published_or_final_version / abstract / Geography and Geology / Master / Master of Philosophy

Att skapa starka och långsiktiga relationer till sina kunder har för företag blivit en nödvändighet i den industriella marknadsföringen, där relationerna i sig själva kan ses som den viktigaste tillgången för verksamheten. Från området inom relationsmarknadsföring har Key Account Management vuxit fram och blivit ett populärt begrepp, där en koncentrerad mängd av företagets kunder prioriteras högre än övriga. Syftet med denna uppsats är att beskriva och konkretisera det potentiella värde, sett som mellanskillnaden mellan fördelar och nackdelar, som skapas för det säljande tjänsteföretaget i användningen av KAM. Uppsatsen utgår från en kvalitativ ansats där en komparativ studie har genomförts genom att undersöka företag som uttalat använder Key Account Management mot företag som ej använder KAM, samt kundföretag. För att få tillgång till empririn har sex stycken intervjuer med företag genomförts. Två som har KAM, två som inte har KAM. Dessutom har intervjuer utförts med kund till ett KAM-företag, samt en kund till ett företag som inte använder KAM. Genom att ha en stödjande organisation, fyra centrala delar i sitt KAM, kompetenta Key Account Managers, samt aktiva kunder är mjuka värden såsom förbättrad relation och kundförståelse givet. Dessa kan i sin tur leda till andra mjuka och hårda värden och därför ökad lönsamhet. KAM är däremot en investering som tar mycket resurser, samtidigt som flertalet potentiella nackdelar är tänkbara. Värdet har i denna studie identifierats som skillnaden mellan tänkbara fördelar och nackdelar, men detta skiljer sig åt från företag till företag vilket gör att det faktiska värdet varierar. / To build strong and long-lasting customer relationships has become a necessity in industrial marketing, whereat the relationships in itself can be viewed as the most important asset for the company. Key Account Management has its roots in relationship marketing and has grown in popularity the past decades. By selecting and focusing primarily on a few key customers, which the company deems to be the most important, Key Account Management is purposed to generate and locate value. The purpose of this paper is to describe and substantiate the potential value, seen as the difference between advantages and disadvantages, that Key Account Management may provide for the selling company. The study has a qualitative approach consisting of six interviews. Two companies with Key Account Management, two companies without KAM and two customer companies were interviewed in a comparative design. One of the customers had a relationship to one of the companies with KAM, whilst the other one did not. By having a supporting organization, four critical aspects to the companies KAM, a qualified Key Account Manager, and active customers, soft values as improved relationships and customer understanding are guaranteed. These can in turn enable access to other soft and hard values that leads to higher profit. KAM is however an investment which occupies a lot of resources, alongside with creating potential disadvantages. The value has in this study been identified as the difference between potential advantages and disadvantages, but these differ from company to company which in turn makes the actual value from KAM various.

Cette thèse est divisée en trois parties. Dans une première partie, on donne une description nouvelle des points récurrents par chaînes d'un système dynamique comme ensemble d'Aubry projeté d'une barrière ultramétrique. Cette approche permet de munir l'ensemble des composantes transitives par chaînes d'une structure d'espace ultramétrique expliquant leur topologie totalement discontinue, et de retrouver un théorème célèbre de Charles Conley concernant l'existence de fonctions de Lyapunov décroissant strictement le long des orbites non-récurrentes par chaînes. Dans une deuxième partie, on développe une théorie d'Aubry-Mather pour les homéomorphismes d'un espace métrique compact. On introduit dans ce cadre un ensemble d'Aubry métrique, puis topologique, ainsi qu'un ensemble de Mañé. Ces notions, plus fines que la récurrence par chaînes, permettent de mieux comprendre les fonctions de Lyapunov d'un tel système dynamique. Dans une dernière partie, on montre un résultat général de densité de certains contre-exemples au théorème de Sard pour lesquels l'ensemble des points critiques est un arc topologique et on donne des applications dynamiques de ce résultat. Celles-ci sont liées à des problèmes d'unicité, à constantes près, des solutions KAM faibles (ou solutions de viscosité) de certaines équations d'Hamilton-Jacobi. / This thesis is divided into three parts. In the first part, we give a new description of chain-recurrence using an ultrametric barrier. This barrier allows to endow the space of chain-transitive components with an ultrametric structure, explaining its topology and leading to the famous result of Charles Conley about Lyapunov function decreasing along non chain-recurrent orbits. Most of the results, first given in the setting of a continuous map on a compact metric space are then generalised to multivalued map on arbitrary separable metric spaces. In the second part, we develop an Aubry-Mather theory for a homeomorphism on a compact metric space. In this setting, we introduce metric and topological Aubry set and Mañé set, allowing a better understanding of Lyapunov functions arising in such a dynamical system. In the last part, we prove a general density result for some counterexamples of Sard's theorem for which the set of critical points is a topological arc and we give applications to dynamics.

