223,667 research outputs found
An operating system for future aerospace vehicle computer systems
The requirements for future aerospace vehicle computer operating systems are examined in this paper. The computer architecture is assumed to be distributed with a local area network connecting the nodes. Each node is assumed to provide a specific functionality. The network provides for communication so that the overall tasks of the vehicle are accomplished. The O/S structure is based upon the concept of objects. The mechanisms for integrating node unique objects with node common objects in order to implement both the autonomy and the cooperation between nodes is developed. The requirements for time critical performance and reliability and recovery are discussed. Time critical performance impacts all parts of the distributed operating system; e.g., its structure, the functional design of its objects, the language structure, etc. Throughout the paper the tradeoffs - concurrency, language structure, object recovery, binding, file structure, communication protocol, programmer freedom, etc. - are considered to arrive at a feasible, maximum performance design. Reliability of the network system is considered. A parallel multipath bus structure is proposed for the control of delivery time for time critical messages. The architecture also supports immediate recovery for the time critical message system after a communication failure
BSML: A Binding Schema Markup Language for Data Interchange in Problem Solving Environments (PSEs)
We describe a binding schema markup language (BSML) for describing data
interchange between scientific codes. Such a facility is an important
constituent of scientific problem solving environments (PSEs). BSML is designed
to integrate with a PSE or application composition system that views model
specification and execution as a problem of managing semistructured data. The
data interchange problem is addressed by three techniques for processing
semistructured data: validation, binding, and conversion. We present BSML and
describe its application to a PSE for wireless communications system design
Using Links to prototype a Database Wiki
Both relational databases and wikis have strengths that make them attractive for use in collaborative applications. In the last decade, database-backed Web applications have been used extensively to develop valuable shared biological references called curated databases. Databases offer many advantages such as scalability, query optimization and concurrency control, but are not easy to use and lack other features needed for collaboration. Wikis have become very popular for early-stage biocuration projects because they are easy to use, encourage sharing and collaboration, and provide built-in support for archiving, history-tracking and annotation. However, curation projects often outgrow the limited capabilities of wikis for structuring and efficiently querying data at scale, necessitating a painful phase transition to a database-backed Web application. We perceive a need for a new class of general-purpose system, which we call a Database Wiki, that combines flexible wiki-like support for collaboration with robust database-like capabilities for structuring and querying data. This paper presents DBWiki, a design prototype for such a system written in the Web programming language Links. We present the architecture, typical use, and wiki markup language design for DBWiki and discuss features of Links that provided unique advantages for rapid Web/database application prototyping
Contract-Based General-Purpose GPU Programming
Using GPUs as general-purpose processors has revolutionized parallel
computing by offering, for a large and growing set of algorithms, massive
data-parallelization on desktop machines. An obstacle to widespread adoption,
however, is the difficulty of programming them and the low-level control of the
hardware required to achieve good performance. This paper suggests a
programming library, SafeGPU, that aims at striking a balance between
programmer productivity and performance, by making GPU data-parallel operations
accessible from within a classical object-oriented programming language. The
solution is integrated with the design-by-contract approach, which increases
confidence in functional program correctness by embedding executable program
specifications into the program text. We show that our library leads to modular
and maintainable code that is accessible to GPGPU non-experts, while providing
performance that is comparable with hand-written CUDA code. Furthermore,
runtime contract checking turns out to be feasible, as the contracts can be
executed on the GPU
ISICSoo: a class for the calculation of ionization cross sections from ECPSSR and PWBA theory
ISICS, originally a C language program for calculating K-, L- and M-shell
ionization and X-ray production cross sections from ECPSSR and PWBA theory, has
been reengineered into a C++ language class, named ISICSoo. The new software
design enables the use of ISICS functionality in other software systems. The
code, originally developed for Microsoft Windows operating systems, has been
ported to Linux and Mac OS platforms to facilitate its use in a wider
scientific environment. The reengineered software also includes some fixes to
the original implementation, which ensure more robust computational results and
a review of some physics parameters used in the computation. The paper
describes the software design and the modifications to the implementation with
respect to the previous version; it also documents the test process and
provides some indications about the software performance.Comment: Preprint submitted to Computer Physics Communication
Proceedings of the 3rd Workshop on Domain-Specific Language Design and Implementation (DSLDI 2015)
The goal of the DSLDI workshop is to bring together researchers and
practitioners interested in sharing ideas on how DSLs should be designed,
implemented, supported by tools, and applied in realistic application contexts.
We are both interested in discovering how already known domains such as graph
processing or machine learning can be best supported by DSLs, but also in
exploring new domains that could be targeted by DSLs. More generally, we are
interested in building a community that can drive forward the development of
modern DSLs. These informal post-proceedings contain the submitted talk
abstracts to the 3rd DSLDI workshop (DSLDI'15), and a summary of the panel
discussion on Language Composition
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