Search results for "Discriminant"

Proba-V cloud detection Round Robin: Validation results and recommendations

2017

This paper discusses results from 12 months of a Round Robin exercise aimed at the inter-comparison of different cloud detection algorithms for Proba-V. Clouds detection is a critical issue for satellite optical remote sensing, since potential errors in cloud masking directly translates into significant uncertainty in the retrieved downstream geophysical products. Cloud detection is particularly challenging for Proba-V due to the presence of a limited number of spectral bands and the lack of thermal infrared bands. The main objective of the project was the inter-comparison of several cloud detection algorithms for Proba-V over a wide range of surface types and environmental conditions. Prob…

P300-based brain computer interface experimental setup

2009

A Brain-Computer interface (BCI) is a communication system that enables the generation of a control signal from brain signals such as sensorymotor rhythms and evoked potentials; therefore, it constitutes a novel communication option for people with severe motor disabilities (such as Amyotrophic Lateral Sclerosis patients). This paper presents the development of a P300-based BCI. This prototype uses a homemade six-channel electroencephalograph for the acquisition of the signals, and a visual stimulation matrix; since this matrix contains letters of the alphabet as well as images associated to them, it permits word-writing and the elaboration of messages with the images. To process the signal…

A teacher-report measure of children's task-avoidant behavior: A validation study of the Behavioral Strategy Rating Scale

2011

Abstract This study aims to validate a teacher-report measure of children's task-avoidant behavior, namely the Behavioral Strategy Rating Scale (BSRS), in a sample of 352 Finnish children. In each of the four waves from Kindergarten to Grade 2, teachers rated children's task-avoidant behavior using the BSRS, children completed reading and mathematics tests, and trained testers rated children's task-avoidant and social-dependent behavior after the test situation. Mothers also rated children's task-avoidant behavior in the last two waves. The results showed that a two-factor model including one factor representing task avoidance and one method factor accounting for wording effects among the n…

Spanish Adaptation of the Left-Wing Authoritarianism Index

2021

Notwithstanding long-simmering controversies around the construct, several studies have gathered consistent evidence of authoritarian attitudes among left-wing voters and activists. Recently, Costello et al. (Clarifying the structure and nature of left-wing authoritarianism. Journal of Personality and Social Psychology, 2021) validated, in the English-speaking context, a three-factor scale to measure left-wing authoritarianism, as well as two shortened versions of the same scale (Costello & Patrick, Development and initial validation of two brief measures of left-wing authoritarianism: A machine learning approach, 2021; composed of 39, 25 and 13 items, respectively). In this article, we use…

2020

Abstract Challenge is a key motivation for videogame play. But what kind of challenge types videogames include, and which of them players prefer? This article helps to answer the above questions by developing and validating Videogame Challenge Inventory (CHA), a psychometrically sound measurement for investigating players’ challenge preferences in videogames. Based on a review of literature, we developed a 38-item version of CHA that was included in a social media user survey (N = 813). An exploratory factor analysis (EFA) revealed a latent structure of five challenge types: Physical, Analytical, Socioemotional, Insight, and Foresight. CHA was amended in another EFA with USA-based survey da…

Pengembangan Kriteria dan Klasifikasi Tingkat Kekritisan Lahan pada Skala Tinjau di Kawasan Budidaya Pertanian Lahan Kering di Kabupaten Bogor

2018

<em>The objectives of this research are to develop critical land criteria and classification on the reconnaissance scales. The method used in this research is survey method through case studies. Data analysis methods include: bivariate correlation analysis, cluster analysis, and discriminant analysis. The results showed development criteria at reconnaissance scale resulted three determinant variables, namely: effective soil depth, stones, and degree of erosion; and produced two classes of critical land, namely: Critical class and Non-Critical class.</em>

Rapid and Nondestructive Determination of Egg Freshness Category and Marked Date of Lay using Spectral Fingerprint

2020

The potential of nondestructive prediction of egg freshness based on near-infrared (NIR) spectra fingerprints would be beneficial to quality control officers and consumers alike. In this study, handheld NIR spectrometer in the range of 740 nm to 1070 nm and chemometrics were used to simultaneously determine egg freshness based on marked date of lay for eggs stored under cold and ambient conditions. The spectra acquired from the eggs were preprocessed using multiplicative scatter correction and principal component analysis (MSC-PCA). Linear discriminant analysis (LDA) was used to build identification model to predict the category of freshness, while partial least square regression (PLS-R) wa…

Determination of aerobic-anaerobic metabolism-related compounds in aChaoborus flavicans population by infusion ion trap mass spectrometry of extracts…

2006

In a daily migration, the aquatic larvae of Chaoborus flavicans (a phantom midge) alternate oxygen-saturated and anoxic lake strata. To investigate this cycle, larvae were collected at a natural environment, and acetate, propionate, pyruvate, lactate, glycerol, phosphate, maleate, succinate, glucose and citrate were determined. Each larva was homogenized with 200 microL water and deproteinized with a spin-filter; 50 microL aliquots were mixed with 50 microL of a buffer containing 80 mM propylamine, 20 mM HCl and 0.06 mM 2,4-dihydroxybenzoic acid (internal standard) in methanol. The extracts were infused in an electrospray ionization ion-trap mass spectrometer. The limits of detection for th…

Near Infrared Spectroscopy Detection and Quantification of Herbal Medicines Adulterated with Sibutramine.

2015

There is an increasing demand for herbal medicines in weight loss treatment. Some synthetic chemicals, such as sibutramine (SB), have been detected as adulterants in herbal formulations. In this study, two strategies using near infrared (NIR) spectroscopy have been developed to evaluate potential adulteration of herbal medicines with SB: a qualitative screening approach and a quantitative methodology based on multivariate calibration. Samples were composed by products commercialized as herbal medicines, as well as by laboratory adulterated samples. Spectra were obtained in the range of 14,000-4000 per cm. Using PLS-DA, a correct classification of 100% was achieved for the external validatio…

Parasite infracommunities as predictors of harvest location of bogue (Boops boops L.): a pilot study using statistical classifiers

2005

The accuracy of classifying bogue (Boops boops) according to the fishery from which it was harvested was evaluated by applying several statistical classification techniques to fish parasite abundances. Bogue captured in 2001 in two fisheries off the Atlantic coast of Spain were compared with one off the Spanish Mediterranean coast. One hundred bogue were classified to each harvest location (fishery) using different numbers of parasite species chosen as predictors by a best subset method. Two parametric methods of classification (linear and quadratic discriminant analysis) were compared with two non-parametric approaches (k-nearest neighbour classification and feed-forward neural network) an…