Archives-May 2014

This paper presents comparative study and simulation results for different Hybrid Multilevel Inverter configurations. This paper covers hybrid multilevel inverters such as cascaded multilevel inverter with high voltage low-frequency pulse width-modulation (PWM) and low voltage high frequency pulse width-modulation (PWM) and series connected half-bridge modules hybrid multilevel inverters. Here the operating principle of each topology is discussed with a review of the relevant modulation method focusing mainly on total harmonic distortion (THD). Such multilevel inverters achieve higher power quality with a given switch count when compared to traditional multilevel inverters. The purpose of the circuits presented here is to minimize the reverse voltage stress that affects the power switches and decrease the harmonic distortion of the voltage applied to the load.

The effect of Foreign Accented Speech (FAS) on listening comprehension has been under investigation for many years. FAS studies examine the effect of different accents on listeners’ intelligibility and perceived comprehensibility. In this study, the effects of Persian, Spanish, and American accents on Iranian students’ listening comprehension were investigated. Two hundred and fifty undergraduate English Translation students took part in a TOEFL test. Students were divided into two proficiency groups. Thirty students were chosen as the high proficiency group and thirty others were selected for the low proficiency group. Then each group was randomly divided into three sub-groups of ten students, and each group was exposed to Persian-accented English, Spanish-accented English, and standard American English. By analyzing the resulting figures with a repeated measure design of ANOVA, it was realized that for both proficiency groups the Persian accent had been the most influential one on the students’ listening comprehension. It was found that American and Spanish accents did not have any significant effect on Iranian students’ listening comprehension, although the American accent was more effective than the Spanish accent.

This paper presents Maximum likelihood (M L) estimation approach to derive reliability measures of a two component identical system in the presence of Common Cause Shock failures (CCS) as well as human errors. The M L estimates of system reliability measures like frequency of failures were derived for both series and parallel systems. We also developed the confidence interval in the present study. The approach used is empirical one with Monte Carlo simulation.

Glass fiber reinforced polymer composites are finding its increased applications in variety of engineering applications such as aerospace, automobile, electronics and other industries. The main objective of this study is to optimize the process parameters with multiple machinability characteristics. The performance characteristics considered were surface roughness (Ra), Cutting force (Fz) and cutting power (P). Optimal combination of process parameters can then be determined by Taguchi method using the grey relational grade as performance index. The process parameters considered were cutting speed, feed, depth of cut and fiber orientation angle (work piece). Experiments are planned according to Taguchi’s L25 orthogonal array in the design of experiments and were carried out on an all geared lathe using carbide (K20) cutting tool insert. The experimental results reveal that the feed is the most significant process parameter on the multiple machinability characteristics, this proposed method can be effectively used to improve the machining characteristics of GFRP composites.

Marriage nowadays faces a various issues especially when divorce becomes trend among Malaysian. It is believed that success in marriage by maintaining quality of relationship may influence the other aspect of life.However, it is important to know the roles of marital communication and conflict resolution in order to maintain quality of relationship. This study examines the role of communication and conflict resolution on Muslim newlywed couples' marital quality. The Family Stress Theory (FST) and Marital Communication Theory (MCT) of marital communication and conflict resolutionwere used to explain influence between communication dimension, conflict resolution, and marital quality. Participants were 571 married Muslim individually selected from area Selangor. Self-administered questionnaire was used for data collection. Results indicate that there are significant differences in conflict resolution between the genders. However, people who are olderand more educated reported higher marital quality. It also noted high levels on communication and conflict resolution ensure better quality marriage among respondents. Meanwhile, increasing on total household among them tend to have lower marital quality. Future studies need to consider using longitudinal data Marriage nowadays faces a various issues especially when divorce becomes trend among Malaysian. It is believed that success in marriage by maintaining quality of relationship may influence the other aspect of life.However, it is important to know the roles of marital communication and conflict resolution in order to maintain quality of relationship. This study examines the role of communication and conflict resolution on Muslim newlywed couples' marital quality. The Family Stress Theory (FST) and Marital Communication Theory (MCT) of marital communication and conflict resolutionwere used to explain influence between communication dimension, conflict resolution, and marital quality. Participants were 571 married Muslim individually selected from area Selangor. Self-administered questionnaire was used for data collection. Results indicate that there are significant differences in conflict resolution between the genders. However, people who are olderand more educated reported higher marital quality. It also noted high levels on communication and conflict resolution ensure better quality marriage among respondents. Meanwhile, increasing on total household among them tend to have lower marital quality. Future studies need to consider using longitudinal data to fully understand the impact of communication and conflict resolution towards marital quality.

