Analysis of Marine Traffic Feature for Safety Assessment at Southern Entrance of the Istanbul Strait-I

Volkan Aydogdu,박진수,Yavuz Keceli,박영수 한국항해항만학회 2008 한국항해항만학회지 Vol.32 No.7

The Istanbul Strait is one of the important waterways in the world. And its southern entrance has a highly congested local traffic. Till now there are several studies regarding how the Istanbul Strait is dangerous to navigate and how those dangers can be mitigated. But there is no study regarding local traffic which is posing great collision risk. In a certain traffic area, marine traffic safety assessment parameters are traffic volume, frequency of collision avoidance maneuver, traffic density, traffic flow and potential encounter. In this paper local traffic volume, traffic flow and potential encounter number of local traffic vessels and possibility of collision are investigated in order to find degree of danger at the southern entrance of the Istanbul Strait. Finally by utilizing those, risky areas are determined for southern entrance of the Istanbul Strait. Results have been compared to a previous study regarding risk analysis at congested areas of the Istanbul Strait (Aydogdu, 2006) and consistency of the results were presented. The Istanbul Strait is one of the important waterways in the world. And its southern entrance has a highly congested local traffic. Till now there are several studies regarding how the Istanbul Strait is dangerous to navigate and how those dangers can be mitigated. But there is no study regarding local traffic which is posing great collision risk. In a certain traffic area, marine traffic safety assessment parameters are traffic volume, frequency of collision avoidance maneuver, traffic density, traffic flow and potential encounter. In this paper local traffic volume, traffic flow and potential encounter number of local traffic vessels and possibility of collision are investigated in order to find degree of danger at the southern entrance of the Istanbul Strait. Finally by utilizing those, risky areas are determined for southern entrance of the Istanbul Strait. Results have been compared to a previous study regarding risk analysis at congested areas of the Istanbul Strait (Aydogdu, 2006) and consistency of the results were presented.

Analysis of Marine Traffic Feature for Safety Assessment at Southern Entrance of the Istanbul Strait-I

Aydogdu, Volkan,Park, Jin-Soo,Keceli, Yavuz,Park, Young-Soo Korean Institute of Navigation and Port Research 2008 한국항해항만학회지 Vol.32 No.7

The Istanbul Strait is one of the important waterways in the world. And its southern entrance has a highly congested local traffic. Till now there are several studies regarding how the Istanbul Strait is dangerous to navigate and how those dangers can be mitigated. But there is no study regarding local traffic which is posing great collision risk. In a certain traffic area, marine traffic safety assessment parameters are traffic volume, frequency of collision avoidance maneuver, traffic density, traffic flow and potential encounter, In this paper local traffic volume, traffic flow and potential encounter number of local traffic vessels and possibility of collision are investigated in order to find degree of danger at the southern entrance of the Istanbul Strait. Finally by utilizing those, risky areas are determined for southern entrance of the Istanbul Strait. Results have been compared to a previous study regarding risk analysis at congested areas of the Istanbul Strait (Aydogdu, 2006) and consistency of the results were presented.

Forced vibration of nanorods using nonlocal elasticity

Aydogdu, Metin,Arda, Mustafa Techno-Press 2016 Advances in nano research Vol.4 No.4

Present study interests with the longitudinal forced vibration of nanorods. The nonlocal elasticity theory of Eringen is used in modeling of nanorods. Uniform, linear and sinusoidal axial loads are considered. Dynamic displacements are obtained for nanorods with different geometrical properties, boundary conditions and nonlocal parameters. The nonlocal effect increases dynamic displacement and frequency when compared with local elasticity theory. Present results can be useful for modeling of the axial nanomotors and nanoelectromechanical systems.

Vibration of axially functionally graded nano rods and beams with a variable nonlocal parameter

Aydogdu, Metin,Arda, Mustafa,Filiz, Seckin Techno-Press 2018 Advances in nano research Vol.6 No.3

Vibration of axially functionally graded nano-rods and beams is investigated. It is assumed that the material properties change along the rod and beam length. The Ritz method with algebraic polynomials is used in the formulation of the problems. Stress gradient elasticity theory is utilized in order to include the nonlocal effects. Frequencies are obtained for different boundary conditions, geometrical and material properties. Nonlocal parameter is assumed as changing linearly or quadratically along the length of the nanostructure. Frequencies are compared to constant nonlocal parameter cases and considerable differences are observed between constant and variable nonlocal parameter cases. Mode shapes in various cases are depicted in order to explain the effects of axial grading.

RINGS CLOSE TO SEMIREGULAR

Aydogdu, Pinar,Lee, Yang,Ozcan, A. Cigdem Korean Mathematical Society 2012 대한수학회지 Vol.49 No.3

A ring $R$ is called semiregular if $R/J$ is regular and idem-potents lift modulo $J$, where $J$ denotes the Jacobson radical of $R$. We give some characterizations of rings $R$ such that idempotents lift modulo $J$, and $R/J$ satisfies one of the following conditions: (one-sided) unit-regular, strongly regular, (unit, strongly, weakly) ${\pi}$-regular.

