Showing papers by "Concordia University published in 1987"

Constitutive rhetoric: The case of the peuple québécois

Abstract: The rhetoric of Quebec sovereignty is based upon an appeal to a particular motivated subject, the Quebecois. Rhetorical theory usually takes such a subject as a given. A theory of constitutive rhetoric, based on the principle of identification, can account for the constitution of subjects of this type. Such subjects, agents within ideological discourse, are interpellated or called into being through rhetorical narratives. Such narratives constitute collective political subjects through a series of formal discursive effects. These effects result in a discursively constituted subjectivity that can form the basis for an ideological appeal to action.

Reinstatement of Drug-Taking Behavior as a Method of Assessing Incentive Motivational Properties of Drugs

Abstract: Noncontingent “priming” presentations of positive reinforcers (or incentive events) can enhance and reinstate previously acquired instrumental responding for these reinforcers We describe how this phenomenon may be used to study the motivational control of drug-taking behavior and the relapse to drug-taking in drug-free individuals

Scientific progress of management information systems

Abstract: The objective of this paper is to explore the historical progress of management information systems (MIS) from a philosophic scientific perspective. The study is based on the thematic analysis of research strategies of 536 articles published during the period 1977-1985. The results of this survey indicate that MIS has been undergoing significant shifts in terms of the research strategies employed by researchers. More specifically, there has been a shift from non-empirical research to empirical studies over the past nine years. However, it seems that in spite of recent progress in the demarcation of its boundaries, MIS has not made very significant progress as a scientific discipline. The paper takes the position that this state of the arts will not change until MIS develops a body of substantive theories specific to its domain.

An Empirical Study of Software Metrics

Abstract: Software metrics are computed for the purpose of evaluating certain characteristics of the software developed. A Fortran static source code analyzer, FORTRANAL, was developed to study 31 metrics, including a new hybrid metric introduced in this paper, and applied to a database of 255 programs, all of which were student assignments. Comparisons among these metrics are performed. Their cross-correlation confirms the internal consistency of some of these metrics which belong to the same class. To remedy the incompleteness of most of these metrics, the proposed metric incorporates context sensitivity to structural attributes extracted from a flow graph. It is also concluded that many volume metrics have similar performance while some control metrics surprisingly correlate well with typical volume metrics in the test samples used. A flexible class of hybrid metric can incorporate both volume and control attributes in assessing software complexity.

Conditioned Place Preference: A Parametric Analysis Using Systemic Heroin Injections

Abstract: A series of experiments is described that explores some of the parametric aspects of place preference conditioning Several procedures that affect classical conditioning were used, such as increasing the intensity of the unconditioned stimulus and increasing the number of conditioning trials These manipulations had little effect on the strength of the conditioned response Alternative explanations for the shift in place preference were also examined, and none of these factors could adequately account for the data Although place preference is usually tested in drug-free subjects, the strongest place preference was seen when subjects were tested following injections of the conditioning drug This suggests that the drug cue may be the most salient stimulus associated with the rewarding action of the drug, and the absence of this stimulus may limit the strength of the conditioning seen in most place preference studies

Optimality Criteria and Risk in Inventory Models: The Case of the Newsboy Problem

Abstract: This paper examines the use of market-valuation models in analysing stochastic inventory problems. As an example, the one-period newsboy problem is treated using the capital asset pricing model (CAPM). It is pointed out that, unlike other working-capital decisions, the use of CAPM to analyse inventory problems need not imply conflicting assumptions. The resulting optimal policy is characterized and is compared with the classical expected benefit maximization framework. It is shown that when the relevant risk of the inventory investment is considered, results are dramatically different.

