126 research outputs found
Supervised Hashing for Retrieval of Multimodal Biometric Data
Biometric systems commonly utilize multi-biometric approaches where a person is verified or identified based on multiple biometric traits. However, requiring systems that are deployed usually require verification or identification from a large number of enrolled candidates. These are possible only if there are efficient methods that retrieve relevant candidates in a multi-biometric system. To solve this problem, we analyze the use of hashing techniques that are available for obtaining retrieval. We specifically based on our analysis recommend the use of supervised hashing techniques over deep learned features as a possible common technique to solve this problem. Our investigation includes a comparison of some of the supervised and unsupervised methods viz. Principal Component Analysis (PCA), Locality Sensitive Hashing (LSH), Locality-sensitive binary codes from shift-invariant kernels (SKLSH), Iterative quantization: A procrustean approach to learning binary codes (ITQ), Binary Reconstructive Embedding (BRE) and Minimum loss hashing (MLH) that represent the prevalent classes of such systems and we present our analysis for the following biometric data: Face, Iris, and Fingerprint for a number of standard datasets. The main technical contributions through this work are as follows: (a) Proposing Siamese network based deep learned feature extraction method (b) Analysis of common feature extraction techniques for multiple biometrics as to a reduced feature space representation (c) Advocating the use of supervised hashing for obtaining a compact feature representation across different biometrics traits. (d) Analysis of the performance of deep representations against shallow representations in a practical reduced feature representation framework. Through experimentation with multiple biometrics traits, feature representations, and hashing techniques, we can conclude that current deep learned features when retrieved using supervised hashing can be a standard pipeline adopted for most unimodal and multimodal biometric identification tasks.</p
REMOTE TRACKING OF ANDROID SMARTPHONES
The Purpose of the paper is to trace out the status and progress of the employee mobile and the relevant information is transferred to the mobile of the project manager and updated in the web server. The employee’s problem related to the company can be monitored by the project manager and he can also track the employee’s current location through the GPS. In existing system, the CBI alone can trace the mobile phone of any person with the help of unique IMEI number in telephone exchange. So there is no possibility to trace any information regarding the employee’s mobile details by the project manager. So to overcome, this system was implemented
Pressure simulation for footstep energy harvesting paver
Amongst all the energy sources from human motion, footstep has the potential of producing electrical energy as an alternative source to non-conventional renewable energy. Researchers have shown that human footstep kinetic energy can be converted to electrical energy by devised mechanism for low power application such as powering lights, radio and charging phones. Eventually, a novel fluid based energy harvesting paver was developed and tested to contribute towards sustainable development. The paver uses mini hydro generators to produce energy as fluid is forced through these mini hydro generators upon human stepping. This paper presents the pressure simulation of fluid bag system when subjected to an applied human force and the quarter ellipsoid shaped proved to be the best performer which can produce upto 1.4J per step. The pressure simulation provides a relation between pressure and output power
Lattice Boltzmann - Langevin simulations of binary mixtures
We report a hybrid numerical method for the solution of the model H
fluctuating hydrodynamic equations for binary mixtures. The momentum
conservation equations with Landau-Lifshitz stresses are solved using the
fluctuating lattice Boltzmann equation while the order parameter conservation
equation with Langevin fluxes are solved using the stochastic method of lines.
Two methods, based on finite difference and finite volume, are proposed for
spatial discretisation of the order parameter equation. Special care is taken
to ensure that the fluctuation-dissipation theorem is maintained at the lattice
level in both cases. The methods are benchmarked by comparing static and
dynamic correlations and excellent agreement is found between analytical and
numerical results. The Galilean invariance of the model is tested and found to
be satisfactory. Thermally induced capillary fluctuations of the interface are
captured accurately, indicating that the model can be used to study nonlinear
fluctuations
Drought tolerance in MnSOD transgenic Hevea brasiliensis in a dry sub-humid environment
One year old bud-grafted plants of MnSOD transgenic Hevea lines (L1 and L2) and an untransformed line of clone RRII 105 were used in the present study to evaluate their physiological performance in a dry sub-humid environment by withholding irrigation and to assess the recovery by re-watering. The dry matter partitioning was more towards the root in transgenic lines (55% and 60% in Ll and L2, respectively) but, was less in the untransformed RRII 105 (43%). After six days of moisture stress in polybags, pre-dawn leaf water potential and relative water content declined in all the lines, however, transgenic line L1 showed higher tissue water content throughout the drought as well as recovery period. Chlorophyll content did not show any significant reduction. Net photosynthetic rate (PN) declined rapidly and it reached near zero on the third day of drought imposition except for line L1, which showed lesser decline in PN. The decline in stomatal conductance (gs) was more rapid than PN in all the lines. On re-watering, recovery of PN and gs was better in the transgenic lines than untransformed RRII 105, which did not recover fully from the drought impact. Antioxidant enzymes, superoxide dismutase and peroxidase did not show a definite trend in their activities in these lines. However, it was found that the transgenic line L1 had better drought tolerant capacity in terms of lesser inhibition of photosynthetic rate under drought and faster recovery on re-watering
