基于嵌入式技术的开关寿命测试仪的设计

为了对开关的寿命进行快速准确地测试,设计了开关寿命测试仪。设计过程如下:首先设计了测试仪的硬件,该硬件使用LPC2138CPU芯片采集开关触头对应的开关量,并与TG12864液晶模块接口输出提示信息;其次设计了判断开关好坏算法和识别坏触头算法;最后根据算法给出了测试仪软件的流程图。应用表明,用这种设计方法实现的测试仪工作可靠、容易使用,适合在开关生产行业推广应用。     

电容式倾角传感器在底盘悬挂系统中的应用

以P89V51RD2FN单片机为控制核心,采用电容式倾角传感器实时测量车辆底盘的倾斜角,并用光电传感器检测车辆最终运动姿态和车速。光电传感器和倾角传感器将实时测量信号馈送至单片机,并采用增量式PID控制算法确保车辆能够达到平衡。利用CANBUS 2.0将数据传输至车载电脑来达到智能化车姿控制。实验结果表明:系统响应时间快,精度高,性能稳定。     

离轴式拖车移动机器人的任意路径跟踪控制

离轴式拖车移动机器人属于非完整系统,当车头线速度随时间变化且过零变号时,难以用一个控制器实现系统对期望路径的跟踪.本文研究离轴式拖车移动机器人系统的任意路径跟踪问题.首先由系统和虚拟小车的运动学方程得到误差状态模型,线性化后用坐标变换将其化为标准型,然后基于Lyapunov方法构造出一种跟踪控制律.只要车头的运动线速度有界且不趋于零,其导数有界,则所设计的控制律就可以保证系统跟踪任意的期望路径,且跟踪误差最终一致有界,最终界的大小与期望路径的曲率变化率成比例.当期望路径的曲率变化率为零或趋于零时,所设计的控制律可以保证拖车移动机器人指数收敛到期望路径.仿真结果证实了控制律的有效性.     

Edge location to subpixel values in digital imagery

A new method for locating edges in digital data to subpixel values and which is invariant to additive and multiplicative changes in the data is presented. For one-dimensional edge patterns an ideal edge is fit to the data by matching moments. It is shown that the edge location is related to the so-called ``Christoffel numbers.' Also presented is the study of the effect of additive noise on edge location. The method is extended to include two-dimensional edge patterns where a line equation is derived to locate an edge. This in turn is compared with the standard Hueckel edge operator. An application of the new edge operator as an edge detector is also provided and is compared with Sobel and Hueckel edge detectors in presence and absence of noise.     

基于文本分类TFIDF方法的改进与应用

TFIDF是文档特征权值表示常用方法。该方法简单易行，但低估了在一个类中频繁出现的词条，该词条是能够代表这个类的文本特征的，应该赋予其较高的权重。通过修改TFIDF中IDF的表达式，来增加那些在一个类中频繁出现的词条的权重，用改进的TFIDF选择特征词条、用遗传算法训练分类器来验证其有效性。该方法优于其它算法，实验表明了改进的策略是可行的。     

Monitoring Smoothly Degrading Systems for Increased Dependability

A strategy is presented for determining when it is advantageous to take some action to restore a system to full capacity. A determination is made of the types of data that need to be collected and circumstances under which the strategy is likely to be useful. Production traffic data is presented for a very large industrial telecommunications project, and the strategy is applied. An investigation is made of when the application of the strategy leads to increased system availability and decreased packet loss experienced by users.     

钢铁企业生产能力平衡模型及启发式算法

针对钢铁企业生产能力平衡配置问题,建立了非线性数学模型,形式化地描述了钢铁产品对资源和能力的竞合关系,提出了平衡下的多个优化目标。针对问题的模型及其特点,提出了基于约束满足技术的启发式算法,算法通过优化目标指导变量排序,在变量赋值过程中采用约束传播和回溯技术,缩减变量值域、解消约束冲突,提高了计算效率。基于企业实际生产数据的仿真实验结果验证了模型和算法的有效性。     

网络端点接入控制的实现

互联网用户数目在迅速增长,对各种接入方式的需求在飞快扩大,对用户的操作水平的挑战也已经大大提高,如何让用户更方便、更安全的接入到网络中去已经是一个亟待研究解决的问题。网络端点接入控制通过对要求接入的网络端点进行自动地检测与修补,保证了每个接入端点的安全级别,进而使整个网络保持在较高的安全水平,方便了网络用户管理终端。文中提出了一种网络端点接入控制的实现方法,其较高效地解决了以上的问题,并在市场上也有了相应的产品。     

