Showing papers by "Carleton University published in 1986"

Characterisation and modeling of mismatch in MOS transistors for precision analog design

Abstract: A characterization methodology is presented that accurately predicts the mismatch in drain current over a wide operating range using a minimum set of measured data. The physical causes of mismatch are discussed in detail for both p- and n-channel devices. Statistical methods are used to develop analytical models that relate the mismatch to the device dimensions. It is shown that these models are valid for small-geometry devices only. Extensive experimental data from a 3-/spl mu/m CMOS process are used to verify the models. The application of the transistor matching studies to the design of a high-performance digital-to-analog converter (DAC) is discussed. A circuit design methodology is presented that highlights the close interaction between the circuit yield and the matching accuracy of devices. It has been possible to achieve a circuit yield of greater than 97% as a result of the knowledge generated regarding the matching behavior of transistors and due to the systematic design approach.

Hypnotic behavior: A social-psychological interpretation of amnesia, analgesia, and “trance logic”

Abstract: This paper examines research on three hypnotic phenomena: suggested amnesia, suggested analgesia, and “trance logic.” For each case a social-psychological interpretation of hypnotic behavior as a voluntary response strategy is compared with the traditional special-process view that “good” hypnotic subjects have lost conscious control over suggestion-induced behavior. I conclude that it is inaccurate to describe hypnotically amnesic subjects as unable to recall the material they have been instructed to forget. Although amnesics present themselves as unable to remember, they in fact retain control over retrieval processes and accommodate their recall (or lack of it) to the social demands of the test situation. Hypnotic suggestions of analgesia do not produce a dissociation of pain from phenomenal awareness. Nonhypnotic suggestions of analgesia and distractor tasks that deflect attention from the'noxious stimuli are as effective as hypnotic suggestions in producing reductions in reported pain. Moreover, when appropriately motivated, subjects low in hypnotic suggestibility report pain reductions as large as those reported by highly suggestible hypnotically analgesic subjects. Finally, the data fail to support the view that a tolerance for logical incongruity (i.e., trance logic) uniquely characterizes hypnotic responding. So-called trance-logic-governed responding appears to reflect the attempts of “good” subjects to meet implicit demands to report accurately what they experience.

Tracking properties and steady-state performance of RLS adaptive filter algorithms

Abstract: Adaptive signal processing algorithms derived from LS (least squares) cost functions are known to converge extremely fast and have excellent capabilities to "track" an unknown parameter vector. This paper treats analytically and experimentally the steady-state operation of RLS (recursive least squares) adaptive filters with exponential windows for stationary and nonstationary inputs. A new formula for the "estimation-noise" has been derived involving second- and fourth-order statistics of the filter input as well as the exponential windowing factor and filter length. Furthermore, it is shown that the adaptation process associated with "lag effects" depends solely on the exponential weighting parameter λ. In addition, the calculation of the excess mean square error due to the lag for an assumed Markov channel provides the necessary information about tradeoffs between speed of adaptation and steady-state error. It is also the basis for comparison to the simple LMS algorithm, in a simple case of channel identification, it is shown that the LMS and RLS adaptive filters have the same tracking behavior. Finally, in the last part, we present new RLS restart procedures applied to transversal structures for mitigating the disastrous results of the third source of noise, namely, finite precision arithmetic.

Research and Development and Intraindustry Spillovers: an Empirical Application of Dynamic Duality

Abstract: In this paper we estimate a model of production and investment based on the theory of dynamic duality and are particularly Interested in the effects of R&D spillovers and in calculating the social and private rates of return We identify and estimate three effects associated with the intraindustry R&D spillover First, costs decline as knowledge expands for the externality-receiving firms Second, production structures are affected, as factor demands change in response to the spillover Third, the rates of capital accumulation are affected by the R&D spillover These cost-reducing, factor-biasing and capital adjustment effects of the spillover are estimated for four industries The existence of R&D spillovers implies that the social and private rates of return to R&D capital differ We estimate that the social return exceeds the private return in each industry However, there is significant variation across industries in the differential between the social and private rates of return

Computer modeling of heat flow in welds

Abstract: This paper summarizes progress in the development of methods, models, and software for analyzing or simulating the flow of heat in welds as realistically and accurately as possible. First the fundamental equations for heat transfer are presented and then a formulation for a nonlinear transient finite element analysis (FEA) to solve them is described. Next the magnetohydrodynamics of the arc and the fluid mechanics of the weld pool are approximated by a flux or power density distribution selected to predict the temperature field as accurately as possible. To assess the accuracy of a model, the computed and experimentally determined fusion zone boundaries are compared. For arc welds, accurate results are obtained with a power density distribution in which surfaces of constant power density are ellipsoids and on radial lines the power density obeys a Gaussian distribution. Three dimensional, in-plane and cross-sectional kinematic models for heat flow are defined. Guidelines for spatial and time discretization are discussed. The FEA computed and experimentally measured temperature field,T(x, y, z, t), for several welding situations is used to demonstrate the effect of temperature dependent thermal properties, radiation, convection, and the distribution of energy in the arc.

