فصلنامه علوم و فناوری دریا
سال چهاردهم شماره 54 (تابستان 1389)

Due to the complexity of analytical and special boundary conditions of offshore structures,accurate analysis control is always requires. Today, using the computer programs instead of hand Calculations is useful for analysis and design of such structures. SACS is pioneer inoffshore structural design and this paper has been discussed about the software evaluation on non-linear finite element analysis. This type of analyze is often used for older structures in order to achieve the ultimate strength of members. In this study, in addition to previous researches, by using the ANSYS and ABAQUS results, the results of the SACS has been described and compared. The software has predicted properly the ultimate strength of structure.

The earth is warming. Scientists have known the increase of greenhouse gases (controller of earth temperature) the reason of this global warming. One of the possible consequences of this warming is increase of Sea Surface Temperature. Generally sea and ocean have important role in control of heat condition in global climate system because of high special heat capacity of water. On the other hand, the atmosphere conditions and its changes are dependent to conditions of ocean and sea and specially Sea Surface Temperature. Therefore, any discussion or study about atmosphere conditions inevitablyneeds previous knowledge of annual status of SST. Also change of Sea Surface Temperature will cause change in physical parameters including change in slope heat depth, change in sound speed and audio channel, change in sea water level and etc that this subject from various aspects is important in sea studies. This research by collecting and analyzing the long-term data of annual mean of global temperature (Gtemp) and annual average of Sea Surface Temperature (SST) related to coasts ofHormozgan province, at first surveys the significance of their changes in 5 year groupings during recent 20 years with a long-term group from each variable as control and then compares by Duncan test. The results of this survey shows that increasing trend of annual mean of quantities of experimental groups leading to 2008 in each of 2 mentioned variables has had significant difference with previous groups before themselves (during recent 20 years) and also with control group (longterm mean of each of the groups). Also, it has calculated the method and the amount of influence of variable Gtemp on variable SST with obtaining regression equation which this amount in the linearregression equation has a coefficient equal to 1.58.

Riveting is one of the common method in connecting the surfaces to the hull of the marin vehicle. Between the various methods in mechanical temporary connection, this procedure (riveting) because of robustness and neatness and simplicity in comparison to other method is preferred. In fact riveting is a metallic pinning which is used in order to maintaining two or multiple plate or metallic surfaces to each other. In this paper meanwhile the cause of the failure of a group of rivets which is used in manufacturing a hovercraft are discussed, based on standards and investigation the suitable rivets are selected and used in the marine vehicle.Investigation shows that in the parts which the structure is directly contact with the sea water, all the riveting which is mentioned in the standards can not be used in these positions. In these positions in addition to precise design point’s consideration, as insulation and painting, only rivets with special alloys must be used.

High speed crafts equipped with hydrfoils otherwise known as HYSUCAT is one of the most well known vessels. They exit water with high speed and at design speed, part of their structures is in motion outside of the water. In addition to their moving ability with high speed, hysucats posses high manuverability, suitable stability and ideal performance under wave conditions. In this article, effort has been made to obtain pressure distribution over various types of hydrfoils by ANSYS-CFX software. This has been accomplished by considering different aspect ratios and angles of attack. Based on the obtained results, relations between the shape of the foil and the attained pressure distribution have been achieved. Computational results indicate that a particular type of hydrofil, i.e. NACA 5503, because of having a low aspect ratio and a particular geomtery with uniform pressure distribution along its span, has the most optimized hydrodynamic charateristics to be used in HYSUCAT vessels.

In this paper we have proposed a target tracking algorithm that can be used in radar and sonar systems. This algorithm is based on Rao-Blackwellized filter and Monte-Carlo dataassociation technique. It can be implemented with a high speed and its accuracy iscomparable to other algorithms. The use of Monte-Carlo sampling technique has made thealgorithm easy to be implemented and the computational capacity needed is reduced.

An important source of knowledge power to preserve the valuable heritage, learning newcases, solving problems, creating core competitiveness and build new opportunities forindividuals and organizations, now and for the future.The main challenge related to knowledge management strategy applied in developedcountries such as Iran in developing, producing and how to manage knowledge. If we accept that knowledge management platform skills and dynamic competitiveness, for implementing knowledge management, it is necessary that main structural axes include: sources of knowledge, knowledge management systems, organizational knowledge management, innovation and organizational areas to consider.the development of knowledge-based systems and knowledge age, knowledge management a key component in strategy development is considered. Inconsistency between the centers for scientific research, technology owners and lack clear strategy and codified, it is necessary indigenous knowledge management model suitable for organizations looking to be created, because in all organizations looking to knowledge is not the same.This paper knowledge management model to suit local conditions and characteristics ofmarine organizations, Where the definition of knowledge management critical successfactors and knowledge management, organizations need to marine solutions are provided.

In this Paper We have Studied Asaluyeh Port basin Calmness by using field measurementsand Numerical Modeling, The measurements have been done ADCP installed in 40metersdepth for from Asaluyeh Coast for one year.Besides these measurements, Wave modeling in the port basin has been done by MIKE21Software.The results of numerical modeling show that the configuration of the Port Strueture is well and port basin calmness parameters are satisfied.