m. alavi

Examining and analyzing text contrasts to achieve the nature of the central concept in a work through dual contrast analysis is one of the methods of studying texts in the constructivist method. Claude Levi-Strauss is a constructivist linguist who believes in bipolar opposition or semantic opposition. Based on the confrontational attitude, many of the stories of Shahnameh are formed from dual confrontations; The main purpose of this article is to investigate the contrast between the two stories in the historical part of Shahnameh based on Strauss's constructivist theory.

In this article, the authors have emphasized the descriptiveanalytical method based on the method of document mining and library studies in three stories of the historical part of Shahnameh, namely the story of Bahram Gour, Khosrow Anoshirvan and Bahman.

The findings of this study show that in the historical part of Shahnameh, under the influence of its mythological part and also the concept of duality in mythology, we are still faced with the infrastructure of dual contrasts to historical events.

The findings of the study indicate that the confrontations in the historical part of Shahnameh such as the confrontation of justice and oppression, Iran and Iran, the battle between good and evil, the confrontation between father and son or confrontation with predatory and wild animals all serve as general confrontations. And in order to strengthen the fundamental reciprocal aspects of myth, that is, the idea of good and evil.

In this paper, the behavior of free vibrations of the thick sandwich panel with  multi-layer face sheets and an electrorheological (ER) fluid core using  Exponential Shear Deformation Theory were investigated. For the first time, Exponential shear deformation theory is used for the face sheets while the Displacement field based on the second Frostig's model is used for the core. The governing equations and the boundary conditions are derived by Hamilton’s principle. Closed form solution is achieved using the Navier method and solving the eigenvalues. Primary attention is focused on the effects of electric field magnitude, geometric aspect ratio,and ER core layer thickness on the dynamic characteristics of the sandwich plate. The rheological property of an ER material, such as viscosity, plasticity, and elasticity may be changed when applying an electric field. When an electric field is applied, the damping of the system is more effective. The effects of the natural frequencies and loss factors on the dynamic behaviorof the  sandwich plate are studied.the natural frequency of the sandwich plate increases and the modal loss factor decreases. With increasing the thickness of the ER layer, the natural frequencies of the sandwich plate are decreased.

In this article, a novel method based on measuring the number of range cells in detected range profiles has been introduced according to two different aspects by two same high range resolution radars. At first, using rectangular approximation and measurement of the length and width of marine targets, calculation of the number of range cells is used in detected range profiles. On the following, according to the measurement of the angle between the two radars and target, Feature spaces are formed. Finally, classification of marine targets is formed using neural network. After completing the above steps and for testing the accuracy of the proposed algorithm, three real floatings are simulated in feko software. Then, range profiles obtained are mixed with noise and are imported to the neural network designed. Thus, the algorithm accuracy is measured according to different levels of signal to noise ratio. Accuracy of the algorithm, in certain confines, is above the 99%.

Aviation in IRAN and world has actors that need coordination .Coordination for using space, between units of army and Civil are necessary.
With refer to record and accidents , delay , many letter writing in national level and challenge meeting in proficiency level and high management find that required coordinations in lowest level, objective, executive and some more tactical, rated difficult process.
In eveny country there are tow main organ in aviation department : 1- Military department. 2- Civil department.
civil aviation filed including private, commercial govermental airlins parts, that is mostly employed the passenger and freight transportation in national and international manner .military aviation filed including: sovereignty air lines that is employed transportation , training , security and defense. both of the filds are necessary for global esistance and economice.
with the view to pending causes ,the basic question of this study is the lack of strategic management model of aviation system in the I.R.I and the problems caused by this ,which led the researcher to suggest the model of stertegic management of aviation in the space of I.R.I and act the field and library multi layer investigation .this is a strategic research ,and in terms of methodology data ,it is the discriptiveof the type of contex ,that performe by the means of interview , survey ,aviation men ,air traffic control men ,and military forces of I.R.I.

Purpose and aim:

The aim of this study was to assess the safety, occupational health and safety in the University Central Library is located in Tehran.

This study is a descriptive survey. The study included 18 central libraries and free public universities in Tehran using a researcher made questionnaire data were collected with 5 of safety and security library Narrative research with professors and professionals to investigate the validity and reliability coefficient Cronbach's alpha(0/963) was approved. The data obtained from the questionnaires using SPSS and Excel and descriptive statistics techniques such as frequency tables, draw, and circular histograms were analyzed. Components of Friedman test was used to rank.

The results showed that the mean compliance of safety measures,  5% of the libraries in very bad condition, 14% in poor condition, 24 percent of the state average, 28% In good condition and 2% in very good condition is obtained in 27% of libraries improper safety measures. Ranking of factors indicate that the components of fire safety, building physics, the conservation of biological damage, ventilation, protection against physical damage sources have the highest rank.

Measurement of immunity in university libraries in Tehran does not fully comply with the safety component is mainly in respect of each component did not succeed, and are not in good condition.