Reconstruction of Initial Beam Conditions at the Exit of the DARHT II Accelerator

We consider a technique to determine the initial beam conditions of the DARHT II Accelerator by measuring the beam size under three different magnetic transport settings. This may be time gated to resolve the parameters as a function of time within the 2000 nsec pulse. This technique leads to three equations in three unknowns with solution giving the accelerator exit beam radius, tilt and emittance. We find that systematic errors cancel and so are not a problem in unfolding the initial beam conditions. Random uncorrelated shot to shot errors can be managed by one of three strategies: 1) make the transport system optically de-magnifying; 2) average over many individual shots; or 3) make the random uncorrelated shot to shot errors sufficiently small. The high power of the DARHT II beam requires that the beam transport system leading to a radius measuring apparatus be optically magnifying. This means that the shot to shot random errors must either be made small (less than about 1%) or that we average each of the three beam radius determinations over many individual shots.Comment: 3 pages, 3 figures, LINAC2000 paper TUB1

Does Public Good Provision Determine Incumbent’s Fate? Evidence from India

In this paper we empirically examine whether public facilities like providing primary school, medical clinics, electricity etc help incumbents to stay in power. Specifically, we analyze the parliamentary election outcomes in 483 constituents in rural India from 1971 to 1991. This study is based on a simple voter model where the voter looks at the supply of public goods provided by the incumbent and then decides whether to re-elect the incumbent. We find empirical evidence that voters do significantly care about educational, electricity and communication facilities, whereas incumbents face defeat if they provide more medical or safe drinking water facilities.Election and voting behavior; performance of government; public good; inter-jurisdictional differential and their effect; India

Engineering technology for networks

Space Network (SN) modeling and evaluation are presented. The following tasks are included: Network Modeling (developing measures and metrics for SN, modeling of the Network Control Center (NCC), using knowledge acquired from the NCC to model the SNC, and modeling the SN); and Space Network Resource scheduling

The Role of the European Union as a Peace Builder: Northern Ireland as a Case Study

The United Kingdom and Ireland joined the European Economic Community in 1973 at a time when bitter communal conflict engulfed Northern Ireland. It appeared to be a deviant case in a modernising Europe anxious to unleash the shackles of the first half of the twentieth century. In fact the unusual conjunction of conflict within a disputed region of the British/Irish archipelago and joint membership of the European Community offered an opportunity to move beyond the excessive intimacy of an ancient quarrel through different temporal and spatial lenses. This article addresses the issue of dealing with minority grievances in an inter- and intra-state dispute by analysing the role of functional regimes and the deliverance of “peace in parts” through the changing context of statehood within Europe where sovereignty may be divisible and borders more permeable. It will conclude that the EU has made an essential contribution to the changing relations between Britain and Ireland and to conflict management within Northern Ireland

A Compressed Sensing Algorithm for Sparse-View Pinhole Single Photon Emission Computed Tomography

Single Photon Emission Computed Tomography (SPECT) systems are being developed with multiple cameras and without gantry rotation to provide rapid dynamic acquisitions. However, the resulting data is angularly undersampled, due to the limited number of views. We propose a novel reconstruction algorithm for sparse-view SPECT based on Compressed Sensing (CS) theory. The algorithm models Poisson noise by modifying the Iterative Hard Thresholding algorithm to minimize the Kullback-Leibler (KL) distance by gradient descent. Because the underlying objects of SPECT images are expected to be smooth, a discrete wavelet transform (DWT) using an orthogonal spline wavelet kernel is used as the sparsifying transform. Preliminary feasibility of the algorithm was tested on simulated data of a phantom consisting of two Gaussian distributions. Single-pinhole projection data with Poisson noise were simulated at 128, 60, 15, 10, and 5 views over 360 degrees. Image quality was assessed using the coefficient of variation and the relative contrast between the two objects in the phantom. Overall, the results demonstrate preliminary feasibility of the proposed CS algorithm for sparse-view SPECT imaging