نتایج جستجو برای: random noise attenuation and spectral decomposition are introduced. hilbert spectrum is a time

تعداد نتایج: 20842332  

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 شیراز 1379

‏‎for the first time nakayama introduced qf-ring. in 1967 carl. faith and elbert a. walker showed that r is qf-ring if and only if each injective right r-module is projective if and only if each injective left r-modules is projective. in 1987 s.k.jain and s.r.lopez-permouth proved that every ring homomorphic images of r has the property that each cyclic s-module is essentialy embeddable in dire...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علوم پایه دامغان 1390

the space now known as complete erdos space ec was introduced by paul erdos in 1940 as the closed subspace of the hilbert space ?2 consisting of all vectors such that every coordinate is in the convergent sequence {0} ? { 1 n : n ? n}. in a solution to a problem posed by lex g. oversteegen we present simple and useful topological characterizations of ec. as an application we determine the ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه گیلان - دانشکده فنی و مهندسی 1390

magnetic resonance imaging (mri) is a notable medical imaging technique that makes of phenomenon of nuclear magnetic resonance. because of the resolution and the technology being harmless, mri has considered as the most desirable imaging technique in clinical applications. the visual quality of mri plays an important role in accuracy of medical delineations that can be seriously degraded by exi...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه فردوسی مشهد - دانشکده علوم 1376

in chapter 1, charactrizations of fragmentability, which are obtained by namioka (37), ribarska (45) and kenderov-moors (32), are given. also the connection between fragmentability and its variants and other topics in banach spaces such as analytic space, the radone-nikodym property, differentiability of convex functions, kadec renorming are discussed. in chapter 2, we use game characterization...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان - دانشکده جغرافیا 1392

adolescents and young adults and their problems is an issue whose importance is obvious to anyone because youth are the founders of our countrys future and requires proper planning to be on leisure. given the importance of leisure,this study to investigate needs assessment and planning how adolescents and young adults spend their leisure time in urban of case study of high school girls and boys...

Seismic waves are non-stationary due to its propagation through the earth. Time-frequency transforms are suitable tools for analyzing non-stationary seismic signals. Spectral decomposition can reveal the non-stationary characteristics which cannot be easily observed in the time or frequency representation alone. Various types of spectral decomposition methods have been introduced by some resear...

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

the main objective in sampling is to select a sample from a population in order to estimate some unknown population parameter, usually a total or a mean of some interesting variable. a simple way to take a sample of size n is to let all the possible samples have the same probability of being selected. this is called simple random sampling and then all units have the same probability of being ch...

Journal: :فیزیک زمین و فضا 0
هدی آراسته مؤسسه ژئوفیزیک دانشگاه تهران- کارشناس ارشد عبدالرحیم جواهریان مؤسسه ژئوفیزیک دانشگاه تهران- استاد

one of the most fundamental reservoir characteristics is the thickness. the analysis of thin bed tuning on seismic reflectivity has been studied extensively by wides (1973) and neidel and pogiaggliomi (1977), who discussed the limits of seismic resolution. during the past decade, the industry has developed a plethora of new attributes in studying thin beds by employing spectral decomposition (p...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه ولی عصر (عج) - رفسنجان - دانشکده ریاضی 1392

let h be a separable hilbert space and let b be the set of bessel sequences in h. by using several interesting results in operator theory we study some topological properties of frames and riesz bases by constructing a banach space structure on b. the convergence of a sequence of elements in b is de_ned and we determine whether important properties of the sequence is preserved under the con...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید