10,599 research outputs found
Vectorization and parallelization of the finite strip method for dynamic Mindlin plate problems
The finite strip method is a semi-analytical finite element process which allows for a discrete analysis of certain types of physical problems by discretizing the domain of the problem into finite strips. This method decomposes a single large problem into m smaller independent subproblems when m harmonic functions are employed, thus yielding natural parallelism at a very high level. In this paper we address vectorization and parallelization strategies for the dynamic analysis of simply-supported Mindlin plate bending problems and show how to prevent potential conflicts in memory access during the assemblage process. The vector and parallel implementations of this method and the performance results of a test problem under scalar, vector, and vector-concurrent execution modes on the Alliant FX/80 are also presented
THE INTELLECTUAL STRUCTURE OF ELECTRONIC RECORDS MANAGEMENT
A number of countries have launched projects with a particular emphasis on using information technologies (IT) to provide electronic information and services to citizens and businesses. Through various IT, tremendous amount of electronic records in government agencies are created. These records and archives are the basis of knowledge management. Electronic records management (ERM) is a fast growing field throughout the last decades. Theoretical foundations for ERM have remained obscure from the research community. To map the intellectual structure of ERM research, this study identifies the high-impact articles as well as the correlations among these scholar publications. In this study, co-citation, co-word, association rule and cluster analysis techniques are used to investigate the intellectual pillars of the ERM literature. This study exposes researchers to a new way of profiling knowledge networks and their relationships the area of ERM, thereby helping academia and practitioners better understand contemporary studies. The results of the mapping can help identify the research direction of ERM research, provide a valuable tool for researchers to access ERM literature, and acts as an exemplary model for future researches
A broadband polygonal cloak for acoustic wave designed with linear coordinate transformation
Previous acoustic cloaks designed with transformation acoustics always involve inhomogeneous material. In this paper, a design of acoustic polygonal cloak is proposed using linear polygonal transformation method. The designed acoustic polygonal cloak has homogeneous and anisotropic parameters, which is much easier to realize in practice. Furthermore, a possible acoustic metamaterial structure to realize the cloak is proposed. Simulation results on the real structure show that the metamaterial acoustic cloak is effective to reduce the scattering of the object.National Natural Science Foundation (China) (Grants 61322501, 61574127, and 61275183)Program for New Century Excellent Talents in University (China) (NCET-12-0489)Fundamental Research Funds for the Central Universities of ChinaZhejiang University. Innovation Joint Research Center for Cyber-Physical-Society SystemChina Postdoctoral Science FoundationUnited States. Office of Naval Research. Multidisciplinary University Research Initiative (Grant 2015M581930)Top-Notch Young Talents Program of Chin
STAR-RIS-Assisted-Full-Duplex Jamming Design for Secure Wireless Communications System
Physical layer security (PLS) technologies are expected to play an important
role in the next-generation wireless networks, by providing secure
communication to protect critical and sensitive information from illegitimate
devices. In this paper, we propose a novel secure communication scheme where
the legitimate receiver use full-duplex (FD) technology to transmit jamming
signals with the assistance of simultaneous transmitting and reflecting
reconfigurable intelligent surface (STARRIS) which can operate under the energy
splitting (ES) model and the mode switching (MS) model, to interfere with the
undesired reception by the eavesdropper. We aim to maximize the secrecy
capacity by jointly optimizing the FD beamforming vectors, amplitudes and phase
shift coefficients for the ESRIS, and mode selection and phase shift
coefficients for the MS-RIS. With above optimization, the proposed scheme can
concentrate the jamming signals on the eavesdropper while simultaneously
eliminating the self-interference (SI) in the desired receiver. To tackle the
coupling effect of multiple variables, we propose an alternating optimization
algorithm to solve the problem iteratively. Furthermore, we handle the
non-convexity of the problem by the the successive convex approximation (SCA)
scheme for the beamforming optimizations, amplitudes and phase shifts
optimizations for the ES-RIS, as well as the phase shifts optimizations for the
MS-RIS. In addition, we adopt a semi-definite relaxation (SDR) and Gaussian
randomization process to overcome the difficulty introduced by the binary
nature of mode optimization of the MS-RIS. Simulation results validate the
performance of our proposed schemes as well as the efficacy of adapting both
two types of STAR-RISs in enhancing secure communications when compared to the
traditional selfinterference cancellation technology.Comment: 12 pages, 7 figure
SUPRASPECIFIC TAXA OF THE BIVALVIA FIRST NAMED, DESCRIBED, AND PUBLISHED IN CHINA (1927–2007)
A total of 209 bivalve generic (subgeneric) and 19 familial (subfamilial) names first proposed by Chinese palaeontologists and published in China are treated herein as an annotated database. The present paper is designed especially for the Treatise on Invertebrate Paleontology Bivalvia revision project, because access to bivalve taxa published by Chinese authors in China has been difficult for non-Chinese researchers. The original diagnoses of these taxa, including the original descriptions and explanation of figures of all the type species, have been translated from Chinese into English, so that non-Chinese colleagues can more easily have access to them
Compact electric-LC resonators for metamaterials
Alternative designs to an electric-LC (ELC) resonator, which is a type of
metamaterial inclusion, are presented in this article. Fitting the resonator
with an interdigital capacitor (IDC) helps to increase the total capacitance of
the structure. In effect, its resonance frequency is shifted downwards. This
implies a decreased overall resonator size with respect to its operating
wavelength. As a result, the metamaterial, composed of an array of IDC-loaded
ELC resonators with their collective electromagnetic response, possesses
improved homogeneity and hence is less influenced by diffraction effects of
individual cells. The impact of incorporating an IDC into ELC resonators in
terms of the electrical size at resonance and other relevant properties are
investigated through both simulation and experiment.Comment: 5 pages, 5 figure
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