Conditioned Drug Effects

Abstract: The repeated administration of a drug or hormone in the presence of a common set of environmental stimuli leads to conditions under which the organism can learn the contingent relation between the environmental stimulus and the drug-produced stimulus. In the terminology of Pavlovian conditioning, the stimulus that signals the occurrence of drug-produced stimuli is the conditioned stimulus (CS) and the drug-produced stimulus is the unconditioned stimulus (US). Evidence that the relation between the CS and the US is learned comes from the change in the way the organism responds to the originally neutral CS. If the CS reliably predicts the occurrence of the US, the CS becomes capable of eliciting responses in anticipation of the US that were originally elicited, unconditionally, by the US; that is, the CS becomes a substitute for the US. Although conditioning experiments in which the USs are drug produced have been carried out for over 75 years (see Lynch et al., 1976; Wikler, 1973), only in the last 10 years has the study of conditioned drug effects become of major interest in psychopharmacology (see Baker and Tiffany, 1985; Eikelboom and Stewart, 1982; Goudie and Demellweek, 1985; Grabowski and O’Brien, 1981; Hinson, 1985;Poulos etal., 1981a; Siegel, 19776, 1983, 1985; Solomon, 1977; Stewart et al, 1984). No doubt, the possible relevance of conditioned effects for understanding drug tolerance, sensitization, and compulsive drug use has sparked the large increase in the number of studies. In this chapter, we review the evidence for conditioned drug effects and discuss its implications.

Formulation of Joint Trajectories for Industrial Robots Using B-Splines

Abstract: In this paper, we describe a new procedure for constructing robot trajectories. The procedure uses the theory of B-splines. The motion of the robot, as specified by a time sequence of position and orientation knots of the end effector, is first transformed into sets of joint displacements. B-splines are then used to fit these sequences for each joint. The procedure consists of a simple recursive algorithm and allows constraints to be imposed on the magnitudes of the joint velocities and accelerations as well as on their initial and final values. A trajectory constructed by this method has the property that a local modification can be made quickly and easily without recomputing the entire trajectory. The method has been used for generating trajectories for a PUMA 560 robot.

Stability of intelligence: a 40-year follow-up.

Abstract: The Revised Examination "M," a measure of intelligence, was re- administered to 260 men approximately 40 years after they had received this test as World War II army recruits. Their average age and educational level was 64.7 years and Grade 8.7, respectively. Three sets of scores were compared: those obtained at the time of army enlistment; current scores obtained within the regular time limits of the test; and current scores obtained within double the test's regular time limits. The results indicated a reliable but minor decline in total score in the regular speeded condition and a reliable improvement over wartime total scores in the double-time condition. Slower performance did not account for the decline observed on the nonverbal cognitive tasks, particularly spatial problem-solving, but was associated with the decrements recorded for mathematical and verbal reasoning skills. Significant gains in score were observed on the measures of vocabulary and mechanical knowledge in the speeded condition, with further gains noted in the double-time extension. Test-retest correlation coefficients, in general, attested to the long-term stability of individual differences among members of the sample, irrespective of the direction of cognitive performance changes. Gains in the double- time extension were associated with educational status but not with current age. Both age and educational level, in addition to early adult intellectual status, predicted current intellectual functioning. Finally, self-reported current activity level, as an indicator of personal lifestyle, was related both to early and to late adult intellectual ability.

Intravenous Drug Self-Administration: A Special Case of Positive Reinforcement

Abstract: Much has been made of parallels between drug reinforcement and food reinforcement. In several important ways, however, the two differ. Unlike food reinforcement, drug reinforcement has rapid and direct effects in the central nervous system. Where two classes of response—operant and consummatory—are required for food reinforcement, only one—having some of the properties of an operant and some of the properties of a consummatory response—is required for drug reinforcement. Where satiety is delayed by many minutes after food reward, it is immediate with drug reinforcement. These differences must be taken into account when interpreting drug reinforcement studies; in particular, they have important implications for interpreting changes in response and hourly drug intake.

Conditioned locomotion and place preference elicited by tactile cues paired exclusively with morphine in an open field.

