Search results for "methods"

Real-time acquisition of complex optical fields by binary amplitude modulation

2017

We describe, through simulations and experiments, a real-time wavefront acquisition technique using random binary amplitude masks and an iterative phase retrieval algorithm based on the Fresnel propagator. By using a digital micromirror device, it is possible to recover an unknown complex object by illuminating with this set of masks and simultaneously recording the resulting intensity patterns with a high-speed camera, making this technique suitable for dynamic applications.

A multiscale method for gamma/h discrimination in extensive air showers

2011

We present a new method for the identification of extensive air showers initiated by different primaries. The method uses the multiscale concept and is based on the analysis of multifractal behaviour and lacunarity of secondary particle distributions together with a properly designed and trained artificial neural network. The separation technique is particularly suited for being applied when the topology of the particle distribution in the shower front is as largely detailed as possible. Here, our method is discussed and applied to a set of fully simulated vertical showers in the experimental framework of ARGO-YBJ, taking advantage of both the space and time distribution of the detected sec…

Testing Soil Encasing Materials for Measuring Hydraulic Conductivity of a Sandy-Loam Soil by the Cube Methods

2008

The Cube Method (CM) and the Modified Cube Method (MCM) were developed for measuring vertical (K v ) and horizontal (K h ) saturated hydraulic conductivity of a single soil sample. By these methods, a cube of soil is carved out in situ and a suitable material is applied to enclose the cube in a tightly fitting casing before moving the sample to the laboratory. Problems may be associated with the use of gypsum, originally used to encase soil. The suitability of molten wax and expandable polyurethane foam to encase a soil cube was tested for a sandy-loam soil. Wax-treated samples yielded lower conductivity results than untreated samples by a maximum factor of 3.7. The observed discrepancies w…

Constructing Knowledge through a Role-Play in a Web-Based Learning Environment

2003

This study aimed to find out how and on what level the students of two separate secondary schools shared and constructed knowledge on imperialism by interacting through historical role characters in a Web-based environment. Furthermore, the study aimed to find out how social and contextual features affected the nature of knowledge sharing and construction. The data about the history project were gathered by various means in order to validate the findings of the case study. The results demonstrated that the level of the Web-based messages remained quite low. Also the use of the Web-based environment in terms of shared knowledge construction was rather weak. In comparison, different instruct…

Complex adaptative systems and computational simulation in Archaeology

2017

Traditionally the concept of ‘complexity’ is used as a synonym for ‘complex society’, i.e., human groups with characteristics such as urbanism, inequalities, and hierarchy. The introduction of Nonlinear Systems and Complex Adaptive Systems to the discipline of archaeology has nuanced this concept. This theoretical turn has led to the rise of modelling as a method of analysis of historical processes. This work has a twofold objective: to present the theoretical current characterized by generative thinking in archaeology and to present a concrete application of agent-based modelling to an archaeological problem: the dispersal of the first ceramic production in the western Mediterranean.

Introduction to: Enabling Collaborative Governance through Systems Modeling Methods

2020

This opening chapter sets out a structure for considering collaborative governance for public policy and managerial problem-solving through systemic principles, as well as through the use of group processes to facilitate agreement and buy-in in collective strategies. Such a collection of tools, techniques, and frameworks is needed to establish the value of these approaches and to accelerate their dissemination through the field.

Early warning for VHE gamma-ray flares with the ARGO-YBJ detector

2011

Detecting and monitoring emissions from flaring gamma-ray sources in the very-high-energy (VHE, > 100 GeV) band is a very important topic in gamma-ray astronomy. The ARGO-YBJ detector is characterized by a high duty cycle and a wide field of view. Therefore, it is particularly capable of detecting flares from extragalactic objects. Based on fast reconstruction and analysis, real-time monitoring of 33 selected VHE extragalactic sources is implemented. Flares exceeding a specific threshold are reported timely, hence enabling the follow-up observation of these objects using more sensitive detectors, such as Cherenkov telescopes. (C) 2011 Elsevier B.V. All rights reserved.

Change and stability: Within-person life satisfaction over a 20-year period using data from the HUNT survey

2020

Background: The aim of the present study was to investigate within-person life satisfaction (LS) dynamics for two age groups, 20–29 and 30–39 years, from 1984 to 1986 and to follow them over a 20-year period. Methods: Data from 1984 to 2008 were extracted from the large, prospective, longitudinal North-Trøndelag Health Study (HUNT), Norway. This paper includes data from more than 14,500 persons. Data were analysed using logistic regression, and LS dynamics were modelled using gender, time and self-rated health. Results: The analyses revealed that about 20% of people in these age groups had a stable level in LS, also known as set point. Long-term LS change, defined as ⩾2 SDs, was reported f…

El alcoholismo femenino : una perspectiva sociológica

2003

Overview and Essentials of Biomass Gasification Technologies and Their Catalytic Cleaning Methods

2016

Obtaining a tar-free biosyngas from biomass gasification processes has been the subject of many studies in the past 2 decades, and it still remains the major technologic and economic challenge. Unfortunately, the countless publications about gasification technologies and different techniques permitting reduction of the tar present at the outlet of gasifier reactors usually confuse inexperienced persons who attempt to further research this subject. More than presenting the basis of biomass gasification technologies and positioning them among other bioenergies, this work mainly aims at reviewing and comparing the different methods developed in order to produce a tar-free biosyngas. In this wa…