The conformal bootstrap method is a non-perturbative method that uses the symmetry in a conformal field theory to constrain and solve for the observables in the theory. We consider a conformal field theory with the symmetry group SU(N) and four general scalar fields as the only low dimensional operators. The four-point correlation function of a quartic interaction of four general scalar fields in a conformal field theory can be written as a sum over primary operators. In order to study the four-point correlator a large-N expansion is made, where N comes from the symmetry group SU(N). Using the conformal bootstrap method the anomalous dimension of the primary operators in the four-point correlator is calculated. Using the AdS/CFT correspondence the anomalous dimension of the primary operators is also calculated using Witten diagrams. / Konform fältteori är en kvantfältteori med konform symmetri. Konform symmetri är en symmetri som bevarar vinklar och lokalt ser ut som en kombination av en rotation och en förändring i skala. En metod för att beräkna de observerbara kvantiteterna i en konform fältteori är metoden "conformal boostrap". Denna metod går ut på att använda symmetrin i en konform fältteori för att begränsa och beräkna värdet på de observerbara kvantiteterna i teorin.En av de observerbar kvantiteterna i en fältteori är en korrelationsfunktion. Korrelationsfunktioner beskriver interaktionerna mellan partiklarna i en fältteori.  I detta arbete studerar vi en interaktion mellan fyra skalärfält genom att studera fyra-punkts korrelationsfunktionen för denna interaktion. Metoden vi använder är "conformal bootstrap" men vi testar också om AdS/CFT dualiteten håller för våra beräkningar. AdS/CFT dualiteten är en ekvivalens av två olika teorier, en strängteori i ett (d+1)-dimensionellt anti-de Sitter (AdS) rum och en konform fältteori (CFT) i den d-dimensionella gränsen av anti-de Sitter rummet. Enligt denna dualitet kan en observerbar kvantitet beräknas från båda dessa två teorier och ge samma resultat. Teorin vi studerar har symmetrigrupp SU(N) och vi arbetar i dimension två. Vi arbetar också med att N, matrisrangen i teorin, är stort då detta är den gräns där AdS/CFT dualiteten gäller. Enligt konform fältteori så kan en fyra-punkts korrelationsfunktion av fyra skalärer beskrivas som en summa över vad som kallas primära fält. Genom att använda "conformal bootstrap" metoden beräknas den anormala dimensionen, vilket är en korrektion av första icke-triviala ordning till dimensionen, av dessa primära fält. Samma kvantitet beräknas också från strängteorisidan av AdS/CFT dualiteten genom användandet av så kallade Witten diagram. Resultatet från båda sidor av dualiteten visas stämma överens.

<p>The need for increased safety and efficiency in civil aviation is pushing the introduction of Automatic Dependent Surveillance - Broadcast (ADS-B). The basic principle of ADS-B is that each aircraft is able to communicate its position and status over a radio data link to surrounding aircraft. In this way each aircraft obtains a detailed picture of the surrounding traffic. During a period of transition from today's radar surveillance to ADS-B many aircraft will not be equipped with the new data link technology and will therefore be invisible to the ADS-B equipped aircraft. The Traffic Information Service - Broadcast (TIS-B) has been conceived to be the solution to this problem. TIS-B is defined as a broadcast surveillance service in which data from the ordinary ground radar system is transmitted from a ground station to airborne systems, providing an air situation picture of the non-ADS-B stations. </p><p>The topics of this thesis are the definition and implementation of a TIS-B server. The presented solution is an evaluation TIS-B server that will receive data from a data-fusing tracker and provide one or several TIS-B ground stations with data filtered according to the settings of the server.</p>

