Double Plays

Abstract

For companies faced with the need to deliver new applications more quickly and at lower costs than before, client/server computing is becoming a reality. End-user computing, although not directly involved in creating the new applications, is affected by the shift in computing architecture.     

双GPS接受机双单片机的硬件实现

介绍了GPS定位的一些知识以及设计利用双单片机进行GPS数据采集的硬件实现，在硬件实现时可能遇见的一些问题和解决的手段。     

双私钥双随机数认证方案

计算机网络是一个开放的系统,也正是由于其开放性导致计算机网络中存在相当多的安全漏洞和安全威胁,网络中的各类资源很容易被人非法访问和复制.因此对网络资源访问者的合法身份进行认证就显得非常重要.1981年,Lamport提出了一种基于密码表的用户认证方案.此方案可以抵抗重传攻击,然而,当存储在主机的口令一旦遭到攻击者的攻击,方案将无任何安全可言.智能卡可以作为一种更有效的用以认证身份的个人持有物,许多基于智能卡的认证方案被提出.首先对Das的双线性对身份认证方案进行了详细分析,针对其存在时钟同步问题,易遭受伪造攻击等安全隐患,提出了一种基于双线性对并利用智能卡完成的交互认证方案.为防止在认证过程中被伪造攻击,提出双私钥双随机数的方法,增强了认证系统的安全性,可安全地完成用户和远程系统间的交互认证.     

双半桥双膜片微型差压传感器

针对双膜片式微型差压传感器提出由双半桥组成一种差压全桥的桥路设计，并给出了理论推导及实测结果，且它们符合较好。并通过零位调节和满量程调节，在实际上使两个半桥的满量程相等，零位近似为零。     

Double Horn Functions

In this paper, we define double Horn functions, which are the Boolean functionsfsuch that bothfand its complement (i.e., negation)fare Horn, and investigate their semantical and computational properties. Double Horn functions embody a balanced treatment of positive and negative information in the course of the extension problem of partially defined Boolean functions (pdBfs), where a pdBf is a pair (T, F) of disjoint setsT, F⊆{0, 1}ⁿof true and false vectors, respectively, and an extension of (T, F) is a Boolean functionfthat is compatible withTandF. We derive syntactic and semantic characterizations of double Horn functions, and determine the number of such functions. The characterizations are then exploited to give polynomial time algorithms (i) that recognize double Horn functions from Horn DNFs (disjunctive normal forms), and (ii) that compute the prime DNF from an arbitrary formula, as well as its complement and its dual. Furthermore, we consider the problem of determining a double Horn extension of a given pdBf. We describe a polynomial time algorithm for this problem and moreover an algorithm that enumerates all double Horn extensions of a pdBf with polynomial delay. However, finding a shortest double Horn extension (in terms of the size of a formula?representing it) is shown to be intractable.     

日蚀劳动_多媒体工厂

出于对影像共同的理解和喜好，项砚冬和汤一虎在2000开始实验电影《殒云》的创作，同年成立了日蚀影像。“日蚀”源于项砚冬94年想组建的重金属乐队，并将这一名称用于实验电影的片头，而“劳动”则是对工作室严谨专业的工作作风及文化理念的最好阐释。     

基于双口RAM的双CPU之间的实时双向通信

介绍一种通过双口RAM和可编程逻辑器件实现单片机80C196KC和工控机PCI04之间实时双向通信的方法.对双口RAM-IDT7130和可编程逻辑器件ISP1032E的性能和特点作了详细介绍,给出了利用IDT7130和ISP1032E实现单片机80C196KC和PC104之间进行高速数据通信的接口电路及软件实现方案.     

双信号预测控制

提出一种双信号预测控制算法，该算法包含预测模型、滚动优化、反馈校正和导前信号校正４个环节。仿真结果表明，在一定条件下，所提出的算法优于传统的预测控制。     

Implementing the Double Bootstrap

The single bootstrap already is popular in economics, though the double bootstrap has better convergence properties. We discuss the theory and implementation of the double bootstrap, both with and without the pivotal transformation, and give detailed examples of each. One example is a nonlinear double bootstrap of a Cobb-Douglas production function, and explains the use of Gauss-Newton Regressions as a device to decrease computational time. Another example is double bootstrapping elasticities from a translog production function.     

