Showing papers by "Carleton University published in 1972"
TL;DR: A modulation system is proposed that continuously adjusts its data rate in response to signal strength variations in a fading channel, revealing a reduction on the order of 14 dB in transmitter power for a typical duplex link.
Abstract: A modulation system is proposed that continuously adjusts its data rate in response to signal strength variations in a fading channel. The optimum variation of data rate with channel conditions is determined, and includes the effects of feedback channel time delay, the interval between rate changes, and restriction of the number of allowable rates. Application of these results to a full duplex situation allows determination of the optimum fraction of the data stream to be devoted to service information. Comparison of this scheme with diversity transmission on the basis of error probability and bandwidth utilization reveals a reduction on the order of 14 dB in transmitter power for a typical duplex link.
282 citations
207 citations
TL;DR: In this article, the authors argue that the concept of ideology does not provide criteria for distinguishing ideological thought from non-ideological thought, and thus it fails to achieve empirical relevance.
Abstract: Although the term “ideology” is ubiquitous in modern political discourse, it is used in diverse and usually ambiguous ways which limit its value as an analytical concept. The main ambiguity arises from the fact that, as most writers use it, the concept of ideology does not provide criteria for distinguishing ideological thought from nonideological thought. Lacking this power to make concrete discriminations, the concept fails to achieve empirical relevance. This paper attempts to remedy that deficiency and save the concept of ideology for the explanation of politics. The problem of conceptualization is approached by viewing ideology primarily as a cultural phenomenon. As such, it is argued, ideology has characteristics that distinguish it from other symbol systems. Of special importance in this regard is the identification of basic differentia between ideology on the one hand, and myth and Utopia (with which ideology is often confused) on the other. The features of ideology identified in this comparative analysis are then discussed in fuller detail with a view to understanding (1) the significance of ideology in politics, and (2) the way in which the concept of ideology can help us to understand politics, insofar as politics involves ideology.
164 citations
164 citations
TL;DR: A heuristically optimal saturating nonlinearity is introduced and analyzed and two methods of compensating an arbitrary saturating device to obtain this optimal characteristic are presented.
Abstract: There are many instances in communication systems where bandpass signals are passed through nonlinear devices, such as traveling wave tubes, which exhibit both amplitude and phase nonlinearities. When the input signal is narrow band, the device may be characterized by measurements of its single-carrier amplitude and phase transfer functions. A sufficient model for such a device is a quadrature structure that includes two nonlinearities each of which, acting on its own, would exhibit only amplitude distortion. The outputs of the two halves of this model are linearly independent for arbitrary narrow-band input signals so that their power spectra add. Consequently, almost all previously published results for amplitude nonlinearities can be readily applied to the analysis of the general device. Emphasis is laid on practical procedures for analysis based directly on measured device characteristics rather than analytic approximations and accuracy is checked by comparison of certain intermodulation results with previous results and with measurements. A new result is the performance of an Intelsat IV tube for a large number of independent equal-power-density signals. A heuristically optimal saturating nonlinearity is introduced and analyzed and two methods of compensating an arbitrary saturating device to obtain this optimal characteristic are presented. Two methods of inverting the Chebyshev transform are used in this paper and the choice of basis functions for obtaining series representations of the measured device characteristics is discussed.
158 citations
TL;DR: Amorphous tricalcium phosphate (ACP) is the in vitro and in vivo precursor of hydroxyapatite (HA) and bone apatite, respectively.
128 citations
TL;DR: In this article, a class of space-time stochastic processes that arise as solutions of the Ito Stochastic Evolution Equation (SDE) is discussed. And an equation for the covariance function of the solution is obtained.
Abstract: A class of space-time stochastic processes that arise as solutions of stochastic evolution equations is discussed. By analogy with Ito stochastic differential equations, a stochastic evolution equation is given by the formal equation ∂X ∂t = AX + f(X)W where A is a positive self-adjoint operator and W is a space-time white noise. Existence and continuity results are obtained for equations of the foregoing type when f is a Lipschitz mapping. In addition, an equation is obtained for the covariance function of the solution.
115 citations
TL;DR: Phage IKe is sex-factor specific and was isolated using as host a strain of Salmonella typhimurium bearing a transmissible drug-resistance factor (R factor) of the type that does not inhibit F-promoted fertility (fi − ).
99 citations
TL;DR: A durable, inexpensive micro-miniature headplug which has been used successfully for centrally stimulating and recording from rats performing vigorous movements is described.
91 citations
80 citations
TL;DR: Animals with unilateral lesions and without a contralaterally kindled focus acquired the CER at a similar rate to normal animals, but when required to learn a conditioned emotional response following the rest period these animals were greatly impaired.
TL;DR: Alternating temperatures resulted in higher values of the innate capacity for increase of Drosophila melanogaster Meigen than mean constant temperatures within the range of temperature favorable for growth and reproduction.
Abstract: Alternating temperatures resulted in higher values of the innate capacity for increase (rm) of Drosophila melanogaster Meigen than mean constant temperatures within the range of temperature favorable for growth and reproduction. This difference resulted from slightly faster development and earlier attainment of maximum fecundity at alternating temperatures.
