This study presents a numerical method for optimizing hull form in calm water with respect to total drag which contains a viscous drag and a wave drag. The ITTC 1957 model-ship correlation line was used to predict fri...This study presents a numerical method for optimizing hull form in calm water with respect to total drag which contains a viscous drag and a wave drag. The ITTC 1957 model-ship correlation line was used to predict frictional drag and the corrected linearized thin-ship theory was employed to estimate the wave drag The evolution strategy （ES） which is a member of the evolutionary algorithms （EAs） family obtains an optimum hull form by considering some design constraints. Standard Wigley hull is considered as an initial hull in optimization procedures for two test cases and new hull forms were achieved at Froude numbers 0.24, 0.316 and 0.408. In one case the ES technique was ran for the initial hull form, where the main dimensions were fixed and the only variables were the hull offsets. In the other case in addition to hull offsets, the raain dimensions were considered as variables that are optimized simultaneously. The numerical results of optimization procedure demonstrate that the optimized hull forms yield a reduction in total drag.展开更多
D.H.Lawrence is a great writer and Woman in Love is considered as his masterpiece and one of the undoubted classic ofthe 20tb century. Through his flexible application of symbolism, the novel is presented with fragmen...D.H.Lawrence is a great writer and Woman in Love is considered as his masterpiece and one of the undoubted classic ofthe 20tb century. Through his flexible application of symbolism, the novel is presented with fragmentary scenes instead of the usual plots, and a lot of separate and unrelated images are employed to reflect the mental conflicts among the major characters. By analyzing the symbolism in this paper, the author hopes to find the importance of symbolism in strengthening the distinct characteristics, enhancing the development of the plot, and hence the emphasis of the theme of the novel.展开更多
The plow of the submarine plowing trencher is one of the main functional mechanisms, and its optimization is very important. The design parameters play a very significant role in determining the requirements of the to...The plow of the submarine plowing trencher is one of the main functional mechanisms, and its optimization is very important. The design parameters play a very significant role in determining the requirements of the towing force of a vessel. A multi-objective genetic algorithm based on analytical models of the plow surface has been examined and applied in efforts to obtain optimal design of the plow. For a specific soil condition, the draft force and moldboard surface area which are the key parameters in the working process of the plow are optimized by finding the corresponding optimal values of the plow blade penetration angle and two surface angles of the main cutting blade of the plow. Parameters such as the moldboard side angle of deviation, moldboard lift angle, angular variation of the tangent line, and the spanning length are also analyzed with respect to the force of the moldboard surface along soil flow direction. Results show that the optimized plow has an improved plow performance. The draft forces of the main cutting blade and the moldboard are 10.6% and 7%, respectively, less than the original design. The standard deviation of Gaussian curvature of moldboard is lowered by 64.5%, which implies that the smoothness of the optimized moldboard surface is much greater than the original.展开更多
The Chinese expression of the direction and progress of the international rule of law is an important part of showcasing China＇s stand and ideas in international relations, and serves as a major interactive link betw...The Chinese expression of the direction and progress of the international rule of law is an important part of showcasing China＇s stand and ideas in international relations, and serves as a major interactive link between the Chinese rule of law and the international rule of law. The progress of the international rule of law rests on the active, full and effective expression of various countries including China, so that it can become more just and rational. In order to express itself explicitly and effectively, China needs to participate actively in the practices of international rule of law, in a bid to expand its horizon, enlist public support, and obtain opportunities.展开更多
基金marine research institute (MRC) of AUT for some financial support of this project
文摘This study presents a numerical method for optimizing hull form in calm water with respect to total drag which contains a viscous drag and a wave drag. The ITTC 1957 model-ship correlation line was used to predict frictional drag and the corrected linearized thin-ship theory was employed to estimate the wave drag The evolution strategy （ES） which is a member of the evolutionary algorithms （EAs） family obtains an optimum hull form by considering some design constraints. Standard Wigley hull is considered as an initial hull in optimization procedures for two test cases and new hull forms were achieved at Froude numbers 0.24, 0.316 and 0.408. In one case the ES technique was ran for the initial hull form, where the main dimensions were fixed and the only variables were the hull offsets. In the other case in addition to hull offsets, the raain dimensions were considered as variables that are optimized simultaneously. The numerical results of optimization procedure demonstrate that the optimized hull forms yield a reduction in total drag.
文摘D.H.Lawrence is a great writer and Woman in Love is considered as his masterpiece and one of the undoubted classic ofthe 20tb century. Through his flexible application of symbolism, the novel is presented with fragmentary scenes instead of the usual plots, and a lot of separate and unrelated images are employed to reflect the mental conflicts among the major characters. By analyzing the symbolism in this paper, the author hopes to find the importance of symbolism in strengthening the distinct characteristics, enhancing the development of the plot, and hence the emphasis of the theme of the novel.
基金Supported the National Natural Science Foundation of China （No. 51179040） Natural Science Foundation of Heilongjiang Province （No. E200904）
文摘The plow of the submarine plowing trencher is one of the main functional mechanisms, and its optimization is very important. The design parameters play a very significant role in determining the requirements of the towing force of a vessel. A multi-objective genetic algorithm based on analytical models of the plow surface has been examined and applied in efforts to obtain optimal design of the plow. For a specific soil condition, the draft force and moldboard surface area which are the key parameters in the working process of the plow are optimized by finding the corresponding optimal values of the plow blade penetration angle and two surface angles of the main cutting blade of the plow. Parameters such as the moldboard side angle of deviation, moldboard lift angle, angular variation of the tangent line, and the spanning length are also analyzed with respect to the force of the moldboard surface along soil flow direction. Results show that the optimized plow has an improved plow performance. The draft forces of the main cutting blade and the moldboard are 10.6% and 7%, respectively, less than the original design. The standard deviation of Gaussian curvature of moldboard is lowered by 64.5%, which implies that the smoothness of the optimized moldboard surface is much greater than the original.
文摘The Chinese expression of the direction and progress of the international rule of law is an important part of showcasing China＇s stand and ideas in international relations, and serves as a major interactive link between the Chinese rule of law and the international rule of law. The progress of the international rule of law rests on the active, full and effective expression of various countries including China, so that it can become more just and rational. In order to express itself explicitly and effectively, China needs to participate actively in the practices of international rule of law, in a bid to expand its horizon, enlist public support, and obtain opportunities.
