831 resultados para Computer Terminals
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This case study examines the impact of a computer information system as it was being implemented in one Ontario hospital. The attitudes of a cross section of the hospital staff acted as a barometer to measure their perceptions of the implementation process. With The Mississauga Hospital in the early stages of an extensive computer implementation project, the opportunity existed to identify staff attitudes about the computer system, overall knowledge and compare the findings with the literature. The goal of the study was to develop a greater base about the affective domain in the relationship between people and the computer system. Eight exploratory questions shaped the focus of the investigation. Data were collected from three sources: a survey questionnaire, focused interviews, and internal hospital documents. Both quantitative and qualitative data were analyzed. Instrumentation in the study consisted of a survey distributed at two points in time to randomly selected hospital employees who represented all staff levels.Other sources of data included hospital documents, and twenty-five focused interviews with staff who replied to both surveys. Leavitt's socio-technical system, with its four subsystems: task, structure, technology, and people was used to classify staff responses to the research questions. The study findings revealed that the majority of respondents felt positive about using the computer as part of their jobs. No apparent correlations were found between sex, age, or staff group and feelings about using the computer. Differences in attitudes, and attitude changes were found in potential relationship to the element of time. Another difference was found in staff group and perception of being involved in the decision making process. These findings and other evidence about the role of change agents in this change process help to emphasize that planning change is one thing, managing the transition is another.
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This study investigated the effectiveness of a computer program, PERSONAL CAREER DIRECTIONS (PC DIRECTIONS) (Anderson, Welborn, & Wright, 1983) on career planning and exploration for twenty-four Brock University students (18 women and 6 men) who requested career planning assistance at the Career/Placement Services of the Counselling Centre. A one-group pretest/posttest design was used in the study_ Progress in career planning and exploration was measured by Career Planning (CP) and Career Exploration (CE) scales of the Career Development Inventory (College and University Form) (Super, Thompson, Lindeman, Jordaan, & Myers, 1981). A paired samples 2-tailed t test for Career Development Attitudes (CDA) , the combined CP and CE scales, revealed the posttest scores were significantly higher than the pretest scores, t(23) = 3.74, 2 < .001. Student progress was also assessed by self-report lists of job titles which reflected positive changes after students used PC DIRECTIONS. In response to several questions, students' attitudes were more positive than negative toward the program. Implications are that PC DIRECTIONS is an effective component in promoting career planning for university students. Further studies may reveal that different types of students may benefit from different interventions in the career planning process.
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This study was undertaken in order to determine the effects of playing computer based text adventure games on the reading comprehension gains of students. Forty-five grade five students from one elementary school were randomly assigned to experimental and control groups, and were tested with regard to ability, achievement and reading skills. An experimental treatment, consisting of playing computer based interactive fiction games of the student's choice for fifteen minutes each day over an eight-week period, was administered. A comparison treatment engaged the control group in sustained silent reading of materials of the student's choice for an equal period of time. Following the experimental period all students were post-tested with an alternate form of the pre-test in reading skills, and gain scores were analysed. It was found that there were no significant differences in the gain scores of the experimental and control groups for overall reading comprehenSion, but the experimental group showed greater gains than the control group in the structural analysis reading sub-skill. Extreme variance in the data made generalization very difficult, but the findings indicated a potential for computer based interactive fiction as a useful tool for developing reading sl<ills. The great need for further research in the same vein was highlighted in the conclusions.
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Please consult the paper edition of this thesis to read. It is available on the 5th Floor of the Library at Call Number: Z 9999 E38 D56 1992
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While the influence of computer technology has been widely studied in a variety of contexts, the drawing teaching studio is a particularly interesting context because of the juxtaposition of traditional medium and computer technology. For this study, 5 Canadian postsecondary teachers engaged in a 2-round Delphi interview process to discuss their responses to computer technology on their drawing pedagogy. Data sources included transcribed interviews. Findings indicated that artist teachers are both cautious to embrace and curious to explore appropriate use of computer technology on their drawing pedagogy. Artist teachers are both critical and optimistic about the influence of computer technology.
