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  • 51.
    Alonso-Fernandez, Fernando
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Bigun, Josef
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Biometric Recognition Using Periocular Images2013Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    We present a new system for biometric recognition using periocular images based on retinotopic sampling grids and Gabor analysis of the local power spectrum at different frequencies and orientations. A number of aspects are studied, including: 1) grid adaptation to dimensions of the target eye vs. grids of constant size, 2) comparison between circular- and rectangular-shaped grids, 3) use of Gabor magnitude vs. phase vectors for recognition, and 4) rotation compensation between query and test images. Results show that our system achieves competitive verification rates compared with other periocular recognition approaches. We also show that top verification rates can be obtained without rotation compensation, thus allowing to remove this step for computational efficiency. Also, the performance is not affected substantially if we use a grid of fixed dimensions, or it is even better in certain situations, avoiding the need of accurate detection of the iris region.

  • 52.
    Alonso-Fernandez, Fernando
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Bigun, Josef
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Exploting Periocular and RGB Information in Fake Iris Detection2014Inngår i: 2014 37th International Conventionon Information and Communication Technology, Electronics and Microelectronics (MIPRO): 26 – 30 May 2014 Opatija, Croatia: Proceedings / [ed] Petar Biljanovic, Zeljko Butkovic, Karolj Skala, Stjepan Golubic, Marina Cicin-Sain, Vlado Sruk, Slobodan Ribaric, Stjepan Gros, Boris Vrdoljak, Mladen Mauher & Goran Cetusic, Rijeka: Croatian Society for Information and Communication Technology, Electronics and Microelectronics - MIPRO , 2014, s. 1354-1359Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Fake iris detection has been studied by several researchers. However, to date, the experimental setup has been limited to near-infrared (NIR) sensors, which provide grey-scale images. This work makes use of images captured in visible range with color (RGB) information. We employ Gray-Level CoOccurrence textural features and SVM classifiers for the task of fake iris detection. The best features are selected with the Sequential Forward Floating Selection (SFFS) algorithm. To the best of our knowledge, this is the first work evaluating spoofing attack using color iris images in visible range. Our results demonstrate that the use of features from the three color channels clearly outperform the accuracy obtained from the luminance (gray scale) image. Also, the R channel is found to be the best individual channel. Lastly, we analyze the effect of extracting features from selected (eye or periocular) regions only. The best performance is obtained when GLCM features are extracted from the whole image, highlighting that both the iris and the surrounding periocular region are relevant for fake iris detection. An added advantage is that no accurate iris segmentation is needed. This work is relevant due to the increasing prevalence of more relaxed scenarios where iris acquisition using NIR light is unfeasible (e.g. distant acquisition or mobile devices), which are putting high pressure in the development of algorithms capable of working with visible light. © 2014 MIPRO.

  • 53.
    Alonso-Fernandez, Fernando
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Bigun, Josef
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Eye Detection by Complex Filtering for Periocular Recognition2014Inngår i: 2nd International Workshop on Biometrics and Forensics (IWBF2014): Valletta, Malta (27-28th March 2014), Piscataway, NJ: IEEE Press, 2014, artikkel-id 6914250Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We present a novel system to localize the eye position based on symmetry filters. By using a 2D separable filter tuned to detect circular symmetries, detection is done with a few ID convolutions. The detected eye center is used as input to our periocular algorithm based on retinotopic sampling grids and Gabor analysis of the local power spectrum. This setup is evaluated with two databases of iris data, one acquired with a close-up NIR camera, and another in visible light with a web-cam. The periocular system shows high resilience to inaccuracies in the position of the detected eye center. The density of the sampling grid can also be reduced without sacrificing too much accuracy, allowing additional computational savings. We also evaluate an iris texture matcher based on ID Log-Gabor wavelets. Despite the poorer performance of the iris matcher with the webcam database, its fusion with the periocular system results in improved performance. ©2014 IEEE.

  • 54.
    Alonso-Fernandez, Fernando
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Laboratoriet för intelligenta system.
    Bigun, Josef
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Fake Iris Detection: A Comparison Between Near-Infrared and Visible Images2014Inngår i: Proceedings: 10th International Conference on Signal-Image Technology and Internet-Based Systems, SITIS 2014 / [ed] Kokou Yetongnon, Albert Dipanda & Richard Chbeir, Piscataway, NJ: IEEE Computer Society, 2014, s. 546-553Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Fake iris detection has been studied so far using near-infrared sensors (NIR), which provide grey scale-images, i.e. With luminance information only. Here, we incorporate into the analysis images captured in visible range, with color information, and perform comparative experiments between the two types of data. We employ Gray-Level Cocurrence textural features and SVM classifiers. These features analyze various image properties related with contrast, pixel regularity, and pixel co-occurrence statistics. We select the best features with the Sequential Forward Floating Selection (SFFS) algorithm. We also study the effect of extracting features from selected (eye or periocular) regions only. Our experiments are done with fake samples obtained from printed images, which are then presented to the same sensor than the real ones. Results show that fake images captured in NIR range are easier to detect than visible images (even if we down sample NIR images to equate the average size of the iris region between the two databases). We also observe that the best performance with both sensors can be obtained with features extracted from the whole image, showing that not only the eye region, but also the surrounding periocular texture is relevant for fake iris detection. An additional source of improvement with the visible sensor also comes from the use of the three RGB channels, in comparison with the luminance image only. A further analysis also reveals that some features are best suited to one particular sensor than the others. © 2014 IEEE

  • 55.
    Alonso-Fernandez, Fernando
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Bigun, Josef
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Halmstad University submission to the First ICB Competition on Iris Recognition (ICIR2013)2013Annet (Annet vitenskapelig)
  • 56.
    Alonso-Fernandez, Fernando
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Laboratoriet för intelligenta system.
    Bigun, Josef
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Laboratoriet för intelligenta system.
    Iris Boundaries Segmentation Using the Generalized Structure Tensor: A Study on the Effects of Image Degradation2012Inngår i: Biometrics: Theory, Applications and Systems (BTAS), 2012 IEEE Fifth International Conference on, Piscataway, N.J.: IEEE Press, 2012, s. 426-431, artikkel-id 6374610Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We present a new iris segmentation algorithm based onthe Generalized Structure Tensor (GST), which also includesan eyelid detection step. It is compared with traditionalsegmentation systems based on Hough transformand integro-differential operators. Results are given usingthe CASIA-IrisV3-Interval database. Segmentation performanceunder different degrees of image defocus and motionblur is also evaluated. Reported results shows the effectivenessof the proposed algorithm, with similar performancethan the others in pupil detection, and clearly betterperformance for sclera detection for all levels of degradation.Verification results using 1D Log-Gabor wavelets arealso given, showing the benefits of the eyelids removal step.These results point out the validity of the GST as an alternativeto other iris segmentation systems. © 2012 IEEE.

  • 57.
    Alonso-Fernandez, Fernando
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Bigun, Josef
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Iris Pupil Detection by Structure Tensor Analysis2011Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    This paper present a pupil detection/segmentation algorithm for iris images based on Structure Tensor analysis. Eigenvalues of the structure tensor matrix have been observed to be high in pupil boundaries and specular reflections of iris images. We exploit this fact to detect the specular reflections region and the boundary of the pupil in a sequential manner. Experimental results are given using the CASIA-IrisV3-Interval database (249 contributors, 396 different eyes, 2,639 iris images). Results show that our algorithm works specially well in detecting the specular reflections (98.98% success rate) and pupil boundary detection is correctly done in 84.24% of the images.

  • 58.
    Alonso-Fernandez, Fernando
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Laboratoriet för intelligenta system.
    Bigun, Josef
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Laboratoriet för intelligenta system.
    Iris Segmentation Using the Generalized Structure Tensor2012Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    We present a new iris segmentation algorithm based on the Generalized Structure Tensor (GST). We compare this approach with traditional iris segmentation systems based on Hough transform and integro-differential operators. Results are given using the CASIA-IrisV3-Interval database with respect to a segmentation made manually by a human expert. The proposed algorithm outperforms the baseline approaches, pointing out the validity of the GST as an alternative to classic iris segmentation systems. We also detect the cross positions between the eyelids and the outer iris boundary. Verification results using a publicly available iris recognition system based on 1D Log-Gabor wavelets are also given, showing the benefits of the eyelids removal step.

