نتایج جستجو برای: time or frequency

تعداد نتایج: 5006214  

Journal: :iranian economic review 0
vladimir motorin national research university “higher school of economics”, moscow, russian federation

the paper presents unified analytical solution for combining high-frequency and low-frequency economic time-series by additive and proportional denton methods with parametrical dependence on the initial values of variable and indicator in evident form. this solution spans denton’s original and cholette’s advanced benchmarking initial conditions as the subcases. computational complexity of the o...

Journal: :فیزیک زمین و فضا 0
محمد صادق پرکان دانشجوی کارشناسی ارشد مؤسسة ژئوفیزیک دانشگاه تهران حمیدرضا سیاه کوهی استاد، گروه فیزیک زمین، موسسه زئوفیزیک دانشگاه تهران، ایران علی غلامی دانشیر، گروه فیزیک زمین، موسسه ژئوفیزیک دانشگاه تهارن، ایران

in this paper some new applications of empirical mode decomposition (emd) and hilbert spectrum in seismic ground-roll attenuation, random noise attenuation and spectral decomposition are introduced. hilbert spectrum is a time-frequency representation for hilbert-huang transform which is obtained by combination of instantaneous frequency (if) concept and intrinsic mode function of empirical mode...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1390

in this thesis, a better reaction conditions for the synthesis of spirobarbiturates catalyzed by task-specific ionic liquid (2-hydroxy-n-(2-hydroxyethyl)-n,n-dimethylethanaminium formate), calcium hypochlorite ca(ocl)2 or n-bromosuccinimide (nbs) in the presence of water at room temperature by ultrasonic technique is provided. the design and synthesis of spirocycles is a challenging task becaus...

Journal: :Adv. Comput. Math. 2006
Say Song Goh Tim N. T. Goodman

We obtain an inequality on a measure of the spread in time of periodic functions that are concentrated in frequency, i.e. all but a fixed finite number of Fourier coefficients vanish with meansquared error up to . We characterize an extremal function and give an asymptotic formula for the measure of spread of this extremal function as approaches 0. We also consider the corresponding problem for...

2015
Georg T. Becker

In this paper we demonstrate the first real-world cloning attack on a commercial PUF-based RFID tag. The examined commercial PUFs can be attacked by measuring only 4 protocol executions, which takes less than 200 ms. Using a RFID smartcard emulator, it is then possible to impersonate, i.e., “clone” the PUF. While attacking the 4-way PUF used by these tags can be done using traditional machine l...

Journal: :Lexikos 2023

The possibility of compiling electronic corpora, as the second half last cen­tury, has provided new opportunities for vocabulary research. This also resulted in devel­op­ment a series computer software solutions lexical analysis texts and building lists language learners. In this article, differences tech­nical vocabu­lary according to their frequency keyness corpora English Specific Purposes (...

1995
Michael S. Richman Thomas W. Parks Ramachandra G. Shenoy

A discrete-time, discrete-frequency Wigner distribution is derived using a group-theoretic approach. It is based upon a study of the Heisenberg group generated by the integers mod N , which represents the group of discrete-time and discrete-frequency shifts. The resulting Wigner distribution satis es several desired properties. An example demonstrates that it is a full-band time-frequency repre...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه صنعتی اصفهان - دانشکده فیزیک 1390

in this thesis, barium ferrite nano particles were prepared by sol-gel method. their structural and magnetic properties of samples have been investigated using thermo gravimetric analysis (tg-dta), x-ray powder diffractometer (xrd), fourier transform infrared (ftir), scanning electron microscopy (sem), field emission scanning electron microscopy (fesem), ac susceptometer, vibrating sample magne...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید