6,501 research outputs found
Towards Parameterized Regular Type Inference Using Set Constraints
We propose a method for inferring \emph{parameterized regular types} for
logic programs as solutions for systems of constraints over sets of finite
ground Herbrand terms (set constraint systems). Such parameterized regular
types generalize \emph{parametric} regular types by extending the scope of the
parameters in the type definitions so that such parameters can relate the types
of different predicates. We propose a number of enhancements to the procedure
for solving the constraint systems that improve the precision of the type
descriptions inferred. The resulting algorithm, together with a procedure to
establish a set constraint system from a logic program, yields a program
analysis that infers tighter safe approximations of the success types of the
program than previous comparable work, offering a new and useful efficiency vs.
precision trade-off. This is supported by experimental results, which show the
feasibility of our analysis
A multiplexing architecture for mixed-signal CMOS fuzzy controllers
Limits to precision impose limits to the complexity of analog circuits, hence fuzzy analog
controllers are usually oriented to fast low-power systems with low-medium complexity. This
paper presents a strategy to preserve most of the advantages of an analog implementation, while
allowing a marked increment in system complexity.The works in this papaer has been partially funded by the spanish
C.I.C.Y.T. under contract TIC96-1392-C02-02 (SIVA
Australian Asian options
We study European options on the ratio of the stock price to its average and viceversa. Some of these options are traded in the Australian Stock Exchange since 1992, thus we call them Australian Asian options. For geometric averages, we obtain closed-form expressions for option prices. For arithmetic means, we use dierent approximations that produce very similar results.Asian options, arithmetic average, geometric average, edgeworth expansion, lognormal distribution, gamma distribution
Volterra Model Based Predictive Control, application to a Pem Fue Cell
14th Nordic Process Control Workshop - Espoo, Finland
Duration: 23 Aug 2007 → 25 Aug 2007This paper presents a non linear model predictive controller for a PEM fuel
cell for which the starvation control is the main objective. A second order Volterra
model for control is obtained using input/output data for which the power supplied by
the fuel cell is considered as a measurable disturbance. The controller developed allows
to solve the nonlinear objective function in a way that it can be actually implemented
in fast systems like Fuel cells. The use of a nonlinear controller is justified while
comparing the outcome obtained with a linear controller of the same class
Danzas Espanolas
https://digitalcommons.library.umaine.edu/mmb-ps/3531/thumbnail.jp
Aplicabilidad de las TIG en la generación de escenarios de futuro para una gestión integrada de las zonas costeras
Para una planificación y gestión coherente de las zonas costeras es fundamental que exista una profunda
comprensión de las interacciones entre el hombre y el medio físico, siendo preciso integrar la información sobre el
conocimiento del medio natural aportada por las diferentes disciplinas científicas, junto con la información del
contexto socio-económico, normativo y cultural. Por tanto, la toma de decisiones en los espacios litorales debe
apoyarse en instrumentos interdisciplinares, capaces de operar con distintos tipos de datos y abordar situaciones
complejas e impredecibles.
La simulación de escenarios es una importante herramienta para evaluar desarrollos futuros en sistemas
complejos y dinámicos que poseen un número alto de incertidumbres, y por ello es una técnica muy adecuada para
la gestión de las zonas costeras. Los escenarios permiten integrar modelos socioeconómicos con modelos físicos,
químicos o biológicos, reflejar una amplia gama de tendencias y dinámicas, y trabajar con distintas escalas
temporales y espaciales.