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Un rsum en franais est galement disponible.
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Dans un contexte o les virus informatiques prsentent un risque srieux pour les rseaux travers le globe, il est impratif de retenir la responsabilit des compagnies qui ny maintiennent pas une scurit adquate. ce jour, les tribunaux qubcois nont pas encore t saisis daffaires en responsabilit pour des virus informatiques. Cet article brosse un portrait gnral de la responsabilit entourant les virus informatiques en fonction des principes gnraux de responsabilit civile en vigueur au Qubec. Lauteur propose des solutions pour interprter les trois critres traditionnels la faute, le dommage et le lien causal en mettant laccent sur lobligation de prcaution qui repose sur les paules de ladministrateur de rseau. Ce joueur cl pourrait bnficier de ladoption de dispositions gnrales afin de limiter sa responsabilit. De plus, les manufacturiers et les distributeurs peuvent galement partager une partie de la responsabilit en proportion de la gravit de leur faute. Les entreprises ont un devoir lgal de sassurer que leurs systmes sont scuritaires afin de protger les intrts de leurs clients et des tiers.
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L'interface cerveau-ordinateur (ICO) dcode les signaux lectriques du cerveau requise par llectroencphalographie et transforme ces signaux en commande pour contrler un appareil ou un logiciel. Un nombre limit de tches mentales ont t dtects et classifier par diffrents groupes de recherche. Dautres types de contrle, par exemple lexcution d'un mouvement du pied, rel ou imaginaire, peut modifier les ondes crbrales du cortex moteur. Nous avons utilis un ICO pour dterminer si nous pouvions faire une classification entre la navigation de type marche avant et arrire, en temps rel et en temps diffr, en utilisant diffrentes mthodes. Dix personnes en bonne sant ont particip lexprience sur les ICO dans un tunnel virtuel. Lexprience fut a tait divis en deux sances (48 min chaque). Chaque sance comprenait 320 essais. On a demand au sujets dimaginer un dplacement avant ou arrire dans le tunnel virtuel de faon alatoire daprs une commande crite sur l'cran. Les essais ont t mens avec feedback. Trois lectrodes ont t montes sur le scalp, vis--vis du cortex moteur. Durant la 1re sance, la classification des deux taches (navigation avant et arrire) a t ralise par les mthodes de puissance de bande, de reprsentation temporel-frquence, des modles autorgressifs et des rapports dasymtrie du rythme avec classificateurs danalyse discriminante linaire et SVM. Les seuils ont t calculs en temps diffr pour former des signaux de contrle qui ont t utiliss en temps rel durant la 2e sance afin dinitier, par les ondes crbrales de l'utilisateur, le dplacement du tunnel virtuel dans le sens demand. Aprs 96 min d'entrainement, la mthode online biofeedback de la puissance de bande a atteint une prcision de classification moyenne de 76 %, et la classification en temps diffr avec les rapports dasymtrie et puissance de bande, a atteint une prcision de classification denviron 80 %.
