Many statistics methods require one or more least squares problems to be solved. There are several ways to perform this calculation, using objects from the base R system and using objects in the classes defined in the Matrix package. We compare the speed of some of these methods on a very small example and on a example for which the model matrix is large and sparse. 1 Linear least squares calcu...

The current OWL specification does not include a syntax for specifying calculated values for data type properties. Their introduction, although acknowledged among the desiderata, seems yet unlikely to appear in the forthcoming OWL 2.0. This paper shows one way of working around this absence using annotations. The aim here is not to suggest a standard but, rather, to individuate the potential is...

In the present work WRF model is used to generate meteorological fields for the HYSPLIT dispersion model. Sensitivity and validation of the WRF model, is conducted by utilizing different combinations of physical parameterization schemes. For this purpose, eight different configurations are examined. Assessment of the predictions of the WRF model is carried out by computing the statistical param...

The thermodynamic functions such as enthalpy (H), Gibbs free energy (G) and entropy (S) ofPyrazole was theoretically studied at 5 different temperatures 25, 30, 35, 40 and 45°C by usingGussian o3, software. First, the structural optimization of isolated Pyrazole was done in the gas phaseby appling the Density Functional Theory (B3LYP) level with 3-21G, 6-31G and 6-31+G(d) basissets. Moreover, v...

Introduction: Successful radiotherapy requires the precise application of a radiation dose to cancerous tissue, which can be achieved by the design of proper treatment methods by radiotherapy physicists. Tasks performed by radiotherapy physicists include verifying the accuracy of dose calculations, correct treatment planning and the proper functioning of accelerators. They are...

In the present work WRF model is used to generate meteorological fields for the HYSPLIT dispersion model. Sensitivity and validation of the WRF model, is conducted by utilizing different combinations of physical parameterization schemes. For this purpose, eight different configurations are examined. Assessment of the predictions of the WRF model is carried out by computing the statistical param...

In this work the performance of a wavelength division multiple access (WDMA) system with direct detection receiver is investigated. For this purpose, the probability of error in a WDMA network with OOK modulation considering crosstalk, ISI, photo detector noise and thermal noise is calculated and the effect of each on system performance is investigated. The system performance in presence of PIN...

propene dissociation channels were characterized by ab initio ccsd(t)/6-311++g(d,p) calculations. inthis work the detailed mechanism of propene dissociation to c2h4+ch2, c2h2+h+ch3, c2h2+ch4 andc3h3+h2+h have been investigated. according to our calculations, ten fragments can be classified intofive dissociated channels. our results point out that two mechanisms come into play in the h2 eliminat...