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Showing papers by "RAND Corporation published in 1980"


Journal ArticleDOI
TL;DR: The characteristics of the speech problem in particular, the special kinds of problem-solving uncertainty in that domain, the structure of the Hearsay-II system developed to cope with that uncertainty, and the relationship between Hearsey-II's structure and those of other speech-understanding systems are discussed.
Abstract: The Hearsay-II system, developed during the DARPA-sponsored five-year speech-understanding research program, represents both a specific solution to the speech-understanding problem and a general framework for coordinating independent processes to achieve cooperative problem-solving behavior. As a computational problem, speech understanding reflects a large number of intrinsically interesting issues. Spoken sounds are achieved by a long chain of successive transformations, from intentions, through semantic and syntactic structuring, to the eventually resulting audible acoustic waves. As a consequence, interpreting speech means effectively inverting these transformations to recover the speaker's intention from the sound. At each step in the interpretive process, ambiguity and uncertainty arise. The Hearsay-II problem-solving framework reconstructs an intention from hypothetical interpretations formulated at various levels of abstraction. In addition, it allocates limited processing resources first to the most promising incremental actions. The final configuration of the Hearsay-II system comprises problem-solving components to generate and evaluate speech hypotheses, and a focus-of-control mechanism to identify potential actions of greatest value. Many of these specific procedures reveal novel approaches to speech problems. Most important, the system successfully integrates and coordinates all of these independent activities to resolve uncertainty and control combinatorics. Several adaptations of the Hearsay-II framework have already been undertaken in other problem domains, and it is anticipated that this trend will continue; many future systems necessarily will integrate diverse sources of knowledge to solve complex problems cooperatively. Discussed in this paper are the characteristics of the speech problem in particular, the special kinds of problem-solving uncertainty in that domain, the structure of the Hearsay-II system developed to cope with that uncertainty, and the relationship between Hearsay-II's structure and those of other speech-understanding systems. The paper is intended for the general computer science audience and presupposes no speech or artificial intelligence background.

1,422 citations


Journal ArticleDOI
TL;DR: The IAU/IAG Working Group on cartographic coordinates and rotational elements of the planets and satellites revises tables giving the directions of the north poles of rotation and the prime meridians of the asteroids as discussed by the authors.
Abstract: Every three years the IAU/IAG Working Group on cartographic coordinates and rotational elements of the planets and satellites revises tables giving the directions of the north poles of rotation and the prime meridians of the planets, satellites, and asteroids. Also presented are revised tables giving their sizes and shapes. Changes since the previous report are summarized in the Appendix.

526 citations


Journal ArticleDOI
TL;DR: An analysis of the performance of experienced map users suggested that learning depended on particular procedures and not on familiarity with the task, and subjects' visual memory ability predicted the magnitude of theperformance differential.

308 citations


Journal ArticleDOI
TL;DR: In this paper, a Monte Carlo study of the small sample properties of various estimators of the linear regression model with first-order autocorrelated errors is presented. But none of the feasible estimators performs well in hypothesis testing; all seriously underestimate standard errors, making estimated coefficients appear to be much more significant than they actually are.

176 citations


Journal ArticleDOI
TL;DR: In this paper, the authors examined the methodological problems in the economics literature related to the demand for medical care and showed that in both cases estimates contained in the literature are inconsistent, and the direction of the inconsistency is obtained a priori.

109 citations


Journal ArticleDOI
TL;DR: In this article, a cutting plane algorithm is developed for reverse convex programs with disconnected feasible regions and basic solutions are defined and properties of the latter and of the convex hull of the feasible region are derived.
Abstract: Reverse convex programs generally have disconnected feasible regions. Basic solutions are defined and properties of the latter and of the convex hull of the feasible region are derived. Solution procedures are discussed and a cutting plane algorithm is developed.

