Interactive multiobjective decision making in environmental systems using sequential proxy optimization techniques (SPOT)

In this paper, a new interactive multiobjective decision-making technique for solving multiobjective optimization problems: the sequential proxy optimization technique (SPOT), is presented. Using this technique, the preferred solution for the decision maker can be derived efficiently from among a pareto optimal solution set by assessing his marginal rates of substitution and maximizing the local proxy preference functions sequentially. Based on the algorithm of SPOT, a time-sharing computer program is also written to implement man-machine interactive procedures. The industrial pollution control problem in Osaka City in Japan is formulated and the interaction processes are demonstrated together with the computer outputs.     

Designing cyclic pressure pulsing in naturally fractured reservoirs using an inverse looking recurrent neural network

In this paper, an inverse looking approach is presented to efficiently design cyclic pressure pulsing (huff ‘n’ puff) with N₂ and CO₂, which is an effective improved oil recovery method in naturally fractured reservoirs. A numerical flow simulation model with compositional, dual-porosity formulation is constructed. The model characteristics are from the Big Andy Field, which is a depleted, naturally fractured oil reservoir in Kentucky. A set of cyclic pulsing design scenarios is created and run using this model. These scenarios and corresponding performance indicators are fed into the recurrent neural network for training. In order to capture the cyclic, time-dependent behavior of the process, recurrent neural networks are used to develop proxy models that can mimic the reservoir simulation model in an inverse looking manner. Two separate inverse looking proxy models for N₂ and CO₂ injections are constructed to predict the corresponding design scenarios, given a set of desired performance characteristics. Predictive capabilities of developed proxy models are evaluated by comparing simulation outputs with neural-network outputs. It is observed that networks are able to accurately predict the design parameters, such as the injection rate and the duration of injection, soaking and production periods.     

Repairing Inconsistent Curve Networks on Non‐parallel Cross‐sections

In this work we present the first algorithm for restoring consistency between curve networks on non‐parallel cross‐sections. Our method addresses a critical but overlooked challenge in the reconstruction process from cross‐sections that stems from the fact that cross‐sectional slices are often generated independently of one another, such as in interactive volume segmentation. As a result, the curve networks on two non‐parallel slices may disagree where the slices intersect, which makes these cross‐sections an invalid input for surfacing. We propose a method that takes as input an arbitrary number of non‐parallel slices, each partitioned into two or more labels by a curve network, and outputs a modified set of curve networks on these slices that are guaranteed to be consistent. We formulate the task of restoring consistency while preserving the shape of input curves as a constrained optimization problem, and we propose an effective solution framework. We demonstrate our method on a data‐set of complex multi‐labeled input cross‐sections. Our technique efficiently produces consistent curve networks even in the presence of large errors.     

Reconstruction of linearly parameterized models from single imageswith a camera of unknown focal length

This paper deals with the problem of recovering the dimensions of an object and its pose from a single image acquired with a camera of unknown focal length. It is assumed that the object in question can be modeled as a polyhedron where the coordinates of the vertices can be expressed as a linear function of a dimension vector. The reconstruction program takes as input, a set of correspondences between features in the model and features in the image. From this information, the program determines an appropriate projection model for the camera, the dimensions of the object, its pose relative to the camera and, in the case of perspective projection, the focal length of the camera. This paper describes how the reconstruction problem can be framed as an optimization over a compact set with low dimension (no more than four). This optimization problem can be solved efficiently by coupling standard nonlinear optimization techniques with a multistart method. The result is an efficient, reliable solution system that does not require initial estimates for any of the parameters being estimated     

Discrete-time output feedback sliding-mode control design for uncertain systems using linear matrix inequalities

An output feedback-based sliding-mode control design methodology for discrete-time systems is considered in this article. In previous work, it has been shown that by identifying a minimal set of current and past outputs, an augmented system can be obtained which permits the design of a sliding surface based upon output information only, if the invariant zeros of this augmented system are stable. In this work, a procedure for realising discrete-time controllers via a particular set of extended outputs is presented for non-square systems with uncertainties. This method is applicable when unstable invariant zeros are present in the original system. The conditions for existence of a sliding manifold guaranteeing a stable sliding motion are given. A procedure to obtain a Lyapunov matrix, which simultaneously satisfies both a Riccati inequality and a structural constraint, is used to formulate the corresponding control to solve the reachability problem. A numerical method using linear matrix inequalities is suggested to obtain the Lyapunov matrix. Finally, the design approach given in this article is applied to an aircraft problem and the use of the method as a reconfigurable control strategy in the presence of sensor failure is demonstrated.     

