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All wireless receivers have some degree of nonlinearity that can negatively impact performance. Two major effects from this nonlinearity are power compression, which leads to amplitude and phase distortions in the received signal, and desensitization caused by a high powered interfering signal at an adjacent channel. As the RF spectrum becomes more crowded, the interference caused by these adjacent signals will become a more significant problem for receiver design. Therefore, having bit and symbol error rate expressions that take the receiver nonlinearity into account will allow for determining the linearity requirements of a receiver. This thesis examines the modeling of the probability density functions of M-PAM and M-QAM signals through an AWGN channel taking into account the impact of receiver nonlinearity. A change of variables technique is used to provide a relationship between the pdf of these signals with a linear receiver and the pdf with a nonlinear receiver. Additionally, theoretical bit and symbol error rates are derived from the pdf expressions. Finally, this approach is extended by deriving pdf and error rate expressions for these signals when nearby blocking signals cause desensitization of the signal of interest. Matlab simulation shows that the derived expressions for a nonlinear receiver have the same accuracy as the accepted expressions for linear receivers. / Master of Science / All wireless receivers have some amount of nonlinearity that can distort a received signal and impact performance. For amplitude modulated signals, the power compression caused by the nonlinear receiver will cause distortions in the amplitude and phase of the received signal. Additionally, a high powered interfering signal at a close frequency can decrease the gain and distort the received signal. This thesis examines how the probability density of an amplitude modulated signal with a nonlinear receiver can be modeled for both of these situations. These theoretical probability density functions are used to derive theoretical error rate expressions for the signals both with and without the adjacent channel interference. Simulations in Matlab show that the accuracy of these derived expressions is similar to the accuracies of the linear receiver expressions. These derived expressions will be able to remove the need for time consuming simulation when designing receivers for wireless systems.

Web page loading time is one of the critical challenges on the Internet. This topic attracts more researchers as it largely reflects the user satisfaction. A web page resources typically consists of Hyper Text Markup Language (HTML), Cascading Style-Sheet (CSS), JavaScript (JS), media files, etc. As the complexity of the web page increases, the size of files fetched from server also increases which causes delay in transmitting, loading, parsing and rendering the web page. The web page is not rendered until HTML, CSS and JS files are loaded and parsed. Not all such files are needed to be rendered for the first page. Optimizing and loading only critical les required for the first page, can considerably reduce time taken to load the web page. After the first page is rendered, the rest of the files can be loaded and executed. In this thesis, we focus on improving the time taken for First Meaningful Paint(FMP) of website by loading the critical files initially. We used Design Science Research( DSR) methodology and created a PhantomJS application, to identify and segregate used and unused CSS for the first meaningful paint of the web page. We also analyzed script files to load only critical files required for FMP and the rest later. We evaluated our experiment by studying a case on Axis Communications AB and measured its website's performance to find if our experiment reduced FMP time. It showed improvement in time taken for FMP from 1284ms to 372.6ms. Based on the results, we suggest to web developers to separate and load the files required for FMP and load the rest of the files needed for the website later, so that the first page is rendered quickly.

Multi-queue has been a proven solution for problems related to high input and output for any type of hardware. Therefore, improving it with task batching may increase performance and reduce overhead. While multi-queue and task batching have been studied, combining them has only been mentioned briefly, specifically for priority queues. For this experiment, system metrics of timers and block misses will show potential areas where task batching is beneficial. The result from the performed experiment show that the size of batches has similarities with the number of input workers. The result gives some insight into further improvements of the multi-queue, and the overhead was found to be reduced whenever task batching was used.

