In this study, the researchers explored child welfare workers’ perceptions on placement changes for youth in foster care and the impact these changes had on youths’ overall outcomes. Using a Post Positivist paradigm, qualitative research was completed using snowball-sampling procedures. The researchers conducted in-depth interviews with sixteen members from their personal networks of child welfare social workers that have direct contact with foster youth. The research participants included current child welfare social workers from two counties in Southern California. The study’s findings suggest that children’s behaviors and foster parents’ reactions to those behaviors impacted placement changes. Further, participants felt that these changes significantly impacted youths’ educational outcomes. Participants identified a variety of interventions they used to try to mitigate placement changes, some with more or less success. Finally, workers identified barriers within the child welfare system, including communications and compensation, that might have an impact on placement changes. Implications for social work practice, policy and research are discussed.

This work deals with the design of a CMOS pixel sensor prototype (called MIMOSA 31) for the outer layers of the International Linear Collider (ILC) vertex detector. CMOS pixel sensors (CPS) also called monolithic active pixel sensors (MAPS) have demonstrated attractive performance towards the requirements of the vertex detector of the future linear collider. MIMOSA 31developed at IPHC-Strasbourg is the first pixel sensor integrated with 4-bit column-level ADC for the outer layers. It is composed of a matrix of 64 rows and 48 columns. The pixel concept combines in-pixel amplification with a correlated double sampling (CDS) operation in order to reduce the temporal and fixed pattern noise (FPN). At the bottom of the pixel array, each column is terminated with an analog to digital converter (ADC). The self-triggered ADC accommodating the pixel readout in a rolling shutter mode completes the conversion by performing a multi-bit/step approximation. The ADC design was optimized for power saving at sampling frequency. Accounting the fact that in the outer layers of the ILC vertex detector, the hit density is inthe order of a few per thousand, this ADC works in two modes: active mode and inactive mode. This thesis presents the details of the prototype chip and its laboratory test results.

Le sujet de cette thèse est de concevoir un prototype de capteur à pixel CMOS adapté aux couches extérieures du détecteur de vertex de l'International Linear Collider (ILC).Il est le premier prototype de capteur CMOS intégrant un ADC en bas de colonne de 4-bit et une matrice de pixels, dédié aux couches externes. L'architecture du prototype nommé MIMOSA 31 comprend une matrice de pixels de 48 colonnes par 64 lignes, des ADC en bas de colonne. Les pixels sont lus ligne par ligne en mode d'obturation roulant. Les ADCs reçoivent la sortie des pixels en parallèle achève réalisent la conversion en effectuant une approximation de multi-bit/step. Sachant que dans les couches externes de l'ILC, la densité de pixels touchés est de l'ordre de quelques pour mille, !'ADC est conçu pour fonctionner en deux modes (actifs et inactifs) afin de minimiser la consommation d'énergie. Les résultats indiquent que MIMOSA 31 répond aux performances nécessaires pour cette couche de capteurs. / This work deals with the design of a CMOS pixel sensor prototype (called MIMOSA 31) for the outer layers of the International Linear Collider (ILC) vertex detector. CMOS pixel sensors (CPS) also called monolithic active pixel sensors (MAPS) have demonstrated attractive performance towards the requirements of the vertex detector of the future linear collider. MIMOSA 31developed at IPHC-Strasbourg is the first pixel sensor integrated with 4-bit column-level ADC for the outer layers. It is composed of a matrix of 64 rows and 48 columns. The pixel concept combines in-pixel amplification with a correlated double sampling (CDS) operation in order to reduce the temporal and fixed pattern noise (FPN). At the bottom of the pixel array, each column is terminated with an analog to digital converter (ADC). The self-triggered ADC accommodating the pixel readout in a rolling shutter mode completes the conversion by performing a multi-bit/step approximation. The ADC design was optimized for power saving at sampling frequency. Accounting the fact that in the outer layers of the ILC vertex detector, the hit density is inthe order of a few per thousand, this ADC works in two modes: active mode and inactive mode. This thesis presents the details of the prototype chip and its laboratory test results.