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La fibrillation auriculaire, l'arythmie la plus frquente en clinique, affecte 2.3 millions de patients en Amrique du Nord. Pour en tudier les mcanismes et les thrapies potentielles, des modles animaux de fibrillation auriculaire ont t dvelopps. La cartographie lectrique picardique haute densit est une technique exprimentale bien tablie pour suivre in vivo l'activit des oreillettes en rponse une stimulation lectrique, du remodelage, des arythmies ou une modulation du systme nerveux autonome. Dans les rgions qui ne sont pas accessibles par cartographie picardique, la cartographie endocardique sans contact ralise l'aide d'un cathter en forme de ballon pourrait apporter une description plus complte de l'activit auriculaire. Dans cette tude, une exprience chez le chien a t conue et analyse. Une reconstruction lectro-anatomique, une cartographie picardique (103 lectrodes), une cartographie endocardique sans contact (2048 lectrodes virtuelles calcules partir un cathter en forme de ballon avec 64 canaux) et des enregistrements endocardiques avec contact direct ont t raliss simultanment. Les systmes d'enregistrement ont t galement simuls dans un modle mathmatique d'une oreillette droite de chien. Dans les simulations et les expriences (aprs la suppression du nud atrio-ventriculaire), des cartes d'activation ont t calcules pendant le rythme sinusal. La repolarisation a t value en mesurant l'aire sous l'onde T auriculaire (ATa) qui est un marqueur de gradient de repolarisation. Les rsultats montrent un coefficient de corrlation picardique-endocardique de 0.8 (exprience) and 0.96 (simulation) entre les cartes d'activation, et un coefficient de corrlation de 0.57 (exprience) and 0.92 (simulation) entre les valeurs de ATa. La cartographie endocardique sans contact apparait comme un instrument exprimental utile pour extraire de l'information en dehors des rgions couvertes par les plaques d'enregistrement picardique.
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Lobjectif de cette thse par articles est de prsenter modestement quelques tapes du parcours qui mnera (on espre) une solution gnrale du problme de lintelligence artificielle. Cette thse contient quatre articles qui prsentent chacun une diffrente nouvelle mthode dinfrence perceptive en utilisant lapprentissage machine et, plus particulirement, les rseaux neuronaux profonds. Chacun de ces documents met en vidence lutilit de sa mthode propose dans le cadre dune tche de vision par ordinateur. Ces mthodes sont applicables dans un contexte plus gnral, et dans certains cas elles on tt appliques ailleurs, mais ceci ne sera pas abord dans le contexte de cette de thse. Dans le premier article, nous prsentons deux nouveaux algorithmes dinfrence variationelle pour le modle gnratif dimages appel codage parcimonieux spike- and-slab (CPSS). Ces mthodes dinfrence plus rapides nous permettent dutiliser des modles CPSS de tailles beaucoup plus grandes quauparavant. Nous dmontrons quelles sont meilleures pour extraire des dtecteur de caractristiques quand trs peu dexemples tiquets sont disponibles pour lentranement. Partant dun modle CPSS, nous construisons ensuite une architecture profonde, la machine de Boltzmann profonde partiellement dirige (MBP-PD). Ce modle a t conu de manire simplifier dentranement des machines de Boltzmann profondes qui ncessitent normalement une phase de pr-entranement glouton pour chaque couche. Ce problme est rgl dans une certaine mesure, mais le cot dinfrence dans le nouveau modle est relativement trop lev pour permettre de lutiliser de manire pratique. Dans le deuxime article, nous revenons au problme dentranement joint de machines de Boltzmann profondes. Cette fois, au lieu de changer de famille de modles, nous introduisons un nouveau critre dentranement qui donne naissance aux machines de Boltzmann profondes multiples prdictions (MBP-MP). Les MBP-MP sont entranables en une seule tape et ont un meilleur taux de succs en classification que les MBP classiques. Elles sentranent aussi avec des mthodes variationelles standard au lieu de ncessiter un classificateur discriminant pour obtenir un bon taux de succs en classification. Par contre, un des inconvnients de tels modles est leur incapacit de gnrer deschantillons, mais ceci nest pas trop grave puisque la performance de classification des machines de Boltzmann profondes nest plus une priorit tant donn les dernires avances en apprentissage supervis. Malgr cela, les MBP-MP demeurent intressantes parce quelles sont capable daccomplir certaines tches que des modles purement superviss ne peuvent pas faire, telles que celle de classifier des donnes incompltes ou encore celle de combler intelligemment linformation manquante dans ces donnes incompltes. Le travail prsent dans cette thse sest droul au milieu dune priode de transformations importantes du domaine de lapprentissage rseaux neuronaux profonds qui a t dclenche par la dcouverte de lalgorithme de dropout par Geoffrey Hinton. Dropout rend possible un entranement purement supervis darchitectures de propagation unidirectionnel sans tre expos au danger de sur- entranement. Le troisime article prsent dans cette thse introduit une nouvelle fonction dactivation spcialement con cue pour aller avec lalgorithme de Dropout. Cette fonction dactivation, appele maxout, permet lutilisation de aggrgation multi-canal dans un contexte dapprentissage purement supervis. Nous dmontrons comment plusieurs tches de reconnaissance dobjets sont mieux accomplies par lutilisation de maxout. Pour terminer, sont prsentons un vrai cas dutilisation dans lindustrie pour la transcription dadresses de maisons plusieurs chiffres. En combinant maxout avec une nouvelle sorte de couche de sortie pour des rseaux neuronaux de convolution, nous dmontrons quil est possible datteindre un taux de succs comparable celui des humains sur un ensemble de donnes coriace constitu de photos prises par les voitures de Google. Ce systme a t dploy avec succs chez Google pour lire environ cent million dadresses de maisons.
