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"BIOMETRIA"
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SVM-RFE: selection and visualization of the most relevant features through non-linear kernels
2018
Background
Support vector machines (SVM) are a powerful tool to analyze data with a number of predictors approximately equal or larger than the number of observations. However, originally, application of SVM to analyze biomedical data was limited because SVM was not designed to evaluate importance of predictor variables. Creating predictor models based on only the most relevant variables is essential in biomedical research. Currently, substantial work has been done to allow assessment of variable importance in SVM models but this work has focused on SVM implemented with linear kernels. The power of SVM as a prediction model is associated with the flexibility generated by use of non-linear kernels. Moreover, SVM has been extended to model survival outcomes. This paper extends the Recursive Feature Elimination (RFE) algorithm by proposing three approaches to rank variables based on non-linear SVM and SVM for survival analysis.
Results
The proposed algorithms allows visualization of each one the RFE iterations, and hence, identification of the most relevant predictors of the response variable. Using simulation studies based on time-to-event outcomes and three real datasets, we evaluate the three methods, based on pseudo-samples and kernel principal component analysis, and compare them with the original SVM-RFE algorithm for non-linear kernels. The three algorithms we proposed performed generally better than the gold standard RFE for non-linear kernels, when comparing the truly most relevant variables with the variable ranks produced by each algorithm in simulation studies. Generally, the RFE-pseudo-samples outperformed the other three methods, even when variables were assumed to be correlated in all tested scenarios.
Conclusions
The proposed approaches can be implemented with accuracy to select variables and assess direction and strength of associations in analysis of biomedical data using SVM for categorical or time-to-event responses. Conducting variable selection and interpreting direction and strength of associations between predictors and outcomes with the proposed approaches, particularly with the RFE-pseudo-samples approach can be implemented with accuracy when analyzing biomedical data. These approaches, perform better than the classical RFE of Guyon for realistic scenarios about the structure of biomedical data.
Journal Article
Az automatikus biometrikus azonosság-ellenőrző rendszerek védelmének kérdései - Prezentációs támadások, megtévesztés
Aim: The aim of the study is to present the currently known challenges of presentation attacks against biometric systems, their law enforcement and national security aspects, and to draw attention to the importance and possibilities of solutions and devices that provide different levels of security in system design and biometric identity verification, and their limitations, to regular and target-oriented risk analysis. Methodology: The study presents the results of the latest research on presentation attacks, by processing the professional publications, studies, test reports, reports of leading international organizations, and by reviewing the solutions provided by existing standards, it presents the attacks against biometric systems and draws conclusions. Findings: Biometric systems are systems using artificial intelligence technologies, they have enormous advantages and the opportunities provided by the technology, and, of course, parallel to this, the challenges arising from the technology and the tasks to be solved. The threats arising from the use of technology for bad purposes, the deception of biometric systems are a real, increasingly challenging problem, and the recognition and prevention of forgery and deception is not yet easy due to the complexity of the task. Extensive research is currently being carried out in this area, but it has been established that there is no generally usable solution or tool or application that can be integrated into the systems to protect against such threats. Technical solutions and tools help, but only with a risk-based approach, setting up risk levels and corresponding system design and thoughtful security policy measures, false data communications and attacks deceiving biometric systems can be successfully recognized and prevented or the damage mitigated. Value: Knowledge of the challenges of automatic identity verification technology and current methods of deceiving biometric systems is the basis for planning defense methods and procedures, and is also in the interest of law enforcement and national security. The article aims to provide support for this with the analysis. Cél: A tanulmány célja, hogy bemutassa a biometrikus rendszerek elleni prezentációs támadások ma ismert kihívásait, ennek rendvédelmi, nemzetbiztonsági vetületeit, és felhívja a figyelmet a rendszerek alkalmazásának tervezésénél, a biometrikus személyazonosság-ellenőrzésnél a különböző szintű biztonságot jelentő megoldások, eszközök jelentőségére, lehetőségeire és ezek korlátaira, a rendszeres és célorientált kockázatelemzésre. Módszertan: A tanulmány a prezentációs támadásokkal kapcsolatos legújabb kutatások eredményeit, a megjelent szakmai közlemények, tanulmányok valamint teszteredmények, és irányadó nemzetközi szervezetek jelentéseinek feldolgozásával, a meglévő szabványok által nyújtott megoldások áttekintésével mutatja be a biometrikus rendszerek elleni támadásokat és von le következtetéseket. Megállapítások: A biometrikus rendszerek mesterséges intelligencia technológiákat alkalmazó rendszerek, óriási előnyökkel és a technológia által nyújtott lehetőségekkel rendelkeznek, és persze ezzel párhuzamosan a technológiából adódó kihívásokkal, megoldandó feladatokkal. A technológia rossz célokra való használatából adódó fenyegetések, a biometrikus rendszerek megtévesztése ma valós, egyre nagyobb kihívásokat jelentő probléma, és a hamisítás, megtévesztés felismerése, kivédése a feladat komplexitása okán ma még nem egyszerű. Kiterjedt kutatások folynak ma ezen a területen, de nincs általánosan használható, a rendszerekbe beépíthető megoldás vagy eszköz, alkalmazás az ilyen fenyegetések kivédésére. Egyes esetekre vannak már technikai megoldások, eszközök, de csakis kockázat alapú megközelítéssel, kockázati szintek felállításával és ennek megfelelő rendszertervezéssel és átgondolt biztonságpolitikai intézkedésekkel lehet a biometrikus rendszereket megtévesztő hamis adatközléseket, támadásokat jó eredménnyel felismerni és kivédeni, vagy a károkat mérsékelni. Érték: Az automatikus azonosság-ellenőrzés technológia kihívásainak, a biometrikus rendszerek megtévesztése aktuális módszereinek az ismerete a védekezési módszerek, eljárások tervezésének az alapja és rendvédelmi, nemzetbiztonsági érdek is. Az elemzéssel kíván a cikk ehhez támogatást nyújtani.
