Considering the characteristics of spatial straightness error, this paper puts forward a kind of evaluation method of spatial straightness error using Geometric Approximation Searching Algorithm (GASA). According to t...Considering the characteristics of spatial straightness error, this paper puts forward a kind of evaluation method of spatial straightness error using Geometric Approximation Searching Algorithm (GASA). According to the minimum condition principle of form error evaluation, the mathematic model and optimization objective of the GASA are given. The algorithm avoids the optimization and linearization, and can be fulfilled in three steps. First construct two parallel quadrates based on the preset two reference points of the spatial line respectively;second construct centerlines by connecting one quadrate each vertices to another quadrate each vertices;after that, calculate the distances between measured points and the constructed centerlines. The minimum zone straightness error is obtained by repeating comparing and reconstructing quadrates. The principle and steps of the algorithm to evaluate spatial straightness error is described in detail, and the mathematical formula and program flowchart are given also. Results show that this algorithm can evaluate spatial straightness error more effectively and exactly.展开更多
In this paper, we show a clustering method supported on evolutionary algorithms with the paradigm of linear genetic programming. “The Straight-Line Programs (slp)”, which uses a data structure which will be useful t...In this paper, we show a clustering method supported on evolutionary algorithms with the paradigm of linear genetic programming. “The Straight-Line Programs (slp)”, which uses a data structure which will be useful to represent collections of documents. This data structure can be seen as a linear representation of programs, as well as representations in the form of graphs. It has been used as a theoretical model in Computer Algebra, and our purpose is to reuse it in a completely different context. In this case, we apply it to the field of grouping library collections through evolutionary algorithms. We show its efficiency with experimental data we got from traditional library collections.展开更多
建立了大直径中空直孔掏槽爆破的力学模型,采用FEM-SPH(Finite Element Method-Smooth Particle Hydrodynamics)耦合算法对破岩过程进行了数值模拟。结果表明:该数值模拟方法能够直观展示大直径中空直孔掏槽爆破破岩全过程,爆破破岩过...建立了大直径中空直孔掏槽爆破的力学模型,采用FEM-SPH(Finite Element Method-Smooth Particle Hydrodynamics)耦合算法对破岩过程进行了数值模拟。结果表明:该数值模拟方法能够直观展示大直径中空直孔掏槽爆破破岩全过程,爆破破岩过程分为端部爆破漏斗形成和槽腔岩体抛掷两个阶段;理论计算所得端部爆破漏斗边界与数值模拟所得漏斗边界基本一致,而理论计算所得最终槽腔边界与数值模拟所得槽腔边界存在差异,数值模拟所得最终槽腔边界呈倒立钟形,更符合最终槽腔边界的实际观测情况。研究结果为合理确定大直径中空直孔掏槽爆破参数提供了理论依据。展开更多
文摘Considering the characteristics of spatial straightness error, this paper puts forward a kind of evaluation method of spatial straightness error using Geometric Approximation Searching Algorithm (GASA). According to the minimum condition principle of form error evaluation, the mathematic model and optimization objective of the GASA are given. The algorithm avoids the optimization and linearization, and can be fulfilled in three steps. First construct two parallel quadrates based on the preset two reference points of the spatial line respectively;second construct centerlines by connecting one quadrate each vertices to another quadrate each vertices;after that, calculate the distances between measured points and the constructed centerlines. The minimum zone straightness error is obtained by repeating comparing and reconstructing quadrates. The principle and steps of the algorithm to evaluate spatial straightness error is described in detail, and the mathematical formula and program flowchart are given also. Results show that this algorithm can evaluate spatial straightness error more effectively and exactly.
文摘In this paper, we show a clustering method supported on evolutionary algorithms with the paradigm of linear genetic programming. “The Straight-Line Programs (slp)”, which uses a data structure which will be useful to represent collections of documents. This data structure can be seen as a linear representation of programs, as well as representations in the form of graphs. It has been used as a theoretical model in Computer Algebra, and our purpose is to reuse it in a completely different context. In this case, we apply it to the field of grouping library collections through evolutionary algorithms. We show its efficiency with experimental data we got from traditional library collections.
文摘建立了大直径中空直孔掏槽爆破的力学模型,采用FEM-SPH(Finite Element Method-Smooth Particle Hydrodynamics)耦合算法对破岩过程进行了数值模拟。结果表明:该数值模拟方法能够直观展示大直径中空直孔掏槽爆破破岩全过程,爆破破岩过程分为端部爆破漏斗形成和槽腔岩体抛掷两个阶段;理论计算所得端部爆破漏斗边界与数值模拟所得漏斗边界基本一致,而理论计算所得最终槽腔边界与数值模拟所得槽腔边界存在差异,数值模拟所得最终槽腔边界呈倒立钟形,更符合最终槽腔边界的实际观测情况。研究结果为合理确定大直径中空直孔掏槽爆破参数提供了理论依据。
