31 research outputs found
A study on Micro-Actuators for Atomic Force Microscopes
No full textPrecision and Microsystems EngineeringMechanical, Maritime and Materials Engineerin
Values in the filter bubble Ethics of Personalization Algorithms in Cloud Computing
No full textCloud services such as Facebook and Google search started to use personalization algorithms in order to deal with growing amount of data online. This is often done in order to reduce the “information overload”. User’s interaction with the system is recorded in a single identity, and the information is personalized for the user using this identity. However, as we argue, such filters often ignore the context of information and they are never value neutral. These algorithms operate without the control and knowledge of the user, leading to a “filter bubble”. In this paper, by building on existing philosophical work, we discuss three human values implicated in personalized filtering: autonomy, identity, and transparency.Values and TechnologyTechnology, Policy and Managemen
Sub-micrometer accurate passive alignment of photonic chips - Submicrometer nauwkeurige passieve uitlijning van fotonische chips
No full textPrecision and Microsystems EngineeringMechanical, Maritime and Materials Engineerin
Focal plane flatness of an electrostatic lens
No full textHolistic lithography uses feedback from a chip to improve the production process for the following batches of chips. However, as the features on a chip are on a nanometer scale, acquiring feedback is not simple. The features are too small for conventional light based metrology systems, therefore, scanning electron microscopes (SEM’s) are used.As a SEM uses one single beam it is too slow to implement in the lithography production process. To improve the speed multibeam SEM’s have been designed. These microscopes use the same operating principle but with multiple beams simultaneously.Each beam has its own focal point, which together form the focal plane. To acquire a sharp image the focal plane needs to very precisely align with the sample that has to be measured. To achieve this the focal plane has to be very flat, which requires a very precise electrostatic lens.In this thesis the flatness tolerances are evaluated and determined whether they are feasible. This is evaluated by calculating the errors with FEM software and by experimentally testing the remaining errors.Mechanical Engineering | Mechatronic System Design (MSD
Application of Bézier curves in Computer-Aided Design
No full textDIAMElectrical Engineering, Mathematics and Computer Scienc
Understand the War, J.F.C. Fuller
No full textLa thèse est une étude analytique de la pensée du Major-general J-F-C Fuller au travers l’ensemble de ses écrits. Elle s’articule en cinq parties principales, chacune d’entre elles étant divisée en 4 chapitres. Pour aborder l’étude Comprendre la guerre, JFC Fuller : une approche évolutionniste, il était fondamental de commencer par présenter l’homme dans toute son épaisseur et sous toutes ses facettes. Cette première partie,biographique, permet de répondre à la question : Qui est le Major-general JFC Fuller ? Elle conduit ainsi à découvrir ce que représente le cadre civilisationnel de l’homme, un citoyen qui évolue dans un jardin anglais,un ilien. Le personnage « Fuller » doit ensuite être compris dans ses trois dimensions c’est-à-dire au travers dela carrière d’un soldat de métier, un officier, puis à l’aide du prisme de ses idées politiques et enfin par les écrits d’un penseur prolixe. La seconde partie se concentre sur la matrice intellectuelle du jeune officier. Il s’agit de rechercher la filiation de la pensée et des premiers évènements qui vont profondément influencer sa vie. Sa participation à la seconde guerre des Boërs puis son affectation dans une garnison des Indesbritanniques sont deux jalons fondateurs de cette matrice. Á partir de 1907, le retour du capitaine Fuller enAngleterre marque le début de son goût pour l’écriture. La troisième partie cherche à montrer quelles sont les véritables caractéristiques d’une pensée novatrice. Confronté à l’impasse tactique des années 1915 et 1916, Fuller pose le problème- comment retrouver la mobilité opérative ?