Abstract: A novel version of the conditioned place preference (CPP) technique was used in an attempt to determine whether tactile stimuli previously associated with morphine elicit approach and sustained contact. Empirical support for this view has been equivocal, prompting some to question the validity of the CPP technique. In the present study, rats received, during conditioning, morphine (10 mg/kg, IP) paired exclusively with an open field floor made of four quadrants of one texture (CS+) and saline with another floor made of four quadrants of a different texture (CS−). On the test for CPP, rats were given saline and placed in an open field containing either 1, 2, or 4 quadrants of the CS+ (with 3, 2, 0 quadrants of the CS−, respectively). These animals showed high absolute CPP scores on the test, spending, on average, as much as 83% and 75% of their time on the CS+ when two and one CS+ quadrants, respectively, were present. Concurrent measures of activity indicated that animals were most active when all four quadrants were CS+ and least active when zero or one CS+ quadrant was present. Thus, once an animal approached and made contact with the CS+ it tended to maintain contact with this stimulus and to reduce its approach to and contact with other stimuli. The differentiating features of this version of the CPP technique, as well as the relationship between morphine-induced conditioned locomotion and CPP, are discussed.

A New Concept in Semi-Active Vibration Isolation

Abstract: Nouvelle conception pour des amortisseurs de vibrations semi-actifs (c'est-a-dire sans apport d'energie exterieur)

Morphine conditioned place preference and locomotion: the effect of confinement during training.

Abstract: The effect of confinement during conditioning on subsequent test levels of locomotor activity and conditioned place preference (CPP) was investigated by giving rats discrimination training with morphine and saline in the presence of different tactile floor cues in an open field. Groups of rats were trained under one of three levels of confinement (not confined, confined to 1/4, or confined to 1/16 of the open field) and tested for locomotor activity and CPP in the entire open field after receiving a saline injection. Confined rats subsequently spent less time on the morphine-paired floor cues (CS+) and were more active throughout the open field during the test than rats not confined during conditioning. Rats confined to the smallest area spent the least time on the CS+ and were the most active. It is suggested that confinement may preserve the novelty of the testing environment, which in turn may interfere with rats' usual responses to incentive drug-paired stimuli. These findings may have important implications for versions of the CPP technique in which training and testing environments differ considerably.

An Efficient Nearest Neighbor Search Method

Abstract: A simple, but efficient, nearest neighbor search algorithm is proposed and simulation results demonstrating its effectiveness in the case of vector quantization for a given source are presented. The simulation results indicate that use of this approach reduces the number of multiplications and additions to as low as 9 percent of those required for the conventional full search method. The reduction in the number of subtractions is also considerable. The increase in the number of comparisons is moderate, and therefore, the total number of operations can be as low as 28 percent of those required by the full search method. An additional advantage of the described algorithm is the fact that it requires no precomputations and/or extra memory.

Large Tree Classifier with Heuristic Search and Global Training

Abstract: In the tree classifier with top-down search, a global decision is made via a series of local decisions. Although this approach gains in classification efficiency, it also gives rise to error accumulation which can be very harmful when the number of classes is very large. To overcome this difficulty, a new tree classifier with the following characteristics is proposed: 1) fuzzy logic search is used to find all ``possible correct classes,'' and some similarity measures are used to determine the ``most probable class''; 2) global training is applied to generate extended terminals in order to enhance the recognition rate; 3) both the training and search algorithms have been given a lot of flexibility, to provide tradeoffs between error and rejection rates, and between the recognition rate and speed. A computer simulation of the decision trees for the recognition of 3200 Chinese character categories yielded a very high recognition rate of 99.93 percent and a very high speed of 861 samples/s, when the program was written in a high level language and run on a large multiuser time-sharing computer.

Assessing Organizational Commitment in a Developing Country: Pakistan, A Case Study

Abstract: This study examines commitment of male and female employees to their organizations in a less affluent society (Pakistan). It uses a blend of the "exchange" and "role" theories as its basic framework. Results indicate that both groups of workers are highly committed to their organizations. Unlike the results of most previous studies involving industrialized societies, the degree of female commitment in Pakistan appears to be much higher than that of male workers, and age seems inversely related with commitment. Also, the psychological and role-related factors seem to exert greater influence on commitment than the exchange-based and personal factors.

