Welcome to Journal of Theoretical and Applied Information Technology

Author:

Source:

Abstract

The term Distributed Systems is used to describe a system with the following characteristics: i) it consists of several computers that do not share memory or a clock, ii) the computers communicate with each other by exchanging messages over a communication network, iii) each computer has its own memory and runs its own operating system. In the mobile distributed system, some of the processes are running on mobile hosts (MHs).A checkpoint algorithm for mobile computing systems needs to handle many new issues like: mobility, low bandwidth of wireless channels, and lack of stable storage on mobile nodes, disconnections, limited battery power and high failure rate of mobile nodes. These issues make traditional checkpointing techniques unsuitable for such environments. Minimum-process coordinated checkpointing is an attractive approach to introduce fault tolerance in mobile distributed systems transparently. In this paper, we propose a minimum-process coordinated checkpointing algorithm for deterministic mobile distributed systems, where no useless checkpoints are taken, no blocking of processes takes place, and anti-messages of very few messages are logged during checkpointing. We try to reduce the loss of checkpointing effort when any process fails to take its checkpoint in coordination with others.

Checkpointing algorithm, Mobile computing, Distributed Mobile systems

 Full Text

Author:

M. BELGHACHI, M. FEHAM

Source:

Abstract

The technology "sensor networks" is currently training an emerging area of research and has been the subject of numerous studies in recent years. The wireless sensor networks (WSNs) raises fundamental problems for the scientific community. These problems, in addition to the problems encountered in ad hoc networks classics, are due to wireless communications, the density distribution of nodes, the constraints of resources (energy, processor, and memory), the low reliability of nodes, and the highly distributed nature of the application and supported the mobility of nodes. These features specific to sensor networks systems are unreliable and whose behaviour is hardly predictable.
Currently, sensors equipped with cameras have emerged which will undoubtedly strengthen the monitoring application in all areas. However, applications of multimedia transport in WSNs are in embryonic stage and very little work has been done so far. A multimedia stream is characterized primarily by its needs delivered in terms of bandwidth, a scarce resource in WSNs.
The rapid development of multimedia technology and the commercial interest of companies to popularize this type of application, the quality of service (QoS) a sector of great importance. In addition, ensure QoS in such networks is very delicate. However, the unexpected change of topology may affect the continuity of service and makes it extremely difficult if not impossible. It is therefore legitimate to consider the reliability of roads as the main constraint on QoS to be considered for the transmission of video streams. The mission of routing is to determine the best path between the source and destination in the network according to a certain performance criterion.
This article presents a solution that allows to extend the protocol AODV (AODV: Ad hoc On-demand Distance Vector) to ensure the quality of service in terms of bandwidth for the transmission of video streams. The improvement we make is to define a function that maximizes the chances of selecting the road more easily repairable and therefore whose deadlines reconstruction will lowest since involve a re-routing local. In this decision-making phase, we seek to maximize the parameters contained in messages connection request reached the destination. These parameters are, for each route, the number of nodes involved the average density and the number of bottlenecks. But use of these data is not obvious.
In this context, we must choose the road with the following characteristics:
-- The number of nodes lowest.
-- The average density strongest possible.
-- The number of bottlenecks lowest.
A road is even more difficult to repair a partial re-routing it involves long chains of nodes around which the density is low. A topology which contains such sequences is regarded as somewhat interesting because its maintenance is complicated. The local re-routing in case of failure of a node on these roads will be carried not effective. It will therefore more often carry out a re-routing more greedy in time and bandwidth that a local re-routing.

 WSNs; Flow multimedia; AODV; global Re-routing; partial Re-routing; Density; availability; bandwidth estimate; road Notation.

Author:

Source:

Abstract

Cell phones are the perfect way to stay connected with other and provide the user with a sense of security. However, the importance of cell phone goes way beyond personal safety. Modem cell phones are capable of internet access, sending and receiving photos and files, and some cell phones are equipped with GPS technology, allowing for use the most locations around the world and allowing the cell phone to be found or the user located in the event of loss or emergency.
This research focuses on the establishment of rules and basic foundations for imaging the car plate number by using a set of different types of Mobil phones.
Also this research can cent rates on provide the foundations in image transmission between the phones. The type of the used phone will be determined and used as a sender and receiver depending on the transmitted image size. The image will be send to the main computer for processing.

Plate Image, Mobil Phone, Image Rules, Car Number, Image Size.

Author:

Source:

Abstract

Images are often received in defective conditions due to poor scanning and transmitting devices. Consequently, it creates problems for the subsequent process to read and understand such images. This paper presents a novel recursive intelligent approach based on cellular neural network (CNN) to denoise an image even in the presence of very high ratio of noise. Image denoising is devised as a regression problem between the noise and signals; finally, it is solved using CNN. Accordingly, noises are detected with surrounding information and are removed. Initial experiments show that proposed approach could achieve a higher peak signal-to-noise ratio (PSNR) on images. The proposed algorithm exhibits promising results from quantitatively and qualitatively points of view.

