检索结果-南通市图书馆

Deep Feature Learning for Intrinsic Signature Based Camera Discrimination

在线全文

学校读者我要写书评

暂无评论

Big Data Mining and Analytics 2022年第3期5卷 206-227页

作者： Chaity Banerjee Tharun Kumar Doppalapudi Eduardo Pasiliao Jr. tathagata mukherjee Department of Idustrial&Systems Engineering University of Central FloridaOrlandoFL 32816USA Department of Computer Science University of Alabama in HuntsvilleHuntsvilleAL 35806USA Air Force Research Labs United States Air ForceEglin Air Force BaseShalimarFL 32579USA

In this paper we consider the problem of“end-to-end”digital camera identification by considering sequence of images obtained from the *** problem of digital camera identification is harder than the problem of identifying its analog counterpart since the process of analog to digital conversion smooths out the intrinsic noise in the analog *** it is known that identifying a digital camera is possible by analyzing the camera’s intrinsic sensor artifacts that are introduced into the images/videos during the process of photo/video *** is known that such methods are computationally intensive requiring expensive pre-processing *** this paper we propose an end-to-end deep feature learning framework for identifying cameras using images obtained from *** conduct experiments using three custom datasets:the first containing two cameras in an indoor environment where each camera may observe different scenes having no overlapping features,the second containing images from four cameras in an outdoor setting but where each camera observes scenes having overlapping features and the third containing images from two cameras observing the same checkerboard pattern in an indoor *** results show that it is possible to capture the intrinsic hardware signature of the cameras using deep feature representations in an end-to-end *** deep feature maps can in turn be used to disambiguate the cameras from each *** system is end-to-end,requires no complicated pre-processing steps and the trained model is computationally efficient during testing,paving a way to have near instantaneous decisions for the problem of digital camera identification in production *** we present comparisons against the current state-of-the-art in digital camera identification which clearly establishes the superiority of the end-to-end solution.

关键词： deep learning visual signatures camera identification convolutional neural networks deep feature learning

LoSI: Large Scale Location Inference Through FM Signal Integration and Estimation

在线全文

学校读者我要写书评

暂无评论

Big Data Mining and Analytics 2019年第4期2卷 319-348页

作者： tathagata mukherjee Piyush Kumar Debdeep Pati Erik Blasch Eduardo Pasiliao Liqin Xu Department of Computer Science University of Alabama in HuntsvilleHuntsvilleAL 35806USA CompGeom Inc. TallahasseeFL 32311USA Department of Statistics Texas A&M UniversityCollege StationTX 77843USA Air Force Research Laboratory RomeNY 13441USA Air Force Research Laboratory ShalimarFL 32579USA CompGeom Inc. TallahasseeFL 32579USA

In this paper we present a large scale, passive positioning system that can be used for approximate localization in Global Positioning System(GPS) denied/spoofed environments. This system can be used for detecting GPS spoofing as well as for initial position estimation for input to other GPS free positioning and navigation systems like Terrain Contour Matching(TERCOM). Our Location inference through Frequency Modulation(FM)Signal Integration and estimation(LoSI) system is based on broadcast FM radio signals and uses Received Signal Strength Indicator(RSSI) obtained using a Software Defined Radio(SDR). The RSSI thus obtained is used for indexing into an estimated model of expected FM spectrum for the entire United States. We show that with the hardware for data acquisition, a single point resolution of around 3 miles and associated algorithms, we are capable of positioning with errors as low as a single pixel(more precisely around 0.12 mile). The algorithm uses a largescale model estimation phase that computes the expected FM spectrum in small rectangular cells(realized using geohashes) across the Contiguous United States(CONUS). We define and use Dominant Channel Descriptor(DCD) features, which can be used for positioning using time varying models. Finally we use an algorithm based on Euclidean nearest neighbors in the DCD feature space for position estimation. The system first runs a DCD feature detector on the observed spectrum and then solves a subset query formulation to find Inference Candidates(IC).Finally, it uses a simple Euclidean nearest neighbor search on the ICs to localize the observation. We report results on 1500 points across Florida using data and model estimates from 2015 and 2017. We also provide a Bayesian decision theoretic justification for the nearest neighbor search.

