Optimal Control of Nonlinear Systems Using Experience Inference Human-Behavior Learning

Safety critical control is often trained in a simulated environment to mitigate risk. Subsequent migration of the biased controller requires further adjustments. In this paper, an experience inference human-behavior learning is proposed to solve the migration problem of optimal controllers applied to real-world nonlinear systems. The approach is inspired in the complementary properties that exhibits the hippocampus, the neocortex, and the striatum learning systems located in the brain. The hippocampus defines a physics informed reference model of the real-world nonlinear system for experience inference and the neocortex is the adaptive dynamic programming (ADP) or reinforcement learning (RL) algorithm that ensures optimal performance of the reference model. This optimal performance is inferred to the real-world nonlinear system by means of an adaptive neocortex/striatum control policy that forces the nonlinear system to behave as the reference model. Stability and convergence of the proposed approach is analyzed using Lyapunov stability theory. Simulation studies are carried out to verify the approach.      

一种利用实化视图快速响应查询的技术

实化视图可以显著改进查询处理的性能，针对拥有大量实化视图的实际系统，提出了层次索引和视图合并两种方法来有效减少可能被利用的实化视图的搜索空间，还提出了实用的启发式算法以找出较优重写查询。实验表明，所给算法可用来快速地响应查询。     

Using Stress Functions to Obtain OWA Operators

The ordered weighted averaging operator attempts to provide a user-friendly class of mean type aggregation operators by allowing a user to easily and naturally go from a mental model of a desired type of aggregation to its formal realization. Our objective in this paper is to support this agenda by providing a new methodology to help a user describe the type of aggregation they desire using the idea of a stress function. With this stress function, a user can "stress" which argument values they want to give more weight in the aggregation. An important feature of this stress function is that it is only required to be nonnegative function on the unit interval. This allows a user to completely focus on the issue of where to put the stress in the aggregation without having to consider satisfaction of any other requirements.     

Fast Surface Segmentation Guided by User Input Using Implicit Extension of Minimal Paths

We introduce a novel implicit approach for single object segmentation in 3D images. The boundary surface of this object is assumed to contain two or more known curves (the constraining curves), given by an expert. The aim of our method is to find the desired surface by exploiting the information given in the supplied curves as much as possible. We use a cost potential which penalizes image regions of low interest (for example areas of low gradient). In order to avoid local minima, we introduce a new partial differential equation and use its solution for segmentation. We show that the zero level set of this solution contains the constraining curves as well as a set of paths joining them. These paths globally minimize an energy which is defined from the cost potential. Our approach, although conceptually different, can be seen as an implicit extension to 3D of the minimal path framework already known for 2D image segmentation. As for this previous approach, and unlike other variational methods, our method is not prone to local minima traps of the energy. We present a fast implementation which has been successfully applied to 3D medical and synthetic images. Roberto Ardon graduated from the Ecole Centrale Paris in 2001 with a major in applied mathematics, obtained his master degree in image processing from the Ecole Normale Supérieure de Cachan in the same year and his Ph.D. degree in applied mathematics from the University Paris-Dauphine in 2005. Currently he is a research scientist in Philips Medical Systems Research Paris. His research interests include calculus of variations mainlly focused on medical image processing. Laurent D. Cohen was at Ecole Normale Superieure Ulm in Paris from 1981 to 1985. He received Master's and Ph.D. degrees in Applied Mathematics from Paris 6 in 1983 and 1986. From 1985 to 1987, he was member at the Computer Graphics and Image Processing group at Schlumberger Palo Alto Research, California and Schlumberger Montrouge Research, and remained consultant there for a few years afterwards. He began working with INRIA, France in 1988, mainly with the medical image understanding group Epidaure. Since 1990, he is Research Scholar (Charge then Directeur de Recherche) with CNRS in the Applied Mathematics and Image Processing group at CEREMADE, University Paris-Dauphine. His research interests and teaching at the university are applications of variational methods and Partial Differential Equations to Image Processing and Computer Vision, like deformable models, minimal paths, surface reconstruction, Image registration, Image segmentation and restoration. He obtained CS 2002 Prize for Image and Signal Processing. He has been member in program committees for boards for about 20 international conferences. Anthony Yezzi obtained his Ph.D. in 1997 through the Department of Electrical Engineering at the University of Minnesota. After completing a postdoctoral research position in the Laboratory for Information and Decision Systems (LIDS) at Massacusetts Institute of Technology, he joined the faculty of the School of Electrical and Computer Engineering at Georgia Institute of Technology in 1999 where he currently holds the position of Associate Professor. Prof. Yezzi has also consulted for a number of medical imaging companies including GE, Picker, and VTI, and has been an IEEE member since 1999. His research lies primarily within the fields of image processing and computer vision. He has worked on a variety of problems including image denoising, edge-detection, segmentation and grouping, shape analysis, multi-frame stereo reconstruction, tracking, and registration. Some central themes of his research include curve and surface evolution theory, differential geometry, and partial differential equations.     

