On axiomatizations of the Shapley value for assignment games

We consider the problem of axiomatizing the Shapley value on the class of assignment games. We first show that several axiomatizations of the Shapley value on the class of all TU-games do not characterize this solution on the class of assignment games by providing alternative solutions that satisfy these axioms. However, when considering an assignment game as a communication graph game where the game is simply the assignment game and the graph is a corresponding bipartite graph buyers are connected with sellers only, we show that Myerson's component efficiency and fairness axioms do characterize the Shapley value on the class of assignment games. Moreover, these two axioms have a natural interpretation for assignment games. Component efficiency yields submarket efficiency stating that the sum of the payoffs of all players in a submarket equals the worth of that submarket, where a submarket is a set of buyers and sellers such that all buyers in this set have zero valuation for the goods offered by the sellers outside the set, and all buyers outside the set have zero valuations for the goods offered by sellers inside the set. Fairness of the graph game solution boils down to valuation fairness stating that only changing the valuation of one particular buyer for the good offered by a particular seller changes the payoffs of this buyer and seller by the same amount.

Effects of Dehydration on Balance as Measured by the Balance Error Scoring System

The purpose of this study was to identify the effects of active dehydration on balance in euthermic individuals employing the Balance Error Scoring System (BESS). The results indicate that dehydration significantly negatively affects balance.

Hallux rigidus: Arthroplasty or arthrodesis. What technique produces better results?

Hallux rígidus (HR) affects the first metatarsophalangeal joint (MTPJ) between 35% and 60% of the population over 65 years and there are multiple ways of treatment. Depending on the radiological stage where you find the deformity determines the procedure to be performed; in the early stages cheilectomy techniques and corrective osteotomy is performed while the more advanced ratings, the surgeon chooses destructive techniques considered as arthrodesis and arthroplasty. This final of degree project aims to focus on 1 MTPJ destructive techniques to clarify which of the procedures generates better results by a number of parameters; outcomes of the American Orthopaedic Foot scale and Ankle Society Hallux metatarsophalangeal Interphalangeal-scale (AOFAS), range of motion (ROM) of the 1ºAMTF, radiological classification. As for the implant arthroplasty technique, this article offers information on material and design that generates better relating to patient characteristics such as age, inflammatory joint diseases, viability and durability of the implant results. The conclusion from this review is that the values obtained in the arthrodesis according AOFAS decrease due to loss of mobility, but both techniques have similar values of effectiveness and concludes with the decision that the technique used is determined taking into account various factors and patient characteristics. Keywords: Hallux rígidus; (Hallux Rígidus) and surgery treatment; Hallux Rígidus arthrodesis; Hallux Rígidus arthroplasty; Hallux Rígidus (arthroplasty and arthrodesis).

