Classification of trunk motion based on inertial sensors

55 páginasPor mucho tiempo en la ingeniería se ha trabajado para la valoración y prevención de desórdenes musculo esqueléticos de la espalda. El uso de sistemas de captura de movimiento es una de las técnicas más utilizadas en este ámbito, considerada el estándar, es un sistema de alto costo y limitaciones considerables. El uso de sensores de inercia en los últimos años ha llegado a ser muchos más frecuente gracias a los avances tecnológicos que lo han llevado a ser más accesible y compacto. Este proyecto se basa en el uso de sensores de inercia para la clasificación de movimientos de la espalda, lo cual ayuda a la valoración y prevención de desórdenes musculo esqueléticos. En el presente texto, se presenta todo el proceso de desarrollo de un sistema para la identificación de movimientos de la espalda, mediante el uso de las señales de los sensores de inercia. Se presentaran experimentos y resultados del uso de un sistema de captura de movimiento comparado con el sistema de sensores de inercia. El programa propuesto para la clasificación de los tres movimientos del tronco (flexión, lateral y rotación) trae consigo importantes ventajas de fiabilidad y libertad espacial. El sistema desarrollado permite la valoración de los movimientos del tronco. La clasificación de estos movimientos utilizando sensores de inercia es un método considerablemente mucho más portable comparado con un sistema de captura de movimiento. También, este sistema se puede usar en diferentes espacios sin mayores esfuerzos y los límites transnacionales de movimientos son mucho más amplios en comparación con sistemas de captura de movimientos. La clasificación permite la adición de nuevas características para la identificación más precisa de movimientos o posturas que permitirán una mejor valoración para la prevención de desórdenes musculo esqueléticos del trono.PregradoIngeniero(a) Biomédico(a

A Note on Optimal Allocation Mechanisms

This paper studies revenue-maximizing allocation mechanisms for multiple goods where the buyerís utility can depend non-linearly in his type. We point out that despite strictly increasing virtual utilities, the allocation rule obtained via pointwise optimization may fail to be increasing and thus it may violate incentive compatibility. More importantly, the revenue maximizing allocation may involve randomizations between di§erent allocations

The Role of Outside Options in Auction Design

This paper studies revenue maximizing auctions when buyersíoutside options depend on their private information. The set-up is very general and encompasses a large number of potential applications. The main novel message of our analysis is that with type-dependent non-participation payo§s, the revenue maximizing assignment of objects can crucially depend on the outside options that buyers face. Outside options can therefore a§ect the degree of e¢ ciency of revenue maximizing auctions. We show that depending on the shape of outside options, sometimes an optimal mechanism will allocate the objects in an ex-post e¢ cient way, and other times, buyers will obtain objects more often than it is e¢ cient. Our characterization rings a bell of caution. Modeling buyersíoutside options as being independent of their private information, is with loss of generality and can lead to quite misleading intuitions. Our solution procedure can be useful also in other models where type-dependent outside options arise endogenously, because, for instance, buyers can collude or because there are competing sellers

What to Put on the Table

This paper investigates under which circumstances negotiating simultaneously over multiple issues or assets helps reduce ine¢ ciencies due to the presence of asymmetric information. We Önd that a simultaneous negotiation over multiple assets that are substitutes reduces ine¢ ciencies. The e§ect is stronger if goods are heterogeneous, and in this case the ine¢ ciency can be eliminated altogether. When assets are not substitutes ine¢ ciencies always prevail. We also study cases where co-ownership is possible (partnerships), allowing for asymmetric distributions, general valuation functions and for multiple assets. We show that e¢ cient dissolution is possible if all agents valuations at their types where gains of trade are minimal are equal: For this to hold, the agent that most likely has the highest valuation for a given asset should initially own a bigger share of that asset. We discuss implications of these Öndings for the design of partnerships and joint ventures

What to Put on the Table

This paper investigates under which circumstances negotiating simultaneously over multiple issues or assets helps reduce ine¢ ciencies due to the presence of asymmetric information. We Önd that a simultaneous negotiation over multiple assets that are substitutes reduces ine¢ ciencies. The e§ect is stronger if goods are heterogeneous, and in this case the ine¢ ciency can be eliminated altogether. When assets are not substitutes ine¢ ciencies always prevail. We also study cases where co-ownership is possible (partnerships), allowing for asymmetric distributions, general valuation functions and for multiple assets. We show that e¢ cient dissolution is possible if all agents valuations at their types where gains of trade are minimal are equal: For this to hold, the agent that most likely has the highest valuation for a given asset should initially own a bigger share of that asset. We discuss implications of these Öndings for the design of partnerships and joint ventures

A Practical Monadic Aspect Weaver

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A Typed Monadic Embedding of Aspects

International audienceWe describe a novel approach to embed pointcut/advice aspects in a typed functional programming language like Haskell. Aspects are first-class, can be deployed dynamically, and the pointcut language is extensible. Type soundness is guaranteed by exploiting the un- derlying type system, in particular phantom types and a new anti- unification type class. The use of monads brings type-based rea- soning about effects for the first time in the pointcut/advice setting, thereby practically combining Open Modules and EffectiveAdvice, and enables modular extensions of the aspect language