Showing papers on "Class (philosophy) published in 1995"

Objects and classes, co-algebraically

Abstract: The coalgebraic perspective on objects and classes in object-oriented programming is elaborated: objects consist of a (unique) identifier, a local state, and a collection of methods described as a coalgebra; classes are coalgebraic (behavioural) specifications of objects. The creation of a ``new'''' object of a class is described in terms of the terminal coalgebra satisfying the specification. We present a notion of ``totally specified'''' class, which leads to particularly simple terminal coalgebras. We further describe local and global operational semantics for objects. Associated with the local operational semantics is a notion of bisimulation (for objects belonging to the same class), expressing observational indistinguishability.

System of relational entities for object-oriented computer-aided geometric design

Abstract: A method of computer aided design of geometric models including the steps of: defining a set of geometric entities for use in constructing the geometric models, each of the geometric entities being an abstract geometric object type that is adapted to be actualized into one or more geometric objects, the geometric entities including point class entities, curve class entities, and surface class entities; identifying some of the geometric objects by corresponding unique object identifiers; defining a plurality of relational entities along the set of geometric entities, each of which is adapted to be actualized into corresponding relational objects having having a dependency relationship upon one or more other geometric objects whose object identifiers are specified within the relational objects; wherein the relational entities include a curve class entity having a dependency relationship on a point class object; wherein at least one of the relational entities is a surface class entity having a dependency relationship on a point class object or a curve class object; and defining a set of subroutines for evaluating the plurality of geometric objects, there being a corresponding subroutine for each of the abstract geometric object types, wherein those subroutines which evaluate relational objects are programmed to make calls to an appropriate one or more subroutines to evaluate the geometric objects on which that relational object depends.

System and method for maintenance and deferred propagation of schema changes to the affected objects in an object oriented database

Abstract: A method and system for use with object oriented databases provides schema evolution with deferred propagation of schema changes. The method and system provide a schema that persistently maintains class objects by storing an initial class definition, and shape objects associated with particular class objects and storing subsequent class definitions. The shape objects associated with a particular class object form a shape chain, the last shape object in the shape chain being the current shape object, and maintaining the current class definition. Client objects representing actual instances of data in the database, are instantiated from whichever client object or shape object is current at the time of instantiation, so the all newly created client objects always have the current class definition. Existing client objects, which are those that were created prior to one or more subsequent modifications of the class definition and instantiations of the shape objects in the shape chain of the class, are updated to the current class definition only when they are accessed in the database, thereby providing deferred propagation. Updating such client objects includes copying data members for which there was no change in the definition of the member, and performing type conversion on those data members for which there was a change in the definition of the member.

Integrating rules into object-oriented programming systems

Abstract: Techniques for integrating rules into imperative object-oriented languages such as C++. C++ is extended to permit definition of rules as members of classes. When a rule is defined as a member of a class, a preprocessor receives the declaration of the rule's class and of any other class involved in the rule and generates additional data members and member functions for the classes. The additional members of the classes permit a complete implementation of the rule. No additional rule interpreter or decision network is required. The rule definition defines collections of objects linked by interobject pointers to which the rule applies. A rule is evaluated only if there is a change in a value mentioned in the rule in an object belonging to a collection of objects for the rule. The rule's condition is a sequence of bindings and tests. The bindings define a path through a collections of objects to which the rule applies, and the path is followed during evaluation. The rules thus implement access-limited logic.

Optimization methods for brain-like intelligent control

Abstract: This paper defines a more restricted class of designs, to be called "brain-like intelligent control". The paper explains the definition and concepts behind it, describes benefits in control engineering, emphasizing stability, mentions 4 groups who have implemented such designs, for the first time, since late 1993, and discusses the brain as a member of this class, one which suggests features to be sought in future research. These designs involve approximate dynamic programming-dynamic programming approximated in generic ways to make it affordable on large-scale nonlinear control problems. These designs are based on learning. They permit a neural net implementation-like the brain but do not require it. They include some but not all "reinforcement learning" or "adaptive critic" designs.

