Mathematical modeling of a steam generator for sensor fault detection

A dynamic model for a nuclear power plant steam generator (vertical, preheated, U-tube recirculation-type) is formulated as a sixth-order nonlinear system. The model integrates nodal mass and energy balances for the primary water, the U-tube metal and the secondary water and steam. The downcomer flow is determined by a static balance of momentum. The mathematical system is solved using transient input data from the Philippsburg 2 (FRG) nuclear power plant. The results of the calculation are compared with actual measured values. The proposed model provides a low-cost tool for the automatic control and simulation of the steam generating process. The “parity-space” algorithm is used to demonstrate the applicability of the mathematical model for sensor fault detection and identification purposes. This technique provides a powerful means of generating temporal analytic redundancy between sensor signals. It demonstrates good detection rates of sensor errors using relatively few steps of scanning time and allows the reconfiguration of faulty signals.     

10ns～500ns宽度连续可调的快速光脉冲发生器

脉宽可调的脉冲发生器常用于精密检测。本文阐述了一种运用叠加原理设计的脉冲宽度从10ns到500ns连续可调的快速光脉冲发生器。在驱动电路中应用了脉冲叠加原理。     

Cyclic codes of length 2 m

In this paper explicit expressions ofm + 1 idempotents in the ring are given. Cyclic codes of length 2 ^m over the finite fieldF _q, of odd characteristic, are defined in terms of their generator polynomials. The exact minimum distance and the dimension of the codes are obtained.     

CHARACTERISTIC CONDITIONS FOR THECOMPLETE INFINITESIMAL GENERATORS OFANALYTIC SEMIGROUPS OF GROWTH ORDER α

1IntroductionandMainResultLetXbeacomPlexBanachspaceandletB(X)bethesetofaJlboundedlinearoperatorsfromXintoitselLAccordingtoDaPratol1],Sobole.skii[4]andZafievskii[6],aoneparameter~ly{T(t);t>o}CB(X)iscalledasemigroupofgrowtl1ordercr>Oif(Al)T(t s)=T(t)T(s)fort,s>oandT(t)xiscolltinuousillt>oforeachxEX;(Az)IfT(t)z=oforallt>O,thenx=o;(As)Ilt"T(t)IIisboundedast-O ;(A4)Xo=U,>.T(t)XisdenseinX.TheinfinitesimalgeneratorAoof{T(t);t>o}isdefinedbyItisknown[2]thatAoisclosable.LetA=Ao,thenA…     

DESIGN OF TWO-PHASE SINUSOIDAL POWER CLOCK AND CLOCKED TRANSMISSION GATE ADIABATIC LOGIC CIRCUIT

First the research is conducted on the design of the two-phase sinusoidal power clock generator in this paper. Then the design of the new adiabatic logic circuit adopting the two-phase sinusoidal power clocks--Clocked Transmission Gate Adiabatic Logic （CTGAL） circuit is presented. This circuit makes use of the clocked transmission gates to sample the input signals, then the output loads are charged and discharged in a fully adiabatic manner by using bootstrapped N-Channel Metal Oxide Semiconductor （NMOS） and Complementary Metal Oxide Semiconductor （CMOS） latch structure. Finally, with the parameters of Taiwan Semiconductor Manufacturing Company （TSMC） 0.25um CMOS device, the transient energy consumption of CTGAL, Bootstrap Charge-Recovery Logic （BCRL） and Pass-transistor Adiabatic Logic （PAL） including their clock generators is simulated. The simulation result indicates that CTGAL circuit has the characteristic of remarkably low energy consumption.     

Pseudo Random Number Generator Based on Back Propagation Neural Network

Random numbers play an increasingly important role in secure wire and wireless communication. Thus the design quality of random number generator（RNG） is significant in information security. A novel pseudo RNG is proposed for improving the security of network communication. The back propagation neural network（BPNN） is nonlinear, which can be used to improve the traditional RNG. The novel pseudo RNG is based on BPNN techniques. The result of test suites standardized by the U.S shows that theRNGcan satisfy the security of communication.     

一种适用于无线传感器通信的UWB收发机结构

论文介绍了一种使用低速率超宽带技术实现的适用于无线传感器网络通信的收发机结构,这种结构采用结构简单的IR-UWB(Impulse Radio UWB)方法,能满足无线传感器节点低功耗、低硬件复杂度的要求。这种结构发射机采用SRD(Step Recovery Diode)二极管来产生UWB脉冲信号,接收机则使用结构简单的能量检测方法。     

柴油发电机组选型细则

简要介绍柴油发电机组的主要特征、各种应用场合的选型、功率匹配及功率修正应关注的几个问题。     

车载通信方舱供电系统的设计与应用

结合工程实例,探讨如何设计高可靠性、安全的车载通信方舱不间断供电系统。由于车载通信方舱供电系统兼顾市电/电站集中供电方式,要确保通信系统稳定可靠、不间断地实施通信指挥,供电系统的设计尤为重要,除了满足一般供电系统的功能外,还应具有良好的机动性、环境适应性以及安全可靠等技术指标要求。文中从供电系统设计原则、设计过程等方面介绍了供电系统的设计方式,并分析了不间断电源的选型和蓄电池容量的选择等问题。     

1 ns脉宽延迟可调码型发生器在低速时钟下的实现方案

利用Altera公司高端FPGA芯片StratixIIFPGA的内嵌式增强型锁相环的特性,在采用较低速率时钟的情况下,通过配置锁相环参数,实现了高速率、占空比和延迟均可调的码型发生器,精度可达1ns.文中给出该算法的实现方案,并对其实现误差进行了讨论.最后用EP2S30F484C5芯片对该算法进行了实现,取得了预期的效果.