966 resultados para information behavior
Resumo:
This paper shows theoretical models (analytical formulations) to predict the mechanical behavior of thick composite tubes and how some parameters can influence this behavior. Thus, firstly, it was developed the analytical formulations for a pressurized tube made of composite material with a single thick ply and only one lamination angle. For this case, the stress distribution and the displacement fields are investigated as function of different lamination angles and reinforcement volume fractions. The results obtained by the theoretical model are physic consistent and coherent with the literature information. After that, the previous formulations are extended in order to predict the mechanical behavior of a thick laminated tube. Both analytical formulations are implemented as a computational tool via Matlab code. The results obtained by the computational tool are compared to the finite element analyses, and the stress distribution is considered coherent. Moreover, the engineering computational tool is used to perform failure analysis, using different types of failure criteria, which identifies the damaged ply and the mode of failure.
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BACKGROUND: Evaluations of clinical depression are traditionally based on verbal information. Nonverbal expressive behavior, however, being associated with a person's reflexive responses, may reveal negative emotional or social processes that are not under complete control of the patients. However, investigations of nonverbal behavior in the evaluation of depressed patients are still scarce. This study examines the nonverbal behaviors of a group of Brazilian patients, associating their nonverbal behavior with severity of depression. METHODS: Forty depressed patients were evaluated at baseline (T0) and after a two-week transcranial direct current stimulation treatment (T1), according to rating scales and through a 21-category Ethogram for assessment of the frequency of nonverbal behaviors displayed during an interview. RESULTS: Behaviors that were related to negative feelings and social disinterest decreased with corresponding clinical improvement and were associated with increased severity of symptoms at T0 and greater negative affect and dissatisfaction at T1. Pro-social behaviors were associated with milder symptoms at T0 and increased after treatment. Facial, head and hand expressive movements stood out as important indicators because of their associations with severity of depression. LIMITATIONS: Duration of behaviors was not assessed and there was not a healthy control group with which to compare the findings. CONCLUSIONS: These results support the usefulness of nonverbal behavior as an evaluation technique in the assessment of clinical depression.
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[EN]A thermodynamic study is carried out on binary systems composed of propyl ethanoate with six alkanes, from pentane to decane. Vapor pressures of the ester and the isobaric vapor−liquid equilibria of these six mixtures were measured at 101.32 kPa in a small-capacity ebulliometer and also the mixing properties yE = vE,hE over a range of temperatures and at atmospheric pressure. Adequate correlations are drawn for the surfaces yE = yE(x,T) with an interpretation on the behavior of the mixtures and also using cp E data from literature.
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The central objective of research in Information Retrieval (IR) is to discover new techniques to retrieve relevant information in order to satisfy an Information Need. The Information Need is satisfied when relevant information can be provided to the user. In IR, relevance is a fundamental concept which has changed over time, from popular to personal, i.e., what was considered relevant before was information for the whole population, but what is considered relevant now is specific information for each user. Hence, there is a need to connect the behavior of the system to the condition of a particular person and his social context; thereby an interdisciplinary sector called Human-Centered Computing was born. For the modern search engine, the information extracted for the individual user is crucial. According to the Personalized Search (PS), two different techniques are necessary to personalize a search: contextualization (interconnected conditions that occur in an activity), and individualization (characteristics that distinguish an individual). This movement of focus to the individual's need undermines the rigid linearity of the classical model overtaken the ``berry picking'' model which explains that the terms change thanks to the informational feedback received from the search activity introducing the concept of evolution of search terms. The development of Information Foraging theory, which observed the correlations between animal foraging and human information foraging, also contributed to this transformation through attempts to optimize the cost-benefit ratio. This thesis arose from the need to satisfy human individuality when searching for information, and it develops a synergistic collaboration between the frontiers of technological innovation and the recent advances in IR. The search method developed exploits what is relevant for the user by changing radically the way in which an Information Need is expressed, because now it is expressed through the generation of the query and its own context. As a matter of fact the method was born under the pretense to improve the quality of search by rewriting the query based on the contexts automatically generated from a local knowledge base. Furthermore, the idea of optimizing each IR system has led to develop it as a middleware of interaction between the user and the IR system. Thereby the system has just two possible actions: rewriting the query, and reordering the result. Equivalent actions to the approach was described from the PS that generally exploits information derived from analysis of user behavior, while the proposed approach exploits knowledge provided by the user. The thesis went further to generate a novel method for an assessment procedure, according to the "Cranfield paradigm", in order to evaluate this type of IR systems. The results achieved are interesting considering both the effectiveness achieved and the innovative approach undertaken together with the several applications inspired using a local knowledge base.