<p>Advertising is something that we get in touch with on a daily basis and more or less everywhere. Advertising is used in different mediums, such as magazines, television, radio, internet, cellphones et.c. The aim of the present study is to find out if there are any recurrent dissimilarities how advertising is constructed among the mediums regarding rhetorical and semiotical theories. Two different mediums have been chosen for a comparison, printed advertisments versus internetbanners. The study has been based on a total of ten qualitative image analyses. To get a spread among the input material regarding the adverts, five different types of businesses have been chosen from a set of criteria that has been decided for this specific study. From every type of business, one advertisment from magazines or newspapers and one type of internetbanner have been chosen and have resulted in a total of five pair of matches which has been analyzed with an image analysis model. The result of this study clearly showed that there are recurrent dissimilarities among the two analyzed mediums. Adverts in magazines or newspapers contained generally more text than the internetbanners did, the adverts in papers also used more arguments than the internetbanners. The result also showed that the adverts in the papers contained more rhetorical figures than the internetbanners did. One potential reason why there were less text in the internet banners may be due to the phenomena called Banner blindness and the differences of the mediums.</p> / <p>Reklam är något vi kommer i kontakt med dagligen mer eller mindre överallt. Den återfinns i olika medier, såsom tidningar, TV, radio, internet, mobiltelefoner etc. Målet med denna undersökning är ett ta reda på om det finns några återkommande skillnader i hur reklam utformas i olika medier, utifrån retoriska och semiotiska teorier. Två skilda medier har valts ut för en jämförelse, tidningsannonser och internetbanners. Undersökningen har baserats på totalt tio kvalitativa bildanalyser. För att få en spridning på analysmaterialet har fem olika branscher valts ut efter uppsatta urvalskriterier. Från varje bransch har en utvald annons från tidningar respektive internet bildat fem parmatchningar som har analyserats med hjälp av en bildanalysmodell. Resultatet av undersökningen visade konkret att det finns återkommande skillnader eftersom tidningsannonserna innehåller mer text och fler argument än internetbanners. Vidare finns det också en skillnad mellan medierna då tidningsannonser har en tendens till att innehålla fler retoriska figurer än vad internetbanners gör. En möjlig anledning till att det var mindre text i internetbanners skulle kunna härledas till fenomenet Banner blindness likaså skillnaderna som finns mellan medierna.</p>

This thesis is devoted to the investigation of passivesafety and inherent features of subcritical nucleartransmutation systems - accelerator-driven systems. The generalobjective of this research has been to improve the safetyperformance and avoid elevated coolant temperatures inworst-case scenarios like unprotected loss-of-ow accidents,loss-of-heat-sink accidents, and a combination of both theseaccident initiators. The specific topics covered are emergencydecay heat removal by reactor vessel auxiliary cooling systems,beam shut-off by a melt-rupture disc, safety aspects fromlocating heat-exchangers in the riser of a pool-type reactorsystem, and reduction of pressure resistance in the primarycircuit by employing bypass routes. The initial part of the research was focused on reactorvessel auxiliary cooling systems. It was shown that an 80 MWthPb/Bi-cooled accelerator-driven system of 8 m height and 6 mdiameter vessel can be well cooled in the case of loss-of-owaccidents in which the accelerator proton beam is not switchedoff. After a loss-of-heat-sink accident the proton beam has tobe interrupted within 40 minutes in order to avoid fast creepof the vessel. If a melt-rupture disc is included in the wallof the beam pipe, which breaks at 150 K above the normal coreoutlet temperature, the grace period until the beam has to beshut off is increased to 6 hours. For the same vessel geometry,but an operating power of 250 MWth the structural materials canstill avoid fast creep in case the proton beam is shut offimmediately. If beam shut-off is delayed, additional coolingmethods are needed to increase the heat removal. Investigationswere made on the filling of the gap between the guard and thereactor vessel with liquid metal coolant and using water spraycooling on the guard vessel surface. The second part of the thesis presents examinationsregarding an accelerator-driven system also cooled with Pb/Bibut with heat-exchangers located in the risers of the reactorvessel. For a pool type design, this approach has advantages inthe case of heat-exchanger tube failures, particularly if wateris used as the secondary uid. This is because a leakage ofwater from the secondary circuit into the Pb/Bi-cooled primarycircuit leads to upward sweeping of steam bubbles, which wouldcollect in the gas plenum. In the case of heatexchangers in thedowncomer steam bubbles may be dragged into the ADS core andadd reactivity. Bypass routes are employed to increase the owspeed in loss-of-ow events for this design. It is shown thatthe 200 MWth accelerator-driven system with heat-exchangers inthe riser copes reasonably well with both a loss-of-ow accidentwith the beam on and an unprotected loss-of-heat-sink accident.For a total-loss-of-power (station blackout) and an immediatebeam-stop the core outlet temperature peaks at 680 K. After acombined loss-of-ow and loss-of-heat-sink accident the beamshould be shut off within 4 minutes to avoid exceeding the ASMElevel D of 977 K, and within 8 minutes to avoid fast creep.Assuming the same core inlet temperature, both the reactordesign with heat-exchanger in the risers and the downcomershave similar temperature evolutions after a total-loss-ofpoweraccident. A large accelerator-driven system of 800 MWth with a 17 mtall vessel may eventually become a standard size. For thishigher power ADS, the location of the heat-exchangers hasgreater impact on the natural convection capability. This isdue to that larger heatexchangers have more inuence on thedistance between the thermal centers during a lossof- owaccident. The design with heat-exchangers in the downcomers,the long-term vessel temperature peaks at 996 K during aloss-of-ow accident with the beam on. This does not pose athreat of creep rupture for the vessel. However, the locationof the heat-exchangers in the downcomers will probably requiresecondary coolant other than water, like for example oil (fortemperatures not higher than 673 K) or Pb/Bi coolant.

