today, scouring is one of the important topics in the river and coastal engineering so that the most destruction in the bridges is occurred due to this phenomenon. whereas the bridges are assumed as the most important connecting structures in the communications roads in the country and their importance is doubled while floodwater, thus exact design and maintenance thereof is very crucial. f...

in this thesis, ‎‎using‎‎ ‎concept‎s‎ ‎of‎ ‎wavelet‎s‎ ‎theory ‎‎‎som‎e‎ ‎methods‎‎ ‎of‎ ‎th‎e ‎solving‎‎ ‎optimal‎‎ ‎‎con‎tr‎ol‎ problems ‎(ocps)‎‎. ‎g‎overned by time-delay systems is investigated. ‎th‎is‎ thesis contains ‎tw‎o parts. ‎‎first, the method of obtaining ‎o‎f ‎the‎ ‎‎ocps‎ in time delay systems by linear legendre multiwavelets is ‎ ‎presented‎.‎‎‎‎ the main advantage of the meth...

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 ...

some researches made in the field of agency problem issue, deal with the role of control systems regarding owners and managers. in this research the relationship between the two control mechanisms, namely the voluntary disclosure (external control mechanism) and outside directors (internal control mechanism), which are reductive of agency problems, has been studied. for this reason, a sample ...

vocabulary as a major component of language learning has been the object of numerous studies each of which has its own contribution to the field. finding the best way of learning the words deeply and extensively is the common objective of most of those studies. however, one effective way for achieving this goal is somehow neglected in the field. using a variety of activities such as games can r...

the aim of this paper is eliminating cr(vi) by natural hap. hap is a inexpensive material which is used from bovine critical bone ash in order to remove heavy metal ions like cr(vi). some experiments in different ph are performed (ph=2,3,7). maximum adsorption was appeared at ph=2, dosage=0.3 gr, c0=10 mg/l. cr(vi) removal depends on ph value and initial amount of cr(vi) result of experiments w...

abstract : the purpose of this research is to study a bout multiple manifestations of poem music in hakim sanaee ghaznavi poems yherefore the first seetion of this book study and describes the complete works of this research about poem music love poem sanaee poem and this known and famous poets life and works the second section explained the external music of sanaee poems that for better u...

a significant problem in multicarrier communication systems is the necessity to reduce the value of papr (peak-to-average power ratio) of transmitting signal. in this thesis we study the effect of the system parameters such as coding and modulation types on papr and ultimate ber in a mc-cdma system. in this study we consider fading channel as well as the nonlinearity of transmitter’s amplifier ...

کتاب تبصره المومنین(نگارش در سال1080ق) تالیف محمد مومن حسینی تنکابنی، جوابیه و ردّیه ای بر سخنان ملامحمد طاهر قمی در کتاب تحفه الاخیار است. این تحقیق تصحیح انتقادی و نقد وبررسی این کتاب است که نسخه مجلس شورای اسلامی اساس قرارداده شده و با سه نسخه دیگر مقابله شده است. نویسنده کتاب یکی از پزشکان دربار شاه سلیمان صفوی(1077) است. وی در عصری زندگی می کند که تصوف وصوفیان اگرچه درحمایت نسبی حکومت هستند...

according to webster and wind (1972) and anderson et al (1987), “organizational buying is a complex process and involves many people from different functional areas, multiple goals and potentially conflicting decision criteria. moreover, the customers of today are also more knowledgeable and selective when making their purchasing decisions. since a key to organizational survival is the retentio...