基于Cadmatic Hull船体三维一体化典型节点标准建立

作为近年来船舶三维一体化设计的一种解决方案,Cadmatic Hull软件在大段建模、分段切分以及数据兼容等方面有其自身特点。但是在使用过程中,我们也意识到其原始节点配置还不够完善、建模界面还有很大的优化空间。为了充分提高Cadmatic Hull软件三维一体化设计效率,同时为不同设计平台的数据兼容创造条件,通过对比当前主流船舶三维设计软件,以Cadmatic Hull软件为平台,建立了一套统一的船体三维一体化典型节点标准。

Buckling Properties of Water-Drop-Shaped Pressure Hulls with Various Shape Indices Under Hydrostatic External Pressure

The water-drop-shaped pressure hull has a good streamline,which has good application prospect in the underwater observatory.Therefore,this study conducted analytical,experimental and numerical investigation of the buckling properties of water-drop-shaped pressure hulls under hydrostatic pressure.A water-drop experiment was conducted to design water-drop-shaped pressure hulls with various shape indices.The critical loads for the water-drop-shaped pressure hulls were resolved by using Mushtari’s formula.Several numerical simulations including linear buckling analysis and nonlinear buckling analysis including eigenmode imperfections were performed.The results indicated that the critical loads resolved by Mushtari's formula were in good agreement with the linear buckling loads from the numerical simulations.This formula can be extended to estimate the buckling capacity of water-drop-shaped pressure hulls.In addition,three groups of pressure hulls were fabricated by using stereolithography,a rapid prototyping technique.Subsequently,three groups of the pressure hulls were subjected to ultrasonic measurements,optical scanning,hydrostatic testing and numerical analysis.The experimental results were consistent with the numerical results.The results indicate that the sharp end of the water-drop-shaped pressure hulls exhibited instability compared with the blunt end.This paper provides a new solution to the limitations of experimental studies on the water-drop-shaped pressure hulls as well as a new configuration and evaluation method for underwater observatories.

Improved spatio-temporal alignment measurement method for hull deformation

In this paper,an improved spatio-temporal alignment measurement method is presented to address the inertial matching measurement of hull deformation under the coexistence of time delay and large misalignment angle.Large misalignment angle and time delay often occur simultaneously and bring great challenges to the accurate measurement of hull deformation in space and time.The proposed method utilizes coarse alignment with large misalignment angle and time delay estimation of inertial measurement unit modeling to establish a brand-new spatiotemporal aligned hull deformation measurement model.In addition,two-step loop control is designed to ensure the accurate description of dynamic deformation angle and static deformation angle by the time-space alignment method of hull deformation.The experiments illustrate that the proposed method can effectively measure the hull deformation angle when time delay and large misalignment angle coexist.

Numerical Investigation on Hydrodynamic Characteristics of a Tunneled Planing Hull in Calm Water

A tunneled planing hull has unique hybrid hydrodynamic and aerodynamic characteristics due to the presence of a tunnel.In this paper,experimental and numerical investigations on hydrody namic analysis of a tunneled planing hull are carried out.The resistance tests of models with three dif ferent masses(127.4 kg,159.5 kg,202.9 kg)are conducted for the Froude number in the range of 0.761≤Fn≤1.925.The results of resistance measured by towing tank imply that the tunneled planing hull with a larger displacement has a superior resistance performance.The numerical simulation of Reynolds Average Navier Stokes(RANS)equations based on the finite volume method is performed to analyze the hull characteristics in calm water(M=159.5 kg)with two degrees of freedom(sinkage and trim).The numerical results are compared with the experimental data,which shows good agreement.Pressure distribution,wave profiles and lift forces obtained by SST k-ωand Realizable k-εturbulence models are compared and discussed.Finally,the local fluid flow of streamline around the hull can be divided into four regions due to the presence of a tunnel,which is different from the behaviors of the conventional planing monohull with prismatic form.

Machine learning model based on non-convex penalized huberized-SVM

The support vector machine(SVM)is a classical machine learning method.Both the hinge loss and least absolute shrinkage and selection operator(LASSO)penalty are usually used in traditional SVMs.However,the hinge loss is not differentiable,and the LASSO penalty does not have the Oracle property.In this paper,the huberized loss is combined with non-convex penalties to obtain a model that has the advantages of both the computational simplicity and the Oracle property,contributing to higher accuracy than traditional SVMs.It is experimentally demonstrated that the two non-convex huberized-SVM methods,smoothly clipped absolute deviation huberized-SVM(SCAD-HSVM)and minimax concave penalty huberized-SVM(MCP-HSVM),outperform the traditional SVM method in terms of the prediction accuracy and classifier performance.They are also superior in terms of variable selection,especially when there is a high linear correlation between the variables.When they are applied to the prediction of listed companies,the variables that can affect and predict financial distress are accurately filtered out.Among all the indicators,the indicators per share have the greatest influence while those of solvency have the weakest influence.Listed companies can assess the financial situation with the indicators screened by our algorithm and make an early warning of their possible financial distress in advance with higher precision.