Double hashing with passbits

Double hashing with bucket capacity one is augmented with multiple passbits to obtain significant reduction to unsuccessful search lengths. This improves the analysis of Martini et al. [P.M. Martini, W.A. Burkhard, Double hashing with multiple passbits, Internat. J. Found. Theoret. Comput. Sci. 14 (6) (2003) 1165-1188] by providing a closed form expression for the expected unsuccessful search lengths.     

Double Greibach operator grammars

Every context-free grammar can be transformed into one in double Greibach operator form, that satisfies both double Greibach form and operator form. Examination of the expressive power of various well-known subclasses of context-free grammars in double Greibach and/or operator form yields an extended hierarchy of language classes. Basic decision properties such as equivalence can be stated in stronger forms via new classes of languages in this hierarchy.     

双机通信分析

微机与外部的信息交换称为通信，基本方式有并行与串行两种。本文主要说明串行方式，主要掌握微机串行通信的连接方法，熟悉其工作方式及其功能，运用程序流程图说明了其工作过程。     

Double speed single production line

This paper presents a hybrid push and pull production management approach called double speed single production line (DSSPL), developed for industries that produce a large variety of slightly different items subject to highly variable demand. Because of this framework, only mediocre lead times for all their products can be guaranteed. The DSSPL system suggests improving their logistic performances by splitting products into A- and B-classes, according to a market oriented policy, then by producing, on a single line, but at different speeds, the A- (fast) and the B-products (slow), thus leading to a better allocation of production resources. A discrete event simulator has been developed in order to evaluate performances of the DSSPL approach to pure push and pull systems. First results are presented and the performance of the DSSPL system is discussed.     

一种双电容式料位传感器

采用双电容器的结构设计了一种新型双电容式料位传感器。传感器结构简单,安装灵活,可工作在恶劣的环境中,可减小因温度和湿度造成的测量误差,可减小分布电容和寄生电容对测量结果的影响,不仅适用于金属容器,也适用于非金属容器的料位测量。     

以双字线双阈值4T SRAM为基础的存内计算设计

为了应对冯·诺依曼计算架构的存储墙,存内计算(CIM)架构将逻辑嵌入到存储器中,在读取数据的同时完成运算,使存储单元具备计算能力并且减少了处理器和存储器之间的数据传输.为实现大容量、低成本存储器设计,提出了一种以双字线双阈值4T SRAM为基础的存储系统,不仅可实现数据的存储与读取,而且还可实现BCAM运算和与、或非、异或等逻辑运算.逻辑运算时,经译码电路任选两行存储数据,位线均预放电至低电平,位线电压通过位线端灵敏放大器与参考电压比较后输出运算结果.BCAM运算时,外部输入数据经译码电路译码后实现对存储单元左右传输管的开、断控制,位线端灵敏放大器经或非门输出匹配结果.在65 nm CMOS工艺下对所提电路进行搭建并仿真.4T存储单元相较于6T存储单元的存储面积减少了25％,双字线4T存储结构相较于单字线4T存储结构在超大规模集成电路(VLSI)应用中读功耗可节省47％左右.BCAM运算时数据匹配最大功耗为909.72 FJ,N列的阵列运算速度在字线电压为600 mV时可达16161.6×N MB/Hz.     

二级倒立摆系统设计

自行设计了二级倒立摆硬件系统，完成了机械部分与电路部分的总体设计、加工、组装和调试。自行设计并制作了倒立摆系统控制盒，利用控制盒实现了对角度、位移等状态变量信息的滤波、处理与控制指令的输出。利用Lagrange方法建立了二级倒立摆系统的完整数学模型，同时利用滑动模态变结构控制算法设计了相应的控制率，基于VisualStudi06．0环境编写了控制算法，成功的实现了对于二级倒立摆系统的稳定控制。     

双边开关磁阻直线电动机的设计

介绍了双边开关磁阻直线电动机(LSRM)的组成、工作原理及其尺寸设计方法,给出了LSRM样机的尺寸设计结果,并采用有限元法分析LSRM磁场分布规律,进行磁场分段计算,从而得到了最大电感、最小电感和相绕组匝数。测试结果表明,该LSRM样机启动力较大且出力不受电流方向影响,但也存在出力有脉动和噪声较大等问题,该问题可通过优化结构设计和控制算法解决。