A numerical study of unsteady hydromagnetic flow of Casson liquid passed through the oscillatory ... more A numerical study of unsteady hydromagnetic flow of Casson liquid passed through the oscillatory moving surface is presented. The interaction of radiation term is reported in the energy equation. The flow is generated by the rapid move?ment of elastic surface that stretched back and forth periodically. The number of variables is reduced by introducing dimensionless variables. An implicit technique developed on finite difference algorithm is implemented to the system of PDE. The impact of various parameters like Casson liquid parameter, the oscillation frequency and stretching rate ratio, Hartmann number and effective Prandtl number are shown through various graphs. The observation indicates that the amplitude of the velocity declines by enhancing Casson liquid parameter, oscillation frequency and stretching rate ratio and Hartmann number. The temperature declines by increasing Casson fluid parameter and effective Prandtl number. The results also indicate that the time-series of loca...
The study sought to examine the timber dependency on forests and evolve wasteland reclamation str... more The study sought to examine the timber dependency on forests and evolve wasteland reclamation strategy to eliminate the forest dependency in Bundu block of Ranchi District in Jharkhand, India. Multi-stage random sampling technique was applied to select 164 tribal households from 9 sample villages. Data were collected using structured interviews and non-participant observations which were analyzed using descriptive statistics viz., frequency, percentage, mean and range. Results revealed that forests contributed maximum timber (136.36 m3 annum-1) followed by traditional agroforestry (69.09 m3 annum-1), community forestry (41.33 m3 annum-1) and homestead forestry (35.71 m3 annum-1). Timber extracted is mostly consumed in housing (124.66 m3 annum-1) followed by agricultural implements (82.71 m3 annum-1), furniture (35.25 m3 annum-1), carts/ carriages (17.60 m3 annum-1), fencing (10.23 m3 annum-1), cattle shed/ store house (9.10 m3 annum-1) and others (2.94 m3 annum-1). Forests were expo...
SPECTRUM SCHEDULING: THE KEY FACTOR FOR MAXIMUM THROUGHPUT AND OPTIMAL RESOURCE UTILIZATION IN COGNITIVE RADIO NETWORK. Institute of Communication Networks and satellite Communications
Radio spectrum is the most valuable resource in wireless communication. The cognitive radio and c... more Radio spectrum is the most valuable resource in wireless communication. The cognitive radio and cognitive based networking are transforming the static spectrum allocation based communication systems in to dynamic spectrum allocation. Cognitive radios are intelligent devices with ability to sense environmental conditions and can change its parameters according to the requirements to get the optimized performance at the individual nodes or at network level. This paper covers the basics and origin of software defined radio, cognitive radio, cognitive radio network, cognitive cycle, performance metrics and the concept of cross layer design. The performance metrics explain the node and network level performance measurements. This paper also covers the different network paradigms.
The idea of software defined radio was proposed by J. Mittola. It was a radio designed on program... more The idea of software defined radio was proposed by J. Mittola. It was a radio designed on programmable chips. The idea of SDR was further enhanced in the form of Cognitive radios. It was proposed by the J.Mittola for the solution of the Spectrum Scarcity problem. Cognitive Radio based networks have the two types of users. One type of the users is known as primary users and the other are known as the secondary users. The Primary users are licensed users and the secondary users are the cognitive users(unlicensed) users .The Primary users have the priority of spectrum usage .While the cognitive user have the opportunistic nature of the spectrum usage . Cognitive user can use the primary user's frequency when the spectrum holes (primary user is not communicating) are available. There are many signal processing operations in the background of the Cognitive Radios. One of these operations is the Spectrum sensing. Signal detection theory is used for the separation and recognition of in...
