融合专家综合知识的贝叶斯网络参数学习方法

贝叶斯网络模型是经典概率图模型,目前已经广泛应用到各个领域中.在贝叶斯网络模型的参数获取方面,以往的方法往往仅依靠数据集或者专家知识.实际情况中,数据集往往存在缺失或者存在噪声,而单一专家指定的参数存在较大的主观因素,两类方法所得参数与实际存在较大偏差.提出基于D-S证据理论的专家综合知识结合小数据集的贝叶斯网络参数学习方法,克服了依靠数据集小的情况下造成的参数不准确或依靠单一专家知识主观性较强的问题.通过实验验证,提出的方法在小数据集的情况下,所获得的贝叶斯网络参数更为准确.并将提出的方法用于公安机关刑事案件线索研判,综合专家知识与小数据集获取模型参数,研判结果能够较好地反映实际情况,证明了方法的有效性.     

铝合金框架结构的弹体穿击损伤特性

针对直升机机身框架易受子弹弹击导致损伤问题,有必要开展机身铝合金框架结构的子弹穿击损伤特性研究.基于ABAQUS软件平台,采用修正后的Johnson-Cook模型,建立机身铝合金框架弹伤冲击的显示动力学模型,研究子弹弹头倾角和子弹材料等参数对铝合金框架的损伤特性影响.结果 表明:弹头倾角影响子弹穿透能力,但该影响存在临界值,到达临界值前,子弹穿透能力随着倾角的减小而增大;到达临界值后,继续减小倾角不再增大穿透能力;同时随着倾角的减小,框架的损伤面积先增大后减小,倾角为45°时损伤面积最大.子弹材料影响子弹的强度和刚度,影响子弹的穿透能力和破坏能力,计算结果表明铜质子弹的穿透能力大于钢质子弹,钢质子弹破坏能力大于铜质子弹.     

带梁式转换层框支剪力墙结构抗连续倒塌分析

为研究带梁式转换层框支剪力墙结构的抗连续倒塌能力及变形程度,通过有限元软件建立本结构的三维模型,基于备用荷载路径法,以某带梁式转换层的框支剪力墙结构为研究对象,选取不同失效工况分别进行非线性分析,研究初始破坏后剩余结构的节点位移、内力机制及内力重分布过程.结果表明:根据各个工况下对失效点变形情况可得底层位移大于转换层位移;同层不同位置柱的对应位移大小依次为角柱、内柱、长边中柱、短边中柱;承重柱失效后其相邻构件的不平衡内力分担情况遵循"就近原则".     

汽车风扇磁流变液离合器模糊智能控制系统设计

介绍了磁流变液风扇离合器的工作原理和测控系统的设计。提出了大偏差饱和分段控制及小偏差模糊控制的组合控制策略,给出了模糊控制器的详细设计。结果表明,该系统不仅可以提高冷却水温度的控制精度,提高发动机输出效率,也实现了节能。     

高句丽将军坟稳定性数值分析及加固措施

通过现场调研、工程地质调查以及经验分析等手段,研究了将军坟变形破坏特征,分析了将军坟稳定性影响因素。结合FLAC 3D数值模拟方法,分析将军坟在自重应力、粉质黏土局部积水和地震3种情况下位移场和应力场特点和规律,着重揭示了不同等级地震作用下坟体结构变形破坏趋势以及动力学响应特性,并提出针对性的防治措施,包括完善坟体附近排水设施建设,并最低按照Ⅵ级地震设防,同时对坟体北侧抗震能力弱的区域采取加固措施。     

Improved hemimorphite flotation using xanthate as a collector with S(Ⅱ) and Pb(Ⅱ) activation

The flotation of hemimorphite using the S(Ⅱ)–Pb(Ⅱ)–xanthate process,which includes sulfidization with sodium sulfide,activation by lead cations,and subsequent flotation with xanthate,was investigated.The flotation results indicated that hemimorphite floats when the S(Ⅱ)–Pb(Ⅱ)–xanthate process is used; a maximum recovery of approximately 90% was obtained.Zeta-potential,contact-angle,scanning electron microscopy–energy-dispersive spectrometry(SEM–EDS),and diffuse-reflectance infrared Fourier transform spectroscopy(DRIFTS) measurements were used to characterize the activation products on the hemimorphite surface and their subsequent interaction with sodium butyl xanthate(SBX).The results showed that a Zn S coating formed on the hemimorphite surface after the sample was conditioned in an Na2 S solution.However,the formation of a Zn S coating on the hemimorphite surface did not improve hemimorphite flotation.With the subsequent addition of lead cations,Pb S species formed on the mineral surface.The formation of the Pb S species on the surface of hemimorphite significantly increased the adsorption capacity of SBX,forming lead xanthate(referred to as chemical adsorption) and leading to a substantial improvement in hemimorphite flotation.Our results indicate that the addition of lead cations is a critical step in the successful flotation of hemimorphite using the sulfidization–lead ion activation–xanthate process.     

Variable Selection via Generalized SELO-Penalized Cox Regression Models

The seamless-L_0(SELO) penalty is a smooth function that very closely resembles the L_0 penalty, which has been demonstrated theoretically and practically to be effective in nonconvex penalization for variable selection. In this paper, the authors first generalize the SELO penalty to a class of penalties retaining good features of SELO, and then develop variable selection and parameter estimation in Cox models using the proposed generalized SELO(GSELO) penalized log partial likelihood(PPL) approach. The authors show that the GSELO-PPL procedure possesses the oracle property with a diverging number of predictors under certain mild, interpretable regularity conditions. The entire path of GSELO-PPL estimates can be efficiently computed through a smoothing quasi-Newton(SQN) with continuation algorithm. The authors propose a consistent modified BIC(MBIC) tuning parameter selector for GSELO-PPL, and show that under some regularity conditions, the GSELOPPL-MBIC procedure consistently identifies the true model. Simulation studies and real data analysis are conducted to evaluate the finite sample performance of the proposed method.     

基于EPR的供应链治理机制博弈分析

研究了生产者责任延伸(EPR)制度背景下的供应链系统中主体决策影响因素和治理机制的融合问题,基于供应链治理和博弈的理论视角,构造了个体生产者责任(IPR)模式下的非合作博弈模型和集体生产者责任(CPR)模式下的合作博弈模型,分别得出了IPR和CPR模式下企业污染治理技术的最佳决策.研究结果表明,企业的污染治理决策主要取决于企业之间生产技术的差距,以及相互依赖程度.强技术差距和强依赖性更容易导致CPR模式的产生;反之,IPR模式更容易出现在低依赖性和实力相当的企业当中.最后总结了EPR制度下供应链系统动态均衡治理的内部效率机制和外部合法性机制.     

初探地理国情普查与省级基础测绘的协同生产

本文主要讲述地理国情普查与基础测绘的主要技术工艺及其协同生产的方式方法。明确基础测绘与地理国情项目的区别与联系,在实际作业中突出重点、避免重复,可以事半功倍。