Application of battery energy storage in the Québec interconnection

Le Système Stockage de l’Énergie par Batterie ou Batterie de Stockage d’Énergie (BSE) offre de formidables atouts dans les domaines de la production, du transport, de la distribution et de la consommation d’énergie électrique. Cette technologie est notamment considérée par plusieurs opérateurs à travers le monde entier, comme un nouveau dispositif permettant d’injecter d’importantes quantités d’énergie renouvelable d’une part et d’autre part, en tant que composante essentielle aux grands réseaux électriques. De plus, d’énormes avantages peuvent être associés au déploiement de la technologie du BSE aussi bien dans les réseaux intelligents que pour la réduction de l’émission des gaz à effet de serre, la réduction des pertes marginales, l’alimentation de certains consommateurs en source d’énergie d’urgence, l’amélioration de la gestion de l’énergie, et l’accroissement de l’efficacité énergétique dans les réseaux. Cette présente thèse comprend trois étapes à savoir : l’Étape 1 - est relative à l’utilisation de la BSE en guise de réduction des pertes électriques ; l’Étape 2 - utilise la BSE comme élément de réserve tournante en vue de l’atténuation de la vulnérabilité du réseau ; et l’Étape 3 - introduit une nouvelle méthode d’amélioration des oscillations de fréquence par modulation de la puissance réactive, et l’utilisation de la BSE pour satisfaire la réserve primaire de fréquence. La première Étape, relative à l’utilisation de la BSE en vue de la réduction des pertes, est elle-même subdivisée en deux sous-étapes dont la première est consacrée à l’allocation optimale et le seconde, à l’utilisation optimale. Dans la première sous-étape, l’Algorithme génétique NSGA-II (Non-dominated Sorting Genetic Algorithm II) a été programmé dans CASIR, le Super-Ordinateur de l’IREQ, en tant qu’algorithme évolutionniste multiobjectifs, permettant d’extraire un ensemble de solutions pour un dimensionnement optimal et un emplacement adéquat des multiple unités de BSE, tout en minimisant les pertes de puissance, et en considérant en même temps la capacité totale des puissances des unités de BSE installées comme des fonctions objectives. La première sous-étape donne une réponse satisfaisante à l’allocation et résout aussi la question de la programmation/scheduling dans l’interconnexion du Québec. Dans le but de réaliser l’objectif de la seconde sous-étape, un certain nombre de solutions ont été retenues et développées/implantées durant un intervalle de temps d’une année, tout en tenant compte des paramètres (heure, capacité, rendement/efficacité, facteur de puissance) associés aux cycles de charge et de décharge de la BSE, alors que la réduction des pertes marginales et l’efficacité énergétique constituent les principaux objectifs. Quant à la seconde Étape, un nouvel indice de vulnérabilité a été introduit, formalisé et étudié ; indice qui est bien adapté aux réseaux modernes équipés de BES. L’algorithme génétique NSGA-II est de nouveau exécuté (ré-exécuté) alors que la minimisation de l’indice de vulnérabilité proposé et l’efficacité énergétique représentent les principaux objectifs. Les résultats obtenus prouvent que l’utilisation de la BSE peut, dans certains cas, éviter des pannes majeures du réseau. La troisième Étape expose un nouveau concept d’ajout d’une inertie virtuelle aux réseaux électriques, par le procédé de modulation de la puissance réactive. Il a ensuite été présenté l’utilisation de la BSE en guise de réserve primaire de fréquence. Un modèle générique de BSE, associé à l’interconnexion du Québec, a enfin été proposé dans un environnement MATLAB. Les résultats de simulations confirment la possibilité de l’utilisation des puissances active et réactive du système de la BSE en vue de la régulation de fréquence.

Effects of various salt purity levels on lipid oxidation and sensory characteristics of ground turkey and pork

Salt use in meat products is changing. Consumers desire sea salt which may also contain trace metals and the government is demanding a reduction in sodium. Therefore a need exists to understand how varying impurity levels in salt affect meat quality. This study evaluated the effects of various salt preparations on lipid oxidation, sensory characteristics, protein extractability, and bind strength of ground turkey and pork. This study was a completely randomized design with 5 treatment groups and 6 replications in 2 species. Ground, turkey and pork meat was formulated into one hundred and fifty gram patties with sodium chloride (1%) containing varying amounts of metal impurities (copper, iron, and manganese). Samples were randomly assigned to frozen storage periods of 0, 3, 6, and 9 weeks. After storage, samples were packaged in PVC overwrap and stored under retail display for 5 days. Samples were evaluated for proximate analysis to ensure the fat content was similar for all of the starting material.Thiobarbituric acid reactive substances (TBARS) were determined on raw and cooked samples to evaluate lipid oxidation. A trained six member sensory panel evaluated the samples at each storage period for saltiness, off flavor, and oxidized odor. Break strength was conducted using a Texture Analyzer and compared with salt soluble proteins (increasing salt concentrations) to evaluate protein extractability characteristics. Statistical analyses were conducted using the MIXED procedure of SAS within repeated measures over time where appropriate. No significant differences were observed among the salt treatments for raw and cooked TBARS when the control group was removed (P>0.05). Sensory panelists detected increased levels of off flavor and oxidized odor over the entire storage duration. Less force was required to break the patties from the control group when compared with the salt treatments (P<0.05). As salt concentration increased salt-soluble protein extraction increased, but there was no effect of salt type. Overall, no meaningful statistical differences among the various salt treatments were observed for all of the parameters evaluated for turkey and pork. Salt at a 1% inclusion rate containing varying levels of copper, iron, and manganese impurities in ground turkey thigh meat and ground pork served as a prooxidant. However, if a meat processor uses a 1% inclusion rate of salt in turkey and pork regardless of impurities included, it is unlikely that differences in shelf life or protein functionality would be observed.

