In this paper, we explore the bifurcation analysis of a discrete-time predator-prey model in the interior of R_+^2. It is investigated that model has two boundary equilibria: O(0,0),A(1,0) and the unique positive equilibrium point B(r/(a+r),r/(a+r)). We studied the topological classification about equlibria: O(0,0),A(1,0) and B(r/(a+r),r/(a+r)) of the discrete-time model by utilizing method of Linearization. It is investigated that about A(1,0), predator population become extinction while prey undergoes a period-doubling bifurcation to chaos by taking r as bifurcation parameter. It is also investigated that model undergoes a Neimark-Sacker bifurcation in a small nbhd of B(r/(a+r),r/(a+r)) and in the meantime closed stable curve appears. In the perspective of biology, these curves correspond to periodic or quasi-periodic oscillations between predator and prey populations. Finally theoretical results are verified numerically.

One of the most easily accessible renewable energy resources, Palm Oil Residues: POR from palm oil production can be burned in the grate- fired furnace to provide electricity and heat to supply the plant. However, grate-firing is yet to be further developed towards a better technology for POR combustion, particularly higher efficiency, lower emissions and better reliability and availability. To better understand detail knowledge of grate-firing of POR and to establish a mathematical and CFD modeling methodology. This study, mathematical and CFD modeling methods have been employed to simulate the operation of a 37 MW POR burning power plant to obtain detailed information on the flow and combustion characteristics in the furnace and predict the effect of operating conditions. The modelling predicted results are compared with in-flame measurement and flue gas emission in the 37 MW boiler, which shows an acceptable agreement. However, the discrepancies between the simulation results and the measurements are observed. It is mainly because the boundary conditions used in the model could be different from those in the real grate-fired furnace. For instance, the dis-continuous POR feeding, the combustion instabilities inside the packed bed, and the irregular deposit formed on the furnace walls and air nozzles all make it difficult to derive the boundary conditions that the CFD modeling requires. Anyway, the gained knowledge from this case study are summarized and discussed in detail which can facilitate the modeling validation efforts as well as improve grate-fired furnace.

This paper originally proposes a photovoltaic (PV) array model for PV system with commercial PV modules. This novel PV array model was hierarchically developed by directly calling one of the built-in PV models that have well-verified accuracy and sufficient confidence. Based on both thermal and electrical characteristics of commercial PV modules available from the manufacturer datasheet, the hierarchical PV model for commercial PV modules is implemented in the MATLAB/Simulink environment. Both rear-surface temperatures and electrical characteristics of a commercially available PV array are evaluated through in-the-field experiments where not only weather conditions but PV operating parameters can be acquired by a LabVIEW-based measurement system. Comparing to the experimental results, the proposed PV array model is validated and the results illustrate a close agreement between simulation and measurement. This work features the hierarchical development of PV model for commercial PV devices with sufficient accuracy confidence.

Mobile communication has become fundamental for the human life; there is a thriving in the developed technologies. So, the operators are facing a lot of problems for the best uses of the different radio access technology (RATs) that they may have. In this paper, RAT selection algorithm based on four different Radio Access Technologies (RATs).These technologies coexist, namely [UMTS and LTE with Omni directional Antenna, GSM with three sectors and DCS with three sectors. Voice and data application are considered in the heterogeneous wireless networks.sumulation results show the improvement of the whole capacity, Qos and decreases the percentage of UN served users after applying the Proposed Model. For common propagation model (free space). The paper is done via Mat lab tool which will be built based on a random distribution of the customer

Data hiding is hiding the confidential information into the digital medium like image, audio, video etc. Data hidden in these mediums cannot be determined by human visual perception. To retrieve back this confidential information and cover image used, we have to do Reversible Data Hiding (RDH). Through Reversible Data Hiding the original cover image is recovered after the message is extracted. The qualities of Reversible Data Hiding are measured by Peak Signal to Noise Ratio (PSNR), image quality, reversibility of both image and data, and data embedding capacity. Presently there are many different Reversible Data Hiding methods proposed. But the fact is that they have to compromise with any of these quality determining factors. Our proposed method improves all the quality measurements. The ultimate aim of our proposed method is to enhance the data embedding capacity and to keep the PSNR value above 48 dB. It works with peak pairs; select 2 pairs of the peak values from the histogram generated from the cover image and hide our data in the peak pairs. The data capacity of our method is enhanced by performing XOR operation. In XOR operation we create a duplicate peak pixel value, or in other terms it is limiting the gray scale values in the cover image. This embedding process is repeated number of times in order to improve the data capacity. The contrast enhancement is obtained by performing histogram equalization along with data hiding. The experiment shows the proposed method worked well in all the measures. This method is tested with normal, aerial and medical images and we obtained good result in all these different image sets.