Showing papers by "University of Toronto published in 1972"
TL;DR: This paper reviewed the evidence for multistore theories of memory and pointed out some difficulties with the approach and proposed an alternative framework for human memory research in terms of depth or levels of processing.
8,195 citations
2,995 citations
TL;DR: In this article, the controllability of nonlinear systems described by the equation dx/dt - F(x,u) was discussed and it was shown that strong accessibility implies strong accessibility for a large class of manifolds including Euclidean spaces.
718 citations
TL;DR: The controllability properties of systems which are described by an evolution equation in a Lie group are studied in this paper, where revelant Lie algebras induced by a right invariant system are singled out, and the basic properties of attainable sets are derived.
610 citations
TL;DR: In this article, a model of role conflict coping behavior is presented based upon three levels in the role process: structural role redefining, personal role redefinition, changing one's expectations and perception of one's own behavior in a given position.
Abstract: A model of role conflict coping behavior is presented based upon three levels in the role process. Type I coping, structural role redefinition, involves altering external, structurally imposed expectations relative to a person's position. Type II coping is personal role redefinition, changing one's expectations and perception of one's own behavior in a given position. Type III coping, reactive role behavior, entails attempting to find ways to meet all role expectations, assuming that demands are unchangeable and must be met. Through a pilot sample and a subsequent survey of college educated women, sixteen specific behavioral strategies are identified and classified under these three general types. The relat onship between coping behavior and satisfaction is explored both in bivariate and moderator analyses. The results indicate that the simple act of coping (as opposed to noncoping) may be more strongly related to satisfaction in women than the particular type of coping strategy employed.'
453 citations
TL;DR: The literature on the tension-reducing effects of alcohol is reviewed in this paper, and the evidence is negative, equivocal and often contradictory, and much of the evidence on the effect of alcohol on tension reduction is negative.
Abstract: The literature on the tension-reducing effects of alcohol is reviewed. Much of the evidence is negative, equivocal and often contradictory.
421 citations
419 citations
TL;DR: A rumple graph model of computer systems is developed, and its deadlock propertms are investigated, which unifies a number of previous results, leads to efficient deadlock detection and prevenUon algorithms, and is useful for teaching purposes.
Abstract: Several examples of deadlock occurring in present day computer systems are given Next, there is a discussion of the strategms which can be ~sed to deal with the deadlock problem A theory of computer systems is developed so that the terms "process" and "deadlock" can be defined. "Reusable resources" are introduced to model objects that are shared among processes, and "consumable resources" are introduced to model signals or messages passed among processes. Then a rumple graph model of computer systems m developed, and its deadlock propertms are investigated This graph model unifies a number of previous results, leads to efficient deadlock detection and prevenUon algorithms, and ~s useful for teaching purposes.
383 citations
TL;DR: In this article, a general closed function for the tcp dependence of the transverse relaxation times of nuclei exchanging between two sites is described, and the frequency and temperature dependence of this function is examined.
375 citations
TL;DR: This chapter discusses on analyzing the kinds of constraints on learning that have appeared with increasing frequency in recent studies of animal learning by psychologists, and proposes many suggestions for future investigation of the constraints.
Abstract: Publisher Summary This chapter discusses on analyzing the kinds of constraints on learning that have appeared with increasing frequency in recent studies of animal learning by psychologists. The constraints of learning that are considered are: motivational or associative factors peculiar to certain stimuli, responses, or reinforcers or arising out of the relationship of any two, or even three of them. The main constraints on learning proposed in the chapter are: (1) The relative salience or effectiveness of external stimuli may vary with the animal's motivational state, (2) the effects of variations in parameters of reinforcement may depend on the reinforce and different reinforcers may act in different ways, (3) some responses may be performed as operants only if at the same time their own normal causal factors are present, (4) the ease with which a response can be brought under the control of reinforcement contingencies may depend on how tightly it is linked to its own normal causal factors and the relationship of these factors to the internal state necessary for the reinforcer to be effective, (5) some external stimuli may acquire control of certain responses especially readily, while they do not control other equally conditionable responses at all, (6) some external stimuli may be especially easily associated with certain unconditioned stimuli, while they are not associated with others at all, and (7) the ways in which learning occurs may reflect the causal relationships among environmental events in the natural situation where the learning occurs. The chapter concludes by sharing many suggestions for future investigation of the constraints on learning.
