O padrão de codificação MPEG contém algoritmos que analisam a redundância temporal e espacial do vídeo. Devido a esta característica, grandes variações na taxa de dados são observadas numa sequência de vídeo. Deste modo, os sistemas multimídia apresentam dificuldades no planejamento, projeto e utilização dos recursos necessários para a reprodução adequada do vídeo. A proposta deste trabalho é avaliar o uso das abordagens "Network Calculus" (NC) e "Variability Characterization Curve" (VCC) na caracterização de vídeos MPEG, fornecendo informações úteis para a composição de sistemas multimídia. Usualmente, o NC é uma teoria utilizada para se obter limitantes de desempenho em redes de pacotes, enquanto o VCC apresenta técnicas para se obter limitantes inferior e superior de desempenho de um sistema computacional. Neste trabalho, porém, tanto o NC quanto o VCC são utilizados para definir limitantes de desempenho na forma de parâmetros a serem usados na caracterização de vídeo. Além disso, uma variação do VCC usando curvas aproximadas é utilizada neste trabalho para avaliação da economia de recursos. Adicionalmente aos métodos NC e VCC, é proposto um novo método para agregar informação ao conjunto de parâmetros utilizados na caracterização de vídeo. De forma a avaliar os métodos em diversas condições, são realizados testes com vídeos em diferentes configurações e conteúdos, usando os padrões MPEG-2, MPEG-4, H264/AVC. O resultado da aplicação destes métodos é um conjunto de parâmetros que podem ser utilizados para caracterizar os vídeos e indicar as particularidades e exigências que cada vídeo impõe aos sistemas multimídia. Além disso, uma ferramenta computacional para avaliação desta caracterização é proposta e implementada. / The MPEG video coding standard has algorithms for analyzing temporal and spatial video’s redundancies. Therefore, a great variation of data rate is observed in a video sequence. Consequently, planning, design and utilization of the necessary resources for playing video is not an easy task in multimedia systems. This work evaluates the application of Network Calculus (NC) and Variability Characterization Curve (VCC) approaches in MPEG video characterization by providing useful information to setup multimedia systems. Usually, NC theory is applied to obtain performance bounds for packet networks while VCC provides techniques to obtain lower and upper performance bounds for a computational system. However in this work, both NC and VCC are applied to define performance limits expressed as parameters to be used in this work to evaluate resource savings. In addition, a new method is proposed by adding information to the set of parameters used for video characterization. For evaluating these methods in several conditions, a set of tests in accomplished in different configurations with videos MPEG-2, MPEG-4 and H264/AVC. The result is a set of parameters that can be used to characterize videos and point out particularities and requirements imposed by each video to multimedia systems. Finally, a computational tool for evaluating this characterization is also proposed and implemented.

The project represents an ethnographic study of second grade children using video technology to facilitate self-evaluation in the reading/writing processes.

Background: Delivery room management (DR) of the newly born infant should be performed according to international guidelines, but no recommendations are available for an infant’s position immediately after birth. The present study was performed to answer the following questions: 1. How often is DR-management performed in term infants in side position? 2. Is routine DR-management possible in side position? 3. Is there any benefit of side position with respect to agitation or vital parameters? Methods: Cross-sectional study of video-recorded DR-management in term newborns delivered by C-section in 2012. Videos were analysed for infant’s position, administered interventions, vital parameters and agitation. Results: 187 videos were analysed. The Main Position (defined as position spent more than 70% of the time) was “supine” in 91, “side” in 63 and “not determinable” in 33 infants. “Supine” infants received significantly (p < 0.001) more often stimulation (12.5% of the total time) than “side” infants (3.9% of time). There were no differences between both groups with regard to suctioning; CPAP was exclusively (98%) administered in supine position. Newborns on side were less agitated than those on supine. There was a trend towards a better oxygenation in “side” positioned infants (p = 0.055) and significantly (p = 0.04) higher saturation values in “left-sided” infants than “right-sided” infants at 8th minute. “Side” positioned infants reached oxygen saturation values >90% earlier than “supine” positioned infants (p = 0.16). Conclusions: DR-management is feasible in the side position in term infants. Side position seems to be associated with reduced agitation and improved oxygenation. However, it remains unclear whether this represents a causal relationship or an association. The study supports the need for a randomized controlled trial.

