effective suggested the usefulness of ALP in differentiating breast cancer stages and metastasis
PCR based detection of toxoplasmosis in tissue samples: A step towards detection of toxoplasmosis in meat and post mortem samples
The aim of the study was to find out a suitable marker gene for diagnosis of toxoplasmosis in tissue and meat samples during meat inspection and/or during post mortem studies. PCR was used to diagnose toxoplasmosis in ten inbred Swiss albino mice after experimental inoculation of 100 tachyzoites of laboratory maintained human RH strain of the parasite. Blood, peritoneal lavage and tissue from lung, liver spleen, brain, heart and kidney were taken from experimental murine models in duplicate. The samples were subjected to PCR, using primers directed to the multicopy of Surface Antigen 3 (SAG 3 gene). Blood, kidney and heart tissue were found negative while peritoneal lavage along with lung, liver spleen and brain tissue yielded desired positive amplicons. The significance of the studied molecule vis-Ã -vis future projections in regard to diagnosis of toxoplasmosis during meat sample examination and/or during routine post mortem is being described
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