Earticle

This paper has investigated the harmful effects of Gamma irradiation on fiber communication system links under thermal environment effects over wide range of the operating parameters. Both the ambient temperature and the irradiation dose possess sever effects on the system transmission link characteristics and consequently the performance characteristics of optical communication systems. As well as we have deeply developed the modelling basics of transmission communication systems, which may be used to analyzed the total dispersion for first and second orders, system rise time, 3-dB bandwidth, transmitted signal bandwidth, transmission bit rates and products using different transmission techniques of these irradiated optical transmission communication systems after different irradiation fluences.

The initial release of LTE provided extensive support for deployment in spectrum allocations of various characteristics, with bandwidth ranging roughly from 1.3 MHz up to 20 MHz in both paired and unpaired bands. In LTE release 10 the transmission bandwidth can be further extended by means of so-called Carrier Aggregation (CA), where multiple component carriers are aggregated and jointly used for transmission to/from a single terminal. There are up to five component carriers, possibly each of different bandwidth, which can be aggregated, allowing for transmission bandwidth up to 100 MHz backwards compatibility where, each component carrier (CC) uses the release-8 structure. Hence, to a release-8/9 terminal, each CC will appear as an LTE release-8 carrier, while a carrier-aggregation capable terminal can exploit the total aggregated bandwidth, enabling higher data rates. In general case, a different number of component carriers can be aggregated for the downlink and uplink. Therefore, this paper highlights the carrier aggregation which supports the inter-band aggregation contiguous component carriers, intra-band aggregation non-contiguous component carriers and inter-band aggregation. This paper also presents the enhancement of LTE spectrum flexibility through carrier aggregation, further extension of multi-antenna transmission and provision of improvements in the area of inter-cell interference coordination in heterogeneous network deployments.

In this paper the concept of hyperfuzzy set is introduced and thereafter we define hyperfuzzy subgroup and a few of its properties are discussed. Also we define hyperfuzzy cosets and hyperfuzzy normal subgroup and study a few of their properties.

The Handover is one of the key subjects in maintaining the quality of service offered by non-geostationary constellation systems. As the satellite coverage moves according to the satellite motion, the continuity of a call must be maintained from one satellite to another. In case of the Handover fails, the call is dropped, resulting in a quality degradation of service. In this paper, the performance of several channel assignment strategies for a LEO satellite constellation is evaluated. The FCA method is considered where its advantages and disadvantages are highlighted. Moreover, the Handover process implication in the call blocking probability is assessed via simulation. Strategies able to cope with the high number of Handovers, due to the high speed of the satellites, without affecting strongly the capacity of the system are investigated. Simulation models have been developed to implement all the features evaluated in this paper including the mobility model. An analytical description and interpretation of results are also presented.

This paper presents a method to transfer voice message through SMS in GSM network with and without using compression technique and then their results are compared. Generally, SMS is not used to transfer voice because it doesn’t have high bandwidth data service like GPRS, EDGE, and HSDPA. In this paper two approaches are used to transfer voice through SMS. Firstly, voice message is transferred without using compression technique, Secondly; Prediction by Partial Matching (PPM) technique is used to compress payload text of SMS. Major functionality of the algorithm is to convert voice message in to characters, than apply compression method on those characters. Finally, set those compressed characters as a payload text of SMS, and transmit it over GSM Network. For testing the proposed method an application is developed using J2ME language. We test our application on Nokia N95 with different voice messages up to 360 times.

1:1 and 2:1 adducts of trimethylgallium (TMGa) with 4-dimethylaminopyridine (DMAP) were synthesized and characterized by 1H, 13C NMR, FAB-MS and Trace elemental analyses using ICP-MS. Both adducts are non-pyrophoric, thermally dissociable and easy to handle. FAB-MS study suggests that the adducts are associated in tetrameric forms. TMGa of purity more than 99.999% (5N) was released from these adducts, which shows the adducts are potential candidates to produce high pure metal alkyl sources for Metal-Organic Chemical Vapor Deposition (MOCVD).

Image registration refers to finding a geometrical transformation that correspond any point from one image to its homologous on the other image. There are several similarity measures that are classified in two groups based on features and intensity. In medical imaging, accuracy of registration algorithm is important. Since intensity-based methods, are more accurate than feature based ones, we select intensity-based registration; But intensity based methods usually need to global or local similarity measure optimization. Due to large search space, global methods optimization is time-consuming and when image irregularities are large, local methods cannot reach to an optimum amount. Despite these challenges, we found that learning based methods can be an appropriate policy to overcome these problems. Accordingly, in this paper, instead of using a fixed similarity measure, learning based similarity measure methods will present. Using the presented approaches in this paper can have been an effective role in analyzing and evaluating multi modal medical image registration and will increase three main functional measures – accuracy, speed and robustness – in medical image registration.

In this paper, we made a comprehensive study to evaluate the performance of a multi antenna supported multi carrier Code Division Multiple Access (MC-CDMA) system on color image transmission. The 2-by-2 spatially multiplexed ½-rated Convolutinally encoded MC-CDMA system under investigation implements three linear signal detection techniques (Equalizers) such as Minimum Mean Square Error (MMSE), Zero Forcing (ZF) and Sphere Decoding (SD) under BPSK, DPSK, QPSK and QAM digital modulations. The simulation results elucidate that a significant improvement of system performance is achieved in BPSK modulation with MMSE based signal detection scheme under AWGN and Rayleigh fading channels. The results are also indicative of noticeable reduction of BER performance with increase in order of digital modulation and noise power as compared to signal power.

In this paper we present a novel container ISO-code recognition method which uses vertical edge information, a spatial structure window, and texture clustering. The vertical edge information is extracted using a top-hat transform. The candidate region and type of ISO-Code is obtained using a Spatial Structure Window (SSW) which wraps around the vertical edges. The ISO-Code is extracted using texture clustering by the K-Means algorithm which is then recognized by a Back-propagation Neural Network (BP). Experiments confirmed the robustness of the recognition algorithm on real images and videos.