一种基于分支覆盖的测试数据自动生成算法

通过构造新的程序流图，利用Fibonacci法优化选取路径．为指定的分支生成测试数据。提出了路径测试数据生成代价的概念，并给出了代价的计算方法。当所选路径的分支谓词均为线性表达式时，直接求解线性约束集即可生成测试数据，或判定路径不可行；当分支谓词含有非线性表达式时，利用均差近似导数将非线性函数线性化，通过简单的迭代，亦能容易生成测试数据或判定路径在很大程度上不可行。若所选路径不可行或在很大程度上不可行，则选取新的路径，重复以上过程，直至求出所期望的数据，或无新的路径被选取，给定分支不可达。实例和实验表明，算法可行、有效。     

Design and implementation of deep learning strategy based smart signature verification System

The signature verification is broadly used for personal identification. The person is identified automatically using signature verification method to avoid forgery persons. The signature verification is classified into the static method and the dynamic method. The static verification method is based on stored images and the dynamic verification method is based on dynamic features of the signature. The integer wavelet transformation method is used to identify the breath and height ratio of the signature features. In addition to that spurious noise also removed before extracting the signature feature. And the signature is isolated from the background of the images. The extracted feature is analyzed using integer wavelet transformation and a neural network is selected to decide according to that original and forgery signature. As compared with the conventional system the proposed found to be about 20% error ratio. The database SVC2004 is selected to verify the signature.     

Control performance assessment for multivariable systems based on a modified relative variance technique

In this paper, a new technique is presented which enables the relative performance of both single and multiple loop control systems to be determined. The technique is based on the relative variance index technique which has been proposed recently for monitoring single loop control systems. This technique provides a control loop performance metric that considers the performance of the control system relative to both minimum variance and open-loop control. A major limitation with this technique is that it requires a highly restrictive assumption to be made regarding the structure of the disturbance to the process and the extension of the technique to multiple loop systems is not straight forward. The technique proposed in this paper does not require any assumptions to be made regarding the structure of the disturbance and can be extended to multiple loop situations with relative ease. The ability of the proposed technique to assess the performance of controllers applied to two simulated systems and also an industrial process is examined and it is shown that the proposed approach is superior to alternative techniques. A further benefit of the proposed technique is that it is able to provide an estimate of the potential improvement to the performance of the control loop that is achievable if the control system is retuned or redesigned.     

Constrained clustering as an optimization method

A deterministic annealing approach to clustering is derived on the basis of the principle of maximum entropy. This approach is independent of the initial state and produces natural hierarchical clustering solutions by going through a sequence of phase transitions. It is modified for a larger class of optimization problems by adding constraints to the free energy. The concept of constrained clustering is explained, and three examples are are given in which it is used to introduce deterministic annealing. The previous clustering method is improved by adding cluster mass variables and a total mass constraint. The traveling salesman problem is reformulated as constrained clustering, yielding the elastic net (EN) approach to the problem. More insight is gained by identifying a second Lagrange multiplier that is related to the tour length and can also be used to control the annealing process. The open path constraint formulation is shown to relate to dimensionality reduction by self-organization in unsupervised learning. A similar annealing procedure is applicable in this case as well     

基于通用比较模型的t-可诊断系统的特征化及并行诊断算法

文中介绍了一种系统级故障诊断模型－－通用比较模型,该模型处理器作为自身的比较器,综合经典的ＰＭＣ模型和Ｍａｅｎｇ／Ｍａｌｅｋ模型的优点,基于该报多处理器系统的ｔ＿可诊断性问题,给出了ｔ＿可诊断系统的特征化,证明了一个系统成为ｔ－可诊断系统的新的充分必要条件,其次,证明在通用比较模型中,确定故障顺集的问题等价于求解一个超图的最小横切集（Ｍｉｎｉｍｕｍ ｔｒａｖｅｒｓａｌ）,该超图是根据多处理器的通信     

基于中间变量的空间直角坐标到大地坐标的转换方法研究

利用迭代法实现空间直角坐标向大地坐标的转换,虽然精度较高,但是运算复杂,效率低.为了提高坐标转换的精度和运算效率,提出了一种新的空间直角坐标到大地坐标的转换方法,仅仅引入了几个中间变量就实现了坐标的转换,计算过程简单并且结果精确.采用卫星接收机的实测数据进行算法验证,最后通过与迭代法比较进行了精度评定.结果表明,该方法对经纬度的转换精度比迭代法高出两个数量级,对高度的转换精度也高出0.2m左右.     