Problem-Solving Strategies

Abstract: This article reviews recent research on problem-solving strategies and their relationship to leaning and problem-solving processes. A distinction is made between schema-driven and search-based problem-solving strategies, and expert-novice differences in the use of these strategies are discussed. General strategies that facilitate the learning of problem schemata associated with expertise are contrasted with strategies that hinder schema learning. Constraints on the use of problem-solving strategies and the consequent implications for education are discussed. Suggestions for future research are made, which include the study of search-based strategies in experts and the effects of training on strategy use.

Consumer attitudes toward Canadian-made versus imported products

Abstract: A survey of 635 Canadian men and women revealed that overall attitudes toward Canadian-made products were positive, especially among women. Cynicism existed among men and among persons who were older, had higher educations, higher incomes and higher status occupations. For clothing and footwear products Canadian-made rated high, but Japanese-made rated higher for automobiles and home entertainment equipment, while European wines were rated ahead of Canadian wines. The last purchase in each product category studied was frequently Canadian-made. Consumers favored purchasing Canadian-made products in the future except for home entertainment equipment. Implications for Canadian industry, marketing and government policy are drawn.

HAL: A Multi-Paradigm Approach to Automatic Data Path Synthesis

Abstract: A novel approach to automatic data path synthesis is presented. This approach features innovations in the synthesis process as well as in the system implementation. The synthesis process exhibits three new features. The first relates to a subtask that performs an expert analysis of the input data flow graph and attempts to evenly distribute operations requiring similar resources. This is done using a novel "load balancing" technique. The second consists of a global preselection of operator cells to fulfill an explicit speed constraint. Finally, the third deals with new techniques for register and multiplexer optimization. These features support extended design space search by taking an explicit performance specification into account. The system implementation is based on the LOOPS multiparadigm programming system. In this approach the overall task can be partitioned into complementary subtasks requiring different programming paradigms. These subtasks will be realized using an object-based paradigm, a knowledge-based expert system paradigm, a functional paradigm, or combinations of all three. Two complete examples are given to demonstrate the functionality of the system and to allow comparison with existing systems.

Min-max heaps and generalized priority queues

Abstract: A simple implementation of double-ended priority queues is presented The proposed structure, called a min-max heap, can be built in linear time; in contrast to conventional heaps, it allows both FindMin and FindMax to be performed in constant time; Insert, DeleteMin, and DeleteMax operations can be performed in logarithmic timeMin-max heaps can be generalized to support other similar order-statistics operations efficiently (eg, constant time FindMedian and logarithmic time DeleteMedian); furthermore, the notion of min-max ordering can be extended to other heap-ordered structures, such as leftist trees

A social-cognitive skills approach to the successful modification of hypnotic susceptibility.

Abstract: Subjects low and medium in hypnotic susceptibility were administered cognitive strategy and instructional set information and also practiced responding to test suggestions in order to enhance susceptibility. Those in one modification treatment received this information both from the experimenter and by observing a videotaped female model who responded successfully to suggestions and reported on the cognitive strategies she used to do so. Those in a second modification treatment received the information and practice but were not exposed to the model. Low and medium susceptibles in a third condition (practice alone) received a hypnotic induction procedure and practice suggestions but neither modification information nor modeling. No-treatment controls performed a filler task. All subjects were posttested on two different susceptibility scales. Information plus modeling produced significantly greater increments on all objective and subjective indices of susceptibility on both posttests than did practice-alone or control treatments. Susceptibility increments in the information without model treatment always fell between those of the model and practice-alone treatments. In the modeling treatment, over half of the initial low susceptibles and over two thirds of the initial medium susceptibles scored as high susceptibles on both posttests. These findings provide strong support for a social-cognitive skill formulation of hypnotic susceptibility.