One of the main topics in the modern String Theory are the conjectured string/gauge (AdS/CFT) dualities. Proving such conjectures is extremely difficult since the gauge and string theory perturbative regimes do not overlap. In this perspective, the discovery of infinitely many conserved charges, i.e. the integrability, in the planar AdS/CFT has allowed us to reach immense progresses in understanding and confirming the duality.The first part of this thesis is focused on the gravity side of the AdS5/CFT4 duality: we investigate the quantum integrability of the type IIB superstring on AdS5 x S5. In the pure spinor formulation we analyze the operator algebra by computing the operator product expansion of the Maurer-Cartan currents at the leading order in perturbation theory. With the same approach at one loop order, we show the path-independence of the monodromy matrix which implies the charge conservation law, strongly supporting the quantum integrability of the string sigma-model. We also verify that the Lax pair field strength remains well-defined at one-loop order being free from UV divergences. The same string sigma-model is analyzed in the Green-Schwarz formalism in the near-flat-space (NFS) limit. Such a limit remarkably simplifies the string world-sheet action but still leaving interesting physics. We use the NFS truncation to show the factorization of the world-sheet S-matrix at one-loop order. This property defines a two-dimensional field theory as integrable: it is the manifestation of the higher conserved charges. Hence, we have explicitly checked their presence at quantum level. The second part is dedicated to the AdS4/CFT3 duality: in particular the type IIA superstring on AdS4 x CP3. We compute the leading quantum corrections to the string energies for string configurations with a large but yet finite angular momentum on CP3 and show that they match the conjectured all-loop Bethe Ansatz equations.

The potential of the Chinese outbound tourism market is substantial; however, research on this market to Canada is limited. This may be due, in part, to the lack of Approved Destination Status (ADS). This study examined the possible perceived image of Canada obtained by potential Chinese tourists, and to compare to the marketing position of Canada by CTC China Division-in effect, to conduct a product-market match between two concepts. Content analysis and an importance and performance analysis were used in the study. A questionnaire distributed at the Beijing Capital International Airport solicited perceptions of tourism in Canada, importance of selected attributes in travel decision making, performance of selected attributes on Canada, and trip preferences. The marketing position of Canada was examined through a content analysis of the promotional materials circulated from CTC China Division in Beijing, China. The coherences and gaps between perceived image of Canada and marketing position of Canada provide some marketing implications. This study concludes that the general tourism image of Canada is vague but positive, which is probably derived from the historically favorable image of Canada in china. Potential Chinese tourists had little knowledge on specific tourism sights; however, they recognized star attractions of Vancouver, Niagara Falls, and Toronto. Potential Chinese tourists prefer slow-paced trips; group tours; two weeks in length; in fall season; featuring mid-budget accommodation, preferably bed-and-breakfasts; on motor coach; visiting nature based sights at majority; and providing foods of various cultures. The current marketing position of Canada reflected through promotional materials by CTC and its partners has coherences in promoting tourism attractions in Canada to the image of Canada. Gaps exist on the promotion of travel issues and unconventional attractions, which inspires the marketing implications. Promotional resources should be allocate to unconventional tourism attractions with consideration rather than the presence of Chinese and mandarin speaking environment in Canada because of Chinese tourists’ demand for culture diversity. Promotion should include more information about travel expense and visas to establish reasonable consumer expectations.

