Aspect] is a simple and practical aspect-oriented extension to Java With just a few new constructs, AspectJ provides support for modular implementation of a range of crosscutting concerns. In AspectJ's dynamic join point model, join points are well-defined points in the execution of the program; pointcuts are collections of join points; advice are special method-like constructs that can be attached to pointcuts; and aspects are modular units of crosscutting implementation, comprising pointcuts, advice, and ordinary Java member declarations. AspectJ code is compiled into standard Java bytecode. Simple extensions to existing Java development environments make it possible to browse the crosscutting structure of aspects in the same kind of way as one browses the inheritance structure of classes. Several examples show that AspectJ is powerful, and that programs written using it are easy to understand.

An overview of AspectJ

A number of library based parallel and sequential network simulators have been designed. The paper describes a library, called GloMoSim (Global Mobile system Simulator), for parallel simulation of wireless networks. GloMoSim has been designed to be extensible and composable: the communication protocol stack for wireless networks is divided into a set of layers, each with its own API. Models of protocols at one layer interact with those at a lower (or higher) layer only via these APIs. The modular implementation enables consistent comparison of multiple protocols at a given layer. The parallel implementation of GloMoSim can be executed using a variety of conservative synchronization protocols, which include the null message and conditional event algorithms. The paper describes the GloMoSim library, addresses a number of issues relevant to its parallelization, and presents a set of experimental results on the IBM 9076 SP, a distributed memory multicomputer. These experiments use models constructed from the library modules.

GloMoSim: a library for parallel simulation of large-scale wireless networks

[서평]「Component Software」 - Beyond Object-Oriented Programming -

http://www.eis.mdx.ac.uk/staffpages/juanaugusto/CookAJ2009.pdf

Review: Ambient intelligence: Technologies, applications, and opportunities

The Internet of Things (IoT) envisages a future in which digital and physical things or objects (e.g., smartphones, TVs, cars) can be connected by means of suitable information and communication technologies, to enable a range of applications and services. The IoT’s characteristics, including an ultra-large-scale network of things, device and network level heterogeneity, and large numbers of events generated spontaneously by these things, will make development of the diverse applications and services a very challenging task. In general, middleware can ease a development process by integrating heterogeneous computing and communications devices, and supporting interoperability within the diverse applications and services. Recently, there have been a number of proposals for IoT middleware. These proposals mostly addressed wireless sensor networks (WSNs), a key component of IoT, but do not consider RF identification (RFID), machine-to-machine (M2M) communications, and supervisory control and data acquisition (SCADA), other three core elements in the IoT vision. In this paper, we outline a set of requirements for IoT middleware, and present a comprehensive review of the existing middleware solutions against those requirements. In addition, open research issues, challenges, and future research directions are highlighted.

/pdf/middleware-for-internet-of-things-a-survey-5b3i33k9fm.pdf

Middleware for Internet of Things: A Survey

This paper presents a software architecture for simulating and implementing Petri nets. It is based on object-oriented techniques and autonomous agents. Object-orientation enables the adaptation and extension of the software architecture with new or alternatively defined features. Agents allow to model a net as a set of autonomous, cooperating entities. The result is a flexible and extendible framework of reusable components for efficiently implementing a large family of Petri net classes.The execution can be performed on a mono-processor, a parallel or distributed system. This is the result of using the XENOOPS execution environments for parallel applications.

Using agents for simulating and implementing Petri nets

Systems must adapt themselves to (evolving) user requirements or to their (changing) environment. One way to address this problem is through component composition, systematically (re-)building systems from their requirements by composing reusable components. Our work addresses composition of multi-flow architectures. Composition is performed in a top-down stepwise refinement manner, while composing also the structure of components. This strategy allows to handle the complexity of the system and to realize very fine-tuned compositions even when the composition decision is made automatically, as it is necessary for self-customizable systems. The goal is to perform unanticipated customizations with as few user interventions as possible. We identify as sources of uncertainty evolving requirements and discovery of new component types. The component composition model presented in this paper is able to cope with this degree of unanticipated variability. We evaluate and discuss our composition approach by examples from our work on selfcustomizable network protocol stacks.

A Component Composition Model to Support Unanticipated Customization of Systems

Currently, paradigms such as component-based software development and service-oriented software architectures promote modularization of software systems into highly decoupled and reusable software components and services. In addition, to improve manageability and evolveability, software systems are extended with management capabilities and self-managed behavior. Because of their very nature, these self-managed software systems often are mission critical and highly available. In this paper, we focus on the complexity of preserving correctness in modularized self-managed systems. We discuss the importance of consistent software compositions in the context of self-managed systems, and the need for a correctness-preserving adaptation process. We also give a flavor of possible approaches for preserving correctness, and conclude with some remarks and open questions.

Towards preserving correctness in self-managed software systems

Sender-initiated and receiver-initiated coordination in a global object space

This paper features a case study of a complex parallel application (in the area of Molecular Dynamics Simulation) modelled in a concurrent object-oriented language. In this computational model, application objects can exhibit some autonomous behaviour and reside in a global object space. At runtime, this object space can physically be mapped onto a distributed memory machine.

Pierre Verbaeten

Papers

Using agents for simulating and implementing Petri nets

A Component Composition Model to Support Unanticipated Customization of Systems

Towards preserving correctness in self-managed software systems

Sender-initiated and receiver-initiated coordination in a global object space

Sender-Initated and Receiver-Initated Coordination in a Global Object Space