  • 59.
    Alonso-Fernandez, Fernando
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Bigun, Josef
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Near-infrared and visible-light periocular recognition with Gabor features using frequency-adaptive automatic eye detection2015Inngår i: IET Biometrics, ISSN 2047-4938, E-ISSN 2047-4946, Vol. 4, nr 2, s. 74-89Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Periocular recognition has gained attention recently due to demands of increased robustness of face or iris in less controlled scenarios. We present a new system for eye detection based on complex symmetry filters, which has the advantage of not needing training. Also, separability of the filters allows faster detection via one-dimensional convolutions. This system is used as input to a periocular algorithm based on retinotopic sampling grids and Gabor spectrum decomposition. The evaluation framework is composed of six databases acquired both with near-infrared and visible sensors. The experimental setup is complemented with four iris matchers, used for fusion experiments. The eye detection system presented shows very high accuracy with near-infrared data, and a reasonable good accuracy with one visible database. Regarding the periocular system, it exhibits great robustness to small errors in locating the eye centre, as well as to scale changes of the input image. The density of the sampling grid can also be reduced without sacrificing accuracy. Lastly, despite the poorer performance of the iris matchers with visible data, fusion with the periocular system can provide an improvement of more than 20%. The six databases used have been manually annotated, with the annotation made publicly available. © The Institution of Engineering and Technology 2015.

  • 60.
    Alonso-Fernandez, Fernando
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Bigun, Josef
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Periocular Biometrics: Databases, Algorithms and Directions2016Inngår i: 2016 4th International Workshop on Biometrics and Forensics (IWBF): Proceedings : 3-4 March, 2016, Limassol, Cyprus, Piscataway, NJ: IEEE, 2016, artikkel-id 7449688Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Periocular biometrics has been established as an independent modality due to concerns on the performance of iris or face systems in uncontrolled conditions. Periocular refers to the facial region in the eye vicinity, including eyelids, lashes and eyebrows. It is available over a wide range of acquisition distances, representing a trade-off between the whole face (which can be occluded at close distances) and the iris texture (which do not have enough resolution at long distances). Since the periocular region appears in face or iris images, it can be used also in conjunction with these modalities. Features extracted from the periocular region have been also used successfully for gender classification and ethnicity classification, and to study the impact of gender transformation or plastic surgery in the recognition performance. This paper presents a review of the state of the art in periocular biometric research, providing an insight of the most relevant issues and giving a thorough coverage of the existing literature. Future research trends are also briefly discussed. © 2016 IEEE.

  • 61.
    Alonso-Fernandez, Fernando
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Laboratoriet för intelligenta system.
    Bigun, Josef
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Periocular Recognition Using Retinotopic Sampling and Gabor Decomposition2012Inngår i: Computer Vision – ECCV 2012: Workshops and demonstrations : Florence, Italy, October 7-13, 2012, Proceedings. Part II / [ed] Fusiello, Andrea; Murino, Vittorio; Cucchiara, Rita, Berlin: Springer, 2012, Vol. 7584, s. 309-318Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We present a new system for biometric recognition using periocular images based on retinotopic sampling grids and Gabor analysis of the local power spectrum. A number of aspects are studied, including: 1) grid adaptation to dimensions of the target eye vs. grids of constant size, 2) comparison between circular- and rectangular-shaped grids, 3) use of Gabor magnitude vs. phase vectors for recognition, 4) rotation compensation between query and test images, and 5) comparison with an iris machine expert. Results show that our system achieves competitive verification rates compared with other periocular recognition approaches. We also show that top verification rates can be obtained without rotation compensation, thus allowing to remove this step for computational efficiency. Also, the performance is not affected substantially if we use a grid of fixed dimensions, or it is even better in certain situations, avoiding the need of accurate detection of the iris region. © 2012 Springer-Verlag.

  • 62.
    Alonso-Fernandez, Fernando
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Bigun, Josef
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Periocular biometrics: Databases, Algorithms and Directions2016Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Periocular biometrics has been established as an independent modality due to concerns on the performance of iris or face systems in uncontrolled conditions. Periocular refers to the facial region in the eye vicinity, including eyelids, lashes and eyebrows. It is available over a wide range of acquisition distances, representing a tradeoff between the whole face (which can be occluded at close distances) and the iris texture (which do not have enough resolution at long distances). Since the periocular region appears in face or iris images, it can be used also in conjunction with these modalities. Features extracted from the periocular region have been also used successfully for gender classification and ethnicity classification, and to study the impact of gender transformation or plastic surgery in the recognition performance. This paper presents a review of the state of the art in periocular biometric research, providing an insight of the most relevant issues and giving a thorough coverage of the existing literature. Future research trends are also briefly discussed.

  • 63.
    Alonso-Fernandez, Fernando
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Bigun, Josef
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Quality Factors Affecting Iris Segmentation and Matching2013Inngår i: Proceedings – 2013 International Conference on Biometrics, ICB 2013 / [ed] Julian Fierrez, Ajay Kumar, Mayank Vatsa, Raymond Veldhuis & Javier Ortega-Garcia, Piscataway, N.J.: IEEE conference proceedings, 2013, artikkel-id 6613016Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Image degradations can affect the different processing steps of iris recognition systems. With several quality factors proposed for iris images, its specific effect in the segmentation accuracy is often obviated, with most of the efforts focused on its impact in the recognition accuracy. Accordingly, we evaluate the impact of 8 quality measures in the performance of iris segmentation. We use a database acquired with a close-up iris sensor and built-in quality checking process. Despite the latter, we report differences in behavior, with some measures clearly predicting the segmentation performance, while others giving inconclusive results. Recognition experiments with two matchers also show that segmentation and matching performance are not necessarily affected by the same factors. The resilience of one matcher to segmentation inaccuracies also suggest that segmentation errors due to low image quality are not necessarily revealed by the matcher, pointing out the importance of separate evaluation of the segmentation accuracy. © 2013 IEEE.

  • 64.
    Alonso-Fernandez, Fernando
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Bigun, Josef
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Englund, Cristofer
    RISE Viktoria, Gothenburg, Sweden.
    Expression Recognition Using the Periocular Region: A Feasibility Study2018Inngår i: 2018 14th International Conference on Signal-Image Technology & Internet-Based Systems (SITIS) / [ed] Gabriella Sanniti di Baja, Luigi Gallo, Kokou Yetongnon, Albert Dipanda, Modesto Castrillón-Santana & Richard Chbeir, Los Alamitos: IEEE Computer Society, 2018, s. 536-541Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper investigates the feasibility of using the periocular region for expression recognition. Most works have tried to solve this by analyzing the whole face. Periocular is the facial region in the immediate vicinity of the eye. It has the advantage of being available over a wide range of distances and under partial face occlusion, thus making it suitable for unconstrained or uncooperative scenarios. We evaluate five different image descriptors on a dataset of 1,574 images from 118 subjects. The experimental results show an average/overall accuracy of 67.0%/78.0% by fusion of several descriptors. While this accuracy is still behind that attained with full-face methods, it is noteworthy to mention that our initial approach employs only one frame to predict the expression, in contraposition to state of the art, exploiting several order more data comprising spatial-temporal data which is often not available.

  • 65.
    Alonso-Fernandez, Fernando
    et al.
    ATVS/Biometric Recognition Group, Escuela Politecnica Superior, Univ. Autonoma de Madrid, Spain.
    Bigun, Josef
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS).
    Fierrez, Julian
    ATVS/Biometric Recognition Group, Escuela Politecnica Superior, Univ. Autonoma de Madrid, Spain.
    Fronthaler, Hartwig
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS).
    Kollreider, Klaus
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS).
    Ortega-Garcia, Javier
    ATVS/Biometric Recognition Group, Escuela Politecnica Superior, Univ. Autonoma de Madrid, Spain.
    Fingerprint Recognition2009Inngår i: Guide to Biometric Reference Systems and Performance Evaluation / [ed] Dijana Petrovska-Delacrétaz, Gérard Chollet, Bernadette Dorizzi, London: Springer London, 2009, s. 51-88Kapittel i bok, del av antologi (Annet vitenskapelig)
    Abstract [en]

    First, an overview of the state of the art in fingerprint recognition is presented, including current issues and challenges. Fingerprint databases and evaluation campaigns, are also summarized. This is followed by the description of the BioSecure Benchmarking Framework for Fingerprints, using the NIST Fingerpint Image Software (NFIS2), the publicly available MCYT-100 database, and two evaluation protocols. Two research systems are compared within the proposed framework. The evaluated systems follow different approaches for fingerprint processing and are discussed in detail. Fusion experiments involving different combinations of the presented systems are also given. The NFIS2 software is also used to obtain the fingerprint scores for the multimodal experiments conducted within the BioSecure Multimodal Evaluation Campaign(BMEC’2007) reported in Chap.11.

