No / The illegal proliferation of small arms and light weapons (SALW) is a global problem, and one consequence of this illicit trade is that regions can become flooded with these guns before, during and following a violent conflict. Effective tracing of these arms requires adequate marking and record-keeping systems as well as improved international co-operation by relevant authorities. This publication argues that the main obstacles to progress in this area are political in nature, rather than technological. Other issues discussed include: the selection of categories and types of SALWs for inclusion in a tracing mechanism; and the structures and institutions required for an effective firearms tracing system.

To gain observability in distributed systems, some telemetry generation and gathering must be implemented. This is especially important when systems have layers of dependencies on other microservices. One method for observability is called distributed tracing. Distributed tracing is the act of building causal event chains between microservices, which are called traces. Finding bottlenecks and dependencies within each call chain is possible with the traces. One framework for implementing distributed tracing is OpenTelemetry. The developer must determine design choices when deploying OpenTelemetry in a Kubernetes cluster. For example, OpenTelemetry provides a collector that collects spans, which are parts of a trace from microservices. These collectors can be deployed one on each node, called a daemonset. Or it can be deployed with one for each service, called sidecars. This study compared the performance impact of the sidecar and daemonset setup to that of having no OpenTelemetry implemented. The resources analyzed were CPU usage, network usage, and RAM usage. Tests were done in a permutation of 4 different scenarios. Experiments were run on 4 and 2 nodes, as well as a balanced and unbalanced service placement setup. The experiments were run in a cloud environment using Kubernetes. The tested system was an emulation of one of Nasdaq's systems based on real data from the company. The study concluded that having OpenTelemetry added overhead / increased resource usage in all cases. Having the daemonset setup, compared to no OpenTelemetry, increased CPU usage by 46.5 %, network usage by 18.25 %, and memory usage by 47.5 % on average. Sidecar did, in most cases, perform worse than the daemonset setup in most cases and resources, especially in RAM and CPU usage.

This thesis explores the overhead of distributed tracing in OpenTelemetry, using different sampling strategies, in a cloud environment. Distributed tracing is telemetry data that allows developers to analyse causal events in a system with temporal information. This comes at the cost of overhead, in terms of CPU, memory and network usage, as the telemetry data has to be generated and sent through collectors that handle traces and at last sends them to a backend. By sampling using three different sampling strategies, head and tail based sampling and a mixture of those two, overhead can be reduced at the price of losing some information. To gain a measure of how this information loss impacts application performance, synthetic error messages are introduced in traces and used to gauge how many traces with errors the sampling strategies can detect. All three sampling strategies were compared for services that sent more and less data between nodes in Kubernetes. The experiments were also tested in a two and four nodes setup. This thesis was conducted with Nasdaq as it is of their interest to have high performing monitoring tools and their systems were analysed and emulated for relevance. The thesis concluded that tail based sampling had the highest overhead (71.33% CPU, 23.7% memory and 5.6% network average overhead compared to head based sampling) for the benefit of capturing all the errors. Head based sampling had the least overhead, except in the node that had deployed Jaeger as the backend for traces, where its higher total sampling rate added on average 12.75% CPU overhead for the four node setup compared to mixed sampling. Although, mixed sampling captured more errors. When measuring the overall time taken for the experiments, the highest impact could be observed when more requests had to be sent between nodes.

During the Syrian conflict the number of European Foreign Fighters has increased exponentially and has become an ever-growing concern for European policymakers. This phenomenon presents host of major security challenges for European policymakers and governments. Among European countries, France provides the highest number of citizens who have gone to Syria to fight against Assad´s regime. The French authorities have estimated that by mid-2014, over 700 French citizens have left France and travelled to Syria to fight. Historically France has had a relationship with Syria which started with its role as a border-drawing colonial power. Grounded in a framework of realism, that emphasizes nation-states as the primary actor within the international system, the analysis concentrates on the role of France´s foreign policy on the Syria as push factor for terrorism and radicalization. This paper attempts to determinate a specific correlation between the policy that France has been conducting towards Syria between 2000 and 2015, and the phenomenon of French Foreign Fighters. Findings suggest that France´s foreign policy towards Syria is the main root cause of the French Foreign Fighters phenomenon.