Background: Whereas good data are available on the resuscitation of infants, little is known regarding support of postnatal transition in low-risk term infants after c-section. The present study was performed to describe current delivery room (DR) management of term infants born by c-section in our institution by analyzing videos that were recorded within a quality assurance program. Methods: DR- management is routinely recorded within a quality assurance program. Cross-sectional study of videos of term infants born by c-section. Videos were analyzed with respect to time point, duration and number of all medical interventions. Study period was between January and December 2012. Results: 186 videos were analyzed. The majority of infants (73%) were without support of postnatal transition. In infants with support of transition, majority of infants received respiratory support, starting in median after 3.4 minutes (range 0.4-14.2) and lasting for 8.8 (1.5-28.5) minutes. Only 33% of infants with support had to be admitted to the NICU, the remaining infants were returned to the mother after a median of 13.5 (8-42) minutes. A great inter- and intra-individual variation with respect to the sequence of interventions was found. Conclusions: The study provides data for an internal quality improvement program and supports the benefit of using routine video recording of DR-management. Furthermore, data can be used for benchmarking with current practice in other centers.

This study investigated how 2 different rating conditions, the controlled rating condition (CRC) and the uncontrolled rating condition (URC), effected rater behavior and the reliability of a performance assessment (PA) known as the Missionary Teaching Assessment (MTA). The CRC gives raters the capability to manipulate (pause, rewind, fast-forward) video recordings of an examinee's performance as they rate while the URC does not give them this capability (i.e., the rater must watch the recording straight through without making any manipulations). Few studies have compared the effect of these two rating conditions on ratings. Ryan et al. (1995) analyzed the impact of the CRC and URC on the accuracy of ratings, but few, if any, have analyzed its impact on reliability. The Missionary Teaching Assessment is a performance assessment used to assess the teaching abilities of missionaries for the Church of Jesus Christ of Latter-day Saints at the Missionary Training Center. In this study, 32 missionaries taught a 10-minute lesson that was recorded and later rated by trained raters based on a rubric containing 5 criteria. Each teaching sample was rated by 4 of 6 raters. Two of the 4 ratings were rated using the CRC and 2 using the URC. Camtasia Studio (2010), a screen capture software, was used to record when raters used any type of manipulation. The recordings were used to analyze if raters manipulated the recordings and if so, when and how frequently. Raters also performed think-alouds following a random sample of the ratings that were performed using the CRC. These data revealed that when raters had access to the CRC they took advantage of it the majority of the time, but they differed in how frequently they manipulated the recordings. The CRC did not add an exorbitant amount of time to the rating process. The reliability of the ratings was analyzed using both generalizability theory (G theory) and many-facets Rasch measurement (MFRM). Results indicated that, in general, the reliability of the ratings obtained from the 2 rating conditions were not statistically significantly different from each other. The implications of these findings are addressed.

High levels of water stress and increased demand for potable water generated via desalination pose significant challenges for sustainable waste brine management in arid regions. Electrochemical techniques, like brine electrolysis, offer an approach for treating brine, preventing environmentally harmful disposal, and facilitating the recycling of valuable ions found in brine. As the large concentration of ions can precipitate and degrade conventional electrolyzer components, membraneless electrolyzers, which lack membranes, can be an alternative for direct brine electrolysis. The absence of membranes enables operation in the presence of impurities and a wide range of pH environments. However, membraneless electrolyzers suffer from a trade-off between current density and current utilization that stems from undesired back-reactions that arise from the crossover of gaseous and aqueous products between the anode and cathode. In this dissertation work, a combination of in situ high-speed video, colorimetric pH imaging, modeling, and electroanalytical methods were used to evaluate how the performance of a porous flow-through cathode is affected by operating current density, electrolyte flow rate, and choice of catalyst placement on a porous support. It was found that catalyst placement is a key knob to control the location of product generation and thereby minimize product crossover and maximize pH differential. Placing the catalyst on the outer surface of the cathode resulted in an average increase of 51% in current utilization, a metric for measuring crossover, compared to the opposite configuration. This finding is explained by the ability of the porous electrode support to serve as a barrier to suppress crossover for the outward-facing catalyst configuration. In addition, the outward-facing catalyst configuration leads to more stable operation while incurring minor increases (90-170 mV) in overpotentials. For both catalyst configurations, it was also shown that the Damköhler number (𝐷𝑎) is a practical descriptor for predicting operating conditions that maximize the concentration of OH⁻ in the cathode effluent stream. Furthermore, this dissertation evaluated the performance of a platinized cathode within a membraneless electrolyzer in the presence of Mg²⁺ impurities. In a 3-hour stability test at 50 mA cm⁻² during brine electrolysis, electrolytes with Mg²+ concentration below 5 mM showed a negligible influence on cathode performance. Electrolytes with Mg²⁺ concentration below 1.2 mM at similar operating conditions exhibited improved cathode performance compared to Mg-free brine. All learnings during this study were captured in a mathematical model that predicts the tolerance threshold at which the cathode would cease to operate due to accumulations of Mg(OH)₂ deposits at different current densities and superficial velocities. Overall, these studies demonstrated the potential of membraneless electrolyzers as an emerging technology for treating brine and converting it into high-value products. Finally, applying an oxide overlayer to planar electrodes has been demonstrated to improve their stability, activity, and/or selectivity. This is relevant for direct brine electrolysis, as brine contains many impurities that can compromise the integrity of electrodes and promote undesirable reactions, generating toxic products like chlorine gas. However, given that high-surface electrodes are required for industrial applications, it is necessary to develop a method to encapsulate high-surface-area electrodes. Applying nanoscopic oxide encapsulation layers to high-surface-area electrodes such as nanoparticle-supported porous electrodes is not an easy task. This dissertation work demonstrated that the recently developed condensed layer deposition (CLD) method can be used for depositing nanoscopic (sub-10 nm thick) titanium oxide (TiO₂) overlayers onto high surface area platinized carbon foam electrodes. Characterization of the overlayers by transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS) showed they are amorphous, while X-ray photoelectron microscopy confirmed that they exhibit TiO₂ stoichiometry. Electrodes were also characterized by hydrogen underpotential deposition (Hupd) and carbon monoxide (CO) stripping, demonstrating that the Pt electrocatalysts remain electrochemically active after encapsulation. Furthermore, copper underpotential deposition (Cuupd) measurements for bare Pt and TiO₂-encapsulated Pt electrocatalysts revealed that the TiO₂ overlayer effectively prevented Cu₂+ from reaching the buried, allowing this method to determine the coverage of the TiOx coating. In summary, this portion of the dissertation demonstrated that CLD is a promising method for applying nanoscopic overlayers on high-surface electrodes.

