数字电子秤模拟量自动调零的研究

在自动检测系统中，对于零漂的现有些控制系统在一定精度范围内允许，但对行有些控制系统不允许，本文对电子秤自动测量系统中出现零的漂情况，给出一种模拟量自动调零电路，其中保持电路时间为数小时之久，解决了检测过程中的零漂自补偿问题。     

GPS调零天线的数字接收机阵列

研究了GPS调零天线系统数字接收机阵列的一种高效实现方案.提出采用新型的可配置时分复用FIR滤波器组,实现了多通道数字下变频处理中的采样速率转换与滤波器系数重加载,通过对GPS调零天线系统四通道数字接收机阵列的设计实现与测试分析可以得出,此方法与多通道并行重复处理的常规数字下变频方式相比,可以节约大约60%的FPGA硬件资源,并可增强系统实现的灵活性.     

自动调零伺服器倾角传感器的设计与实现

零位偏差和漂移是所有倾角传感器都待解决的技术难题。本文通过水泡尺旋转1800找平的古老方法深八研究传感器的调平原理，建立一套倾角传感器自动调零的理论和方法。采用步进电机和单片机控制技术设计实现自动调零伺服倾角传感器，很好的解决了零位偏差，时间漂移和温度漂移等问题，使倾角传感器的性能得到提高，具有非常重要的应用价值。     

自动调零伺服倾角传感器的设计与实现

零位偏差和漂移是所有倾角传感器都待解决的技术难题.本文通过水泡尺旋转180°找平的古老方法深入研究传感器的调平原理,建立一套倾角传感器自动调零的理论和方法.采用步进电机和单片机控制技术设计实现自动调零伺服倾角传感器,很好的解决了零位偏差,时间漂移和温度漂移等问题,使倾角传感器的性能得到提高,具有非常重要的应用价值.     

一种采用DAC0832实现程控调零与放大的方法

本文介绍了一种采用Ｄ／Ａ转换芯片ＤＡＣ０８３２实现程控调零和程控放大的方法，采用该方法能够实现２５５级的调零和放大精度，具有使用方便、稳定可靠的特点，适合于自动测控系统     

一种自动调零应变信号调理器的设计

使用电阻应变片测量物体的承受载荷情况是最常用的测量方法。受电阻应变片个体操作差异性、传输线路损耗、温度漂移等因素的影响,初始零位的固定对实际测量数据的读取有重要的意义。基于STM32微控制器,配合多种电子元器件,设计出了一种具有自动调零能力的应变信号调理电路,完全实现了自动化,方便快捷,提高了调零精度。     

抗干扰兼容型卫星导航接收机设计与仿真

抗干扰兼容型卫星导航接收机既可以使用组合卫星定位系统进行高精度定位,又具有优良的抗干扰性能。其抗干扰性能通过自适应调零天线实现,介绍了系统硬件电路实现,并在相应硬件平台上,采用功率反演算法进行干扰抑制。仿真测试结果表明,自适应调零天线有效地提高了接收信号的信噪比,提高了兼容型卫星导航接收机的应用范围。     

基于数字电位器的电子水平仪自动调零方法

零点漂移是所有传感仪表都必须考虑的一个问题,本文基于所设计的电子水平仪,提出了一种用单片机控制数字电位器实现水平仪自动调零的方法,并给出了硬件设计电路和软件控制流程。实验表明该方法能够快速有效地实现仪表系统的自动调零。     

厚度传感器接口电路中自动换挡及调零技术

自动换挡和自动调零是传感器接口电路的关键技术,它直接影响到测量过程中的测量分辨率、精度和误差,如果解决好这个问题就能对信号采集、处理起到决定性作用.本文介绍了厚度传感器信号采集电路的自动换挡和自动调零技术.     

基于数字电位器的电子水平仪自动调零方法

零点漂移是所有传感仪表都必须考虑的一个问题,本文基于所设计的电子水平仪,提出了一种用单片机控制数字电位器实现水平仪自动调零的方法,并给出了硬件设计电路和软件控制流程.实验表明该方法能够快速有效地实现仪表系统的自动调零.     

