基于事件-条件-状态的通用框架设计

设计一个基于事件一条件一状态的通用框架,通过对GOF状态模式中的Context进行适当的重新划分,将其拆分为一个负责状态管理的类和一个负责操作接口的类,并将状态管理、状态转移表检索、事件触发机制等功能包含在框架中。将该框架应用于多种不同平台的手机输入法的开发中,发现其可以简化输入法程序的开发,为不同版本输入法程序的维护提供方便。     

设计PLC输入输出电路需注意的问题

PLC作为工业控制通用装置,广泛应用于各种生产机械和生产过程。PLC控制系统运行中,外部故障远高于PLC本身。文章就设计PLC外部电路需要注意的实际问题,进行了分析与总结;就明确输入输出器件间逻辑关系,减少PLC的点数,采用了多种实用的方法。     

基于差分隐私的数据世系发布方法

数据世系描述数据产生、演化的机理和流程,对数据质量评估、数据恢复、数据分析有重要意义.伴随着数据共享的日益深化,对数据世系的主要表现结构世系工作流进行共享的需求也日益迫切.世系工作流中包含的节点模块,以及节点间的时序关系可能涉及数据所有者的隐私,对其进行共享不可避免地会带来隐私保护问题.已有研究侧重世系工作流局部映射关系的维持,对世系工作流可用性的重要表现--工作流时序约束关系维持效果较弱;也缺少对工作流相邻节点有向度分布隐私的保护.针对上述问题,引入输入/输出度序列(Input and Output Degree Sequence with Scale i,IO-iD)模型,在描述世系工作流节点度分布的同时,兼顾对工作流方向特性的提取;提出Previous-Next时序序列结构,描述工作流中节点与其邻接节点的子结构特征;在此基础上,提出基于差分隐私的隐私保护世系工作流发布算法DpriPP,实现弱背景知识依赖的隐私保护世系工作流发布与工作流时序依赖关系可用性的有效维持.理论分析和实验结果表明,所提算法在保护世系工作流局部相邻节点有向度分布隐私的同时,能有效维持世系工作流节点局部与整体时序依赖关系的可用性.     

Prediction‐based Adaptive Robust Tracking Control of an Uncertain First‐Order Time‐Delay System

This paper considers the tracking problem of a delayed uncertain first‐order system which is simultaneously subject to (possibly large) known input delay, unknown but bounded time‐varying disturbance, and unknown plant parameter. The proposed predictor adaptive robust controller (PARC) involves prediction‐based projection type adaptation laws with model compensation and prediction‐based continuous robust feedback such that the closed loop system has global exponential convergence with an ultimate bound proportional to delay, disturbance bound, and switching gain. Further, if there are only delay and parameter uncertainties after some finite time, then semi‐global asymptotic tracking is guaranteed. The proposed design is shown to have significant closed loop performance improvement over the baseline controller.     

Light Chisel: 6DOF Pen Tracking

We present a novel interaction device tracked in 6 degrees of freedom by two commodity cameras. The inexpensive Light Chisel is statically illuminated with two LEDs, and uses no additional sensor (e.g. inertial or magnetic) or means of communication or synchronization. Its form factor is well suited for a screwdriver or chisel grip, allowing the Light Chisel to be rolled between the fingers. The position and orientation of the tool is tracked absolutely, making the Light Chisel suited for complex interaction, e.g. geometric modeling in augmented reality. The Light Chisel is physically small, limiting the physical and optical collisions with the real world. The orientation of the tool is tracked in a wide range of angles: pitch and yaw ±90°, roll ±180°. We evaluated our system against the OptiTrack optical tracking system. Our system achieved mean differences from OptiTrack reference of 2.07 mm in position, 1.06° in yaw and pitch, and 5.26° in roll using a pair of VGA cameras. We demonstrate usefulness of our Light Chisel in four applications: character animation, modeling by swirls, volumetric modeling, and docking of CAD models.     

基于特征值分布的自适应MIMO接收方法

多输入多输出(MIMO)系统性能优劣依赖于信道的相关特性,空分复用技术适用于低相关信道,而波束形成技术适用于高相关信道。依据上述信道相关特性,提出一种基于信道特征值分布的自适应MIMO接收方法。该方法以均匀圆形天线阵列结构为基础,能够根据信道相关情况动态选择接收方式:当角度扩展较大时,选用传统MIMO接收方式(称为天线MIMO方式);当角度扩展较小、多径独立时,选用基于智能天线的多波束接收方式(称为波束MIMO方式)。分析角度扩展、多径对信道特征值分布的影响,并给出自适应MIMO接收切换的条件。仿真结果表明,该方法能够适应复杂的无线环境,误码率较低,性能更加稳定可靠。     

On robustness of predictor feedback control of linear systems with input delays

This paper is concerned with the robustness of the predictor feedback control of linear systems with input delays. By applying certain equivalent transformations on the characteristic equation associated with the closed-loop system, we first transform the robustness problem of a predictor feedback control system into the stability problem of a neutral time-delay system containing an integral operator in the derivative. The range of the allowable input delay for this neutral time-delay system can be computed by exploring its delay dependent stability conditions. In particular, delay dependent stability conditions for the neutral time-delay system are established by partitioning the delay into segments. The conservatism of this method can be reduced when the number of segments in the partition is increased. Numerical examples are worked out to illustrate the effectiveness of the proposed method.     

快速获取汉字任意输入码的方法与实现

以UCDOS为例简要分析了该平台下的汉字输入码反查机制，给出了以此机制为基础实现在应用程序中获取汉字输入码的方法，从而为各种可操作的输入码对照表的生成提供了方便与可能。     

Anti-disturbance control for nonlinear systems subject to input saturation via disturbance observer

This paper is concerned with the problem of the disturbance observer based control for a class of continuous-time uncertain systems subject to input saturation and nonlinearity. The input of the system includes two parts, the control input and the disturbance input. The nonlinearity of the system, which satisfies a global Lipschitz condition, is considered as two cases of known nonlinearity and unknown nonlinearity. By virtue of the technique of the disturbance observer based controller, the anti-disturbance controllers are designed respectively with both the polytopic and dead-zone representations of the saturation function, which ensure that the resulting closed-loop systems are asymptotically stable with an estimation of the domain of attraction described by the level set of the Lyapunov function. Further, an iterative optimization method is used to obtain the maximum estimation of the domain of the set of initial states. An example of application design for a flight control system illustrates the effectiveness of the proposed results.     

Selection of significant input variables for time series forecasting

Appropriate selection of inputs for time series forecasting models is important because it not only has the potential to improve performance of forecasting models, but also helps reducing cost in data collection. This paper presents an investigation of selection performance of three input selection techniques, which include two model-free techniques, partial linear correlation (PLC) and partial mutual information (PMI) and a model-based technique based on genetic programming (GP). Four hypothetical datasets and two real datasets were used to demonstrate the performance of the three techniques. The results suggested that the model-free PLC technique due to its computational simplicity and the model-based GP technique due to its ability to detect non-linear relationships (demonstrated by its relatively good performance on a hypothetical complex non-linear dataset) are recommended for the input selection task. Candidate inputs which are selected by both these recommended techniques should be considered as significant inputs.