Modern oil and gas exploration depends on a variety of geophysical prospect tools. One of them is reflection seismology that allows to obtain interwell information of sufficient resolution economically. This exploration method collects reflection seismic data on the surface of an area of prospect interest and then uses them to build seismic images of the subsurface. All imaging approaches can be divided into two groups: wave equation-based methods and integral schemes. Kirchhoff migration, which belongs to the second group, is an indispensable tool in seismic imaging due to its flexibility and relatively low computational cost. Unfortunately, the classic formulation of this method images only a part of the surface data, if so-called multipathing is present in it. That phenomenon occurs in complex geologic settings, such as subsalt areas, when seismic waves travel between a subsurface point and a surface location through more than one path. The quality of imaging with Kirchhoff migration in complex geological areas can be improved if multiple paths of ray propagation are included in the integral. Multiple arrivals can be naturally incorporated into the imaging operator if it is expressed as an integral over subsurface take-off angles. In this form, the migration operator involves escape functions that connect subsurface locations with surface seismic data values through escape traveltime and escape positions. These escape quantities are functions of phase space coordinates that are simply related to the subsurface reflection system. The angle-domain integral operator produces output scattering- and dip-angle image gathers, which represent a convenient domain for subsurface analysis. Escape functions for angle-domain imaging can be simply computed with initial-value ray tracing, a Lagrangian computational technique. However, the computational cost of such a bottom-up approach can be prohibitive in practice. The goal of this work was to construct a computationally efficient phase space imaging framework. I designed several approaches to computing escape functions directly in phase space for mapping surface seismic reflection data to the subsurface angle domain. Escape equations have been introduced previously to describe distribution of escape functions in the phase space. Initially, I employed these equations as a basis for building an Eulerian numerical scheme using finite-difference method in the 2-D case. I show its accuracy constraints and suggest a modification of the algorithm to overcome them. Next, I formulate a semi-Lagrangian approach to computing escape functions in 3-D. The second method relies on the fundamental property of continuity of these functions in the phase space. I define locally constrained escape functions and show that a global escape solution can be reconstructed from local solutions iteratively. I validate the accuracy of the proposed methods by imaging synthetic seismic data in several complex 2-D and 3-D models. I draw conclusions about efficiency by comparing the compute time of the imaging tests with the compute time of a well-optimized conventional initial-value ray tracing. / text

<p>Over the past 20 years, the development in ComputationalElectromagnetics has produced a vast choice of methods based onthe large number of existing mathematical formulations of theMaxwell equations. None of them dominate over the others,instead they complement each other and the choice of methoddepends on the frequency range of the electromagnetic waves.This work is focused on the most popular method in the highfrequency scenario, namely the Geometrical Theory ofDiffraction (GTD). The main advantage of GTD is the ability topredict the electromagnetic field asymptotically in the limitof vanishing wavelength, when other methods, such as the Methodof Moments, become computationally too expensive.</p><p>The low cost of GTD is due to both the fact that there is noruntime penalty in increasing the frequency and that the raytracing, which GTD is based on, is a geometrical technique. Thecomplexity is then no longer dependent on electrical size ofthe problem but instead on geometrical sub problems which aremanageable. For industrial applications the geometricalstructures, with which the rays interact, are modelled bytrimmed Non-Uniform Rational B-Spline (NURBS) surfaces, themost recent standard used to represent complex free-formgeometries.</p><p>Due to the introduction of NURBS, the geometrical subproblems tend to be mathematically and numerically cumbersome,but they can be highly simplified by proper Object Orientedprogramming techniques. This allowed us to create a flexiblesoftware package, MIRA: Modular Implementation of Ray Tracingfor Antenna Applications, with an architecture that separatesmathematical algorithms from their implementation details andmodelling. In addition, its design supports hybridisationtechniques in combination with other methods such as Method ofMoment (MoM) and Physical Optics (PO).</p><p>In a first hybrid application, a triangle-based PO solveruses the shadowing information calculated with the ray tracerpart of MIRA. The occlusion is performed between triangles andtheir facing NURBS surfaces rather than between their facingtriangles, thus reducing the complexity. Then the shadowinginformation is used in an iterative MoM-PO process in order tocover higher frequencies, where the contribution of theshadowing effects, in the hybrid formulation, is believed to bemore significant.</p><p>Thesis presented at the Royal Institute of Technology ofStockholm in 2003, for the degree of Licentiate in ScientificComputing.</p>

