BEHAVIOUR OF SELF-SUPPORTED TRANSMISSION LINES UNDER TORNADO LOADING

Localized wind events in the form of tornadoes and downbursts are the main cause of the large number of failure incidents of electrical transmission line structures worldwide. In this study, a numerical model is developed to assess the behaviour of self-supported transmission lines under various tornado events. The tornado wind fields used are based on a full three-dimensional computational fluid dynamics analysis that was developed in an earlier study. A three-dimensional finite element model of an existing self-supported transmission line belonging to Manitoba Hydro is developed. The tornado velocity wind fields are then used to predict the forces applied to the modelled transmission line system. A comprehensive parametric study is performed to assess the effects of the location of the tornado relative to the transmission line. This part of the study is used to identify critical tornado configurations which can be used when designing transmission line systems. The study is extended to assess the line’s progressive failure mechanisms under critical tornado configurations. It predicts the progressive failure mechanism of the modelled transmission line as well as the maximum tornado velocity the system can withstand before experiencing global failure. This part also predicts the main type of failure experienced by the line as well as the path of members susceptible to failure. This could then be used to retrofit existing transmission lines economically by increasing the capacity of the identified members

Quranic letter pronunciation analysis based on spectrogram technique: case study on Qalqalah letters

Recitation of the Holy Quran with Tajweed is an essential activity as a Muslim. Reciting Quran correctly indicates the correct meaning of the words of Allah has been received from this significant resource among Muslims. That is why Muslims stress on the Quranic Education since in the early age. It is important to pronounce the letter correctly based on its characteristics as well as the articulation point of each letter. In this paper, the characteristic based on Qalqalah letters is considered to be analyzed. The audio signal from a person who is very good at Quranic recitation was taken and analyzed. We implement spectral analysis to find the features of Qalqalah letters and extract the correlation between the first formant frequency and the pharyngeal space of the signal. Spectrogram was successfully implemented and proved this relation, and it described the mechanism of Qalqalah correctly, which is unique as compared to other Quranic letters

Analysis of two adjacent articulation Quranic letters based on MFCC and DTW

—Reciting al-Quran in the correct way is an obligatory duty for Muslims, and therefore learning al-Quran is a continuous education until the correct recitation is achieved. It is important to learn Tajweed rules to master the recitation of Quranic verses. Moreover, mastering the pronunciation of Arabic sounds is the first and key step to achieve accurate recitation of al-Quran. The rules were guided by the Islamic Scholars in fields related to al-Quran from their knowledge and experiences. Very limited researches were found in the perspective of sciences and engineering. In this paper two Quranic letters (ذ and ز) that are articulated from adjacent points of articulation were analyzed using Mel- frequency coefficient analysis. MFCCs matrices were calculated then compared using the dynamic time warping DTW technique to calculate the similarity matrices and find the similarity distance. Results show that letters from the same point of articulation have less similarity distance compared to the letters from different point of articulation

Lips tracking identification of a correct pronunciation of Quranic alphabets for tajweed teaching and learning

Mastering the recitation of the Holy Quran is an obligation among Muslims. It is an important task to fulfill other Ibadat like prayer, pilgrimage, and zikr. However, the traditional way of teaching Quran recitation is a hard task due to the extensive training time and effort required from both teacher and learner. In fact, learning the correct pronunciation of the Quranic letters or alphabets is the first step in mastering Tajweed (Rules and Guidance) in Quranic recitation. The pronunciation of Arabic alphabets is based on its points of articulation and the characteristics of a particular alphabet. In this paper, we implement a lip identification technique from video signal acquired from experts to extract the movement data of the lips while pronouncing the correct Quranic alphabets. The extracted lip movement data from experts helps in categorizing the alphabets into 5 groups and in deciding the final shape of the lips. Later, the technique was tested among a public reciter and then compared for similarity verification between the novice and the professional reciter. The system is able to extract the lip movement of the random user and draw the displacement graph and compare with the pronunciation of the expert. The error will be shown if the user has mistakenly pronounced the alphabet and suggests ways for improvement. More subjects with different backgrounds will be tested in the very near future with feedback instructions. Machine learning techniques will be implemented at a later stage for the real time learning application. Menguasai bacaan Al-Quran adalah satu kewajipan di kalangan umat Islam. Ia adalah satu tugas yang penting untuk memenuhi Ibadat lain seperti solat, haji, dan zikir. Walau bagaimanapun, cara tradisional pengajaran bacaan Al-Quran adalah satu tugas yang sukar kerana memerlukan masa latihan dan usaha yang banyak daripada guru dan pelajar. Malah, mempelajari sebutan yang betul bagi huruf Al-Quran adalah langkah pertama dalam menguasai Tajweed (Peraturan dan Panduan) pada bacaan Al-Quran. Sebutan huruf Arab adalah berdasarkan cara penyebutan tiap-tiap huruf dan ciri-ciri huruf tertentu. Dalam kertas ini, kami membina teknik pengenalan bibir dari isyarat video yang diperoleh daripada bacaan Al Quran oleh pakar-pakar untuk mengekstrak data pergerakan bibir ketika menyebut huruf Al-Quran yang betul. Data pergerakan bibir yang diekstrak daripada pembacaan oleh pakar membantu dalam mengkategorikan huruf kepada 5 kumpulan dan dalam menentukan bentuk akhir bibir. Kemudian, teknik ini diuji dengan pembaca awam dan kemudian bacaan mereka dibandingkan untuk pengesahan persamaan bacaan antara pembaca awam dan pembaca Al-Quran profesional. Sistem ini berjaya mengambil pergerakan bibir pengguna rawak dan melukis graf perbezaan sebutan mereka apabila dibandingkan dengan sebutan pakar. Jika pengguna telah tersilap menyebut sesuatu huruf, kesilapan akan ditunjukkan dan cara untuk penambahbaikan dicadangkan. Lebih ramai pengguna yang mempunyai latar belakang yang berbeza akan diuji dalam masa terdekat dan arahan maklum balas akan diberi. Teknik pembelajaran mesin akan dilaksanakan di peringkat seterusnya bagi penggunaan pembelajaran masa nyata