La croissance continue et rapide du trafic de données dans les infrastructures de télécommunications, impose des niveaux de débit de transmission ainsi que de puissance de traitement de l’information, que les capacités intrinsèques des systèmes et microcircuits électroniques ne seront plus en mesure d’assurer à brève échéance : le développement de nouveaux scenarii technologiques s’avère indispensable pour répondre à la demande de bande passante imposée notamment par la révolution de l’internet, tout en préservant une consommation énergétique raisonnable. Dans ce contexte, l’intégration hétérogène fonctionnelle sur silicium de dispositifs photoniques à émission par la surface de type VCSEL utilisant des miroirs large-bandes ultra-compacts à cristaux photoniques constitue une stratégie prometteuse pour surmonter l’impasse technologique actuelle, tout en ouvrant la voie à un développement rapide d’architectures et de systèmes de communications innovants dans le cadre du mariage entre photonique et micro-nano-électronique. / The ever-growing demand for high-volume fast data transmission and processing is nowadays rapidly attaining the intrinsic limit of microelectronic circuits to offer high modulation bandwidth at reasonable power dissipation. Silicon photonics is set to break the technological deadlock aiming at a functional photonics-on-CMOS integration for innovative optoelectronic systems paving the way towards next-era communication architectures. Among the others photonic building blocks such as photodiodes, optical modulators and couplers, power-efficient compact semiconductors sources in the near-infrared telecommunication bands, characterized by performing modal features as well as thermal resiliency constitute an essential landmark to be achieved. Within such context, InP-based long-wavelength vertical-cavity surface-emitting lasers (VCSELs) using one-dimensional Si/SiO2 photonic crystals as wideband compact mirrors are proposed as next generation emitters for CMOS integration.

This thesis proposes an Ecosystem perspective for the engineering of SoS and CPS and illustrates the impact of this perspective in three areas of contribution category First, from a conceptual and Systems Engineering perspective, a conceptual framework including the Ecosystems of System Unified Language Modeling (EoS-UML) profile, a set of Ecosystem Ensemble Diagrams, the Arms :Length Trust Model and the Cyber Physical Threat Model are provided. Second, having established this conceptual view of the ecosystem, we recognize unique role of the cryptographic credentials within it, towards enabling the ecosystem long-term value proposition and acting as a value transfer agent, implementing careful balance of properties meet stakeholder needs. Third, we propose that the ecosystem computers can be used as a distributed compute engine to run Collaborative Algorithms. To demonstrate, we define access control scheme, risk-balanced Cellular Access Control (rbCAC). The rbCAC algorithm defines access control within a cyber-physical environment in a manner which balances cost, risk, and net utility in a multi-authority setting. rbCAC is demonstrated it in an Air Travel and Border Services scenario. Other domains are also discussed included air traffic control threat prevention from drone identity attacks in protected airspaces. These contributions offer significant material for future development, ongoing credential and ecosystem design, including dynamic perimeters and continuous-time sampling, intelligent and self optimizing ecosystems, runtime collaborative platform design contracts and constraints, and analysis of APT attacks to SCADA systems using ecosystem approaches.

No description available.

Currently manufacturers in the European Surface Mount Technology (SMT) industry seeproduction changeover, machine downtime and process optimization as their biggestchallenges. They also see a need for collecting data and sharing information betweenmachines, people and systems involved in the manufacturing process. Internet of Things (IoT)technology provides an opportunity to make this happen. This research project gives answers tothe question of what the potentials and challenges of IoT implementation are in European SMTmanufacturing. First, key IoT concepts are introduced. Then, through interviews with expertsworking in SMT manufacturing, the current standpoint of the SMT industry is defined. The studypinpoints obstacles in SMT IoT implementation and proposes a solution. Firstly, local datacollection and sharing needs to be achieved through the use of standardized IoT protocols andAPIs. Secondly, because SMT manufacturers do not trust that sensitive data will remain securein the Cloud, a separation of proprietary data and statistical data is needed in order take a stepfurther and collect Big Data in a Cloud service. This will allow for new services to be offered byequipment manufacturers. / I dagsläget upplever tillverkare inom den europeiska ytmonteringsindustrin för elektronikproduktionsomställningar, nedtid för maskiner och processoptimering som sina störstautmaningar. De ser även ett behov av att samla data och dela information mellan maskiner,människor och system som som är delaktiga i tillverkningsprocessen.Sakernas internet, även kallat Internet of Things (IoT), erbjuder teknik som kan göra dettamöjligt. Det här forskningsprojektet besvarar frågan om vilken potential som finns samt vilkautmaningar en implementation av sakernas internet inom europeisk ytmonteringstillverkning avelektronik innebär. Till att börja med introduceras nyckelkoncept inom sakernas internet. Sedandefinieras utgångsläget i elektroniktillverkningsindustrin genom intervjuer med experter.Studien belyser de hinder som ligger i vägen för implementation och föreslår en lösning. Dettainnebär först och främst att datainsamling och delning av data måste uppnås genomanvändning av standardiserade protokoll för sakernas internet ochapplikationsprogrammeringsgränssnitt (APIer). På grund av att elektroniktillverkare inte litar påatt känslig data förblir säker i molnet måste proprietär data separeras från statistisk data. Dettaför att möjliggöra nästa steg som är insamling av så kallad Big Data i en molntjänst. Dettamöjliggör i sin tur för tillverkaren av produktionsmaskiner att erbjuda nya tjänster.