This thesis presents a very efficient hybrid method for analysis and design of optical and passive photonic devices. The main focus is on unbounded wave structures. This class of photonic systems are in general very large in terms of the wavelength of the driving optical sources. The size of the problem space makes the electromagnetic modelling of these structure a very challenging problem. Our approach and main contribution has been to combine or hybridize three methods that together can handle this class of photonic structures as a whole. <br /><br /> The basis of the hybrid method is a novel Gaussian Beam Tracing method GBT. Gaussian Beams (GB) are very suitable elementary functions for tracing and tracking purposes due to their finite extent and the fact that they are good approximations for actual laser beams. The GBT presented in this thesis is based on the principle of phase matching. This method can be used to model the reflection and refraction of Gaussian beams from general curved surfaces as long as the curvature of the surface is relatively small. It can also model wave propagation in free space. The developed GBT is extremely fast as it essentially uses simple algebraic equations to find the parameters of the reflected and refracted beams once the parameters of the incident beam is known. Therefore sections of the systems whose dimensions are large relative to the optical wavelength are simulated by the GBT method. <br /><br /> Fields entering a photonic system may not possess an exact Gaussian profile. For example if an aperture limits the input laser to the system, the field is no longer a GB. In these and other similar cases the field at some aperture plane needs to be expanded into a sum of GBs. Gabor expansion has been used for this purpose. This method allows any form of field distribution on a flat or curved surface to be expanded into a sum of GBs. The resultant GBs are then launched inside the system and tracked by GBT. Calculation of the coefficients of the Gabor series is very fast (1-2 minutes on a typical computer for most applications). <br /><br /> In some cases the dimensions or physical properties of structures do not allow the application of the GBT method. For example if the curvature of a surface is very large (or its radius of curvature is very small) or if the surface contains sharp edges or sub-wavelength dimensions GBT is no longer valid. In these cases we have utilized the Finite Difference Time Domain method (FDTD). FDTD is a rigorous and very accurate full wave electromagnetic solver. The time domain form of Maxwell's equations are discretized and solved. No matrix inversion is needed for this method. If the size of the structure that needs to be analyzed is large relative to the wavelength FDTD can become increasingly time consuming. Nevertheless once a structure is simulated using FDTD for a given input, the output is expanded using Gabor expansion and the resultant beams can then be efficiently propagated through any desired system using GBT. For example if a diffraction grating is illuminated by some source, once the reflection is found using FDTD, it can be propagated very efficiently through any kind of lens or prism (or other optical structures) using GBT. Therefore the overall computational efficiency of the hybrid method is very high compared to other methods.

Saab AB Training &amp; Simulation is specialized on military training, including laserbased training. To continue being the world leader in this area, a new generationof laser simulators needs to be developed. To simplify the development of thishighly complex system, this master thesis have resulted in a MATLAB/Simulinkmodel which simulates the electro-opto/mechanical system representing theirlaser based simulation platform. The focus of this master thesis has been to simulateand control the laser beam deflection. To be more precise, the motors usedto rotate the Risley-prisms deflecting the laser beam is modelled. With a goodmodel of the motors, a control system is applied steering the wedges to a referencerotation angle. The reference rotation angle is difficult to calculate though,since the deflection following several rotary wedges is severely nonlinear. Thereare many ways to calculate the rotation angles, but in this master thesis it will bedone by solving optimization problems in MATLAB. / Saab AB Training &amp; Simulation är specialiserade på militär träning, bland annatbaserad på laser och för att fortsätta vara världsledande inom detta områdekrävs utveckling av en ny generation lasersimulatorer. För att underlätta utvecklingsarbetetav detta högst komplexa system, har i detta examensarbete en simulerbarmodell skapats i MATLAB/Simulink för att kunna simulera det elektroopto/mekaniska system som beskriver deras laserbaserade simulatorplattform.Fokus för detta examensarbete har varit att modellera avlänkningen. Mer ingåendeså modelleras de motorer som används för att rotera Risley-prisman så atten laserstråle uppnår önskad avlänkning. Med en bra modell av motorerna applicerasett reglersystem som styr de roterbara kilarna till referensposition. Referenspositionenär dock komplicerad att beräkna eftersom avlänkningen frånflera roterande kilar beter sig högst olinjärt. För att göra detta finns flera tillvägagångssätt,men i detta examensarbete kommer det att göras genom att lösaoptimeringsproblem i MATLAB.

