[52] | Laszlo Böszörmenyi, Harald Kosch, Renata Slota, PARMED-Information system for long distance collaboration in medicine, In Proceedings of the 3rd International Austrian-Israeli Technion Symposium, 26.-27. April 1999, RISC Linz, Austrian Technion Society (Helmut Gutmann, ed.), Austrian Technion Society, Wien, pp. 157-164, 1999.
[bib] [pdf] [abstract]
Abstract: This paper describes the PARMED project initiative The aim of PARMED is to provide medical stu with a large virtual database of image and video data distributed over several medical centers Clients can access the PARMED system by an active client software which provides graphical interfaces to query the virtual database Incoming video streams and image data is postprocessed by the active client software to allow analysis of this data for diagnostics or virtual teaching Quality of service and security aspects are crucial for such kind of distributed system and will be addressed with priority
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[51] | Laszlo Böszörmenyi, Günter Hölzl, Emanuel Pirker, Parallel Cluster Computing with IEEE-1394, In Parallel Computatuin. 4th International ACPC Conference Including Special Tracks on Parallel Numerics (ParNum'99) and Parallel Computing in Image Processing, Video Processing, and Multimedia Salzburg, Austria, February 16-18, 1999, Proceedings (Peter Zinterhof, Marian Vajtersic, Andreas Uhl, eds.), Springer Verlag, Berlin [u. a.], pp. 552-532, 1999.
[bib] [pdf] [abstract]
Abstract: Diverging demands on computer networks, such as high bandwidth, guaranteed quality of service and low latency lead to growing heterogeneity. IEEE1394-1995 is a standardized low-cost highperformance serial-bus-system with both isochronous and asynchronous operation. It might be an interesting candidate for all-round local and system area networks, providing a good compromise in fulfilling the above demands for low costs. Beside providing some technical background we show the possibilities and advantages of building parallel clusters on top of IEEE1394-1995. The main advantage is that minimal speed-up can be guaranteed, as shown on the basis of the parallel implementation of discrete Fourier transformation.
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[50] | Laszlo Böszörmenyi, Andreas Stopper, Semi-automatic parallelization of object-oriented simulations, In Simulation Practice and Theory, Elsevier, vol. Vol. 7, no. Issue 4, Oxford, United Kingdom, pp. 295-307, 1999.
[bib] [abstract]
Abstract: An approach is introduced for semi-automatic parallelization of object-oriented simulations. The basic idea is to prepare parallelization at the earliest possible stage in the life-cycle of the creation of new simulations (i.e. at modeling), thus minimizing causality conflicts at run-time. The object-oriented model of a simulation is enriched by hints, describing the estimated load and communication costs between major classes and objects. This helps to grasp the inherent parallelism of the model. Based on this additional information, a partitioning with minimal communication between partitions can be generated automatically. Remaining dependency-conflicts must be resolved at run-time. The GoSim [A. Stopper, GoSim, ein Ansatz zur Beschleunigung diskreter, objektorientierter, verteilter Simulationen, Ph.D. Thesis, Institute of Informatics, University Klagenfurt, 1997] simulation system is presented, which implements the described proposal and provides semi-automatic parallelization of large-scale and/or high-performance simulations. It provides a description language, a partitioning tool, a program-skeleton generator and a simulation engine. Some measurements prove the usability of the approach.
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[49] | Laszlo Böszörmenyi, Andreas Wickner, Harald Wolf, Performance Evaluation of Object Oriented Middleware, In Euro-Par 1999, Parallel Processing, Proceedings of 5th International EuroPar Conference, Toulouse, France, August 31 - September 3, 1999 (Patrick Amestoy, Philippe Berger, Michael Daydé, Iain Duff, Valerie Frayssé, Luc Giraud, Daniel Ruiz, eds.), Springer Verlag, Berlin [u. a.], pp. 258-261, 1999.
[bib][url] [doi] [abstract]
Abstract: A method for evaluating several aspects of the performance of object oriented middleware is introduced. Latency, data transfer, parameter marshalling and scalability are considered. A portable benchmark toolkit has been developed to implement the method. A number of actual middleware products have been measured, such as C++ and Java based CORBA implementations, DCOM and Java/RMI. The measurements are evaluated and related to each other.
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[48] | Erzsébet Angster, Joseph Bergin, Laszlo Böszörmenyi, Introducing OO Programming - with Special Emphasis on Concrete Examples, In Object-Oriented Technology: ECOOP´99 Workshop Reader; ECOOP´99 Workshops, Panels, and Poster: Lisbon, Portugal, June 14-18, 1999; Proceedings (Serge Demeyer, A Moreira, eds.), Springer Verlag, Berlin [u. a.], pp. 338-358, 1999.
