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

A component platform for flexible protocol stacks

Evaluating Communication Overhead in Helios

Specifying and enforcing constraints and invariants such as architectural constraints and data typing, strongly enhances the safety and reliability of the software system. Next to design and development constraints, the composition of software systems in component-based software also introduces composition time constraints and dependencies. In data-centered software systems, for example, the software composer implicitly creates dataflow dependencies between software components. Describing composition time constraints and enforcing these constraints at deploy time or at run-time strongly improves the safety and reliability of the software. In this paper, we present an approach for expressing and enforcing dataflow dependencies in data-centered software systems, and conclude with a validation of the approach in a servlet-based case study.

/pdf/improving-software-reliability-in-data-centered-software-47azsj9rpm.pdf

Improving software reliability in data-centered software systems by enforcing composition time constraints

Transparent observation of Xenoops objects

Correlate is a concurrent object-oriented language, which supports active objects as a unit of concurrency. In this paper, we discuss the migration of active objects in Correlate. First, we will show that the architecture of the run-time system simplifies the realisation of a migration mechanism that supports active objects, because this particular run-time system has complete control over all scheduling aspects. Secondly, we will show that object migration in Correlate can be exploited by a broad range of (e.g. load balancing) subsystems, mainly because policies can be designated on a per object basis.

Pierre Verbaeten

Papers

A component platform for flexible protocol stacks

Evaluating Communication Overhead in Helios

Improving software reliability in data-centered software systems by enforcing composition time constraints

Transparent observation of Xenoops objects

Mobile active objects in correlate