代理盲签名的不可跟踪性分析

张学军在《基于身份的代理盲签名方案的分析与改进》(《计算机工程》,2009年第23期)一文中分析指出,农强等的代理盲签名方案(《计算机应用》,2008年第8期)不具有不可跟踪性。对此,通过反证法证明张学军的方法有误,在此基础上提出一种新的分析方法,利用其证明胡江红的方案(《计算机工程与应用》,2007年第18期)不满足不可跟踪性,并对该方案进行改进,使其满足不可跟踪性且效率得到提高。     

Ultrastructural and biochemical changes of hepatocytes during ether and fluothane anesthesia under experimental conditions

A study was made of a possibility of using Soviet made membranes "Vladipor" with a pore diameter of 16--17 nm for the purpose of concentration and purification of antigenic extracts from stab cultures of S. typhi obtained by the action of typsin, hydrogen peroxide and detergents. Preparations, complete by antigenic structure, were obtained by ultrafiltration, with a good yield. The maximal rate of ultrafiltration was noted in case of "peroxide" antigenic preparations. The use of diafiltration provided a significant reduction of the ash content in the end products.     

The critical control of progesterone levels and pregnancy by antiprogesterone

Circulating plasma progesterone (P) has been quantitatively controlled in the rat "model" through highly specific binding by treatment with anti-P (A-P). Knowing the constant, which characterizes the binding of P to A-P in plasma, sequential assays of circulating A-P and A-P bound total P (Pt) revealed the levels of the biologically active unbound P (Pu). The studies showed that at different stages of gestation the mechanisms through which A-P reduces Pu and terminates pregnancy are the same. However, the doses of AP which effectively reduce Pu and also the critical levels of Pu at which pregnancy terminates are different. The moderate and transient physiologic P-withdrawal (Pw) at midterm permits the continuation of normal gestation, but pregnancy is terminated by a drastic and sustained reduction in Pu. In contrast, when Pu is only slightly and briefly reduced below physiologic levels, pregnancy continues and only retarded conceptus growth signals that Pw occurred. Apparently Pw has to be controlled and measured with "razor's-edge" precision to fully expose and define the regulatory significance of this steroid in the maintenance and termination of pregnancy. Short of this precision, the key regulator of the pregnant uterus will remain buried, as it has been during 40 years, in controversial findings.     

Morphology of pneumopathies and their role in the development of asphyxia neonatorum

Histories of deliveries and development records of 44 newborns with penumopathies who had died on the first days of life in the presence of phenomena of the syndrome of respiratory disorder were analysed and the newborns' lungs were morphologically investigated. The investigation made it possible to single out the following forms of pneumopathy in newborns: edematous-hemorrhagic, hyaline, atelectatic, aspirated, and mixed. In the majority of cases the syndrome of respiratory disorder was a sequela of hypoxia of the intrauterine origin which continued during the first hours and days of life after birth. Such "primary asphyxia" may lead to the development of pneumopathy in a neonate. On the other hand, "secondary asphyxia" in many cases represent sequelae of penumopathy destructural and functional immaturity of the pulmonary tissue, hypoxia, a higher permeability of vessels of the microcirculatory bed, spasm of small pulmonary arteris contributed considerably to the development of penumopathies.     

飞机训练模拟器视景系统非线性失真校正技术研究

柱面实像投影是飞机训练模拟器视景系统采用的主要投影方式之一,可以得到很大的观察视野,但是不可避免地会产生非线性失真。根据具体的工程背景,针对大视场角的柱面实像投影的非线性失真,分析了其产生的原因,并设计了投影仪的离轴安装方案,从而提出了基于预失真的柱面投影非线性失真校正算法。实际的校正结果表明,采用预失真的方法进行柱面非线性失真校正,是一种行之有效的方法。通过相应的数据结构设计,保证了程序执行的实时性。     

新型风力发电系统

瑞典纳苏登Ⅲ风力发电场中的发电机是一种高压永磁发电机,入网采用轻型HVDC系统,从而构成了一种新型的发电系统.     

基于人工神经网络的高压水射流混凝土构件表面处理模型

目的应用高压水射流进行混凝土构件表面处理前确定机械的初始参数。实现对处理深度全面合理的控制．方法用AJP-E25135型高压泵，RG-2002HNDF型、口径为0．25mm七喷嘴旋转喷枪，对36组不同的初始参数、同批制作的砾石混凝土试块进行了高压水射流表面处理试验，并运用人工神经网络技术，对试验数据进行理论分析．结果建立了压力、靶距、口径、S／A（砂率）与处理深度关系的预测模型并把模型的预测结果与实验结果进行了比较，平均相对误差为0．0005．结论模型能够满足工程实际需要．可用于混凝土构件表面处理深度的估计与分析，以及特定处理深度条件下初始参数的预测．并可广泛应用于高压水表面处理深度模型的参数优化选择。智能化控制等领域．     

面向电信运营流程的数据稽核方法

针对电信收入保障的主要任务数据稽核，结合电信运营流程的特点，提出了一种新的数据稽核方法. 该方法抽象了电信运营流程的数据流模型，根据一个数据两处体现的电信业务数据处理和变换的原理，基于数据之间的平衡关系和完整性约束关系，定义出电信运营流程中的数据稽核关系；应用这种数据稽核关系可以检测并诊断电信运营流程不规范造成的故障，更好地支持企业的内控管理.      

大型工程细长薄壁结构振动仿真中的不完全等效研究

采用不完全等效刚度和不完全等效质量法,应用MSC Patran和MSC Nastran软件对某大型工程细长薄壁结构振动进行有限元计算,并分析计算结果,为工程设计提供参考.     

H.264编码工具性能及实时性研究

H．264具有更好的编码效率，但其高复杂度无法满足实时应用。针对低码率应用，分析各编码工具的性能并选取合理编码框架，同时利用单指令多数据（SIMD）技术并行实现快速搜索及整数变换。