Preliminary mathematical models relating rm to constant and alternating temperatures are derived. These models are:
rm = 0.587-0.0228(7.80e0.00012(30.3-t°C)2) for constant temperatures, and
rm = 0.587-0.0228(9.96e0.0137(25.3-t°C)2) for alternating temperatures. Average deviation between empirical and computed values is 2.3%. The efficacy of these models is restricted to temperatures favorable for reproduction.
TL;DR: In this paper, a negative correlation between nucleolar synthetic activity and vacuole formation is seen when, after the water treatment, tissue is stimulated to growth through treatment with hormones.
TL;DR: This exploratory study reports a first attempt to measure general family status in an urban setting in an experimental way using the vignette, a plain-language description of a family containing a measured amount of information.
TL;DR: In this paper, a direct linear relationship was obtained between food consumption and larval growth on tomato and potato, and it was shown that potato was more efficient in terms of food conversion to body matter.
Abstract: Larvae of Leptinotarsa decemlineata (Say) reared on tomato fed longer, consumed more foliage, and had a lower survival rate than when reared on potato, its principal host. On both plants, a direct linear relationship was obtained between food consumption and larval growth. Potato was the more efficient of the two plants in terms of food conversion to body matter. This was reflected by increased weight gain of the larvae and greater pupal size.Adults from larvae reared on tomato were smaller and less fecund than those from larvae reared on potato. Half of them rejected tomato as food. However, egg-laying increased when they were transferred to potato after 50 days. The present investigation indicates that L. decemlineata can survive and attain maturity on tomato in the absence of its principal host plant. However, when potato is once again available, it is able to increase growth, accelerate development, and achieve a greater reproductive potential.
TL;DR: In this article, the authors propose a model that accommodates both this sequence of events and the emplacement of three major contemporaneous suites of basic igneous rocks, which they suggest were emplaced during successive tensional phases related to the waning stages of motion along a strike-slip plate juncture.
Abstract: RADIOMETRIC1, seismic2 and palaeomagnetic3,4 data suggest that the Grenville Structural Province was once displaced with respect to the rest of the Canadian Shield. The latter, referred to here as the Pre-Grenvillian Plate (Fig. 1), became stabilized about 1,800 m.y. BP during the Hudsonian orogeny and has not been subject to large-scale internal movements since then5. The palaeomagnetic evidence indicates, first, that a substantial part of the Province (the Grenville Plate) was once several thousand kilometres east-south-east of the Pre-Grenville Plate; second, that the Grenville Plate was brought into its present position with respect to the Pre-Grenville Plate as a result of motions that were predominantly dextral strike-slip and third, that these movements began about 1,300 m.y. ago or earlier and ceased about 1,100 m.y. BP, when the Grenville Plate became locked to the Pre-Grenville plate3. We now propose a model that accommodates both this sequence of events and the emplacement of three major contemporaneous suites of basic igneous rocks. We suggest that these three suites of igneous rocks were emplaced during successive tensional phases related to the waning stages of motion along a strike-slip plate juncture and not during the early stages of plate divergence with which such igneous rocks are commonly associated.
TL;DR: All histone fractions contribute to the integrity of the 200 A chromatin fibrils found in fixed preparations, and are concluded that non-histone proteins and the nuclear membrane are probably also important for such structure.
TL;DR: In this article, the effects of a possible anomalous coupling of the muon to a speculative scalar meson of the type suggested by Weinberg were discussed, and the results reduce, but do not eliminate, the discrepancies.
Abstract: In view of the recently reported discrepancies between theoretical calculations and accurate experimental measurements of muonic x-ray energies for several elements in the energy range 150-440 keV, we have recalculated the vacuum polarization corrections. Our results reduce, but do not eliminate, the discrepancies. We discuss the effects of a possible anomalous coupling of the muon to a speculative scalar meson of the type suggested by Weinberg.
01 Jun 1972
TL;DR: A mathematical model which simulates the transient response of a twin-spool gas turbine engine on a general purpose digital computer is described together with test results verifying the simulation.
Abstract: A mathematical model which simulates the transient response of a twin-spool gas turbine engine on a general purpose digital computer is described together with test results verifying the simulation.
TL;DR: The Parke Siltstone, Hermannsburg Sandstone and Brewer Conglomerate of the Late Devonian to Early Carboniferous Pertnjara Group in the Amadeus Basin, central Australia, have been subdivided into eight new members.
Abstract: The Parke Siltstone, Hermannsburg Sandstone and Brewer Conglomerate of the Late Devonian to Early Carboniferous Pertnjara Group in the Amadeus Basin, central Australia, have been subdivided into eight new members. The Parke Siltstone at the base is an alternating sequence of siltstone and sandstone occurring in the central part of the basin. It has been subdivided into the following members in ascending stratigraphic order—Deering Siltstone Member, Harajica Sandstone Member, Dare Siltstone Member, and Amulda Member. The overlying Hermannsburg Sandstone is the most extensive formation of the Pertnjara Group and the following members have been recognised—the quartz-rich Ooraminna Sandstone and Owen Springs Sandstone Members, both of localised extent, and the Ljiltera Member which is more widespread and forms the upper pebbly part of the formation. The Undandita Member has been erected to distinguish the interbedded sandstone and conglomerate in the upper part of the Brewer Conglomerate from the mas...