Resumo:
[ITA]La demenza consiste nel deterioramento, spesso progressivo, dello stato cognitivo di un individuo. Chi è affetto da demenza, presenta alterazioni a livello cognitivo, comportamentale e motorio, ad esempio compiendo gesti ossessivi, ripetitivi, senza uno scopo preciso. La condizione dei pazienti affetti da demenza è valutata clinicamente tramite apposite scale e le informazioni relative al comportamento vengono raccolte intervistando chi se ne occupa, come familiari, il personale infermieristico o il medico curante. Spesso queste valutazioni si rivelano inaccurate, possono essere fortemente influenzate da considerazioni soggettive, e sono dispendiose in termini di tempo. Si ha quindi l'esigenza di disporre di metodiche oggettive per valutare il comportamento motorio dei pazienti e le sue alterazioni patologiche; i sensori inerziali indossabili potrebbero costituire una valida soluzione, per questo scopo. L'obiettivo principale della presente attività di tesi è stato definire e implementare un software per una valutazione oggettiva, basata su sensori, del pattern motorio circadiano, in pazienti affetti da demenza ricoverati in un'unità di terapia a lungo termine, che potrebbe evidenziare differenze nei sintomi della malattia che interessano il comportamento motorio, come descritto in ambito clinico. Lo scopo secondario è stato quello di verificare i cambiamenti motori pre- e post-intervento in un sottogruppo di pazienti, a seguito della somministrazione di un programma sperimentale di intervento basato su esercizi fisici. --------------- [ENG]Dementia involves deterioration, often progressive, of a person's cognitive status. Those who suffer from dementia, present alterations in cognitive and motor behavior, for example performing obsessive and repetitive gestures, without a purpose. The condition of patients suffering from dementia is clinically assessed by means of specific scales and information relating to the behavior are collected by interviewing caregivers, such as the family, nurses, or the doctor. Often it turns out that these are inaccurate assessments that may be heavily influenced by subjective evaluations and are costly in terms of time. Therefore, there is the need for objective methods to assess the patients' motor behavior and the pathological changes; wearable inertial sensors may represent a viable option, so this aim. The main objective of this thesis project was to define and implement a software for a sensor-based assessment of the circadian motor pattern in patients suffering from dementia, hospitalized in a long-term care unit, which could highlight differences in the disease symptoms affecting the motor behavior, as described in the clinical setting. The secondary objective was to verify pre- and post-intervention changes in the motor patterns of a subgroup of patients, following the administration of an experimental program of intervention based on physical exercises.
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WNS-affected bats did so over similar time frames as WNSunaffected bats. The behaviors of bats with WNS did not change as drastically as expected. Thereseems to be little to no effect on their ability to fly/forage until much later stages of the disease when they are likely near death. WNS-affected bats are grooming more which could be altering the way they use energy reserves during hibernation possibly leading tostarvation and eventually death. The decreased likelihood of arousals in response to external cues may be the result of spending more energy during previous and increasingly frequent arousals. While it is clear that WNS does result in changes in behavior whether these changes are directly in response to fungal skin infection or to some other component of the syndrome such as decreased energy availability or loss of homeostasis is unknown. bat behavior, white-nose syndrome, behavior, video surveillance, arousal patterns White-Nose Syndrome (WNS) is a disease of hibernating bats caused by the fungal pathogen Geomyces destructans. The fungus, which was first noted in 2006, invades bats wings and other exposed membranes, eventually resulting in death. Researchers have yet to understand many aspects of this disease, including basic etiology and epidemiology. There is also a lack of information on how fungal infection may change the behavior of healthy bats during hibernation or how changes in behavior may influence disease progression. Based upon the physiological changes that are known to occur in affected bats, and upon anecdotal observations of aberrant behavior in these bats, I hypothesized that WNS would significantly change the behavior of the little brown myotis (Myotis lucifugus). My research examined the behavior of hibernating bats during arousals from torpor. I compared WNS-affected and unaffected bats, in the field and incaptivity, using motion-sensitive infrared cameras. Flight maneuverability and echolocation were also tested between WNS-affected and unaffected bats during arousalsfrom hibernation to detect changes in the bats' ability to perform basic locomotion or potentially catch insect prey. Lastly, hibernating bats were artificially disturbed and theirarousal patterns were monitored to examine changes in the response to external stimuli between WNS-affected and unaffected bats.Bats with WNS groomed for longer periods of time after arousing from torpor, both in the field and in captivity. They also engaged in longer periods of any sort of activity during these arousals. There were no changes in acoustical signaling during flight tests and changes in flight maneuverability were only found in bats were seen staging" near the entrance of the mine which is itself a unique behavior exhibited by affected bats. At this point these bats were likely near death and could barely fly at all. In response toexternal stimuli bats with WNS were less likely to arouse than unaffected bats. However when they did arouse WNS-affected bats did so over similar time frames as WNSunaffected bats. The behaviors of bats with WNS did not change as drastically as expected. Thereseems to be little to no effect on their ability to fly/forage until much later stages of the disease when they are likely near death. WNS-affected bats are grooming more which could be altering the way they use energy reserves during hibernation possibly leading tostarvation and eventually death. The decreased likelihood of arousals in response to external cues may be the result of spending more energy during previous and increasingly frequent arousals. While it is clear that WNS does result in changes in behavior whetherthese changes are directly in response to fungal skin infection or to some other component of the syndrome such as decreased energy availability or loss of homeostasis is unknown."
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Developers rely on the mechanisms provided by their IDE to browse and navigate a large software system. These mechanisms are usually based purely on a system's static source code. The static perspective, however, is not enough to understand an object-oriented program's behavior, in particular if implemented in a dynamic language. We propose to enhance IDEs with a program's runtime information (eg. message sends and type information) to support program comprehension through precise navigation and informative browsing. To precisely specify the type and amount of runtime data to gather about a system under development, dynamically and on demand, we adopt a technique known as partial behavioral reflection. We implemented navigation and browsing enhancements to an IDE that exploit this runtime information in a prototype called Hermion. We present preliminary validation of our experimental enhanced IDE by asking developers to assess its usefulness to understand an unfamiliar software system.
Resumo:
Code queries focus mainly on the static structure of a system. To comprehend the dynamic behavior of a system however, a software engineer needs to be able to reason about the dynamics of this system, for instance by querying a database of dynamic information. Such a querying mechanism should be directly available in the IDE where the developers implements, navigates and reasons about the software system. We propose (i) concepts to gather dynamic information, (ii) the means to query this information, and (iii) tools and techniques to integrate querying of dynamic information in the IDE, including the presentation of results generated by queries.
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We investigate whether insiders of bankrupt firms hold less stock or reduce their stockholdings compared to what we observed for insiders of similar firms that do not go bankrupt. We find little evidence of such time-series and cross-sectional differences in spite of the fact that the stock value of bankrupt firms falls by more than ninety percent in the five years preceding bankruptcy. One implication of our results is that the amount of stock owned and the magnitude of the trades undertaken by corporate insiders of both bankrupt and nonbankrupt firms appear to provide no information about firm value.