Die auf mitgliedstaatlicher und EU-Ebene grundrechtlich verbürgte Freiheit des Eigen-tums verlangt, das Urheberrecht effektiv zu schützen. Staatlich durchgeführte oder ange-ordnete technische Maßnahmen wie Netzsperren (IP- oder DNS-Sperren) und Deep Packet Inspection ermöglichen es u.a., gezielt die Übertragung von Daten zu blockieren, deren unlizenzierter Austausch über das Internet – etwa über Streaming-Portale – das Urheber-recht verletzt. Im Internet besteht ohne derartige technische Maßnahmen ein Durchset-zungsdefizit, da die unmittelbaren („Content Provider“) und mittelbaren Anbieter („Host-Provider“) der Inhalte oft nicht effektiv in Haftung genommen werden können; die techni-schen Betreiber der Infrastruktur des Internets („Internet Service Provider“) hingegen können dem staatlichen Zugriff nicht ausweichen. Die angesprochenen technischen Maß-nahmen greifen jedoch in verschiedene Grundrechte des Grundgesetzes und der Charta der Grundrechte der Europäischen Union ein. Betroffen sind insbesondere die unterneh-merische Freiheit (Art. 16 Charta) der Internet Service Provider, die Informationsfreiheit (Art. 11 Abs. 1 Charta), das Recht auf Achtung der Kommunikation (Art. 7 Charta), das Recht auf Schutz personenbezogener Daten (Art. 8 Abs. 1 Charta) der Internet-Nutzer sowie die jeweiligen mitgliedstaatlichen Entsprechungen dieser Grundrechte. Der Gegen-stand dieser Arbeit ist die Untersuchung der Vereinbarkeit der Anwendung technischer Maßnahmen zur Durchsetzung des Urheberrechts mit europäischem Primärrecht und dem Grundgesetz. / The Fundamental Right to Property, which is guaranteed at Member State and EU level, requires that copyright be effectively protected. Technical measures implemented by or required by states, such as IP/DNS blocking or Deep Packet Inspection, enable, inter alia, the targeted blocking of transmissions of data whose unlicensed exchange over the inter-net – e.g. via streaming portals – infringes copyrights. Without such technical measures, there is an enforcement deficit in the internet, as the direct ("content providers") and indi-rect providers ("host providers") of the content often cannot be effectively held liable; the technical operators of internet infrastructure ("internet service providers"), on the other hand, cannot evade governmental intervention. The technical measures mentioned, how-ever, affect various fundamental rights of the German Constitution (the “Grundgesetz”) and the Charter of Fundamental Rights of the European Union. The rights affected are, in particular, the Freedom to Conduct a Business (Article 16 of the Charter) of internet ser-vice providers, the Freedom of Information (Article 11(1) of the Charter), the Right to Re-spect for Communications (Article 7 of the Charter) and the Right to Protection of Person-al Data (Article 8 (1) of the Charter) of internet users, and the respective Member State equivalents of these fundamental rights. Subject matter of this thesis is to examine whether the use of technological measures to enforce copyrights is in compliance with Eu-ropean primary law and the German Grundgesetz.

This thesis documents a collection of experimental investigations in which a differentially-heated annulus was used to investigate the effects of topography on the atmospheric and oceanic circulation. To this end a number of experiments were devised, each using a different topographic base to study a different aspect of the impact of topography, motivated by the most notable outstanding questions found in a review of the literature, namely exploring the effects of topographic resonance, blocking via partial barriers, and azimuthally differential-heating via thermal topography. First of all, whilst employing sinusoidal wavenumber-3 topography to extend the experimental parameter space of a similar study, namely Read and Risch (2011), a new regime within a region of structural vacillation was encountered. Denoted as the ‘stationary-transition’ regime, it featured periodic oscillations between a dominant stationary wavenumber-3 flow and axisymmetric or chaotic flow. An investigation into topographic resonance followed, keeping the wavenumber-3 base, but with a sloped lid to add a beta effect to the annulus. This acted to increase the occurrence of stationary waves, along with the ‘stationary-transition’ regime, which was discovered to be a near-resonant region where nonlinear topographic resonant instability led to a 23 to 42 ‘day’ oscillatory structure. The base was then replaced with an isolated ridge, forming a partial barrier to study the difference between blocked and unblocked flow. The topography was found to impact the circulation at a level much higher than its own peak, causing a unique flow structure when the drifting flow and the topography interacted in the form of an ‘interference’ regime at low Taylor Numbers, as well as forming an erratic ‘irregular’ regime at higher Taylor Numbers. Lastly, this isolated ridge was replaced by flat heating elements covering the same azimuthal extent, in order to observe whether thermal topography could be comparable to mechanical topography. These azimuthally-varying heating experiments produced much the same results as the partial barriers study, despite the lack of a physical peak or bottom-trapped waves, suggesting that blocking is independent of these activities. Evidence of resonant wave-triads was noted in all experiments, though the component wavenumbers of the wave-triads and their impact on the flow was found to depend on the topography in question.

