双边沿触发计数器的设计和应用

双边沿触发计数器由偶数、奇数加法计数器及数据选择器组成.两个加法计数器在时钟信号作用下并行工作,交替处于计数和保持状态.数据选择器则将两个计数器中处于保持状态的奇偶数据交替输出,实现双边沿触发加法计数器的功能.该触发计数器采用Verilog语言设计和软件仿真,可用于计数、定时和分频三种情况.     

微带一分四路功率分配器的研究

提出了一种新的多端口功率分配器,其通过一个扇形结构将信号等分为四路.通过增加输入和输出匹配网络,提高功率分配器的工作带宽,同时避免了高特性阻抗传输线的出现.文章的最后分析了一个实例,功率分配器工作频带由12.5%扩展到了34%,通过与文献比较,可以看到性能的明显提高.     

基于FPGA的数控测试系统设计

基于超高速集成电路硬件描述语言(VHDL)的数控测试系统,含控制信号、接收数据、数据处理及发送数据模块.根据不同控制信号,数据处理模块得到分频数据、主轴编码器输出个数和主轴编码器线数.由数据SPDL_SD产生主轴脉冲分频脉冲,再由分频脉冲DIV控制产生SPDL NUM/4个正交的A、B脉冲,同时根据数据SPDL_XS产生Z脉冲.通过外部的输出电路,把产生的主轴A、B、Z脉冲发送到被测的数控系统.     

基于两台机组脱硫的公共系统设计

厦门嵩屿电厂二期的#3、#4脱硫机组,各采用1套FGD_DCS系统.为使公共系统接收到的信号与现场一致,通过4～20mA模拟信号隔离放大分配器,将信号转换后分别送入#3/#4脱硫系统实现信号共享.其分配器电源直接从DPU柜内电源取,现场信号经一分二信号输入,解决了模拟量一致的问题.     

基于ISP的信号接口设计

利用ISP器件和VHDL语言设计的专用信号接口由继电器阵列、多路开关和相关驱动电路组成.采用计算机ISA总线控制,通过继电器触点切换实现测试信号的分配.并用VHDL语言描述逻辑、定义管脚、增加读写、编译原理图、产生JED文件,将JED文件存入可编程逻辑器件以完成编程设计.     

基于VHDL的高速可编程遥测数据采编器的设计

采用自上而下的设计方法,利用VHDL硬件语言实现高速可编程数据采编器的设计,通过编程完成对遥测数据的采集和发送信道的编排工作,并对码速率、帧长、字长和码型等主要指标实现现场可编程,增加了遥测系统的灵活性和适应性。     

基于RTPA规范的实时任务调度

基于RTPA规范的实时任务调度器与时间和事件管理器协同可完成处理器上不同任务间的切换,有效解决实时系统中的优先级反转和多任务阻塞及死锁.资源管理器将所有等待资源的任务按照优先级递减排序,只有优先级最高的任务有资格获得资源.SWAI/OS任务调度器通过资源分配器分配系统资源,同时也向系统中引入新的或删除不再需要的任务等.     

基于Kalman的电-永磁混合磁悬浮系统过流检测

电-永磁混合悬浮系统中,因电感时滞效应及含噪声电流输入导致过流保护不及时或误判,故采用FPGA硬件检测平台设计了基于卡尔曼的电流预报器.其步骤包括确定输入值、预测下一时刻电流值、利用VHDL语言进行系统设计.仿真表明,该系统能准确预测电流值并较强抑制噪声信号,对双向电流斩波器的过流保护可靠有效.     

