Search results for "Data type"
showing 10 items of 1183 documents
A novel application of fuzzy-set qualitative comparative analysis to GEM data
2016
Abstract This study constitutes a novel application of fuzzy-set qualitative comparative analysis to Global Entrepreneurship Monitor (GEM) data. This study seeks to demonstrate that fsQCA enriches previous conclusions from linear regression analyses that state that a relationship exists between the GEM's Total Entrepreneurial Activity rate (TEA) and variables representing entrepreneurial attitudes and social values of adult populations toward entrepreneurship. FsQCA allows researchers to estimate which of these attitudes and social values are necessary, sufficient, or both for full membership in the set of most entrepreneurial active countries within the set of GEM innovation-driven countri…
Tabu search with strategic oscillation for the maximally diverse grouping problem
2013
We propose new heuristic procedures for the maximally diverse grouping problem (MDGP). This NP-hard problem consists of forming maximally diverse groups—of equal or different size—from a given set of elements. The most general formulation, which we address, allows for the size of each group to fall within specified limits. The MDGP has applications in academics, such as creating diverse teams of students, or in training settings where it may be desired to create groups that are as diverse as possible. Search mechanisms, based on the tabu search methodology, are developed for the MDGP, including a strategic oscillation that enables search paths to cross a feasibility boundary. We evaluate co…
Aggregation methods to calculate the average price
2015
Abstract Average price is a numerical value that represents a set of prices, which may relate to firms, countries, or regions. This study presents new methods of average price aggregation that build on the unified aggregation operator (UAO). The UAO combines a wide range of sub-aggregation processes into a single formulation capable of accounting for the importance of each concept in the analysis. The aggregation system is flexible, can adapt to different environments, and provides a complete representation of relevant information. The UAO can calculate the average price for numerous geographical contexts such as supranational regions and countries. The study illustrates the UAO's utility b…
Aggregation systems for sales forecasting
2015
Abstract Sales forecasting consists of calculating the expected sales of a specific product or company. An important issue when dealing with sales forecasting is the calculation of the average sales, usually using the arithmetic mean or the weighted average. This study introduces new methods for calculating the average sales. These methods are two modern aggregation operators: the ordered weighted average, and the unified aggregation operator. The main advantage of this approach is the possibility to deal with uncertain and complex environments in a more complete way. The study develops some key examples through multi-person and multi-criteria techniques. The study also presents a numerical…
Application of Genetic Algorithms to 3-D Shape Reconstruction in an Active Stereo Vision System
2001
In this paper, a new method for reconstructing 3-D shapes is proposed. It is based on an active stereo vision system composed of a camera and a light system which projects a set of structured laser rays on the scence to be analyzed. The depth information is provided by matching the laser rays and the corresponding spots appearing in the image. The matching task is performed by using Genetic Algorithms (GAs). The process converges towards the optimum solution which proves that GAs can effectively be used for this problem. An efficient 3-D reconstruction method is introduced. The experimental results demonstrate that the proposed approach is stable and provides high accuracy 3-D object recons…
Stereo Matching Tecniques for Cloud-top Height Retrieval
2006
This paper presents an ongoing study for the estimation of the cloud-top height by using only geometrical methods. It is based on the hypothesis that an infra-red camera is on board a satellite and pairs of images concern nearly the same scene. Stereo-vision techniques are therefore explored in order to test the methodology for height retrieval and in particular results of several techniques of stereo matching are evaluated. This study includes area-based matching algorithms by implementing the basic versions, without considering any further steps of optimisation to improve the results. Dense depth maps are the final outputs whose reliability is verified by computing error statistics with r…
EDA: EXAFS data-analysis software package
2021
The EXAFS data-analysis software package EDA consists of a suite of programs running under a Windows operating system environment that is designed to perform all steps of conventional EXAFS data analysis such as extraction of the XANES/EXAFS parts of the X-ray absorption coefficient, Fourier filtering and EXAFS fitting using the Gaussian and cumulant models. The package also includes two advanced approaches which allow the reconstruction of the radial distribution function (RDF) from EXAFS based on the regularization-like method and the calculation of configuration-averaged EXAFS using a set of atomic configurations obtained from molecular-dynamics or Monte Carlo simulations.---- / / / ----…
Characterization process to measure the electrical contact resistance of Gas Diffusion Layers under mechanical static compressive loads
2016
AEM2016. International conference on Advanced Energy Materials, University of Surrey, Guildford, ROYAUME-UNI, 12-/09/2016 - 14/09/2016; Recent research has identified the mechanical properties of the fuel cell internal components (in particular, the Gas Diffusion Layers - GDLs) as key-parameters to obtain high final performances of the generator. The mechanical compression modulus of these components, the stability of their mechanical properties with respect to temperature and humidity, and their ability to interact with water have an impact on the electrical contact resistances in the stack and, by consequence, on the overall performance of the electric generator. Reducing the losses by co…
High voltage vacuum-deposited CH3NH3PbI3-CH3NH3PbI3 tandem solar cells
2018
The recent success of perovskite solar cells is based on two solid pillars: the rapid progress of their power conversion efficiency and their flexibility in terms of optoelectrical properties and processing methods. That versatility makes these devices ideal candidates for multi-junction photovoltaics. We report an optically optimized double junction CH3NH3PbI3–CH3NH3PbI3 tandem solar cell where the matched short-circuit current is maximized while parasitic absorption is minimized. The use of an additive vacuum-deposition protocol allows us to reproduce calculated stack designs, which comprise several charge selective materials that ensure appropriate band alignment and charge recombination…
Flexible MgO-Based Magnetic Tunnel Junctions on Silicon Substrate
2018
Flexible electronic devices are emerging in many areas, providing novel features and creating new applications [1]. Due to their ubiquitous utilization, flexible magnetic sensors [2] play a critical part in this development. In particular, magnetic tunnel junctions (MTJs) are of great interest, because of advantages like low power consumption or high sensitivity. We report the development of flexible MTJs on a silicon substrate fabricated by a low-cost batch process [3]. Thereby, conventionally fabricated MTJ devices are transformed into flexible ones by thinning down the silicon wafer from 500 μm to 5 μm. This process leads to thin, bendable silicon devices, while maintaining their origina…