关键词： Global Positioning System(GPS)-free positioning Frequency Modulation(FM) radio signals of opportunity nearest neighbor search

Excitonic effects in absorption spectra of carbon dioxide reduction photocatalysts

在线全文

学校读者我要写书评

暂无评论

npj Computational Materials 2021年第1期7卷 1752-1761页

作者： tathagata Biswas Arunima K.Singh Department of Physics Arizona State UniversityTempeAZ 85287USA

The formation and disassociation of excitons play a crucial role in any photovoltaic or photocatalytic ***,excitonic effects are seldom considered in materials discovery studies due to the monumental computational cost associated with the examination of these ***,we study the excitonic properties of nearly 50 photocatalysts using state-of-the-art Bethe–Salpeter ***~50 materials were recently recognized as promising photocatalysts for CO_(2) reduction through a data-driven screening of 68,860 ***,we propose three screening criteria based on the optical properties of these materials,taking excitonic effects into account,to further down select six ***,we study the correlation between the exciton binding energies obtained from the Bethe–Salpeter formalism and those obtained from the computationally much lessexpensive Wannier–Mott model for these chemically diverse~50 *** work presents a paradigm towards the inclusion of excitonic effects in future materials discovery for solar-energy harvesting applications.

关键词： materials properties dioxide

pyGWBSE:a high throughput workflow package for GW-BSE calculations

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

npj Computational Materials 2023年第1期9卷 2127-2136页

作者： tathagata Biswas Arunima K.Singh Department of Physics Arizona State UniversityTempe 85287 AZUSA

We develop an open-source python workflow package,pyGWBSE to perform automated first-principles calculations within the GW-BSE(Bethe-Salpeter)***-BSE is a many body perturbation theory based approach to explore the quasiparticle(QP)and excitonic properties of *** approximation accurately predicts bandgaps of materials by overcoming the bandgap underestimation issue of the more widely used density functional theory(DFT).BSE formalism produces absorption spectra directly comparable with experimental *** package achieves complete automation of the entire multi-step GW-BSE computation,including the convergence tests of several parameters that are crucial for the accuracy of these *** is integrated with Wannier90,to generate QP bandstructures,interpolated using the maximally-localized wannier *** also enables the automated creation of databases of metadata and data,including QP and excitonic properties,which can be extremely useful for future material discovery studies in the field of ultra-wide bandgap semiconductors,electronics,photovoltaics,and photocatalysis.

关键词： automated python enable

Evaluation of flow characteristics in an onshore horizontal separator using computational fluid dynamics

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Ocean Engineering and Science 2020年第3期5卷 261-268页

作者： tathagata Acharya Lucio Casimiro Department of Physics and Engineering California State UniversityBakersfield9001 Stockdale HighwayBakersfieldCA 93311United States

In the petrochemical industry,separation of oil from water is a very important *** produce mixtures of gas,oil,and water which undergo a primary stage of separation inside horizontal gravity *** performance of these vessels is evaluated by measuring mean residence time(MRT)and residence time distribution(RTD).Although many researchers studied flow characteristics in horizontal separators,limited number of articles exist that discuss separator MRT and RTD with varying *** this article,the authors study an experiment using a horizontal gravity separator by previous researchers and perform computational fluid dynamics(CFD)simulations on the same geometry under similar *** simulation results show qualitative agreement with the experiments by previous *** shown by experiments before,CFD results showed that MRT of the organic phase increased with increase in *** addition,the RTD characteristics show very similar trends between CFD and experimental results.

