Showing papers by "Carnegie Mellon University published in 1969"
Book•
01 Jan 1969TL;DR: A new edition of Simon's classic work on artificial intelligence as mentioned in this paper adds a chapter that sorts out the current themes and tools for analyzing complexity and complex systems, taking into account important advances in cognitive psychology and the science of design while confirming and extending Simon's basic thesis that a physical symbol system has the necessary and sufficient means for intelligent action.
Abstract: Continuing his exploration of the organization of complexity and the science of design, this new edition of Herbert Simon's classic work on artificial intelligence adds a chapter that sorts out the current themes and tools -- chaos, adaptive systems, genetic algorithms -- for analyzing complexity and complex systems. There are updates throughout the book as well. These take into account important advances in cognitive psychology and the science of design while confirming and extending the book's basic thesis: that a physical symbol system has the necessary and sufficient means for intelligent action. The chapter "Economic Reality" has also been revised to reflect a change in emphasis in Simon's thinking about the respective roles of organizations and markets in economic systems.
11,845 citations
TL;DR: In this paper, the first principles for the first-principle calculation of the rate of decay of a metastable phase were outlined for a wide variety of thermally activated nucleation and growth processes, possibly including decay of superflow in liquid helium.
1,008 citations
TL;DR: In this paper, a numerical solution capability is developed for the solution of problems in three dimensional elastostatics, which utilizes singular integral equations which can be solved numerically for the unknown surface tractions and displacements for the fully mixed boundary value problem.
521 citations
TL;DR: In this article, acute toxicity and irritation data on about 200 compounds are presented, accumulated in a continuing program for screening potential commercial products, and the authors present a detailed discussion of the results.
Abstract: Acute toxicity and irritation data on about 200 compounds are presented, accumulated in a continuing program for screening potential commercial products.
438 citations
TL;DR: This paper describes an implicit enumeration procedure that solves the problem by generating a sequence of circuit-free graphs and solving a slightly amended critical-path problem for each graph in the sequence.
Abstract: One formulation of the machine sequencing problem is that of finding a mini-maximal path in a disjunctive graph. This paper describes an implicit enumeration procedure that solves the problem by generating a sequence of circuit-free graphs and solving a slightly amended critical-path problem for each graph in the sequence. Each new term of the sequence is generated from an earlier one by complementing one disjunctive arc. The search tree is drastically cut down by the fact that the only disjunctive arcs that have to be considered for being complemented are those on a critical path. An evaluation of these candidates is used to direct the search at each stage. The procedure can start with any feasible schedule like the one actually used in production, or generated by some heuristics, and gradually improve it. Thus one can possibly stop short of the optimum, with a reasonably "good" feasible schedule. Storage requirements are limited to the data pertinent to the current node of the search tree.
374 citations
TL;DR: In this paper, a thermodynamische Theorie of nichteinfachen, elastischen Stoffen wird gezeigt, dass Substanzen vom Grade hoher als eins vorkommen konnen; vorausgesetzt, man das eventuelle Vorhandensein zweier verschiedener Temperaturen in Betracht zieht.
Abstract: Diese Arbeit behandelt eine thermodynamische Theorie von nichteinfachen, elastischen Stoffen Es wird gezeigt, dass Substanzen vom Grade hoher als eins vorkommen konnen; vorausgesetzt, dass man das eventuelle Vorhandensein zweier verschiedener Temperaturen in Betracht zieht
349 citations
TL;DR: In this paper, it was shown that the Hermitian semi-definite matrices form a commutative partially ordered semigroup under the parallel sum operation, and the norms are found to satisfy the inequality ∥ A : B ∥ ⩽ ∥ ∥ a ∥ : ∥ b ∥.
346 citations
TL;DR: Algorithms are presented which examine a request in the light of the current allocation of resources and determi whether or not the granting of the request will introduce the possibility of a deadlock.
