Cloud top height plays an important roll in the energy budget and is also important for aviation. This thesis concerns the quality control of cloud top height (CTH) retrievals. The approach for quality controlling retrieved CTH has been using the forward simulating software RTTOV. An error estimation function has been developed as well as an investigation to what simplifications can be done regarding the forward simulations for CTH purposes at SMHI. The purpose of the error estimation function is to validate CTH output from CTH retrieval algorithms by giving a rough error estimate of the retrieved CTH compared to what forward simulations predict. For simplifying the forward simulations the most promising results have been shown for lower clouds. Further testing is still of interest and for future work suggestions are provided regarding the error estimation function as well as for simplifying the forward simulations.

Three measurements of top-quark pair production cross sections in proton-proton collisions at sqrt(s) = 13 TeV using data collected by the ATLAS experiment are presented. The single-lepton final states are used, where one electron or muon, two b-jets and two other jets can be identified. The inclusive ttbar production cross section is measured to be sigma(ttbar) = 817 +/- 13 (stat.) +/- 103 (syst.) +/- 88 (lum.) pb, which is in good agreement with predictions and with other measurements. Absolute and relative differential cross sections of ttbar production are also measured, showing an overall good agreement with predictions, except for the top-quark transverse momentum distribution. As already reported in measurements at lower proton-proton collision energies, this distribution is shifted towards higher momenta in all predictions with respect to the observations. Total and differential fiducial cross sections of ttbar production in association with heavy-flavour jets are also presented. All tested models are found to agree with data within the uncertainties of these measurements.

This thesis presents measurements of inclusive and differential cross-sections for top quark pair-production in fiducial and full phase-space regions, as well as an analysis of gas compositions in the ATLAS inner detector cooling systems. The inclusive top-anti-top quark production cross-section was measured using a sample of 0.085 1/fb of proton--proton collisions recorded by the ATLAS experiment at centre-of-mass energy of 13 TeV, using dilepton top-anti-top quark events with an opposite-sign ee or ÂμÂμ pair in the final state. The numbers of events with exactly one and exactly two jets originating from b-quarks were counted to determine the top-anti-top quark production cross-section . The efficiency to reconstruct and identify a jet as originating from a b-quark from a top quark decay was extracted simultaneously, minimising the associated systematics. The cross-section was measured to be 749 ± 57 (stat.) ± 79 (syst.) ± 74 (lumi.) pb, giving a total relative uncertainty of 16%. The differential top-anti-top quark production production cross-sections were measured using top-anti-top quark events with one electron and one muon of opposite sign electric charge, and at least two jets, one of which was required to be tagged as containing a b-hadron. Initially, the differential cross-sections were measured in a fiducial phase-space region, using an integrated luminosity of 3.2 1/fb of proton--proton data at a centre-of-mass energy of 13 TeV, recorded by the ATLAS experiment in 2015. Subsequently, the single and double differential cross-sections were measured in both a fiducial phase-space region and the full phase-space, using 36.1 1/fb of proton--proton data at 13 TeV, recorded by the ATLAS experiment in 2015 and 2016. The measured differential cross-sections are compared to predictions of next-to-leading order generators matched to parton showers. Custom ultrasonic instruments have been developed for simultaneous monitoring of binary gas mixture and flow in the ATLAS inner detector. These instruments are sensitive to leaks in the cooling systems of the ATLAS inner detector. Software for on- and off-line analysis of these instruments has been developed and proven with the analysis of the cool-down to operation temperature in January 2016.

