Analysis of ITU-R Performance and Characterization of Ku Band Satellite Downlink Signals during Rainy Season over Chennai Region of India

In this paper, we present the analysis of Ku band Satellite signal reception during rainy season over Chennai region, India (Latitude: 12° 56' 60 N, Longitude: 80° 7' 60 E). We also examine the effectiveness of International Telecommunication Union – Radio communication (ITU-R) model in predicting the rainfall induced attenuation in Ku band, over this region. An improved Simulink model for Digital Video Broadcast – Satellite (DVB-S2) downlink channel incorporating rain attenuation and Cross Polarization Discrimination (XPD) effects is developed to study the rain attenuation effects, by introducing the experimental data in the ITU-R model pertaining to that region. Based on the improved model, a Monte Carlo simulation of the DVB–S2 signal link is carried out and the performance is analyzed by received constellation and Bit Error Rate (BER) parameters

An M-QAM Signal Modulation Recognition Algorithm in AWGN Channel

Computing the distinct features from input data, before the classification, is a part of complexity to the methods of Automatic Modulation Classification (AMC) which deals with modulation classification was a pattern recognition problem. Although the algorithms that focus on MultiLevel Quadrature Amplitude Modulation (M-QAM) which underneath different channel scenarios was well detailed. A search of the literature revealed indicates that few studies were done on the classification of high order M-QAM modulation schemes like128-QAM, 256-QAM, 512-QAM and1024-QAM. This work is focusing on the investigation of the powerful capability of the natural logarithmic properties and the possibility of extracting Higher-Order Cumulant's (HOC) features from input data received raw. The HOC signals were extracted under Additive White Gaussian Noise (AWGN) channel with four effective parameters which were defined to distinguished the types of modulation from the set; 4-QAM~1024-QAM. This approach makes the recognizer more intelligent and improves the success rate of classification. From simulation results, which was achieved under statistical models for noisy channels, manifest that recognized algorithm executes was recognizing in M-QAM, furthermore, most results were promising and showed that the logarithmic classifier works well over both AWGN and different fading channels, as well as it can achieve a reliable recognition rate even at a lower signal-to-noise ratio (less than zero), it can be considered as an Integrated Automatic Modulation Classification (AMC) system in order to identify high order of M-QAM signals that applied a unique logarithmic classifier, to represents higher versatility, hence it has a superior performance via all previous works in automatic modulation identification systemComment: 18 page

Worked Example of X-by-Wire Technology in Electric Vehicle: Braking and Steering

The chapter emphasizes on the worked example of braking system and steering system for electric vehicle. The x-by-wire technology is investigated and validated comprehensively. Brake-by-wire is considered a new brake technology that uses electronic devices and control system instead of conventional brake components to carry out braking function based on wire-transmitted information. However, the physical parameters associated with braking function cause nonlinear characteristics and variations in the braking dynamics, which eventually degrade stability and performance of the system. Therefore, this study presents the design of fuzzy-PID controller for brake-by-wire (BBW) to overcome these undesired effects and also to derive optimal brake force that assists to perform braking operation under distinct road conditions and distinct road types. Electric power-assisted steering (EPAS) system is a new power steering technology for vehicles especially for electric vehicles (EV). It has been applied to displace conventional hydraulic power-assisted steering (HPAS) system due to space efficiency, environmental compatibility, and engine performance. An EPAS system is a driver-assisting feedback system designed to boost the driver input torque to a desired output torque causing the steering action to be undertaken at much lower steering efforts

A Useful Framework for Identification and Analysis of Different Query Expansion Approaches based on the Candidate Expansion Terms Extraction Methods

Query expansion is a method for improving retrieval performance by supplementing an original query with additional terms. This process improves the quality of search engine results and helps users to find the required information. In the recent years, different methods have been proposed in this area. In addition to such a variety of different approaches in this area and necessity of the study of their characteristics, the lack of a comprehensive classification based on candidate expansion terms extraction methods and also suitable and complete criteria to evaluate them, make the precise study, comparison and evaluation of methods for query expansion and choosing appropriate method based on need difficult for researchers. Therefore, in this paper a new useful framework is presented. In the proposed framework, in addition to the identification of three basic approaches based on the candidate expansion terms extraction methods for query expansion and expressing their properties, appropriate criteria for qualitative evaluation of these methods will be described. Next, the proposed approaches will be evaluated qualitatively based on these criteria. Using the systematic and structured framework proposed in this paper leads a useful platform for researchers to be provided for the comparative study of existing methods in the field, investigating their features specially their drawbacks to improve them and choosing appropriate method based on their needs

