38,193 research outputs found
Finite element solver for 3-D compressible viscous flows
The space shuttle main engine (SSME) has extremely complex internal flow structure. The geometry of the flow domain is three-dimensional with complicated topology. The flow is compressible, viscous, and turbulent with large gradients in flow quantities and regions of recirculations. The analysis of the flow field in SSME involves several tedious steps. One is the geometrical modeling of the particular zone of the SSME being studied. Accessing the geometry definition, digitalizing it, and developing surface interpolations suitable for an interior grid generator require considerable amount of manual labor. There are several types of grid generators available with some general-purpose finite element programs. An efficient and robust computational scheme for solving 3D Navier-Stokes equations has to be implemented. Post processing software has to be adapted to visualize and analyze the computed 3D flow field. The progress made in a project to develop software for the analysis of the flow is discussed. The technical approach to the development of the finite element scheme and the relaxation procedure are discussed. The three dimensional finite element code for the compressible Navier-Stokes equations is listed
BANKING SECTOR REFORMS AND EQUITY - A SUB-REGIONAL ANALYSIS IN ANDHRA PRADESH
The changes in government policies are continuous to correct the ill effects of its earlier policies. In this study an attempt is made to examine the equity aspect due to reforms in the banking sector at sub-regional level in the state of Andhra Pradesh covering the period 1985 to 2004. The analysis indicates that the share of rural areas in number of branches, number of accounts, deposits and credit declined during pre and post liberalisation periods. Despite declining shares in most of the parameters especially those of credit and deposits, there is positive growth in both the periods. However, the growth of these parameters is more in urban areas. The distribution of credit among the sectors indicates that the share of agricultural sector in accounts and credit declined during pre and post liberalisation periods. The share of agricultural credit declined in all the regions during pre and post liberalisation periods. This is true with respect to credit and number of credit accounts. In the case of other sectors, the share in accounts and credit increased in both the periods. Though, the share in the agriculture sector declined in all the regions, per account credit increased in all the regions during both the periods. It may be concluded that liberalisation has increased inequalities. But the rate of increase in inequalities is arrested to a certain extent in the recent past. But if one looks at the growth of credit given to different sectors and growth of credit in rural and urban areas, one may not come to this kind of conclusion.Banking Sector Reforms, Equity, Andhra Pradesh
Modeling quasi-static magnetohydrodynamic turbulence with variable energy flux
In quasi-static MHD, experiments and numerical simulations reveal that the
energy spectrum is steeper than Kolmogorov's spectrum. To explain
this observation, we construct turbulence models based on variable energy flux,
which is caused by the Joule dissipation. In the first model, which is
applicable to small interaction parameters, the energy spectrum is a power law,
but with a spectral exponent steeper than -5/3. In the other limit of large
interaction parameters, the second model predicts an exponential energy
spectrum and flux. The model predictions are in good agreement with the
numerical results.Comment: 16 pages, 5 figure
Physiological antioxidant system and oxidative stress in stomach cancer patients with normal renal and hepatic function
Role of free radicals has been proposed in the pathogenesis of many diseases. Gastric cancer is a common disease worldwide, and leading cause of cancer death in India. Severe oxidative stress produces reactive oxygen species (ROS) and induces uncontrolled lipid peroxidation. Albumin, uric acid (UA) and Bilirubin are important physiological antioxidants. We aimed to evaluate and assess the role of oxidative stress (OS) and physiological antioxidant system in stomach cancer patients. Lipid peroxidation measured as plasma Thio Barbituric Acid Reactive substances (TBARS), was found to be elevated significantly (p=0.001) in stomach cancer compared to controls along with a decrease in plasma physiological antioxidant system. The documented results were due to increased lipid peroxidation and involvement of physiological antioxidants in scavenging free radicals but not because of impaired hepatic and renal functions
A locally implicit method for fluid flow problems
The fluid flow inside the space shuttle main engine (SSME) traverses through a complex geometrical configuration. The flow is compressible, viscous, and turbulent with pockets of separated regions. Several computer codes are being developed to solve three dimensional Navier-Stokes equations with different turbulence models for analyzing the SSME internal flow. The locally implicit scheme is a computationally efficient scheme which converges rapidly in multi-grid modes for elliptic problems. It has the promise of providing a rapidly converging algorithm for steady-state viscous flow problems
Moore-Penrose inverses of Gram matrices Leaving a Cone Invariant in an Indefinite Inner Product Space
In this paper we characterize Moore-Penrose inverses of Gram matrices leaving
a cone invariant in an indefinite inner product space using indefinite matrix
multiplication. This characterization includes the acuteness (or obtuseness) of
certain closed convex cones
Modeling On-Line Art Auction Dynamics Using Functional Data Analysis
In this paper, we examine the price dynamics of on-line art auctions of
modern Indian art using functional data analysis. The purpose here is not just
to understand what determines the final prices of art objects, but also the
price movement during the entire auction. We identify several factors, such as
artist characteristics (established or emerging artist; prior sales history),
art characteristics (size; painting medium--canvas or paper), competition
characteristics (current number of bidders; current number of bids) and auction
design characteristics (opening bid; position of the lot in the auction), that
explain the dynamics of price movement in an on-line art auction. We find that
the effects on price vary over the duration of the auction, with some of these
effects being stronger at the beginning of the auction (such as the opening bid
and historical prices realized). In some cases, the rate of change in prices
(velocity) increases at the end of the auction (for canvas paintings and
paintings by established artists). Our analysis suggests that the opening bid
is positively related to on-line auction price levels of art at the beginning
of the auction, but its effect declines toward the end of the auction. The
order in which the lots appear in an art auction is negatively related to the
current price level, with this relationship decreasing toward the end of the
auction. This implies that lots that appear earlier have higher current prices
during the early part of the auction, but that effect diminishes by the end of
the auction. Established artists show a positive relationship with the price
level at the beginning of the auction. Reputation or popularity of the artists
and their investment potential as assessed by previous history of sales are
positively related to the price levels at the beginning of the auction. The
medium (canvas or paper) of the painting does not show any relationship with
art auction price levels, but the size of the painting is negatively related to
the current price during the early part of the auction. Important implications
for auction design are drawn from the analysis.Comment: Published at http://dx.doi.org/10.1214/088342306000000196 in the
Statistical Science (http://www.imstat.org/sts/) by the Institute of
Mathematical Statistics (http://www.imstat.org
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