4,296 research outputs found

    Bounds on Tensor wave and Twisted Inflation

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    We study the bounds on tensor wave in a class of twisted inflation models where D(4+2k)D(4+2k)-branes are wrapped on cycles in the compact manifold and wrap the KK-direction in the corresponding effective field theory. While the lower bound is found to be analogous to that in Type IIB models of brane inflation, the upper bound turns out to be significantly different. This is argued for a range of values for the parameter gsMg_s M satisfying the self-consistency relation and the WMAP data. Further, we observe that the wrapped D8D8-brane appears to be the most attractive from a cosmological perspective.Comment: 5 page

    Prioritization of Strategies to Overcome Barriers for Cleaner and Energy Efficient Alternatives in Urban Transportation - Multi-criteria Approach

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    Adoption of cleaner and energy efficient technologies (CEETs) in urban transport experiences certain barriers and deriving a set of policies to remove/reduce barrier in the case of Delhi and Mumbai transport systems was attempted in this study. A set of policy alternatives and measures (PAMs) were identified for each barrier and a pool of barriers PAMs for all barriers were identified which were finally analysed for their potential based on 4 important criteria namely administrative costs, financial burden, human resource benefits, administrative backup and political acceptability. Based on aggregated multi-criteria assessment, the policy of distinct colouring scheme for alternate fuel vehicles (AFVs) stood first followed by awareness campaigns to the drivers, training programs to the workers, single window/priority check points, financial incentives and task force to carry out check. To realize the completeness, potential of PAMs in handling barriers was analysed considering not only a set of criteria but also their potential in handling more than one barrier. In overall ranking, policy to develop partnerships among major stakeholders and awareness campaigns to the drivers showed highest potential in removing barriers for the adoption of CEETs. Based on the ranking under both approaches a set of seven policy measures and alternatives were selected to remove barriers to CEETS and they are partnership between the Government, public sector undertakings and private actors in proving better infrastructure; Financial incentives like free or priority parking, separate lanes for alternative fuel vehicles and free inspection and maintenance; Task force to carry our checks; Heavy fines on defaulters; Distinct colour coding for AFVs; Demonstration of AFVs and their advantages; and Awareness campaigns to drivers. This set of PAMs would be able to control all seven pre-identified barriers to the adoption of CEETs in Delhi and Mumbai urban transportation systems.Barriers, CEETs, multi-criteria, policy analysis, urban transport

    Application of Analytic Hierarchy Process to Prioritize Urban Transport Options - Comparative Analysis of Group Aggregation Methods

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    The present study presents a comparative analysis of different group aggregation methods adopted in AHP by testing them against social choice axioms with a case study of Delhi transport system. The group aggregation (GA) methods and their correctness were tested while prioritizing the alternative options to achieve energy efficient and less polluting transport system in Delhi It was observed that among all group aggregation methods, geometric mean method (GMM) - the most widely adopted GA method of AHP - showed poor performance and failed to satisfy the most popular pareto optimality and non-dictatorship axiom raising questions on its validity as GA method adopted in AHP. All other group aggregation methods viz. weighted arithmetic mean method with varying weights and equal weights (WAMM, WeAMM) and arithmetic mean of individual priorities (AMM) resulted in concurring results with the individual member priorities. This study demonstrates that WeAMM resulted in better aggregation of individual priorities compared to WAMM. Comparative analysis between individual and group priorities demonstrates that the arithmetic mean (AMM) of priorities by individual members of the group showed minimum deviation from the group consensus making it the most suitable and simple method to aggregate individual preferences to arrive at a group consensus.AHP, decision making, GMM, group aggregation, transportation, WAMM

    Application of analytic hierarchy process to prioritize urban transport options: Comparative analysis of group aggregation methods

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    The present study presents a comparative analysis of different group aggregation methods adopted in AHP by testing them against social choice axioms with a case study of Delhi transport system. The group aggregation (GA) methods and their correctness were tested while prioritizing the alternative options to achieve energy efficient and less polluting transport system in Delhi. It was observed that among all group aggregation methods, geometric mean method (GMM) - the most widely adopted GA method of AHP - showed poor performance and failed to satisfy the most popular "pareto optimality and non-dictatorship axiom" raising questions on its validity as GA method adopted in AHP. All other group aggregation methods viz. weighted arithmetic mean method with varying weights and equal weights (WAMM, WeAMM) and arithmetic mean of individual priorities (AMM) resulted in concurring results with the individual member priorities. This study demonstrates that WeAMM resulted in better aggregation of individual priorities compared to WAMM. Comparative analysis between individual and group priorities demonstrates that the arithmetic mean (AMM) of priorities by individual members of the group showed minimum deviation from the group consensus making it the most suitable and simple method to aggregate individual preferences to arrive at a group consensus.AHP, decision making, GMM, group aggregation, transportation, WAMM