En el presente artículo se examina el uso actual y el potencial de las TIG en la generación de escenarios de futuro
para la gestión integrada de las zonas costeras. Para ello se ha realizado un análisis de su aplicabilidad de las TIG,
identificando en qué fases de la elaboración de escenarios se pueden utilizar. Los resultados indican que estas
tecnologías tienen un alto potencial y son aplicables en todas las fases de la generación de los escenarios. Una de
las fortalezas identificadas es que las TIG incrementan la transparencia y fiabilidad de la generación de escenarios
de futuro facilitando los procesos equitativos y participativos de negociación, toma de decisiones y planificación en
las zonas costeras.To achieve a coherent planning and management of coastal areas it is necessary having a deep understanding of
the interactions existing between human-being and the physical environment, integrating information from different
scientific disciplines (hydrology, morphodynamics, soil science, ecology, etc.) and socio-economic, normative and
cultural context information. Therefore decision-making in coastal areas must be based on interdisciplinaryinstruments capable of working with different type of data and dealing with complex and unpredictable situations.
Scenario-making is one of the most important tools for assessing future developments in complex and dynamic
systems which have a high number of uncertainties; thus it is a very suitable approach for coastal zone
management. Scenarios can integrate socio-economic models with physical, chemical or biological models, reflect a
broad range of trends and dynamics, and work with different temporal and spatial scales.
In this paper the current and potential use of Geographical Information Technologies (GIT) is examined in the
generation of future scenarios for an integrated management of coastal areas. An analysis of the applicability of the
GIT has been done, identifying at which stage of scenario development GIT can be used. The results indicate that GIT
have great potential and are applicable at all stages of the scenarios generation. One of the strengths identified is
that GIT increase the transparency and reliability of the generation of future scenarios and facilitate equitable and
participatory processes of negotiation, decision making and planning in coastal areas
Spreading the use of economic methods in coastal risk management: a simple but insightful “calculator”
Navas, F.; Malvárez, G.; Penning-Rowsell, E., and Parker, D.J., 2020. Spreading the use of economic methods in coastal risk management: A simple but insightful "calculator". In: Malvárez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 1217–1222. Coconut Creek (Florida), ISSN 0749-0208.
European Directives, such as the EU Floods Directive (2007/60/EC) require that decision makers include objective methodologies, such as benefit-cost analysis, in their assessments of flood risk reduction measures.
Methodologies to establish a sustainable knowledge framework addressing the costs and benefits of prevention and response to coastal hazards resulting from hydro-meteorological, hydrographic and other natural events and processes (e.g. flooding, beach erosion, cliff erosion, sea level rise) are not homogeneously implemented in the European Union. Until now, investment decisions in this field have been made more on local political imperatives than logical economic risk assessments. This paper aims to overcome some these limitations by demonstrating the usefulness of a simplified benefit-cost methodology and its application to a coastal case where a number of alternative flood risk reduction schemes are considered. The method allows the economically optimal scheme to be identified. The method is discussed within the context of generally poorly comprehended aspects; issues presented in coupling benefit-cost methods with vulnerability and related assessments; and key data uncertainties
An integrated approach toward the incorporation of clouds in the temperature retrievals from microwave measurements
In this paper, we address the characterization of clouds and its inclusion in
microwave retrievals in order to study its effect on tropospheric temperature
profiles measured by TEMPERA radiometer. TEMPERA is the first ground-based
microwave radiometer that makes it possible to obtain temperature profiles in the
troposphere and stratosphere at the same time. In order to characterize the
clouds a multi-instrumental approach has been adopted. Cloud base altitudes
were detected using ceilometer measurements while the integrated liquid water
was measured by TROWARA radiometer. Both instruments are co-located with
TEMPERA in Bern (Switzerland). Using this information and a constant Liquid
Water Content value inside the cloud a liquid profile is provided to
characterize the clouds in the inversion algorithm. Microwave temperature
profiles have been obtained incorporating this water liquid profile in the
inversion algorithm and also without considering the clouds, in order to
assess its effect on the retrievals. The results have been compared with the
temperature profiles from radiosondes which are launched twice a day at the
aerological station of MeteoSwiss in Payerne (40 km W of Bern). Almost 1
year of data have been analysed and 60 non-precipitating cloud cases were
studied. The statistical analysis carried out over all the cases evidenced
that temperature retrievals improved in most of the cases when clouds were
incorporated in the inversion algorithm
- …