Image contrast enhancement is a fundamental pre-processing stage in applications requiring image processing operations. Among revenues of available approaches, histogram equalization is a popular and attractive candidate method to produce resultant images of increased contrast. However, images obtained from canonical histogram equalization frequently suffer from the accompanying artefacts and give rises to uncomfortable viewing particularly in homogeneous regions. In ...

The IEEE 802.16j standard for WiMAX introduced the concept of relay station in order to increase the service area and decrease the deployment cost of the network. In this paper, we have proposed an efficient scheduling scheme for IEEE 802.16j networks, which maximizes the number of connections that are scheduled in a particular time slot. The proposed scheme ...

The k-ary n-cube has been used as the underlying topology for many practical multicomputers, and has been extensively studied in the past. In this article, we will prove that any k-ary n-cube Qnk, where n⩾2 is an integer and k⩾4 is an even integer, contains 2n mutually independent Hamiltonian cycles. More specifically, let N=|V(Qnk)|,...

In this work a comparative analysis of typical power variables is made using several hardware architectures and GNU/Linux software. Voltage and current data are simulated for an industrial device, comparing the performance of x86 and ARM in order to demonstrate the technical feasibility of using embedded hardware to manage high volumes of interesting data in the study of power ...

In 2008, Lee et al. proposed two multiple-key agreement protocols, first one based on elliptic curve cryptography (ECC) and the other one, based on bilinear pairings. Shortly after publication, Vo et al. showed that the Lee–Wu–Wang’s pairing-based protocol is vulnerable to impersonation attack then for removing the problem, they proposed an improved protocol. In this paper, ...

For image denoising, the main challenge is how to preserve the information-bearing structures such as edges and textures to get satisfactory visual quality when improving the signal-to-noise-ratio (SNR). Edge-preserving image denoising has become a very intensive research topic. In this paper, we describe a method for removing noise from digital images, based on bilateral filter ...

In wireless networks, users expect to get access to the network securely and seamlessly to share the data flow of access points anytime and anywhere. However, either point-to-point or point-to-multipoint methods in traditional wireless networks make the network bandwidth decrease rapidly, which cannot meet the requirements of users. Recently, a new wireless broadband access network, wireless ...

A software based lossless ECG compression algorithm is developed here. The algorithm is written in the C-platform. The algorithm has applied to various ECG data of all the 12 leads taken from PTB diagnostic ECG database (PTB-DB). Here, a difference array has been generated from the corresponding input ECG data and this is multiplied by a large number ...

Chameleon signatures simultaneously provide the properties of non-repudiation and non-transferability for the signed message. However, the initial constructions of chameleon signatures suffer from the key exposure problem of chameleon hashing. This creates a strong disincentive for the recipient to compute hash collisions, partially undermining the concept of non-transferability. Recently, some constructions of discrete logarithm based chameleon hashing ...

This paper introduces a novel image segmentation method that performs histogram thresholding on an image with consideration to spatial information. The spatial information is the joint gray level values of the pixel to be segmented and its neighboring pixels that are based on the gray level co-occurrence matrix (GLCM). The new method was obtained by extending the one-dimensional (...

In this paper, an approach to the performance analysis of dual-branch switch-and-stay combining (SSC) diversity receiver, operating over correlated α–μ fading channels in the presence of co-channel interference (CCI), is presented. Very useful novel infinite series expressions are obtained for the probability density function (PDF) and cumulative distribution function (CDF) of the SSC output signal-...

LT codes are convenient and popular kind of rateless codes that could easily tolerate different patterns of loss in erasure channels. In this paper an LT code with unequal packet protection (UPP) property is proposed. The proposed code could provide unequal packet recovery to any importance-sorted data packets. Simulation results indicate the enhanced performance of the suggested scheme and ...

In this paper, a time-area efficient hardware decoder of the (23, 12, 7) quadratic residue code, or Golay code, is presented. The key feature of this proposed algorithm lies in fast determination of error positions through the analysis on the weight of syndromes without large operations in finite fields. Comparing with the algorithm using one syndrome, the proposed algorithm ...

Common sense dictates that single-shot timer mechanisms are more suitable for real-time applications than periodic ones, specially in what concerns precision and jitter. Nevertheless, real-time embedded systems are inherently periodic, with tasks whose periods are almost always known at design-time. Therefore a carefully designed periodic timer should be able to incorporate much of the advantages of ...

Real-time scheduling refers to the problem in which there is a deadline associated with the execution of a task. In this paper, we address the scheduling problem for a uniprocessor platform that is powered by a renewable energy storage unit and uses a recharging system such as photovoltaic cells. First, we describe our model where two constraints need to ...