A Hybrid Bayesian-Frequentist Approach to SLAM

A hybrid Bayesian/ frequentist approach is presented for the Simultaneous Localization and Mapping Problem (SLAM). A frequentist approach is proposed for mapping a dense environment when the robotic pose is known and then extended to the case when the pose is uncertain. The SLAM problem is then solved in two steps: 1) the robot is localized with respect to a sparse set of landmarks in the map using a Bayes filter and a belief on the robot pose is formed, and 2) this belief on the robot pose is used to map the rest of the map using the frequentist estimator. The frequentist part of the hybrid methodology is shown to have complexity linear (constant time complexity under the assumption of bounded noise) in the map components, is robust to the data association problem and is provably consistent. The complexity of the Bayesian part is kept under control owing to the sparseness of the features, which also improves the robustness of the technique to the issue of data association. The hybrid method is tested on standard datasets on the RADISH repository.     

一种大数据量可靠快速通信的解决方案

对某工厂的锌钡白干煅窑炉过程监控系统采取了IPC PLC的二级结构,IPC和PLC之间的数据通信是二级监控系统最关键的问题。由于被控对象的特殊性,系统的通信数据量很大,为解决通信的可靠、快速性,提高数据显示的实时性,提出了校验和的差错检验方法检查通信数据。对不经常改变的通信数据存储于文件中以供显示,以分组读写相间的方式解决读写PLC冲突的问题,在实际应用中,取得满意的效果。     

不确定性研讨信息的结构化与融合方法

基于流形正则化框架提出一种分类算法(MLD-RLSC),以解决高维文档分类问题。该算法通过构建训练样本的最近邻图来估计数据空间的几何结构并将其作为流形正则化项,结合多变量线性回归获得高维文档的低维流形结构,并采用k近邻分类器对低维流形进行分类,得到针对多类问题的分类器。该算法能够充分利用训练样本的类别信息来帮助学习以提取有效特征。通过在Reuters-21578数据集上的实验,证明该算法的分类性能和运行速度比传统分类器有较大的提高。     

电容式传感器在义齿检测系统中的应用

详细给出了一种用微型电容式压力传感器镶入义齿基托的义齿受力检测系统。根据电容式压力传感器的工作原理,采用微机电系统(MEMS)工艺,研制出微型电容式压力传感器。通过传感器的埋入封装工艺,在与义齿基托相同材料的作底基的树脂上挖一个边长为2 mm平整的方形小坑,将传感器分布式埋植入底基,并用自制施加压力的装置对义齿对口腔下方组织的作用力进行测试。测量结果表明:本系统能够准确地测量出当牙齿咬合时,义齿基托所承受的力和力的分布。该传感器性能良好,具有比较稳定的输入与输出关系,适用于口腔恶劣环境下测量义齿对口腔下方的组织作用力。     

Persistent caching: an implementation technique for complex objectswith object identity

Many recent complex object database systems support the concepts of object identity and object identifier. Following an object identifier to access the referenced object is called navigation operation and is an essential operation in dealing with complex objects. Navigation operation is a difficult operation to implement efficiently since every navigation operation inherently causes one disk access operation. A scheme to notably accelerate the navigation operation among a sea of complex objects, by increasing the effective number of objects in one disk page is proposed. The main concept of the presented technique is threefold. The first idea is to store a cached value within a complex object that is referencing another complex object. The second is that when the referenced object is to be updated the update propagation is delayed until the time when the cached value is referenced. The third is to utilize a hashed table on main memory to efficiently validate the consistency between the cached values and the original values     

一种新的删除AVL树的结点的算法

所有传统的删除AVL树的结点的算法的主要思想都是先删除结点再自下而上处理某些子树,涉及自下而上的后退。提出一种新的删除AVL树的结点的算法,其主要思想是先自上而下处理某些子树再删除结点,不涉及自下而上的后退。举例说明新算法的执行过程。证明新算法是正确的。与目前通常采用的Foster的算法相比,新算法不涉及辅助栈的使用。设n是AVL树的结点的个数。新算法的时间复杂性是O(log2n),与Foster的算法相同。实验结果表明新算法的平均执行时间比Foster的算法的短。新算法的空间复杂性是O(1),比Foster的算法的低。