https://hdl.handle.net/20.500.12619/1464 2026-04-11T19:20:54Z https://hdl.handle.net/20.500.12619/69649 A Novel Hypogenetic Chaotic Jerk System: Modeling, Circuit Implementation, and Its Application ; Jiancheng Liu; Karthikeyan Rajagopal; Tengfei Lei; Kaçar, Sezgin; Arıcıoğlu, Burak; Çavuşoğlu, Ünal; Kökçam, Abdullah Hulusi; Anitha Karthikeyan ; When revising the polarity and amplitude information in the feedback, a unique hypogenetic jerk system was obtained which has two controllers to switch the equilibria between stable and unstable. After providing some basic dynamical analysis, an electronic circuit was implemented, and the phase trajectory in the oscilloscope agrees with the numerical simulation. Further exploration shows that this unique chaotic system has superior performance as a random number generator or in voice encryption application. 2020-01-01T00:00:00Z https://hdl.handle.net/20.500.12619/69650 Coarse Segmentation With GDD Clustering Using Color and Spatial Data ; Emre Gungor; Özmen, Ahmet ; Segmentation is a challenging and important task in image processing while developing vision based decision support systems. Color and brightness are widely used properties for extracting segments, however color information usage becomes more crucial for better region distinction, especially on outdoor scenes where brightness value makes segmentation difficult. In this study, a novel segmentation algorithm which incorporates downscaling and clustering methods has been developed to find consistent coarse regions in a given input image. The new method does not require external parameters and produces consistent segmentation results on different runs. In the algorithm, two intermediate segmentation results are obtained by feeding dissimilar downscaled image information to GDD (Gaussian Density Distance) clustering method. The outputs form two different perspectives from the same image: one shows global level color distinction, and the other shows spatial color similarity information. A merging process of these two outputs is implemented to improve the final segmentation. During the study, an experimental framework is designed for analysis of the proposed approach and its evaluation. The method is extensively tested using benchmark images. Some of the selected results are presented in the paper along with a comparative study with well-known segmentation algorithms. 2020-01-01T00:00:00Z https://hdl.handle.net/20.500.12619/69647 An exponential jerk system, its fractional-order form with dynamical analysis and engineering application ; Karthikeyan Rajagopal; Akgül, Akif; Sajad Jafari; Anitha Karthikeyan; Çavuşoğlu, Ünal; Kaçar, Sezgin ; A simple jerk system with only one exponential nonlinearity is proposed and discussed. Dynamic analysis of the integer-order jerk system shows the existence of chaotic oscillations. A model for the fractional-order jerk system is derived. The Adomian decomposition method is used to analyse the fractional-order jerk system. Stability analysis of the fractional-order jerk system shows that chaotic oscillations exist in orders less than one and bifurcation analysis shows the range of fractional orders for periodic and chaotic oscillations. To show the randomness of the fractional-order jerk system, a pseudorandom number generator is designed and tested. The NIST-800-22 tests show that the proposed fractional-order jerk system is effective in showing randomness. Finally, an image hiding application to the audio data has been realized by using the developed RNG algorithm. The encrypted image is hidden by being embedded in the audio data, and then, on the receiver side, the data are recovered by taking the image data from the hidden audio file. 2020-01-01T00:00:00Z https://hdl.handle.net/20.500.12619/69646 GPU-Based Dynamic Solar Potential Estimation Tool Using 3D Plans ; Kaynak, Sümeyye; Kaynak, Baran; Özmen, Ahmet ; Estimations of the solar potential from the building design files may affect placement considerations in favor of more sunlight reception that reduces the energy costs and saves the environment. In this study, a GPU based system (GPU-DSRM) is proposed to estimate direct and diffuse solar radiation aggregated on 3D structures at urban or individual scale. In the proposed approach, finite element method, back-face detection and ray-tracing algorithms are customized to run in parallel to reduce the execution time. Thus, real-time shadow analysis with adjustable sampling rate and time scale can be performed without compromising precision and accuracy of the estimations. The most important novel aspect of the study is that it can be used anywhere in the world without the need for meteorological data. Some of the test results obtained from a site with 10 buildings are presented in this paper that shows a speedup value of 45 with the new GPU-based implementation compared to the CPU-based model. The GPU-DSRM tool has also been compared with geometric tools in the literature. Solar energy potential analysis of building designs or existing urban formations can be completed faster and more precisely with this new approach. 2020-01-01T00:00:00Z