4,194 research outputs found

    A New Biometric Template Protection using Random Orthonormal Projection and Fuzzy Commitment

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    Biometric template protection is one of most essential parts in putting a biometric-based authentication system into practice. There have been many researches proposing different solutions to secure biometric templates of users. They can be categorized into two approaches: feature transformation and biometric cryptosystem. However, no one single template protection approach can satisfy all the requirements of a secure biometric-based authentication system. In this work, we will propose a novel hybrid biometric template protection which takes benefits of both approaches while preventing their limitations. The experiments demonstrate that the performance of the system can be maintained with the support of a new random orthonormal project technique, which reduces the computational complexity while preserving the accuracy. Meanwhile, the security of biometric templates is guaranteed by employing fuzzy commitment protocol.Comment: 11 pages, 6 figures, accepted for IMCOM 201

    Mycelia Growth and Production of Total Flavonoids and 4H-pyran-4-one, 2,3-dihydro-3,5-dihydroxy-6-methyl- by Schizophyllum commune Using a Bubble Column Bioreactor Considering Aeration Effect and Mass Transfer Study

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    Higher fungi are a major source of bioactive secondary metabolites, and Schizophyllum commune secreted Schizophyllan that could possess antifungal activity. 4H-pyran-4-one, 2,3-dihydro-3,5-dihydroxy-6-methyl- (DDMP), a compound with flavonoid fraction, is an important bioactive chemical which exhibited antifungal activity to inhibit growth or spore germination. In view of the potential of DDMP, bench scale production of total flavonoid content (TFC) and DDMP of Schizophyllum commune was carried out in laboratory fermenter at 1.5 L scale. The growth of S. commune was affected by the supply of oxygen during the fermentation. The optimum condition of aeration rate for TFC and DDMP production from S. commune was found to be 4 L min–1. The mass transfer coefficient (kLa) of S. commune was also studied to investigate the oxygen transfer capabilities in the bioreactor by considering the effect of aeration rate. On the other hand, the kLa value increased with increasing the aeration rate and the maximum kLa value (0.0814 s–1) was obtained with aeration rate of 8 L min–1

    Myxomatous mitral valve disease in a Shih Tzu dog

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    An 11-year-old intact male Shih Tzu dog was referred to the University Veterinary Hospital (UVH) with history of coughing and laboured breathing. Auscultation revealed that the dog had a left systolic heart murmur grade V/VI at the base of the heart. Radiography showed findings of cardiomegaly and pulmonary oedema. Echocardiography findings revealed that dog has a myxomatous mitral valve disease. The mitral valve was severely thickened and prolapsed into the left atrium. Congestive heart failure (CHF) was treated with an angiotensin converting enzyme (ACE) inhibitor and diuretic. An anti-mucolytic agent was prescribed as a symptomatic treatment for the coughing that could be due to mild bronchitis. Dog did not response well with treatment as the frequency of cough was not reduced and the duration was longer each time. Pimobendan was then added on to the initial treatment and there was a tremendous improvement seen from the patient after that. Episodes of productive cough were noticed greatly reduced and dog was much more active at home post two weeks of ACE inhibitor, diuretic and dual-acting inodilator. We successfully maintained the dog with minimal coughing episodes. However, the prognosis is moderate to poor in this case due to possibilities of refraction towards medications

    Opinion diversity and community formation in adaptive networks

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    It is interesting and of significant importance to investigate how network structures co-evolve with opinions. The existing models of such co-evolution typically lead to the final states where network nodes either reach a global consensus or break into separated communities, each of which holding its own community consensus. Such results, however, can hardly explain the richness of real-life observations that opinions are always diversified with no global or even community consensus, and people seldom, if not never, totally cut off themselves from dissenters. In this article, we show that, a simple model integrating consensus formation, link rewiring and opinion change allows complex system dynamics to emerge, driving the system into a dynamic equilibrium with co-existence of diversified opinions. Specifically, similar opinion holders may form into communities yet with no strict community consensus; and rather than being separated into disconnected communities, different communities remain to be interconnected by non-trivial proportion of inter-community links. More importantly, we show that the complex dynamics may lead to different numbers of communities at steady state with a given tolerance between different opinion holders. We construct a framework for theoretically analyzing the co-evolution process. Theoretical analysis and extensive simulation results reveal some useful insights into the complex co-evolution process, including the formation of dynamic equilibrium, the phase transition between different steady states with different numbers of communities, and the dynamics between opinion distribution and network modularity, etc.Comment: 12 pages, 8 figures, Journa

    Cognitive Style as a Factor in Accounting Students\u27 Performance on Multiple Choice Examinations

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    Using 59 final year accounting students as subjects and multiple regression analysis, this paper tests the hypothesis that accounting students\u27 performance on multiple choice examinations is related to field dependence cognitive style. Results support the hypothesis and suggest that in evaluating student performances in multiple choice examinations, accounting academics should bear in mind that the scores on these examinations may be partly a function of students\u27 cognitive style. This finding has implications for the use of multiple choice examinations in classroom evaluations

    Ion trap long-range XY model for quantum state transfer and optimal spatial search

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    Linear ion trap chains are a promising platform for quantum computation and simulation. The XY model with long-range interactions can be implemented with a single side-band MĂžlmer–SĂžrensen scheme, giving interactions that decay as 1/r α, where α parameterises the interaction range. Lower α leads to longer range interactions, allowing faster long-range gate operations for quantum computing. However, decreasing α causes an increased generation of coherent phonons and appears to dephase the effective XY interaction model. We characterise and show how to correct for this effect completely, allowing lower α interactions to be coherently implemented. Ion trap chains are thus shown to be a viable platform for spatial quantum search in optimal O( √ N) time, for N ions. Finally, we introduce a O( √ N) quantum state transfer protocol, with a qubit encoding that maintains a high fidelity

