Search results for "VALIDATION"
showing 10 items of 620 documents
Classification of SD-OCT Volumes Using Local Binary Patterns: Experimental Validation for DME Detection
2016
International audience; This paper addresses the problem of automatic classification of Spectral Domain OCT (SD-OCT) data for automatic identification of patients with Diabetic Macular Edema (DME) versus normal subjects. Optical Coherence Tomography (OCT) has been a valuable diagnostic tool for DME, which is among the most common causes of irreversible vision loss in individuals with diabetes. Here, a classification framework with five distinctive steps is proposed and we present an extensive study of each step. Our method considers combination of various pre-processings in conjunction with Local Binary Patterns (LBP) features and different mapping strategies. Using linear and non-linear cl…
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…
Dose calculation in biological samples in a mixed neutron-gamma field at the TRIGA reactor of the University of Mainz
2010
To establish Boron Neutron Capture Therapy (BNCT) for non-resectable liver metastases and for in vitro experiments at the TRIGA Mark II reactor at the University of Mainz, Germany, it is necessary to have a reliable dose monitoring system. The in vitro experiments are used to determine the relative biological effectiveness (RBE) of liver and cancer cells in our mixed neutron and gamma fi eld. We work with alanine detectors in combination with Monte Carlo simulations, where we can measure and characterize the dose. To verify our calculations we perform neutron fl ux measurements using gold foil activation and pin-diodes . Material and methods . When L- α -alanine is irradiated with ionizing …
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…
Style partycypacji kulturalnej człowieka dorosłego : walidacja narzędzia pomiarowego
2017
Artykuł przedstawia proces walidacji narzędzia pomiarowego, diagnozującego style partycypacji kulturalnej człowieka dorosłego. Jego celem jest opis uzyskanych wyników w poszczególnych etapach walidacji oraz określenie związku pomiędzy stylami partycypacji kulturalnej a układami kultury prezentowanymi przez socjologów kultury. W związku z czym przedmiotem badań jest styl partycypacji kulturalnej człowieka dorosłego. Badania pilotażowe, jak i właściwe zostały przeprowadzone w województwie opolskim, próba badawcza kolejno liczyła 100, a następnie 400 respondentów. Za podstawę teoretyczno-metodologiczną rozważań przyjęto konstrukt teoretyczny Kazimierza Obuchowskiego, opisujący podmiotowy oraz …
Improving statistical methodologies for landslide susceptibility modelling at regional and basin scale. Applications in the Sicilian and Salvadoran t…
2022
Detecting Authoritarianism Efficiently: Psychometric Properties of the Screening Instrument Authoritarianism – Ultra Short (A-US) in a German Represe…
2020
With right-wing-extremist and -populist parties and movements on the rise throughout the world, the concept of authoritarianism has proven to be particularly valuable to explain the psychological underpinnings of these tendencies. Even though many scales to measure the different dimensions of authoritarianism exist, no short screening instrument has been tested and validated on a large scale so far. The present study examines the psychometric properties of the screening instrument Authoritarianism ��� Ultrashort (A-US) in three representative German samples (n = 2,524, n = 2,478, and n = 2,495). Using exploratory and confirmatory factor analysis, the A-US demonstrated acceptable internal co…