基于一种类似TTA的特殊应用的资源估计方法

在嵌入式系统设计中,由于系统的日益复杂性和设计时限使得高级语言综合正在越来越受到重视。尽管可以在系统级进行功能验证,但是在设计的早期对其影射成相应硬件后的资源消耗的估计变得非常的困难。文中描述了一种将高级语言影射成一种类似TTA硬件结构的方法,以此得到了一种可用于硬件资源估计的模型,并提出了基于这种模型的硬件资源估计方法。我们得到的资源估计的相对误差小于10％,并通过一个GPS来演示了整个流程,最后的结果也验证了我们的方法。我们相信我们的方法在早期的设计空间探索中会对系统设计者和结构搭建者有很大帮助。     

Gabor滤波器组实现颅脑图像的边缘快速提取

在医学图像处理过程中,针对一般方法提取颅脑图像边缘不是很清晰的情况,提出了一种基于短时傅立叶变换的新的Gabor滤波方法。该方法通过选取一组能够覆盖整个频域的滤波器,分别提取图像的局部边缘信息,然后按照一定的规则将提取出局部信息的多幅图像整合成一幅图像。普通Gabor滤波计算量较大,耗时较长,而该文所述方法能显著地减少运算量。并且相对于其他几种滤波方法也表现出定位准确,检测效果明显,以及鲁棒性较好的特点。     

线性切换系统的积分不变性原理

将积分不变性原理进行推广, 用来讨论线性切换系统的稳定性. 作为LaSalle不变性原理的推广, 文中推广的积分不变性原理无需构造Lyapunov函数, 而是利用系统输出的可积性, 讨论线性切换系统输出为零的状态集合的稳定性. 另外, 讨论了切换系统状态集合稳定性与切换信号之间的关系. 利用线性切换系统的可观测性, 讨论了系统平衡点的渐近稳定性. 数值例子说明了文中方法的有效性.     

一类根式不等式的有理化算法与机器证明

文中讨论了一类根式不等式的有理等价问题.证明了这类根式不等式可等价转化为一组有理不等式.建立了一个算法RFD,并用Maple编程实现.对一个给定的这类根式不等式,RFD可自动快速地产生一组有理等价不等式.将RFD算法和差分代换方法相结合,给出了一大类具有相当难度的几何不等式的机器证明.此前该课题仅有的工作是杨路关于二次根式的结果.     

面向崩溃预测的寄存器软错误故障传播分析

故障注入是研究软错误故障传播的传统手段,但随着程序复杂性不断增加,采用故障注入对大量软错误的故障传播进行研究将花费巨大的时间成本。提出一种基于程序动态指令进行分析和建模从而快速获取软错误结果的方法。将程序转化为动态指令序列,通过体系结构正确执行分析将所有可能的软错误划分为对程序运行结果有影响和没有影响两部分;基于动态依赖图建立软错误故障传播分析模型,并建立判断程序崩溃的标准,进而提出一个算法对任意制定的能够影响程序运行结果的软错误进行故障传播分析并重点预测程序崩溃的发生。实验显示,预测的漏报率和分析单个软错误的平均用时明显低于现有方法。     

低秩特征选择多输出回归算法

针对现有回归算法没有考虑利用特征与输出的关系,各输出之间的关系,以及样本之间的关系来处理高维数据的多输出回归问题易输出不稳定的模型,提出一种新的低秩特征选择多输出回归方法。该方法采用低秩约束去构建低秩回归模型来获取多输出变量之间的关联结构;同时创新地在该低秩回归模型上使用[L2,p]-范数来进行样本选择,合理地去除噪音和离群点的干扰;并且使用[L2,p]-范数正则化项惩罚回归系数矩阵进行特征选择,有效地处理特征与输出的关系和避免“维灾难”的影响。通过实际数据集的实验结果表明,提出的方法在处理高维数据的多输出回归分析中能获得非常好的效果。     

MERGING SEPARATELY GENERATED PLANS WITH RESTRICTED INTERACTIONS

Generating action sequences to achieve a set of goals is a computationally difficult task. When multiple goals are present, the problem is even worse. Although many solutions to this problem have been discussed in the literature, practical solutions focus on the use of restricted mechanisms for planning or the application of domain dependent heuristics for providing rapid solutions (i.e., domain-dependent planning). One previously proposed technique for handling multiple goals efficiently is to design a planner or even a set of planners (usually domain-dependent) that can be used to generate separate plans for each goal. The outputs are typically either restricted to be independent and then concatenated into a single global plan, or else they are merged together using complex heuristic techniques. In this paper we explore a set of limitations, less restrictive than the assumption of independence, that still allow for the efficient merging of separate plans using straightforward algorithmic techniques.
In particular, we demonstrate that for cases where separate plans can be individually generated, we can define a set of limitations on the allowable interactions between goals that allow efficient plan merging to occur. We propose a set of restrictions that are satisfied across a significant class of planning domains. We present algorithms that are efficient for special cases of multiple plan merging, propose a heuristic search algorithm that performs well in a more general case (where alternative partially ordered plans have been generated for each goal), and describe an empirical study that demonstrates the efficiency of this search algorithm.     

Collecting and Analyzing Data from Distributed Control Programs

This paper describes a set of tools that allows a developer to instrument a C/C++ program to log data at run-time and then analyze that data to verify correct behavior. The logging tools provide the developer with a means to log a variety of different data to a variety of different outputs. They also allow for synchronized logging of data from distributed programs. One logging output option is an SQL database. We have developed a set of analysis tools that retrieve data from the database to answer common developer questions. The analysis tools use an interval temporal logic to frame database queries. The data logging tools are fully implemented and performance results are given in this paper. The data analysis tools are currently being tested on data from real NASA applications.     

