Dans les embarras de Rouen. Le transport de l’armée britannique à l’Ouest en 1914-1918

Les accords franco-britanniques nés de l’Entente cordiale de l’année 1904 laissent espérer la participation d’un Corps expéditionnaire britannique aux côtés de l’armée française dans l’hypothèse où l’Empire allemand se livrerait à une agression armée contre la France ou contre le royaume de Belgique. En pareil cas l’état-major français a étudié un plan de transport du contingent britannique débarqué initialement dans les ports du Havre, de Rouen et de Boulogne et acheminé vers le front de bataille par les réseaux ferroviaires français. Entre août 1914 et novembre 1918, l’armée française comme l’armée britannique s’adaptent à la dimension industrielle de la guerre. Elle implique la mise en œuvre d’une énorme logistique et son transport, particulièrement complexes dans la région de Rouen et lors de l’engagement britannique massif sur la Somme en 1916. Il s’ensuit sur les réseaux ferroviaires très surchargés du Nord et de l’État des difficultés d’exploitation marqués par une crise des matériels roulants et par les travaux massifs conduits par les compagnies de sapeurs des chemins de fer et les sections de chemins de fer de campagne. Le trafic dépasse parfois les limites de la saturation. Le service automobile, un expédient initialement, conquiert peu à peu une place prépondérante stratégiquement, notamment aux moments décisifs des batailles de 1918. Sur le plan des relations humaines, les commissaires militaires et techniques sont solidaires et les rapports des régulateurs militaires français avec leurs homologues britanniques sont cordiaux mais les relations entre les dirigeants des deux réseaux du Nord et de l’État sont difficiles. La priorité accordée aux transports de guerre ne peut occulter le climat de concurrence commerciale qui existait avant-guerre entre les deux compagnies notamment en Haute-Normandie. La suggestion avancée par les militaires d’un réseau unifié conduit le gouvernement français à reprendre la main à la fin de 1917 par la création d’un ministère des Transports, puis à confier l’autorité sur les réseaux ferroviaires au ministère des Travaux publics, agissant par délégation du ministre de la Guerre, gage d’une meilleure efficacité dans la gestion de ces réseaux confrontés à de graves difficultés financières et techniques par suite des épreuves d’un conflit interminable.The Franco-British agreements resulting of the Entente Cordiale of 1904 suggested a British Expeditionary Corps involvement alongside the French Army in case of an armed aggression of France or of Belgian Kingdom by the German Empire. For such a case, the French Staff had studied a transportation plan of the British contingent originally landed in the ports of Le Havre, Rouen and Boulogne and routed to the front of battle by the French rail networks. From August 1914 to November 1918, the French army and the British army coped with the industrial dimension of the war. It brought to implement enormous capabilities in the field of logistics and transport, particularly complex in the region of Rouen and during the massive British engagement on the Somme in 1916. On the overloaded “Nord” and “État” networks, this resulted in operating problems related to rolling stock shortage and to massive works carried out by the sappers of the Engineers Railway companies and Field Railway sections. Traffic sometimes exceeded the limits of saturation. Mechanical Transport, initially an expedient, conquered a prominent strategic role, notably during the decisive moments of the battles of 1918. On the human level, the military and technical commissioners remained supportive of each other’s while the relationships of French military regulators with their British counterparts were cordial. On the contrary, the leaders of the “Nord” and “État” networks had difficulties to work together. The priority given to war transportation could not overshadow the climate of commercial competition that existed before the war between the two companies, especially in Haute-Normandie. The suggestion made by the military of a unified network led the French Government to take over at the end of 1917, firstly by the creation of a Ministry of transportation, then entrusting the authority on the rail networks to the Ministry of public works, by delegation of the Minister of war. It was the guarantee of greater efficiency in the management of these networks, which, before long, would face serious financial and technical difficulties caused by an endless conflict

Du plan stratégique au plan de transport. Deux succès de logistique pour deux stratégies en échec (août 1914-septembre 1939)