[bib][url] [doi] [abstract]
Abstract: This book constitutes the joint refereed post-proceedings of 20 workshops, one panel session, and one poster session held during the 13th European Conference on Object-Oriented Programming, ECOOP'99, in Lisbon, Portugal in June 1999. The volume presents overviews of the 20 workshops as well as more than 200 individual short presentations by the contributing authors in a coherent and systematic way. The wealth of up-to-date information provided spans the whole spectrum of object technology, from theoretical and foundational issues to applications in various domains.
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[47] | Wolfram Amme, Markus Schordan, Laszlo Böszörmenyi, Willibald Rossak, PAOLA-Program Analysis of Object-Oriented Languages, In Object-Oriented Technology, ECOOP 99 Workshop Reader. ECOOP´99 Workshops, panels, posters, Lisbon, Portugal, June 14-18, 1999 Proceedings (Anna Moreiera, Serge Demeyer, eds.), Springer Verlag, Berlin [u. a.], pp. 143-146, 1999.
[bib] [abstract]
Abstract: Aliasing in Object-Oriented Systems.
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[46] | Martin Schulz, Hermann Hellwagner, Global Virtual Memory based on SCI-DSM, In Proceedings of SCI-Europe ´98 (A N, ed.), N, A, N, A, pp. 59-67, 1998.
[bib] |
[45] | Martin Schulz, Hermann Hellwagner, Extending NT Virtual Memory by SCI-based Hardware DSM, In Proceedings of 2nd USENIX Windows NT Symposium (A N, ed.), USENIX Association, Seattle, WA, USA, pp. -, 1998.
[bib] |
[44] | Harald Richter, Richard Kleber, Hermann Hellwagner, Cost-Efficient SCI-based Banyan Networks, In Proceedings of the High Performance Computing Symposium (A N, ed.), N, A, N, A, pp. -, 1998.
[bib] [pdf] |
[43] | Michael Gerndt, Hermann Hellwagner, Implementing Automatic Coordination on Networks of Workstations, IEEE Computer Society, N, A, pp. 10, 1998.
[bib] |
[42] | Michael Eberl, Hermann Hellwagner, Bjarne Geir Herland, Common Messaging Layer for MPI and PVM over SCI, In Proceedings of HPCN-Europe 98 (Peter Sloot, Marian Bubak, Bob Hertzberger, eds.), Springer Verlag, NA, pp. 576-587, 1998.
[bib] [abstract]
Abstract: This paper describes the design of a common message passing layer for implementing both MPI and PVM over the SCI interconnect in a workstation or PC cluster. The design is focused at obtaining low latency. The message layer encapsulates all necessary knowledge of the underlying interconnect and operating system. Yet, we claim that it can be used to implement such different message passing libraries as MPI and PVM without sacrificing efficiency. Initial results obtained from using the message layer in SCI clusters are presented.
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[41] | Laszlo Böszörmenyi, Harald Kosch, High Performance Sets, In High-Performance Computing and Networking (Peter Sloot, Marian Bubak, Bob Hertzberger, eds.), Springer, Heidelberg, pp. 972-974, 1998.
[bib] [abstract]
Abstract: This short paper presents a system offering parallel persistent and polymorphic sets of objects, on the level of an existing general purpose object-oriented programming language, like Modula-3 and JAVA. The user of such a system gets distribution and persistence in the same natural way, as users of traditional systems get volatile arrays of numbers of objects. In addition, advantages are taken from sophisticated optimization techniques.
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[40] | Laszlo Böszörmenyi, Carsten Weich, Simple and Efficient Transactions for a Distributed Object Store, In Proceedings of Database and Expert Systems Applications (DEXA '98) (Roland Wagner, ed.), IEEE, Wien, pp. 693-698, 1998.
[bib] [doi] [pdf] [abstract]
Abstract: Even the more or less "canonical'', lower-level architecture of information systems needs to be revisited from time to time. Notions like persistence and transactions belong traditionally to the area of database management systems. There are, however, many applications, such as CAD, VLSI design or simulation, which need persistence and could take advantage of transactions, but require especially fast implementations not provided by DBMS. In this paper we are describing a low-level transaction concept used to implement our parallel main memory object store (PPOST), to provide main memory access times combined with the safety and convenience of transactions.