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With improving clinical CT scanning technology, the accuracy of CT-based finite element (FE) models of the human skeleton may be ameliorated by an enhanced description of apparent level bone mechanical properties. Micro-finite element (μFE) modeling can be used to study the apparent elastic behavior of human cancellous bone. In this study, samples from the femur, radius and vertebral body were investigated to evaluate the predictive power of morphology–elasticity relationships and to compare them across different anatomical regions. μFE models of 701 trabecular bone cubes with a side length of 5.3 mm were analyzed using kinematic boundary conditions. Based on the FE results, four morphology–elasticity models using bone volume fraction as well as full, limited or no fabric information were calibrated for each anatomical region. The 5 parameter Zysset–Curnier model using full fabric information showed excellent predictive power with coefficients of determination ( r2adj ) of 0.98, 0.95 and 0.94 of the femur, radius and vertebra data, respectively, with mean total norm errors between 14 and 20%. A constant orthotropy model and a constant transverse isotropy model, where the elastic anisotropy is defined by the model parameters, yielded coefficients of determination between 0.90 and 0.98 with total norm errors between 16 and 25%. Neglecting fabric information and using an isotropic model led to r2adj between 0.73 and 0.92 with total norm errors between 38 and 49%. A comparison of the model regressions revealed minor but significant (p<0.01) differences for the fabric–elasticity model parameters calibrated for the different anatomical regions. The proposed models and identified parameters can be used in future studies to compute the apparent elastic properties of human cancellous bone for homogenized FE models.
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Recognizing the increasing amount of information shared on Social Networking Sites (SNS), in this study we aim to explore the information processing strategies of users on Facebook. Specifically, we aim to investigate the impact of various factors on user attitudes towards the posts on their Newsfeed. To collect the data, we program a Facebook application that allows users to evaluate posts in real time. Applying Structural Equation Modeling to a sample of 857 observations we find that it is mostly the affective attitude that shapes user behavior on the network. This attitude, in turn, is mainly determined by the communication intensity between users, overriding comprehensibility of the post and almost neglecting post length and user posting frequency.
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According to the 2000 United States Census, the Asian population in Houston, Texas, has increased more than 67% in the last ten years. To supplement an already active consumer health information program, the staff of the Houston Academy of Medicine-Texas Medical Center Library worked with community partners to bring health information to predominantly Asian neighborhoods. Brochures on health topics of concern to the Asian community were translated and placed in eight informational kiosks in Asian centers such as temples and an Asian grocery store. A press conference and a ribbon cutting ceremony were held to debut the kiosks and to introduce the Consumer Health Information for Asians (CHIA) program. Project goals for the future include digitizing the translated brochures, mounting them on the Houston HealthWays Website, and developing touch-screen kiosks. The CHIA group is investigating adding health resources in other Asian languages, as well as Spanish. Funding for this project has come from outside sources rather than from the regular library budget.
