Showing papers by "Carnegie Mellon University published in 1979"
TL;DR: In this article, the authors focus on avoidable moral hazard and offer one explanation for limited insurance markets, for closely held firms, and for seemingly simple as opposed to contingent forms of debt.
2,713 citations
TL;DR: In this paper, it was hypothesized that the receipt of a benefit after the person has been benefited leads to greater attraction when an exchange relationship is preferred and decreases attraction when a communal relationship is desired.
Abstract: Communal relationships, in which the giving of a benefit in response to a need for the benefit is appropriate, are distinguished from exchange relationships, in which the giving of a benefit in response to the receipt of a benefit is appropriate. Based on this distinction, it was hypothesized that the receipt of a benefit after the person has been benefited leads to greater attraction when an exchange relationship is preferred and decreases attraction when a communal relationship is desired. These hypotheses were supported in Experiment 1, which used male subjects. Experiment 2, which used a different manipulation of exchange versus communal relationships and female subjects, supported the hypotheses that (a) a request for a benefit after the person is aided by the other leads to greater attraction when an exchange relationship is expected and decreases attraction when a communal relationship is expected, and (b) a request for a benefit in the absence of prior aid from the other decreases attraction when an exchange relationship is expected.
1,392 citations
TL;DR: Algorithms that count the number of pairwise intersections among a set of N objects in the plane and algorithms that report all such intersections are given.
Abstract: An interesting class of "geometric intersection problems" calls for dealing with the pairwise intersections among a set of N objects in the plane, These problems arise in many applications such as printed circuit design, architectural data bases, and computer graphics. Shamos and Hoey have described a number of algorithms for detecting whether any two objects in a planar set intersect. In this paper we extend their work by giving algorithms that count the number of such intersections and algorithms that report all such intersections.
1,062 citations
TL;DR: In this article, a synthesis of Bayesian and sample-reuse approaches to the problem of high structure model selection geared to prediction is presented. But this approach is not suitable for high-dimensional models.
Abstract: This article offers a synthesis of Bayesian and sample-reuse approaches to the problem of high structure model selection geared to prediction. Similar methods are used for low structure models. Nested and nonnested paradigms are discussed and examples given.
940 citations
936 citations
TL;DR: The purpose of this paper is to acquaint the reader with the structures currently avadable for solving the particular problem of range searching, and to display a set of general methods for attacking multikey searching problems.
Abstract: Much research has recently been devoted to "multikey" searching problems. In this paper the partmular multlkey problem of range searching Is investigated and a number of data structures that have been proposed as solutions to this problem are surveyed. The purposes of this paper are to bring together a collection of widely scattered results, to acquaint the reader with the structures currently avadable for solving the particular problem of range searching, and to display a set of general methods for attacking multikey searching problems.
652 citations
TL;DR: In this article, the setter's problem under certainty and the importance of the reversion point are discussed, as well as budget-maximizing with uncertain turnout and exploiting a sequence of elections.
Abstract: I. The setter's problem under certainty and the importance of the reversion point, 565.—II. Budget-maximizing with uncertain turnout, 571.—III. Exploiting a sequence of elections, 579.—IV. Implications for empirical research, 581.—Appendix, 585.
587 citations
TL;DR: PROBLEM SOLVING .
Abstract: PROBLEM SOLVING . Strategies as Intenening Variables . The Experts Knowledge .. Semantically Rich Domains .. Production Systems . 'f:o�::;s;r���t/::o�.���� ... :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: SEMANTIC MEMORY ..
476 citations
TL;DR: The purposes of this paper are to cast k-D trees in a database framework, to collect the results on k-d trees that have appeared since the structure was introduced, and to show how the basic data structure can be modified to facilitate implementation in large (and very large) databases.
Abstract: The multidimensional binary search tree (abbreviated k-d tree) is a data structure for storing multikey records. This structure has been used to solve a number of "geometric" problems in statistics and data analysis. The purposes of this paper are to cast k-d trees in a database framework, to collect the results on k-d trees that have appeared since the structure was introduced, and to show how the basic data structure can be modified to facilitate implementation in large (and very large) databases.
463 citations
TL;DR: The following material is discussed in this article : Incidence coalgebras for PO sets, reduced Boolean coalgegebra, Dirichlet coalgebra, Eulerian coalgebra and Faa di Bruno Bialgebra.