基于CPLD的串行接口芯片的设计与实现

在某武器系统中,提出了利用Ahera的CPLD器件(EPM7256),采用VHDL实现串行通信的设计思路、电路结构和设计方法。较专用串行通信芯片具有数据通信速度高、能简化系统电路和更好的可控性等优点。     

相控阵雷达导引头总体技术研究

相控阵雷达导引头具有波束扫描灵活、空间功率和时间资源分配可控等优点,具有有源/无源相控阵列组成形式.前者每个天线单元用1个接收机和发射功率放大器,后者共用1个或几个发射机和接收机,采用时需综合考虑.有源相控阵雷达导引头的组成有相控阵天线、波束控制计算机、T/R组件、激励器、功率分配器、波束形成网络、接收机、信号处理、数据处理、中央控制计算机等部分.     

Nitrosation and Nitration of Tetraacetyldibenzylhexaazaisowurtzitane

Tetraacetyldibenzylhitane (TADBIW) was subjected to debenzylation by nitrosating with inorganic materials available commercially to synthesize tetraacetyldinitrosohexaazaisowurtzitane (TADNSIW). TADNSIW was purified, and its structure was determined by FTIR, 1H NMR, MS and element analysis. The debenzylation reaction of TADBIW gave quantitative benzaldehyde as a by-product. This indicates that the reaction produces an imine cation as an intermediate. Hexanitrohexaazaisowurtzitane (HNIW) was prepared from unpurified TADNSIW with the yield over 96.0 % and the purity more than 98.0 %. And the mechanism of the reaction from TADNSIW to HNIW is proposed to be oxidation of nitroso and nitration of acetyl on the molecule of TADNSIW, This reaction system involved is simple, and the reaction can complete within a short time and under mild conditions. The product can be easily to separate and the waste disposed readily.     

A Robust Algorithm for Watermarking 2D Vector Maps with Low Shape-Distortions

The technique of watermarking has been introduced into 2D vector maps for many potential applications such as protecting the copyright of important GIS （geographical information system） data and tracing the data source of military maps. In most previous works, although the validity of the map data could be preserved during the embedding procedure, the shape-distortions of the map elements are usually neglected which would tend to degrade the invisibility of the watermarking schemes. A shape-preserving algorithm for watermarking 2D vector maps is presented in this paper. A 1D distance sequence extracted from the original map is adopted as the cover data instead of 2D coordinates. A watermark bit is represented by changing the distributions of the cover data. The embedding procedure induces lower shape-distortions than in former works. Experimental results indicate better invisibility of the proposed scheme, as well as its robustness to certain attacks such as map simplification, interpolation, additive noise and most geometric transforms.     

Stability of the Third Generation Intensifier under Illumination

The stability under illumination of transmission-mode GaAs photocathode sealed in the third generation intensifier is investigated by use of spectral response testing instruments. The variations of spectral response with the illumination times under weak and intense illumination are compared. The variations of photoemission performance parameters are also characterized. The results show that during initial several weak illuminations photocathode behaves no evident decay and a maximum sensitivity is achieved, while under intense illumination the sensitivity of photocathode begin to decrease largely at the first illumination. The calculated performance parameters show that the variation of surface escape probability with illumination times is a direct cause of instability of photocathode. It is also found that under intense illumination peak wavelength is moved towards short-wave and peak response is decreased, which shows that the ability of long-wave response of photocathode is decreased.     

Open Rule-setting System Applied to Conceptual Design of Engines

Open rule-setting method advanced in this paper concentrates on providing designers of engines with a convenient way to express their design innovations and develop the expected prototypes in the early CAD stage, and constitute effective models for the following analysis process of CAE and CAPP. The problems arisen in the process of conceptual design with the traditional experience-based development method are analyzed. Based on those analyses, open rule-setting method is presented and some associated technical problems are discussed. The functional framework of open rule-setting system was built as software engineering methods. The speciality of the engine product as a kind of complex product and the requirement of the engine product based on its structural particularity to rule-setting system are considered carefully. A demonstration is supplied to illustrate how the open rule-setting method enhances the efficiency and quality of the engine conceptual design.     

