On the Modelling of Price Effects in the Diffusion of Optional Contingent Products

In this chapter, we study the pricing strategies of firms in a multi-product diffusion model where we use a new formalization of the price effects. More particularly, we introduce the impact of prices on one of the factors that affect the diffusion of new products: the innovation coefficient. By doing so, we relax one of the hypotheses in the existing literature stating that this rate is constant. In order to assess the impact of this functional form on the pricing policies of firms selling optional contingent products, we use our model to study two scenarios already investigated in the multiplicative form model suggested by Mahajan and Muller (1991) (M&M). We follow a ‘logical experimentation’ perspective by computing and com- paring the results of three models: (i) The M&M model, (ii) a modified version of M&M where the planning horizon is infinite, and (iii) our model, where the new formalization of the innovation effect is introduced. This perspective allows us to attribute the differences in results to either the length of the planning horizon, or to our model’s formalization. Besides its contribution to the literature on pricing and diffusion, this paper highlights the sensitiv- ity of results to the hypothesis used in product diffusion modelling and could explain the mixed results obtained in the empirical validations of diffusion models (Mesak, 1996).MINECO under projects ECO2014-52343-P and ECO2017-82227-P (AEI) and by Junta de Castilla y León VA024P17 and VA105G18 co-financed by FEDER funds (EU)

Price Coordination in Distribution Channels: A Dynamic Perspective

Producción CientíficaIn this study, we investigate two important questions related to dynamic pricing in distribution channels: (i) Are coordinated pricing decisions efficient in a context where prices have carry-over effects on demand? (ii) Should fi rms practice a skimming or a penetration strategy if they choose to coordinate or to decentralize their activities? To answer these questions, we consider a differential game that takes place in a bilateral monopoly where the past retail prices paid by consumers contribute to the building of a reference price. The latter is used by consumers as a benchmark to evaluate the value of the product, and by fi rms to decide whether to adopt a skimming or a penetration strategy. We then compute and compare strategies, total channel profi ts and individual profits under vertical integration and decentralization at steady state and along the optimal time-paths. One of our main fi ndings states that, for some values of the initial reference price, there is a time interval where channel decentralization performs better than coordination. During this transition period, at least one of the channel members could be tempted to end his cooperation, especially if he is not farsighted and if there are no binding agreements with the other channel partners.The rst author's research is partially supported by MICINN under projects ECO2008-01551/ECON, ECO2011-24352, co- nanced by FEDER funds and the COST Action IS1104 \The EU in the new economic complex geography: models, tools and policy evaluation". The second author's research is supported by NSERC, Canada

Indoor Localization Using Wi-Fi Signals

RÉSUMÉ Plusieurs approches ont été développées pour localiser des appareils mobiles à l'intérieur de bâtiments d’une façon précise. Certaines donnent une précision de moins d'un mètre, mais elles nécessitent des infrastructures et du matériel spécifiques. D'autres utilisent une infrastructure qui est déjà déployée, mais donnent une position avec une précision inférieure. Dans ce mémoire, nous proposons plusieurs méthodes de positionnement basées sur les mesures de l'intensité du signal reçu d'une infrastructure Wi-Fi existant. Le but de ces méthodes de positionnement est de localiser le plus précisément possible l'emplacement du dispositif mobile utilisé. La première méthode de positionnement que nous proposons transforme la puissance du signal reçue en une entité appelée signature. Cette entité caractérise chaque emplacement de l'environnement où la localisation doit être effectuée. Pour localiser l'appareil mobile, la signature calculée est jumelée avec les signatures de référence les plus représentatives et qui sont déjà enregistrées dans une base de données. Dans ce mémoire, nous proposons deux approches pour produire les signatures de référence: une empirique et une théorique. La deuxième méthode de positionnement que nous proposons dans ce mémoire est de localiser les appareils mobiles en utilisant la différence entre les mesures de puissance de signaux reçus. On a appelé cette méthode la différence de puissances des signaux reçues (RSSD). Cette méthode consiste à convertir la différence de puissances des signaux reçues en des distances et d’utiliser ces distances pour estimer la position des appareils mobiles. Ensuite, nous décrivons les expériences qui nous ont conduits à développer la méthode de traitement du signal et les algorithmes de localisation. Les algorithmes et les méthodes proposés ont conduit à un système de localisation précis qui atteint 2 mètres de précision dans 90% des cas. Les résultats actuels des systèmes proposés montrent que les emplacements estimés sont précis (moins de 2 mètres) dans un environnement fermé en utilisant la méthode des signatures et une localisation précise dans les espaces ouverts en utilisant la méthode de la RSSD. Certains endroits critiques ont besoin de plus de collecte de données et plus d'informations sur l'environnement pour atteindre le même niveau de précision. Les résultats obtenus sont décrits et discutés à l’aide de cartes et de statistiques.----------ABSTRACT Several approaches have been developed to provide an accurate estimation of the position of mobile devices inside buildings. Some of them give a precision of less than one meter but they require special infrastructure and materials. Some others use an infrastructure that is already deployed but gives a position with lower precision. In this thesis, we propose several positioning methods based on the received signal strength (RSS) measurements of an existing Wi-Fi infrastructure. The aim of these positioning methods is to locate a mobile device as accurately as possible. The first method that we propose transforms the RSS to an entity called signature. This entity characterises each location of the environment where the localization should be performed. This computed signature is matched with the most representative reference signatures already recorded in a database in order to locate the mobile device. In this thesis, we propose two approaches to produce the reference signatures: an empirical and a theoretical one. The second method that we propose in this thesis is about locating the mobile devices using the difference between the received signals strength measurements. We call this method the received signal strength difference (RSSD) method. We then describe the experiments that led us to develop the signal processing method and the localization algorithms. The algorithm proposed led to an accurate localization system that reaches 2 meters of accuracy in 90% of the cases. Current results of the proposed systems show that the estimated locations are accurate (less than 2 meters) in closed environments when using the fingerprinting method and in open spaces when using the RSSD method. Some critical locations need more collected data and more information about the environment to reach the same level of accuracy. The results obtained are described and discussed using maps and statistics

