Showing papers by "Carnegie Mellon University published in 1978"
Book•
01 Jan 1978TL;DR: In this article, the authors present a coherent treatment of computational geometry in the plane, at the graduate textbook level, and point out the way to the solution of the more challenging problems in dimensions higher than two.
Abstract: From the reviews: "This book offers a coherent treatment, at the graduate textbook level, of the field that has come to be known in the last decade or so as computational geometry...The book is well organized and lucidly written; a timely contribution by two founders of the field. It clearly demonstrates that computational geometry in the plane is now a fairly well-understood branch of computer science and mathematics. It also points the way to the solution of the more challenging problems in dimensions higher than two."
3,419 citations
TL;DR: In this article, the effect of coherent forward scattering on neutrinos traveling through matter is taken into account when considering the oscillations of neutrino traveling through the matter, where the neutral current has an off-diagonal piece connecting different neutrini types.
Abstract: The effect of coherent forward scattering must be taken into account when considering the oscillations of neutrinos traveling through matter. In particular, for the case of massless neutrinos for which vacuum oscillations cannot occur, oscillations can occur in matter if the neutral current has an off-diagonal piece connecting different neutrino types. Applications discussed are solar neutrinos and a proposed experiment involving transmission of neutrinos through 1000 km of rock.
3,050 citations
TL;DR: In a recent paper as mentioned in this paper, a general theory of surface stress was presented and several simple solutions within this theory were discussed, e.g., a simple solution to the problem of surface compression.
1,321 citations
TL;DR: In this article, an approximate fourth-order expression for the electron correlation energy in the Moller-Plesset perturbation scheme is proposed, which takes into account all the contributions to the fourthorder energy neglecting only those of the triple-substituted determinants.
Abstract: An approximate fourth-order expression for the electron correlation energy in the Moller–Plesset perturbation scheme is proposed. It takes into account all the contributions to the fourthorder energy neglecting only those of the triple-substituted determinants. It is size consistent and correct to fourth order for an assembly of isolated two-electron systems. Illustrative calculations are reported for a series of small molecules.
1,188 citations
1,115 citations
TL;DR: In the case of a single good to be allocated politically, standard assumptions lead to'single-peakedness' of voter preferences over the set of alternatives as mentioned in this paper, which is not the case when the setter has monopoly power over the proposal placed before the electorate.
Abstract: Economic analysis requires modelling political as well as market resource allocation. Voting institutions, in particular two-candidate majority rule elections and voting on motions, have been a primary focus of recent analytical developments. In the case of a single good to be allocated politically, standard assumptions lead to 'single-peakedness' of voter preferences over the set of alternatives. When, in choosing between a pair of available alternatives, every voter votes for his preferred alternative, the allocative equilibrium is the 'Condorcet point' or political allocation most desired by the median voter (Bowen, 1943; Black, 1958; Riker and Ordeshook, 1973). This result concerning the dominance of the median voter's ideal allocation depends importantly on the nature of competition in the allocation process. In the context of the political allocation of economic goods, the 'median voter' outcome is typically justified on the basis of an underlying but usually unmodeled process of political competition between two candidates for elective office, wherein the dominant strategy for each candidate is to offer to provide the level of public spending that corresponds to the median voter's ideal expenditure. Such a view of equilibrium under majority rule (when equilibrium exists) may be very unrepresentative of political processes. Many such processes, particularly those related to collective expenditure determination, may be more appropriately characterized as ones in which some group has the power to make a proposal to the voters, and thereby set the agenda. This group, which we call the agenda setter, by having monopoly power over the proposal placed before the electorate, can confront the voters with a 'take it or leave it' choice. Because 'competitive' substitutes to the setter's proposal are not offered, the median voter cannot simply 'hold out' until the Condorcet point is proposed. When the setter has monopoly power, voters are forced to choose between
1,026 citations
TL;DR: In this article, an implementation of the coupled cluster theory with double substitutions (CCD) was described, and the authors applied this method and closely related fourth-order perturbation methods to some simple molecules and reaction potential surfaces.
