3,273 research outputs found

    LIPIcs

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    The monitoring of event frequencies can be used to recognize behavioral anomalies, to identify trends, and to deduce or discard hypotheses about the underlying system. For example, the performance of a web server may be monitored based on the ratio of the total count of requests from the least and most active clients. Exact frequency monitoring, however, can be prohibitively expensive; in the above example it would require as many counters as there are clients. In this paper, we propose the efficient probabilistic monitoring of common frequency properties, including the mode (i.e., the most common event) and the median of an event sequence. We define a logic to express composite frequency properties as a combination of atomic frequency properties. Our main contribution is an algorithm that, under suitable probabilistic assumptions, can be used to monitor these important frequency properties with four counters, independent of the number of different events. Our algorithm samples longer and longer subwords of an infinite event sequence. We prove the almost-sure convergence of our algorithm by generalizing ergodic theory from increasing-length prefixes to increasing-length subwords of an infinite sequence. A similar algorithm could be used to learn a connected Markov chain of a given structure from observing its outputs, to arbitrary precision, for a given confidence

    Keynote: The first-order logic of signals

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    Formalizing properties of systems with continuous dynamics is a challenging task. In this paper, we propose a formal framework for specifying and monitoring rich temporal properties of real-valued signals. We introduce signal first-order logic (SFO) as a specification language that combines first-order logic with linear-real arithmetic and unary function symbols interpreted as piecewise-linear signals. We first show that while the satisfiability problem for SFO is undecidable, its membership and monitoring problems are decidable. We develop an offline monitoring procedure for SFO that has polynomial complexity in the size of the input trace and the specification, for a fixed number of quantifiers and function symbols. We show that the algorithm has computation time linear in the size of the input trace for the important fragment of bounded-response specifications interpreted over input traces with finite variability. We can use our results to extend signal temporal logic with first-order quantifiers over time and value parameters, while preserving its efficient monitoring. We finally demonstrate the practical appeal of our logic through a case study in the micro-electronics domain

    LNCS

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    Contract-based design is a promising methodology for taming the complexity of developing sophisticated systems. A formal contract distinguishes between assumptions, which are constraints that the designer of a component puts on the environments in which the component can be used safely, and guarantees, which are promises that the designer asks from the team that implements the component. A theory of formal contracts can be formalized as an interface theory, which supports the composition and refinement of both assumptions and guarantees. Although there is a rich landscape of contract-based design methods that address functional and extra-functional properties, we present the first interface theory that is designed for ensuring system-wide security properties. Our framework provides a refinement relation and a composition operation that support both incremental design and independent implementability. We develop our theory for both stateless and stateful interfaces. We illustrate the applicability of our framework with an example inspired from the automotive domain

    New Zealand: The State of Liberal Democracy

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    This article is a brief report on constitutional developments and cases in New Zealand in 2017. The authors discuss several topics including the operation of New Zealand’s Mixed-Member Proportional voting system, New Zealand’s constitutional commitment to liberal democracy, and the issue of prisoner voting

    Predicción del diámetro máximo sobre muñón en árboles podados de Pinus taeda L. origen Marion en el NE de Corrientes, Argentina