基于纹理延伸和三角块拼接的快速曲面纹理合成

对相邻的已合成三角形个数为1的待合成三角形使用"纹理延伸"的方法进行纹理合成;对相邻的已合成三角形个数大于1的待合成三角形采用梯形模板匹配的三角块拼接方法进行纹理合成.实验结果与理论分析表明,该算法合成质量较高,合成速度较现有方法提高了1/3.     

Interaction of Waves with Frictional Interfaces Using Summation-by-Parts Difference Operators: Weak Enforcement of Nonlinear Boundary Conditions

We present a high-order difference method for problems in elastodynamics involving the interaction of waves with highly nonlinear frictional interfaces. We restrict our attention to two-dimensional antiplane problems involving deformation in only one direction. Jump conditions that relate tractions on the interface, or fault, to the relative sliding velocity across it are of a form closely related to those used in earthquake rupture models and other frictional sliding problems. By using summation-by-parts (SBP) finite difference operators and weak enforcement of boundary and interface conditions, a strictly stable method is developed. Furthermore, it is shown that unless the nonlinear interface conditions are formulated in terms of characteristic variables, as opposed to the physical variables in terms of which they are more naturally stated, the semi-discretized system of equations can become extremely stiff, preventing efficient solution using explicit time integrators.     

基于跨事件理论的缺失事件角色填充研究

事件抽取是信息抽取领域的研究热点。针对ACE事件抽取局限于当前单个句子而造成大量事件论元角色缺失的现象,提出了基于跨事件的缺失事件角色填充理论并实现了原型系统。系统分为缺失角色填充识别和缺失角色填充分类两个部分,识别部分用于判定缺失角色是否可被填充,分类部分用于从其它事件描述中选择合适的角色(实体)对可被填充的缺失角色进行填充。对ACE2005语料进行了后期标注,实验中两个阶段的F值分别达到72.97和74.68。     

利用分块循环矩阵对离散图象进行重建

论文讨论了图象重建的意义,提出了离散图象采样的Nyquist准则,并将图象重建的问题变成了矩阵方程的解的问题,讨论了分块Toeplitz矩阵,分块循环矩阵和离散傅立叶变换之间的关系,并利用其关系对非均匀采样图象提出了一种重建方法,该方法可以直接利用离散傅立叶变换,不需要迭代,并且可以实时进行。在文章末尾用该方法对一离散图象进行了仿真,结果表明该算法是确实有效的。     

On-board Vehicle Data Stream Monitoring Using MineFleet and Fast Resource Constrained Monitoring of Correlation Matrices

This paper considers the problem of monitoring vehicle data streams in a resource-constrained environment. It particularly focuses on a monitoring task that requires frequent computation of correlation matrices using lightweight on-board computing devices. It motivates this problem in the context of the MineFleet Real-Time system and offers a randomized algorithm for fast monitoring of correlation (FMC), inner product, and Euclidean distance matrices among others. Unlike the existing approaches that compute all the entries of these matrices from a data set, the proposed technique works using a divide-and-conquer approach. This paper presents a probabilistic test for quickly detecting whether or not a subset of coefficients contains a significant one with a magnitude greater than a user given threshold. This test is used for quickly identifying the portions of the space that contain significant coefficients. The proposed algorithm is particularly suitable for monitoring correlation and related matrices computed from continuous data streams.     

一种基于粗糙集的多级安全数据库推理问题的量化分析方法

信息大都存放在数据库中,信息安全很大程度上依赖数据库的安全。推理是从已知的信息推出新的信息,它是对数据库安全的一个重要威胁,特别数据挖掘的发展,这个威胁变得更加严重。简单描述了多级安全数据库系统的推理问题;介绍了粗糙集理论的相关概念;利用粗糙集理论提出了一种对推理风险进行量化的方法,它不依赖系统安全员的知识,能够处理确定性和非确定性的推理通道;并给出了一个分析例子。     

AO4BPEL: An Aspect-oriented Extension to BPEL

Process-oriented composition languages such as BPEL allow Web Services to be composed into more sophisticated services using a workflow process. However, such languages exhibit some limitations with respect to modularity and flexibility. They do not provide means for a well-modularized specification of crosscutting concerns such as logging, persistence, auditing, and security. They also do not support the dynamic adaptation of composition at runtime. In this paper, we advocate an aspect-oriented approach to Web Service composition and present the design and implementation of AO4BPEL, an aspect-oriented extension to BPEL. We illustrate through examples how AO4BPEL makes the composition specification more modular and the composition itself more flexible and adaptable.     