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[39] | Laszlo Böszörmenyi, Why Java is not my favorite first-course language, In Software - Concepts & Tools, Springer, no. Volume 19, Number 3, Berlin, Heidelberg, New York, pp. 141-145, 1998.
[bib] [doi] [pdf] [abstract]
Abstract: The choice of the first-course programming language for a university-level computer science curriculum has pedagogical ramifications in terms of comprehensibility and mastery of fundamental concepts. This paper compares the merits of Java and Modula-3 as a first-course language.
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[38] | Wolfgang Mayerle, Hermann Hellwagner, Konzepte und funktionaler Vergleich von Thread-Systemen (2), In Praxis der Informationsverarbeitung und Kommunikation, Spani, vol. 20, no. 4, Mannheim, Germany, pp. 225-229, 1997.
[bib] |
[37] | Wolfgang Mayerle, Hermann Hellwagner, Konzepte und funktionaler Vergleich von Thread-Systemen (1), In Praxis der Informationsverarbeitung und Kommunikation, Spaniol, Otto, vol. 20, Mannheim, Germany, pp. 164-174, 1997.
[bib] [pdf] [abstract]
Abstract: Dieses Papier gibt eine allgemeine Einführung in Threads und vergleicht einige derzeit für Arbeitsplatzrechner erhältliche Thread-Systeme. Aufbauend auf einer Motivation und grundlegenden Erläuterung des Thread-Konzepts werden wichtige Aspekte und Probleme von Thread-Bibliotheken vorgestellt. Nach einigen Hinweisen zur Programmierung mit Threads werden mehrere Implementierungen einander gegenübergestellt.
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[36] | Hermann Hellwagner, Arbeitsspeicher- und Bussysteme, In Informatik-Handbuch (Peter Rechenberg, Gustav Pomberger, eds.), Carl Hanser Verlag, München, pp. 239-255, 1997.
[bib] |
[35] | Hermann Hellwagner, Wolfgang Karl, Markus Leberecht, Enabling a PC Cluster for High-Performance Computing, In Speedup Journal, Proceedings, 21st Workshop, March 13-14, 1997, Cadro-Lugano, N, A, vol. Vol. 11, no. 1, N, A, pp. 18-23, 1997.
[bib] [pdf] [abstract]
Abstract: Due to their excellent cost/performance ratio, clusters of PCs can be attractive high-performance computing (HPC) platforms. Yet, their limited communication performance over standard LANs is still prohibitive for parallel applications. The project "Shared Memory in a LAN-like Environment" (SMiLE) at LRR-TUM adopts Scalable Coherent Interface (SCI) interconnect technology to build, and provide software for, a PC cluster which, with hardware-based distributed shared memory (DSM) and high-performance communication characteristics, is regarded as well suited for HPC. The paper describes the key features of the enabling technology, SCI. It then discusses the developments and important results of the SMiLE project so far: the development and initial performance of a PCI/SCI interface card, and the design and initial performance results of low-latency communication layers, Active Messages and a sockets emulation library.
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[34] | Hermann Hellwagner, High-Level Programming Models and Supportive Environments (HIPS'97), IEEE Computer Society, Los Alamitos, CA, pp. 900, 1997.
[bib] |
[33] | Hermann Hellwagner, Proceedings Second International Workshop on High-Level Parallel Programming Models and Supportive Environments, IEEE, N, A, pp. 135, 1997.
[bib] |
[32] | Hermann Hellwagner, Wolfgang Karl, Markus Leberecht, Fast Communication Mechanisms--Coupling Hardware Distributed Shared Memory and User-Level Messaging, In Proceedings of the International Conference on Parallel and Distributed Processing Techniques and Applications, 1997: PDPTA (Hamid R Arabnia, ed.), CSREA Press, Las Vegas, Nevada, USA, pp. 8, 1997.
[bib] [pdf] [abstract]
Abstract: Low latencies for small messages are an important factor of efficient fine-grained parallel computation. The Active Messages concept provides this minimal overhead by eliminating certain parts of the critical path of sending and receiving messages, that is the context switch into the operating system kernel when using user-mode I/O, and multiple buffering in the network layer. Hardware-supported distributed shared memory (DSM) architectures exhibit various properties that make them particularly useful for an implementation of the aforementioned messaging mechanisms. This paper thus describes the concept, implementation, and the performance of a DSM-based Active Messages layer.
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[31] | Michael Eberl, Hermann Hellwagner, Bjarne Geir Herland, Martin Schulz, SISCI - Implementing a Standard Software Infrastructure on an SCI Cluster, In Tagungsband zum 1. Workshop Cluster Computing (Wolfgang Rehm, ed.), N, A, N, A, pp. 49-61, 1997.