In this paper, we will investigate the implementation of the parallelization approaches used in the program of discharge simulation along resin insulator surfaces in SF6/N2 gas mixture which initially consumes a great deal of computational time. In a general way, this simulation program spent 10 days of execution to achieve satisfactory research results. For this reason, the goal of ...

For multimedia document, watermarking provides many advantages; however, its vulnerability due to attacks using signal processing methods offers challenge in designing robust techniques. This paper presents a novel method for enhancing robustness in copyright marking into mid-frequency discrete cosine transform (DCT) coefficients of an image. We establish that Weibull distribution suitably models mid-frequency coefficients well and use it ...

Hypermesh is a promising network topology and is suitable for a range of network-based computing systems. Although there are few models reported for hypermeshes with uniform traffic pattern, no analytical model has been reported to deal with hot-spot traffic. Since many parallel applications exhibit non-uniform traffic patterns such as hot-spots, uniform traffic assumption is not always ...

According to the model of compressed sampling in shift-invariant space, the over-complete dictionary is usually a function matrix, which increases the complexity of reconstructing samples. In order to reduce the complexity of reconstructing samples, this paper proposes a reconstruction method based on matrix factorization. The method transforms over-complete dictionary into the multiplication of a reversible function matrix ...

Wireless technologies which serve multimedia applications have to guarantee the Quality of Service (QoS) demands along with seamless connectivity. The complexity in attaining such demands increases if the network is heterogeneous in nature. This paper proposes a QoS guaranteed integration methodology for a heterogeneous wireless local area network (WLAN) – worldwide interoperability for microwave access (WiMAX) network. An integrated protocol stack ...

In this paper, we present a strongly secure identity-based (ID-based) two-party authenticated key agreement (AKA) protocol, which captures all basic desirable security properties including master key forward secrecy, ephemeral secrets reveal resistance and so on, and is provably secure in the extended Canetti–Krawczyk (eCK) model. The security of the protocol can be reduced to the standard ...

Keystream reuse, also known as the two time pad problem, is a well known weakness in stream ciphers. The implementers of the cryptographic algorithms are still underestimating this threat. The keystream reuse exploitation techniques presented so far assume the underlying plaintext to be textual data and all the heuristics presented previously are based on the language characteristics of the underlying ...

Reconfigurable MPSoCs (Multiprocessor System-on-Chip) could be viable for certain applications niche where the flexibility of FPGAs (Field-Programmable Gate Array) and software is needed, and a small number of units dismiss other silicon options. However, their design complexity is very high, and raises additional problems, i.e. the definition of a suitable programming model, an efficient memory organization, ...

An attack tree is a useful analytical technique to model security threats and/or risks, and hence model attacks as actual realizations of the former. Research on attack trees have focused either on applying such trees to model various ranges of security systems, or on advancements to this technique in itself. In this paper, we revisit the notion of attack ...

This article presents a novel technique for fault detection as well as fault location in a reversible combinational circuit under the missing gate fault model. It is shown that in an (n×n) reversible circuit implemented with k-CNOT gates, addition of only one extra control line along with duplication each k-CNOT gate, yields an easily testable design, which admits ...

Fast search algorithms (FSA) used for variable block size motion estimation follow irregular search (data access) patterns. This poses as the main challenge in designing hardware architectures for them. In this study, we build a baseline architecture for fast search algorithms using state-of-the-art components available in academia. We improve its performance by introducing: (1) a super 2-...

In this paper, we propose a fast algorithm to solve the well known total variation (TV) inpainting model. Classically, the Euler–Lagrange equation deduced from TV inpainting model is solved by the gradient descent method and discretized by an explicit scheme, which produces a slow inpainting process. Sometimes an implicit scheme is also used to tackle the problem. Although the ...

Journal: Computers & Electrical Engineering - CEE, vol. 37, no. 2, pp. 127-128, 2011]]>http://academic.research.microsoft.com/Publication/39333112Thu, 23 May 2013 23:55:54 GMT39333112Aiman El-Maleh, Saif al Zahir, Esam Khanview publication

The increasing complexity of systems-on-a-chip with the accompanied increase in their test data size has made the need for test data reduction imperative. In this paper, we introduce a novel and efficient test-independent compression technique based on geometric shapes. The technique exploits reordering of test vectors to minimize the number of shapes needed to encode the ...

Secure user authentication is an important issue for wireless environment such as GSM, CDPD, and 3G and 4G wireless systems. Especially, anonymity of the mobile users should be guaranteed to protect the privacy of the mobile users. This paper proposes a user friendly authentication scheme with anonymity for wireless communications that not only can overcome the weaknesses of the previous ...

Digital watermarking techniques are a means of protecting the copyrights of digital contents. In this paper, we propose an identity-based (ID-based) digital watermarking protocol and point out several previously unpublished flaws in Hwang et al. (2005)’s scheme. We hope that by identifying the design flaws, similar structural mistakes can be avoided in future designs. We also claim ...