Arnold a démontré l'existence de solutions quasipériodiques dans le problème planétaire à trois corps plan, sous réserve que la masse de deux des corps, les planètes, soit petite par rapport à celle du troisième, le Soleil. Cette condition de petitesse dépend de façon cachée de la largeur d'analyticité de l'hamiltonien du problème, dans des coordonnées transcendantes. Hénon ex- plicita un rapport de masses minimal nécessaire à l'application du théorème de Arnold. L'objectif de cette thèse sera de donner une condition suffisante sur les rapports de masses. Une première partie de mon travail consiste à estimer cette largeur d'analyticité, ce qui passe par l'étude précise de l'équation de Kepler dans le complexe, ainsi que celle des singularités complexes de la fonction perturbatrice. Une deuxième partie consiste à mettre l'hamiltonien sous forme normale, dans l'optique d'une application du théorème KAM (du nom de Kolmogorov-Arnold-Moser). Il est nécessaire d'étudier le hamiltonien séculaire pour le mettre sous une forme normale adéquate. On peut alors quantifier la non-dégénérescence de l'hamiltonien séculaire, ainsi qu'estimer la perturbation. Enfin, il faut démontrer une version quantitative fine du théorème KAM, inspirée de Pöschel, avec des constantes explicites. A l'issue de ce travail, il est montré que le théorème KAM peut être appliqué pour des rapports de masses entre planètes et étoile de l'ordre de 10^(-85). / Arnold showed the existence of quasi-periodic solutions in the plane planetary three-body prob- lem, provided that the mass of two of the bodies, the planets, is small compared to the mass of the third one, the Sun. This smallness condition depends in a sensitive way on the analyticity widths of the Hamiltonian of the three-body problem, expressed with the help of some tran- scendental coordinates. Hénon gave a minimal ratio of masses necessary to the application of Arnold’s theorem. The main objective of this thesis is to determine a sufficient condition on this ratio. A first part of this work consists in estimating these analyticity widths, which requires a precise study of the complex Kepler equation, as well as the complex singularities of the disturb- ing function. A second part consists in reworking the Hamiltonian to put it under normal form, in order to apply the KAM theorem (KAM standing for Kolmogorov-Arnold-Moser). In this aim, it is essential to work with the secular Hamiltonian to put it under a suitable normal form. We can then quantify the non-degeneracy of the secular Hamiltonian, as well as estimate the perturbation. Finally, it is necessary to derive a quantitative version of the KAM theorem, in order to identify the hypotheses necessary for its application to the plane three-body problem. After this work, it is shown that the KAM theorem can be applied for a ratio of masses that is close to 10^(−85) between the planets and the star.

Syfte: Syftet med studien är att skapa en fördjupad förståelse för revisorsrotationens inverkan på revisionskvalitet utifrån ett klientperspektiv.  Metod: Studien bygger på en kvalitativ forskningsmetod. För datainsamling genomfördes nio semistrukturerade intervjuer med ledamöter från styrelser och revisionsutskott i börsnoterade bolag.     Resultat och slutsats: Studien visar att revisionsklienterna upplever att revisorsrotation har en positiv inverkan på revisionskvaliteten. Vidare visar studien att revisorernas kompetens och revisorernas oberoende är de centrala delarna av revisionskvaliteten.      Examensarbetets bidrag: Studien ger en insyn i hur implementeringen av de obligatoriska rotationsreglerna påverkar revisionskvaliteten i praktiken. Till skillnad från tidigare forskning har den här studien fokuserat på hur revisorernas egna klienter upplever att revisionskvaliteten påverkas av revisorsrotation.     Förslag till fortsatt forskning: Ett förslag till fortsatt forskning är att gå djupare in på antalet rotationer som de svenska börsnoterade bolagen varit med om. Här kan framtida forskning studera antalet rotationer av bolagens påskrivande revisor, antal rotationer av revisionsteamet samt antalet rotationer av revisionsbyrå. / Aim: The purpose of this study is to create a deeper understanding of the impact of auditor   rotation on audit quality from a client perspective.       Method: The study is based on a qualitative research methodology. För data collection, nine semi-structured interviews were conducted with members of boards and audit committees of listed companies.     Results and conclusions: The study shows that audit clients perceive auditor rotation as having a positive positive impact on audit quality. Furthermore, the study shows that auditor competence and auditor independence are the key elements of audit quality.   Contribution of the thesis: The study provides an insight into how the implementation of the mandatory rotation rules affects audit quality in practice. In contrast to previous research, this study focuses on how auditors’ own clients perceive audit quality to be affected by auditor rotation.  Suggestion for future research: One suggestion for further research is to go deeper into the number of rotations that Swedish listed companies have experienced. Future research could study the number of rotations of the company’s signing auditor, the number of rotations of the audit team and the number of rotations of audit firms.