Descripción de resultados de la reconstrucción de placa plantar en inestabilidad de la segunda articulación metatarsofalángica

Objetivo: Describir los desenlaces funcionales, complicaciones postoperatorias, dolor y satisfacción de un grupo de pacientes con diagnóstico de inestabilidad de segunda articulación metatarsofalángica y lesión de la placa plantar, que fueron intervenidos quirúrgicamente para su reconstrucción en el Hospital Universitario de cuarto nivel Fundación Santa Fé de Bogotá, en el periodo comprendido entre Enero de 2010 hasta Diciembre de 2015. Métodos: Estudio descriptivo de corte transversal que evalúa desenlaces funcionales, dolor y satisfacción para un grupo consecutivo de pacientes con diagnóstico de inestabilidad de la segunda articulación metatarsofalángica que fueron intervenidos quirúrgicamente mediante reconstrucción de la placa plantar entre Enero de 2010 a Diciembre de 2015 en el Hospital Universitario Fundación Santa fe de Bogotá. Resultados: El procedimiento se realizó a 39 pacientes (40 MTF), encontrando mejoría en dolor, función y satisfacción. El dolor postoperatorio paso de severo a leve en el 80% de los pacientes, 67.5% de los pacientes presentaron prueba de aprehensión positiva, 85% alineamiento adecuado, el reporte de escala de AOFAS postoperatoria fue de 87, y los resultados fueron satisfactorios en un 94.5%. La principal complicación con la cirugía fue la extensión residual del dedo operado (22.5%). Conclusiones: La reconstrucción de la placa plantar en casos de inestabilidad metatarsofalángica ha demostrado tener resultados satisfactorios, en el presente estudio encontramos mejoría respecto a dolor, función y satisfacción posterior a la realización del procedimiento. Sin embargo puede presentar complicaciones como extensión residual del dedo o elevación, rigidez y recidiva.

Configuración y dislocación de los espacios de trabajo

Esta tesis se presenta como el inicio de una larga reflexión que se pregunta por los espacios de trabajo, sus significados, las relaciones y decisiones que los configuran y a la vez ellos configuran, y la manera como se transforman, transgreden y superan a través de la adopción de las tecnologías. Los resultados que aquí se presentan parten del análisis de once (11) organizaciones ubicadas en Bogotá que acompañé durante el 2014 y 2015 en sus procesos de cambio de oficina.

La cultura y el liderazgo en la estrategia de crecimiento por exportaciones del modelo de desarrollo japonés (1960-1980)

Normalmente el desarrollo de un país se ha explicado desde una perspectiva tradicional en términos de su crecimiento económico, teniendo en cuenta indicadores macroeconómicos como el PIB, la inflación y el desempleo. Poca atención se le ha puesto a la importancia que para el desarrollo de un país representan el capital humano y el proceso de liderazgo. Debido a lo anterior, mediante este estudio de caso, se pretende entender el éxito de la estrategia de crecimiento por exportaciones de Japón entre los años 1960-1980 teniendo en cuenta estos aspectos. Así, se busca sustentar que la incorporación de un tipo de liderazgo transformacional- transaccional y los elementos propios de su cultura como el confucianismo y el budismo, le imprimieron una perspectiva no economicista al éxito del modelo de desarrollo como parte de la triada empresa-estado-universidad. Lo anterior se realizará partiendo de un análisis cualitativo y con un enfoque en la economía política internacional y en el liderazgo. Este último estudiado desde las disciplinas de la administración, la sociología y la psicología

Analysis of the impact of stationary energy storage systems in trolleybus grids using Simulink-based modelling