Abstract: The following material is discussed in this paper: Incidence Coalgebras for PO sets; Reduced Boolean Coalgebras; Divided Powers Coalgebra; Dirichlet Coalgebra; Eulerian Coalgebra; Faa di Bruno Bialgebra; Incidence Coalgebras for Categories; The Umbral Calculus; Infinitesimal Coalgebras; Creation and Annihilation Operators; Point Lattice Coalgebras; Restricted Placements; Cleavages; and Hereditary Bialgebras.
436 citations
TL;DR: The resident-intruder situation appears to be a reliable, easy-to-use procedure detecting differential behavioral effects of psychomotor stimulants, such as d-amphetamine and cocaine, while avoiding the confounding influence of aversive stimulation, conditioning, and screening of suitable subjects typically associated with aggression tests in the laboratory.
Abstract: A procedure has been developed which reliably engenders agonistic behavior between alpha males of small colonies of laboratory rats and intruder rats. Drugs were administered either to the alpha resident male rat, who showed the pattern of attack and threat behavior, or to the intruder rat, who engaged in defensive, submissive, and flight reactions. The 5-min test also permitted assessment of drug effects on nonagonistic social and solitary behavior. Administration of d-amphetamine at a very low dose (0.063 mg/kg) to resident alpha rats increased the frequency of their attacks, sideways threats, and pursuits, while low doses of cocaine (0.5, 2.0 mg/kg) failed to alter any of these behaviors significantly. Attack and threat behavior was effectively decreased by 0.25–1.0 mg/kg d-amphetamine and by 8 and 32 mg/kg cocaine. The antiaggressive effects of amphetamine, but not cocaine, were accompanied by a marked increase in nonagonistic rearing and walking. Amphetamine administration to intruder rats produced an increase in nonagonistic locomotor activity and caused the intruders to be attacked more frequently, to escape more often, and to emit fewer ultrasonic vocalizations. Cocaine did not alter significantly the intruders' behavior. The resident-intruder situation appears to be a reliable, easy-to-use procedure detecting differential behavioral effects of psychomotor stimulants, such as d-amphetamine and cocaine, while avoiding the confounding influence of aversive stimulation, conditioning, and screening of suitable subjects typically associated with aggression tests in the laboratory.
TL;DR: Transforms for converting a static structure into a dynamic structure, for adding 'range variables' to queries, and for making preprocessing/query time tradeoffs are presented.
TL;DR: The Hidden Curriculum as discussed by the authors, a covert pattern of socialization which prepares students to function in the existing workplace and in other social/political spheres, has been largely ignored by social studies curriculum developers.
Abstract: This paper reviews recent studies on the relationship of classroom life to larger social/political institutions. It analyzes the phenomenon which Philip Jackson has identified as the “hidden curriculum”, that covert pattern of socialization which prepares students to function in the existing workplace and in other social/political spheres. The authors argue that this pattern has been largely ignored by social studies curriculum developers. By ignoring the values contained in the social processes of schooling, social studies developers failed to influence school programs in a fundamental way. To promote a more complete understanding of the dynamics of classroom life and its relationship to the larger society, the authors have identified social processes of school and classroom life which give specific meaning to the term hidden curriculum. They argue that a new set of processes will have to replace existing ones if the goals of social education are to be realized. In the latter part of the paper, ...
TL;DR: The median voter model has been a mainstay of empirical public finance for three decades and has been used to estimate demand functions for a wide variety of public goods and services as mentioned in this paper.
TL;DR: The fundamental result is that a K-dimensional Euclidean Voronoi diagram of N points can be constructed by transforming the points to K + I-space, which extends straightforwardly to higher dimensions.
TL;DR: In this paper, an interpretation of LP residual by considering the effect of the shape of glottal pulses, inaccurate estimation of formants and bandwidths, phase angles of formant at the instants of excitation, and zeros in the vocal tract system is presented.
Abstract: In voiced speech analysis epochal information is useful in accurate estimation of pitch periods and the frequency response of the vocal tract system. Ideally, linear prediction (LP) residual should give impulses at epochs. However, there are often ambiguities in the direct use of LP residual since samples of either polarity occur around epochs. Further, since the digital inverse filter does not compensate the phase response of the vocal tract system exactly, there is an uncertainty in the estimated epoch position. In this paper we present an interpretation of LP residual by considering the effect of the following factors: 1) the shape of glottal pulses, 2) inaccurate estimation of formants and bandwidths, 3) phase angles of formants at the instants of excitation, and 4) zeros in the vocal tract system. A method for the unambiguous identification of epochs from LP residual is then presented. The accuracy of the method is tested by comparing the results with the epochs obtained from the estimated glottal pulse shapes for several vowel segments. The method is used to identify the closed glottis interval for the estimation of the true frequency response of the vocal tract system.
