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Reprezentace chemických sloučenin a její využití v podobnostním vyhledávání / Representation of chemical compounds and its utilization in similarity searchŠkoda, Petr January 2019 (has links)
Virtual screening is a well-established part of computer-aided drug design, which heavily employs similarity search and similarity modeling methods. Most of the popular methods are target agnostic, leaving space for design of new methods that would take into account the specifics of the particular molecular target. Additionally, newly developed methods suffer from two related issues: benchmarking and availability. Benchmarking in the domain often suffers from the use of inappropriate reference methods, lack of reproducibility, and the use of nonstandard benchmark datasets. Although there have been several benchmarking studies in the domain that aim at addressing these issues, mainly by offering a standardized comparison, they often suffer from similar drawbacks. For these reasons, new methods fail to gain trust and therefore fail to become a part of the standard toolbox, which thus consists mostly of older methods. In this work, we address the above-described issues. First, we introduce new adaptive methods for virtual screening. Then, to make our and other newly developed methods readily available, we have designed and implemented a virtual screening tool. To address the benchmarking issue, we have compiled a publicly available collection of benchmarking datasets and proposed a platform offering a...
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Simulace projevu kožního onemocnění s využitím GAN / Simulation of Skin Diseases Effect Using GANBak, Adam January 2021 (has links)
Cieľom tejto diplomovej práce je vygenerovanie datasetu syntetických snímkov odtlačkov prstov, ktoré vykazujú známky kožných ochorení. Práca sa zaoberá poškodením spôsobeným kožnými ochoreniami v odtlačkoch prstov a generovaním syntetických odtlačkov prstov. Odtlačky prstov s prejavom kožných ochorení boli generované s využitím modelu založeného na Wasserstein GAN s penalizáciou gradientu. Na trénovanie GAN modelu bola použitá unikátna databáza odtlačkov prstov s prejavom kožných ochorení vytvorená na FIT VUT. Daný model bol trénovaný na troch typoch kožných ochorení: atopický ekzém, psoriáza a dyshidrotický ekzém. Sieť generátoru z natrénovaného WGAN-GP modelu bola použitá na vygenerovanie datasetov syntetických odtlačkov prstov. Tieto syntetické odtlačky boli porovnané s reálnymi odtlačkami s využitím NFIQ a FiQiVi nástrojov na určenie kvality spoločne s porovnaním rozložení lokácií a orientácii markantov v snímkoch odtlačkov prstov.
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The use of Automated Fingerprint Identification System in identifying fraudulent voters’ registration in LesothoChigando, Lesole John January 2018 (has links)
The research was prompted by constant criticism of the Independent Electoral
Commission (IEC) because of its poor voter registration and voters’ roll. Free
and fair elections are the strong arm of democracy. The identified research
problem was investigated by means of qualitative research. A thorough
literature study from various sources of information, a case file analysis and
structured interviews were used to gather the required data. The interviews
were conducted with fingerprint experts, a data processor and constituency
electoral assistants from the Lesotho Mounted Police Service, the National
Identity and Civil Registry at the Ministry of Home Affairs and the IEC
respectively.
It was found that using fingerprints and the Automated Fingerprint Identification
System (AFIS) can assist in investigations and in combating voter’s fraud, as
fingerprints are unique. AFIS can be utilised for various purposes by institutions
in the private and public sectors. Like any apparatus, AFIS has its own strengths
and weaknesses. / Criminology and Security Science / M. Tech. (Forensic investigation)
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Genetinių algoritmų taikymas biometrijoje / Genetic algorithm in biometricGibavičius, Darius 17 June 2010 (has links)
Baigiamajame magistro darbe nagrinėjamas genetinių algoritmų taikymas biometrijoje. Išnagrinėta plačiausiai naudojama biometrinė informacija, aprašytos labiausiai paplitusios biometrinės sistemos, genetiniai algoritmai bei jų pritaikymas biometrinių sistemų optimizavimui. Baigiamajame darbe pasiūlytas naujas rankos atpažinimo metodas. Šiam metodui pritaikyti genetiniai algoritmai. Darbą sudaro 7 dalys: įvadas, biometrija, genetiniai algoritmai, genetinių algoritmų taikymas biometrinėse sistemose, genetinių algoritmų taikymas rankos atpažinimui, išvados ir literatūra. Darbo apimtis – 51 p. teksto be priedų, 30 pav., 4 lent., 32 bibliografiniai šaltiniai. / In the graduation thesis to receive the master‘s degree the application of genetic algorithms in biometrics is analysed. The most widely used biometric information have been examined, the most common biometric systems, genetic algorithms and their customization in biometric systems optimization have been described. A new method is proposed for hand recognition. Genetic algorithms have been customized for this method. Structure: introduction, biometry, genetic algorithms, application of genetic algorithms in biometric systems, application of genetic algorithms for hand recognition, the conclusions and bibliography. Thesis consist of: 51 p. text without appendixes, 30 pictures, 4 tables, 32 bibliographical entries.
