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1.
Scene change detection techniques for video database systems   总被引:1,自引:0,他引:1  
Scene change detection (SCD) is one of several fundamental problems in the design of a video database management system (VDBMS). It is the first step towards the automatic segmentation, annotation, and indexing of video data. SCD is also used in other aspects of VDBMS, e.g., hierarchical representation and efficient browsing of the video data. In this paper, we provide a taxonomy that classifies existing SCD algorithms into three categories: full-video-image-based, compressed-video-based, and model-based algorithms. The capabilities and limitations of the SCD algorithms are discussed in detail. The paper also proposes a set of criteria for measuring and comparing the performance of various SCD algorithms. We conclude by discussing some important research directions.  相似文献   
2.
Fifteen Baladi and 20 Angora intact males raised together from birth until 8 months of age were grown on a commercial concentrate mixture fed at the rate of 0·6 kg/head/day with chopped wheat straw fed at 0·5 kg/head/day for 14 weeks. Body measurements were taken before slaughter and carcass measurements and offal weights after it. The right sides of all carcasses were dissected into cuts, weighed and deboned. Fat was separated from the 9-10-11 rib joints and estimated. The two breeds did not significantly differ in birth weight, weaning weight, carcass weight, dressing percentage, most body measurements, all carcass measurements and most offal weights. Sigmificant differences were only found in body length, height at withers, weights of spleen and kidney fat. However, the Baladi had significant heavier loin and shoulder (P < 0·05) and breast and flank (P < 0·05) than the Angora which had heavier legs (P < 0·05). The carcasses of the two breeds had very similar percentage of edible meat (68·38 versus 68·65), lean (57·47 versus 57·38) and fat in the rib joint (10·91 versus 11·27).  相似文献   
3.
This paper addresses the optimal distributed generation sizing and siting for voltage profile improvement, power losses, and total harmonic distortion (THD) reduction in a distribution network with high penetration of non-linear loads. The proposed planning methodology takes into consideration the load profile, the frequency spectrum of non-linear loads, and the technical constraints such as voltage limits at different buses (slack and load buses) of the system, feeder capacity, THD limits, and maximum penetration limit of DG units. The optimization process is based on the Genetic Algorithm (GA) method with three scenarios of objective function: system power losses, THD, and multi-objective function-based power losses and THD. This method is executed on the IEEE 31-bus system under sinusoidal and non-sinusoidal (harmonics) operating conditions including load variations within the 24-hr period. The simulation results using Matlab environment show the robustness of this method in optimal sizing and siting of DG, efficiency for improvement of voltage profile, reduction of power losses, and THD. A comparison with particle swarm optimization (PSO) method shows that the proposed method is better than PSO in reducing the power losses and THD in all suggested scenarios.  相似文献   
4.
The availability of multiple technologies to access the Internet is even more common in today's connectivity scenarios. As an example, smartphones make use of 3G/4G data technology but, when a Wi‐Fi access point is available, they switch from 3G/4G (which typically is a paid per volume service) to the wireless local access. The same principle is applicable for fixed access, when terrestrial ADSL or optical fiber and satellite technologies can be typically available in the same place. This paper focuses on the simultaneous availability of different access technologies with the capability to use them in combination, to offer better performance than the traditional single technology access.  相似文献   
5.
This paper examines channel choice and the digital divide in Egyptian electronic government or e-government. Citizens have access to a variety of service delivery channels when they initiate contact with their government, ranging from e-government to more traditional channels such as the phone and in-person visits to a government office. This paper examines the extent of use of both contact channels for citizens and the impact of the digital divide on channel use. A public opinion survey of Egyptian citizens was analyzed, and the results showed that there was a digital divide in the use of e-government by citizens. The digital divide also extended to other contact channels such as the phone and when citizens used multiple contact channels for public service delivery. The results of this study imply that for the development of e-government, especially in the context of a developing country such as Egypt, policy-makers need to understand that e-government is one of many channels that citizens can use when they initiate contact with their government. The results of this study should encourage policy-makers to recognize the importance of public service delivery in a multichannel environment. Shirin Madon is the accepting Associate Editor for this article. View all notes  相似文献   
6.
Neural Computing and Applications - Security is one of the primary concerns when designing wireless networks. Along detecting user identity, it is also important to detect the devices at the...  相似文献   
7.
Idiopathic or congenital coronary artery ectasias and aneurysms are uncommon forms of coronary artery disease. The prognosis and optimal management of such patients remains unknown. The authors describe the case of an otherwise healthy 30-year-old man with concomitant severe right coronary artery ectasia and left main coronary artery aneurysm who sustained a mild anterior myocardial infarction. There was no obstructive coronary artery disease, and no cause for the lesions could be identified. Chronic anticoagulation and antiplatelet therapy were initiated with resolution of symptoms.  相似文献   
8.
Terahertz digital holography (THz-DH) has the potential to be used for non-destructive inspection of visibly opaque soft materials due to its good immunity to optical scattering and absorption. Although previous research on full-field off-axis THz-DH has usually been performed using Fresnel diffraction reconstruction, its minimum reconstruction distance occasionally prevents a sample from being placed near a THz imager to increase the signal-to-noise ratio in the hologram. In this article, we apply the angular spectrum method (ASM) for wavefront reconstruction in full-filed off-axis THz-DH because ASM is more accurate at short reconstruction distances. We demonstrate real-time phase imaging of a visibly opaque plastic sample with a phase resolution power of λ/49 at a frame rate of 3.5 Hz in addition to real-time amplitude imaging. We also perform digital focusing of the amplitude image for the same object with a depth selectivity of 447 μm. Furthermore, 3D imaging of visibly opaque silicon objects was achieved with a depth precision of 1.7 μm. The demonstrated results indicate the high potential of the proposed method for in-line or in-process non-destructive inspection of soft materials.  相似文献   
9.
AgFeO2 delafossite was successfully prepared by a facile and low-cost method which was flash auto-combustion technique. X-ray diffraction pattern (XRD) confirmed that the sample was in the nanosize range. Also, the morphology analyzed by high resolution transmission electron microscopy (HRTEM) and field emission scanning electron microscopy (FESEM) clarified that AgFeO2 delafossite was in the nanoscale range. The composition of the sample was determined using energy dispersive X-ray (EDX) analysis. The magnetic properties assured that the sample had ferromagnetic behavior. The optical properties were measured for the investigated sample and the energy gap was 3.4 eV. The antimicrobial activities were screened against Gram positive and Gram negative bacteria and the results revealed a strong antibacterial activity of AgFeO2 delafossite. Moreover, Fungi activity was studied against Aspergillus flavus and Candida albicans and the results revealed that no activity by adding AgFeO2 delafossite had happened. The application of this study promotes the use of AgFeO2 as antibacterial agent.  相似文献   
10.
Satellites represent a solution for Internet access in locations with no other telecom infrastructures, for example, on high mobility platforms such as planes, ships or high‐speed trains, or for disaster recovery applications. However, due to peculiar characteristics, satellite networks are prone to different security threats. In this paper, we introduce a novel, robust security architecture for securing digital video broadcasting‐return channel via satellite satellite networks, inspired by the robust security mechanism available in the Institute of Electrical and Electronic Engineers (IEEE) 802.11i wireless local area network. We propose an efficient authentication and key management mechanism, which is exploited through three round‐trips only, demonstrating that it is as secure as IEEE 802.11i. Furthermore, the simulation results show that the proposed security framework needs a very small data overhead and shows better performance than internet protocol security (IPSec), which is commonly used as an end‐to‐end security solution over internet protocol satellite networks. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
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