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51.
Hana Marko Janez Marina Santo Silvo Sre
o Marija 《Sensors and actuators. B, Chemical》2008,133(2):699-704
In this paper we present a novel approach to preparing large-displacement 65Pb(Mg1/3Nb2/3)O3–35PbTiO3/Pt (65/35 PMN–PT/Pt) bimorph actuators. These “substrate-free”, bending-type actuators were prepared by screen-printing the 65/35 PMN–PT and Pt thick-film pastes as the electrodes on alumina substrates. After this screen printing and the subsequent firing the 65/35 PMN–PT/Pt composites were peeled off from the substrates. Displacements of nearly 100 μm at 18 V were achieved for actuators with dimensions of 1.8 cm × 2.5 mm × 50 μm for the 65/35 PMN–PT layer. The normalized displacement (the displacement per unit length) was 40 μm/cm at 18 V. The experimental results together with a computation procedure were used to obtain the material parameters for a finite-element analysis of the 65/35 PMN–PT/Pt bimorph actuators. 相似文献
52.
The virtual path (VP) can simplifyAtm network management by minimizing connection routing and admission costs, and by facilitating the layered control of resources. However, fully exploiting these advantages may lead to a large number of relatively low capacity virtual paths travelling on each physical link. If each VP is treated as a separate unit, as is commonly assumed, low path capacities will lead to low network utilisation. This paper carefully examines the trade-off between simplification through traffic separation and improved efficiency due to traffic consolidation. We review existing vp bandwidth assignment and control techniques, and propose a new vp tagging control method. A comparison shows that by permitting resource sharing between paths it is possible to influence significantly the trade-off between simplified network management and multiplexing gain from traffic consolidation. 相似文献
53.
L Tonella BJ Walsh JC Sanchez K Ou MR Wilkins M Tyler S Frutiger AA Gooley I Pescaru RD Appel JX Yan A Bairoch C Hoogland FS Morch GJ Hughes KL Williams DF Hochstrasser 《Canadian Metallurgical Quarterly》1998,19(11):1960-1971
The combination of two-dimensional polyacrylamide gel electrophoresis (2-D PAGE), computer image analysis and several protein identification techniques allowed the Escherichia coli SWISS-2DPAGE database to be established. This is part of the ExPASy molecular biology server accessible through the WWW at the URL address http://www.expasy.ch/ch2d/ch2d-top.html . Here we report recent progress in the development of the E. coli SWISS-2DPAGE database. Proteins were separated with immobilized pH gradients in the first dimension and sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the second dimension. To increase the resolution of the separation and thus the number of identified proteins, a variety of wide and narrow range immobilized pH gradients were used in the first dimension. Micropreparative gels were electroblotted onto polyvinylidene difluoride membranes and spots were visualized by amido black staining. Protein identification techniques such as amino acid composition analysis, gel comparison and microsequencing were used, as well as a recently described Edman "sequence tag" approach. Some of the above identification techniques were coupled with database searching tools. Currently 231 polypeptides are identified on the E. coli SWISS-2DPAGE map: 64 have been identified by N-terminal microsequencing, 39 by amino acid composition, and 82 by sequence tag. Of 153 proteins putatively identified by gel comparison, 65 have been confirmed. Many proteins have been identified using more than one technique. Faster progress in the E. coli proteome project will now be possible with advances in biochemical methodology and with the completion of the entire E. coli genome. 相似文献
54.
It is widely recognised that impaired social relations are characteristic of school-aged children with behavioural disorders, and predict a poor long-term outcome (Parker & Asher, 1987). However, little is known about the early antecedents of social impairment in behaviourally disturbed children. The aim of the present study was to explore three areas of potential dysfunction in younger children: theory of mind, emotion understanding, and executive function. Forty preschoolers, rated by their parents on the Strengths and Difficulties Questionnaire (Goodman, 1994) as "hard to manage" (H2M) were compared with a control group on a set of: (1) theory of mind tasks (including an emotion prediction task involving either a nice or a nasty surprise); (2) emotion understanding stories (that required affective perspective-taking skills as well as situational understanding); and (3) simple executive function tasks (adapted for preschoolers, and tapping inhibitory control, attentional set-shifting, and working memory). Small but significant group differences were found in all three cognitive domains. In particular, hard-to-manage preschoolers showed poor understanding of emotion and executive control, poor prediction or recall of a false belief, and better understanding of the belief-dependency of emotion in the context of a trick than a treat. Moreover, executive function was associated with performance on the theory of mind tasks for the hard-to-manage group alone, suggesting both direct and indirect links between executive dysfunction and disruptive behaviour. 相似文献
55.