99 citations


Proceedings Article
18 Aug 1980
TL;DR: ROSS, a Rule-Oriented Simulation System, that simulates military air battles and contains alternative decision-making behaviors extracted from experts and encoded as object-oriented rules.
Abstract: Knowledge engineering has been successfully applied in many domains to create knowledge-based "expert" systems. We have applied this technology to the area of large-scale simulation and have implemented ROSS, a Rule-Oriented Simulation System, that simulates military air battles. Alternative decision-making behaviors have been extracted from experts and encoded as object-oriented rules. Browsing of the knowledge and explanation of events occur at various levels of abstraction.

69 citations


Journal ArticleDOI
TL;DR: In this paper, it was shown that the convex hull of the feasible region is a convex polytope and, as a result, there is an optimal solution on an edge of the polytoope defined by only the linear constraints.
Abstract: A constraintg(x)⩾0 is said to be a reverse convex constraint if the functiong is continuous and strictly quasi-convex. The feasible regions for linear programs with an additional reverse convex constraint are generally non-convex and disconnected. It is shown that the convex hull of the feasible region is a convex polytope and, as a result, there is an optimal solution on an edge of the polytope defined by only the linear constraints. The only possible edges which can contain such an optimal solution are characterized in relation to the best feasible vertex of the polytope defined by only the linear constraints. This characterization then provides a finite algorithm for finding a globally optimal solution.

62 citations



Book ChapterDOI
David J. Armor1
01 Jan 1980
TL;DR: Among the many debates that have raged over school busing, few have engaged social scientists with more intensity than the “White flight” debate as mentioned in this paper, which became a controversial issue in sociology until Coleman, Kelly, and Moore's (1975) well-publicized work on the subject, which concluded that school desegregation was a significant cause of declining White enrollments in public schools.
Abstract: Among the many debates that have raged over school busing, few have engaged social scientists with more intensity than the “White flight” debate. Although the White flight phenomenon has a long history in both public and social science discussions, it did not become a truly controversial issue in sociology until Coleman, Kelly, and Moore’s (1975) well-publicized work on the subject, which concluded that school desegregation was a significant cause of declining White enrollments in public schools.

55 citations


Journal ArticleDOI
Richard R. Lau1, Robert L. Kane, Sandra Berry1, John E. Ware1, Douglas Roy1 
TL;DR: This article reviews efforts to assess the effectiveness of television programs on changing health behaviors and discusses the several methodologic problems and some potential means of surmounting them.
Abstract: This article reviews efforts to assess the effectiveness of television programs on changing health behaviors. The relatively limited literature to date has featured primarily correlational studies which permit ted no causal conclusions. The few experimental studies available present a mixed picture. Numerous methodologic problems beset any effort at assess ment of effectiveness. Perhaps the greatest difficulty is operationalizing a design that permits true experimental manipulation on a relevant sample without contamination. The several methodologic problems and some potential means of surmounting them are discussed.

Proceedings Article
18 Aug 1980
TL;DR: A rule-based legal decisonmaking system (LDS) that embodies the skills and knowledge of an expert in product liability law that is being used to study the effect of changes in legal doctrine on settlement strategies and practices.
Abstract: This paper describes a rule-based legal decisonmaking system (LDS) that embodies the skills and knowledge of an expert in product liability law. The system is being used to study the effect of changes in legal doctrine on settlement strategies and practices. LDS is implemented in ROSIE, a rule-oriented language designed to facilitate the development of large expert systems. The ROSIE language is briefly described and our approach to modeling legal expertise using a prototype version of LDS is presented.

Journal ArticleDOI
D. Deirmendjian1
TL;DR: In this paper, a critical survey of the literature on the use of light-scattering mechanisms in the remote monitoring of atmospheric aerosols, their geographical and spatial distribution, and temporal variations was undertaken to aid in the choice of future operational systems, both ground based and air or space borne.
Abstract: A critical survey of the literature on the use of light-scattering mechanisms in the remote monitoring of atmospheric aerosols, their geographical and spatial distribution, and temporal variations was undertaken to aid in the choice of future operational systems, both ground based and air or space borne. An evaluation, mainly qualitative and subjective, of various techniques and systems is carried out. No single system is found to be adequate for operational purposes. A combination of earth surface and space-borne systems based mainly on passive techniques involving solar radiation with active (lidar) systems to provide auxiliary or backup information is tentatively recommended.

