Analysis of Drivers’ Characteristics Concerning Speeding Behavior and Crash Involvement in Oman | Author : Muhammad Ashraf Javid, Arwa Faris Ahmed Al-Roushadi, Amani Rashid Al-Hashimi | Abstract | Full Text | Abstract :This study aims to identify the significance of driver’s socioeconomic demographics (SEDs) in the decision to speed and crash involvement. A questionnaire was designed consisting of a driver’s SEDs, speeding propensity, and crash experience. This questionnaire was conducted with the students and employees of the University of Nizwa and other drivers at the selected locations. A total of 604 usable samples were obtained. Simple frequency distribution and discriminant multivariate analysis were conducted on the driver’s responses. Survey results revealed that about 47.7% of the drivers have experienced a crash. The driver’s gender nationality, profession, age, type of vehicle drive, driving experience, and past crash experience are significant attributes of the driver’s speeding behavior. Ordered probit analysis for speeding behavior and simple probit regression analysis for crash involvement was conducted. The male drivers and those who are under the age of 30 years and have driving experience of more than 3 years have more likelihood to exceed the speed limits than other drivers. Similarly, the driver’s gender, age (= 30 years), and those who are employees have a significant correlation with the propensity of crash involvement. Male and young drivers have more likelihood to be involved in a crash. |
| Comparative Analysis of AC and DC Distribution System with Respect to Harmonic Distortion Considering Daily Load Profile | Author : Faisal Shahzad, Haroon Farooq, Waqas Ali, Hassan Erteza Gillani, Naeem Abas Kalair, Mohamed Emad Farrag | Abstract | Full Text | Abstract :Electrical energy is the most efficient and the cleanest form of energy at the moment that is being transmitted and distributed amongst end-users. From its earlier days, the AC system was preferred as an economical solution for transmission and distribution. However, the development in the power electronics technology and the evolution of highly efficient power electronic converters have established the resurgence of DC power system. Furthermore, the trend is shifting towards DC loads as various energy efficient appliances, such as DC inverter air conditioners, operate on DC nowadays. This further advocates the shift towards the DC power system. This research works is an effort to perform the comparative analysis of AC Distribution System (ACDS) and DC Distribution System (DCDS), with regards to power quality and harmonic distortion in particular. The comparison is performed considering load profile and load variation on daily basis. Simulations are performed in MATLAB. It has been concluded at the end that ACDS is better than DCDS in terms of power quality as total harmonic distortion of the DCDS under the same loading and same load variation during the whole day was significantly higher than that of ACDS. |
| Simulative Analysis of Power Conversion System for Hybrid Electric Vehicles Based on Dual Input Sources Including Charging From Solar Panel | Author : Shafquat Hussain, Waqar Ahmed, Ahmed Muddassir Khan, Mir Shahanawaz, Rizwan Ali | Abstract | Full Text | Abstract :Renewable energy sources are highly recommended in hybrid electric vehicles (HEV) applications. The power converters play an important role in hybrid electric vehicle system. The design of control system for such converters is discussed in the paper. The design of both DC-DC dual input converter and 3 phase VSC is done using MATLAB simulation. The design of SVPWM technique is presented for three phase VSC and PI control is for DC-DC converter. By the integration of this system a 3 phase induction motor will be operated, which in turn can be utilized for running of shaft of any vehicle. The dual input converter feed by two sources one is PV system and other is battery which is being charged by the PV system. |
| Functional MRI Based Brain Mapping in Occipital Gyrus using Face Stimuli | Author : Anwar Ali Gaho, Ahmed Muddassir Khan, Muhammad Abul Hasan | Abstract | Full Text | Abstract :Functional magnetic resonance imaging (fMRI) is one of the most powerful neuroimaging modalities due to its high spatio-temporal resolution characteristics. This known modality is applied on mapping the temporal, occipital, frontal cortices of the brain for localizing the neural activities generated due to any visual, physical or mental task or brain diseases or brain disorders. The occipital cortex is composed of middle, left, right, interior and exterior occipital gyrus and is responsible for visional function of human brain. The occipital gyrus reflects the neural image generated in the brain due to any visual activity. In this research paper, four different visual stimuli images of faces, scrambled, scenes and objects along with gap of blank space, forming a long sequence of stimuli observed by two female subjects, are experimented to examine and localize the most contrasting neural image generated in occipital gyrus of the brain. The visual fMRI brain data received from the two subjects is processed through fMRI-SPM12 toolbox based on Matlab software. In order to demonstrate the results statistically, two regressions such as T-contrast and F-contrast vectors are applied on fMRI images to highlight, and to localize the most active neural stimuli activities generated in the occipital gyrus of brain. In the results, it is demonstrated that maximum neural response can be mapped only for face stimulus in the bilateral occipital gyrus of the brain by applying T-contrast vectors regressions as when compared to other stimuli conditions and F-contrast vectors regressions. Further, it is also investigated that, the response of the face stimulus in F-contrast regressions achieved is somehow dispersed and unclear due to the large variances and interlinked communication of other stimuli or induced neural noises generated in entire volume of the brain. Further from the given images, it is also investigated that the most reflecting and contrast area for any visual stimuli (such as face stimulus in this case) is either the middle or bilateral part of occipital gyrus of the human brain as identified through application of T-contrast vectors regressions. |
| Power Generation of Pure Sine Wave in Batteryless Solar System using Advanced Control | Author : Muhammad Siddique, Muhammad Usman, Malik Yasir Iqbal, Safdar Raza, Muhammad Waleed, Laaj Batool | Abstract | Full Text | Abstract :A novel technique for conversion of DC power to AC power is introduced using solar powered sine wave generation system is presented. DC power extracted from solar system is made utilitarian for driving the BLDC (brushless DC) motor with constant speed constraints. The back EMF signals of each phase of the BLDC motor facilitated the development of technique for the sine wave generation from solar system without battery backup. This motor is coupled with AC generator, which yields the AC power on demand. The constant speed constraint indispensable for fixed electrical frequency at the output of generator. A new control technique is rendered for reference tracking speed control of BLDC motor using Lyapunov theory by changing switching frequency, and also maintaining the voltage level at the output of converter driving BLDC by regulating the switching frequency of the zeta converter. The proposed methodology for generation of AC power from solar power system is also tested on prototype. The comparison of conventional technique for generation of sine wave power and proposed scheme is mentioned at later section of this paper for describing the efficacy of newly presented scheme. |
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