Koval D.O. Bocancea R.A. Kai Yao Hughes M.B. 《Industry Applications, IEEE Transactions on》1998,34(5):904-910
The occurrence of voltage sags and surges originating on the primary and secondary sides of industrial facilities can disrupt continuous and noncontinuous industrial computer processes, a costly issue for society. This paper attempts to answer several questions concerning the frequency and duration of voltage sags and surges posed by industrial customers. The answers to these questions are based on the national survey results of the frequency and duration of voltage sags and surges at industrial sites monitored at their utilization voltage levels (e.g. 120, 347 V) and on the utility primary side of their facilities. The survey results provide a knowledge base for monitoring, designing, and utilizing voltage sag and surge mitigating technologies 相似文献
56.
R Wrigglesworth CS Walpole S Bevan EA Campbell A Dray GA Hughes I James KJ Masdin J Winter 《Canadian Metallurgical Quarterly》1996,39(25):4942-4951
Structural features of three regions of the capsaicin molecule necessary for agonist properties were delineated by a previously reported modular approach. These in vitro agonist effects were shown to correlate with analgesic potency in rodent models. Combination of optimal structural features from each of these regions of the capsaicin molecule have led to highly potent agonists (eg., 1b). Evaluation in vivo established that 1b had analgesic properties but poor oral activity, short duration of action, and excitatory side effects which precluded further development of this compound. Preliminary metabolism studies had shown that the phenol moiety of 1b was rapidly glucuronidated in vivo, providing a possible explanation for the poor pharmacokinetic profile. Subsequent specific modification of the phenol group led to compounds 2a-j, which retained in vitro potency. The in vivo profiles of two representatives of this series, 2a,h, were much improved over the "parent" phenol series, and they are candidates for development as analgesic agents. 相似文献
57.
Jennifer J. Burg Sheau-Dong Lang Charles E. Hughes 《Annals of Mathematics and Artificial Intelligence》1996,17(2):189-211
CLP() is a constraint logic programming language in which constraints can be expressed in the domain of real numbers. Computation in this specialized domain gives access to information useful in intelligent backtracking. In this paper, we present an efficient constraint satisfaction algorithm for linear constraints in the real number domain and show that our algorithm directly generates minimal sets of conflicting constraints when failures occur. We demonstrate how information gleaned during constraint satisfaction can be integrated with unification failure analysis. The resulting intelligent backtracking method works in the context of a two-sorted domain, where variables can be bound to either structured terms or real number expressions. We discuss the implementation of backtracking and show examples where the benefit of pruning the search tree outweights the overhead of failure analysis. 相似文献
58.
Stephanie Kemna Michael J. Hamilton David T. Hughes Kevin D. LePage 《Intelligent Service Robotics》2011,4(4):245-258
Autonomous underwater vehicles (AUVs) have gained more interest in recent years for military as well as civilian applications.
One potential application of AUVs is for the purpose of undersea surveillance. As research into undersea surveillance using
AUVs progresses, issues arise as to how an AUV acquires, acts on, and shares information about the undersea battle space.
These issues naturally touch on aspects of vehicle autonomy and underwater communications, and need to be resolved through
a spiral development process that includes at sea experimentation. This paper presents a recent AUV implementation for active
anti-submarine warfare tested at sea in the summer of 2010. On-board signal processing capabilities and an adaptive behavior
are discussed in both a simulation and experimental context. The implications for underwater surveillance using AUVs are discussed. 相似文献
59.
60.
Brice T. Hughes Jordan M. Berg Darryl L. James Akif Ibraguimov Shaorong Liu Henryk Temkin 《Microfluidics and nanofluidics》2008,5(6):761-774
This paper presents a numerical steady-state model of ion transport in micro- and nanofluidic devices with widely varying
geometric scale, such as transitions between micro- and nanochannels. Finite element or finite volume simulation of such problems
is challenging, due to the number of elements needed to produce a satisfactory mesh. Here, only the lengthwise channel dimension
is meshed; standard analytical approximations are used to incorporate cross-channel properties. Singularly perturbed cases
are built up by continuation. The method is shown to reproduce our previously reported measurements of electric double-layer
effects on conductivity, ion concentration, and ion enhancement and depletion. Comparison with 2-D simulations reported in
the literature shows that effects on accuracy due to the 1-D approximation are small. The model incorporates analytical models
of surface charge density taken from the literature. This enables predictive simulation with reasonable accuracy using published
parameter values, or these values may be tuned based on experiment to give improved results. Use of the model for iterative
design and parameter estimation is demonstrated. 相似文献