关键词： Multiphase separators Computational fluid dynamics Mean residence time Residence time distribution

The formation of authigenic deposits during Paleogene warm climatic intervals:A review

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Palaeogeography 2020年第4期9卷 388-414页

作者： Santanu Banerjee tathagata Roy Choudhury Pratul Kumar Saraswati Sonal Khanolkar Department of Earth Sciences Indian Institute of Technology BombayPowaiMumbai-400076India Department of Earth Sciences Indian Institute of Technology KanpurKanpur-208016India

Although Paleogene warm climatic intervals have received considerable attention for atmospheric and oceanographic changes,the authigenic mineralization associated with these time spans remains *** extensive review of the literature reveals a close correspondence between the high abundance of glauconite and warm climatic intervals during the Paleogene *** abundance of phosphorite,ironstone,lignite and black shale deposits reveals similar *** investigated thoroughly,the origin of these authigenic deposits is never understood in the background of Paleogene warming climatic intervals.A combination of factors like warm seawater,hypoxic shelf,low rate of sedimentation,and enhanced rate of continental weathering facilitated the *** last factor caused the excess supply of nutrients,including Fe,Si,K,Mg and Al through the rivers,the cations needed for the formation of *** excessive inflow of nutrient-rich freshwater into the shallow seas further ensured high organic productivity and stratification in shallow shelves,causing *** consequent rapid rise in sea-level during the warm periods created extensive low-relief shallow marine shelves starved in ***-deficiency in the shallow marine environment facilitated the fixation of Fe into the glauconite *** inflow of nutrient-rich water during the warm climatic intervals facilitated the formation of phosphorite,ironstone,and organic-matter-rich sedimentary deposits as *** global factors primarily controlled the formation of these authigenic deposits,local factors played significant roles in some of the ***,phosphorites formed in marine conditions with open circulation within the tropical *** lush growth of rainforest covers in the tropical belt facilitated the formation of coastal lignite.

关键词： Warm climatic intervals Hyperthermal events Glauconite Phosphorite Oolitic ironstone Lignite Hypoxia Paleogene

Prevalence of Mycobacterium tuberculosis Strains Isolated from Both Pulmonary and Extra Pulmonary Samples and Their Resistance to Rifampicin: A Study from Kolkata and Surrounding Suburbs

在线全文

学校读者我要写书评

暂无评论

Journal of Tuberculosis Research 2016年第2期4卷 61-71页

作者： Soma Chakraborty Arindam Chakraborty tathagata Talukder Mita mukherjee Tridip Chatterjee Department of Microbiology Suraksha Diagnostics DD-18/1 Kolkata India Suraksha Genomics (R & D Division of Suraksha Diagnostics) DD-18/1 Kolkata India

Tuberculosis (TB) is one of the major causes of morbidity and mortality worldwide. In India, nearly 1.8 million new cases of TB are reported annually, which accounts for a fifth of new cases in the world—greater than in any other country. Anti-tubercular drugs (ATDs) have been used for decades, and widespread resistance to them is a very serious public health concern in any part of the world. Aim of this study was to determine the prevalence of Rifampicin (the first line Anti-TB drug) resistance among both pulmonary and extra-pulmonary samples tested positive for Mycobacterium tuberculosis and thereby predict the prevalence of Multi-drug resistant (MDR) tuberculosis in Kolkata and its Suburban regions. All 331 randomly collected clinical samples (both Pulmonary and Extra Pulmonary) were initially screened by Zeihl-Neelsen AFB staining followed by culture on BacT/Alert 3D system and on Lowenstein-Jensen medium and the positive samples were subjected to detection of Mycobacterium tuberculosis complex (MTBC) and simultaneous analysis of Rifampicin resistance by Xpert MTB/RIF assay. Out of the 51 (15.40%) culture positive samples, 13.7% of pulmonary samples and 9.09% of extra-pulmonary samples were Rifampicin resistant. The prevalence of Rifampicin resistant TB in our study is high and the possible reasons can be mixing of new as well as retreatment cases and smaller sample size but, yet it can help Government and public health regulatory bodies to formulate adequate strategies to fight against drug resistant tuberculosis, especially in this part of the world.