Abstract: A well-known problem in the design of operating systems is the selection of a resource allocation policy that will prevent deadlock. Deadlock is the situation in which resources have been allocated to various tasks in such a way that none of the tasks can continue. The various published solutions have been somewhat restrictive: either they do not handle the problem in sufficient generality or they suggest policies which will on occasion refuse a request which could have been safely granted. Algorithms are presented which examine a request in the light of the current allocation of resources and determi.~e whether or not the granting of the request will introduce the possibility of a deadlock. Proofs given in the appendixes show that the conditions imposed by the algorithms are both necessary and sufficient to prevent deadlock. The algorithms have been successfully used in the THE system.
310 citations
TL;DR: The theory is particularized in a computer program to simulate the eye movements of subjects choosing a move in chess, and its consistency is shown with data on memory of chess positions and with existing knowledge of short-term memory parameters.
Abstract: A theory is proposed to explain, in information-processing terms, some common phenomena in the initial perceptual phases of problem solving, to show that some existing computer programs for heuristic search and learning already contain basic processes that will produce these phenomena, and to show how simple organizations of the processes enable the programs to parallel human behavior. The theory is particularized in a computer program to simulate the eye movements, during the first 5 seconds, of subjects choosing a move in chess. The application of the theory is illustrated by an example, and its consistency is shown with data on memory of chess positions and with existing knowledge of short-term memory parameters.
158 citations
TL;DR: In this paper, a loanable funds model was proposed for the first time, and empirical results showed that the model can be used to evaluate the suitability of the loanable fund model.
Abstract: I. Introduction, 127. — II. A loanable funds model, 130. — III. Empirical results, 132. — IV. Macauley's criticism reconsidered, 138. — V. Conclusions, 139.
153 citations
TL;DR: By exploiting fully the ability to linearize the procedure format (isolating the format from a tree structure form) and by representing lemmas by clauses, the description of the Model Elimination procedure is greatly simplified.
Abstract: An alternate approach to the formulation of the Model Elimination proof procedure is presented. By exploiting fully the ability to linearize the procedure format (isolating the format from a tree structure form) and by representing lemmas by clauses, the description of the Model Elimination procedure is greatly simplified.
Proceedings Article•
07 May 1969TL;DR: A protocol of problem solving in architectural design and its analysis is presented and the significant difference between well-and ill-defined problem solving is shown to be a specification process similar to information retrieval processes now studied in artificial intelligence.
Abstract: In this paper the information processing theory of problem solving is extended to include ill-defined problems. A protocol of problem solving in architectural design and its analysis is presented. The significant difference between well-and ill-defined problem solving is shown to be a specification process similar to information retrieval processes now studied in artificial intelligence. A variety of issues in this retrieval process are examined. The search process involved in the space planning aspect of design is shown to correspond well with existing formulations of search. The interactive effects of retrieval and search processes are examined.
Proceedings Article•
07 May 1969TL;DR: It is shown that PROW can be used as a question-answering program by modifying the part of PROW that translates an algorithm to a LISP program.
Abstract: This paper Describes a program, called "PROW", which writes programs PROW accepts the specification of the program in the language of predicate calculus, decides the algorithm for the program and then produces a LISP program which is an implementation of the algorithm. Since the construction of the algorithm is obtained by formal theorem-proving techniques, the programs that PROW writes are free from logical errors and do not have to be debugged The user of PROW can make PROW write programs in languages other than LISP by modifying the part of PROW that translates an algorithm to a LISP program. Thus PROW can be modified to write programs in any language In the end of this paper, it is shown that PROW can also be used as a question-answering program
TL;DR: In the sedimentation velocity analyses the separation was manifested by a transformation of the hypersharp boundary of the EGTA-sensitizing factor complex into two broader boundaries representative of tropomyosin and troponin.
TL;DR: The introduction of DATA BASE as a new quarterly journa l of SIGBDP to replace the former Newsletter provided an opportunity to reconsider the style, format, and functio n of a "Book Reviews" column.
