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Yayın Design and implementation of a low cost telematic control system(Işık Üniversitesi, 2002-09) Şişman, Alper; Yarman, Bekir Sıddık Binboğa; Işık Üniversitesi, Fen Bilimleri Enstitüsü, Elektronik Mühendisliği Yüksek Lisans ProgramıThe thesis explains phases from ideation to concretize of a device that aims to solve continuously increase security needs in everyday life more effective, more reliable and cheaper way; however the device has so many application fields such as home automation projects, factory automation, SCADA systems, alarm and security systems, agricultural watering systems etc. A device that controls any desired event has been occurred, then informs the user over GSM, or activates any other electronic device when the user sends an SMS message over GSM, has been designed and realized in this thesis. All of the adjustments can be configured by user via SMS and serial port. Also all of the inform messages and output setting messages can be configured by serial port. For example, device's first input can be configured to send such a message 2Alert!3 when it is activated.Yayın Solid-state arrays and beamformers for side-looking intravascular ultrasonic imaging(Işık Üniversitesi, 2010-06-08) Şişman, Alper; Karaman, Mustafa; Işık Üniversitesi, Fen Bilimleri Enstitüsü, Elektronik Mühendisliği Doktora ProgramıCurrent solid-state intravascular ultrasound (IVUS) devices use a one-dimensional (1-D) rectangular array wrapped around the cylindrical catheter. Beamforming in these devices is limited to synthetic phased array processing, and the image quality is degraded by low signal to noise ratio (SNR) and lack of focusing in elevation. We propose new solid-state reconfigurable cylindrical array configurations, based on non-uniform aperture sampling, enabling realization of low-cost integrated phased array beamformers based on the latest IC and transducer integration techniques. We employed non-uniform (Fresnel) aperture sampling with identical differential delays between adjacent elements to reduce dynamic beamformer complexity. For this purpose, the angles of the element boundaries and centers are determined by equalizing path difference of neighboring elements. For Side Looking-IVUS (SLIVUS), the image plane is scanned through stepping the active aperture, and the active array must be reformed in each step. Fresnel sampled ring array leads to a simplified phased array beamformer with N/2 identical differential delays. The same logic applies to a two-dimensional (2-D) array with NL×NE-elements over a cylindrical patch. We compared the proposed and existing array designs through numerical point spread function (PSF) simulations. The uniform and Fresnel sampled 1-D ring arrays perform similarly in terms of beam quality while the latter improves image SNR by a factor of ?NL due to synthetic vs full phased array processing. The Fresnel sampled 2-D array performs dramatically better in elevation compared to 1-D ring array. The additional contribution of 2-D array on image quality is high SNR produced by phased array beamforming. The proposed Fresnel sampling of cylindrical aperture simplifies phased array beamformer by halving the required delay element count and transforms the complex 2-D beamformer into a separable beamformer that requires simple 1-D beamformers. The resulting 1-D and 2-D SLIVUS array configurations could be realizable using monolithic integration of the analog beamformers with transducer arrays.
