Human and animal studies show significant delays in neurobehavioral development in offspring after prolonged prenatal exposure to moderate and high ethanol doses resulting in high blood alcohol concentration (BECs). However, none have investigated the effects of lower ethanol doses given acutely during specific developmental time periods. Here, we sought to create a mouse model for modest and circumscribed human drinking during the 3rd and 4th weeks of pregnancy.We acutely treated mice during embryo gastrulation on gestational day (GD) 7 or neurulation on GD8 with a low or moderate ethanol dose given via gavage that resulted in BECs of 107 and 177. mg/dl, respectively. We assessed neonatal physical development (pinnae unfolding, and eye opening); weight gain from postnatal day (PD) 3-65; and neurobehavioral maturation (pivoting, walking, cliff aversion, surface righting, vertical screen grasp, and rope balance) from PD3 to 17. We used a multiple linear regression model to determine the effects of dose, sex, day of treatment and birth in animals dosed during gastrulation or neurulation, relative to their vehicle controls.We found that ethanol exposure during both time points (GD7 and GD8) resulted in some delays of physical development and significant sensorimotor delays of pivoting, walking, and thick rope balance, as well as additional significant delays in cliff aversion and surface righting after GD8 treatment. We also found that treatment with the low ethanol dose more frequently affected neurobehavioral development of the surviving pups than treatment with the moderate ethanol dose, possibly due to a loss of severely affected offspring. Finally, mice born prematurely were delayed in their physical and sensorimotor development.Importantly, we showed that brief exposure to low dose ethanol, if administered during vulnerable periods of neuroanatomical development, results in significant neurobehavioral delays in neonatal mice. We thus expand concerns about alcohol consumption during the 3rd and 4th weeks of human pregnancy to include occasional light to moderate drinking.

Network connectivity is a fundamental property affecting network performance. Given the reliability of each link, network connectivity determines the probability that a message can be delivered from the source to the destination. In this thesis, we study the directed network connectivity where the message will be forwarded toward the destination hop by hop, so long as the neighbor(s) is (are) closer to the destination. Directed connectivity, closely related to directed percolation, is very complicated to calculate. The existing state-of-the-art can only calculate directed connectivity for a lattice network up-to-the size of 10 × 10. In this thesis, we devise a new approach that is simpler and more scalable and can handle general network topology and heterogeneous links. The proposed approach uses an unambiguous hop count to divide the networks into hops and gives two steps of pre-process to transform hop-count ambiguous networks into unambiguous ones, and derive the end-to-end connectivity. Then, using the Markov property to obtain the state transition probability hop by hop. Second, with tens of thousands of Low Earth Orbit (LEO) satellites covering the Earth, LEO satellite networks can provide coverage and services that are otherwise not possible using terrestrial communication systems. The regular and dense LEO satellite constellation also provides new opportunities and challenges for network protocol design. In this thesis, we apply the directed connectivity analytical model on LEO satellite backbone networks to ensure ultra-reliable and low-latency (URLL) services using LEO networks, and propose a directed percolation routing (DPR) algorithm to lower the cost of transmission without sacrificing speed. Using Starlink constellation (with 1,584 satellites) as an example, the proposed DPR can achieve a few to tens of milliseconds latency reduction for inter-continental transmissions compared to the Internet backbone, while maintaining high reliability without link-layer retransmissions. Finally, considering the link redundancy overhead and delay/reliability tradeoff, DPR can control the size of percolation. In other words, we can choose a part of links to be active links considering the reliability and cost tradeoff. / Graduate

