A study of set-sharing analysis via cliques

We study the problem of efñcient, scalable set-sharing analysis of logic programs. We use the idea of representing sharing information as a pair of abstract substitutions, one of which is a worst-case sharing representation called a clique set, which was previously proposed for the case of inferring pair-sharing. We use the clique-set representation for (1) inferring actual set-sharing information, and (2) analysis within a topdown framework. In particular, we define the abstract functions required by standard top-down analyses, both for sharing alone and also for the case of including freeness in addition to sharing. Our experimental evaluation supports the conclusión that, for inferring set-sharing, as it was the case for inferring pair-sharing, precisión losses are limited, while useful efñciency gains are obtained. At the limit, the clique-set representation allowed analyzing some programs that exceeded memory capacity using classical sharing representations.

Efficient representations for set-sharing analysis

Abstract is not available.

Precise set sharin analysis for java-style programs (and proofs).

Finding useful sharing information between instances in object- oriented programs has recently been the focus of much research. The applications of such static analysis are multiple: by knowing which variables definitely do not share in memory we can apply conventional compiler optimizations, find coarse-grained parallelism opportunities, or, more importantly, verify certain correctness aspects of programs even in the absence of annotations. In this paper we introduce a framework for deriving precise sharing information based on abstract interpretation for a Java-like language. Our analysis achieves precision in various ways, including supporting multivariance, which allows separating different contexts. We propose a combined Set Sharing + Nullity + Classes domain which captures which instances do not share and which ones are definitively null, and which uses the classes to refine the static information when inheritance is present. The use of a set sharing abstraction allows a more precise representation of the existing sharings and is crucial in achieving precision during interprocedural analysis. Carrying the domains in a combined way facilitates the interaction among them in the presence of multivariance in the analysis. We show through examples and experimentally that both the set sharing part of the domain as well as the combined domain provide more accurate information than previous work based on pair sharing domains, at reasonable cost.

Precise set sharing and nullity analysis for java-style program

Finding useful sharing information between instances in object- oriented programs has been recently the focus of much research. The applications of such static analysis are multiple: by knowing which variables share in memory we can apply conventional compiler optimizations, find coarse-grained parallelism opportunities, or, more importantly,erify certain correctness aspects of programs even in the absence of annotations In this paper we introduce a framework for deriving precise sharing information based on abstract interpretation for a Java-like language. Our analysis achieves precision in various ways. The analysis is multivariant, which allows separating different contexts. We propose a combined Set Sharing + Nullity + Classes domain which captures which instances share and which ones do not or are definitively null, and which uses the classes to refine the static information when inheritance is present. Carrying the domains in a combined way facilitates the interaction among the domains in the presence of mutivariance in the analysis. We show that both the set sharing part of the domain as well as the combined domain provide more accurate information than previous work based on pair sharing domains, at reasonable cost.

Diseño de un modelo de riesgo integral de incendios forestales mediante técnicas multicriterio y su automatización en sistemas de información geográfica : una aplicación en la Comunidad Valenciana

Los incendios forestales son la principal causa de mortalidad de árboles en la Europa mediterránea y constituyen la amenaza más seria para los ecosistemas forestales españoles. En la Comunidad Valenciana, diariamente se despliega cerca de un centenar de vehículos de vigilancia, cuya distribución se apoya, fundamentalmente, en un índice de riesgo de incendios calculado en función de las condiciones meteorológicas. La tesis se centra en el diseño y validación de un nuevo índice de riesgo integrado de incendios, especialmente adaptado a la región mediterránea y que facilite el proceso de toma de decisiones en la distribución diaria de los medios de vigilancia contra incendios forestales. El índice adopta el enfoque de riesgo integrado introducido en la última década y que incluye dos componentes de riesgo: el peligro de ignición y la vulnerabilidad. El primero representa la probabilidad de que se inicie un fuego y el peligro potencial para que se propague, mientras que la vulnerabilidad tiene en cuenta las características del territorio y los efectos potenciales del fuego sobre el mismo. Para el cálculo del peligro potencial se han identificado indicadores relativos a los agentes naturales y humanos causantes de incendios, la ocurrencia histórica y el estado de los combustibles, extremo muy relacionado con la meteorología y las especies. En cuanto a la vulnerabilidad se han empleado indicadores representativos de los efectos potenciales del incendio (comportamiento del fuego, infraestructuras de defensa), como de las características del terreno (valor, capacidad de regeneración…). Todos estos indicadores constituyen una estructura jerárquica en la que, siguiendo las recomendaciones de la Comisión europea para índices de riesgo de incendios, se han incluido indicadores representativos del riesgo a corto plazo y a largo plazo. El cálculo del valor final del índice se ha llevado a cabo mediante la progresiva agregación de los componentes que forman cada uno de los niveles de la estructura jerárquica del índice y su integración final. Puesto que las técnicas de decisión multicriterio están especialmente orientadas a tratar con problemas basados en estructuras jerárquicas, se ha aplicado el método TOPSIS para obtener la integración final del modelo. Se ha introducido en el modelo la opinión de los expertos, mediante la ponderación de cada uno de los componentes del índice. Se ha utilizado el método AHP, para obtener las ponderaciones de cada experto y su integración en un único peso por cada indicador. Para la validación del índice se han empleado los modelos de Ecuaciones de Estimación Generalizadas, que tienen en cuenta posibles respuestas correlacionadas. Para llevarla a cabo se emplearon los datos de oficiales de incendios ocurridos durante el período 1994 al 2003, referenciados a una cuadrícula de 10x10 km empleando la ocurrencia de incendios y su superficie, como variables dependientes. Los resultados de la validación muestran un buen funcionamiento del subíndice de peligro de ocurrencia con un alto grado de correlación entre el subíndice y la ocurrencia, un buen ajuste del modelo logístico y un buen poder discriminante. Por su parte, el subíndice de vulnerabilidad no ha presentado una correlación significativa entre sus valores y la superficie de los incendios, lo que no descarta su validez, ya que algunos de sus componentes tienen un carácter subjetivo, independiente de la superficie incendiada. En general el índice presenta un buen funcionamiento para la distribución de los medios de vigilancia en función del peligro de inicio. No obstante, se identifican y discuten nuevas líneas de investigación que podrían conducir a una mejora del ajuste global del índice. En concreto se plantea la necesidad de estudiar más profundamente la aparente correlación que existe en la provincia de Valencia entre la superficie forestal que ocupa cada cuadrícula de 10 km del territorio y su riesgo de incendios y que parece que a menor superficie forestal, mayor riesgo de incendio. Otros aspectos a investigar son la sensibilidad de los pesos de cada componente o la introducción de factores relativos a los medios potenciales de extinción en el subíndice de vulnerabilidad. Summary Forest fires are the main cause of tree mortality in Mediterranean Europe and the most serious threat to the Spanisf forest. In the Spanish autonomous region of Valencia, forest administration deploys a mobile fleet of 100 surveillance vehicles in forest land whose allocation is based on meteorological index of wildlandfire risk. This thesis is focused on the design and validation of a new Integrated Wildland Fire Risk Index proposed to efficient allocation of vehicles and specially adapted to the Mediterranean conditions. Following the approaches of integrated risk developed last decade, the index includes two risk components: Wildland Fire Danger and Vulnerability. The former represents the probability a fire ignites and the potential hazard of fire propagation or spread danger, while vulnerability accounts for characteristics of the land and potential effects of fire. To calculate the Wildland Fire Danger, indicators of ignition and spread danger have been identified, including human and natural occurrence agents, fuel conditions, historical occurrence and spread rate. Regarding vulnerability se han empleado indicadores representativos de los efectos potenciales del incendio (comportamiento del fuego, infraestructurasd de defensa), como de las características del terreno (valor, capacidad de regeneración…). These indicators make up the hierarchical structure for the index, which, following the criteria of the European Commission both short and long-term indicators have been included. Integration consists of the progressive aggregation of the components that make up every level in risk the index and, after that, the integration of these levels to obtain a unique value for the index. As Munticriteria methods are oriented to deal with hierarchically structured problems and with situations in which conflicting goals prevail, TOPSIS method is used in the integration of components. Multicriteria methods were also used to incorporate expert opinion in weighting of indicators and to carry out the aggregation process into the final index. The Analytic Hierarchy Process method was used to aggregate experts' opinions on each component into a single value. Generalized Estimation Equations, which account for possible correlated responses, were used to validate the index. Historical records of daily occurrence for the period from 1994 to 2003, referred to a 10x10-km-grid cell, as well as the extent of the fires were the dependant variables. The results of validation showed good Wildland Fire Danger component performance, with high correlation degree between Danger and occurrence, a good fit of the logistic model used and a good discrimination power. The vulnerability component has not showed a significant correlation between their values and surface fires, which does not mean the index is not valid, because of the subjective character of some of its components, independent of the surface of the fires. Overall, the index could be used to optimize the preventing resources allocation. Nevertheless, new researching lines are identified and discussed to improve the overall performance of the index. More specifically the need of study the inverse relationship between the value of the wildfire Fire Danger component and the forested surface of each 10 - km cell is set out. Other points to be researched are the sensitivity of the index component´s weight and the possibility of taking into account indicators related to fire fighting resources to make up the vulnerability component.