The present study has considered cellular and molecular requirements in T cell responses. The central role of T cell growth factors (TCGF) in T cell responses prompted us to study the regulatory events directing TCGF production in lectin stimulated cultures. It was found that normal spleen cells, activated with Concanavalin A for 24 h, develop suppressive cells that block de novo TCGF production by fresh spleen cells. The induction time for effector suppressor cells (nonadherent, Lyt-2-positive T cells) was found to be 18 h and to parallel the termination of TCGF production in situ. The suppressive mechanism is neither iji situ absorption of TCGF produced at control rates nor killing of TCGF producing cells. These results suggest that suppression of TCGF production is an active process which directly and reversibly blocks TCGF-producing cells. This study also indicated that ConA induced a very limited proliferation of Lyt-2- T helper cells (TH) in unselected T cell populations. The activation and growth requirements of Lyt-1+ TH cells were directly investigated and compared with those of Lyt-2+ cytotoxic T lymphocytes (CTL), as defined by the selective expression of Lyt differentiation antigens and functional activities. This analysis revealed a profound difference in activation and growth requirements between these T cell subsets. Thus, while Lyt-2+ CTL precursors can be induced to TCGF reactivity by soluble lectins, in the absence of specialized accessory cells,; Lyt-2" TH cell precursors show a strict accessory cell requirement both for activation and proliteration. Finally, the low level of TH cell effector function, detected in a primary responses to allo-MHC-antigens or lectins, appears to be due to the development of suppressive Lyt2+ T cells. The functional relevance of Lyt-2 antigens expressed on CTL membranes was further assessed in the last part of this study. Two distinct activation systems were used, namely MHC-antigens, provided as UV-irradiated stimulator cells or polyclonal induction by a 4 h pulse, with lectins. Both procedures were shown to selectively induce Lyt-2+ CTL precursors into TCGF reactivity without leading to mitosis, unless TCGF was added. In both cases it was found that monoclonal anti-Lyt-2 antibodies inhibited the two antigen- dependent phases of CTL responses namely, the initial induction step and target cytolysis. The analogy observed between antigen specific and lectin mediated indueton and target cytolysis, with regard to the susceptibility of inhibition by anti-Lyt-2 antibodies has lead to a general hypothesis on CTL activation. / <p>[4] s., s. 1-58: sammanfattning, s. 59-130, [12] s.: 6 uppsatser</p> / digitalisering@umu

E-handeln inom Europa växer explosionsartat och tillgång till varor och tjänster är i dagsläget endast några få knapptryck bort. Eftersom åtkomsten till internet är global kan hemsidor och webbshoppar få en enorm internationell spridning. Näringsidkare som bedriver fysisk handel kan enkelt anpassa sig till lagar, språk, valuta mm. i landet där deras verksamhet är placerad, men anpassningen på internet, i cybervärlden, är svårare. Geolokalisering är en teknik som gör det möjligt för näringsidkare att kunna anpassa sig, genom att lokalisera och fastställa var internetanvändare befinner sig. När en internetanvändares geografiska placering är fastställd, kan näringsidkaren anpassa utbud, reklam, språk och valuta på hemsidan som denne bedriver. Möjligheten att kunna lokalisera internetanvändare på detta sätt, är ur ett affärsmässigt perspektiv mycket lönsamt för en näringsidkare. Geolokaliseringen ger även näringsidkaren en möjlighet till att geoblockera internetanvändare från dennes hemsida, genom att exempelvis helt blockera åtkomst, anpassa vilka produkter internetanvändaren får åtkomst till eller omdirigera internetanvändare från en version av hemsidan till en annan. Geoblockering kan därför underlätta det för en näringsidkare att följa regler och lagar i de olika länderna där dennes hemsida är