WorldCat Identities

Hewitt, Carl

Overview
Works: 50 works in 151 publications in 1 language and 286 library holdings
Genres: Conference papers and proceedings 
Roles: Author, Editor, Thesis advisor
Classifications: Q335.M41, 651.84
Publication Timeline
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Most widely held works about Carl Hewitt
 
Most widely held works by Carl Hewitt
Third ACM-SIGOIS Conference on Office Information Systems, October 6-8, 1986, Providence, Rhode Island by 1986, Providence, RI) Conference on Office Information Systems (3( Book )

8 editions published in 1986 in English and Undetermined and held by 43 WorldCat member libraries worldwide

Description and theoretical analysis (using schemata) of PLANNER, a language for proving theorems and manipulating models in a robot by Carl Hewitt( Book )

16 editions published between 1971 and 1972 in English and held by 20 WorldCat member libraries worldwide

PLANNER is a formalism for proving theorems and manipulating models in a robot. The formalism is built out of a number of problem-solving primitives together with a hierarchical multiprocess backtrack control structure. Statements can be asserted and perhaps later withdrawn as the state of the world changes. Under BACKTRACK control structure, the hierarchy of activations of functions previously executed is maintained so that it is possible to revert to any previous state. Thus programs can easily manipulate elaborate hypothetical tentative states. In addition PLANNER uses multiprocessing so that there can be multiple loci of control over the problem-solving
Actors and continuous functionals by Carl Hewitt( Book )

6 editions published in 1977 in English and held by 14 WorldCat member libraries worldwide

This paper presents precise versions of some 'laws' that must be satisfied by computations involving communicating parallel processes. The laws take the form of stating plausible restrictions on the histories of computations that are physically realizable. The laws are very general in that they are obeyed by parallel processes executing on a time varying number of distributed physical processors. For example, some of the processors might be in orbiting satellites. The laws are justified by appeal to physical intuition and are to be regarded as falsifiable assertions about the kinds of computations that occur in nature rather than as proved theorems in mathematics. The laws are intended to be used to analyze the mechanisms by which multiple processes can communicate to work effectively together to solve difficult problems. The laws presented in this paper are intended to be applied to the design and analysis of systems consisting of large numbers of physical processors. The development of such systems is becoming economical because of rapid progress in the development of large scale integrated circuits. We generalize the usual notion of the history of a computation as a sequence of events to the notion of a partial order of events. Partial orders of events seem better suited to expressing the causality involved in parallel computations than totally ordered sequences of events obtained by 'considering all shuffles' of the elementary steps of the various parallel processes. The utility of partial orders is demonstrated by using them to express our laws for distributed computation. These laws in turn can be used to prove the usual induction rules for proving properties of procedures
A real time garbage collector that can recover temporary storage quickly by Henry Lieberman( Book )

6 editions published in 1980 in English and Undetermined and held by 12 WorldCat member libraries worldwide

In previous heap storage systems, the cost of creating objects and garbage collection is independent of the lifetime of the object. Since temporary objects account for a large portion of storage use, it's worth optimizing a garbage collector to reclaim temporary storage faster. We present a garbage collection algorithm which: Makes short term storage cheaper. Operates in real time - object creation and access times are bounded. Works well with multiple processors and a large address space. (Author)
Foundations for office semantics by Gerald M Barber( Book )

4 editions published between 1982 and 1987 in English and held by 10 WorldCat member libraries worldwide

Comparative schematology by Michael S Paterson( Book )

6 editions published between 1970 and 1978 in English and Undetermined and held by 10 WorldCat member libraries worldwide