Efficient transformation of alfalfa protoplasts by the intranuclear microinjection of Ti plasmids

Abstract: Intranuclear microinjection of alfalfa (Medicago sativa L.) protoplasts yielded transformation frequencies of 15–26%. Over 70 transformed callus lines were recovered without selection by microinjecting a variety of plasmids. Analyses of several lines transformed with pTiC58 showed that integration did not occur by the T–DNA mechanism typical for crown gall tissues. The presence of a functional T–DNA right border on smaller plasmids or the coinjection of a functional vir region on a separate plasmid did not increase the transformation frequencies. The novelty of this approach to the genetic transformation of plants is that selection systems are not required and restrictions on the host range of Agrobacterium tumefaciens may be circumvented.

Behavioral and Neurochemical Consequences Associated with Stressors

Abstract: A series of neurochemical changes occur in response to stressors that may permit the organism to contend with environmental demands. When the organism is exposed to a stressor the utilization and synthesis of brain NE and DA increases. Under conditions where utilization exceeds synthesis, owing either to the nature of the stressor (uncontrollability), experiential factors (e.g., prior exposure to acute stressors), or organismic variables (e.g., strain, age), reductions of the amine may be incurred. It is suggested that the reduced amine concentrations leave the organism less well prepared to deal with the demands placed upon it, and ultimately increase vulnerability to psychological disturbances. It follows that the more persistent the amine reduction, the greater the probability of pathology being engendered. In effect, in our analyses of stressor effects it is not sufficient merely to determine whether amine reductions occur, but also to assess the ability of the system to re-establish adequate levels and turnover. Additionally, since stressors may result in the conditioning or sensitization of neurochemical processes, it is essential not only to assess the immediate impact of the stressor, but also the neurochemical variations that occur upon re-exposure to stressors or cues associated with the stressor. In considering the consequences of stressors and the potential implications for human pathology, it is important to consider the impact of chronic stressors. After all, many stressors encountered by humans are chronic in nature, particularly if one considers ruminations associated with the aversive event. It seems that with repeated stressor application a further series of adaptive neurochemical changes occur. The activity of tyrosine hydroxylase is increased, and concentrations of NE and DA approach those of nonstressed animals. Indeed, it appears that after stressor termination the increased amine synthesis may persist for some time leading to a further increase of amine concentrations, which may enable the organism to deal with environmental demands. In addition, receptor variations may occur, including down-regulation of beta-NE receptors, and possibly alterations of alpha-1 and alpha-2 receptors as well. It is believed that the receptor variations may be the essential element in maintaining the integrity of the organism. It is our contention that where such adaptive changes do not occur or are slow in occurring, pharmacological intervention may be necessary to engender such neuronal variations.

Some water‐related physical properties of maize root‐cap mucilage

Abstract: The dry weight (0.1%) and water potential -7 kPa) of root-cap mucilage from 3-d-old axenically grown maize seedlings have been determined. The results suggest strong gelling properties and weak water-holding capacity for the mucilage. Root tips from seedlings grown under low or high water stress were fixed by freeze-substitution. Micrographs showed that in both conditions, mucilage was secreted into the periplasmic space and extruded through the cell wall, though in dry conditions, the mucilage was tightly pressed against the root-cap surface. Histochemical and structural evidence is presented indicating chemical changes in the composition of the mucilage upon extrusion and a sharp increase in its hydration at increasing distance from the secretory cells. The possible functions of the root-cap mucilage in the rhizosphere are examined in light of these findings.

An exemplar based Smalltalk

Abstract: Two varieties of object-oriented systems exist: one based on classes as in Smalltalk and another based on exemplars (or prototypical objects) as in Act/1. By converting Smalltalk from a class based orientation to an exemplar base, independent instance hierarchies and class hierarchies can be provided. Decoupling the two hierarchies in this way enables the user's (logical) view of a data type to be separated from the implementer's (physical) view. It permits the instances of a class to have a representation totally different from the instances of a superclass. Additionally, it permits the notion of multiple representations to be provided without the need to introduce specialized classes for each representation. In the context of multiple inheritance, it leads to a novel view of inheritance (or-inheritance) that differentiates it from the more traditional multiple inheritance notions (and-inheritance). In general, we show that exemplar based systems are more powerful than class based systems. We also describe how an existing class based Smalltalk can be transformed into an exemplar-based Smalltalk and discuss possible approaches for the implementation of both and-inheritance and or-inheritance.

Development in Malaysia : Poverty, Wealth and Trusteeship

Abstract: Part One 1. The origins of Economic Trusteeship Part Two 2. The Structure and Incidence of Rural Poverty in Malaysia 3. Rural Poverty and Policy Interventions Under Trusteeship 4. Managed Industrialisation Under Trusteeship Part Three 5. Wealth Concentration Under Trusteeship: Corporate and Human Capital 6. The Social Costs of Trusteeship: Deficits, 'Distributional Coalitions' and Quasi-rents Part Four 7. Summing Up: Problems, Prospects and Alternatives Index

Dream self-reflectiveness as a learned cognitive skill.

