Search results for "ISO"

Strategies of Identification of a Base-Isolated Hospital Building by Coupled Quasi-Static and Snap-Back Tests

2020

In this paper, the description of a series of quasi-static pushing tests and dynamic snap-back tests is proposed, involving the base-isolated emergency building of the Palermo university hospital. The base isolation system is characterized by a set of double-curved friction pendulum isolators placed on the top of the columns of the underground level, characteristics that cannot be found in the experimental studies available in the literature. The aim of the work was to investigate the static and dynamic properties of the building in question and comparing the in-situ results with the characteristics assigned during the design process and to assess the level of agreement. Static lateral push…

Characterization of the porous structure of Chilean volcanic soils by nitrogen adsorption and mercury porosimetry

2004

Pore volume, specific surface area (SSA), and total intragranular porosity (TIP) of Chilean soils derived from volcanic materials were studied. Soil samples involving the 0-15 and 15-30 cm depth of virgin and cultivated Collipulli (Ultisol) and Diguillin (Andisol) soils at two particle size fractions (<1 mm and <2 µm) were considered. From mercury porosimetry and N2 adsorption, mainly mesopores (pore diameter, dpore, about 10 nm) were determined for <1 mm Collipulli samples. Diguillin <1 mm soil shows macroporosity with dpore from 70 nm to 7000 nm. The clay fraction of Collipulli has macropores (dpore from 2000 nm to 40000 nm) and mesopores (dpore from 3 nm to 23 nm), while for Diguillin cl…

Experimental study of a naturally weathered stiff clay

2016

Studying the shear strength of a naturally weathered clay is important to understand rain-induced slope failures in weathered soils. However, experimental studies on naturally weathered soils are limited. The paper focuses on the laboratory experimental investigation carried out to analyse the shear strength of a naturally weathered stiff clay that can be found in unsaturated conditions in situ. This has an important practical relevance in the evaluation of the stability conditions of natural slopes at clay outcrops. Different experimental techniques of suction measurement were used to obtain the soil-water retention curve of the clay over a wide range of suctions. Scanning electronic micr…

Selection of time windows in the horizontal-to-vertical noise spectral ratio by means of cluster analysis

2016

The selection of the elementary analysis windows in continuous noise recordings for optimal estimation of the mean horizontal‐to‐vertical spectral ratio (HVSR) curve is generally performed by visual inspection of HVSR curves considered as functions of time. Starting from full‐length records, HVSR curves are determined in consecutive time windows of appropriate lengths. Time windows with HVSR curves that are anomalous on the basis of a simple visual inspection are generally ignored in the computation of the average HVSR curve. It is often very difficult to optimize the selection of time windows to be used for the calculation of the HVSR curve representative of a site. The use of nonobjective…

Las normas ISO/IEC como mecanismos de responsabilidad proactiva en el Reglamento General de Protección de Datos

2021

El mercado de la certificación ha experimentado un auge sin precedentes tras la entrada en vigor y ulterior aplicación del RGPD. Ello obliga a poner de relieve la relevancia de estos mecanismos como elementos claves en la prevención de potenciales violaciones de la seguridad de los datos personales. En el presente trabajo examinamos cómo la naturaleza técnica de estos instrumentos ha cedido hacia su corregulación a los efectos de garantizar una adaptación efi ciente a los continuos cambios de una gran tipología de productos, servicios o sistemas. Pretende proporcionarse una panorámica holística sobre la práctica totalidad de estándares que afectan a las dimensiones de privacidad y protecció…

HyperWall: A Hypervisor for Detection and Prevention of Malicious Communication

2020

Malicious programs vary widely in their functionality, from key-logging to disk encryption. However, most malicious programs communicate with their operators, thus revealing themselves to various security tools. The security tools incorporated within an operating system are vulnerable to attacks due to the large attack surface of the operating system kernel and modules. We present a kernel module that demonstrates how kernel-mode access can be used to bypass any security mechanism that is implemented in kernel-mode. External security tools, like firewalls, lack important information about the origin of the intercepted packets, thus their filtering policy is usually insufficient to prevent c…

The regression Tsetlin machine: a novel approach to interpretable nonlinear regression

2019

Relying simply on bitwise operators, the recently introduced Tsetlin machine (TM) has provided competitive pattern classification accuracy in several benchmarks, including text understanding. In this paper, we introduce the regression Tsetlin machine (RTM), a new class of TMs designed for continuous input and output, targeting nonlinear regression problems. In all brevity, we convert continuous input into a binary representation based on thresholding, and transform the propositional formula formed by the TM into an aggregated continuous output. Our empirical comparison of the RTM with state-of-the-art regression techniques reveals either superior or on par performance on five datasets. Thi…

Seismic behavior of structures equipped with variable friction dissipative (VFD) systems

2021

Usually, to mitigate the stresses in framed structures, different strategies are used. Among them, base isolation, viscous/friction/metallic yielding dampers and tuned mass dumpers have been widely investigated. Fluid Viscous Dampers (FVD) probably result the most diffused for the simplicity in the applications. However, these type of dampers request limited interstorey drifts to avoid dangerous effects. Further, they have an elevate cost. On the contrary, friction dampers are not so expensive but request high interstorey drifts to give a significant contribute in the dissipation of energy during an earthquake. In this paper an approach for the energy dissipation by friction, modified with …

2018

Physical fitness is crucial to warfighters' performance in the battlefield. Previous studies have shown negative changes in their hormonal and neuromuscular responses induced by military field training (MFT). The purpose of this study was to investigate the changes in hormonal and immunological values and body composition during a prolonged MFT and to find out how warfighters' physical condition influences these changes. Conscripts (n = 49, age 20 ± 1 years, height 179 ± 9 cm, body mass 73.8 ± 7.8 kg, fat 12.6 ± 3.7% and BMI 23 kg/m²) were measured before, during, after MFT, and after a 4-day recovery period. Serum insulin-like growth factor-1 (IGF-1), tumor necrosis factor alpha (TNF-α), i…

Rendimiento de las pruebas complementarias en el estudio de pacientes con dolor abdominal crónico

2021

Resumen: Introducción: El dolor abdominal crónico (DAC) en la infancia es un motivo de consulta frecuente que afecta a la vida familiar, y en ocasiones precisa realización de pruebas complementarias. El objetivo fue realizar el análisis cualitativo, cuantitativo y económico de las pruebas que se solicitan. Pacientes y métodos: Estudio observacional, prospectivo y multicéntrico, incluyendo pacientes entre 4-15 años con DAC. Se diferenciaron 2 grupos: orgánico y funcional. Se recogieron las siguientes variables: clínicas, pruebas complementarias y su coste. Resultados: Se incluyeron 235 niños con DAC (edad media 9,7 ± 2,7 años). Un 79% resultaron trastornos funcionales y un 21% orgánicos. Cas…