New trends in electrical vehicle powertrains

The electric vehicle and plug-in hybrid electric vehicle play a fundamental role in the forthcoming new paradigms of mobility and energy models. The electrification of the transport sector would lead to advantages in terms of energy efficiency and reduction of greenhouse gas emissions, but would also be a great opportunity for the introduction of renewable sources in the electricity sector. The chapters in this book show a diversity of current and new developments in the electrification of the transport sector seen from the electric vehicle point of view: first, the related technologies with design, control and supervision, second, the powertrain electric motor efficiency and reliability and, third, the deployment issues regarding renewable sources integration and charging facilities. This is precisely the purpose of this book, that is, to contribute to the literature about current research and development activities related to new trends in electric vehicle power trains.Peer ReviewedPostprint (author's final draft

Inspección visual automática de superficies continuas, caracterizando anomalías locales en el dominio Espacio-Frecuencial

Esta tesis propone una metodología para la inspección visual automática de superficies continuas que abarca las etapas de adquisición de imágenes, su procesamiento y la utilización de los resultados obtenidos. Su objetivo es determinar qué zonas de la superficie son defectuosas por alejarse de la homogeneidad esperada y cuál es el tipo de defecto presente. Para ello, se caracterizan anomalías en el dominio espacio-frecuencial, explotando las posibilidades que ofrece el filtro de Gabor. Se ha definido una metodología para el diseño de bancos de filtros de Gabor que analiza una zona del espacio de frecuencias y orientaciones. La información extraída por estos filtros son las características evaluadas en la detección y clasificación de defectos. Este enfoque general ha sido particularizado a la resolución de tres problemas reales de reconocida trascendencia: la inspección de bobinas de chapa de acero laminado, del pavimento de carreteras y del revestimiento de túneles de hormigón.Departamento de Ingeniería de Sistemas y Automátic

Metodología de detección de óxido residual en superficies de acero inoxidable mediante visión por computador

La presente tesis doctoral es una investigación que propone una alternativa basada en visión por computador a la detección, por parte de un operador humano, de un defecto superficial denominado óxido residual que puede producirse durante el procesamiento de bobinas de acero inoxidable en una línea de recocido y decapado de la industria siderúrgica. Se trata de un defecto cuya eliminación incompleta puede producir problemas operativos durante el procesamiento posterior que va a sufrir la bobina (laminación en frío, recocido final, revestimiento, tintado especial, etc.) afectando claramente a la calidad superficial del producto final. La tesis tiene dos objetivos fundamentales. Un primer objetivo que consiste en la elaboración de una metodología para la detección de óxido residual en superficies de acero inoxidable basada en visión por computador que cumple con una serie de requisitos: detecta el defecto sobre superficies en movimiento de manera fiable, robusta y eficiente, considera una amplia variedad de tipos de acero y acabados superficiales, cuantifica la cantidad de defecto existente sobre la superficie y lo clasifica dimensionalmente y, finalmente, es viable para su aplicación en un entorno industrial agresivo. Un segundo objetivo complementario donde se construye e implanta un sistema de inspección visual automatizado para la detección y clasificación de defectos de óxido residual basado en la metodología previamente elaborada y que permite la obtención de los datos necesarios para su validación. En la memoria de tesis se realiza un estudio del arte sobre detección y clasificación de defectos en la producción de acero y otro, más específico, sobre sistemas para la detección de óxido residual en superficies de acero. El proceso de adquisición de imágenes integra un nuevo sistema de iluminación difusa estroboscópica para inspección de superficies en movimiento que ilumina de forma homogénea la superficie de inspección y evita la formación de sombras provocadas por la topografía de la superficie del material. La estrategia de procesamiento de imágenes para la detección y clasificación dimensional de manchas de defecto integra una nueva técnica de segmentación basada en la umbralización automática del histograma a partir de conocimiento empírico. Para ello, se crea una base de conocimiento constituida por índices estadísticos descriptivos extraídos de una población de imágenes previamente caracterizadas por un experto. Sobre esta base de conocimiento, se construye un modelo matemático empírico basado en una red neuronal que permite establecer un rango de búsqueda del umbral de binarización final. La complejidad del sistema de inspección se reduce mediante una inspección automatizada basada en un muestreo aleatorio simple de la superficie de acero que agiliza la adquisición y el tratamiento de datos. El diseño de la arquitectura de adquisición y procesamiento de imagen, el accionamiento de los movimientos del sistema de inspección visual automatizado y la técnica de inspección basada en muestreo aleatorio han dado lugar a una patente internacional reconocida en varios países