Journal Article
Comparing multiple criteria for species identification in two recently diverged seabirds
by
Militão, Teresa
,
Gómez Díaz, Elena
,
González-Solís, Jacob
in
Animal genetics
,
Biometria
,
Biometry
2014
Correct species identification is a crucial issue in systematics with key implications for prioritising conservation effort. However, it can be particularly challenging in recently diverged species due to their strong similarity and relatedness. In such cases, species identification requires multiple and integrative approaches. In this study we used multiple criteria, namely plumage colouration, biometric measurements, geometric morphometrics, stable isotopes analysis (SIA) and genetics (mtDNA), to identify the species of 107 bycatch birds from two closely related seabird species, the Balearic (Puffinus mauretanicus) and Yelkouan (P. yelkouan) shearwaters. Biometric measurements, stable isotopes and genetic data produced two stable clusters of bycatch birds matching the two study species, as indicated by reference birds of known origin. Geometric morphometrics was excluded as a species identification criterion since the two clusters were not stable. The combination of plumage colouration, linear biometrics, stable isotope and genetic criteria was crucial to infer the species of 103 of the bycatch specimens. In the present study, particularly SIA emerged as a powerful criterion for species identification, but temporal stability of the isotopic values is critical for this purpose. Indeed, we found some variability in stable isotope values over the years within each species, but species differences explained most of the variance in the isotopic data. Yet this result pinpoints the importance of examining sources of variability in the isotopic data in a case-by-case basis prior to the cross-application of the SIA approach to other species. Our findings illustrate how the integration of several methodological approaches can help to correctly identify individuals from recently diverged species, as each criterion measures different biological phenomena and species divergence is not expressed simultaneously in all biological traits.
Journal Article
Editorial note on weight_length relations of fishes
by
Froese, R.,GEOMAR, Kiel (Germany). Helmholtz Center of Ocean Research
,
Stergiou, K.I.,Aristotle University, Thessaloniki (Greece). School of Biology, Dept. of Zoology
,
Tsikliras, A.C
in
ANIMAL POPULATION
,
BIOMASA
,
BIOMASS
2011
Weight-length relations of fishes are useful for estimation of biomass from length observations, e.g., in fisheries or conservation research. Here we provide some guidance to authors of such papers, in order to facilitate the publication and review process
Journal Article
EVERREST prospective study: a 6-year prospective study to define the clinical and biological characteristics of pregnancies affected by severe early onset fetal growth restriction
2017
Background
Fetal growth restriction (FGR) is a serious obstetric condition for which there is currently no treatment. The EVERREST Prospective Study has been designed to characterise the natural history of pregnancies affected by severe early onset FGR and establish a well phenotyped bio-bank. The findings will provide up-to-date information for clinicians and patients and inform the design and conduct of the EVERREST Clinical Trial: a phase I/IIa trial to assess the safety and efficacy of maternal vascular endothelial growth factor (VEGF) gene therapy in severe early onset FGR. Data and samples from the EVERREST Prospective Study will be used to identify ultrasound and/or biochemical markers of prognosis in pregnancies with an estimated fetal weight (EFW) <3rd centile between 20+0 and 26+6 weeks of gestation.
Methods
This is a 6 year European multicentre prospective cohort study, recruiting women with a singleton pregnancy where the EFW is <3rd centile for gestational age and <600 g at 20+0 to 26+6 weeks of gestation. Detailed data are collected on: maternal history; antenatal, peripartum, and postnatal maternal complications; health economic impact; psychological impact; neonatal condition, progress and complications; and infant growth and neurodevelopment to 2 years of corrected age in surviving infants. Standardised longitudinal ultrasound measurements are performed, including: fetal biometry; uterine artery, umbilical artery, middle cerebral artery, and ductus venosus Doppler velocimetry; and uterine artery and umbilical vein volume blood flow. Samples of maternal blood and urine, amniotic fluid (if amniocentesis performed), placenta, umbilical cord blood, and placental bed (if caesarean delivery performed) are collected for bio-banking. An initial analysis of maternal blood samples at enrolment is planned to identify biochemical markers that are predictors for fetal or neonatal death.