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Are Meaningful Use Stage 2 certified EHRs ready for interoperability? Findings from the SMART C-CDA Collaborative
Background and objective Upgrades to electronic health record (EHR) systems scheduled to be introduced in the USA in 2014 will advance document interoperability between care providers. Specifically, the second stage of the federal incentive program for EHR adoption, known as Meaningful Use, requires use of the Consolidated Clinical Document Architecture (C-CDA) for document exchange. In an effort to examine and improve C-CDA based exchange, the SMART (Substitutable Medical Applications and Reusable Technology) C-CDA Collaborative brought together a group of certified EHR and other health information technology vendors. Materials and methods We examined the machine-readable content of collected samples for semantic correctness and consistency. This included parsing with the open-source BlueButton.js tool, testing with a validator used in EHR certification, scoring with an automated open-source tool, and manual inspection. We also conducted group and individual review sessions with participating vendors to understand their interpretation of C-CDA specifications and requirements. Results: We contacted 107 health information technology organizations and collected 91 C-CDA sample documents from 21 distinct technologies. Manual and automated document inspection led to 615 observations of errors and data expression variation across represented technologies. Based upon our analysis and vendor discussions, we identified 11 specific areas that represent relevant barriers to the interoperability of C-CDA documents. Conclusions: We identified errors and permissible heterogeneity in C-CDA documents that will limit semantic interoperability. Our findings also point to several practical opportunities to improve C-CDA document quality and exchange in the coming years
Electrically-driven phase transition in magnetite nanostructures
Magnetite (FeO), an archetypal transition metal oxide, has been
used for thousands of years, from lodestones in primitive compasses[1] to a
candidate material for magnetoelectronic devices.[2] In 1939 Verwey[3] found
that bulk magnetite undergoes a transition at T 120 K from a
high temperature "bad metal" conducting phase to a low-temperature insulating
phase. He suggested[4] that high temperature conduction is via the fluctuating
and correlated valences of the octahedral iron atoms, and that the transition
is the onset of charge ordering upon cooling. The Verwey transition mechanism
and the question of charge ordering remain highly controversial.[5-11] Here we
show that magnetite nanocrystals and single-crystal thin films exhibit an
electrically driven phase transition below the Verwey temperature. The
signature of this transition is the onset of sharp conductance switching in
high electric fields, hysteretic in voltage. We demonstrate that this
transition is not due to local heating, but instead is due to the breakdown of
the correlated insulating state when driven out of equilibrium by electrical
bias. We anticipate that further studies of this newly observed transition and
its low-temperature conducting phase will shed light on how charge ordering and
vibrational degrees of freedom determine the ground state of this important
compound.Comment: 17 pages, 4 figure
Radiation Effects in Ultraviolet Sensitive Pd/4H-SiC Schottky Detectors
9-154H-SiC, by virtue of its intrinsic properties, is a very promising semiconductor material for fabricating rad-hard UV detectors suitable for harsh radiation environments. This paper aims to investigate the radiation tolerance of indigenously developed Pd/4H-SiC Schottky detectors, in order to determine their feasibility for space applications. 4H-SiC detectors of active area 1 × 1 mm2 were irradiated with electrons of energy 10 MeV at fluence of 2×1013 e-/cm2 and gamma rays from a Co-60 source with a total dose of 1 Mrad. The impact of these irradiations on electro-optical characteristics of the devices was studied by analyzing the changes in electrical parameters like reverse saturation current (Is), ideality factor (n), barrier height (ɸB), effective doping concentration (Neff) derived from I-V and C-V characteristics as well as in the UV spectral responsivity (i.e., from 248 to 365 nm) of the irradiated detectors. The electron irradiated device showed negligible change in I-V and C-V characteristics whereas its UV spectral responsivity at the peak wavelength of 290 nm reduced by 48.7 %. Gamma irradiated device displayed a noticeable variation in its electrical characteristics and 15.8 % reduction in the spectral responsivity (optical characteristics) at the peak wavelength. The results show that the radiation hardness of 4H-SiC detectors is better than that of conventional semiconductor ones, making it a more appealing choice as radiation detectors in space systems
On-Orbit Performance of Pd/4H-SiC Schottky UV Detectors in a Low-Earth Orbit
The monitoring of solar ultraviolet radiation from a space platform is now considered essential for a wide range of fieldsincluding solar physics, atmospheric science and astrobiology. 4H-Silicon Carbide (4H-SiC) is a superior alternative toconventional materials like silicon for the fabrication of UV detectors for adverse space conditions due to its inherentradiation hardness and visible-blind nature. This paper describes the space qualification and deployment of indigenouslydeveloped Pd/4H-SiC Schottky UV detectors in a low-earth orbit (LEO) and their on-board performance. Two SiC UVdetectors were flown as a rad-hard sun detection sensor in the nanosatellite INS-2TD. The sensor has carried out solar UVflux observations continuously since its launch in February 2022 and the data gathered during the first seven months offlight is discussed in this paper
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