Abstract: This paper serves two purposes. The first is to describe an implementation of the coupled cluster theory with double substitutions (CCD) previously developed by Cizek. The second is to apply this method and closely related fourth-order perturbation methods to some simple molecules and reaction potential surfaces. These studies show that CCD theory gives results close to those of a Moller-Plesset perturbation treatment to fourth order in the space of double and quadruple substitutions MP4(DQ). Addition of contributions from single substitutions at fourth order makes little change in predicted relative energies. Preliminary results on the potential surfaces for 1,2-hydrogen shifts in C2H2, HCN, CH2O, and N2H2 are discussed and compared with previous studies.
873 citations
TL;DR: In this article, the authors predict that subjects who chose the activities and time allotments would be more intrinsically motivated than subjects doing the same activity without choice, and find that subjects with additional self-determination would have more intrinsic motivation.
Abstract: Yoked pairs of subjects solved puzzles such that one member of each pair was given choice about what puzzles to work on and how much time to allot to each, while the yoked subject was assigned the same puzzles and time allotments as those chosen by the first subject. It was predicted and found that subjects who chose the activities and time allotments -in other words, who had additional self-determination--would be more intrinsically motivated than subjects doing the same activity without choice.
606 citations
TL;DR: In this paper, the maximum velocity principle was replaced by a stability criterion of the form υρ 2 = constant, where υ is the growth rate and ρ the tip radius of a dendrite.
603 citations
TL;DR: A general segmentation method which can be applied to many different types of scenes and the potential performance of other segmentation techniques on general scenes is discussed.
540 citations
TL;DR: A class of asynchronous iterative methods is presented for solving a system of equations corresponding to a parallel implementation on a multiprocessor system with no synchronization between cooperating processes to show clearly the advantage of purely asynchronous Iterative methods.
Abstract: : A class of asynchronous iterative methods is presented for solving a system of equations. Existing iterative methods are identified in terms of asynchronous iterations, and new schemes are introduced corresponding to a parallel implementation on a multiprocessor system with no synchronization between cooperating processes. A sufficient condition is given to guarantee the convergence of any asynchronous iterations, and results are extended to include iterative methods with memory. Asynchronous iterative methods are then evaluated from a computational point of view, and bounds are derived for the efficiency. The bounds are compared with actual measurements obtained by running various asynchronous iterations on a multiprocessor, and the experimental results show clearly the advantage of purely asynchronous iterative methods. (Author)
TL;DR: This article found that subjects who were also asked to explain the imaginary event were no different from subjects who only imagined, and several other attributional distortions are interpreted in terms of the availability heuristic.
01 Jan 1978
TL;DR: A recurrence relation is derived for computing the average number of maxunal vectors m a set of n vectors m d-space under the assumpUon that all (nl) a relative ordermgs are equally probable.
Abstract: A maximal vector of a set ~s one which is not less than any other vector m all components We derive a recurrence relation for computing the average number of maxunal vectors m a set of n vectors m d-space under the assumpUon that all (nl) a relative ordermgs are equally probable. Solving the recurrence shows that the average number of maxmaa is O((ln n) a-~) for fixed d We use this result to construct an algorithm for finding all the maxima that have expected running tmae hnear m n (for sets of vectors drawn under our assumptions) We then use the result to find an upper bound on the expected number of convex hull points m a random point set
TL;DR: In this paper, the complex hydrogen trapping characteristics of iron-titanium-carbon alloys, contain-ing both reversible and irreversible traps have been fully analyzed and the key to this quantitative analysis is a complete identification of the type and number of each operating trap.
