Pictorial Narratives and Temporal Refinement

Refinements are proposed to the default reading of two successive pictures p,p' as p and then p'. The refinements are based on the Aristotelian dictum, no time without change, and the principle of inertia, no change without force, guided by the adage, a picture's worth a thousand words. Words describing pictures are formalized as predicates, some stative and some non-stative (expressing forces), and interpreted (in either case) over strings qua models, subject to finite-state projections supporting variable granularity. A form of string iconicity is explored, with an eye to more transparent representations

Managerial Overconfidence and Corporate Risk Management

We show that managerial overconfidence, which has been found to influence a number of corporate financial decisions, also affects corporate risk management. We find that managers increase their speculative activities using derivatives following speculative gains, while they do not reduce their speculative activities following speculative losses. This asymmetric response follows from selective selfattribution: successes tend to be attributed to one’s own skill, while failures tend to be attributed to bad luck. Thus, our results show that managerial behavioral biases can also impact corporate risk management.corporate risk management, behavioral biases, managerial overconfidence, speculation

Nanorod optical antennas for dipolar transitions

Optical antennas link objects to light. Here, we analyze metal nanorod antennas as cavities with variable reflection coefficients to derive the interaction of dipolar transitions with radiation through the antenna modes. The presented analytical model accurately describes the complete emission process, and is summarized in a phase-matching equation. We show how antenna modes evolve as they become increasingly more bound, i.e. plasmonic. The results illustrate why efficient antennas should not be too plasmonic, and how subradiant even modes can evolve into weakly-interacting dark modes. Our description is valid for the interaction of nanorods with light in general, and is thus widely applicable.Comment: 10 pages, 4 figures, submitte

Why Do Firms Engage in Selective Hedging?

Surveys of corporate risk management document that selective hedging, where managers incorporate their market views into firms’ hedging programs, is widespread in the U.S. and other countries. Stulz (1996) argues that selective hedging could enhance the value of firms that possess an information advantage relative to the market and have the financial strength to withstand the additional risk from market timing. We study the practice of selective hedging in a 10-year sample of North American gold mining firms and find that selective hedging is most prevalent among firms that are least likely to meet these valuemaximizing criteria -- (a) smaller firms, i.e., firms that are least likely to have private information about future gold prices; and (b) firms that are closest to financial distress. The latter finding provides support for the alternative possibility suggested by Stulz that selective hedging may also be driven by asset substitution motives. We detect weak relationships between selective hedging and some corporate governance measures, especially board size, but find no evidence of a link between selective hedging and managerial compensation.Corporate risk management, selective hedging, speculation, financial distress, corporate governance, managerial compensation

Researching the emerging impacts of open data: revisiting the ODDC conceptual framework

Open data has rapidly moved from being a niche interest, to being part of the global policy mainstream. Government-led open data initiatives have spread across the globe, and civil society or technologist experiments using data to improve governance have been spreading organically, from budget monitoring in Nigeria, to court transparency projects in Argentina. It is increasingly seen as enabler of a “data revolution” in the process of decision-making and accountability.  However, understanding how experience of open data will vary from country to country and context to context, and, understanding the common features of open data that are shaping its implementation in these diverse settings, requires broad-based research framework. It requires research that can engage with both existing realities of decision-making in sectors, acknowledging the growing complexity of this process in an increasingly networked society. In this paper we have reviewed the framework of the “Open Data in Developing Countries”(ODDC) project, the largest research project on the impact of open data in developing countries to date.  The framework was designed to help explore the link between openness in the data ecosystem, decentralized changes in decision-making, and positive and negative emerging impacts such as transparency and accountability, inclusion and empowerment as well as innovation and economic development.  It was tested to generate cross-learning from 17 in-depth cases studies in 14 countries, as well as generate policy-relevant findings.  This paper reviews and updates the original framework based on the findings and reflections developed during the research project

Evaluación de reglas de prioridad para la asignación de recursos en la gestión de proyectos

En el proyecto se va a afrontar el problema de la gestión de proyectos con restricciones de recursos llamado Resource-Constraint Project Scheduling Problem (RCPSP). Hace referencia a la gestión de cualquier proyecto en el que se tengan unos recursos por unidad de tiempo limitados y que por lo tanto no haga posible la realización simultánea de todas las actividades paralelas sino que haya que elegir un orden para la realización de las mismas. El objetivo principal es el de realizar el proyecto empleando el menor tiempo posible y para ello hay que encontrar el orden más beneficioso de ejecución de las actividades teniendo en cuenta no solo la cantidad de recursos y material necesaria para cada una sino también su duración, así como cuales son sus sucesores y predecesores. Para ello se utilizan las ´priority rules´ o reglas de prioridad que asignan a cada actividad un determinado valor y son a continuación elegidas y ejecutadas atendiendo al propio valor. Dentro de este apartado se buscará en la bibliografía existente y se realizará a través del programa Plant Simulation las 10 reglas de prioridad que según la documentación relativa a este tema supuestamente mejor funcionan y se analizarán y compararán para 1920 proyectos distintos. Por último se introducirá un recurso novedoso en este tema al que se denominará recurso tipo área. Consiste en la introducción de una nueva restricción para la ejecución de las actividades. Es útil cuando se tiene una superficie determinada, por ejemplo una empresa con distintas máquinas y a cada actividad se le asigna una cierta zona de la empresa para ser desarrollada (por ejemplo requiere ser realizada por una determinada máquina). Así pues mientras haya otra actividad empleando esa zona requerida, no podrá ser ejecutada al no estar disponible este nuevo recurso por lo que puede variar en cierta medida el orden preestablecido por las reglas de prioridad. Se considera que además de para la planificación de proyectos a realizar dentro de empresas, puede ser de gran importancia en la gestión en proyectos de obra (requerimientos de grúas, restringir el paso hacia determinados lugares en el que se están desarrollando actividades etc.

Managerial Overconfidence and Corporate Risk Management

We show that managerial overconfidence, which has been found to influence a number of corporate financial decisions, also affects corporate risk management. We find that managers increase their speculative activities using derivatives following speculative gains, while they do not reduce their speculative activities following speculative losses. This asymmetric response follows from selective selfattribution: successes tend to be attributed to one’s own skill, while failures tend to be attributed to bad luck. Thus, our results show that managerial behavioral biases can also impact corporate risk management