En 1914, il est possible de définir le plan de transport que doit mettre en œuvre l’état-major général français comme un espace vectoriel de dimension 3 : moyens, espace, temps. Les moyens sont constitués surtout par le matériel humain appuyé pour l’essentiel par le canon de 75. L’espace assigné aux opérations militaires relève de considérations diplomatiques : une action offensive doit-elle être dirigée vers la frontière de l’Est, en Alsace-Lorraine, ou vers le Nord ? La décision influence les délais d’acheminement des troupes et la capacité des réseaux ferrés à les respecter. Le troisième facteur, le temps, est régulé par l’aptitude du chemin de fer à concentrer sur les frontières plus de 800 000 hommes dans un délai au plus égal à 14 jours sitôt la mobilisation décrétée. Sachant que la vitesse moyenne du déplacement des trains d’un corps d’armée est de 30 kilomètres à l’heure, le réseau ferroviaire français est-il en mesure de répondre à cette problématique ? Il faut pour cela innover dans les domaines du matériel, des dépôts, des installations fixes, de l’exploitation. Il faut surtout améliorer les infrastructures, créer les quais d’embarquement, élargir le gabarit des tunnels, concevoir des itinéraires de détournement. Grâce à ces mesures judicieuses, la concentration s’avère un succès. Dès le 15 août 1914, l’objectif est atteint. En 1939, le chemin de fer s’inspire des mêmes principes qu’en 1914 et bénéficie de l’expérience acquise et des effets de la modernisation ; il assume son rôle plus complexe d’une façon très satisfaisante comme le reconnaissent les autorités civiles et militaires. Malheureusement, en dépit d’un succès logistique indéniable, la jeune SNCF est la cible d’une nouvelle dimension de la guerre, la suprématie aérienne.In 1914, one can define the transportation plan that the General Staff is to implement as a vectorial space in three dimensions: means, space, time. Means are mostly human material, essentially supported by the 75 mm cannon. Space devoted to military operations depends on diplomatic considerations: where should an offensive action be directed, toward the eastern border, in Alsace-Lorraine, or toward the North? The decision has an impact on the time limit necessary for the troop’s transportation and the capacity of railway networks to comply with it. The third factor, time, is regulated by the ability of railway to concentrate at the border more than 800.000 men in a deadline at most equal to 14 days as soon as the mobilisation proclaimed. Given that the average speed of the trains of an Army Corp is 30 km/h, is the French railway network up to the problem? For that one has to innovate in the domain of rolling stock, depots, fixe facilities, exploitation. Overall, infrastructures had to be improved, departure platforms created, tunnel template enlarged, alternative routes set up. Thanks to these well-advised decisions, the concentration is a success. From August the 15th, the goal is achieved. In 1939, the railway takes inspiration of the same principles as in 1914, takes advantage of the acquired experience and of modernisation effects. Its more complex part is quite well carried out as acknowledged by civilian and military authorities. Unfortunately, in spite of an undisputable success, the young SNCF falls prey to a new dimension of the war, air supremacy

Sexuality in the context of physical rehabilitation as perceived by occupational therapists

Introduction: One of the challenges for rehabilitation professionals is to discuss sexuality with their clients. The main objective of this study was to explore occupational therapists’ perceptions of the factors that influence their practice regarding the domain of sexuality, as well as the prioritization of these factors and the exploration of their needs. Methodology: Descriptive qualitative study who took place in Montreal, Canada. Two focus groups were realized with seven occupational therapists working in outpatient setting in two different rehabilitation centers for physical disabilities. The focus group guide was based on the Theoretical Domains Framework (TDF). The verbatims were coded using QDA-Miner software and analyzed according to the principles of the Framework approach. Results: The majority of participants were women (n = 6/7). Three main themes to answer the main objective emerged: (1) Occupational therapist’s intrinsic factors such as professional identity and knowledge/skills; (2) Contextual and process factors of practice, including assessment/analysis and human resources; (3) Client factors such as identity factors and capabilities. Several influencing factors that have a significant impact on practice have been prioritized, for instance, the perception of the skill level of occupational therapists, interdisciplinary collaboration, culture/language and openness of the client to the subject of sexuality. The needs related to the acquisition of knowledge/know-how, human resources and continuing education were raised by clinicians. Conclusion: There is a need in developing training tools to support clinical practice and to overcome the many barriers encountered by occupational therapists regarding the domain of sexuality

Employer Learning, Biased Beliefs, and Labor Market Discrimination

My dissertation proposes and tests a new theory of labor market discrimination based on employers developing persistent negatively biased beliefs about the productivity of worker groups through their hiring experiences with these groups. My first chapter presents a statistical discrimination model in which employers are initially uncertain about the productivity of groups and endogenously learn about it through their hiring experiences. An employer's hiring history determines their beliefs about group productivity, but also shapes their subsequent incentives to hire from the group and learn more about their productivity. Positive experiences create positive biases which correct themselves by leading to more hiring and learning. Negative experiences create negative biases which decrease hiring and therefore learning, leading to the persistence of negative biases. Differential hiring and learning across employers thus generates a negatively-skewed belief distribution about worker group productivity. Endogenous employer learning disproportionately affects workers from minority or underrepresented groups if there is less initial information available about their productivity in the labor market, making employers more reliant on their own experiences to assess these groups. I show that discrimination in the form of a wage below these groups' expected productivity can arise and persist from this initial information asymmetry even with market competition and without true productivity differences between groups, prior bias, or prejudice. The model generates analogous predictions to taste-based discrimination, in a statistical framework with beliefs replacing preferences, providing a new way to understand prejudice as the result of "incorrect" statistical discrimination. The model helps explain the persistence and pervasiveness of discrimination, also generating new implications for policies like affirmative action which can induce employers to hire from specific groups and learn about their productivity. My second chapter tests how hiring experiences of employers with worker groups impact hiring and beliefs about group productivity. I design an experiment where employers hire a worker from one of two groups each period, with one group framed as a minority about whose productivity employers are initially given less information. Employers are incentivized to hire productive workers, observe their hire's productivity after they perform a real-effort task, and then report their beliefs about group productivity. The results show that negative experiences with the minority group, captured through the hiring of low productivity workers, lead to negatively-biased beliefs about the group's productivity by decreasing subsequent hiring and learning. In contrast, positive biases which arise from positive experiences are mitigated through increased hiring, leading to a negatively-skewed belief distribution across employers. My third chapter joint with Alan Benson at the University of Minnesota uses employment records of a large retail firm to study how hiring experiences of managers with worker groups influence their hiring. We study the hiring of black and white workers, relating current hiring decisions of a manager to measures of their previous experiences with these groups. We find that negative experiences with previous hires of a group, measured by a higher fraction quickly being fired or quitting, decrease subsequent hiring of the group. More positive experiences, measured by a higher fraction of previous hires achieving long tenure, increase subsequent hiring of the group. These impacts are substantively larger for black workers, and early negative experiences with them lead to particularly persistent decreases in relative hiring of the group.PHDEconomicsUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/170020/1/lepagelp_1.pd

