807 resultados para Task Performance and Analysis
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The elimination of all external incisions is an important step in reducing the invasiveness of surgical procedures. Natural Orifice Translumenal Endoscopic Surgery (NOTES) is an incision-less surgery and provides explicit benefits such as reducing patient trauma and shortening recovery time. However, technological difficulties impede the widespread utilization of the NOTES method. A novel robotic tool has been developed, which makes NOTES procedures feasible by using multiple interchangeable tool tips. The robotic tool has the capability of entering the body cavity through an orifice or a single incision using a flexible articulated positioning mechanism and once inserted is not constrained by incisions, allowing for visualization and manipulations throughout the cavity. Multiple interchangeable tool tips of the robotic device initially consist of three end effectors: a grasper, scissors, and an atraumatic Babcock clamp. The tool changer is capable of selecting and switching between the three tools depending on the surgical task using a miniature mechanism driven by micro-motors. The robotic tool is remotely controlled through a joystick and computer interface. In this thesis, the following aspects of this robotic tool will be detailed. The first-generation robot is designed as a conceptual model for implementing a novel mechanism of switching, advancing, and controlling the tool tips using two micro-motors. It is believed that this mechanism achieves a reduction in cumbersome instrument exchanges and can reduce overall procedure time and the risk of inadvertent tissue trauma during exchanges with a natural orifice approach. Also, placing actuators directly at the surgical site enables the robot to generate sufficient force to operate effectively. Mounting the multifunctional robot on the distal end of an articulating tube provides freedom from restriction on the robot kinematics and helps solve some of the difficulties otherwise faced during surgery using NOTES or related approaches. The second-generation multifunctional robot is then introduced in which the overall size is reduced and two arms provide 2 additional degrees of freedom, resulting in feasibility of insertion through the esophagus and increased dexterity. Improvements are necessary in future iterations of the multifunctional robot; however, the work presented is a proof of concept for NOTES robots capable of abdominal surgical interventions.
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Objective: This study assessed the relation of child oral health-related quality of life with school performance and school absenteeism. Methods: We followed a cross-sectional design with a multistage random sample of 312 12-year-old schoolchildren living in Brazil. The participants completed the child perceptions questionnaire (CPQ1114) that provides information about psychological factors, while their parents or guardians answered questions on their socioeconomic status measured by parents' education level and household income. A dental examination of each child provided information on the prevalence of caries and dental trauma. Data on school performance, which included the results of baseline Brazilian language (Portuguese) tests, and school absenteeism (school days missed) were obtained from the school register. Multilevel linear regression was used to investigate the association among psychological and socioeconomic status and children's school performance. Results: In the multiple model, after adjusting for individual covariates, being a girl was associated with higher school performance (P < 0.05), whereas low household income (P < 0.05), higher mean of CPQ1114 (P < 0.05), and higher school days missed (P < 0.001) were identified as individual determinants of lower school performance. When the school-level covariates were included in the model, the association between subjects' level characteristics and school performance still persisted. Conclusion: Children's school performance and absence were influenced by psychological and socioeconomic conditions.
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The aim of the work is to conduct a finite element model analysis on a small – size concrete beam and on a full size concrete beam internally reinforced with BFRP exposed at elevated temperatures. Experimental tests performed at Kingston University have been used to compare the results from the numerical analysis for the small – size concrete beam. Once the behavior of the small – size beam at room temperature is investigated and switching to the heating phase reinforced beams are tested at 100°C, 200°C and 300°C in loaded condition. The aim of the finite element analysis is to reflect the three – point bending test adopted into the oven during the exposure of the beam at room temperature and at elevated temperatures. Performance and deformability of reinforced beams are straightly correlated to the material properties and a wide analysis on elastic modulus and coefficient of thermal expansion is given in this work. Develop a good correlation between the numerical model and the experimental test is the main objective of the analysis on the small – size concrete beam, for both modelling the aim is also to estimate which is the deterioration of the material properties due to the heating process and the influence of different parameters on the final result. The focus of the full – size modelling which involved the last part of this work is to evaluate the effect of elevated temperatures, the material deterioration and the deflection trend on a reinforced beam characterized by a different size. A comparison between the results from different modelling has been developed.