  • 66.
    Alonso-Fernandez, Fernando
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Farrugia, Reuben A.
    University of Malta, Msida, Malta.
    Bigun, Josef
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Eigen-patch iris super-resolution for iris recognition improvement2015Inngår i: 2015 23rd European Signal Processing Conference (EUSIPCO), Piscataway, NJ: IEEE Press, 2015, s. 76-80, artikkel-id 7362348Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Low image resolution will be a predominant factor in iris recognition systems as they evolve towards more relaxed acquisition conditions. Here, we propose a super-resolution technique to enhance iris images based on Principal Component Analysis (PCA) Eigen-transformation of local image patches. Each patch is reconstructed separately, allowing better quality of enhanced images by preserving local information and reducing artifacts. We validate the system used a database of 1,872 near-infrared iris images. Results show the superiority of the presented approach over bilinear or bicubic interpolation, with the eigen-patch method being more resilient to image resolution reduction. We also perform recognition experiments with an iris matcher based 1D Log-Gabor, demonstrating that verification rates degrades more rapidly with bilinear or bicubic interpolation. ©2015 IEEE

  • 67.
    Alonso-Fernandez, Fernando
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Farrugia, Reuben A.
    University of Malta, Msida, Malta.
    Bigun, Josef
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Improving Very Low-Resolution Iris Identification Via Super-Resolution Reconstruction of Local Patches2017Inngår i: 2017 International Conference of the Biometrics Special Interest Group (BIOSIG) / [ed] Arslan Brömme, Christoph Busch, Antitza Dantcheva, Christian Rathgeb & Andreas Uhl, Bonn: Gesellschaft für Informatik, 2017, Vol. P-270, artikkel-id 8053512Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Relaxed acquisition conditions in iris recognition systems have significant effects on the quality and resolution of acquired images, which can severely affect performance if not addressed properly. Here, we evaluate two trained super-resolution algorithms in the context of iris identification. They are based on reconstruction of local image patches, where each patch is reconstructed separately using its own optimal reconstruction function. We employ a database of 1,872 near-infrared iris images (with 163 different identities for identification experiments) and three iris comparators. The trained approaches are substantially superior to bilinear or bicubic interpolations, with one of the comparators providing a Rank-1 performance of ∼88% with images of only 15×15 pixels, and an identification rate of 95% with a hit list size of only 8 identities. © 2017 Gesellschaft fuer Informatik.

  • 68.
    Alonso-Fernandez, Fernando
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Farrugia, Reuben A.
    University of Malta, Msida, Malta.
    Bigun, Josef
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Iris Super-Resolution Using Iterative Neighbor Embedding2017Inngår i: 2017 IEEE Conference on Computer Vision and Pattern Recognition Workshops / [ed] Lisa O’Conner, Los Alamitos: IEEE Computer Society, 2017, s. 655-663Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Iris recognition research is heading towards enabling more relaxed acquisition conditions. This has effects on the quality and resolution of acquired images, severely affecting the accuracy of recognition systems if not tackled appropriately. In this paper, we evaluate a super-resolution algorithm used to reconstruct iris images based on iterative neighbor embedding of local image patches which tries to represent input low-resolution patches while preserving the geometry of the original high-resolution space. To this end, the geometry of the low- and high-resolution manifolds are jointly considered during the reconstruction process. We validate the system with a database of 1,872 near-infrared iris images, while fusion of two iris comparators has been adopted to improve recognition performance. The presented approach is substantially superior to bilinear/bicubic interpolations at very low resolutions, and it also outperforms a previous PCA-based iris reconstruction approach which only considers the geometry of the low-resolution manifold during the reconstruction process. © 2017 IEEE

  • 69.
    Alonso-Fernandez, Fernando
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Farrugia, Reuben A.
    University of Malta, Msida, Malta.
    Bigun, Josef
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Reconstruction of Smartphone Images for Low Resolution Iris Recognition2015Inngår i: 2015 IEEE International Workshop on Information Forensics and Security (WIFS), Piscataway, NJ: IEEE Press, 2015, artikkel-id 7368600Konferansepaper (Fagfellevurdert)
    Abstract [en]

    As iris systems evolve towards a more relaxed acquisition, low image resolution will be a predominant issue. In this paper we evaluate a super-resolution method to reconstruct iris images based on Eigen-transformation of local image patches. Each patch is reconstructed separately, allowing better quality of enhanced images by preserving local information. We employ a database of 560 images captured in visible spectrum with two smartphones. The presented approach is superiorto bilinear or bicubic interpolation, especially at lower resolutions. We also carry out recognition experiments with six iris matchers, showing that better performance can be obtained at low-resolutions with the proposed eigen-patch reconstruction, with fusion of only two systems pushing the EER to below 5-8% for down-sampling factors up to a size of only 13x13. © 2015 IEEE.

  • 70.
    Alonso-Fernandez, Fernando
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Farrugia, Reuben A.
    University of Malta, Msida, Malta.
    Bigun, Josef
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Fierrez, Julian
    Universidad Autonoma de Madrid, Madrid, Spain.
    Gonzalez-Sosa, Ester
    Nokia Bell-Labs, Madrid, Spain.
    A Survey of Super-Resolution in Iris Biometrics with Evaluation of Dictionary-Learning2019Inngår i: IEEE Access, E-ISSN 2169-3536, Vol. 7, s. 6519-6544Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The lack of resolution has a negative impact on the performance of image-based biometrics. While many generic super-resolution methods have been proposed to restore low-resolution images, they usually aim to enhance their visual appearance. However, an overall visual enhancement of biometric images does not necessarily correlate with a better recognition performance. Reconstruction approaches need thus to incorporate specific information from the target biometric modality to effectively improve recognition performance. This paper presents a comprehensive survey of iris super-resolution approaches proposed in the literature. We have also adapted an Eigen-patches reconstruction method based on PCA Eigentransformation of local image patches. The structure of the iris is exploited by building a patch-position dependent dictionary. In addition, image patches are restored separately, having their own reconstruction weights. This allows the solution to be locally optimized, helping to preserve local information. To evaluate the algorithm, we degraded high-resolution images from the CASIA Interval V3 database. Different restorations were considered, with 15 × 15 pixels being the smallest resolution evaluated. To the best of our knowledge, this is among the smallest resolutions employed in the literature. The experimental framework is complemented with six publicly available iris comparators, which were used to carry out biometric verification and identification experiments. Experimental results show that the proposed method significantly outperforms both bilinear and bicubic interpolation at very low-resolution. The performance of a number of comparators attain an impressive Equal Error Rate as low as 5%, and a Top-1 accuracy of 77-84% when considering iris images of only 15 × 15 pixels. These results clearly demonstrate the benefit of using trained super-resolution techniques to improve the quality of iris images prior to matching. © 2018, Emerald Publishing Limited.

