The statistical and distribution characteristics of the responses of a floater and its mooring lines are essential in designing floating/mooring systems.In general,the dynamic responses of offshore structures obey a G...The statistical and distribution characteristics of the responses of a floater and its mooring lines are essential in designing floating/mooring systems.In general,the dynamic responses of offshore structures obey a Gaussian distribution,assuming that the structural system,and sea loads are linear or weakly nonlinear.However,mooring systems and wave loads are considerably nonlinear,and the dynamic responses of hull/mooring systems are non-Gaussian.In this study,the dynamic responses of two types of floaters,semi-submersible and spar platforms,and their mooring lines are computed using coupled dynamic analysis in the time domain.Herein,the statistical characteristics and distributions of the hull motion and mooring line tension are discussed and compared.The statistical distributions of the dynamic responses have strong non-Gaussianity and are unreasonably fitted by a Gaussian distribution for the two floating and mooring systems.Then,the effects of water depth,wave parameters,and low-frequency and wave-frequency components on the non-Gaussianity of the hull motion,and mooring line tension are investigated and discussed.A comparison of the statistical distributions of the responses with various probability density functions,including the Gamma,Gaussian,General Extreme Value,Weibull,and Gaussian Mixture Model(GMM)distributions,shows that the GMM distribution is better than the others for characterizing the statistical distributions of the hull motion,and mooring line tension responses.Furthermore,the GMM distribution has the best accuracy of response prediction.展开更多
The QTL qHUS6 for hull silicon content in rice was previously located on the short arm of rice chromosome 6. By using an F2：3 population segregating in the RM587-RM19784 region harboring qHUS6 in an isogenic backgrou...The QTL qHUS6 for hull silicon content in rice was previously located on the short arm of rice chromosome 6. By using an F2：3 population segregating in the RM587-RM19784 region harboring qHUS6 in an isogenic background, two QTLs for hull silicon content were detected, of which qHUS6-1 was located in the distal region and qHUS6.2 in the region proximal to the centromere. Three rice plants carrying small heterozygous segments in the target region were selected, of which two covered the qHUS6-1 region and the other covered the qHUS6-2 region. Three F2：3 populations were derived from the selfed seeds of the three plants, respectively. QTL mapping was performed using the two populations segregating in the qHUS6-1 region, and qHUS6-1 was delimited to a 147.0-kb region flanked by the markers RM510 and RM19417. Five groups of F3 lines with different genotypic compositions in the qHUS6-2 region were selected from the other F2-3 population. Two QTLs were separated with two-way ANOVA, of which qHUS6-2a was located in the interval defined by RM19706-RM19795 and qHUS6-2b in the interval RM314-RM19665.展开更多
The need to have naval units ever faster pushed the ship design to design hull shapes with increasingly higher performance thanks to the use of lightweight materials such as aluminum, and more powerful engines, etc., ...The need to have naval units ever faster pushed the ship design to design hull shapes with increasingly higher performance thanks to the use of lightweight materials such as aluminum, and more powerful engines, etc., but without substantially modifying the traditional forms of hull. The hull patented Monotricat high hydrodynamic efficiency and energy saving it represents an evolution of the traditional architectures of the hulls, as its shape is adapted to recover wave formation engendered from the bow and sprays associated with it so as to reduce the resistance to the benefit of the speed, and navigating in displacement at speeds of planing hulls with an efficiency of about 20%. The patented hull Monotricat represents the overcoming of distinction between displacement and planing hulls, because, unlike previous solutions, the hull conventionally called Monotricat is the first displacement hull that can navigate at both displacement and planning speeds, with a resistance curve almost straight, maintaining the characteristics of a displacement hull, since it combines the characteristics of displacement and planning hull. It presents an innovative architecture that could be defined as a hybrid between a monohull and catamaran, navigating on spray self-produced. The combination of these three types of naval hulls allows it to ensure： safety, comfort navigation, best seakeeping and maneuverability in restricted waters, stability, reduction of resistance to motion, cost management, regularity on the routes even in adverse weather-sea. These characteristics of the hull have been studied, tested and validated by leading research institutes and universities with more ameliorative results in each subsequent experimentation, reported in the present work, which demonstrated a greater hydrodynamic efficiency compared to conventional hulls of 20%.展开更多