Abstract: The complex hydrogen trapping characteristics of iron-titanium-carbon alloys, contain-ing both reversible and irreversible traps have been fully analyzed. The key to this quantitative analysis is a complete identification of the type and number of each operating trap. The trapping parameters were obtained from an analysis of the relevant hydrogen permeation transients. Titanium substitutional atoms have been shown to be reversible, low occupancy traps with an interaction energy with hydrogen,E (Ti-H), of 0.27 eV. Typi-cal rate constants for these alloys are; a hydrogen capture rate constant of approximately 10-24 cm3/atom .s a release rate constant of approximately 10-3 s-1 and a trapping rate of the order of 1015 atoms, H/cm3 .s. TiC particles are irreversible traps with a large oc-cupancy and an interaction energy, .E(TiC-H), of 0.98 eV. The irreversible trapping parameters are calculated from the first permeation transient, where mixed trapping oc-curs. The trapping kinetics are about an order of magnitude faster than when only rever-sible trapping exists. The role of trapping on the effective diffusivity of hydrogen is dis-cussed as is, briefly, its role in affecting hydrogen-induced damage. Finally, guidelines are given to permit the trapping behavior of more general alloys to be analyzed.
TL;DR: Using this improved method, ts and hr mutations in intact DNA have been rescued with restriction endonuclease fragments of DNA bearing the corresponding wild-type genetic markers and a number of mutations have been located unequivocally within the left quarter of the genome.
TL;DR: This paper shows that the composition and reversion problems are equivalent (up to constant factors), and gives algorithms which require only order (n log n) ~/2 operations in many cases of practical importance.
Abstract: The classical algorithms require order n ~ operations to compute the first n terms in the reversion of a power series or the composition of two series, and order nelog n operations if the fast Founer transform is used for power series multiplication In this paper we show that the composition and reversion problems are equivalent (up to constant factors), and we give algorithms which require only order (n log n) ~/2 operations In many cases of practical importance only order n log n operations are required, these include certain special functions of power series and power series solution of certain differential equations Applications to root-finding methods which use inverse mterpolauon and to queuemg theory are described, some results on multivariate power series are stated, and several open questions are mentioned
TL;DR: D-Amphetamine, methamphetamine, methylphenidate, cocaine, and l-dopa decreased attack and threat behavior by resident mice, the isolates requiring 2–4 times higher drug doses for the antiaggressive effects than the nonisolates.
Abstract: Adult male Swiss-Webster mice were housed either singly (isolated) or with a female (nonisolated). Aggressive behavior was evoked by introducing a group-housed male mouse (intruder) into the home cage of the isolated or nonisolated mouse (resident). d-Amphetamine, methamphetamine, methylphenidate, cocaine, and l-dopa decreased attack and threat behavior by resident mice, the isolates requiring 2–4 times higher drug doses for the antiaggressive effects than the nonisolates. d-Amphetamine, methamphetamine, and methylphenidate caused intruder mice to be more frequently attacked by their nontreated resident opponents, to escape more often, to assume the defensive upright posture less, and to move about more often. l-Dopa nonspecifically decreased all elements of agonistic and nonagonistic behavior, while the amphetamines and methylphenidate suppressed attacks, increased escapes, decreased upright postures, and increased nonagonistic locomotion. By contrast, cocaine's antiaggressive effects were remarkably specific, i.e., not accompanied by changes in other behavioral elements.
TL;DR: In this article, it is argued that data collection methods are needed that will yield data on predecisional behavior in order to identify what information a decision maker has and how it is being processed.
TL;DR: Juxtanuclear birefringent caps (FC) containing 10-nm filaments form during the early stages of baby hamster kidney (BHK-21) cell spreading and are isolated from spreading cells after replating by treatment with 0.6 M KCl and DNase I.
Abstract: Juxtanuclear birefringent caps (FC) containing 10-nm filaments form during the early stages of baby hamster kidney (BHK-21) cell spreading. FC are isolated from spreading cells after replating by treatment with 0.6 M KCl, 1% Triton X-100 (Rohm & Haas Co., Philadelphia, Pa.) and DNase I in phosphate-buffered saline. Purified FC are birefringent and retain the pattern of distribution of 10-nm filaments that is seen in situ. Up to 90% of the FC protein is resolved as two polypeptides of approximately 54,000 and 55,000 molecular weight on sodium dodecyl sulfate (SDS) polyacrylamide gels. The protein is immunologically and biochemically distinct from tubulin as determined by indirect immunofluorescence, double immunodiffusion, one-dimensional peptide mapping by limited proteolysis in SDS gels, and amino acid analysis. The BHK-21 FC amino acid composition, however, is very similar to that obtained for 10-nm filament protein derived from other sources including brain and smooth muscle. Partial disassembly of 10-nm filaments has been achieved by treatment of FC with 6 mM sodium-potassium phosphate buffer, pH 7.4. The solubilized components assemble into distinct 10-nm filaments upon the addition of 0.171 M sodium chloride.
