Decades of research on compression ignition engines have led to a highly efficient combustion cycle in contemporary diesel engines. Nonetheless, the combustion process is being studied perpetually to meet both current and future emission regulations. One of the most influential parameters that impacts the combustion quality, is the fuel spray evolution during injection, and subsequent fuel-air mixture formation inside the engine cylinder. The spray evolution has been investigated to a high level of detail, and the highly complex processes of mixture formation and combustion are well-documented for diesel engines. Most of these investigations are limited to studying either research-grade injectors, or brand new production injectors. Injectors in real-world diesel engines, i.e. normal passenger cars and trucks that are used on a daily basis, are however subject to deposit formation at the tip of the injector nozzle. These deposits have the potential of altering the internal nozzle flow and fuel spray pattern, which in turn degrades combustion quality and increases engine emissions. In the work presented in this thesis the spray evolution of production injectors has been studied over a wide range of injector conditions. Common rail light-duty injectors with a usage history of up to 90 000 miles were acquired from the UK commuter car parc, and several brand new injectors were studied for comparison purposes. It is shown that the spray pattern of the injected fuel changes over the lifetime of the injector. For used injectors a reduced penetration rate was observed in the transient regime of fuel injection, during needle lift. The reduced penetration rate was often accompanied by anomalous radial expansions. Although the magnitude of the effects varied from injector to injector, the highest mileage injectors tended to produce the strongest spray deviations. For several high-mileage injectors the end of injection appeared retarded with respect to new injectors. Expulsions of liquid ligaments and droplets after the end of injection were observed from all injectors, irrespective of the mileage of the injector.

This DPhil thesis is a collection of three empirical papers that study the role of firms in the UK labour market. Each chapter focuses on firms at different points in their lifecycle. Young firms are an engine of job creation but little is known about the quality of the jobs that they offer. In Chapter 1, I use a matched employer-employee dataset to study how starting wages and lifecycle earnings of employees differ between young and mature firms. I find that young firms pay a small premium to new hires, but subsequent wage growth is better at mature firms, both within continuing job matches and when individuals change jobs. Crucially, highly-paid and stable jobs at young firms have become increasingly rare over time, as young firms themselves have become less likely to survive and attain high productivity levels - both in absolute terms and relative to mature firms over the same period. Policies that aim to stimulate job growth by encouraging the formation of new firms should therefore pay close attention to the types of firms that form. Chapter 2 asks what determines the proportion of a firm's income that workers receive as compensation. I use longitudinal firm data from a period of substantial labour share variation to understand the firm-level determinants of the labor share of income - a question that has typically only been addressed with country- and sector-level data. Estimating a dynamic model using GMM, I find that firms with greater market power and a higher ratio of capital to labour allocate a smaller proportion of their value added to workers. Testing the impact of tangible and intangible capital on low- and high-wage firms leads to conclusions consistent with the hypothesis of capital-skill complementarity. Overall, the results suggest that firm-level drivers play a key role in the evolution of the aggregate labour share, which has declined significantly since the 1970s. Chapter 3 co-authored with Brian Bell, focuses on mature firms and asks how wages at such firms respond to idiosyncratic firm-level cost shocks. We create a unique dataset that links longitudinal data on workers' compensation to the unexpected costs related to firms' legacy defined benefit pension plans. We show that firms are able to share the burden of such costs when a significant share of their workers are current or former members of the plan. We also find that firms that respond to deficits by closing down the pension plans effectively reduce the total compensation of plan members. These results point to significant frictions in the labour market, which we show are a direct result of the pension arrangement that workers have. Yet closing schemes has an implicit cost for firms, since it reduces the frictions that workers face, and increases mobility.