Journal ArticleDOI
TL;DR: In this paper, the effects of children on asset accumulation, asset composition, consumption, and family income were investigated using panel data on families, and it was found that young children are found to depress savings for young families but to increase savings for marriages of duration greater than five years.
Abstract: Utilizing panel data on families, estimates are made of the effects of children on asset accumulation, asset composition, consumption, and family income. Young children are found to depress savings for young families but to increase savings for marriages of duration greater than five years. The principal channel through which children act to reduce savings is the decline in female earnings associated with the child-induced withdrawal of wives from the labor force. Family consumption actually decreases with the birth of a child, but this reduction is insufficient, for young families, to offset the fall in income. For families in which the wife does not work the estimates suggest that savings may actually increase with children.

Journal ArticleDOI
TL;DR: Much research is needed to provide the basis for examining the variety of proposed alternatives to nursing homes to allow us to compare costs and benefits in some reasonable fashion.
Abstract: cost implications have spurred strong interest in seeking alternatives to nursing homes. The rationale for such alternatives is a mixture of prevention, displacement, and deinstitutionalization; none may result. The alternative services may prove to be additive rather than substitutive. Much research is needed to provide the basis for examining the variety of proposed alternatives to allow us to compare costs and benefits in some reasonable fashion.

Journal ArticleDOI
TL;DR: In this paper, a disaggregated economic study of 3825 geographic areas of Los Angeles County was used to estimate electricity demand under declining-block rates, and the results were given in terms of short and long-run changes and income elasticities.
Abstract: A disaggregated economic study of 3825 geographic areas of Los Angeles County was used to estimate electricity demand under declining-block rates. Micro-level data were collected on the marginal price of households, the control of eight major appliances, and weather variables. Several biases are noted, but demand theory under declining-block rates is confirmed. The results are given in terms of short- and long-run changes and income elasticities. 15 references, 5 figures, 3 tables. (DCK)

Julie DaVanzo1
01 Jan 1980
TL;DR: In this paper, the authors investigated reasons for repeat and return migration in the United States according to number recency and outcome of previous moves, and proposed an extended human capital model of migration in which the concepts of location-specific capital and information costs are considered.
Abstract: The author investigates reasons for repeat and return migration in the United States according to number recency and outcome of previous moves. An extended human capital model of migration is discussed in which the concepts of location-specific capital and information costs are considered. Six hypotheses are then formulated and tested in an attempt to discover a systematic pattern of multiple movement propensities (ANNOTATION)

Journal ArticleDOI
TL;DR: In this article, the authors studied the optimal number and size of committees for a given number of majority members in the full house and the assumption that the majority party seeks to maximize the proportion of its favored bills which are reviewed and passed in voting trials.
Abstract: In this paper we seek to explain why legislative committees exist and what is the optimal number and size of committees in a legislature. Our theory is based on the idea that committees are a "sample" taken from the full house and on the assumption that the majority party seeks to maximize the proportion of its favored bills which are reviewed and passed in voting trials. We show that for a given size of majority fewer and larger committees lead to larger passage rates, if majority members do not always vote the party-line.

Patent
16 Jan 1980
TL;DR: In this paper, a crop roll forming machine with a reversibly rotatable bale forming means and a drive means is considered, where a control means is affixed to the frame movable between at least a first position and a second position.
Abstract: In a crop roll forming machine having a reversibly rotatable bale forming means and a drive means there is provided a control means affixed to the frame movable between at least a first position and a second position for cooperative interaction with the drive means and the bale forming means to selectively cause the bale forming means to cease being driven in a first direction and cause it to be driven in an opposing second direction when the control means is moved from the first position to the second position so that a completed crop roll is ejected rearwardly from the machine onto the ground.

