Showing papers on "Domain (software engineering) published in 1978"

Model-directed learning of production rules1

Abstract: The Meta-DENDRAL program is described in general terms that are intended to clarify the similarities and differences to other learning programs. Its approach of model-directed heuristic search through a complex space of possible rules appears well suited to many induction tasks. The use of a strong model of the domain to direct the rule search has been demonstrated for rule formation in two areas of chemistry. The high performance of programs that use the generated rules attests to the success of this learning strategy.

Generalizability in Factorable Domains: "Domain Validity and Generalizability"1

Abstract: It is shown that if a behavior domain can be described by the common factor model with a finite number of factors, the squared correlation between the sum of a selection of items and the domain tot...

The Effectiveness of Resource Programming

Abstract: This article reviews the results of 17 studies of resource programs and their effects on the academic achievement and personal-social development of exceptional children. Only those studies which include relevant comparison groups are reviewed. Problems in efficacy research are discussed; many of the limitations of studies of special class placement are applicable to research on resource room programming. Results are not definitive in either domain. In the academic domain, programs for learning-disabled and mildly disturbed children proved generally more effective than programs for retarded children. In the personal-social domain, positive effects of resource programming have not been established. In general, the most carefully designed studies support the effectiveness of resource programming. Finally, the authors recommend the incorporation of formative evaluation procedures into resource program development as a supplement to traditional summative methodology.

Development and trial of a model for developing domain referenced tests of reading comprehension

Abstract: , about aspects of reading comprehension. in this imper, the definition,s.validation, and use of domain's are described, and ote strategy for developing domain-referenced \measures is proposed. The strategy involves identifying a pladsible Candidate domain, identifying prototypic items from that domain, specifying relevant variables thought to affect the difficulty of responding correctly,to those items, creating sample items, and verifying the domain. empirically. An attempt was made to implement this strategy in , measuring "ability to find the main point of a passage." In general, the strategy seems to be a useful approach tb test deielcpment and theory refineient, in that it effectively sakples and screens variables affecting performance in the dcmaih. On the basis of this stay, suggestions are made for further research On finding the main point, and approprilte next steps in developing domain-referenced measures are proposed. (Author)

A systematic procedure for generating useful conformal mappings

Abstract: A Procedure is presented for generating a class of conformal mappings useful in the formulation of finite−difference problems involving curved boundaries. The method provides a systematic approach that is capable, in principle, of reducing the geometry to a nearly−rectangular domain for a wide variety of partical problems. The introduction of sheared co−ordinates in this computational domain then provides for solution of the problem in a nearly−orthogonal (in fact, nearly−conformal) co−ordinate system, with its boundaries corresponding to co−ordinate lines. The method is based upon the Schwarz−Christoffel transformation and is quite simple to apply. Several examples illustrating the types of geometries which can be treated in this manner are presented.

Digital Control Law Synthesis in the w' Domain

Abstract: Utility of w' transform domain analysis/synthesis procedures for linear, constant, single-rate sampled-data systems is explored. Basic properties of the wf domain are reviewed and compared with corresponding Z-,H>-, and s-domain properties. The main contribution of the paper is recognition that sampling and data-hold operations are modeled exactly in the w' domain, regardless of the sampling rate employed, and that the w' variable is analogous to the s variable in the sense that all familiar frequency domain design concepts, procedures, and interpretations can be carried over directly. Moreover, the imaginary part of w' approximates angular frequency to for Ico 1 < ir/lT, which further facilitates interpretation. Two example applications illustrate the procedure and make clear (by means of transfer functions and Bode plots) the nonminimum phase effects of sampling and data-hold operations and of sampling rate. It is demonstrated that acceptable closed-loop performance can be achieved at sampling rates that are an order of magnitude less than those employed when an emulation design approach is used.

A general approach to analysis of distributed resistive structures

Abstract: A new general method for calculation of thin-film-distributed resistive structures is presented. This method is based on the conformal mapping of the analyzed domain on the complex upper half-plane and the determination of the complex potential function as the solution of a boundary-values Volterra problem. Although the method inherently applies only to single-connected domains with known conformal representations on the upper half-plane, it may be extended also to other symmetrical multiple-connected configurations and in all cases when the positions of the conducting terminals in the upper half-plane are known. Two examples of application are given.

Indirect responses to loaded questions

Abstract: Casual users of Natural Language (NL) computer systems are typically inexpert not only with regard to the technical details of the underlying programs, but often with regard to the structure and/or content of the domain of discourse. Consequently, NL systems must be designed to respond appropriately when they can detect a misconception on the part of the user. Several conventions exist in cooperative conversation that allow a speaker to indirectly encode their intentions and beliefs about the domain into their utterances, ("loading" the utterances), and allow (in fact, often require) a cooperative respondent to address those intentions and beliefs beyond a literal, direct response. To be effective, NL computer systems must do the same. The problem, then, is to provide practical computational tools which will determine both when an indirect response is required, and wh-~ that response should be, without requiring that large amounts of domain dependent world knowledge be encoded in special formalisms. This paper will take the position that distinguishing language driven inferences from domain driven inferences provides a framewor-~r a s--~ution to this problem in the Data Base (DB) query domain. An implemented query system (CO-OP) is described that uses this distinction to provide cooperative responses to DB queries, using only a standard (CODASYL) DB and a lexicon as sources of world knowledge.