Active feedback control in magnetic confinement fusion devices is desirable to mitigate plasma instabilities and enable robust operation. Among various diagnostics, optical high-speed cameras provide a powerful, non-invasive diagnostic and can be suitable for these applications. This thesis reports the first application of high-speed imaging videography and deep learning as real-time diagnostics of rotating MHD modes in a tokamak device. The developed system uses a convolutional neural network (CNN) to predict the amplitudes of the ?=1 sine and cosine mode components using solely optical measurements acquired from one or more cameras. Using the newly assembled high-speed camera diagnostics on the High Beta Tokamak – Extended Pulse (HBT-EP) device, an experimental dataset consisting of camera frame images and magnetic-based mode measurements was assembled and used to develop the mode-tracking CNN model. The optimized models outperformed other tested conventional algorithms given identical image inputs. A prototype controller based on a field-programmable gate array (FPGA) hardware was developed to perform real-time mode tracking using the high-speed camera diagnostic with the mode-tracking CNN model. In this system, a trained model was directly implemented in the firmware of an FPGA device onboard the frame grabber hardware of the camera’s data readout system. Adjusting the model size and its implementation-related parameters allowed achieving an optimal trade-off between a model’s prediction accuracy, its FPGA resource utilization and inference speed. Through fine-tuning these parameters, the final implementation satisfied all of the design constraints, achieving a total trigger-to-output latency of 17.6 ?s and a throughput of up to 120 kfps. These results are on-par with the existing GPU-based control system using magnetic sensor diagnostic, indicating that the camera-based controller will be capable to perform active feedback control of MHD modes on HBT-EP.

No / To assess the reliability of duration of treatment time measured by physiotherapy staff in early-stage stroke patients. DESIGN: Comparison of physiotherapy staff's recording of treatment sessions and video recording. SETTING: Rehabilitation stroke unit in a general hospital. SUBJECTS: Thirty-nine stroke patients without trunk control or who were unable to stand with an erect trunk without the support of two therapists recruited to a randomized trial evaluating the Oswestry Standing Frame. Twenty-six physiotherapy staff who were involved in patient treatment. MAIN MEASURES: Contemporaneous recording by physiotherapy staff of treatment time (in minutes) compared with video recording. STATISTICAL ANALYSIS: Intraclass correlation with 95% confidence interval and the Bland and Altman method for assessing agreement by calculating the mean difference (standard deviation; 95% confidence interval), reliability coefficient and 95% limits of agreement for the differences between the measurements. RESULTS: The mean duration (standard deviation, SD) of treatment time recorded by physiotherapy staff was 32 (11) minutes compared with 25 (9) minutes as evidenced in the video recording. The mean difference (SD) was -6 (9) minutes (95% confidence interval (CI) -9 to -3). The reliability coefficient was 18 minutes and the 95% limits of agreement were -24 to 12 minutes. Intraclass correlation coefficient for agreement between the two methods was 0.50 (95% CI 0.12 to 0.73). CONCLUSIONS: Physiotherapy staff's recording of duration of treatment time was not reliable and was systematically greater than the video recording.

