Study of resonances in 1 x 25 kV AC traction systems with external balancing equipment

© 20xx IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.AC traction systems are 1 × 25 or 2 × 25 kV/50 Hz single-phase, nonlinear, time-varying loads that can cause power-quality problems, such as unbalanced or distorted voltages. To reduce unbalance, external balancing equipment is usually connected to these systems, forming the Steinmetz circuit. Parallel resonances can occur in these types of circuits, exciting the harmonic emissions (below 2 kHz) of railway-adjustable speed drives. This paper studies these resonances at pantograph terminals and provides analytical expressions to determine their harmonic frequencies. The expressions are validated from several traction systems in the literature and PSCAD simulations.Postprint (author's final draft

On the Efficient Simulation of the Left-Tail of the Sum of Correlated Log-normal Variates

The sum of Log-normal variates is encountered in many challenging applications such as in performance analysis of wireless communication systems and in financial engineering. Several approximation methods have been developed in the literature, the accuracy of which is not ensured in the tail regions. These regions are of primordial interest wherein small probability values have to be evaluated with high precision. Variance reduction techniques are known to yield accurate, yet efficient, estimates of small probability values. Most of the existing approaches, however, have considered the problem of estimating the right-tail of the sum of Log-normal random variables (RVS). In the present work, we consider instead the estimation of the left-tail of the sum of correlated Log-normal variates with Gaussian copula under a mild assumption on the covariance matrix. We propose an estimator combining an existing mean-shifting importance sampling approach with a control variate technique. The main result is that the proposed estimator has an asymptotically vanishing relative error which represents a major finding in the context of the left-tail simulation of the sum of Log-normal RVs. Finally, we assess by various simulation results the performances of the proposed estimator compared to existing estimators

STUDY OF APPROACHES, METHODS, SOURCES AND INTERPRETATION INSTRUMENTS OF MULLA SADRA

This research is carried out on some uniqueness found in the interpretation of the Al-Qur'an by Mulla Sadra, including: he is a philosopher who is the foremost in interpreting the Al-Qur'an and productive writers who have produced many works. In the hands of Mulla Sadra, the synthesis of the three Islamic intellectual schools, namely Sufi makrifat, philosophy or theosophy, and Shiite theology was finally reached, and directly reflected in the field of esoteric interpretation of the Al-Qur'an. Based on the uniqueness, the author is interested in examining it with the title: "Mulla Sadra's Interpretation Methodology (Study of Approaches, Methods, Sources and Instruments of Interpretation)". The purpose of this study is to find out and explore the methodology of the interpretation of Al-Quran Mulla Sadra, as well as describe how the approach, methods, sources and instruments of interpretation of the Al-Quran that he initiated. And to find out and criticize the application of the interpretation methodology of Al-Quran Mulla Sadra in its interpretation product. This type of research is a library research based on the book of Tafsir al-Qur'an al-Karim as a primary data source. Based on this research, we can draw the conclusion that Sadra's work is a combination of approaches and interpretive methods that have developed in the Islamic world. The advantage is that it combines two approaches, namely f irfani and philosophy. This is then considered a bridge from the different interpretive traditions in the Islamic worl

On the Sum of Order Statistics and Applications to Wireless Communication Systems Performances

We consider the problem of evaluating the cumulative distribution function (CDF) of the sum of order statistics, which serves to compute outage probability (OP) values at the output of generalized selection combining receivers. Generally, closed-form expressions of the CDF of the sum of order statistics are unavailable for many practical distributions. Moreover, the naive Monte Carlo (MC) method requires a substantial computational effort when the probability of interest is sufficiently small. In the region of small OP values, we propose instead two effective variance reduction techniques that yield a reliable estimate of the CDF with small computing cost. The first estimator, which can be viewed as an importance sampling estimator, has bounded relative error under a certain assumption that is shown to hold for most of the challenging distributions. An improvement of this estimator is then proposed for the Pareto and the Weibull cases. The second is a conditional MC estimator that achieves the bounded relative error property for the Generalized Gamma case and the logarithmic efficiency in the Log-normal case. Finally, the efficiency of these estimators is compared via various numerical experiments

Mechanical Properties of Engineered Cementitious Composite Mixture

The concrete is the man-made material which is well-known and enormously utilized by the whole world. This matter leads to crucial problems related to its design and expectation to finally gain an economic cost of the product for both short and long duration. The concrete need to be also environmental friendly during its fabrication process. Engineered Cementitious Composite (ECC) has different abilities compare to the normal concrete. It has the passing and filling ability plus give higher strength with the addition of Polyvinyl Alcohol (PVA). The aim of the research work reported in this thesis is to develop engineered cementitious composite mixtures satisfying the self-compacting requirements and to evaluate the hardened properties of self-compacted ECC mixtures. To enhance the concrete performance, PVA is used. The PVA improved some characteristics and properties of the concrete. Ten mixes with different Polyvinyl Alcohol (PVA) fiber contents (0.0%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5% and 5.0%) have been prepared. Three cubes (100mm x 100mm x 100mm), three beams (100mm x 100mm x 500mm) and three cylinders (150mm diameter and 300mm height) have been cast for each mix and tested at the age of 7 and 28 days for compressive strength and at age of 28 days for splitting and flexural strength. The V-funnel, L-box and slump test also have been conducted to access the fresh properties like workability and flowability of the concrete. The results indicated the increase in the strength of the concrete and the formulas for predicting the compressive, splitting and flexural strength from PVA (%) has been developed

PEMBUATAN GAME RACING 2D “SAFETY RIDING” DENGAN PENERAPAN ALGORITMA PERLIN NOISE UNTUK MEMBUAT PETA DENGAN UNITY

Game merupakan sebuah permainan dengan adanya sistem yang melibatkan player dengan konflik buatan yang telah ditentukan atau adanya peraturan untuk memberikan hasil yang terukur dan adanya interaksi antara player dengan sistem didalam permainan tersebut. Aplikasi permainan terbagi menjadi dua yaitu aplikasi permainan 2D (dua dimensi) dan 3D (tiga dimensi). Metode Perlin Noise merupakan teknik yang digunakan untuk mensimulasikan sesuatu yang terlihat berantakan dan natural. Peta merupakan rancangan dua dimensi yang berskala medium dari kumpulan objek untuk membuat suatu jalan, tempat, untuk mengetahui apa saja yang ada disekitar, biasanya digunakan untuk titik tujuan.Map sangat penting dalam permainan petualangan. Genre permainan petualangan adalah genre dengan setting tempat yang luas untuk menjelajahi suatu tempat atau wilayah. Unity merupakan software yang dapat digunakan untuk pengembangan game yang digunakan diberbagai platform..   Kata kunci : Game, Perlin Noise, Petualangan, Unity, Ma