Desynchronization attack is known as one of the most difficult attacks to resist, for it can desynchronize the location of the watermark and hence causes incorrect watermark detection. It is a challenging work to design a robust audio watermarking scheme against desynchronization attacks. Based on pseudo-Zernike moment and synchronization code, we propose a new digital audio watermarking algorithm with ...

Efficient medium access control (MAC) protocol should be able to provide high throughput performance and efficient share of the medium. In this paper, a new contention-based MAC protocol based on adaptive fuzzy controlled sliding backoff interval is proposed to maximize the channel throughput and improve the fairness of random access channels. In the proposed protocol, every node that experiences ...

The radio-based medium of satellite communication systems is vulnerable to interference on physical channels: unintentional interferences occur frequently and jamming attacks can be achieved using low-grade technology. While application layer security protocols cannot defend against denial of service (DoS) attacks where the attacker jams continuously, effective security protocols ensure that communication can continue after such interference has stopped....

This paper presents the design of a new clustering algorithm for images having wide range of variations in appearances and shape. The major chore of the clustering process involves in creating the partitions, reassigning the elements of the partitions and identifying the compact cluster obtained. The clusters are created from various low-dimensional spaces of the data set. Hierarchically related ...

Modular processing of large numbers requires high speed computing resources. In particular an operation slowing the whole computing process heavily is modular exponentiation.A previous method reduces the computation of |xe|m to n simpler modular exponentiations |xiηi|mi at most, where mi is an element of the factorization of m, xi=|x|mi and ηimi. A technique speeding up |...

The major disadvantage of wavelet based Orthogonal Frequency Division Multiplexing (WOFDM) system is high peak-to-average power ratio (PAPR) of the transmit signal. A new method is presented to obtain a set of optimal wavelet packet basis by constructing the PAPR optimization model and the optimal PAPR of system can be obtain by modulating the signal with the optimal ...

Advances in science and engineering have put high demands on tools for high performance large-scale data exploration and analysis. Visualization is a powerful technology for analyzing data and presenting results. Todays science and engineering have benefited from state-of-the-art of Grid technologies and modern visualization systems. To visualize the large amount of data, rendering technologies are widely ...

When using wireless sensor networks for real-time image transmission, some critical points should be considered. These points are limited computational power, storage capability, narrow bandwidth and required energy. Therefore, efficient compression and transmission of images in wireless sensor network is considered. To address the above mentioned concerns, an efficient adaptive compression scheme that ensures a significant computational and energy ...

It has been shown in several works that some preprocessing techniques can improve data detection performance when they are applied to the channel matrix of MIMO wireless systems. In particular, these techniques can be used previously to K-Best tree search algorithms, and they are known to achieve successful results. Throughout this work, the performance and complexity of two preprocessing ...

The widespread usage of image fusion causes an increase in the importance of assessing the performance of different fusion algorithms. The problem of introducing a suitable quality measure for image fusion lies in the difficulty of defining an ideal fused image. In this paper, we propose a non-reference objective image fusion metric based on mutual information which calculates the ...

Rate control plays a critical role in the video encoder. In this paper, an effective macroblock (MB) layer rate control algorithm is proposed for H.264/AVC to improve video quality and reduce the computational complexity. By thoroughly analyzing the temporal–spatial correlation and object direction, the mean absolute difference (MAD) value of current MB is a weighted combination of ...

We introduce a new cryptographic primitive which is the signature analog of fuzzy identity based encryption (FIBE). We call it fuzzy identity based signature (FIBS). It possesses similar error-tolerance property as FIBE that allows a user with the private key for identity ω to decrypt a ciphertext encrypted for identity ω′ if and only if ω and ω′ are ...

In Certificate-Based Encryption, introduced by Gentry, a certificate, -or, more generally, a signature-acts not only as a certificate but also as a decryption key. However, the security model of Gentry’s scheme relies on an unrealistic assumption, where the adversary must reveal its partial private key to the challenger in attack games. In this paper, we propose an enhanced ...

In a multi-proxy signature scheme, an original signer could authorize a proxy group as his proxy agent. Then only the cooperation of all the signers in the proxy group can generate the proxy signatures on behalf of the original signer. Recently, Cao and Cao gave the first formal definition and security model of an identity-based multi-proxy signature ...

Chen (Computers and Electrical Engineering, vol. 30, 2004) illustrated that Tseng et al.’s authenticated encryption schemes, with message linkages for message flows, do not achieve their claimed integrity and authenticity properties. Furthermore, Chen presented some modified schemes to repair these flaws. In this paper, we show that the modified schemes proposed by Chen are not secure. In particular, we ...

