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Le premier chapitre dresse un état des lieux de la littérature relative l’activité partielle et introduit les trois questions de recherche développées dans cette thèse, à savoir la diffusion locale du recours à l’activité partielle en France au cours de la période2003-2014, l’effet de l’activité partielle sur l’emploi en France au cours de la Grande Récession 2008-2009 et l’effet des réformes de 2012-2013 de l’activité partielle et du recours récurrent à ce dispositif sur la production agrégée en France. Dans le second chapitre, nous mettons en lumière la diffusion locale du recours à l’activité partielle en France sur la période 2003-2014. Pour ce faire, nous évaluons l’effet de la proximité géographique d’établissements ayant déjà recouru à l’activité partielle par le passé sur le recours à l’activité partielle d’un établissement pour la première fois sur la période 2003-2014. En effet, nous soutenons que l’information dont disposent les établissements au sujet du dispositif et de sa procédure, notamment par le biais des établissements voisins, constitue un déterminant essentiel du recours à l’activité partielle. Nos faits stylisés révèlent que le recours à l’activité partielle est concentré au niveau géographique et que cette concentration revêt un caractère dynamique. Nous utilisons comme mesure de la diffusion locale de l’information relative à l’activité partielle un indice de concentration spatiale (fondé sur les distances inter-établissements) et prenons en compte les autres caractéristiques des établissements afin de distinguer l’effet de cette transmission d’information d’autres déterminants du recours au dispositif et ainsi mettre en évidence son impact sur le recours à l’activité partielle d’un établissement pour la première fois. Nos résultats montrent l’importance de la diffusion locale de l’information relative à l’activité partielle, que cette diffusion décroît dans les premiers kilomètres et que cette information transite à la fois au sein d’un secteur donné et entre secteurs.Dans le troisième chapitre, nous évaluons l’effet de l’activité partielle sur l’emploi en France an cours de la Grande Récession 2008-2009. Nous développons un modèle théorique suivant lequel l’effet de l’activité partielle varie selon la situation financière des entreprises. Pour des entreprises faisant face à une forte diminution de leur chiffre d’affaires, l’activité partielle permet de sauvegarder l’emploi, tandis que pour des entreprises dont la réduction du chiffre d’affaires est modérée, l’activité partielle entraîne une diminution des heures travaillées sans pour autant préserver l’emploi. Ces effets théoriques contrastés sont confirmés par nos résultats empiriques, qui mettent en évidence que l’activité partielle a réduit le nombre d’emplois détruits uniquement en cas de réduction importante du chiffre d’affaires mais n’a eu aucun effet significatif sur l’emploi pour les autres entreprises, qui représentent environ 40 % des utilisateurs de l’activité partielle. Ces effets d’aubaine, bien que considérables au regard du dispositif d’activité partielle, demeurent négligeables par rapport à d’autres mesures telles que les subventions salariales et à l’embauche. De plus, l’activité partielle n’a pas contribué à maintenir en vie des entreprises en difficultés structurelles. L’activité partielle a donc constitué un dispositif efficace à la sauvegarde de l’emploi en France au cours de la Grande Récession 2008-2009. / The literature review on short-time work presented in the first chapter underlines the motivation behind the three research questions developed in this dissertation, namely the local diffusion of short-time work, the impact of short-time work on employment during the great 2008-2009 recession in France, and the impact of the 2012-2013 reforms of short-time work and its recurrent use on aggregate production in France.In the second chapter, we assess the local diffusion of short-time work. We argue that the geographical proximity of establishments having already used short-time work in the past is a major information channel regarding this scheme. Relying on distance-based methods, our stylized facts highlight the spatial and dynamic concentration of short-time work use in France between 2002 and 2014. Our econometric analysis reveals that the local information about short-timework constitutes a determinant of its use, that it attenuates rapidly in the first kilometers and that this information is both transmitted within and between sectors. We interpret this significant spatial concentration of short-time use,after controlling for the determinants of short-time work at the establishment level, as an evidence of information spillovers.In the third chapter, we estimate the impact of short-time work on employment during the great 2008-2009 recession in France.The model we develop shows that the effect of short-time work varies depending on the financial situation of the firms. For firms facing a strong decline in their revenue, short-time work saves employment, whereas for firms facing a moderate decline in their revenue, short-time work entails a drop in hours worked without reducing job losses. These heterogeneous effects are confirmed by our empirical results, which demonstrate that short-time work has reduced the number of job losses for firms which faced dramatic drop in their revenue, but has had no significant impact on employment for the other firms. These windfall effects, although sizeable within the short-time workscheme, are negligible compared to other policies such as wage and hiring subsidies. Additionally, short-time work didn’t help structurally weak firms to survive. Hence, short-time work has been an efficient policy to save jobs during the great 2008-2009recession in France.In the fourth chapter, we evaluate the impact of the 2012-2013reforms of short-time work and its recurrent use on aggregate production in France. The 2012-2013 reforms have increased the generosity of short-time work and hence have suppressed the remaining cost supported by the firm. Our stylized facts highlight that short-time work is essentially used by a small number of firms in a recurrent way and this repeated use has aggravated following these reforms. The theoretical model we develop shows that such reforms of short-time work have entailed cross subsidies towards recurrent short-time work users and have reduced aggregate production compared to the social optimum.According to our model, the efficient policy should provide unemployment insurance benefits funded by experience rated employers’ contributions instead of short-time work benefits.

