637 research outputs found
Separation of soft and collinear infrared limits of QCD squared matrix elements
We present a simple way of separating the overlap between the soft and
collinear factorization formulae of QCD squared matrix elements. We check its
validity explicitly for single and double unresolved emissions of tree-level
processes. The new method makes possible the definition of helicity-dependent
subtraction terms for regularizing the real contributions in computing
radiative corrections to QCD jet cross sections. This implies application of
Monte Carlo helicity summation in computing higher order corrections.Comment: 14 pages, 1 figure, references adde
Hungarian meat sector restructuration in the post-EU accession period
other Hungarian food industry sectors and also compared to the concentration level in West European countries. In the sector the share of foreign capital is also very low (17%). Because of the low share of foreign capital and relatively small concentration, structural and ownership changes were to be expected, resulting in a more concentrated and competitive sector. The restructuring process involved a number of steps. First of all, Sándor Csányi acquired Délhús and then later acquired Pick Szeged, and in 2005 these two corporations’ sectoral share was about 25%. As for the other two large corporations – R-KO-N and Carnex – in late 2005 the latter weakened significantly causing a loss in market share and the bankruptcy of two companies within its industrial group. Currently the meat sector is undergoing rationalisation of costs and activities, coordination, and an elimination process, all brought on by increasing competition. Pork consumption tends to run counter to the rising standard of living as consumption has been stagnating for years. Domestic production of pork is going down but imports (mainly live pigs) are shooting up. Now a portion of produced pork (mainly carcass meat) can be sold in Hungarian’s export markets at the re-accession level. Even today the elimination process is affecting numerous abattoirs. Changes in ownership structure could hasten the elimination process, leading to a reduction in the large surplus capacities. For example, in 2003 50% of pig slaughtering capacities were used, similar to the capacity used in salami and sausage production.Pig, food industry, EU Accession, trade, Food Consumption/Nutrition/Food Safety, Industrial Organization, International Relations/Trade,
A model based DC analysis of SiPM breakdown voltages
A new method to determine the breakdown voltage of SiPMs is presented. It is
backed up by a DC model which describes the breakdown phenomenon by distinct
avalanche turn-on () and turn off () voltages. It is shown that
is related to the 'breakdown voltage' that previous DC methods derive
from simple reverse current-voltage measurements, while is the 'real'
breakdown voltage commonly obtained from complex gain-voltage measurements. The
proposed method reveals how the microcell population distributes around
and . It is found that if this distribution is assumed to be
normal, then both voltages and even their standard deviation can readily be
extracted from current-voltage curves. Measurements are in good agreement with
the theoretical model
Development of an optimized short-span steel bridge design package
West Virginia Department of Transportation indicates that a significant number of bridges in West Virginia are structurally deficient or functionally obsolete. One third of the nation\u27s bridges have similar conditions due to the age of the infrastructure and ever increasing traffic demands. The resources available to replace or rehabilitate those structures are finite, hence cost effective means of replacing the inadequate structures is necessary. One of the solutions intended to ease the increasing demands of replacing those structures are standardized bridge plans by providing a cost effective method to save time and resources. Therefore, the focus of this effort is the development of an optimized short-span steel bridge package.;The study focused on developing optimized plans for two roadway sections for spans ranging from 40 feet to 140 feet in 5 feet increments. The girders designed in this effort were optimized based on weight and targeted various cross section depth to span length ratios incorporating homogeneous, hybrid and rolled sections.;This effort also focused on the feasibility of incorporating limited plate sizes in the design of steel girders. Designs from the optimized study and the limited plate size study were compared and evaluated to offer cost and time savings
GEFCOM 2014 - Probabilistic Electricity Price Forecasting
Energy price forecasting is a relevant yet hard task in the field of
multi-step time series forecasting. In this paper we compare a well-known and
established method, ARMA with exogenous variables with a relatively new
technique Gradient Boosting Regression. The method was tested on data from
Global Energy Forecasting Competition 2014 with a year long rolling window
forecast. The results from the experiment reveal that a multi-model approach is
significantly better performing in terms of error metrics. Gradient Boosting
can deal with seasonality and auto-correlation out-of-the box and achieve lower
rate of normalized mean absolute error on real-world data.Comment: 10 pages, 5 figures, KES-IDT 2015 conference. The final publication
is available at Springer via http://dx.doi.org/10.1007/978-3-319-19857-6_
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