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    El diámetro máximo sobre muñones (dmsm) de ejemplares de Pinus taeda L. origen Marion en el NE de Corrientes, Argentina, puede ser estimado con precisión en rodales aplicando de uno a cuatro levantes de poda, hasta una altura de 8,7 m. Las variables de los arboles empleadas en el modelo ajustado para estimar el dmsm para un número de levantes de poda dado fueron el diámetro a la altura del pecho (dap), la altura total (H) y la altura de la base de copa verde previo a la poda (bcvpp). El mejor modelo ajustado y validado contra una muestra independiente fue: dmsm (cm) = 2,66941 + 0,374445*dap + 0,50723* DAPO Donde DAPO = dap * ((H - bcvpp) / (H – 1,3)) dmsm y dap son expresados en centímetros y tanto H como bcvpp en metros. Cotejada la bondad del ajuste contra una muestra independiente el error promedio fue 0,04 cm y el error absoluto promedio alcanzo 0,91 cm.The maximum diameter over stub (dos) in trees of Pinus taeda L. origin Marion in the Northeast of the Province of Corrientes, Argentina, can be predicted with accuracy tor any pruning lift up to a maximum of four, and a dos height of 8.7 m above the ground. Tree variables employed for maximum dos prediction were diameter at breast height (D.B.H.), total height (Ht) and height above ground of the base of green crown before pruning (gcbbp) The best fitting and validated model against an independent database was: dos (cm) = 2.66941 + 0.374445* D.B.H. + 0.50723* DAPO Where DAPO = D.B.H. * ((H - bcvpp) / (H – 1,3)) D.B.H and dos are expressed in centimeters, Ht and gcbbp are in meters In the validation of the model, a mean error of 0.04 cm and an absolute mean error of 0.91 cm was obtained.EEA MontecarloFil: Fassola, Hugo Enrique. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Montecarlo; ArgentinaFil: Ferrere, Paula. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Montecarlo; ArgentinaFil: Rodríguez A., Francisco. Papelera del Plata S.A.; Argentin

    HV/HR-CMOS sensors for the ATLAS upgrade—concepts and test chip results

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    In order to extend its discovery potential, the Large Hadron Collider (LHC) will have a major upgrade (Phase II Upgrade) scheduled for 2022. The LHC after the upgrade, called High-Luminosity LHC (HL-LHC), will operate at a nominal leveled instantaneous luminosity of 5× 1034 cm−2 s−1, more than twice the expected Phase I . The new Inner Tracker needs to cope with this extremely high luminosity. Therefore it requires higher granularity, reduced material budget and increased radiation hardness of all components. A new pixel detector based on High Voltage CMOS (HVCMOS) technology targeting the upgraded ATLAS pixel detector is under study. The main advantages of the HVCMOS technology are its potential for low material budget, use of possible cheaper interconnection technologies, reduced pixel size and lower cost with respect to traditional hybrid pixel detector. Several first prototypes were produced and characterized within ATLAS upgrade R&D effort, to explore the performance and radiation hardness of this technology. In this paper, an overview of the HVCMOS sensor concepts is given. Laboratory tests and irradiation tests of two technologies, HVCMOS AMS and HVCMOS GF, are also given

    Radiation-hard active pixel sensors for HL-LHC detector upgrades based on HV-CMOS technology

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    Luminosity upgrades are discussed for the LHC (HL-LHC) which would make updates to the detectors necessary, requiring in particular new, even more radiation-hard and granular, sensors for the inner detector region. A proposal for the next generation of inner detectors is based on HV-CMOS: a new family of silicon sensors based on commercial high-voltage CMOS technology, which enables the fabrication of part of the pixel electronics inside the silicon substrate itself. The main advantages of this technology with respect to the standard silicon sensor technology are: low material budget, fast charge collection time, high radiation tolerance, low cost and operation at room temperature. A traditional readout chip is still needed to receive and organize the data from the active sensor and to handle high-level functionality such as trigger management. HV-CMOS has been designed to be compatible with both pixel and strip readout. In this paper an overview of HV2FEI4, a HV-CMOS prototype in 180 nm AMS technology, will be given. Preliminary results after neutron and X-ray irradiation are shown

    Stand density management diagrams of Eucalyptus viminalis: predicting stem volume, biomass and canopy cover for different production purposes

