Dr. James J. Hunt

CEO aicas GmbH Haid-und-Neu-Str. 18 76131 Karlsruhe Germany phone +49 721 663 968-22 fax +49 721 663 968-99 email jjh@aicas.com web http://www.aicas.com/JamesJeffersHunt.html

Program Committees

Projects

Publications

JTRES 2012 - 24-26 October 2012, Copenhagen, Denmark

Abstract

The Real-Time Specification for Java (RTSJ) does not only provide features for realtime programming but also for direct device access. Both reading and writing to a device and reacting to external signals are supported. Unfortunately, the APIs provided have two major drawbacks: since a single class is used to access all types of I/O devices, it is hard to provide an efficient implementation; and there is no mechanism for the user to add new external signals. Alleviating this situation requires APIs that both provide the necessary extensibility and are still compatible with the existing APIs. This is achieved by using factories to provide type specific accessor classes and making happenings first class objects instead of just strings. The new design proposal also unifies happenings, timers, and POSIX signals.

Download: PDF (500KB)

FASE 2012 - 15th International Conference on Fundamental Approaches to Software Engineering, 24 March - 1 April 2012, Tallinn, Estonia

Abstract

The abstract will be available after the FASE 2012 conference

Download: (Available after the FASE 2012 Conference)

JavaOne 2010 - 19-23 September 2010, San Francisco, California, USA

Abstract

Real-Time Java has been used in avionics systems; however, its use has been limited due to the difficulty of certifying Java programs. Containing a supplement for using object-oriented technology in avionics, the next generation of software certification standards will change this. This supplement gives clear guidance for using object-oriented features such as dynamic dispatch and inheritance as well as other features of Real-Time Java such as interpretation and garbage collection. Designing in accordance with the supplement will enable certification of Real-Time Java, both in and outside of avionics. This session will focus on Real-Time Java in avionics and cover issues such as dynamics dispatch, inheritance, interpretation, and more.

Download: (Available after the JavaOne 2010 Conference)

JTRES 2010 - 19-21 August 2010, Prague, Czech Republic

Abstract

The SC-205/WG-71 joint Plenary is scheduled to finish the next update of the software certification standards for avionics by the end of this year. This includes the new DO-178C/ED-12C for in flight software and DO-278A/ED-109A for ground-based software. This is the biggest change to the standards in the last decade. The new standards will provide clear guidance that can be used to qualify Java technology and verify realtime Java programs for use in avionics systems.

Download: PDF (1.33MB)

Science of Computer Programming, vol. 71, no. 3, 2008

Abstract

Abstract. The Real-time Specification for Java (RTSJ) introduced a range of language features for explicit memory management. While the RTSJ gives programmers fine control over memory use and allows linear allocation and constant-time deallocation, the RTSJ relies upon dynamic runtime checks for safety making it unsuitable for safety critical applications. We introduce ScopeJ, a staticallytyped, multi-threaded, object calculus in which scopes are first class constructs. Scopes reify allocation contexts and provide a safe alternative to automatic memory management. Safety follows from the use of an ownership type system that enforces a topology on run-time patterns of references. ScopeJ’s type system is novel in that ownership annotations are implicit. This substantially reduces the burden for developers and increases the likelihood of adoption. The notion of implicit ownership is particularly appealing when combined with pluggable type systems, as one can apply different type constraints to different components of an application depending on the requirements without changing the source language. In related work we have demonstrated the usefulness of our approach in the context of highly-responsive systems and stream processing.

Download: PDF (410KB)

JTRES'08 - The 6th International Workshop on Java Technologies for Real-Time and Embedded Systems - 24-26 September 2008, Santa Clara, California, USA

Abstract

Though realtime Java offers significant advantages over other programming languages for safe programming, the analysis of worst case execution of realtime Java programs is considerably more difficult. The extra complexity can be addressed using a minimal set of parameterized annotations and data flow analysis to provide a standard worst case execution time analysis tool with the additional information necessary to determine the worst case execution time analysis of realtime Java programms. This methodology has the advantage over existing methods in that it is equally applicable to general purpose library code as to application specific implementation code.

Download: PDF (0.2MB)

JTRES'07 - The 5th International Workshop on Java Technologies for Real-Time and Embedded Systems - 26-28 September 2007, Vienna, Austria

Abstract

The current trend in Model Driven Architecture is to use model transformation to refine a model from a platformindependent model to a platform-specific model, resulting in a linear development process. With the advent of commercially available realtime and safety critical Java implementations as a basis for platform neutral realtime systems, one could raise the level of reuse in modeling realtime systems by keeping platform independent information completely separate from platform specific information, so that model refinement is done by adding modeling aspects and maps between aspects rather than by model transformation. The result is a modeling process that is less order dependent, thereby supporting the full flexibility of Java Technology even for realtime system design.

Download: PDF (2,8MB)

JTRES'06 - The 4th International Workshop on Java Technologies for Real-time and Embedded Systems - 11-13 October 2006, Paris, France

Abstract

Determining concrete bounds for loops is one of the more vexing problems of resource analysis of realtime programs. Current mechanisms are limited in scope and require considerable user input that can not be verified. The authors present a methodology for providingmore general loop bounds where the correctness can be demonstrated with formal techniques. The methodology combines data flow analysis and deductive formal verification to attain this goal.

