Discriminative multimodal biometric authentication based on quality measures

This is the author’s version of a work that was accepted for publication in Pattern Recognition. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Pattern Recognition, 38, 5, (2005) DOI: 10.1016/j.patcog.2004.11.012A novel score-level fusion strategy based on quality measures for multimodal biometric authentication is presented. In the proposed method, the fusion function is adapted every time an authentication claim is performed based on the estimated quality of the sensed biometric signals at this time. Experimental results combining written signatures and quality-labelled fingerprints are reported. The proposed scheme is shown to outperform significantly the fusion approach without considering quality signals. In particular, a relative improvement of approximately 20% is obtained on the publicly available MCYT bimodal database.This work has been supported by MCYT project TIC2003-08382-C05-01

Seismic Fault Preserving Diffusion

This paper focuses on the denoising and enhancing of 3-D reflection seismic data. We propose a pre-processing step based on a non linear diffusion filtering leading to a better detection of seismic faults. The non linear diffusion approaches are based on the definition of a partial differential equation that allows us to simplify the images without blurring relevant details or discontinuities. Computing the structure tensor which provides information on the local orientation of the geological layers, we propose to drive the diffusion along these layers using a new approach called SFPD (Seismic Fault Preserving Diffusion). In SFPD, the eigenvalues of the tensor are fixed according to a confidence measure that takes into account the regularity of the local seismic structure. Results on both synthesized and real 3-D blocks show the efficiency of the proposed approach.Comment: 10 page

Adaptive structure tensors and their applications

The structure tensor, also known as second moment matrix or Förstner interest operator, is a very popular tool in image processing. Its purpose is the estimation of orientation and the local analysis of structure in general. It is based on the integration of data from a local neighborhood. Normally, this neighborhood is defined by a Gaussian window function and the structure tensor is computed by the weighted sum within this window. Some recently proposed methods, however, adapt the computation of the structure tensor to the image data. There are several ways how to do that. This article wants to give an overview of the different approaches, whereas the focus lies on the methods based on robust statistics and nonlinear diffusion. Furthermore, the dataadaptive structure tensors are evaluated in some applications. Here the main focus lies on optic flow estimation, but also texture analysis and corner detection are considered

Diel time-courses of leaf growth in monocot and dicot species: endogenous rhythms and temperature effects

Diel (24 h) leaf growth patterns were differently affected by temperature variations and the circadian clock in several plant species. In the monocotyledon Zea mays, leaf elongation rate closely followed changes in temperature. In the dicotyledons Nicotiana tabacum, Ricinus communis, and Flaveria bidentis, the effect of temperature regimes was less obvious and leaf growth exhibited a clear circadian oscillation.These differences were related neither to primary metabolism nor to altered carbohydrate availability for growth. The effect of endogenous rhythms on leaf growth was analysed under continuous light in Arabidopsis thaliana, Ricinus communis, Zea mays, and Oryza sativa. No rythmic growth was observed under continuous light in the two monocotyledons, while growth rhythmicity persisted in the two dicotyledons. Based on model simulations it is concluded that diel leaf growth patterns in mono- and dicotyledons result from the additive effects of both circadian-clock-controlled processes and responses to environmental changes such as temperature and evaporative demand. Apparently very distinct diel leaf growth behaviour of monocotyledons and dicotyledons can thus be explained by the different degrees to which diel temperature variations affect leaf growth in the two groups of species which, in turn, depends on the extent of the leaf growth control by internal clocks

The Development of Customer Relationships and business : Epe's Music Store

The commissioner for this thesis was Epe’s Music Store, which operates in Tampere. The author did her internship for Poko Rekords record label and the idea for the research came from there. The record labels’ personnel works closely with Epe’s music store. There was a necessity to research the current level of customer satisfaction, find out possible weaknesses and shortages in business operations as well as come up with possible solutions and decisions in order to have a more successful business. At the time, there was an evident lack of customers as well as advanced business functions and something needed to be done quickly in order to save the legendary record store. Empirical evidence was collected from various sources by designing two questionnaires and an interview, which were then passed on to current customers and lost customers. Discussions between the owner of the store, the staff and the author were held as well. After gathering the answers they were analysed and revised for further conclusions and improvement ideas can be found at the end of this thesis. Theory on customer relationship management, customer loyalty and service quality was used as a base for the solutions and study. The main questionnaire was the one done for current customers, which gave a wider view on the actual findings. The most generalised outcome was that the customer age base ruled out the youth, the customer visits were rare, improvements on music genres needed to be made and the general appearance of the store needed to be improved among other aspects. The questionnaire completed for lost customers as well as the discussions held with the staff showed some deeper and further information regarding the study.Tämä opinnäytetyö on tehty Epe’s Music Store –levykaupalle, joka toimii Tampereella. Levy-yhtiön työntekijät työskentelevät läheisesti Epe’s levykaupan kanssa. Yrityksellä oli tarve tutkia asiakastyytyväisyyden nykytilannetta, saada selville mahdollisia heikkouksia ja puutteita yritystoiminnassa sekä kehittää mahdollisia ratkaisuja, jotta levykaupan toiminta olisi menestyvää. Tutkimusta tehtäessä yritys kärsi selvästi asiakkaiden puutteesta sekä lähes kehittymättömästä liiketoiminnasta. Empiiristä todistusaineistoa kerättiin eri lähteistä suunnittelemalla kaksi kyselyä nykyisille sekä menetetyille asiakkaille sekä pitämällä keskustelutilaisuuksia Epe’sin omistajan sekä työntekijöiden kanssa. Vastaukset analysoitiin ja arvioitiin uudelleen, jonka jälkeen muodostettiin ratkaisuja sekä kehitysideoita ongelmiin. Tutkielman ja ratkaisujen pohjana on käytetty teoriaa asiakassuhteiden johtamisesta, asiakaslojaliteetista sekä palvelun laadusta. Tärkein kysely tehtiin nykyisille asiakkaille, ja se antoi laajemman käsityksen eräisiin ongelmakohtiin. Päätulos oli se, että asiakkaiden ikäryhmästä puuttuivat tyystin nuoret, asiakaskäynnit olivat harvoja sekä parannuksia musiikkityyleihin, oheistuotteisiin ja yleisilmeeseen täytyi tehdä. Kysely menetetyille asiakkaille sekä keskustelut omistajan ja työntekijöiden kanssa antoivat syvempää tietoa itse aiheesta sekä ongelmista