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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

MPS-based Domain-specific Language for Defining RTSJ Systems / MPS-based Domain-specific Language for Defining RTSJ Systems

Fechtner, Tomáš January 2012 (has links)
The Real-time Specification of Java (RTSJ) is an intention to introduce Java as a language for developing real-time system. However, the complexity of their development and a non-trivial programming model of RTSJ with its manual memory management often lead to programming errors. To mitigate the development of RTSJ systems it would be beneficial to provide an internal domain-specific language (DSL) extending the Java language which would allow to develop the systems in more intuitive and safer way. However, it is needed to find compromise between solution's power and level of usability, because this two attributes go often against each other. One possible way of DSLs creation concerns the Meta-Programming System (MPS). It allows to develop new domain-specific languages and corresponding projectional editors enabling different views on code. This thesis proposes a design and implementation of the DSL on the top of the MPS platform and corresponding code generator enabling development of RTSJ systems. Furthermore, the thesis provides a simple case-study to evaluate a proposed DSL. Additionally, the thesis assesses the suitability of MPS as a DSL-development platform.
2

A distributed hard real-time Java system for high mobility components

Rho, Sangig 17 February 2005 (has links)
In this work we propose a methodology for providing real-time capabilities to component-based, on-the-fly reconfigurable, distributed systems. In such systems, software components migrate across computational resources at run-time to allow applications to adapt to changes in user requirements or to external events. We describe how we achieve run-time reconfiguration in distributed Java applications by appropriately migrating servers. Guaranteed-rate schedulers at the servers provide the necessary temporal protection and so simplify remote method invocation management. We describe how we manage overhead and resource utilization by controlling the parameters of the server schedulers. According to our measurements, this methodology provides real-time capability to component-based reconfigurable distributed systems in an effcient and effective way. In addition, we propose a new resource discovery protocol, REALTOR, which is based on a combination of pull-based and push-based resource information dissemination. REALTOR has been designed for real-time component-based distributed applications in very dynamic or adverse environments. REALTOR supports survivability and information assurance by allowing the migration of components to safe locations under emergencies suchas externalattack, malfunction, or lackofresources. Simulation studies show that under normal and heavy load conditions REALTOR remains very effective in finding available resources, and does so with a reasonably low communication overhead.REALTOR 1)effectively locates resources under highly dynamic conditions, 2) has an overhead that is system-size independent, and 3) works well in highlyadverse environments.We evaluate the effectiveness of a REALTOR implementation as part of Agile Objects, an infrastructure for real-time capable, highly mobile Java components.
3

Η Real Time Java στην ανάπτυξη ενσωματωμένων συστημάτων

Ασσιούρας, Ιωάννης 05 January 2011 (has links)
Η Real time Specification of Java (RTSJ) ξεπερνάει τους περιορισμούς της Java που την κρίνουν ακατάλληλη για την ανάπτυξη συστημάτων πραγματικού χρόνου. H Real Time Java έχει ήδη χρησιμοποιηθεί στην ανάπτυξη βιομηχανικών συστημάτων ελέγχου με θετικά αποτελέσματα. Ωστόσο, η ευρεία χρήση στην ανάπτυξη εφαρμογών του πεδίου αυτού περιορίζεται σημαντικά από το γεγονός ότι οι μηχανικοί συστημάτων ελέγχου δεν είναι εξοικοιωμένοι με τις σύγχρονες τεχνολογίες ανάπτυξης λογισμικού. Το IEC61499 RTSJ-Based Framework, το οποίο παρουσιάζεται και επεκτείνεται στην παρούσα διπλωματική εργασία αξιοποιεί το νέο IEC61499 πρότυπο, το οποίο είναι βασισμένο στην έννοια του Function Block. Το framework αυτό επιτρέπει στον μηχανικό συστημάτων ελέγχου να δουλέψει στο επίπεδο σχεδίασης χρησιμοποιώντας την ευρέως διαδεδομένη έννοια του FB, εκμεταλλευόμενος το αυτόματα παραγόμενο Real time Java μοντέλο υλοποίησης του συστήματος. Στην παρούσα διπλωματική εργασία αρχικά παρουσιάζονται οι επεκτάσεις που προσφέρει το RTSJ στην standard Java ώστε να μπορεί να χρησιμοποιηθεί σε εφαρμογές πραγματικού χρόνου. Στην συνέχεια παρουσιάζεται το IEC61499 RTSJ-Based Framework και οι επεκτάσεις που έγιναν σε αυτό, ώστε να μπορεί να υποστηριχθεί η ανάπτυξη κατανεμημένων εφαρμογών. Ακολουθεί η ανάλυση της απόδοσης του περιβάλλοντος εκτέλεσης του framework και η περίπτωση χρήσης ενός συστήματος γραμμής παραγωγής, του Festo MPS. / The Real Time Specification of Java (RTSJ) addresses successfully the limitations of Java that make it inappropriate for the development of real time applications.Many positive experiences of using Real Time Java in the control and automation domain have already been reported so far.In spite of the many positive results, the wide use of Java in control and automation domain is prohibited due to the fact that the control engineers are not familiar with current software engineering technologies. The IEC61499 RTSJ-Based Framework, that is presented and extended in the context of this thesis exploits the new IEC61499 standard that is based on the Function Block(FB) concept.This framework allows the control engineer to work in the design level using the already widely accepted concept of FB and transparently use real-time Java for the implementation model of the system. In this thesis the extensions that the RTSJ provides to standard Java are initially presented.Next, the IEC61499 RTSJ-Based Framework is presented as well as the extensions that were added in the context of this thesis in order to support the development of distributed applications.In addition, the performance analysis of the framework's run-time environment is presented as well as the case study of a modular production system the Festo MPS
4