<p>Program anomaly detection — modeling normal program executions to detect deviations at runtime as cues for possible exploits — has become a popular approach for software security. To leverage high performance modeling and complete tracing, existing techniques however focus on subsets of applications, e.g., on system calls or calls to predefined libraries. Due to limited scope, it is insufficient to detect subtle control-oriented and data-oriented attacks that introduces new illegal call relationships at the application level. Also such techniques are hard to apply on devices that lack a clear separation between OS and the application layer. This dissertation advances the design and implementation of program anomaly detection techniques by providing application context for library and system calls making it powerful for detecting advanced attacks targeted at manipulating intra- and inter-procedural control-flow and decision variables. </p> <p><br></p> <p>This dissertation has two main parts. The first part describes a statically initialized generic calling context program anomaly detection technique LANCET based on Hidden Markov Modeling to provide security against control-oriented attacks at program runtime. It also establishes an efficient execution tracing mechanism facilitated through source code instrumentation of applications. The second part describes a program anomaly detection framework EDISON to provide security against data-oriented attacks using graph representation learning and language models for intra and inter-procedural behavioral modeling respectively.</p> <p><br> This dissertation makes three high-level contributions. First, the concise descriptions demonstrates the design, implementation and extensive evaluation of an aggregation-based anomaly detection technique using fine-grained generic calling context-sensitive modeling that allows for scaling the detection over entire applications. Second, the precise descriptions show the design, implementation, and extensive evaluation of a detection technique that maps runtime traces to the program’s control-flow graph and leverages graphical feature representation to learn dynamic program behavior. Finally, this dissertation provides details and experience for designing program anomaly detection frameworks from high-level concepts, design, to low-level implementation techniques.</p>

Работа посвящена установлению методами сканирующей электронной микроскопии, в частности впервые применяемой для данного рода материала ориентационной микроскопии, структурного состояния после штатной технологии изготовления и последующего влияния длительного нейтронного облучения образцов из сплава Zr-2,5% Nb, который используется основным материалом для труб канала системы и управления защитой, а также определению причин высокого разброса результатов механических испытаний. Работа проводилась на трубном изделии из сплава Zr-2,5% Nb после эксплуатации в РБМК-1000 в течение 38 лет. В первом разделе работы рассмотрены производство труб каналов СУЗ, рассмотрены основные сплавы Zr, применяемых в качестве конструкционных материалов ядерных реакторов и влияние на них радиационного облучения. Во втором разделе описаны материалы и методы исследования для анализа мелкозернистой структуры трубного изделия из сплава Zr-2,5% Nb и повышенного разброса результатов механических испытаний. В третьем разделе приведены результаты анализа основных параметров структуры материала трубы канала СУЗ, подвергнутого нейтронному облучению и образцов свидетелей после штатной технологии изготовления, а также определено влияние наклепанного слоя на результаты механических свойств образцов типа двойная лопатка из сплава Zr-2,5% Nb после эксплуатации в РБМК-1000. / The work is devoted to the establishment of the structural state after the standard manufacturing technology and the subsequent influence of prolonged neutron irradiation of samples from the Zr-2.5% Nb alloy by the methods of scanning electron microscopy, in particular the orientation microscopy used for the first time for this kind of materials. The alloy is used as the main material for the pipes of the system and protection management, as well as determining the causes of high variance in mechanical test results. The work was carried out on a tubular product made of Zr-2.5% Nb alloy after operation in RBMK-1000 for 38 years. In the first section of the work, the production of CPS channel pipes is considered, the main Zr alloys used as structural materials for nuclear reactors and the effect of radiation exposure on them are considered. The second section describes materials and research methods for analyzing the fine-grained structure of a pipe product made of Zr-2.5% Nb alloy and an increased scatter of mechanical test results. The third section presents the results of the analysis of the CPS channel pipe material structure main parameters subjected to neutron irradiation. As well as samples of testifier after the standard manufacturing technology, along with the influence of the work-hardened layer on the results of the mechanical properties of double blade type samples made of Zr-2.5% Nb alloy after operation in RBMK-1000.

Self-adaptive systems have limited time to adjust their configurations whenever their adaptation goals, i.e., quality requirements, are violated due to some runtime uncertainties. Within the available time, they need to analyze their adaptation space, i.e., a set of configurations, to find the best adaptation option, i.e., configuration, that can achieve their adaptation goals. Existing formal analysis approaches find the best adaptation option by analyzing the entire adaptation space. However, exhaustive analysis requires time and resources and is therefore only efficient when the adaptation space is small. The size of the adaptation space is often in hundreds or thousands, which makes formal analysis approaches inefficient in large-scale self-adaptive systems. In this thesis, we tackle this problem by presenting an online learning approach that enables formal analysis approaches to analyze large adaptation spaces efficiently. The approach integrates with the standard feedback loop and reduces the adaptation space to a subset of adaptation options that are relevant to the current runtime uncertainties. The subset is then analyzed by the formal analysis approaches, which allows them to complete the analysis faster and efficiently within the available time. We evaluate our approach on two different instances of an Internet of Things application. The evaluation shows that our approach dramatically reduces the adaptation space and analysis time without compromising the adaptation goals.