2,101 research outputs found
Non-Zero and in a Neutrino Mass Model with Symmetry
In this paper, we consider a neutrino mass model based on symmetry. The
spontaneous symmetry breaking in this model is chosen to obtain tribimaximal
mixing in the neutrino sector. We introduce invariant
perturbations in this model which can give rise to acceptable values of
and . Perturbation in the charged lepton sector
alone can lead to viable values of , but cannot generate
. Perturbation in the neutrino sector alone can lead to acceptable
and maximal CP violation. By adjusting the magnitudes of
perturbations in both sectors, it is possible to obtain any value of
.Comment: 16 pages, 3 figure
Measuring the impact of the investment climate on total factor productivity : the cases of China and Brazil
This study measures the impact of investment climate factors on total factor productivity (TFP) of firms in Brazil and China. The analysis is conducted in two steps: first an econometric production function is estimated to produce a measure of TFP at the firm level. In the second step, variation in TFP across firms is statistically related to a indicators of the investment climate as well as firm characteristics. The results yield a number of insights about the factors underlying productivity. In both countries, and in a variety of industry groups, indicators of poor investment climate, especially delays in customs clearance and interruptions in utility services, have significant negative effects on TFP. Reducing customs clearance time by one day in China could increase TFP by 2-6 percent. Indicators such as email usage have positive effects on TFP. In the case of China, state-owned firms and firms located in the interior are shown to be much less productive than privately owned firms and firms located in the east. In Brazil, the results present an interesting contrast between the apparel industry and the electronics industry. In the apparel industry, older firms in competitive markets are more productive, while in the case of electronics, newer firms with higher market shares are more productive.Economic Theory&Research,Technology Industry,Water and Industry,ICT Policy and Strategies,Economic Growth
Discovery of Blue Luminescence in the Red Rectangle: Possible Fluorescence from Neutral Polycyclic Aromatic Hydrocarbon Molecules?
Here we report our discovery of a band of blue luminescence (BL) in the Red
Rectangle (RR) nebula. This enigmatic proto-planetary nebula is also one of the
brightest known sources of extended red emission as well as of unidentified
infra-red (UIR) band emissions. The spectrum of this newly discovered BL is
most likely fluorescence from small neutral polycyclic aromatic hydrocarbon
(PAH) molecules. PAH molecules are thought to be widely present in many
interstellar and circumstellar environments in our galaxy as well as in other
galaxies, and are considered likely carriers of the UIR-band emission. However,
no specific PAH molecule has yet been identified in a source outside the solar
system, as the set of mid-infra-red emission features attributed to these
molecules between the wavelengths of 3.3 micron and 16.4 micron is largely
insensitive to molecular sizes. In contrast, near-UV/blue fluorescence of PAHs
is more specific as to size, structure, and charge state of a PAH molecule. If
the carriers of this near-UV/blue fluorescence are PAHs, they are most likely
neutral PAH molecules consisting of 3-4 aromatic rings such as anthracene
(C14H10) and pyrene (C16H10). These small PAHs would then be the largest
molecules specifically identified in the interstellar medium.Comment: 4 pages, 4 figures, Accepted for publication in ApJL (LaTeX, uses
emulateapj.sty
समुद्री जैवविविधता - चुनौतियाँ एवं समाधान
समुद्री जैवविविधता - चुनौतियाँ एवं समाधा
The effect of a light radion on the triviality bound on higgs mass
In this paper we study how the triviality bound on higgs mass in the context
of the SM is modified by a light stabilized radion of the Goldberger-Wise
variety. Our approach is inherently perturbative. Including the radion
contribution to \bt(\l) and \bt(g_t) to one loop we evolve the higgs self
coupling \l from the cut off \L(=\vphi) down to the EW scale .
The triviality bound is obtained by requiring that \l(\L) = \sqrt{4 \pi}
which is the perturbative limit. We also study the effect of small changes in
the UVBC on the triviality bound both in the presence and absence of a light
radion.Comment: 9 pages, latex, 2 eps figure
Distribuirani obrambeni mehanizmi za clone napade temeljeni na algoritmu za istraživanje gravitacije (GSA) u WSN
Wireless Sensor Networks (WSN) are often deployed in hostile environment and are vulnerable to attacks because of the resource constrained nature of the sensors. Clone attack in WSN is one of the major issues where the messages are eavesdropped, the captured node is cloned, and multiple nodes with same identity are produced by attacker. In order to overcome these issues, in this paper, a Distributed Defense Mechanism for Clone Attacks based on Gravitational Search Algorithm (GSA) in WSN is proposed. For efficiently detecting the suspect nodes, the nodes in the channel can be divided into witness node and the claimer node. The witness nodes are responsible for the suspect nodes detection, whereas the claimer nodes should provide their identities for the detection process. For the witness nodes selection, we utilize the GSA to pick out the best witness nodes set. After selecting the witness nodes, clone attack detection is performed by observing the behavior of the neighbor nodes. On detecting the clone attack, revocation procedure is triggered to revoke the clone attack in the witness nodes. By simulation results, it can be concluded that the proposed algorithm provides better protection to clone attacks by reducing the packet drop and increasing the packet delivery ratio.Bežične senzorske mreže (WSN) često su raspoređene u neprijateljskom okruženju i ranjive su na napade zbog prirode senzora koji su tehnološki ograničeni. Clone napad u WSN jedan je od glavnih problema gdje se poruke prisluškuju, zarobljeni čvor se klonira te napadač proizvede višestruke čvorove istog identiteta. Kako bi nadvladali te probleme, ovaj rad predlaže distribuirani obrambeni mehanizam za clone napade temeljen na algoritmu za istraživanje gravitacije (GSA) u WSN. Kako bi se sumnjivi čvorovi efikasno detektirali, čvorovi u kanalu mogu se podijeliti u čvorove svjedoke i tražene čvorove. Čvorovi svjedoci odgovorni su za otkrivanje sumnjivih čvorova, dok traženi čvorovi trebaju za potrebe procesa detekcije navesti svoj identitet. Za izbor čvorova svjedoka, koristi se GSA kako bi se izabrala grupa čvorova koji su najprikladniji. Nakon izbora čvorova svjedoka, otkivanje clone napada vrši se promatranjem ponašanja susjednih čvorova. Otkrivanjem clone napada aktivira se proces opoziva kako bi se opozvao clone napad u čvorovima svjedocima. Prema rezultatima dobivenim iz simulacije može se zaključiti kako predloženi algoritam pruža bolju zaštitu od clone napada smanjivanjem odbacivanja paketa i povećavanjem omjera isporuke paketa
Studies on Mixed Ligand Complexes Containing β-Dicarbonyls: Part II - Complexes of Cu(II) & Ni(II)
324-32
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