TPython：一种扩充的Python语言

Python是一种流行的动态语言,但是由于完全的动态性影响了其执行效率和使用。因此,在Python基础上进行了静态化扩充,研制了TPython语言。该语言在注释中引入了可选的类型声明,并提供了包括类型检查在内的静态检查。相对于动态语言而言,TPython能够提高程序的可读性和可靠性,降低调试成本,相对于静态语言而言,TPython又具有语法简单,易于开发的优势。     

Knowledge Is a Terrible Thing to Waste: Using Inference in Discrete-Event Control Problems

The role of inference is added to the capabilities of decentralized supervisors in a modal logic setting for discrete-event systems. In previous work, a decentralized supervisor made a control decision through formal reasoning, using only information obtained from direct observation of a given system. The framework is extended so that when a supervisor cannot make a definitive control decision based on its own knowledge of the system, the supervisor may reason about whether other supervisors have sufficient knowledge to eventually make the correct control decision     

基于神经网络非线性模型的多级工作点阶跃响应扩展DMC预测控制

利用前馈神经网络建立对象的非线性预测模型,在不同工作点做阶跃响应,建立其局部线性模型,用隶属函数将局部线性模型加权得到全局线性模型,全局线性模型用于滚动优化,非线性模型用于预测系统输出和校正线性模型,实现非线性预测控制,仿真结果表明该方法控制效果良好,可满足实时要求。     

结合互补度的基于扩展规则#SAT问题求解方法

#SAT问题又称模型计数(model counting)问题是人工智能领域的研究热点之一,在人工智能领域被广泛应用.在对基于扩展规则的#SAT问题求解方法CER(counting models using extension rules)深入研究的基础上,提出一种结合互补度的#SAT问题求解方法.在计算给定子句集的模型个数时,利用SE-Tree(set enumeration tree)形式化地表达计算过程,逐步生成需要计算的子句集合,并在SE-Tree中添加终止结点,避免大部分含互补文字子句集合的生成,且不会因剪枝而导致求解不完备.提出互补度的概念,在扩展SE-Tree结点时按照互补度由大到小的顺序扩展,较早地生成含互补文字且长度较小的子句集合,有效减少枚举树生成的结点个数,进而减少对子句集合判断是否含互补文字的计算次数.实验结果表明：与CER方法相比该方法效率较好,且进一步改进了CER方法在互补因子较低时求解效率低下的不足.     

Using SDRAM Memories for High-Performance Accesses to Two-Dimensional Matrices Without Transpose

The data throughput of SDRAMs is significantly reduced by the control overhead required for access or transposition of large two-dimensional data matrices stored in SDRAM memories. In this paper, a new address mapping scheme is introduced, taking advantage of multiple banks and burst capabilities of modern SDRAMs. In this way, the data throughput is maximized when reading or writing rows or columns of a two-dimensional data matrix. Other address mapping strategies minimize the total number of SDRAM page-opens while traversing the two-dimensional index-space in row or column direction. In order to achieve a higher data throughput, the new approach uses an alternative bank interleaving method to hide additional wait cycles. In this way, the number of data bus wait cycles do not depend on the overall number of page-opens directly any more. It is shown, that the data bus utilization can be increased significantly. In particular, the new mapping strategy is optimized for access of parallel samples, distributed among a number of SDRAM chips. Therefore, double buffering can be omitted. As a special operation, 2D-FFT processing for radar applications is considered. Depending on SDRAM parameters and dimensions, a continuous bandwidth utilization of 96–98 % is achieved for accesses in both matrix dimensions, including all page-opens and refresh operations.     

TurboPixels: Fast Superpixels Using Geometric Flows

We describe a geometric-flow-based algorithm for computing a dense oversegmentation of an image, often referred to as superpixels. It produces segments that, on one hand, respect local image boundaries, while, on the other hand, limiting undersegmentation through a compactness constraint. It is very fast, with complexity that is approximately linear in image size, and can be applied to megapixel sized images with high superpixel densities in a matter of minutes. We show qualitative demonstrations of high-quality results on several complex images. The Berkeley database is used to quantitatively compare its performance to a number of oversegmentation algorithms, showing that it yields less undersegmentation than algorithms that lack a compactness constraint while offering a significant speedup over N-cuts, which does enforce compactness.     

Improved ADI Scheme for Linear Hyperbolic Equations: Extension to Nonlinear Cases and Compact ADI Schemes

This paper studies the Galerkin finite element approximation of time-fractional Navier–Stokes equations. The discretization in space is done by the mixed finite element method. The time Caputo-fractional derivative is discretized by a finite difference method. The stability and convergence properties related to the time discretization are discussed and theoretically proven. Under some certain conditions that the solution and initial value satisfy, we give the error estimates for both semidiscrete and fully discrete schemes. Finally, a numerical example is presented to demonstrate the effectiveness of our numerical methods.