TL;DR: In this article, the effect of self-consciousness on self-reported aggression was studied in research on aggression, and the correlation between self-report of aggressiveness and aggressive behavior was significantly higher for high-than for low-private selfconscious subjects.
TL;DR: In this article, a stochastic utility model was proposed and estimated by use of a sample of students admitted to Carnegie-Mellon Univer..., which was used to study the college choice behavior of graduate business school applicants.
Abstract: The college choice behavior of graduate business school applicants is studied. A stochastic utility model is proposed and estimated by use of a sample of students admitted to Carnegie-Mellon Univer...
TL;DR: In this paper, it is shown how to have vacuum neutrino oscillations in which on the average each of the three neutrinos types becomes an equal mixture of all three types.
Abstract: If ${\ensuremath{
u}}_{e}$ ${\ensuremath{
u}}_{\ensuremath{\mu}}$ and ${\ensuremath{
u}}_{\ensuremath{\tau}}$ are treated symmetrically in a $\mathrm{CP}$-invariant theory, it is impossible to have vacuum neutrino oscillations in which on the average each of the three neutrino types becomes an equal mixture of all three. It is shown how this becomes possible for a $\mathrm{CP}$-noninvariant theory.
TL;DR: Two arguments are presented, one thermodynamic and one microscopic, which suggest that the permeability of pure lipid vesicles and dispersions is proportional to the lateral compressibility, and two previously published theoretical models are calculated.
TL;DR: In this article, the authors investigated the extent to which discounts and premiums provided information about future expected rates of return on closed-end investment company shares and found that discounted fund shares, adjusted for risk, tended to outperform the market in the period 1940 to 1975.
TL;DR: In this article, a hybrid field effect liquid crystal light valve (LCLV) is proposed for real-time coherent optical data processing, where the input image is directed onto the photo-conductor to reduce the impedance of the photoconductor, thereby switching the ac voltage that is impressed across the electrodes onto the liquid crystal to activate the device.
Abstract: This paper reviews the hybrid field-effect liquid crystal light valve (LCLV) and its application to real-time coherent optical data processing. The light valve is basically a high resolution optical-to-optical image converter. The device embodies a CdS photoconductor, a CdTe light-absorbing layer, a dielectric mirror, and a biphenyl liquid crystal layer sandwiched between indium-tin-oxide transparent electrodes deposited on optical quality glass flats. The input image is directed onto the photo-conductor to reduce the impedance of the photoconductor, thereby switching the ac voltage that is impressed across the electrodes onto the liquid crystal to activate the device. The ac operation ensures long operating life for the device. The liquid crystal is operated in a hybrid field-effect mode. It utilizes the twisted nematic effect to create a dark off-state (voltage off the liquid crystal) and optical birefringence to create the bright on-state. The liquid crystal modulates the phase of the coherent readout light. By an additional analyzer an intensity modulation is created.
TL;DR: In this paper, the mixed finite element approximation of variational inequalities is studied, taking as model problems the so-called "obstacle problem" and "unilateral problem".
Abstract: We study the mixed finite element approximation of variational inequalities, taking as model problems the so called "obstacle problem" and "unilateral problem" Optimal error bounds are obtained in both cases
TL;DR: In this article, a multistage method of sophisticated voting is proposed, which is easy to apply and intuitively understandable, and it is shown that if a majority alternative exists, sophisticated voting leads to an outcome at least as good as and sometimes preferred to the outcome of sincere voting.
TL;DR: In this article, a model for the price of default-free discount bonds of all maturities is found using a Black-Scholes type of arbitrage model which is based on the assumption that a portfolio of three default free discount bonds can be managed to be a perfect substitute for any other defaultfree discount bond.