نتایج جستجو برای: distribution of frequency

تعداد نتایج: 21222023  

When a distribution network consisting of Distributed Generations (DGs) is disconnected from upstream network, the system may be exposed to severe power imbalance. In order to prevent the damage of power plants, frequency relays operate and remove DGs from the network. In contrast to traditional methods, the main objective in new methods is to keep DG units in service in the islanded distributi...

Journal: :IEEE Trans. Information Theory 2001
Richard G. Baraniuk Patrick Flandrin Augustus J. E. M. Janssen Olivier J. J. Michel

The generalized entropies of Rényi inspire new measures for estimating signal information and complexity in the time–frequency plane. When applied to a time–frequency representation (TFR) from Cohen’s class or the affine class, the Rényi entropies conform closely to the notion of complexity that we use when visually inspecting time–frequency images. These measures possess several additional int...

Journal: :تحقیقات جغرافیایی 0
سید ابوالفضل مسعودیان دانشگاه اصفهان اسماعیل نصرآبادی دانشگاه اصفهان حسین عساکره

in this research, the daily precipitation data of 1437 synoptic, climatic and rain gauging stations of iran in the time interval 1961- 2004 (equal to 15705 days) was utilized. using kriging geostatistics method, the data were interpolated on the pixels of 15 *15km2, so as an array to the dimension of 15705 * 7187 was formed. to identify the fittest distribution of the days with over 5.0mm preci...

This paper presents an optimal method of frequency load shedding (UFLS) based on the rate of change of frequency of load (ROCOFL) in islanded distribution networks (DN). The proposed method minimizes the average amount of penalties paid by the independent operator of the network by utilizing the relevant cost function. The function of islanded distribution network occurs after an error in the s...

Journal: :iranian journal of public health 0
d.d.farhud p.amirshahi sh.hedayat

the distribution of haptoglobin types of iranian living in bandaranbas (n=1246) is reported. hp1 gene frequencies reported in the literature for different populations in iran are given. comparison of the know hp1 distribution patterns show that the present hp1 frequency (0.266) is similar to other populations in iran.

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه اصفهان - پژوهشکده تربیت بدنی و علوم ورزشی 1391

چکیده معضل چاقی به عنوان عارضه ای جدی برای زندگی بی تحرک و ماشینی، مورد توجه اغلب مراکز بهداشتی و درمانی دنیا قرار گرفته است. چاقی عامل زمینه ساز و در واقع عامل خطری برای بروز بیماری های قلبی - عروقی است که عموماً با کاهش طول عمر مورد انتظار و افزایش بیماری همراه است. هدف پژوهش حاضر تأثیر 12 هفته تمرینات ویبریشن کل بدن، تمرینات هوازی و تمرینات ترکیبی( هوازی و ویبریشن کل بدن) بر ترکیب بدنی زنان ...

Journal: :IEEE Trans. Signal Processing 2003
Peter J. Schreier Louis L. Scharf

We challenge the perception that we live in a “proper world,” where complex random signals can always be assumed to be proper (also called circularly symmetric). Rather, we stress the fact that the analytic signal constructed from a nonstationary real signal is in general improper, which means that its complementary correlation function is nonzero. We explore the consequences of this finding in...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علامه طباطبایی - دانشکده اقتصاد 1389

abstract: about 60% of total premium of insurance industry is pertained?to life policies in the world; while the life insurance total premium in iran is less than 6% of total premium in insurance industry in 2008 (sigma, no 3/2009). among the reasons that discourage the life insurance industry is the problem of adverse selection. adverse selection theory describes a situation where the inf...

Variation along the successional stage of a plant community is not limited to plant composition and diversity but also related to nutrient resources and plant species abundance distribution. Therefore, the use of models that consider the distribution of ecological niches in addition to the relative frequency of species in the distribution of species is also important. The object of current stud...

Journal: :the modares journal of electrical engineering 2016
r. rahmani a. fakharian

microgrids are small-scale, low voltage (lv) power networks which employ renewable distribution energy resources (ders) with power electronic interfaces (peis). microgrids as single controlled units and active distribution networks require flexible control systems to ensure reliable and secure operation in different modes. these various operations of microgrid cause variations in voltage and fr...

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