A presente dissertação faz um estudo dos tipos de inovação promovidos por 11 empresas apoiadas pelo programa PIPE da FAPESP. Seu objetivo é descrever os tipos de inovação promovidos pelas empresas em seus primeiros dez anos de existência. Pretendeu-se aqui responder à pergunta \"Que tipo(s) de inovação as empresas de sucesso paulistas, intensivas em conhecimento, promovem nos dez primeiros anos de suas existências?\". Para tanto, o autor utilizou, em um primeiro nível de classificação, a tipologia do Manual de Oslo (2005), que estabelece e denomina a inovação como a) em produto b) em processo c) em marketing d) organizacional. Em um segundo nível de classificação, este só para a inovação em produto, o autor utilizou a tipologia de Garcia e Calantone (2002), que estabelece e denomina a inovação em produto como a) incremental b) realmente nova c) radical. Para desenvolver a pesquisa, qualitativa, de perfil exploratório-descritivo, o autor enviou email convite a 603 empresas beneficiárias de apoio do programa PIPE da FAPESP, apoio este obtido entre maio de 2002 e dezembro de 2009. Com as informações fornecidas pelos respondentes, denominadas ações empreendedoriais, o autor preencheu a parte inicial do instrumento de pesquisa, concluindo assim a primeira etapa do trabalho. A segunda etapa constituiu-se de entrevista, quando as ações empreendedoriais descritas pelos respondentes foram classificadas por tipo de inovação. Os resultados obtidos descrevem os tipos de inovações promovidos pelas empresas constantes da amostra em seus dez primeiros anos de existência. / The present dissertation studies the innovations promoted by 11 companies supported by the program PIPE of FAPESP. It aims at describing the types of innovations promoted by those companies in their first ten years of existence. One intended to answer the question \"What types of innovation successful companies of São Paulo state promoted in their first ten years of existence?\" At the first level, the typology of Oslo\'s Manual (2005) was used to classify the innovations in product, process, marketing and organizational. At the second level, this one only for products, the typology of Garcia e Calantone (2002) was used to classify the innovations in radical, really new and incremental. In order to develop this study, the author contacted companies supported by the program PIPE of FAPESP. Eleven companies were interviewed. The results do describe the type of innovations promoted by the companies in their first ten years of existence.

The act of reading has benefits for individuals and societies, yet studies show that reading declines, especially among the young. Recommender systems (RSs) can help stop such decline. There is a lot of research regarding literary books using natural language processing (NLP) methods, but the analysis of textual book content to improve recommendations is relatively rare. We propose content-based recommender systems that extract elements learned from book texts to predict readers’ future interests. One factor that influences reading preferences is writing style; we propose a system that recommends books after learning their authors’ writing style. To our knowledge, this is the first work that transfers the information learned by an author-identification model to a book RS. Another approach that we propose uses over a hundred lexical, syntactic, stylometric, and fiction-based features that might play a role in generating high-quality book recommendations. Previous book RSs include very few stylometric features; hence, our study is the first to include and analyze a wide variety of textual elements for book recommendations. We evaluated both approaches according to a top-k recommendation scenario. They give better accuracy when compared with state-of-the-art content and collaborative filtering methods. We highlight the significant factors that contributed to the accuracy of the recommendations using a forest of randomized regression trees. We also conducted a qualitative analysis by checking if similar books/authors were annotated similarly by experts. Our content-based systems suffer from the new user problem, well-known in the field of RSs, that hinders their ability to make accurate recommendations. Therefore, we propose a Topic Model-Based book recommendation component (TMB) that addresses the issue by using the topics learned from a user’s shared text on social media, to recognize their interests and map them to related books. To our knowledge, there is no literature regarding book RSs that exploits public social networks other than book-cataloging websites. Using topic modeling techniques, extracting user interests can be automatic and dynamic, without the need to search for predefined concepts. Though TMB is designed to complement other systems, we evaluated it against a traditional book CB. We assessed the top k recommendations made by TMB and CB and found that both retrieved a comparable number of books, even though CB relied on users’ rating history, while TMB only required their social profiles.

Background: Companies nowadays cannot differentiate efficiently enough through their products, therefore require strong brand identities. Especially start-up companies without fully developed products rely on the brand identity to communicate efficiently with its potential customers. Purpose: The purpose of this paper is to describe the brand identity of a start-up by applying commonly used models of brand identity and to see the extent of applicability of these models in the case of a start-up. Design/Methodology/Approach: Qualitative research that includes semi-structured interviews with seven participants, where five interviewees work within the company and two interviewees who have a close working connection to it. Findings: The models used are to a small extent applicable in terms of brand personality and brand culture. A brand identity has been described from the same perspectives. Theoretical and Managerial Implication: Adjustment of existing models according to changes in business related settings is argued. Further establishment of the components of brand culture is recommended.