Abstract: The introduction of DATA BASE as a new quarterly journa l of SIGBDP to replace the former Newsletter provided a n opportunity to reconsider the style, format, and functio n of a "Book Reviews" column . In the February 1968 issu e of the Newsletter, I noted that one of the goals of thi s column is to provide an informal forum for acknowledgin g new publications on business data processing . The emphasi s was to be on books, although "significant" journal articles would also be reviewed when appropriate . Thes e reviews were not intended as " . . .complete professiona l critiques . . . , but rather an abstracting and recommendatio n of the publication to a particular audience based on th e relative level of discussion and degree of professionalis m in the volume ." Subsequent Book Reviews discussions hav e had the character of a "buyer's guide" to the busines s data processing literature—occasionally biased with a n opinion, but for the most part an impartial summary . In reflecting on that column, one might question th e need for another "buyer's guide" to BDP publications , given the alternative sources currently available . For example, Computing Reviews continues to provide relativel y complete and comprehensive abstracting of the compute r literature . Commercial periodicals, such as Computerworid, Computers and Automation, Datamation, or Data Processin g Digest to name several, include book reviews as a regula r feature . In addition, several of these periodicals also includ e a short synopsis of new books received but not reviewed — for example, the "Book Briefs" feature in Datamation . O n the supposition that most SIGBDP members subscribe t o one or more commercial publications, redundancy in th e approach to book reviews by DATA BASE appears to offe r only marginal returns to the membership . With this thought in mind, two alternative approache s to the column are suggested that potentially could serv e SIGBDP members in a manner not readily available fro m existing sources . One approach would be to feature article length discussions of "major books" on business dat a processing and allied fields . These books would not necessarily be brand new, but rather important works that i n the reviewer's opinion really deserve the attention of th e readership . In this regard, the book (or significant journa l article) could provide a vehicle for discussion and appraisa l of developments within an identified subject area . In som e cases, perhaps, this could permit a broadening of th e discussion beyond a single volume by reviewing severa l allied works by the same author over time . A second and related approach to the book review s column would be to feature comparative reviews . Comparative reviews could take the form of either selective reviews of several different publications on a designate d topic area, or multiple reviews of the same book b y different individuals, such as contrasting an academic an d industrial appraisal of the same work . Beyond the potential service to DATA BASE reader s of either or both of these approaches to a book review s column, there is the obvious implication that such a colum n would require considerably more work to prepare than th e present column. Recognizing these very real consequences , I decided to solicit the interest and participation of severa l colleagues active in the field as editorial coordinators wh o would assist in expanding the scope of Book Reviews . The response to this appeal was very encouraging and i t is a pleasure to acknowledge these individuals in th e following listing :
TL;DR: A simple variation of the (restricted) conditional complexity measure investigated by Martin-Lof is noted because of interesting characteristics not shared by the measures proposed by Kolmogorov.
Abstract: Kolmogorov in 1965 proposed two related measures of information content (alternately, measures of complexity) based on the size of a program which when processed by a suitable algorithm (machine) yields the desired object. The main emphasis was placed on a conditional complexity measure. In this paper a simple variation of the (restricted) conditional complexity measure investigated by Martin-Lof is noted because of interesting characteristics not shared by the measures proposed by Kolmogorov. The characteristics suggest situations in which this variant is the most desirable measure to employ. The interpretation of the measure offers some desirable general qualities; also the measure is relatively advantageous when working with entities of low complexity and maintains the important properties of the Kolmogorov conditional complexity measure when concerned with high complexity.
TL;DR: In this paper, minimal basis LCAO SCF molecular orbital calculations have been performed to determine the energies and configurations of small groups of water molecules, and it is found that polymers having OH3. chains are preferred, and that hydrogen bond energies deviate considerably from additivity.
TL;DR: The results indicate that the harmonic mean formula for additive joint toxicity satisfactorily predicted the toxicity of a large proportion of the pairs and the soundest hypothesis for the joint action of untested pairs is that of additive toxic action.