Mobile cloud gaming (MCG) is an emerging concept which aims to deliver video games on-demand to users with the use of cloud technologies. Cloud technology allows the offloading of computation from a less powerful user device or thin client to more robust cloud servers to minimize power consumption and provide additional cloud services such as storage. MCG is therefore very helpful that can reduce the costs of expensive hardware, but the challenge is that it requires a high Quality of Service (QoS) in order to stream and play the games where the users have a high Quality of Experience (QoE). The goal of the study is to investigate how users' QoE is affected by network conditions while playing MCG and compare the results from a previous study. A testbed was made in order to conduct subjective tests where users are going to play Counter Strike: Global Offensive (CS: GO) on a smartphone using Steam Remote Play. The testbed consists of a router, tablet, smartphone, headset, Xbox controller, USB-C multi-port adapter and four different PC's. Participants on campus, both students and non-students, were invited to participate in the experiment. A total of 24 participants completed the tests; however, results from two participants were excluded due to software issues. There were 23 network conditions that was tested for each user and included factors such as round-trip time (RTT), packet losses, bursty jitter, random jitter or combinations of different factors. A multi-platform tool, ALTRUIST, was used to control the applications and facilitate the data collection from the devices and NetEm changed the network conditions. The results showed that the network condition [bj(rtt200i15)] had the highest mean opinion score (MOS) of the QoE of 4.5 for the users with 200 milliseconds of bursty jitter every 15 seconds. The worst network condition tested with the lowest QoE rating of 1.4 was network condition [rtt25pl12] that had 25 milliseconds of RTT and 12% packet losses. There were differences between the male and female participants where the MOS of the QoE results was significantly higher with up to 1.5 MOS QoE rating differences for the females compared to the males in network conditions with RTT with packet losses. However, the sample size was low with only 5 female participants compared to 18 male participants. The MOS of the QoE results separating play time under 10 hours per week and 10 or more hours per week showed no significant changes, where the largest QoE rating difference was 0.5 points. Network condition [rtt25pl12] and [rtt2pl35] had the largest differences in the MOS QoE ratings compared to the previous study, while both was not compared to the same corresponding network condition. The largest difference comparing the same network condition to the previous study was network condition [bj(rtt200i15)] with a difference of 1.1 points higher in the MOS QoE rating.

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The rapid evolution of portable devices and social media has enabled pervasive forms of distributed cooperation. A group could perform a task using a heterogeneous set of the devices (desktop, mobile), connections (wireless, wired, 3G) and software clients. We call this form of systems Distributed Dynamic Cooperative Environments (DDCEs). Content in DDCEs is created and shared by the users. The content could be static (e.g., video or audio), dynamic (e.g.,wikis), and/or Objects with behavior. Objects with behavior are programmed objects that take advantage of the available computational services (e.g., cloud-based services). Providing a desired Quality of Experience (QoE) in DDCEs is a challenge for cooperative systems designers. DDCEs are expected to provide groups with the utmost flexibility in conducting their cooperative activities. More flexibility at the user side means less control and predictability of the groups' behavior at the system side. Due to the lack of Quality of Service (QoS) guarantees in DDCEs, groups may experience changes in the system behavior that are usually manifested as delays and inconsistencies in the shared state. We question the extent to which cooperation among group members is sensitive to system changes in DDCEs. We argue that a QoE definition for groups should account for cooperation emergence and sustainability. An experiment was conducted, where fifteen groups performed a loosely-coupled task that simulates social traps in a 3D virtual world. The groups were exposed to two forms of system delays. Exo-content delays are exogenous to the provided content (e.g., network delay). Endo-content delays are endogenous to the provided content (e.g., delay in processing time for Objects with behavior). Groups' performance in the experiment and their verbal communication have been recorded and analyzed. The results demonstrate the nonlinearity of groups' behavior when dealing with endo-content delays. System interventions are needed to maintain QoE even though that may increase the cost or the required resources. Systems are designed to be used rather than understood by users. When the system behavior changes, designers have two choices. The first is to expect the users to understand the system behavior and adjust their interaction accordingly. That did not happen in our experiment. Understanding the system behavior informed groups' behavior. It partially influenced how the groups succeeded or failed in accomplishing its goal. The second choice is to understand the semantics of the application and provide guarantees based on these semantics. Based on our results, we introduce the following design guidelines for QoE provision in DDCEs. • If possible the system should keep track of information about group goals and add guarding constraints to protect these goals. • QoE guarantees should be provided based on the semantics of the user-generated content that constitutes the group activity. • Users should be given the option to define the content that is sensitive to system changes (e.g., Objects with behavior that are sensitive to delays or require intensive computations) to avoid the negative impacts of endo-content delays. • Users should define the Objects with behavior that contribute to the shared state in order for the system to maintain the consistency of the shared state. • Endo-content delays were proven to have significantly negative impacts on the groups in our experiment compared to exo-content delays. We argue that system designers, if they have the choice, should trade processing time needed for Objects with behavior for exo-content delay. / Ph. D.