  • 71.
    Alonso-Fernandez, Fernando
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Farrugia, Reuben A.
    University of Malta, Msida, Malta.
    Fierrez, Julian
    Universidad Autonoma de Madrid, Madrid, Spain.
    Bigun, Josef
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Super-Resolution for Selfie Biometrics: Introduction and Application to Face and Iris2019Inngår i: Selfie Biometrics: Advances and Challenges / [ed] Ajita Rattani, Reza Derakhshani & Arun A. Ross, Cham: Springer, 2019, 1, s. 105-128Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    Biometric research is heading towards enabling more relaxed acquisition conditions. This has effects on the quality and resolution of acquired images, severly affecting the accuracy of recognition systems if not tackled appropriately. In this chapter, we give an overview of recent research in super-resolution reconstruction applied to biometrics, with a focus on face and iris images in the visible spectrum, two prevalent modalities in selfie biometrics. After an introduction to the generic topic of super-resolution, we investigate methods adapted to cater for the particularities of these two modalities. By experiments, we show the benefits of incorporating super-resolution to improve the quality of biometric images prior to recognition. © Springer Nature AG 2019

  • 72.
    Alonso-Fernandez, Fernando
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Farrugia, Reuben
    University of Malta, Msida, Malta.
    Bigun, Josef
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Learning-Based Local-Patch Resolution Reconstruction of Iris Smart-phone Images2017Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Application of ocular biometrics in mobile and at a distance environments still has several open challenges, with the lack quality and resolution being an evident issue that can severely affects performance. In this paper, we evaluate two trained image reconstruction algorithms in the context of smart-phone biometrics. They are based on the use of coupled dictionaries to learn the mapping relations between low and high resolution images. In addition, reconstruction is made in local overlapped image patches, where up-scaling functions are modelled separately for each patch, allowing to better preserve local details. The experimental setup is complemented with a database of 560 images captured with two different smart-phones, and two iris comparators employed for verification experiments. We show that the trained approaches are substantially superior to bilinear or bicubic interpolations at very low resolutions (images of 13×13 pixels). Under such challenging conditions, an EER of ∼7% can be achieved using individual comparators, which is further pushed down to 4-6% after the fusion of the two systems. © 2017 IEEE

  • 73.
    Alonso-Fernandez, Fernando
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Farrugia, Reuben
    University of Malta, Msida, Malta.
    Bigun, Josef
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Very Low-Resolution Iris Recognition Via Eigen-Patch Super-Resolution and Matcher Fusion2016Inngår i: 2016 IEEE 8th International Conference on Biometrics Theory, Applications and Systems (BTAS), Piscataway: IEEE, 2016, artikkel-id 7791208Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Current research in iris recognition is moving towards enabling more relaxed acquisition conditions. This has effects on the quality of acquired images, with low resolution being a predominant issue. Here, we evaluate a super-resolution algorithm used to reconstruct iris images based on Eigen-transformation of local image patches. Each patch is reconstructed separately, allowing better quality of enhanced images by preserving local information. Contrast enhancement is used to improve the reconstruction quality, while matcher fusion has been adopted to improve iris recognition performance. We validate the system using a database of 1,872 near-infrared iris images. The presented approach is superior to bilinear or bicubic interpolation, especially at lower resolutions, and the fusion of the two systems pushes the EER to below 5% for down-sampling factors up to a image size of only 13×13.

  • 74.
    Alonso-Fernandez, Fernando
    et al.
    University de Madrid, Madrid, Spain.
    Fierrez, J.
    Universidad Autonoma de Madrid.
    Ortega-Garcia, J.
    Universidad Autónoma de Madrid.
    Gonzalez-Rodriguez, J.
    Universidad Autónoma de Madrid.
    Fronthaler, Hartwig
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS).
    Kollreider, Klaus
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS).
    Bigun, Josef
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Intelligenta system (IS-lab).
    A Comparative Study of Fingerprint Image-Quality Estimation Methods2007Inngår i: IEEE Transactions on Information Forensics and Security, ISSN 1556-6013, E-ISSN 1556-6021, Vol. 2, nr 4, s. 734-743Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    One of the open issues in fingerprint verification is the lack of robustness against image-quality degradation. Poor-quality images result in spurious and missing features, thus degrading the performance of the overall system. Therefore, it is important for a fingerprint recognition system to estimate the quality and validity of the captured fingerprint images. In this work, we review existing approaches for fingerprint image-quality estimation, including the rationale behind the published measures and visual examples showing their behavior under different quality conditions. We have also tested a selection of fingerprint image-quality estimation algorithms. For the experiments, we employ the BioSec multimodal baseline corpus, which includes 19 200 fingerprint images from 200 individuals acquired in two sessions with three different sensors. The behavior of the selected quality measures is compared, showing high correlation between them in most cases. The effect of low-quality samples in the verification performance is also studied for a widely available minutiae-based fingerprint matching system.

  • 75.
    Alonso-Fernandez, Fernando
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Laboratoriet för intelligenta system.
    Fierrez, Julian
    Universidad Autonoma de Madrid, Madrid, Spain.
    Fingerprint Databases and Evaluation2015Inngår i: Encyclopedia of Biometrics / [ed] Stan Z. Li & Anil K. Jain, New York: Springer Science+Business Media B.V., 2015, 2, s. 599-606Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    This is an excerpt from the content

    Synonyms

    Fingerprint benchmark; Fingerprint corpora; Fingerprint dataset

    Definition

    Fingerprint databases are structured collections of fingerprint data mainly used for either evaluation or operational recognition purposes.

    Fingerprint data in databases for evaluation are usually detached from the identity of corresponding individuals. These databases are publicly available for research purposes, and they usually consist of raw fingerprint images acquired with live-scan sensors or digitized from inked fingerprint impressions on paper. Databases for evaluation are the basis for research in automatic fingerprint recognition, and together with specific experimental protocols, they are the basis for a number of technology evaluations and benchmarks. This is the type of fingerprint databases further covered here.

    On the other hand, fingerprint databases for operational recognition are typically proprietary, they usually incorporate personal information about the enrolled people together with the fingerprint data, and they can incorporate either raw fingerprint image data or some form of distinctive fingerprint descriptors such as minutiae templates. These fingerprint databases represent one of the modules in operational automated fingerprint recognition systems, and they will not be adressed here.

  • 76.
    Alonso-Fernandez, Fernando
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Laboratoriet för intelligenta system.
    Fierrez, Julian
    Universidad Autonoma de Madrid, Madrid, Spain.
    Bigun, Josef
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Quality Measures in Biometric Systems2015Inngår i: Encyclopedia of Biometrics / [ed] Stan Z. Li & Anil K. Jain, New York: Springer Science+Business Media B.V., 2015, 2, s. 1287-1297Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    This is an excerpt from the content

    Synonyms

    Quality assessment; Biometric quality; Quality-based processing

    Definition

    Since the establishment of biometrics as a specific research area in the late 1990s, the biometric community has focused its efforts in the development of accurate recognition algorithms [1]. Nowadays, biometric recognition is a mature technology that is used in many applications, offering greater security and convenience than traditional methods of personal recognition [2].

    During the past few years, biometric quality measurement has become an important concern after a number of studies and technology benchmarks that demonstrate how performance of biometric systems is heavily affected by the quality of biometric signals [3]. This operationally important step has been nevertheless under-researched compared to the primary feature extraction and pattern recognition tasks [4]. One of the main challenges facing biometric technologies is performance degradation in less controlled situations, and the problem of biometric quality measurement has arisen even stronger with the proliferation of portable handheld devices, with at-a-distance and on-the-move acquisition capabilities. These will require robust algorithms capable of handling a range of changing characteristics [2]. Another important example is forensics, in which intrinsic operational factors further degrade recognition performance.

    There are number of factors that can affect the quality of biometric signals, and there are numerous roles of a quality measure in the context of biometric systems. This section summarizes the state of the art in the biometric quality problem, giving an overall framework of the different challenges involved.

  • 77.
    Alonso-Fernandez, Fernando
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Laboratoriet för intelligenta system. Fernando.Alonso-Fernandez@hh.se.
    Fierrez, Julian
    Universidad Autonoma de Madrid, Madrid, Spain.
    Ortega-Garcia, Javier
    Universidad Autonoma de Madrid, Madrid, Spain.
    Quality Measures in Biometric Systems2012Inngår i: IEEE Security and Privacy, ISSN 1540-7993, E-ISSN 1558-4046, Vol. 10, nr 6, s. 52-62Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Biometric technology has been increasingly deployed in the last decade, offering greater security and convenience than traditional methods of personal recognition. But although the performance of biometric systems is heavily affected by the quality of biometric signals, prior work on quality evaluation is limited. Quality assessment is a critical issue in the security arena, especially in challenging scenarios (e.g. surveillance cameras, forensics, portable devices or remote access through Internet). Different questions regarding the factors influencing biometric quality and how to overcome them, or the incorporation of quality measures in the context of biometric systems have to be analyzed first. In this paper, a review of the state-of-the-art in these matters is provided, giving an overall framework of the main factors related to the challenges associated with biometric quality.