Download: PDF (133kB)

JTRES'06 - The 4th International Workshop on Java Technologies for Real-time and Embedded Systems - 11-13 October 2006, Paris, France

Abstract

The HIJA initiative is currently working on creating the technology conditions to achieve architecture neutrality for real-time systems. To this end it has developed a number of profiles based on RTSJ and developed a number of proofs of concept. In doing so, HIJA came across a number of integration issues which are not specific to the chosen technologies, and therefore need to be addressed by the embedded systems technology community in the large. This paper reports on the following issues: (1) integration in the software engineering process, (2) integration of an architecture neutral platform with an underlying RTOS, and (3) provision of QoS for multiple independent applications.

Download: PDF (400kB)

JTRES'06 - The 4th International Workshop on Java Technologies for Real-time and Embedded Systems - 11-13 October 2006, Paris, France

Abstract

The literature for deductive formal verification is quite rich; however, very few case studies have been done. The authors present a case study of using deductive formal verification of a navigation system from the avionics domain. Both writing the specifications and their verification with a runtime assertion checker and KEY, a tool using automatic theorem proving techniques for verifying JAVA programs, are covered.

Download: PDF (421kB)

ENTCS Vol. 133 May 2005 - Electronic Notes in Theoretical Computer Science (ENTCS) Volume 133, May, 2005

Abstract

We propose a new development scheme for quality-aware applications, quality-driven development (QDD), based on the Model-Driven Architecture (MDA) of Object Management Group OMG. We argue that software development in areas, such as real-time systems, should not only rely on code verification, but also on design verification, and show that a slightly extended MDA process offers the opportunity to integrate system development together with design verification. As an instance of the method, we present the MDA-based tool environment of the HIDOORS project [Karlsruhe James Hunt. Forschungszentrum Informatik. High-integrity distributed object- oriented real-time systems. http://www.hidoors.org]. In this environment, a real-time model checker is interpreted as a platform in the sense of MDA. UML designs can be annotated with verification markup, which is not only compiled to code, but also to a design verification model of the verification platform, the model-checker. In this way, model-checking for real-time designs is integrated into the model-driven development process and allows for early verification. The approach can easily be transfered to other verification techniques. We give a preliminary classification of the possible verification platforms and analyse their interplay. The analysis reveals that for quality-aware application areas, the standard MDA approach should be extended by one or more MDA stacks for model-driven verification (MDV). The resulting approach, quality-driven development (QDD), is, to our knowledge, the first systematic approach to integrate code generation and verification in model-driven development.

Download: Archive link

ASE vol 10 issue 2 , Apr 2003 - Automated Software Engineering Volume 10 Issue 2, April 2003

Abstract

Finding changed identifiers is important for understanding the difference between two versions of a program and for detecting and resolving conflicts while merging variants of a program together. Standard practice for differencing and merging relies on line based techniques that do not recognize renamed identifiers. The design and implementation of a tool to automatically detect renamed identifiers between two versions of a program is presented. The system uses an abstract representation of language constructs to enable language awareness without introducing language dependence. Modules for Java and Scheme have been written. The detector works with multiple file pairs, taking into account renamings that span several files. A case study is presented that demonstrates proof of concept. The detector is part of a suite of intelligent differencing and merging programs that exploit the static semantics of programming languages.

Download: Publisher Site, PDF (398kb)

ICSM 2002 - International Conference on Software Maintenance, 3-6 October 2002, Montreal, Canada

Abstract

Parallel development has become standard practice in software development and maintenance. Though almost every revision control and configuration management system provides some form of merging for combining changes made in parallel, these mechanisms often yield unsatisfactory results. The authors present a new merging algorithm, that uses a fast differencing algorithm and renaming analysis to provide better merge results. The system is language aware, but not language dependent and does not require a special editor so it can be easily integrated in current development environments.

Download: Link on IEEE site

Seventh IEEE International Workshop on Object-oriented Real-time Dependable Systems (WORDS), San Diego, 7.-9. January 2002

Abstract

This paper presents the design of HIDOORS, an intergrated deveopment environment suitable for embedded distributed real-time sytems, based on the Java programming language. HIDOORS will cover all the life-cycle of real-time software development with extensions to existing tools (UML modeling, Java compiler, Java Virtual Machine, and a worst case execution time analysis tool) that will all be integrated into a single integrated development environment. The sytem will also assist the developer in distributing the application, by providing faster RMI and a distributed event managert that provides strict timing guarantees. This paper is written at the beginning of HIDDORS development, and as such, it presents only the defined objectives and the early architecture of the sytem; further developments will be the subject of future work.

Download:

paper (gzip'ed Postscript, 108KB)

slides (PDF, 1,8Meg)

Softwaretechnik-Trends, Vol. 21 No. 3, 2001

Abstract

Parallel development has become standard practice in software development and maintenance. Though almost every revision control and configuration management system provides some form of merging for combining changes made in parallel, these mechanisms often yield unsatisfactory results. The authors present a new merging algorithm, that uses a fast differencing algorithm and renaming analysis to provide better merge results. The system is language aware, but not language dependent and does not require a special editor so it can be easily integrated in current development environments.

