The understanding of the physics of the Coherent Structures and their interaction with the remaining fluid motions is of paramount interest in Turbulence Research. <p>Indeed, recently had been suggested that separating and understanding the the different physical behavior of Coherent Structures and "uncoherent" background might very well be the key to understand and predict Turbulence. Available understanding of Coherent Structures shows that their size is considerably larger than the turbulent macro-scale, making permissible the application of Large Eddy Simulation to their simulation and study, with the advantage to be able to study their behavior at higher Re and more complex geometry than a Direct Numerical Simulation would normally allow. Original purpose of the present work was therefore the validation of the use of Large Eddy Simulation for the study of Coherent Structures in Shear-Layer and the its application to different flow cases to study the effect of the flow topology on the Coherent Structures nature.<p>However, during the investigation of the presence of Coherent Structures in numerically generated LES flow fields, the aging in house Large Eddy Simulation (LES) code of the Environmental & Applied Fluid Dynamics Department has shown a series of limitations and shortcomings that led to the decision of relegating it to the status of Legacy Code (from now on indicated as VKI LES legacy code and of discontinuing its development. A new natively parallel LES solver has then been developed in the VKI Environmental & Applied Fluid Dynamics Department, where all the shortcomings of the legacy code have been addressed and modern software technologies have been adopted both for the solver and the surrounding infrastructure, delivering a complete framework based exclusively on Free and Open Source Software (FOSS ) to maximize portability and avoid any dependency from commercial products. The new parallel LES solver retains some basic characteristics of the old legacy code to provide continuity with the past (Finite Differences, Staggered Grid arrangement, Multi Domain technique, grid conformity across domains), but improve in almost all the remaining aspects: the flow can now have all the three directions of inhomogeneity, against the only two of the past, the pressure equation can be solved using a three point stencil for improved accuracy, and the viscous terms and convective terms can be computed using the Computer Algebra System Maxima, to derive discretized formulas in an automatic way.<p>For the convective terms, High Resolution Central Schemes have been adapted to the three-dimensional Staggered Grid Arrangement from a collocated bi-dimensional one, and a system of Master-Slave simulations has been developed to run in parallel a Slave simulation (on 1 Processing Element) for generating the inlet data for the Master simulation (n - 1 Processing Elements). The code can perform Automatic Run-Time Load Balancing, Domain Auto-Partitioning, has embedded documentation (doxygen), has a CVS repository (version managing) for ease of use of new and old developers.<p>As part of the new Frame Work, a set of Visual Programs have been provided for IBM Open Data eXplorer (OpenDX), a powerful FOSS Flow visualization and analysis tool, aimed as a replacement for the commercial TecplotTM, and a bug tracking mechanism via Bugzilla and cooperative forum resources (phpBB) for developers and users alike. The new M.i.O.m.a. (MiOma) Solver is ready to be used again for Coherent Structures analysis in the near future. / Doctorat en sciences appliquées / info:eu-repo/semantics/nonPublished

John Warden är en inflytelserik luftmaktsteoretiker som låg bakom koalitionens luftkampanj mot Irak 1991. Han menar att luftmakt bör användas för att slå ut motståndarens motståndskraft genom att rikta anfall mot kritiska tyngdpunkter. Han illustrerar tyngdpunkterna genom att måla upp motståndaren som ett system bestående av fem ringar som visar hur systemet bör angripas. Shaun Clarke menar att småstater inte kan använda Wardens luftmaktsteori eftersom det kräver stor massa och därför en stormakts resurstillgångar. Han lanserar därför SPOT-paradigmet som en väg för småstaten att anamma strategisk bombning på ett resurseffektivt sätt. Denna studie prövar Wardens och Clarkes förklaringskraft genom en fallstudie på Israels luftmaktsutövande under operation Protective Edge 2014, för att se om Clarkes påstående är giltigt och om SPOT-paradigmet är användbart för småstaten.Studien visar att femringsmodellen har låg förklaringskraft på Israels nyttjande av luftmakt. Man har i huvudsak inte följt Wardens rekommendationer. SPOT-paradigmet har däremot hög förklaringskraft och studien förefaller stärka teorin i småstatens luftanfall mot en svagare motståndare.

