Integration of Agricultural Commodity Markets in Punjab

Efficiency of resource allocation in agriculture depends on the functioning of commodity markets. Although the larger markets that are better connected with the transport and communication network are expected to be well-integrated, the same cannot be said about the smaller, more remote markets. This paper tests integration of agricultural commodity markets in Southeastern Punjab. The region is located off the main trading axis of Pakistan, the Peshawar-Karachi highway, and is mostly served by relatively small markets known as mandis. This study focuses on markets for cotton, wheat, and rice in five towns in the region. Cotton and wheat are the main crops in the area while rice is mostly grown as part of crop rotation aimed at controlling salinity. The analytical framework developed by Ravallion was used to conduct tests of market integration for the three selected commodities. Within this framework, it is possible to test for short-run integration, long-run integration or complete market segmentation. The results indicate that, generally, markets are integrated only in the long run, with short-run integration limited to some special cases. Moreover, the smaller markets are more likely to be isolated as compared to the larger markets. The small markets also take longer to fully adjust to the price shock originating from a more dominant central market. Finally, in the case of rice, it is more likely that a market would be isolated if it were small. This implies that farmers’ incentives to grow rice as a means of combating salinity may be constrained by local demand conditions.

Slepian Spatial-Spectral Concentration on the Ball

We formulate and solve the Slepian spatial-spectral concentration problem on the three-dimensional ball. Both the standard Fourier-Bessel and also the Fourier-Laguerre spectral domains are considered since the latter exhibits a number of practical advantages (spectral decoupling and exact computation). The Slepian spatial and spectral concentration problems are formulated as eigenvalue problems, the eigenfunctions of which form an orthogonal family of concentrated functions. Equivalence between the spatial and spectral problems is shown. The spherical Shannon number on the ball is derived, which acts as the analog of the space-bandwidth product in the Euclidean setting, giving an estimate of the number of concentrated eigenfunctions and thus the dimension of the space of functions that can be concentrated in both the spatial and spectral domains simultaneously. Various symmetries of the spatial region are considered that reduce considerably the computational burden of recovering eigenfunctions, either by decoupling the problem into smaller subproblems or by affording analytic calculations. The family of concentrated eigenfunctions forms a Slepian basis that can be used be represent concentrated signals efficiently. We illustrate our results with numerical examples and show that the Slepian basis indeeds permits a sparse representation of concentrated signals.Comment: 33 pages, 10 figure

An Optimal Dimensionality Sampling Scheme on the Sphere for Antipodal Signals In Diffusion Magnetic Resonance Imaging

We propose a sampling scheme on the sphere and develop a corresponding spherical harmonic transform (SHT) for the accurate reconstruction of the diffusion signal in diffusion magnetic resonance imaging (dMRI). By exploiting the antipodal symmetry, we design a sampling scheme that requires the optimal number of samples on the sphere, equal to the degrees of freedom required to represent the antipodally symmetric band-limited diffusion signal in the spectral (spherical harmonic) domain. Compared with existing sampling schemes on the sphere that allow for the accurate reconstruction of the diffusion signal, the proposed sampling scheme reduces the number of samples required by a factor of two or more. We analyse the numerical accuracy of the proposed SHT and show through experiments that the proposed sampling allows for the accurate and rotationally invariant computation of the SHT to near machine precision accuracy.Comment: Will be published in the proceedings of the International Conference Acoustics, Speech and Signal Processing 2015 (ICASSP'2015

Analysis of Casing and Tubing Buckling in Inclined Well

This report presents an analysis on the effect of different angle of well inclination towards the buckling effects on the casing. The buckling effects are including the stress, shear stress, strain and minimum buckling force required for the casing to start buckle. It is essential to analyse the buckling effect on the inlined well as failure in tubing and casing will cause loss of wells, which give a negative impact economically. J. D. Clegg (1971) mentioned in his paper that combination of non- uniform load and hydrostatic external pressure is believed to have caused most of the casing and tubing failures. The interaction between angle of inclination and minimum buckling force required for the casing to start buckle is calculated theoritically, while the effect of different angle of inclination on stress distribution were simulated and observed using ANSYS 14. ANSYS software has proven to be a successful tool in studying and simulating the effect of different angle of inclination towards the stress distribution of on the casing surface. The result obtained from the simulations are succesful. As the angle of the well inclination increases, the stress exerted on casing surface was changed. Besides, increase in the angle of inclination also increased the shear stress on the casing surface. The distribution of the stress also changed as the angle is changed

Integration of Agricultural Commodity Markets in Punjab

Efficiency of resource allocation in agriculture depends on the functioning of commodity markets. Although the larger markets that are better connected with the transport and communication network are expected to be well-integrated, the same cannot be said about the smaller, more remote markets. This paper tests integration of agricultural commodity markets in Southeastern Punjab. The region is located off the main trading axis of Pakistan, the Peshawar-Karachi highway, and is mostly served by relatively small markets known as mandis. This study focuses on markets for cotton, wheat, and rice in five towns in the region. Cotton and wheat are the main crops in the area while rice is mostly grown as part of crop rotation aimed at controlling salinity. The analytical framework developed by Ravallion was used to conduct tests of market integration for the three selected commodities. Within this framework, it is possible to test for short-run integration, long-run integration or complete market segmentation. The results indicate that, generally, markets are integrated only in the long run, with short-run integration limited to some special cases. Moreover, the smaller markets are more likely to be isolated as compared to the larger markets. The small markets also take longer to fully adjust to the price shock originating from a more dominant central market. Finally, in the case of rice, it is more likely that a market would be isolated if it were small. This implies that farmers’ incentives to grow rice as a means of combating salinity may be constrained by local demand conditions