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101.
The growing popularity of the information superhighway has opened up exciting opportunities for companies looking to, not only maintain their current customer base, but also to reach new customers. One of the most popular methods to enter into cybermarketing has been to establish a home page or Web site on the Internet. Almost two-thirds of Fortune 500 companies currently maintain home pages on the Web. An analysis of the content of corporate home pages provides useful insights. Over four-fifths of the companies display products and services (93.2%) and company overview (86.1%) information. Roughly three-fourths of the companies present interactive feedback (79.3%) and what's new (71.1%). Less than one-third (26.2%) of Fortune 500 companies provide for online business. An analysis of the data also provides valuable insight into the future trends of home page usage by large business organizations. 相似文献
102.
tienne Fortin Jean-Franois Chatelain Louis Rivest 《Computers & Industrial Engineering》2004,46(4):655-667
Over the years, machine tool evolution has allowed faster equipment, using new configurations, to manufacture parts that were almost impossible to machine in the past. Despite this tremendous evolution in machine and control technologies, the metalworking industry is still using the old ISO 6983 G-Codes programming interface to control the motion of these machines. This programming interface is not the most flexible or most appropriate for use by new open-architecture machine controllers and object-oriented high-level machining interfaces such as ISO 14649 (STEP-NC). This work proposes an innovative language, the ‘Base Numerical Control Language (BNCL),’ which is based on a low-level simple instruction set-like approach. The architecture is designed around two concepts: the BNCL virtual machine, which acts as a virtual microprocessor, and the BNCL virtual hardware, which is an abstraction of the machine tool. The language is characterised by its simplicity and flexibility, two qualities that are critical in a market in which the capabilities and performance of machines are constantly improving. The proposed architectural concepts are validated through various computer simulation and physical tests, including performance throughput, trajectory driving, and CNC controller extension capabilities. 相似文献
103.
Louis Wang Gang Feng 《IEEE transactions on systems, man, and cybernetics. Part B, Cybernetics》2004,34(1):682-686
This paper presents a new H infinity controller design method for the discrete time fuzzy systems based on the piecewise Lyapunov functions. The basic idea of the proposed approach is to construct the controller for the fuzzy systems in such a way that a discrete time piecewise Lyapunov function can be used to establish the global stability with H infinity-disturbance attenuation performance of the resulting close loop fuzzy control systems. It is shown that the control laws can be obtained by solving a set of linear matrix inequalities (LMIs) that is numerically tractable with commercially available software. Numerical example is given to demonstrate the advantage of the proposed method. 相似文献
104.
研究了贝叶斯频谱估计的基本理论和基本方法 ,分别对无噪声和有噪声的简谐正弦信号进行了频谱估计。计算结果显示 :无噪声信号频率估计偏倚为零 ;当信号噪声系数S/N =1时 ,贝叶斯频率估计的偏倚与Jaynes的理论值一致 相似文献
105.
Diguer Louis; Pelletier Sylvie; Hébert étienne; Desc?teaux Jean; Rousseau Jean-Pierre; Daoust Jean-Philippe 《Canadian Metallurgical Quarterly》2004,21(2):259
This study examined the hypothesis that psychotic, borderline, and neurotic personality organizations (POs) present a progressive differentiation between self and object representations and an increasing integration of their bad and good aspects. Fifty patients participated in the study. Measures included scales of self and object representations (S. J. Blatt, S. A. Bers, & C. E. Schaffer, 1993; S. J. Blatt, H. Wiseman, E. Prince-Gibson, & C. Gatt, 1991), as well as the Personality Organization Diagnostic Form (L. Diguer & L. Normandin, 1997) and estimations of psychiatric severity. Results showed that PO groups differed in terms of the integration of the object and its valence. It was also observed that although object and self representations were closely intertwined, the latter showed more discrimination between POs than the former. Psychiatric severity was shown to correlate more with object representations than self representations. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
106.
Beardsley Patrick M.; Aceto Mario D.; Cook Charles D.; Bowman Edward R.; Newman Jennifer L.; Harris Louis S. 《Canadian Metallurgical Quarterly》2004,12(3):163
Despite oxycodone's (4,5-epoxy-14-hydroxy-3-methoxy-17-methylmorphinan-6-one) history of clinical use and the attention it has received as a drug of abuse, few reports have documented its pharmacology's relevance to its abuse or its mechanism of action. The purposes of the present study were to further characterize the analgesic effects of oxycodone, its mechanism of action, and its effects in terms of its relevance to its abuse liability. The results indicate that oxycodone had potent antinociceptive effects in the mouse paraphenylquinone writhing, hot-plate, and tail-flick assays, in which it appeared to be acting as a μ-opioid receptor agonist. It generalized to the heroin discriminative stimulus and served as a positive reinforcer in rats and completely suppressed withdrawal signs in morphinedependent rhesus monkeys. These results suggest that the analgesic and abuse liability effects of oxycodone are likely mediated through μ-opioid receptors and provide the first laboratory report of its discriminative stimulus, reinforcing, and morphine cross-dependency effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
107.
Friction and adhesion measurements between surfaces of cross-linked, stiff polymers of varying roughness against smooth, bare
mica surfaces were carried out in dry air as well as in the presence of lubricating oil. The nominal (macroscopic) contact
area varies with the applied load according to the Johnson, Kendall and Roberts (JKR) theory, yet shows significant hysteresis
due to the irreversibility arising from the loading/unloading curves of multiple asperities. Upon introducing the oil between
the surfaces, the critical shear stress is reduced to zero due to the elimination of the adhesion force. However, the effect
is less noticeable on the friction coefficient. Lastly, the effect of increasing the (RMS) roughness was greatest over the
first few nanometers due to the diminution of the adhesion-controlled contribution to the friction, after which a further
increase in roughness had less dramatic effects. A model is presented to account for the observed adhesion hysteresis during
repeated loading/unloading cycles of purely elastically deforming rough surfaces.
Bruno Zappone and Kenneth J. Rosenberg made equal contributions. 相似文献
108.
Pabitra K. Nayak Ron Rosenberg Lee Barnea-Nehoshtan David Cahen 《Organic Electronics》2013,14(3):966-972
Contact potential difference (CPD) measurements of the relative work functions of a range of organic semiconductor thin films show that oxygen causes effective p-type doping (with work functions increasing 0.1–0.3 eV). This doping effect is found to be reversible by exposure to high vacuum or heating in inert atmosphere. The mechanism of doping is explained by a model, based on a reversible formation of an O-substrate charge transfer state. Conductivity measurements of p-phthalocyanine films at variable temperatures support this doping model. The oxygen doping effect is consistent with filling of tail states in the gap, as shown by the increase of activation energy of hole transport with decreased O-doping, and by the good fit between experimental data and simulations of the in-gap density of states. A model hybrid solar cell configuration also shows the effect of doping by O2 and corroborates the fact that O-doping fills the tail states in the system. 相似文献
110.
Louis Kruh 《Cryptologia》2013,37(2):78-82
The third Britisher who, in addition to Alastair Denniston and Dillwyn Knox, met the Poles near Pyry in 1939 to to receive a copy of the Enigma machine has been wrongly identified as Stewart Menzies, head of the British foreign Intelligence service. In fact he was Humphrey Sandwith, head of the Admiralty's interception and direction-finding service. 相似文献