Facial animation retargeting and control based on a human appearance space

Expressive facial animations are essential to enhance the realism and the credibility of virtual characters. Parameter‐based animation methods offer a precise control over facial configurations while performance‐based animation benefits from the naturalness of captured human motion. In this paper, we propose an animation system that gathers the advantages of both approaches. By analyzing a database of facial motion, we create the human appearance space. The appearance space provides a coherent and continuous parameterization of human facial movements, while encapsulating the coherence of real facial deformations. We present a method to optimally construct an analogous appearance face for a synthetic character. The link between both appearance spaces makes it possible to retarget facial animation on a synthetic face from a video source. Moreover, the topological characteristics of the appearance space allow us to detect the principal variation patterns of a face and automatically reorganize them on a low‐dimensional control space. The control space acts as an interactive user‐interface to manipulate the facial expressions of any synthetic face. This interface makes it simple and intuitive to generate still facial configurations for keyframe animation, as well as complete temporal sequences of facial movements. The resulting animations combine the flexibility of a parameter‐based system and the realism of real human motion. Copyright © 2010 John Wiley & Sons, Ltd.     

Primary high-dose intradermal hepatitis B vaccination in hemodialysis: cost-effectiveness evaluation at 2 years

Reinforced hepatitis B (HB) vaccination schedules have been tested in nonresponsive hemodialysis (HD) patients. Primary high-dose intradermal (ID) vaccination in HD has been proposed in one study with higher seroconversion rate, but no cost analysis was made. The aim of this prospective study was to confirm this previous report and focus on a cost-effectiveness evaluation of the thorough vaccination with a maintenance program. Thirty-five chronic incident HD patients received primary ID HB vaccination with a reinforced schedule (20 microg Engerix-B every 2 weeks). Revaccination with a monthly single ID dose of 20 microg was performed whenever anti-HBs titer fell under 20 IU/L and continued until a titer of 20 U/L was reached. Outcome measures were cumulative seroconversion rates, mean levels of anti-HBs, maintenance booster doses, rate of seroprotection at the end of the 2-year follow-up and subsequent costs. The present study was associated with an earlier peak of anti-HBs titer (3.9+/-1.7 months) and a higher cumulative seroconversion rate (96.9%) after 1 year. Moreover, a low-booster shot (17.4 microg) of ID Engerix-B/year/patient confers a 100% seroprotection for all responders for a second-year period. The mean cost of our schedule is 127.7 euro/patient for a 2-year period, revaccination included. This current study demonstrates that primary reinforced ID HB vaccination with a maintenance program for a 2-year period warrants the best cost-effectiveness ratio with rapid and sustained seroprotection in almost all HD patients.     

Efficient Implementations of Software Architectures via Partial Evaluation

The notion of flexibility (that is, the ability to adapt to changing requirements or execution contexts) is recognized as a key concern in structuring software, and many architectures have been designed to that effect. However, the corresponding implementations often come with performance and code size overheads. The source of inefficiency can be identified to be in the loose integration of components, because flexibility is often present not only at the design level but also in the implementation. To solve this flexibility vs. efficiency dilemma, we advocate the use of partial evaluation, which is an automated technique to produce efficient, specialized instances of generic programs. As supporting case studies, we consider several flexible mechanisms commonly found in software architectures: selective broadcast, pattern matching, interpreters, software layers, and generic libraries. Using Tempo, our specializer for C, we show how partial evaluation can safely optimize implementations of those mechanisms. Because this optimization is automatic, it preserves the original genericity and extensibility of the implementation.     

Minimalist Z chair assembly by rotational dowel welding

The minimalist Z-chair of Rietveld is an example of a piece of furniture which is now possible to manufacture by using dowel welding technology.     

Ultrastructural evidence for intra- and extranuclear projections of GABAergic neurons of the suprachiasmatic nucleus

GABAergic projections of the suprachiasmatic nucleus (SCN) were demonstrated in a double-labelling ultrastructural study which visualised the efferents of the SCN by PHA-L tracing, diaminobenzidine (DAB) immunocytochemistry, and GABA with immunogold postembedding staining. The results show a strong contralateral projection of the SCN that is partly GABA-containing. In addition, ipsilateral SCN projections to the dorsomedial hypothalamus and periventricular part of the paraventricular nucleus and sub-paraventricular nucleus were shown to contain GABA. The present results indicate that the SCN may utilize this inhibitory neurotransmitter to regulate and organize its own circadian rhythm as well as using GABA to transmit its diurnal information to other regions of the brain.     

An active microphotodiode array of oscillating pixels for retinal stimulation

We have developed an active microphotodiode array (MPDA) for retinal stimulation. The unique feature of the device is that each pixel acts as an independent oscillator, whose frequency is controlled by the incident light intensity. The design is based on a double inverter relaxation oscillator, and the photodiodes are of PIN-type. These oscillating pixels stimulate the nervous tissue with bipolar pulses. The prototype stimulator chips are realized in standard 0.35 μm CMOS technology. The reported preliminary data and performance demonstrate the potential of the new concept for future retinal prostheses.     

INFLUENCE OF AXISYMMETRIC DEFORMATION PROCESSING METHODS ON THE MECHANICAL PROPERTIES OF Cu-Nb COMPOSITES

It has been shown that deformation processed Cu-19% Nb alloys with good strength and electrical conductivity can be developed in sizes that are useful for engineering applications. Mot extrusion of bundled sub-elemental Cu-19% Nb wires followed by cold drawing to make a composite wire of diameter equal to that of the initial sub-elemental wires resulted in a 67% increase in the ultimate tensile stress. However, on subsequent cold drawing of this composite wire the strength increased at a slower rate than that obtained on continuing cold drawing of the sub-elemental wire and the strength differential decreased. In addition, after cold drawing to equivalent diameters the electrical conductivity of the composite wire was less than that of the sub-elemental wire. These results indicate that while high strengths and good electrical conductivities can be produced in larger size deformation processed Cu-Nb composites by a process of bundling, extrusion and cold drawing of sub-elemental wires, there appears to be a limit to the amount of subsequent cold drawing feasible before the benefit in properties ceases.