Sediments negatively impact the quality of surface waters and are a significant source of contaminants, such as nutrients and pesticides in agricultural watersheds. Sediment fingerprinting is a relatively recent technique capable of determining the origin of suspended sediment. In this thesis, we investigated the sources of suspended sediments in a predominantly rural watershed in Atlantic Canada. Our first objective was to determine sediment source apportionment estimates by treating the watershed as a single catchment, and making the assumption that conditions affecting source production and transport, from the land to the stream, were uniform across the watershed. For the first objective, suspended sediments were collected at a single target location for sediment apportionment (main outlet) and used to represent sediment dynamics throughout the entire catchment. For the second objective, we examined not only the whole watershed but also sub-watersheds within it, to better understand processes affecting sediment dynamics. / October 2016

Biota des Kohlenstoffkreislaufs spielen bei der Speicherung und Verteilung des Kohlen-stoffs im Bodennahrungsnetz eine herausragende Rolle. Wobei der Abbau organischer Bodensubstanz stark von deren Verfügbarkeit für Mikroorganismen und Enzyme abhängt. Rhizosphäre und Detritusphäre verfügen über außerordentlich große Mengen an organischem Kohlenstoff. Dies macht diese Biosphären zu Hot-Spots mikrobieller Aktivität. Während der letzten Jahrzehnte stieg das Interesse an der Forschung zu mikrobieller Aktivität im Boden. Dennoch herrscht noch immer kein umfassendes Verständinis von Indikatoren und Triebkräften mikrobieller Aktivität in der Rhizosphäre und Detritusphäre. Dies ist nicht zuletzt der Tatsache geschuldet, dass es mehr als einer einzigen Methode zur Bestimmung dieser Faktoren bedarf. Aus diesem Grund setzt sich diese Arbeit zum Ziel, die mikrobielle Aktivität, ihre Indikatoren und Treiber zu explorieren. Folglich wurden diverse Indikatoren mikrobieller Aktivität, wie mikrobielle Respiration, mikrobielle Biomasse und Enzymkinetik, an Proben aus einem Feldexperiment mit diffe-rierendem Substrat-Eintrag (Mais-Rhizodeposite vs. Mais-Streu) ermittelt. Tiefengradienten der Indikatoren mikrobieller Aktivität dienten der Beurteilung der Auswirkungen sinkender Substratqualität und -quantität in Rhizo- und Detritusphäre mit zunehmender Bodentiefe. Besonderer Fokus lag dabei auf den Indizes unterschiedlicher Enzyme und deren Aktivität (z. B. spezifische Aktivität, katalytische Effizienz und Verhältnisse zwischen Enzymen des Kohlenstoff- und Stickstoff-Kreislaufs) im Tiefenprofil des Bodens. Neben dieser Feldstudie wurde das Verhältinis von RNA zu dsDNA als Indikator mikrobieller Aktivität entlang eines klimatischen Grandienten ermittelt, um den metabolischen Status innerhalb unterschiedlicher Bodentypen zu bestimmen. Die Feldstudien wurden um Experimente in Labor und Gewächshaus ergänzt, in denen mittels Isoto-penmarkierungsverfahren die Effekte von Wurzelhaaren und Protisten auf die mikrobielle Aktivität beleuchtet wurden. Diese Methode ermöglichte ein Nachvollziehen des C- und N-Flusses und trug damit zum Verständnis der Verflechtungen der Organismen im terrestrischen Boden-Nahrungsnetz bei. Die räumliche Verteilung der Enzymaktivität in der Rhizosphäre wurde anhand der Boden-Zymographie