植物根尖细胞有丝分裂的周期性

本文采取一天当中对大蒜根尖细胞进行几个时间取材实验。结果表明:植物体细胞和其它生物体细胞一样其繁殖过程有自身的规律性,在生长区内大蒜根尖细胞有着周期性的分裂。     

适应网格环境的物流网络研究

随着物流网络这一概念的明确,对物流网络运行环境特性与对应发展模式等问题的探索已接踵而至.本文论证了物流网络应与将逐步兴起的网格环境协调发展的合理性,并展开了对物流网络与网格环境协调发展的框架结构、网络服务资源管理等一些关键问题的进一步分析.     

金融信息网格

金融信息网格利用网格技术优化、整合金融系统的异构计算机,实现广域、异 构信息的共享、互连、互操作和更高程度的资源共享。根据金融系统具有的分布性、异构性 、实时性和协同性等特征,结合我国金融信息管理的实际情况和信息网格技术,分析了金融 行业对网格技术的需求,提出了金融信息网格的体系结构和系统设计思想以及建设金融信息 网格的实施建议。     

NEAREST NEIGHBOUR ANALYSIS OF UNEQUALLY REPLICATED TRIALS

There has been much work on the use of neighbouring plots to control environmental variation in the analysis of agricultural field experiments. In particular, the Residual Maximum Likelihood Neighbour (REMLN) analysis of Gleeson&Cullis (1987) appears very promising. The application of the REMLN analysis to an unequally replicated field trial augmented with an additional variety planted every six plots in a grid system is here compared with a covariance (COV) analysis using the neighbouring grid or check plot values as the covariate. The results indicate that the REMLN analysis gives more accurate estimates of treatment contrasts than the COV analyses, but that the estimate of treatment means can be biased. The bias depends on the mean of the check plot. This bias can be removed by adjusting the estimates of the treatment means such that their average equals the average of the raw means rather than that of the raw data.     

GTEM Cell的坐标变换分析

文献［１］提出用坐标变换将ＧＴＥＭｃｅｌｌ变换成均匀矩形偏心同轴线，然后用数值方法求解场分布，但是其变换后的二阶偏微分方程存在错误。文中经过严格的推导，获得了正确的结果，纠正了文献［１］中的错误。     

一种双层小区结构中的切换控制策略

在宽带码分多址双层小区结构系统中提出了一种基于小区覆盖范围和信号能干比判决的切换策略,切换策略使用了基于概率的动态资源预留方案,即在切换时,如果系统中没有空闲资源,则对切换呼叫进行排队。通过仿真表明,该切换策略相对于采用固定资源预留的切换策略,在轻负荷的条件下对话音呼叫的阻塞概率有一定的改善。     

不可压缩管流的广义有限元方法

本文将广义有限元法用于求解不可压缩管流.通过泛函的变域变分理论推导出严格的网格自适应性条件,可以在给定网格节点数目的条件下,在计算时自动调整网格的分布,使泛函取得极值,同时也使流场参数和网格节点位置取得最优值.对一维喷管的计算结果表明,广义有限元法理论上严密,在计算中是可行的,是常规有限元法向高精度的自适应网格方向的合理推广.     

The analysis of some biological data

This paper considers the building of stochastic models and the related analysis of discrete data in two biological problems, The first arises from the reproduction of yeast cells, while the secondis concerned with the aggregation of nucleoli. Galton-Watson and aggregation models are constructed for the respective processes and their goodness of fit to the data tested     

Estimating mixtures of normal distributions via empirical characteristic function

This paper uses the empirical characteristic function (ECF) procedure to estimate the parameters of mixtures of normal distributions. Since the characteristic function is uniformly bounded, the procedure gives estimates that are numerically stable. It is shown that, using Monte Carlo simulation, the finite sample properties of th ECF estimator are very good, even in the case where the popular maximum likelihood estimator fails to exist. An empirical application is illustrated using the monthl excess return of the Nyse value-weighted index.     

Generalized phase I-II designs to increase long term therapeutic success rate

Designs for early phase dose finding clinical trials typically are either phase I based on toxicity, or phase I-II based on toxicity and efficacy. These designs rely on the implicit assumption that the dose of an experimental agent chosen using these short-term outcomes will maximize the agent's long-term therapeutic success rate. In many clinical settings, this assumption is not true. A dose selected in an early phase oncology trial may give suboptimal progression-free survival or overall survival time, often due to a high rate of relapse following response. To address this problem, a new family of Bayesian generalized phase I-II designs is proposed. First, a conventional phase I-II design based on short-term outcomes is used to identify a set of candidate doses, rather than selecting one dose. Additional patients then are randomized among the candidates, patients are followed for a predefined longer time period, and a final dose is selected to maximize the long-term therapeutic success rate, defined in terms of duration of response. Dose-specific sample sizes in the randomization are determined adaptively to obtain a desired level of selection reliability. The design was motivated by a phase I-II trial to find an optimal dose of natural killer cells as targeted immunotherapy for recurrent or treatment-resistant B-cell hematologic malignancies. A simulation study shows that, under a range of scenarios in the context of this trial, the proposed design has much better performance than two conventional phase I-II designs.