  • 78.
    Alonso-Fernandez, Fernando
    et al.
    ATVS, Escuela Politecnica Superior, Campus de Cantoblanco, Avda. Francisco Tomas y Valiente 11, 28049 Madrid, Spain.
    Fierrez-Aguilar, Julian
    ATVS, Escuela Politecnica Superior, Campus de Cantoblanco, Avda. Francisco Tomas y Valiente 11, 28049 Madrid, Spain.
    Fronthaler, Hartwig
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS).
    Kollreider, Klaus
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS).
    Ortega-Garcia, Javier
    ATVS, Escuela Politecnica Superior, Campus de Cantoblanco, Avda. Francisco Tomas y Valiente 11, 28049 Madrid, Spain.
    Gonzalez-Rodriguez, Joaquin
    ATVS, Escuela Politecnica Superior, Campus de Cantoblanco, Avda. Francisco Tomas y Valiente 11, 28049 Madrid, Spain.
    Bigun, Josef
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Combining multiple matchers for fingerprint verification: A case study in biosecure network of excellence2007Inngår i: Annales des télécommunications, ISSN 0003-4347, E-ISSN 1958-9395, Vol. 62, nr 1-2, s. 62-82Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We report on experiments for the fingerprint modality conducted during the First BioSecure Residential Workshop. Two reference systems for fingerprint verification have been tested together with two additional non-reference systems. These systems follow different approaches of fingerprint processing and are discussed in detail. Fusion experiments involving different combinations of the available systems are presented. The experimental results show that the best recognition strategy involves both minutiae-based and correlation-based measurements. Regarding the fusion experiments, the best relative improvement is obtained when fusing systems that are based on heterogeneous strategies for feature extraction and/or matching. The best combinations of two/three/four systems always include the best individual systems whereas the best verification performance is obtained when combining all the available systems.

  • 79.
    Alonso-Fernandez, Fernando
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Mikaelyan, Anna
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Bigun, Josef
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Compact Multi-scale Periocular Recognition Using SAFE Features2016Inngår i: Proceedings - International Conference on Pattern Recognition, Washington: IEEE Communications Society, 2016, s. 1455-1460, artikkel-id 7899842Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper, we present a new approach for periocular recognition based on the Symmetry Assessment by Feature Expansion (SAFE) descriptor, which encodes the presence of various symmetric curve families around image key points. We use the sclera center as single key point for feature extraction, highlighting the object-like identity properties that concentrates to this unique point of the eye. As it is demonstrated, such discriminative properties can be encoded with a reduced set of symmetric curves. Experiments are done with a database of periocular images captured with a digital camera. We test our system against reference periocular features, achieving top performance with a considerably smaller feature vector (given by the use of a single key point). All the systems tested also show a nearly steady correlation between acquisition distance and performance, and they are also able to cope well when enrolment and test images are not captured at the same distance. Fusion experiments among the available systems are also provided. © 2016 IEEE

  • 80.
    Alonso-Fernandez, Fernando
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Mikaelyan, Anna
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS).
    Bigun, Josef
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Compact Multi-scale Periocular Recognition Using SAFE Features2017Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper, we present a new approach for periocular recognition based on the Symmetry Assessment by Feature Expansion (SAFE) descriptor, which encodes the presence of various symmetric curve families around image key points. We use the sclera center as single key point for feature extraction, highlighting the object-like identity properties that concentrates to this unique point of the eye. As it is demonstrated, such discriminative properties can be encoded with a reduced set of symmetric curves. Experiments are done with a database of periocular images captured with a digital camera. We test our system against reference periocular features, achieving top performance with a considerably smaller feature vector (given by the use of a single key point). All the systems tested also show a nearly steady correlation between acquisition distance and performance, and they are also able to cope well when enrolment and test images are not captured at the same distance. Fusion experiments among the available systems are also provided.

  • 81.
    Alonso-Fernandez, Fernando
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Mikaelyan, Anna
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Bigun, Josef
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Comparison and Fusion of Multiple Iris and Periocular Matchers Using Near-Infrared and Visible Images2015Inngår i: 3rd International Workshop on Biometrics and Forensics, IWBF 2015, Piscataway, NJ: IEEE Press, 2015, s. Article number: 7110234-Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Periocular refers to the facial region in the eye vicinity. It can be easily obtained with existing face and iris setups, and it appears in iris images, so its fusion with the iris texture has a potential to improve the overall recognition. It is also suggested that iris is more suited to near-infrared (NIR) illu- mination, whereas the periocular modality is best for visible (VW) illumination. Here, we evaluate three periocular and three iris matchers based on different features. As experimen- tal data, we use five databases, three acquired with a close-up NIR camera, and two in VW light with a webcam and a dig- ital camera. We observe that the iris matchers perform better than the periocular matchers with NIR data, and the opposite with VW data. However, in both cases, their fusion can pro- vide additional performance improvements. This is specially relevant with VW data, where the iris matchers perform sig- nificantly worse (due to low resolution), but they are still able to complement the periocular modality. © 2015 IEEE.

  • 82.
    Alonso-Fernandez, Fernando
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Mikaelyan, Anna
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Bigun, Josef
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Keypoint Description by Symmetry Assessment–Applications in BiometricsManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    We present a model-based feature extractor to describe neighborhoods around keypoints by finite expansion, estimating the spatially varying orientation by harmonic functions. The iso-curves of such functions are highly symmetric w.r.t. the origin (a keypoint) and the estimated parameters have well defined geometric interpretations. The origin is also a unique singularity of all harmonic functions, helping to determine thel ocation of a keypoint precisely, whereas the functions describe the object shape of the neighborhood. This is novel and complementary to traditional texture features which describe texture shape properties i.e. they are purposively invariant to translation (within a texture). We report on experiments of verification and identification of keypoints in forensic fingerprints by using publicly available data (NIST SD27), and discuss the results in comparison to other studies. These support our conclusions that the novel features can equip single cores or single minutia with a significant verification power at 19% EER, and an identification power of 24-78% for ranks of 1-20. Additionally, we report verification results of periocular biometrics using near infrared images, reaching an EER performance of 13%, whichis comparable to the state of the art. More importantly, fusion of two systems, our and texture features (Gabor), result in a measurable performance improvement. We report reduction ofthe EER to 9%, supporting the view that the novel features capture relevant visual

  • 83.
    Alonso-Fernandez, Fernando
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Raja, Kiran B.
    Norwegian University of Science and Technology, Gjøvik, Norway.
    Busch, Christoph
    Norwegian University of Science and Technology, Gjøvik, Norway.
    Bigun, Josef
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Log-Likelihood Score Level Fusion for Improved Cross-Sensor Smartphone Periocular Recognition2017Inngår i: 2017 25th European Signal Processing Conference (EUSIPCO), Piscataway: IEEE, 2017, s. 281-285, artikkel-id 8081211Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The proliferation of cameras and personal devices results in a wide variability of imaging conditions, producing large intra-class variations and a significant performance drop when images from heterogeneous environments are compared. However, many applications require to deal with data from different sources regularly, thus needing to overcome these interoperability problems. Here, we employ fusion of several comparators to improve periocular performance when images from different smartphones are compared. We use a probabilistic fusion framework based on linear logistic regression, in which fused scores tend to be log-likelihood ratios, obtaining a reduction in cross-sensor EER of up to 40% due to the fusion. Our framework also provides an elegant and simple solution to handle signals from different devices, since same-sensor and crosssensor score distributions are aligned and mapped to a common probabilistic domain. This allows the use of Bayes thresholds for optimal decision making, eliminating the need of sensor-specific thresholds, which is essential in operational conditions because the threshold setting critically determines the accuracy of the authentication process in many applications. © EURASIP 2017

