132 research outputs found

    Antifouling activity of crude extracts from some Red Sea soft corals

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    EnThe antifouling activity of crude extracts of 5 common Red Sea soft corals was examined. The extracts were mixed with a marine paint, applied to PVC panels immersed in the seawater of Suez Bay (Red Sea). The barnacle Balanus amphitrite (Crustacea) and tube worms Hydroides elegans (Polychaeta) are the dominant fouling organisms in this area. The results demonstrated that all the tested soft coral extracts exhibited significant antifouling activities with varying degrees. Extracts of Sinularia heterospiculata and Sinularia variabilis showed the highest and potent wide spectrum antifouling activity, particularly in the first 17 days of fouling formation. Extracts of Sinularia polydactyla exhibited significant selective inhibition against settlement of barnacle, while the extracts of Lithophyton arboreum showed significant antifouling activity against the latter successional stages of tube worms. The results of the current study propose that these soft corals may contain bioactive compounds with antifouling activity. These bioactive molecules can be isolated, purified, identified and chemically synthesized for commercial uses in the development of nontoxic and environmentally acceptable antifouling coatings

    ON THE LOCATION-AWARE COOPERATIVE SPECTRUM SENSING IN URBAN ENVIRONMENT

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    Spectrum sensing is a key enabling technology for cognitive radio networks (CRNs). The main objective of spectrum sensing is to provide more spectrum access opportunities to cognitive radio users without interfering with the operations of the licensed network. Spectrum sensing decisions can lead to erroneous sensing with low performance due to fading, shadowing and other interferences caused by either terrain inconsistency or dense urban structure. In order to improve spectrum sensing decisions, in this paper a cooperative spectrum sensing scheme is proposed. The propagation conditions such as the variance and intensity of terrain and urban structure between two points with respect to signal propagation are taken into consideration. We have also derived the optimum fusion rule which accounts for location reliability of secondary users (SUs). The analytical results show that the proposed scheme slightly outperforms the conventional cooperative spectrum sensing approaches

    Eye Gesture Analysis with Head Movement for Advanced Driver Assistance Systems

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    Road traffic accidents are a major cause of death worldwide. In an attempt to reduce accidents, some research efforts have focused on creating Advanced Driver Assistance Systems (ADAS) able to detect vehicle, driver and environmental conditions and to use this information to identify cues for potential accidents. This paper presents continued work on a novel Non-intrusive Intelligent Driver Assistance and Safety System (Ni-DASS) for assessing driver point of regard within vehicles. It uses an onboard CCD camera to observe the driver’s face. A template matching approach is used to compare the driver’s eye-gaze pattern with a set of eye-gesture templates of the driver looking at different focal points within the vehicle. The windscreen is divided into cells and comparison of the driver’s eye-gaze pattern with templates of a driver’s eyes looking at each cell is used to determine the driver’s point of regard on the windscreen. Results indicate that the proposed technique could be useful in situations where low resolution estimates of driver point of regard are adequate. For instance, To allow ADAS systems to alert the driver if he/she has positively failed to observe a hazard

    Illegal parking detection using Gaussian mixture model and kalman filter

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    Automatic analysis of videos for traffic monitoring has been an area of significant research in the recent past. In this paper, we proposed a system to detect and track illegal vehicle parking using Gaussian Mixture Model and Kalman Filter. i-LIDS dataset is used to test and evaluate the algorithm by comparing the results with the ground truth provided, we have tested the system using 4 full videos from i-LIDS to detect parked vehicle whiten specific area. Region of interest has been used to detect Vehicle parks in a no parking zone over sixty seconds and remains stationary.Within the scope of this work, we highlighted the components of an automated traffic surveillance system, including background modeling, foreground extraction, Kalman filter and Gaussian mixture model. © 2017 IEEE

    A Methodology to Measure СP / CV Ratio Using U-shape Acoustic Resonance Tube

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    The specific heat ratio of gases can be determined using several measuring instruments. Recently acoustic resonance instruments have shown great versatility and are used in various branches of industrial applications. This article proposes a simple measurement methodology to measure the specific heat ratio i.e., Сp / Cv using a free mode of acoustic resonance within a U-shape resonator. The specific heat ratio is calculated by measuring the speed of sound in a tube filled by the sample of the gas under test. For this purpose, the signal of standing wave is acquired using a sound card of Personal Computer. The received signal is rocessed by LabVIEW software. The experimental results show that the measured value of the specific heat ratio of several types of gases can be calculated using the proposed methodology and the relative error is about 2%

    Mid-infrared dual-rhombic air hole Ge 20 Sb 15 Se 65 chalcogenide photonic crystal fiber with high birefringence and high nonlinearity

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    We propose a mid-infrared dual-rhombic air hole hexagonal lattice photonic crystal fiber with high birefringence and large nonlinearity based on Ge20Sb15Se65 chalcogenide glass. The properties of birefringence, dispersion, nonlinearity, and confinement loss were investigated in the 3 µm~5 µm mid-infrared range by using the Finite Difference Time Domain (FDTD) method with perfectly matched layer (PML) absorption boundary conditions. The results indicate that for the optimized structural parameters of Λ= 2.0 µm, D= 1.932 µm, d= 0.8 µm, and H= 0.8 µm, an ultrahigh birefringence of 0.041, a very low confinement loss of 0.0013 dB/km (for x-polarization modes) and 0.0342 dB/km (for y-polarization modes), and the maximum nonlinearity coefficient of 4375 w−1km−1 (for x-polarization modes) and 3960 w−1km−1 (for y-polarization modes) were achieved, respectively. The proposed PCF has a lower confinement loss and higher birefringence than an elliptical-hole PCF with the same air-filling fraction. Thus, it will be an excellent candidate for mid-infrared optical fiber sensing, precision optical instruments and nonlinear optics

    Quantum particle filter: a multiple mode method for low delay abrupt pedestrian motion tracking

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    Pedestrian tracking is a key building block in many emerging technologies, and there are many applications that require a very accurate and reliable pedestrian tracking. Two problems, namely the abrupt changes in motion and the delay in the tracking process are addressed in the reported work. The approach seeks to simulate the uncertainty of the position of electrons around the nucleus by propagating particles in areas where the person is more likely to be, depending on the person's possible motions and taking into account various sources of uncertainty. A novel feature of the presented approach is that it can track abrupt motions accurately with a low delay. The robustness of this approach for abrupt motion situations is demonstrated

    LDL Decomposition-based Real-time FPGA Implementation of DOA Estimation

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    An FPGA implementation and real-time experimental verification of proposed direction of arrival (DOA) estimation algorithm employing LDL factorization are presented in this paper. The proposed algorithm is implemented on a Xilinx FPGA using LabVIEW software and its real-time experimental verification is performed using National Instruments (NI) PXI platform. The proposed method has several advantages over well-known methods which are based on either eigenvalue decomposition (EVD) or singular value decomposition (SVD). It provides faster execution since LDL factorization requires O(n3/6) number of operations whereas EVD requires O(n3). Results from Matlab simulations and real-time experiments demonstrate the effectiveness of the proposed method. Successful FPGA compilation reports show low resource usage and faster computation time for LDL-based method compared with QRbased implementations. Performance comparison is done in terms of estimation accuracy, FPGA processing time and resource utilization
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