The paper considers the dynamic positioning problem for a ship having only two independent controls, namely surge force and yaw moment. A time-varying feedback control law including integral action is developed and proved to exponentially stabilize both the North and East positions and the orientation of the ship. Experimental results are presented where the controller is implemented on a model...

The paper considers the dynamic positioning problem for a ship having only two independent controls, namely surge force and yaw moment. A time-varying feedback control law including integral action is developed and proved to exponentially stabilize both the North and East positions and the orientation of the ship. Experimental results are presented where the controller is implemented on a model...

this paper aims to probe the nature of possible responses to the actions taken by certain foreign companies to unilaterally terminate their services to the iranian public and private internet service providers. the paper examines specifically the procedural aspects of the issue and concludes that due to the lack of the biased nature of relationship between sysops and internet users and the abse...

abstract. in this paper, we introduce the notion of fuzzy obstinate ideals in mv -algebras. some properties of fuzzy obstinate ideals are given. not only we give some characterizations of fuzzy obstinate ideals, but also bring the extension theorem of fuzzy obstinate ideal of an mv -algebra a. we investigate the relationships between fuzzy obstinate ideals and the other fuzzy ideals of an mv -a...

For ship detection, X-band synthetic aperture radar (SAR) imagery provides very useful data, in that ship targets look much brighter than surrounding sea clutter due to the corner-reflection effect. However, there are many phenomena which bring out false detection in the SAR image, such as noise of background, ghost phenomena, side-lobe effects and so on. Therefore, when ship-detection algorith...

Background and objectives: Despite the vast production of new antibiotics in the last three decades, resistance to these drugs by microorganisms has increased and essential oils (EOs) have been recognized to possess antimicrobial properties. Methods:  In the present study, EOs obtained from aerial parts of Thymus vulgaris L., Lavandula angustifolia Mill., Rosmarinus offici...

in this paper we define ?-independent (a weak-version of independence), kronecker and dissociate sets on hypergroups and study their properties and relationships among them and some other thin sets such as independent and sidon sets. these sets have the lacunarity or thinness property and are very useful indeed. for example varopoulos used the kronecker sets to prove the malliavin theorem. in t...

determining the responses of floating structures at sea are the most important concerns in shipbuilding industry. in physical and dynamical principles a ship can be analyzed as a free elastic beam floating in sea without any supports. the analysis of corresponding dynamic equations are difficult and time- consuming, thus investigation on the behavior of floating structures can be done numerical...