Discussion
The findings of the EVERREST Prospective Study will support the development of a novel therapy for severe early onset FGR by describing in detail the natural history of the disease and by identifying women whose pregnancies have the poorest outcomes, in whom a therapy might be most advantageous. The findings will also enable better counselling of couples with affected pregnancies, and provide a valuable resource for future research into the causes of FGR.
Trial registration
NCT02097667
registered 31
st
October 2013.
Journal Article
A biometria elterjedésének elemzése
Aim: A brief introduction to this article gives an overview of the main parameters of identification solutions and the most common biometric identification solutions. The article then describes the biometric identification solutions used by border police in the EU and gives a brief comparison between current solutions and the vascular network-based solutions, highlighting the advantages of the vascular network-based solutions compared to the previous solutions. Next, the article summarises previous research related to the uptake of biometric solutions by presenting the results of a recent research.Methodology: An analytical comparison of previous research on the uptake of biometrics at Óbuda University with the results with a recent study from 2022.Findings: Education about biometrics can deepen awareness of the risks associated with the solutions, which can increase the risk of rejection and fear of the most powerful fears related to the handling and security of biometric data.Value: The article points out that the risks could be reduced by stronger regulation of the use of biometrics and by standardisation and diffusion of data management and privacy solutions designed for biometrics. Cél: A cikk rövid bevezetése áttekintést ad az azonosítási megoldások fő paramétereiről és a legelterjedtebb biometrikus azonosítási megoldásokról. Ezt követően a cikk az EU-ban a határrendészetnél használt biometrikus azonosítási megoldásokat mutatja be, illetve rövid összehasonlítást ad a jelenlegi megoldások és az érhálózat-alapú megoldások között, kiemelve az érhálózat-alapú megoldások előnyeit a korábbi megoldásokhoz képest. A cikk a továbbiakban a korábbi, biometrikus megoldások elterjedésével összefüggő kutatásokat foglalja össze egy új kutatás eredményeinek bemutatásával.Módszertan: A biometria elterjedésével összefüggő korábbi, Óbudai Egyetemen végzett kutatás elemző összehasonlítása egy 2022-es friss kutatás eredményeivel.Megállapítások: A biometriával összefüggő oktatás mélyítheti a megoldásokkal kapcsolatos kockázatok ismeretét, ami növelheti az elutasítottságát és a legerősebb félelem kialakulását, ami a biometrikus adatok kezelésével és biztonságával kapcsolatos.Érték: A cikk felhívja a figyelmet, hogy a kockázatokat a biometrikus megoldások felhasználásának erősebb szabályozásával és az adatkezelési, adatvédelmi megoldások biometriára kialakított szabványosításával és elterjedésével lehetne csökkenteni.
Journal Article
Neurogra w kino. Neuronaukowe perspektywy badania filmu
2024
Celem artykułu jest przedstawienie neuronaukowych perspektyw badania filmu. W pierwszej kolejności zostają zarysowane podstawy rozwoju badań empirycznych i konceptualnych: teoria kognitywna, koncepcja ucieleśnionego poznania, neuroestetyka oraz szczególne modele kina (kino ucieleśnione oraz kino enaktywne). Następnie, odwołując się do ustaleń Vittoria Gallesego oraz Miguela Guerry, autorka tekstu wskazuje trzy główne perspektywy rozwoju neuronaukowych badań kina: 1) częściową reinterpretację teorii i historii kina przez pryzmat nowych narzędzi badawczych, 2) badania empiryczne dotyczące technik i strategii filmowych, 3) rozwój nowych form technologicznych implementowanych do przemysłu filmowego. W dalszej kolejności zostają zaprezentowane wybrane eksperymenty z zakresu neurobadań filmu, w tym pionierski eksperyment grupy badawczej Uriego Hassona oraz badanie dotyczące identyfikacji z postaciami filmowymi przeprowadzone na podstawie serialu Gra o tron (Game of Thrones, HBO, 2011-2019). Pojawia się tu również odniesienie do badań nad montażem filmowym prowadzonych głównie przez grupę Javiera Sanz-Aznara. Autorka przedstawia je w perspektywie krytycznej, uwzględniając problem neurorealizmu. Ostatnia część artykułu zawiera analizę założeń neurofilmologii będącej próbą centralizacji rozproszonych refleksji nad neurokinem (ujęcie Adriana D’Aloii i Ruggera Eugeniego oraz krytyczna perspektywa Marii Poulaki). Autorka tekstu uzupełnia ów namysł własnymi konkluzjami co do potencjalnych kierunków rozwoju neurobadań nad kinem.
Journal Article
Biostatistics for oral healthcare
2008
Biostatistics for Oral Healthcare offers students, practitioners and instructors alike a comprehensive guide to mastering biostatistics and their application to oral healthcare. Drawing on situations and methods from dentistry and oral healthcare, this book provides a thorough treatment of statistical concepts in order to promote in-depth and correct comprehension, supported throughout by technical discussion and a multitude of practical examples.