Earticle

Transmission of block-coded images over wireless channels results in lost blocks. These losses may occur in region-of-interest (ROI) of images which contain important information of images. In this paper, we propose a new error concealment method for covering up the high packet losses of an original image after its transmission through an error-prone channel. In this scheme, Discrete Wavelet Transform (DWT) is applied to each block of the original image in order to produce a lower resolution copy of the block. Then, we choose approximation coefficients of each block as replica of the block and embed it into a remote block (called masking block) of the image in the spatial domain. We use a new algorithm to find the masking block for embedding the replica. The advantage of this algorithm is that it avoids losing simultaneously the information of the block and its masking block. It is shown that the proposed scheme provides significant improvement over existing algorithms in terms of both subjective and objective evaluations. This technique can be implemented for wireless channels to combat degradations in a backward-compatible scheme. It is also shown that this scheme can efficiently restore the lost blocks in the ROI of images.

This paper presents Adaptive methodology to compensate the On Chip Variations (OCV), aging effect and manufacturing uncertainties in sub threshold circuits. “Canary flip-flop (FF),” is used to predict the timing violations. A FSM, 4-bit Counter, in CMOS 90nm technology whose performance is controlled by automatically changing voltage levels (DVS) as per the timing error prediction. In addition, the voltage supply is further scaled down if no timing error is predicted within certain time period to save more power at different PVT conditions. Back end simulation results shows, the design under observation with this technique can compensate process, supply voltage and temperature instability with an efficient power savings of nearly 40% with respect to the conventional worst case design with timing margins approach. Here we also demonstrate how to define the delay of delay chain during the design phase itself.

As the web, social networking, and smartphone application have been popular, the data has grown drastically everyday. Thus, such data is called Big Data. Google met Big Data earlier than others and recognized the importance of the storage and computation of Big Data. Thus, Google implemented its parallel computing platform with Map/Reduce approach on Google Distributed File Systems (GFS) in order to compute Big Data. Map/Reduce motivates to redesign and convert the existing sequential algorithms to Map/Reduce algorithms for Big Data so that the paper presents Market Basket Analysis algorithm with Map/Reduce, one of popular data mining algorithms. The algorithm is to sort data set and to convert it to (key, value) pair to fit with Map/Reduce. Amazon Web Service (AWS) provides Apache Hadoop platform that provide Map/Reduce computing on Hadoop Distributed File Systems (HDFS) as one of many its services. In the paper, the proposed algorithm is executed on Amazon EC2 Map/Reduce platform with Hadoop. The experimental results show that the code with Map/Reduce increases the performance as adding more nodes but at a certain point, Map/Reduce has the limitation of exploring the parallelism with a bottle-neck that does not allow the performance gain. It is believed that the operations of distributing, aggregating, and reducing data in the nodes of Map/Reduce should cause the bottle-neck.

Design a nonlinear controller for second order nonlinear uncertain dynamical systems is one of the most important challenging works. This paper focuses on the design of a robust rule base fuzzy-based tuning fuzzy sliding mode controller for second order nonlinear system in presence of uncertainties. Rule base is one of the important key factors in design of fuzzy based tuning controller. In order to provide high performance nonlinear methodology, fuzzy sliding mode controller is selected. Fuzzy sliding mode controller can be used to control of partly unknown nonlinear dynamic parameters of nonlinear system. Error-based fuzzy sliding mode controller has difficulty in handling unstructured model uncertainties. To solve this problem applied improve rule base fuzzy-based tuning method to error-based fuzzy sliding mode controller for adjusting the rule base in adaptive fuzzy-based tuning. This controller has acceptable performance in presence of uncertainty (e.g., overshoot=0%, rise time=0.4 second, steady state error = 1.3e-11 and RMS error=1.2e-11).

In this paper we studied a set of knapsack problems involving the notion of dimensions, demands and multiple choice constraints. Specifically, we defined a new problem called the multiple demand multidimensional multiple choice knapsack problem and we showed it as a generalization of other related problems. Moreover, we presented a set of transformations between the different integer linear programs of the studied problems. Using these transformations, we showed that any algorithm able to solve the generalized problem can definitely solve its related problems. Then, we tested the new integer linear programs on different sets of benchmarks using the commercial software Cplex 9.0 . Computational results highlighted the ability of the generated formulations to produce a reasonable CPU time value compared with the original ones.

