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61.
Giovan B. Quaglia Angelo Massacci 《Journal of the science of food and agriculture》1982,33(7):634-638
Previous studies have shown the anticlotting effect of papain on slaughter-house blood to be due to its proteolytic activity on fibrin. This has suggested its possible use in a protein recovery process. Blood proteolysate has been obtained using microbial proteases or papain; the haemolysis of the cells was then effected and the haem extracted with acidified acetone to decolourise the product. 相似文献
62.
Albanese Massimiliano Chianese Angelo Moscato Vincenzo Sansone Lucio 《Multimedia Tools and Applications》2004,24(3):253-272
The first step in a video indexing process is the segmentation of videos into meaningful parts called shots. In this paper we present a formal model of the video shot segmentation process. Starting from a mathematical characterization of the most common transition effects, a video segmentation algorithm capable to detect both abrupt and gradual transitions is proposed. The proposed algorithm is based on the computation of an arbitrary similarity measure between consecutive frames of a video. The algorithm has been tested adopting a similarity metric based on the Animate Vision theory and results have been reported. 相似文献
63.
Popescu F Viceconti M Grazi E Cappello A 《Computer methods and programs in biomedicine》2003,71(2):117-127
The present study describes an automatic method to evaluate the efficacy of a computer aided orthopaedic surgery system by comparing the position of the joint implant, as derived from post-operative computed tomography (CT) scans, to that planned by the surgeon before the operation. The method relies on two spatial registrations, one to align the post-operative femur with the pre-operative femur, the second to compute the planned versus achieved (PVA) accuracy as the roto-translation that registers the pre-operative implant position with the post-operative position. Two surface registration algorithms (a generic average distance minimisation and the specialised iterative closest point (ICP) method) were comparatively evaluated first on a set of test cases to measure the absolute accuracy and robustness with respect to peculiar situations such as a distant starting point. The average distance method failed the registration of one test case and showed peak errors of 0.97 degrees on the rotations and 3.09 mm on the translations. The ICP method was found much more efficient and was able to register all test cases. The peak error was 0.44 degrees on the rotations and 0.67 mm on the translations. The ICP method was then used to compute the PVA accuracy on six clinical cases treated with a CT-based planning system in combination with conventional surgical procedures. The method successfully processed all cases demonstrating the efficacy of the proposed procedure in the specific application. 相似文献
64.
Madonna AJ Voorhees KJ Taranenko NI Laiko VV Doroshenko VM 《Analytical chemistry》2003,75(7):1628-1637
A novel approach to microbial detection using atmospheric pressure matrix-assisted laser desorption/ionization with an ion trap mass spectrometer to analyze whole cell bacteria is introduced. This new approach was tested with lyophilized spores and cultures of Bacillus globigii (BG) grown on agar media for 4 days or longer. At each stage of growth, it was found that biomarkers, identified as cyclic lipopeptides known as fengycin and surfactin, could be detected by pulsed ultraviolet laser irradiation of intact BG cells (approximately 5 mg) cocrystallized with alpha-cyano-4-hydroxycinnamic acid. Furthermore, definitive amino acid sequence information was obtained by performing tandem mass spectrometry on the precursor ions of the cyclic lipopeptides. The investigation was broadened to include the examination of aerosolized BG spores collected from the atmosphere and directly deposited onto double-sided tape. Subsequent analysis of the recovered spores resulted in the production of mass peaks consistent with fengycin. Other Bacillus species were analyzed for comparison and showed mass spectral peaks also identified as originating from various cyclic lipopeptides. Further studies were conducted using a pulsed infrared laser as the excitation source to analyze BG cells (approximately 5 mg) suspended in a matrix of 0.03 M ammonium citrate and glycerol resulting in the production of ions characteristic of fengycin and surfactin. 相似文献
65.
Marocco D Cangelosi A Nolfi S 《Philosophical transactions. Series A, Mathematical, physical, and engineering sciences》2003,361(1811):2397-2421
Evolutionary robotics is a biologically inspired approach to robotics that is advantageous to studying the evolution of communication. A new model for the emergence of communication is developed and tested through various simulation experiments. In the first simulation, the emergence of simple signalling behaviour is studied. This is used to investigate the inter-relationships between communication abilities, namely linguistic production and comprehension, and other behavioural skills. The model supports the hypothesis that the ability to form categories from direct interaction with an environment constitutes the grounds for subsequent evolution of communication and language. In the second simulation, evolutionary robots are used to study the emergence of simple syntactic categories, e.g. action names (verbs). Comparisons between the two simulations indicate that the signalling lexicon emerged in the first simulation follows the evolutionary pattern of nouns, as observed in related models on the evolution of syntactic categories. Results also support the language-origin hypothesis on the fact that nouns precede verbs in both phylogenesis and ontogenesis. Further extensions of this new evolutionary robotic model for testing hypotheses on language origins are also discussed. 相似文献
66.
Ruggero Lanotte Andrea Maggiolo-Schettini Angelo Troina 《Formal Aspects of Computing》2007,19(1):93-109
We develop a model of parametric probabilistic transition Systems (PPTSs), where probabilities associated with transitions
may be parameters. We show how to find instances of the parameters that satisfy a given property and instances that either
maximize or minimize the probability of reaching a certain state. As an application, we model a probabilistic non-repudiation
protocol with a PPTS. The theory we develop allows us to find instances that maximize the probability that the protocol ends
in a fair state (no participant has an advantage over the others).
A preliminary version of this paper was presented at SEFM’04 [LMT04].
05 April 2006 相似文献
67.
Optical channels are currently able to carry 10 Gbit/s and even 40 Gbit/s traffic flows. However, it is not usual to have
such amounts of traffic between any pair of client nodes. This article proposes using point-to-multipoint optical channels
for the allocation of point-to-point connections in transparent wavelength-routed optical networks. Specifically, when an
optical connection between a source-destination node pair has to be established, the optical signal is also sent to some adjacent
nodes by introducing passive optical splitters; in this way a light-tree is built. Then, the already established point-to-multipoint
optical channel can be used to groom further point-to-point connections between the same source node and each of the other
nodes composing the light-tree. The benefits of this strategy are 2-fold: first, the reduction of optical transmission equipments
allowing cost savings with respect to the traditional typical point-to-point approach and, second, the optimization of the
optical channels utilization meeting in such a way Traffic Engineering objectives. The merits of proposed approach are evaluated
by simulation. 相似文献
68.
A full-order state observer for a class of nonlinear continuous-time systems is presented as generalization of the high-gain observer for having a time-varying gain that is let to be small in the first time instants, increases over time up to its maximum, and then is kept constant. The global stability of the resulting estimation error is proved by means of a Lyapunov functional via a change of coordinate. The design of such an observer is obtained by solving a nonlinear programming problem and using series expansions to set the time-varying gain. 相似文献
69.
70.
A very important issue in optical burst switching (OBS) networks is the excessive burst drop when no suitable network resources
are found during path reservation. In this study, a network scenario is evaluated in which AWG-based optical nodes are used
as burst router nodes within the optical network. The two classical solutions to solve the burst contentions on the channels
outgoing from the node are considered, that is, either based on buffering within the node, or by exploiting deflection routing.
A performance evaluation is carried out to evaluate and compare these solutions for different network topologies with different
node and traffic parameters. Our main contribution is to set numerical tradeoffs between burst deflection through the network
and buffering in the node, so that a guidance in optical network design is provided where node buffering is inherently technologically
limited. 相似文献