Image denoising, wavelet, parameter selection, CNN, PSNR

Author:

Source:

Abstract

Governments and public sector organizations around the world are facing to reform their public administration organizations and deliver more efficient and cost effective services, as well as better information and knowledge to their stakeholders. E-governance is the effective use of Information & Communication Technology (ICT) to improve the system of governance that is in place, and thus provide better services to the Citizens. e-Governance is considered as a high priority agenda in India, as it is considered to be the only means of taking IT to the �Common Public�. Developments in e-Governance provide opportunities to harness the power of Information and Communication Technology (ICT) to make the business of governance inexpensive, qualitatively responsive, and truly encompassing. In this paper we discuss about the basic problems and acceptability of e-Governance in India.

ICT, e-Governance, accountability, acceptability

Author:

Source:

Abstract

This paper present a new computationally efficient improved stochastic algorithm for solving multi-area DC Optimal Power Flow (DC-OPF) in interconnected power systems. This algorithm is based on the combined application of Fuzzy Logic strategy incorporated in Particle Swarm Optimization (PSO) algorithm, hence termed as Fuzzy PSO (FPSO). Multi-area DC-OPF calculations determine optimum generation schedule, optimal control variables and system quantities of each area with due consideration of generation and transmission system limitations for efficient power system operation. The proposed method is tested on IEEE 30-bus interconnected three area system. The investigation reveals that the proposed method can provide accurate solution with fast convergence and has the potential to be applied to other power engineering problems.

DC-Optimal Power Flow, Fuzzy Logic, Particle Swarm Optimization

Author:

Source:

Abstract

Extracting three-dimensional objects from volume data, with previous techniques, were based on stitching a series of two-dimensional contours together or connecting two-dimensional contours using surface interpolation. Deformable simplex meshes DSM proposes an original surface representation to recover 3D object boundaries and treats data set as a complete volume as opposed to a series of slices. However, it requires that object of interest has been previously isolated from the other objects and the result of reconstruction depends on the interaction process between segmentation and interpolation. Moreover, as like as deformable models, it reveal poor convergence to concave boundaries and require initialization.
In this paper, we propose to solve the problem resulting from the internal force formulation by adding a balloon force. Then, we combine the improved deformable simplex meshes (DSM-Balloon) with watershed method. The segmentation strategy is to use the segmentation result of watershed as prior information for DSM-Balloon. On one hand, the watershed prepares the initial lines for the DSM-Balloon which ensures automatic initialization and simplex meshes convergence. On other hand, the result of DSM-Balloon will overcome the over-segmentation and smoothing problem of watershed.

hybrid reconstruction, deformable simplex meshes, watershed, balloon force, 3D medical objects

Author:

Source:

Abstract

Multi Carrier Code Division Multiple Access (MC-CDMA), a promising technology for the 4G communication systems is considered in this paper. The foremost limitation of such system is the Multiple Access Interference (MAI) which is due to frequency-selective fading, near-far effect, frequency offset, and nonlinear power amplification. The performance of MC-CDMA under such scenario is poor and optimal detection is one of the solutions with a high complexity tag attached. Use of global optimization for such detectors, especially using Global Search algorithm is considered in this paper. The Bit Error Rate (BER) performance analysis is performed for frequency fading channels with and without non linear distortion.

MC-CDMA system, Multi User Detectors, Clipping Noise, Rayleigh fading channel,
Global search algorithm

Author:

Source:

Abstract

The introduction of flexible AC transmission system (FACTS) in a power system improves the stability, reduces the losses, reduces the cost of generation and also improves the loadability of the system. In the proposed work, a non-traditional optimization technique, genetic algorithm is used to optimize the various process parameters involved in introduction of FACTS devices in a power system. The various parameters taken into consideration were the location of the device, their type, and their rated value of the devices. The simulation was performed on a 30-bus power system with various types of FACTS controllers, modeled for steady state studies. The optimization results clearly indicate that introduction of FACTS devices in a right location increases the loadability of the system and genetic algorithm can be effectively used for this kind of optimization.

Genetic Algorithm, Optimization, loadability, FACTS, optimal power flow.

Author:

Source:

Abstract

Service-Oriented Applications are being regarded as the main practical solution for distributed environments. In such systems, though each service is able to response the user request independently, it is essential to compose them for supplying a compound value-added service enable us to address the complex requests. Since, there may be a number of compositions to providing the requested service, it is so important to find one whose properties are close to user�s desires. In this paper, a new approach for evaluating the service compositions is presented which attempts to obtain the user desires. This approach uses fuzzy logic to infer on the basis of quality measures ranked by user.

Web service, service composition, Quality of Service (QoS), user preferences, fuzzy logic