983 resultados para Open-circuit voltage


Relevância:

20.00% 20.00%

Publicador:

Resumo:

The article provides a method for long-term forecast of frame alignment losses based on the bit-error rate monitoring for structure-agnostic circuit emulation service over Ethernet in a mobile backhaul network. The developed method with corresponding algorithm allows to detect instants of probable frame alignment losses in a long term perspective in order to give engineering personnel extra time to take some measures aimed at losses prevention. Moreover, long-term forecast of frame alignment losses allows to make a decision about the volume of TDM data encapsulated into a circuit emulation frame in order to increase utilization of the emulated circuit. The developed long-term forecast method formalized with the corresponding algorithm is recognized as cognitive and can act as a part of network predictive monitoring system.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Drosophila Fallen, 1823 (Diptera, Drosophilidae) is for long a well-established model organism for genetics and evolutionary research. The ecology of these flies, however, has only recently been better studied. Recent papers show that Drosophila assemblies can be used as bioindicators of forested environment degradation. In this work the bioindicator potential of drosophilids was evaluated in a naturally opened environment, a coastal strand-forest (restinga). Data from nine consecutive seasonal collections revealed strong temporal fluctuation pattern of the majority of Drosophila species groups. Drosophila willistoni group was more abundant at autumns, whereas D. cardini and D. tripunctata groups were, respectively, expressive at winters and springs, and D. repleta group at both seasons. The exotic species D. simulans Sturtevant, 1919 (from D. melanogaster group) and Zaprionus indianus Gupta, 1970 were most abundant at summers. Overall, the assemblage structure did not show the same characteristics of forested or urban environments, but was similar to the forests at winters and to cities at summers. This raises the question that this locality may already been under urbanization impact. Also, this can be interpreted as an easily invaded site for exotic species, what might lead to biotic homogenization and therefore can put in check the usage of drosophilid assemblages as bioindicators at open environments.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Descriptive memorial of a chronograph made from a common chronoscop (Eastman Timer). The chronoscop has been modified in order to permit to adjust distinct cog-wheels, everyone in its turn, to the axis of the seconds hand. Each of these cog-wheels holds a definite number of teeth accordingly with the time interval ones desire to record. A wheel with 20 teeth, for instance, is available for recording time in periods of each three seconds, another wheel with 6 teeth, will reckon time in intervals of 10 seconds and so on. These wheels may be interchanged most easily, which enables, with the same apparatus, to have at hand a time recorder for any time interval between one and sixty seconds. To register the time the apparatus is connected with a dry cell. A wire is attached to a binding post on the metal case of the apparatus, another wire being connected with an isolated binding post placed in front of the cog-wheel and fastened to a platinum point allowing open or shut the circuit, every time one of the cogs of the wheel comes into contact with this platinum point. A signal magnet is placed also in the circuit for writing the time intervals on the revolving drum.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Combined media on paper. 42" x 87"

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Two claims pervade the literature on the political economy of market reforms: that economic crises cause reforms; and that crises matter because they bring into question the validity of the economic model held to be responsible for them. Economic crises are said to spur a process of learning that is conducive to the abandonment of failing models and to the adoption of successful models. But although these claims have become the conventional wisdom, they have been hardly tested empirically due to the lack of agreement on what constitutes a crisis and to difficulties in measuring learning from them. I propose a model of rational learning from experience and apply it to the decision to open the economy. Using data from 1964 through 1990, I show that learning from the 1982 debt crisis was relevant to the first wave of adoption of an export promotion strategy, but learning was conditional on the high variability of economic outcomes in countries that opened up to trade. Learning was also symbolic in that the sheer number of other countries that liberalized was a more important driver of others’ decisions to follow suit.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

En aquest treball s’implementa un model analític de les característiques DC del MOSFET de doble porta (DG-MOSFET), basat en la solució de l’equació de Poisson i en la teoria de deriva-difussió[1]. El MOSFET de doble porta asimètric presenta una gran flexibilitat en el disseny de la tensió llindar i del corrent OFF. El model analític reprodueix les característiques DC del DG-MOSFET de canal llarg i és la base per construir models circuitals tipus SPICE.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Columnar cell apical membranes (CCAM) in series with goblet cell apical membranes (GCAM) form an electroosmotic barrier separating the midgut lumen from epithelial cell cytoplasm. A unique K+ ATPase in GCAM generates three gradients across this barrier. A greater than 180 mV electrical gradient (lumen positive) drives amino acid uptake through voltage-dependent K+ symports. A greater than 1000-fold [H+] gradient (lumen alkaline) and a greater than 10-fold [K+] gradient (lumen concentrated) are adaptations to the high tannin and high K+ content, respectively, in dietary plant material. Agents which act on the apical membrane and disrupt the PD, H+, or K+ gradients are potential insecticides. Insect sensory epithelia and mammalian stria vascularis maintain similar PD and K+ gradients but would not be exposed to ingested anti-apical membrane insecticides. Following the demonstration by Sacchi et al. that Bacillus thuringiensis delta-endotoxin (Bt) induces specifically a K+ conductance increase in CCAM vesicles, we find that the K+ channel blocking agent, Ba2+, completely reverses Bt inhibition of the K+-carried short circuit current in the isolated midgut of Manduca sexta. Progress in characterizing the apical membrane includes finding that fluorosulfonylbenzoyladenosine binds specifically to certain GCAM polypeptides and that CCAM vesicles can be mass produced by Ca2+ or Mg2+ precipitation from Manduca sexta midgut.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fault tolerance has become a major issue for computer and software engineers because the occurrence of faults increases the cost of using a parallel computer. RADIC is the fault tolerance architecture for message passing systems which is transparent, decentralized, flexible and scalable. This master thesis presents the methodology used to implement the RADIC architecture over Open MPI, a well-know large-used message passing library. This implementation kept the RADIC architecture characteristics. In order to validate the implementation we have executed a synthetic ping program, besides, to evaluate the implementation performance we have used the NAS Parallel Benchmarks. The results prove that the RADIC architecture performance depends on the communication pattern of the parallel application which is running. Furthermore, our implementation proves that the RADIC architecture could be implemented over an existent message passing library.