An Efficient Performance of Mimo - Ofdm Based Cognitieve Radio System for Arr...IOSR Journals
Abstract: The wireless channel is central within this context, thus estimating the channel is the key to make CR operational, taking in consideration that the transmission-reception technology is available. In this thesis, we design a MIMO system using OFDM modulation technology to transmit and receive two signals over the mobile wireless channel. First formulate the pilot design as a new optimization problem. We use MIMO concept to enhance system capacity and robustness of the wireless transmission. In Multi-Input Multi-Output (MIMO) based cognitive radio (CR) systems, with the increasing demand for data rate and reliability in Wireless communicationsand devices, several issues become very important like bandwidth efficiency, quality of service and radio coverage. In this new scheme, adaptive arrays are group-selected in the spatial domain. Simulation shows that the proposed system can get significant performance improvements over the conventional array based OFDM systems over frequency-selective multipath fading channels with cognitive radio (CR) system. Keywords: Cognitive radios, MIMO, OFDM, and Joint transmit and receive group selected arrays.
The Evaluation of the Seismic Vulnerability of Reinforced Concrete Building i...IOSR Journals
The work is presented in the context of estimating the seismic vulnerability of reinforced concrete
building by determining the maximum displacements of all levels of the studied building and stability factors, by
comparing the seismic shifts in the three areas of Morocco, using seismic regulations 2000, different
vulnerabilities studies allowed us to establish a new concept of the economic impact of the optimal sizing and
CR- Submanifoldsof a Nearly Hyperbolic Cosymplectic ManifoldIOSR Journals
This document discusses properties of CR-submanifolds of a nearly hyperbolic cosymplectic manifold. It begins with definitions of nearly hyperbolic cosymplectic manifolds and CR-submanifolds. The paper then obtains some results about the horizontal and vertical distributions on CR-submanifolds, including that the horizontal distribution is invariant by the structure tensor φ, while the vertical distribution is anti-invariant by φ. Lemmas are proved relating the covariant derivatives of φ on the horizontal and vertical distributions to terms involving the second fundamental form and normal connection.
1) The document discusses providing security against distributed denial of service (DDOS) attacks in mobile ad hoc networks. It focuses on intrusion detection systems and detecting black hole and wormhole attacks.
2) Black hole attacks involve malicious nodes pretending to have valid routes to destinations in order to intercept packets. Wormhole attacks involve tunneling packets between two points in the network to attract traffic.
3) The document proposes using intrusion detection systems that use both signature-based and anomaly-based detection to identify these types of attacks without prior knowledge of signatures. It aims to provide a solution for detecting and mitigating DDOS attacks in ad hoc networks.
An Efficient Performance of Mimo - Ofdm Based Cognitieve Radio System for Arr...IOSR Journals
Abstract: The wireless channel is central within this context, thus estimating the channel is the key to make CR operational, taking in consideration that the transmission-reception technology is available. In this thesis, we design a MIMO system using OFDM modulation technology to transmit and receive two signals over the mobile wireless channel. First formulate the pilot design as a new optimization problem. We use MIMO concept to enhance system capacity and robustness of the wireless transmission. In Multi-Input Multi-Output (MIMO) based cognitive radio (CR) systems, with the increasing demand for data rate and reliability in Wireless communicationsand devices, several issues become very important like bandwidth efficiency, quality of service and radio coverage. In this new scheme, adaptive arrays are group-selected in the spatial domain. Simulation shows that the proposed system can get significant performance improvements over the conventional array based OFDM systems over frequency-selective multipath fading channels with cognitive radio (CR) system. Keywords: Cognitive radios, MIMO, OFDM, and Joint transmit and receive group selected arrays.
