291 research outputs found

    Sensor fault detection with low computational cost : a proposed neural network-based control scheme

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    The paper describes a low computational power method for detecting sensor faults. A typical fault detection unit for multiple sensor fault detection with modelbased approaches, requires a bank of estimators. The estimators can be either observer or artificial intelligence based. The proposed control scheme uses an artificial intelligence approach for the development of the fault detection unit abbreviated as ‘i-FD’. In contrast with the bank-estimators approach the proposed i-FD unit is using only one estimator for multiple sensor fault detection. The efficacy of the scheme is tested on an Electro-Magnetic Suspension (EMS) system and compared with a bank of Kalman estimators in simulation environment

    Agricultural cooperatives and quality-enhancing R&D in the agri-food system

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    This paper develops a game - theoretic model of heterogeneous consumers to analyze the effect of cooperative involvement on quality- enhancing product innovation activity, the pricing of food products, and the welfare of the groups involved in the context of a mixed duopoly where an openmembership consumer co- op competes with an IOF. Analytical results show that the involvement of the member welfare- maximizing co- op in R&D can be quality and welfare enhancing by increasing the arrival rate of product innovations and reducing the prices of food products. The effectiveness of the co- op is shown to depend on the nature of product differentiation and the relative quality of its products, the degree of consumer heterogeneity, and the size of innovation costs .Open Membership Cooperatives, Product Innovation, Mixed Oligopoly, Retained Earnings., Agribusiness, Research and Development/Tech Change/Emerging Technologies,

    THE EFFECT OF MARKETING COOPERATIVES ON COST-REDUCING PROCESS INNOVATION ACTIVITY

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    This paper examines the market and welfare effects of cooperative involvement in cost-reducing process innovation activity in the context of a mixed oligopsony where an open-membership marketing co-op competes with an IOF. The presence of the marketing co-op is shown to result in increased producer prices and welfare gains for all farmers, members and non-members of the co-op. The effect of the marketing co-op on process innovation activity depends on the relative quality of its final products, the degree of producer heterogeneity, and the size of innovation costs.Agribusiness,

    THE EFFECT OF COOPERATIVES ON PRODUCT INNOVATION IN THE AGRI-FOOD SYSTEM

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    This paper develops a game-theoretic model of heterogeneous consumers to analyze the effect of cooperative involvement on quality-enhancing product innovation activity, the pricing of food products, and the welfare of the groups involved in the context of a mixed duopoly where an openmembership consumer co-op competes with an IOF. Analytical results show that the involvement of the member welfare-maximizing co-op in R&D can be quality and welfare enhancing by increasing the arrival rate of product innovations and reducing the prices of food products. The effectiveness of the coop is shown to depend on the nature of product differentiation and the relative quality of its products, the degree of consumer heterogeneity, and the size of innovation costs.cooperatives, product innovation, mixed oligopoly, retained earnings, Agribusiness,

    Physically Based Lighting Models for Real Time Graphics Engines

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    Το αντικείμενο της πτυχιακής εργασίας αφορά τα ρεαλιστικά μοντέλα φωτισμού σε μηχανές γραφικών πραγματικού χρόνου. Τις τελευταίες δεκαετίες έχει γίνει σημαντική πρόοδος στα μοντέλα φωτισμού, ωστόσο το πρόβλημα της εξισορρόπησης μεταξύ του καλύτερου οπτικού αποτελέσματος και της καλύτερης επίδοσης παραμένει και ποικίλει ανάλογα το τελικό υλικό υπολογιστή που θα κληθεί να σχεδιαγραφήσει τα γραφικά.The subject of this thesis pertains to the physically based lighting models for real time game engines. Over the last decades, we have seen a great improvement in the lighting models, however, the dilemma between a good visual result and better performance still exists and has many variations depending on the hardware that will render the graphics

    Central Serous Chorioretinopathy with Subretinal Deposition of Fibrin-Like Material and Its Prompt Response to Ranibizumab Injections

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    Purpose: Central serous chorioretinopathy (CSCR) manifests as neurosensory detachment of the macula and can be attributed to focal or multifocal leakage in the retinal pigment epithelium (RPE). Fibrin accumulation in the subretinal space is an unusual and heretofore unreported visually damaging manifestation of severe CSCR. Methods: The patient was followed up with the use of biomicroscopy, fluorescein angiography, and optical coherence tomography (OCT). Results: A 32-year-old woman was referred to our department complaining of metamorphopsia and decreased visual acuity in the right eye. Best-corrected visual acuity (BCVA) was 20/40 in the right eye and 20/20 in the left eye. Biomicroscopy revealed an irregularly shaped foveal elevation and wrinkling in the right eye. OCT showed a steep neurosensory retina elevation with a highly reflective material accumulation in the subretinal space, presumably fibrin. Our diagnosis was CSCR complicated by subretinal fibrin accumulation. Since most of these cases resolve spontaneously, the patient was kept under observation; 1 month later, the fibrin accumulation had expanded subfoveally (BCVA 20/200). The patient was offered 3 intravitreal ranibizumab injections. After the initial injection, BCVA improved to 20/50 and, after the 3 injections, to 20/30. Two months later (BCVA 20/30), fresh leakage was observed at the margin of the original lesion, and an additional intravitreal ranibizumab injection was performed. After another 2 months, BCVA stabilized at 20/25 and remained stable throughout the 12 months after the initial injection. Conclusions: Prompt recognition of CSCR complicated by subretinal fibrin and immediate intervention may result in recovery from this potentially devastating complication. Ranibizumab may be an alternative treatment option in the management of refractory CSCR complicated by subretinal fibrin accumulation
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