Nowadays, various mechanical, electrical systems or combination of both systems are used tohelp or ease human beings either during the daily life activity or during the worst condition faced by them. The system that can be used to increase human life quality are such as in military operations, pipeline survey, agricultural operations and border patrol. The worst condition that normally faced by human are such as earthquake, flood, nuclear reactors explosion and etc. One of the combinations of both systems is unmanned hovercraft system which is still not thoroughly explored and designed. Hovercraft is a machine that can move on the land surface or water and it is supported by cushion that has high compressed air inside. The cushion is a close canvas and better known as a skirt. A hovercraft moves on most of surfaces either in rough, soft or slippery condition will be developed. The main idea for this project is to develop a dynamic modelling and controller for autonomous hovercraft. The model of the hovercraft will be initially calculated using Euler Lagrange method. The model of the hovercraft is derived using Maple software. The model that is developed then needs to be tested with open loop simulation in the MATLAB/Simulink environment. The LQR controller to regulate the small scale autonomous hovercraft then will be developed and tested with MATLAB.

The availability of smart hand held devices increases rapidly and the need for their interconnection is demand that can not wait. IEEE wireless standards are one of the leading factors of the wireless revolution. All IP networks with centralized management are reality. IMS platforms are providing advanced IP based voice and multimedia services. Technical standards are currently defined that address both the methods of wireless/wired interconnection. TCP remains as the most important and most used transport protocol used for non real time services such as web, email, ftp, which are basis for additional value-added or novel IP-based services. Not much work is done in direction of understanding how can TCP be adapted to handle this scenario for efficiency delivering digital contents. The focus should continue to be on the transport protocol development, its optimization and predetermined behavior in variety of environments. Hence, in this paper we conduct detailed analysis of the impact of the Duplicated ACK and Delayed ACK parameters on the throughput, congestion window change and average packet delay in wireless chain scenario with incorporated loss models under traffic load provided by different TCP versions and IFQ buffer size.

This study presents a fatigue life prediction based on finite element analysis under non constant amplitude proportional loading. Parabolic spring is the vital component in a vehicle suspension system, commonly used in trucks. It needs to have excellent fatigue life and recently, manufacturers rely on constant loading fatigue data. The objective of this study is to simulate the non constant amplitude proportional loading for the fatigue life analysis. The finite element method (FEM) was performed on the spring model to observe the distribution of stress and damage. The fatigue life simulation was performed and analyzed for materials SAE1045-450-QT, SAE1045-595-QT, and SAE5160-825-QT. when using the loading sequences is predominantly tensile in the nature; the life of mounting in Goodman approach is more conservative. When the loading is predominantly tensile in nature, the life of the component in Morrow approach is more sensitive and is therefore recommended. It can be concluded that material SAE 1045-595-QT gives constantly higher life than material SAE5160-825-QT SAE1045-450-QT for all loading conditions under both methods.

In workplaces, phone calls constitute a very common way of communication. However, the callee typically has no means to know what the caller wants to talk about. This can be counterproductive if the callee is busy performing a task that is more important and/ or urgent than the conversation that is about to be initiated by the caller. The present article addresses this issue and comes up with a new enhanced communication service. First, a communication model based on speech acts is proposed. Speech acts are used by the caller to indicate the call intention or subject to the callee in the most clear and unambiguous possible way. Then, an Internet telephony implementation of the speech acts-based model is designed to fit the Session Initiation Protocol (SIP). The solution is validated through a case study.

In this paper, three phase four wire active power filter is proposed to eliminate harmonic currents both in the phases and in the neutral conductor of un unbalanced three-phase four wire electrical distribution system, feeding three single non-linear loads. A new method for identifying reference currents will be developed. It is based on pq theory using two improvements: multi-variable filter having the advantage of extracting harmonic voltages directly from the  axis and the second improvement consists on the use of fuzzy logic controller to extract current harmonics components. A comparison between classical method and the new approach has been illustrated in order to find the best way to reduce network harmonic currents. The Matlab numerical code is used for all simulations in this paper.

CONTEXT- Offshore software development outsourcing (OSDO) is an emerging business approach adopted by many software development organisations in developed countries. There are many motivations for developing software at offshore locations including access to large labor pool, low development cost, high quality and round-the-clock development. However, in spite of these motivations OSDO presents a variety of challenges to the software development organisations including temporal, geographical and intercultural differences. Intercultural differences cause many relationship problems between vendors and client organisations in OSDO. OBJECTIVES- This research seeks to identify the potential intercultural challenges faced by vendor organisations in OSDO relationships by reviewing the literature in a systematic way. METHODOLOGY- We have developed a systematic literature review (SLR) protocol, and are in the process of implementing the protocol. SLR is based on a structured protocol, and is therefore, different from ordinary literature review. SLR provides in-depth and more thorough results than ordinary literature review.SLR finding will be validated using case study method in different outsourcing industries. EXPECTED OUTCOMES- The expected outcomes of this review will be the identification of intercultural challenges or barriers faced by vendor organisations in the establishment and maintenance of OSDO relationships. The final outcome of this research is to develop an Intercultural Challenges Mitigation Model (ICCMM).