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Öğe Hybrid Pattern Recognition System for Detecting Buried Object in GPR Images(BIOAXIS DNA RESEARCH CENTRE PRIVATE LIMITED, 2018) Ozkaya, U.; Seyfi, L.It is very difficult to evaluate the shape of the buried objects using Ground Penetrating Radar (GPR). In this study, 180 GPR B scan images were classified by using different classification algorithms. GPR-B scan images of objects with different shapes in various depths were obtained by using GprMax simulation program. Noise in these images were eliminated by Wavelet transform and then, Gray Level Co-occurrence Matrices (GLCM), run length matrix (RLM) and Autocorrelation function (ACF) features were extracted from the segmented images Some feature reduction methods, which are Principle Component Analysis and Independent Component Analysis, provided that size of the feature vectors was decreased. All the modified vectors were given as inputs to various classifiers. Outputs of the classifier systems were evaluated and compared with each other. Accuracy values of proposed algorithm results were computed. Consequently, it is possible to use in real application of GPR devices.Öğe Investigating the Role of Buried-object Radius and Surface Slope in Energy Efficiency of the Developed GPR Algorithm(Taylor & Francis Ltd, 2012) Seyfi, L.; Yaldız, E.Since ground penetrating radar (GPR) is a portable device, its battery life is very important for finishing scanning problematic area at the first time. Thus, importance of energy-efficient algorithm of GPR that we developed previously becomes more evident. This paper aims to investigate the effect of radius of buried object and layer surface slope on energy efficiency of the developed energy-efficient algorithm of GPR via computer simulations. Simulation models having a layer with wavy rough surface and a buried object were separately created. Critical values of wavy rough surface slope and buried object radius that guarantee energy efficiency at GPR scanning were determined. It was found that critical values changed with relative dielectric constant, conductivity, and depth of the layer or buried object. The simulations were carried out using 2D-finite difference time domain (FDTD) method in Matlab environment. Transverse electric mode and perfectly matched layer were applied while using 2D-FDTD approach.Öğe Measurement of Electromagnetic Signal Strengths of Four GSM Base Stations at 900 MHz in a Pilot Region(INT ASSOC ENGINEERS-IAENG, 2013) Durduran, S. S.; Seyfi, L.; Avci, C.; Ozan, A. M.Mobile phones are used by a wide range of people. Even children use mobile phone although they are in high risk group. Because of this, use of mobile phone should be evaluated based on valid and safe information and measurements. We can utilize mobile phone in a way we desire, that is, we can turn it off in order to avoid its radiation when we do not want to use it. However, we cannot control base stations; moreover we do not know where they are mounted. So, radiation of base stations has more importance than that of mobile phones in this respect. Additionally, some GSM service providers may prefer to conceal base station in a way people cannot notice when people are probably opposed to mounting of base station very close to their live space. In this paper, signal strength of base stations (900 MHz) in a pilot region were measured and recorded. The selected region was averagely 500,000 m2 and has 4 base stations. 53 measurement points were determined on the streets of the region. The measurement region had nearly 97 apartments and these apartments had between 400 and 500 flats. The population living in this region was between 1500 and 2000. The averaged signal strength over 53 points in this pilot region were estimated as - 72.7 dBm. The minimum and maximum measurements were recorded as - 87 and - 47 dBm, respectively. The standard deviation of the measurement values was calculated as - 8.5 dBm.Öğe A Novel Software for an Energy Efficient GPR(Elsevier Sci Ltd, 2010) Seyfi, L.; Yaldız, E.In this paper, a simulator software based on MATLAB environment has been developed so that an energy efficient ground penetrating radar (GPR) can be modelled. Thus, applications of the radar in practice will easily be performed. In the software, the output power of GPR has been assumed as variable in order to reduce energy consumption. Power values have been computed in simulations with the proposed software for two different models which have comprised mediums with horizontal sublayer and inclined sublayer. Compared with common algorithm, power savings (PS) of 43% for the horizontal situation and 22% for the inclined one have been obtained.
