D-oids: a model for dynamic data-types

1995 ◽  
Vol 5 (2) ◽  
pp. 257-282 ◽  
Author(s):  
Egidio Astesiano ◽  
Elena Zucca
Keyword(s):  
Algebraic Approach ◽  
Mathematical Structure ◽  
Object Identity ◽  
Data Types ◽  
Static Structure ◽  
Semantic Framework ◽  
Model Object ◽  
Abstract Notion ◽  
Point To Point ◽  
Dynamic Signature

We propose a semantic framework for dynamic systems, which, in a sense, extends the well-known algebraic approach for modelling static data structures to the dynamic case. The framework is based on a new mathematical structure, called a d-oid, consisting of a set of instant structures and a set of dynamic operations. An instant structure is a static structure, e.g. an algebra; a dynamic operation is a transformation of instant structures with an associated point to point map, which allows us to keep track of the transformations of single objects and thus is called a tracking map. By an appropriate notion of morphism, the d-oids over a dynamic signature constitute a category.It is shown that d-oids can model object systems and support an abstract notion of possibly unique object identity; moreover, for a d-oid satisfying an identity preserving condition, there exists an essentially equivalent d-oid where the elements of instant structures are just names.

DERIVING AND SCHEDULING COMMUNICATION OPERATIONS FOR GENERIC SKELETON IMPLEMENTATIONS

2005 ◽  
Vol 15 (03) ◽  
pp. 337-352 ◽  
Author(s):  
THOMAS NITSCHE
Keyword(s):  
Iterative Solution ◽  
Synchronous Communication ◽  
Data Types ◽  
Communication Scheduling ◽  
Overlapping Data ◽  
Abstract Notion ◽  
Algebraic Data Types ◽  
Data Elements ◽  
Communication Operations

Data distributions are an abstract notion for describing parallel programs by means of overlapping data structures. A generic data distribution layer serves as a basis for implementing specific data distributions over arbitrary algebraic data types and arrays as well as generic skeletons. The necessary communication operations for exchanging overlapping data elements are derived automatically from the specification of the overlappings. This paper describes how the communication operations used internally by the generic skeletons are derived, especially for the asynchronous and synchronous communication scheduling. As a case study, we discuss the iterative solution of PDEs and compare a hand-coded MPI version with a skeletal one based on overlapping data distributions.

scholarly journals A Uniform Treatment of Aggregates and Constraints in Hybrid ASP

2020 ◽  
Author(s):  
Pedro Cabalar ◽  
Jorge Fandinno ◽  
Torsten Schaub ◽  
Philipp Wanko
Keyword(s):  
Semantic Framework ◽  
Basic Properties ◽  
Smt Solving ◽  
Abstract Notion ◽  
Uniform Treatment ◽  
Aggregate Functions

Characterizing hybrid ASP solving in a generic way is difficult since one needs to abstract from specific theories. Inspired by lazy SMT solving, this is usually addressed by treating theory atoms as opaque. Unlike this, we propose a slightly more transparent approach that includes an abstract notion of a term. Rather than imposing a syntax on terms, we keep them abstract by stipulating only some basic properties. With this, we further develop a semantic framework for hybrid ASP solving and provide aggregate functions for theory variables that adhere to different semantic principles, show that they generalize existing aggregate semantics in ASP and how we can rely on off-the-shelf hybrid solvers for implementation.

scholarly journals Answering Research Questions Using Semantic Traits

2019 ◽  
Vol 3 ◽  
Author(s):  
Paula Mabee
Keyword(s):  
Language Processing ◽  
Design Patterns ◽  
Phylogenetic Trees ◽  
Semantic Annotation ◽  
Model Organisms ◽  
Data Types ◽  
Computational Tools ◽  
Semantic Framework ◽  
Manual Curation ◽  
Research Questions

Phenoscape has developed methods to render phylogenetic characters from the systematic literature machine computable and interoperable with genetic data from model organisms, by annotating them with taxon, anatomy, quality, other ontologies. Moving these trait data into a semantic framework enables their integration with other data types and provides the potential for powerful new computational tools to aid discovery. For example, trait similarities can be quantified, assessed against phylogenetic trees to determine whether they are based in homology or homoplasy, and linked back to candidate genes. Another example is the ability to automatically construct a matrix on the fly, for a user-selected set of traits and taxa. Guidelines for consistent representation of characters have been developed through manual annotation of over 20,000 systematic characters. These represent a limited number of design patterns that are applicable to traits from any source. The level of detail to which characters are annotated will influence how they may be used in research; a minimal approach will still enable basic trait aggregation. Manual curation effort is substantial and does not scale well to biodiversity traits. Natural Language Processing (NLP) methods, using our newly developed Gold Standard for semantic traits, can accelerate annotation from published text, particularly with well-provisioned ontologies. Efforts to establish new trait databases might profitably explore machine learning for morphological discrimination and semantic annotation from digitized images for a high-throughput approach.

