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991.
992.
Expert systems is a rapidly developing application of artificial intelligence technology for the capture and dissemination of human knowledge. A number of very practical implementations of knowledge bases have been achieved, using program shells which are quite accessible by people other than programmers. Since college business students have a high probability of encountering expert systems in the workplace, it is appropriate that their curriculum expose them to this expanding arena. This paper presents an expert system demonstration designed to provide a hands-on educational environment for allowing students to explore the capabilities of artificial intelligence in business organizations. 相似文献
993.
1 group of 6 overweight undergraduates received 6 sessions of covert sensitization. A 2nd similar group received 6 sessions of a realistic attention-control condition, while a 3rd group served as nontreated controls. At the end of treatment, covert sensitization Ss reporting the greatest reaction to the imagined scene showed greater weight loss than the attention-control and control groups. At a 6-wk follow-up, the treatment effect including all covert sensitization Ss was highly significant. Self-report measures indicate that covert sensitization Ss perceived their treatment positively and were highly motivated. Anxiety reduction and weight loss were found to be uncorrelated. Results offer considerable support for the efficacy of covert sensitization in the treatment of obesity. (29 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
994.
A detailed study of the variation of properties and characteristics of Victorian brown coal both within seams and between fields has been carried out. Within a seam, the organic coal properties are lithotype dependent whilst the exchangeable inorganic elements, Na, Mg, Ca and Fe, show no relation to lithotype and, hence, are believed to be of post-depositional origin. Considerable variation in coal properties between different brown coal fields has been demonstrated by analyses of 219 samples from 10 coal fields. The coal properties which correlate best with hydrogenation reactivity are primarily associated with the hydrogen content of the coal. The mineral matter also influences the hydrogenation reactivity, as demonstrated by the occurrence of the value for ash level in multiple linear regression equations. 相似文献
995.
If coating solutions obtained by dissolving poly(p-trimethylsiloxystyrene) together with one of the salts (C6H5)2(C6H5SC6H4)SSbF6 or (C6H5)3SAsF6 in a solvent such as 3-pentanone are aged, the percentage of O? Si(CH3)3 bonds cleaved by irradiation at a given intensity (λ = 254 nm) and after post-annealing depends on the amount of salt introduced. The same result is observed with respect to the solubility of the resist when it is treated with the basic solvent MF-319. 相似文献
996.
997.
C Racine R Rey MG Forest F Louis A Ferré I Huhtaniemi N Josso N di Clemente 《Canadian Metallurgical Quarterly》1998,95(2):594-599
Strong overexpression of anti-Müllerian hormone (AMH) in transgenic mice leads to incomplete fetal virilization and decreased serum testosterone in the adult. Conversely, AMH-deficient mice exhibit Leydig cell hyperplasia. To probe the mechanism of action of AMH on Leydig cell steroidogenesis, we have studied the expression of mRNA for steroidogenic proteins in vivo and in vitro and performed a morphometric analysis of testicular tissue in mice overexpressing the hormone. We show that overexpression of AMH in male transgenic mice blocks the differentiation of Leydig cell precursors. Expression of steroidogenic protein mRNAs, mainly cytochrome P450 17 alpha-hydroxylase/C17-20 lyase (P450c17), is decreased in transgenic mice overexpressing AMH and in AMH-treated purified Leydig cells. In contrast, transgenic mice in whom the AMH locus has been disrupted show increase expression of P450c17. In vitro, but not in vivo, AMH also decreases the expression of the luteinizing hormone receptor. The effect of AMH is explained by the presence of its receptor on Leydig cells. Our results provide insight into the action of AMH as a negative modulator of Leydig cell differentiation and function. 相似文献
998.
Yvon Erhel Alexis Bisiaux Dominique Lemur Louis Bertel François Marie 《电信纪事》2002,57(11-12):1036-1058
This paper presents an operational system of digital transmission within the h.f. frequency range, aiming at a significant increase of the data transfer rate compared with the current standard (4800 bit/s). Therefore, an array processing algorithm performs with a set of collocated sensors, the spatial responses of which are different one from each other. The dependence of the incoming polarization relatively to the direction of arrival induces a significant decorrelation of the received signals though no geometrical phase exists. Signal processing techniques run at the output of the spatial filter resorting for the synchronisation and the filtering (lms algorithm) to classical and well-tested techniques involving training sequences. An experimental radio link with a 250 km range has been set up to test the sensibility of the performances in reception regarding the choice of waveforms. The operational results reach the expected goal as the data transfer rate increases up to 20 kbit/s in a bandwidth of 6 kHz. 相似文献
999.
1000.
Rogers Ronald F.; Talk Andrew C.; Matzel Louis D. 《Canadian Metallurgical Quarterly》1994,108(6):1030
In behaving Hermissenda, a preparatory conditioned response developed across repeated pairings of light (conditioned stimulus; CS) and rotation (unconditioned stimulus; US) with intertrial intervals (ITIs) of 60 and 120 s, but not 30 s. Likewise, contiguous in vitro stimulation of the visual and vestibular receptors, an analog of behavioral conditioning, resulted in an increase in the input resistance (i.e., excitability, a correlate of conditioning) of the B photoreceptors of the Hermissenda's eye, but only with ITIs greater than 60 s. Calcium signaling in the B cell, critical to the induction of this neuronal plasticity, was attenuated with shorter ITIs owing to (a) a reduction of the light-induced generator potential and hence voltage-dependent Ca2+ influx during the light CS, (b) a depression of the Ca2+ current that persisted throughout shorter ITIs, and (c) a steady-state inactivation of the Ca2+ current as a result of a sustained depolarization persisting from the previous trial. These results are consistent with a 2-process theory of associative learning in which a primary process (Ca2+ influx) may be opposed by a secondary process (depression of the Ca2+ current) during short ITIs. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献