ACTNET: End-to-End Learning of Feature Activations and Multi-stream Aggregation for Effective Instance Image Retrieval

International Journal of Computer Vision - We propose a novel CNN architecture called ACTNET for robust instance image retrieval from large-scale datasets. Our key innovation is a learnable...     

The effect of a synthetic neuromelanin on yield of free hydroxyl radicals generated in model systems

Neuromelanin is an amorphous pigment of the catecholamine origin that accumulates in certain dopaminergic neurons of the substantia nigra of human brain. In Parkinson's disease, there appears to be selective degeneration of the most heavily pigmented neurons of the substantia nigra, and this process has been linked to the presence of neuromelanin. It has been postulated that neuromelanin could increase the risk of oxidative stress reactions. On the other hand, melanin is usually considered to be an efficient antioxidant. Here we analyze experimental conditions that stimulate, or inhibit, antioxidant properties of neuromelanin. Using electron spin resonance (ESR)--spin trapping technique and salicylate hydroxylation assay, we monitored the formation of free hydroxyl radicals generated by a Fenton system in the presence of varying concentration of dopamine-melanin, a synthetic model for neuromelanin. Our data clearly indicate that the antioxidant action of neuromelanin is predominantly due to its ability to sequester redox-active metal ions such as iron. Using direct ESR spectroscopy, we have shown that ferric complexes with neuromelanin are resistant to reduction by mild biological reductants such as ascorbate. We have demonstrated that dopamine-melanin saturated with ferric ions, could enhance the formation of free hydroxyl radicals by redox activation of the ions. Thus, under the conditions that stimulate the release of accumulated metal ions, neuromelanin may actually become an efficient prooxidant. It is conceivable that neuromelanin, which normally is able to protect pigmented dopaminergic neurons against metal-ion related toxicity, could under extreme conditions have a cytotoxic role.     

Image Processing-Based Methodology for Optimizing Automotive Ignition Timing

Modern fuel-injected automobiles use an electronic engine control unit (ECU) that is programmed to ignite the air-fuel mixture in a way that maximizes the torque (TQ) and power output of the engine without compromising its reliability. The ECU achieves this by reading a base value from the primary ignition map (PIM) and then manipulating various other parameters to come up with the final solution. Each input into the final solution comes from a so-called map, which is a 3-D image that represents a set of all the possible values that each parameter can take on. In this paper, we develop a robust methodology using image processing techniques to optimize the PIM for automobiles. The techniques are used to compare, combine, manipulate, and reconstruct various maps. Experiments show that the process yields a gain of about 7 hp and a TQ of 15 ft middotlb measured at the wheels.     

Polyaniline–silver composites prepared by the oxidation of aniline with silver nitrate in solutions of sulfonic acids

Aniline was oxidized with silver nitrate in aqueous solutions of sulfonic acids: camphorsulfonic, methanesulfonic, sulfamic, or toluenesulfonic acids. Polyaniline–silver composites were produced slowly in 4 weeks in good yield, except for the reaction, which took place in sulfamic acid solution, where the yield was low. Polyaniline in the emeraldine form was identified with UV–visible, FTIR, and Raman spectra. Thermogravimetric analysis was used to determine the silver content, which was close to the theoretical prediction of 68.9 wt.%. Transmission electron microscopy demonstrated the presence of silver nanoparticles of ca 50 nm average sizes as the dominating species, and hairy polyaniline nanorods having diameter 150–250 nm accompanied them. The highest conductivity of 880 S cm⁻¹ was found with the composite prepared in methanesulfonic acid solution. Its conductivity decreased with temperature increasing in the 70–315 K range, which is typical of metals such as silver. The conductivity of composites prepared in solutions of other acids was lower and increased with increasing temperature. Such dependence is typical of semiconductors, reflecting the dominating role of polyaniline in the conductivity behaviour. It is proposed that interfaces between the polyaniline matrix and dispersed silver nanoparticles play a dominating role in macroscopic level of conductivity.     

Optimization of ceramic setting as a function of their heat absorption from the radiating walls of the furnace

An experimental study involving a model unit was conducted on heat absorption from the radiating walls of a kiln by the ceramic ware set up on a kiln car. It was shown that there is always optimal spacing between the ceramic pieces in the setting above which any further increase in the spacing would not increase the rate of heat absorption by the ware. Translated from Steklo i Keramika, No. 6, pp. 25–27, June, 1997.     

Laparoscopic peroperative cholangiography--indications and significance

The authors have performed 35 peroperative laparoscopic cholangiographies by means of transcystic cannylation of the choledochus in 410 patients subdued to laparoscopic cholecystectomy. Choledocholelithiasis was found in 8 patients (22.85%). The authors advocate for the application of peroperative cholangiography in indicated cases since the method is simple, safe and sufficiently successful. (Tab. 5, Ref. 9.)     

Estimation of complex multimodal motion: an approach based on robust statistics and Hough transform

An application of robust statistics in a Hough transform based motion estimation approach is presented. The algorithm is developed and experiments are performed, proving its superior performance in terms of estimate accuracy, convergence, robustness and better segmentation. Comparative results with standard methods are also included.     

On the interpretation of vapor pressure measurements on oxide fuel at very-high temperatures for fast reactor safety analysis

Safety analysis of fast reactors requires knowledge of the evaporation behavior and the total vapor pressure of oxide fuel materials in the temperature region from 3000 K upwards. Dynamic vapor pressure measurements on liquid oxide fuels performed in open-evaporation experiments with laser heating techniques imply strong alterations in the composition of the incongruently evaporating fuel surface, since, during evaporation, the depletion in the preferentially evaporating components cannot be resupplied by diffusion from the bulk material. After a short transient evaporation period stationary surface-evaporation is reached with a surface composition which differs greatly from the given fuel composition and depends on the actual evaporation temperature. When this stationary forced-congruent evaporation mode is reached, the gross vapor composition is well-defined and is identical to the bulk composition of the fuel but is quite different from the actual surface composition. In consequence, the total vapor pressure developing in open surface-evaporation of a liquid oxide fuel can substantially deviate from its thermodynamic equation-of-state, in the case of (U_0.80Pu_0.20) mixed oxide by a factor of 2 to 7 depending on the $\text{O}\text{M}$-ratio. Following these thermodynamic calculations direct measurement of the equation-of-state in open-evaporation experiments is practically impossible. Theoretically fitted expressions applicable in reactor safety analysis are presented for the equations-of-state and the vapor pressure equations for open surface-evaporation and also for the heats of evaporation of liquid (U_0.80Pu_0.20)O_1.95…2.00 mixed oxides.