- et découvre le tank. Sa réflexion devient le germe des idées nouvelles qui permettent au chef des opérations du Tank Corps de planifier, de préparer puis de conduire le 20 novembre 1917, la bataille de Cambrai.Each part equally divided into 4 chapters. To start with this study it was basically relevant to depict the manthroughout his different aspects. Thus the aim of the first part is to answer the question: Who is genuinely Major-generalJFC Fuller. One can discover what the British Empire framework as JFC Fuller matrix is. The man needs also to beunderstood as 3 different ways such as a British officer, his political ideas and as a prolix writer.The second part focuseson Fuller intellectual matrix. Here the goals are to find the filiations of his thoughts and his early events thatbenchmarked his life. His commitment during the Boer War and his 3 years assignment in India are 2 importantmilestones to be studied. From 1907 with his come back in England , Fuller start to write his first military essay. His firstwriting and the article Tactics of Penetration are his main stuff as Staff College Student in Camberley that are deeplyrelevant to be analysed.The third part underlines what the very true characteristics are of a new school of thought. Facingthe tactical deadlock in years 1915 and 1916, Fuller fixed the following issue: How to recover the operational mobilityback? Newly posted in the Heavy Machine Gun his discovered the tanks. His thought gradually became the core of newIdeas that allows to plan and conduct the tank attack at Cambrai on November 20th, 1917. All his studies carried on asGSO 1 of the Tank Corps lead Fuller to write the visionary Plan 1919. This paper will became the leading document forthe interwar strategical thinking for Germans and Soviets senior officers. Then The Journal of the Royal United ServiceInstitution awarded Fuller thought and wrting through The Gold Military Prize Essay for year 1919. The fourth partdepicts the never-ending ambition to implement carefully a scientific method to study War. Within the scope of his firstbook, Training Soldiers for War, one can discover the links with the French school pre-1914. An historical analysisbound to the senior officers behaviour give the floor to understand what is Generalship. An other leading subject lead tofollow Fuller evolution towards his own definition of the principles of war. Then. The Fondations of the Science of Warhis the very books to understand what is Fuller’s scientific method to analyse War.Finally, the fifth part helps to stressthe influence and relevancy of Fuller writings. British Empire crisis at the beginning of the 20’s strengthened the militaryOld school of thought that hampered the evolution pf the Army through mechanisation. Nevertheless in the USA, inFrance but mainly in Germany and in Soviet Union, Fuller name means the reception of a new way of thinking. This newthought is not opposed to Clausewitz’ one because Fuller writings are the very continuation of the former. At last, Fullerrelevancy is this of a brilliant military theorist that each officer must read. In order to summarize Fuller works and toextend his writings the author has underlined what is Military Darwinism
Preliminary trajectory design for a solar polar observatory using SEP and multiple gravity assists
No full textSatellite solar observatories have always been of central importance to heliophysics; while there have been numerous such missions, the solar poles have been extremely under-observed. This paper proposes to use low-thrust as well as multiple gravity assists to reach the enormous energies required obtain high heliocentric inclinations. Two novel methods are used to provide initial guesses to a low-thrust trajectory optimizer. Results show that the complete trajectory would take between 3-4 years, although scientific observations can start already after 2 years. This assumes starting masses of 1000-2000 kg, and payload masses of 500-1300 kg. The best inclinations reached are 55-65 degrees to the ecliptic, while maintaining a perihelion and aphelion of 0.5 and 1 AU respectively. More research still needs to be performed to attempt to reach a global optimum. Further investigation is suggested to extend the mission for further objectives, such as lowering perihelion, or further cranking inclination.Space EngineeringAerospace Engineerin
Modeling and optimization of a sugar plant using hybrid: Batch model predictive control
No full textApplied Science
Systematic approach for tolerance analysis of photonic systems
No full textPassive alignment of photonic components is an assembly method compatible with a high production volume. Its precision performance relies completely on the dimensional accuracies of geometrical alignment features. A tolerance analysis plays a key role in designing and optimizing these passive alignment features. The objective of this paper is to develop a systematic approach for conducting such tolerance analysis, starting with a conceptual package design, setting up the tolerance chain, describing it mathematically and converting the misalignment to a coupling loss probability distribution expressed in dB. The method has successfully been applied to a case study where an indium phosphide (InP) chip is aligned with a TriPleX1 (SiO2 cladding with Si3N4 core) interposer via a silicon optical bench (SiOB).Precision and Microsystems EngineeringMechanical, Maritime and Materials Engineerin