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01 Dec 1979TL;DR: In this paper, a composite, two-dimensional, linear elastic wedge for singular stresses at its vertex is examined and a full range of wedge boundary and matching conditions is considered, using separation of variables on the Airy stress function.
Abstract: This paper examines the composite, two-dimensional, linear elastic wedge for singular stresses at its vertex. A full range of wedge boundary and matching conditions is considered. Using separation of variables on the Airy stress function, the usual determinant conditions for singularities of the formO(r
-λ) asr → 0 are established and further conditions are derived for singularities of the formO(r
-λ lnr) asr → 0. The order of the determinant involved in these conditions depends upon the number of materials comprising the wedge. Two systematic methods of expanding the determinant for theN-material wedge are presented.
TL;DR: In this paper, a method of life testing is proposed which combines both ordinary and accelerated life-testing procedures, where the amount of stress is fixed in advance and is the same for all items to be tested, however, the time x at which an item on lest is taken out of the standard environment and put under stress can be chosen by the experimenter subject to a given cost structure.
Abstract: A method of life testing is proposed which combines both ordinary and accelerated life-testing procedures. It is assumed that an item can be tested either in a standard environment or under stress. The amount of stress is fixed in advance and is the same for all items to be tested However, the time x at which an item on lest is taken out of the standard environment and put under stress can be chosen by the experimenter subject to a given cost structure. When an item is put under stress its lifetime is changed by the factor α. Let the random variable T denote the lifetime of an item in the standard environment, and let γ denote its lifetime under the partially accelerated test procedure just described. Then Y = T if T ≦ x, and Y = x + α (T > x) if T > x. It is assumed that T has an exponential distribution with parameter θ. The estimation of θ and α and the optimal design of a partially accelerated life test are studied in the framework of Bayesian decision theory.
TL;DR: Users may be able to compromise databases by asking a series of questions and then inferring new information from the answers, and the complexity of protecting a database against this technique is discussed here.
Abstract: Users may be able to compromise databases by asking a series of questions and then inferring new information from the answers. The complexity of protecting a database against this technique is discussed here.
TL;DR: The algorithm, which is named B*, finds a proof that an arc at the root of a search tree is better than any other by attempting to find both the best arc atThe root and the simplest proof, in best-first fashion.
TL;DR: The treatment of contextual effects in the social science literature has traditionally focused on statistical phenomena more than on social processes as mentioned in this paper, and the existence of contextual processes has been traditionally overlooked in the literature.
Abstract: Treatments of contextual effects in the social science literature have traditionally focused on statistical phenomena more than on social processes. Typically, the existence of contextual processes...
01 May 1979
TL;DR: Cellular logic computers have become a commercial product in biomedical image processing where they are used in clinical instruments whose purpose is to classify white blood cell images at rates of several thousand per hour.
Abstract: Cellular logic operations (CLO's) are performed digitally to transform an array of data P(I,J) into a new data array P'(I,J). The value of each element in the new array is determined by its value in the original array and the orginal values of its nearest neighbors. The neighborhood configuration (tessellation) is usually called the "cell"; whence the term "cellular logic." CLO's may be categorized acording to the tessellation in which they are embedded and according to the type or types of CLO sequences: sequences which are carried out in a single step; those which iterate the same CLO for many steps; those which repetitively alternate subsequences of CLO strings. The effect of the CLO sequence on the contents of the data array is frequently one of boundary modification. Depending on the CLO sequence(s) utilized, a boundary may be expanded to form the convex hull, or reduced so as to form the convex kernel, skeleton, or residue. As of 1977, cellular logic computers have become a commercial product in biomedical image processing where they are used in clinical instruments whose purpose is to classify white blood cell images at rates of several thousand per hour. Many other applications are foreseen and, as further examples, preliminary results in automatic X-ray image analysis and tissue image analysis are presented.
TL;DR: Issues and alternatives in geometric modelling are discussed and illustrated with comparisons of 11 existing modelling systems, in particular coherently-structured models of polyhedral solids where the faces may be either planar or curved.