Questionnaire Survey on the Risk Perception in the Istanbul Strait

Aydogdu, Y. Volkan,Yurtoren, Cemil,Kum, Serdar,Park, Jin-Soo Korean Institute of Navigation and Port Research 2010 한국항해항만학회지 Vol.34 No.7

There are enormous challenges in the Istanbul Strait- one of the most important, congested and narrow waterways in the world - from the view point of risk determination and risk mitigation for the local traffic. Previously several traffic parameters such as; traffic volume for local vessels, traffic flow and potential encounters of local traffic, in addition to the possibility of collision, were investigated in order to determine the degree of dangers in the southern entrance of the Istanbul Strait. Furthermore, risky zones were also determined in this waterway. On the basis of the results of those, a group of expert was surveyed. These experts were pilots, Vessel Traffic Services Operators (VTS-O), Local Traffic Vessel Captains and Master Mariners who had several experience of navigation through the Istanbul Strait. In order to assess experts perceptions of danger and to propose further studies based on this survey. The questionnaire was analyzed by using SPSS (Statistical Package for the Social Sciences) program version 13.0. Finally, some differences and/or shares on risk perceptions of expert in the Istanbul Strait are considered.

On the vibration of aligned carbon nanotube reinforced composite beams

Aydogdu, Metin Techno-Press 2014 Advances in nano research Vol.2 No.4

Carbon nanotubes have exceptional mechanical, thermal and electrical properties, and are considered for high performance structural and multifunctional composites. In the present study, the natural frequencies of aligned single walled carbon nanotube (CNT) reinforced composite beams are obtained using shear deformable composite beam theories. The Ritz method with algebraic polynomial displacement functions is used to solve the free vibration problem of composite beams. The Mori-Tanaka method is applied to find the composite beam mechanical properties. The continuity conditions are satisfied among the layers by modifying the displacement field. Results are found for different CNT diameters, length to thickness ratio of the composite beam and different boundary conditions. It is found that the use of smaller CNT diameter in the reinforcement element gives higher fundamental frequency for the composite beam.

Optimum design of steel space structures using social spider optimization algorithm with spider jump technique

Ibrahim Aydogdu,Perihan Efe,Metin Yetkin,Alper Akin 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.62 No.3

In this study, recently developed swarm intelligence algorithm called Social Spider Optimization (SSO) approach and its enhanced version of SSO algorithm with spider jump techniques is used to develop a structural optimization technique for steel space structures. The improved version of SSO uses adaptive randomness probability in generating new solutions. The objective function of the design optimization problem is taken as the weight of a steel space structure. Constraints’ functions are implemented from American Institute of Steel Construction-Load Resistance factor design (AISC-LRFD) and Ad Hoc Committee report and practice which cover strength, serviceability and geometric requirements. Three steel space structures are optimized using both standard SSO and SSO with spider jump (SSO_SJ) algorithms and the results are compared with those available in the literature in order to investigate the performance of the proposed algorithms.

Introduction Of Istanbul VTS and Local Traffic Control Center

Volkan Aydogdu 한국항해항만학회 2008 한국항해항만학회 학술대회논문집 Vol.2008 No.추계

Istanbul Strait is one of the difficult and congested water ways in the world. Number of transit vessel is increasing day by day. Last year over than 55,000 vessels passed through Istanbul Strait and over than 2100 local vessel running at the southern entrance of the strait. VTS has been established in order to provide navigational assistance and minimize risks due to difficult navigational characteristic of strait and congested marine traffic in 2003. In the Istanbul Strait VTS system consist from 5 sectors which are controlled by different operators. AIS Class-A is compulsory for all the vessels which are navigating at international waters and over than 300 grt. AIS is highly effective and useful tool for VTS and AIS device has been used effectively in the Strait, since the establishment of VTS. But local vessels were not using AIS device and local vessel traffic one of the problem in the strait due to high number of ship movement. Turkish Government wanted to control local vessels same as transit vessel and supported AIS Class-B research and development. Finally, AIS Class-B device and local traffic control center established. In this presentation Istanbul Strait VTS, Local Traffic Control Center and AIS Class-B device will be introduced.

Questionnaire Survey on the Risk Perception in the Istanbul Strait

Volkan Aydogdu,Cemil Yurtoren,Serdar Kum,박진수 한국항해항만학회 2010 한국항해항만학회지 Vol.34 No.7

There are enormous challenges in the Istanbul Strait- one of the most important, congested and narrow waterways in the world – from the view point of risk determination and risk mitigation for the local traffic. Previously several traffic parameters such as; traffic volume for local vessels, traffic flow and potential encounters of local traffic, in addition to the possibility of collision, were investigated in order to determine the degree of dangers in the southern entrance of the Istanbul Strait. Furthermore, risky zones were also determined in this waterway. On the basis of the results of those, a group of expert was surveyed. These experts were pilots, Vessel Traffic Services Operators (VTS-O), Local Traffic Vessel Captains and Master Mariners who had several experience of navigation through the Istanbul Strait. In order to assess experts perceptions of danger and to propose further studies based on this survey. The questionnaire was analyzed by using SPSS (Statistical Package for the Social Sciences) program version 13.0. Finally, some differences and/or shares on risk perceptions of expert in the Istanbul Strait are considered