10 research outputs found

    Face Recognition Methods Based on Feedforward Neural Networks, Principal Component Analysis and Self-Organizing Map

    Get PDF
    In this contribution, human face as biometric is considered. Original method of feature extraction from image data is introduced using MLP (multilayer perceptron) and PCA (principal component analysis). This method is used in human face recognition system and results are compared to face recognition system using PCA directly, to a system with direct classification of input images by MLP and RBF (radial basis function) networks, and to a system using MLP as a feature extractor and MLP and RBF networks in the role of classifier. Also a two-stage method for face recognition is presented, in which Kohonen self-organizing map is used as a feature extractor. MLP and RBF network are used as classifiers. In order to obtain deeper insight into presented methods, also visualizations of internal representation of input data obtained by neural networks are presented

    Error Concealment using Neural Networks for Block-Based Image Coding

    Get PDF
    In this paper, a novel adaptive error concealment (EC) algorithm, which lowers the requirements for channel coding, is proposed. It conceals errors in block-based image coding systems by using neural network. In this proposed algorithm, only the intra-frame information is used for reconstruction of the image with separated damaged blocks. The information of pixels surrounding a damaged block is used to recover the errors using the neural network models. Computer simulation results show that the visual quality and the MSE evaluation of a reconstructed image are significantly improved using the proposed EC algorithm. We propose also a simple non-neural approach for comparison

    Extraction of Facial Features from Color Images

    Get PDF
    In this paper, a method for localization and extraction of faces and characteristic facial features such as eyes, mouth and face boundaries from color image data is proposed. This approach exploits color properties of human skin to localize image regions – face candidates. The facial features extraction is performed only on preselected face-candidate regions. Likewise, for eyes and mouth localization color information and local contrast around eyes are used. The ellipse of face boundary is determined using gradient image and Hough transform. Algorithm was tested on image database Feret

    Effects of AP39, a novel triphenylphosphonium derivatised anethole dithiolethione hydrogen sulfide donor, on rat haemodynamic parameters and chloride and calcium Cav3 and RyR2 channels.

    No full text
    Copyright © 2014 Elsevier Inc. All rights reserved.H2S donor molecules have the potential to be viable therapeutic agents. The aim of this current study was (i) to investigate the effects of a novel triphenylphosphonium derivatised dithiolethione (AP39), in the presence and absence of reduced nitric oxide bioavailability and (ii) to determine the effects of AP39 on myocardial membrane channels; CaV3, RyR2 and Cl(-). Normotensive, L-NAME- or phenylephrine-treated rats were administered Na2S, AP39 or control compounds (AP219 and ADT-OH) (0.25-1 µmol kg(-1)i.v.) and haemodynamic parameters measured. The involvement of membrane channels T-type Ca(2+) channels CaV3.1, CaV3.2 and CaV3.3 as well as Ca(2+) ryanodine (RyR2) and Cl(-) single channels derived from rat heart sarcoplasmic reticulum were also investigated. In anaesthetised Wistar rats, AP39 (0.25-1 µmol kg(-1) i.v) transiently decreased blood pressure, heart rate and pulse wave velocity, whereas AP219 and ADT-OH and Na2S had no significant effect. In L-NAME treated rats, AP39 significantly lowered systolic blood pressure for a prolonged period, decreased heart rate and arterial stiffness. In electrophysiological studies, AP39 significantly inhibited Ca(2+) current through all three CaV3 channels. AP39 decreased RyR2 channels activity and increased conductance and mean open time of Cl(-) channels. This study suggests that AP39 may offer a novel therapeutic opportunity in conditions whereby (•)NO and H2S bioavailability are deficient such as hypertension, and that CaV3, RyR2 and Cl(-) cardiac membrane channels might be involved in its biological actions.Slovak Research and Development AgencyBMBS COST Actio

    Vision-Related Quality of Life in Patients with Diabetic Macular Edema Treated with Intravitreal Aflibercept: The AQUA Study

    Get PDF
    Purpose: To examine vision-related quality of life in patients with diabetic macular edema (DME) treated with intravitreal aflibercept (EYLEA, Regeneron Pharmaceuticals, Inc, Tarrytown, NY). Design: AQUA was a multicenter, open-label, single-arm, phase 4 study. Participants: Adults 18 years of age or older with type 1 or 2 diabetes mellitus and DME. Methods: Patients received intravitreal aflibercept 2 mg every 8 weeks for 52 weeks, after 5 initial doses every 4 weeks. Main Outcome Measures: The primary outcome was the change in 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25) total score from baseline to week 52. Secondary outcomes included the change in NEI VFQ-25 near and distant activities subscale scores, best-corrected visual acuity (BCVA; Early Treatment Diabetic Retinopathy Study [ETDRS] letters), and central retinal thickness (CRT) from baseline to week 52. Change in NEI VFQ-25 score at week 52 for better-seeing eyes (BSEs) and worse-seeing eyes (WSEs) also was evaluated. Results: A total of 553 patients comprised the full analysis set, and 560 patients comprised the safety analysis set. At baseline, the mean NEI VFQ-25 total score was 70.12, mean BCVA was 61.5 ETDRS letters, and mean CRT was 464.81 \u3bcm. A mean of 8.8 injections were administered over 52 weeks. At week 52, the mean improvement from baseline in the NEI VFQ-25 total score was +6.11 (standard deviation [SD], 11.46); the corresponding improvements in near and distant activities were +11.37 (SD, 18.01) and +7.33 (SD, 17.32), respectively. Similarly, improvements in patients whose BSE and WSE were treated were 7.74 (SD, 13.59) and 5.48 (SD, 9.70), respectively. At week 52, mean change in BCVA was +10.0 ETDRS letters (SD, 8.0 ETDRS letters), and mean change in CRT was \u2013175.38 \u3bcm (SD, 132.62 \u3bcm). Overall, 53.6% of patients reported treatment-emergent adverse events (TEAEs), of whom 26.8% experienced an ocular TEAE in the study eye. The most common serious ocular TEAE was endophthalmitis (0.5% [n = 3]). Five deaths (0.9%) were reported, but were not considered treatment related. Conclusions: Intravitreal aflibercept was associated with clinically meaningful improvements in NEI VFQ-25 total score over 52 weeks in patients with DME; these were even more pronounced for near than for distant activities. Adverse events were consistent with the known safety profile of intravitreal aflibercept
    corecore