737 resultados para COMPUTERIZED TOMOPGRAPHY
Resumo:
J R Firth first gave prominence to collacation in linguistic theory. Halliday, Sinclair, Stubbs, and Hoey have all extended Firth's ideas. Palmer and Hornby recognized the pedagogical value of collocation, and incorporated it into their early EFL dictionaries. More recent EFL dictionaries, based on large, computerized language corpora, have used complex software and statistical measures to gain further insights into the way that collocational patterns are woven into language, and the results are visible in the dictionary entries of later editions. This has fed back into language pedagogy, and is also influencing translation and computational research. © 2006 Elsevier Ltd. All rights reserved.
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This research was concerned with identifying factors which may influence human reliability within chemical process plants - these factors are referred to as Performance Shaping Factors (PSFs). Following a period of familiarization within the industry, a number of case studies were undertaken covering a range of basic influencing factors. Plant records and site `lost time incident reports' were also used as supporting evidence for identifying and classifying PSFs. In parallel to the investigative research, the available literature appertaining to human reliability assessment and PSFs was considered in relation to the chemical process plan environment. As a direct result of this work, a PSF classification structure has been produced with an accompanying detailed listing. Phase two of the research considered the identification of important individual PSFs for specific situations. Based on the experience and data gained during phase one, it emerged that certain generic features of a task influenced PSF relevance. This led to the establishment of a finite set of generic task groups and response types. Similarly, certain PSFs influence some human errors more than others. The result was a set of error type key words, plus the identification and classification of error causes with their underlying error mechanisms. By linking all these aspects together, a comprehensive methodology has been forwarded as the basis of a computerized aid for system designers. To recapitulate, the major results of this research have been: One, the development of a comprehensive PSF listing specifically for the chemical process industries with a classification structure that facilitates future updates; and two, a model of identifying relevant SPFs and their order of priority. Future requirements are the evaluation of the PSF listing and the identification method. The latter must be considered both in terms of `useability' and its success as a design enhancer, in terms of an observable reduction in important human errors.
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Computer integrated monitoring is a very large area in engineering where on-line, real time data acquisition with the aid of sensors is the solution to many problems in the manufacturing industry as opposed to the old data logging method by graphics analysis. The raw data which is collected this way however is useless in the absence of a proper computerized management system. The transfer of data between the management and the shop floor processes has been impossible in the past unless all the computers in the system were totally compatible with each other. This limits the efficiency of the systems because they get governed by the limitations of the computers. General Motors of U.S.A. have recently started research on a new standard called the Manufacturing Automation Protocol (MAP) which is expected to allow data transfer between different types of computers. This is still in early development stages and also is currently very expensive. This research programme shows how such a shop floor data acquisition system and a complete management system on entirely different computers can be integrated together to form a single system by achieving data transfer communications using a cheaper but a superior alternative to MAP. Standard communication character sets and hardware such as ASCII and UARTs have been used in this method but the technique is so powerful that totally incompatible computers are shown to run different programs (in different languages) simultaneously and yet receive data from each other and process in their own CPUs with no human intervention.
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Background: Investigating genetic modulation of emotion processing may contribute to the understanding of heritable mechanisms of emotional disorders. The aim of the present study was to test the effects of catechol- O-methyltransferase (COMT) val158met and serotonin-transporter-linked promoter region (5-HTTLPR) polymorphisms on facial emotion processing in healthy individuals. Methods: Two hundred and seventy five (167 female) participants were asked to complete a computerized facial affect recognition task, which involved four experimental conditions, each containing one type of emotional face (fearful, angry, sad or happy) intermixed with neutral faces. Participants were asked to indicate whether the face displayed an emotion or was neutral. The COMT-val158met and 5-HTTLPR polymorphisms were genotyped. Results: Met homozygotes (COMT) showed a stronger bias to perceive neutral faces as expressions of anger, compared with val homozygotes. However, the S-homozygotes (5-HTTLPR) showed a reduced bias to perceive neutral faces as expressions of happiness, compared to L-homozygotes. No interaction between 5-HTTLPR and COMT was found. Conclusions: These results add to the knowledge of individual differences in social cognition that are modulated via serotonergic and dopaminergic systems. This potentially could contribute to the understanding of the mechanisms of susceptibility to emotional disorders. © 2013 Elsevier Masson SAS.
Activity and affect:repeated within-participant assessment in people after joint replacement surgery
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Objective: Between-participant research has shown that high negative affectivity predicts greater activity limitations and vice versa. This study examined both between- and within-participant associations of negative and positive affectivity with activity levels using ecological momentary assessment. Method: Participants were 25 people who had undergone joint replacement surgery 12 months previously. Participants made multiple reports of their activity and positive and negative affectivity over a single day using, a computerized diary. Activity was also objectively recorded using an activity monitor. The following day, participants made a self-report of their activity over the measurement day and general positive and negative affectivity levels were recorded. Results: Higher self-reported walking time over the whole measurement day was associated with higher general positive affectivity but not negative affectivity. However, using ecological momentary assessment, higher diary reports of negative affectivity predicted increased activity levels while positive affectivity neither predicted nor was predicted by activity. Conclusion: These findings demonstrate the importance of within-participant methodology in detecting subtle and immediate effects of individuals' mood on behavior that may differ from findings investigating between-participant effects over longer time periods.
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An expert system (ES) is a class of computer programs developed by researchers in artificial intelligence. In essence, they are programs made up of a set of rules that analyze information about a specific class of problems, as well as provide analysis of the problems, and, depending upon their design, recommend a course of user action in order to implement corrections. ES are computerized tools designed to enhance the quality and availability of knowledge required by decision makers in a wide range of industries. Decision-making is important for the financial institutions involved due to the high level of risk associated with wrong decisions. The process of making decision is complex and unstructured. The existing models for decision-making do not capture the learned knowledge well enough. In this study, we analyze the beneficial aspects of using ES for decision- making process.
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More powerful computers and affordable digital-video equipment means that desktop-video editing is now accessible and popular. In two experiments, we investigated whether seeing fake-video evidence, or simply being told that video evidence exists, could lead people to believe they committed an act they never did. Subjects completed a computerized gambling task, and when they returned later the same day, we falsely accused them of cheating on the task. All of the subjects were told that incriminating video evidence existed, and half were also exposed to a fake video. See-video subjects were more likely to confess without resistance, and to internalize the act than told-video subjects, and see-video subjects tended to confabulate details more often than told-video subjects. We offer a metacognitive-based account of our results. Copyright © 2008 John Wiley & Sons, Ltd.
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In article the problems of mutual adapting of the humans and computer environment are reviewed. Features of image-intuitive and physical-mathematical modes of perception and thinking are investigated. The problems of choice of means and methods of the differential education the computerized society are considered.
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We investigate the effects of organizational culture and personal values on performance under individual and team contest incentives. We develop a model of regard for others and in-group favoritism that predicts interaction effects between organizational values and personal values in contest games. These predictions are tested in a computerized lab experiment with exogenous control of both organizational values and incentives. In line with our theoretical model we find that prosocial (proself) orientated subjects exert more (less) effort in team contests in the primed prosocial organizational values condition, relative to the neutrally primed baseline condition. Further, when the prosocial organizational values are combined with individual contest incentives, prosocial subjects no longer outperform their proself counterparts. These findings provide a first, affirmative, causal test of person-organization fit theory. They also suggest the importance of a 'triple-fit' between personal preferences, organizational values and incentive mechanisms for prosocially orientated individuals.
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The purpose of this study was twofold. It was designed to determine (a) the efficacy of an intervention designed to increase the frequencies of appropriate study behaviors on the part of community college students who were preparing for academic mathematics activities and (b) whether any increase in appropriate study behavior frequency was accompanied by increased academic achievement in college preparatory mathematics classes. A total of 126 Miami Dade College students participated in this study. Two developmental (remedial) mathematics classes were randomly assigned as the experimental group, and two others were assigned as the control group. All students also took a College Survival (SLS) class. The Study Behavior Inventory (SBI) and the Computerized Placement Test (CPT) were administered to the four classes. The SBI was used as a pre- and post-test. The SLS curriculum and classroom time were the same for both groups. However, students in the treatment groups received instruction designed to increase the frequency of effective study behaviors associated with the three factors identified in the SBI, while the students in the control group participated in activities that did not emphasize study behaviors. A series of analysis of covariance procedures were used to analyze four hypotheses. The first three hypotheses proposed that students who were instructed in the use of appropriate study behaviors would score higher on the three factors of the Study Behavior Inventory than those who were not. The fourth hypothesis proposed that a greater proportion of mathematics students who were instructed in the use of appropriate study behaviors would receive a passing grade in their course than students who were in the control group. The four hypotheses were tested at the .05 level of significance. This study revealed that students who received instruction in appropriate study behaviors scored higher in the use of appropriate study behaviors and in mathematics achievement than students who did not. Additional research is needed to investigate whether these effects would persist over time, or be found in subjects other than mathematics.
