in order to obtain maximum information from magnetic and gravity anomaly maps, application of an edgedetection method is necessary. in this regard two commonly used methods are derivative filters and local phase filters. in this paper, a matlab code is expanded to combine an analytic signal filter and a tilt angle filter as a new edge detection filter called asta filter. this method was demonst...

‎In this paper‎, ‎the notion of the radical of a filter in‎ ‎residuated lattices is defined and several characterizations of‎ ‎the radical of a filter are given‎. ‎We show that if F is a‎ ‎positive implicative filter (or obstinate filter)‎, ‎then‎ ‎Rad(F)=F‎. ‎We proved the extension theorem for radical of filters in residuated lattices‎. ‎Also‎, ‎we study the radical‎ ‎of filters in linearly o...

In this paper, we introduce the concepts of n-fold obstinate pseudo-hoop and n-fold obstinate filter in pseudo-hoops. Then we investigated these notions and proved some properties of them. Also, we discussed the relationship between n-fold obstinate pseudo-hoop and n-fold obstinate filter and other types of n-fold pseudo-hoops and n-fold filters such as n-fold (positive) implicative filter and ...

Periodic noises are unwished and spurious signals that create repetitive pattern on images and decreased the visual quality. Firstly, this paper investigates various methods for reducing the effects of the periodic noise in digital images. Then an adaptive optimum notch filter is proposed. In the proposed method, the regions of noise frequencies are determined by analyzing the spectral of noisy...

This paper presents a novel microstrip low-pass filter with good performance. A complete detailed theoretical analysis for the proposed filter is given using equivalent circuit models. The proposed filter applying multiple cascaded modified radial stubs resonators provides a sharp cut off frequency response that has a 185 dB/GHz roll off rate. Also, U-shaped attenuators provide a wide stop-band...

Background: Butterworth, Gaussian, Hamming, Hanning, and Parzen are commonly used SPECT filters during filtered back-projection (FBP) reconstruction, which greatly affect the quality and size accuracy of image. Materials and Methods: This study involved a cardiac phantom in which 1.10 cm thick cold defect was inserted into its myocardium wall and filled with 4.0 μCi/ml (0.148 MBq/ml) 99mTc conc...

in this research, active capacitance circuit and the feature of negative resistance are analysed in details. also, a new active filter is presented based on active capacitance circuit. for simulations, we used matlab and advanced design system(ads). proposed active filter (rf) is a narrow band filter. the results of simulation shows some aspects of sustainability and low noise feature. the circ...

abstractbackground: an electron beam generated x-ray spectrum consists of characteristic x-ray and continuous bermsstrahlung. the aim of this research is calculating and comparing x-ray spectra for different target filter of mammograms. materials and methods: monte carlo is a very powerful tool to simulate a series of different target-filter assembly in order to calculate the x-ray spectra. mcn...