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Attraverso un excursus storico, teorico e metodologico, questa tesi di dottorato analizza la nascita, gli sviluppi e l’attuale dimensione costitutivo-identitaria dei Performance Studies, un ambito di ricerca accademica che, nato negli Stati Uniti alla fine degli anni Settanta, ha sempre palesato una natura restia nei confronti di qualunque tentativo definitorio. Se i Performance Studies concepiscono la performance sia come oggetto d’analisi sia come lente metodologica, e se, come evidenziato da Richard Schechner, praticamente tutto può essere “elevato a performance” e quindi indagato secondo le categorie analitiche di questa disciplina, ecco allora che, con uno slittamento transitivo e “meta-metodologico”, questa ricerca dottorale ha scelto come proprio oggetto di studio i Performance Studies stessi, osservandoli “as performance” e avvalendosi degli strumenti metodologici suggeriti dal suo stesso oggetto d’analisi. Questo lavoro indaga come l’oggetto di studio dei Performance Studies sia, seguendo la teoria schechneriana, il “behaved behavior”, e dunque come di conseguenza, il repertorio, prima ancora che l’archivio, possa essere considerato il fedele custode delle “pratiche incorporate”. Soffermandosi su esempi di “reenactment” performativo come quelli messi in atto da Marina Abramović e Clifford Owens, così come sui tentativi condotti dalla sezione dell’Intangible Cultural Heritage dell’UNESCO, suggerisce validi esempi di “archiviazione” della performance. L’elaborato prende poi in esame casi che esemplificano la proficua identificazione tra “studiare performance” e “fare performance”, sottolinea il ruolo cruciale e imprenscindibile determinato dal lavoro di ricerca sul campo inteso come “osservazione partecipante”, ed evidenzia il costante coinvolgimento sociale e politico assunto dai Performance Studies. Questa dissertazione affronta e supporta l’efficacia dei Performance Studies nel proporsi come uno strumento innovativo in grado di analizzare un mondo sempre più performativo nelle sue dinamiche. La loro natura tanto interdisciplinare quanto interculturale sembra farne una lente adeguata attraverso cui promuovere livelli diversi di performance dialogica tra culture localmente distinte ma globalmente assimilabili.
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To prospectively evaluate a 3-dimensional spoiled gradient-dual-echo (3D SPGR-DE) magnetic resonance imaging (MRI) sequence for the qualitative and quantitative analysis of liver fat content (LFC) in patients with the suspicion of fatty liver disease using histopathology as the standard of reference.
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This is the first part of a study investigating a model-based transient calibration process for diesel engines. The motivation is to populate hundreds of parameters (which can be calibrated) in a methodical and optimum manner by using model-based optimization in conjunction with the manual process so that, relative to the manual process used by itself, a significant improvement in transient emissions and fuel consumption and a sizable reduction in calibration time and test cell requirements is achieved. Empirical transient modelling and optimization has been addressed in the second part of this work, while the required data for model training and generalization are the focus of the current work. Transient and steady-state data from a turbocharged multicylinder diesel engine have been examined from a model training perspective. A single-cylinder engine with external air-handling has been used to expand the steady-state data to encompass transient parameter space. Based on comparative model performance and differences in the non-parametric space, primarily driven by a high engine difference between exhaust and intake manifold pressures (ΔP) during transients, it has been recommended that transient emission models should be trained with transient training data. It has been shown that electronic control module (ECM) estimates of transient charge flow and the exhaust gas recirculation (EGR) fraction cannot be accurate at the high engine ΔP frequently encountered during transient operation, and that such estimates do not account for cylinder-to-cylinder variation. The effects of high engine ΔP must therefore be incorporated empirically by using transient data generated from a spectrum of transient calibrations. Specific recommendations on how to choose such calibrations, how many data to acquire, and how to specify transient segments for data acquisition have been made. Methods to process transient data to account for transport delays and sensor lags have been developed. The processed data have then been visualized using statistical means to understand transient emission formation. Two modes of transient opacity formation have been observed and described. The first mode is driven by high engine ΔP and low fresh air flowrates, while the second mode is driven by high engine ΔP and high EGR flowrates. The EGR fraction is inaccurately estimated at both modes, while EGR distribution has been shown to be present but unaccounted for by the ECM. The two modes and associated phenomena are essential to understanding why transient emission models are calibration dependent and furthermore how to choose training data that will result in good model generalization.
