Les clochers des petites églises rurales de Bourgogne du Sud sont étudiés pour leur architecture et leur décor mural des XIe-XIIe siècles. Ces deux éléments peuvent être à la fois partenaires et étrangers l'un à l'autre. Cette double situation entraîne des jugements parfois erronés quand on les rapproche dans une même classification. De fait, la première impression donnée par leur décor mural rappelle les caractéristiques du « premier art roman ». Or, construire un mur avec des moellons simplement équarris et un abondant mortier correspond au bon usage des matériaux disponibles et ne classe pas automatiquement les clochers en «premier art roman». À partir d'un corpus de 112 clochers, les choix constructifs et décoratifs de leurs commanditaires et maîtres ­maçons font apparaître l'existence d'un «modèle-type» de clocher auquel un décor mural du «premier art roman» est parfois ajouté. Il y a donc un élément invariant : celui du matériau, simple, peu coûteux et un «phénomène de mode». La répétition de ce modèle joue un rôle unificateur dans un paysage qui apparaît alors comme participant de la chrétienté voulue par la Réforme grégorienne. / This thesis studies South Burgundy small rural churches steeple focusing on their 11th-12th centuries architecture and wall decoration. These two elements can be either connected or unrelated. This opens the door to erroneous judgments when both are approached into a single classification. In fact, the first impression mural a decoration often conveys is reminiscent of the "first Romanesque art". However, building a wall out of simply squared rubble stones and heavy mortar corresponds to the proper use of available materials and does not automatically classify the steeples in "first Romanesque art". The analysis of constructive and decorative choices made by master masons and sponsoring benefactors across the corpus of 112 steeples considered in this research reveals the existence of a typical "standard" bell tower constructive design to which a mural decoration is added. This highlights the existence of a clear constant: the choice of construction materials, simple expensive, low-tech, while also fashionable. The recurrence of this model has played a unifying role in the Christian landscape the resulting from and aspired to by the Gregorian reform.

In the Beneventan region, chant manuscripts and the chants they transmitted served as a documentary ritualization of political and liturgical transition. In the twelfth century, circumstances relegated the Beneventan monastery of San Pietro extra muros, for which the chant manuscript Ben 35 was destined, and its parent monastery San Vincenzo al Volturno, to liminal frontier positions between political and liturgical factions. Newly-composed music such as that found in Ben 35 anchored the alliegances of these monasteries within a fluctuating political and liturgical context at a time when ties to Rome and assertion of local practices were both necessary to assure the continuation of a monastery's influence. Thus Ben 35's unusual features are more easily explained when greater consideration is given to the context of its origin and destination. In particular, the destination of Ben 35 played a very important role in determining the musical styles of the chants that were associated with the feasts of Saint Vincent and Saint Peter, saints whose cults were most closely tied to the location of the manuscript. / text

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The kings of Norway issued coins on a regular basis starting in the mid-11th century, and probably conducted renovatio monetae whenever a new king came to power. As a privilege of bona regalia, the king could use coin production to serve his own interests. Economic factors are usually the main focus of discussions on coinage, but there were also political, religious and cultural dimensions that must have been important both for the production of coins and in the choice of motives, form and style. From the outset, manipulation of the coinage is visible in the debasement of silver content, followed by a reduction in weight to re-establish the silver level.  In the 12th century, the weights continued to drop and single-faced coins and bracteates became the standard; only a few biface coins are known. These small coins and bracteates from the 12th century carry little or no information concerning issuer, date or place of production. This lack of information has resulted in a gap in our knowledge about the role of these coins in medieval society in Norway. This role was dependent both on the intentions of the producer and on how the coins were perceived by the people, and their will to use them in certain ways. What were the reasons behind issuing the smallest coins ever produced in coin history, and what impact did this dramatic reduction in weight have on the understanding and use of the coin? To advance the discussion it has been vital to establish new knowledge about chronology, coin-issuing authority and mints. These areas have been addressed through two analyses using numismatic and archaeological methods. The results of the initial analyses are combined with an investigation of the size of the coin production and a study of archaeological contexts, in order to reveal how, where and when the bracteates were used.  The theoretical approach to understanding the role of coins is inspired by theories in anthropology and sociology about the many ways in which money can be incorporated in a society, emphasising the complex social component of coins in contrast to the traditional economic emphasis on their neutral qualities as a means of exchange. Central to this are the concepts behind formalism and substantivist and post-substantivist theory. The study concludes with a discussion that explores what can be said about economy and economic systems based on the 12th-century Norwegian coins.