The Diploma thesis deals with beginnings of entrepreneur, who is going to set up his first company. The objective of thesis is checking hypothesis that visionary company is viable, with economic potencial and possibilities for growth. Theoretical part descripes major factors, which are important for health and strength of the enterprise. In these factors belong demands on entrepreneur's personality, knowledge and skills. Further protection of company -- how protect company and its own know-how before rivals. Chosing suitable legal form and choise of compaion. Thesis also saying about usefulness to have a mission. Practical part shows how the business is conceived for real market. Thesis also thinking about growth of the business and how to do it to not be such a little company with one branch. Financial statements show economical potencial, which the business is able to generate to all investors and companions in this concept of the business. The conclusion is dedicated to commentary related to objectives of this Diploma thesis.

La thèse vise à expliquer la dynamique de l’évolution des projets de création d’entreprises de haute technologie à travers les différentes configurations empruntées par le développement technologique et organisationnel. La revue de littérature dans le domaine de l’entrepreneuriat technologique a montré une grande richesse de facteurs explicatifs de l’évolution des projets de création d’entreprises mais aussi des déficiences du rôle attribué à la technologie qui lui confèrent un statut d’artéfact et non celui de processus à part entière. Une approche conceptuelle de la création de l’entreprise de haute technologie fondée sur la théorie de l’acteur réseau permet de dépasser les approches déterministes afin de s’intéresser au développement conjoint de la technologie et de l’organisation. Le cas d’une innovation de hautes technologies de l’invention à son exploitation est analysé en profondeur selon une démarche de recherche-intervention. L’analyse conduit a l’élaboration d’un outil d’aide à la décision (le dispositif d’intervention) et d’un modèle dynamique de la création de l’entreprise de haute technologie différent de ceux présentés dans la littérature entrepreneuriale. Les principaux apports résident dans l’aide à la prise de décisions stratégiques et à celui de la construction de l’organisation. Cette aide, au départ fondée sur les pratiques de l’intervention, s’est transformée peu à peu en un processus d’apprentissage collectif basé sur une modélisation rationnelle de la construction de l’entreprise technologique en favorisant l’émergence de nouveaux savoirs partageables et durables dans le temps. / This research aims to explain the dynamics of the evolution of the projects of high-technology new business start-up through the various configurations derived from by the technological and organizational development. The review of literature in the field of the technological entrepreneurship shows a vast amount of explanatory factors of the evolution of the projects of new business start-up but also the lack of the role granted to the technology which confers it a status of artefact and not that of the full process. A conceptual approach on the high-technology company based on the theory of the network actor allows to overtake the determinist approaches to be interested in the joint development of the technology and the organization. The case of an innovation of high technologies of the invention in its exploitation is analyzed in deeply according to the research-intervention methodology. The analysis leads the elaboration of a decision-making tool (le dispositif d’intervention) and of a dynamic high-technology model of the creation of the company different from those presented in the entrepreneurial literature. The main contribution lives in the assistance to the strategic decision-making and to that of the construction of the organization. This assistance, at first established on the practices of the intervention, was transformed progressively into a process of collective learning built on a rational modeling of the construction of the technological company by favoring the emergence of new shared and long-lasting knowledge in the time.