346 citations
TL;DR: In this paper, a model of the characteristic pattern of relaxation of a nonthermal rotational distribution of hydrogen halide, peaked initially at high rotational quantum number J, to a thermal distribution without generating a peak at intermediate J, is presented.
Abstract: A model is presented which describes the characteristic pattern of relaxation of a nonthermal rotational distribution of hydrogen halide, peaked initially at high rotational quantum number J, to a thermal distribution without generating a peak at intermediate J. A method for correcting infrared chemiluminiscence data for modest rotational relaxation is also suggested.
TL;DR: In this paper, the authors examined personal and organizational correlates of organizational identification in two types of organizations-the Roman Catholic Church and research and development laboratories' and compared with those obtained in the United States Forest Service (Hall, Schneider, and Nygren, 1970).
Abstract: This study examines personal and organizational correlates of organizational identification in two types of organization-the Roman Catholic Church and research and development laboratories' The results are compared with those obtained in the United States Forest Service (Hall, Schneider, and Nygren, 1970) Priests and foresters typically spend their entire careers in one organization (the single-organization career pattern), while research professionals are more mobile (the multiorganization career pattern) Because of differences in organizational socialization and mobility, tenure is a stronger correlate of organizational identification in the single-organization career The effects of tenure are independent of other correlates-job challenge, job involvement, self-image, need importance, and satisfaction Job challenge, through the intervening effects of job satisfaction, is a strong correlate of identification for both career types The researcher's self-image is more strongly tied to his work involvement and the forester's to his organizational involvement This is consistent with the differential mobility patterns Higher-order need satisfaction is correlated with high organizational involvement for both career patterns, although the importance of needs correlates differentially; for the single-organization career, organizational identification is related to security and affiliation, while identification is linked to low concern for self-fulfillment for the multiorganization career The single-organization career thus combines security and localism with growth and cosmopolitanism, whereas in the multiorganization career the professional must choose between these alternatives
TL;DR: Analysis of interactions between each of these cataleptogenic agents and naloxone, 1-DOPA and apomorphine strongly suggests that morphine influences striatal dopamine metabolism and produces catalepsy by a mechanism different from that of chlorpromazine.
TL;DR: In this article, a photographic spectra of the 9th magnitude BOIb star HDE 226868 was taken to look for velocity and spectrum variations that might be correlated with the X-ray fluctuations.
Abstract: THE ninth magnitude BOIb star HDE 226868 is closely coincident with the position of Cygnus X-1 and its associated variable radio source1. Dolan2 has pointed out that Cyg X-1 appears to be a two component X-ray source. One component has a synchrotron spectrum, and the other has a thermal (or bremsstrahlung) spectrum. The latter component varies on a time scale of days in a way that suggests it is being eclipsed. Therefore I decided to take photographic spectra of HDE 226868 to look for velocity and spectrum variations that might be correlated with the X-ray fluctuations. I find that the velocity of the star varies with a period consistent with that of the X-ray variation. It may not be possible, however, to interpret the X-ray variations in terms of simple eclipses.
TL;DR: In this article, necessary and sufficient conditions are derived for a minimal order linear time-invariant differential feedback control system to exist for a linear time invariant multivariable system with unmeasurable arbitrary disturbances of a given class occurring in it.
Abstract: Necessary and sufficient conditions are derived for a minimal order linear time-invariant differential feedback control system to exist for a linear time-invariant multivariable system with unmeasurable arbitrary disturbances of a given class occurring in it, such that the outputs of the system asymptotically become equal to preassigned functions of a given class of outputs, independent of the disturbances occurring in the system, and such that the closed-loop system is controllable. The feedback gains of the control system are obtained so that the dynamic behavior of the closed-loop system is specified by using either an integral quadratic optimal control approach or a pole assignment approach. The result may be interpreted as being a generalization of the single-input, single-output servomechanism problem to multivariable systems or as being a solution to the asymptotic decoupling problem.