TL;DR: The authors conducted an experiment to determine the effects of interaction among group members on both their generation and evaluation of solutions to problems and found that groups in which members interacted with one another during generation produced fewer high quality solutions, fewer high-quality solutions and a smaller number of different kinds of solutions.
TL;DR: In this article, the IR spectra of Linde X- and Y- type zeolites, charge-balanced with different monovalent and divalent cations, were examined in the OH and NH regions after evacuation at various temperatures and when H 2 O or NH 3 was added back.
TL;DR: The results suggest a sliding filament mechanism of smooth muscle contraction; however, in smooth muscle, unlike striated muscle, the thick filaments appear to be in a highly labile condition in the contractile process.
Abstract: Fresh taenia coli and chicken gizzard smooth muscle were studied in the contracted and relaxed states. Thick and thin filaments were observed in certain (but not all) cells fixed in contraction. Relaxed smooth muscle contained only thin filaments. Several other morphological differences were observed between contracted and relaxed smooth muscle. The nuclear chromatin is clumped in contraction and evenly dispersed in the relaxed state. The sarcolemma is more highly vesiculated in contraction than in relaxation. In contraction, the sarcoplasm also appears more electron opaque. Over-all morphological differences between cells fixed in isometric and in unloaded contraction were also noticeable. The results suggest a sliding filament mechanism of smooth muscle contraction; however, in smooth muscle, unlike striated muscle, the thick filaments appear to be in a highly labile condition in the contractile process. The relation between contraction and a possible change in pH is also discussed.
TL;DR: The correctness and equivalence problems of abstract programs are shown to be reducible to the termination problem and known proof procedures for the first-order predicate calculus can be applied to prove the termination of both programs and abstract programs.
Abstract: This paper is concerned with the relationship of the termination problem for programs and abstract programs to the validity of certain formulas in the first-order predicate calculus. By exploiting this relationship, subclasses of abstract programs for which the termination problem is decidable can be isolated. Moreover, known proof procedures for the first-order predicate calculus (e.g. resolution) can be applied to prove the termination of both programs and abstract programs. The correctness and equivalence problems of abstract programs are shown to be reducible to the termination problem.
TL;DR: The present paper gives an algorithm for finding the maximum number of edges that can be removed from a digraph without affecting its reachability properties.
Abstract: : A directed graph or digraph can be thought of as a communication network among a set of persons, where the vertices of the graph correspond to persons and edges of the graph to directed channels of communication from one person to another. A person is said to be able to 'reach' another if he can send a message to that person. The present paper gives an algorithm for finding the maximum number of edges that can be removed from a digraph without affecting its reachability properties. (Author)
TL;DR: In this paper, Raman and infrared spectra have been obtained for K[PtCl3(C2H4)]·H2O (Zeise's salt), K[pCl3[C2D4]·H 2O, and [ptCl2[C 2H4]2]2.
TL;DR: An examination of the electron micrographs of four native asphalties, a vanadium-enriched asphaltene, an asphalte from a visbreaker tar, a resin, and a gilsonite, has revealed in all cases irregular polyhedral shaped particles of average diameter 20-30A, suggesting that the associated aliphatic and naphthenic portions of the molecule must be closely bound to the aromatic nucleus as mentioned in this paper.
TL;DR: The literature on second order linear oscillation is voluminous, and the result of Sturm's separation theorem is of particular relevance to the present paper; see, e.g., the work of.
Abstract: (1) x"+a(t)x = 0, t > 0, where a(t) is a locally integrable function of t. We call equation (1) oscillatory if all solutions of (1) have arbitrarily large zeros on [0, oo), otherwise, we say equation (1) is nonoscillatory. As a consequence of Sturm's Separation Theorem [21], if one of the solutions of (1) is oscillatory, then all of them are. The same is true for the nonoscillation of (1). The literature on second order linear oscillation is voluminous. The first such result is of course the classical theorem of Sturm which asserts that