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Primates as a taxonomic Order have the largest brains corrected for body size in the animal kingdom. These large brains have allowed primates to evolve the capacity to demonstrate advanced cognitive processes across a wide array of abilities. Nonhuman primates are particularly adept at social learning, defined as the modification of behavior by observing the actions of others. Additionally, primates often exploit resources differently depending on their social context. In this study, capuchin monkeys (Cebus apella) were tested on a cognitive task in three social contexts to determine if social context influenced their performance on the task. The three social contexts included: alone, having a dominant individual in an adjacent compartment, and having a subordinate individual in the adjacent compartment. The benefits to this design were thatthe social context was the only variable influencing performance, whereas in previous studies investigating audience effects other animals could physically and directly influence a subject's performance in an open testing situation. Based on past studies, Ipredicted that the presence of a dominant individual would reduce cognitive task performance compared to the other conditions. The cognitive test used was a match-tosample discrimination task in which animals matched combinations of eight geometric shapes. Animals were trained on this task in an isolated context until they reached a baseline level of proficiency and were then tested in the three social contexts in a random order multiple times. Two subjects (Mt and Dv) have successfully completed trials under all conditions. Results indicated that there were no significant difference in taskperformance across the three conditions (Dv x^2 (1) = 0.42, p=0.58; Mt x^2 (1) = 0.02, p=0.88). In all conditions, subjects performed significantly above chance (i.e., 39/60 trials determined by a binomial distribution). Results are contrary to previous studies thatreport low status monkeys 'play dumb' when testing in a mixed social context, possibly because other studies did not account for aggressive interference by dominants while testing. Results of this study suggest that the mere presence of a dominant individualdoes not necessarily affect performance on a cognitive task, but rather the imminence of physical aggression is the most important factor influencing testing in a social context.
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Interpretations of Shakespeare’s characters have been subject to the pressures of history, exhibiting a progression of performance styles in accordance with changes in ideas and concerns over time. Shakespeare’s complex portrayals of women leave room for cultural influences of a time period to greatly influence interpretations because of the ambiguous nature of some of his major female characters. Lady Macbeth and Much Ado About Nothing’s Beatrice both overstep and challenge gender boundaries, and the combination of their defiant natures and textual ambiguities have made these characters highly controversial over the past four centuries.Various cultures over time have imposed specific readings of the characters that serve to reinforce the male-dominated expectations of a given society. The examination of variations in performance styles and interpretations of these two extremely canonical characters revealinsights into gender ideologies that existed during various time periods throughout history. The combination of this analysis with an exploration of the effects of the more recent applications offeminism and film, which have both helped to reshape the cultural images of both Lady Macbeth and Beatrice, will aide in an observation of the status of gender relations in our contemporary society. The current trend of interpretations of these characters could also provide predictions about future gender relations in our culture.
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Within the next few years, the medical industry will launch increasingly affordable three-dimensional (3D) vision systems for the operating room (OR). This study aimed to evaluate the effect of two-dimensional (2D) and 3D visualization on surgical skills and task performance.
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Immersive virtual environments (IVEs) have the potential to afford natural interaction in the three-dimensional (3D) space around a user. However, interaction performance in 3D mid-air is often reduced and depends on a variety of ergonomics factors, the user's endurance, muscular strength, as well as fitness. In particular, in contrast to traditional desktop-based setups, users often cannot rest their arms in a comfortable pose during the interaction. In this article we analyze the impact of comfort on 3D selection tasks in an immersive desktop setup. First, in a pre-study we identified how comfortable or uncomfortable specific interaction positions and poses are for users who are standing upright. Then, we investigated differences in 3D selection task performance when users interact with their hands in a comfortable or uncomfortable body pose, while sitting on a chair in front of a table while the VE was displayed on a headmounted display (HMD). We conducted a Fitts' Law experiment to evaluate selection performance in different poses. The results suggest that users achieve a significantly higher performance in a comfortable pose when they rest their elbow on the table.
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The assumption that social skills are necessary ingredients of collaborative learning is well established but rarely empirically tested. In addition, most theories on collaborative learning focus on social skills only at the personal level, while the social skill configurations within a learning group might be of equal importance. Using the integrative framework, this study investigates which social skills at the personal level and at the group level are predictive of task-related e-mail communication, satisfaction with performance and perceived quality of collaboration. Data collection took place in a technology-enhanced long-term project-based learning setting for pre-service teachers. For data collection, two questionnaires were used, one at the beginning and one at the end of the learning cycle which lasted 3 months. During the project phase, the e-mail communication between group members was captured as well. The investigation of 60 project groups (N = 155 for the questionnaires; group size: two or three students) and 33 groups for the e-mail communication (N = 83) revealed that personal social skills played only a minor role compared to group level configurations of social skills in predicting satisfaction with performance, perceived quality of collaboration and communication behaviour. Members from groups that showed a high and/or homogeneous configuration of specific social skills (e.g., cooperation/compromising, leadership) usually were more satisfied and saw their group as more efficient than members from groups with a low and/or heterogeneous configuration of skills.