01 May 1972
TL;DR: This paper introduces a formal model for random access computers and argues that the model is a good one to use in the theory of computational complexity and shows the existence of a time complexity hierarchy which is finer than any standard abstract computer model.
Abstract: In this paper we introduce a formal model for random access computers and argue that the model is a good one to use in the theory of computational complexity. Results are proved which compare run times for recognizing sets using this model (which has a fixed program) with a stored program model and with Turing machines. The main result, theorem 3, shows the existence of a time complexity hierarchy which is finer than that of any standard abstract computer model. An Algol-like programming language is introduced which facilitates proofs of the theorems.
TL;DR: The Walvis Ridge is the trail of a hot spot marking the relative motion of the African plate over the mantle since the opening of the South Atlantic, and the termination of the ridge at Tristan and Gough records the cessation of this relative motion.
Abstract: THE islands of St Helena, Tristan da Cunha and Gough lie respectively 500 km, 450 km and 450 km east of the crest of the Mid-Atlantic Ridge1 (Fig. 1). We believe that they overlie hot spots or convective plumes in the mantle and that the Walvis Ridge is the trail of a hot spot marking the relative motion of the African plate over the mantle since the opening of the South Atlantic2,3. We suggest that the termination of the ridge at Tristan and Gough records the cessation of this relative motion. That this occurred about 25 m.y. ago is indicated by a spreading rate of 1.7 cm/yr/side and because the two islands lie just east of magnetic anomaly six4. Spreading of the sea floor continued and has moved the crest west from the hot spots. The Discovery and Meteor seamount chains are concentric with the Walvis Ridge; they too terminate some distance east of the crest of the Mid-Atlantic Ridge and may also be hot spot trails terminating on the same isochron. The position of Bouvet Island is harder to interpret because of its location at the western end of the Atlantic-Indian Ridge.
TL;DR: In this paper, Curry et al. investigated the association between the spatial distribution of jobs and homes using a spatial regression operator which is interpreted as the impulse response function of a second order difference equation.
Abstract: Curry L. (1972) A spatial analysis of gravity flows, Reg. Studies 6, 131–147. Since Wilson gave theoretical substance to the gravity model, it is possible to treat it analytically. His derivation is discussed and calibration problems examined. In particular, the general constraints on the maximum entropy solution he obtains can be particularized. Here the association between the spatial distribution of jobs and homes is investigated using a spatial regression operator which is interpreted as the impulse response function of a second order difference equation. By using Z transforms, the regression and gravity operators are applied in paralle. Feedback from the resulting trip pattern allows the job-home relation to be changed sequentially. Measures of spatial entropy and joint information are introduced and related to travel entropy.
TL;DR: In this paper, a method of deriving the remanent coercivity spectrum from the isothermal remanence vs. applied field characteristic is described and applied to a series of Triassic sandstones and late Cretaceous-early Tertiary clays and limestones from France.
Abstract: Summary
A method of deriving the remanent coercivity spectrum from the isothermal remanence vs. applied field characteristic is described and applied to a series of Triassic sandstones and late Cretaceous–early Tertiary clays and limestones from France. Low- (0-1 kOe), intermediate- (1-3 kOe), and high- (3-18 kOe) coercivity remanence fractions are identified with magnetite, specularite, and haematite pigment respectively. In the limestones, specularite is the only important magnetic phase; the sandstones contain in addition considerable pigment; and the clays contain all three phases. The relative pigment content indicated magnetically agrees with the colour of each rock type. When the sandstones are heated in air, enough magnetite is produced below 675°C to account for 20-25 per cent of the saturation remanence. Secondary magnetite production may therefore be serious when red beds are thermally demagnetized, even though the heating is done in air. The source of this secondary magnetite seems to be a non-magnetic mineral, rather than haematite. Secondary haematite production is insignificant below 675°C, but the pigment coercivity spectrum becomes harder with annealing, as observed previously with synthetic fine-particle haematites. Either annealing-out of defect ferromagnetism or impurities entering the haematite lattice could explain the results. Either coercivity spectra or rotational hysteresis curves can be used to estimate pigment/specularite ratios in red beds and to monitor mineralogical changes resulting from heating, but the coercivity spectrum method is much simpler to use.