Increased demands on fuel-efficient propulsion motivate the use of complex hybrid hydromechanical transmissions in heavy construction machines. These transmissions offer attractive fuel savings but come with an increased level of complexity and dependency on computer-based control. This trend has increased the use of computer-based simulations as a cost-effective alternative to hardware prototyping when developing and testing control strategies. Hardware-In-the-Loop (HWIL) simulations that combine physical and virtual model representations of a system may be considered an attractive compromise that combine the benefits of these two concepts. This paper explores how HWIL simulations may be used to evaluate powertrain control strategies for hybrid hydromechanical transmissions. Factors such as hardware/software partitioning and causality are discussed and applied to a test rig used for HWIL simulations of an example transmission. The results show the benefit of using HWIL simulations in favour of pure offline simulations and prototyping and stress the importance of accurate control with high bandwidth in the HWIL interface.

Due to the robustness and flexibility of hydraulic components, hydraulic control systems are used in a wide range of applications under various environmental conditions. However, the coverage of this broad field of applications often comes with a loss of performance. Especially when conditions and working points change often, hydraulic control systems cannot work at their optimum. Flexible electronic controllers in combination with techniques from the field of machine learning have the potential to overcome these issues. By applying a reinforcement learning algorithm, this paper examines whether learned controllers can compete with an expert-tuned solution. Thereby, the method is thoroughly validated by using simulations and experiments as well.

Climate change and economic opportunities motivate investigating electric distributed power for working hydraulics in non-road mobile machinery (NRMM) instead of conventional hydraulics. This recent method allows significant energy savings in hydraulic systems, which was demonstrated previously by many independent studies. In this study, zonal hydraulics (as electrically distributed) are realized with direct driven hydraulics drive (DDH) units. Unlike conventional hydraulic drives the DDH units are disconnected from the engine (main prime mover) and distributed throughout the system. In a DDH unit, a single fixed displacement pump/motor with a speed-controlled electric servomotor directly controls the flow. The aim of this paper is to determine functionality of this new two-cylinder DDH-system in a lifting work cycle (or a swerve motion of the work machine). For this purpose, a model was created to investigate performance of the new test rig Dolores. The results of the simulation model will be utilized in future research to discover and compare other alternatives for working hydraulics architectures.

Selective laser melting (SLM), is a type of additive manufacturing, which selectively melts a pre-spread layer of metal powders and produce a part by a layer-on-layer manner. SLM has demonstrated a great potential to reduce size and weight in hydraulic manifolds. However, a theoretical base is lacking since friction loss is unclear in a SLMed fluid passage. In this study, various fluid passages without supports, from diameters from 4 mm to 16 mm, were produced horizontally using SLM. The profile was measured using a 3D scanner and surface roughness was measured using a confocal laser scanning microscope. Friction factor was studied using simulation, experiments, and classical theory. The hydraulic diameter of the SLMed passages is smaller than the design diameter. Surface roughness is extremely high on the top part of the inner wall while the rest part is around 10 μm. Such trends are irrelevant of passage diameters. Friction factors in SLMed passage is much larger than those predicted using Moody theory, particularly in laminar flow. The transition from laminar flow to turbulent flow appears at a smaller Reynolds number with increased passage diameter. The influence of the profile overweighs that of the surface roughness on friction factor.

Manifolds usually consist of metallic, rectangular base bodies into which lines are inserted by means of drilling, thus logically linking the built-on or built-in valves according to the hydraulic circuit diagram. Using additive manufacturing methods, additional degrees of freedom can be used in the design of manifolds, resulting in further benefit in hydraulic drives and their controls. The challenge is not only to understand and apply additive manufacturing technology, but also to align the entire value chain with it.

Selective laser melting (SLM), one type of metal additive manufacturing (AM) technology, uses a highintensity laser to selectively melt pre-spread metal powders by a layer-on-layer manner. The technology does not only provide a new way of manufacturing but also innovates product design methodology. In this study, a hydraulic block manifold is designed and manufactured using SLM. In this paper, we present an AM-driven design approach of hydraulic manifolds based on a case study. The target is not only to reduce weight but also to enhance fluid flow by optimizing fluid path to reduce pressure drop. The novelty of the research includes developing a design approach of hydraulic manifolds using SLM with a particular focus on fluid flow. Compared to the traditional hydraulic manifold, the weight of the new SLMed hydraulic manifold was reduced by more than 80%, size by half. Pressure loss of the main functional oil circuit was reduced by 31%, illustrating that the new hydraulic manifold design simultaneously achieves lightweight and high performance. This study contributes to providing theoretical guidance to the design of additively manufactured hydraulic components with high performance.