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Organizations are increasingly relying on teams to do the work that has traditionally been done by individuals. At the same time, the environments in which these organizations and teams operate have been becoming progressively more complex and uncertain. These trends raise important questions about the factors that enable teams to adapt. In response to these questions, the current study sought to identify the cognitive, behavioral, and motivational processes and emergent states that promote a team's adaptation to unforeseen changes and novel events, and the team compositional characteristics and leadership processes that enabled these processes and emergent states. Two hundred twenty two undergraduate students from a large Southeastern University composed 74 3-person teams, and participated in a computerized decision-making simulation where each team formed the governing body (i.e., Mayor's cabinet) for two separate simulated cities, and made strategic decisions about city operations. Participants were randomly assigned to one of three roles, distributing expertise and creating mutual interdependence. External team leader sensegiving was manipulated through video recorded communications from an external team leader. Results indicate that team cognitive ability, achievement striving, and psychological collectivism, as well as external team leader sensegiving, were all related to the similarity and quality of team members' strategy-focused mental models (cognitive emergent states), and to the amount of information sharing among members (behavioral process). In turn, teams with more similar and higher quality mental models, and who shared greater levels of information, were found to have a greater ability to react and adapt to environmental changes, and to have greater levels of decision-making effectiveness. Results indicate a pattern of relationships consistent with hypotheses, and have important implications for organizations and knowledge-based teams charged with management responsibilities. Organizations should staff teams with the compositional characteristics that enable the development of similar and high quality mental models, and that promote information sharing among teammates. Similarly, organizations which train and develop leaders to engage in sensegiving behaviors enable team adaptability and promote enhanced decision-making effectiveness when faced with unforeseen changes and novel situations.
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Respiratory gating in lung PET imaging to compensate for respiratory motion artifacts is a current research issue with broad potential impact on quantitation, diagnosis and clinical management of lung tumors. However, PET images collected at discrete bins can be significantly affected by noise as there are lower activity counts in each gated bin unless the total PET acquisition time is prolonged, so that gating methods should be combined with imaging-based motion correction and registration methods. The aim of this study was to develop and validate a fast and practical solution to the problem of respiratory motion for the detection and accurate quantitation of lung tumors in PET images. This included: (1) developing a computer-assisted algorithm for PET/CT images that automatically segments lung regions in CT images, identifies and localizes lung tumors of PET images; (2) developing and comparing different registration algorithms which processes all the information within the entire respiratory cycle and integrate all the tumor in different gated bins into a single reference bin. Four registration/integration algorithms: Centroid Based, Intensity Based, Rigid Body and Optical Flow registration were compared as well as two registration schemes: Direct Scheme and Successive Scheme. Validation was demonstrated by conducting experiments with the computerized 4D NCAT phantom and with a dynamic lung-chest phantom imaged using a GE PET/CT System. Iterations were conducted on different size simulated tumors and different noise levels. Static tumors without respiratory motion were used as gold standard; quantitative results were compared with respect to tumor activity concentration, cross-correlation coefficient, relative noise level and computation time. Comparing the results of the tumors before and after correction, the tumor activity values and tumor volumes were closer to the static tumors (gold standard). Higher correlation values and lower noise were also achieved after applying the correction algorithms. With this method the compromise between short PET scan time and reduced image noise can be achieved, while quantification and clinical analysis become fast and precise.