Integrated modelling and design for realizing a two-wheeled wheelchair for disabled

Two-wheeled wheelchairs are considered highly nonlinear and complex systems. The systems mimic a double-inverted pendulum scenario and will provide better manoeuvrability in confined spaces and also to reach higher level of height for pick and place tasks. The challenge resides in modelling and control of the two-wheeled wheelchair to perform comparably to a normal four-wheeled wheelchair. Most common modelling techniques have been accomplished by researchers utilizing the basic Newton’s Laws of motion and some have used 3D tools to model the system where the models are much theoretical and quite far from the practical implementation. This paper is aimed at closing the gap between the conventional mathematical modelling approaches where the integrated 3D modelling approach with validation on the actual hardware implementation was conducted. To achieve this, both nonlinear and a linearized model in terms of state space model were obtained from the mathematical model of the system for analysis and, thereafter, a 3D virtual prototype of the wheelchair was developed, simulated and analysed. This have increased the confidence level for the proposed platform and facilitated the actual hardware implementation of the two-wheeled wheelchair. Results show that the prototype developed and tested has successfully worked within the specific requirements established

Analysis of Formant Frequencies of the Correct Pronunciation of Quranic Alphabets Between Kids and Adults

It is an obligation for a Muslim to become skilled and proficient in reciting Al-Quran considering that Al-Quran is the fundamental source of revelation from Allah SWT. In Al-Quran, there are 28 alphabets where each of them has their own unique sound. The Quranic alphabets produce sound that are characterized from their point of articulation (Makhraj) and their characteristics (Sifaat). Knowing the correct way of pronunciation through engineering perspective may help Muslim in learning Al-Quran, in the sense that the signal of the experts can be used in Quranic teaching and learning as a reference model. Since both adults and children possess different vocal tract, therefore there will be different outcomes of the pronunciation between both experts. The features identification of the pronunciation of both experts is needed to represent the actual and correct pronunciation that will be used as a reference for Quranic teaching and learning at later. In this paper, the focus was on the identification and analysis of the correct pronunciation of the Quranic alphabets on the data obtained from adults and children experts. The first and second formant frequencies (F1 and F2) were used as the features where they were used to represent the pronunciation of each alphabet for both adults and children category. The speech analysis software PRAAT was used to accomplish the pre-processing of the data using Spectral Subtraction technique and also used to measure the F1 and F2 values. Linear Discriminant Analysis (LDA) was used for classification of the signals and results shows that some of the alphabets can be identified uniquely using F1 and F2 features of the two categories

Characteristics with opposite of quranic letters mispronunciation detection: a classifier-based approach

Reading Quran for non-Arab is a challenge due to different mother tongues. learning Quran face-to-face is considered time-consuming. The correct pronunciation of Makhraj and Sifaat are the two things that are considered difficult. In this paper, Sifaat evaluation system was developed, focusing on Sifaat with opposites for teaching the pronunciation of the Quranic letters. A classifier-based approach has been designed for evaluating the Sifaat with opposites, using machine learning technique; the k-nearest neighbour (KNN), the ensemble random undersampling (RUSBoosted), and the support vector machine (SVM). Five separated classifiers were designed to classify the Quranic letters according to group of Sifaat with opposites, where letters that are classified to the wrong groups are considered mispronounced. The paper started with identifying the acoustic features to represent each group of Sifaat. Then, the classification method was identified to be used with each group of Sifaat, where best models were selected relying on various metrics; accuracy, recall, precision, and F-score. Cross-validation scheme was then used to protect against overfitting and estimate an unbiased generalization performance. Various acoustic features and classification models were investigated, however, only the outperformed models are reported in this paper. The results showed a good performance for the five classification models