Le sujet de cette thèse est « L’étude dans le canal avec deux leptons de même signe de la physique du top au-delà du Modèle Standard avec le détecteur ATLAS au LHC et l’étude du niveau de déclenchement L1 du calorimètre ». Cette thèse porte sur la recherche de processus de nouvelle physique au LHC faisant jouer au quark top un rôle particulier. Le LHC est un collisionneur de protons, conçu pour un fonctionnement nominal avec une énergie dans le centre de masse de 14 TeV. Jusqu’à fin 2011 il a fonctionné avec une énergie de 7 TeV dans le centre de masse. Les premières données recueillies (5 fb−1 à 7 TeV) nous ont permis de contraindre certains paramètres de la nouvelle physique recherchée. C’est dans ce cadre que s’inscrit cette thèse. Celle-ci est divisée en trois parties. La première décrit rapidement l’accélérateur avant de s’intéresser à l’expérience ATLAS et au fonctionnement de son détecteur. Le bon fonctionnement des cartes de sommation du signal du calorimètre électromagnétique pour le premier niveau de déclenchement des événements a été tout particulièrement étudié. La deuxième partie est une analyse phénoménologique de la physique au-delà du Modèle Standard avec quatre quarks top dans l’état final pour plusieurs modèles théoriques. Cette étude a été effectuée principalement au niveau générateur pour 14 TeV dans le centre de masse mais nous commentons également les perspectives à 7 TeV. Elle peut être appliquée à l’expérience ATLAS comme à l’expérience CMS. La troisième partie est une étude expérimentale, réalisée avec le détecteur ATLAS, recherchant des manifestations d’un modèle de Higgs composite prédisant l’existence de partenaires exotiques au quark top (T5/3) et d’un modèle de théorie effective de production des 4 tops. Une limite sur la masse du partenaire exotique a été obtenue ainsi qu’une limite sur la section efficace des événements exotiques à quatre tops. / The subject of this thesis is the « Study in the two same sign leptons channel of top Beyond Standard Model Physics with the ATLAS detector at the LHC and the study of the L1 Calo Trigger ». The central subject of this thesis is the search for new physics in which the top quark plays a crucial role. The LHC is a proton collider, designed for a nominal operation with 14TeV. in the center of mass. Until december 2011 it worked with an energy of 7 TeV in the center of mass. The first 5 fb−1 of collected data allowed us to constrain some parameters of the new physics processes presented in this thesis. The document is divided into three parts : the first one describes briefly the LHC accelerator before presenting the ATLAS experiment and operation of the detector. The Tower Builder Boards for the electromagnetic level one trigger are especially studied. The second part is a phenomenological analysis of physics beyond the Standard Model with four top quarks in the final state. This analysis is presented for several theoretical models. This study was performed mainly at the generator level for 14 TeV in the center of mass but we also comments on prospects at 7 TeV. It can be applied to both ATLAS and CMS experiments. The third part is an experimental study, performed with the ATLAS detector, searching for two exotic processes with two same signe leptons in the final state (T5/3 and four tops production). A limit on the mass of the top partner T5/3 has been obtained as well as a limit on the cross section of exotic events with four tops.

<p>The purpose of this thesis was to open up the black boxed TMT process by examining the interaction between TMT members using cognitive and demographic diversity variables, and to see how organisational performance could be affected by the process. By opening the process, a model of the process was developed, which can be tested in further research. The major findings are that there are some aspects that stand out; the CEO and the functional responsibilities that influence the process. Further, the integration within the TMT is not that high, so the upper echelon theory should not be used without considerations on studies where composition is related to organisational performance. These have shown to influence performance in different ways. The functional responsibility has shown to create subgroups that practice problem solving and decision making more frequent than the TMT hence also communicate more.</p>