The potential of the Chinese outbound tourism market is substantial; however, research on this market to Canada is limited. This may be due, in part, to the lack of Approved Destination Status (ADS). This study examined the possible perceived image of Canada obtained by potential Chinese tourists, and to compare to the marketing position of Canada by CTC China Division-in effect, to conduct a product-market match between two concepts. Content analysis and an importance and performance analysis were used in the study. A questionnaire distributed at the Beijing Capital International Airport solicited perceptions of tourism in Canada, importance of selected attributes in travel decision making, performance of selected attributes on Canada, and trip preferences. The marketing position of Canada was examined through a content analysis of the promotional materials circulated from CTC China Division in Beijing, China. The coherences and gaps between perceived image of Canada and marketing position of Canada provide some marketing implications. This study concludes that the general tourism image of Canada is vague but positive, which is probably derived from the historically favorable image of Canada in china. Potential Chinese tourists had little knowledge on specific tourism sights; however, they recognized star attractions of Vancouver, Niagara Falls, and Toronto. Potential Chinese tourists prefer slow-paced trips; group tours; two weeks in length; in fall season; featuring mid-budget accommodation, preferably bed-and-breakfasts; on motor coach; visiting nature based sights at majority; and providing foods of various cultures. The current marketing position of Canada reflected through promotional materials by CTC and its partners has coherences in promoting tourism attractions in Canada to the image of Canada. Gaps exist on the promotion of travel issues and unconventional attractions, which inspires the marketing implications. Promotional resources should be allocate to unconventional tourism attractions with consideration rather than the presence of Chinese and mandarin speaking environment in Canada because of Chinese tourists’ demand for culture diversity. Promotion should include more information about travel expense and visas to establish reasonable consumer expectations.

AbstractAuthor: Sofie JakobssonCourse: Media and Communication Studies CUniversity: Division of Media and Communication, Department of Information Science, Uppsala UniversityPeriod: Spring 2012Key words: Job ads, Professional Communicator, Public Relations Officer, Trait Theory, Five Factor Theory, Big Five, personal traits, work tasks.Title: The Independent Specialist. A study of requested personal types in Professional Communicators.Number of pages: 35Purpose/ Aim: The study aims to evaluate what kind of personality type that would make a good fit for a Professional Communicator. The study examines personal traits and work tasks that are presented in job ads for Professional Communicators in Sweden today. From this material the author wants to calculate what kind of personal type that characterize the profession with the help of the Big Five theory.Material/ Method: Quantitative research method based on job ads.Main results: The study shows that personal traits that employers look for in Professional Communicators today are mainly traits from the Conscientiousness group with characteristics such as independent, structured and planning. The second biggest personality group is Extraversion where personal traits like driving, outgoing and social were put. The results also indicate that the professional should enjoy working independently but also be able to cooperate with other people. A big part of the profession involves tasks which are of a producing nature which indicates that a talent or personality that fits for that kind of tasks is to prefer.