  • 84.
    Aloulou, Hamdi
    et al.
    Institut Mines Telecom, Paris, France & Laboratory of Informatics, Robotics and Microelectronics, Montpellier, France.
    Abdulrazak, Bessam
    Laboratory of Informatics, Robotics and Microelectronics, Montpellier, France & University of Sherbrooke, Sherbrooke, Canada.
    Endelin, Romain
    Institut Mines Telecom, Paris, France & Laboratory of Informatics, Robotics and Microelectronics, Montpellier, France.
    Bentes, João
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab). Image and Pervasive Access Laboratory, Singapore, Singapore.
    Tiberghien, Thibaut
    Institut Mines Telecom, Paris, France & Image and Pervasive Access Laboratory, Singapore, Singapore.
    Bellmunt, Joaquim
    Institut Mines Telecom, Paris, France & Image and Pervasive Access Laboratory, Singapore, Singapore.
    Simplifying Installation and Maintenance of Ambient Intelligent Solutions Toward Large Scale Deployment2016Inngår i: Inclusive Smart Cities and Digital Health: 14th International Conference on Smart Homes and Health Telematics, ICOST 2016, Wuhan, China, May 25-27, 2016. Proceedings / [ed] Chang C.K., Jin H., Cao Y., Aloulou H., Mokhtari M., Chiari L., Heidelberg: Springer, 2016, s. 121-132Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Simplify deployment and maintenance of Ambient Intelligence solutions is important to enable large-scale deployment and maximize the use/benefit of these solutions. More mature Ambient Intelligence solutions emerge on the market as a result of an intensive investment in research. This research targets mainly the accuracy, usefulness, and usability aspects of the solutions. Still, possibility to adapt to different environments, ease of deployment and maintenance are ongoing problems of Ambient Intelligence. Existing solutions require an expert to move on-site in order to install or maintain systems. Therefore, we present in this paper our attempt to enable quick large scale deployment. We discuss lessons learned from our approach for automating the deployment process in order to be performed by ordinary people. We also introduce a solution for simplifying the monitoring and maintenance of installed systems. © Springer International Publishing Switzerland 2016.

  • 85.
    ALRimawi, Mohammed
    Högskolan i Halmstad, Akademin för informationsteknologi.
    Doppler Wheel for Emulation of Automotive Radar Target2019Independent thesis Advanced level (degree of Master (One Year)), 10 poäng / 15 hpOppgave
    Abstract [en]

    Automotive radar is an emerging field of research and development. Technological ‎advancements in this field will improve safety for vehicles, pedestrians, and ‎bicyclists, and enable the development of autonomous vehicles. Usage of the ‎Automotive radar is expanding ‎in car and road areas to reduce collisions and ‎accident. Automotive radar ‎developers face a problem to test their radar sensor in ‎the street since there are a lot of interferences ‎signals, noise and unpredicted ‎situations. This thesis provides a part of the solution for this problem by designing a ‎device can demonstrate a different speeds value. This device will help the developer ‎to test their radar sensor inside an anechoic chamber room that provides accurate ‎control of the environmental conditions. This report shows how to ‎build the ‎measuring setup device, step by step to demonstrate the people and vehicle’s speed ‎‎in the street by a Doppler emulator using the wheel for millimetre FWMC radar. ‎Linear speed system needs a large space for testing, but using the rotational wheel ‎allow the developer to test the radar sensor in a small area. It begins with the wheel ‎design specifications and the relation between the ‎rotational speed (RPM) of the ‎wheel and the Doppler frequency. The Doppler ‎frequency is changed by varying the ‎speed of the wheel. Control and power circuit ‎was carefully designed to control the ‎wheel speed accurately. All the measuring ‎setup device parts were assembled in one ‎box. Also, signal processing was done by ‎MATLAB to measure the Doppler frequency ‎using millimetre FMCW radar sensor. ‎The measuring setup device was tested in the ‎anechoic chamber room for different speeds. the ‎manual and automatic tests show ‎good results to measure the different wheel speeds ‎with high accuracy.‎

  • 86.
    Alzghoul, Ahmad
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Verikas, Antanas
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Hållander, Magnus
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Bacauskiene, Marija
    Kaunas University of Technology, Studentu 50, Kaunas LT-51368, Lithuania.
    Gelzinis, Adas
    Kaunas University of Technology, Studentu 50, Kaunas LT-51368, Lithuania.
    Screening paper runnability in a web-offset pressroom by data mining2009Inngår i: Proceedings of the 9th Industrial Conference on Advances in Data Mining: Applications and Theoretical Aspects, Berlin: Springer Berlin/Heidelberg, 2009, s. 161-175Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper is concerned with data mining techniques for identifying the main parameters of the printing press, the printing process and paper affecting the occurrence of paper web breaks in a pressroom.Two approaches are explored. The first one treats the problem as a task of data classification into “break” and “non break” classes. The procedures of classifier design and selection of relevant input variables are integrated into one process based on genetic search. The search process results in a set of input variables providing the lowest average loss incurred in taking decisions. The second approach, also based on genetic search, combines procedures of input variable selection and data mapping into a low dimensional space. The tests have shown that the web tension parameters are amongst the most important ones. It was also found that, provided the basic off-line paper parameters are in an acceptable range, the paper related parameters recorded online contain more information for predicting the occurrence of web breaks than the off-line ones. Using the selected set of parameters, on average, 93.7% of the test set data were classified correctly. The average classification accuracy of the break cases was equal to 76.7%.

  • 87.
    Amadeo, Marica
    et al.
    Dipartimento DIIES, Università Mediterranea di Reggio Calabria, Reggio Calabria, Italy.
    Campolo, Claudia
    Dipartimento DIIES, Università Mediterranea di Reggio Calabria, Reggio Calabria, Italy.
    Molinaro, Antonella
    Dipartimento DIIES, Università Mediterranea di Reggio Calabria, Reggio Calabria, Italy & Laboratoire des Signaux et Systémes (L2S), CentraleSupélec-CNRS-Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France.
    Harri, Jerome
    Department of Communication Systems, EURECOM, Sophia Antipolis, France.
    Rothenberg, Christian Esteve
    School of Electrical and Computer Engineering, University of Campinas (UNICAMP), Campinas, Brazil.
    Vinel, Alexey
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Enhancing the 3GPP V2X Architecture with Information-Centric Networking2019Inngår i: Future Internet, ISSN 1999-5903, E-ISSN 1999-5903, Vol. 11, nr 9, artikkel-id 199Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Vehicle-to-everything (V2X) communications allow a vehicle to interact with other vehicles and with communication parties in its vicinity (e.g., road-side units, pedestrian users, etc.) with the primary goal of making the driving and traveling experience safer, smarter and more comfortable. A wide set of V2X-tailored specifications have been identified by the Third Generation Partnership Project (3GPP) with focus on the design of architecture enhancements and a flexible air interface to ensure ultra-low latency, highly reliable and high-throughput connectivity as the ultimate aim. This paper discusses the potential of leveraging Information-Centric Networking (ICN) principles in the 3GPP architecture for V2X communications. We consider Named Data Networking (NDN) as reference ICN architecture and elaborate on the specific design aspects, required changes and enhancements in the 3GPP V2X architecture to enable NDN-based data exchange as an alternative/complementary solution to traditional IP networking, which barely matches the dynamics of vehicular environments. Results are provided to showcase the performance improvements of the NDN-based proposal in disseminating content requests over the cellular network against a traditional networking solution. © 2019 by the authors.

  • 88.
    Amin, Mohammed Nurul
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi. amin _ m 154@yahoo.com.
    Alam, Md. Obaidul
    Högskolan i Halmstad, Akademin för informationsteknologi. obai_ aust@yahoo.com.
    Landin, Lars
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Tillämpad matematik och fysik (MPE-lab).
    Electrical and optical characteristics of Infrared Photodetectors based on InP nanowire2011Inngår i: 14th International Conference on Computer and Information Technology, ICCIT 2011, s. 629-634, artikkel-id 6164864Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    High speed photodetectors are most sophisticated optoelectronic devices, because it has high photo sensitivity, and allow a large wavelength range of detection as a receiver from 750 nm to 1.3-1.55 μm in the optical communication system. Since the last decade, the electrical and optical characteristics of photodetectors have been investigated to improve their performance and price. We have worked on two different type of infrared photodetectors based on nanowire. One photodetector was p-n photodiode, and the other one was p-i-n structure. We investigated the detector performance at 77K-300K temperature corresponding with wavelength in darkness and under illumination as regarding breakdown voltage, sensitivity, and quantum efficiency. We have also compared the differences between the two photodetectors performance characteristics. © 2011 IEEE.

