23,141 research outputs found
Sketch-based virtual human modelling and animation
Animated virtual humans created by skilled artists play a remarkable role in todayâs public entertainment. However, ordinary users are still treated as audiences due to the lack of appropriate expertise, equipment, and computer skills. We developed a new method and a novel sketching interface, which enable anyone who can draw to âsketch-outâ 3D virtual humans and animation.
We devised a âStick FigureFleshing-outSkin Mappingâ graphical pipeline, which decomposes the complexity of figure drawing and considerably boosts the modelling and animation efficiency. We developed a gesture-based method for 3D pose reconstruction from 2D stick figure drawings. We investigated a âCreative Model-based Methodâ, which performs a human perception process to transfer usersâ 2D freehand sketches into 3D human bodies of various body sizes, shapes and fat distributions. Our current system supports character animation in various forms including articulated figure animation, 3D mesh model animation, and 2D contour/NPR animation with personalised drawing styles. Moreover, this interface also supports sketch-based crowd animation and 2D storyboarding of 3D multiple character interactions. A preliminary user study was conducted to support the overall system design. Our system has been formally tested by various users on Tablet PC. After minimal training, even a beginner can create vivid virtual humans and animate them within minutes
Sketching-out virtual humans: From 2d storyboarding to immediate 3d character animation
Virtual beings are playing a remarkable role in todayâs public entertainment, while ordinary users are still treated as audiences due to the lack of appropriate expertise, equipment, and computer skills. In this paper, we present a fast and intuitive storyboarding interface, which enables users to sketch-out 3D virtual humans, 2D/3D animations, and character intercommunication. We devised an intuitive âstick figurefleshing-outskin mappingâ graphical animation pipeline, which realises the whole process of key framing, 3D pose reconstruction, virtual human modelling, motion path/timing control, and the final animation synthesis by almost pure 2D sketching. A âcreative model-based methodâ is developed, which emulates a human perception process, to generate the 3D human bodies of variational sizes, shapes, and fat distributions. Meanwhile, our current system also supports the sketch-based crowd animation and the storyboarding of the 3D multiple character intercommunication. This system has been formally tested by various users on Tablet PC. After minimal training, even a beginner can create vivid virtual humans and animate them within minutes
Sketching-out virtual humans: A smart interface for human modelling and animation
In this paper, we present a fast and intuitive interface for sketching out
3D virtual humans and animation. The user draws stick figure key frames first and
chooses one for âfleshing-outâ with freehand body contours. The system
automatically constructs a plausible 3D skin surface from the rendered figure, and
maps it onto the posed stick figures to produce the 3D character animation. A
âcreative model-based methodâ is developed, which performs a human perception
process to generate 3D human bodies of various body sizes, shapes and fat
distributions. In this approach, an anatomical 3D generic model has been created with
three distinct layers: skeleton, fat tissue, and skin. It can be transformed sequentially
through rigid morphing, fatness morphing, and surface fitting to match the original
2D sketch. An auto-beautification function is also offered to regularise the 3D
asymmetrical bodies from usersâ imperfect figure sketches. Our current system
delivers character animation in various forms, including articulated figure animation,
3D mesh model animation, 2D contour figure animation, and even 2D NPR animation
with personalised drawing styles. The system has been formally tested by various
users on Tablet PC. After minimal training, even a beginner can create vivid virtual
humans and animate them within minutes
Maximizing the Probability of Delivery of Multipoint Relay Broadcast Protocol in Wireless Ad Hoc Networks with a Realistic Physical Layer
It is now commonly accepted that the unit disk graph used to model the
physical layer in wireless networks does not reflect real radio transmissions,
and that the lognormal shadowing model better suits to experimental
simulations. Previous work on realistic scenarios focused on unicast, while
broadcast requirements are fundamentally different and cannot be derived from
unicast case. Therefore, broadcast protocols must be adapted in order to still
be efficient under realistic assumptions. In this paper, we study the
well-known multipoint relay protocol (MPR). In the latter, each node has to
choose a set of neighbors to act as relays in order to cover the whole 2-hop
neighborhood. We give experimental results showing that the original method
provided to select the set of relays does not give good results with the
realistic model. We also provide three new heuristics in replacement and their
performances which demonstrate that they better suit to the considered model.
