background and aim: it has been several decades since the technology of frequency lowering (fl) has been proposed. however, primary research has revealed no benefits regarding the use of this technique. currently, new methods for fl and improvement of perception of speech and fricative sounds have led to the application of these methods by numerous companies to produce hearing aids. in this stu...

In this paper, a computational goal for a monaural speech separation system is proposed. Since this goal is derived by maximizing the signal-to-noise ratio (SNR), it is called the optimal ratio mask (ORM). Under the approximate W-Disjoint Orthogonality assumption which almost always holds due to the sparse nature of speech, theoretical analysis shows that the ORM can improve the SNR about 10log...

Background: We investigated whether the lungheart ratio parameter (LHR) can be used to identify the optimum cut off frequency for Butterworth filter in 99mTc myocardial SPECT imaging. Materials and Methods: This study involved a cardiac phantom system consisting of cardiac insert in which 1.10 cm cold defect was inserted into its myocardium wall and filled with 4.0 μCi/ml (0.148 MBq/ml...

Subalpine ecosystems are highly fragile as compared to biological andenvironmental factors. Landslide is one of the ruinous upshots of this ecosystem. One of theimpressionable areas in the cause of natural factor is Masoleh watershed in western AlborzMt, (Iran). In order to landslide hazard zonation, landslide index and frequency ratio methodbased on twelve causative factors such as slope, slop...

Introduction: Micro perforated panel (MPP) absorbents promise the next generation of sound absorbers as they have significant advantages over other porous adsorbents. In this study, we will investigate the acoustic performance of MPP absorbents made of biodegradable polylactic acid composite reinforced with natural corkwood fibers (PLA/Corkwood) by 3D printing technology. Material and Methods:...

In Multiple Input Multiple Output Orthogonal Frequency Division Multiplexing system using beamforming improve the receive Signal to Noise Ratio. In the transmission signals after beam forming the Peak-to-Average Power Ratio (PAPR) is a major issue in Orthogonal Frequency Division Multiplexing systems, High Peak to Average Power Ratio is complicated to design the power amplifier and also increas...

background: in 2-4% of couples in fertile ages, recurrent pregnancy loss (rpl) occurs which consisted one out of 300 pregnancies. the aim of this study was to comparison insulin resistance (ir) in patients with rpl to normal individuals. materials and methods: in a case-controlled, prospective study, 49 non-pregnant, non-diabetic women with early rpl as the case group and 49 non-pregnant, non-d...

film coating solutions containing different grades of hpmc (e5, e15 and e50) with and without polyethylene glycol (with various molecular weights) were examined by an oscillatory method, using haake cv 100 rheometer. fundamental rheological parameters (?, g? and g² ) were measured over the frequency range from 0.04 to 2 hz. the variation with frequency of the loss tangent (a ratio of viscous to...

in this paper the breast lesions, more particularly the carcinomas. have been studied in the taj pahlavi cancer institute, teheran , iran, from 1956 through 1971. in this period of 15 years the number of breast lesions observed have been 2107 cases of which 1023 cases or 48.5 %have had reference to carcinomas especially among women, the ratio of females to males suffering from this type oflesio...