基金the support by the National Natural Science Foundation of China(Nos.51709247 and 51490675)the National Key R&D Program of China(No.2016YFE0200100)
文摘The statistical and distribution characteristics of the responses of a floater and its mooring lines are essential in designing floating/mooring systems.In general,the dynamic responses of offshore structures obey a Gaussian distribution,assuming that the structural system,and sea loads are linear or weakly nonlinear.However,mooring systems and wave loads are considerably nonlinear,and the dynamic responses of hull/mooring systems are non-Gaussian.In this study,the dynamic responses of two types of floaters,semi-submersible and spar platforms,and their mooring lines are computed using coupled dynamic analysis in the time domain.Herein,the statistical characteristics and distributions of the hull motion and mooring line tension are discussed and compared.The statistical distributions of the dynamic responses have strong non-Gaussianity and are unreasonably fitted by a Gaussian distribution for the two floating and mooring systems.Then,the effects of water depth,wave parameters,and low-frequency and wave-frequency components on the non-Gaussianity of the hull motion,and mooring line tension are investigated and discussed.A comparison of the statistical distributions of the responses with various probability density functions,including the Gamma,Gaussian,General Extreme Value,Weibull,and Gaussian Mixture Model(GMM)distributions,shows that the GMM distribution is better than the others for characterizing the statistical distributions of the hull motion,and mooring line tension responses.Furthermore,the GMM distribution has the best accuracy of response prediction.
基金supported by the National Natural Science Foundation of China(GrantNo.30571062)National Hi-Tech Research and Development Program of China(Grant No.2006AA10Z1E8)the Program of Super Rice from Chinese Agricultural Ministry(Grant No.200906)
文摘The QTL qHUS6 for hull silicon content in rice was previously located on the short arm of rice chromosome 6. By using an F2：3 population segregating in the RM587-RM19784 region harboring qHUS6 in an isogenic background, two QTLs for hull silicon content were detected, of which qHUS6-1 was located in the distal region and qHUS6.2 in the region proximal to the centromere. Three rice plants carrying small heterozygous segments in the target region were selected, of which two covered the qHUS6-1 region and the other covered the qHUS6-2 region. Three F2：3 populations were derived from the selfed seeds of the three plants, respectively. QTL mapping was performed using the two populations segregating in the qHUS6-1 region, and qHUS6-1 was delimited to a 147.0-kb region flanked by the markers RM510 and RM19417. Five groups of F3 lines with different genotypic compositions in the qHUS6-2 region were selected from the other F2-3 population. Two QTLs were separated with two-way ANOVA, of which qHUS6-2a was located in the interval defined by RM19706-RM19795 and qHUS6-2b in the interval RM314-RM19665.
文摘The need to have naval units ever faster pushed the ship design to design hull shapes with increasingly higher performance thanks to the use of lightweight materials such as aluminum, and more powerful engines, etc., but without substantially modifying the traditional forms of hull. The hull patented Monotricat high hydrodynamic efficiency and energy saving it represents an evolution of the traditional architectures of the hulls, as its shape is adapted to recover wave formation engendered from the bow and sprays associated with it so as to reduce the resistance to the benefit of the speed, and navigating in displacement at speeds of planing hulls with an efficiency of about 20%. The patented hull Monotricat represents the overcoming of distinction between displacement and planing hulls, because, unlike previous solutions, the hull conventionally called Monotricat is the first displacement hull that can navigate at both displacement and planning speeds, with a resistance curve almost straight, maintaining the characteristics of a displacement hull, since it combines the characteristics of displacement and planning hull. It presents an innovative architecture that could be defined as a hybrid between a monohull and catamaran, navigating on spray self-produced. The combination of these three types of naval hulls allows it to ensure： safety, comfort navigation, best seakeeping and maneuverability in restricted waters, stability, reduction of resistance to motion, cost management, regularity on the routes even in adverse weather-sea. These characteristics of the hull have been studied, tested and validated by leading research institutes and universities with more ameliorative results in each subsequent experimentation, reported in the present work, which demonstrated a greater hydrodynamic efficiency compared to conventional hulls of 20%.