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    Stand density management diagrams (SDMD) provide a guide for forest density management taking into account stands attributes such as trees´ diameter or volume. One of the most common species planted in Pampean plains of Argentina is Eucalyptus viminalis for multiple objectives: solid wood use or firewood in local markets, pulp for cellulose industry and to provide services for agriculture and cattle raising (windbreaks or cattle refuge). The objective of this study was to gather the available production information /inventory dataand to develop a first SDMD for estimating standing volume, biomass and canopy cover of E. viminalis as a tool for forest managers aiming at different plantation purposes. Data to develop the SDMD were obtained from 161 plots, distributed along a climate and soil gradient. We also generated two predictive equations capable of estimating dominant height from the diameter of the trees as well as canopy cover from stand basal area. As an example of application, the SDMD was used to estimate the wood production of three alternative systems: a) an unmanaged plantation (simulating a common practice in the region), b) a mixed production system such as an agroforestry system, and c) a plantation that maximizes wood biomass or volume production.Fil: Gyenge, Javier Enrique. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Agencia de Extensión Rural Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Lupi, A.. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Ferrere, P.. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Milione, Germán Marcelo. Universidad Nacional del Centro de la Provincia de Buenos Aires. Rectorado. Instituto de Hidrología de Llanuras - Sede Azul. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto de Hidrología de Llanuras - Sede Azul; ArgentinaFil: Martinez Meier, Alejandro Gabriel. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Caballé, G.. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Dominguez Daguer, Diego Rafael. No especifíca;Fil: Fernandez, Maria Elena. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Agencia de Extensión Rural Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentin

    Evolución de las principales variables de árboles de Pinus taeda L. sometidos a diferentes tratamientos silviculturales en el nordeste de la provincia de Corrientes, Argentina.

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    A study was developed in order to examine the relationship between thinning, pruning and increment of trees and stands of Pinus taeda L., as well as to determine models that could predict production and quality of logs. Information on diameter at breath height (dbh), total height (h) and volume (dbh2* h) were obtained in a trial established in 1996, close to St. Tome city in Corrientes Province (Argentina). A systematic design was employed; at age three years plots of the original plantation were thinned to 1666, 833, 416 and 208 stem/ha. In each density, pruning was applied with four intensities, 0, 30, 50 and 70 % of green crown depth removal and with one year interval different pruning-lift were applied, 2,3, and 4 lifts. Five years old data were analyzed. After the analysis it was concluded that tree variables were affected in different grades by thinning,  pruning and number of pruning lift applied. Height was the less affected variable, although high intensity pruning (more than 50 %) have a negative effect on height growth. Thinning practice was effective when done in stands of low densities with pruning up to 30 % of green crown removal, growth of these trees was similar to those growing in the control plots.El presente estudio fue desarrollado con el propósito de cuantificar las relaciones existentes entre raleos, podas y crecimiento tanto en plantaciones, como en árboles de Pinus taeda L., y con la finalidad de construir modelos que puedan predecir la producción y calidad de productos futuros. Se propuso como objetivo analizar la información de las variables diámetro a la altura del pecho (dap), altura total y volumen cilindrométrico (dap2* h) en un ensayo, instalado en el año 1996 en las cercanías de la localidad de Santo Tomé, Provincia de Corrientes (Argentina). Para cumplir con el objetivo propuesto se generaron mediante raleo selectivo a los 3 años cuatro densidades diferentes (1666; 833; 416 y 208 pla/ha). En cada densidad se aplicaron cuatro intensidades de podas (0; 30; 50 y 70%, respecto de la profundidad de copa verde), las cuales se efectuaron en 2, 3 y 4 realces con intervalos de un año entre podas. Una vez analizados los datos obtenidos, después de 5 años de observación, se puede concluir que las variables analizadas se vieron afectadas, en distintos grados, por la intensidad de los raleos y por los grados y número de podas aplicados. La altura total fue la variable menos afectada, aunque las podas fuertes (mayores a 50% de remoción de copa verde) alteraron negativamente su evolución. La práctica de raleos fue efectiva cuando se realizaron podas del 30% trabajando en densidades bajas (416 plantas por hectárea) debido a que los ejemplares lograron igual crecimiento que los tratamientos sin poda
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