Performance of multiple cabin optimization methods in airline revenue management

Thesis (S.M. in Operations Research)--Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2013.Cataloged from PDF version of thesis.Includes bibliographical references (pages 85-86).Although many airlines offer seats in multiple cabins (economy vs. premium classes) with different service quality, previous work on airline revenue management has focused on treating the cabins separately. In this thesis, we develop several single-leg multiple cabin revenue management optimization algorithms. We extend two different single-leg separate cabin dynamic programming algorithms to the multiple cabin case, and also present three Expected Marginal Seat Revenue (EMSR) based heuristics and a dynamic programming decomposition heuristic. We then evaluate the revenue and passenger mix performance of the different algorithms using the Passenger Origin-Destination Simulator (PODS) which simulates competitive markets with passenger choice of fare options and cabin. We first test the methods in a simple single market network and then in a more realistic complex network. We find that multiple cabin methods do not lead to a systematic revenue increase. Indeed, simulation results show that the performance of the different methods ranges from a decrease of 9.6% to an increase of 2.4% in revenues. The discrepancies in performance between the different methods are explained by the trade-off between revenue gains from additional economy bookings and the losses from displaced premium passengers. Further, we observe that successful methods lead to a revenue increase by accepting additional bookings in top economy classes rather than in low economy classes. Finally, the poor performance of the dynamic programming methods tested is due to a misalignment between the underlying assumptions of the algorithms and the reality of the booking and passenger choice process.by Pierre-Olivier Lepage.S.M.in Operations Researc

Effets d'une expérimentation d'enseignement interdisciplinaire sur la motivation des étudiants et des professeurs : rapport de recherche ACPQ /

La présente recherche a été subventionnée par le ministère de l'Éducation, du Loisir et des Sports dans le cadre du programme de recherche et d'expérimentation du réseau privé de l'enseignement collégial (PREP) et par l'Association des collèges privés du Québec

Effets d'une expérimentation d'enseignement interdisciplinaire sur la motivation des étudiants et des professeurs

La présente recherche a été subventionnée par le ministère de l'Éducation, du Loisir et des Sports dans le cadre du programme de recherche et d'expérimentation du réseau privé de l'enseignement collégial (PREP) et par l'Association des collèges privés du Québec

A Monte Carlo study of old, new and tadpole improved actions

Scaling of mass ratios in intermediate volumes, obtained with improved SU(2) lattice actions is tested against analytic results for the Wilson and continuum action. A new improved action is introduced by adding a 2X2 plaquette to the Symanzik action. Completing a square leads to a covariant propagator that simplifies perturbative calculations. Data is presented on lattices of size 4**3X128, with lattice spacings of approximately 0.02 and 0.12 fermi. For the latter case no further improvement as compared to the tree-level action was observed when including the Lepage-Mackenzie tadpole correction to the one-loop improved Luscher-Weisz Symanzik action.Comment: 12 pages, including 2 tables and 2 figures, late

Improved action and Hamiltonian in finite volumes

We introduce a new Symanzik improved action by adding a 2x2 plaquette in such a way that the Feynman rules in the covariant gauge simplify. We call this the square Symanzik action. Some comparisons with the continuum and the standard Wilson action are made in intermediate volumes, where mass ratios are accurately known and the precise amount of improvement can be determined. Ratios of the Lambda parameters will be presented, as well as partial results for the one-loop improvement coefficients. We discuss some of the intricacies that arise because of violations of unitarity at the scale of the cutoff. In particular we show how a field redefinition in the zero-momentum effective action allows one to remove scaling violations linear in the lattice spacing.Comment: 6 pages, 2 figures. Talk presented at LATTICE96(improvement