Dis-Ease about Kinds: Reply to D'Amico

Abstract: In The Nature of Disease I argued that a value-free account of our concept of disease cannot be given. Part of this argument consisted in showing that diseases as a class do not constitute a natural kind. To understand this, we need only see that we define and classify conditions into diseases and non-diseases not in terms of their causes but in terms of their effects. While no philosophical position is watertight, the arguments overwhelmingly favour the conclusion that diseases do not constitute a natural kind.

“Meta”-rigid motions and frames of reference

Abstract: We define the “meta”-rigid motions as particular classes of time-like congruences which are solutions of intrinsically defined partial differential equations that generalize Born's conditions. We consider in particular two hierarchies of such congruences. The first one is a geometrically motivated direct generalization of the symmetry concept inherent in Born congruences. The second one is an indirect generalization based on the conditions which guarantee the existence of a particular class of adapted coordinates of space, named quo-harmonic coordinates, whose definition is akin to the definition of harmonic coordinates but which differs from it in an essential point.

Determination: postcolonialism, poststructuralism and the problem of ideology

Abstract: informed by none of the theoretical insights that such a "history of the imperial adventure" might be expected to rely upon. Of course, Culture and Imperialism consists mainly of a series of textual commentaries, foregrounded more by a This content downloaded from 207.46.13.86 on Fri, 14 Oct 2016 04:35:25 UTC All use subject to http://about.jstor.org/terms DETERMINATION: THE PROBLEM OF IDEOLOGY 1 1 conventional sense of literary history than anything else, but for a treatise that focuses so centrally on the nineteenth century, it is remarkable how prenineteenth century Culture and Imperialism seems, from an historico-philosophical point of view. Nothing, here, even of Hegel, much less of Marx. Listen, for example, to Said discussing the need to "set.. .art in the global, earthly context": Territory and possessions are at stake, geography and power. Everything about human history is rooted in the earth, which has meant that we must think about habitation, but it has also meant that people have planned to have more territory and therefore must do something about its indigenous residents. At some very basic level, imperialism means thinking about, settling on, controlling land that you do not possess, that is distant, that is lived on and owned by others. (7) That imperialism, "at some very basic level," concerns "territory" may surely be granted but Culture and Imperialism never advances beyond this level. In an almost Physiocratic reprise, Said commits the double anachronism here of projecting feudal and early capitalist notions of landed property both backwards onto epochs that knew nothing of "territory" in the sense he gives it (the Taino/Arawak tribespeople encountered by Columbus at the time of his first American landfall would have been surprised indeed to know that they "owned" any "territory" at all), and forward onto a stage of historical development whose imperial elites have long since come to marshal their "power" for the "possession," not of "territory," but of an "immense accumulation of commodities," labor power chief among them. The result is that imperialism that entity, the cultural history of which Said has promised to tell is emptied at the beginning of any historical concreteness. The class determination of "territory" and "possession" effectively drops out here. Instead we are presented with a "focus on actual contests over land and the land's people," with a "kind of geographical inquiry into historical experience" (7). This sounds intriguing, but in practice it reduces imperialism itself to a kind of geography, an unequal distribution of "possession" or "sovereignty" over a pre-existing map of "territories." It thus comes as no surprise that the history of this "imperialism" and of the "resistance" to it is virtually oblivious to both the Russian and the Chinese revolutions, arguably the two most signal acts of "resistance" to imperialism in this century. In a book replete with invocations of Gramsci, Fanon, Nkrumah, С. L. R. James, etc., a book that claims repeatedly to stand on the shoulders of the great anticolonial leaders and visionaries of the third world, it is to be noted that the name of Mao Zedong does not receive, unless I am mistaken, a single mention. And that, whatever one's sympathies or antipathies towards Maoism, is an omission that surely says as much about the Saidian view of imperialism as the entire text of Culture and Imperialism itself. Given such an oddly anachronistic theory of imperialism, it becomes more difficult to be confident of what Said will have to say about its "culture." To take just This content downloaded from 207.46.13.86 on Fri, 14 Oct 2016 04:35:25 UTC All use subject to http://about.jstor.org/terms