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Department of Computer Applications, Cochin University of Science and Technology
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Modern computer systems are plagued with stability and security problems: applications lose data, web servers are hacked, and systems crash under heavy load. Many of these problems or anomalies arise from rare program behavior caused by attacks or errors. A substantial percentage of the web-based attacks are due to buffer overflows. Many methods have been devised to detect and prevent anomalous situations that arise from buffer overflows. The current state-of-art of anomaly detection systems is relatively primitive and mainly depend on static code checking to take care of buffer overflow attacks. For protection, Stack Guards and I-leap Guards are also used in wide varieties.This dissertation proposes an anomaly detection system, based on frequencies of system calls in the system call trace. System call traces represented as frequency sequences are profiled using sequence sets. A sequence set is identified by the starting sequence and frequencies of specific system calls. The deviations of the current input sequence from the corresponding normal profile in the frequency pattern of system calls is computed and expressed as an anomaly score. A simple Bayesian model is used for an accurate detection.Experimental results are reported which show that frequency of system calls represented using sequence sets, captures the normal behavior of programs under normal conditions of usage. This captured behavior allows the system to detect anomalies with a low rate of false positives. Data are presented which show that Bayesian Network on frequency variations responds effectively to induced buffer overflows. It can also help administrators to detect deviations in program flow introduced due to errors.
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The application of computer vision based quality control has been slowly but steadily gaining importance mainly due to its speed in achieving results and also greatly due to its non- destnictive nature of testing. Besides, in food applications it also does not contribute to contamination. However, computer vision applications in quality control needs the application of an appropriate software for image analysis. Eventhough computer vision based quality control has several advantages, its application has limitations as to the type of work to be done, particularly so in the food industries. Selective applications, however, can be highly advantageous and very accurate.Computer vision based image analysis could be used in morphometric measurements of fish with the same accuracy as the existing conventional method. The method is non-destructive and non-contaminating thus providing anadvantage in seafood processing.The images could be stored in archives and retrieved at anytime to carry out morphometric studies for biologists.Computer vision and subsequent image analysis could be used in measurements of various food products to assess uniformity of size. One product namely cutlet and product ingredients namely coating materials such as bread crumbs and rava were selected for the study. Computer vision based image analysis was used in the measurements of length, width and area of cutlets. Also the width of coating materials like bread crumbs was measured.Computer imaging and subsequent image analysis can be very effectively used in quality evaluations of product ingredients in food processing. Measurement of width of coating materials could establish uniformity of particles or the lack of it. The application of image analysis in bacteriological work was also done
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Self- and cross-velocity correlation functions and related transport coefficients of molten salts are studied by molecular-dynamics simulation. Six representative systems are considered, i.e., NaCl and KCl alkali halides, CuCl and CuBr noble-metal halides, and SrCl2 and ZnCl2 divalent metal-ion halides. Computer simulation results are compared with experimental self-diffusion coefficients and electrical conductivities. Special attention is paid to dynamic cross correlations and their dependence on the Coulomb interactions as well as on the size and mass differences between anions and cations.
