Fabrication of high aspect ratio microfluidic devices using direct FS ablation

We present a single stage direct fs ablation results which show that it is possible to make high quality and high aspect ratio devices in a single stage process using a CAD optimised approach.

Effect of aspect ratio on thermal convection in open and closed systems

Internally heated fluids are found across the nuclear fuel cycle. In certain situations the motion of the fluid is driven by the decay heat (i.e. corium melt pools in severe accidents, the shutdown of liquid metal reactors, molten salt and the passive control of light water reactors) as well as normal operation (i.e. intermediate waste storage and generation IV reactor designs). This can in the long-term affect reactor vessel integrity or lead to localized hot spots and accumulation of solid wastes that may prompt local increases in activity. Two approaches to the modeling of internally heated convection are presented here. These are based on numerical analysis using codes developed in-house and simulations using widely available computational fluid dynamics solvers. Open and closed fluid layers at around the transition between conduction and convection of various aspect ratios are considered. We determine optimum domain aspect ratio (1:7:7 up to 1:24:24 for open systems and 5:5:1, 1:10:10 and 1:20:20 for closed systems), mesh resolutions and turbulence models required to accurately and efficiently capture the convection structures that evolve when perturbing the conductive state of the fluid layer. Note that the open and closed fluid layers we study here are bounded by a conducting surface over an insulating surface. Conclusions will be drawn on the influence of the periodic boundary conditions on the flow patterns observed. We have also examined the stability of the nonlinear solutions that we found with the aim of identifying the bifurcation sequence of these solutions en route to turbulence.

An aspect-oriented and model-driven approach for managing dynamic variability

Constructing and executing distributed systems that can adapt to their operating context in order to sustain provided services and the service qualities are complex tasks. Managing adaptation of multiple, interacting services is particularly difficult since these services tend to be distributed across the system, interdependent and sometimes tangled with other services. Furthermore, the exponential growth of the number of potential system configurations derived from the variabilities of each service need to be handled. Current practices of writing low-level reconfiguration scripts as part of the system code to handle run time adaptation are both error prone and time consuming and make adaptive systems difficult to validate and evolve. In this paper, we propose to combine model driven and aspect oriented techniques to better cope with the complexities of adaptive systems construction and execution, and to handle the problem of exponential growth of the number of possible configurations. Combining these techniques allows us to use high level domain abstractions, simplify the representation of variants and limit the problem pertaining to the combinatorial explosion of possible configurations. In our approach we also use models at runtime to generate the adaptation logic by comparing the current configuration of the system to a composed model representing the configuration we want to reach. © 2008 Springer-Verlag Berlin Heidelberg.

Fabrication of high aspect ratio microfluidic devices using direct FS ablation

We present a single stage direct fs ablation results which show that it is possible to make high quality and high aspect ratio devices in a single stage process using a CAD optimised approach.

Bifurcation study for a vertical channel with constant flux and large aspect ratio

Using suitable coupled Navier-Stokes Equations for an incompressible Newtonian fluid we investigate the linear and non-linear steady state solutions for both a homogeneously and a laterally heated fluid with finite Prandtl Number (Pr=7) in the vertical orientation of the channel. Both models are studied within the Large Aspect Ratio narrow-gap and under constant flux conditions with the channel closed. We use direct numerics to identify the linear stability criterion in parametric terms as a function of Grashof Number (Gr) and streamwise infinitesimal perturbation wavenumber (making use of the generalised Squire’s Theorem). We find higher harmonic solutions at lower wavenumbers with a resonance of 1:3exist, for both of the heating models considered. We proceed to identify 2D secondary steady state solutions, which bifurcate from the laminar state. Our studies show that 2D solutions are found not to exist in certain regions of the pure manifold, where we find that 1:3 resonant mode 2D solutions exist, for low wavenumber perturbations. For the homogeneously heated fluid, we notice a jump phenomenon existing between the pure and resonant mode secondary solutions for very specific wavenumbers .We attempt to verify whether mixed mode solutions are present for this model by considering the laterally heated model with the same geometry. We find mixed mode solutions for the laterally heated model showing that a bridge exists between the pure and 1:3 resonant mode 2D solutions, of which some are stationary and some travelling. Further, we show that for the homogeneously heated fluid that the 2D solutions bifurcate in hopf bifurcations and there exists a manifold where the 2D solutions are stable to Eckhaus criterion, within this manifold we proceed to identify 3D tertiary solutions and find that the stability for said 3D bifurcations is not phase locked to the 2D state. For the homogeneously heated model we identify a closed loop within the neutral stability curve for higher perturbation wavenumubers and analyse the nature of the multiple 2D bifurcations around this loop for identical wavenumber and find that a temperature inversion occurs within this loop. We conclude that for a homogeneously heated fluid it is possible to have abrup ttransitions between the pure and resonant 2D solutions, and that for the laterally heated model there exist a transient bifurcation via mixed mode solutions.

