6,232 research outputs found
THE ROLE OF NON-PARAMETRIC APPROACH IN ADJUSTING PRODUCTIVITY MEASURES FOR ENVIRONMENTAL IMPACTS
This paper addresses the role of non-parametric analysis in adjusting agricultural productivity measures for environmental impacts. The modified Tornquist-Theil index computed using shadow prices derived from the programming procedures is compared and contrasted with a non-parametric hyperbolic graph productivity index for the case of Nebraska agriculture.Nonparametric, Shadow price, Productivity, Environmental Economics and Policy, Productivity Analysis,
NON-PARAMETRIC ENVIRONMENTAL ADJUSTED PRODUCTIVITY (EAP) MEASURES: NEBRASKA AGRICULTURE SECTOR
Traditional Total factor productivity [TFP] misrepresents the true change in agricultural productivity because environmental bads jointly produced with desirable outputs are unaccounted. Nonparametric measures incorporating environmental bads support the hypothesis that prior [after] to 1980's the traditional TFP overstate [understate] production growths, reflecting peak use of chemicals.Environmental Economics and Policy, Productivity Analysis,
Returns to Scale of Production Function: Pooled, Within and Between Quantile Regression Approach
Production function, Pooled, Between and Within Quantile Regression, Panel data, Production Economics, Research Methods/ Statistical Methods,
Do Farm Programs Explain Mean and Variance of Technical Efficiency? Stochastic Frontier Analysis
Past literature has examined the importance of farm programs on the volatility and returns on general and agriculture economic growth. The objective of this study was to assess the impact of farm program payments on technical efficiency. The study used aggregate state level panel data from the U.S agricultural sector. Results indicate production increasing with increasing units of inputs. Results from this study indicate that farm program payments play an important role in technical efficiency. For example, farm program payments indicate a negative and positive effect on mean and variance of technical efficiency in the long-run and short-run, respectivelyProduction Economics, Productivity Analysis, Risk and Uncertainty,
Aggregation Issues in the Estimation of Linear Programming Productivity Measures
This paper demonstrates the sensitivity of the linear programming approach in the estimation of productivity measures in the primal framework using Malmquist productivity index and Malmquist total factor productivity index models. Specifically, the sensitivity of productivity measure to the number of constraints (level of dis-aggregation) and imposition of returns to scale constraints of linear programing is evaluated. Further, the shadow or dual values are recovered from the linear program and compared to the market prices used in the ideal Fisher index approach to illustrate sensitivity. Empirical application to U.S. state-level time series data from 1960-2004 reveal productivity change decreases with increases in the number of constraints. Further, the input and output shadow or dual values are skewed, leading to the difference in the productivity measures due to aggregation.Aggregation, Share-weights, single and multiple output and input, Malmquist productivity index, Malmquist total factor productivity index, Agribusiness, Production Economics,
A single-phase synchronization technique for grid-connected energy storage system under faulty grid conditions
The control of a single-phase grid-connected energy storage system (ESS) requires a very fast and accurate estimation of grid voltage frequency and phase angle. A phase-locked loop (PLL) based synchronization algorithm usually extracts this information. The operation and control of the entire system are directly affected by the performance of PLL. In this article, a novel advanced single-phase PLL (ASϕPLL) technique with reduced complexity is proposed for the fast and accurate extraction of grid information in an ESS under distorted and abnormal grid conditions, including harmonics, interharmonics, dc offset, and grid faults. The proposed method provides a faster dynamic response, lower frequency overshoot, and accurate estimation under off-nominal grid frequencies with reduced computational complexity in comparison with the existing method. The advanced performance of the proposed ASϕPLL is verified through the simulation and experimental results
An Assessment of the Efficiency of Agribusiness Trucking Companies: A Data Envelopment Analysis Approach
The purpose of this study is to investigate the issue of efficiency in the U.S. motor carrier industry using DEA and SFA. While both methods used the same variables, the resulting efficiency scores were significantly different. This leads to the question of which method is a better measure of efficiency.Public Economics,
Rates of Short-GRB afterglows in association with Binary Neutron Star mergers
Assuming all binary Neutron Star mergers produce Short Gamma Ray Bursts
(SGRBs), we combine the merger rates of binary Neutron Stars (BNS) from
population synthesis studies, the sensitivities of advanced Gravitational Wave
(GW) interferometer networks, and of the electromagnetic (EM) facilities in
various wave bands, to compute the detection rate of associated afterglows in
these bands. Using the inclination angle measured from GWs as a proxy for the
viewing angle and assuming a uniform distribution of jet opening angle between
3 to 30 degrees, we generate light curves of the counterparts using the open
access afterglow hydrodynamics package BoxFit for X-ray, Optical and Radio
bands. For different EM detectors we obtain the fraction of EM counterparts
detectable in these three bands by imposing appropriate detection thresholds.
In association with BNS mergers detected by five (three) detector network of
advanced GW interferometers, assuming a BNS merger rate of ~\citep{dominik2012double}, we find the afterglow
detection rates (per year) to be (), ()
and () in the X-ray, optical and radio bands respectively.
Our rates represent maximum possible detections for the given BNS rate since we
ignore effects of cadence and field of view in EM follow up observations.Comment: Published in MNRA
Exploring Short-GRB afterglow parameter space for observations in coincidence with gravitational waves
Short duration Gamma Ray Bursts(SGRB) and their afterglows are among the most
promising electro-magnetic (EM) counterparts of Neutron Star (NS) mergers. The
afterglow emission is broadband, visible across the entire electro-magnetic
window from -ray to radio frequencies. The flux evolution in these
frequencies is sensitive to the multi-dimensional afterglow physical parameter
space. Observations of gravitational wave (GW) from BNS mergers in spatial and
temporal coincidence with SGRB and associated afterglows can provide valuable
constraints on afterglow physics. We run simulations of GW-detected BNS events
and assuming all of them are associated with a GRB jet which also produces an
afterglow, investigate how detections or non-detections in X-ray, optical and
radio frequencies can be influenced by the parameter space. We narrow-down the
regions of afterglow parameter space for a uniform top-hat jet model which
would result in different detection scenarios. We list inferences which can be
drawn on the physics of GRB afterglows from multi-messenger astronomy with
coincident GW-EM observations.Comment: Published in MNRA
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