This thesis studies two optimization problems: the optimization of a staffing policy assuming non stationary Poisson demand, and exponential travel and job times, and the optimization of investment decisions with an investment lag. In the staffing policy optimization, we solve a novel time-dynamic Hamilton-Jacobi-Bellman equation that models jobs as a Poisson jump process. The model gives the employer the flexibility to control the number of staff hired by two factors: the cost of hiring and the effect of delay. We have solved the optimal staffing policy problem using different approaches, which are compared. We produce accurate numerical results for different parameters, and discuss the advantages and disadvantages of each approach. Moreover, we have solved a staffing problem for a national utility company, using a standard linear programming approach, which is compared with our methods. In addition to the Poisson jump process, we extend the model to treat a continuous job model, and two locations model that is extendible to a larger network problem. In the investment lag problem, we use a mixture of numerical methods including finite difference and body fitted co-ordinates to form a robust and stable numerical scheme which is applied to solve the investment lag problem for a geometric Brownian motion presented in the paper by Bar-Ilan and Strange (1996). The problem is to calculate the optimal price to invest in a project that have a time lag period between the decision to invest and production, and the optimal price to mothball the project. The method presented in this thesis is more flexible as we compare it with the previous results, and solves the problem for different stochastic processes, such as Cox-Ingersoll-Ross model, which does not have analytic solution.

This dissertation consists of three essays. In the first essay, we attempt to answer the following three questions about the new capital raised in IPOs: Why do some IPO companies raise a lot of new capital while some others don’t? Where do the IPO companies use the new capital they raise in IPOs? How does the use of new capital affect the operating performance of IPO companies? We find that companies with higher R&D spending, higher capital expenditure, lower working capital and more long term debt tend to raise more capital in IPOs. These firms also spend more on R&D and capital expenditure. The more new capital firms raise in IPOs, the lower sales growth rate they have. However, firms spending a higher proportion of new capital on R&D seem to have higher sales growth rate. In the second essay, we examine the relation between IPO valuation and offering size. Using a sample of 3,885 IPOs from the US, we find that IPO firms with larger offering size have lower valuation. Both primary share offering and secondary share offering are negatively related to IPO firm valuation. The valuation measures are positively related to the levels of capital expenditure and R&D before IPO, lending support to explanations based on Jensen (1986)’s free cash flow hypothesis. We also find evidence consistent with negative signals from larger secondary share offering size. Results of tests about long run IPO stock performance do not support the hypothesis that IPO stock demand curve is downward sloping. In the third essay, we examine how analysts react to IPO offering size. We find that analysts predict lower long-term growth rates for IPOs with larger offering size. The sizes of both primary and secondary offering are negatively related to long-term growth rate forecasts. We find evidence that the free cash flow effect may be related to the negative relation between primary offering size and growth forecast.