SHAPE : a machine learning system from examples

Abstract: This paper presents a new machine learning system called SHAPE. The input data are vectors of properties (represented as attribute-value pairs) which are used to describe individual cases, examples or observations in a given world. Each case belongs to exactly one of a set of classes, and the aim is to produce a collection of decision rules concluding the class according to the properties observed. SHAPE follows three steps. First, we build up an acyclic graph capturing dependencies among the properties involved. Since we endow this net with a semantic interpretation, we are allowed to read the net as a first draft of classification rules. Secondly, we will rewrite these rules to compact their syntactic description using automata minimization techniques, Finally, the rules are generalized in order to obtain the definite intensional description of the thus learned concepts. Let us remark that the last two stages could be applied to a set of rules attached to a collection of examples coming from any other learning system. To close the paper, we also present different experiments made with SHAPE to illustrate the performance of the system in a wide range of applications.

Academic Ideology and the New Attention to Teaching

Abstract: I am using the term "academic ideology" in a sense similar to Jay Lemke's.1 He discusses classroom decorum and the balance be tween the "rule" that students are not to speak to one another during class and the fact that a certain amount of interstudent conversa tion is permitted during any class meeting except examinations. Lemke sees the "code of student silence" as belonging to that category found in many social situations where the rules are largely pro forma, yet nevertheless honored as the rules. "I propose that they [only-sometimes enforced rules] operate as part of an ideology ; that is, as a system of beliefs that systematically hides its own true social functions. If the rules were strictly enforced, the ideology would be exposed as such because we would have to question the basis of a rule whose enforcement made our lives impossible. But by permitting a rule to be broken as often as necessary to avoid this, this maintenance continues to serve its hidden function" (LS 236). In this essay, and in his subsequent book Talking Science,2 Lemke explores how the teaching of science is governed by the ideology of individualism, which, in class, stays back, so to speak, and emerges in a few selected places, one of which is testing. Lemke describes how the restrictions on talk create a "picture of classroom learning that distorts its social nature to make it seem as if each student is solely responsible for what he or she learns or fails to learn in class" (LS 236). He argues that this classroom ideology is a fundamental part of the social "system of awarding grades, opportunities, jobs, and radically different standards of living." In turn, "At the base of this system, of course, behind the grades and before the opportunities, most often stand test results. According to this interpretation, it is no accident that the only classroom activity type in which the rule against talk between students is strictly enforced is test taking, that moment when the social process of the classroom is temporarily replaced by an artificial set of separate, isolated individuals" (LS 236). Tests in science courses represent an ideological node that exercises the influence of the "technocratic elite" {TS 139) in the teaching philosophy of most American schools. When in any classroom, this ideology constrains the

From compositional to systematic semantics

Abstract: We prove a theorem stating that any semantics can be encoded as a compositional semantics, which means that, essentially, the standard definition of compositionality is formally vacuous. We then show that when compositional semantics is required to be "systematic" (that is, the meaning function cannot be arbitrary, but must belong to some class), it is possible to distinguish between compositional and non-compositional semantics. As a result, we believe that the paper clarifies the concept of compositionality and opens a possibility of making systematic formal comparisons of different systems of grammars.

On the Proof Theory of Program Transformations

Abstract: §1 Abstract We provide an intensional semantics for certain elementary program transformations by describing a translation from these transformations to the derivations of a simple theory of operations and types and we show that this semantics is intensionally faithful. Our objective is to understand more precisely the intensional structure of a class of semi-formal program derivations.