This paper deals with the consensus problem under communication network inducing delays. It is well-known that introducing a delay leads in general to a reduction of the performance or to instability due to the fact that timedelay systems are infinite dimensional. For instance, the set of initial conditions of a time-delay system is not a vector but a function taken in an interval. Therefore, investigating the effect of time-delays in the consensus problem is an important issue. In the present paper, we assume that each agent receives instantaneously its own state information but receives the state information from its neighbors after a constant delay. Two stability criteria are provided based on the frequency approach and on Lyapunov-Krasovskii techniques given in terms of LMI. An analytic expression of the consensus equilibrium which depends on the delay and on the initial conditions taken in an interval is derived. The efficiency of the method is tested for different network communication schemes. / <p>QC 20110120</p>

The utilisation of navigation systems in cars has given rise to road safety concerns, and the design and functionality of such systems must therefore be adjusted to the users’ needs, since they have to divide their attention between driving and the operation of the navigation system. The study was aimed at finding the optimum system response time (SRT) which would enable a driver to focus as much as possible on the road while attaining an efficient task completion time using an electronic navigational system. The research project consists of two separate experiments and was completed by 10 subjects. Experiment 1 included a temporal reproduction task and a secondary memory task. The subjects had to memorise two symbols and then reproduce six time spans ranging from 1 to 30 s to provide a baseline measurement of their time estimation abilities. Experiment 2 consisted of a simulated automobile driving task. While driving in the simulator the subjects completed a memorising task displayed on a touch screen. The task was presented with seven different system response times (SRTs) ranging from 0 to 30 s. The effects of different SRTs on the eye movement from road to monitor, regarding the duration of fixation and the frequency of change were evaluated. The distribution of gazes to the secondary task was analysed to provide information about the time estimation performance in the driving simulator. Other dependent variables tested were the accuracy of selected items, memory game performance, drive performance and the subjective state of the test person. The results of this study can be employed to find the optimum duration of inter-task delays for in-vehicle technical devices. / Psychology / M.A. (Psychology)

Cette thèse se situe dans le cadre de l’analyse et de la synthèse des systèmes périodiques. Les contributions présentées dans ce mémoire portent sur la commande sous contraintes des systèmes linéaires discrets périodiques. Ces contraintes, portant sur l’état du système et/ ou sur la commande, peuvent être des contraintes de positivité ou de bornitude. Dans ce travail, des conditions d’analyse en stabilité et positivité des systèmes périodiques en termes de LMI (Inégalité Matricielle Linéaire) strictes, sont présentées. Ces outils d’analyse ont ensuite permis d’élaborer une loi de commande par retour d’état périodique. Les résultats obtenus sont exploités par la suite pour développer une commande par retour d’état périodique robuste pour les systèmes périodiques incertains. Des conditions de stabilisation robuste sont élaborées en utilisant la S-procédure. En outre, des conditions de stabilité et stabilisation par retour d’état périodique des systèmes périodiques avec retards sont établies. Le problème de stabilisation de ce type de systèmes sous un certain nombre de contraintes est résolu en suivant deux approches, la première est basée sur les techniques de Lyapunov la seconde fait appel à la programmation linéaire. Outre la notion de stabilité, la notion de performance des systèmes en boucle fermée est traitée. Pour cela, nous proposons une commande de type H∞ pour résoudre le problème de rejet de perturbations. / This thesis deals with the analysis and the control problem of periodic linear discrete systems (PLDS). The contributions presented in this work focuses on the constrained control of PLDS. Conditions for stability analysis and positivity are established in terms of strict LMI (Linear Matrix Inequalities). The stabilization of PLDS under the condition that the closed-loop system is positive and stable is addressed as well as the case of bounded state and/ or control variables. The obtained results are then extended to the synthesis of robust state feedback controllers, where some of which are based on the S − procedure technique. Furthermore, some conditions of stability and stabilization of PLDS with delays are established. The problem of stabilization of constrained PLDS is addressed based on the Lyapunov techniques or the Linear Programming techniques. The robust H∞ state feedback control in which both robust stability and a prescribed H∞ performance are required is investigated.