Finding the Right Problems: Some HREM Applications to Interfaces

1984 ◽  
Vol 42 ◽  
pp. 376-379
Author(s):  
D. Cherns
Keyword(s):  
Grain Boundaries ◽  
High Resolution Electron Microscopy ◽  
Boundary Structure ◽  
Atomic Structures ◽  
Grain Boundary Structure ◽  
Resolution Electron ◽  
Point To Point ◽  
The Right ◽  
New Generation ◽  
Better Than

The use of high resolution electron microscopy (HREM) to determine the atomic structure of grain boundaries and interfaces is a topic of great current interest. Grain boundary structure has been considered for many years as central to an understanding of the mechanical and transport properties of materials. Some more recent attention has focussed on the atomic structures of metalsemiconductor interfaces which are believed to control electrical properties of contacts. The atomic structures of interfaces in semiconductor or metal multilayers is an area of growing interest for understanding the unusual electrical or mechanical properties which these new materials possess. However, although the point-to-point resolutions of currently available HREMs, ∼2-3Å, appear sufficient to solve many of these problems, few atomic models of grain boundaries and interfaces have been derived. Moreover, with a new generation of 300-400kV instruments promising resolutions in the 1.6-2.0 Å range, and resolutions better than 1.5Å expected from specialist instruments, it is an appropriate time to consider the usefulness of HREM for interface studies.

An x-ray microprobe based upon a close-coupled focal-spot / glass capillary arrangement

1992 ◽  
Vol 50 (2) ◽  
pp. 1758-1759
Author(s):  
D. A. Carpenter ◽  
M. A. Taylor
Keyword(s):  
Imaging Techniques ◽  
Fluorescence Analysis ◽  
High Sensitivity ◽  
Specimen Preparation ◽  
X Rays ◽  
Glass Capillary ◽  
Close Coupling ◽  
X Ray ◽  
Point To Point ◽  
Beam Damage

The development of intense sources of x rays has led to renewed interest in the use of microbeams of x rays in x-ray fluorescence analysis. Sparks pointed out that the use of x rays as a probe offered the advantages of high sensitivity, low detection limits, low beam damage, and large penetration depths with minimal specimen preparation or perturbation. In addition, the option of air operation provided special advantages for examination of hydrated systems or for nondestructive microanalysis of large specimens.The disadvantages of synchrotron sources prompted the development of laboratory-based instrumentation with various schemes to maximize the beam flux while maintaining small point-to-point resolution. Nichols and Ryon developed a microprobe using a rotating anode source and a modified microdiffractometer. Cross and Wherry showed that by close-coupling the x-ray source, specimen, and detector, good intensities could be obtained for beam sizes between 30 and 100μm. More importantly, both groups combined specimen scanning with modern imaging techniques for rapid element mapping.

Atomic structure imaging of the Si/SiO2 interface with high-resolution electron microscopy

1986 ◽  
Vol 44 ◽  
pp. 390-391
Author(s):  
J.L. Batstone ◽  
J.M. Gibson ◽  
Alice.E. White ◽  
K.T. Short
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Atomic Structure ◽  
High Resolution Electron Microscopy ◽  
Medium Voltage ◽  
Voltage Electron ◽  
Resolution Electron ◽  
Structural Image ◽  
Electron Microscopes ◽  
Point To Point

High resolution electron microscopy (HREM) is a powerful tool for the determination of interface atomic structure. With the previous generation of HREM's of point-to-point resolution (rpp) >2.5Å, imaging of semiconductors in only <110> directions was possible. Useful imaging of other important zone axes became available with the advent of high voltage, high resolution microscopes with rpp <1.8Å, leading to a study of the NiSi2 interface. More recently, it was shown that images in <100>, <111> and <112> directions are easily obtainable from Si in the new medium voltage electron microscopes. We report here the examination of the important Si/Si02 interface with the use of a JEOL 4000EX HREM with rpp <1.8Å, in a <100> orientation. This represents a true structural image of this interface.

Profile Imaging of Silicon Surface Reconstructions

1985 ◽  
Vol 43 ◽  
pp. 262-263
Author(s):  
O.L. Krivanek ◽  
G.J. Wood
Keyword(s):  
Electron Microscopy ◽  
Surface Structure ◽  
Structure Determination ◽  
Silicon Surface ◽  
Good Resolution ◽  
Surface Reconstructions ◽  
Bulk Structure ◽  
Point To Point ◽  
The Relationship

Electron microscopy at 0.2nm point-to-point resolution, 10-10 torr specimei region vacuum and facilities for in-situ specimen cleaning presents intere; ing possibilities for surface structure determination. Three methods for examining the surfaces are available: reflection (REM), transmission (TEM) and profile imaging. Profile imaging is particularly useful because it giv good resolution perpendicular as well as parallel to the surface, and can therefore be used to determine the relationship between the surface and the bulk structure.

Sign in / Sign up

Export Citation Format

Share Document