Behavioral Refinement of Graph Transformation-Based Models

Model-driven software engineering requires the refinement of abstract models into more concrete, platform-specific ones. To create and verify such refinements, behavioral models capturing recon- figuration or communication scenarios are presented as instances of a dynamic meta-model, i.e., a typed graph transformation system specifying the concepts and basic operations scenarios may be composed of. Possible refinement relations between models can now be described based on the corresponding meta-models.In contrast to previous approaches, refinement relations on graph transformation systems are not defined as fixed syntactic mappings between abstract transformation rules and, e.g., concrete rule expressions, but allow for a more loose, semantically defined relation between the transformation systems, resulting in a more flexible notion of refinement.     

基于MDA的模型转换方法研究

模型驱动方法提高了软件开发的产品及效率,而模型转换是开发基于MDA应用工具的关键技术。该文首先简要介绍了MDA的基本理论,着重分析模型转换的研究方法、分类及其在开发工具中的应用,并且通过实例说明模型转换器的规范化和实现,最后,列举了未来研究方向上一些需要考虑的问题。     

MDA模型转换的OCL扩展

模型驱动架构(MDA)是继CORBA,UML之后由OMG推出的重要的软件开发方法学.MDA的核心是模型转换,模型转换语言又是实施模型转换的关键.本文从MOF元模型的角度首先对OCL进行动态特性的扩展,使其具备表达动态行为语义的能力;然后通过扩展相关关键字,定义了一个完整的模型转换程序框架;并提出创建中间转换对象实现了模型转换的可追溯性以及源模型和目标模型转换的同步性.     

MDA模型转换的同步技术

给出一种源模型和目标模型间的链接技术及其实现方法,该方法能很好地实现源模型和目标模型间的双向可追踪。既可以对源模型的更新执行正向转换,还可以实现目标模型向源模型的逆向转换。     

模型转换的重写逻辑构架研究

规则式的模型转换技术在模型驱动构架的模型转换实施中占有重要地位,但目前诸实施对于转换规则的定义存在多种解释、转换的协调方面、终止性和一致性等数学属性缺乏支持。该文提出一种Maude重写逻辑基础的构架(RLBA)以实施模型转换,通过产生式规范、多方法风格的重写规则集设计、OC(对象配置)和OM(对象消息)重写规则分类等技术并结合模型检查工具,为自动产生元模型和模型的面向对象可执行代数规范、转换规则的严格形式化定义、转换协调方面的刻画、终止性和一致性等的验证提供支持。     

模型驱动架构中模型转换技术的研究

模型转换是模型驱动构架中的核心，查询/视图／转换(QVT)是OMG提出的模型转换的标准化方案。文中介绍了各种模型转换技术和QVT模型转换标准，通过研究和比较八个机构对QVT实现标准的提案，从三大方面提出了对实现最终QVT标准的一些可参考性规则，最后提出了QVT语言分层模型和基于映射的多层体系QVT结构。     

基于面向对象的MDA三级建模技术研究

模型在模型驱动架构(MDA)软件开发生命周期中驱动整个开发过程,建模在MDA中起关键作用,建模是否成功是模型转换的前提,也决定MDA软件开发的成败。通过对当前建模技术的研究分析,根据对系统抽象级别的不同,提出基于MDA的三级建模技术,即计算无关模型(CIM)建模,平台无关模型(PIM)建模,平台相关模型(PSM)建模。详细介绍三个不同抽象级别模型的建模过程,并对它们之间的模型转换加以说明,从整体上描述MDA软件开发的过程,得出一种MDA软件开发方法。     

An Iterative Algebraic Geometric Approach for Identification of Switched ARX Models with Noise

The algebraic geometric (AG) approach has been used to identify switched auto regressive exogenous (SARX) models in hybrid systems, and it has several advantages over other SARX identification methods. This paper is focused on improving the estimation accuracy of the AG approach for systems corrupted with indispensable noises. A stochastic hybrid decoupling polynomial (SHDP) is constructed by reformulating the hybrid decoupling polynomial (HDP) used in the original AG method. An iterative scheme is developed to estimate parameters of the SHDP, which are used to calculate the SARX model parameters. This estimation involves linear regression with multiplicative noises, therefore a novel approach is proposed to solve this regression problem. Then, the parameters are recovered from the SHDP. Finally, all these steps for SARX model identification are summarized in an algorithm called the iterative algebraic geometric (IAG) approach. Simulations and experimental validation results are shown to demonstrate the effectiveness of and the improvement made by the proposed IAG method.     