TL;DR: In this article, the finite element method is applied to the free transverse vibration of circular and annular plates of varying thickness and stiffness and inertia matrices are presented for elements with linear and parabolic variations in thickness.
Abstract: The finite element method is applied to the free transverse vibration of circular and annular plates of varying thickness An annular element is derived which incorporates the number of diametral modes in the deflection function This results in an element having only four degrees of freedom, these being the deflection and slopes at the inner and outer radii of the element at an anti-node of the particular vibration mode Thickness variation in the radial direction is readily introduced, and stiffness and inertia matrices are presented for elements with linear and parabolic variations in thickness
The method is checked with several numerical examples Calculations of free vibration of circular and annular plates of constant, linear and parabolic thickness variation are compared with available exact solutions
TL;DR: This study of Indian behavior in the fur trade is offered more as a report of a study in progress than a completed piece of historical research as mentioned in this paper. But in spite of its unfinished state, the tentative results of the work I have done to this point may be of some interest as an illustration of the way in which the recent revival of analytical interest in institutions may be used to develop an approach to the economic history of the Fur trade.
Abstract: This study of Indian behavior in the fur trade is offered more as a report of a study in progress than a completed piece of historical research. In fact, the research has barely begun. But in spite of its unfinished state, the tentative results of the work I have done to this point may be of some interest as an illustration of the way in which the recent revival of analytical interest in institutions may be used to develop an approach to the economic history of the fur trade.
TL;DR: It is concluded that the adaptive algorithm using a combination of filtering, estimation, prediction and control to maintain a constant predetermined glucose concentration in a human subject is practical, robust and successful forin vivo blood-glucose regulation.
Abstract: From a control engineer's viewpoint, the human blood-glucose metabolism is a nonlinear system whose structure and parameters are imperfectly known. Moreover, disturbances are present, and measurement of sugar concentration involves a significant transport delay. This paper examines one approach to online regulation of such a process. A simple linear stochastic model of the glucose system is assumed, and provision is made for time variation of the parameters, corresponding to real-system nonlinearities. The adaptive algorithm uses a combination of filtering, estimation, prediction and control to maintain a constant predetermined glucose concentration in a human subject. Close agreement is obtained between simulations and online experimental results. It is concluded that the control algorithm is practical, robust and successful forin vivo blood-glucose regulation.
TL;DR: In this article, male and female Es were seated at one of three distances from a water fountain in a public building, and male passersby were less likely to drink when they were near (1 ft) the fountain than when the E was seated at less proximate positions (5 and 10 ft).
Abstract: Male and female Es were seated at one of three distances from a water fountain in a public building. Male passersby were less likely to drink when the E was near (1 ft) the fountain than when the E was seated at less proximate positions (5 and 10 ft). This finding supports previous research on reactions to spatial invasions, while eliminating some of the problems with previous invasion manipulations.
TL;DR: Trimethoprim, which is known to restrict formylation of methionyl-tRNAf, caused an equivalent inhibition of protein accumulation in a rel+ and rel− strain of E. coli K-12 as discussed by the authors.
TL;DR: The Kuder-Richardson formulas have been used widely to estimate the reliability coefficient from a single administration of a test (Ihde r and Richardson, 1937).
Abstract: THE Kuder-Richardson formulas, the K R 20 and the K R 21, have been used widely to estimate the reliability coefficient from a single administration of a test ( Ihde r and Richardson, 1937). The appeal of the idea of finding reliability from item statistics which are available after one testing, togcther with the computational simplicity of the formulas, probably accounts for their popularity. Although a great deal of attention has been devoted over a period of years to the estimation of reliability from item statistics (Jackson and Ferguson, 1941; Guttman, 1945; Gulliksen, 1950; Cronbach, 1951; Lyerly, 1958; Novick and Lewis, 1967, and others) , there are still gaps in the mathematical derivation of the IcuderRichardson results. The main purpose of this paper is to fill some of these gaps, using language consistent with modern probability theory (see, for example, Feller, 1968; Thomasian, 1969). This approach, i t is hoped, will also lead to a better understanding of conditions under which the formulas are applicable to test data. A test score is regarded as a sum of scores on items which are either “correct” or “incorrect.” Subtest scores which are continuous random variables can also be considered, and the structure of the model is essentially the same in that case. I n the present paper the former case is stressed, since we are concerned with another sort of generality, in which assumptions about independence of item scores (“experimental independence”) , correlations between certain scores, and random sampling procedures, are not made. Initially, there are no restrictions of this kind on the probability distributions of item
TL;DR: In this article, the absolute efficiency of a plastic scintillator neutron counter has been measured as a function of bias at thirteen neutrons energies between 1.0 and 200 MeV.