    Selective catalytic oxidation of ammonia over nano Cu/zeolites with different topologies

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    The selective catalytic oxidation of ammonia (NH3-SCO) is the last mitigation step in exhaust treatment using a 4-way catalytic converter to convert any excess and unreacted NH3 (that was used as a reductant of NOx) into environmentally benign N2 and H2O. Here, we report a series of highly reactive and selective nano Cu/zeolites for the NH3-SCO reaction. The NH3-SCO activity was found in the order nano Cu/ZSM-5 (MFI topology) > Cu/Beta (BEA) > Cu/MCM-49 (MWW) > Cu/Y (FAU) > Cu/Mordenite (MOR) > Cu/Ferrierite (FER). The best catalyst, i.e., nano Cu/ZSM-5, achieves 98% NH3 conversion at 250 °C with the N2 yield maintained at >98% even at up to 500 °C. When assessed under practical exhaust conditions in the presence of moisture (5% H2O) as well as that after hydrothermal aging (5% H2O, 850 °C, 8 h), the nano Cu/ZSM-5 exhibited only minor deactivation as a result of its good retention of Cu dispersion, pore structure and specific surface area. Furthermore, small micropore (10-membered ring, 10-MR) topologies were found to be crucial in maintaining high N2 yields. For Cu/Y and Cu/Mordenite, composed of 12-MR pores that are non-interconnected with smaller pores, their N2 yields were compromised by forming NOx at temperatures above 400 °C. Based on the in situ DRIFTS study, the iSCR mechanism appears to be applicable for all fresh and aged Cu/zeolites with the exception of fresh Cu/MCM-49 that follows the imide mechanism

    Evolution of precision agriculture computing towards sustainable oil palm industry

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    Precision technology elements have not been implemented yet into the sustainable oil palm industry because the knowledge and technology gap. To resolve the gaps, promote sustainability and integrate the technologies, Oil Palm Management System (OPAMS) was introduced. The precision technologies in OPAMS comprises of Geographical Information System (GIS), Global Positioning System (GPS), remote sensing and yield monitoring. A phase by phase System Development Life Cycle (SDLC) methodology was used to generate the said system with feedbacks from oil palm planters as the inputs for OPAMS’s key features. OPAMS ultimately aims to increase the awareness of the industry on the benefits of utilizing technology to improve plantation performances, increase business and environmental sustainability

    Electrospun organic–inorganic nanohybrids as sustained release drug delivery systems

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    In this work, the non-steroidal anti-inflammatory drugs ibuprofen (ibu) and ketoprofen (ket), both poorly soluble in water, were first intercalated into layered double hydroxide (LDH) nanoparticles. The drug–LDH composites were then mixed with poly(Δ-caprolactone) (PCL) at 5% and 10% w/w ratios and processed into fibers via electrospinning, yielding organic–inorganic nanohybrids. PCL/drug fibers were additionally prepared as controls. The average diameter of the fibers ranged from 400 to 1000 nm. The fibers are found to be smooth and cylindrical, with the LDH-containing systems having more homogenous fibers than those without the inorganic filler. From in vitro drug release tests, it was determined that more than 90% of the intercalated ibu and ket were released from the drug–LDH nanohybrids within the first 4 hours. Similarly, more than 60% of the incorporated drug was freed from the PCL/drug fibers in this time period. However, the release rates of both ibu and ket from the drug–LDH loaded PCL fibers were significantly slower. Only 44–48% of ibu was released from the PCL/ibu–LDH system after 5 days, while the amount released in the case of ket was 20–25%. In addition, drug release was still ongoing after 5 days for all the PCL/drug–LDH samples. These systems are thus proposed to have potential as implantable drug delivery systems

    Modeling the dynamic rupture propagation on heterogeneous faults with rate- and state-dependent friction

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    We investigate the effects of non-uniform distribution of constitutive parameters on the dynamic propagation of an earthquake rupture. We use a 2D finite difference numerical method and we assume that the dynamic rupture propagation is governed by a rate- and state-dependent constitutive law. We first discuss the results of several numerical experiments performed with different values of the constitutive parameters a (to account for the direct effect of friction), b (controlling the friction evolution) and L (the characteristic length-scale parameter) to simulate the dynamic rupture propagation on homogeneous faults. Spontaneous dynamic ruptures can be simulated on velocity weakening (a < b) fault patches: our results point out the dependence of the traction and slip velocity evolution on the adopted constitutive parameters. We therefore model the dynamic rupture propagation on heterogeneous faults. We use in this study the characterization of different frictional regimes proposed by Boatwright and Cocco (1996) based on different values of the constitutive parameters a, b and L. Our numerical simulations show that the heterogeneities of the L parameter affect the dynamic rupture propagation, control the peak slip velocity and weakly modify the dynamic stress drop and the rupture velocity. Moreover, a barrier can be simulated through a large contrast of L parameter. The heterogeneity of a and b parameters affects the dynamic rupture propagation in a more complex way. A velocity strengthening area (a > b) can arrest a dynamic rupture, but can be driven to an instability if suddenly loaded by the dynamic rupture front. Our simulations provide a picture of the complex interactions between fault patches having different frictional properties and illustrate how the traction and slip velocity evolutions are modified during the propagation on heterogeneous faults. These results involve interesting implications for slip duration and fracture energy
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