Earticle

The designs of dual band microstrip patch antennas because of their multi-functionality are becoming popular. Satellite mobile and fixed communication for Space Research, Met. Satellite, Radiolocation, Meteorological aids, aeronautical Radio navigation data and analysis has got lot of attentions in the recent years. Achieving selected multiband operation requires precise bandwidth and mutually exclusive resonating bands. Several designs with a bit modification in the basic design are proposed by placement of appropriate slots to achieve multi-band functionality in this paper. Proposed design deals with the four slot patch antenna that can control dual band operation in the range of 1.5 GHz - 2.5 GHz and 6 GHz - 10 GHz. Stable radiation patterns for the whole frequency range and for all the applications are achieved. Wide band impedance matching is achieved through slot dimension variations near feed line. Mathematical model for the resonant frequency as a function of dimensions of the slots is also proposed in the paper.

The importance of social network analysis has become more remarkable in recent years. The social network researches which focus on the behavior of users propagating messages have been growing in recent years. Besides, most of the researches of influence evaluation in the past focused on the behavior of propagating between users, instead of considering the behavior of propagating between different social communities. Hence, this research provides a system to evaluate the pattern of propagating messages. The information propagation, however, can take place at different levels of social groups-among individuals and among groups or communities. Adapting from a generalized suffix tree, our proposed methodology can be constructed to form a framework for querying various kinds of related propagation effects, and the effects can be observed corresponding to different levels of granularities of social communities.

It is very important to achieve high performance in the SC-FDMA (single carrier frequency division multiple access) system that is used for LTE (long term evolution) and LTE-advanced system. To simultaneously resolve ICI(inter-subcarrier interference) and PAPR(peak to average power ratio) problem, focused on the two transmit(Tx) / one receive(Rx) antenna configuration, phase noise influence on the 2 1 SFBC(space frequency block coding) SC-FDMA system is first analyzed, then compared with MISO(multiple input single output) SC-FDMA using several selected ICI self-cancellation methods. SC-FDMA induces more interference problem than OFDM because of the DFT spreading phase offset mismatch caused by random phase noise. By using ICI self-cancellation methods, the system performance significantly improves only by simple data encoding. Simulation results show that in the SFBC SC-FDMA system, the ICI and SCI interference cannot be neglected because 2  1 SFBC SC-FDMA even make phase noise influence seriously due to the simultaneous generation of more SCI and ICI than 2  1 SC-FDMA only, so, interference compensation is necessary. It is found that 2  1 SC-FDMA with data-conjugate ICI selfcancellation method and 2 1 SC-FDMA with symmetric ICI self-cancellation method can achieve considerable performance improvement than 2 1 SFBC SC-FDMA system, besides, data-conjugate method is superior to the symmetric data-conjugate method.

Since solar, wind and tidal energies mainly depend upon statistical parameters with respect to changing climate and environment, focus on hybrid generation system design increases the availability of the power generation system. The hybrid system also reduces the dependence on one environment parameter thus providing the consumer with reliable and cheap electricity. Therefore optimal combination and sizing design of hybrid generation system considering the battery has a very important role in the use of renewable energy effectively and economically. Several approaches were developed to achieve the optimal configurations of the hybrid systems such as the least square method, the trade-off method and the probabilistic approach method. This study presents a method to design the optimal combination and unit sizing for new and renewable hybrid systems. The method is to find the optimal configuration and sizing among sets of system components, that meets the desired system requirements, with the lowest value of the energy cost. The availability of the methodology is demonstrated with the field data acquired from sets of experiments.

In this paper, we introduce a new method to represent, discover and share context information in a mobile ad hoc networking environment. The structure of the context information has been defined in a repository structure called CiB. The context information is manipulated to implement context exchange via a communication protocol. The protocol has been simulated in NS-2, where high discovery success and efficient bandwidth consumption have been depicted.

