973 resultados para Transmission line parameters
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ROTEM(®) is considered a helpful point-of-care device to monitor blood coagulation. Centrally performed analysis is desirable but rapid transport of blood samples and real-time transmission of graphic results are an important prerequisite. The effect of sample transport through a pneumatic tube system on ROTEM(®) results is unknown. The aims of the present work were (i) to determine the influence of blood sample transport through a pneumatic tube system on ROTEM(®) parameters compared to manual transportation, and (ii) to verify whether graphic results can be transmitted on line via virtual network computing using local area network to the physician in charge of the patient.
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Non-destructive, visual evaluation and mechanical testing techniques were used to assess the structural properties of 374 samples of chestnut (Castanea sativa). The principal components method was applied to establish and interpret correlations between variables obtained of modulus of elasticity, bending strength and density. The static modulus of elasticity presented higher correlation values than those obtained using non-destructive methods. Bending strength presented low correlations with the non-destructive parameters, but there was some relation to the different knot ratios defined. The relationship was stronger with the most widely used ratio, CKDR. No significant correlations were observed between any of the variables and density.
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In the present paper the influence of the reference system with regard to the characterization of the surface finishing is analyzed. The effect of the reference system’s choice on the most representative surface finishing parameters (e.g. roughness average Ra and root mean square values Rq) is studied. The study can also be applied to their equivalent parameters in waviness and primary profiles. Based on ISO and ASME standards, three different types of regression lines (center, mean and orthogonal) are theoretically and experimentally analyzed, identifying the validity and applicability fields of each one depending on profile’s geometry.
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Adult Xenopus laevis frogs made transgenic by restriction enzyme-mediated integration were bred to test the feasibility of establishing lines of frogs that express transgenes. All of the 19 animals raised to sexual maturity generated progeny that expressed the transgene(s). The patterns and levels of expression of green fluorescent protein transgenes driven by a viral promoter, rat promoter, and four X. laevis promoters were all unaffected by passage through the germ line. These results demonstrate the ease of establishing transgenic lines in X. laevis.
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An important technology in model organisms is the ability to make transgenic animals. In the past, transgenic technology in zebrafish has been limited by the relatively low efficiency with which transgenes could be generated using either DNA microinjection or retroviral infection. Previous efforts to generate transgenic zebrafish with retroviral vectors used a pseudotyped virus with a genome based on the Moloney murine leukemia virus and the envelope protein of the vesicular stomatitis virus. This virus was injected into blastula-stage zebrafish, and 16% of the injected embryos transmitted proviral insertions to their offspring, with most founders transmitting a single insertion to approximately 2% of their progeny. In an effort to improve this transgenic frequency, we have generated pseudotyped viral stocks of two new Moloney-based genomes. These viral stocks have titers up to two orders of magnitude higher than that used previously. Injection of these viruses resulted in a dramatic increase in transgenic efficiency; over three different experiments, 83% (110/133) of the injected embryos transmitted proviral insertions to 24% of their offspring. Furthermore, founders made with one of the viruses transmitted an average of 11 different insertions through their germ line. These results represent a 50- to 100-fold improvement in the efficiency of generating transgenic zebrafish, making it now feasible for a single lab to rapidly generate tens to hundreds of thousands of transgenes. Consequently, large-scale insertional mutagenesis strategies, previously limited to invertebrates, may now be possible in a vertebrate.
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We present a framework for calculating globally optimal parameters, within a given time frame, for on-line learning in multilayer neural networks. We demonstrate the capability of this method by computing optimal learning rates in typical learning scenarios. A similar treatment allows one to determine the relevance of related training algorithms based on modifications to the basic gradient descent rule as well as to compare different training methods.
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We introduce a novel transmission technique of periodic in-line all-optical format conversion between return-to-zero and non-return-to-zero-like aimed at delaying the accumulation of format-specific impairments. A particular realization of this approach using in-line normal dispersion fibre-enhanced nonlinear optical loop mirrors at 40Gbit/s data rate is presented. © 2004 Optical Society of America.
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Applying direct error counting, we compare the accuracy and evaluate the validity of different available numerical approaches to the estimation of the bit-error rate (BER) in 40-Gb/s return-to-zero differential phase-shift-keying transmission. As a particular example, we consider a system with in-line semiconductor optical amplifiers. We demonstrate that none of the existing models has an absolute superiority over the others. We also reveal the impact of the duty cycle on the accuracy of the BER estimates through the differently introduced Q-factors.
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We analyze a soliton-like phase-shift keying 40-Gb/s transmission system using cascaded in-line semiconductor optical amplifiers. Numerical optimization of the proposed soliton-like regime is presented.
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In this letter, we numerically demonstrate that the use of inline nonlinear optical loop mirrors in strongly dispersion-managed transmission systems dominated by pulse distortion and amplitude noise can achieve all-optical passive 2R regeneration of a 40-Gb/s return-to-zero data stream. We define the tolerance limits of this result to the parameters of the input pulses.
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We numerically demonstrate the feasibility of return-to-zero differential phase-shift keying transmission at 8.0 Gbit/s channel rate using cascaded in-line semiconductor optical amplifiers.
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We introduce a novel transmission technique of periodic in-line all-optical format conversion between return-to-zero and non-return-to-zero-like aimed at delaying the accumulation of format-specific impairments. A particular realization of this approach using in-line normal dispersion fibre-enhanced nonlinear optical loop mirrors at 40Gbit/s data rate is presented.
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All-optical passive regeneration in 40 Gbit/s-based wavelength-division-multiplexed (WDM) dispersion-managed return-to-zero (RZ) transmission system was discussed. In-line nonlinear optical loop mirrors (NOLM) were used. A feasibility of 300 GHz-spaced two channel unlimited transmission and 150 GHz-spaced two channel 25000 km transmission over the standard fiber were found.