Fenômenos que ocorrem a tempos curtos em sistemas quânticos abertos são caracterizados por possuírem um tempo característico de uma ordem muito menor que o tempo de relaxação do sistema. Como exemplos podemos citar o efeito de decoerência, que em resumo tenta explicar como a natureza quântica de um sistema é perdida ao longo da interação com o ambiente e o fenômeno de superradiância, onde estuda-se como alguns sistemas emitem um pulso energético muito rápido gerando um pico de intensidade fino localizado muito antes da relaxação do sistema. O objetivo desse trabalho é não só estudar esses fenômenos mas como apresentar uma técnica alternativa para a quantificação das medidas associadas e de seus tempos característicos. A técnica apresentada se baseia em fazer uma expansão perturbativa no tempo para o operador densidade a partir de uma equação mestra quântica e com seu uso calcular grandezas físicas relevantes a fenômenos que ocorrem a tempos curtos. A simplicidade da técnica e seu uso abrangente são os principais fatores motivadores deste trabalho. / Short-time phenomena in open quantum systems are characterized by having a characteristic time of a much lower order than the relaxation time of the system. As examples we can mention the effect of decoherence, which in summary tries to explain how the quantum nature of a system is lost along the interaction with the environment and the superradiance phenomenon, where is studied how some systems emit a very fast energy pulse generating a peak of fine intensity located long before the relaxation of the system. The aim of this work is not only study these phenomena but to present an alternative technique for quantifying the associated measures and their characteristic times. The presented technique is based on making a perturbative expansion in time for the density operator from a quantum master equation and use it to calculate physical quantities relevant to phenomena occurring at short times. The simplicity of the technique and its widespread use are the main motivating factors of this work.

O planejamento de lavra de curto prazo é normalmente executado utilizando-se número reduzido de informações de sondagem. Para aprimorar o gerenciamento de riscos geológicos no planejamento de lavra de curto prazo é necessário utilizar um universo maior de informações. Como é normalmente inviável obter novas informações de sondagem, esta dissertação propõe uma metodologia de utilização de amostras de pó de perfuratriz (a partir de furos de desmonte) como uma fonte de informação secundária e assim aprimorar a qualidade das estimativas. Neste sentido, foi adotada uma técnica de co-estimativa da variável P2O5 das sondagens (variável primária) em conjunto com a variável P2O5 do desmonte (variável secundária) baseado no modelo Marcoviano MM2, pelo qual é possível combinar as duas informações (sondagem e desmonte) na estimativa de um modelo de blocos. Este processo permitiu a modelagem de atributos geológicos de forma mais detalhada o que contribuiu para uma melhor interface entre o planejamento de curto prazo e a operação da mina. A metodologia proposta também possibilitou acessar uma população maior de informações geológicas o que contribui para a criação de planos operacionais mais aderentes aos objetivos de produção mensal ou semanal, e, ao mesmo tempo, respeitando o sequenciamento importado do planejamento de longo e médio prazo. Como resultado, foi demonstrado que é possível criar programas operacionais mais precisos com base em estimativas de áreas próximas à lavra mesmo quando apenas um pequeno número de informações primárias (sondagens) esteja disponível. / Short-term mine planning is normally carried out over a limited number of drillhole information. In order to improve the management of geological risks in mine planning, a larger population of samples is required. However, it is normally very difficult to obtain additional drillhole samples once mining takes place. This research addresses that issue by proposing a methodology for the incorporation of additional information from blastholes (secondary information) to the original drillhole samples (primary information). A co-estimation technique for using P2O5 samples from the drillholes (primary variable) in conjunction with P2O5 from blastholes (secondary variable) based on the Markovian estimation model (MM2), through which is possible to combine both sources of information for a better estimation of mineable blocks. This process has allowed more detailed modeling of geological attributes and a better interface between short-term mine planning and mine operations. The proposed methodology also allowed the access to a larger sample population which meant more accurate mine plans for the daily and weekly mine schedules. As a result, it has been demonstrated that it is possible to crate operational plans that are more precise through the use of models that are properly estimated even in those areas where only a small amount of primary information (drillhole samples) is available.