This paper outlines the design of a high-precision graphic audio equalizer with digital filters in parallel, along with its implementation in MATLAB App Designer. The equalizer is comprised of 31 bands separated with a one-third octave frequency ratio, and its frequency response is controlled by 63 filters. Furthermore, the application can process audio signals, in real time, recorded by microphone and from audio files. While processing, it displays an FFT plot of the output sound, also in real time, equipped with a knob by which the refreshing pace can be adjusted. The actual frequency response proved to match the desired one accurately, but the matching is computationally demanding for the computer. An even higher accuracy would entail a computational complexity beyond the power of ordinary computers, and was thus concluded to be inappropriate. As a result, the final application manages to provide most laptops with both high precision and proper functionality.

To investigate how protein folding is affected by sequence connectivity five topological variants of the ribosomal protein S6 were constructed through circular permutation.  In these constructs, the chain connectivity (i.e. the order of secondary-structure elements) is changed without changing the native-state topology.  The effects of the permutations on the folding process were then characterised by φ-value analysis, which estimates the extent of contact formations in the transition-state ensemble.  The results show that the folding nuclei of the wild-type and permutant proteins comprises a common motif of one α-helix docking against two β-sheets, i.e. the minimal structure for folding.  However, this motif is recruited in different parts of the S6 structure depending on the permutation, either in the α1 or α2 half of the protein.  This minimal structure is not unique for S6 but can also be seen in other proteins.  As an effect of the dual nucleation possibilities, the transition-state changes describe a competition between two parallel pathways, which both include the central β-stand 1.  This strand constitutes thus a structural overlap between the two competing nuclei.  As similar overlap between competing nuclei is also seen in other proteins, I hypothesise that the coupling of several small nuclei into extended ‘super nuclei’ represents a general principle for propagating folding cooperativity across large structural distances.  Moreover, I demonstrate by NMR analysis that the existence of multiple folding nuclei renders the H/D-exchange kinetics independent of the folding pathway. / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper IV: Manuscript

Den amerikanske luftmaktsteoretikern John A Warden III har skrivit ett flertal artiklar och böcker om vad han anser är det bästa sättet att använda luftmakt. Warden förordar luftmaktens offensiva natur och eftersträvar ett snabbt, för egen del, fördelaktigt slut på en konflikt. Warden har bl.a. liknat fienden vid ett system, där han menar att strävan skall ligga i att slå ut fiendens ledarskikt vilket får tillföljd att dess vilja till strid upphör. I detta arbete ges en sammanfattning av, enligt författaren, centrala delar av Wardens teorier. Sammanfattningen mynnar ut i tre stycken parametrar som kommer att utgöra Wardens teorier i detta arbete. De tre parametrarna är "enemy as a system", "center of gravity" samt "parallell attack". Dessa parametrar ligger sedan till grund för en analys av Israels luftkampanjer i dess krig mot Hizbollah 2006, Operation Change of Direction samt dess krig mot Hamas 2008-09, Operation Cast Lead. Syftet med detta är att ta reda på om Israel använde sig av Wardens teorier under dessa båda operationer. Anledningen till valet av dessa två konflikter är att Israel bl.a. sin doktrin slagit fast att de aldrig har råd att förlora ett krig. Detta tvingar Israel att optimera sin taktisering. Slutsatsen blev att det tydligt går att se att Wardens teorier genomsyrade Operation Change of Direction. Det var enbart "parallell attack" som inte tydligt efterföljdes genom hela operationen. Under Operation Cast Lead däremot så följde Israel Wardens teorier i mycket mindre utsträckning. Det var enbart "center of gravity" som följdes genom hela den operationen.

