4,090 research outputs found
Shell-model half-lives for r-process waiting point nuclei including first-forbidden contributions
We have performed large-scale shell-model calculations of the half-lives and
neutron-branching probabilities of the r-process waiting point nuclei at the
magic neutron numbers N=50, 82, and 126. The calculations include contributions
from allowed Gamow-Teller and first-forbidden transitions. We find good
agreement with the measured half-lives for the N=50 nuclei with charge numbers
Z=28-32 and for the N=82 nuclei 129Ag and 130Cd. The contribution of forbidden
transitions reduce the half-lives of the N=126 waiting point nuclei
significantly, while they have only a small effect on the half-lives of the
N=50 and 82 r-process nuclei.Comment: 14 pages, 17 figures, submitted to Phys. Rev.
On one-sided division infinite-dimensional normed real algebras
In this note we introduce the concept of Cayley homomorphism which is closely related with those of composition algebra and normalized orthogonal multiplication. The key result shows the existente of certain types of Cayley homomorphisms for infinite dimension. As an application we prove the existente of left division infinite-dimensional complete normed real algebras with left unity
Reducing the complexity of a multiview H.264/AVC and HEVC hybrid architecture
With the advent of 3D displays, an efficient encoder is required to compress the video information needed by them. Moreover, for gradual market acceptance of this new technology, it is advisable to offer backward compatibility with existing devices. Thus, a multiview H.264/Advance Video Coding (AVC) and High Efficiency Video Coding (HEVC) hybrid architecture was proposed in the standardization process of HEVC. However, it requires long encoding times due to the use of HEVC. With the aim of tackling this problem, this paper presents an algorithm that reduces the complexity of this hybrid architecture by reducing the encoding complexity of the HEVC views. By using Na < ve-Bayes classifiers, the proposed technique exploits the information gathered in the encoding of the H.264/AVC view to make decisions on the splitting of coding units in HEVC side views. Given the novelty of the proposal, the only similar work found in the literature is an unoptimized version of the algorithm presented here. Experimental results show that the proposed algorithm can achieve a good tradeoff between coding efficiency and complexity
Torsion of Undescended Testis in a 14-Month-Old Child Refusing to Bear Weight
In this report, we discuss a case of a 14-month-old male presenting in the emergency department with refusal to bear weight on his left leg. Plain radiographic studies revealed no evidence of effusion, fracture, or dislocation. Laboratory studies were significant for an elevated white blood cell count, erythrocyte sedimentation rate, and C-reactive protein. Further studies included unremarkable ultrasound of the left hip and normal magnetic resonance imaging (MRI) of both hips. An incidental finding on MRI was a left inguinal mass concerning an incarcerated hernia. Ultrasound of this mass demonstrated a left undescended testis within the inguinal canal and possible incarcerated paratesticular inguinal hernia. The final pathologic diagnosis of a torsed gangrenous left testicle within the inguinal canal was confirmed during surgery
Multirate control strategies for avoiding sample losses. Application to UGV path tracking
When in a digital control strategy there are samples lost due to limitations,
diff t multirate (MR) control options can be used for solving the problem:
Dual-rate inferential control (IC) and model-based dual-rate control (MBDR).
The objective of this contribution is to analyze, compare, and to assess their
behavior under different perspectives. Is a dual-rate inferential control
better than a model-based dual-rate control? Both options lead to a
periodically time-varying discrete-time system and for this reason a lifted
modeling is considered. An efficient algorithm is used for computing a MR
systems frequency response for these control structures. The robust performance
and disturbance effects are studied in detail under sample losses and process
uncertainty, and some considerations are reported. A new QFT (quantitative
feedback theory) procedure for dual-rate systems analysis is also described.
Analysis and simulation examples and experimental results for UGV path tracking
are introduced in this work, revealing that MBDR outperforms IC when the model
contains important uncertainties.Comment: 41 pages, 24 figure
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