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Fingerprint image enhancement and minutiae extraction algorithmCao, Letian, Wang, Yazhou January 2017 (has links)
This work aims to study the procedures of fingerprint identification system and to present some efficient algorithms for pre-processing and minutiae extraction. Most pre-processing steps consist of normalization, segmentation and orientation estimation, and background which focus on decreasing the variance of fingerprints, separating fore and background areas and tracking the direction of ridge lines, respectively. Minutiae extractionis typically divided into two approaches: binarization based method and directgray scale extraction. However, we put emphasis on binarization based method in thisresearch since it is more commonly used method in research papers. The results of simulationbased on a set of fingerprints downloaded from FVC 2006 database showed thatalgorithms we used are accurate and reliable.
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The feasibility of transferring cells from archived buccal swabs to FTA card for long term and simple storage of forensic samplesKhoory, Haifa January 2008 (has links)
[Truncated abstract] The collection of buccal cells is common practise in the epidemiological and forensic science. Unlike venipuncture collection of blood; it is a safer, non-invasive method for collection of biological material. The methods by which these cells are collected from the inner cheek of an individual and stored are the key elements in preserving DNA. Typically, forensic samples require long term storage. Samples are commonly collected on cotton swabs and stored moist at low to ultra-low temperatures (less than -20oC). Although this is the method of choice in most forensic facilities, there are drawbacks. The samples are inherently contaminated with microflora within the oral cavity and the moisture allows a plethora of microorganisms to grow. As the time frame that has elapsed from collection to storage increases, there is an exponential increase in bacterial cells. Storage of containers containing swabs coated with cells at temperatures below 20oC is also costly due to requirements for large freezers which are running and monitored over 24 hours. In the pass 10 to 15 years, researchers have focussed on alternative ways to store buccal cells. The FTA card system by Whatman is one such development. The FTA card is unique in that it provides a means for the collection of buccal cells for storage at room temperature. DNA profiling from samples stored in this way for 11 years has been successfully achieved. The filter paper matrix of the FTA card binds and subsequently lyses cells. ... (2) The second component of this thesis describes a study which subjected cells on buccal swabs to various conditions of increased temperature over periods of time to establish if DNA could be amplified. The aim was to mimic exposure to the vigours of field conditions, particularly in the extreme local environments that prevail in the United Arab Emirates. a. Initially, buccal cells stored at -20oC over 360 days were used to mimic standard archiving procedures. The cells were subsequently transferred to FTA cards, amplified and profiled by using ABI AmpFLSTR Identifiler PCR Amplification Kit (Applied Biosystems, Foster City, CA). Complete STR profiles were successfully recovered from the archived swabs. In most cases 100% of alleles were recovered, suggesting that it is feasible to transfer DNA from properly archived buccal swabs to FTA cards. b. The second phase involved the storage of fresh swabs that had been artificially aged by using incubation temperatures ranging from 40oC to 100oC. Partial profiles resulted from artificially aged samples, indicating that the prevailing conditions prior to low temperature storage of the swabs plays an important role in ensuring cellular integrity and thus, DNA quality. Results from this study suggest that it is possible for biological samples stored under correct conditions to be transferred from swabs to FTA card. In combination, the two chapters presented in this study show that it is feasible to transfer achieved forensic biology samples from swabs to the FTA card system. However, it is necessary to ensure that the samples are treated in the correct manner so as to minimise contamination from external sources and to maintain the correct environmental state to maintain intact cells and usable DNA.
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HPLC method development for characterisation of the phenolic composition of Cyclopia subternata and C. maculata extracts and chromatographic fingerprint analysis for quality controlSchulze, Alexandra Elizabeth 12 1900 (has links)
Thesis (MScFoodSc)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: The phenolic composition of Cyclopia species is believed to be partially responsible for the numerous health
promoting properties associated with their extracts. Current quality control measures do not accommodate
variation in phenolic profiles of Cyclopia species. In this study, comprehensive high performance liquid chromatography
(HPLC) methods were developed for the improved characterisation of the phenolic composition of
aqueous extracts of two Cyclopia species (C. subternata and C. maculata). The methods were developed to be
suitable for both routine quantitative analysis on conventional HPLC instrumentation, and the construction of
chromatographic fingerprints for further data analysis. The latter entailed similarity analysis and prediction of
total antioxidant capacity (TAC).