01 Feb 1972
TL;DR: Palmitoyl-CoA inhibition of acetylCoA carboxylase is reversible and competitive with citrate and, therefore, may play an important role in the regulation of fatty acid synthesis in vivo.
TL;DR: This chapter focuses on the first stage, the identification of those enzymes at which metabolic regulation is exerted, and the analysis of the properties of enzymes, which permits analysis of intact tissue preparations, and is potentially able to provide unequivocal identification of control sites.
Abstract: Publisher Summary A four-stage approach to the analysis of control mechanisms has been suggested: (1) the enzymes involved in metabolic regulation are identified; (2) their kinetic properties are investigated in detail; (3) the kinetic properties are used to postulate a hypothesis of metabolic control; and (4) the hypothesis is tested and is modified as necessary. This chapter focuses on the first stage, that is, the identification of those enzymes at which metabolic regulation is exerted. Three general methods of approaching this question have been suggested. The teleological approach depends on the belief that control should occur early in the pathway and shortly after branch points to avoid long stretches of uncontrolled metabolism. A second approach is based on the analysis of the properties of enzymes, on the premise that enzymes possessing such phenomena as changing maximal activities on dietary or hormonal manipulation, low maximal activities in comparison with other enzymes of the pathway, or activation or inhibition by other intermediates are likely control sites. In the third method, intact tissue preparations are subjected to various treatments to give different rates of flow through the metabolic pathway and the steady-state concentrations of intermediates measured and used to deduce sites of metabolic control. This approach permits analysis of intact tissue preparations, and is potentially able to provide unequivocal identification of control sites.
TL;DR: I-Acyl lysophosphatidylcholine, labelled with [3H]stearate and [14C]glycerol, injected intracerebrally, was incorporated intact into diacyl phosphatidylethanolamine, confirming that direct acylation of lysointermediates could occur in brain.
TL;DR: It is shown that any nonlinear functional of the Poisson process with finite variance can be developed in terms of these orthogonal functionals, corresponding to the Cameron-Martin theorem in the case of the Brownian-motion process.
Abstract: In analogy to the orthogonal functionals of the Brownian-motion process developed by Wiener, lto, and others, a theory of the orthogonal functionals of the Poisson process is presented making use of the concept of multivariate orthogonal polynomials. Following a brief discussion of Charlier polynomials of a single variable, multivariate Charlier polynomials are introduced. An explicit representation as well as an orthogonality property are given. A multiple stochastic integral of a multivariate function with respect to the Poisson process, called the multiple Poisson-Wiener integral, is defined using the multivariate Charlier polynomials. A multiple Poisson-Wiener integral, which gives a polynomial functional of the Poisson process, is orthogonal to any other of different degree. Several explicit forms are given for the sake of application. It is shown that any nonlinear functional of the Poisson process with finite variance can be developed in terms of these orthogonal functionals, corresponding to the Cameron-Martin theorem in the case of the Brownian-motion process. Finally, some possible applications to nonlinear problems associated with the Poisson process are briefly discussed.
TL;DR: In this paper, the authors used the "arrested relaxation" variant of the infrared chemiluminescence method to obtain the initial vibrational, rotational and translational energy distributions in the products of exothermic reactions.
Abstract: Study of the F + H2 reaction, which is of special theoretical interest since it is one of the simplest examples of an exothermic chemical reaction. The FH2 system involves only 11 electrons, and the computation of a potential-energy hypersurface to chemical accuracy may now be within the reach of ab initio calculations. The 'arrested relaxation' variant of the infrared chemiluminescence method is used to obtain the initial vibrational, rotational and translational energy distributions in the products of exothermic reactions.
TL;DR: The role of context in recognition memory was examined in seven experiments and recognition was impaired both when the context word added or deleted was associatively related and when it was Associatively unrelated.