微处理器功能验证程序生成

根据指令集构造的指令功能、语法格式和语义要求,建立了微处理器指令类型集合和指令操作数集合;以此为基础,为每个指令类型集合构建一个指令生成模型.根据指令生成模型、验证计划等创建微处理器功能验证程序模板,并结合微处理器流水线状态控制部件的有限状态机的基本状态转移路径,提出一种指令序列的功能验证方法.根据程序模板实现功能验证程序伪随机生成.实验结果表明：采用该方法可以高效生成功能覆盖率高、仿真时间短的RISC3200功能验证程序.     

Algorithms for computing a primary ideal decomposition without producing intermediate redundant components

In Noro (2010) we proposed an algorithm for computing a primary ideal decomposition by using the notion of a separating ideal and showed that it can efficiently decompose several examples which are hard to decompose using existing algorithms. In particular, the number of redundant components produced in the algorithm is zero or very small in many examples, but no theoretical explanation for the efficiency was given.In this paper we define a more sophisticated class of separating ideals: saturated separating ideals. By using this notion we modify the algorithm of Noro (2010) such that it directly outputs a minimal primary decomposition without producing any intermediate redundant component.By modifying the process of extraction of a primary component via the pseudo-primary decomposition proposed in Shimoyama and Yokoyama (1996), we find a method for intermediate decomposition of an ideal and propose a variant of the new primary decomposition algorithm based on this intermediate decomposition. Our experiment shows that this variant efficiently decomposes many examples which are still hard to decompose even if we apply the original version of the new algorithm. Furthermore, in this algorithm we can bypass the computation of primary components and obtain directly the set of all associated primes of an ideal.     

Multi-output parameter estimation of dynamic systems by output shapes

A multi-output method of parameter estimation is introduced for dynamic systems that relies on the shape attributes of model outputs. The shapes of outputs in this method are represented by the surfaces that are generated by continuous wavelet transforms (CWTs) of the outputs in the time-scale domain. Since the CWTs also enhance the delineation of outputs and their sensitivities to model parameters in the time-scale domain, regions in the time-scale plane can be identified wherein the sensitivity of the output with respect to one model parameter dominates all the others. This allows approximation of the prediction error in terms of individual model parameters in isolated regions of the time-scale domain, thus enabling parameter estimation based on a small set of wavelet coefficients. These isolated regions of the time-scale plane also reveal numerous transparencies to be exploited for parameter estimation. It is shown that by taking advantage of these transparencies, the robustness of parameter estimation can be improved. The results also indicate the potential for improved precision and faster convergence of the parameter estimates when shape attributes are used in place of the magnitude.     

The Cost of Complex Communication on Simple Networks

Endowing a communication network with the ability to realize arbitrary communication patterns is an expensive proposition, both in hardware and in system software. One might instead ask whether, for a given application program, a simple network can be built that performs well for that particular program. In this paper, we model an application program by the set of communication patterns it uses. We then consider the problem of determining when such a set of communication patterns is suitable for fast realization on a simple network. We show that the question of whether there exists a simple, inexpensive network for an algorithm is closely related to the VLSI layout question. In particular, we show how the VLSI framework can be used to produce a simple test that tells how complex such a network must be. Within this context we show that, contrary to common wisdom, the communication necessary for block-matrix transpose does not require complex hardware—in fact, it is efficiently realizable on a mesh. However, other important patterns, such as perfect shuffle, do indeed require either expensive hardware or large amounts of message congestion.     

一种基于单条程序执行路径的错误定位方法

当程序在测试中发生错误时,将形成一条错误的程序执行路径,程序员将会花费很多精力去检测程序代码和定位最终的程序错误．提出一种基于单条程序执行路径的错误定位方法,该方法通过对程序进行反向执行,计算出多个最弱前置条件及其相对应的疑似错误语句集,并生成错误定位树,来辅助程序员进行快速错误定位．对西门子测试数据集进行的实验表明了该方法具有良好的效果．     

一种覆盖测试中路径集的自动生成方法

覆盖测试是软件测试中的重要方法,路径覆盖测试中路径集的自动生成能提高测试效率。该文提出了一种描述程序分支情况的分支关系图,给出了基于分支关系图的路径集自动生成算法,实验证明了该方法的正确性,能有效地求出程序路径集。     

A parallel algorithm for real-time decision making: A rough set approach

We consider decision tables with the values of conditional attributes (conditions) measured by sensors. These sensors produce outputs after an unknown but finite number of time units. We construct an algorithm for computing a highly parallel program represented by a Petri net from a given decision table. The constructed net allows to identify objects in decision tables to an extent which makes appropriate decisions possible. The outputs from sensors are propagated through the net with maximal speed. This is done by an appropriate implementation of all rules true in a given decision table. Our approach is based on rough set theory (Pawlak, 1991). It also seems to have some significance for theoretical foundations of real-time systems.