Tuning of morphological and antibacterial properties of poly(3,4-ethylenedioxythiophene):peroxodisulfate by methyl violet

This study demonstrates a one-step synthesis of poly(3,4-ethylenedioxythiophene) (PEDOT) in the presence of the methyl violet (MV) dye. The structural properties of PEDOT:peroxodisulfate were studied using Raman and MALDI-TOF spectroscopies. The use of the MV dye in the polymerization process resulted in a change in the typical irregular morphology of PEDOT:peroxodisulfate, leading to the formation of spherical patterns. SEM and TEM analyses revealed that increasing the dye concentration can produce larger spherical aggregates probably due to the hydrophobic and π–π interactions. These larger aggregates hindered the charge transport and reduced the electrical conductivity. Interestingly, at higher dye concentrations (0.05 and 0.075 M), the PEDOT:peroxodisulfate/MV films exhibited significantly improved antibacterial activity against Staphylococcus aureus and Escherichia coli. Furthermore, the PEDOT:peroxodisulfate films with the incorporated MV dye exhibited a well-defined and repeatable redox behavior. The remarkable amalgamation of their optical, electrochemical and antibacterial properties provides the PEDOT:peroxodisulfate/MV materials with an immensely diverse spectrum of applications, including in optical sensors and medical devices.DKRVO, (RP/CPS/2022/001); Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT; Akademie Věd České Republiky, AV ČR, (RVO 61389013

Somatostatin Inhibits Cell Migration and Reduces Cell Counts of Human Keratinocytes and Delays Epidermal Wound Healing in an Ex Vivo Wound Model

The peptide hormone somatostatin (SST) and its five G protein-coupled receptors (SSTR1-5) were described to be present in the skin, but their cutaneous function(s) and skin-specific signalling mechanisms are widely unknown. By using receptor specific agonists we show here that the SSTRs expressed in keratinocytes are functionally coupled to the inhibition of adenylate cyclase. In addition, treatment with SSTR4 and SSTR5/1 specific agonists significantly influences the MAP kinase signalling pathway. As epidermal hormone receptors in general are known to regulate re-epithelialization following skin injury, we investigated the effect of SST on cell counts and migration of human keratinocytes. Our results demonstrate a significant inhibition of cell migration and reduction of cell counts by SST. We do not observe an effect on apoptosis and necrosis. Analysis of signalling pathways showed that somatostatin inhibits cell migration independent of its effect on cAMP. Migrating keratinocytes treated with SST show altered cytoskeleton dynamics with delayed lamellipodia formation. Furthermore, the activity of the small GTPase Rac1 is diminished, providing evidence for the control of the actin cytoskeleton by somatostatin receptors in keratinocytes. While activation of all receptors leads to redundant effects on cell migration, only treatment with a SSTR5/1 specific agonist resulted in decreased cell counts. In accordance with reduced cell counts and impaired migration we observe delayed re-epithelialization in an ex vivo wound healing model. Consequently, our experiments suggest SST as a negative regulator of epidermal wound healing

Régulation de la migration des kératinocytes par la signalisation purinergique

L épiderme est un tissu stratifié, majoritairement constitué de kératinocytes et constitue la première barrière de l organisme contre les agressions extérieures. En cas de blessure cutanée, plusieurs des voies de signalisations sont déclenchées dans le but de rétablir l homéostasie de l épiderme. Parmi ces différentes voies de signalisation intervenant dans le contrôle de l homéostasie de l épiderme, la voie des PI3K occupe une place de choix en régulant la migration et la prolifération des kératinocytes. Dans ce travail de thèse, nous avons examiné la régulation des PI3K par les nucléotides extracellulaires, agissant via les récepteurs purinergiques. Nous avons pu montré que l activation de la signalisation purinergique inhibe l isoforme p110a de la PI3K, ce qui a pour effet d affecter la morphologie et diminuer la vitesse de migration des kératinocytes. La découverte de cette nouvelle voie de signalisation permettra de mieux comprendre la migration des kératinocytes, un phénomène important dans le physiologie cutanée.AIX-MARSEILLE1-BU Sci.St Charles (130552104) / SudocSudocFranceF

Are Retailers’ Private Labels Always Detrimental to National Brand Manufacturers? A Differential Game Perspective

We study the competition between national and private brands (or private labels) in a vertical channel structure. Our main objective is to analyze the impacts of the private label’s existence on strategies, sales, and profits of the members and the whole channel. We use a differential game, where the control variables are price and non-price marketing decisions, and investigate two scenarios. The first one, used as a benchmark, considers an exclusive retailer that distributes only a national brand provided by a manufacturer. The latter invests in national advertising to build its brand’s goodwill. In the second scenario, the retailer owns a private label that competes with the national brand. By computing the results under both scenarios, we provide answers to the following research questions: (1) What should the price and the non-price marketing strategies be, with and without the private label? (2) How do they compare? (3) Is the presence of a private label always profitable for the retailer and harmful to the manufacturer? One of our main results indicates that the manufacturer is not necessarily always hurt by the private label, as the existing literature suggests