Shadow Analysis of Soil Surface Roughness Compared to the Chain Set Method and Direct Measurement of Micro-relief.

Erosion potential and the effects of tillage can be evaluated from quantitative descriptions of soil surface roughness. The present study therefore aimed to fill the need for a reliable, low-cost and convenient method to measure that parameter. Based on the interpretation of micro-topographic shadows, this new procedure is primarily designed for use in the field after tillage. The principle underlying shadow analysis is the direct relationship between soil surface roughness and the shadows cast by soil structures under fixed sunlight conditions. The results obtained with this method were compared to the statistical indexes used to interpret field readings recorded by a pin meter. The tests were conducted on 4-m2 sandy loam and sandy clay loam plots divided into 1-m2 subplots tilled with three different tools: chisel, tiller and roller. The highly significant correlation between the statistical indexes and shadow analysis results obtained in the laboratory as well as in the field for all the soil?tool combinations proved that both variability (CV) and dispersion (SD) are accommodated by the new method. This procedure simplifies the interpretation of soil surface roughness and shortens the time involved in field operations by a factor ranging from 12 to 20.

Analytic free-form lens design in 3D: coupling three ray sets using two lens surfaces

The two-dimensional analytic optics design method presented in a previous paper [Opt. Express 20, 5576–5585 (2012)] is extended in this work to the three-dimensional case, enabling the coupling of three ray sets with two free-form lens surfaces. Fermat’s principle is used to deduce additional sets of functional differential equations which make it possible to calculate the lens surfaces. Ray tracing simulations demonstrate the excellent imaging performance of the resulting free-form lenses described by more than 100 coefficients.

A linear chained approach for service invocation in IP multimedia subsystem.

IP Multimedia Subsystem (IMS) is considered to provide multimedia services to users through an IP-based control plane. The current IMS service invocation mechanism, however, requires the Serving-Call Session Control Function (S-CSCF) invokes each Application Server (AS) sequentially to perform service subscription pro?le, which results in the heavy load of the S-CSCF and the long session set-up delay. To solve this issue, this paper proposes a linear chained service invocation mechanism to invoke each AS consecutively. By checking all the initial Filter Criteria (iFC) one-time and adding the addresses of all involved ASs to the ?Route? header, this new approach enables multiple services to be invoked as a linear chain during a session. We model the service invocation mechanisms through Jackson networks, which are validated through simulations. The analytic results verify that the linear chained service invocation mechanism can effectively reduce session set-up delay of the service layer and decrease the load level of the S-CSCF

Analytic free-form lens design for imaging applications with high aspect ratio

A new three-dimensional analytic optics design method is presented that enables the coupling of three ray sets with only two free-form lens surfaces. Closely related to the Simultaneous Multiple Surface method in three dimensions (SMS3D), it is derived directly from Fermat?s principle, leading to multiple sets of functional differential equations. The general solution of these equations makes it possible to calculate more than 80 coefficients for each implicit surface function. Ray tracing simulations of these free-form lenses demonstrate superior imaging performance for applications with high aspect ratio, compared to conventional rotational symmetric systems.