While we may have the intuitive idea of one programming language having greater power than another, or of some subset of a language being an adequate 'core' for that language, we find when we try to formalize this notion that there is a serious theoretical difficulty. This lies in the fact that even quite rudimentary languages are nevertheless 'universal' in the following sense. If the language allows us to program with simple arithemtic or list-processing functions than any effective control structure can be simulated, traditionally, by encoding a Turing machine computation in some way. In particular, a simple language with some basic arithmetic can express programs for any partial recursive function. Such an encoding is usually quite unnatural and impossibly inefficient. Thus in order to carry on a practical study of the comparative power of different languages we are led to banish explicit functions and deal instead with abstract, uninterpreted programs, or schemas. What follows is a brief report on some preliminary exploration in this area. (Author)
Viewing control structures as patterns of passing messages by Carl Hewitt( Book )

5 editions published in 1976 in English and Undetermined and held by 8 WorldCat member libraries worldwide

The purpose of this paper is to discuss some organizational aspects of programs using the actor model of computation. This paper presents an approach to modelling intelligence in terms of a society of communicating knowledge-based problem-solving experts. In turn each of the experts can be viewed as a society that can be further decomposed in the same way until the primitive actors of the system are reached. Investigated are the nature of the communication mechanisms needed for effective problem-solving by a society of experts and the conventions of discourse that make this possible
Analyzing the Roles of Descriptions and Actions in Open Systems by Carl Hewitt( Book )

5 editions published in 1983 in English and held by 7 WorldCat member libraries worldwide

This paper analyzes relationships between the roles of descriptions and actions in large scale, open ended, geographically distributed, concurrent systems. Rather than attempt to deal with the complexities and ambiguities of currently implemented descriptive languages, we concentrate our analysis on what can be expressed in the underlying frameworks such as the lambda calculus and first order logic. By this means we conclude that descriptions and actions complement one another; neither being sufficient unto itself. This paper provides a basis to begin the analysis of the very subtle relationships that hold between descriptions and actions in Open Systems. (Author)
The incremental garbage collection of processes by Henry G Baker( Book )

6 editions published in 1977 in English and Undetermined and held by 7 WorldCat member libraries worldwide

This paper investigates some problems associated with an expression evaluation order that we call 'future' order, which is different from call-by-name, call-by-value, and call-by-need. In future order evaluation, an object called a 'future' is created to serve as the value of each expression that is to be evaluated and separate process is dedicated to its evaluation. This mechanism allows the fully parallel evaluation of the expressions in a programming language. We discuss an approach to a problem that arises in this context: futures which were thought to be relevant when they were created become irrelevant through not being needed later in the computation. The problem of irrelevant processes also appears in multiprocessing problem-solving systems which start several processors working on the same problem but with different methods, and return with the solution which finishes first. This parallel method strategy has the drawback that the processes which are investigating the losing methods must be identified, cleanly stopped, and the processors they are using re-assigned to more useful tasks. The solution we propose is that of incremental garbage collection. The goal structure of the solution plan should be explicitly represented in memory as part of the graph memory (like Lisp's heap) so that a garbage collection algorithm can discover which processes are performing useful work, and which can be recycled for a new task. An incremental algorithm for the unified garbage collection of storage and processes is described. (Author)
A session with Tinker : interleaving program testing with program design by Henry Lieberman( Book )

5 editions published in 1980 in English and Undetermined and held by 7 WorldCat member libraries worldwide

Tinker is an experimental interactive programming system which integrates program testing with program design. New procedures are created by working out the steps of the procedure in concrete situations. Tinker displays the results of each step as it is performed, and constructs a procedure for the general case from sample calculations. The user communicates with Tinker mostly by selecting operations from menus on an interactive graphic display rather than by typing commands. This paper presents a demonstration of our current implementation of Tinker. (Author)
Symbolic evaluation using conceptual representations for programs with side-effects by Akinori Yonezawa( Book )

4 editions published in 1976 in English and held by 7 WorldCat member libraries worldwide

Symbolic evaluation is a process which abstractly evaluates a program on abstract data. A formalism based on conceptual representations is proposed as a specification language for programs with side-effects. Relations between algebraic specifications and specifications based on conceptual representations are discussed and limitations of the current algebraic specification techniques are pointed out. Symbolic evaluation is carried out with explicit use of a notion of situations. Uses of situational tags in assertions make it possible to state relations about properties of objects in different situations. The proposed formalism can deal with problems of side-effects which have been beyond the scope of Floyd-Hoare proof rules and give a solution to McCarthy's frame problem. (Author)
Planner : a language for proving theorems by Carl Hewitt( Book )