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There is growing popularity in the use of composite indices and rankings for cross-organizational benchmarking. However, little attention has been paid to alternative methods and procedures for the computation of these indices and how the use of such methods may impact the resulting indices and rankings. This dissertation developed an approach for assessing composite indices and rankings based on the integration of a number of methods for aggregation, data transformation and attribute weighting involved in their computation. The integrated model developed is based on the simulation of composite indices using methods and procedures proposed in the area of multi-criteria decision making (MCDM) and knowledge discovery in databases (KDD). The approach developed in this dissertation was automated through an IT artifact that was designed, developed and evaluated based on the framework and guidelines of the design science paradigm of information systems research. This artifact dynamically generates multiple versions of indices and rankings by considering different methodological scenarios according to user specified parameters. The computerized implementation was done in Visual Basic for Excel 2007. Using different performance measures, the artifact produces a number of excel outputs for the comparison and assessment of the indices and rankings. In order to evaluate the efficacy of the artifact and its underlying approach, a full empirical analysis was conducted using the World Bank's Doing Business database for the year 2010, which includes ten sub-indices (each corresponding to different areas of the business environment and regulation) for 183 countries. The output results, which were obtained using 115 methodological scenarios for the assessment of this index and its ten sub-indices, indicated that the variability of the component indicators considered in each case influenced the sensitivity of the rankings to the methodological choices. Overall, the results of our multi-method assessment were consistent with the World Bank rankings except in cases where the indices involved cost indicators measured in per capita income which yielded more sensitive results. Low income level countries exhibited more sensitivity in their rankings and less agreement between the benchmark rankings and our multi-method based rankings than higher income country groups.
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Experimental and theoretical studies regarding noise processes in various kinds of AlGaAs/GaAs heterostructures with a quantum well are reported. The measurement processes, involving a Fast Fourier Transform and analog wave analyzer in the frequency range from 10 Hz to 1 MHz, a computerized data storage and processing system, and cryostat in the temperature range from 78 K to 300 K are described in detail. The current noise spectra are obtained with the “three-point method”, using a Quan-Tech and avalanche noise source for calibration. ^ The properties of both GaAs and AlGaAs materials and field effect transistors, based on the two-dimensional electron gas in the interface quantum well, are discussed. Extensive measurements are performed in three types of heterostructures, viz., Hall structures with a large spacer layer, modulation-doped non-gated FETs, and more standard gated FETs; all structures are grown by MBE techniques. ^ The Hall structures show Lorentzian generation-recombination noise spectra with near temperature independent relaxation times. This noise is attributed to g-r processes in the 2D electron gas. For the TEGFET structures, we observe several Lorentzian g-r noise components which have strongly temperature dependent relaxation times. This noise is attributed to trapping processes in the doped AlGaAs layer. The trap level energies are determined from an Arrhenius plot of log (τT2) versus 1/T as well as from the plateau values. The theory to interpret these measurements and to extract the defect level data is reviewed and further developed. Good agreement with the data is found for all reported devices. ^
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This study examined the motivation of college and university faculty to implement service-learning into their traditional courses. The benefits derived by faculty, as well as those issues of maintenance, including supports and/or obstacles, were also investigated in relation to their impact on motivation. The focus was on generating theory from the emerging data. ^ Data were collected from interviews with 17 faculty teaching courses that included a component of service-learning. A maximum variation sampling of participants from six South Florida colleges and universities was utilized. Faculty participants represented a wide range of academic disciplines, faculty ranks, years of experience in teaching and using service-learning as well as gender and ethnic diversity. For data triangulation, a focus group with eight additional college faculty was conducted and documents, including course syllabi and institutional service-learning handbooks, collected during the interviews were examined. The interviews were transcribed and coded using traditional methods as well as with the assistance of the computerized assisted qualitative data analysis software, Atlas.ti. The data were organized into five major categories with themes and sub-themes emerging for each. ^ While intrinsic or personal factors along with extrinsic factors all serve to influence faculty motivation, the study's findings revealed that the primary factors influencing faculty motivation to adopt service-learning were those that were intrinsic or personal in nature. These factors included: (a) past experiences, (b) personal characteristics including the value of serving, (c) involvement with community service, (d) interactions and relationships with peers, (e) benefits to students, (f) benefits to teaching, and (g) perceived career benefits. Implications and recommendations from the study encompass suggestions for administrators in higher education institutions for supporting and encouraging faculty adoption of service-learning including a well developed infrastructure as well as incentives, particularly during the initial implementation period, rewards providing recognition for the academic nature of service-learning and support for the development of peer relationships among service-learning faculty. ^