The Evaluation of the Seismic Vulnerability of Reinforced Concrete Building i...IOSR Journals
The work is presented in the context of estimating the seismic vulnerability of reinforced concrete
building by determining the maximum displacements of all levels of the studied building and stability factors, by
comparing the seismic shifts in the three areas of Morocco, using seismic regulations 2000, different
vulnerabilities studies allowed us to establish a new concept of the economic impact of the optimal sizing and
CR- Submanifoldsof a Nearly Hyperbolic Cosymplectic ManifoldIOSR Journals
This document discusses properties of CR-submanifolds of a nearly hyperbolic cosymplectic manifold. It begins with definitions of nearly hyperbolic cosymplectic manifolds and CR-submanifolds. The paper then obtains some results about the horizontal and vertical distributions on CR-submanifolds, including that the horizontal distribution is invariant by the structure tensor φ, while the vertical distribution is anti-invariant by φ. Lemmas are proved relating the covariant derivatives of φ on the horizontal and vertical distributions to terms involving the second fundamental form and normal connection.
1) The document discusses providing security against distributed denial of service (DDOS) attacks in mobile ad hoc networks. It focuses on intrusion detection systems and detecting black hole and wormhole attacks.
2) Black hole attacks involve malicious nodes pretending to have valid routes to destinations in order to intercept packets. Wormhole attacks involve tunneling packets between two points in the network to attract traffic.
3) The document proposes using intrusion detection systems that use both signature-based and anomaly-based detection to identify these types of attacks without prior knowledge of signatures. It aims to provide a solution for detecting and mitigating DDOS attacks in ad hoc networks.
La Master Edition de Legend of Zelda incluye una estatua de la Master Sword, el juego de Legend of Zelda, un estuche Sheikah para Nintendo Switch, un soundtrack con 24 canciones, una moneda conmemorativa y una caja especial, además de un 10% de descuento en la compra.
Nintendo ha lanzado una nueva versión de su consola híbrida Switch con una pantalla OLED de 7 pulgadas, 64 GB de almacenamiento interno y mejoras en el audio. La Nintendo Switch OLED ofrece una experiencia de juego mejorada con colores más vibrantes y negros más profundos gracias a su pantalla OLED, además de una base más ancha con un soporte ajustable.
La Master Edition de Legend of Zelda incluye una estatua de la Master Sword, el juego de Legend of Zelda, un estuche Sheikah para Nintendo Switch, un soundtrack con 24 canciones, una moneda conmemorativa y una caja especial, además de un 10% de descuento en la compra.
Nintendo ha lanzado una nueva versión de su consola híbrida Switch con una pantalla OLED de 7 pulgadas, 64 GB de almacenamiento interno y mejoras en el audio. La Nintendo Switch OLED ofrece una experiencia de juego mejorada con colores más vibrantes y negros más profundos gracias a su pantalla OLED, además de una base más ancha para jugar de forma portátil.
La Master Edition de Legend of Zelda incluye una estatua de la Master Sword, el juego de Legend of Zelda, un estuche Sheikah para Nintendo Switch, un soundtrack con 24 canciones, una moneda conmemorativa y una caja especial, además de un 10% de descuento en la compra.
Nintendo ha lanzado una nueva versión de su consola híbrida Switch con una pantalla OLED de 7 pulgadas, 64 GB de almacenamiento interno y mejoras en el audio. La Nintendo Switch OLED ofrece una experiencia de juego mejorada con colores más vibrantes y negros más profundos gracias a su pantalla OLED, además de una base más ancha con un soporte ajustable.
La Master Edition de Legend of Zelda incluye una estatua de la Master Sword, el juego de Legend of Zelda, un estuche Sheikah para Nintendo Switch, un soundtrack con 24 canciones, una moneda conmemorativa y una caja especial, además de un 10% de descuento en la compra.
Nintendo ha lanzado una nueva versión de su consola híbrida Switch con una pantalla OLED de 7 pulgadas, 64 GB de almacenamiento interno y mejoras en el audio. La Nintendo Switch OLED ofrece una experiencia de juego mejorada con colores más vibrantes y negros más profundos gracias a su pantalla OLED, además de una base más ancha para jugar de forma portátil.