4 editions published in 1967 in English and held by 6 WorldCat member libraries worldwide

Functional abstraction in LISP and PLANNER by Carl Hewitt( Book )

4 editions published in 1968 in English and held by 6 WorldCat member libraries worldwide

Concurrent programming using actors : exploiting large-scale parallelism by Gul A Agha( Book )

4 editions published between 1984 and 1985 in Undetermined and English and held by 6 WorldCat member libraries worldwide

We argue that the ability to model shared objects with changing local states, dynamic reconfigurability, and inherent parallelism are desirable properties of any model of concurrency. The actor model addresses these issues in a uniform framework. This paper briefly describes the concurrent programming language Act3 and the principles that have guided its development. Act3 advances the state of the art in programming languages by combining the advantages of object-oriented programming with those of functional programming. We also discuss considerations relevant to large-scale parallelism in the context of open systems, and define an abstract model which establishes the equivalence of systems defined by actor programs. (Author)
Modelling distributed systems by Akinori Yonezawa( Book )

5 editions published between 1977 and 1978 in English and Undetermined and held by 6 WorldCat member libraries worldwide

Distributed systems are multi-processor information processing systems which do not rely on the central shared memory for communication. This paper presents ideas and techniques in modelling distributed systems and its application to Artificial Intelligence. In section 2 and 3, we discuss a model of distributed systems and its specification and verification techniques. We introduce a simple example of air line reservation systems in Section 4 and illustrate our specification and verification techniques for this example in the subsequent sections. Then we discuss our further work. (Author)
Design Issues in Parallel Architectures for Artificial Intelligence by Carl Hewitt( Book )

5 editions published between 1983 and 1984 in English and held by 5 WorldCat member libraries worldwide

Development of highly intelligent computers requires a conceptual foundation that will overcome the limitations of the von Neumann architecture. Architectures for such a foundation should meet the following design goals: Address the fundamental organizational issues of large-scale parallelism and sharing in a fully integrated way. This means attention to organizational principles, as well as hardware and software. Serve as an experimental apparatus for testing large-scale artificial intelligence systems. Explore the feasibility of an architecture based on abstractions, which serve as natural computational primitives for parallel processing. Such abstractions should be logically independent of their software and hardware host implementations. In this paper we lay out some of the fundamental design issues in parallel architecture for Artificial Intelligence, delineate limitations of previous parallel architectures, and outline a new approach that we are pursuing. (Author)
PLANNER : a language for manipulating models and proving theorems in a robot by Carl Hewitt( Book )

3 editions published between 1968 and 1970 in English and held by 5 WorldCat member libraries worldwide

Open systems by Carl Hewitt( Book )

3 editions published in 1982 in English and Undetermined and held by 5 WorldCat member libraries worldwide

Office information systems by ACM-SIGOIS Conference on Office Information Systems( Book )

2 editions published in 1986 in English and held by 4 WorldCat member libraries worldwide

3. ACM-SIGOIS Conference on Office Information Systems, Oct. 6-8, 1986, Providence, Rhode Island by Carl Hewitt( Book )

3 editions published in 1986 in English and held by 1 WorldCat member library worldwide

 
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Audience Level
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Audience level: 0.76 (from 0.67 for PLANNER : ... to 0.93 for Office inf ...)

Alternative Names
Carl Hewitt Amerikaans wiskundige

Carl Hewitt amerikanischer Informatiker

Carl Hewitt amerikansk datavetare och matematiker

Carl Hewitt amerikansk informatikar og matematikar

Carl Hewitt amerikansk informatiker og matematiker

Hewitt, Carl E. (Carl Eddie)

كارل هيويت

칼 휴잇

カール・ヒューイット

Languages
English (92)