离散系统区域极点/协方差等价实现一种代数方法

提出了离散随机系统的模型简化新方法:区域极点/协方差等价实现方法.即构造降阶模型,使其匹配给定的区域极点和稳态协方差值,在暂态性能和稳态性能这两个重要方面近似于给定的满阶模型.文中证明了满足要求的降阶模型的存在性,并直接给出了降阶模型的解析表达式,最后提供了说明性的数值例子.     

基于MDA的移动应用开发框架

手机应用软件开发需要耗费大量时间用于跨平台的移植,但该过程通常是重复的编码工作。为此,提出一种基于模型驱动架构的手机应用软件开发框架(MDMF)。利用模板将抽象出的平台无关模型转换为多个手机平台上的特定模型,进而生成对应的应用程序。应用结果表明了MDMF的有效性。     

小模型大数据:一种分析软件行为的代数方法

采用问题框架方法分析软件需求通过借助领域知识及其之间的结构关系,论述用户的需求是可以被软件系统满足的.这类定性的可满足性论述支持早期需求决策,选择合理的软件体系结构和设计方案.但是,当前的移动软件需求方是偏好各异的用户个体,需求差异化明显,而且根据应用场景这些需求发生动态变化.在这种情况下,现有的定性分析方法不再适用.大数据分析提供一种数据驱动的深度学习机制,为很多实践者采用.但依靠数据驱动的软件分析往往就事论事,仍然不能从根本上提供一个合理的论述来说明大量软件用户的需求到底是什么,也无法对可信软件的安全和私密性提供可靠的论证.再多的数据也只能提供统计意义的表象,而无法彻底防范别有用心的漏洞利用.本文尝试从提炼软件抽象目标行为的角度进一步深化问题框架的研究思路,针对各类个体行为建立概率模型,提出一种基于模型代数分析的方法,以避开纯粹数据驱动思路的大数据分析盲点.通过对安全和隐私性问题的分析,对所提出的方法可用性及局限性进行探讨,对未来大数据软件需求研究给予一定的启示.     

A Model Transformation Approach for Automatic Composition of COTS User Interfaces in Web-Based Information Systems

Globalization of the information and the Knowledge Society requires the modernization of Web-based Information Systems (WIS) into evolutive and adaptable user interfaces. Today, WIS user interfaces are built following traditional development paradigms. This article is inspired on a Model-Driven Development (MDD) perspective to produce runtime automatic composition of user interfaces from model and metamodel representations of widgets-type COTS interface components architectures and model transformation.     

An optimization framework for “build-or-buy” decisions in software architecture

Building a software architecture that meets functional requirements is a quite consolidated activity, whereas keeping high quality attributes is still an open challenge. In this paper we introduce an optimization framework that supports the decision whether to buy software components or to build them in-house upon designing a software architecture. We devise a non-linear cost/quality optimization model based on decision variables indicating the set of architectural components to buy and to build in order to minimize the software cost while keeping satisfactory values of quality attributes. From this point of view, our tool can be ideally embedded into a Cost Benefit Analysis Method to provide decision support to software architects. The novelty of our approach consists in building costs and quality attributes on a common set of decision variables related to software development. We start from a special case of the framework where the quality constraints are related to the delivery time and the product reliability, and the model solution also devises the amount of unit testing to be performed on built components. We generalize the framework formulation to represent a broader class of architectural cost-minimization problems under quality constraints, and discuss advantages and limitations of such approach.     