As genes with similar expression pattern are very likely having the same biological function, cluster analysis becomes an important tool to understand and predict gene functions from gene expression profi les. In many situations, each gene expression profi le only contains a few data points. Directly applying traditional clustering algorithms to such short gene expression profi les does not yield satisfactory results. Developing clustering algorithms for short gene expression profi les is necessary. In this thesis, two novel methods are developed for clustering short gene expression pro files. The fi rst method, called the network-based clustering method, deals with the defect of short gene expression profi les by generating a gene co-expression network using conditional mutual information (CMI), which measures the non-linear relationship between two genes, as well as considering indirect gene relationships in the presence of other genes. The network-based clustering method consists of two steps. A gene co-expression network is firstly constructed from short gene expression profi les using a path consistency algorithm (PCA) based on the CMI between genes. Then, a gene functional module is identi ed in terms of cluster cohesiveness. The network-based clustering method is evaluated on 10 large scale Arabidopsis thaliana short time-course gene expression profi le datasets in terms of gene ontology (GO) enrichment analysis, and compared with an existing method called Clustering with Over-lapping Neighbourhood Expansion (ClusterONE). Gene functional modules identi ed by the network-based clustering method for 10 datasets returns target GO p-values as low as 10-24, whereas the original ClusterONE yields insigni cant results. In order to more speci cally cluster gene expression profi les, a second clustering method, namely the protein-protein interaction (PPI) integrated clustering method, is developed. It is designed for clustering short gene expression profi les by integrating gene expression profi le patterns and curated PPI data. The method consists of the three following steps: (1) generate a number of prede ned profi le patterns according to the number of data points in the profi les and assign each gene to the prede fined profi le to which its expression profi le is the most similar; (2) integrate curated PPI data to refi ne the initial clustering result from (1); (3) combine the similar clusters from (2) to gradually reduce cluster numbers by a hierarchical clustering method. The PPI-integrated clustering method is evaluated on 10 large scale A. thaliana datasets using GO enrichment analysis, and by comparison with an existing method called Short Time-series Expression Miner (STEM). Target gene functional clusters identi ed by the PPI-integrated clustering method for 10 datasets returns GO p-values as low as 10-62, whereas STEM returns GO p-values as low as 10-38. In addition to the method development, obtained clusters by two proposed methods are further analyzed to identify cross-talk genes under fi ve stress conditions in root and shoot tissues. A list of potential abiotic stress tolerant genes are found.

[Truncated abstract] Centrifugal pumps are designed to operate at a capacity that maximizes the efficiency of the pump. Operation below this design capacity results in reduction of pump efficiency as the geometric configuration of the impeller and casing no longer provide an ideal flow pattern. Consequently there are changes in the flow field within the pump, including flow separation and regions of localized, non-uniform, unsteady flow. This flow interacts with rotating and stationary components inside the pump creating additional disturbance and hydraulic excitation. It is anticipated that the local hydrodynamic and global hydroacoustic excitation due to partial-flow operation will affect the structural vibration measured on the pump. In this study, the effects of partial-flow operation on the vibration signal at the pump bearing housing are measured on a number of industrial double-suction pump units. These are a particular class of centrifugal pump commonly used in high volume applications such as water distribution. The aims are to understand how the vibration signals change at the different operating conditions and to determine which parameters are best suited to monitoring the observed changes. Comparison is made between the response, under similar operating conditions, of pumps both within sets of identical size and design, across sets of similar design and different sizes, and between different designs. The pumps are all in-service industrial units. In double-suction pumps the impeller motion in the axial direction (along the line of the shaft) is not constrained. Due to symmetry in impeller design, axial stability is maintained by equal and opposite hydraulic forces on the two opposing sides of the impeller. The potential for loss of axial hydraulic balance during partial-flow operation is examined from a theoretical perspective, based on a literature review, and by measurement of the axial displacement of the shaft. Structural vibration is measured using accelerometers mounted at the non-drive end bearing housing in the horizontal and axial orientations. Changes in signal contribution and characteristics are examined using a variety of qualitative and quantitative techniques. Test signals are used to assess the limitations of the techniques and the effect of parameter selection on the interpretation of the signals.

