376 research outputs found
Form factors and decay rate of decays in the QCD sum rules
Rare exclusive decays are analyzed in
the framework of the three--point QCD sum rules approach. The two gluon
condensate corrections to the correlation function are included and the form
factors of this transition are evaluated. Using the form factors, the decay
width and integrated decay rate for these decays are also calculated.Comment: 17 pages, 3 figure
Multi-Dimensional Cosmology and GUP
We consider a multidimensional cosmological model with FRW type metric having
4-dimensional space-time and -dimensional Ricci-flat internal space sectors
with a higher dimensional cosmological constant. We study the classical
cosmology in commutative and GUP cases and obtain the corresponding exact
solutions for negative and positive cosmological constants. It is shown that
for negative cosmological constant, the commutative and GUP cases result in
finite size universes with smaller size and longer ages, and larger size and
shorter age, respectively. For positive cosmological constant, the commutative
and GUP cases result in infinite size universes having late time accelerating
behavior in good agreement with current observations. The accelerating phase
starts in the GUP case sooner than the commutative case. In both commutative
and GUP cases, and for both negative and positive cosmological constants, the
internal space is stabilized to the sub-Planck size, at least within the
present age of the universe. Then, we study the quantum cosmology by deriving
the Wheeler-DeWitt equation, and obtain the exact solutions in the commutative
case and the perturbative solutions in GUP case, to first order in the GUP
small parameter, for both negative and positive cosmological constants. It is
shown that good correspondence exists between the classical and quantum
solutions.Comment: 21 pages, 15 figures, minor revision, references adde
MULTI-DIMENSIONAL COSMOLOGY AND DSR–GUP
A multi-dimensional cosmology with FRW type metric having four-dimensional spacetime and d-dimensional Ricci-flat internal space is considered with a higher-dimensional cosmological constant. The classical cosmology in commutative and Doubly Special Relativity–Generalized Uncertainty Principle (DSR–GUP) contexts is studied and the corresponding exact solutions for negative and positive cosmological constants are obtained. In the positive cosmological constant case, it is shown that unlike the commutative as well as GUP cases, in DSR–GUP case both scale factors of internal and external spaces after accelerating phase will inevitably experience decelerating phase leading simultaneously to a big crunch. This demarcation from GUP originates from the difference between the GUP and DSR–GUP algebras. The important result is that unlike GUP which results in eternal acceleration, DSR–GUP at first generates acceleration but prevents the eternal acceleration at late-times and turns it into deceleration
Exclusive B \rar \rho \ell^+ \ell^- Decay in the Standard Model with Fourth--Generation
We investigate the influence of the fourth generation of quarks on the
branching ratio, the CP-asymmetry and the polarization asymmetries in B \rar
\rho \ell^+ \ell^- decay. Taking with phase about
, which is consistent with the of the CKM and the
mixing parameter , we obtain that for both ()
channels the branching ratio is increased and the magnitude of CP-asymmetry and
polarization asymmetries decreased by the mass and mixing parameters of the 4th
generation of quarks . These results can serve as a good tool to search for new
physics effects, precisely, to search for the fourth generation of quarks( via its indirect manifestations in loop diagrams.Comment: 17 pages, 7 figure
Two Jets Flow Attack-Induced Turbulence
Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv
The study of the relationship between managers’ roles and motivation among personnel
In addition to doing their organizational tasks, the managers play their roles such as interpersonal, communicative, and decision making roles. On the other hand, properly perceived management toward personnel’s motivation may also serve as a valuable tool in order to recognize the reasons for behavior in organizations and prediction of the impact of their administrative measures. In this sense, the current investigation deals with study on the relationship between the roles of managers and creation of motive among personnel. The research statistical population comprises of all personnel of Mashiz Gharzolhasaneh and saving fund branches in Kerman province (Iran) where 196 of them were chosen as sample group by means of statistical formula. Data were collected by means of questionnaire and with simple randomized sampling technique. Research findings showed that there is less correlation between interpersonal roles and creation of motive compared to managers’ roles while the maximum correlation corresponds to communicative roles and motivation. Similarly, there is also relatively high correlation between roles of decision making and motivation
The study of the relationship between managers’ roles and motivation among personnel
In addition to doing their organizational tasks, the managers play their roles such as interpersonal, communicative, and decision making roles. On the other hand, properly perceived management toward personnel’s motivation may also serve as a valuable tool in order to recognize the reasons for behavior in organizations and prediction of the impact of their administrative measures. In this sense, the current investigation deals with study on the relationship between the roles of managers and creation of motive among personnel. The research statistical population comprises of all personnel of Mashiz Gharzolhasaneh and saving fund branches in Kerman province (Iran) where 196 of them were chosen as sample group by means of statistical formula. Data were collected by means of questionnaire and with simple randomized sampling technique. Research findings showed that there is less correlation between interpersonal roles and creation of motive compared to managers’ roles while the maximum correlation corresponds to communicative roles and motivation. Similarly, there is also relatively high correlation between roles of decision making and motivation
Mobile data acquisition and processing in support of an urban heat island study
Global warming and changes in Earth’s weather patterns are the main consequences of climate change, and bioclimate discomfort has significant public health problems, especially for the elderly. Normally, the thermal characteristics of urban areas are poor due to a phenomenon known as urban heat island. Mobile and fixed temperature measurements were performed on 19 March 2021 in the city of Bologna, Italy. Mobile measurements took place with a car, along a 75-km transect, starting at 22:16 with a duration of 2 hours and 41 minutes, while fixed measurements were done using 15 present weather stations and also placing five thermometers in the city center. Various interpolation models (i.e., Traditional, Voronoi Tessellation, Global Trends, Triangulated Irregular Networks, Inverse Distance Weighting and Kriging) were applied to correct the mobile measurements using fixed data. Kriging fulfilled the best result with a correlation coefficient of 0.99 compared to the raw temperatures
BOLA360: Near-optimal View and Bitrate Adaptation for 360-degree Video Streaming
Recent advances in omnidirectional cameras and AR/VR headsets have spurred
the adoption of 360-degree videos that are widely believed to be the future of
online video streaming. 360-degree videos allow users to wear a head-mounted
display (HMD) and experience the video as if they are physically present in the
scene. Streaming high-quality 360-degree videos at scale is an unsolved problem
that is more challenging than traditional (2D) video delivery. The data rate
required to stream 360-degree videos is an order of magnitude more than
traditional videos. Further, the penalty for rebuffering events where the video
freezes or displays a blank screen is more severe as it may cause
cybersickness. We propose an online adaptive bitrate (ABR) algorithm for
360-degree videos called BOLA360 that runs inside the client's video player and
orchestrates the download of video segments from the server so as to maximize
the quality-of-experience (QoE) of the user. BOLA360 conserves bandwidth by
downloading only those video segments that are likely to fall within the
field-of-view (FOV) of the user. In addition, BOLA360 continually adapts the
bitrate of the downloaded video segments so as to enable a smooth playback
without rebuffering. We prove that BOLA360 is near-optimal with respect to an
optimal offline algorithm that maximizes QoE. Further, we evaluate BOLA360 on a
wide range of network and user head movement profiles and show that it provides
to more QoE than state-of-the-art algorithms. While ABR
algorithms for traditional (2D) videos have been well-studied over the last
decade, our work is the first ABR algorithm for 360-degree videos with both
theoretical and empirical guarantees on its performance.Comment: 25 page
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