In this paper, we first propose two learning automata based decentralized dynamic guard channel algorithms for cellular mobile networks. These algorithms use learning automata to adjust the number of guard channels to be assigned to cells of network. Then, we introduce a new model for nonstationary environments under which the proposed algorithms work and study their steady state behavior when ...

Nowadays, several computational techniques for speech recognition have been proposed. These techniques suppose an important improvement in real time applications where speaker interacts with speech recognition systems. Although researchers proposed many methods, none of them solve the high false alarm problem when far-field speakers interfere in a human-machine conversation. This paper presents a two-class (speech and non-...

The paper proposes a new fuzzy-based two-step filter for restoring images corrupted with additive noise. The goal of the first step is to compute the difference between the central pixel and its neighborhood in a selected window and to compute a fuzzy membership degree for each difference value using a Gaussian membership function. Computed fuzzy membership values are ...

In this paper, we propose a notion of contract signature used in e-commerce applications. We propose a contract signature scheme based on the discrete logarithm assumption. The contract signature scheme adopts a digital multi-signature scheme in public-key cryptography to facilitate fair signature exchange over network. This proposed solution allows multiple signers of a contract signature to exchange ...

Performance of ad hoc networks dramatically declines as network grows. Cluster formation in which the network hosts are hierarchically partitioned into several autonomous non-overlapping groups, based on proximity, is a promising approach to alleviate the scalability problem of ad hoc networks. In this paper, we propose a localized learning automata-based clustering algorithm for wireless ad hoc networks. The ...

In this paper, a non-symmetry and anti-packing image representation model (NAM) has been proposed. NAM is a hierarchical image representation method and it aims to provide faster operations and less storage requirement. By taking a rectangle sub-pattern, for example, we describe the idea of NAM and its encoding algorithm.In addition, an approach for adaptive area histogram ...

Delivering digital video content with enhanced quality of experience to the end users over error-prone multi-hop wireless networks is a challenging issue. In video transmission over such wireless networks, many network-based (packet loss, delay, etc.) and source-based (encoding quantization level etc.) parameters can impose some levels of impairment on the perceived video quality. In a video ...

Based on the support vector regression (SVR) geometric distortions correction, we propose a robust image watermarking algorithm in nonsubsampled contourlet transform (NSCT) domain with good visual quality and reasonable resistance toward geometric attacks in this paper. Firstly, the NSCT is performed on original host image, and corresponding low-pass subband is selected for embedding watermark. Then, the selected low-pass ...

Group key agreement is the core of secure group communication. In wireless networks, the privacy problem becomes more crucial and urgent for mobile users due to the open nature of radio media. In this paper, we proposed a novel group key agreement protocol based on trusted third Party, applied in collaboration between mobile users for wireless Mesh network. The security ...

This paper proposes a multiscale texture classifier which uses features extracted from both magnitude and phase responses of subbands at different resolutions of the dual-tree complex wavelet transform decomposition of a texture image. The mean and entropy in the transform domain are used to form a feature vector. The proposed method can achieve a high texture classification rate even ...

In this paper, we present a novel multilinear algebra based feature extraction approach for face recognition which preserves some implicit structural or locally-spatial information among elements of the original images. We call this method three-dimensional modular discriminant analysis (3DMDA). Our approach uses a new data model called third-order tensor model (3TM) for representing the face images. In ...

Journal: Computers & Electrical Engineering - CEE, vol. 37, no. 2, pp. 191-198, 2011]]>http://academic.research.microsoft.com/Publication/49153688Thu, 23 May 2013 23:55:24 GMT49153688J. Leiview publication

Compressed sensing (CS) is considered as a promising signal processing technique, and successful applications of the CS theory depend mainly on the accuracy and speed of the reconstruction algorithms. In this paper, a generalized objective functional, which has been developed using the combinational estimation and an extended stabilizing functional, is proposed. An efficient iterative scheme, which integrates the beneficial advantages ...

A low-complexity partial transmit sequence (PTS) technique for reducing the peak-to-average power ratio (PAPR) of an orthogonal frequency division multiplexing (OFDM) system is presented. However, PTS technique requires an exhaustive search over all combinations of allowed phase weighting factors, and the search complexity increases exponentially with the number of sub-blocks in OFDM system. Hence, there has ...

In this paper, the existing Generalized Autocorrelation based Estimator (GAE) has been modified for estimation of time delays in multipath environment in the presence of uncorrelated noise. Here the multipath propagation output signal is modeled as a superposition of the delayed, attenuated, and filtered versions of the stationary Gaussian stochastic input signal. Accuracy Percentage (AP) performance measure has been used ...

We consider the problem of optimal preemption control in preemptive systems with loss. Based on a designed cost function composed by the following criteria: blocking cost function, preemption cost function, degradation cost function, and processing and signaling load cost function; we use the semi-Markov decision process framework as well as the value iteration algorithm to get the optimal policies. ...