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Saving Energy using Intra-Cluster Routing in Wireless Sensor Networks
( Trong Thua Huynh ),( Choong Seon Hong ) 한국정보처리학회 2004 한국정보처리학회 학술대회논문집 Vol.11 No.2
An important challenge in wireless sensor network (WSN) is that how to route data packets from sources to base station energy efficiently. Inspiring data fusion feature and multi-hop routing, in this paper, we introduce a clustering approach called SEIC (Saving Energy using Intra-Cluster Routing) for saving energy and distributing data dissipation evenly by improving BS cluster formation algorithm of LEACH-Centralized and providing 3-hop routing algorithm within clusters. Hence, it prolongs the lifetime of WSN. Our simulation results show that SEIC consumes less energy and reduces communication overhead, and extends the network lifetime compared with other approaches.
Estimation of Hydrodynamic Derivatives of Full-Scale Submarine using RANS Solver
Tien Thua Nguyen,Hyeon Kyu Yoon,Youngbum Park,Chanju Park 한국해양공학회 2018 韓國海洋工學會誌 Vol.32 No.5
It is necessary to predict hydrodynamic derivatives when assessing the maneuverability of a submarine. The force and moment acting on the vehicle may affect its motion in various modes. Conventionally, the derivatives are determined by performing captive model tests in a towing tank or applying a system identification method to the free running model test. However, a computational fluid dynamics (CFD) method has also become a possible tool to predict the hydrodynamics. In this study, virtual captive model tests for a full-scale submarine were conducted by utilizing a Reynolds-averaged Navier-Stokes solver in ANSYS FLUENT version 18.2. The simulations were carried out at design speed for various modes of motion such as straight forward, drift, angle of attack, deflection of the rudder, circular, and combined motion. The hydrodynamic force and moment acting on the submarine appended rudders and stern stabilizers were then obtained. Finally, hydrodynamic derivatives were determined, and these could be used for evaluating the maneuvering characteristics of the submarine in a further study.
Delay-Constrained Energy-Efficient Cluster-based Multi-Hop Routing in Wireless Sensor Networks
Trong-Thua Huynh,Anh-Vu Dinh-Duc,Cong-Hung Tran 한국통신학회 2016 Journal of communications and networks Vol.18 No.4
Energy efficiency is the main objective in the design of awireless sensor network (WSN). Inmany applications, sensing datamust be transmitted fromsources to a sink in a timelymanner. Thispaper describes an investigation of the trade-off between two objectivesinWSN design: minimizing energy consumption and minimizingend-to-end delay. We first propose a new distributed clusteringapproach to determining the best clusterhead for each clusterby considering both energy consumption and end-to-end delayrequirements. Next, we propose a new energy-cost function and anew end-to-end delay function for use in an inter-cluster routingalgorithm. We present a multi-hop routing algorithm for use indisseminating sensing data from clusterheads to a sink at the minimumenergy cost subject to an end-to-end delay constraint. Theresults of a simulation are consistent with our theoretical analysisresults and show that our proposed performs much better thansimilar protocols in terms of energy consumption and end-to-enddelay.
Tien Thua Nguyen,Hyeon Kyu Yoon 한국항해항만학회 2017 한국항해항만학회지 Vol.41 No.2
A marine flapped rudder is designed to improve the effective lift generated by the rudder; this also improves the maneuverability of the ship. The flap is a high lift device installed at the trailing edge of the rudder to augment lift. In this paper, the characteristics of a thick flapped rudder are analyzed at a low Reynolds number with various ratios of flap chord length to total chord length and various aspect ratios, based on the computational fluid dynamics technique. The performance of the rudder with respect to lift, drag, and center of pressure are investigated, and the efficient ratio of flap chord length to total chord length and improved aspect ratio are determined. Ed: highlight – or ‘superior’. As a case study, the flow on the flapped rudder of an NACA0021 section shape in free stream condition is simulated. The standard k-epsilon turbulence model is used to model the flow around the flapped rudder. The results indicate that the efficient ratio of the flap chord length to total chord length and aspect ratio are 0.3 and 1.4, respectively.
