Accessing files in an Internet: The Jade file system

Jade is a new distribution file system that provides a uniform way to name and access files in an internet environment. It makes two important contributions. First, Jade is a logical system that integrates a heterogeneous collection of existing file systems, where heterogeneous means that the underlying file systems support different file access protocols. Jade is designed under the restriction that the underlying file system may not be modified. Second, rather than providing a global name space, Jade permits each user to define a private name space. These private name spaces support two novel features: they allow multiple file systems to be mounted under one directory, and they allow one logical name space to mount other logical name spaces. A prototype of the Jade File System was implemented on Sun Workstations running Unix. It consists of interfaces to the Unix file system, the Sun Network File System, the Andrew File System, and FTP. This paper motivates Jade's design, highlights several aspects of its implementation, and illustrates applications that can take advantage of its features

Integrating Naming and Addressing of Persistent data in Programming Language and Operating System Contexts

There exist a number of desirable transparencies in distributed computing, viz., name transparency: having a uniform way of naming entities in the system, regardless of their type or physical make up; location transparency: having a uniform way of addressing entities, regardless of their physical location; representation transparency: having a uniform way of representing data, which simplifies sharing data between applications written in different highlevel languages and running on different hardware architectures (interoperability) and finally invocation transparency: having a uniform way of invoking operations on entities. The advent of persistency in programming language contexts has created a need for the integration of these four important concepts, viz., naming, addressing, representation and manipulation of data in programming language and operating system contexts. This paper attempts to address the first three transparencies, postponing the fourth to a later paper. First, we make up a list of things that are needed to construct a persistent programming environment and relate this list to existing persistent object models, revealing their inadequacies. We then describe a new model which merges programming language and operating system naming contexts into a global name space which, while enforcing uniformity through the use of globally unique names, still allows the application of personal nicknames. Furthermore, we explain how persistent data is stored and retrieved using a client/server model of interaction, and how it could be acted upon correctly, through the concept of typed data. We conclude by checking how well our model scores on the wish list, listing the current status and future directions for research

A 3D radiative transfer framework: X. Arbitrary Velocity Fields in the Co-moving Frame

3-D astrophysical atmospheres will have random velocity fields. We seek to combine the methods we have developed for solving the 1-D problem with arbitrary flows to those that we have developed for solving the fully 3-D relativistic radiative transfer problem in the case of monotonic flows. The methods developed in the case of 3-D atmospheres with monotonic flows, solving the fully relativistic problem along curves defined by an affine parameter, are very flexible and can be extended to the case of arbitrary velocity fields in 3-D. Simultaneously, the techniques we developed for treating the 1-D problem with arbitrary velocity fields are easily adapted to the 3-D problem. The algorithm we present allows the solution of 3-D radiative transfer problems that include arbitrary wavelength couplings. We use a quasi-analytic formal solution of the radiative transfer equation that significantly improves the overall computation speed. We show that the approximate lambda operator developed in previous work gives good convergence, even neglecting wavelength coupling. Ng acceleration also gives good results. We present tests that are of similar resolution to what has been presented using Monte-Carlo techniques, thus our methods will be applicable to problems outside of our test setup. Additional domain decomposition parallelization strategies will be explored in future work.Comment: 9 pages, 9 figures, A&A, in press, new version matches copy edited version, definition restore

Hierarchical Event Descriptors (HED): Semi-Structured Tagging for Real-World Events in Large-Scale EEG.

Real-world brain imaging by EEG requires accurate annotation of complex subject-environment interactions in event-rich tasks and paradigms. This paper describes the evolution of the Hierarchical Event Descriptor (HED) system for systematically describing both laboratory and real-world events. HED version 2, first described here, provides the semantic capability of describing a variety of subject and environmental states. HED descriptions can include stimulus presentation events on screen or in virtual worlds, experimental or spontaneous events occurring in the real world environment, and events experienced via one or multiple sensory modalities. Furthermore, HED 2 can distinguish between the mere presence of an object and its actual (or putative) perception by a subject. Although the HED framework has implicit ontological and linked data representations, the user-interface for HED annotation is more intuitive than traditional ontological annotation. We believe that hiding the formal representations allows for a more user-friendly interface, making consistent, detailed tagging of experimental, and real-world events possible for research users. HED is extensible while retaining the advantages of having an enforced common core vocabulary. We have developed a collection of tools to support HED tag assignment and validation; these are available at hedtags.org. A plug-in for EEGLAB (sccn.ucsd.edu/eeglab), CTAGGER, is also available to speed the process of tagging existing studies

Overview of the CEAMMC PureData distribution and library

This text is a report about the CEAMMC PureData distribution - also known as “Pd-ceammc” - and the CEAMMC external library for the official Pure Data distribution by Miller Puckette - also known as “Pd Vanilla”. The CEAMMC Pure Data repository is available at https://github.com/uliss/pure-data. This distribution is a software package that comprises the original Pure Data distribution with several user interface enhancements and the CEAMMC object library plus yet other external libraries. The CEAMMC library itself is also available via the Deken package manager so it can be installed in Pd Vanilla. This paper focuses on our main concepts for this work, current features and future plan

Managing writing systems using orthography profiles

This text is a practical guide for linguists, and programmers, who work with data in multilingual computational environments. We introduce the basic concepts needed to understand how writing systems and character encodings function, and how they work together at the intersection between the Unicode Standard and the International Phonetic Alphabet. Although these standards are often met with frustration by users, they nevertheless provide language researchers and programmers with a consistent computational architecture needed to process, publish and analyze lexical data from the world's languages. Thus we bring to light common, but not always transparent, pitfalls which researchers face when working with Unicode and IPA. Having identified and overcome these pitfalls involved in making writing systems and character encodings syntactically and semantically interoperable (to the extent that they can be), we created a suite of open-source Python and R tools to work with languages using orthography profiles that describe author- or document-specific orthographic conventions. In this cookbook we describe a formal specification of orthography profiles and provide recipes using open source tools to show how users can segment text, analyze it, identify errors, and to transform it into different written forms for comparative linguistics research