Cette thèse a pour objet les ordres, les valuations et les C-relations sur les groupes, ainsi que les corps différentiels valués tels qu’étudiés par Rosenlicht. Elle accomplit trois objectifs principaux. Le premier est d’introduire et d’étudier une notion de quasi-ordre sur les groupes qui a pour but de réunir les ordres et les valuations dans un même cadre. Nous donnons un théorème de structure des groupes munis d’un tel quasi-ordre, ce qui nous permet ensuite de donner un “théorème de plongement de Hahn” pour ces groupes. Le second objectif de cette thèse est de décrire les C-groupes à l’aide des quasi-ordres. Nous donnons un théorème de structure pour les C-groupes, qui énonce que tout C-groupe est un “mélange” de groupes ordonnés et de groupes valués. Nous utilisons ensuite ce résultat pour caractériser les groupes C-minimaux à l’intérieur de la classe des C-groupes. Le troisième objectif de cette thèse est d’introduire et d’étudier une notion de rang différentiel d’un corps différentiel valué. Nous définissons cette notion par analogie avec les notions de rang exponentiel d’un corps exponentiel et de rang de différence d’un corps aux différences. Nous montrons que cette notion de rang n’est pas tout à fait satisfaisante, et introduisons donc une meilleure notion de rang appelée le rang différentiel déployé. Nous donnons ensuite une méthode pour définir une dérivation “de type Hardy” sur un corps de séries formelles généralisées, ce qui nous permet de construire des corps différentiels valués dont le rang différentiel et le rang différentiel déployé ont été arbitrairement choisis. / This thesis deals with orders, valuations and C-relations on groups, and with differential-valued fields à la Rosenlicht. It achieves three main objectives. The first one is to introduce and study a notion of quasi-order on groups meant to encompass orders and valuations in a common framework. We give a structure theorem for groups endowed with such a quasi-order, which then allows us to give a “Hahn’s embedding theorem” for these groups. The second objective of this thesis is to describe C-groups via quasi-orders. We give a structure theorem for C-groups, which basically states that any C-group is a “mix” of ordered groups and valued groups. We then use this result to characterize C-minimal groups inside the class of C-groups. The third objective of this thesis is to introduce and study a notion of differential rank for differential-valued fields. We define this notion by analogy with the exponential rank of an exponential field and with the difference rank of a difference field. We show that this notion of rank is not quite satisfactory, so we introduce a better notion of rank called the unfolded differential rank. We then give a method to define “Hardy-type” derivations on fields of generalized power series, which allows us to build differential-valued fields of arbitrary given differential rank and unfolded differential rank.

This thesis investigates the connections between henselian valuations and absolute Galois groups. There are fundamental links between these: On one hand, the absolute Galois group of a field often encodes information about (henselian) valuations on that field. On the other, in many cases a henselian valuation imposes a certain structure on an absolute Galois group which makes it easier to study. We are particularly interested in the question of when a field admits a non-trivial parameter-free definable henselian valuation. By a result of Prestel and Ziegler, this does not hold for every henselian valued field. However, improving a result by Koenigsmann, we show that there is a non-trivial parameter-free definable valuation on every henselian valued field. This allows us to give a range of conditions under which a henselian field does indeed admit a non-trivial parameter-free definable henselian valuation. Most of these conditions are in fact of a Galois-theoretic nature. Throughout the thesis, we discuss a number of applications of our results. These include fields elementarily characterized by their absolute Galois group, model complete henselian fields and henselian NIP fields of positive characteristic, as well as PAC and hilbertian fields.

Este trabalho trata da uniformização local, que é um passo do método de Zariski para provar resolução de singularidades em variedades algébricas. O método consiste numa abordagem por teoria de valorizações, e esta dissertação se baseia no artigo [NS], de Novacoski e Spivakovsky, que consiste em reduzir a prova da uniformização local para valorizações de qualquer posto, a provar apenas para os casos de posto um. / This work deals with local uniformization, which is a step in the method of Zariski to prove resolution of singularities for algebraic varieties. The method consists in an approach using valuation theory and this dissertation is based on the paper [NS], by Novacoski and Spivakovsky, which consists in reduce the proof of local uniformization for all cases to prove only the cases of rank one.

