Comparative Evaluation of Model Transformation Specification Approaches

Model transformations have become a key element of model-driven software development, being used to transform platform-independent models to platform-specific models, to improve model quality, to introduce design patterns and refactorings, and to map models from one language to another. A large number of model transformation notations and tools exist. However, there are no guidelines on how to select appropriate notations for particular model transformation tasks, and no comprehensive comparisons of the relative merits of particular approaches. In this paper we provide a unified semantic treatment of model transformations, and show how correctness properties of model transformations can be defined using this semantics. We evaluate several approaches which have been developed for model transformation specification, with respect to their expressivity, complexity and support for verification, and make recommendations for resolving the outstanding problems concerning model transformation specification.     

SoC通讯体系结构的高层建模技术研究

片上通讯设计是SoC系统设计的关键。本文着重从高层建模上研究SOC通讯体系结构设计。首先概述了SoC的通讯体系结构设计,其次介绍了片上通讯体系结构的高层建模方法,然后介绍了高层片上通讯体系结构的快速仿真方法,最后介绍了我们设计实现的Hi-SoComm系统。     

Bidirectional model transformations in QVT: semantic issues and open questions

We consider the OMG’s queries, views and transformations standard as applied to the specification of bidirectional transformations between models. We discuss what is meant by bidirectional transformations, and the model-driven development scenarios in which they are needed. We analyse the fundamental requirements on tools which support such transformations, and discuss some semantic issues which arise. In particular, we show that any transformation language sufficient to the needs of model-driven development would have to be able to express non-bijective transformations. We argue that a considerable amount of basic research is needed before suitable tools will be fully realisable, and suggest directions for this future research.     

Model-driven migration of supervisory machine control architectures

Supervisory machine control is the high-level control in advanced manufacturing machines that is responsible for the coordination of manufacturing activities. Traditionally, the design of such control systems is based on finite state machines. An alternative, more flexible approach is based on task-resource models. This paper describes an approach for the migration of supervisory machine control architectures towards this alternative approach. We propose a generic migration approach based on model transformations that includes normalisation of legacy architectures before their actual transformation. To this end, we identify a number of key concerns for supervisory machine control and a corresponding normalised design idiom. As such, our migration approach constitutes a series of model transformations, for which we define transformation rules. We illustrate the applicability of this model-driven approach by migrating (part of) the supervisory control architecture of an advanced manufacturing machine: a wafer scanner developed by ASML. This migration, towards a product-line architecture, includes a change in architectural paradigm from finite state machines to task-resource systems.     

构件式体系结构模型映射的形式化语义

语义一致性是模型驱动开发中模型转换正确性的一个重要标准,但目前模型转换中语义特性保持的定义、描述和验证仍是一个尚未解决的难题.基于软件体系结构,利用范畴理论和代数规范形式化描述体系结构模型及其间的映射关系,使之具有精确的语义.体系结构模型的形式化语义用类型范畴图表来表示,态射合成被用来追踪构件模型之间的关联和映射,不同层次模型间的映射关系用态射和函子来形式化描述.以此为基础,进一步分析了模型转换应保持的语义特性.范畴理论支持图形化建模,可以使模型中的构件关系以及结构特征可视化,有利于对模型转换的理解和追踪.应用研究表明,该描述框架很好地把握了模型驱动开发的实质、过程和要求,为模型转换和模型驱动开发提供了新的认知、设计和语义计算的指导架构.     

Toward the automation of a QoS-driven SLA establishment in the Cloud

Composite software as a service (SaaS)-based SOA offers opportunities for enterprises to offer value-added services. The cornerstone for such a business is service level agreements between Cloud customers and Cloud providers. In spite of the hype surrounding composite SaaS, standardized methods that enable a reliable management of service level agreements starting from the SLA derivation from the customer requirements to the SLA establishment between the two stockholders are still missing. To overcome such a drawback, we propose a method for SLA establishment guided by QoS for composite SaaS. Our method provides: (1) a requirement specification language for the Cloud customer to define the composition schemas of the requested services along with its QoS constraints; (2) a Cloud provider offer specification language and method to help in identifying the services and resources that satisfy the customer requirements; and (3) an SLA document definition language and method to specify a deployable composite SaaS on the Cloud. Our approach for SLA establishment embraces model-driven architecture principles to automate the SLA document generation from the customer requirements document. The automation is handled through model transformations along with enrichment algorithms to ensure the generation of complete SLA documents.     

Performance evaluation of network processor architectures: combining simulation with analytical estimation

The designs of most systems-on-a-chip (SoC) architectures rely on simulation as a means for performance estimation. Such designs usually start with a parameterizable template architecture, and the design space exploration is restricted to identifying the suitable parameters for all the architectural components. However, in the case of heterogeneous SoC architectures such as network processors the design space exploration also involves a combinatorial aspect––which architectural components are to be chosen, how should they be interconnected, task mapping decisions––thereby increasing the design space. Moreover, in the case of network processor architectures there is also an associated uncertainty in terms of the application scenario and the traffic it will be required to process. As a result, simulation is no longer a feasible option for evaluating such architectures in any automated or semi-automated design space exploration process due to the high simulation times involved. To address this problem, in this paper we hypothesize that the design space exploration for network processors should be separated into multiple stages, each having a different level of abstraction. Further, it would be appropriate to use analytical evaluation frameworks during the initial stages and resort to simulation techniques only when a relatively small set of potential architectures is identified. None of the known performance evaluation methods for network processors have been positioned from this perspective.We show that there are already suitable analytical models for network processor performance evaluation which may be used to support our hypothesis. To this end, we choose a reference system-level model of a network processor architecture and compare its performance evaluation results derived using a known analytical model [Thiele et al., Design space exploration of network processor architectures, in: Proc. 1st Workshop on Network Processors, Cambridge, MA, February 2002; Thiele et al., A framework for evaluating design tradeoffs in packet processing architectures, in: Proc. 39th Design Automation Conference (DAC), New Orleans, USA, ACM Press, 2002] with the results derived by detailed simulation. Based on this comparison, we propose a scheme for the design space exploration of network processor architectures where both analytical performance evaluation techniques and simulation techniques have unique roles to play.