Computer recognition of totally unconstrained handwritten zip codes

Abstract: Techniques for the recognition of totally unconstrained handwritten numerals are developed and tested on a large set (8540 numerals) of real-life Postal ZIP code samples. Different approaches, including statistical, structural and hybrid are developed and their performance measured. The use of extended characteristic loci codes with statistical approach as a front-end recognizer and predictor of an unknown character has been investigated. The expected prediction capability of this approach lies in the interval (90%, 100%). Its recognition reliability ranges in the interval (88.55%, 89.02%) with substitution and rejection rates between (10.40%, 10.85%) and (5.23%, 5.32%) respectively. A new approach to define and extract structural features based on edge classification has been implemented. Shapes, such as holes, simple cavities and end points, are used as structural features and the relational data-model is used as a tool to organize the information related to each shape. Furthermore, a fuzzy set theoretic technique has been developed for the identification of unknown characters. The structural approach is used as a back-end recognizer, and the unknown characters are identified by incorporating the predicted information as well as the structural identification score. Its recognition reliability lies in the interval (99.06%, 99.8%) with substitution and rejection rates between (0.18%, 0.73%) and (7.13%, 22.48%) respectively. In the hybrid approach, unknown characters are identified either by the statistical approach or structural approach. Characters with strong predictions (normal characters) are recognized by the statistical approach and those with weak prediction (abnormal characters) by the structural approach. Using this approach, one of the many possible combinations of the statistical and structural recognition schemes has been investigated, and its recognition reliability improved to the interval (95.94%, 96.29) with substitution and rejection rates between (3.45%, 3.96%) and (2.36%, 7.01%) respectively. Image processing (enhancement, binarization, and segmentation) techniques were also developed to obtain suitable binary characters from the raw images of the ZIP codes. The techniques, image processing together with recognition, described in this thesis present a complete model of an optical reader for ZIP code recognition. The model, in general, is applicable to the text recognition problem.

The nature of managerial moral standards

Abstract: Descriptions of how managers think about the moral questions that come up in their work lives are analyzed to draw out the moral assumptions to which they commonly refer. The moral standards thus derived are identified as (1) honesty in communication, (2) fair treatment, (3) special consideration, (4) fair competition, (5) organizational responsibility, (6) corporate social responsibility, and, (7) respect for law. It is observed that these normative standards assume the cultural form of social conventions but because managers invoke them as largely private intuitions, their cultural status remains precarious and unclear. This is the second in a research series of three papers.

A novel approach for minimizing high frequency transformer copper losses

Abstract: As power supply frequencies approach the megahertz level, skin and proximity effects become significant factors to consider when calculating copper losses in transformers. Using electromagnetic theory and mmf diagrams in both space and time, a method that provides insight into the mechanism of skin and proximity effect losses and also yields quantitative results is proposed. Using this method several winding geometries for various topologies are covered. The analysis and optimization process is experimentally verified using an interleaved flyback transformer.

A fast algorithm for two dimensional median filtering

Abstract: The median of a set of numbers is a number which partitions the given set, excluding that number, into two subsets with an equal number of elements such that the number is greater than or equal to the elements in one subset and less than or equal to in the other In image processing, in order to compute the running median, the window is moved from one neighborhood to the next In this paper, a fast two-dimensional median filtering algorithm is proposed The algorithm is designed in such a way that in order to find the median of a window, the results obtained during the partitioning of the previous window are used Test results obtained by running the algorithm on VAX 11/780 are presented and its performance is compared with the Huang's histogram algorithm for median filtering It is shown that the proposed algorithm's execution time is faster and is independent of the number of bits used to represent the data values The novel features in the algorithm design that contribute to fast execution are also presented

The Strategy and Structure of Collective Action

Abstract: The developing literature on collective strategy points to the need to manage relations between a population of organizations and the broader social context in which they are located. This paper complements this perspective by examining the problems of collective action at the task environment level. It is proposed that collective action is a necessary response to environmental turbulence; which presents both opportunities and threatens organizations' resource base, and demands operational and output adaptations. It is suggested that different strategies require the solution of different crucial tasks and that specific modes of interorganizational coordination are needed to do this. The hypotheses are illustrated by four cases of collective action prompted by deregulation and technical change in the U.K. telecommunications industry.