This paper describes a technique to animate three-dimensional sampled volumes. The technique gives the animator the ability to treat volumes as if they were standard polygonal models and to use all of the standard animation/motion capture tools on volumetric data. A volumetric skeleton is computed from a volumetric model using a multi-resolution thinning procedure. The volumetric skeleton is centered in the object and accurately represents the shape of the object. The thinning process is reversible in that the volumetric model can be reconstructed from the volumetric skeleton. The volumetric skeleton is then connected and imported into a standard graphics animation package for animation. The animated skeleton is used for reconstruction, which essentially recreates a deformed volume around the deformed skeleton. Polygons are never computed and the entire process remains in the volumetric domain. This technique is demonstrated on one of the most complex 3D datasets, the Visible Male, resulting in actual “human animation”. 相似文献
This work presents development of a two-dimensional finite element model to predict temperature distribution and ablation depth in a laser ablation process. The model considers a number of aspects of the process, which hitherto have been considered independently in the literature. The aspects considered include: temperature dependent material properties of the target material, effect of plasma shielding on the incident laser flux, and temperature dependent absorptivity and absorption coefficient of the target. It was evident that these considerations have resulted in a significant improvement in the ability of the model to predict the ablation depth. Finally, the predicted ablation depth was found to match extremely well with experimental results at lower laser fluences, though at higher fluences there is a marginal overestimation. 相似文献
The addition of hollow fillers having appropriate mechanical properties can decrease the density of the resulting composite,
called syntactic foams, while concurrently improving its mechanical properties. In this study, hollow fly ash particles, called
cenospheres, are used as fillers in polyester matrix material. Cenospheres are a waste by-product of coal combustion and,
as such, are available at very low cost. In this study, the composites were synthesized by settling cenospheres in a glass
tube filled with liquid polyester resin and subsequently curing the resin. This process resulted in a functionally graded
structure containing a gradient in the cenosphere volume fraction along the sample height. Uniform radial sections were cut
from each composite and were characterized to observe the relationship between cenosphere volume fraction and compressive
properties of the composite. The composite was also tested using ultrasonic non-destructive evaluation method. Results show
that the modulus of the composites increases with increasing cenosphere volume fraction. The modulus of composites containing
more than 4.9 vol% cenosphere was found to be higher than the matrix resin. In general, the modulus of composites increased
from 1.33 to 2.1 GPa for composites containing from 4.9–29.5 vol% cenospheres. The specific strength of the composite was
found to be as high as 2.03 MPa/(kg/m3) compared to 0.96 MPa/(kg/m3) for the neat resin. Numerous defects present in fly ash particles caused a reduction in the strength of the composite. However,
the reduction in the strength was found to be only up to 22%. Increase of over 110% in the specific modulus and only a slight
decrease in the strength indicates the possibility of significant saving of weight in the structures using polyester/fly ash
syntactic foams. 相似文献
Wireless Personal Communications - The massive growth in modern wireless technologies and devices has resulted in increase in spectrum demands and energy consumption of wireless sensor network... 相似文献
Silicon - This investigation reports the preparation and properties of thermoplastic polyurethane/silica nanocomposite prepared via melt mixing process. In this case, nanosilica at different... 相似文献
AbstractWe show how various concentrations ranging from 0 to 5.0?wt% of the ionic liquid (IL) trihexyltetradecylphosphonium bis(2-ethylhexyl)phosphate added to a fully formulated aviation DOD-PRF-85734 gearbox lubricant affects the properties of the lubricant, including scuffing resistance under starved lubrication conditions, coefficient of friction (COF), wear rate, and lubricant chemical stability. Specimen surfaces were then characterized using scanning electron microscopy, energy-dispersive spectroscopy, and auger electron spectroscopy. Scuffing and wear properties were found to generally improve with IL concentration, which we hypothesize is due to the presence of a phosphorous-rich film observed on specimens exposed to IL. 相似文献
In this study, non-orthogonal multiple access (NOMA) together with cognitive radio (CR) benefit to the vehicle-to-everything (V2X) as promising application with high spectrum efficiency. We have higher priority to evaluate system performance of the secondary network in such CR-NOMA system operating in the context of V2X. We first arrange vehicles belonging to serving group in this CR-NOMA assisted V2X, and it is beneficial to serve massive connections for vehicles. There are two scenarios studied in this paper, with and without the support of CR scheme. In our proposed system, two system metrics need be investigated to evaluate performance of vehicles that need higher quality of service (QoS). Our results indicate that the outage performance gap among two vehicles exists since different transmit power allocation factors were assigned to them. In particular, the outage probability is first derived in exact forms and then the bit error rate (BER) can be further achieved. In specific situations, the optimal outage probability can be obtained by numerical simulations. Simulation results are also provided to verify the correctness of the derived expressions and it exhibits advantages of the proposed CR-NOMA assisted V2X system in terms of two main metrics such as outage probability and BER.
We developed and fabricated the world's highest resolution (18 megapixel, 1443 ppi) OLED on glass display panel. The design uses a white OLED with color filter structure for high density pixelization and an n‐type LTPS backplane for faster response time than mobile phone displays. A custom high bandwidth driver IC was fabricated. We developed a foveated pixel pipeline appropriate for virtual reality and augmented reality applications, especially mobile systems. 相似文献