Elektrik - Elektronik Mühendisliği Bölümü Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/202
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Article Step by Step Design Procedure of a Distribution Static Synchronous Compensator (DSTATCOM)(ÇUKUROVA ÜNİVERSİTESİ, 2015) Teke, Ahmet; Yoldaş, Yeliz; Latran, Mohammad Barghi; Barghı, Mohammed LatranDSTATCOM is one of the power conditioning devices that is used to mitigate power quality problems in distribution systems. The overall performance of the DSTATCOM is strictly related with the proper selection of power circuit configuration and controller algorithm. The power circuit of DSTATCOM consists of dc link capacitor, inverter and passive filter. The control circuit of DSTATCOM consists of reference signal extraction, DC link voltage control, AC voltage control and switching signal generation. Compensating current reference signal is generally derived from the measured quantities by the use of the Instantaneous Symmetrical Component Theory (ISCT) and dq theory based method. A proportional integral (PI) controller is generally used to maintain a constant voltage at the dc-link of a Voltage-Source Inverter (VSI). Furthermore, by connecting a delta connected inductor-capacitor-inductor (LCL) passive filter at inverter output, the high order harmonics generated by the DSTATCOM can be easily and effectively eliminated. This study presents the design procedures for power and control circuits of 300 kVA DSTATCOM in detail.Conference Object Effect of Bilinear Interpolation on the Texture Analysis of Colonoscopy Images(IEEE345 E 47TH ST, NEW YORK, NY 10017 USA, 2017) Kacmaz, Rukiye Nur; Yilmaz, BulentInterpolation is a method that is used to obtain unknown intensities with the help of known intensities on an image. This method is frequently used in the literature to eliminate light reflection on colonoscopy images. Texture features are the most important characteristics used to describe the region or objects of interest in the image. They are the measures of intensity variation of a surface that determine properties such as smoothness, roughness, and regularity. The aim of this study is to find out the how bilinear interpolation applied on colonoscopy images with reflection impact texture features obtained from the same images. A research carried out to make reasonable comparison between a texture feature from an image with no reflection and the same feature obtained from the same image with synthetically added reflections with various percentages. Using the approaches like gray level co-occurence matrix (GLCM), gray level run length matrix (GLRLM), neighborhood gray tone difference matrix (NGTDM) 126 features were extracted from each 32x32 sub-images coming from 610 colonoscopy images. Several of the features extracted from sub-images with no reflection and reflection were not statistically significantly different, while majority of them were affected from the reflections.Conference Object Redesign of commercial color filters for color enriched LCD displays(Gdansk University of Technology (GUT),, 2018) Genç, Sinan; Uran, Can; Mutlugün, EvrenHaving as much as different colors on displays is the main aim for a high color gamut LCD. Using conventional backlight systems, a blue LED with a YAG phosphor layer implemented onto it, a high portion of CIE 1931 color space is missed [1,2]. Not only broad emission spectrum of Yttrium Aluminum Garnet (YAG) for yellow light, but also crosstalk of commercial RGB color filters have huge impact of that result. Using quantum dots (QDs) which are promising backlight agents in terms of color quality can increase the number of different colors on displays thanks to their narrow emission spectra, ease in controllability of optical properties and high photoluminescence efficiency [3:5]. However, when it comes to the color filters, broad transmission spectra and crosstalk between those spectra reduces the quality [6]. In this study, we design, simulate, analyze a QD based backlighting system and compare it with conventional phosphor based white light. Simulating both yellow phosphor based LED and QD based LED in software, we engineer spectral parameters i.e. full width at half maximum, peak emission wavelength and intensities of emitters. Furthermore, we investigate the effect of commercial color filters on those two systems and propose a new, industrially appropriate color filter spectra. Using QD based backlight increases the NTSC color gamut area from 65-70% to 127% with more than 99.8% coverage and the negative effect of commercial color filters, around 15% that reduced the gamut ratio to 109%, is balanced with suggested spectral transmission parameters of RGB color filters for QD based backlighting systems.