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2017-04-12
15:43
Detection of Differential Item Functioning with Non-Linear Regression: Non-IRT Approach Accounting for Guessing
Drabinová, Adéla ; Martinková, Patrícia
In this article, we present a new method for estimation of Item Response Function and for detection of uniform and non-uniform Differential Item Functioning (DIF) in dichotomous items based on Non-Linear Regression (NLR). Proposed method extends Logistic Regression (LR) procedure by including pseudoguessing parameter. NLR technique is compared to LR procedure and Lord’s and Raju’s statistics for three-parameter Item Response Theory (IRT) models in simulation study based on Graduate Management Admission Test. NLR shows superiority in power at low rejection rate over IRT methods and outperforms LR procedure in power for case of uniform DIF detection. Our research suggests that the newly proposed non-IRT procedure is an attractive and user friendly approach to DIF detection.
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Úplný záznam
2017-04-04
15:25

Úplný záznam
2017-04-04
15:25

Úplný záznam
2017-04-04
15:25

Úplný záznam
2017-04-04
15:25

Úplný záznam
2017-04-04
15:25
Popis TDD modelu verze 3.71
Chytil, Michal ; Novák, J. ; Jiřina jr., M. ; Benešová, M.
Zpráva je závěrečnou roční zprávou pro rok 2016 v rámci Projektu TDD-ČR. Cílem je předat metodiky pro užití modelu jak provozovatelem distribuční soustavy, tak operátorem trhu a dále informovat o aktuálním stavu modelu. Jsou popsány předávané soubory včetně vzorového výpočtu na reálných datech a jejich obsah.

Úplný záznam
2017-03-27
15:27
The thermal regime of ice pits of the Borec hill
Türkott, L. ; Martinčíková, Eva ; Potop, V.
The ecological stability of the sites with stenoec organisms is important factor for maintaining them at given location. Phonolite system of the Borec hill creates a unique labyrinth of vents. Thermal anomalies occur during the year in the fissure system and create specific microclimate. Flow direction is given by the temperature gradient inside and outside of the system. The lower part of fissure system is located in the debris fields, while the upper part on top of the hill. Phonolite rocks are cooled down by air streaming from the debris fields during the winter. Direction of the air flow changes in the spring and summer. The cold air is exhaled from these vents on the lower parts of system and creates ice pits with the typical vegetation.

Úplný záznam
2017-03-17
18:38
A Statistical Approach to Planning Reserved Electric Power for Railway Infrastructure Administration
Brabec, Marek ; Pelikán, Emil ; Konár, Ondřej ; Kasanický, Ivan ; Juruš, Pavel ; Sadil, J. ; Blažek, P.
One of the requirements on railway infrastructure administration is to provide electricity for day-to-day operation of railways. We propose a statistically based approach for the estimation of maximum 15-minute power within a calendar month for a given region. This quantity serves as a basis of contracts between railway infrastructure administration and electricity distribution system operator. We show that optimization of the prediction is possible, based on underlying loss function derived from the contract, using either a parametric or non-parametric approach.

Úplný záznam
2017-02-15
15:49

Úplný záznam
2017-02-15
15:49

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