Dynamic Demand Analysis of India Domestic Coffee Market

Coffee, although an important commodity in India agricultural exports, has faced fluctuating international prices and decreasing unit value realisation, especially in the post-reform period. Hence, domestic market for coffee cannot be neglected altogether. In fact, Coffee Board has proposed a promotional campaign to increase domestic demand for coffee. In this context, it becomes necessary to understand weather the emphasis should be on price incentives or nonprice factors. We estimate coffee demand for the Indian domestic market using the dynamic error-correction methodology (ECM). Results show that while demand for coffee is inelastic in the long-run, it is highly inelastic in the short-run. This suggests that Coffee Board may focus efforts on non-price factors rather than price incentives in their generic coffee promotional campaign.

Rethinking Ricardian "Sum of Enjoyments": Gains from Trade in a Co-Creational Economy

The Ricardian principle of comparative advantage has long been at the foundation of a wide range of economic models. In the new Internetworked economy where co-creational experiences of value is rapidly gaining momentum, the vision of this principle has weakened. We provide a framework to align economic thinking on the principle of comparative advantage with co-creational value creation embedded at the core. We show how patterns of specialization and the resultant gains from trade, within or across borders, must be sensitive to value gained through co-creational experiences. In particular, an individual’s co-creational experience of value is at the foundation of what we posit as the principle of comparative co-creationaladvantage.http://deepblue.lib.umich.edu/bitstream/2027.42/101120/1/1211_Chakrabarti.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/101120/4/1211_Chakrabarti.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/101120/5/1211_Dec13_Ramaswamy.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/101120/7/1211_Oct14VRamaswamypdf.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/101120/9/1211_Jan2015VRamaswamy.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/101120/11/1211_Ramaswamy_May2015.pdfDescription of 1211_Ramaswamy_May2015.pdf : May 2015 revision (new title)Description of 1211_Jan2015VRamaswamy.pdf : SUPERSEDED: January 2015 revisionDescription of 1211_Oct14VRamaswamypdf.pdf : SUPERSEDED: October 2014 revisionDescription of 1211_Dec13_Ramaswamy.pdf : SUPERSEDED: Dec 2013 revisionDescription of 1211_Chakrabarti.pdf : SUPERSEDED: Nov 2013 updateDescription of 1211_Chakrabarti.pdf : SUPERSEDE

Benchmarking AssemblyScript for Faster Web Applications

As web applications are becoming increasingly complex, it is crucial now more than ever to be able to develop web apps with an emphasis on performance to ensure a responsive and smooth user experience. Since the introduction of Webassembly as a compilation target for the web, the promise of writing programs that can run at native speed seemed revolutionary in theory. But the real world performance benefits of Webassembly in comparison to Javascript is not clearly understood. This paper evaluates the current performance of Assemblyscript - a strict subset of TypeScript that compiles to Webassembly, and Javascript in the areas of numerical computing across multiple browsers. A set of benchmarks were developed in Assemblyscript that includes numerical computing problems from the Ostrich Benchmark suite. The tests were executed across Chrome and Firefox. After studying the results from the benchmarks that were created, we find that Assemblyscript demonstrates speedups that range between 1.1-7.2x. It is also noticed that writing idiomatic Typescript can slow down Assemblyscript in certain scenarios. In conclusion, this study suggests that Assemblyscript (and Webassembly) provides far more consistent and predictable performance in comparison to Javascript

First person – Venkatram Yellapragada

Peer reviewe

A three-dimensional dual potential procedure for rotational flows

A dual potential decomposition of the velocity field into a scalar and a vector potential function is extended to three dimensions and used in the finite-difference simulation of steady three-dimensional inviscid rotational flow and viscous flow;The finite-difference procedure has been used to simulate the flow through the 80- by 120-Foot Wind Tunnel at NASA Ames Research Center. Rotational flow produced by the stagnation pressure drop across vanes and screens which are located at the entrance of the inlet is modeled using actuator disk theory. Results are presented for two different inlet vane and screen configurations. The numerical predictions are in good agreement with experimental data;The dual potential procedure has also been applied to calculate the viscous flow along two and three-dimensional troughs. Viscous effects are simulated by injecting vorticity which is computed from a boundary-layer algorithm. For attached flow over a three-dimensional trough, the present calculations are in good agreement with other numerical predictions. For separated flow, it is shown from a two-dimensional analysis that the boundary-layer approximation provides an accurate measure of the vorticity in regions close to the wall; whereas further away from the wall, caution has to be exercised in using the boundary-layer equations to supply vorticity to the dual potential formulation

Finding unstable periodic orbits for nonlinear dynamical systems using polynomial optimisation