In this study the energy consumption of orange orchards was surveyed and various Artificial Neural Networks (ANNs) developed to estimate the farmer’s production in the Sari region as a case study. The data were collected using a face-to-face questionnaire method from 86 farmers in the Sari region. The results indicated that the total amount of energy input and output were 54284.8 and 59223.4 MJ ha-1, respectively. Among all inputs involved, diesel fuel had the highest energy values per hectare. Also, energy efficiency, energy productivity and net energy were calculated as 1.09, 0.57 kg MJ-1 and 4938.5 MJ ha-1, respectively. Performance of developed ANN models were evaluated using the coefficient of determination (R2), mean absolute error (MAE) and root mean squared error (RMSE). The resulting tests showed that best performance was achieved by a momentum training algorithm resulting in R2=0.84, and MAE= 0.32 and RMSE=0.38 with 8-4-1 topology. Additionally, sensitivity analysis revealed that fertilizer and electricity energy had the highest and the lowest sensitivity on output, respectively.

E-Banking (also known as On-line banking or Internet banking) refers to doing the financial transactions using the banks website from anywhere in the world. Just by having a computer/laptop with Internet connection the customer can do their financial transactions like transferring money from one account to another account, paying bills like EB Bill, telephone bill, mobile recharge, online purchase etc., Even though the e-banking offers lot of facilities to customers, still customers are facing some of the problems like security issues, loss of password, misuse of funds etc., There were lot of studies conducted to identify the customer perception and satisfaction on e-banking services. The objective of this article is to identify the various empirical studies conducted on customer perception on e-banking by using the literature survey. The outcome of this literature survey is to analyze the areas in which the empirical studies are carried out on customer perception on e-banking and to identify the research gap where the research is not covered so far.

This paper examines the ‘O’ level mathematics themes specifically to identify the most difficult content areas in order to improve students’ achievement in mathematics. In this study, questionnaire made up of the content areas in ‘O’ level mathematics were administered in classrooms using random sample technique. The sample consists of 214 students; 102 males and 112 females of some selected Secondary schools in Nasarawa State. The respondents are all SS III students of 2012/2013 academic session. The data collected was analysed using simple arithmetic percentages. It was established that a great number of the respondents perceived Plane Geometry as the most difficult content area in “O” level mathematics and this constitute 80 (37.4%) of the 214 respondents. This is followed by 55 (25.7%) of the respondents who are of the view that Algebraic Processes is the most difficult.

A high gain microstrip patch fed horn antenna operating in C-band at 6 GHz is presented. The proposed antenna uses H-shaped microstrip excited patch in FR4 and a surface mounted horn integrated on metal. The peak antenna gain is 8.6dBi and directivity is 8.9dBi. VSWR bandwidth is 24%. The proposed design is simulated with Zeland Program Manager IE3D 9.0 version software.

Nickel is a metal of widespread distribution in the environment: there are almost 100 minerals of which it is an essential constituent and which have many industrial and commercial uses. Nickel and nickel compounds belong to the classic noxious agents encountered in industry but are also known to affect non-occupationally exposed individuals. The general population may be exposed to nickel in the air, water and food. Inhalation is an important route of occupational exposure to nickel in relation to health risks. Most nickel in the human body originates from drinking water and food; however, the gastrointestinal route is of lesser importance, due to its limited intestinal absorption. The toxicity and carcinogenicity of some nickel compounds (in the nasal cavity, larynx and lungs) in experimental animals, as well as in the occupationallyexposed population, are well documented. The objective of this paper is to summarize the current overview of the occurrence and sources of nickel in the environment, and the effect of this metal and its compounds on living organisms.