This paper provides an explanation of the concepts John A. Warden III describes regarding the use of air power and if this theory can be found, within the confines of an unconventional war. The U.S. ability to air power is overwhelming, however the right kind of warfare can force this great power to abandon their military and political objectives by exhausting its resources over time as it becomes increasingly costly, both economically, politically and morally, to wage war. The research deals with operation Rolling Thunder and John A. Warden IIIs theory in relation to this massive bombing campaign. Firstly, you will find an analysis of John. A. Warden III's works. Five concepts can be found: Airspace Control, center of gravity, air interdiction, the enemy as a system and parallel attack. Secondly, a content analysis of relevant literature in the context of a case study on Operation Rolling Thunder. Thirdly a comparative analysis between the two results with a subsequent discussion relating the main problem and an effort is made to determine the outcome of the investigation and if the purpose of this paper has been met. Within the implementation phases of Operation Rolling Thunder, it is possible to distinguish som of Wardens key concepts regarding air power utilization. Even though the four phases illustrate a continuous change in strategy, Wardens theory The Enemy as a system was never implemented. / Denna uppsats ger en förklaring av John A. Warden IIIs teori om nyttjande av luftmakt och de begrepp som utgör grunden för denna. Frågan om grundbegreppen går att återfinna inom ramarna för ett otraditionellt krig tas upp. USAs förmåga till luftmakt är stor, men med rätt sorts krigföring kan även denna makt tvingas överge sina militära och politiska mål genom utmattning över en längre tidsperiod eftersom det blir allt dyrare, både ekonomiskt, politiskt och moraliskt, att föra krig. Här avhandlas operationen Rolling Thunder och John A. Warden IIIs teoris anknytning till denna enorma bombkampanj. Inledningsvis återfinns en innehållsanalys av John. A. Warden IIIs litteratur, vilket utmynnar i fem begrepp: Luftrumskontroll, tyngdpunkter, flyganfall på djupet, fienden som ett system och parallell attack. Efter det följer en innehållsanalys av relevant litteratur inom ramen för en fallstudie om Rolling Thunder och slutligen påträffas en komparativ analys mellan de två resultaten och en efterföljande diskussion knyter an till problemformuleringen och försöker utröna resultatet av undersökningen och om syftet med uppsatsen uppfyllts. I genomförandefaserna av Operation Rolling Thunder är det möjligt att urskilja vissa av Wardens centrala begrepp och tankar om luftmaktens nyttjande, men hans teori som helhet går inte att återfinna i genomförandet av Rolling Thunder. Trots att de fyra faserna åskådliggör en upprepad förändring i strategi, användes aldrig Wardens teori om fienden som ett system.

Slaget om Malta, under andra världskriget, hade en avgörande roll vad gäller kriget i Medelhavet. Maltas strategiska läge gjorde att det var en åtråvärd ö för axelmakterna och britterna kämpade för att försvara sin position. I kampen om sjöherraväldet hade luftrummet stor betydelse och hur flygstridskrafterna användes var direkt avgörande. John A. Warden III och John Boyd är båda framstående luftmaktsteoretiker och deras teorier har fått stort genomslag, framförallt i västvärlden. Syftet med denna uppsats är att tillämpa dessa teorier på ett empiriskt exempel, slaget om Malta, beträffande luftstridskrafternas användande. Undersökningen bär mot att utröna hur långt teorierna är användbara för analysen av slaget om Malta. Uppsatsen genomförs med en kvalitativ innehållsanalys och komparativ analys för att jämföra teorierna med händelseförloppet. Resultatet av undersökningen visar att teorierna är tillämpningsbara för händelseförloppet under slaget. Hela Boyds teori samt delar ur Wardens teori är långt användbara för analysen.