Research on Linux Network Device Driver

By analyzing the working principle of Linux network device driver, discussing the Linux network driver structure and its key technologies, the general network driver structure and its design methodologies in Linux system are summarized. Through modifying the network device driver of Linux device driver 3rd version snull, c and improving the COW technology, the Zero-Copy technology in Linux （kernel version 2.6.11 ） is implemented. In the end, the success test tells us that the thorough analysis of network device driver is the foundation of many applications, and it also provides a certain improvement to a lot of real applications, even to military application development.     

Improvement and Experiment of the Reamer in Vibra Cutter Against Wave Edge of Titanium Sheet Alloy Parts

By analyzing the influencing factors of part quality making of sheet alloy of titanium by vibra cutter, the shape of upper reamer is set as cylinder and wedge-shaped form, and the lower reamer as plain and hemicycle form, and its main structural parameters are defined as well. Then it is validated further that such improved vibra cutter reamer can be used to process curve-edged parts of titanium alloy sheet. The experimental result shows that the titanium alloy sheet parts processed by above equipment have no sharpen angles for convex parts and evident crevasse of concave-edged part. In summary, such improvement can eliminate the free-waved edge and improve the manufacture quality of titanium alloy sheet parts greatly.     

Experimental Study on the Small Flyer Initiating Behavior of Fine-grained Explosives

The initiating behavior of fine-grained explosives by small flyer is studied. The diameter of small flyer in this device is 1 ram. The test results indicate that the granularity of explosives has great effect on its flyer initiating sensitivity.The flyer initiating sensitivity of the fine-grained explosives is higher and the critical initiating energy is lower than that of common explosives. For common explosive, the flyer initiating sensitivity increases as the density is reduced. But for the fine-grained explosive, the test results are exactly opposite.     

Passive Acoustic Radar for Detecting Supersonic Cruise Missile

A Passive Acoustic Radar is presented as a necessary complement to electromagnetic wave radar, which will be expected to be an effective means for detecting cruise missiles. Acoustic characteristics of supersonic flying projectiles with diverse shapes are expounded via experiment. It is pointed out that simulation experiment could be implemented using bullet or shell instead of cruise missile. Based on theoretical analysis and experiment, the ““acoustic fingerprint““ character of cruise missile is illustrated to identify it in a strong noise environment. After establishing a locating mathematical model, the technique of acoustic embattling is utilized to resolve a problem of confirming the time of early-warning, considering the fact that velocity of sound is much slower than that of light. Thereby, a whole system of passive acoustic radar for detecting supersonic cruise missile is formed.     

Algorithm for Multi-laser-target Tracking Based on Clustering Fusion

Multi-laser-target tracking is an important subject in the field of signal processing of laser warners. A clustering method is applied to the measurement of laser warner, and the space-time fusion for measurements in the same cluster is accomplished. Real-time tracking of multi-laser-target and real-time picking of multi-laser-signal are introduced using data fusion of the measurements. A prototype device of the algorithm is built up. The results of experiments show that the algorithm is very effective.     

Super-resolution Restoration of Remote-sensing Images

A novel image restoration scheme, which is super-resolution image restoration algorithm Poisson-maximum-afterword-probability based on Markvo constraint （MPMAP） combined with evaluating image detail parameter D, has been proposed. The advantage of super-resolution algorithm MPMAP incorporated with parameter D lies in the fact that superresolution algorithm MPMAP model is discrete, which is in accordance with remote-sensing imaging model, and the algorithm MPMAP is proved applicable to linear and non-linear imaging models with a unique solution when noise is not severe. According to simulation experiments for practical images, super-resolution algorithm MPMAP can retain image details better than most of traditional restoration methods; at the same time, the proposed parameter D can help to identify real point spread function （PSF） value of degradation process. Processing result of practical remote-sensing images by MPMAP combined with parameter D are given, it illustrates that MPMAP restoration scheme combined PSF estimation has a better restoration result than that of Photoshop processing, based on the same original images. It is proved that the proposed scheme is helpful to offset the lack of resolution of the original remote-sensing images and has its extensive application foreground.