K-TSP问题的近似算法

利用△TSP问题的Christofides算法及其在K TSP问题上的扩展 ,通过权函数变换c′ij=cij-ui-vj 使c′ij>0 ,c′ik c′kj≥c′ij,给出了求解K TSP问题的有效途径 ,得到了目标函数的更好的界值估计 ,C(Ha)≤λ(n)C(H ) -(λ(n) -1 ) {(k-1 )c11 ∑ni=1 cii}.     

基于AHP的电子商务企业快递服务商决策分析

采用层次分析法，找到了影响电子商务企业选择快递服务商最重要的因素，这些因素包括延误晚点、服务态度、物件丢失和损坏、代收货款和价格.在民营快递企业中，“直营”模式优于“加盟”模式. 通过对比三家快递企业发现，EMS 的价格高、服务质量低.     

向量的次正交及其性质

给出了向量的次正交与次正交向量组等有关概念及性质。     

ρ~n次幂对径向波函数R_(ne)平均值的计算通式

本文用广义Ｌａｇｕｅｒｒｅ多项式的母函数表达式，证得文献〔１〕中，计算ρｎ次幂的类氢原子径向波函数Ｊｄ平均值的通式。     

环上的矩阵方程AX-YB=C

给出了环上的矩阵方程AX-YB=C相容的充要条件及一般解的表达式。     

用哈密特式分析闭环网络的自激振蕩

将一个闭环网络断开成一个双口网络,用哈密特矩阵的性质分析这个双口网络有功平衡的条件,用无功的概念定义电纳性矩阵,以晶体管混合π模型引起的寄生振荡为例,论证无损耗等价于自激。     

Extracellular matrix and neuronal movement

Summary During brain development, both neuronal migration and axon guidance are influenced by extracellular matrix molecules present in the environment of the migrating neuronal cell bodies and nerve fibers. Glial laminin is an extracellular matrix protein which these early brain cells preferentially attach to. Extracellular glycosaminoglycans are suggested to function in restricting neuronal cell bodies and axons from certain brain areas. Since laminin is deposited along the radial glial fibers and along the developing nerve pathways in punctate form, the punctate assemblies may be one of the key factors in routing the developing neurons in vivo. This review discusses the role of laminin in neuronal movement given the present concept of the extracellular matrix molecules and their proposed interactions.     

用划分序列构造时序机核实序列的方法

任何既约的、强联结的时序机 ,必存在核实序列 .若该机存在区分序列 ,构造其核实序列的方法已经形成 ;但是 ,若该机不存在区分序列 ,需寻求构造其核实序列的方法 .作者从时序机的状态表出发 ,定义了划分序列 ,并针对无区分序列的时序机 ,提出了利用划分序列构造时序机核实序列的一种方法 .该方法中求划分序列部分建立在时序机的矩阵模型上 ,易于工程实现     

Metabonomic analysis of hepatitis B virus-induced liver failure： identification of potential diagnostic biomarkers by fuzzy support vector machine

Hepatitis B virus （HBV）-induced liver failure is an emergent liver disease leading to high mortality. The severity of liver failure may be reflected by the profile of some metabolites. This study assessed the potential of using metabolites as biomarkers for liver failure by identifying metabolites with good discriminative performance for its phenotype. The serum samples from 24 HBV-indueed liver failure patients and 23 healthy volunteers were collected and analyzed by gas chromatography-mass spectrometry （GC-MS） to generate metabolite profiles. The 24 patients were further grouped into two classes according to the severity of liver failure. Twenty-five eommensal peaks in all metabolite profiles were extracted, and the relative area values of these peaks were used as features for each sample. Three algorithms, F-test, k-nearest neighbor （KNN） and fuzzy support vector machine （FSVM） combined with exhaustive search （ES）, were employed to identify a subset of metabolites （biomarkers） that best predict liver failure. Based on the achieved experimental dataset, 93.62% predictive accuracy by 6 features was selected with FSVM-ES and three key metabolites, glyeerie acid, cis-aeonitie acid and citric acid, are identified as potential diagnostic biomarkers.     

矩阵的次迹及其性质

给出了矩阵次迹的概念,并研究了它的若干性质及应用,得出了关于矩阵次迹的一些新结果.