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The hippocampus receives input from upper levels of the association cortex and is implicated in many mnemonic processes, but the exact mechanisms by which it codes and stores information is an unresolved topic. This work examines the flow of information through the hippocampal formation while attempting to determine the computations that each of the hippocampal subfields performs in learning and memory. The formation, storage, and recall of hippocampal-dependent memories theoretically utilize an autoassociative attractor network that functions by implementing two competitive, yet complementary, processes. Pattern separation, hypothesized to occur in the dentate gyrus (DG), refers to the ability to decrease the similarity among incoming information by producing output patterns that overlap less than the inputs. In contrast, pattern completion, hypothesized to occur in the CA3 region, refers to the ability to reproduce a previously stored output pattern from a partial or degraded input pattern. Prior to addressing the functional role of the DG and CA3 subfields, the spatial firing properties of neurons in the dentate gyrus were examined. The principal cell of the dentate gyrus, the granule cell, has spatially selective place fields; however, the behavioral correlates of another excitatory cell, the mossy cell of the dentate polymorphic layer, are unknown. This report shows that putative mossy cells have spatially selective firing that consists of multiple fields similar to previously reported properties of granule cells. Other cells recorded from the DG had single place fields. Compared to cells with multiple fields, cells with single fields fired at a lower rate during sleep, were less likely to burst, and were more likely to be recorded simultaneously with a large population of neurons that were active during sleep and silent during behavior. These data suggest that single-field and multiple-field cells constitute at least two distinct cell classes in the DG. Based on these characteristics, we propose that putative mossy cells tend to fire in multiple, distinct locations in an environment, whereas putative granule cells tend to fire in single locations, similar to place fields of the CA1 and CA3 regions. Experimental evidence supporting the theories of pattern separation and pattern completion comes from both behavioral and electrophysiological tests. These studies specifically focused on the function of each subregion and made implicit assumptions about how environmental manipulations changed the representations encoded by the hippocampal inputs. However, the cell populations that provided these inputs were in most cases not directly examined. We conducted a series of studies to investigate the neural activity in the entorhinal cortex, dentate gyrus, and CA3 in the same experimental conditions, which allowed a direct comparison between the input and output representations. The results show that the dentate gyrus representation changes between the familiar and cue altered environments more than its input representations, whereas the CA3 representation changes less than its input representations. These findings are consistent with longstanding computational models proposing that (1) CA3 is an associative memory system performing pattern completion in order to recall previous memories from partial inputs, and (2) the dentate gyrus performs pattern separation to help store different memories in ways that reduce interference when the memories are subsequently recalled.
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BACKGROUND There is ample evidence that a subgroup of Parkinson's disease patients who are treated with dopaminergic drugs develop certain behavioral addictions such as pathological gambling. The fact that only a subgroup of these patients develops pathological gambling suggests an interaction between dopaminergic drug treatment and individual susceptibility factors. These are potentially of genetic origin, since research in healthy subjects suggests that vulnerability for pathological gambling may be linked to variation in the dopamine receptor D4 (DRD4) gene. Using a pharmacogenetic approach, we investigated how variation in this gene modulates the impact of dopaminergic stimulation on gambling behavior in healthy subjects. METHODS We administered 300 mg of L-dihydroxyphenylalanine (L-DOPA) or placebo to 200 healthy male subjects who were all genotyped for their DRD4 polymorphism. Subjects played a gambling task 60 minutes after L-DOPA administration. RESULTS Without considering genetic information, L-DOPA administration did not lead to an increase in gambling propensity compared with placebo. As expected, however, an individual's DRD4 polymorphism accounted for variation in gambling behavior after the administration of L-DOPA. Subjects who carry at least one copy of the 7-repeat allele showed an increased gambling propensity after dopaminergic stimulation. CONCLUSIONS These findings demonstrate that genetic variation in the DRD4 gene determines an individual's gambling behavior in response to a dopaminergic drug challenge. They may have implications for the treatment of Parkinson's disease patients by offering a genotype approach for determining individual susceptibilities for pathological gambling and may also afford insights into the vulnerability mechanisms underlying addictive behavior.
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The aim of this study was to associate changes in dairy farmers' self-reported attitude, knowledge, and behavior with the decrease in incidence rate of clinical mastitis (IRCM). Farmer-diagnosed clinical mastitis cases were obtained from two surveys conducted before (July 2004-June 2005) and at the end (2009) of a mastitis control program in the Netherlands. Information on farmers' attitude, knowledge, and behavior was also obtained by sending the farmers the same questionnaire during both surveys. Multivariable linear regression models identified that the herd level 2004 IRCM explained 28% of the variation in the decrease of IRCM. Changes in farmers' attitude and knowledge, and changes in farmers' behavior additionally explained 24% and 5%, respectively. These results suggest that the way management measures are executed may be at least as important as the fact that they are executed. No control group was available for this study because the intervention was applied at the national level. We therefore do not claim any causal relationships.