3d Animation For Hand Preshaping

Guler, Mehmet Soner 01 March 2006 (has links) (PDF)
The human hand is an essential part of human body, capable of making complex and expressive motions. Its complicated structure makes it a formidable challenge for animators to animate hand motions. Most computer graphics research on hand motion has focused on preshaping, preshaping and gestures with application to areas of human computer interaction and sign language. There are also a number of educational applications such as typing, playing of musical instruments etc. From a computer graphics standpoint, these applications are difficult in animation of hand. This thesis aims to animate 3D hand preshaping activity for a chosen virtual 3D object in real-time. Researches on human hand kinematics, structure and geometric stability analysis on preshaping are the main motivation for the algorithms developed in this thesis for animating 3D preshaping. The algorithm that we developed is made of two main parts. The first part is related with the precision type preshaping requiring the finger-tips positioning for a given object such as the cube, cylinder or sphere. First part is completed by procedural approach which is based on kinematics to generate the motion of the hand for the given virtual object at the determined finger-tip positions. Second part related with the wrap type preshaping aims to have maximum interaction between hand and object. For this purpose, we have developed the collision detection algorithm to find intersection surfaces between hand and object. Even though developed algorithm based on the kinematics was used for the precision type preshaping application, it can also be used for many other applications requiring hand animation given the positions of finger tips.
5

Ανάπτυξη ενσωματωμένων συστημάτων σε πολυπήρηνο ή πολυεπεξεργαστικό περιβάλλον με χρήση Real Time Java

Δημητρακόπουλος, Γεώργιος 20 October 2010 (has links)
Ο σκοπός της παρούσας διπλωματικής εργασίας είναι να μελετηθεί με ποιον τρόπο μια εφαρμογή μπορεί να αξιοποιήσει την παρουσία πολλών επεξεργαστών σε ένα σύστημα. Το σύστημα προς μελέτη είναι το Festo MPS, το οποίο είναι ένα κατανεμημένο ενσωματωμένο σύστημα πραγματικού χρόνου, αποτελούμενο από τρεις υπομονάδες. Το σύστημα έχει υλοποιηθεί σε Real Time Java, μια επέκταση της Java, η οποία ανταποκρίνεται σε απαιτήσεις πραγματικού χρόνου. Η εφαρμογή εκτελείται σε μια Java Virtual Machine πραγματικού χρόνου, η οποία με τη σειρά της εκτελείται σε ένα λειτουργικό σύστημα τύπου Linux. Το κάθε επίπεδο έχει διάφορους μηχανισμούς έτσι ώστε να αξιοποιεί τους διαθέσιμους επεξεργαστές. Ερευνούνται τρόποι με τους οποίους ο προγραμματιστής μπορεί να διευκολυνθεί στο έργο του, γράφοντας αποδοτικότερο, μικρότερο και καθαρότερο παράλληλο κώδικα, καθώς και οι επιλογές, ώστε να καθορίζει ο ίδιος επακριβώς τον τρόπο εκτέλεσης, όταν αυτό απαιτείται. Τελικός στόχος είναι να εκτελεστεί μια προσομοίωση του συστήματος, όπου κάθε υπομονάδα θα εκτελείται σε διαφορετικό επεξεργαστή. Αυτό επιτυγχάνεται με τη βοήθεια των κλήσεων του λειτουργικού συστήματος μέσω Java Native Interface. / The purpose of this thesis is to study how an application can exploit many processors available in a system. The case study system is the Festo MPS, which is a distributed embedded real time system consisting of three subunits. The system has been implemented in Real Time Java, an extension of Java, which responds to real-time requirements. The application runs on a Real Time Java Virtual Machine, which in turn runs on a Linux type operating system. Each level has several mechanisms to utilize the available processors. There are explored ways in which the programmer can be facilitated in his work by writing more efficient, smaller and cleaner parallel code and also the options to set himself how the code will be executed when required. The ultimate goal is to run a simulation of the system where each subunit will run on its own processor. This is achieved through calls to the operating system through Java Native Interface.

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