Patent
05 Sep 1980
TL;DR: A multi-row crop header for a harvesting machine has a plurality of fore-and-aft extending row crop units, each having an elongated passageway with a front inlet opening and a rear discharge opening as mentioned in this paper.
Abstract: A multi-row crop header for a harvesting machine has a plurality of fore-and-aft extending row crop units, each having an elongated passageway with a front inlet opening and a rear discharge opening. The row crop units are pivotally mounted such that they can be swung toward and away from one another so as to vary the lateral distance between the inlet openings of adjacent units to thereby accommodate crops planted in various width row spacings.

Patent
25 Aug 1980
TL;DR: In this paper, an accurate radio frequency ranging system is provided for measuring the time of transmission of a signal from a first station to a second station and back to the first station without coherent turn-around of the signal.
Abstract: An accurate radio frequency ranging system is provided for measuring the time of transmission of a signal from a first station to a second station and back to the first station without coherent turn-around of the signal. Each of the two stations is provided with its own range measuring means and its own reference clock. The first station range measuring device is started by the first station reference marker and is stopped by the second station reference marker start signal transmitted from the second station to provide a first range measurement. The second station range measuring device is started by the second station reference marker and is stopped by the reference marker start signal transmitted from the first station to provide a second range measurement. The sum of the two range measurements contains the data necessary to calculate the true range between stations and the difference between the two range measurements contains the data necessary to calculate the offset between the two reference clocks without the two reference clocks being synchronized or locked to each other.

Journal ArticleDOI
TL;DR: A model of behavior and a statistical technique for estimating it for individuals who make sequential decisions under uncertainty are developed that differences among individuals are reflected in their behavior rather than being swept into the error term.

Journal ArticleDOI
TL;DR: Methods for estimating the crime commission rates of criminal offenders are discussed in the context of a potential selective incapacitation strategy that would assign different sentence lengths according to whether the estimated crime rate is above or below a specified threshold.
Abstract: Methods for estimating the crime commission rates of criminal offenders are discussed in the context of a potential selective incapacitation strategy that would assign different sentence lengths according to whether the estimated crime rate is above or below a specified threshold. Any such strategy is subject to error because the true crime rate of an offender may differ from his estimated crime rate. For two strategies having the same cost, one of them is favored over the other if it has a higher expected number of crimes averted or if it has a lower probability of assigning long sentences to offenders with low crime rates. Both of these criteria are met by using a Bayes estimate of the crime rate rather than a maximum likelihood estimate. This is demonstrated by calculating the distribution of true crime rates for offenders whose estimates are above a threshold.

Journal ArticleDOI
TL;DR: Demand is quite sensitive to variation in a deductible in the region of $50 and becomes steadily less sensitive as the deductible rises above $75, which is consistent with a theoretical model of demand for medical care.
Abstract: Using data on insurance premiums for policies with varying deductibles, together with a distribution of medical expense at a fixed ($50) deductible, we estimate the relationship between deductibles and the demand for medical care. We assume that as the deductible changes, the distribution shrinks toward zero in a multiplicative fashion. The results indicate that demand is quite sensitive to variation in a deductible in the region of $50 and becomes steadily less sensitive as the deductible rises above $75, which is consistent with a theoretical model of demand for medical care. The size of the deductible will importantly affect the costs of a national health insurance program.

Patent
27 May 1980
TL;DR: In this paper, a beam feedback synchronization system for optical sweeping apparatuses is described, which includes a multi-faceted rotating reflection mirror which acts on a collimated light beam such as a laser beam to cause it to sweep periodically in parallel straight lines across a rotating photoconducting drum.
Abstract: A beam feedback synchronization system for optical sweeping apparatuses is disclosed. The system includes a multi-faceted rotating reflection mirror which acts on a collimated light beam such as a laser beam to cause it to sweep periodically in parallel straight lines across a rotating photoconducting drum. A portion of the light beam is split off and caused to sweep across an equispaced linear array of fiber optic apertures held in place by a fiber optic assembly. The light entering the fiber optic apertures is carried along fiber optic elements to one or more photodetectors which generate periodic electrical signals in response thereto. The frequency of occurrence of the electrical signals from the photodetector is a measure of the velocity of the sweeping light beam across the fiber optic array. A phase locked loop circuit connected to the photodetector(s) provides a character clock signal which is synchronized to the electrical signals received from the photodetector and compensates for variations in the speed of the light beam across the fiber optic array. The phase locked loop further comprises a fast synchronization circuit which provides immediate synchronization between the character clock signal and the first electrical signal occurring at the beginning of a new light beam sweep. In addition, hold circuitry is provided which holds the frequency of the character clock signal coming from the phase locked loop constant during the dead time occurring between laser light beam sweeps.

