O aprimoramento de um software de estúdio virtual por meio de técnicas de matting digital e registro de objetos virtuais

A virtual studio system can use technologies as augmented reality and digital matting to decrease production costs at the same time it provides the same resources of a conventional studio. With this, it’s possible for the current studios, with low cost and using conventional devices, to create productions with greater image quality and effects. Some difficulties are recurrent in virtual studio applications that use augmented reality and digital matting. The virtual objects registration in augmented reality techniques suffer from problems caused by optical distortions in the camera, errors in the marker tracking system, lack of calibration on the equipments or on the environment (lighting, for example), or even by delays in the virtual objects display. On the other hand, the digital matting’s main problem is the real-time execution to preview the scene, which must have optimized processing speed at the same time while maintain the best image quality possible. Taking the given context into consideration, this work aims to give continuity to a virtual studio system called ARStudio, by enhancing digital matting, virtual objects registration and introducing a segmentation based on depth map, yet adding better control over functionalities previously implemented

A Comparison of Deep Drawing and Ironing of Metal Alloy Strip Produced conventionally and Non-conventionally via Semi Solid Material Processing

A semi solid thin strip continuous casting process was used to obtain 50%wt Pb/50%wtSn strip by single and twin roll processing at speed of 15 m/min. A 50%wt Pb/50%wtSn plate ingot was also cast for rolling conventionally into strips of 1.4 mm thickness and 45 mm width for comparison with those achieved non-conventionally. This hypoeutectic alloy has a solidification interval and fusion temperature of approximately 31 degrees C and 215 degrees C respectively. The casting alloy temperature was around 280 degrees C as measured by a type K immersion thermocouple prior to pouring into a tundish designed to maintain a constant melt flow on the cooling slope during semi solid material production. A nozzle with a weir ensures that the semi solid material is dragged smoothly by the lower roll, producing strip with minimum contamination of slag/oxide. The temperatures of the cooling slope and the lower roll were also monitored using K type thermocouples. The coiled semi solid strip, which has a thickness of 1.5 mm and 45 mm width, was rolled conventionally in order to obtain 1.2 mm thick strip. The coiled thixorolled strip had a thickness of 1.2 mm and achieved practically the same width as the conventional strips. Blanks of 40 mm diameter were cut from the strips in a mechanical press, ready for deep drawing and ironing for mechanical characterization. All the strips achieved from non-conventional processing had the same mechanical performance as those achieved conventionally. The limiting drawing ratio (LDR) achieved was approximately 2.0 for all strips. Microscopy examination was made in order to observe phase segregation during processing.

Material processing by plasma shock wave generated in an inverse Z-pinch plasma expander

The applicability of plasma shock wave for material processing was investigated using modified inverse Z-pinch device. Shock wave expanding speed and plasma spectral analysis were studied using an internal magnetic,probe and spatially collimated light spectroscopy. The material processing capability of the device was shown by many different surface analysis techniques such as AES, IRS, EPM and SEM. The interactions between a plasma shock wave of similar to4x10(6) cm/s speed with a Si substrate surface shows some ion implantation capability using a nitrogen plasma and thin film formation using a methane plasma.

A high speed 3.3V current mode CMOS comparators with 10-b resolution

This paper presents a high speed current mode CMOS comparator. The comparator was optimized for allows wide range input current 1mA, ±0.5uA resolution and has fast response. This circuit was implemented with 0.8μm CMOS n-well process with area of 120μm × 105μm and operates with 3.3V(±1.65V).

Water flow in high-speed handpieces

Objectives: This study measured the water flow commonly used in high-speed handpieces to evaluate the water flow's influence on temperature generation. Different flow speeds were evaluated between turbines that had different numbers of cooling apertures. Method and materials: Two water samples were collected from each high-speed handpiece at private practices and at the School of Dentistry at São José dos Campos. The first sample was collected at the customary flow and the second was collected with the terminal opened for maximum flow. The two samples were collected into weighed glass receptacles after 15 seconds of turbine operation. The glass receptacles were reweighed and the difference between weights was recorded to calculate the water flow in mL/min and for further statistical analysis. Results: The average water flow for 137 samples was 29.48 mL/min. The flow speeds obtained were 42.38 mL/min for turbines with one coolant aperture; 34.31 mL/min for turbines with two coolant apertures; and 30.44 mL/min for turbines with three coolant apertures. There were statistical differences between turbines with one and three coolant apertures (Tukey-Kramer multiple comparisons test with P < .05). Conclusion: Turbine handpieces with one cooling aperture distributed more water for the burs than high-speed handpieces with more than one aperture.