Radio access technologies for cellular mobile networks are continuously being evolved to meet the future demands for higher data rates, and lower end‐to‐end delays. In the research and development of LTE, radio network simulations play an essential role. The evolution of parallel processing hardware makes it desirable to exploit the potential gains of parallelizing LTE radio network simulations using multithreading techniques in contrast to distributing experiments over processors as independent simulation job processes. There is a hypothesis that parallel speedup gain diminishes when running many parallel simulation jobs concurrently on the same machine due to the increased memory requirements. A proposed multithreaded prototype of the Ericsson LTE simulator has been constructed, encapsulating scheduling, execution and synchronization of asynchronous physical layer computations. In order to provide implementation transparency, an algorithm has been proposed to sort and synchronize log events enabling a sequential logging model on top of non‐deterministic execution. In order to evaluate and compare multithreading techniques to parallel simulation job distribution, a large number of experiments have been carried out for four very diverse simulation scenarios. The evaluation of the results from these experiments involved analysis of average measured execution times and comparison with ideal estimates derived from Amdahl’s law in order to analyze overhead. It has been shown that the proposed multithreaded task‐oriented framework provides a convenient way to execute LTE physical layer models asynchronously on multi‐core processors, still providing deterministic results that are equivalent to the results of a sequential simulator. However, it has been indicated that distributing parallel independent jobs over processors is currently more efficient than multithreading techniques, even though the achieved speedup is far from ideal. This conclusion is based on the observation that the overhead caused by increased memory requirements, memory access and system bus congestion is currently smaller than the thread management and synchronization overhead of the proposed multithreaded Java prototype.

The project evaluates how well a haptic device can be used to interact with a visualization of volumetric data. Since the interface to the haptic device require explicit surface descriptions, triangles had to be constructed from the volumetric data. The algorithm used to extract these triangles is marching cubes. The triangles produced by marching cubes are then transmitted to the haptic device to enable the force feedback. Marching cubes was suitable for parallelization and it was executed using OpenCL. Graphs in the report shows how this parallelization ran almost 70 times faster than the sequential CPU counterpart of the same algorithm. Further development of the project would give medical students the opportunity to practice difficult procedures on a simulation instead of a real patient. This would give a realistic and accurate simulation to practice on. / Projektet går ut på att utvärdera hur väl en haptisk utrustning går att använda för att interagera med en visualisering av volumetrisk data. Eftersom haptikutrustningen krävde explicit beskrivna ytor, krävdes först en triangelgenerering utifrån den volymetriska datan. Algoritmen som används till detta är marching cubes. Trianglarna som producerades med hjälp av marching cubes skickas sedan vidare till den haptiska utrustningen för att kunna få gensvar i form av krafter för att utnyttja sig av känsel och inte bara syn. Eftersom marching cubes lämpas för en parallelisering användes OpenCL för att snabba upp algoritmen. Grafer i projektet visar hur denna algoritm exekveras upp emot 70 gånger snabbare när algoritmen körs som en kernel i OpenCL istället för ekvensiellt på CPUn. Tanken är att när vidareutveckling av projektet har gjorts i god mån, kan detta användas av läkarstuderande där övning av svåra snitt kan ske i en verklighetstrogen simulering innan samma ingrepp utförs på en individ.

John A. Warden III is renowned as one of the theorists closest to devising a new paradigm in air power. His praised theory about the enemy as a system has showed applicable on terrorist organizations amongst other areas. The most recent developed domain for warfare is the so-called “cyberspace”. There is an on-going debate concerning the importance and definition of this domain and furthermore what potential and challenges it withholds as a future arena for warfare. Some claims that a cyberattack can’t be seen as an act of war due to its lack of physical violence. Previous research show however a lack in application of theories within this domain. This thesis therefore aims to examine to which extent Warden’s theory of the enemy as a system could be applied to the cyberattack known as Stuxnet. Results show that Warden’s theory have some applicatory power on the cyberattack Stuxnet, although primarily in an indirect aspect. This study therefore shows an ability concerning the theory’s applicatory power on other areas than air power. The findings of the research regarding previous arguments about cyberwar also states that a cyberattack now could be seen as physical violent. / <p><strong>Uppsatsen skriven VT 2017 under Termin 4 Officersprogrammet 15-18 med inriktning </strong><strong>mot flyg. Examen genomförs VT 2018.</strong></p>