A benchmark solution is of great importance in validating algorithms and codes for magnetohydrodynamic(MHD) flows.Hunt and Shercliff's solutions are usually employed as benchmarks for MHD flows in a duct with insu...A benchmark solution is of great importance in validating algorithms and codes for magnetohydrodynamic(MHD) flows.Hunt and Shercliff's solutions are usually employed as benchmarks for MHD flows in a duct with insulated walls or with thin conductive walls,in which wall effects on MHD are represented by the wall conductance ratio.With wall thickness resolved,it is stressed that the solution of Sloan and Smith's and the solution of Butler's can be used to check the error of the thin wall approximation condition used for Hunt's solutions.It is noted that Tao and Ni's solutions can be used as a benchmark for MHD flows in a duct with wall symmetrical or unsymmetrical,thick or thin.When the walls are symmetrical,Tao and Ni's solutions are reduced to Sloan and Smith's solution and Butler's solution,respectively.展开更多
The steel plate shear wall system has been used in a number of buildings as an innovative lateral force resistant system.Openings often exist in the steel plate shear walls due to the various functional requirements o...The steel plate shear wall system has been used in a number of buildings as an innovative lateral force resistant system.Openings often exist in the steel plate shear walls due to the various functional requirements of structures.These openings may negatively impact the lateral stiffness of steel plate shear walls.Therefore,an experimental research was instituted to investigate the seismic behavior of steel plate shear walls,with and without openings.The experimental results showed that steel plate shear walls have the satisfying seismic behavior,and,as expected,the strength and stiffness characteristics of the walls were reduced due to openings.Then a single-story wall panel FE model and an analytical deep beam model are developed in order to find the critical factors dominating the thickness reduction coefficient of wall panels with the opening.Furthermore,extensive parametric analysis is conducted to derive a simplified formula for the determination of the thickness reduction coefficient of wall panels with the opening for substituting solid wall panels with reduced thickness for actual wall panels with the opening.Finally,the design method for calculating the lateral stiffness is verified by some experimental programs and recommended for the routine practice of steel plate shear walls.展开更多
An important task for quantum cloud computing is to make sure that there is a real quantum computer running,instead of classical simulation.Here we explore the applicability of a cryptographic verification scheme for ...An important task for quantum cloud computing is to make sure that there is a real quantum computer running,instead of classical simulation.Here we explore the applicability of a cryptographic verification scheme for verifying quantum cloud computing.We provided a theoretical extension and implemented the scheme on a 5-qubit NMR quantum processor in the laboratory and a 5-qubit and 16-qubit processors of the IBM quantum cloud.We found that the experimental results of the NMR processor can be verified by the scheme with about 1.4%error,after noise compensation by standard techniques.However,the fidelity of the IBM quantum cloud is currently too low to pass the test(about 42%error).This verification scheme shall become practical when servers claim to offer quantum-computing resources that can achieve quantum supremacy.展开更多
A novel lower-complexity construction scheme of quasi-cyclic low-density parity-check(QC-LDPC) codes for optical transmission systems is proposed based on the structure of the parity-check matrix for the Richardson-Ur...A novel lower-complexity construction scheme of quasi-cyclic low-density parity-check(QC-LDPC) codes for optical transmission systems is proposed based on the structure of the parity-check matrix for the Richardson-Urbanke(RU) algorithm. Furthermore, a novel irregular QC-LDPC(4 288, 4 020) code with high code-rate of 0.937 is constructed by this novel construction scheme. The simulation analyses show that the net coding gain(NCG) of the novel irregular QC-LDPC(4 288,4 020) code is respectively 2.08 d B, 1.25 d B and 0.29 d B more than those of the classic RS(255, 239) code, the LDPC(32 640, 30 592) code and the irregular QC-LDPC(3 843, 3 603) code at the bit error rate(BER) of 10^(-6). The irregular QC-LDPC(4 288, 4 020) code has the lower encoding/decoding complexity compared with the LDPC(32 640, 30 592) code and the irregular QC-LDPC(3 843, 3 603) code. The proposed novel QC-LDPC(4 288, 4 020) code can be more suitable for the increasing development requirements of high-speed optical transmission systems.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 11125212 and 50936066)the National Magnetic Confinement Fusion Science Program of China (Grant No. 2009GB10401)
文摘A benchmark solution is of great importance in validating algorithms and codes for magnetohydrodynamic(MHD) flows.Hunt and Shercliff's solutions are usually employed as benchmarks for MHD flows in a duct with insulated walls or with thin conductive walls,in which wall effects on MHD are represented by the wall conductance ratio.With wall thickness resolved,it is stressed that the solution of Sloan and Smith's and the solution of Butler's can be used to check the error of the thin wall approximation condition used for Hunt's solutions.It is noted that Tao and Ni's solutions can be used as a benchmark for MHD flows in a duct with wall symmetrical or unsymmetrical,thick or thin.When the walls are symmetrical,Tao and Ni's solutions are reduced to Sloan and Smith's solution and Butler's solution,respectively.