Abstract: Computer programs are being developed to aid the design of physical systems ranging from individual mechanical parts to entire buildings or ships. These efforts highlight the importance of computer models of three dimensional objects. Issues and alternatives in geometric modelling are discussed and illustrated with comparisons of 11 existing modelling systems, in particular coherently-structured models of polyhedral solids where the faces may be either planar or curved. Four categories of representation are distinguished: data representations that store full, explicit shape information; definition languages with which the user can enter descriptions of shapes into the system, and which can constitute procedural representations; special subsets of the information produced by application programs; and conceptual models that define the logical structure of the data representation and/or definition language.
TL;DR: In this article, a primary feeder model using small area demand locations to represent nonuniform loads, and feeder segments having variable distribution costs and limited capacities is formulated, and the solution of problems having 1000 demand locations and 100 substations can be found in a fraction of a second by using a current fast upper bounded transshipment code.
Abstract: A primary feeder model using small area demand locations to represent nonuniform loads, and feeder segments having variable distribution costs and limited capacities is formulated The solution of problems having 1000 demand locations and 100 substations can be found in a fraction of a second by using a current fast upper bounded transshipment code The problem of restructuring the solution to satisfy other kinds of constraints is also discussed
TL;DR: In this article, the authors present a selective review of planar guided-wave acoustooptics, including some of the most recent results, focusing on those aspects which relate to wide-band multichannel optical communications and real-time signal processing.
Abstract: This paper presents a selective review of planar guided-wave acoustooptics, including some of the most recent results. The emphasis is on those aspects which relate to wide-band multichannel optical communications and real-time signal processing. First to be discussed are the analytical and numerical techniques required for the treatment of a Bragg modulator which uses a single aperture SAW transducer. The frequency responses generated for Y -cut LiNbO_3 waveguides using a digital computer serve as the basic data for the design of such a basic modulator. Next the key device parameters relevant to modulation and signal processing are discussed. The design parameters and procedures for wide-band Bragg modulators and deflectors are then established. Finally, some potential applications of such wide-band modulators and deflectors in optical communications and RF signal processing together with the best measured performance figures are described.
TL;DR: In this paper, the kinetics and extent of hydrogen-induced grain boundary cracking in iron-titanium alloys have been theoretically modelled and experimentally investigated, and a general set of criteria for the design of alloys resistant to hydrogen induced cracking was proposed.
TL;DR: In this paper, it was shown that if a Borel function f is such that T transforms a Sobolev space W1, p(Ω) (1 ⩽ p < ∞) into itself, then T is necessarily continuous.
TL;DR: In this article, the basic equations of the theory reduce to systems of ordinary differential equations, and they discuss certain qualitative aspects of these systems; in particular, they show that for many cases of interest periodic solutions are not possible.
Abstract: This paper presents two simple models for nonlinear age-dependent population dynamics. In these models the basic equations of the theory reduce to systems of ordinary differential equations. We discuss certain qualitative aspects of these systems; in particular, we show that for many cases of interest periodic solutions are not possible.
TL;DR: The results constitute a quantitative description of in vitro reassembly of IF from homogeneous cultures of nonkeratinizing cells and establish conditions for further studies on the regulation of IF assembly.
Abstract: Intermediate filaments (IF) from baby hamster kidney (BHK-21) cells can be disassembled at low ionic strength and reassembled upon addition of salt. Turbidimetric analyses show that reassembled IF exhibit the light scattering properties of long rods under physiological conditions (5 mM Na+/K+ phosphate, pH 7.2/170 mM NaCl at 21 degrees C). IF weight concentration, determined by centrifugation, is directly proportional to the optical density at 3000 nm. Thus, turbidity can be used as a quantitative assay for IF assembly. Turbidimetric and centrifugation analyses both indicate that IF assembly exhibits a critical protein concentration of 0.05-0.15 mg/ml. Above the critical concentration, IF weight concentration at steady-state is a linear function of the total protein concentration. Negative stain observations at early stages of the assembly process suggest lateral association of protofilaments to form short IF. This lateral association is accompanied by a rapid turbidity increase which is then followed by IF elongation and a slower turbidity increase to plateau. Further purification of IF by low/high-NaCl-induced cycles of disassembly/reassembly results in retention of 54- and 55-kilodalton (decamin) polypeptides. These results constitute a quantitative description of in vitro reassembly of IF from homogeneous cultures of nonkeratinizing cells and establish conditions for further studies on the regulation of IF assembly.