Curvature corrections and topology change transition in brane-black hole systems: A perturbative approach

2009 ◽  
Vol 80 (10) ◽  
Author(s):  
Viktor G. Czinner ◽  
Antonino Flachi
Keyword(s):  
Black Hole ◽  
Topology Change ◽  
Perturbative Approach ◽  
And Topology

Optimization of profile and damping layer of plates embedded with acoustic black hole indentations for broadband energy dissipation

2022 ◽  
pp. 1045389X2110721
Author(s):  
Wei Huang ◽  
Chongcong Tao ◽  
Hongli Ji ◽  
Jinhao Qiu
Keyword(s):  
Black Hole ◽  
Energy Dissipation ◽  
Vibration Suppression ◽  
Optimal Solution ◽  
Simultaneous Optimization ◽  
Optimal Arrangement ◽  
Focusing Effect ◽  
Upper Limit ◽  
And Topology ◽  
Design Variables

Acoustic Black Hole (ABH) plate structure has shown promising potentials of vibration suppression above a cut on frequency. For energy dissipation below the cut on frequency, however, the ABH is less effective due to the absence of wave focusing effect. This work reports a simultaneous optimization of ABH plates for broadband energy dissipation. Two sets of design variables of ABH plates, that is, geometry of the profile and topology of the damping layer, are optimized in an alternatively nested procedure. A novel objective function, namely the upper limit of kinetic energy, is proposed. Modeling of ABH structures is implemented and dynamic characteristic is solved using finite element method. A rectangular plate embedded with two ABH indentations is presented as a numerical example. Influence of frequency ranges in the calculation and mass ratios of the damping layer on results are discussed. The achieved optimal arrangement of the damping layer is found to cover equally, if not more, above the non-ABH (uniform) part of the plate than the ABH area. This is inconsistent with the conventional believe that damping layers should cover as much of the ABH area as possible. Mechanism of the broadband energy dissipation by the optimal solution is demonstrated.

RESEARCH OF METHODS FOR DECREASE OF THE CAPACITANCE RATIO IN THE STW-RESONATORS

2021 ◽  
pp. 43-56
Author(s):  
S. A. Dobershtein ◽  
N. M. Zhilin ◽  
I. V. Veremeev
Keyword(s):  
Experimental Data ◽  
Quality Factor ◽  
Quality Factors ◽  
Topology Change ◽  
Series Connection ◽  
Capacitance Ratio ◽  
And Topology

This paper presents the research of methods for decrease of the capacitance ratio in the STW-resonators without significant degradation of the quality factor by use of the external inductors and topology change: IDT division on parts and their series connection. The calculated and experimental data are presented for 416 MHz and 766 MHz STW-resonators with quality factors Q = 7000–7978. The capacitance ratio has been reduced from 1200 to 301.

scholarly journals Quantum gravity as a multitrace matrix model

2017 ◽  
Vol 32 (31) ◽  
pp. 1750180
Author(s):  
Badis Ydri ◽  
Cherine Soudani ◽  
Ahlam Rouag
Keyword(s):  
Quantum Gravity ◽  
Matrix Models ◽  
Large Class ◽  
Matrix Model ◽  
Two Dimensions ◽  
Two Dimensional ◽  
Topology Change ◽  
New Model ◽  
And Topology ◽  
Emergent Geometry

We present a new model of quantum gravity as a theory of random geometries given explicitly in terms of a multitrace matrix model. This is a generalization of the usual discretized random surfaces of two-dimensional quantum gravity which works away from two dimensions and captures a large class of spaces admitting a finite spectral triple. These multitrace matrix models sustain emergent geometry as well as growing dimensions and topology change.

scholarly journals Programming Protocol-Independent Packet Processors High-Level Programming (P4HLP): Towards Unified High-Level Programming for a Commodity Programmable Switch

Electronics ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 958 ◽  
Author(s):  
Zijun Hang ◽  
Mei Wen ◽  
Yang Shi ◽  
Chunyuan Zhang
Keyword(s):  
Programming Language ◽  
Building Blocks ◽  
Limited Resources ◽  
Topology Change ◽  
Network Algorithms ◽  
Network Applications ◽  
Modular Programming ◽  
And Topology ◽  
Data Plane ◽  
High Level

Network algorithms are building blocks of network applications. They are inspired by emerging commodity programmable switches and the Programming Protocol-Independent Packet Processors (P4) language. P4 aims to provide target-independent programming neglecting the architecture of underlying infrastructure. However, commodity programmable switches have tight programming restrictions due to limited resources and latency. In addition, manufacturers tailor P4 according to their architecture, putting more restrictions on it. These intrinsic and extrinsic restrictions dilute the goal of P4. This paper proposes P4 high-level programming (P4HLP) framework, a suite of toolchains that simplifies P4 programming. The paper highlights three aspects: (i) E-Domino, a high-level programming language that defines both stateless and stateful processing of data plane in C-style codes; (ii) P4HLPc, a compiler that automatically generates P4 programs from E-Domino programs, which removes the barrier between high-level programming and low-level P4 primitives; (iii) modular programming that organizes programs into reusable modules, to enable fast reconfiguration of commodity switches. Results show that P4HLPc is efficient and robust, thus is suitable for data plane high-level programming. Compared with P4, E-Domino saves at least 5.5× codes to express the data plane algorithm. P4HLPc is robust to policy change and topology change. The generated P4 programs achieve line-rate processing.

scholarly journals GAUGE GROUP AND TOPOLOGY CHANGE

2011 ◽  
Vol 08 (06) ◽  
pp. 1225-1238 ◽  
Author(s):  
IZUMI TANAKA ◽  
SEIJI NAGAMI
Keyword(s):  
Group Action ◽  
Transformation Group ◽  
High Symmetry ◽  
Topology Change ◽  
Yang Mills ◽  
And Topology ◽  
Present Universe ◽  
Klein Theory ◽  
Kaluza Klein ◽  
Bundle Structure

The purpose of this study is to examine the effect of topology change in the initial universe. In this study, the concept of G-cobordism is introduced to argue about the topology change of the manifold on which a transformation group acts. This G-manifold has a fiber bundle structure if the group action is free and is related to the spacetime in Kaluza–Klein theory or Einstein–Yang–Mills system. Our results revealed the fundamental processes of compactification in G-manifolds. In these processes, the initial high symmetry and multidimensional universe changes to present universe by the mechanism which lowers the dimensions and symmetries.

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