The first one maximizes the probability of correct reception between the node
and the considered relays multiplied by their coverage in the 2-hop
neighborhood. The second one replaces the coverage by the average of the
probabilities of correct reception between the considered neighbor and the
2-hop neighbors it covers. Finally, the third heuristic keeps the same concept
as the second one, but tries to maximize the coverage level of the 2-hop
neighborhood: 2-hop neighbors are still being considered as uncovered while
their coverage level is not higher than a given coverage threshold, many
neighbors may thus be selected to cover the same 2-hop neighbors
Cryptanalysis of the Hillery-Buzek-Berthiaume quantum secret-sharing protocol
The participant attack is the most serious threat for quantum secret-sharing
protocols. We present a method to analyze the security of quantum
secret-sharing protocols against this kind of attack taking the scheme of
Hillery, Buzek, and Berthiaume (HBB) [Phys. Rev. A 59 1829 (1999)] as an
example. By distinguishing between two mixed states, we derive the necessary
and sufficient conditions under which a dishonest participant can attain all
the information without introducing any error, which shows that the HBB
protocol is insecure against dishonest participants. It is easy to verify that
the attack scheme of Karlsson, Koashi, and Imoto [Phys. Rev. A 59, 162 (1999)]
is a special example of our results. To demonstrate our results further, we
construct an explicit attack scheme according to the necessary and sufficient
conditions. Our work completes the security analysis of the HBB protocol, and
the method presented may be useful for the analysis of other similar protocols.Comment: Revtex, 7 pages, 3 figures; Introduction modifie
Multiplication and excess noise characteristics of thin 4H-SiC UV avalanche photodiodes
The avalanche multiplication and excess noise characteristics of thin 4H-SiC avalanche photodiodes with an i-region width of 0.1 ”m have been investigated. The diodes are found to exhibit multiplication characteristics which change significantly when the wavelength of the illuminating light changes from 230 to 365 nm. These multiplication characteristics show unambiguously that ÎČ > α in 4H-SiC and that the ÎČ/α ratio remains large even in thin 4H-SiC diodes. Low excess noise, corresponding to k=0.1 in the local model where k=α/ÎČ for hole injection, was measured using 325-nm light. The results indicate that 4H-SiC is a suitable material for realizing low-noise UV avalanche photodiodes requiring good visible-blind performance
A Consumer-Centric Open Innovation Framework for Food and Packaging Manufacturing
This article has been archived following written permission from IGI Global.Closed innovation approaches have been employed for many years in the food industry. But, this sector recently perceives its end-user to be wary of radically new products and changes in consumption patterns. However, new product development involves not only the product itself but also the entire manufacturing and distribution network. In this paper, we present a new ICT based framework that embraces open innovation to place customers in the product development loop but at the same time assesses and eventually coordinates the entire manufacturing and supply chain. The aim is to design new food products that consumers will buy and at the same time ensure that these products will reach the consumer in time and at adequate quantity. On the product development side, our framework enables new food products that offer an integrated sensory experience of food and packaging, which encompass customization, healthy eating, and sustainability
Nanopillar Arrays on Semiconductor Membranes as Electron Emission Amplifiers
A new transmission-type electron multiplier was fabricated from
silicon-on-insulator (SOI) material by integrating an array of one dimensional
(1D) silicon nanopillars onto a two dimensional (2D) silicon membrane. Primary
electrons are injected into the nanopillar-membrane system from the flat
surface of the membrane, while electron emission from the other side is probed
by an anode. The secondary electron yield (SEY) from nanopillars is found to be
about 1.8 times that of plane silicon membrane. This gain in electron number is
slightly enhanced by the electric field applied from the anode. Further
optimization of the dimensions of nanopillars and membrane and application of
field emission promise an even higher gain for detector applications and allow
for probing of electronic/mechanical excitations in nanopillar-membrane system
excited by incident particles or radiation.Comment: 4 figure
Hadronic Rapidity Spectra in Heavy Ion Collisions at SPS and AGS energies in a Quark Combination Model
The quark combination mechanism of hadron production is applied to
nucleus-nucleus collisions at the CERN Super Proton Synchrotron (SPS) and BNL
Alternating Gradient Synchrotron (AGS). The rapidity spectra of identified
hadrons and their spectrum widths are studied. The data of ,
, , , , , and
at 80 and 40 AGeV, in particular at 30 and 20 AGeV where the onset of
deconfinement is suggested to happen, are consistently described by the quark
combination model. However at AGS 11.6 AGeV below the onset the spectra of
, and can not be simultaneously explained,
indicating the disappearance of intrinsic correlation of their production in
the constituent quark level. The collision-energy dependence of the rapidity
spectrum widths of constituent quarks and the strangeness of the hot and dense
quark matter produced in heavy ion collisions are obtained and discussed.Comment: 7 pages, 5 figure
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