tillgänglig. Immaterialrätter är i regel skyddade inom olika territorium. Med immaterialrätter följer ensamrätt till användande av rättigheten inom skyddsområdet. En näringsidkare som säljer varor på sin e-handels hemsida, som är eller kan vara omfattade av andra innehavares rättighetsskydd, kan använda geoblockering som ett verktyg för att helt undvika eller anpassa sig till de olika immaterialrättsliga skyddsområdena. Kommissionen har meddelat att ett av EU:s mål är att skapa en digital inre marknad och förhindra diskriminering mot konsumenter baserat på nationalitet, bostadsort eller geografisk placering. Diskrimineringen kan utgöras av exempelvis olika begränsningar för en konsument som vill få tillgång till ett innehåll eller köpa varor på internet. En sådan begränsning kan vara geoblockering. Den 25 maj 2016 lade Kommissionen fram ett förordningsförslag, som syftar till att förbjuda omotiverad geoblockering. I november 2016 enades Rådet om ett utkast till förordningen. Förordningsförhandlingarna förväntas påbörja så snart som Europaparlamentet enats om sin ståndpunkt. Frågan är hur ett förbud mot geoblockering kan komma att påverka näringsidkare inom e-handeln, ur ett immaterialrättsligt perspektiv.

L'objectif de cette thèse a été d'analyser la dynamique de l'interaction entre les ondes baroclines (ou rail des dépressions) et la variabilité basse fréquence de l'atmosphère aux moyennes latitudes. Deux approches distinctes ont été suivies pour étudier le rôle des déferlements d'ondes baroclines sur les courants-jets, l'une reposant sur les données réanalysées et l'autre sur des simulations numériques. La première partie de la thèse a plus précisément consisté à étudier le lien entre les déferlements d'ondes de Rossby et les quatre régimes de temps sur l'Atlantique Nord en hiver en utilisant les réanalyses ERA40. Le calcul des fréquences d'occurrence des déferlements d'ondes a montré que ceux-ci tendent généralement à renforcer les régimes sauf le blocage scandinave qui est détruit par du déferlement cyclonique au sud du Groenland. Ensuite, les précurseurs des transitions entre régimes de temps ont été identifiés. Le premier précurseur est relié à la propagation linéaire d'anomalies basse fréquence (période supérieure à 10 jours). Ce précurseur n'est pas systématique mais il survient durant la transition du régime zonal vers le blocage environ une semaine avant ce dernier où il prend la forme d'un train d'ondes quasi-stationnaire excité par des anomalies convectives dans l'Atlantique subtropical. Le second précurseur plus systématique intervient au niveau des interactions non-linéaires entre les tourbillons transitoires haute et basse fréquences et a pu être relié aux déferlements d'ondes. La formation et la destruction du blocage scandinave ont ensuite été plus particulièrement étudiées en analysant respectivement les transitions préférentielles du régime zonal au blocage et du blocage vers l'anticyclone groenlandais en lien avec les dépressions de surface et les déferlements d'ondes. Les dépressions de surface atteignent les mêmes intensités pendant la formation et la destruction du blocage mais ne suivent pas les mêmes trajectoires. Pendant la formation du blocage, les dépressions de surface ont des trajectoires rectilignes se dirigeant vers le nord de la Scandinavie et sont liées à un déferlement anticyclonique. Pendant la destruction du blocage, les trajectoires des dépressions de surface sont courbées sur l'Atlantique Nord en direction du Groenland et sont reliées à du déferlement cyclonique qui favorise ainsi l'apparition de l'anticyclone groenlandais. Notre analyse suggère que cette différence de comportement provient de la forme de l'écoulement basse fréquence qui n'est pas le même pendant la formation et la destruction du blocage et qui favorise un certain type de déferlement plutôt qu'un autre. Dans la seconde partie de la thèse, nous avons analysé le lien entre les températures de surface de la mer (SSTs) et le comportement du rail des dépressions avec le