Discrimination | EPFL Graph Search

Le mot discrimination vient du latin discriminis, qui signifie « séparation ». Action de distinguer, traiter, considérer, sélectionner des entités selon des critères spécifiques ou distinctifs. La discrimination sociale est un processus lié au fait d'opérer une distinction concernant une personne ou une catégorie sociale en créant des frontières dites « discriminantes », c'est-à-dire produisant un rejet visant à l'exclusion sociale sur des critères tels que l'origine sociale ou ethnique, la religion, le genre, le niveau de son intelligence, l'état de santé, etc. Introduction Le concept de discrimination sociale fait son apparition à la suite des luttes politiques pour l'égalité de droit entre les hommes qui aboutissent dans la plupart des pays occidentaux au début de la seconde moitié du à l'abolition progressive des différences légales de traitement (fin de la colonisation, de la ségrégation raciale aux États-Unis, etc.). Dans un contexte où la société évolue dans le s

The triangular value of patents

Albina Khairullina

This thesis addresses the question of a patent value from three different angles. It comprises three papers on the patent valuation methods. The patent valuation issues are well-known to the world of research and practice. However, the debates over what the patent contributes to the business and the economy overall remain open. The main contribution of my dissertation is that I present novel ways of addressing the value of patents from both micro- and macroeconomic perspectives. I bridge the theoretical modeling with real-world estimations, which sheds light on the legitimacy of certain hypothetical assumptions in patent valuation. In the first paper, I develop a factor model to value patents in a corporate patent portfolio. According to the results, the patent value is determined by five factors, such as forward and backward citations, family size, the number of oppositions received, and the number of claims. I contribute to the literature by introducing an interaction of a quantitative measure of a patent value with its qualitative assessment derived from a survey of patent managers. The results show that model estimates are weakly consistent with an expert opinion on the value of patents. In the second paper, we collaborate with a large multinational company and analyze internal and highly confidential data on product sales, revenues, and other corporate performance measures by tracing each patent down to its product market. To establish causality, we design a randomized controlled trial together with the management of the company, in which some randomly chosen patents are dropped from the portfolio, while others are kept for the duration of the study. To our knowledge, this is the first study that conducts a randomized controlled trial to measure the real market effect of patent protection. In the third paper, we study whether the regulator expands production possibilities of the economy by assigning a standard-essential status to patents. As we show, the innovatorsâ risk of losing the standard-setting game ex-ante attenuates the anticipation of a larger market share. Secondly, since the discovery of new technologies is typically slower than the discounting rate for the monopoly profits, standards with a positive contribution to productivity tend to be growth-reducing. Our results have significant policy implications. Regulators impose Fair, Reasonable, And Non-Discriminatory (FRAND) pricing on standard-essential technologies to compensate for the larger market-share the innovators get. We demonstrate how FRAND regulation of mark-ups has an unambiguously negative effect on growth and long-term growth-destroying consequences.

EPFL2020

Operando XAS insight in the redox dynamics of VOx species and reducible supports involved in oxidative dehydrogenation of alcohols

Anna Zabilska

Supported vanadia (VOx) belongs to some of the most versatile selective oxidation and reduction catalysts applied for many reactions in the chemical industry and pollution control. Among them, the oxidative dehydrogenation (ODH) of alcohols is particularly attractive since it is one of the main industrial methods of formaldehyde production and a possible route for the transformation of renewable bioethanol to value-added products, such as acetaldehyde and acetic acid. Despite many spectroscopic methods used to investigate the mechanism of this reaction, the details about the redox involvement of VOx species and promoting supports (CeO2 and TiO2) remain debated. In this study, we used an element-specific operando X-ray absorption spectroscopy (XAS) to probe the redox transformations of active sites in vanadia-titania and vanadia-ceria catalysts during ethanol and methanol ODH. By carefully designing the steady-state and transient operando XAS experiments and by applying advanced chemometric methods, we could discriminate specifically and often quantitatively, which role plays each redox couple during the alcohol ODH cycle and uncover hidden structure activity-relationships.Chapter 1 introduces the relevant literature and summarizes the goals and the scope of the thesis.In Chapter 2, we investigate the redox dynamics of active sites in a bilayered VOx/TiOx/SiO2 catalyst (an analog of a widely used VOx/TiO2 catalyst with comparable activity) during ODH of ethanol. Operando time-resolved V and Ti K-edge XAS coupled with a transient experimental strategy quantitatively showed that the formation of acetaldehyde over VOx/TiOx/SiO2 catalyst is kinetically coupled to the formation of a V4+ intermediate, while the formation of V3+ is delayed and its rate is 10-70 times lower. The only very weak redox activity of the Ti4+/Ti3+ couple was detected, which suggests that TiOx species promote the redox activity of VOx indirectly, either via the fast electron transport between VOx species or by changing the electronic structure of VOx species.In Chapter 3, we report on possible difficulties, which can occur during in situ XAS studies of supported vanadia (VOx) catalysts at synchrotron beamlines related to X-ray-induced photochemical reduction of vanadium. We rigorously tested this phenomenon and suggest approaches, which can help to identify and mitigate vanadium photoreduction interfering chemical speciation.In Chapter 4, we focused on the structure-activity relationships in VOx/CeO2 system. We prepared a series of VOx/CeO2 catalysts using high-surface-area CeO2 Using time-resolved operando quick XAS at V K- and Ce L3-edges, we demonstrated that during oxygen cut-off experiments vanadium and cerium change their oxidation states in concert with each other and with the production of acetaldehyde. It suggests that both reducible vanadium and cerium are parts of the same active sites. The maximum VOx/CeO2 activity per mass of catalyst observed at ca. 3 V/nm2 coincides with the maximal amount of cerium atoms, which reversibly change their oxidation state during oxygen cut-off experiments.In Chapter 5, we prove that the mechanistic findings described in Chapter 4 for ethanol ODH over VOx/CeO2 catalysts are also valid for methanol ODH. Moreover, we confirm that the VOx surface density is the main descriptor of the activity for VOx/CeO2 catalysts in alcohol ODH.

EPFL2022

Scalable peer-to-peer Web search using highly discriminative keys

Vinh Toan Luu

Standard general-purpose Web retrieval relies on centralized search engines that do not realistically scale when applied to the exponentially growing number of documents available on the Web. By taking advantage of the resource sharing principle, Peer-to-Peer (P2P) techniques represent a promising architectural alternative for building decentralized Web search engines offering true Web-size scalability, provided that enough peers are available. However, in all such P2P approaches proposed so far, excessive network bandwidth consumption during retrieval, caused by the necessary transmission of possibly very long posting lists, was identified as the major bottleneck for implementing truly scalable P2P full-text Web retrieval. The main objective of the present research is thus to find a decentralized indexing/retrieval strategy that fully exploits the distributed computation possibilities provided by P2P networks, but keeps the required network bandwidth consumption scalable, while guaranteeing an acceptable retrieval quality. To address this problem we introduce a novel indexing/retrieval model based on Highly Discriminative Keys (HDKs), which correspond to carefully selected indexing terms and term sets associated with posting lists truncated to the top-k most relevant documents with respect to the associated key. Using HDKs for indexing thus increases the number of indexing features but, at the same time, strictly limits the size of the associated posting lists. When combined with an adequate retrieval model, this leads to strongly reduced network traffic. More precisely, our experimental results show that HDK-based indexing and retrieval lead to storage and bandwidth requirements that remain manageable with respect to the growth of document collection while preserving a fully acceptable retrieval quality.

EPFL2007