An improved likelihood model for eye tracking

While existing eye detection and tracking algorithms can work reasonably well in a controlled environment, they tend to perform poorly under real world imaging conditions where the lighting produces shadows and the person’s eyes can be occluded by e.g. glasses or makeup. As a result, pixel clusters associated with the eyes tend to be grouped together with background-features. This problem occurs both for eye detection and eye tracking. Problems that especially plague eye tracking include head movement, eye blinking and light changes, all of which can cause the eyes to suddenly disappear. The usual approach in such cases is to abandon the tracking routine and re-initialize eye detection. Of course this may be a difficult process due to missed data problem. Accordingly, what is needed is an efficient method of reliably tracking a person’s eyes between successively produced video image frames, even in situations where the person’s head turns, the eyes momentarily close and/or the lighting conditions are variable. The present paper is directed to an efficient and reliable method of tracking a human eye between successively produced infrared interlaced image frames where the lighting conditions are challenging. It proposes a log likelihood-ratio function of foreground and background models in a particle filter-based eye tracking framework. It fuses key information from even, odd infrared fields (dark and bright-pupil) and their corresponding subtractive image into one single observation model. Experimental validations show good performance of the proposed eye tracker in challenging conditions that include moderate head motion and significant local and global lighting changes. The paper presents also an eye detector that relies on physiological infrared eye responses and a modified version of a cascaded classifier.     

Understanding and using the IEC 61850: a case for meta-modelling

This paper argues for means to rigorously specify data models and communications services of industrial data communications standards. It uses the example of the recently published IEC 61850 standard “Communications networks and systems in substations”. The latter applies mainly to electrical supply systems such as substations and decentralised power resources (based on wind, photovoltaic, fuel cells, hydropower). However, the concepts of the IEC 61850 could be used in other industrial areas, as well.

The paper shows how the complex standard can be modelled elegantly and precisely with a meta-modelling approach, in which we utilise the UML for the model representation. The conceptual approach presented makes the inherent complexity of the standard's data model manageable for both humans and machines. That is, it facilitates human comprehension and machine processability and thereby contributes to a better understanding of the standard as well as to a better utilisation of the standard through functionality provided in today's CASE tools. One important aspect is that it allows one to establish and maintain consistency across the standard's data and communications models.     

An Algebraic Method for Pole Placement in Multivariable Systems with Internal and External Point Delays by Using Single Rate or Multirate Sampling

This paper considers the pole placement in multivariable systems involving known delays by using dynamic controllers subject to single rate and multirate sampling. The controller parametrizations and auxiliary compensating signals which are introduced to deal with the contribution of the delays are calculated from systems of algebraic equations which are solved by using the Kronecker product of matrices.     

Nondeterministic dependencies in relations: An extention of the concept of functional dependency

In the present article, some special semantic integrity constraints—so called nondeterministic dependencies—are proposed. These dependencies can be regarded as stochastic extensions of functional dependencies. After some basic definitions, the concept of nondeterministic dependency is introduced. Examples are given and an implementation for a statistical analysis system is described. Some properties are discussed.     

An environment for DEVS-based multiformalism simulation in Common Lisp/CLOS

The paper presents the realization of an object-oriented kernel of a new modeling and simulation environment. The kernel system stands out as it is based on systems theoretical concepts and facilitates combined discrete-continuous, modular, hierarchical modeling. Its implementation language is the AI language Common Lisp and its object-oriented superset CLOS. The kernel system serves as the basis for a knowledge-based modeling and simulation environment supporting interactive modeling and simulation and automatic model construction. This research was supported in part by SIEMENS Munich, ZFE, ST.     

Emergency service systems: The use of the hypercube queueing model in the solution of probabilistic location problems

Probabilistic location problems are surveyed from the perspective of their use in the design of emergency service systems, with special emphasis on emergency medical systems. Pioneering probabilistic models were defined in the 1980s, as a natural extension of deterministic covering models (first generation models) and backup models (second generation). These probabilistic models, however, adopted simplifying assumptions that in many cases do not correspond to real-world situations, where servers usually cooperate and have specific individual workloads . Thus the idea of embedding the hypercube queueing model into these formulations is to make them more adherent to the real world. The hypercube model and its extensions are initially presented in some detail, which is followed by a brief review of exact and approximate methods for its solution. Probabilistic models for the design of emergency service systems are then reviewed. The pioneering models of Daskin and ReVelle and Hogan are extended by embedding the hypercube model into them. Solution methods for these models are surveyed next, with comments on specialized models for the design of emergency medical systems for urban areas and highways.     

炭素煅烧回转窑自动监控系统开发与应用

介绍了炭素煅烧回转窑生产过程中计算机自动监控系统的开发.通过对生产过程关键工艺进行实时监视与优化控制,实现了煅烧过程自动化和过程优化控制,提高石油焦回收率,减轻工人劳动强度;同时,针对给料系统存在时滞性和随机干扰的特点,提出了基于CARMA模型的自校正调节器算法.