O desmonte de rocha com uso de explosivos, aplicado à extração subterrânea de recursos minerais é uma tarefa impar que exige perícia e planejamento detalhado. Nesse contexto, essa dissertação tem sua relevância devido à apresentação de metodologias que visam aprimorar os processos envolvidos com o desmonte de rocha com uso de perfurações radiais, aplicado ao método de mineração subterrânea câmaras transversais, variante do método sublevel stoping. Para cumprir esse objetivo foram estabelecidas metodologias embasadas na utilização de registros sismográficos dos desmontes, mapeamento por laser das câmaras de lavra, registros operacionais da mina estudada. As metodologias aplicadas nas operações de mina incluíram: a segregação entre as atividades de perfuração e desmonte de rocha para assim aprimorar o ciclo operacional, a implantação de desmontes massivos como forma de aumentar a taxa de produção. A mudança na geometria das câmaras, a fim preservar o teto das mesmas. Um experimento com diferentes arranjos de retardo nos desmontes, como forma de determinar a configuração temporal menos nociva em termos de vibração, e por fim, a aplicação de uma nova malha de perfuração baseada no método dos triângulos reorientados de Hagan (1988), que visava diminuir a necessidade de perfuração e melhorar a distribuição energética dos desmontes em leque. As modificações propostas geraram resultados positivos, respectivamente quanto: aumento da eficiência dos ciclos de perfuração em 49% e aumento de 54% na produtividade das câmaras no período estudado, devido a implementação de desmontes massivos somados a segregação das atividades de perfuração e desmonte. Observou se a diminuição significativa da sobre-quebra (back break) do teto, da mesma forma os danos aos cabos de ancoragem (cable-bolts) foram reduzidos, resultados estes oriundos das modificações na geometria das câmaras. Os testes com diferentes arranjos de retardos demonstraram que o arranjo: 50ms entre furos e 200ms entre linhas, gerou a menor intensidade de vibração. O teste com o padrão de perfuração baseado na técnica de Hagan apresentou melhor índice de perfuração específica, porém, resultou em uma recuperação menor do que a média usual das câmaras, (76% contra 85%). Pode-se concluir que as metodologias propostas foram validas como medidas de aprimoramento das operações de perfuração e desmonte de rocha, a exceção da técnica dos triângulos reorientados de Hagan. Também foi possível concluir que a razão entre os valores de retardos intra linhas (L-L) e intra furos (F-F) influi diretamente na intensidade de vibração. / The blasting of rocks, applied to the underground extraction of mineral resources is a difficult task that requires expertise and detailed planning. In this context, this dissertation has its relevance due to the presentation of methodologies that aim to improve the processes involved with the blasting of rocks utilizing ring drilling, applied to the underground mining method transversal stopes, a variant of the method sublevel stoping. To fulfill this objective, methodologies based on the use of seismographic records of the blasting events, laser scanners of the stopes and operational records of the mine were used, as well as the use of Micromine software. The methodologies applied in mine operations included: segregation between rock drilling and blasting activities to improve the operational cycle, the implantation of the concept of mass blasting as a way to increase the production rate, the change in the drilling pattern in order to preserve the roof of the stopes, an experiment with different arrangements of delays for the blasting, as a way to determine the less harmful configuration in terms of vibration and finally the application of a new drilling pattern based on the reoriented triangles method of Hagan (1988), which aimed to reduce the need for drilling and to improve the energy distribution of the rings of drilling. The proposed modifications generated positive results, respectively: increase in the efficiency of the drilling cycles by 49% and a 54% increase in the productivity of the studied period, due to the implementation of mass blasting concept added to the segregation of drilling and blasting activities. It was observed that the significant decrease of the back break of the roof, in the same way the damages to the cables of reinforcement (cable-bolts) were reduced, as a result from the modifications in the drillings. The tests with different delay arrangements showed that the arrangement: 50ms between holes and 200ms between rows, generated the lowest vibration intensity. The Hagan technique-based drilling test showed a better specific drilling index, but resulted in a lower ore recovery than the usual to the stopes mean (76% vs. 85%). It can be concluded that the proposed methodologies were valid as measures of improvement of the operations of drilling and blasting of rock, except for the technique of the reoriented triangles of Hagan. It was also possible to conclude that the ratio between inter ring and inter-hole delays directly influences the vibration intensity.