Computing unstable periodic orbits (UPOs) for systems governed by ordinary differential equations (ODEs) is a fundamental problem in the study of nonlinear dynamical systems that exhibit chaotic dynamics. Success of any existing method to compute UPOs relies on the availability of very good initial guesses for both the UPO and its time period. This thesis presents a computational framework for computing UPOs that are extremal, in the sense that they optimise the infinite-time average of a certain observable. Constituting this framework are two novel techniques. The first is a method to localise extremal UPOs for polynomial ODE systems that does not rely on numerical integration. The UPO search procedure relies on polynomial optimisation to construct nonnegative polynomials whose sublevel sets approximately localise parts of the extremal periodic orbit. Points inside the relevant sublevel sets can then be computed efficiently through direct nonlinear optimisation. Such points provide good initial conditions for UPO computations with existing algorithms. The second technique involves the addition of a control term to the original polynomial ODE system to reduce the instability of the extremal UPO, and, in some cases, to provably stabilise it. This control methodology produces a family of controlled systems parametrised by a control amplitude, to which existing UPO-finding algorithms are often more easily applied. The practical potential of these techniques is demonstrated by applying them to find extremal UPOs for a nine-dimensional model of sinusoidally forced shear flow, an extended version of the Lorenz system, and two different three-dimensional chaotic ODE systems. Extensions of the framework to non-polynomial and Hamiltonian ODE systems are also discussed.Open Acces

Micromachined Magnetoelastic Sensors and Actuators for Biomedical Devices and Other Applications.

Magnetoelastic materials exhibit coupling between material strain and magnetization; this coupling provides the basis for a number of wireless transducers. This thesis extends past work on microfabricated magnetoelastic sensors in three ways. First, a new class of strain sensors based on the ΔE effect are presented. Two sensor types are described – single and differential. The single sensor has an active area of 7×2 mm2 and operates at a resonant frequency of 230.8 kHz with a sensitivity of 13×103 ppm/mstrain and a dynamic range of 0.05-1.05 mstrain. The differential sensor includes a strain-independent 2×0.5 mm2 reference resonator in addition to a 2.5×0.5 mm2 sensing element. The sensor resonance is at 266.4 kHz and reference resonance is at 492.75 kHz. The differential sensor has a dynamic range of 0-1.85 mstrain, a sensitivity of 12.5×103¬¬ ppm/mstrain, and is temperature compensated in the 23-60°C range. Second, fluidic actuation by resonant magnetoelastic devices is presented. This transduction is performed in the context of an implantable device, specifically the Ahmed glaucoma drainage device (AGDD). Aspherical 3D wireless magnetoelastic actuators with small form factors and low surface profiles are integrated with the AGDD; the fluid flow generated by the actuators is intended to limit cellular adhesion to the implant surface that ultimately leads to implant encapsulation and failure. The actuators measure 10.3×5.6 mm2 with resonant frequencies varying from 520 Hz to 4.7 kHz for the different actuator designs. Flow velocities up to 266 μm/s are recorded at a wireless activation range of 25-30 mm, with peak actuator vibration amplitudes of 1.5 μm. Finally, detection techniques for improving the measurement performance of wireless magnetoelastic systems are presented. The techniques focus on decoupling of the excitation magnetic signal from the sensor response to improve measurement sensitivity and noise immunity. Three domains – temporal, frequency, and spatial – are investigated for signal feedthrough. Quantitative results are presented for temporal and frequency domain decoupling. Temporal decoupling is used to measure strain sensors with resonant frequencies in the 125 kHz range, whereas frequency domain decoupling is implemented to measure 44 kHz magnetoelastic resonators.PhDElectrical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/116647/1/venkatp_1.pd

ESTIMATING METEOROLOGICAL INPUTS FOR URBAN DISPERSION MODELS

Meteorological variables such as surface friction velocity and heat flux are critical inputs to the current generation of dispersion models such as AERMOD. This paper examines methods to estimate these variables by applying Monin-Obukhov (M-O) similarity to measurements made on towers located in urban areas. The inputs to these methods are restricted to the wind speed and the standard deviation of temperature fluctuations data measured at a single level on a tower. The performance of these methods are evaluated with data collected at one urban and two suburban towers in Riverside, California during two months in 2007, The data consisted of mean winds and temperatures as well as heat and momentum fluxes using a sonic anemometer at one level on each tower. The major conclusions of this study are that during unstable conditions: 1) M-O theory provides adequate estimates of micrometeorological variables using urban measurements of mean winds and temperatures at one level when the standard deviation of temperature fluctuations is used to estimate heat flux, 2) the simple free convection estimate provides estimates of the heat flux that compare well with those from methods that account for stability effects through the M-O length, 3) all the methods overestimate heat flux close to neutral conditions, 4) the overestimation of heat flux does not appear to affect estimates of surface friction velocity, but results in overestimation of the vertical turbulent velocity. During stable conditions, 1) vertical and horizontal velocity fluctuations are related to friction velocity through similarity relationships derived in flat terrain, 2) estimates of the surface friction velocity based on temperature fluctuations do not improve upon those based on a constant value o

Birational geometry of the space of rational curves in homogeneous varieties

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mathematics, 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. 55-56).In this thesis, we investigate the birational geometry of the space of rational curves in various homogeneous spaces, with a focus on the quasi-map compactification induced by the Quot and Hyperquot functors. We first study the birational geometry of the Quot scheme of sheaves on P1 via techniques from the Mori program, explicitly describing its associated cones of ample and effective divisors as well as the various Mori chambers within the latter. We compute the base loci of all effective divisors, and give a conjectural description of the induced birational models. We then partially extend our results to the Hyperquot scheme of sheaves on P', which gives the analogous compactification for rational curves in flag varieties. We fully describe the cone of ample divisors in all cases and the cone of effective divisors in certain ones, but only claim a partial description of the latter in general.by Kartik Venkatram.Ph.D