Design of digital signal processor based adaptive beamformer using hybrid residual least mean square algorithm for improved performance

This paper proposes a novel hybrid residual least mean square (HRLMS) algorithm for adaptive filtering followed by an antenna beamformer using 16‐element linear array. The hybridization process involves a switching between the residual‐LMS (RLMS) and the conventional‐LMS (CLMS) algorithms after the eighth iteration, if the square errors for four consecutive iterations are less than a threshold. The novelty of HRLMS lies in estimating best step size factor through residuals for speedy convergence followed by the CLMS switching for minimum steady state error (SSE). The novelty also includes in realizing a real‐time antenna beamformer with significant sidelobe level (SLL) reduction and improved interference nulling by integration of HRLMS and space selective digital filter (SSDF). The adaptive filter and smart beamformer, based on HRLMS and HRLMS‐SSDF have been implemented on TMS320VC5416 digital signal processor. The comparative performance evaluation of HRLMS has been done for convergence speed, SSE, interference nulling and SLL reduction with the existing variable step size LMS (VSSLMS) algorithms. The iteration count for convergence has been reduced by about 50% with paltry additional computational burden over the other VSSLMS algorithms. The HRLMS‐SSDF provide attenuations of about 76, 33, and >50 dB, respectively for interfering signals, first SLL and higher order SLLs of beamformer.     

Amplitude‐only pattern nulling of linear antenna arrays with the use of an immune algorithm

This article presents an optimization immune algorithm (opt‐IA) for null steering of linear antenna arrays by controlling only the element amplitudes. Nulling of the pattern is also achieved by controlling the phase‐only and the complex weights (both the amplitude and phase) of the array elements. The opt‐IA is a new evolutionary computing algorithm based on the clonal selection principle of immune system. To show the accuracy and flexibility of the proposed opt‐IA, several examples of Chebyshev array pattern with the imposed single, multiple, and broad nulls are given. It is found that the nulling technique based on opt‐IA is capable of steering the array nulls precisely to the undesired interference directions. © 2008 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2008.     

协商式的物流联盟运输规划模型优化研究

通过分析一次完整的物流联盟企业项目型物流配送过程,提出物流联盟规划问题的两阶段解决方案。首先,针对当前大型物流配送系统的现状,采用实例化路径视图的策略,预先计算和存储可行路径,给出相应算法。其次,在信息不完备情况下,采用基于协商的Agent技术优化可行路径。实验证明：在不完全信息下,解决方案能求得在指定时间约束下的最优成本方案。     

数据流查询计划的并行迁移策略

数据流中的查询计划需要不断进行适应性优化,针对该特征提出一种查询计划的并行迁移策略。该策略能确保在输出过程中不丢。失元组或产生冗余元组,维持正确的元组输出时序。实验结果证明,该策略可以使查询计划平滑过渡,避免迁移过程出现无元组输出的空自期,在系统资源紧张和数据流流速过大时,维持较少的中间元组数和较大输出速率。     

面向资源本体的山地生物多样性空间分析研究*

研究了面向山地生物多样性保护的资源本体空间分析问题;建立了基于Mereotopology与定位理论的山地多层生物资源本体模型,并在此基础上完成了数字峨眉资源环境动态监测系统。实验证明,该系统不仅存储了峨眉山自然保护区内濒危物种的分布、植被、气候等丰富的资源信息,而且通过空间分析技术,揭示了保护对象与生境的存在状态、破碎程度和变化趋势之间的内在关系。本研究为本体论与山地生物多样性保护工作相结合探索了一条新的途径。     

三网融合下基于资源池化的视频业务管理策略

对现有KAD协议在高并发、高实时性需求环境中的优缺点进行分析。为减少系统信息的冗余和延迟时间,提出一种在三网融合背景下,基于服务节点资源池划分的改进KAD网络视频业务系统的调度管理策略。采用基于网络连通性的准则将视频业务网的服务节点划分为若干资源池,各池内部网络采用KAD方式进行组织。根据用户请求量的预测,采用池间资源租借的方式解决单个资源池由于业务量增大而导致的服务过载问题。实验结果表明,对于典型的视频业务请求,马尔科夫链预测法能够实现过载漏报率为0的精确预警,从而根据预测结果,并利用KAD网络灵活的扩展性及时地补充服务资源。     

