4,435 research outputs found
Secure Authentication Using Click Draw Based Graphical Password Scheme
Graphical passwords are an alternative to alphanumeric passwords in which users click on images to authenticate themselves rather than type alphanumeric strings. We have developed one such system, called Secure Authentication using Click Draw Based graphical password scheme, and evaluated it with human users. Secure Authentication using Click Draw Based graphical password scheme, including USAbility and security evaluations, and implementation considerations. An important USAbility goal for knowledge-based authentication systems is to support users in selecting passwords of higher security, in the sense of being from an expanded effective security pace. We use the sequence of multiple images along with a dummy image and alsoa pattern on any single image to influence user choice in click draw based graphical passwords, encouraging users to select more random, and hence more difficult to guess patterns
Experimental Investigation of Lobe Coupling for Formulation of an Approximate Generalized Experimental Data Based Model
This paper presents an approach to establish operational characteristics of ball joint-lobe type coupling by performing extensive experimentation. The experimentation must perform by changing independent physical quantities of the coupling over a wide range and response data is gathered. Based on the response data, the mathematical model is formulated correlating the responses in terms of independent variables. These models can be used as a design data for this coupling. Because of complexity in kinematics and dynamics of coupling, logic based modeling is difficult for this type of coupling. This type of coupling is mainly used in harvester. Thus, this research outcome is useful in the design of mechanical transmission system of harvester. An emphasis is laid on the study of response of the coupling towards the variation in misalignment
Application Of Spatial Technology In Conjunction With Bathymetry For Sediment Assessment In Tansa And Modaksagar Reservoir Near Mumbai
Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv
Anomalous current transport in Au/low-doped n-GaAs Schottky barrier diodes at low temperatures
The current-voltage characteristics of Au=low doped
n-GaAs Schottky diodes were determined at various
temperatures in the range of 77-300 K. The estimated
zero-bias barrier height and the ideality factor assuming
thermionic emission (TE) show a temperature dependence of
these parameters. While the ideality factor was found to show
the T0 effect, the zero-bias barrier height was
found to exhibit two different trends in the temperature
ranges of 77-160 K and 160-300 K. The variation in the
flat-band barrier height with temperature was found to be
-(4.7±0.2)× 104 eVK-1,
approximately equal to that of the energy band gap. The value
of the Richardson constant, A∗∗, was
found to be 0.27 Acm-2K-2 after
considering the temperature dependence of the barrier height.
The estimated value of this constant suggested the
possibility of an interfacial oxide between the metal and the
semiconductor. Investigations suggested the possibility of a
thermionic field-emission-dominated current transport with a
higher characteristic energy than that predicted by the
theory. The observed variation in the zero-bias barrier
height and the ideality factor could be explained in terms of
barrier height inhomogenities in the Schottky
diode
The Complex Time WKB Approximation And Particle Production
The complex time WKB (CWKB) approximation has been an effective technique to
understand particle production in curved as well as in flat spacetime. Earlier
we obtained the standard results on particle production in time dependent gauge
in various curved spacetime. In the present work we generalize the technique of
CWKB to the equivalent problems in space dependent gauge. Using CWKB, we first
obtain the gauge invariant result for particle production in Minkowski
spacetime in strong electric field. We then carry out particle production in
de-Sitter spacetime in space dependent gauge and obtain the same result that we
obtained earlier in time dependent gauge. The results obtained for de-Sitter
spacetime has a obvious extension to particle production in black hole
spacetime. It is found that the origin of Planckian spectrum is due to repeated
reflections between the turning points. As mentioned earlier, it is now
explicitly shown that particle production is accompanied by rotation of
currents.Comment: 12 pages, Revte
Experimental and Modeling Studies of the Combustion Characteristics of Conventional and Alternative Jet Fuels. Final Report
The objectives of this project have been to develop a comprehensive set of fundamental data regarding the combustion behavior of jet fuels and appropriately associated model fuels. Based on the fundamental study results, an auxiliary objective was to identify differentiating characteristics of molecular fuel components that can be used to explain different fuel behavior and that may ultimately be used in the planning and design of optimal fuel-production processes. The fuels studied in this project were Fischer-Tropsch (F-T) fuels and biomass-derived jet fuels that meet certain specifications of currently used jet propulsion applications. Prior to this project, there were no systematic experimental flame data available for such fuels. One of the key goals has been to generate such data, and to use this data in developing and verifying effective kinetic models. The models have then been reduced through automated means to enable multidimensional simulation of the combustion characteristics of such fuels in real combustors. Such reliable kinetic models, validated against fundamental data derived from laminar flames using idealized flow models, are key to the development and design of optimal combustors and fuels. The models provide direct information about the relative contribution of different molecular constituents to the fuel performance and can be used to assess both combustion and emissions characteristics
Inhomogeneous cosmologies with Q-matter and varying
Starting from the inhomogeneous shear--free Nariai metric we show, by solving
the Einstein--Klein--Gordon field equations, how a self--interacting scalar
field plus a material fluid, a variable cosmological term and a heat flux can
drive the universe to its currently observed state of homogeneous accelerated
expansion. A quintessence scenario where power-law inflation takes place for a
string-motivated potential in the late--time dominated field regime is
proposed.Comment: 11 pages, Revtex. To be published in Physical Review
A Computer Vision-Based Approach for Non-contact Modal Analysis and Finite Element Model Updating
Computer vision-based techniques for modal analysis and system identification are rapidly becoming of great interest for both academic research and engineering practice in structural engineering. For instance, this is particularly relevant in fields such as bridge or tall building monitoring, where the large size of the structure would require an expensive sensor network, and for the characterisation of very slender, highly-flexible structural components, where physically-attached sensors cannot be deployed without altering the mass and stiffness of the system under investigation. This study concerns the latter case. Here, an algorithm for the full-field, non-contact extraction and processing of useful information from vibrational data is applied. Firstly, video acquisition is used to capture rapidly very spatially- and temporally-dense information regarding the vibrational behaviour of a high-aspect-ratio (HAR) prototype wing, with high image quality and high frame rate. Video processing is then applied to extract displacement time histories from the collected data; in turn, these are used to perform Modal Analysis (MA) and Finite Element Model Updating (FEMU). Results are benchmarked against the ones obtained from a single-point laser Doppler vibrometer (LDV). The study is performed on the beam-like spar of the wing prototype with and without the sensors attached to appreciate the disruptive effects of sensor loading. Promising results were achieved
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