Improving accuracy and speed of optimum-path forest classifier using combination of disjoint training subsets

The Optimum-Path Forest (OPF) classifier is a recent and promising method for pattern recognition, with a fast training algorithm and good accuracy results. Therefore, the investigation of a combining method for this kind of classifier can be important for many applications. In this paper we report a fast method to combine OPF-based classifiers trained with disjoint training subsets. Given a fixed number of subsets, the algorithm chooses random samples, without replacement, from the original training set. Each subset accuracy is improved by a learning procedure. The final decision is given by majority vote. Experiments with simulated and real data sets showed that the proposed combining method is more efficient and effective than naive approach provided some conditions. It was also showed that OPF training step runs faster for a series of small subsets than for the whole training set. The combining scheme was also designed to support parallel or distributed processing, speeding up the procedure even more. © 2011 Springer-Verlag.

Effects of processing on physical properties of extruded snacks with blends of sour cassava starch and flaxseed flour

The opportunity to supplement common cassava biscuits with a product of higher nutritional value meets consumer expectations. In this work it was studied the effects of process parameters and flaxseed addition on physical properties of expanded snacks. Extrusion process was carried out using a single screw extruder in a factorial central composite rotatable design with four factors: flaxseed flour percentage (0-20%), moisture (12-20%), extrusion temperature (90-130 °C) and screw speed (190-270). The effect of extrusion variables was investigated in terms of expansion index, specific volume, water absorption index, water solubility index, color parameters (L*, a* ,b*) and hardness. The data analysis showed that variable parameters of the extrusion process and flaxseed flour affected physical properties of puffed snacks. Among the experimental conditions used in the present study, expanded snack products with good physical properties can be obtained under the conditions of 10% flaxseed flour, 230 rpm screw speed, temperature of 90 °C and moisture of 12%.

Comparative Studies of Bacillus thuringiensis var. israelensis Metabolism in Different Concentrations of Cassava Flour Processing Waste Based Media

Techniques of production of enthomopatogenic bacteria are developed aiming to increase the productivity and to reduce the costs of the fermentative process. Like this, it has been using agroindustrial wastes or by-products as nutrient sources in culture medium, having been used, in this study, the manipueira, a by-product of the processing of the cassava flour. Fermentations were performed in flasks of Erlenmeyer of 500 mL containing 250 mL of culture media, conditioned in shaker at 180 r.p.m. and 28°C, and the media were composed by manipueira, in concentrations that varied between 400 and 1000 mL/L. The time of the process varied between 48 and 120 hours. They appraised the following parameters: cellular growth, the production of spores, the reduction of organic matter (COD analysis) and the variation of reduction sugar. Although there was a proportional cellular growth to the manipueira concentration, the production of spores was similar in all the cases, at the end of the process, in spite of the smallest speed of production of the same ones in the highest concentrations. In relation to the variation of COD, it has, also, a percentile minor of reduction in the highest concentrations. In the analysis of variation of reduction sugars, the higher concentrations are the ones that they present larger slowness in the reduction of this.

Fluorescence Level of Composites Assessed by Computer Processing of Digital Images - ScanWhite

The human dentition is naturally translucent, opalescent and fluorescent. Differences between the level of fluorescence of tooth structure and restorative materials may result in distinct metameric properties and consequently perceptible disparate esthetic behavior, which impairs the esthetic result of the restorations, frustrating both patients and staff. In this study, we evaluated the level of fluorescence of different composites (Durafill in tones A2 (Du), Charisma in tones A2 (Ch), Venus in tone A2 (Ve), Opallis enamel and dentin in tones A2 (OPD and OPE), Point 4 in tones A2 (P4), Z100 in tones A2 ( Z1), Z250 in tones A2 (Z2), Te-Econom in tones A2 (TE), Tetric Ceram in tones A2 (TC), Tetric Ceram N in tones A1, A2, A4 (TN1, TN2, TN4), Four seasons enamel and dentin in tones A2 (and 4SD 4SE), Empress Direct enamel and dentin in tones A2 (EDE and EDD) and Brilliant in tones A2 (Br)). Cylindrical specimens were prepared, coded and photographed in a standardized manner with a Canon EOS digital camera (400 ISO, 2.8 aperture and 1/ 30 speed), in a dark environment under the action of UV light (25 W). The images were analyzed with the software ScanWhite©-DMC/Darwin systems. The results showed statistical differences between the groups (p < 0.05), and between these same groups and the average fluorescence of the dentition of young (18 to 25 years) and adults (40 to 45 years) taken as control. It can be concluded that: Composites Z100, Z250 (3M ESPE) and Point 4 (Kerr) do not match with the fluorescence of human dentition and the fluorescence of the materials was found to be affected by their own tone.