Design of a cell selection mechanism to mitigate interference for cell-edge macro users in femto-macro heterogeneous network

The Femto-Macro heterogeneous network is a promising solution to improve the network capacity and coverage in mobile network. However interference may rise due to femtocell deployment nearby to macro user equipment (MUE) within macrocell network coverage. Femtocell offers main priority in resource allocation to its subscribed femto user equipment (FUE) rather than unsubscribed MUE. MUEs will suffer severe interference when they are placed near or within the femtocell area range especially at the cell edge. This phenomenon occurs due to the distance is far from its serving macro base station (MBS) to receive good signal strength. This paper presents a design of cell selection scheme for cell-edge MUE to select an optimal femto base station (FBS) as its primary serving cell in physical resource block allocation. In this study, the proposed cell selection consists of four main elements: measuring the closest FBS distance, Signal to Interference-plus-Noise-Ratio (SINR), physical resource block (PRB) availability and node density level for the selected base station. The main goal is to ensure cell-edge MUE has priority fairly with FUE in physical resource block allocation per user bandwidth demand to mitigate interference. Hence, the cell-edge MUE has good experienced on receiving an adequate user data rate to improve higher network throughput

Experimental study on transient response of fuel cell

This research work discusses a control strategy to enhance the transient response of the fuel cell and boost the real and reactive power flow from grid connected to fuel cell. The current output of the fuel cell depends on the availability of hydrogen in the fuel cell stack, a battery bank is implemented to supply the transient current and to prevent it from hydrogen saturation. The battery should only supply when there is a transient. During steady state the total power is produced by the fuel cell by regulating its hydrogen input. A prototype of the system will be created to study a control scheme which regulates the current from an input source and a battery which is connected to a dc motor. The control philosophy is based on d-q transformation and subsequently generating a reference signal that is tracked by an IGBT based inverter. The speed of the motor is controlled using pulse with modulation. The dynamic modeling of the standalone fuel cell that is connected to a dc motor is carried out using MATLAB/SIMULINK platform. The simulation results show that the control scheme works well, although the dynamic response of the system can be improved. The testing carried on the prototype proves that the concept works well, but a hydrogen control scheme should be developed to improve the efficiency of the control scheme

Performance of europium aluminium doped polymer optical waveguide amplifier

In this paper, the graded index (GI) multimode rare-earth metal (RE-M) doped polymer optical waveguide amplifier has been prepared and tested optically. A 10-cm Europium Aluminum Benzyl Methacrylate ( was fabricated via a unique technique known as the “Mosquito Method” which utilizes a micro-dispenser machine. Optical gain from 75 to 150 µm circular core diameter waveguide of 13 wt.% concentration has been demonstrated and measured under forward pumping condition. The cladding monomer deployed in this research is Acrylate resin XCL01, which is a modified photocurable acrylate material. Fundamentally, -30 decibel (dBm) red light signal input and 23 dBm pump power of 532 nm green laser wavelength is implemented within the range of 580 to 640 nm optical amplification wavelength. A maximum gain of 12.96 dB at 617 nm wavelength has been obtained for a 100 µm core diameter of Eu-Al polymer optical waveguide. The effect of different coupler diameter for pumping and the comparison of insertion loss before and after amplification against the performance of the Eu-Al polymer waveguide amplifier are also studied. There exists an optimum core diameter of which the amplifier gain enhancement is at maximum value

Modeling and simulation of three phases cascaded H-bridge grid-tied PV inverter

In this paper a control scheme for three phase seven level cascaded H-bridge inverter for grid tied PV system is presented. As power generation from PV depends on varing environmental conditions, for extractraction of maximum power from PV array, fuzzy MPPT controller is incorporated with each PV array. It gives fast and accurate response. To maintain the grid current sinusoidal under varying conditions, a digital PI controller scheme is adopted. A MATLAB/Simulink model is developed for this purpose and results are presented. At last THD analysis is carried out in order to validate the performance of the overall system. As discussed, with this control strategy the balanced grid current is obtained keeping THD values with in the specified range of IEEE-519 standard

Comparative study on the accelerated thermal aging behavior between palm and rapeseed natural ester oils

The suitability of natural ester oils as an insulating medium in power transformers is discussed in this paper. Owing to environmental concerns, natural ester oils have great potential as mineral oil substitutes in power transformers. In this paper, the aging behaviors of palm and rapeseed natural ester oils were compared with that for mineral oil. The performance of these natural ester oils was assessed based on their properties (moisture content, acidity, and relative content of dissolved decay products) after accelerated thermal aging. The results showed that the palm oil has better performance compared to the rapeseed oil after accelerated thermal aging for 1500 h because of its lower acidity. This was further supported by the presence of sludge in the rapeseed oil after 1500 h of aging

