Güncel Gönderiler: Fen Bilimleri Enstitüsü
Toplam kayıt 86, listelenen: 61-80
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Dynamic range enhancement in light field imaging systems
(İstanbul Medipol Üniversitesi Fen Bilimleri Enstitüsü, 2019)High dynamic range imaging has been an active research area in computational photography over the last two decades. The main reason is that the dynamic range of a traditional camera is typically less than the dynamic range ... -
Image enhancement through new techniques in computational photography
(İstanbul Medipol Üniversitesi Fen Bilimleri Enstitüsü, 2019)Quality of a digital image depends on several factors operative during the image formation process, e.g. sensor defects, sensor dynamic range, poor spatial resolution,lens distortion, camera shake and object motion. This ... -
Directivity enhancement of 60 GHz microstrip patch antennas using dielectric fabry-perot resonantors
(İstanbul Medipol Üniversitesi Fen Bilimleri Enstitüsü, 2019)The 60 GHz frequency band offers many opportunities for innovations in the wireless network technology, unlike other bands. Since the wavelength in the 60 GHz band is millimetric, this band can suitably represent the ... -
FM band channel measurements and modelling
(İstanbul Medipol Üniversitesi Fen Bilimleri Enstitüsü, 2018)As the demand for higher data rates increases every day, the need for new frequency bands becomes more and more prominent. The FM band between 88 and 108 MHz is one of the bands that are not fully utilized. This band for ... -
Wireless channel modeling in the TVWS band based on measurements
(İstanbul Medipol Üniversitesi Fen Bilimleri Enstitüsü, 2018)In this thesis, we study TV white space (TVWS) bands, which can be used in next generation networks, in indoor-indoor and indoor-outdoor environments. Path loss measurements are taken at the beginning, middle, and at the ... -
NOMA multi-numerology and guard reduction methods in OFDM systems for 5g networks
(İstanbul Medipol Üniversitesi Fen Bilimleri Enstitüsü, 2018)Non-orthogonal multiple access (NOMA) is a promising technique which outperforms the traditional multiple access schemes in many aspects. It uses superposition coding (SC) to share the available resources among the users ... -
Super resolution of light fields using convolutional neural network
(İstanbul Medipol Üniversitesi Fen Bilimleri Enstitüsü, 2018)Light field imaging extends the traditional photography by capturing both spatial and angular distribution of light, which enables new capabilities, including post-capture refocusing, post-capture aperture control, and ... -
Aerial platforms utilization for future networks
(İstanbul Medipol Üniversitesi Fen Bilimleri Enstitüsü, 2018)Challenges facing the next generation of communication systems include utilizing the wireless networks in the rural areas and disaster situations, as well as the requirements of high capacity services and connectivity ... -
Emulation techniques for small scale fading aspects of wireless channels by using reverberation chamber
(İstanbul Medipol Üniversitesi Fen Bilimleri Enstitüsü, 2018)Reverberation chambers (RVCs) are used to provide an effective and reliable testbed for emulating wireless channel effects in the laboratory environment. Various techniques that enrich the capabilities of the RVC in channel ... -
Design of a voltammetry system for in vivo measurement of dopamine concentration
(İstanbul Medipol Üniversitesi Fen Bilimleri Enstitüsü, 2018)Dopamine has a critical role in motor control, motor learning, reinforcement learning, cognition, attention and motivation. Consequently, the physiology of the dopaminergic system is an important and highly active research ... -
5G challenges : Waveform design and D2D communication
(İstanbul Medipol Üniversitesi Fen Bilimleri Enstitüsü, 2018)Fifth generation (5G) of communication systems is expected to satisfy a wide variety of requirements with regards to different applications. Flexibility, low latency, low power consumption are the most important ones. Using ... -
Advanced cross-layer secure communication designs for future wireless systems
(İstanbul Medipol Üniversitesi Fen Bilimleri Enstitüsü, 2018)Due to the inherent vulnerability of wireless transmission to eavesdropping, con- dentiality arises as a challenging issue especially for future wireless networks because of their unique requirements. To cope with this, ... -
OFDM with index modulation for narrowband iot and mmtc
(İstanbul Medipol Üniversitesi Fen Bilimleri Enstitüsü, 2018)The crucial aim for 5G narrowband Internet of Things (NB-IoT) is to support massive Machine-Type Communications (mMTC) with wide coverage area, low power consumption, low hardware complexity and low data rate. Direct ... -
Development of a wireless multichannel neural data transmission system
(İstanbul Medipol Üniversitesi Fen Bilimleri Enstitüsü, 2017)Implantable microelectrode arrays enable multichannel electrophysiological recordings from the mammalian brain during behavioral experiments. Wireless data transmission systems combined with the microelectrode arrays and ... -
Air-ground channel modeling and waveform containment
(İstanbul Medipol Üniversitesi Fen Bilimleri Enstitüsü, 2017)The content of this work is divided into two main parts. Part I is dedicated for characterizing Air-Ground channels. Applications using Air-Ground communications are expected to grow in the future. Low altitude phases of ... -
On the design of a flexible waveform and low ici symbol boundary alignment
(İstanbul Medipol Üniversitesi Fen Bilimleri Enstitüsü, 2017)Cellular systems of fifth generation (5G) radio access technology is expected to support a wide variety of service requirements in different applications. High reliability, flexibility, spectral efficiency, and low power ... -
Extracting sub-exposure images from a single capture through fourier-based optical modulation
(İstanbul Medipol Üniversitesi Fen Bilimleri Enstitüsü, 2017)Through pixel-wise optical coding of images during exposure time, it is possible to extract sub-exposure images from a single capture. Such a capability can be used for different purposes, including high-speed imaging, ... -
Extending light field camera capabilities
(İstanbul Medipol Üniversitesi Fen Bilimleri Enstitüsü, 2017)A traditional camera captures an image by projecting a scene on a two-dimensional image sensor plane regardless of the direction light rays coming onto the sensor. A light field camera, in contrast, records light rays in ... -
2d CMUT array based ultrasonic micromanipulation of particles
(İstanbul Medipol Üniversitesi Fen Bilimleri Enstitüsü, 2017)The thesis introduces a concept of combining row column addressed CMUT arrays with microfluidic channel to enable trapping and two-dimensional manipulation of micro-particles. In this work a multilayer planar resonator ... -
Signal processing techniques for security enhancement of wireless networks at the physical layer
(İstanbul Medipol Üniversitesi Fen Bilimleri Enstitüsü, 2017)Broadcast nature of wireless communications enables reaching multiple parties simultaneously. However, due to this property, the security of information trans- mission is prone to eavesdropping of unauthorized receivers. ...