  • 89.
    Amin, Muhammed Nurul
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi. amin_m154@yahoo.com.
    Alam, Md. Obaidul
    Högskolan i Halmstad, Akademin för informationsteknologi. obai_aust@yahoo.com.
    Electro-optical characterisation of inp nanowire based p-n, p-i-n infrared photodetectors2012Inngår i: Journal of Communications, ISSN 1796-2021, E-ISSN 1796-2021, Vol. 7, nr 11, s. 808-820Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    High speed photodetectors are most sophisticated optoelectronic devices, because it has high photo sensitivity, low noise, high conversion efficiency and allow a large wavelength range of detection from 750 nm to 1.3-1.55 pm in the optical communication system. These photodetector is used as an optical receiver which transforms the energy of optical radiation such as infrared, visible or ultraviolet into the electrical signal that is convenient for measurement. Since the last decade, the electro-optical characterisation of photodetectors has been investigated to improve their performance and price. In this paper, we are going to discuss the characterisation of the two different type infrared photodectors based on nanowire that we have worked on our project. One photodetector is p- n nanowire structure, and another is p-i-n structure. Both photodetectors is worked based on internal photoelectric effect and on the theory of p-n junction. We investigated the detector performance at 77K-300K temperature corresponding with wavelength in darkness and under illumination as regarding breakdown voltage, sensitivity, and quantum efficiency. We have also compared the differences between the two photodetectors performance characteristics. © 2012 ACADEMY PUBLISHER.

  • 90.
    Andersen, Emelie
    et al.
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap.
    Nilsson, Bertil
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Tillämpad matematik och fysik (MPE-lab).
    Sahlén, Göran
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Bio- och miljösystemforskning (BLESS).
    Survival possibilities of the dragonfly Aeshna viridis (Insecta, Odonata) in southern Sweden predicted from dispersal possibilities2016Inngår i: Journal of Insect Conservation, ISSN 1366-638X, E-ISSN 1572-9753, Vol. 20, nr 2, s. 179-188Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We use public records from 1980 to 2014 to analyse survival of the EU Annex IV species Aeshna viridis in Sweden, a dragonfly strongly associated with the plant Stratiotes aloides. We clustered localities with S. aloides based on assumed dispersal abilities of A. viridis, using a dispersing radius of 2–100 km, calculating the proportion of sites with S. aloides that A. viridis is able to reach. If mean dispersal capability is high (40 km or above) 92.6 % or more of the localities are connected. For a good disperser, the probability of long-time survival is good. We further analysed the species richness of other Odonata and aquatic plants at 98 localities from the dataset. A. viridis co-occurred with more Odonata in the presence of S. aloides and running water but not in lakes. S. aloides sites had a higher number of other aquatic plants. Area had no impact on the occurrence of the species. For the present situation we surveyed 32 localities with known occurrence of the species. Only half of the sites for S. aloides contained any specimens while A. viridis occurred in the same number of sites. The species co-occurred in only 8 of 32 sites. In four sites A. viridis larvae appeared among Menyanthes trifoliata, Phragmites australis, Potamogeton natans and Sphagnum spp., indicating that at high latitudes A. viridis breeds among other species. Indirect monitoring based only on S. aloides would underestimate the number of populations of the dragonfly. © 2016 Springer International Publishing Switzerland

  • 91.
    Andersson, Amanda
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi.
    Karlsson, Daniel
    Högskolan i Halmstad, Akademin för informationsteknologi.
    Konsten att steganografera2016Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Genom tiderna har människan alltid velat ha hemligheter. Dessa kan hemlighållas med hjälp av steganografi, som är konsten att dölja information. Vi kommer i den har rapporten undersöka både text- steganografi, likt bibelkoden men även möjligheterna till visuell identifiering av bilder av steganografisk natur och hur steganografi kan användas i kombination med Snapchat. För att göra detta har ett set med 100 bilder skapats och skickats ut tillsammans med en enkät. Genom att ha undersökt svensk litteratur har vi försökt att ta fram i vilken frekvens som svenska ord förekommer. Detta för att kunna göra en bedömning av om en text är steganograferad eller ej. Med det har arbetet har vi kunnat konstatera att det är möjligt för det mänskliga ögat att identifiera steganograferade bilder. De frekvensanalyser som genomfördes ger oss resultatet att de texter som undersökts inte varit steganograferade. Samt att Snapchat är ett medie som ar kompatibelt med steganografi.

  • 92.
    Andersson, Camilla
    et al.
    Aalto University, Esbo, Finland.
    Mazé, Ramia
    Aalto University, Esbo, Finland.
    Isaksson, Anna
    Högskolan i Halmstad, Akademin för lärande, humaniora och samhälle, Centrum för lärande, kultur och samhälle (CLKS).
    Börjesson, Emma
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS).
    Ehrnberger, Karin
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS).
    Materializing “Ruling Relations”: A Case of Gender, Power and Elder Care in Sweden2017Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper reflects upon our critical (feminist) design research approach developed in response to the Swedish Governmental Agency for Innovation Systems (Vinnova)’s innovation program on equality. As a pilot of the program, the subject of our research is equality within elder care work, a female-dominated employment sector with particular gender and power dynamics. We have responded to this program and sector by rethinking our research methodologies and critical design research method. Inspired by institutional ethnography and the concept of ‘ruling relations’, our research approach involves critical design to materialize structural inequalities manifested within the everyday micro-practices of care work. Stories and sketches (as ‘material theses’) were generated through qualitative fieldwork involving ‘research through design’ processes to observe, document, explore, interpret, discuss and communicate gendered practices of elder care. Three themes emerged along the way, which articulate ruling relations revealed within elder care work. This research case is reported here along with reflections about the potentials of critical design as a (feminist) research approach capable of more critically interrogating power and positionality within design and innovation. From our perspective, equality as a policy and subject of research – including design research – calls for critical (and feminist) theoretical and methodological development. 

  • 93.
    Andersson, Emil
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi.
    Bogga, Anders
    Högskolan i Halmstad, Akademin för informationsteknologi.
    Hexacopter with gripping module2018Independent thesis Basic level (university diploma), 10 poäng / 15 hpOppgave
    Abstract [en]

    The 2018 CPS-VO challenge is a competition focusing on the development of a drone which has the ability to search a area for a lost drone and recover it to a specific destination, all this is to be done autonomous. To participate in the challenge three thesis projects was done by three different teams. Those three projects combined created an autonomous hexacopter to compete with in the challenge. The thesis focuses on the development of a hexacopter with a gripping module which is to be used in the challenge. There are two main goals with the thesis. The first goal was to create a computer model of a hexacopter with a gripping module to be used in a simulation software called Gazebo. The simulation is controlled via Robot Operating System and is used as a basis for hardware development. The second goal was to use the results from the simulation to build a real hexacopter with a gripping module which can be used in the challenge. The hexacopter construction was based on own designs and all fabrication of parts for the gripping module was done using SolidWorks and 3D printers. The result became a hexacopter with a high thrust and a gripping module which can grab and hold on to recovered objects. The hexacopter was used during 2018 CPS-VO Challenge which was taking place in Arizona in May 2018.

  • 94.
    Andersson, Roland
    Högskolan i Halmstad, Akademin för informationsteknologi.
    Utvinning av data ur mobiltelefoner: En valideringsstudie av forensiska verktyg2016Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Den vetenskapliga aspekten i de flesta forensiska discipliner är välgrundad och prövad under ett långt tidsperspektiv. Det ökande användandet av digital teknik har gjort att en ny forensisk disciplin har vuxit fram och den vetenskapliga grunden i detta nya forensiska område är i många avseenden fortfarande outforskat. Inom det svenskarättsväsendet krävs att de forensiska metoder som används inom en brottsutredning ska vara kvalitetssäkrade och i största mån vara ackrediterade av ettackrediteringsorgan. Det finns idag få relevanta studier kring validering av forensiska metoder som hanterar småskaliga enheter som smarta mobiler.

