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81.
Intraphase redox kinetics were monitored across the wüstite, Fe1–xO, phase of the iron-oxygen system in CO2-CO and CO2-CO-Ar mixtures at 1062 and 1106° C. Kinetic data expressed in terms of the chemical diffusion coefficient and the equilibration time as a function of composition strongly indicated the importance of a reaction at the gas-oxide interface in the overall reequilibration of a specimen. Both the chemical diffusion coefficient and the equilibration time were found to be inversely proportional to the deviation from stoichiometry. Surface rate constants calculated from initial linear oxidation data were found to decrease as the deviation from stoichiometry increased. 相似文献
82.
83.
in het Panhuis M Kane-Maguire LA Moulton SE Innis PC Wallace GG 《Journal of nanoscience and nanotechnology》2004,4(8):976-981
The interaction of single wall carbon nanotubes (SWNT) with an aqueous solution of the fully sulfonated polyaniline poly(2-methoxyaniline-5-sulfonic acid) (PMAS) and (+)-1-phenylethylamine (PhEA) has been investigated using spectroscopic methods. UV-vis spectral measurements show that the PMAS backbone undergoes conformational changes upon interaction with both SWNT and PhEA. Partial intercalation of PMAS into SWNTbundles was confirmed by Raman spectroscopy and electron microscopy. 相似文献
84.
Beginning with a model of social perception in which the perceiver is assumed to operate according to the conventional canons of statistical inference, it was hypothesized that trait judgments of groups of individuals represented by facial photographs would match the mean values of these photographs judged individually and that confidence and the amount of information required before a judgment is reported will vary inversely with the variance in the set of photographs comprising the group, and directly with the significance of the judgment for the judge. Using different procedures and measures of the dependent variables, 2 experiments were performed which agreed in supporting the hypotheses. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
85.
86.
Leon O. Chua Juebang Yu Youying Yu 《International Journal of Circuit Theory and Applications》1983,11(2):161-186
Two-terminal devices which exhibit a type-S (current-controlled) or type-N (voltage-controlled) negative differential resistance can be built using only two bipolar transistors and linear positive resistors without any internal biasing power supply. Two general algorithms are presented in this paper for systematically generating all such devices. Hundreds of negative resistance devices have been derived to date using these algorithms and a selection of these circuits is presented in this paper along with their computer-simulated v-i curves. Laboratory measurements of a few sample circuits agree remarkably well with the computer-simulated results. 相似文献
87.
Elisa Barney Smith David Monn Harsha Veeramachaneni Koichi Kise Alessio Malizia Leon Todoran Adnan El-Nasan Rolf Ingold 《International Journal on Document Analysis and Recognition》2003,6(3):200-206
This document is a collection of four working group reports in the areas of digital libraries, document image retrieval, layout analysis, and Web document analysis. These reports were the outcome of discussions by participants at the Fifth IAPR International Workshop on Document Analysis Systems held in Princeton, NJ on 19-21 August 2002.Published online: 16 March 2004 相似文献
88.
Iasemidis LD Shiau DS Chaovalitwongse W Sackellares JC Pardalos PM Principe JC Carney PR Prasad A Veeramani B Tsakalis K 《IEEE transactions on bio-medical engineering》2003,50(5):616-627
Current epileptic seizure "prediction" algorithms are generally based on the knowledge of seizure occurring time and analyze the electroencephalogram (EEG) recordings retrospectively. It is then obvious that, although these analyses provide evidence of brain activity changes prior to epileptic seizures, they cannot be applied to develop implantable devices for diagnostic and therapeutic purposes. In this paper, we describe an adaptive procedure to prospectively analyze continuous, long-term EEG recordings when only the occurring time of the first seizure is known. The algorithm is based on the convergence and divergence of short-term maximum Lyapunov exponents (STLmax) among critical electrode sites selected adaptively. A warning of an impending seizure is then issued. Global optimization techniques are applied for selecting the critical groups of electrode sites. The adaptive seizure prediction algorithm (ASPA) was tested in continuous 0.76 to 5.84 days intracranial EEG recordings from a group of five patients with refractory temporal lobe epilepsy. A fixed parameter setting applied to all cases predicted 82% of seizures with a false prediction rate of 0.16/h. Seizure warnings occurred an average of 71.7 min before ictal onset. Similar results were produced by dividing the available EEG recordings into half training and testing portions. Optimizing the parameters for individual patients improved sensitivity (84% overall) and reduced false prediction rate (0.12/h overall). These results indicate that ASPA can be applied to implantable devices for diagnostic and therapeutic purposes. 相似文献
89.
Ping Jiang Leon C A Bamforth Zuren Feng John E F Baruch YangQuan Chen 《IEEE transactions on systems, man, and cybernetics. Part B, Cybernetics》2007,37(4):863-876
This paper presents a discrete learning controller for vision-guided robot trajectory imitation with no prior knowledge of the camera-robot model. A teacher demonstrates a desired movement in front of a camera, and then, the robot is tasked to replay it by repetitive tracking. The imitation procedure is considered as a discrete tracking control problem in the image plane, with an unknown and time-varying image Jacobian matrix. Instead of updating the control signal directly, as is usually done in iterative learning control (ILC), a series of neural networks are used to approximate the unknown Jacobian matrix around every sample point in the demonstrated trajectory, and the time-varying weights of local neural networks are identified through repetitive tracking, i.e., indirect ILC. This makes repetitive segmented training possible, and a segmented training strategy is presented to retain the training trajectories solely within the effective region for neural network approximation. However, a singularity problem may occur if an unmodified neural-network-based Jacobian estimation is used to calculate the robot end-effector velocity. A new weight modification algorithm is proposed which ensures invertibility of the estimation, thus circumventing the problem. Stability is further discussed, and the relationship between the approximation capability of the neural network and the tracking accuracy is obtained. Simulations and experiments are carried out to illustrate the validity of the proposed controller for trajectory imitation of robot manipulators with unknown time-varying Jacobian matrices. 相似文献
90.
A comprehensive view of agent-oriented patterns 总被引:2,自引:0,他引:2
Ayodele Oluyomi Shanika Karunasekera Leon Sterling 《Autonomous Agents and Multi-Agent Systems》2007,15(3):337-377
This paper presents a comprehensive framework for classifying, analyzing and describing agent-oriented software patterns.
We present a two dimensional scheme for classifying agent-oriented patterns. We define agent-oriented pattern attributes and
use these attributes in a process for analyzing and placing agent-oriented patterns within the classification scheme. Using
the proposed classification scheme, we classify 28 patterns written by a variety of agent researchers, chosen from almost
100 patterns which we have studied. 相似文献