O problema de roteamento de veículos é um dos problemas de otimização combinatória mais estudados nas últimas décadas. Neste trabalho, é estudada uma variante do problema de roteamento de veículos capacitado em que são considerados custos adicionais em viagens que cruzam fronteiras entre estados. Duas abordagens foram apresentadas para considerar tal característica: adicionar custos fixos às viagens de clientes de estados diferentes e adicionar custos que consideram a carga do veículo ao cruzar a fronteira e, para ambas, foram apresentados modelos matemáticos. Um solver comercial foi utilizado para resolver instâncias conhecidas da literatura e devido à resolução ter atingido o tempo máximo computacional para grande parte dos testes, uma Variable Neighborhood Descent com múltiplos inícios foi desenvolvida para a resolução do problema. Os múltiplos inícios são gerados perturbando a solução inicial gerada para a heurística. Como esperado, tanto para a resolução via modelagem quanto a resolução via heurística, considerar custos de fronteira proporcionais a carga apresentaram soluções de melhor qualidade. Essa nova proposta para abordar custos reais de fronteira abre novas possibilidades para considerar custos de fronteira fixos e proporcionais a carga concomitantemente para melhor representar aplicações reais. / The vehicle routing problem is one of the most studied combinatorial optimization problems in the last decades. In this paper, a variant of vehicle routing problem was studied in which the border costs was added to trips that cross borders. In order to consider such characteristic, two approaches were made: add fixed costs for the trips which clients are from different states and add costs that consider the amount of cargo in the vehicle when it crosses the border. In order to consider such characteristics, models were presented. Instances of literature were solved with a commercial solver and due to high computational time obtained from the exact method, a heuristic with Variable Neighborhood Descent as the local search in a multiple start environment was implemented. The multiple starts were generated making a perturbation in the initial solution obtained for the heuristic. As expected, approaching the problem considering the border cost proportional to the cargo in the vehicle presented better results. This study gives the first results for solving the vehicle routing problem considering real border costs and gives the possibility for solving the problem considering real fixed and proportional costs simultaneously in order to better represent real applications.

As emissões de poluentes atmosféricos decorrentes de veículos automotores representam um grave problema ambiental. O modo de operação do veículo influencia diretamente a quantidade de poluentes emitidos. Quando um veículo inicia sua operação com motor frio, efeito denominado de partida a frio, a quantidade de poluentes emitidos torna-se consideravelmente maior em comparação às condições estabilizadas de temperatura do motor. O efeito da partida a frio é bastante representativo em viagens de curta duração, como é o caso dos deslocamentos urbanos. Este estudo propõe um método para a determinação e distribuição espacial do adicional de emissões de poluentes em partida a frio. Este método foi aplicado em Porto Alegre, utilizando informações de tráfego e da frota local coletados na pesquisa de entrevistas domiciliares, realizada no ano de 2003. Os fatores de emissão utilizados embasaram-se em um estudo realizado com veículos brasileiros. Os resultados da aplicação do método indicaram que a maior parte das partidas a frio ocorre na região central de Porto Alegre e suas adjacências, sendo maior no período matinal. Observou-se também que os maiores responsáveis pelo adicional por partida a frio são os veículos equipados com conversores catalíticos e injeção eletrônica de combustível. Entretanto, os veículos mais antigos, sem conversor catalítico e equipados com carburador, são os maiores responsáveis pela emissão total, adicional por partida a frio e emissão estabilizada de CO e HC nos períodos analisados. Através do método proposto neste estudo foi possível identificar áreas críticas que necessitam de ações de controle de emissões em partida a frio. Os resultados deste estudo podem subsidiar o planejamento e gerenciamento das condições ambientais provocadas pelas emissões veiculares em áreas urbanas. / Atmospheric pollution from vehicle emissions is a serious environmental problem. The vehicle operation mode influences directly in the amount of emitted pollutants. When a vehicle begins its operation with the cold engine, called as cold start effect, the amount of emitted pollutant becomes considerably higher than when in stabilized conditions of engine’s temperature. Cold start effect are very representative in short travels, such as urban trips. This study proposes a method to estimate the amount and spacial distribution of the additional cold start pollutant emissions. This method was applied to Porto Alegre, Brazil, using traffic and local fleet data from a household travel survey of 2003. Emissions factors were based on a study of Brazilian fleet. The results from the method application showed that cold start emissions in Porto Alegre are higher in the morning peak and most of the cold start emissions are concentrated in the town center and its adjacencies. The results also showed that the catalyst fuel injection vehicles are the main responsible for the additional cold start emissions. However, old vehicles, without catalyst and equipped with carburetor, are the main responsible for the total, cold start and running emissions, CO and HC emissions in both analyses periods. Through the proposed method, it was possible to identify critical areas that need control actions of cold start emissions. The results from this study can assist planning and management of the environmental conditions deriving from vehicular emissions in urban areas.

This diploma thesis deals with company performance assessment of MEDIN, a.s. Choosen company is analyzed according to multi-criterial model START PLUS. The final score of the company is done by this model, there are indentified company’s strenghts, areas for improvements and in conclusion of this work, there are suggested measures, which should lead to the company’s higher performance.