A numerical method, the so-called multiple monopole（MMoP） method,based on the generalized multipole technique（GMT） is proposed to calculate the band structures of in-plane waves in two-dimensional phononic crystal...A numerical method, the so-called multiple monopole（MMoP） method,based on the generalized multipole technique（GMT） is proposed to calculate the band structures of in-plane waves in two-dimensional phononic crystals, which are composed of arbitrarily shaped cylinders embedded in a solid host medium. To find the eigenvalues（eigenfrequencies） of the problem, besides the sources used to expand the wave fields, an extra monopole source is introduced which acts as the external excitation. By varying the excitation frequency, the eigenvalues can be localized as the extreme points of an appropriately chosen function. By sweeping the frequency range of interest and the boundary of the irreducible first Brillouin zone（FBZ）, the band structures can be obtained. Some typical numerical examples with different acoustic impedance ratios and with inclusions of various shapes are presented to validate the proposed method.展开更多
Using a triangular lattice model to study the designability of proteinfolding, we overcame the parity problem of previous cubic lattice model and enumerated all thesequences and compact structures on a simple two-dime...Using a triangular lattice model to study the designability of proteinfolding, we overcame the parity problem of previous cubic lattice model and enumerated all thesequences and compact structures on a simple two-dimensional triangular lattice model of size4+5+6+5+4. We used two types of amino acids, hydrophobic and polar, to make up the sequences, andachieved 2^(23)+2^(12) different sequences excluding the reverse symmetry sequences. The totalstring number of distinct compact structures was 219,093, excluding reflection symmetry in theself-avoiding path of length 24 triangular lattice model. Based on this model, we applied a fastsearch algorithm by constructing a cluster tree. The algorithm decreased the computation bycomputing the objective energy of non-leaf nodes. The parallel experiments proved that the fast treesearch algorithm yielded an exponential speed-up in the model of size 4+5+6+5+4. Designabilityanalysis was performed to understand the search result.展开更多
基金Project supported by the National Natural Science Foundation of China(No.10632020)the German Research Foundation(Nos.ZH 15/11-1 and ZH 15/16-1)+1 种基金the International Bureau of the German Federal Ministry of Education and Research(No.CHN 11/045)the National Basic Research Program of China(No.2010CB732104)
文摘A numerical method, the so-called multiple monopole（MMoP） method,based on the generalized multipole technique（GMT） is proposed to calculate the band structures of in-plane waves in two-dimensional phononic crystals, which are composed of arbitrarily shaped cylinders embedded in a solid host medium. To find the eigenvalues（eigenfrequencies） of the problem, besides the sources used to expand the wave fields, an extra monopole source is introduced which acts as the external excitation. By varying the excitation frequency, the eigenvalues can be localized as the extreme points of an appropriately chosen function. By sweeping the frequency range of interest and the boundary of the irreducible first Brillouin zone（FBZ）, the band structures can be obtained. Some typical numerical examples with different acoustic impedance ratios and with inclusions of various shapes are presented to validate the proposed method.
文摘Using a triangular lattice model to study the designability of proteinfolding, we overcame the parity problem of previous cubic lattice model and enumerated all thesequences and compact structures on a simple two-dimensional triangular lattice model of size4+5+6+5+4. We used two types of amino acids, hydrophobic and polar, to make up the sequences, andachieved 2^(23)+2^(12) different sequences excluding the reverse symmetry sequences. The totalstring number of distinct compact structures was 219,093, excluding reflection symmetry in theself-avoiding path of length 24 triangular lattice model. Based on this model, we applied a fastsearch algorithm by constructing a cluster tree. The algorithm decreased the computation bycomputing the objective energy of non-leaf nodes. The parallel experiments proved that the fast treesearch algorithm yielded an exponential speed-up in the model of size 4+5+6+5+4. Designabilityanalysis was performed to understand the search result.