Cette thèse traite de l'uniformisation, en caractéristique p>0, d'une valuation rationnelle, dans les cas particuliers où cette valuation est centrée en une singularité définie localement par des hypersurfaces d'équations :<br /><br />- soit z^p+f(x,y)=0, avec f non puissance p-ième et ord f>p,<br /><br />- soit z^p+e(x,y)z+f(x,y)=0, avec ord(ez+f)>p (cas d'Artin-Schreier).<br /><br />Historiquement c'est dans ces cas particuliers que s'est trouvé concentrée la difficulté de résoudre les surfaces en caractéristique positive.<br /><br />Les nouveautés ici consistent en une majoration du nombre minimum<br />d'éclatements de points fermés nécessaires pour uniformiser, et en une<br />description ``d'en bas'' de l'évolution du polygone de Newton ainsi que des<br />paramètres choisis pour les éclatés successifs le long de la valuation. <br /><br />Dans la première partie de la thèse, on revient sur l'obtention de la forme<br />normale de Giraud pour f dans l'anneau O_X(X), où X schéma régulier de<br />dimension deux et de caractéristique p. Le point de départ est une<br />décomposition polynomiale de f en les curvettes associées à la valuation. On<br />prévoit ensuite via une puissance p-ième d'en bas, le comportement du<br />polygone de Newton de f moins cette puissance p-ième, et on majore le nombre<br />minimum d'équerres du graphe dual de la valuation nécessaires à ce qu'il devienne droit de hauteur au plus 1, et minimal, cas correspondant à la forme normale.<br /><br /><br />Dans la deuxième partie de la thèse on utilise cette étude pour les cas particuliers ci-dessus mentionnés, on donne un algorithme permettant de prévoir les translations à faire à la sortie des équerres pour avoir un polygone de Newton minimal. On quantifie combien d'équerres sont suffisantes pour obtenir une singularité quasi-ordinaire.

<p> Vid värdering av företag använder den professionella värderaren sig av olika värderingsmetoder för att fastställa ett värde på säljarens företag. Det är inte helt lätt att göra en bedömning då det kan variera hur mycket information som finns att grunda sin värdering på. Det kan även variera vilken metod som används beroende på vad förslags företag som skall värderas. Det går heller inte att få fram ett exakt värde utan det blir oftast ett intervallvärde som använd.Författarna kom fram till att en professionell företagsvärderare använder sig av två till tre olika värderingsmetoder vid värdering av onoterade företag. Det som avgör vilken metod som används är bland annat syftet med värderingen samt hur mycket information som erhålls av säljaren. Även köpare och säljare har undersökningsplikt respektive informationsplikt. Om detta sker ömsesidigt av båda sidor kommer förvärvet gå mycket lättare</p>

<p>Background: The Swedish retail trading company KappAhl has reorganized all the boutiques in Sweden. Before the reorganization many of the boutiques consisted of four levels: shop manager, assistant shop manager, department managers and regular personel. After the reorganization assistant shop managers and department managers have been replaced by a so called “responsibility group” consisting of some of the employees. The change is presented as a decentralisation. </p><p>Purpose: With this thesis I want to attain knowledge about different change attitudes from the employees before reorganizations, and what different effects that can be the result from an decentralization. Limitations: One shop has been studied closely and that is KappAhl at Gränby outside Uppsala. I have studied the opinions from the employees concerning the decentralization and the effects from this decentralization. </p><p>Procedure: At the boutique of Gränby I interviewed 13 people from the personel, 12 women and 1 man. The literature I´ve used is about work of change in organisations and effects from decentralizations. </p><p>Results: The opinions before the reorganization from the employees at the boutique of Gränby were positive from almost everyone. The effects from the decentralization has been very positive. The intra communication at the boutique is better and the personel thought that is was easier to help the customers, for example when the customers has reclaims.</p>

Background: The Swedish retail trading company KappAhl has reorganized all the boutiques in Sweden. Before the reorganization many of the boutiques consisted of four levels: shop manager, assistant shop manager, department managers and regular personel. After the reorganization assistant shop managers and department managers have been replaced by a so called “responsibility group” consisting of some of the employees. The change is presented as a decentralisation. Purpose: With this thesis I want to attain knowledge about different change attitudes from the employees before reorganizations, and what different effects that can be the result from an decentralization. Limitations: One shop has been studied closely and that is KappAhl at Gränby outside Uppsala. I have studied the opinions from the employees concerning the decentralization and the effects from this decentralization. Procedure: At the boutique of Gränby I interviewed 13 people from the personel, 12 women and 1 man. The literature I´ve used is about work of change in organisations and effects from decentralizations. Results: The opinions before the reorganization from the employees at the boutique of Gränby were positive from almost everyone. The effects from the decentralization has been very positive. The intra communication at the boutique is better and the personel thought that is was easier to help the customers, for example when the customers has reclaims.