关键词： Tuberculosis (TB) Multi Drug Resistant TB (MDR-TB) Rifampicin Resistant TB GeneXpert

Distinguishing celadonite from glauconite for environmental interpretations:a review

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Palaeogeography 2023年第2期12卷 179-194页

作者： Pragya Singh Santanu Banerjee tathagata Roy Choudhury Satadru Bhattacharya Kanchan Pande Department of Earth Sciences Indian Institute of Technology BombayPowaiMumbai400076India Space Applications Centre Indian Space Research OrganisationAhmedabad380015India

Celadonite and glauconite are comparable in terms of physical,chemical and mineralogical *** of both these minerals requires slightly oxygen-depleted conditions in a semiconfined micro-environment,facilitating the uptake of Fe into the *** glauconite is ubiquitous in marine deposits,celadonite forms in both marine and non-marine environments,more commonly by altering intermediate to mafic rocks.A review of data across the geological column shows that both these minerals are more common in the Mesozoic and Cenozoic,which may be related to extensive *** composition of celadonite and glauconite is highly variable and is controlled by the availability of cations within the pore water *** major element composition of celadonite overlaps with that of evolved to highly evolved glauconite to a large *** data and representative samples of celadonite and glauconite reveal subtle differences in X-ray diffraction parameters and Fourier transform infrared(FTIR)*** shows sharper basal and hkl reflections than *** characteristically exhibits distinct 111-021,003-022,023 and 130-131,and 060 reflections at less than 1.51A,indicating a betterordered crystallographic structure than *** FTIR spectra of celadonite and glauconite show similar absorption bands although Si-O bending,Si-O stretching and OH-stretching bands are sharper and well resolved in celadonite than that of *** palaeoenvironmental interpretations,it is,therefore,necessary to examine the subtle differences in X-ray diffraction parameters and FTIR spectra to confirm the identification of these two *** composition of celadonite relates closely to the host rock and depositional *** celadonite associated with mafic rock shows relatively high Fe,Mg and low Al *** contrast,those associated with felsic to intermediate composition rocks show slightly higher contents of Al and

关键词： Celadonite Glauconite Authigenic green silicates Large igneous province Marine Fourier transform infrared spectroscopy X-ray diffraction

Restoration of dysregulated CC chemokine signaling for monocyte/macrophage chemotaxis in head and neck squamous cell carcinoma patients by neem leaf glycoprotein maximizes tumor cell cytotoxicity

在线全文

学校读者我要写书评

暂无评论

Cellular & Molecular Immunology 2010年第5期7卷 396-408页

作者： Krishnendu Chakraborty Anamika Bose tathagata Chakraborty Koustav Sarkar Shyamal Goswami Smarajit Pal Rathindranath Baral Department of Immunoregulation and Immunodiagnostics Chittaranjan National Cancer InstituteKolkataIndia Unit of Clinical Biochemistry Chittaranjan National Cancer InstituteKolkataIndia

Previous studies have shown that the CC chemokine receptor CCR5 is downregulated on monocyte/macrophage(MO/Mw)surfaces in head and neck squamous cell carcinoma(HNSCC)patients(stage IIIB).Ligands(RANTES,MIP-1a and MIP-1b)of this chemokine receptor were also secreted in lesser quantity from MO/Mw of HNSCC patients in comparison with healthy *** an aim to restore this dysregulated receptor–ligand signaling,we have used neem leaf glycoprotein(NLGP),a novel immunomodulator reported from our *** upregulated CCR5 expression,as evidenced from studies on MO/Mw of peripheral blood from HNSCC patients as well as healthy *** of RANTES,MIP-1a and MIP-1b was also upregulated following NLGP treatment of these cells in ***,NLGP has little effect on the expression of CCR5 and the ligand RANTES in oral cancer *** restored CCR5 receptor–ligand signaling seen in MO/Mw was reflected in improved CCR5-dependent,p38 mitogen-activated protein kinase(MAPK)-mediated migration of MO/Mw after NLGP treatment to a standard *** also induces better antigen presentation and simultaneous costimulation to effector T cells by MO/Mw by upregulating human leucocyte antigen(HLA)-ABC,CD80 and *** addition,NLGP-treated MO/Mw-primed T cells can effectively lyse tumor cells in *** effects of NLGP on monocyte migration and T cell-mediated oral tumor cell killing were further demonstrated in transwell assays with or without CCR5 *** results suggest a new approach in cancer immunotherapy by modulating dysregulated CCR5 signals from MO/Mw.

关键词： CCR5 chemokine head and neck squamous cell carcinoma monocytes neem leaf glycoprotein