فصلنامه علوم و فناوری دریا
سال بیست و سوم شماره 89 (بهار 1398)

In this paper, a linear Lagrangian numerical model is used for simulating the solitary wave propagation over the vertical coastal wall, as well as an Impermeable submerged breakwater, called the relatively compact (GCM) hydrodynamic model of relatively compact particles (WCSPH). This model is two-dimensional and considers the fluid to be weakly compressible. In addition to solving theviscous fluid governing equations for velocity and density field uses the state equation for obtaining the pressure. This reduces the computational volume compared to the base method of the particle hydrodynamic model. To simulate fluid turbulence in the wave propagation process on an impermeable submerged breakwater and vertical seawall the SPS turbulence model, which was obtained by large eddy simulation (LES) approach was used. The results of numerical simulations were compared with laboratory experiments. Also, the results of present numerical model were compared with the numerical model of Rambabua and Mani (2005). The results shown, the WCSPH computations produce better results than those of model of Rambabua and Mani (2005), with respect to the experimental data. The results of this study show that WCSPH method provides a useful tool to investigate the wave propagation over coastal structures

This paper analyzes the simulated performance of a Si-poly photovoltaic system connected to a 20 kilowatt network in western Mazandaran. The simulation system consists of 66 modules with a power of 310 watts and is powered by two 9.9 kW inverters to connect to the network. The simulation was performed using PVSyst 6.68 software, and the weather data from the Mazandaran Meteorological Database and Meteororm7.2 software were used for this analysis. The results suggest that a 129-meter-wide land plot will be installed and 66-panel 310 watts installed with 2 in. 9.9 kW and will supply the network with an annual output of 34.05 megawatts per year.

The most important and expensive portion of basic study of onshore and offshore projects include the measurement of wave characteristics. In Iran, however, will not the data collected are solely applied for the calibration and verification of the numerical modeling. Analysis and interpretation of field data independently or in combination with numerical models determine the general state of oceanographic pparameters. The general pattern of waves, their origin, seasonal variation and statistical distribution of height, period and their direction particularly provides valuable information for management concerns and engineering purposes. In this article the wave field data from five stations along the northern coast of Oman sea in the one-year period is considered for processing, analysis and interpretation. The variation of wave pattern from the entrance of Oman sea to strait Hormuz along the northern coast of Oman sea is studied based on the field data. Moreover, the results are compared with the results of both the ISWM numerical model and the simulation of Hormozgan coastline waves. Prediction of wave pattern and their origin and the variation of wave energy throughout the Oman Sea coastline are from the advantages of this study.

The Caspian Sea by reach sources of black caviar and fields of oil and gas is very important water body in the Eurasia region for the lateral countries and for the world. In the last years, the southern part of the sea is important and remarkable due to development of cage culture and tourism industry. The research is based on field works on the southern continental shelf of the Caspian Sea, Nowshahr Port (near the Iranian coastline). Two important dynamical parameters of sea level fluctuation and current were studied. Current data were collected by deployed Recording Current Meter (RCM9) and Acoustic Doppler Current Profiler (ADCP) near over the continental shelf in the middle part of the southern boundary of the sea. Observations on the sea current over the continental shelf showed that general circulation trend is from northwest (west) to east with value less than one m/s near the sea surface. Variations of sea level and dynamics of the coastal waters over the continental shelf are very important for cage culture industry in the region. Recorded data of tide gauges in Nowshahr port showed that the sea water level was collapsed about 1 m in the southern coasts during two last decades.

Decision-making in critical situations has a higher risk and sensitivity to the normal situation, so that sometimes special crisis situations lead to decisions that may bring benefits or harm at the national level. Information management systems will have a very important influence on the decision-making in crisis situations for commanders. Given the nature of its constituents, and the fact that international equivalents can extend beyond the borders of other countries, the probability of a critical situation and the need for a decision in these circumstances that accompany There will be consequences for the rule Intelligence constraints, the need for information and knowledge, the speed of access to a large amount of information in a massive confusion is one of the things that for commanders will face. This research has been conducted with the aim of examining the effects of MIS on fast, accurate and convenient decision making. . Library studies have been used in the field of research and, according to the limitations of experts in this field, a statistical society with a sample size equal to 20 people who have high qualification services are selected on the units that were floating Then, using spss software and T test, a meaningful level was determined and the results of the research findings indicate that all components of MIS are influential in the decision making process of the military crisis at sea.

Caspian Sea, the largest lake in the world, has been geographically and historically position in a privileged position for a long time. Sturgeons are considered to be the most valuable creatures of the Caspian Sea, and the Caspian Sea caviar has long been of worldwide interest. In this study, sturgeon management strategies were considered before and after the Islamic Revolution of Iran. The results showed that before the glorious victory of the Islamic Revolution, there was no management and control over the Caspian Sea, and decisions were made by the Soviet Union, and after the collapse of the Soviet Union and its division into various republics, there were many administrative misunderstandings in this area. This development has led to the emergence of new issues, such as the dramatic decrease in sturgeon species. In the meantime, only the Islamic Republic of Iran has implemented its ethical-environmental mission and improved the rehabilitation of these valuable fish stocks. Investigation of sturgeon catch statistics shows that in recent years, only Persian sturgeon condition has been better than other species, and four other species have experienced a significant reduction. After the glorious victory of the Islamic Revolution, significant activities have been undertaken in this area, including: the restoration of reserves and the release of fish larvae to the sea, the sturgeon culture in unconventional inland waters and in cages, increase of research centers and universities with the management approach of sturgeons stocks and introduce of valuable species of Persian sturgeon.

Creating an appropriate communication strategy is one of the key factors in the success of the organization. To evaluate and select the appropriate communication and advertising media in organizations and companies, different indicators and methods are used, but none of these indicators are universally accepted. The purpose of this study is to present a multi-index decision-making model (MADM) model for determining the criteria, ranking and selecting the best communication media in order to identify suppliers in the Iranian maritime industry. This research is based on objective, applied and based on the nature of the descriptive design that was designed and implemented in four stages. In this study, using Delphi techniques and the views of 10 experts, the effective measures in choosing a communication medium were first determined, then we used the hierarchical analysis of the indicators to weigh the indices and to use the AHR, TOPSIS and ELECTRE methods to prioritize the alternatives. Finally, due to the difference in the results, the final ranking of the options was done by integrating Copeland, Borda and Average methods. A pairwise comparison was obtained by calculating the compliance rate (IR) in the Expert Choice software, which is less than 0.1 and its reliability is confirmed. The results of this research were compared with the final ranking of options television is the best choice, and after wards the new messengers are ranked second; the website and the newspaper are ranked third and fourth respectively.