Showing papers on "Domain (software engineering) published in 1981"

Program slicing

Abstract: Program slicing is a method used by experienced computer programmers for abstracting from programs. Starting from a subset of a program's behavior, slicing reduces that program to a minimal form which still produces that behavior. The reduced program, called a “slice”, is an independent program guaranteed to faithfully represent the original program within the domain of the specified subset of behavior.Finding a slice is in general unsolvable. A dataflow algorithm is presented for approximating slices when the behavior subset is specified as the values of a set of variables at a statement. Experimental evidence is presented that these slices are used by programmers during debugging. Experience with two automatic slicing tools is summarized. New measures of program complexity are suggested based on the organization of a program's slices.

The Formative Years

Abstract: RI is a rule-based program that configures VAX-I 1 computer systems. Given a customer’s purchase order, it determines what, if any, substitutions and additions have to be made to the order to make it consistent and complete and produces a numnber of diagrams showing the spatial and logical relationships among the 90 or so components that typically constitute a system. The program has been used on a regular basis by Digital Equipment Corporation’s manufacturing organization since January of 1980. Rl has sufficient knowledge of the configuration domain and of the pecularities of the various configuration constraints that at each step in the configuration process, it simply recognizes what to do; thus it requires little search in order to configure a computer system. The approach RI takes to the configuration task and the way its knowledge is represented has been described elsewhere [McDermott 80a, MC Dermott 80b]. This article provides a detailed description of Rl’s design and implementation history. As will become apparent, only a part of the effort to develop an expert configurer for Digital dealt in a direct way with AI issues. The other, and in fact larger, part involved providing the ever widening circle of individuals who came in

Transportable natural-language interfaces to databases

Abstract: : Several computer systems have now been constructed that allow users to access databases by posing questions in natural languages, such as English. When used in the restricted domains for which they have been especially designed, these systems have achieved reasonably high levels of performance. However, these systems require the encoding of knowledge about the domain of application in complex data structures that typically can be created for a new database only with considerable effort on the part of a computer professional who has had special training in computational linguistics and the use of databases. This paper describes initial work on a methodology for creating natural-language processing capabilities for new databases without the need for intervention by specially trained experts. The approach is to acquire logical schemata and lexical information through simple interactive dialogues with someone who is familiar with the form and content of the database, but unfamiliar with the technology of natural-language interfaces. A prototype system using this methodology is described and an example transcript is presented.

Explaining and justifying expert consulting programs

Abstract: Traditional methods for explaining programs provide explanations by converting to English the code of the program or traces of the execution of that code While such methods can provide adequate explanations of what the program does or did, they typically cannot provide justifications of the code without resorting to canned-text explanations. That is, such systems cannot tell why what the system is doing is a reasonable thing to be doing. The problem is that the knowledge required to provide these justifications is needed only when the program is being written and does not appear in the code itself. The XPLAIN system uses an automatic programmer to generate the consulting program by refinement from abstract goals. The automatic programmer uses a domain model, consisting of facts about the application domain, and a set of domain principles which drive the refinement process forward. By examining the refinement structure created by the automatic programmer it is possible to provide justifications of the code. This paper discusses the system described above and outlines additional advantages this approach has for explanation.

R1: The Formative Years

Abstract: R1 is a rule-based program that configures VAX-11 computer systems. Given a customer's purchase order, it determines what, if any, substitutions and additions have to be made to the order to make it consistent and complete and produces a number of diagrams showing the spatial and logical relationships among the 90 or so components that typically constitute a system. The program has been used on a regular basis by Digital Equipment Corporation's manufacturing organization since January of 1980. R1 has sufficient knowledge of the configuration domain and of the percliarities of the various configuration constraints that at each step in the configuration process, it simply recognizes what to do; thus it requires little search in order to configure a computer system.

BLOKJE, a computer program to calculate the domain of an atom in a structure

Abstract: A computer program has been written with the aim of calculating the domain of an atom in a structure. The domain may be limited by planes situated half-way between the atoms, or at a distance that takes into account the relative radii of the atoms. Data concerning this domain and the corresponding coordination polyhedron are computed and printed. Punched cards, to be used in a special plotting program, can also be produced. Three types of weighted coordination number are calculated.

Do Outdoor Education Experiences Contribute to Positive Development in the Affective Domain

Abstract: (1981). Do Outdoor Education Experiences Contribute to Positive Development in the Affective Domain? The Journal of Environmental Education: Vol. 12, No. 4, pp. 21-29.

Pseudo-oracles for non-testable programs

Abstract: The most commonly used method of validating a program is by testing. The programmer typically runs the program on some test cases, and if and when they run correctly, the program is considered to be correct. We know that many difficult problems are associated with testing. One such problem is that it is a fundamental part of the testing process to require the ability to infer properties of a program by observing the program's behavior on selected inputs. The most common property that one hopes to infer through testing is correctness. But unless the program is run on the entire input domain, there are infinitely many programs which produce the correct output on the selected inputs, but produce incorrect output for some other element of the domain.