Download: (PDF, 55kb)

ICSE'01 - 23rd International Conference on Software Engineering- 12-19 May 2001, Toronto, Canada

Abstract

Abstract: The current suite of systems that offer client/server capabilities for document versioning relies on proprietary protocols for communicating between a central versioning repository and a remote client. In order to support better document authoring via the Web, the DeltaV working group of the Web-DAV (WWW Distributed Authoring and Versioning) project of the Internet Engineering Task Force is working on a standard protocol for versioning over HTTP. The authors present a prototype of DeltaV based on the 04.5 draft. This system demonstrates that, though important aspects of the protocol need to be revised, versioning via the Web can be a practical means of supporting remote access to a central versioning repository.

Download: Publisher Site, PDF (95kB)

ASE 2000 - 15th IEEE International Conference on Automated Software Engineering, 11-15 September 2000, Grenoble, France

Abstract

Finding changed identifiers is important for understanding the difference between two versions of a program and for detecting and resolving conflicts while merging variants of a program together. Standard practice for differencing and merging relies on line based techniques that do not recognize renamed identifiers. The design and implementation of a tool to automatically detect renamed identifiers between two versions of a program is presented. The system uses an abstract representation of language constructs to enable language awareness without introducing language dependence. Modules for Java and Scheme have been written. The detector works with multiple file pairs, taking into account renamings that span several files. A case study is presented that demonstrates proof of concept. The detector is part of a suite of intelligent differencing and merging programs that exploit the static semantics of programming languages.

Download: (not available)

ACM TOSEM vol 7 issue 4 , Oct 1998 - ACM Transactions on Software Engineering and Methodology Volume 7 Issue 4, October 1998

Abstract

The authors supply machine configurations for experiments reported in 'Delta Algorithms: An Empirical Analysis,' by Hunt et al. (ACM Trans. Softw. Eng. Methodol. 7, 2 (Apr. 1998), pp. 192-214).

Download: PDF (30kb)

ACM TOSEM vol 7 issue 2 , Apr 1998 - ACM Transactions on Software Engineering and Methodology Volume 7 Issue 2, April 1998

Abstract

Delta algorithms compress data by encoding one file in terms of another. This type of compression is useful in a number of situations: strong multiple versions of data, displaying differences, merging changes, distributing updates, storing backups, transmitting video sequences, and others. This article studies the performance parameters of several delta algorithms, using a benchmark of over 1,300 pairs of files taken from two successive releases of GNU software. Results indicate that modern delta compression algorithms based on Ziv-Lempel techniques significantly outperform diff, a popular but older delta compressor, in terms of compression ratio. The modern compressors also correlate better with the actual difference between files without sacrificing performance.

Download: PDF (388kb)

ICSE'97 - 19th International Conference on Software Engineering - 17-23 May 1997, Boston, MA, USA

Abstract

Abstract is not available

Download: Not available

ICSE'96 - 18th International Conference on Software Engineering - 25-29 May 1996, Berlin, Germany

Abstract

This paper demonstrates the possibility of using the World Wide Web for distributed Revision Control. The approach taken at the client side is machineindependent and portable --- adding a new client architecture just means porting the small checkin and checkout helper applications and making cosmetic changes to the existing Browser's configuration file. Furthermore, the techniques used here may also be used to convert other applications to clientserver architectures based on WWW and the Internet. 8. Future Work

Download: Not available

ICSE'96 - 18th International Conference on Software Engineering - 25-29 May 1996, Berlin, Germany

Abstract

Abstract is not available

Download: Not available

ICWSI 1990 (abstract version 6 Aug 2002) - 2nd International Conference on Wafer Scale Integration 1990- 23-25 January 1990, San Francisco, CA, USA

Abstract

The Programmable Image Processor is a laser-restructurable, wafer-scale device fabricated on a 125-mm wafer using an n-well CMOS process with 2.0 micrometer gates. Yield projections indicate that one wafer has enough devices to construct an array of 16 SIMD-programmable processors and 25 shared memories. The memory array can store two images each 128-by-128 pixels. One run of wafers has been fabricated, and these wafers were undergoing testing and restructuring at the time of publication.

Download: Link on IEEE site

ICWSI 1989 (abstract version 6 Aug 2002) - 1st International Conference on Wafer Scale Integration 1989 - 03-05 January 1989, San Francisco, CA, USA

Abstract

The restructurable VLSI (RVLSI) CAD tool SLASH aids the user in carrying out the four-part RVLSI layout/restructuring task, which consists of: creation of a wafer-scale layout, analysis of capacitance test data to determine the location of defects on a particular wafer, mapping (placement and routing) of a logical system onto the usable resources of a particular wafer, and an incremental restructure-and-test cycle during which laser operations implement the prescribed layout. SLASH brings many modules to bear on the task of carrying out these functions. These modules include graphics workstation-based editors, as well as stand-alone `batch' programs.

Download: Link on IEEE site