Experimental Studies on Bond Performance of BFRP bars reinforced Coral Aggregate Concrete

As part of this study, has been developed a numerical method which allows to establish abacuses connecting the normal force with bending moment for a circular section and therefore to predict the rupture of this type of section. This may be for reinforced concrete (traditional steel) or concrete reinforced with steel fibers. The numerical simulation was performed in nonlinear elasticity up to exhaustion of the bearing capacity of the section. The rupture modes considered occur by plasticization of the steel or rupture of the concrete (under compressive stresses or tensile stresses). Regarding the fiber-reinforced concrete, the rupture occurs, usually, by tearing of the fibers. The behavior laws of the different materials (concrete and steel) correspond to the real behavior. The influence of several parameters was investigated, namely; diameter of the section, concrete strength, type of steel, percentage of reinforcement and contribution of concrete in tension between two successive cracks of bending. A comparison was made with the behavior of a section considering the conventional diagrams of materials; provided by the BAEL rules. A second comparative study was performed for fibers reinforced section

Risk Assessment and Mitigation of the Seawater Intrusion Using Modeling Approach

Groundwater is one of the most precious natural resources in the Gaza Strip as it is the only source of drinking water for the majority of the population. The increasing of salinity problem and the dropping in water level are two of the most important and widespread of the numerous potential groundwater problems. The salinity sources in the groundwater of Gaza Strip are from the intrusion of the seawater which caused by increased abstraction from the wells. The problem of high salinity concentrations in drinking water exceeded the WHO standards of 250 mg/l constitutes a major health risk to both humans and stock life. The chloride concentration reached to 1500 mg/l in some wells. The water level will drop to -10 M.S.L in some area in north of Gaza strip within 10 years if the levels of abstraction continues in this regime. Therefore, this work tried to study the increase of chloride concentration and the drop of level of groundwater in North of Gaza Strip area as a result of seawater intrusion. A coupled flow and transport model using a three-dimensional, finite difference simulation model (VMODFLOW Pro.) was applied to simulate the Northern part of Gaza coastal aquifer. Model application was carried out in two steps; (a) The calibrated flow and transport model was used to study management scenarios for the Seawater intrusion problem, (b) Simulation of chloride concentration and water level transport in the Northern part of Gaza Strip coastal aquifer to estimate transport parameters. The approach for selecting the management scenarios was carried out depending on the need to reduce the transport of chloride concentration and improving the water level into the aquifer system during the next 10 years. Six selected management scenarios were tested; (1) work as usual (zero scenario), (2) Management of the pumping to 50%, (3) Injection of treated wastewater to the aquifer, (4) combining the previous two scenarios together, (5) Reduction the abstraction to 20% and injection of treated wastewater (6) Injection of treated wastewater and stopping the abstraction from the aquifer. The best scenario to solve the increasing of chloride concentration and dropping in water level problems in the groundwater is the implementation of the sixth scenario from 2012 to 2020 which cause rising of water level and reversing the seawater toward west

Bond durability of basalt fibre-reinforced polymer bars embedded in concrete under direct pullout conditions

The use of basalt fiber–reinforced polymer (BFRP) bars as a reinforcing material has gained increasing interest worldwide. However, few studies have reported on these bars’ performance in concrete when exposed to harsh environments. This paper investigates the effect of five different accelerated environments, namely (1) tap water, (2) seawater, (3) elevated temperature, (4) elevated temperature followed by tap water, and (5) elevated temperature followed by seawater, on the bond stress-slip response, adhesion to concrete, and bond strength [of two types of BFRP bars and one type of glass fiber–reinforced polymer (GFRP) bar]. The bond-slip responses of all specimens were governed by the surface treatment of each bar and its manufacturing quality, regardless of the fiber type. Sand-coated BFRP bars showed higher bond characteristics than helically grooved bars after conditioning. Moister environments caused enhanced adhesion at the early loading stages for all specimens. Nevertheless, such environments had a detrimental effect on the bond strength at later stages depending on the bar material’s moisture absorption. Finally, exposure to elevated temperatures caused insignificant variation in the bond strength of all tested specimens. Read More: http://ascelibrary.org/doi/10.1061/%28ASCE%29CC.1943-5614.000054