Search results for " Distance"
showing 10 items of 696 documents
Element weighted Kemeny distance for ranking data
2021
Preference data are a particular type of ranking data that arise when several individuals express their preferences over a finite set of items. Within this framework, the main issue concerns the aggregation of the preferences to identify a compromise or a “consensus”, defined as the closest ranking (i.e. with the minimum distance or maximum correlation) to the whole set of preferences. Many approaches have been proposed, but they are not sensitive to the importance of items: i.e. changing the rank of a highly-relevant element should result in a higher penalty than changing the rank of a negligible one. The goal of this paper is to investigate the consensus between rankings taking into accou…
A Neurocomputational Approach to Trained and Transitive Relations in Equivalence Classes
2017
A stimulus class can be composed of perceptually different but functionally equivalent stimuli. The relations between the stimuli that are grouped in a class can be learned or derived from other stimulus relations. If stimulus A is equivalent to B, and B is equivalent to C, then the equivalence between A and C can be derived without explicit training. In this work we propose, with a neurocomputational model, a basic learning mechanism for the formation of equivalence. We also describe how the relatedness between the members of an equivalence class is developed for both trained and derived stimulus relations. Three classic studies on stimulus equivalence are simulated covering typical and at…
Hipotēžu pārbaude divu izlašu lokācijas-mēroga modelim
2020
Darbā aplūkots lokācijas-mēroga modelis un metodes tā noteikšanai. Galvenokārt tika aplūkoti lokācijas-mēroga testi, kā arī Kolmogorova-Smirnova tests, un to robežsadalījumu uzvedība situācijās, kad dati tika transformēti, zinot parametru nobīdi, kā arī izmantojot Mallova distances metodi. Lokācijas-mēroga modeļa apskatei tika pielietoti arī PP, QQ gafiki, un empīriskās ticamības funkcijas metode. Darba gaitā tika pētīta testu uzvedība, testējot gan simulētu, gan reālu datu piemērus.
OXIDATIVE STRESS MARKERS ASSOCIATED WITH MIDDLE DISTANCE RUNNING PERFORMANCE
2014
The aim of this study was to understand the mechanism underlying the physiological adaptation of a kind purely aerobic workout. Particular attention has also been given to the analysis of oxidative stress by detecting some enzymatic blood parameters. We investigate the effect of 2 months of training on middle distance running (800 meters and 1500 meters) agonistic athletes; nine active specifically trained males of mean (± SD) age 19,9 years. The physiological characteristics of middle runners are different from those sprinters and long distance runners because include a variety of aerobic and anaerobic capabilities. Two weeks prior to the 2 months period of exercise, subjects were tested f…
Outlier recognition in crystal-structure least-squares modelling by diagnostic techniques based on leverage analysis.
2005
The identification of the actual outliers in a least-squares crystal-structure model refinement and their subsequent elimination from the data set is a non-trivial task that has to be carried out carefully when a high level of accuracy of the estimates is required. One of the most suitable tools for detecting the influence of each data entry on the regression is the identification of ;leverage points'. On the other hand, the recognition of the actual statistical outliers is effectively possible by using some diagnostics as a function of the leverage, such as Cook's distance, DFFITS and FVARATIO. The evaluation of these estimators makes it possible to achieve a reliable identification of the…
HELMINTH ASSEMBLAGES OF WHITEFISH (COREGONUS LAVARETUS) IN INTERCONNECTED LAKES: SIMILARITY AS A FUNCTION OF SPECIES SPECIFIC PARASITES AND GEOGRAPHI…
2004
This article examined the composition of parasite assemblages of whitefish (Coregonus lavaretus) in 8 interconnected lakes in northeastern Finland and evaluated the role of coregonid specific parasites and the geographical distance between populations in determining the similarity of the assemblages. Parasite assemblages were compared using the Jaccard qualitative similarity index and a quantitative similarity index and by incorporating the allogenic-autogenic species concept and the effects of 2 corresponding measures of geographical distance between the lakes. The majority of the parasite species found (10 of 14) were specific to salmonids. Similarity of assemblages of autogenic parasites…
A Full-Scale Agent-Based Model to Hypothetically Explore the Impact of Lockdown, Social Distancing, and Vaccination During the COVID-19 Pandemic in L…
2021
Background The COVID-19 outbreak, an event of global concern, has provided scientists the opportunity to use mathematical modeling to run simulations and test theories about the pandemic. Objective The aim of this study was to propose a full-scale individual-based model of the COVID-19 outbreak in Lombardy, Italy, to test various scenarios pertaining to the pandemic and achieve novel performance metrics. Methods The model was designed to simulate all 10 million inhabitants of Lombardy person by person via a simple agent-based approach using a commercial computer. In order to obtain performance data, a collision detection model was developed to enable cluster nodes in small cells that can b…
Ureteru akmeņu endoskopiskās ārstēšanas iespējas
2016
Ievads: Urīnakmeņu incidence pasaulē ir 1500-2000 gadījumi uz miljonu iedzīvotāju. Pēc statistikas datiem nierakmeņu izplatības rādītāji svārstās no 1% līdz 20%. Šī slimība ir novērojama pacientiem pārsvarā no 30 līdz 50 gadu vecumā. Pēc Eiropas Urologu asociācijas 2012. gada datiem nierakmeņu slimību sastop aptuveni 20% gadījumu no visām uroloģiskajām saslimšanām. Materiāli un metodes: Retrospektīvā pētījumā tika iekļauti 123 pacienti ar urolitiāzi, kuri ārstējās Paula Stradiņa klīniskā universitātes slimnīcā 4. uroloģijas nodaļā laika posmā no 2013. gada 1. janvāra līdz 2014. gada 31. decembrim. Tiek ievākti un analizēti sekojošie pacientu dati: pētījumu objekta skaits; vecums un to dzimu…
Geometry and analysis of Dirichlet forms
2012
Let $ \mathscr E $ be a regular, strongly local Dirichlet form on $L^2(X, m)$ and $d$ the associated intrinsic distance. Assume that the topology induced by $d$ coincides with the original topology on $ X$, and that $X$ is compact, satisfies a doubling property and supports a weak $(1, 2)$-Poincar\'e inequality. We first discuss the (non-)coincidence of the intrinsic length structure and the gradient structure. Under the further assumption that the Ricci curvature of $X$ is bounded from below in the sense of Lott-Sturm-Villani, the following are shown to be equivalent: (i) the heat flow of $\mathscr E$ gives the unique gradient flow of $\mathscr U_\infty$, (ii) $\mathscr E$ satisfies the Ne…
Observational effects of varying speed of light in quadratic gravity cosmological models
2017
We study different manifestations of the speed of light in theories of gravity where metric and connection are regarded as independent fields. We find that for a generic gravity theory in a frame with locally vanishing affine connection, the usual degeneracy between different manifestations of the speed of light is broken. In particular, the space-time causal structure constant ([Formula: see text]) may become variable in that local frame. For theories of the form [Formula: see text], this variation in [Formula: see text] has an impact on the definition of the luminosity distance (and distance modulus), which can be used to confront the predictions of particular models against Supernovae t…