    Prospects of inflation with perturbed throat geometry

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    We study brane inflation in a warped deformed conifold background that includes general possible corrections to the throat geometry sourced by coupling to the bulk of a compact Calabi-Yau space. We focus specifically, on the perturbation by chiral operator of dimension 3/2 in the CFT. We find that the effective potential in this case can give rise to required number of e-foldings and the spectral index nSn_S consistent with observation. The tensor to scalar ratio of perturbations is generally very low in this scenario. The COBE normalization, however, poses certain difficulties which can be circumvented provided model parameters are properly fine tuned. We find the numerical values of parameters which can give rise to enough inflation, observationally consistent values of density perturbations, scalar to tensor ratio of perturbations and the spectral index nSn_S.Comment: 7 pages and nine figures; typos corrected, minor comments and clarifications added, revised version to appear in PL

    Inflation and dark energy arising from geometrical tachyons

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    We study the motion of a BPS D3-brane in the NS5-brane ring background. The radion field becomes tachyonic in this geometrical set up. We investigate the potential of this geometrical tachyon in the cosmological scenario for inflation as well as dark energy. We evaluate the spectra of scalar and tensor perturbations generated during tachyon inflation and show that this model is compatible with recent observations of Cosmic Microwave Background (CMB) due to an extra freedom of the number of NS5-branes. It is not possible to explain the origin of both inflation and dark energy by using a single tachyon field, since the energy density at the potential minimum is not negligibly small because of the amplitude of scalar perturbations set by CMB anisotropies. However geometrical tachyon can account for dark energy when the number of NS5-branes is large, provided that inflation is realized by another scalar field.Comment: 11 pages, 8 figure

    Prospects of inflation in delicate D-brane cosmology

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    We study D-brane inflation in a warped conifold background that includes brane-position dependent corrections for the nonperturbative superpotential. Instead of stabilizing the volume modulus chi at instantaneous minima of the potential and studying the inflation dynamics with an effective single field (radial distance between a brane and an anti-brane) phi, we investigate the multi-field inflation scenario involving these two fields. The two-field dynamics with the potential V(phi,chi) in this model is significantly different from the effective single-field description in terms of the field phi when the field chi is integrated out. The latter picture underestimates the total number of e-foldings even by one order of magnitude. We show that a correct single-field description is provided by a field psi obtained from a rotation in the two-field space along the background trajectory. This model can give a large number of e-foldings required to solve flatness and horizon problems at the expense of fine-tunings of model parameters. We also estimate the spectra of density perturbations and show that the slow-roll parameter eta_{psi psi}=M_{pl}^2 V_{,psi psi}/V in terms of the rotated field psi determines the spectral index of scalar metric perturbations. We find that it is generally difficult to satisfy, simultaneously, both constraints of the spectral index and the COBE normalization, while the tensor to scalar ratio is sufficiently small to match with observations.Comment: 12 pages, 8 figures, version to appear in Physical Review

    Application Areas of Data Mining in Indian Retail Banking Sector

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    Banking systems collect huge amounts of data on day to day basis be it customer information transaction details risk profiles credit card details credit limit and collateral details compliance and Anti Money Laundering AML related information trade finance data SWIFT and telex messages Thousands of decisions are taken in a bank daily These decisions include credit decisions default decisions relationship start up investment decisions AML and Illegal financing related One needs to depend on various reports and drill down tools provided by the banking systems to arrive at these critical decisions But this is a manual process and is error prone and time consuming due to large volume of transactional and historical data Interesting patterns and knowledge can be mined from this huge volume of data that in turn can be used for this decision making process This article explores and reviews various data mining techniques that can be applied in banking areas It provides an overview of data mining techniques and procedures It also provides an insight into how these techniques can be used in banking areas to make the decision making process easier and productiv

    A Survey of Physical Educational Facilities in Government High Schools in Srikakulam District

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    The object of Physical Education is to learn acquire and perform skills Learning of skills is good at early ages Bodily movement of activities are necessary and powerful The physical Education is a programme by which the students are brought up with the will of mind The coordination of body with mind is got by exercises and activities through sports and games No school should be left off without the improvement of the programme Sport is active by which spirit enlightens and the positivity of the mind is endurance to success Facilities should be freely available without hesitance The students of the schools are seeking for the help of the personnel with the enough facilities The entire success lies on them Otherwise the programme will be so dull that the students get disappointment in the long run keeping this in view an attempt has been made to study the existing physical education facilities in the High School of Srikakulam Distric
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