Colocated MIMO radar waveform-design based on two-step optimizations in spatial and spectral domains

We propose an efficient colocated multiple-input multiple-output radar waveform-design method based on two-step optimizations in the spatial and spectral domains. First, a minimum integrated side-lobe level strategy is adopted to obtain the desired beam pattern with spatial nulling. By recovering the hidden convexity of the resulting fractional quadratically constrained quadratic programming non-convex problem, the global optimal solution can be achieved in polynomial time through a semi-definite relaxation followed by spectral factorization. Second, with the transmit waveforms obtained via spatial optimization, a phase changing diagonal matrix is introduced and optimized via power method-like iterations. Without influencing the shape of the optimized beam pattern, the transmit waveforms are further optimized in the spectral domain, and the desired spectral nulling is formed to avoid radar interference on the overlaid licensed radiators. Finally, the superior performance of the proposed method is demonstrated via numerical results and comparisons with other approaches to waveform design.     

Optimized mobile cloud resource discovery architecture based on dynamic cognitive and intelligent technique

In current world, the Mobile Cloud Computing (MCC) will undergo a dramatic upgrade with integrating of mobile cloud resources in small regions to provide a better MCC service. This paper considers the MCC resource availability problem in integrated mobile cloud environment to optimization resources availability with a better effectiveness, accuracy, reliable, low latency and low complexity. The DCICRD architecture is proposed in this paper optimizes the resource discover process with better resource availability. The proposed DCICRD architecture runs various operations such Resource demand prediction to find the required level of resources, Cloudlet Resource Discovery process which discovers resources based on the requirement predicted using two states expand and shrink. The expand state is used to discover resources on-demand in resource scarcity situation and the shrink state is called when abundant resource available to the required level.  Further, Resource reliability check is performed to identify the reliable resource with energy level and signal strength above the threshold level. Finally, Local Resource Information Management Table is used to store the local resource provider information and Central Resource Information Management Table is used to store all local resource information for handover of resource provider. The implementation and evaluation is conducted by comparing the HARD architecture. The comparison result shows that proposed DCICRD architecture is better than HARD architecture by optimizing the resource discovery process and produce reliable resources on demand as per the required level with a better effectiveness using expand and shrink state, accuracy by making resource available for required level, reliable by sending message for frequent checking of Resource with required energy level and signal strength, low latency by making resource available locally and reduce complexity by performing only on-demand resource discovery operation after initial startup. Thus, the proposed DCICRD architecture is better when compared to HARD architecture.     

Dynamic argument embedding: preserving state on the World Wide Web

At the IBM T.J. Watson Research Center we implemented a way of preserving state during HTTP sessions by modifying hypertext links to encode state information. We call the method dynamic argument embedding, and it was developed in response to problems we encountered implementing the Coyote Virtual Store, a transaction-processing system prototype. Virtual store applications, such as IBM's NetCommerce and Netscape's Merchant System, typically need to maintain information such as the contents of shopping baskets while customers are shopping. We wanted our application to be flexible enough to maintain such state information without restricting the sorts of HTML pages a customer might view. We also wanted a system that did not require extensions to the hypertext transfer protocol (HTTP) and so could be implemented on any standard Web server and client browser. Finally, we wanted to permit customers to access several accounts at once by using the browser's cache to concurrently store pages corresponding to multiple invocations of the virtual store application     

基于UKF和优化组合策略的改进粒子滤波算法

针对标准粒子滤波算法存在的粒子退化与贫化问题,提出了一种新的改进粒子滤波算法。该算法采用无迹卡尔曼滤波、优化组合策略和标准粒子滤波相结合的方法,运用UKF产生重要性密度函数,解决标准PF算法中以先验概率密度函数作为建议分布所引发的退化问题;运用优化组合重采样策略保证所有粒子的信息以一定概率得到继承,维持粒子集中粒子的多样性。理论分析与仿真结果均表明,改进算法能有效地解决标准粒子滤波存在的粒子退化问题并避免粒子贫化现象的出现,具有更高的状态估计精度。