On passe en revue les résultats de l'auteur sur la fonction $\beta$ de Mather.

Este estudo investigou se a qualidade de auditoria aumentou após as modificações implementadas pela ISA 700 revisada, que obrigou a inclusão de itens como os Principais Assuntos de Auditoria (PAAs), considerados mais informativos aos usuários das demonstrações contábeis. Além disso, investigou se os custos associados à auditoria tiveram algum impacto devido a essas novas exigências. A verificação dos possíveis impactos na qualidade de auditoria foi realizada com a utilização da proxy de qualidade das demonstrações contábeis obtida por estimação: (i) dos accruals absolutos anormais pelo Modelo de Kothari et al. (2005) derivado do Modelo de Jones (1991); (ii) dos accruals absolutos anormais pelo Modelo de Dechow e Dichev (2002) modificado; (iii) da qualidade dos accruals das receitas de Stubben (2010) e (iv) do percentual de magnitude dos accruals dos fluxos de caixa de Burgstahler et al. (2006). Os PAAs foram considerados, pois poderiam influenciar em maior qualidade de auditoria, sendo mais informativos aos usuários das demonstrações contábeis, podendo inclusive influenciar em uma gestão menos oportunista dos resultados por parte da administração (mensurado por menores accruals), com resultados ainda conflitantes na literatura contábil. A abordagem quantitativa das estimações foi realizada com dados contábeis e de mercado das companhias de capital aberto do Brasil, dos períodos de 2014 a 2017. A amostra consistiu em 1.554 observações para as quais foram coletadas, de forma manual, as informações sobre as firmas de auditoria responsáveis e as quantidades de PAAs divulgados que poderiam afetar a qualidade de auditoria. A maior parte das regressões, utilizando quatro métricas para os accruals não demonstrou evidências de melhoria na qualidade de auditoria após a adoção da ISA 700 revisada. Tais métricas foram analisadas considerando: (i) Painel A, que verificou a mudança na qualidade de auditoria na comparação do período pré e pós adoção da norma; (ii) Painel B, que incluiu o número de PAAs divulgados e (iii) Painel C, que incluiu as mudanças recorrentes de firmas de auditoria. Para a qualidade dos accruals das receitas foi obtido resultado positivo e significante no nível de 5%, indicando uma possível melhora na qualidade de auditoria. Em contrapartida, o poder explicativo diminuiu devido à alta correlação identificada entre a variável de interesse e a variável de controle que indica especificamente a quantidade de PAAs divulgados. Os honorários de auditoria também foram coletados manualmente, sendo que não apresentaram alterações estatisticamente significantes na comparação do período pré e pós adoção dos novos requerimentos. O presente estudo amplia as discussões acadêmicas para o mercado de capitais brasileiro acerca das implicações da inclusão dos PAAs nos relatórios de auditoria, bem como, na análise dos efeitos práticos da aplicação das normas expedidas pelos órgãos reguladores. Além disso, essa evidência pode auxiliar no aprimoramento das normas na busca por maior qualidade de auditoria e das demonstrações contábeis com foco no usuário que almeja redução de assimetria informacional sobre a realidade econômica das companhias. / This study investigated whether audit quality increased after the modifications implemented by the revised ISA 700, which required the inclusion of items such as Key Audit Matter (KAM), which are considered more informative to the users of the financial statements. Moreover, it investigated whether the costs associated with the audit had any impact due to these new requirements. The verification of possible impacts on audit quality was performed using the quality proxy of the financial statements obtained by estimating: (i) the abnormal absolute accruals by Kothari\'s Model (2005) adapted from the Jones\'s Model (1991); (ii) abnormal absolute accruals by Dechow and Dichev\'s Model (2002); (iii) the quality of accruals revenues of Stubben\'s Model (2010) and (iv) the percentage of magnitude of the accruals of cash flows of Burgstahler et al. (2006). The KAM could influence the quality of the audit, being more informative to the users of the financial statements and may even influence the less opportunistic management of the results by the administration measured by smaller accruals, although there are still conflicting results in the accounting literature. The quantitative approach in the estimates was made with accounting and market data for publicly traded companies in Brazil, from 2014 to 2017. The sample consisted of 1,554 observations for which the information about the responsible audit firms and the amounts of KAM disclosed that could affect audit quality were collected manually. Most of the regressions, using four accruals metrics, did not show evidence of improvement in audit quality after the adoption of ISA 700. These metrics were analyzed considering: (i) Panel A, which verified the change in audit quality in the comparison of the period before and after adoption of the standard; (ii) Panel B, which included the number of PAAs disclosed and (iii) Panel C, which included the recurring changes in audit firms. For the quality of revenue accruals, it was obtained a positive and significant result at the 5% level indicating a possible improvement in audit quality, but the explanatory power decreased due to the high correlation identified between the variable of interest and control variable that specifically indicates the amount of KAM disclosed. The audit fees were also manually collected and did not present statistically significant changes in the comparison of the period before and after the adoption of the new requirements. The present study uses the academic discussions for the Brazilian capital market on the implications of the inclusion of KAM in the audit reports, as well as on the practical effects of the application of the norms issued by the regulatory agencies. In addition, this evidence can help improve standards in the quest for higher audit quality and user-focused financial statements that aim to reduce informational asymmetry about the companies\' economic reality