[bib] [pdf] [abstract]
Abstract: To enable the efficient utilization of clusters of workstations it is crucial to develop a stable and rich software infrastructure. The ESPRIT Project SISCI will provide two widely used message-passing interfaces, MPI and PVM, as well as a POSIX compliant, distributed thread package (Pthreads) on multiple SCI-based clusters. This paper features motivation and background on this projects as well as details of the two core components: the common messaging layer and the Pthreads package.
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[30] | Michael Eberl, Hermann Hellwagner, Wolfgang Karl, Markus Leberecht, Sicherheit und Effizienz in einer Active-Message-Kommunikationsschicht, In Architektur von Rechensystemen: Arbeitsteilige Systemarchitekturen - Konzepte, Lösungen, Anwendungen, Trends (ARCS´97) (Djamshid Tavangarian, ed.), VDE Verlag, N, A, pp. -, 1997.
[bib] [pdf] [abstract]
Abstract: Active Messages haben sich als effizientes Kommunikationsverfahren insbesondere auf Kommunikationstechnologien durchgesetzt, die einen direkten Zugriff des Benutzers ohne Intervention des Betriebssystems zulassen. Als Nachteil der leichtgewichtigen Kommunikation erwiesen sich jedoch die nicht ausreichenden Schutzmechanismen, vor allem bei der Verwendung mehrerer Prozesse, die sich gleichzeitig einer Active-Message-Bibliothek bedienen. Die Spezifikation 2.0 der Berkeley-Active-Messages unternimmt nun den Versuch, f¨ur das bekannte und schnelle Kommunikationsverfahren Schutzabstraktionen vorzusehen. Im Rahmen dieser Arbeit wird die Implementation eines solchen Active-Message-Layers der Version 2.0 auf einem Cluster von SCI-gekoppelten Arbeitsplatzrechnern beschrieben. Wir k¨onnen zeigen, daß die zus¨atzlichen Schutzmechanismen nur wenig Einfluß auf die Leistung haben und somit der Vorteil der Active Messages, die leichtgewichtige, feingranulare Kommunikation, erhalten bleibt.
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[29] | Michael Eberl, Hermann Hellwagner, Wolfgang Karl, Markus Leberecht, Sicherheit und Effizienz in einer Active Message-Kommunikationsschicht, In Architektur von Rechensystemen, Arbeitsteilige Systemarchitekturen: Konzepte, Lösungen, Anwendungen, Trends - Vorträge der 14. ITG/GI-Fachtagung ARCS '97 (Djamshid Tavangarian, ed.), VDE Verlag, N, A, pp. 211-220, 1997.
[bib] [abstract]
Abstract: Active Messages haben sich als effizientes Kommunikationsverfahren insbesondere auf Kommunikationstechnologien durchgesetzt, die einen direkten Zugriff des Benutzers ohne Intervention des Betriebssystems zulassen. Als Nachteil der leichtgewichtigen Kommunikation erwiesen sich jedoch die nicht ausreichenden Schutzmechanismen, vor allem bei der Verwendung mehrerer Prozesse, die sich gleichzeitig einer Active-Message- Bibliothek bedienen. Die Spezifikation 2.0 der Berkeley-Active-Messages unternimmt nun den Versuch, für das bekannte und schnelle Kommunikationsverfahren Schutzabstraktionen vorzusehen. Im Rahmen dieser Arbeit wird die Implementation eines solchen Active- Message-Layers der Version 2.0 auf einem Cluster von SCI-gekoppelten Arbeitsplatzrechnern beschreiben. Wir können zeigen, daß die zusätzlichen Schutzmechanismen nur wenig Einfluß auf die Leistung haben und somit der Vorteil der Active Messages, die leichtgewichtige, feingranulare Kommunikation, erhalten bleibt.
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[28] | Laszlo Böszörmenyi, Roland Mittermeir, Choosing Modula-3 as "Mother Tongue", In Modular Programming Language (Hans-Peter Mössenböck, ed.), Springer, Heidelberg, pp. 382, 1997.
[bib] [abstract]
Abstract: Choosing the "First Computer Language" is still a crucial issue. While the debate is quite often conducted on the language level, the arguments for making the choice are rather of much deeper methodological, didactical, and non-technical nature. Here, we describe the decision process that lead us to choose Modula-3 as the first language to be taught to informatics students at the Universität Klagenfurt and report on the experience gained.
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