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Introduction Musicians often suffer injuries related to their music playing. Therefore, some use Alexander Technique (AT), a mental-physical method that facilitates to release unnecessary muscle tension and to re-educate non-beneficial movement patterns through enhanced kinaesthetic awareness. According to a recent review AT may be effective for chronic back pain [1]. This review aimed to evaluate the evidence for the effectiveness of AT lessons on music performance and musicians’ health and well-being. Methods The following electronic databases were searched up to July 2012 for relevant literature: PUBMED, Google Scholar, CINAHL and EMBASE. The search criteria were "Alexander technique" AND "music*" [all fields]. References were searched, and experts and societies of AT or musicians' medicine contacted for further publications. Results 100 studies were identified. 24 studies were included for further analysis, 5 of which were randomised controlled trials (RCTs), 5 controlled but not randomised (CTs), 5 without control group, 2 mixed methods (RCT and case studies), and 7 surveys. 13 to 72 musicians participated per RCT. In 5 RCTs AT groups received between 12 and 20 one-to-one lessons. In 4 RCTs control groups received no interventions. Primary outcomes were performance anxiety, music performance, "use" as well as respiratory function and pain. Performance anxiety decreased by AT in 3 of 4 RCTs and in 3 of 3 CTs. Music performance was improved by AT in 1 RCT, yet in 2 RCTs comparing neurofeedback (NF) to AT, only NF showed improvements. Discussion and Conclusion To investigate the effectiveness of AT in musicians a variety of study designs and outcome measures have been used. Evidence from RCTs suggests that AT may improve performance anxiety in musicians. Effects on music performance, body use and respiratory function yet remain inconsistent. Future trials with scientifically sound study designs are warranted to further and more reliably explore the potential of AT as a relatively low cost and low risk method in the interest of musicians. References [1] Woodman JP, Moore NR. Evidence for the effectiveness of Alexander Technique lessons in medical and health-related conditions: a systematic review. Int J Clin Pract 2012;66(1):98-112.
Resumo:
Purpose Musicians often suffer injuries related to their music playing. Therefore, some use the Alexander Technique (AT), a psycho-physical method that helps to release unnecessary muscle tension and re-educates non-beneficial movement patterns through enhanced kinaesthetic awareness. According to a recent review AT may be effective for chronic back pain. This review aimed to evaluate the evidence for the effectiveness of AT lessons on music performance and musicians’ health and well-being. Methods The following electronic databases were searched up to July 2012 for relevant literature: PUBMED, Google Scholar, CINAHL and EMBASE. The search criteria were "Alexander technique" AND "music*" [all fields]. References were searched, and experts and societies of AT or musicians' medicine contacted for further publications. Results 100 studies were identified. 35 studies were included for further analysis, 5 of which were randomised controlled trials (RCTs), 5 controlled but not randomised, 5 not controlled, 5 qualitative case studies, 2 mixed-models (RCT and case studies), 7 surveys, 4 qualitative case reports and 2 unpublished pilot studies. 13 to 72 musicians participated per RCT. In 5 RCTs AT groups received between 12 and 20 one-to-one lessons. In 4 RCTs control groups received no interventions. Primary outcomes were performance anxiety, performance, "use" as well as respiratory function and pain. Performance anxiety decreased by AT in 3 of 4 RCTs. Music performance was improved by AT in 1 RCT, yet in 2 RCTs comparing neurofeedback (NF) to AT, only NF showed improvements. Conclusions To investigate the effectiveness of AT in musicians a variety of study designs and outcome measures have been used. Evidence from RCTs suggests that AT may improve performance anxiety in musicians. Effects on music performance, body use and respiratory function yet remain inconsistent. Future trials with well-established study designs are warranted to further and more reliably explore the potential of AT as a relatively low cost and low risk method in the interest of musicians.
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The performance of high-resolution CZE for determination of carbohydrate-deficient transferrin (CDT) in human serum based on internal and external quality data gathered over a 10-year period is reported. The assay comprises mixing of serum with a Fe(III) ion-containing solution prior to analysis of the iron saturated mixture in a dynamically double-coated capillary using a commercial buffer at alkaline pH. CDT values obtained with a human serum of a healthy individual and commercial quality control sera are shown to vary less than 10%. Values of a control from a specific lot were found to slowly decrease as function of time (less than 10% per year). Furthermore, due to unknown reasons, gradual changes in the monitored pattern around pentasialo-transferrin were detected, which limit the use of commercial control sera of the same lot to less than 2 years. Analysis of external quality control sera revealed correct classification of the samples over the entire 10-year period. Data obtained compare well with those of HPLC and CZE assays of other laboratories. The data gathered over a 10-year period demonstrate the robustness of the high-resolution CZE assay. This is the first account of a CZE-based CDT assay with complete internal and external quality assessment over an extended time period.