    I denna rapport analyseras de metoder som används för att utvinna data från mobiltelefon och hur dessa metoder kan anses vara forensiskt korrekta. Rapporten presenterar ett nytt ramverk för att validera de metoder som används av ett forensisk verktyg. Ramverket är kvalitetssäkrat genom att utgå ifrån tidigare vetenskaplig studier och är praktiskt testad i laboratoriemiljö. Ramverket ska kunna användas direkt inom en forensisk verksamhet som kräver validering.

  • 95.
    Andersson, Sanna
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi.
    Lidén, Anna
    Högskolan i Halmstad, Akademin för informationsteknologi.
    IT-system som stöd för personaladministration på sjukhus: En fallstudie om vilka utmaningar med personaladministration som ett sjukhus kan hantera med stöd av IT-system2018Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Det rapporteras om en ansträngd hälso- och sjukvård på grund av begränsat med personalresurser och ett ökat vårdbehov. Statens offentliga utredningar lyfter att svensk sjukvård behöver effektiviseras för att kunna hantera problem med exempelvis överbeläggningar. Digitalisering av svensk hälso- och sjukvård förväntas bidra med bland annat beslutsunderlag för planering och resursfördelning. Digitalisering har visat på bättre effektivitet, genom att använda IT-system. Det behövs dock mer forskning om IT-systems stöd inom sjukhus, eftersom forskningen tidigare har fokuserat på IT-stöd för behandling av patienter snarare än planering av personalresurser. För att säkerställa att IT-systemen stödjer verksamheten finns utmaningar som måste hanteras. Syftet med denna fallstudie är därför att undersöka IT-system som stöd för personaladministration för en effektivare sjukvård genom frågeställningen: Vilka utmaningar med personaladministration på sjukhus kan hanteras med stöd av IT-system? För att undersöka frågeställningen har en kvalitativ ansats använts. Empiriskt material har samlats in genom intervjuer och analyserats med processanalys. Resultatet visar på att den främsta utmaningen med personaladministration som kan hanteras med stöd av ett IT-system är inkorrekta och irrelevanta data. Andra utmaningar som framkommit är att samordna läkare och sjuksköterskor samt personalbrist. Att hitta lösningar på personalbristen är viktigt, men eftersom problemet ligger på en sådan hög nivå kan IT-system endast tillhandahålla underlag för diskussioner kring personalbrist.

  • 96.
    Andreasson, Henrik
    et al.
    Örebro University, Örebro, Sweden.
    Bouguerra, Abdelbaki
    Örebro University, Örebro, Sweden.
    Åstrand, Björn
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Rögnvaldsson, Thorsteinn
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR Centrum för tillämpade intelligenta system (IS-lab).
    Gold-fish SLAM: An application of SLAM to localize AGVs2014Inngår i: Field and Service Robotics: Results of the 8th International Conference / [ed] Kazuya Yoshida & Satoshi Tadokoro, Heidelberg: Springer, 2014, s. 585-598Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The main focus of this paper is to present a case study of a SLAM solution for Automated Guided Vehicles (AGVs) operating in real-world industrial environments. The studied solution, called Gold-fish SLAM, was implemented to provide localization estimates in dynamic industrial environments, where there are static landmarks that are only rarely perceived by the AGVs. The main idea of Gold-fish SLAM is to consider the goods that enter and leave the environment as temporary landmarks that can be used in combination with the rarely seen static landmarks to compute online estimates of AGV poses. The solution is tested and verified in a factory of paper using an eight ton diesel-truck retrofitted with an AGV control system running at speeds up to 3m/s. The paper includes also a general discussion on how SLAM can be used in industrial applications with AGVs. © Springer-Verlag Berlin Heidelberg 2014.

  • 97.
    Andriesse, Carin
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi.
    Edvinsson, Erika
    Högskolan i Halmstad, Akademin för informationsteknologi.
    Utvärdering av Business Intelligence system ur ett nytto-perspektiv: En studie om hur företag kan utvärdera nyttan av ett Business Intelligence system före och efter en implementation2016Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Den ökade mängden data i världen leder till att allt fler företag väljer att investera i BI-system som kan stödja hantering och analys av data. Genom att analysera data kan det leda till nytta för företaget som exempelvis bättre kontroll och beslutsunderlag. Samtidigt har utvärderingen av nyttan med systemen inte följt med i samma utveckling som investeringarna. Svårigheten att utvärdera de mjuka och strategiska nyttorna med ett BI-system är en av anledningarna till det. Genom att utvärdera ett BI-system kan företag få en uppfattning av vilka nyttor som uppnåtts och om ytterligare aktiviteter krävs för att öka nyttan. En kvalitativ intervjustudie har utförts på stora tillverkande företag och konsultföretag för att se hur arbetet med utvärdering av nyttor med BI-system går till i praktiken. Studien inkluderar utvärdering både innan och efter en implementation och resulterar i rekommendationer. Studiens resultat visar att det kan skilja sig hur små företag och stora tillverkande företag använder BI-systemet och därmed hur utvärdering bör ske. Det har även påvisats att det bör ske ökad utvärdering efter att BI-systemen införts i företaget. Genom att inkludera utvärdering av delar som påverkar möjligheten att uppnå nytta, såväl som delar som kan påverka utvärderingen, leder det till en mer realistisk utvärdering och därmed en större chans för företag att öka nyttan med sitt BI-system. 

  • 98.
    Anokhina, Ksenia
    et al.
    Avd. f. Fasta Tillståndets Fysik, Lunds Universitet, Lund, Sweden.
    Graczyk, Mariousz
    Avd. f. Fasta Tillståndets Fysik, Lunds Universitet, Lund, Sweden.
    Kvennefors, Anders
    Avd. f. Fasta Tillståndets Fysik, Lunds Universitet, Lund, Sweden.
    Montelius, Lars
    Avd. f. Fasta Tillståndets Fysik, Lunds Universitet, Lund, Sweden.
    Maximov, Ivan
    Avd. f. Fasta Tillståndets Fysik, Lunds Universitet, Lund, Sweden.
    Pettersson, Håkan
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Tillämpad matematik och fysik (MPE-lab).
    Metal-assisted chemical etching of Si for fabrication of nanoimprint stamps2011Konferansepaper (Fagfellevurdert)
  • 99.
    Antczak, Magdalena
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Tillämpad matematik och fysik (MPE-lab).
    Leniec, Marta
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Tillämpad matematik och fysik (MPE-lab).
    Pricing and Hedging of Defaultable Models2011Independent thesis Advanced level (degree of Master (One Year)), 10 poäng / 15 hpOppgave
    Abstract [en]

    Modelling defaultable contingent claims has attracted a lot of interest in recent years, motivated in particular by the Late-2000s Financial Crisis. In several papers various approaches on the subject have been made. This thesis tries to summarize these results and derive explicit formulas for the prices of financial derivatives with credit risk. It is divided into two main parts. The first one is devoted to the well-known theory of modelling the default risk while the second one presents the results concerning pricing of the defaultable models that we obtained ourselves.

  • 100.
    Antham, Karunakar
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Palle, Chandrashekar reddy
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Mantoor, Ashwin kumar
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Peer to Peer VoIP over IEEE 802.11 WLAN2012Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Voice over Internet Protocol (VoIP) over WLAN is one of the most important technologies in today’s world of communication. VoIP is simply a way to make phone calls through the internet because of the convergence of voice and data networks enables new applications and cost reductions. Voice over WLAN phones are already being offered to enterprises by leading vendors. Most of internet services or applications require centralized network to communicate, but with Ad-hoc networks there is no such requirement at all.

    In this report we have established a VoIP session by forming a network between Android mobile devices without using an Access point. Energy consumption is a major problem for VoIP over wireless LAN applications while using them in hand held devices. We investigated the energy consumption characteristics of our Evaluation kit during VoIP session. We further studied about new technology: “Wi-Fi Direct” which allows Wi-Fi equipped devices to share data without using wireless access points.

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