United Nations has lately stated ambitious health targets for 2030 in the Sustainable Development Goal agenda, following the already achieved progress between 1990 and 2015 when the number of children dying before the age of five was reduced by more than half. However, the mortality reduction in the first month of life after birth has not kept the same pace. Furthermore, a large number of stillbirths have previously not been accounted for. The aim of this thesis was to evaluate the impact of clinical training in neonatal resuscitation, and to identify strategies for an effective implementation at a maternal health facility in Nepal. Focus group discussions were used to explore the perceptions of teamwork among staff working closest to the infant at the facility. A prospective cohort study with nested referents was applied to determine effect on birth outcomes after an intervention with Helping Babies Breathe, a simplified protocol for neonatal resuscitation. Sustainability of the acquired skills after training was addressed by employing a quality improvement cycle. Video recordings of health workers performance were collected to analyse adherence to protocol. Midwives described the need for universal protocols in neonatal resuscitation and management involvement in clinical audit and feedback. There was a reduction of intrapartum stillbirth (aOR 0.46, 95% CI 0.32–0.66) and neonatal mortality within 24 hours of life (aOR 0.51, 95% CI 0.31–0.83) after the intervention. Ventilation of infants increased (OR 2.56, 95% CI 1.67–3.93) and potentially harmful suctioning was reduced (OR 0.13, 95% CI 0.09–0.17). Neonatal death from intrapartum-related complications was reduced and preterm infants survived additional days in the neonatal period after the intervention. Low birth weight was not found to be a predictor of deferred resuscitation in the studied context. This study confirmed the robustness of Helping Babies Breathe as an educational tool for training in neonatal resuscitation. Accompanied with a quality improvement cycle it reduced intrapartum stillbirth and mortality on the day of delivery in a low-income facility setting. Improved postnatal care is needed to maintain the gains in survival through the neonatal period. Increased management involvement in audit and quality of care could improve clinical performance among health workers.

Ce travail de thèse suit une logique exposée dans trois chapitres, pour terminer par un exposé sur des applications futures. La première partie fait l’inventaire des difficultés de l’apprentissage des habiletés de base de la chirurgie robotique, notamment dans ses aspects de l’exploitation des avantages ergonomiques. Elle se fonde notamment les travaux de master 2 des Docteurs N. Hubert et C. Perrenot auxquels l’auteur a participé. On conclut ainsi à la nécessité de développer un outil de monitoring de l’ergonomie plus efficace que celui existant sur les logiciels du simulateur dV-Trainer®. La deuxième partie décrit la conception et la validation d’un système de capteurs de pression des avant-bras sur les appuis-bras de la console du robot et/ou des simulateurs (Système de Surveillance de Pression - SSP-). Il est créé le concept d’Armrest Load, formule plus efficace d’évaluation des performances des stagiaires en matière d’ergonomie que l’évaluation automatique par le simulateur. La troisième partie décrit l’amélioration du système SSP via l’ajout de fonctions supplémentaires et leurs évaluations : - une alarme informant l’étudiant des mauvaises positions. Ce système crée un réflexe conditionné, accélère l’utilisation ergonomique des appuis-bras du simulateur, mais également améliore les performances globales. - des caméras et une interface, « Contrôleur d’Évènement en Simulation Robotique » (CESIR), permettant au stagiaire de visionner à volonté et pour chaque exercice les vidéos de référence, celles avec les erreurs à éviter et ses propres performances. Ces techniques vidéo, largement répandues dans le milieu sportif sont utilisées pour la première fois en chirurgie et prouvent ici leur efficacité. La partie « conclusion » synthétise les résultats de tout le travail de thèse et expose des perspectives d’amélioration du système CESIR et de son utilisation dans la poursuite de la collaboration franco-chinoise en formation robotique. / This thesis is logically split into three chapters, concluding with a discussion on future applications. The first part makes an inventory of the difficulties in learning the basic skills in robotic surgery, especially in the aspects of exploiting the ergonomic benefits. It relies in particular on the master degrees of Drs N. Hubert and C.Perrenot to which the author participated. It is concluded that there is a need to develop a more efficient monitoring tool for ergonomics than the existing software on the dV-Trainer® simulator. The second part describes the design and validation of a system of forearms pressure sensors attached on the robot’s console and/or simulator’s armrests (SSP- Pressure Surveillance System). The concept of Armrest Load is created, a more effective formula for evaluating the trainees’ performance in ergonomics than the automatic evaluation provided by the simulator. The third part describes the improvement of the SSP system by adding additional functions and their evaluation: - An alarm informing the student of bad positions. This system creates a conditioned reflex, speeds up the ergonomic use of armrests on the simulator, and also improves the overall performance. - Cameras and a "Controller of Event in Robotic Simulation " (CESIR) interface, allowing the participant to view at will the reference video, the one with mistakes to avoid and the video of their own performances. This video technique is widely used in sports but is applied for the first time in surgery and proves its effectiveness. The conclusion part summarizes the results of the whole thesis and outlines the possibilities for CESIR’s improvement and its development in the French-Chinese collaboration in robotic training.