A Cloud database management system is a distributed database that delivers computing as a service instead of a product. It is the sharing of resources, software, and nformation between multiple devices over a network which is mostly the internet. It is expected that this number will grow significantly in the future. As a result, there is a growing interest in outsourcing database management tasks to third parties that can provide these tasks for much lower cost due to the economy of scale just like putting it into the cloud. In this paper, we discuss the recent trend in database management system and the possibilities of making it as one of the services offered in the cloud. We also proposed an architecture of database management system in the cloud.

In this paper, we propose a local adaptive transmission power control method to improve the network connectivity and energy efficiency etc. for wireless sensor networks. Path loss exponent and energy control coefficient are studied carefully to show the minimum cover district of each node more accurately based on network environment and the application scenarios. Our proposed local adaptive power control method can also provide self-healing function which makes the network maintain the best performance for a long time when a few nodes exhaust their energy or a fresh batch of nodes are deployed. Simulation results show that our proposed method is very effective in establishing a good logical network structure and prolonging the network lifetime.

Wireless Sensor Network (WSN) is most important present minimizing energy consumption. Among various clustering methods, the Low-Energy Adaptive Clustering Hierarchy (LEACH) mechanism takes the hierarchical approach of segmenting multiple clusters for efficient energy management. The mechanism, however, configures new clusters in every round, so the energy consumed whenever configuring clusters shortens the useful lifetime of the entire network. For this reason, this paper generates clusters and selects candidate cluster head (CCH) in the initial round under the sensor network environment. Subsequent rounds continue, without performing re-clustering, until all candidate cluster heads selected become cluster head (CH), thereby addressing the issue of energy consumption in the setup phase for clustering. The proposed model consumes around 30% more energy than the conventional LEACH in the initial round, but its total energy consumption declines in as the round continues. The network simulation tool (NS-2) proves that its energy efficiency improves by up to 13.3% in the 1,000-node environment compared to when 100 sensor nodes are employed.

In this paper, an intelligent buffer management for packet scheduling algorithm in multihop wireless LANs has been proposed. In the recommended scheme, the mechanism of adaptive scheme will be integrated with a queue scheduler, as an effort to enhance the performance of the packet scheduling. The modus operandi of the strategy is intelligently identified the buffer and route based on the intended server’s availability. By doing so, it has been shown that the problem of packet loss has been successfully avoided. When simulated, the proposed scheme has demonstrated better achievement in per-flow fairness compared to FIFO and max-min algorithm.

Wireless ad hoc network is most important present minimizing energy consumption. Among various clustering methods, the low-energy adaptive clustering hierarchy (LEACH) mechanism takes the hierarchical approach of segmenting multiple clusters for efficient energy management. The mechanism, however, configures new clusters in every round, so the energy consumed whenever configuring clusters shortens the useful lifetime of the entire network. For this reason, this paper generates clusters and selects candidate cluster head (CCH) in the initial round under the ad-hoc network environment. Subsequent rounds continue, without performing re-clustering, until all of the candidate cluster heads selected become cluster head (CH), thereby addressing the issue of energy consumption in the setup phase for clustering. The proposed model consumes around 30% more energy than the conventional LEACH in the initial round, but its total energy consumption declines in as the round continues. The network simulation tool (NS-2) proves that its energy efficiency improves by up to 13.3% in the 1,000-node environment compared to when 100 sink nodes are employed.

NetFPGA is a hardware board that it is becoming increasingly popular in various research areas. It is a hardware customizable router and it can be used to study, implement and test new protocols and techniques directly in hardware. It allows researchers to experience a more real experiment environment. In this paper we present a work about the design and development of four new modules built on top of the NetFPGA Reference Router design. In particular, they compute the input and output bit rate run time and provide an estimation of the input bit rate based on an EWMA lter. Moreover we extended the rate limiter module which is embedded within the output queues in order to test our improved Reference Router. Along the paper we explain in detail each module as far as the architecture and the implementation are concerned. Furthermore, we created a testing environment which show the eectiveness and eciency of our modules.