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91.
Palliative treatment of head and neck cancers needs an initial evaluation based upon clinical symptoms and tumoral behaviour. Local recurrences are the most frequent presentation of tumoral failures. The therapeutic management of these local recurrences requires a mixture of unspecific and specific oncologic procedures. Radiotherapy and chemotherapy are frequently used in those circumstances in order to reduce the tumoral volume and to facilitate the effectiveness of unspecific treatments. Management of metastatic disease is often impaired by the moderate efficiency of chemotherapy while this treatment leads to marked side effects. Basically, the best therapeutic choice depends on the expected positive balance between the improvement of symptoms and the level of treatment-related side effects. However, daily clinical approach is a better way to care these patients than predefined rigid protocols. 相似文献
92.
Remedial services for children with reading problems are often allocated according to discrepancies between reading and IQ scores. Results of some recent research suggest, however, that IQ scores of poor readers do not covary with their levels of functioning in other cognitive domains. This study evaluated whether the external validity of IQ scores (from the Wechsler Intelligence Scale for Children—Revised [WAIS—R]) was moderated by reading levels within 2 separate samples of a total of 382 referred children (aged 7–16 yrs). It was found that IQ scores had expected correlations with external measures of verbal, visual-spatial, short-term memory, and arithmetic ability, and that these relations were invariant across levels of reading skill. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
93.
This article critically analyzes social psychology's assumption that psychological states can explain social behavior. On the basis of an analysis of the logic of classification systems, the author argues that there are no procedures available to independently verify the existence of these psychological states. As a consequence, explanations of social behavior are subject to continual challenge and replacement. Furthermore, it is argued that focusing on psychological states serves to inhibit the systematic study of societal changes (particularly changes in technology) that are affecting and shaping all aspects of human existence. This article describes an alternate paradigm that coordinates one dimension of societal events—technology—with changes in people's consciousness and subsequent behavior. A taxonomy of technology is described in the closing section of the article. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
94.
Adaptive inverse filters for stereophonic sound reproduction 总被引:1,自引:0,他引:1
A general theoretical basis for the design of adaptive digital filters used for the equalization of the response of multichannel sound reproduction systems is described. The approach is applied to the two-channel case and then extended to deal with arbitrary numbers of channels. The intention is to equalize not only the response of the loudspeakers and the listening room but also the crosstalk transmission from right loudspeaker to left ear and vice versa. The formulation is a generalization of the Atal-Schroeder crosstalk canceler. However, the use of a least-squares approach to the digital filter design and of appropriate modeling delays potentially allows the effective equalization of nonminimum phase components in the transmission path. A stochastic gradient algorithm which facilitates the adaptation of the digital filters to the optimal solution, thereby providing the possibility of designing the filters in situ, is presented. Some experimental results for the two-channel case are given 相似文献
95.
There is ample evidence that people cannot generate random series when instructed to do so. Rather, they produce sequences with too few symmetries and long runs and too many alternations among events. The authors propose a psychological theory to account for these findings, which assumes that subjects generate nonrandom sequences that locally represent theoretical random series subject to a constraint on their short-term memory. Closed-form expressions are then derived for the major statistics that have been used to test for deviations from randomness. Results from 3 experiments with 2 and 3 equiprobable alternatives support the model on both the individual and group levels. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
96.
97.
Jue Donald; Meador Kimford J.; Zamrini Edward Y.; Allen Martha E.; Feldman Daniel S.; Loring David W. 《Canadian Metallurgical Quarterly》1992,6(4):331
Studied memory for visuospatial arrays in 28 male and 34 female healthy dextral adults (aged 20–90 yrs). 10 abstract figures were presented in each hemispace over a series of learning trials, and then delayed free recall of figure placement was obtained. Figures were misplaced significantly downward and leftward in both hemispaces. Both vertical and horizontal absolute error increased significanty with age, but no age effects on directional errors were observed. The increase in absolute error over age is consistent with decreased anterograde memory and visuospatial skills in the elderly. The directional errors are believed to result from an attentional shift toward proximal peripersonal space, in combination with attentional shifts from differential left vs right cerebral activation. Gender effects were also observed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
98.
David Sanborn Scott 《International Journal of Hydrogen Energy》2003,28(12):1303-1306
99.
Fault-accommodation with intelligent sensors 总被引:1,自引:0,他引:1
Giacomo Tortora Author Vitae Author Vitae David Clarke Author Vitae 《Automatica》2003,39(7):1227-1233
Optimal sensor fault-accommodation is considered for faults modelled by an increase in measurement noise. This noise is taken to be bounded and its probabilistic properties unknown. It is assumed that intelligent (e.g. self-validating) instrumentation is in use and estimates of the noise bounds are available. The fault-tolerant controller is designed to optimize a noise rejection and a nominal reference tracking index and leads to a mixed norm minimization problem (l1/l2). We exploit known results and a particular feedback configuration to show that it is possible to optimize simultaneously without a trade-off the two performance indices. The results are applied to systems where the presence of auxiliary measurements allows for an optimal fault-accommodation strategy. Using properties of the optimal solution, we define a factorization for the optimal controller alternative to the Youla parametrization, leading to an algorithm which is optimal, transparent and efficient. 相似文献
100.
David Duke 《Network Security》2003,2003(2):4-8
Anti-virus (AV) products and other fingerprint-based systems are typical of the applications used to enforce security. AV products are probably the first step that most organizations take to protect their systems and enhance security. Many small to medium organizations rely almost entirely on AV products. 相似文献