Strong association of de novo copy number mutations with sporadic schizophrenia

Schizophrenia is an etiologically heterogeneous psychiatric disease, which exists in familial and nonfamilial (sporadic) forms. Here, we examine the possibility that rare de novo copy number (CN) mutations with relatively high penetrance contribute to the genetic component of schizophrenia. We carried out a whole-genome scan and implemented a number of steps for finding and confirming CN mutations. Confirmed de novo mutations were significantly associated with schizophrenia (P = 0.00078) and were collectively approximately 8 times more frequent in sporadic (but not familial) cases with schizophrenia than in unaffected controls. In comparison, rare inherited CN mutations were only modestly enriched in sporadic cases. Our results suggest that rare de novo germline mutations contribute to schizophrenia vulnerability in sporadic cases and that rare genetic lesions at many different loci can account, at least in part, for the genetic heterogeneity of this disease.     

基于ADAMS.LifeMOD的人体头颈部动力学仿真与验证

基于多刚体动力学软件ADAMS和生物力学仿真软件LifeMOD,建立了一个人体头颈部三维多刚体动力学模型。该模型包括颅骨、颈椎骨、肩胛骨、躯干上段以及体现粘弹性性质的肌肉组织。采用美国海军力学实验室的前碰撞志愿者实验数据对模型进行了验证。验证结果表明,该模型具有很好的可信度,可以用来研究在碰撞条件下头颈部的动力学响应特性。     

空投设备缓冲气囊的优化设计

利用LS-DYNA对缓冲空投设备的气囊进行仿真计算,模拟其缓冲过程。同时利用遗传算法对气囊的排气孔面积、初始充气压力和排气压力进行优化。优化后的结果对空投实验具有很好的指导意义,可以减少气囊设计实验次数从而降低实验的成本。     

水雷对舰船的毁伤概率计算模型及仿真

水雷障碍的作战效能研究是目前研究的重点.基于具有机动能力的水雷的特点,综合考虑了水雷障碍中水雷的布放成功率、命中概率、水雷的可靠度和动作概率等主要因素对目标舰船毁伤概率的影响,提出了目标舰船航线的选择服从均匀分布时和目标舰船航向服从正态分布时的目标舰船遭遇水雷概率计算模型,建立了基于具有机动能力水雷对目标舰船的毁伤概率模型,并进行了仿真验证,具有较高的实用性.     

Coilin levels and modifications influence artificial reporter splicing

Cajal bodies (CBs) and Gems are nuclear domains that contain factors responsible for spliceosomal small nuclear ribonucleoprotein (snRNP) biogenesis. The marker protein for CBs is coilin. In addition to snRNPs, coilin and other factors, canonical CBs contain the survivor of motor neuron protein (SMN). SMN can also localize to Gems. Considering the important role that coilin plays in the formation and composition of CBs, we tested the splicing efficiency of several cell lines that vary in regards to coilin level and modification using an artificial reporter substrate. We found that cells with both hypomethylated coilin and Gems are more efficient at reporter splicing compared to cells in which SMN localizes to CBs. In contrast, coilin reduction, which induces Gem formation, decreases cell proliferation and artificial reporter splicing. These findings demonstrate that coilin modifications or levels impact artificial reporter splicing, possibly by influencing snRNP biogenesis. Received 26 December 2007; received after revision 5 February 2008; accepted 7 February 2008     

稳健二进前向网络的遗传训练方法

稳健二进前向网络是对逻辑知识的隐式表示和显式表示的有机统一,是性能优良的逻辑知识库、推理机和解释器,但目前还没有一种网络训练算法能够训练出稳健二进前向网络,针对这种情况,本文首先对稳健二进前向网络的神经元辅阈值范围进行了改进和有效描述,并在此基础上提出了一种对稳健二进前向网络进行有效训练的遗传训练方法。在这种训练方法中,网络参数采用三值编码方案,并运用相应的变异机制和有效的适应度函数,经这种方法训练出的网络具有结构最优、稳健性能最强和最易实现的特点。文章最后给出了实验的结果。     

适于大斜视角星载SAR系统的改进距离┐多普勒算法

分析了当天线斜视角增大时,导致传统距离－多普勒成像算法性能下降的主要误差来源。提出了一种适合大斜视角星载ＳＡＲ系统的改进距离－多普勒算法,并给出了处理仿真点目标数据得到图像质量的比较。结果表明,在大斜视角情况下,改进算法的性能远大于传统的距离－多普勒成像算法。     

基于卡尔曼滤波的二次型神经网络学习算法及收敛性分析

提出了二次型多层前馈神经网络的卡尔曼滤波学习算法,并证明了该算法的收敛性。与文献［２,３］中的学习算法和经典的误差反向传播学习算法相比,新的学习算法具有更快的学习速度、良好的泛化能力,并且对学习率有很好的鲁棒性,不容易陷入局部极小点。仿真实验结果表明了新算法的有效性。     

适于大斜视角星载SAR系统的改进距离-多普勒算法

分析了当天线斜视角增大时,导致传统距离-多普勒成像算法性能下降的主要误差来源.提出了一种适合大斜视角星载SAR系统的改进距离-多普勒算法,并给出了处理仿真点目标数据得到图像质量的比较.结果表明,在大斜视角情况下,改进算法的性能远大于传统的距离\|多普勒成像算法.     

随机需求下基于库存责任期的装配系统准时供货模型

以装配系统为研究对象, 考虑在VMI模式下, 当制造商采取设定库存责任期以抵御市场需求时间不确定的风险时, 供应商的最优供货时间决策和制造商最优的库存责任期设置. 文章分别建立了单供应商对单制造商和多供应商对单制造商的主从博弈准时供货模型, 通过数学证明和遍历算法找到了供应链双方在不同模式下的最优选择. 研究结果证明制造商并 不应该选择过长的库存责任期, 而供应商之间的不同步供货会对供应链整体造成巨大损失. 并且通过对比集中与分散决策下的供应链绩效, 给出实现系统协同的必要条件. 最后通过算例分析进一步证明相关结论.