4,545 research outputs found
Modeling alpha-nucleus elastic scattering using a velocity-dependent optical potential
We performed a least-square fit analysis to reproduce the elastic angular
distributions for scattering on various nuclei form C to
Pb for incident energies in the range 18 - 70 MeV using a
velocity-dependent potential (VDP). The model reproduced the experimental data
well including the enhanced angular distributions in the large angle scattering
region, which is commonly known as the anomalous large angle scattering (ALAS).
We compared our results to those we obtained by adopting the conventional
optical model. The VDP reproduced the measured data better particularly for
light nuclei and lower incident energies. The angular momentum dependence of
the velocity-dependent potential may have played an important role in
describing the enhanced elastic angular distributions for scattering angles
greater than . Although the ALAS effect is not present in the case of
scattering on the heavy Pb nucleus, we included this case to
demonstrate the effectiveness of the VDP in describing the angular
distributions for scattering on various light, intermediate and heavy
nuclei.Comment: 21 pages, 5 figure
Predicting the Breach Hydrograph Resulting Due to Hypothetical Failure of Haditha Dam
A hydrologic model is developed to compute the reservoir outflow hydrograph resulting from a hypothetical failure of Haditha dam located across the Euphrates river in Iraq due to enemy attack. In this program, the reservoir routing is analyzed by the level pool method in which storage is a nonlinear function of discharge. The results indicate that the maximum reservoir outflow is (202547 m3/s) which occurred about three and half hours after dam failure, and the reservoir will be depleted after about 65 hours. The results of the hydrologic model are compared with available results reported by Macdonald and Monopolis (1984), and it is found that the hydrologic results situate within the limits of their study
Performances Analysis of Exports and Imports of Livestock Commodities in South Sulawesi
This research aim was to evaluate performance of South Sulawesi Province in the implementation of export and import of livestock commodities using such indicators asthe value of export and import, the share value of export, trade balance and ratio. The study was conducted in the Department of Industry and Trade, the Center Statistics Agency, and the Customs and Excise Duty of Makassarusing a combinaton of interview method and literature review.Research results showed that export import performance has improved as indicated by an increase export volume andvalue of livestock commodities, a decrease import volume and value of livestock commodities.The positive trade balance was an indicator of trade domination of livestock commodities, and fluctuated ratio of trading with a tendency to increase. One aspectthat did not show an improvement compared to other non-oil export value of South Sulawesi was export share of livestock commodities
PROPORTIONAL EFFECT OF OUTLIERS ON OVER-DISPERSION
The impact of outlier on analysis of time series data in causing over-dispersion was examined. The problemof overdispersion is central to all General Linear Models (GLM's) having discrete responses. If the estimated dispersion after fitting is not near the expected values, then the data may be over dispersed. One of the causes of overdispersion is outlier. Outlier is a data which is unusual with respect to the group of data in which it is found. In this paper, data were simulated based on poison model using SPSS and first analysed to see whether the estimated parameters is unbiased of the fixed parameters. Thereafter, two different values of outliers, 10's and 20's were introduced to different percentages of the generated data and then analysed using the STATA package to observe the effect of the outliers being introduced on the data for small, moderate and large samples. The data simulated were replicated 300 times for all categories. The averages of the results were computed. The results showed that the higher the percentage of outliers the more the over-dispersion occurs in the models and the larger the sample sizethe less the over-dispersion
Dispersive Optical Interface Based on Nanofiber-Trapped Atoms
We dispersively interface an ensemble of one thousand atoms trapped in the
evanescent field surrounding a tapered optical nanofiber. This method relies on
the azimuthally-asymmetric coupling of the ensemble with the evanescent field
of an off-resonant probe beam, transmitted through the nanofiber. The resulting
birefringence and dispersion are significant; we observe a phase shift per atom
of \,1\,mrad at a detuning of six times the natural linewidth,
corresponding to an effective resonant optical density per atom of 0.027.
Moreover, we utilize this strong dispersion to non-destructively determine the
number of atoms.Comment: 4 pages, 4 figure
Signal-to-noise ratio of Gaussian-state ghost imaging
The signal-to-noise ratios (SNRs) of three Gaussian-state ghost imaging
configurations--distinguished by the nature of their light sources--are
derived. Two use classical-state light, specifically a joint signal-reference
field state that has either the maximum phase-insensitive or the maximum
phase-sensitive cross correlation consistent with having a proper
representation. The third uses nonclassical light, in particular an entangled
signal-reference field state with the maximum phase-sensitive cross correlation
permitted by quantum mechanics. Analytic SNR expressions are developed for the
near-field and far-field regimes, within which simple asymptotic approximations
are presented for low-brightness and high-brightness sources. A high-brightness
thermal-state (classical phase-insensitive state) source will typically achieve
a higher SNR than a biphoton-state (low-brightness, low-flux limit of the
entangled-state) source, when all other system parameters are equal for the two
systems. With high efficiency photon-number resolving detectors, a
low-brightness, high-flux entangled-state source may achieve a higher SNR than
that obtained with a high-brightness thermal-state source.Comment: 12 pages, 4 figures. This version incorporates additional references
and a new analysis of the nonclassical case that, for the first time,
includes the complete transition to the classical signal-to-noise ratio
asymptote at high source brightnes
Efektivitas Komunikasi Pemuka Pendapat Kelompok Tani dalam Menggunakan Teknologi Usahatani Padi (Kasus di Kecamatan Kupang Tengah Kabupaten Kupang NTT)
Communication effectiveness opinion leader of farmer groups in uses rice farming technology: case at KupangTengah district Kupang regency Nusa Tenggara Timur province. The Research objectives are: (1) to expose opinionleader characteristics, as well as using information source, (2) to detect communication effectiveness among opinionleader, (3) to evaluate applying rice farming technology, (4) to analize to relationship among characteristics,information source, and frequency leader to leader employing, communication effectiveness practicing ricetechnology to farmer at Kupang Tengah district Kupang regency Nusa Tenggara Timur province. Research wasdesigned in descriptive correlation survey method. The data was collecting during March to May 2008.Thepopulation was the entire opinion leader from five rice farmer groups. Total respondents were 99 persons. Data wasanalyzed by rank Spearman statistical test. Result indicated: (1) leader characteristics was potentially enough toapply rice technology, (2) mass media utilization as source of information waslimited, (3) introduce rice technologyby leader, indicating more effective, (4) several characteristics factors which are significantly correlated positivelyas well as negatively to communication effectiveness: social participation, formal education, family size, attitude,social status, farm size, mass media utilization and contact to extension agent
Quantum process tomography with coherent states
We develop an enhanced technique for characterizing quantum optical processes
based on probing unknown quantum processes only with coherent states. Our
method substantially improves the original proposal [M. Lobino et al., Science
322, 563 (2008)], which uses a filtered Glauber-Sudarshan decomposition to
determine the effect of the process on an arbitrary state. We introduce a new
relation between the action of a general quantum process on coherent state
inputs and its action on an arbitrary quantum state. This relation eliminates
the need to invoke the Glauber-Sudarshan representation for states; hence it
dramatically simplifies the task of process identification and removes a
potential source of error. The new relation also enables straightforward
extensions of the method to multi-mode and non-trace-preserving processes. We
illustrate our formalism with several examples, in which we derive analytic
representations of several fundamental quantum optical processes in the Fock
basis. In particular, we introduce photon-number cutoff as a reasonable
physical resource limitation and address resource vs accuracy trade-off in
practical applications. We show that the accuracy of process estimation scales
inversely with the square root of photon-number cutoff.Comment: 18 pages, 2 figure
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