Delay-Constrained Energy-Efficient Cluster-based Multi-Hop Routing in Wireless Sensor Networks
Huynh, Trong-Thua,Dinh-Duc, Anh-Vu,Tran, Cong-Hung The Korea Institute of Information and Commucation 2016 Journal of communications and networks Vol.18 No.4
Energy efficiency is the main objective in the design of a wireless sensor network (WSN). In many applications, sensing data must be transmitted from sources to a sink in a timely manner. This paper describes an investigation of the trade-off between two objectives in WSN design: minimizing energy consumption and minimizing end-to-end delay. We first propose a new distributed clustering approach to determining the best clusterhead for each cluster by considering both energy consumption and end-to-end delay requirements. Next, we propose a new energy-cost function and a new end-to-end delay function for use in an inter-cluster routing algorithm. We present a multi-hop routing algorithm for use in disseminating sensing data from clusterheads to a sink at the minimum energy cost subject to an end-to-end delay constraint. The results of a simulation are consistent with our theoretical analysis results and show that our proposed performs much better than similar protocols in terms of energy consumption and end-to-end delay.
Nguyen, Tien Thua,Yoon, Hyeon-Kyu Korean Institute of Navigation and Port Research 2017 한국항해항만학회지 Vol.41 No.2
A marine flapped rudder is designed to improve the effective lift generated by the rudder; this also improves the maneuverability of the ship. The flap is a high lift device installed at the trailing edge of the rudder to augment lift. In this paper, the characteristics of a thick flapped rudder are analyzed at a low Reynolds number with various ratios of flap chord length to total chord length and various aspect ratios, based on the computational fluid dynamics technique. The performance of the rudder with respect to lift, drag, and center of pressure are investigated, and the efficient ratio of flap chord length to total chord length and improved aspect ratio are determined. Ed: highlight - or 'superior'. As a case study, the flow on the flapped rudder of an NACA0021 section shape in free stream condition is simulated. The standard k-epsilon turbulence model is used to model the flow around the flapped rudder. The results indicate that the efficient ratio of the flap chord length to total chord length and aspect ratio are 0.3 and 1.4, respectively.
Analysis on Hydrodynamic Force Acting on a Catamaran at Low Speed Using RANS Numerical Method
Thi Loan Mai,Tien Thua Nguyen,Myungjun Jeon,Hyeon Kyu Yoon 한국항해항만학회 2020 한국항해항만학회지 Vol.44 No.2
This paper discusses the hydrodynamic characteristics of a catamaran at low speed. In this study, the Delft 372 catamaran model was selected as the target hull to analyze the hydrodynamic characteristics by using the RANS (Reynold-Averaged Navier-Stokes) numerical method. First, the turbulence study and mesh independent study were conducted to select the appropriate method for numerical calculation. The numerical method for the CFD (Computational Fluid Dynamic) calculation was verified by comparing the hydrodynamic force with that obtained experimentally at high speed condition and it rendered a good agreement. Second, the virtual captive model test for a catamaran at low speed was conducted using the verified method. The drift test with drift angle 0-180 degrees was performed and the resulting hydrodynamic forces were compared with the trends of other ship types. Also, the pure rotating test and yaw rotating test proposed by Takashina, (1986) were conducted. The Fourier coefficients obtained from the measured hydrodynamic force were compared with those of other ship types. Conversely, pure sway test and pure yaw test also were simulated to obtain added mass coefficients. By analyzing these results, the hydrodynamic coefficients of the catamaran at low speed were estimated. Finally, the maneuvering simulation in low speed conditions was performed by using the estimated hydrodynamic coefficients.
Nguyen, Van Minh,Nguyen, Tien Thua,Seo, Juwon,Yoon, Hyeon Kyu,Kim, Yeon Gyu Korean Society of Ocean Engineers 2018 Journal of advanced research in ocean engineering Vol.4 No.3
In the past, traditional methods of research on ship maneuvering performance were estimated in calm waters. However, the course-keeping ability and the maneuvering performance of a ship can be influenced by the presence of waves. Therefore, it is necessary to understand the maneuvering behavior of a ship in waves. In this study, the force acting on a moving ship and a rudder behind the model ship will be performed in regular waves in Changwon National University (CWNU). In addition, the prediction force acting on the rudder in calm waters was carried out and compared with those of Computational Fluid Dynamics (CFD). Model test in regular wave was performed to predict the force acting on the ship and the rudder behind the model ship in various wave directions. The effects of wavelength and wave direction on hydrodynamic forces acting on the ship hull versus rudder angle is discussed.
Kim, Sae-Hae,Jung, Dae-Im,Yang, In-Young,Jang, Sun-Hee,Kim, Ju,Truong, Thang Thua,Pham, Thuc Van,Truong, Ninh Uyen,Lee, Kyung-Yeol,Jang, Yong-Suk Oxford University Press 2013 International immunology Vol.25 No.11
<P>Oral vaccination against dengue virus is achieved by targeting M cells.</P>