modèle de circulation générale de l'atmosphère Arpège-Climat en mode aquaplanète pour mieux comprendre les téléconnexions telles que l'Oscillation Arctique et/ou l'Oscillation Nord-Atlantique d'un point de vue idéalisé. / This thesis aims at analyzing the dynamics of the interaction between baroclinic waves (stormtrack) and the atmospheric low-frequency variability at midlatitudes. Two different approaches have been followed to study the impact of baroclinic wave breakings on jet-streams, one using reanalysis data and the other numerical simulations of a climate model. The first part of the PhD dealt with the link between Rossby wave breakings and the four weather regimes over the North Atlantic in winter using ERA40 reanalysis. The calculation of wave breaking frequencies showed that wave breakings tend to reinforce weather regimes except the Scandinavian blocking which is destroyed by cyclonic wave breaking south of Greenland. Then, precursors of weather regime transitions have been identified. The first precursor is linked to the linear propagation of low-frequency anomalies (period greater than ten days). This is not a systematic precursor but it occurs during the zonal to blocking transition about one week before this latter and is related to a quasi-stationary wave train excited by convective anomalies in the North Atlantic subtropics. The systematic second precursor is related to non-linear transient eddy interactions and has been linked to Rossby wave breakings. The link between the surface cyclones, Rossby wave breakings and the formation and decay of the Scandinavian blocking has been more precisely studied through the preferential transitions from the zonal weather regime to the blocking and from the blocking to the Greenland anticyclone. During the formation and decay of the blocking, surface cyclones reach the same intensities but do not follow the same trajectories. During the blocking formation, surface cyclones follow straight trajectories toward the north of Scandinavia and are linked to an anticyclonic wave breaking. Whereas during the blocking decay, surface cyclones trajectories are curved over the North Atlantic toward Greenland and are linked to a cyclonic wave breaking favouring the Greenland anticyclone formation. Our study suggests that this difference of behavior comes from the shape of the low-frequency flow which is not the same during the formation and the decay of the blocking and which can favour a particular type of wave breaking rather than another. The second part dealt with the link between sea surface temperatures (SSTs) and the storm-track in the atmospheric general circulation model Arpège-Climat in aquaplanet mode to better understand teleconnections such as the Arctic Oscillation and/or the North Atlantic Oscillation from an idealized point of view. We performed a sensitivity analysis of the eddy-driven jet variability to various stationary SST profiles.

The practical thesis is based on a visual experimental poetry and its sign system. I am working with own sign system which was inspired by organized fence's structures. These structures were depicted by typographical signs which creates a new graphical compositions. Whole work is organized into three separated author's books. Their interconnection is emphasized by putting into a common case. The first book entitled Poetry of structure – Inspiration establishes contact with readers by means of photographs of spaces and fence's structures. The second book entitled Poetry of structure – Manual is an interlink of the work which informs readers both with the fence's structures and with the typographical compositions. Confrontation of the fence's photographs with the typographical compositions developed an advancement of the reality transformation to the abstract structure. The third book entitled Poetry of structure is the integral poetic anthology. The book presents both the blind blocking of typographical compositions themselves and the final experimental poems based on them.