24,897 research outputs found
On Object-Orientation
Although object-orientation has been around for several decades, its key
concept abstraction has not been exploited for proper application of
object-orientation in other phases of software development than the
implementation phase. We mention some issues that lead to a lot of confusion
and obscurity with object-orientation and its application in software
development. We describe object-orientation as abstract as possible such that
it can be applied to all phases of software development
Event Planner Sensitivity to the Needs of Individuals with Visual Disability at Meetings and Events
Special events, such as fairs, conventions, ballgames, and concerts are typically activities people attend to participate in the festivities and enjoy with friends and family members. For individuals with disabilities, however, these types of events can create more challenges than enjoyment. Despite a thorough review of the literature, no studies were found which evaluated the experiences of individuals who are blind and have visual impairments at events and meetings. The aim of this study was to determine the current level of accessibility at meetings perceived by consumers who are blind and visually impaired. Respondents to the survey indicated many obstacles to accessing meetings including: discrimination, a paucity of accessible features, and accessibility features that are not truly accessible for consumers who are blind and visually impaired. Recommendations are provided for increasing meeting and event accessibility for consumers who are blind and visually impaired
Blue - A Language for Teaching Object-Oriented Programming
Teaching object-oriented programming has clearly become an important part of computer science education. We agree with many others that the best place to teach it is in the CS1 introductory course. Many problems with this have been reported in the literature. These mainly result from inadequate languages and environments. Blue is a new language and integrated programming environment, currently under development explicitly for object-oriented teaching. We expect clear advantages from the use of Blue for first year teaching compared to using other available languages. This paper describes the design principles on which the language was based and the most important aspects of the language itself
On the calibration of the relation between geometric albedo and polarimetric properties for the asteroids
We present a new extensive analysis of the old problem of finding a
satisfactory calibration of the relation between the geometric albedo and some
measurable polarization properties of the asteroids. To achieve our goals, we
use all polarimetric data at our disposal. For the purposes of calibration, we
use a limited sample of objects for which we can be confident to know the
albedo with good accuracy, according to previous investigations of other
authors. We find a new set of updated calibration coefficients for the
classical slope - albedo relation, but we generalize our analysis and we
consider also alternative possibilities, including the use of other
polarimetric parameters, one being proposed here for the first time, and the
possibility to exclude from best-fit analyzes the asteroids having low albedos.
We also consider a possible parabolic fit of the whole set of data.Comment: Accepted by MNRA
Software development: A paradigm for the future
A new paradigm for software development that treats software development as an experimental activity is presented. It provides built-in mechanisms for learning how to develop software better and reusing previous experience in the forms of knowledge, processes, and products. It uses models and measures to aid in the tasks of characterization, evaluation and motivation. An organization scheme is proposed for separating the project-specific focus from the organization's learning and reuse focuses of software development. The implications of this approach for corporations, research and education are discussed and some research activities currently underway at the University of Maryland that support this approach are presented
A distributed Real-Time Java system based on CSP
CSP is a fundamental concept for developing software for distributed real time systems. The CSP paradigm constitutes a natural addition to object orientation and offers higher order multithreading constructs. The CSP channel concept that has been implemented in Java deals with single- and multi-processor environments and also takes care of the real time priority scheduling requirements. For this, the notion of priority and scheduling has been carefully examined and as a result it was reasoned that priority scheduling should be attached to the communicating channels rather than to the processes. In association with channels, a priority based parallel construct is developed for composing processes: hiding threads and priority indexing from the user. This approach simplifies the use of priorities for the object oriented paradigm. Moreover, in the proposed system, the notion of scheduling is no longer connected to the operating system but has become part of the application instead
Real pinor bundles and real Lipschitz structures
We obtain the topological obstructions to existence of a bundle of
irreducible real Clifford modules over a pseudo-Riemannian manifold of
arbitrary dimension and signature and prove that bundles of Clifford modules
are associated to so-called real Lipschitz structures. The latter give a
generalization of spin structures based on certain groups which we call real
Lipschitz groups. In the fiberwise-irreducible case, we classify the latter in
all dimensions and signatures. As a simple application, we show that the
supersymmetry generator of eleven-dimensional supergravity in "mostly plus"
signature can be interpreted as a global section of a bundle of irreducible
Clifford modules if and the underlying eleven-manifold is
orientable and spin.Comment: 94 pages, various tables and diagram
Concurrent Models for Object Execution
In previous work we developed a framework of computational models for the
concurrent execution of functions on different levels of abstraction. It shows
that the traditional sequential execution of function is just a possible
implementation of an abstract computational model that allows for the
concurrent execution of function. We use this framework as base for the
development of abstract computational models that allow for the concurrent
execution of objects
Ada as an implementation language for knowledge based systems
Debates about the selection of programming languages often produce cultural collisions that are not easily resolved. This is especially true in the case of Ada and knowledge based programming. The construction of programming tools provides a desirable alternative for resolving the conflict
Non-involutory Hopf algebras and 3-manifold invariants
We present a definition of an invariant #(M,H), defined for every
finite-dimensional Hopf algebra (or Hopf superalgebra or Hopf object) H and for
every closed, framed 3-manifold M. When H is a quantized universal enveloping
algebra, #(M,H) is closely related to well-known quantum link invariants such
as the HOMFLY polynomial, but it is not a topological quantum field theory.Comment: 36 page
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