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

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

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

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

Inflation and dark energy arising from geometrical tachyons

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

Bounds on Tensor wave and Twisted Inflation

We study the bounds on tensor wave in a class of twisted inflation models where $D(4+2k)$-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 $g_s M$ satisfying the self-consistency relation and the WMAP data. Further, we observe that the wrapped $D8$-brane appears to be the most attractive from a cosmological perspective.Comment: 5 page

Surface Reconstruction and Evolution from Multiple Views

Applications like 3D Telepresence necessitate faithful 3D surface reconstruction of the object and 3D data compression in both spatial and temporal domains. This makes us feel immersed in virtual environments there by making 3D Telepresence a powerful tool in many applications. Hence 3D surface reconstruction and 3D compression are two challenging problems which are addressed in this thesis

Evidence of reworking and resuspension of carbonates during last glacial maximum and early deglacial period along the southwest coast of India

A gravity core collected from the upper slope of southwest of Quilon at a water depth of 776 m (Lat: 8°12′263″N, Long: 76°28′281″E) was analysed for texture (carbonate free), calcium carbonate and organic carbon. Variation in silicic fraction seems to be controlled by silt, i.e., enrichment from 15 ka BP to 10 ka BP and then constant in Holocene. Below 15 ka BP, the silicic fraction gets depleted compared to the Holocene section with a minimum around 21 ka BP. Clay content remains nearly constant except in the Holocene where it shows an enrichment. Carbonate content of less than 63 micron when computed by subtracting coarse fraction content from the total carbonate suggests that the total carbonates are mainly concentrated in the finer fraction. All these carbonate phases show an inverse relationship with silicic fraction except in Holocene. Below 15 ka BP, CaCO3 dominates in sediments comprising more than 65%, such an increase is also seen in the coarse fraction. Coarse fraction from these sections contains abundant nodular type aggregates encrusting small forams. This period is marked by a high sedimentation rate comparable to Holocene. These parameters suggest that the productivity and precipitation have increased in the Holocene due to the intensification of the southwest monsoon. During the last glacial maximum and early deglacial period the high sedimentation rate indicates redeposition of the carbonates from the existing carbonate lithofacies situated between Quilon and Cape Comorin probably due to the slope instability

Prospects of inflation in delicate D-brane cosmology

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