<p>This thesis is devoted to the investigation of passivesafety and inherent features of subcritical nucleartransmutation systems - accelerator-driven systems. The generalobjective of this research has been to improve the safetyperformance and avoid elevated coolant temperatures inworst-case scenarios like unprotected loss-of-ow accidents,loss-of-heat-sink accidents, and a combination of both theseaccident initiators. The specific topics covered are emergencydecay heat removal by reactor vessel auxiliary cooling systems,beam shut-off by a melt-rupture disc, safety aspects fromlocating heat-exchangers in the riser of a pool-type reactorsystem, and reduction of pressure resistance in the primarycircuit by employing bypass routes.</p><p>The initial part of the research was focused on reactorvessel auxiliary cooling systems. It was shown that an 80 MWthPb/Bi-cooled accelerator-driven system of 8 m height and 6 mdiameter vessel can be well cooled in the case of loss-of-owaccidents in which the accelerator proton beam is not switchedoff. After a loss-of-heat-sink accident the proton beam has tobe interrupted within 40 minutes in order to avoid fast creepof the vessel. If a melt-rupture disc is included in the wallof the beam pipe, which breaks at 150 K above the normal coreoutlet temperature, the grace period until the beam has to beshut off is increased to 6 hours. For the same vessel geometry,but an operating power of 250 MWth the structural materials canstill avoid fast creep in case the proton beam is shut offimmediately. If beam shut-off is delayed, additional coolingmethods are needed to increase the heat removal. Investigationswere made on the filling of the gap between the guard and thereactor vessel with liquid metal coolant and using water spraycooling on the guard vessel surface.</p><p>The second part of the thesis presents examinationsregarding an accelerator-driven system also cooled with Pb/Bibut with heat-exchangers located in the risers of the reactorvessel. For a pool type design, this approach has advantages inthe case of heat-exchanger tube failures, particularly if wateris used as the secondary uid. This is because a leakage ofwater from the secondary circuit into the Pb/Bi-cooled primarycircuit leads to upward sweeping of steam bubbles, which wouldcollect in the gas plenum. In the case of heatexchangers in thedowncomer steam bubbles may be dragged into the ADS core andadd reactivity. Bypass routes are employed to increase the owspeed in loss-of-ow events for this design. It is shown thatthe 200 MWth accelerator-driven system with heat-exchangers inthe riser copes reasonably well with both a loss-of-ow accidentwith the beam on and an unprotected loss-of-heat-sink accident.For a total-loss-of-power (station blackout) and an immediatebeam-stop the core outlet temperature peaks at 680 K. After acombined loss-of-ow and loss-of-heat-sink accident the beamshould be shut off within 4 minutes to avoid exceeding the ASMElevel D of 977 K, and within 8 minutes to avoid fast creep.Assuming the same core inlet temperature, both the reactordesign with heat-exchanger in the risers and the downcomershave similar temperature evolutions after a total-loss-ofpoweraccident.</p><p>A large accelerator-driven system of 800 MWth with a 17 mtall vessel may eventually become a standard size. For thishigher power ADS, the location of the heat-exchangers hasgreater impact on the natural convection capability. This isdue to that larger heatexchangers have more inuence on thedistance between the thermal centers during a lossof- owaccident. The design with heat-exchangers in the downcomers,the long-term vessel temperature peaks at 996 K during aloss-of-ow accident with the beam on. This does not pose athreat of creep rupture for the vessel. However, the locationof the heat-exchangers in the downcomers will probably requiresecondary coolant other than water, like for example oil (fortemperatures not higher than 673 K) or Pb/Bi coolant.</p>

This dissertation splits into two distinct halves. The first half is devoted to the study of the holography of higher spin gauge theory in AdS$_3$. We present a conjecture that the holographic dual of $W_N$ minimal model in a 't Hooft-like large $N$ limit is an unusual ``semi-local" higher spin gauge theory on AdS$_3\times $S$^1$. At each point on the S$^1$ lives a copy of three-dimensional Vasiliev theory, that contains an infinite tower of higher spin gauge fields coupled to a single massive complex scalar propagating in AdS$_3$. The Vasiliev theories at different points on the S$^1$ are correlated only through the AdS$_3$ boundary conditions on the massive scalars. All but one single tower of higher spin symmetries are broken by the boundary conditions. This conjecture is checked by comparing tree-level two- and three-point functions, and also one-loop partition functions on both side of the duality. The second half focuses on the holography of higher spin gauge theory in AdS$_4$. We demonstrate that a supersymmetric and parity violating version of Vasiliev's higher spin gauge theory in AdS$_4$ admits boundary conditions that preserve ${\cal N}=0,1,2,3,4$ or $6$ supersymmetries. In particular, we argue that the Vasiliev theory with $U(M)$ Chan-Paton and ${\cal N}=6$ boundary condition is holographically dual to the 2+1 dimensional $U(N)_k\times U(M)_{-k}$ ABJ theory in the limit of large $N,k$ and finite $M$. In this system all bulk higher spin fields transform in the adjoint of the $U(M)$ gauge group, whose bulk t'Hooft coupling is $\frac{M}{N}$. Our picture suggests that the supersymmetric Vasiliev theory can be obtained as a limit of type IIA string theory in AdS$_4\times \mathbb{CP}^3$, and that the non-Abelian Vasiliev theory at strong bulk 't Hooft coupling smoothly turn into a string field theory. The fundamental string is a singlet bound state of Vasiliev's higher spin particles held together by $U(M)$ gauge interactions. / Physics