in situ untersucht. Durch unterschiedliche Substratverfügbarkeit wurde ein Wandel der funktionellen Eigenschaften der Mikroorganismengemeinschaften und des enzymatischen Systems induziert. Speziell der durchwurzelte Oberbodenhorizont zeigte einen Anstieg der mikro-biellen Aktivität im Vergleich zum Boden mit Streueintrag und der Kontrolle. Rhizodeposite sind eine grundlegende Kohlenstoff- und Energiequelle für Bodenmikroorganismen und stimulieren deren Wachstum und Aktivität. Die Präsenz von Rhizodepositen in Hot-Spots macht diese zu bevorzugten Habitaten für Mikroorganismen. Die Mehrzahl der Indikatoren für mikrobielle Aktivität wurde ausschließlich im Oberboden durch den Substrateintrag beeinflusst. Darunter auch die katalytische Effizienz, die – ungeachtet des Substrateintrags – von Oberboden (< 40 cm) zu Unterboden (> 40 cm) um das 2- bis 20-fache abnahm. Dies ließ auf die Relevanz der mit der Tiefe abnehmenden Menge und Qualität der Substrate im Boden als einflussnehmenden Faktor auf die mikrobielle Aktivität schließen. Das Verhältnis von RNA zu dsDNA spiegelte den metabolischen Status der mikrobiellen Organismengesellschaften in den meisten der beprobten Böden wider. Wohingegen das RNA:dsDNA Verhältnis dieser Indikatoreigenschaft widersprach, lagen erhöhte Tongehalte vor, die nach der Extraktion zu Ungenauigkeiten bei der Bestimmung der RNA-Quantität führten. Protozoen wird beim Vorgang des Kohlenstoffflusses von Bakterien zu Organismen höherer Trophieebenen eine bedeutende Rolle zugesprochen, was ebenfalls ihren Einfluss auf die mikrobielle Aktivität im Boden unterstreicht. Um diesen Effekten, im Speziellen jenen der Acanthoamoebe auf den Kohlenstoff- und Stickstofffluss, sowie die Indikatoren mikrobieller Aktivität in der Rhizo- und Detritusphäre nachzugehen, wurde ein dreifaches Isotopenmarkierungs-Experiment durchgeführt. Es ergab, dass Kohlenstoffflüsse und Enzymaktivitäten sowohl von Substrateintrag als auch Substratqualität in Rhizo- wie Detritusphäre sowie deren faunistischer Besiedlung abhängen. Daraus erschloss sich, dass die Besiedlung mit Acanthamoeben als potenzielle Triebkraft mikrobieller Aktivität, besonders innerhalb der Rhizosphäre, gedeutet werden kann. Um den Einfluss von Wurzelhaaren auf die mikrobielle Aktivität und den Priming Effekt in der Rhizosphäre einzuschätzen, wurde ein Experiment im Gewächshaus mit kontinuierlicher Markierung von Boden mit Pflanzenbewuchs und einer Kontrolle ohne Bewuchs mit 13C-Isotopen durchgeführt. Wurzelhaare zeigten sich darin als Initiatoren eines positiven Rhizosphären-Priming Effektes während der Wachstumsphase, wohingegen der Abbau organischer Bodensubstanz in den Kontrollen gehemmt war. Im Falle der positiven Initialwirkung der Wurzelhaare stiegen zudem die Enzymaktivitäten von Chitinase und ß-Xylosidase an, was auf eine Zersetzung stabiler, organischer Bodensubstanz hinwies. Damit konnte ein deutlicher Effekt von Wurzelhaaren auf die mikrobielle Aktivität im Boden während der Phase des Pflanzenwachtums nachgewiesen werden. Somit vermittelt diese Arbeit ein weiterführendes Verständnis der auf mikrobielle Aktivität im Boden einwirkenden Faktoren und stellt eine Auswahl von Indikatoren zur Charakterisierung dieser Aktivität vor, die sowohl auf der Landschaftsebene als auch in der prozessorientierten Forschung im Wurzelraum Anwendung finden kann.