IEEE Concurrency

The paper considers the main contributions of the notion of an agent and how it differs from object oriented concurrent programming View full abstract»

It is time for high-quality products to emerge for HPC systems, but achieving this goal requires a new way of transferring results from the research environment to the application marketplace. As the product of three Italian research agencies and one industrial company: the National Research Council (CNR), National Agency for New Technologies, Energy, and Environment (ENEA), National Institute for... View full abstract»

In large-scale multimedia applications, such as video on demand (VoD), interactive television (ITV), and Web browsers, the sheer number of users and the data size of the systems exacerbate the difficulty of supporting continuous-time presentation. For example, a single video stream requires between 1.5 and 6 Mbps of bandwidth. At 6 Mbps, the typical rate required for ITV, even the 100-stream serve... View full abstract»

Sequencing and assignment are two important issues we need to address a when scheduling real-time tasks on a multiprocessor architecture. Different problem representations can schedule such tasks, each emphasizing either a sequencing or assignment task. A sequence-oriented representation satisfies problem constraints by emphasizing the search for an appropriate tasks order, while an assignment-ori... View full abstract»

Vendors cannot provide all the operating-system services that users demand. So, there has been a persistent desire to make operating systems more flexible and customizable. Naturally, object-oriented technology has come to bear on this area. However the ease of use of many such solutions has been disappointing. Ease of use is a key feature of Frigate, an object-oriented file system. It differs fro... View full abstract»

Although precise numbers are lacking, statistics suggest that the number of concurrent programmers has sky-rocketed over the past few years and will continue to do so. This stems mainly from Java's emergence-it's the first ubiquitous concurrent programming language. The rise in concurrent programmers also reflects an increased use of common C++ multithreaded class libraries and frameworks, Posix p... View full abstract»

The Huge Microphone Array project began in February 1994 to design, construct, debug, and test a real-time 512-microphone array system and to develop algorithms for it. Analysis of known algorithms indicated that signal-processing performance of over 6 Gflops would be required, while the need for portability-fitting it into a small van-also set an upper limit to the power required. These trade-off... View full abstract»

Ada 83 has numerous shortcomings for concurrent systems: it requires additional tasks, adding overhead and increasing interrupt latency, and it has difficulty handling asynchronous transfer of control. Ada 95 offers features that address these shortcomings and simplify concurrent implementation: protected units, interrupt handlers, priority entry queuing, dynamic task priorities, and asynchronous ... View full abstract»

The traditional view of mobile computing (such as it is) typically involves users moving through an environment, or set of environments, with their own personal computing devices. This model works as a rich extension of existing devices such as notebook computers and personal digital assistants. Without some degree of mobility, the problems associated with mobile computing are indistinguishable fr... View full abstract»

To build a multicasting tree in a multicomputer network, the authors propose three strategies based on voting constructing a minimum spanning tree, and repeatedly constructing multiple minimum spanning trees. Typically, performance metrics to evaluate a multicast solution include time and traffic. Simultaneously optimizing both metrics is computationally intractable because the problem is NP-compl... View full abstract»