Load imbalance, together with inefficient utilization of system resource, constitute major factor... more Load imbalance, together with inefficient utilization of system resource, constitute major factors responsible for poor overall performance in Long Term Evolution (LTE) network. In this paper, a novel scheme of joint dynamic resource allocation and load balancing is proposed to achieve a balanced performance improvement in 3rd Generation Partnership Project (3GPP) LTE Self-Organizing Networks (SON). The new method which aims at maximizing network resource efficiency subject to intercell interference and intra-cell resource constraints is implemented in two steps. In the first step, an efficient resource allocation, including user scheduling and power assignment, is conducted in a distributed manner to serve as many users in the whole network as possible. In the second step, based on the resource allocation scheme, the optimization objective namely network resource efficiency can be calculated and load balancing is implemented by switching the user that can maximize the objective function. Lagrange Multipliers method and heuristic algorithm are used to resolve the formulated optimization problem. Simulation results show that our algorithm achieves better performance in terms of user throughput, fairness, load balancing index and unsatisfied user number compared with the traditional approach which takes resource allocation and load balancing into account, respectively.
Frequency Analysis and Selection for Cognitive Radio using Fuzzy Logic System
The spectrum scarcity is a great challenge in the future development of wireless communication de... more The spectrum scarcity is a great challenge in the future development of wireless communication devices. The idea of Cognitive radio was proposed for the solution of this problem. The research work presented in this paper addresses the Frequency Analysis and Selection for Cognitive Radio (CR) using Fuzzy logic based Adaptive Control System. Fuzzy logic controller FLC is designed for this purpose to optimize the use of available radiofrequency (RF) spectrum resources while minimizing the chances of interference due to primary users. The FLC is used to deal with the incompleteness, uncertainty and heterogeneity of a cognitive radio scenario. Two cascaded fuzzy logic controllers are used. The first fuzzy inference system takes four inputs i.e. environment condition, distance between primary user and the secondary user, speed of secondary user and signal power received at SU (Psu). The only one output of FLC-1 is Psu, which is the signal power of secondary user (SU). The second fuzzy inference system FLC-2 will take four inputs i.e. transmission power of SU (Psu), signal to noise ratio (SNRpu), used frequency spectrum and duration of used frequency. The result of FLC-2 is appeared in the form of available frequency hole.
A study was carried out in district Samba of Western Himalayan province of Jammu and Kashmir of I... more A study was carried out in district Samba of Western Himalayan province of Jammu and Kashmir of India. The data were collected in an interview schedule in personal interview with 180 household heads. The association between the level of fuelwood consumption (low versus high consumption) and different factors, each individually, was investigated using chi-square test of association at 0.001 level of significance. It was found that out of 25 socioeconomic , biophysical and alternate fuel factors, 15 factors (each individually) significantly influenced the domestic fuelwood consumption. Logistic regression models of alternate fuel use, social, economic and biophysical factors were developed to identify key variables influencing fuelwood consumption levels within each respective category. A composite model was also developed to identify key factors when all variables in all the pre-said categories were considered simultaneously. Surprisingly, in contrast to expectation the model with alternate fuel use did not provide a good fit. The biophysical model also did not provide a good fit. The economic and composite models were the same with equal level of accuracy of predication. This implies that economic aspects, rather than the availability of alternate fuels, dominate fuelwood consumption levels of rural households. Strategies to increase the exposure of the head of household to outside world needs to formulated to reduce the domestic fuelwood consumption levels. Households nearer to state forests are to be educated about efficient use of fuelwood and be encouraged to intensify use of Liquified Petroleum Gas. The wider implications of study are: the availability of alternate fuels is not a necessary condition to decrease household level domestic fuelwood consumption. Economic factors needs to be considered in designing strategies to reduce fuelwood consumption. Increased employment opportunities would increase the opportunity cost of fuelwood collection and this would reduce its use.
An overview of spectrum sensing in cognitive RADAR systems
2014 IEEE Microwaves, Radar and Remote Sensing Symposium (MRRS), 2014
The spectrum scarcity problem is occurred due to static allocation of the spectrum and increasing... more The spectrum scarcity problem is occurred due to static allocation of the spectrum and increasing no of applications of the wireless communication. The same problem occurs in the field of radar communication. The solution of the said problem is a cognitive radio. The cognitive radio works on the on the principle of dynamic access. The essential part of the dynamic access is the spectrum sensing. In this paper an overview of the spectrum sensing techniques in Cognitive RADAR is given available in open literature. These techniques will help in the development of self-aware, environment aware RADAR systems which can adapt the target variations in a real time within a short interval of time.
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