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Recently, the commutative anisotropic convolution has been defined for signals defined on the 2-sphere. Here, we present exact and efficient methods for computation of commutative convolution of two signals defined on the sphere. For fast computation of commutative convolution, we first review the use of existing efficient techniques developed to evaluate SO(3) convolution. By employing the factoring...
The weighted least-squares design of Farrow-based variable fractional delay filters is known to suffer from numerical difficulties which can lead to design failures. In this paper, we derive a set of analytical expressions to overcome these difficulties. The analytical expressions also allow us to prove conclusively a number of properties that previous researchers have claimed regarding the design...
The incorrect shape and location of initial contour in the level set image segmentation method could lead to unreliable results but the proper initial contour is hard to design in some images. This paper proposes a method that is more independent using four vector flows instead of using edge detector to insert new contour. The geodesic active contour (GAC) is used to compared with the proposed method...
Classifier selection is a problem encountered by multi-biometric systems that aim to improve performance through fusion of decisions. A particular decision fusion architecture that combines multiple instances (n classifiers) and multiple samples (m attempts at each classifier) has been proposed in previous work to achieve controlled trade-off between false alarms and false rejects. Although analysis...
In this paper, the base station identification and timing adjust measurements are used to geolocate mobile subscribers in a WiMAX network. The uplink and downlink subframes of the physical layer and management messages of the medium access control layer are examined to extract the necessary data for geolocation. Using a hidden Markov model [1] based algorithm to estimate the track of the mobile subscriber,...
Localization of sensor networks poses an immense challenge and is considered as a hot research topic in recent days. To address the accuracy on localization this paper proposes constrained simultaneous perturbation stochastic approximation (SPSA) based localization techniques for wireless sensor networks. A simple centralized localization of the non-anchor nodes based on minimizing the summation of...
Mobile indoor localisation has numerous uses for logistics, health, sport and social networking applications. Current wireless localisation systems experience reliability difficulties while operating within indoor environments due to interference caused by the presence of metallic infrastructure. Current position localisation use wireless channel propagation characteristics, such as RF receive signal...
Identification of persons in contact with the information systems of organizations is a very important aspect of the security of the entire system. One of the options used for this purpose is a smart card. Therefore added security in form of combination of more complex architecture and chip card with biometric is desired in today's world. In the implementation of the smart card technology it is necessary...
In order to reduce the effect on node positioning accuracy due to received signal strength (RSSI) fluctuation in wireless sensor network (WSN), a grid localization algorithm based on RSSI probability distribution is proposed. From analyzing the wireless propagation channel model, it divides the location area into grids. Through comparing the value of RSSI probability likelihood function in grid, the...
With the proliferation of location based services (LBS), various indoor localization techniques have been explored based on received signal strength (RSS). To improve performance, many algorithms and techniques have been proposed in the literature. In this paper, a new RSS based statistical location algorithm is proposed to achieve better localization performance, with a focus on statistical analysis...
This paper proposes a cost-effective key management method for multicast networks. This method divides a multicast group into several subgroups, where the multicast transmission is separated into two levels, namely, multicast and unicast level. We model our proposed method based on the cost of join and leave operations in the multicast group using Markov chain and Poisson Arrival Process. Then, we...
Smartphone is more and more important for many people, which may store private confidential information or is used for dealing with important transaction. Many new mobile malware aiming to Smartphone are appearing which pose tremendous threat to mobile user. This paper proposes a behavior-based mobile malware analysis method which can detect the known and new mobile malware efficiently. A Mobile Malware...
The security issues are very important for information technology applications now a day such as ATM and Smart cards. One of the recent public key cryptosystems is Elliptic Curves Cryptography. The group of the elliptic curve points forms an Abelian group, that is a suitable choice for constructing the Elliptic Curve Discrete Logarithm Problem (ECDLP). This led to create cipher system based on the...
Hostile and harsh environments may preclude the possibility of manual redeployment of new sensor nodes, especially in the areas suffering from widespread damage and unbalanced node deployments. Distributed local relocations of currently deployed nodes is one promising solution to this problem. By using expected global node density and force-based movement algorithms inspired by the laws of nature,...
Recently, cooperative communication and Space-Time-Frequency-Codes (STFCs) have been introduced into the Multiband OFDM Ultra-Wideband (MB-OFDM UWB) to improve the reliability, data rate and system capacity. This paper proposes a cooperative communication scheme for a four source node MB-OFDM UWB system using Quasi-Orthogonal STFCs, which is referred to as order-4 Quasi-Orthogonal Cooperative Communication...
An HMM-based motion perception system capable of identifying individual motion of multiple objects present in a scene has been developed. By introducing a new grid-partitioning scheme representing the characteristic motions in the scene, translation invariant perception has been established. An autonomous time indexing scheme has also been developed and implemented in the system. Recognition experiments...
This paper proposes and demonstrates the novel application of a secure wireless sensor network for roadside surveillance and vehicular detection using radio tomographic imaging. Network architecture is based on the well-established Zigbee standard and medium access is provided through a time division multiple access scheme. Wireless security vulnerabilities are considered and a four-part security...
In the last few decades, the number of emergencies has increased worldwide. Often, in these emergencies, both wireless and wired communication infrastructures could be damaged partially or completely. Hence, mobile devices, being ubiquitously present and closely attached, usually become a dominant way of communication. In general, a prior knowledge of user movements in mobile environments can improve...
Mobile agents are the processes that can migrate from one machine of a system to another machine in order to satisfy requests made by their clients. Since mobile agent moves from one server to another server in an itinerary it is easily prone to various faults like server crash or agent crash, which makes fault tolerance one of the main issues for reliability in information retrieval applications...
In Cognitive Radio (CR), spectrum sensing is an essential concept. It exploits the inefficient utilization of Radio spectrum without deteriorating the Quality of Service (QOS) of licensed/primary user communication. This paper presents the cooperative wideband spectrum sensing technique based on entropy estimation in each subband under probable channel impediments. We have proposed generalized extreme...
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