An aspect oriented performance analysis environment

AOSD'03 Practitioner Report Performance analysis is motivated as an ideal domain for benefiting from the application of Aspect Oriented (AO) technology. The experience of a ten week project to apply AO to the performance analysis domain is described. We show how all phases of a performance analysts’ activities – initial profiling, problem identification, problem analysis and solution exploration – were candidates for AO technology assistance – some being addressed with more success than others. A Profiling Workbench is described that leverages the capabilities of AspectJ, and delivers unique capabilities into the hands of developers exploring caching opportunities.

Fabrication of high aspect ratio microfluidic devices using direct fs ablation

We present a single stage direct fs ablation results which show that it is possible to make high quality and high aspect ratio devices in a single stage process using a CAD optimised approach. © 2008 Optical Society of America.

Négy jellegzetesség. A magyar fejlődés politikai gazdaságtani megközelítésben. 1. rész = Four characteristic features. Development in Hungary from the aspect of political economy. First Part

A két részből álló cikk a magyarországi reformfolyamat és posztszocialista átalakulás négy olyan jellegzetességét emeli ki, amelyek megszakítás nélkül, a politikai szférában bekövetkezett rendszerváltást követően is, folyamatosan jellemezték az elmúlt harminc év fejlődését: a lakosság anyagi jólétének prioritása, erős paternalista jóléti állam, a reformfolyamat és átmenet fokozatossága és a politikai nyugalom. Az 1995. március 12­én bejelentett stabilizációs program - amennyiben megvalósul - jelenthet elmozdulást ezektől a jellegzetességektől. A cikk politikai gazdaságtani megközelítésben vizsgálja, hogy miért alakult ki ez a négy jellegzetesség, miképpen hatottak azok egymásra, milyen kedvező és kedvezőtlen hatásokat fejtettek ki. Az első rész az 1956­os forradalom hatásából kiindulva politikatörténeti áttekintést ad, majd a mai jólét, biztonság és nyugalom prioritását és a társadalmi adósság felhalmozódását, végül a stabilizációs program gazdasági és politikai hatásait elemzi. / === / The article, consisting of two parts, emphasizes four characteristic features of the Hungarian reform process and the post­socialist transformation, which, uninterruptedly, characterized the development over the last thirty years, even after the systemic change in the political sphere. These were: priority of the material welfare of the population, a strong, paternalistic welfare state, the gradual progress of the reform process and the transition, as well as political calmness. The stabilization programme, announced on March 12,1995, may imply - if it materializes - a shift away from these characteristics. The article investigates, from the aspect of political economy, why the four characteristic features had developed, how they affected each other and what were their advantageous and disadvantageous impacts. Setting out from the impacts of the 1956 revolution, the first part gives an overview of political history and then analyses the priority of today's welfare, security and calm as well as the accumulation of societal debt and, finally, the economic and political impacts of the stabilization programme.

Négy jellegzetesség. A magyar fejlődés politikai gazdaságtani megközelítésben. 2. rész = Four characteristic features. Development in Hungary from the aspect of political economy - II.

