Search results for " Validation"
showing 10 items of 313 documents
Forward logistic regression for earth-flow landslide susceptibility assessment in the Platani river basin (southern Sicily, Italy)
2013
Forward logistic regression has allowed us to derive an earth-flow susceptibility model for the Tumarrano river basin, which was defined by modeling the statistical relationships between an archive of 760 events and a set of 20 predictors. For each landslide in the inventory, a landslide identification point (LIP) was automatically produced as corresponding to the highest point along the boundary of the landslide polygons, and unstable conditions were assigned to cells at a distance up to 8 m. An equal number of stable cells (out of landslides) was then randomly extracted and appended to the LIPs to prepare the dataset for logistic regression. A model building strategy was applied to enlarg…
Visual attention while solving the test of understanding graphs in kinematics: an eye-tracking analysis
2019
This study used eye-tracking to capture students' visual attention while taking a test of understanding graphs in kinematics (TUG-K). A total of N = 115 upper-secondary-level students from Germany and Switzerland took the 26-item multiple-choice instrument after learning about kinematics graphs in the regular classroom. Besides choosing the correct alternative among research-based distractors, the students were required to judge their response confidence for each question. The items were presented sequentially on a computer screen equipped with a remote eye tracker, resulting in a set of approx. 3000 paired responses (accuracy and confidence) and about 40 h of eye-movement data (approx. 500…
Consumer Engagement in Online Settings: Conceptualization and Validation of Measurement Scales
2015
This paper addresses the conceptualization, scale development and scale validation related to the study of consumer engagement in online settings. It first reviews this concept and draws attention to the multidimensionality of the construct, considering the underlying cognitive, emotional, and behavioral dimensions of consumer engagement. Then, it presents the foundation of this concept in relationship marketing and adds support to this proposition. Further, it proposes the construction and psychometric assessment of a 37 scales that examine all three dimensions, based on an international sample of 110 respondents who engage with a brand on a social media network. Based on multiple and succ…
DOCUMENT MANAGEMENT USING CLUSTERING ALGORITHMS
2015
Document management systems are complex systems, which offer services as storage, versioning, metadata, security, as well as indexing and retrieval capabilities. Large numbers of documents could be automatically grouped into classes of documents, which contain similar information. Therefor we propose to use clustering methods in order to group the documents. Clustering is an important process in text mining used for groping documents based on their contents in order to extract knowledge. In this paper we will present some requirements for clustering algorithms for a document management system
Knowledge discovery from physical activity
2017
Tässä pro gradu -tutkielmassa käydään läpi Knowledge Discovery in Databases (KDD) -prosessi ja sen soveltamismahdollisuuksia fyysiseen aktiivisuuteen liittyvän datan kanssa. KDD-prosessi koostuu monesta eri vaiheesta, sisältäen esikäsittelyn, datan muunnoksen ja tiedonlouhinnan. Tässä tutkielmassa tiedonlouhinnan menetelmänä käytetään klusterointia, joka käydään läpi yksityiskohtaisesti. Vertailemme myös laajan joukon eri klusterointi indeksejä (CVAIs) sekä niiden eri toteutuksia k-means klusteroinnin kanssa ja esittelemme parhaat näistä yleisemmässä muodossa. Tutkielman empiirisessä osassa seitsemäsluokkalaisten koululaisten aktiivisuusdataa tutkitaan KDD-prosessia seuraten ja hyödyntäen m…
La plantilla 3.0, un instrumento para conocer la música de la infancia: Revisión y validación
2015
Este trabajo se interesa por conocer la música de la vida diaria de los niños desde una mirada educativa1. Para estudiarlo el artículo ofrece un instrumento que permite conocer los elementos objetivos de la música que escuchan, prestando especial atención al entorno sonoro de mayor cobertura e impacto, el mediático. El instrumento constituye el paso inicial para estudiar los posibles efectos de la música y proponer alternativas educativas, porque la finalidad última de la investigación es la mejora de la educación. El desarrollo metodológico ha consistido en la creación del instrumento, la plantilla 3.0, y su aplicación, dando cuenta en este artículo de su revisión, características técnicas…
Toolbox for Distance Estimation and Cluster Validation on Data With Missing Values
2022
Missing data are unavoidable in the real-world application of unsupervised machine learning, and their nonoptimal processing may decrease the quality of data-driven models. Imputation is a common remedy for missing values, but directly estimating expected distances have also emerged. Because treatment of missing values is rarely considered in clustering related tasks and distance metrics have a central role both in clustering and cluster validation, we developed a new toolbox that provides a wide range of algorithms for data preprocessing, distance estimation, clustering, and cluster validation in the presence of missing values. All these are core elements in any comprehensive cluster analy…
Species distributions models may predict accurately future distributions but poorly how distributions change: A critical perspective on model validat…
2023
Aim: Species distribution models (SDMs) are widely used to make predictions on how species distributions may change as a response to climatic change. To assess the reliability of those predictions, they need to be critically validated with respect to what they are used for. While ecologists are typically interested in how and where distributions will change, we argue that SDMs have seldom been evaluated in terms of their capacity to predict such change. Instead, typical retrospective validation methods estimate model's ability to predict to only one static time in future. Here, we apply two validation methods, one that predicts and evaluates a static pattern, while the other measures change…
Data from: Fine-scale population dynamics in a marine fish species inferred from dynamic state-space models
2018
Identifying the spatial scale of population structuring is critical for the conservation of natural populations and for drawing accurate ecological inferences. However, population studies often use spatially aggregated data to draw inferences about population trends and drivers, potentially masking ecologically relevant population sub-structure and dynamics. The goals of this study were to investigate how population dynamics models with and without spatial structure affect inferences on population trends and the identification of intrinsic drivers of population dynamics (e.g. density dependence). Specifically, we developed dynamic, age-structured, state-space models to test different hypoth…
Functional Near Infrared Spectroscopy System Validation for Simultaneous EEG-FNIRS Measurements
2019
Functional near-infrared spectroscopy (fNIRS) applied to brain monitoring has been gaining increasing relevance in the last years due to its not invasive nature and the capability to work in combination with other well–known techniques such as the EEG. The possible use cases span from neural-rehabilitation to early diagnosis of some neural diseases. In this work a wireline FPGA–based fNIRS system, that use SiPM sensors and dual-wavelength LED sources, has been designed and validated to work with a commercial EEG machine without reciprocal interference.