Object oriented program examples for high energy physics reconstruction

A number of Object Oriented example programs based on High Energy Physics event reconstruction are worked out

Adaptive streaming of MPEG-based audio/video content over wireless networks

This paper describes a method for robust streaming of combined MPEG audio/video content (encoded either with MPEG-2 or MPEG-4/H.264) over in-home wireless networks. We make use of currently used content distribution format (MPEG Transport Stream) and network protocols (either RTP or TCP/HTTP). The transmitted bit-rate is constantly adapted to the available network bandwidth, such that audio and video artifacts caused by packet loss are avoided. Bit-rate adaptation is achieved by using a packet scheduling technique called I-Frame Delay (IFD), which performs priority-based frame dropping upon insufficient bandwidth. We show an implementation using RTP and an implementation using TCP. Measurements on a real-life demonstrator set-up demonstrate the effectiveness of our approach

NCS calculation method for streaming applications

Our contribution in the context of the Quality of Service (QoS) in IN-home digital networks project was focused on the QoS provided by consumer electronics terminals. In order to achieve a particular level of QoS provided by a terminal, an important issue is resource management supported by performance analysis. The work we present in this article is highlighting ways of predicting the necessary resources (e.g. CPU, memory, bus) needed by a video streaming application to provide a given level of QoS. We introduce a calculation method that involves measuring in isolation the resource needs of each of the individual streaming components, and also a performance composition analysis, which takes into account the Number of Context Switches (NCS) occurring during the execution of the application. We based our calculation for the NCS on the observation that running streaming applications, eventually adopt a pattern of execution that repeats after a specific interval of time (hyperperiod). By finding the NCS induced during a hyperperiod, we deduce the total NCS occurring during the execution of the application. The article gives a characterization of the streaming applications execution and of the component model that lie at the basis of our calculation

The response time distribution in a multi-processor database with single queue static locking

A transaction scheduling mechanism is designed for a shared??memory?? multi??processor database system??. The scheduler used is a variant of static locking?? adapted for real??time and more than one processor??. It is assumed that transactions arrive according to a Poisson process?? execution times of transactions are independent and exponentially distributed?? and all transactions use the same number of data items?? The system is then represented as a Markov model??. A steady state is derived from this model??. By examining the path through the system of a single transaction,?? a recursive relation that describes all moments of a transaction's response time is derived.?? The moments are obtained from this relation with dynamic programming??. The response time distribution is approximated by fi??tting a distribution to the ??first two moments??. Simulation shows that this approximation gives excellent results??

Objected Oriented program examples for High Energy Physics reconstruction

A number of Object Oriented example programs based on High Energy Physics event reconstruction are worked out. 1 Introduction This report presents a set of Object-Oriented (OO) programs that should help the reader to design OO programs for High Energy Physics reconstruction. The writing of these examples seems appropriate at a moment that a large group of people is leaving the FORTRAN language and embrace the OO concepts [Boo94]. Talking with people shows that the step from FORTRAN to C++ [Str97] is easily made. Positive comments on C++ usually concern the pointer handling in C++. Most people that start with OO design are looking for a guide for choosing the appropriate classes. The creation of a class specification that later hides many implementation details is not easily understood. It is difficult to give reasons why one design is better than another (motivation of the design). Apart from the performance and functional aspects of the software product other aspects can be importa..

Introduction

No abstract

Preparation of heterogeneous networks for ambient intelligence

Ambient Intelligence assumes the existence of ubiquitous networked computing. Networking is supported in the home by a so-called home network. Currently, the home network emerges from the purchase of a second PC in the home. Extending the home network confronts the prospective buyer with a multitude of standards. The more important representatives of these standards are discussed and an integration path is described

Atomic objects for real-time distributed systems with mixed time constraints

Two types of applications are considered: hard real-time (HRT) and soft real-time (SRT). HRT applications need to meet their deadlines under all circumstances; deadlines of SRT applications may occasionally be missed. Both applications are constructed from objects. HRT and SRT applications coexist on the same set of processors and share objects to allow a consistent exchange of data via transactions. Several concurrency control algorithms exist to assure consistent transaction results in distributed database systems. The addition of versions to objects can diminish the execution time of read-only transactions and increases the number of permitted interleavings of concurrently executing transactions. Imposing two different orderings, one for read-only transactions and one for all other transactions, the wait-time of read-only transactions is considerably reduced. Small delays increase the probability that SRT deadlines are met or a design is reached in which all HRT requirements are met. The interleaving of HRT- and SRT-transactions is severely reduced when SRT-transactions are not allowed to perturb HRT-transactions. The here-defined transfer-serializability criterion permits the interleaving of HRT- and SRT-transactions