A tulajdonviszonyok és intézmények átalakulását is a fokozatosság, a szerves fejlődés jellemzi; Magyarországon a hosszú reformszocialista fázist a politikai fordulat után sem követte ugrás a piacgazdaság felé, bár az átalakulás felgyorsult. A cikk a fokozatosság érvényesülését az értékesítési stratégia sokféle változatát alkalmazó, burjánzó privatizációban, az új vállalkozások keletkezésének folyamatában, a liberalizálás menetében és a jogi infrastruktúra változásában mutatja be. Elemzi az átmenet során megerősödő korporatista elemek hatását a magyar gazdaságpolitikára. Végül néhány összefoglaló megjegyzést fűz a magyar fejlődéshez a politikai gazdaságtan és a politikai filozófia szemszögéből. Az elmúlt harminc évben a mindenkori kormánynak jól érzékelhető preferenciája volt a radikális intézkedések elodázása, a társadalmi adósság felhalmozódásának vállalása a konfliktusok elkerülése érdekében. A szerző felhívja a figyelmet a különböző nemzedékek eltérő időpreferenciájára és az ezzel kapcsolatos etikai problémákra. Befejezésül a népszerűtlen intézkedéseket az állampolgárok nagy hányadának véleményével szemben is felvállaló kormányzás és a demokrácia viszonyáról szól. / === / Gradualism and organic development also distinguish the transformation of property relations and institutions. Hungary's long reform­socialist phase was not followed, after the political change, by a leap towards a market economy, although the transformation became faster. The article shows how gradualism applies to the proliferating of privatization, with its wide variety of selling strategies, to the foundation process of new firms, to the course of liberalization, and to change in the legal infrastructure. It analyses the effect on Hungarian economic policy of corporatist elements which strengthen during the transition. Finally, it makes some comments summing up Hungarian development in terms of political economy and political philosophy. The government at any time in the last thirty years showed an obvious preference for putting off radical measures and accepting an accumulation of social debt as a way of averting conflict. The article notes differences of time preference between generations and the ethical problems these raise. Finally, it makes remarks on the relationship between democracy and an administration intent on unpopular measures opposed by a high proportion of citizens.

An aspect-oriented approach to designing role-based access control services

Access control (AC) limits access to the resources of a system only to authorized entities. Given that information systems today are increasingly interconnected, AC is extremely important. The implementation of an AC service is a complicated task. Yet the requirements to an AC service vary a lot. Accordingly, the design of an AC service should be flexible and extensible in order to save development effort and time. Unfortunately, with conventional object-oriented techniques, when an extension has not been anticipated at the design time, the modification incurred by the extension is often invasive. Invasive changes destroy design modularity, further deteriorate design extensibility, and even worse, they reduce product reliability. ^ A concern is crosscutting if it spans multiple object-oriented classes. It was identified that invasive changes were due to the crosscutting nature of most unplanned extensions. To overcome this problem, an aspect-oriented design approach for AC services was proposed, as aspect-oriented techniques could effectively encapsulate crosscutting concerns. The proposed approach was applied to develop an AC framework that supported role-based access control model. In the framework, the core role-based access control mechanism is given in an object-oriented design, while each extension is captured as an aspect. The resulting framework is well-modularized, flexible, and most importantly, supports noninvasive adaptation. ^ In addition, a process to formalize the aspect-oriented design was described. The purpose is to provide high assurance for AC services. Object-Z was used to specify the static structure and Predicate/Transition net was used to model the dynamic behavior. Object-Z was extended to facilitate specification in an aspect-oriented style. The process of formal modeling helps designers to enhance their understanding of the design, hence to detect problems. Furthermore, the specification can be mathematically verified. This provides confidence that the design is correct. It was illustrated through an example that the model was ready for formal analysis. ^

Le rôle stratégique des représentations sociales à caractère paysager dans le mouvement de récupération des rivières à des fins récréatives

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

La mesure alternative d’hostilité dans les relations de rivalité interacteur.