Corporations nowadays are in a highly accelerated stage, facing an ever-changing environment. It is no longer accomplishable by a one-man team to survive and prosper in such competitive environment. Hambrick & Mason¡¦s upper echelons theory points out that the top management team (TMT) is an organization¡¦s main decision maker, not individuals. The follow-up researches mostly focus on the relationship between TMT and organizational performance, but lack info on the construction of a TMT and its associated operations. It is therefore this research directs its focus towards how, when today¡¦s corporations start to adopt the TMT theory into their strategy, the number of team members, the selection process, member criteria, and the roles and responsibilities, are decided, and what elements will affect the conflicting communication and decision making process. This research is composed by case studies, and the following is a qualitative analysis conclusion of interviews with six corporations and seven senior managers: 1. There is a close-bonding relationship between the construction of TMT and corporation structure, managerial cognition, and corporation size. Mid-level and small corporations usually base their TMT selection on subjective decisions of the owners, while large corporations base TMT selections on protocols, through set channels such as recruitment or promotion. 2. TMT operation is related to corporation structure and owner¡¦s control. The role of TMT on major decision making depends on the owner¡¦s degree of empowerment. Communication between team members tend to be face-to-face communication, and senior management usually see positive conflicts to be of beneficiary value to the organization, while negative conflicts would be controlled under rules and protocols. It is therefore positive conflicts are not avoided, and actually encouraged, to increase innovation in the organization.

The purpose of this thesis was to open up the black boxed TMT process by examining the interaction between TMT members using cognitive and demographic diversity variables, and to see how organisational performance could be affected by the process. By opening the process, a model of the process was developed, which can be tested in further research. The major findings are that there are some aspects that stand out; the CEO and the functional responsibilities that influence the process. Further, the integration within the TMT is not that high, so the upper echelon theory should not be used without considerations on studies where composition is related to organisational performance. These have shown to influence performance in different ways. The functional responsibility has shown to create subgroups that practice problem solving and decision making more frequent than the TMT hence also communicate more.

We present a measurement of the top anti-top quark (ttbar)production cross section in the dilepton final states from proton-proton collisions at a center of mass energy at 7 TeV at the LHC. A b-tagging algorithm based on tracks displaced from the event interaction vertex is applied to identify bottom quark jets from top quark decay and reject background events. Given the relatively pure sample of bottom quark jets in ttbar dilepton final states, a new technique to measure in-situ the b-tagging efficiency is introduced that uses the distribution of the number of observed b-tagged jets. We present results with data collected at the ATLAS detector in 2010 with an integrated luminosity of 35 pb-1. The measured ttbar cross section is 176 +22/-21 (stat.) ± 20 (syst.) ± 6 (lum.) pb in the dilepton channel. We will also discuss the future prospects of this measurement.

We present a measurement of the top anti-top quark (ttbar)production cross section in the dilepton final states from proton-proton collisions at a center of mass energy at 7 TeV at the LHC. A b-tagging algorithm based on tracks displaced from the event interaction vertex is applied to identify bottom quark jets from top quark decay and reject background events. Given the relatively pure sample of bottom quark jets in ttbar dilepton final states, a new technique to measure in-situ the b-tagging efficiency is introduced that uses the distribution of the number of observed b-tagged jets. We present results with data collected at the ATLAS detector in 2010 with an integrated luminosity of 35 pb-1. The measured ttbar cross section is 176 +22/-21 (stat.) ± 20 (syst.) ± 6 (lum.) pb in the dilepton channel. We will also discuss the future prospects of this measurement.

Denna kvalitativa motivationsstudie utfördes på åtta svenska toppsäljare och utgick i från Vallerands hierarkiska modell om inre och yttre motivation (1997) och även från Czikszentmihalyis teori om flow (1990). Syftet med studien var att ta reda på vilka motivationsfaktorer som förenar toppsäljare. Toppsäljarna intervjuades enskilt genom en semistrukturerad intervjuguide. En tematisk analys utfördes på utskrifterna från intervjuerna och analysen undersöktes utifrån tre huvudkategorier: inre motivation, yttre motivation, och flow. Resultatet visade att toppsäljarna hade en stark inre drivkraft att utvecklas, att nå egna mål och uppnå positiva känslotillstånd av själva utförandet. Den yttre motivationen skiljde sig mellan toppsäljarna, då vissa drevs mer av yttre stimuli såsom pengar och beröm än andra. Resultatet visade att toppsäljarnas drivs till största delen av inre motivationsfaktorer, då de var starkt framträdande hos samtliga. Det är därmed viktigt att skapa en arbetsmiljö- och situation som främjar säljarnas möjlighet att sätta egna mål och autonomi.