The road network is extremely valuable. Road Administrationsare expected to invest maintenance funding in a way thatreturns maximum benefit to road users. Cost-benefit analysis isone method to ensure that an adequate return in terms ofbenefits results from committing expenditure. Today,cost-benefit calculations are frequently used as a base fordecision making of investments. The surges for such methods inthe maintenance management sector are increasing. Up to the present, one reason for not analysing costs andbenefits for various maintenance management measures has beenthe lack of knowledge about comfort benefits for road users inquantitative monetary terms. The aim with this thesis is toinvestigate motorists’apprehension of pavementmaintenance management and winter maintenance operations. Thefinal goal is to find out their willingness to pay fordifferent levels of road maintenance management. Those valuescan later be used in cost-benefit calculations and also ineffect models of road maintenance management. Due to the pioneer status of this study, focus groups andin-depth interviews as well as a number of pilot studies havebeen carried out before a main survey with stated choiceexperiments could be designed. These exploratory studies showedthat the interviewees were familiar with the types of roadsurface damage that exist and in many cases mastered the sameterminology as the Road Administration and others. Showingpictures of well-known types of road damage lead to highermonetary valuations of getting better road standard incomparison with just text descriptions. One reason for thatcould be the requisite severness of the damage in order toillustrate a certain road maintenance shortage. The respondentswith the text descriptions could have stated their preferencesfor an, in their own minds, average shortcoming while the groupwith access to photograph of road damage all saw the samesevere damage. Illustrations of different road maintenancestandards make it possible to control the respondentsinterpretation of the maintenance management standard valuatedbut could lead to high monetary estimations. Driving comfort was very important to the interviewees inthe exploratory studies. That was manifested in the pilotstated choice surveys, which resulted in high willingness topay for better pavement management. The main study consisted of two surveys; the first one wasabout pavement maintenance management and was carried out inOctober to November 2000 and the second one took place inFebruary to March 2001 and was about winter maintenanceoperations. Both the pavement and the winter survey includedattitude questions and two stated choice experiments. Theresult showed that the maintenance management status of theroad network was important to car users. For example, the worstpavement damage was roughness; the motorists were willing topay 1.7 SEK (Swedish Crowns) per kilometre to avoid roadsdamaged in their full length. The least harmful damage of thosestudied was cracks; the willingness to pay to avoid that was0.5 SEK per kilometre. For more rapid snow clearance, the carusers were willing to pay 60 to 80 SEK per year for getting theroads cleared from snow one hour earlier than the currentstandard implies. The willingness to pay for driving on bareroads in comparison with snow roads was 0.4 SEK per kilometre.Statistical tests on the models showed that the parametervalueswere well estimated. In the pavement as well as in the winter survey, a clustergroup analysis was performed in order to test the heterogeneityof attitudes and behaviour to road maintenance management. Theanalysis resulted in two separate groups in each survey. Onegroup consisted of drivers who reported to be very influencedby the level of maintenance management regarding chosen speed,joy of driving and so on. The other group reported to be lessinfluenced and had lower acceptance of higher road tax for thepurpose to increase the maintenance management standard.Separate stated choice models revealed that the differences inattitudes could also reflect the respondents’willingnessto pay for higher road maintenance standard. However, thedifferences were only small and the different groups’monetary valuations were not found to be significantlydifferent from each other. The result of this study, better knowledge aboutmotorists’apprehension of maintenance management, theirattitudes to driving comfort and road standard and theirmonetary valuations of different levels of pavement maintenanceand winter maintenance operations, opens up the possibility tomake cost-benefit analysis of various maintenance managementprojects. The impact of the monetary values found in this studyhas been studied in a limited cost-benefit analysis. <b>Keywords:</b>stated choice, stated preference, valuationsof maintenance management, driving comfort, road standardevaluation