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...

abstract: country’s fiber optic network, as one of the most important communication infrastructures, is of high importance; therefore, ensuring security of the network and its data is essential. no remarkable research has been done on assessing security of the country’s fiber optic network. besides, according to an official statistics released by ertebatat zirsakht company, unwanted disconnec...

abstract nowadays, industries cannot play a crucial role in national and international competitions. the tourism industry is no exception. tourism industry development as the most important economic sector and income generation is one of the key challenges of economic development in the world. therefore, countries were successful that take advantage of the capabilities of tourism sector using ...

in this thesis, a structured hierarchical methodology based on petri nets is used to introduce a task model for a soccer goalkeeper robot. in real or robot soccer, goalkeeper is an important element which has a key role and challenging features in the game. goalkeeper aims at defending goal from scoring goals by opponent team, actually to prevent the goal from the opponent player’s attacks. thi...

this study compared the different effects of form-focused guided planning vs. meaning-focused guided planning on iranian pre-intermediate students’ task performance. the study lasted for three weeks and concentrated on eight english structures. forty five pre-intermediate iranian students were randomly assigned to three groups of guided planning focus-on-form group (gpfg), guided planning focus...

چکیده مجموعه حاضر با هدف معرفی و ارائه ی توصیفی برای اصطلاحات رایج در دانش معنی شناسی تهیه شده است. برای دستیابی به چنین هدفی سعی بر آن بود تا صرفاً به واژگان نقش مند در شاخه ی عمده ی معنی شناسی زبانی توجه شود. در حوزه معنی شناسی زبانی، به اصطلاحات در شاخه ای از این دانش، یعنی معنی شناسی نظری (theoretical semantics) و آنچه معنی شناسی کاربردی (applied semantics) نامیده ایم، اشاره شود. و هدف از ت...

there are two major theories of measurement in psychometrics: classical test theory (ctt) and item-response theory (irt). despite its widespread and long use, ctt has a number of shortcomings, which make it problematic to be used for practical and theoretical purposes. irt tries to solve these shortcomings, and provide better and more dependable answers. one of the applications of irt is the as...

due to lack of knowledge management system in the organization of technical and vocational university of iran (tvuni) and losing good employees because of retirement and substitution causes huge amount of costs to replace the similar expertise. there is no any suitable system in the tvuni to store, to document, and to distribute knowledge. based on the university’s features such as it has diffe...

many mobile and off-grid devices include electronics and other electrical consumers like servo drives, which need a quite low supply power. since the price for photovoltaic modules drops continuously, photovoltaic power supply is interesting in more and more applications. in solar powered systems, a battery is needed to store energy for the night and cloudy periods. the power electronics of suc...

a simple, sensitive and selective method for solvent extraction and spectrophotemetric determination of lanthanum (ii) europium (iii), and cerium (iii) is described , the rare earth metals are extracted into chloroform solution of n-phenylbenzohydroxamic acid (pbha) at ph 9-10 various parameters are studied to optimize the extraction conditions. the molar absorptivity is found to increase from ...