The disruptometer: an artificial intelligence algorithm for market insights

Social media data mining is rapidly developing to be a mainstream tool for marketing insights in today’s world, due to the abundance of data and often freely accessed information. In this paper, we propose a framework for market research purposes called the Disruptometer. The algorithm uses keywords to provide different types of market insights from data crawling. The preliminary algorithm data-mines information from Twitter and outputs 2 parameters-Product-to-Market Fit and Disruption Quotient, which is obtained from a brand’s customer value proposition, problem space, and incumbent space. The algorithm has been tested with a venture capitalist portfolio company and market research firm to show high correlated results. Out of 4 brand use cases, 3 obtained identical results with the analysts ‘studies

An efficient algorithm for monitoring virtual machines in clouds

Cloud computing systems consist of a pool of Virtual Machines (VMs), which are installed physically on the provider's set up. The main aim of the VMs is to offer the service to the end users. With the current increasing demand for the cloud VMs, there is always a huge requirement to secure the cloud systems. To keep these cloud systems secured, they need a continuous and a proper monitoring. For the purpose of monitoring, several algorithms are available with FVMs. FVM is a forensic virtual machine which monitors the threats among the VMs. Our formulated algorithm runs on FVM. In this paper, we formulate the Random-Start-Round-Robin algorithm for monitoring inside FVM

MM-PNEMO: a mathematical model to assess handoff delay and packet loss

Wireless networks incorporate Mobile Nodes (MNs) that use wireless access networks to communicate. However, the communication among these MNs are not remained stable due to the poor network coverage during inter mobility. Moreover, the wireless nodes are typically small that results in resource-constrained. Thus, it is uphill to use algorithms having giant processing power or memory footprint. Accordingly, it is essential to check schemes consistently to evaluate the performance within the probable application scenario. To do so, numerical analysis could be a notable method to grasp the performance of mobility management schemes as well as the constraint of evolving mobility management solutions specifically for multi-interfaced MR in Proxy NEMO environment. This paper analyzes handoff performance by using a mathematical model of Multihoming-based scheme to support Mobility management in Proxy NEMO (MM-PNEMO) environment. Moreover, a comparative study has been made among the standard Network Mobility Basic Support Protocol (NEMO BSP), Proxy NEMO (PNEMO) and MM-PNEMO scheme respectively. The performance metrics estimated for these schemes are mainly handoff delay and packet loss. This paper also analysed the packet loss ratio and handoff gain as a function of cell radius, number of SMR and velocity respectively. It is apparent that, the MM-PNEMO scheme shows lower packet loss ratio (1%) compared to NEMO-BSP (11%) and P-NEMO (6%)

Analysis of airborne dust effects on terrestrialmicrowave propagation in arid area

Sand and dust storms are environmental phenomena ,during these storms optical visibility might be decreased, consequently, atmospheric attenuation is clearly noticed.Micro-wave (MW) and Milimeter-wave (mm) propagation is severely affected by dust and sand storms in considerable areas around the world. Suspended dust particles may directly cause attenuation and cross polarization to the Electromagnetic waves propagating through the storm. In this paper, a thorough investigation of dust storm characteristics based onmeasured optical visibility and relative humidity is presented. In addition,the dust storms effects of on Micro-wave and Millimeter-wave propagation have been studied based on data measured Received Signal levels (RSL)and dust storm characteristics synchronously. Analyticaldustattenuationmodels predictions are matched to the measured attenuationdata at 14 GHz and 21 GHz. It has been found that the measured attenuation is approximately ten times higher than the predicted attenuation for both frequencies

Performance evaluation of 2-port MIMO LTE-U terminal antenna with user’s hand effect

This paper presents the performance evaluation of 2-port MIMO antenna for LTE-U sub 6 GHz band. The evaluation focuses on the effect of user’s hand in a uniform environment and the analysis were carried out on simulation and measurement data of antenna ports. Results show that the highest performance of the design is on the frequency range from 4.5 GHz to 5.5 GHz, and the ports have low envelope correlation coefficient (ECC) less than 0.16 in both cases of without and with user’s hand. However, the presence of the user’s hand reduces mean effective gain (MEG) of ports and diversity combining gain by more than 1.6 dB compared with no-hand case. The multiplexing efficiency is around 81% and reduced by the presence of the user’s hand to 55%. Despite this reduction; the design shows high spatial multiplexing capability in both cases. The capacity carried by the second transmission eigenmode is about 39% from the total capacity under water-filling algorithm transmit power allocation