基金supported by the National Key Technology R&D Program of China(Grant No.2011BAJ09B01)the National Natural Science Foundation of China(Grant Nos.51178246,51222810)Tsinghua University Initiative Scientific Research Program(Grant No.20101081766)
文摘The steel plate shear wall system has been used in a number of buildings as an innovative lateral force resistant system.Openings often exist in the steel plate shear walls due to the various functional requirements of structures.These openings may negatively impact the lateral stiffness of steel plate shear walls.Therefore,an experimental research was instituted to investigate the seismic behavior of steel plate shear walls,with and without openings.The experimental results showed that steel plate shear walls have the satisfying seismic behavior,and,as expected,the strength and stiffness characteristics of the walls were reduced due to openings.Then a single-story wall panel FE model and an analytical deep beam model are developed in order to find the critical factors dominating the thickness reduction coefficient of wall panels with the opening.Furthermore,extensive parametric analysis is conducted to derive a simplified formula for the determination of the thickness reduction coefficient of wall panels with the opening for substituting solid wall panels with reduced thickness for actual wall panels with the opening.Finally,the design method for calculating the lateral stiffness is verified by some experimental programs and recommended for the routine practice of steel plate shear walls.
基金supported by National Key Research and Development Program of China (2018YFA0306600)the National Natural Science Foundation of China (11661161018, and 11927811)+7 种基金Anhui Initiative in Quantum Information Technologies (AHY050000)supported in part by the Australian Research Council (DE180100156)supported by the Natural Science Foundation of Guangdong Province (2017B030308003)the Key R&D Program of Guangdong province (2018B030326001)the Science, Technology and Innovation Commission of Shenzhen Municipality (JCYJ20170412152620376, JCYJ20170817105046702 and KYTDPT20181011104202253)the National Natural Science Foundation of China (11875160 and U1801661)the Economy, Trade and Information Commission of Shenzhen Municipality (201901161512)Guangdong Provincial Key Laboratory (2019B121203002)
文摘An important task for quantum cloud computing is to make sure that there is a real quantum computer running,instead of classical simulation.Here we explore the applicability of a cryptographic verification scheme for verifying quantum cloud computing.We provided a theoretical extension and implemented the scheme on a 5-qubit NMR quantum processor in the laboratory and a 5-qubit and 16-qubit processors of the IBM quantum cloud.We found that the experimental results of the NMR processor can be verified by the scheme with about 1.4%error,after noise compensation by standard techniques.However,the fidelity of the IBM quantum cloud is currently too low to pass the test(about 42%error).This verification scheme shall become practical when servers claim to offer quantum-computing resources that can achieve quantum supremacy.
基金supported by the National Natural Science Foundation of China(Nos.61472464 and 61471075)the Program for Innovation Team Building at Institutions of Higher Education in Chongqing(No.J2013-46)+1 种基金the Natural Science Foundation of Chongqing Science and Technology Commission(Nos.cstc2015jcyjA 0554 and cstc2013jcyjA 40017)the Program for Postgraduate Science Research and Innovation of Chongqing University of Posts and Telecommunications(Chongqing Municipal Education Commission)(No.CYS14144)
文摘A novel lower-complexity construction scheme of quasi-cyclic low-density parity-check(QC-LDPC) codes for optical transmission systems is proposed based on the structure of the parity-check matrix for the Richardson-Urbanke(RU) algorithm. Furthermore, a novel irregular QC-LDPC(4 288, 4 020) code with high code-rate of 0.937 is constructed by this novel construction scheme. The simulation analyses show that the net coding gain(NCG) of the novel irregular QC-LDPC(4 288,4 020) code is respectively 2.08 d B, 1.25 d B and 0.29 d B more than those of the classic RS(255, 239) code, the LDPC(32 640, 30 592) code and the irregular QC-LDPC(3 843, 3 603) code at the bit error rate(BER) of 10^(-6). The irregular QC-LDPC(4 288, 4 020) code has the lower encoding/decoding complexity compared with the LDPC(32 640, 30 592) code and the irregular QC-LDPC(3 843, 3 603) code. The proposed novel QC-LDPC(4 288, 4 020) code can be more suitable for the increasing development requirements of high-speed optical transmission systems.
