F. R. Hashim

Hybrid modified booth encoded algorithm-carry save adder fast multiplier

One of the effective ways to speed up multiplication are by reducing the number of partial products and accelerating the accumulation. In this paper, a new architecture of hybrid Modified Booth Encoded Algorithm (MBE) and Carry Save Adder (CSA) is developed as fast multiplier architecture. Altera Quartus II platform is used to run the simulation. The architecture design is programmed into FPGA using Altera DE2 board to verify the synthesizability on physical hardware. This hybrid fast multiplier delivers good performance in term of higher speed as well as in term of less usage of logic elements.

Systematically study on the magnetism and critical behaviour of layered NdMn1.4Cu0.6Si2

The strong dependence of the field-induced on the body-centered tetragonal ThCr2Si2-type and the critical behaviour of magnetic phase transition in NdMn2-xCuxSi2 based compounds guide us to study the substitution Mn (atomic radius = 1.35 A) by Cu (atomic radius = 1.28 A) in layered NdMn1.4Cu0.6Si2 compound. Room temperature x-ray diffraction study indicates clearly that most of the reflections can be identified with ThCr2Si2-type structure with space group I4/mmm. It found lattice parameters a slightly increases and lattice parameter c decrease compare to NdMn2Si2 as indicated the decreasing of volume structure. The Neel temperature TN is found at 340u2005K while Curie temperature TC found at 75u2005K respectively. The increasing concentration of Cu in replacement of Mn changes the magnetic phase transition from first order type for NdMn2Si2 to second order type for layered NdMn1.4Cu0.6Si2 compound as been determined by particular the S-shaped nature of the Arrott plot near TC. Our results indicate that the magnetic-field-induced magnetic phase transition plays a critical role on producing large magnetocaloric effect in these systems especially on second order type as the key for further investigation. The critical behaviour analysis in the vicinity of TC demonstrates that the magnetism of the layered NdMn1.4Cu0.6Si2 compound is governed by long range interactions.The strong dependence of the field-induced on the body-centered tetragonal ThCr2Si2-type and the critical behaviour of magnetic phase transition in NdMn2-xCuxSi2 based compounds guide us to study the substitution Mn (atomic radius = 1.35 A) by Cu (atomic radius = 1.28 A) in layered NdMn1.4Cu0.6Si2 compound. Room temperature x-ray diffraction study indicates clearly that most of the reflections can be identified with ThCr2Si2-type structure with space group I4/mmm. It found lattice parameters a slightly increases and lattice parameter c decrease compare to NdMn2Si2 as indicated the decreasing of volume structure. The Neel temperature TN is found at 340u2005K while Curie temperature TC found at 75u2005K respectively. The increasing concentration of Cu in replacement of Mn changes the magnetic phase transition from first order type for NdMn2Si2 to second order type for layered NdMn1.4Cu0.6Si2 compound as been determined by particular the S-shaped nature of the Arrott plot near TC. Our results indicate that the magne...

DISSOLVED GAS ANALYSIS (DGA) OF NATURAL ESTER OILS UNDER ARCING FAULTS

Dissolved gas analysis is one of diagnostic technique for monitoring the internal condition of transformer. However, DGA analyses for natural ester especially palm oil and rice bran oil still lacking. Therefore, this paper presents the investigation on natural esters regarding gassing behaviour under lightning impulse breakdown. Two type of natural ester oils were used namely Palm oil (PO) and Rice Bran oil (RBO). The DGA result showed that C2H2 and H2 detected the highest amount of gases for both samples. The gaseous obtained from the experiments were interpreted in different DGA method such as Dornenburg ratio, Roger ratio, IEC Gas method and Duval Triangle method to find the best technique for natural ester oils. The conducted experiment shows that PO and RBO have comparable dielectric performance and gassing characteristics to mineral oil, but still requiring modification of design and operating parameters .

Breakdown strength of transformer oil filled with carbon nanotubes under various gap distances

A new class of colloidal insulating transformer oil is formulated by dispersing CNT nanomaterials with mineral oil in purpose to enhance the breakdown strength performance of existing transformer oil. This paper represents the experimental studied dealing with the influence of CNT nanomaterials mix with transformer mineral oil in term of AC breakdown voltage at various gap distances. The concentrations of CNT nanomaterials were measured in range 0.01g/L to 0.2g/L. The impact of three gap distances (1.5mm, 2.5mm and 3.5mm) for mushroom-mushroom electrode configuration is studied in order to observe and compare the trend between conventional mineral oil and CNT nanofluids. To employ CNTs as effective reinforcement in mineral oil, proper dispersion methods need to be applied.

Reconfigurable antenna using plasma reflector

This paper presents the feasibility study and design of plasma implementation in industrial, scientific and medical (ISM) communication band. A reflector antenna with rounded shaped is proposed to collimate beam in particular direction radiated by a quarter wave antenna operating at 2.4GHz. The simulations result has shown that by using plasma as the reflector elements, the gain, directivity and radiation patterns are identical with metal elements with only small different in the broadside direction. The versatility of the antenna is achievable by introducing electrical reconfigurable option to change the beam pattern.

MLP based LOGSIG transfer function for solar generation monitoring

Solar panel is one of the renewable energy that can reduce the environmental pollution and have a wide potential of application. The exact solar prediction model will give a big impact on the management of solar power plants and the design of solar energy systems. This paper attempts to use Multilayer Perceptron (MLP) neural network based transfer function. The MLP network can be used to calculate the temperature module (TM) in Malaysia. This can be done by simulating the collected data of four weather variables which are the ambient temperature (TA), local wind speed (VW), solar radiation flux (GT) and the relative humidity (RH) as the input into the neural network. The transfer function will be applied to the 14 types of training. Finally, an equation from the best training algorithm will be deduced to calculate the temperature module based on the input of weather variables in Malaysia.

Impact of foliage on LoRa 433MHz propagation in tropical environment

LoRa is being considered as one of the promising system for Low-Power-Wide-Area-Network (LPWAN) to support the growth of Internet of Things (IoT) applications. Designed to operate in the industrial, scientific and medical (ISM) bands, LoRa had been tested and evaluated mainly in Europe and US in the 868u2005MHz and 915u2005MHz modulation bands. Using chirp spread spectrum technology, LoRa is expected to be robust against degredation. This paper provides some early results in the performance of LoRa signal propagation of 433u2005MHz modulation in tropical foliage environments.LoRa is being considered as one of the promising system for Low-Power-Wide-Area-Network (LPWAN) to support the growth of Internet of Things (IoT) applications. Designed to operate in the industrial, scientific and medical (ISM) bands, LoRa had been tested and evaluated mainly in Europe and US in the 868u2005MHz and 915u2005MHz modulation bands. Using chirp spread spectrum technology, LoRa is expected to be robust against degredation. This paper provides some early results in the performance of LoRa signal propagation of 433u2005MHz modulation in tropical foliage environments.

MATLAB implementation of satellite positioning error overbounding by generalized Pareto distribution

In the satellite navigation community, error overbound has been implemented in the process of integrity monitoring. In this work, MATLAB programming is used to implement the overbounding of satellite positioning error CDF. Using a trajectory of reference, the horizontal position errors (HPE) are computed and its non-parametric distribution function is given by the empirical Cumulative Distribution Function (ECDF). According to the results, these errors have a heavy-tailed distribution. Since the ECDF of the HPE in urban environment is not Gaussian distributed, the ECDF is overbound with the CDF of the generalized Pareto distribution (GPD).