Resilience: An Evolutionary Approach to Spatial Economic Systems

The concept of resilience has received a great deal of attention in the past decades. Starting from the first fundamental definitions offered by Holling, Pimms and Perrings in an economic-ecological modeling context, the present paper explores the evolution of the resilience concept—as well as related different measures—in both a continuous and discrete time setting.From this perspective, the paper explores the relevance of the resilience concept in socio-economic systems, by focussing the attention on the relationships among resilience, transition dynamics and lock-in effects, in particular in the light of the dynamics of technological innovation diffusion and adaptive behaviour of firms. In this framework we will describe an empirical application, in which the resilience and dynamics of the West-German labour market will be investigated. This empirical illustration is offered by making use of an algorithm constructed for detecting Lyapunov exponents, so as to classify the resilience among employment sectors in our case study.     

中小规模低成熟度软件企业的项目风险管理

当今大多数软件开发企业规模不大且处于低成熟度水平,而现有的软件项目风险管理理论和实践,主要是针对大中型企业所从事的大型复杂项目.本文以已被检验了的风险管理理论为基础,充分考虑低成熟度企业的特点,提出了一套具有系统性、简捷性和易用性的风险管理方法,说明了程序化该方法的思路,并验证了方法的有效性.最后还说明了方法的优缺点及进一步研究的方向.     

An Iterative Approach to Trustable Systems Management Automation and Fault Handling

Automated systems management solutions aim to reduce the pressure on the administrators of complex, large-scale, distributed systems by enabling the automation of many of the common tasks of management. However, this creates a level of abstraction, which can act as a barrier between the administrator and the elements being controlled. This can impede the transition to new management paradigms required by the increase of off-premise resources and hybrid cloud systems. The resulting loss of control of the managed environment can contribute to a loss of trust in automated systems management solutions and affect their broader use. This paper proposes a novel approach where the administrator can control the automation level on a per task basis. Administrators define a management task as they would perform it directly and allow the solution to identify the triggers that cause the task to be enacted. The solution also allows administrators to define relevant task output that can be analyzed for fault states and enable error recovery without manual intervention. The impact of this approach leads to reduced management effort for the administrator, while retaining controllability and keeping automation costs low, along with reducing the incidence of errors.     

一种信息系统集成方法

传统的信息系统之间缺乏很好的信息共享机制,成为一个个孤立的信息“烟囱”,无法提供面向全局的服务。为解决这个问题,本文提出了在已有的自治信息系统基础上,构造松散耦合分布式信息系统的方法及系统的体系结构,并用Petri网建立了系统的模型,为对系统进行分析和验证打下了理论基础。     

A Two-Dimensional Approach to Systems Development

Abstract

Although many variables can contribute to the failure of a systems development project, the use of the traditional f one-dimensional systems development life cycle approach is often a major factor in the failure of such an effort This article describes an alternative method— the two-dimensional approach to systems development— and discusses why IS managers should consider adopting this new development approach.     

A Two-Dimensional Approach to Systems Development

Although many variables can contribute to the failure of a systems development project, the use of the traditional f one-dimensional systems development life cycle approach is often a major factor in the failure of such an effort This article describes an alternative method— the two-dimensional approach to systems development— and discusses why IS managers should consider adopting this new development approach.     

Contribution to Design of Complex Mechatronic Systems. An Approach through Evolutionary Optimization

This paper describes a new evolutionary methodology aimed at optimizing various and heterogeneous data in common evolution. The representation of solutions uses mixed-integer genotypes and variable-length chromosomes to face a complex problem of task decomposition and high-level control generation. A memory operator is introduced to face convergency uncertainties issued from the irregularities of both discontinuous evaluation function and heterogeneous solution representation. The stability of the evolutionary algorithm is analyzed with dimension changes in the optimization problem.     

An Optimization Approach to Control Reconfiguration

An optimization algorithm for the problem of control reconfiguration in response to operating condition changes or abrupt system component failures is presented here. The algorithm utilizes a version of the Broyden-Fletcher-Goldfarb-Shanno (BFGS) optimization method of conjugate directions. The algorithm provides an output feedback controller that not only stabilizes the new /impaired system, when possible, but also preserves much of the dynamics of the original /unfailed system. The design is such that the closed-loop system is robust with respect to inevitable uncertainties /modelling errors on the state-space matrices of the impaired system. The algorithm is applied to an aircraft longitudinal control system, for which two severe cases of failure are considered, first the loss of an actuator and then the loss of a sensor in addition to the actuator loss.     

Optimization Approach to Guaranteed State Estimation of Dynamic Systems

The optimization approach to set-theoretic estimation problems is developed. Level sets of strictly convex and continuous functions are used as the set estimates. These functions are shown to satisfy, in estimating, the functional equation of dynamic programming.     

Fail-Awareness: An Approach to Construct Fail-Safe Systems

We present a framework for building fail-safe hard real-time applications in timed asynchronous distributed systems subject to communication partitions and performance, omission, and crash failures. Most distributed systems built from commercial-off-the-shelf (COTS) processor and communication services are subject to such partitions because their COTS components do not provide hard real-time guarantees. Also custom designed systems can be subject to partitions due to unmaskable link or router failures. The basic assumption behind our approach is that each processor has a local hardware clock that proceeds within a linear envelope of real-time. This allows one to compute an upper bound on the actual delays incurred by a particular processing sequence or message transmission. Services and applications can use these computed bounds to detect when they cannot guarantee all their standard properties because of excessive delays. This allows an application to be fail-aware, that is, to detect when it cannot guarantee all its safety properties and in particular, to detect when to switch to a fail-safe mode.     

