The response of a 14 MeV neutron-based prompt gamma neutron activation analysis (PGNAA) system,i.e.the prompt gamma-rays count rate and the average thermal neutron flux,is studied with a large concrete sample and with...The response of a 14 MeV neutron-based prompt gamma neutron activation analysis (PGNAA) system,i.e.the prompt gamma-rays count rate and the average thermal neutron flux,is studied with a large concrete sample and with a homogeneous large sample,which is made of polyethylene and metal with various concentrations of hydrogen and cadmium using the MCNP-5 (Monte Carlo N-Particle) code.The average thermal neutron flux is determined by the analysis of the prompt gamma-rays using the thermal neutron activation of hydrogen in the sample,and the thermal and fast neutron activation of carbon graphite irradiation chamber of the PGNAA-system.Our results demonstrated that the graphite irradiation chamber of the PGNAA-system fairly operates,and is useful to estimate the average thermal neutron flux of large samples with various compositions irradiated by 14 MeV neutrons.展开更多
针对支撑向量机(Support vector machine,SVM)在大规模数据的问题,提出了一种基于模糊c-均值聚类样本选择策略的SVC(SVM for classification)迭代训练算法,从样本抽取、迭代训练两个方面进行了改进,并在多个较大规模UCI标准测试集上进...针对支撑向量机(Support vector machine,SVM)在大规模数据的问题,提出了一种基于模糊c-均值聚类样本选择策略的SVC(SVM for classification)迭代训练算法,从样本抽取、迭代训练两个方面进行了改进,并在多个较大规模UCI标准测试集上进行了试验.结果表明,所提出的迭代训练算法收敛快,在保证学习精度的同时使训练速度加倍、支撑向量减少一半.展开更多
The objective of this paper is to propose an adjustment to the three methods of calculating the probability that regularities in a sample data represent a systemic influence in the population data. The method proposed...The objective of this paper is to propose an adjustment to the three methods of calculating the probability that regularities in a sample data represent a systemic influence in the population data. The method proposed is called data profiling. It consists of calculating vertical and horizontal correlation coefficients in a sample data. The two correlation coefficients indicate the internal dynamic or inter dependency among observation points, and thus add new information. This information is incorporated in the already established methods and the consequence of this integration is that one can conclude with certainty that the probability calculated is indeed a valid indication of systemic influence in the population data.展开更多
基金Supported by National Natural Science Foundation of China (No. 10675084)the Forschungszentrum Jülich GmbH, Germany
文摘The response of a 14 MeV neutron-based prompt gamma neutron activation analysis (PGNAA) system,i.e.the prompt gamma-rays count rate and the average thermal neutron flux,is studied with a large concrete sample and with a homogeneous large sample,which is made of polyethylene and metal with various concentrations of hydrogen and cadmium using the MCNP-5 (Monte Carlo N-Particle) code.The average thermal neutron flux is determined by the analysis of the prompt gamma-rays using the thermal neutron activation of hydrogen in the sample,and the thermal and fast neutron activation of carbon graphite irradiation chamber of the PGNAA-system.Our results demonstrated that the graphite irradiation chamber of the PGNAA-system fairly operates,and is useful to estimate the average thermal neutron flux of large samples with various compositions irradiated by 14 MeV neutrons.
文摘针对支撑向量机(Support vector machine,SVM)在大规模数据的问题,提出了一种基于模糊c-均值聚类样本选择策略的SVC(SVM for classification)迭代训练算法,从样本抽取、迭代训练两个方面进行了改进,并在多个较大规模UCI标准测试集上进行了试验.结果表明,所提出的迭代训练算法收敛快,在保证学习精度的同时使训练速度加倍、支撑向量减少一半.
文摘The objective of this paper is to propose an adjustment to the three methods of calculating the probability that regularities in a sample data represent a systemic influence in the population data. The method proposed is called data profiling. It consists of calculating vertical and horizontal correlation coefficients in a sample data. The two correlation coefficients indicate the internal dynamic or inter dependency among observation points, and thus add new information. This information is incorporated in the already established methods and the consequence of this integration is that one can conclude with certainty that the probability calculated is indeed a valid indication of systemic influence in the population data.