Using a methodical approach, two separate HPLC methods, using diode array detection (DAD), were developed
and validated for the analysis of aqueous extracts prepared from unfermented (green) and fermented
plant material of C. subternata and C. maculata. Separation was achieved using the same method parameters
(column, temperature, mobile phases), except for differing mobile phase gradients. Hyphenation of
the developed HPLC methods with mass spectrometry (MS) and tandem MS allowed the confirmation of
phenolic compounds previously identified in Cyclopia, and the tentative identification of several additional
compounds in Cyclopia species, which are reported here for the first time. These included apigenin-6,8-di-
C-glucoside, 3-hydroxyphloretin-30,50-di-C-hexoside, eriodictyol-di-C-glucoside, iriflophenone-di-O,C-hexoside,
hydroxymangiferin and hydroxyisomangiferin. Subsequently, a large number of aqueous extracts of randomly
selected green C. subternata (n = 64) and C. maculata (n = 50) plant material samples were analysed. Large
quantitative variations were observed on intra- and inter-species levels. Cyclopia maculata extracts contained
almost six times more mangiferin than extracts from C. subternata.
HPLC-DAD analysis produced duplicate fingerprints for each extract which were consequently used for
further analysis. The chromatographic fingerprint of a bioactive extract of each species was included in the
respective data sets. Similarity analysis was conducted between the fingerprints from the randomly selected
extracts and the corresponding active extract. For each species several extracts were determined to have similar
“activity” as that of the active extract (n = 15 for C. subternata and n = 45 for C. maculata). Compounds
potentially responsible for the activity were tentatively identified with the aid of principal component analysis
(PCA) in combination with similarity analysis. PCA was more effective in identifying small differences between
fingerprints than similarity analysis based on the correlation coefficients (r) alone.
Furthermore, multivariate data analysis was used to construct partial least squares (PLS) regression models
for the prediction of TAC from fingerprint data of each species, and available data from two microplate TAC
assays. The construction of the models was successful with reasonable errors (< 10%), and permitted the
determination of compounds of interest for future research. These included compounds of known identity that
had large positive contributions toward the predictions of TAC, or unknown compounds that had small UV signals, but relatively large positive contributions to the models. / AFRIKAANSE OPSOMMING: Die talle gesondheidbevorderingseienskappe van ekstrakte van Cyclopia spesies word gedeeltelik geassosieer met
hul fenoliese samestelling. Huidige kwaliteitskontrolemaatreëls is nie in staat om die variasie wat in die fenoliese
profiele van die spesies voorkom, te akkommodeer nie. Omvattende hoë druk vloeistof chromatografiese (HPLC)
metodes is vir twee Cyclopia spesies, naamlik C. subternata en C. maculata, in hierdie studie ontwikkel vir beter
karakterisering van die fenoliese samestelling van waterekstrakte van dié spesies. Die metodes moes ook geskik
wees vir roetine analise van C. subternata en C. maculata ekstrakte op konvensionele HPLC instrumentasie,
en vir die opstel van chromatografiese vingerafdrukke (fenoliese samestellingsprofiele) vir verdere data analise,
soos gelykvormigheidsanalise en die voorspelling van die totale antioksidantkapasiteit (TAC).
Twee HPLC metodes, wat van ’n ultraviolet-diode detektor (DAD) gebruik maak, is ontwikkel deur ’n
sistematiese benadering te volg. Die onderskeie metodes is vir die ontleding van waterekstrakte van groen (ongefermenteerde)
en gefermenteerde plantmateriaal van C. subternata en C. maculata gevalideer. Ongeag die
spesie is optimale skeiding met dieselfde kolom, mobiele fase en kolom-temperatuur bereik, maar met verskillende
mobiele fase gradiënte. Analise met massaspektrometrie (MS) en tandem MS het die teenwoordigheid
van fenoliese verbindings, wat voorheen in Cyclopia spesies geidentifiseer is, bevestig. Verder is ook ’n aantal
verbindings vir die eerste keer in Cyclopia tentatief geidentifiseer. Dit sluit apigenien-6,8-di-C-glukosied, 3-
hidroksiefloretien-30,50-di-C-heksosied, eriodiktiol-di-C-glukosied, iriflofenoon-di-O,C-heksosied, hidroksiemangiferien
en hidroksie-isomangiferien in. Vervolgens is ’n groot aantal ewekansig gekose waterekstrakte van beide
groen C. subternata (n = 64) en C. maculata (n = 50) plantmateriaal geanaliseer, en groot kwantitatiewe variasie
op intra- en inter-spesievlak waargeneem. Cyclopia maculata ekstrakte het byvoorbeeld byna ses maal die
mangiferieninhoud van C. subternata ekstrakte gehad.