Book ChapterDOI
01 Jan 1980
TL;DR: This paper presents a methodology for the systematic construction of fault trees based on decision tables and the construction of a fault tree from the decision tables is shown in a step by step fashion.
Abstract: This paper presents a methodology for the systematic construction of fault trees based on decision tables. The presentation is made through an example. The modeling capability of decision tables is demonstrated and the construction of a fault tree from the decision tables is shown in a step by step fashion.

Patent
Martin J. Casey1
25 Jul 1980
TL;DR: An x-ray mask is made by forming a thin polyimide membrane on a silicon wafer substrate which is then back-etched to form a mask supporting ring of the substrate as mentioned in this paper.
Abstract: An x-ray mask is made by forming a thin polyimide membrane on a silicon wafer substrate which is then back-etched to form a mask supporting ring of the substrate.

Journal ArticleDOI
Jane Sachar1
TL;DR: The partial correlation coefficient is derived analytically under exemplary factor patterns as discussed by the authors, where variables are described as an additive composition of a set of orthogonal factors, including general, common, and specific factors.
Abstract: The partial correlation coefficient is derived analytically under exemplary factor patterns. In these patterns, variables are described as an additive composition of a set of orthogonal factors, including general, common, and specific factors. Viewed in this framework, it is evident that the partial correlation may yield spurious results. Partialling out an infallible variable or a variable with no unique component does not necessarily yield an interpretable coefficient. Examples from the literature are given where an understanding of the underlying factor pattern facilitates interpretation of the computed partial correlation coefficient.

Journal ArticleDOI
TL;DR: In this paper, the shrinkage estimators proposed are based on estimating the parameter measure of a prior Dirichlet process in a nonparametric Bayesian survival curve estimator which is the posterior mean of this process.
Abstract: This paper discusses shrinkage estimation in nonparametric Bayesian survival analysis using censored data. The shrinkage estimators proposed are based on estimating the parameter measure of a prior Dirichlet process in a nonparametric Bayesian survival curve estimator which is the posterior mean of this process. The shrinkage is toward a prior family of exponential survival curves. The estimators are then compared by simulation with the wholly nonparametric estimator of Kaplan-Meier and the maximum likelihood estimator for the exponential family. These comparisons are done in cases where the exponential assumption is both

Journal ArticleDOI
01 Jan 1980
TL;DR: In this paper, the authors identify two areas of ignorance in the current study of terrorism: how terrorists think (is there such a thing as a terrorist mind?) and how terrorists groups make their decisions.
Abstract: : The following paper identifies two areas of ignorance in the current study of the phenomenon of terrorism: how terrorists think (is there such a thing as a terrorist mind?) and how terrorists groups make their decisions. The organization, financing weaponry, and tactics of terrorist groups have been studied. We have acquired a great deal of what might be called 'order of battle' information about terrorist groups. In some cases, a sizable portion of their membership has been identified; we know their names. Articles, or in some cases, books have been written about a few of the more notable leaders of terrorists groups: Ulrike Meinhof, Ilich Ramirez Sanchez, Leila Khaled, Yasir Arafat. A few have written about their own experiences in terrorist groups; Sean MacStiofain about his Irish Republican Army career and Susan Stern about her experiences in the Weather Underground. Some terrorists in prison have agreed to interviews. Some terrorists still at large have even been interviewed by journalists. It has been reported that the West German Bundeskriminalamt maintains a vast file that includes information on the reading habits, dental records, and musical preferences of known terrorists.