A Recommendation Framework Based on the Analytic Network Process and its Application in the Semantic Technology Domain

When users face a certain problem needing a product, service, or action to solve it, selecting the best alternative among them can be a dicult task due to the uncertainty of their quality. This is especially the case in the domains where users do not have an expertise, like for example in Software Engineering. Multiple criteria decision making (MCDM) methods are methods that help making better decisions when facing the complex problem of selecting the best solution among a group of alternatives that can be compared according to different conflicting criteria. In MCDM problems, alternatives represent concrete products, services or actions that will help in achieving a goal, while criteria represent the characteristics of these alternatives that are important for making a decision.

Analytic free-form lens design for tracking integration in concentrating photovoltaics

In this work the concept of tracking integration in concentrating photovoltaics (CPV) is revisited and developed further. With respect to conventional CPV, tracking integration eliminates the clear separation between stationary units of optics and solar cells, and external solar trackers. This approach is capable of further increasing the concentration ratio and makes high concentrating photovoltaics (> 500x) available for single-axis tracker installations. The reduced external solar tracking effort enables possibly cheaper and more compact installations. Our proposed optical system uses two laterally moving plano-convex lenses to achieve high concentration over a wide angular range of ±24°. The lateral movement allows to combine both steering and concentration of the incident direct sun light. Given the specific symmetry conditions of the underlying optical design problem, rotational symmetric lenses are not ideal for this application. For this type of design problems, a new free-form optics design method presented in previous papers perfectly matches the symmetry. It is derived directly from Fermat's principle, leading to sets of functional differential equations allowing the successive calculation of the Taylor series coeficients of each implicit surface function up to very high orders. For optical systems designed for wide field of view and with clearly separated optical surfaces, this new analytic design method has potential application in both fields of nonimaging and imaging optics.

Lineability of the set of holomorphic mappings with dense range

Let U be an open subset of a separable Banach space. Let F be the collection of all holomorphic mappings f from the open unit disc D � C into U such that f(D) is dense in U. We prove the lineability and density of F in appropriate spaces for diferent choices of U. RESUMEN. Sea U un subconjunto abierto de un espacio de Banach separable. Sea F el conjunto de funciones holomorfas f definidas en el disco unidad D del plano complejo con valores en U tales que f(D) es denso en U. En el artículo se demuestra la lineabilidad y densidad del conjunto F para diferentes elecciones de U.

On real analytic functions of unbounded type

In this paper we prove several results on the existence of analytic functions on an infinite dimensional real Banach space which are bounded on some given collection of open sets and unbounded on others. In addition, we also obtain results on the density of some subsets of the space of all analytic functions for natural locally convex topologies on this space. RESUMEN. Los autores demuestran varios resultados de existencia de funciones analíticas en espacios de Banach reales de dimensión infinita que están acotadas en un colección de subconjuntos abiertos y no acotadas en los conjuntos de otra colección. Además, se demuestra la densidad de ciertos subconjuntos de funciones analíticas para varias topologías localmente convexas.

The analytic hierarchy process to support decision-making processes in infrastructure projects with social impact

There is an increasing awareness among all kinds of organisations (in business,government and civil society) about the benefits of jointly working with stakeholders to satisfy both their goals and the social demands placed upon them. This is particularly the case within corporate social responsibility (CSR) frameworks. In this regard, multi-criteria tools for decision-making like the analytic hierarchy process (AHP) described in the paper can be useful for the building relationships with stakeholders. Since these tools can reveal decision-maker’s preferences, the integration of opinions from various stakeholders in the decision-making process may result in better and more innovative solutions with significant shared value. This paper is based on ongoing research to assess the feasibility of an AHP-based model to support CSR decisions in large infrastructure projects carried out by Red Electrica de España, the sole transmission agent and operator of the Spanishelectricity system.

Meromorphic continuation of functions and arbitrary distribution of interpolation points

We characterize the region of meromorphic continuation of an analytic function ff in terms of the geometric rate of convergence on a compact set of sequences of multi-point rational interpolants of ff. The rational approximants have a bounded number of poles and the distribution of interpolation points is arbitrary.