Robust Handwritten Character Recognition with Features Inspired by Visual Ventral Stream

This paper focuses on the applicability of the features inspired by the visual ventral stream for handwritten character recognition. A set of scale and translation invariant C2 features are first extracted from all images in the dataset. Three standard classifiers kNN, ANN and SVM are then trained over a training set and then compared over a separate test set. In order to achieve higher recognition rate, a two stage classifier was designed with different preprocessing in the second stage. Experiments performed to validate the method on the well-known MNIST database, standard Farsi digits and characters, exhibit high recognition rates and compete with some of the best existing approaches. Moreover an analysis is conducted to evaluate the robustness of this approach to orientation, scale and translation distortions.     

Verification and validation of CFD models and dynamic similarity for fluidized beds

Claims and suggestions in the literature that verification or validation of CFD numerical models has been achieved for fluidized beds are shown to be inconsistent with objective criteria and accepted usage of terminology. Verification involves confirming the accuracy of the computational aspect of the model, for example by comparing results against known solutions, something that is virtually impossible in dense multiphase systems, except for trivial cases. Validation requires objective consideration of computational and numerical error, as well as comparison of model predictions and experimental data over broad ranges of conditions. More care is required in applying these terms, and in planning and conducting experiments to test the validity of fluidized bed numerical codes. Similar considerations apply to experimental attempts to confirm the completeness of sets of matched dimensionless groups used for dynamic scaling of multiphase systems.     

Optical properties of vitrinite carbonized at different pressures

The effect of pressure on the optical properties of cokes from a medium volatile bituminous coal (carbon = 87.9 wt% daf), some carbonized at atmospheric pressure and others under hydraulic pressure (21–310 MPa), over temperatures ranging from 350 to 600 °C at 50 °C intervals, has been studied. The cokes formed at atmospheric pressure developed fine grained mosaics, while medium-flow type mosaics formed in coke carbonized under hydraulic pressure. The thermal decomposition stage began at lower temperatures with increasing hydraulic pressure, resulting in a prolonged devolatilization phase for coke formed at a pressure of 21 MPa. Hence the fluidity of samples carbonized under pressure decreases with increasing hydraulic pressure. Pressure promotes the optical anisotropy apparent from the level of bireflectance. The reflectance of coke formed at atmospheric pressure is higher than that of cokes carbonized under hydraulic pressure, perhaps due to the inhibitory effect of entrapped volatile matter during carbonization under hydraulic pressure. The morphological features of vitirinite carbonized under pressure resemble those of coals naturally affected by heat.     

Mineral matter and elemental concentrations in selected western canadian coals

Major and trace element analyses were performed on coals from various locations in western Canada, and on low-temperature (150 °C) and high-temperature (1000 °C) coal ash produced from these coals. Elemental analyses were carried out by X-ray fluorescence spectroscopy and intense neutron activation analyses. Based on their trace elements, the coals in this study fall into two groups: 1. low-rank coals (lignite-subbituminous) of late Cretaceous and Tertiary age; and 2. high-rank coal (bituminous-semianthracite) of Jurassic-Cretaceous age. The elemental analyses of the coals and coal ash indicate that the local conditions had considerable influence on the concentrations of certain trace elements.Antimony and selenium in coals are the only elements which are enriched relative to concentrations in the earth's crust; arsenic is concentrated in lignite to subbituminous coal, but is depleted in bituminous-anthracite coals; as expected the ash of these coals showed many more instances of enrichment.     

Optical properties of carbonized preoxidized vitrinites

The optical properties at 546 nm of three vitrinites (daf carbon contents 82.5, 88.0 and 93.1%) have been examined after pre-oxidation for 14 days at 105 °C and carbonization at intervals of 50 °C within the temperature range 300–800 °C. In general, pre-oxidation prior to carbonization produces only relatively small changes in the trends of optical parameters with temperature that were observed for the same vitrinites when carbonized fresh; the properties of the anthracitic vitrinite displayed little modification. Reflectivities of carbonized pre-oxidized vitrinites of bituminous rank are higher than those for the equivalent fresh vitrinites up to 500 °C, supporting the suggestion that oxidation raises aromaticity and consequently the reflectivity. The most noticeable optical difference occurs with the bituminous-rank vitrinites, in the variation with carbonization temperature of their refractive-index curves, which parallel the behaviour of the L_c curves of X-ray diffraction studies. In particular, the refractive-index track for the carbonized pre-oxidized vitrinite of coking-coal rank no longer shows the same marked contrast to the refractive-index tracks of vitrinites of higher and lower rank, as it does at temperatures above 600 °C when carbonized fresh. The absorptive indices follow similar trends to the reflectivities for all the chars.     

Retention of liptinitic structure in vitrinite chars

Liptinitic macerals in medium and low-volatile bituminous coals (C=87.9 and 90.0 wt% daf) which have undergone a plastic stage during primary carbonization (<600 °C) retain their original botanical structure. The liptinite materials retain their original identity but develop coarser grained mosaics and stronger anisotropy than the vitrinite residues of the same coal. The retention of original botanical structure in liptinitic macerals is probably attributable to their simple polymeric structure, which is different from that of the associated vitrinite and to carbonization at high heating rates (10 and 60 °C min^?1) which facilitates the development of a distinct two-phase optical texture and anisotropy in carbonized residues of bituminous coals.     

Characteristics of pyrolytic carbon in Canadian coals

Isotropic to anisotropic pyrolytic carbon was observed in Canadian subbitumonous to bituminous coals (%R oil = 0.50−1.0) using reflected light microscopy. Morphologically, pyrolytic carbon consiste of large, well-developed spherulitic and laminated forms occuring in coal macerals and carbominerites as cell and crack filling. The spherulitic forms probably developed rapidly and laminated forms over a period of time. The presence of pyrolytic carbon in coal may indicate a thermal event and, in these coals it is of detrital nature and therefore should be grouped with inertodetrinite.     

Stress analysis in a cracked strip

The stress fields in a strip containing climb and glide edge dislocations are obtained utilizing a complex Fourier transform. The dislocation solutions are then employed to perform integral equations for the analysis of a strip weakened by multiple cracks with any configuration and arrangement. The integral equations are solved numerically for the dislocation density on the cracked surfaces. The stress-intensity factors for two straight cracks compared favorably with the results rendered in literature. Three new examples are solved to demonstrate the applicability of the procedure.