An instructable production system: basic design issues1

Abstract: The full advantages of the incremental properties of production systems have yet to be exploited on a large scale. A promising vehicle for this is the task of instructing a system to solve problems in a complex domain. For this, it is important to express the instruction in a language similar to natural language and without detailed knowledge of the inner structure of the system. Instruction and close interaction with the system as it behaves are preferred over a longer feedback loop with more independent learning by the system. The domain is initially an abstract job shop. The beginning system has capabilities for solving problems, processing language, building productions, and interacting with the task environment. All parts of the system are subject to instruction. The main problem-solving strategy, which permeates all four system components, is based on means-ends analysis and goal-subgoal search. This is coupled with an explicit representation of control knowledge. The system's behavior so far is restricted to simple environmental manipulations, a number of which must be taught before more complex tasks can be done.

On-chip bubble domain relational data base system

Abstract: A bubble domain chip is designed to provide the components necessary to perform all essential data-base functions. Many cross-linked loops in parallel allow the interchange of distinct columns of information. The use of an on-chip decoder achieves effective interchangeability of distinct rows of information. Thus, the basic storage structure and access modes conform to the high-level view of data implied by the relational data model, resulting in simpler programming. In addition, a plurality of comparators are provided to the plurality of storage loops to perform context search simultaneously on all the loops. The simultaneous search and the restriction to output of only qualified data greatly reduces the query time.

On a model equation of lagerstrom

Abstract: A model equation of P. A. Lagerstrom is discussed. An existence proof is given, and the validity of the previously obtained outer solution to order unity is established rigorously. A domain of validity is established for the latter. The methods used here differ essentially from those used by Cohen, Fokas, and Lagerstrom [2] who also obtain rigorous results for the same equation, including existence and domain of validity of the outer solution.

The Professions and Government: Engineering as a Case in Point

Abstract: Engineering, among the largest of the professions, has had a substantial impact on American government at nearly all levels. As the domain of government activity has increased and its programs become more complex, engineers have provided an important source of talent for the implementation and the management of wide-scale technical ventures. Engineering's oldest branch, civil engineering, has, since its beginnings, been closely associated with public technology; some of its newer branches, such as aeronautical engineering, depend heavily on governmental support. In this essay, I hope to provide a brief introduction to the engineering profession, examine some characteristics of engineering which influence its impact on government, and raise several issues which surround the role of engineers in the public service.

Maximum electric field in high-field domain

Abstract: A simple formula relating the domain voltage to the maximum domain field and device parameters is derived. The results are used to analyse the limitations of the parameters of GaAs and InP transferred-electron devices related to the impact ionisation within a high-field domain.

DEDALUS - The DEDuctive ALgorithm Ur-Synthesizer.

Abstract: Program synthesis is the automatic construction of programs to meet given specifications. These specifications constitute a high-level description of the desired program which expresses the purpose of the program, without indicating the method by which that purpose is to be achieved. The specifications are expressed in terms of many constructs which are endemic to the particular subject domain of the desired program (e.g., numbers, sets, lists). Because these constructs are only intended to describe the purpose of the program and need not be computed, they can be of a much higher level than the constructs of any programming . language (e.g., they can include logical quantifiers, set constructors, and other noncomputable operations). The specification language can correspond closely with the concepts a programmer actually uses in thinking about the problem. The techniques we are developing are independent of the choice of a target programming language. The particular language we use in our examples and in our experimental system is a simple LISP-like language containing only basic numerical and list-processing operations, conditional expressions, and recursion. In considering the formation of programs with side effects, we extend the language to include assignments to variables, array elements, and other data-structure components. Our basic approach is to transform the specifications repeatedly according to certain rules; each rule replaces one segment of a program description by another, equivalent, segment. The process continues until a description is obtained that is entirely in terms of the primitive constructs of the target language; this description is the desired program.

Comments on a method of Karpovsky

Abstract: Karpovsky has presented methods of multiple-valued logic design using spectral expansion and optimization by functional decomposition. Methods have been. developed after the binary experiences. This paper shows that extending binary procedures to the multiple -valued domain without a concrete technological reference may lead to the wrong conclusions. In this context, a method of Karpovsky is reviewed, and suggestions for improvement are made.

The synthesis of structure-changing programs

Abstract: Deductive techniques are presented for deriving programs systematically from given specifications. The specifications express the purpose of the desired program without giving any hint of the algorithm to be employed. The desired program is intended to achieve this purpose by means of such low-level primitives as assignment statements, the conditional statements, and recursion. The basic approach is to transform the specifications repeatedly according to certain rules, until a satisfactory program is produced. The rules are guided by a number of strategic controls.Many of the transformation rules represent knowledge about the program's subject domain (e.g., numbers, lists, sets); some represent the meaning of the constructs of the specification language and the target programming language; and a few rules represent basic programming principles. The weakest-precondition operator and the concept of protection are employed to construct programs that must achieve more than one condition simultaneously.Our previous work has centered on the synthesis of structure-maintaining programs, which produce an output without altering the value of any variable or changing the configuration of any data structure. Here, we extend our previous techniques to permit the construction of structure-changing programs, which can reset the values of variables, change the contents of an array, and alter the structure of a list or other data object.

The effect of applied tensile stress on the domain structure of grain oriented Si-Fe

Abstract: The effect of an external tensile stress, σ, applied along the [001], on the domain structures of individual grains in polycrystalline

Theoretical Simplicity and Defeasibility

Abstract: Theoretical simplicity is difficult to characterize, and evidently can depend upon a number of distinct factors One such desirable characteristic is that the laws of a theory have relatively few "counterinstances" whose accommodation requires the invocation of a ceteris paribus condition and ancillary explanation It is argued that, when one theory is reduced to another, such that the laws of the second govern the behavior of the parts of the entities in the domain of the first, there is a characteristic gain in simplicity of the sort mentioned: while I see no way of quantitatively measuring the "amount" of defeasibility of the laws of a theory, microreduction can be shown to decrease that "amount"