HPLC-DAD analise van die ekstrakte het duplikaat vingerafdrukke van elke ekstrak geproduseer, wat vir
verdere data analise gebruik is. Die chromatografiese vingerafdruk van ’n bioaktiewe ekstrak van elke spesie
was by die onderskeie datastelle ingesluit. Gelykvormigheidsanalise is tussen vingerafdrukke van die ewekansig
gekose ekstrakte en die ooreenstemmende aktiewe ekstrak uitgevoer. Vir elke spesie is ’n aantal “aktiewe”
ekstrakte aangewys (n = 15 vir C. subternata en n = 45 vir C. maculata). Die verbindings wat potensieel
verantwoordelik kan wees vir die aktiwiteite is met behulp van hoofkomponentontleding (PCA) in kombinasie
met gelykvormigheidsanalise, tentatief aangewys. PCA was egter meer effektief om klein verskille tussen vingerafdrukke
aan te dui, in vergelyking met gelykvormigheidsanalise wat slegs op die korrelasie koëffisiënt (r)
gebaseer is.
Meerveranderlike data analiese is gebruik om “gedeeltelike kleinste kwadrate” (PLS) regressiemodelle, vir
die voorspelling van die TAC van beide spesies te bou. Die voorspelling is gebaseer op hul vingerafdruk data en
TAC data van twee TAC mikroplaat metodes. Die model-konstruksie was suksesvol met aanvaarbare voorspellingsfoute
(< 10%). Verbindings van belang kon ook bepaal word. Dit sluit bekende verbindings in wat groot positiewe bydraes ten opsigte van die voorspelling van TAC getoon het, asook ongeidentifiseerde verbindings
wat klein UV-seine getoon het, maar relatiewe groot bydraes tot die modelle gehad het.
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OCT en phase pour la reconnaissance biométrique par empreintes digitales et sa sécurisation / Phase-based Optical Coherence Tomography (OCT) for a robust and very secure fingerprint biometric recognitionLamare, François 21 March 2016 (has links)
Dans un monde de plus en plus ouvert, les flux de personnes sont amenés à exploser dans les prochaines années. Fluidifier et contrôler ces flux, tout en respectant de fortes contraintes sécuritaires, apparaît donc comme un élément clef pour favoriser le dynamisme économique mondial. Cette gestion des flux passe principalement par la connaissance et la vérification de l’identité des personnes. Pour son aspect pratique et a priori sécurisé, la biométrie, et en particulier celle des empreintes digitales, s’est imposée comme une solution efficace, et incontournable. Néanmoins, elle souffre de deux sévères limitations. La première concerne les mauvaises performances obtenues avec des doigts détériorés. Ces détériorations peuvent être involontaires (travailleurs manuels par exemple), ou bien volontaires, à des fins d’anonymisation. La deuxième concerne les failles de sécurité des capteurs. En particulier, ils sont vulnérables à des attaques avec de fausses empreintes, réalisées par des personnes mal intentionnées dans un but d’usurpation d’identité. D’après nous, ces limitations sont dues à la faible quantité d’information exploitée par les capteurs usuels. Elle se résume souvent à une simple image de la surface du doigt. Pourtant, la complexité biologique des tissus humains est telle qu’elle offre une information très riche, unique, et difficilement reproductible. Nous avons donc proposé une approche d’imagerie, basée sur la Tomographique par Cohérence Optique, un capteur 3D sans contact, permettant de mesurer finement cette information. L’idée majeure de la thèse consiste à étudier divers moyens de l’exploiter, afin de rendre la biométrie plus robuste et vraiment sécurisée / In an increasingly open world, the flows of people are brought to explode in the coming years. Facilitating, streamlining, and managing these flows, by maintaining strict security constraints, therefore represent a key element for the global socio-economic dynamism. This flows management is mainly based on knowledge and verification of person identity. For its practicality and a priori secured, biometrics, in particular fingerprints biometrics, has become an effective and unavoidable solution.Nevertheless, it still suffers from two severe limitations. The first one concerns the poor performances obtained with damaged fingers. This damage can be involuntary (e.g. manual workers) or volunteers, for purposes of anonymity. The second limitation consists in the vulnerability of the commonly used sensors. In particular, they are vulnerable to copies of stolen fingerprints, made by malicious persons for