The voltage profile of the catenary between traction substations (TSSs) is affected by the trolleybus current intake and by its position with respect to the TSSs: the higher the current requested by the bus and the further the bus from the TSSs, the deeper the voltage drop. When the voltage drops below 500V, the trolleybus is forced to decrease its consumption by reducing its input current. This thesis deals with the analysis of the improvements that the installation of an BESS produces in the operation of a particularly loaded FS of the DC trolleybus network of the city of Bologna. The stationary BESS is charged by the TSSs during off-peak times and delivers the stored energy when the catenary is overloaded alleviating the load on the TSSs and reducing the voltage drops. Only IMC buses are considered in the prospect of a future disposal of all internal combustion engine vehicles. These trolleybuses cause deeper voltage drops because they absorb enough current to power their traction motor and recharge the on board battery. The control of the BESS aims to keep the catenary voltage within the admissible voltage range and makes sure that all physical limitations are met. A model of FS Marconi Trento Trieste is implemented in Simulink environment to simulate its daily operation and compare the behavior of the trolleybus network with and without BESS. From the simulation without BESS, the best location of the energy storage system is deduced, and the battery control is tuned. Furthermore, from the knowledge of the load curve and the battery control trans-characteristic, it is formulated a prediction of the voltage distribution at BESS connection point. The prediction is then compared with the simulation results to validate the Simulink model. The BESS allows to decrease the voltage drops along the catenary, the Joule losses and the current delivered by the TSSs, indicating that the BESS can be a solution to improve the operation of the trolleybus network.

Power flow forecasting and smart charging for electric vehicle charging systems with photovoltaic integration

An essential role in the global energy transition is attributed to Electric Vehicles (EVs) the energy for EV traction can be generated by renewable energy sources (RES), also at a local level through distributed power plants, such as photovoltaic (PV) systems. However, EV integration with electrical systems might not be straightforward. The intermittent RES, combined with the high and uncontrolled aggregate EV charging, require an evolution toward new planning and paradigms of energy systems. In this context, this work aims to provide a practical solution for EV charging integration in electrical systems with RES. A method for predicting the power required by an EV fleet at the charging hub (CH) is developed in this thesis. The proposed forecasting method considers the main parameters on which charging demand depends. The results of the EV charging forecasting method are deeply analyzed under different scenarios. To reduce the EV load intermittency, methods for managing the charging power of EVs are proposed. The main target was to provide Charging Management Systems (CMS) that modulate EV charging to optimize specific performance indicators such as system self-consumption, peak load reduction, and PV exploitation. Controlling the EV charging power to achieve specific optimization goals is also known as Smart Charging (SC). The proposed techniques are applied to real-world scenarios demonstrating performance improvements in using SC strategies. A viable alternative to maximize integration with intermittent RES generation is the integration of energy storage. Battery Energy Storage Systems (BESS) may be a buffer between peak load and RES production. A sizing algorithm for PV+BESS integration in EV charging hubs is provided. The sizing optimization aims to optimize the system's energy and economic performance. The results provide an overview of the optimal size that the PV+BESS plant should have to improve whole system performance in different scenarios.

Analisi e progettazione di un sistema di accumulo per applicazioni in ambito industriale

"Electrification" è il concetto su cui è stata fondata l’idea del progetto trattato nell’elaborato. Si sente spesso parlare di elettrificazione e di transizione energetica, specialmente nell’ambito in cui ho avuto occasione di svolgere il tirocinio in preparazione della tesi. L’azienda con cui ho lavorato sull’attività di ricerca e analisi è, infatti, incentrata sul mercato Oil & Gas, per cui, in particolar modo in questo periodo storico, risente di un’enorme spinta all’ electrification e all’ottimizzazione degli impianti. A tal proposito, si sta dirigendo verso soluzioni che possano fornire supporto alla rete ed anche ridurre le emissioni di gas inquinanti in atmosfera. L’attività di ricerca si è basata su quelle che sono le tecnologie e le disponibilità sul mercato per sistemi di accumulo di energia all’interno dell’ambito industriale, con particolare attenzione ad aspetti quali sicurezza e innovazione. Le applicazioni di un sistema di accumulo sono svariate, per cui nell’elaborato ne sono state trattate due in particolare: peak shaving e sistema di backup. Sono stati sviluppati, quindi, tre progetti in parallelo: uno relativo al caso di peak shaving e due riguardanti sistemi di backup all’interno di una control cabin. Nel primo caso si è partiti da un progetto ex novo, mentre negli altri due casi si è fatto riferimento a due casi studio già ben definiti relativi a due impianti già esistenti a cui è stata sostituita la tecnologia alla base delle celle elettrochimiche che costituiscono il rack di batterie. L’obiettivo principale della tesi è stato dunque quello di progettare il sistema di accumulo per i relativi casi studio e di verificarne la fattibilità.