Abstract: This research was directed toward the contradiction sustained by cognitive dream psychology, which on the one hand regards dreaming as higher symbolic activity and, on the other, sees its organizational and functional characteristics as derivative and/or inferior to those of waking consciousness. Study 1 evaluates the degree of self-reflective meta-cognition in dreams from different sleep stages. Subjects were 24 college students selected such that half were self-reported high-frequency dream recallers and half were low-frequency recallers. Both groups were composed equally of men and women. Greater self-reflectiveness (SR) was found in REM dreams as compared with those from stages 2 and 4, which did not differ. High-frequency recallers showed more dream SR than did low-frequency recallers. Study 2 assessed the extent to which self-reflective and lucid dreaming can be learned as a cognitive skill by varying levels of intention and attention paid to dreaming. After 3 weeks of home dream collection, results showed that four experimental groups had greater dream SR than did a baseline group. The most effective treatment was the mnemonic, wherein attention patterning schemas learned in waking resulted in more self-reflective and lucid dreaming than did either baseline or attention-control conditions. These results provide evidence that dreaming is not single-minded but variable along a self-reflective process continuum, and suggest functional and organizational levels that are consistent with the conception of dreaming as higher order cognitive activity.

Production and characterization of somatic hybrids between Solanum melongena L. and S. sisymbriifolium Lam.

Abstract: Protoplasts of 6-azauracil (AU) resistant cell lines of Solanum melongena L. were fused with protoplasts of S. sisymbriifolium Lam. to create somatic hybrids between these sexually-incompatible species. Following fusion, colonies were selected which were capable of growth in medium containing 1mM AU. These colonies were placed on medium containing zeatin which had been shown to stimulate anthocyanin production during shoot organogenesis in tissue explants of S. sisymbriifolium but not in S. melongena. A total of 37 anthocyanin-producing colonies were identified from which 26 hybrid plants were regenerated. The morphological traits intermediate to those of the parents included: flower colour, leaf shape, and trichome density. Cytogenetic analysis revealed that all hybrids were aneuploids but their chromosome numbers were close to the expected number of 48. Isozyme analysis revealed that nuclear genes of both parents were expressed in the hybrids. In addition, isoelectric focussing of the large subunit of ribulose 1,5-bisphosphate carboxylase (Rubisco) provided evidence that each hybrid expressed only the S. sisymbriifolium chloroplast genome. All hybrids regenerated thus far have been sterile.

Reduced and oxidised glutathione and glutathione-reductase activity in tissues of Pisum sativum.

Abstract: In three-week-old pea plants (Pisum sativum L., cv. Little Marvel) grown in the light, total glutathione levels were highest in apex and expanding leaves (1.5 μmol·(g FW)-1), and lower (0.4–0.6 μmol·(g FW)-1) in older leaves and roots. In the light period, levels in expanded leaves increased by about 40%, compared with dark values, with lesser increases in roots and apex. In illuminated plants the proportion in the reduced form was 86–88% in leaves and 80% in roots, and these values fell during the dark period (to 82% and 69%, respectively). Reduced glutathione makes up 65–70% of the low-molecular-weight thiol in leaves, but over 95% in roots. Chloroplasts contained about 10% of the leaf glutathione, at a concentration of 1–2 mM; total glutathione in the chloroplasts, and the proportion of oxidised form (GSSG) increased in light, while NADP+/NADPH ratios decreased, indicating both synthesis and active oxidation of glutathione in light. Chloroplasts contained 52% (young leaf) to 75% (mature leaf) of the GSSG-reductase (EC 1.6.4.2) activity in the leaves. In roots, over 30% of the GSSG reductase was in the plastid fraction. Very little GSSG-reductase activity was associated with mitochondria in leaf or root.

Integer Sets with Distinct Sums and Differences and Carrier Frequency Assignments for Nonlinear Repeaters

Abstract: The problem of assigning n carrier frequencies so as to avoid certain types (third and fifth order) of intermodulation interference is discussed. For the third-order case, close upper and lower bounds on the optimal solution are established; and close to optimal solutions are given for n (previously, suboptimal solutions were known only for n \leq 23 ). For the fifth-order case, it is shown that some existing results can be applied to this problem, and suboptimal solutions obtained by this construction are given for n \leq 17 (no solutions were known previously).