An Approach to Evaluating E-Business Information Systems Projects

Capital investments in the e-business infrastructure add complexity to the IT payoff question because e-business interorganizational investments are deployed across multiple platforms, projects, vendors and partners. Traditional MIS research has been devoted to measuring the payoff from information technology (IT) investment without any specific focus on e-business. Flaws in the mature MIS performance measures seem to yield weak guidance for managers when evaluating IT success, thus diluting the potential for these measures to be adapted for use in the new e-business environment. A review of the conventional MIS payoff literature indicates that these measures may be incomplete, inaccurate, or inefficient for application to electronic commerce investments. This paper brings four new points to the e-business IT investment evaluation dialogue: (1) we first explore performance measurement validity flaws in our long established measures; (2) the paper discusses a two-by-two matrix delineating the gap between the quantitative versus qualitative performance measures of management information systems (MIS) initiatives; (3) sample e-business payoff techniques are discussed and reviewed in light of these historical imperfections, and (4) fourth, the paper proposes and describes an innovative framework derived from production theory economics for future research in evaluating e-business MIS implementations.     

多机服务器任务调度的经济学方法q

本文针对多机服务器提出了一种任务调度的经济学方法以一般均衡理论为基础,依靠价格机制实现资源的优化分配;讨论了多机服务器的系统模型、任务的聚类和效用函数、经济学模型及均衡状态的最优性;最后通过模拟实验验证了经济学方法的有效性。     

网路化双线性系统的预测控制优化算法研究

本文对一类离散时间双线性系统进行网络化预测控制研究.针对控制系统网络信道传输引起的前向通道和反馈通道时延问题,基于双线性系统结构特性提出2种逐步优化算法对非凸优化问题进行求解,进而得到未来时刻的预测控制序列.仿真实例说明所求预测控制序列可以主动补偿网络引起的时延问题,从而说明所提出预测控制算法的有效性.     

An Adversarial Optimization Approach to Efficient Outlier Removal

This paper proposes a novel adversarial optimization approach to efficient outlier removal in computer vision. We characterize the outlier removal problem as a game that involves two players of conflicting interests, namely, model optimizer and outliers. Such an adversarial view not only brings new insights into some existing methods, but also gives rise to a general optimization framework that provably unifies them. Under the proposed framework, we develop a new outlier removal approach that is able to offer a much needed control over the trade-off between reliability and speed, which is usually not available in previous methods. Underlying the proposed approach is a mixed-integer minmax (convex-concave) problem formulation. Although a minmax problem is generally not amenable to efficient optimization, we show that for some commonly used vision objective functions, an equivalent Linear Program reformulation exists. This significantly simplifies the optimization. We demonstrate our method on two representative multiview geometry problems. Experiments on real image data illustrate superior practical performance of our method over recent techniques.     

An Optimization Approach to Petri Net Monitor Design

This note addresses the problem of enforcing generalized mutual exclusion constraints on a Petri net plant. First, we replace the classical partition of the event set into controllable and uncontrollable events from supervisory control theory, by associating a control and observation cost to each event. This leads naturally to formulate the supervisory control problem as an optimal control problem. Monitor places which enforce the constraint are devised as a solution of an integer linear programming problem whose objective function is expressed in terms of the introduced costs. Second, we consider timed models for which the monitor choice may lead to performance optimization. If the plant net belongs to the class of mono-T-semiflow nets, we present an integer linear fractional programming approach to synthesize the optimal monitor so as to minimize the cycle time lower bound of the closed loop net. For strongly connected marked graphs the cycle time of the closed-loop net can be minimized     

An Operational Approach to Requirements Specification for Embedded Systems

The approach to requirements specification for embedded systems described in this paper is called "operational" because a requirements specification is an executable model of the proposed system interacting with its environment. The approach is embodied by the language PAISLey, which is motivated and defined herein. Embedded systems are characterized by asynchronous parallelism, even at the requirements level; PAISLey specifications are constructed by interacting processes so that this can be represented directly. Embedded systems are also characterized by urgent performance requirements, and PAISLey offers a formal, but intuitive, treatment of performance.     

一种用于电子政务系统集成建模的方法

本文介绍了当前电子政务系统集成中面临的一些问题,并结合电子政务系统的特点,利用Web Services技术和MVC模式,提出一种新的电子政务系统集成模型,该模型能够很好地解决当前电子政务系统中原有工作流子系统异构集成的问题,并能提高系统集成后的可管理性。     

一种用于电子政务系统集成建模的方法

本文介绍了当前电子政务系统集成中面临的一些问题,并结合电子政务系统的特点,利用Web Services技术和MVC模式,提出一种新的电子政务系统集成模型,该模型能够很好地解决当前电子政务系统中原有工作流子系统异构集成的问题,并能提高系统集成后的可管理性.     

An Optimal Approach to Fault Tolerant Software Systems Design

A systematic method of providing software system fault recovery with maximal fault coverage subject to resource constraints of overall recovery cost and additional fault rate is presented. This method is based on a model for software systems which provides a measure of the fault coverage properties of the system in the presence of computer hardware faults. Techniques for system parameter measurements are given. An optimization problem results which is a doubly-constrained 0,1 Knapsack problem. Quantitative results are presented demonstrating the effectiveness of the approach.