identity theft purpose. We believe that these limitations are due to the small amount of information brought by the usual biometric sensors. It often consists in a single print of the finger surface. However, the biological complexity of human tissue provides rich information, unique to each person, and very difficult to reproduce. We therefore proposed an imaging approach based on Optical Coherence Tomography (OCT), a 3D contactless optical sensor, to finely measure this information. The main idea of the thesis is therefore to explore novel ways to exploit this information in order to make biometrics more robust and truly secured. In particular, we have proposed and evaluated different fingerprint imaging methods, based on the phase of the OCT signal
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[pt] AVALIAÇÃO DO POTENCIAL DA 4,7-DI-MTOLUILBENZO[C][1,2,5]TIADIAZOLA COMO FLUORÓFORO PARA REVELAÇÃO DE IMPRESSÃO DIGITAL LATENTE / [en] EVALUATION OF THE 4,7-DI-MTOLYLBENZO[C][1,2,5]THIADIAZOLE AS A POTENTIAL FLUOROPHORE FOR LATENT FINGERPRINTINGRAFAELA SILVA DO NASCIMENTO 20 April 2023 (has links)
[pt] A busca por novas técnicas para a revelação de impressões digitais latentes
é constante por conta da importância para a área de Ciências Forenses, em especial,
na elucidação de crimes. O objetivo do presente estudo é avaliar o potencial da 4,7-
di-m-toluilbenzo[c][1,2,5]tiadiazola (BTD 206) como novo marcador para
aplicação na identificação dos grupos fundamentais e pontos característicos dos
desenhos das impressões digitais, visando melhor contraste de imagem em
substratos de diferentes cores, como capa de celular. Seis matrizes diferentes foram
testadas para a análise preliminar do desenvolvimento do pó revelador. A matriz
escolhida, carbonato de cálcio foi a que apresentou maior intensidade de
luminescência no substrato. Esse pó revelador foi desenvolvido e avaliado através
da espectrometria de luminescência em três diferentes concentrações. O programa
Image J foi utilizado para o processamento das imagens. O pó revelador
impregnado com a BTD 206 em metanol, na matriz carbonato de cálcio apresentou
características que auxiliaram na melhoria da qualidade do contraste, que foi
realizada a partir do histograma de imagem, que descreve a estatística dos níveis de
cinza. Dessa forma, em uma imagem com melhor qualidade, é possível extrair
informações da impressão digital, como grupos fundamentais e minúncias. O que
auxilia em um confronto e identificação de um possível suspeito de um crime. O pó
revelador desenvolvido com a BTD 206 teve um desempenho satisfatório para
aplicação pretendida. / [en] The search for new techniques for revealing latent fingerprints is constant
due to the importance for the area of Forensic Sciences, in particular, in the
elucidation of crimes. The objective of the present study is to evaluate the potential
of 4,7-di-m-toluylbenzo[c][1,2,5]thiadiazole (BTD 206) as a new marker for
application in the identification of fundamental groups and characteristic points of
drawings of digital prints, aiming at better image contrast on substrates of different
colors, such as cell phone cases. Six different matrices were tested for the
preliminary analysis of the developer powder development. The matrix chosen,
calcium carbonate, was the one that presented the highest intensity of luminescence
in the substrate. This developer powder was developed and evaluated through
luminescence spectrometry at three different concentrations. The Image J program
was used for image processing. The developer powder impregnated with BTD 206
in methanol, in the calcium carbonate matrix, showed characteristics that helped to
improve the quality of the contrast, which was performed from the image
histogram, which describes the gray levels statistics. In this way, in a better quality
image, it is possible to extract information from the fingerprint, such as fundamental
groups and minutiae. Which helps in a confrontation and identification of a possible
suspect of a crime. The developer powder developed with BTD 206 performed
satisfactorily for the intended application.
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INFORMATION THEORY ENABLED SECURE WIRELESS COMMUNICATION, KEY GENERATION AND AUTHENTICATIONGungor, Onur 30 December 2014 (has links)
No description available.
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