Särskilt Betydelsefulla Områden infördes för att öka informationsvärdet i revisionsberättelsen och bidra till en ökad insikt i revisionsbranschens arbete. Det råder dock delade meningar kring vad SBO faktiskt fyller för funktion och det finns därför ett behov av att undersöka hur SBO påverkar förekomsten av resultatjustering, vilket avgör redovisningskvaliteten. Studien visar att resultatjustering är vanligt förekommande på Stockholmsbörsen, men att den minskar vid högre omfattning av periodiseringsrelaterade SBO i revisionsberättelsen. Större andel periodiseringsrelaterade SBO indikerar alltså bättre redovisningskvalitet. / Key Audit Matters was introduced to increase the informational value of audit reports and contribute to an enhanced insight of the audit process. However, there is a difference of opinion regarding the functionality and efficiency of KAM. Therefore, there is a need to investigate how KAM impacts the extent of earnings management, which decide the accounting quality.

Aquest treball es situa dintre del marc dels sistemes dinàmics hamiltonians de tres graus de llibertat. Allà considerem famílies d'òrbites periòdiques amb una transició estable-complex inestable: sigui L el paràmetre que descriu la família i suposarem que per a valors del paràmetre més petits que un cert valor crític, L', els multiplicadors característics de les òrbites periòdiques corresponents hi són sobre el cercle unitat, quan L=L' aquests col·lisionen per parelles conjugades (òrbita ressonant o crítica) i per L > L', abandonen el cercle unitat cap al pla complex (col·lisió de Krein amb signatura oposada). El canvi d'estabilitat subseqüent es descriu a la literatura com "transició estable a complex inestable". Tanmateix, a partir d'estudis numèrics sobre certes aplicacions simplèctiques (n'esmentarem D. Pfenniger, Astron. Astrophys. 150, 97-111, 1985), és coneguda l'aparició (sota condicions d'incommensurabilitat) de fenòmens de bifurcació quasi-periòdica, en particular, el desplegament de famílies de tors 2-dimensionals. A més aquesta bifurcació s'assembla a la (clàssica) bifurcació d'Andronov-Hopf, en el sentit de què hi sorgeixen objectes linealment estables (tors-2D el·líptics) "al voltant" d'objectes inestables de dimensionalitat més baixa (òrbites periòdiques), i recíprocament, n'apareixen tors inestables (hiperbòlics) "al voltant" d'òrbites periòdiques linealment estables. Nostre objectiu és entendre la dinàmica local en un entorn de l'òrbita periòdica ressonant per tal de provar, analíticament, l'existència dels tors invariants bifurcats segons l'esquema descrit dalt. Això el portem a terme mitjançant l'anàlisi següent: (i) Primer de tot obtenim d'una manera constructiva (això és, donant algorismes) una forma normal ressonant en un entorn de l'òrbita periòdica crítica. Aquesta forma normal la portem fins a qualsevol ordre arbitrari r. Així doncs, mostrem que el hamiltonià inicial es pot posar com la suma de la forma normal (integrable) més una resta no integrable. A partir d'aquí, podem estudiar la dinàmica de la forma normal, prescindint dels altres termes i, amb aquest tractament (formal) del problema, som capaços d'identificar els paràmetres que governen tant l'existència de la bifurcació com la seva tipologia (directa, inversa). Cal, remarcar que el que es fa fins aquí, no és només un procés qualitatiu, ja que a més ens permet derivar parametritzacions molt acurades dels tors no pertorbats. (ii) A continuació, calculem acotacions "òptimes" per a la resta. D'aquesta manera, esperem provar que un bon nombre de tors (en sentit de la mesura) es preserven quan s'afegeix la pertorbació. (iii) Finalment, apliquem mètodes KAM per establir que la majoria (veure comentari dalt) dels tors bifurcats sobreviuen. Aquests mètodes es basen en la construcció d'un esquema de convergència quadràtica capaç de contrarestar l'efecte dels petits divisors que apareixen quan s'aplica teoria de pertorbacions per trobar solucions quasi-periòdiques. En el nostre cas, a més, resulta que alguna de les condicions "típiques" que s'imposen sobre les freqüències (intrínseques i normals) dels tors no pertorbats, no estan ben definides per als tors bifurcats, de manera que ens ha calgut desenvolupar un tractament més específic. keywords: Bifurcation problems, perturbations, normal forms, small divisors, KAM theory. Classificació AMS: 37J20, 37J25, 37J40 / This work is placed into the context of the three-degree of freedom Hamiltonian systems, where we consider families of periodic orbits undergoing transitions stable-complex unstable. More precisely: Let L be the parameter of the family and assuming that, for values of L smaller than some critical value say, L', the characteristic multipliers of the periodic orbits lie on the unit circle, when L=L' they colllide pairwise (critical or resonant periodic orbit) and, for L > L' leave the unit circle towards the complex plane (Krein collision with opposite signature). From numerical studies on some concrete symplectic maps (for instance, D. Pfennniger, Astron. Astrophys. 150, 97-111, 1985) it is known the rising (under certain irrationality conditions), of quasi-periodic bifurcation phenomena, in particular, the appearance of unfolded 2D invariant tori families. Moreover, the bifurcation takes place in a way that resembles the classical Andronov-Hopf one, in the sense that either stable invariant objects (elliptic tori) unfold "around" linear unstable periodic orbits, or conversely, unstable invariant structures (hyperbolic tori) appear "surrounding" stable periodic orbits. Our objective is, thus, to understand the (local) dynamics in a neighbourhood of the critical periodic orbit well enough to prove analytically, the existence of such quasi-periodic solutions together with the bifurcation pattern described above. This is carried out through three steps: (i) First, we derive, in a constructive way (i. e., giving algorithms), a resonant normal form around the critical periodic orbit up to any arbitrary order r. Whence, we show that the initial raw Hamiltonian can be casted --through a symplectic change--, into an integrable part, the normal form itself, plus a (non-integrable) remainder. From here, one can study the dynamics of the normal form, skipping the remainder off. As a result of this (formal) approach, we are able to indentify the parameters governing both, the presence of the bifurcation and its type (direct, inverse). We remark that this is not a merely qualitative process for, in addition, accurate parametrizations of the bifurcated families of invariant tori are derived in this way. (ii) Beyond the formal approach, we compute "optimal" bounds for the remainder of the normal form, so one expects to prove the preservation of a higher (in the measure sense) number of invariant tori --than, indeed, with a less sharp estimates--. (iii) Finally, we apply KAM methods to establish the persistence of (most, in the measure sense) of the bifurcated invariant tori. These methods involve the design of a suitable quadratic convergent scheme, able to overcome the effect of the small divisors appearing in perturbation techniques when one looks for quasi-periodic solutions. In this case though, some of the "typical" conditions that one imposes on the frequencies (intrinsic and normal) of the unperturbed invariant tori do not work, due to the proximity to parabolic tori, so one is bound to sketch specific tricks. keywords: Bifurcation problems, perturbations, normal forms, small divisors, KAM theory AMS classification: 37J20, 37J25, 37J40

We prove the existence and linear stability of quasi-periodic breather solutions in a 1d Hamiltonian lattice of identical, weakly-coupled, anharmonic oscillators with general on-site potentials and under the effect of long-ranged interaction, via de KAM technique. We prove the persistence of finite-dimensional tori which correspond in the uncoupled limit to N arbitrary lattice sites initially excited. The frequencies of the invariant tori of the perturbed system are only slightly deformed from the frequencies of the unperturbed tori.