Le présent travail explore le phénomène de la rivalité interétatique1 et les mesures de son intensité. Chacune des définitions existantes de la rivalité fait la lumière sur l’une de ses caractéristiques. La rivalité durable met l’accent sur la compétition militarisée, la rivalité stratégique accorde une importance particulière à la perception de l’ennemi, tandis que la rivalité interétatique est axée sur les questions autour desquelles la compétition se déroule. Ces visions différentes du phénomène de la rivalité laissent leur empreinte sur son opérationnalisation et sur le choix des paramètres visant à le capter. Nous réunissons ces trois interprétations dans une seule définition de rivalité interacteur, en proposant une nouvelle classification des actions hostiles, ainsi que la mesure alternative d’hostilité fondée sur la fréquence de ces dernières. Les quatre études de cas suivantes nous ont permis d’atteindre ces objectifs : les relations de rivalité entre l’Afghanistan et le Pakistan, entre l’Arménie et l’Azerbaïdjan, entre le Bélize et le Guatemala, ainsi qu’entre la Somalie et l’Éthiopie.

Culture stratégique et libéralisation politique au Myanmar

Le Myanmar traverse un processus de libéralisation politique qui a été entamé par le haut. Le régime militaire a tenu des élections générales en 2010, lesquelles ont placé au pouvoir un nouveau gouvernement composé à la fois de civils et de militaires. Depuis, la majorité des sanctions imposées par plusieurs États occidentaux au Myanmar ont été levées, et on observe une diversification des relations internationales du pays. Imbriqué à la sphère d’influence chinoise depuis quelques années, celui-ci rétablit des contacts diplomatiques et économiques avec l’Occident. Peu de chercheurs ont tenté d’expliquer les causes de cette transition politique, et le lien entre libéralisation politique et diversification des relations internationales n’a pas encore été expliqué. Ce mémoire propose de le faire en utilisant un modèle théorique issu de deux types de littérature, celle sur la culture stratégique et celle sur les transitions politiques. Il suggère que la libéralisation politique du Myanmar s’explique par les luttes d’influences au sein du régime entre deux sous-cultures stratégiques, les hardliners et les softliners. L’application des normes favorisées par les hardliners ayant échoué dans l’atteinte des objectifs stratégiques du régime, les softliners ont pu imposer leurs propres préférences normatives. Il propose également que la libéralisation politique était une étape nécessaire pour que le gouvernement birman puisse diversifier ses relations internationales.

Le rôle stratégique des représentations sociales à caractère paysager dans le mouvement de récupération des rivières à des fins récréatives

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

The “social” aspect of social-ecological systems: a critique of analytical frameworks and findings from a multisite study of coastal sustainability

We evaluate whether society can adequately be conceptualized as a component of social-ecological systems, given social theory and the current outputs of systems-based research. A mounting critique from the social sciences posits that resilience theory has undertheorized social entities with the concept of social-ecological systems. We trace the way that use of the term has evolved, relating to social science theory. Scientometic and network analysis provide a wide range of empirical data about the origin, growth, and use of this term in academic literature. A content analysis of papers in Ecology and Society demonstrates a marked emphasis in research on institutions, economic incentives, land use, population, social networks, and social learning. These findings are supported by a review of systems science in 18 coastal assessments. This reveals that a systems-based conceptualization tends to limit the kinds of social science research favoring quantitative couplings of social and ecological components and downplaying interpretive traditions of social research. However, the concept of social-ecological systems remains relevant because of the central insights concerning the dynamic coupling between humans and the environment, and its salient critique about the need for multidisciplinary approaches to solve real world problems, drawing on heuristic devices. The findings of this study should lead to more circumspection about whether a systems approach warrants such claims to comprehensiveness. Further methodological advances are required for interdisciplinarity. Yet there is evidence that systems approaches remain highly productive and useful for considering certain social components such as land use and hybrid ecological networks. We clarify advantages and restrictions of utilizing such a concept, and propose a reformulation that supports engagement with wider traditions of research in the social sciences.