Persteril (Acidum peraceticum) is a trademark used for a disinfectant with peracetic acid as an active ingredient. It is highly effective biocide and has extensive application possibilities with regard to environmental friendliness, it also has the widest range of disinfection efficacy. The practical part took place in the Genetic centre hatchery at the FROV JU in Vodnany. Persteril? was used for Short-time bath followed by rearing roe in the recirculating system and for short-time bath followed by rearing roe in the flow system. Both versions are breeding quite well; Persteril? detects fungal infection of fish roe in comparison with other liquids, as well as it leaves smaller or no residue in the water or out of the water until the evaporation (according to the concentration).

O planejamento de lavra de curto prazo é normalmente executado utilizando-se número reduzido de informações de sondagem. Para aprimorar o gerenciamento de riscos geológicos no planejamento de lavra de curto prazo é necessário utilizar um universo maior de informações. Como é normalmente inviável obter novas informações de sondagem, esta dissertação propõe uma metodologia de utilização de amostras de pó de perfuratriz (a partir de furos de desmonte) como uma fonte de informação secundária e assim aprimorar a qualidade das estimativas. Neste sentido, foi adotada uma técnica de co-estimativa da variável P2O5 das sondagens (variável primária) em conjunto com a variável P2O5 do desmonte (variável secundária) baseado no modelo Marcoviano MM2, pelo qual é possível combinar as duas informações (sondagem e desmonte) na estimativa de um modelo de blocos. Este processo permitiu a modelagem de atributos geológicos de forma mais detalhada o que contribuiu para uma melhor interface entre o planejamento de curto prazo e a operação da mina. A metodologia proposta também possibilitou acessar uma população maior de informações geológicas o que contribui para a criação de planos operacionais mais aderentes aos objetivos de produção mensal ou semanal, e, ao mesmo tempo, respeitando o sequenciamento importado do planejamento de longo e médio prazo. Como resultado, foi demonstrado que é possível criar programas operacionais mais precisos com base em estimativas de áreas próximas à lavra mesmo quando apenas um pequeno número de informações primárias (sondagens) esteja disponível. / Short-term mine planning is normally carried out over a limited number of drillhole information. In order to improve the management of geological risks in mine planning, a larger population of samples is required. However, it is normally very difficult to obtain additional drillhole samples once mining takes place. This research addresses that issue by proposing a methodology for the incorporation of additional information from blastholes (secondary information) to the original drillhole samples (primary information). A co-estimation technique for using P2O5 samples from the drillholes (primary variable) in conjunction with P2O5 from blastholes (secondary variable) based on the Markovian estimation model (MM2), through which is possible to combine both sources of information for a better estimation of mineable blocks. This process has allowed more detailed modeling of geological attributes and a better interface between short-term mine planning and mine operations. The proposed methodology also allowed the access to a larger sample population which meant more accurate mine plans for the daily and weekly mine schedules. As a result, it has been demonstrated that it is possible to crate operational plans that are more precise through the use of models that are properly estimated even in those areas where only a small amount of primary information (drillhole samples) is available.

Fenômenos que ocorrem a tempos curtos em sistemas quânticos abertos são caracterizados por possuírem um tempo característico de uma ordem muito menor que o tempo de relaxação do sistema. Como exemplos podemos citar o efeito de decoerência, que em resumo tenta explicar como a natureza quântica de um sistema é perdida ao longo da interação com o ambiente e o fenômeno de superradiância, onde estuda-se como alguns sistemas emitem um pulso energético muito rápido gerando um pico de intensidade fino localizado muito antes da relaxação do sistema. O objetivo desse trabalho é não só estudar esses fenômenos mas como apresentar uma técnica alternativa para a quantificação das medidas associadas e de seus tempos característicos. A técnica apresentada se baseia em fazer uma expansão perturbativa no tempo para o operador densidade a partir de uma equação mestra quântica e com seu uso calcular grandezas físicas relevantes a fenômenos que ocorrem a tempos curtos. A simplicidade da técnica e seu uso abrangente são os principais fatores motivadores deste trabalho. / Short-time phenomena in open quantum systems are characterized by having a characteristic time of a much lower order than the relaxation time of the system. As examples we can mention the effect of decoherence, which in summary tries to explain how the quantum nature of a system is lost along the interaction with the environment and the superradiance phenomenon, where is studied how some systems emit a very fast energy pulse generating a peak of fine intensity located long before the relaxation of the system. The aim of this work is not only study these phenomena but to present an alternative technique for quantifying the associated measures and their characteristic times. The presented technique is based on making a perturbative expansion in time for the density operator from a quantum master equation and use it to calculate physical quantities relevant to phenomena occurring at short times. The simplicity of the technique and its widespread use are the main motivating factors of this work.