The use of time domain diakoptics in time discrete models of fields

Abstract: The principles of diakoptics are extended to time domain solutions and the technique is applied to the solution of fields by introducing space approximating polynomials. Since transmission-line networks provide time-discrete models suitable for exact numerical analysis, the topic is approached by tearing these transmission-line models and then showing how reconnection is made in the time domain.

Producing explanations and justifications of expert consulting programs

Abstract: Traditional methods for explaining programs provide explanations by converting to English the code of the program or traces of the execution of that code. While such methods can provide adequate explanations of what the program does or did, they typically cannot provide justifications of the code without resorting to canned-text explanations. That is, such systems cannot tell why what the system is doing is a reasonable thing to be doing. The problem is that the knowledge required to provide these justifications is needed only when the program is being written and does not appear in the code itself. In the XPLAIN system, an automatic programming approach is used to capture some of the knowledge necessary to provide these justifications. The XPLAIN system uses an automatic programmer to generate the consulting program by refinement from abstract goals. The automatic programmer uses a domain model, consisting of facts about the application domain, and a set of domain principles which drive the refinement process forward. By keeping around a trace of the execution of the automatic programmer it is possible to provide justifications of the code using techniques similar to the traditional methods outlined above. This paper discusses the system described above and outlines additional advantages this approach has for explanation.

Stability analysis of complex dynamical systems: Some computational methods

Abstract: We present two new algorithms to estimate the domain of attraction of an isolated asymptotically stable equilibrium and we present a new result (using the comparison principle) which can sometimes be used to extend the applicability of these algorithms to high order systems.

The Coupling of Boundary and Finite Element Methods for Infinite Domain Problems in Elasto- Plasticity

Abstract: The implementation of a coupled analysis capability into an existing Finite Element computer program is discussed. The coupled analysis is then applied to a circular excavation in a infinite domain where the region of plasticity is confined to the Finite Element mesh. Further potential usage of the coupled analysis is then discussed in relation to mine design.

An invited article Facilitating human–computer communication

Abstract: Basic cognitive psychology can provide guidelines for how to design computer systems that are easy for people to use. Prior knowledge of the real world and natural language affect the way people use computers, so computer systems that are consistent with this prior knowledge are easier for people to use. Providing users with mental models for a computer system will allow them to solve more complex problems and understand sequences of commands better. Computer systems should be flexible to accommodate the individual differences between users, but the complexity of understandable computer systems is constrained by the limited information processing capacity of users. The domain of human–computer communication promises to be a fertile domain for applied tests of cognitive theories.

Idiomaticity and functional variation: A case study of international amateur radio talk

Abstract: The linguistic domain of idiomaticity poses many problems for the study of language form, use, and variation. With selected aspects of idiomaticity as a starting point, I will attempt in this paper to develop a description of the use of idioms as a segment of a more general theory of language use. Evidence for this approach is drawn from international amateur radio talk (IART) in English.

Principal values and branch cuts in complex APL

Abstract: Complex numbers are useful in science and engineering and, through analogy to the complex plane, in two-dimensional graphics, such as those for integrated-circuit layouts. The extension of APL to complex numbers requires many decisions. Almost all have been discussed in detail in a recent series of papers. One topic requiring further discussion is the choice of branch cuts and principal values for the primitive APL functions that require them. Conventional mathematical notation and the experience of other computer languages are of only moderate help. For example, one cannot find in the mathematics or computer-science literature a definitive value for the principal value of the arcsin of 3. The extension of APL to the complex domain presents a unique opportunity to define a set of choices that will best serve APL and other languages. This paper recommends locations of all branch cuts, directions of continuity of the branch cuts, and values at the branch points. It also recommends that comparison tolerance be used in the selection of principal values. The results apply to APL, other languages, applications packages, and VLSI hardware for complex calculations.

Search vs. knowledge : an analysis from the domain of games

Abstract: We examine computer games in order to develop concepts of the relative roles of knowledge and search. The paper concentra tes on the relat ion between knowledge appl ied at leaf nodes of a search and the depth of the search that is being conduc ted . Each knowledge of an advantage has a project ion abil ity (t ime to conver t to a more permanent advantage) associated with it. The best programs appear to have the longest pro ject ion abil i ty knowledge in them. If the appl icat ion of knowledge forces a s ingle view of a terminal s i tuat ion, this may at t imes be very w rong . We cons ider the advantages of knowledge del iver ing a range as its output , a method for wh ich some theory exists, but wh ich is as yet unproven. This research was sponsored by the Defense Advanced Research Projects Agency (DCD), ARPA Order No. 3597, moni tored by the Air Force Avionics Laboratory Under Contract F33615-78-C-1551. The views and conc lus ions conta ined in this document are those of the authors and shou ld not be interpreted as represent ing the off icial pol ic ies, either expressed or impl ied, of the Defense Advanced Research Projects Agency or the US Government . Presented at the NATO Symposium Human and Artificial Intelligence, Lyon, France, October, 1981