Optimized Adsorption of Small and Medium Molecules by a Biosorbent Based on Hevea Hulls

In the context of the recovery of agricultural waste, many researches have focused on the preparation of adsorbents from natural waste from fruit trees, egg shells, palm waste or sawdust. This work aims to optimize the preparation of a biosorbent from rubber hulls by studying its ability to adsorb small and medium molecules. The influence of parameters such as drying temperature (X1), particle size (X2), stirring time (X3) and sodium hypochloride mass (X4) was studied. The results indicate that the model used for biosorbent optimization on methylene blue and iodine index is significant. In addition, this model has greater adsorption capabilities on small molecules than with large molecules. Statistical analysis of the data shows that temperature is the most influential factor in the adsorption of small molecules. On the other hand, particle size has a significant influence on the adsorption of large molecules. The optimum biosorbent preparation values are 1.0 for drying temperature (X1), −1.0 for biosorbent grain size (X2), 1.0 for stirring time (X3) and 1.0 for sodium hypochloride mass (X4).

采用带预处理的区间Hull算法求解区间直流潮流

随着间歇性能源接入电网,电网的潮流具有一定的随机性。考虑高压输电网中直流潮流的不确定性问题,文中提出了一种带预处理的区间Hull(P-Hull)算法来求解区间直流潮流。该方法首先通过预处理,形成主对角占优的区间系数矩阵,然后利用区间Hull算法得到系数H-矩阵。为了提高结果的精度,分别利用向上近似和向下近似方法处理H-矩阵的比较矩阵,进而采用迭代方法求得区间直流潮流分布的上下界。采用9节点系统,将文中所提出的算法与蒙特卡洛算法进行比较,揭示了误差主要受网络参数不确定性的影响。此外,采用IEEE 57和IEEE 118节点系统分别对P-Hull算法、区间Hull算法、Krawczyk算子迭代法以及高斯消去法在精度和计算时间上进行比较分析,可以看出P-Hull算法能够得到最高的精度,并且其时间复杂度远小于蒙特卡洛算法。

基于Smart 3D的船体结构开孔参数化工具开发

为了解决船体结构开孔设计建模效率低下的问题,基于Smart 3D二次开发框架,通过研究参数化设计方法,建立一种基于Smart3D二次开发的结构开孔参数化设计方法。在Microsoft Visual Studio集成开发环境下,基于Net FrameWork框架,运用vb.net语言进行船体结构开孔参数化建模工具的二次开发。在此基础上,以某7000 TEU箱船Smart 3D模型为应用实例,借助开发的工具进行实例验证,验证表明,该工具可实现多船体肋位上结构开孔的批量建模功能,与传统开孔技术相比,可进一步提升开孔设计建模效率,增加建模的准确性和规范性。

采用Hull树的贪婪地理位置路由算法的设计

地理位置路由算法是指借助节点获得的地理位置信息进行无线传感网络中的路由发现与数据转发工作。本文提出一种基于Hull树的贪婪地理位置路由算法——Greedy Hull Tree Geographic Routing(GHTGR)。通过图形学中凸包的概念,在网络初始阶段分布式地在各节点上建立Hull树以探查网络局部拓扑结构;同时在数据分组的路由转发阶段,通过Hull树内的搜索,寻找下一跳转发节点,完成数据分组的转发传输。通过仿真实验表明,与现有地理位置路由算法相比,该算法能够正确地寻找数据转发路径,有效地减少网络能耗,提高网络传输性能。

FPSO Hull项目进度测量系统的建立

对国内造船企业的项目进度测量现状进行了分析,并根据FPSOHull建造的管理要求和船舶企业的管理特点,详细论述船舶企业建立FPSOHull建造的进度测量系统原则、思路和方法.提出的思路与方法不仅适用于船舶企业的FPSOHull的建造的进度测量,亦适用于一般船舶的建造进度测量.

Study on Cotton Nursery Substrate Using Cotton Seed Hulls Residue after Producing Edible Mushroom

In order to discuss the localization application technology of cotton seedling using substrate, the author used cotton seed hulls after the production of edible fungi residue, river sand and peat in different proportion formula using in field and laboratory cotton seedling test. The results showed that： dry mass per plant and leaf area per plant of formula 3 were higher than Jiangxi cotton seedling nurs- ery substrate.the higher proportion were 48.4% and 73.5%; the rate of forming plantlets, survival rate of transplant and the unginned cotton yield had no obvious difference with the other matrix seedling and transplanting; nursery substrate was returned using as fertilizer, reduced environment pollution, achieved comprehensive utilization and cyclic utilization. Cotton seed hulls after the production of edible fungi residue was a cotton seedling substrate material of saving work,reducing cost and protecting environment and would have a good application prospect.

Hull-White随机波动率模型的欧式障碍期权

假定标的股票服从Hull-White随机波动率模型,应用鞅方法、条件分布的性质以及Black-Scholes模型的下降敲出欧式看涨障碍期权价格的Taylor展开式获得了期权价格的近似显示解。最后,通过对偶MonteCarlo模拟法比较了近似显示解的准确性,分析了波动率参数对期权价格的影响。

Hull-White随机利率模型在债券价值分析中的应用

Hull-White随机利率模型既考虑了短期利率的均值回复(meanreversion)特性,又与初始期限结构相符合。本文就如何将Hull-White模型应用于债券定价进行了探讨,并将之应用于债券价值的风险分析。

水稻颖壳退化突变体degraded hull 2(dh2)的遗传分析与基因定位

鉴定和克隆水稻花器官突变体新基因,对了解水稻花器官发育的分子遗传机制和分子信号调控途径有重要作用。本研究报道了1个水稻颖壳异常突变体,来源于EMS(ethyl methane sulfonate)处理的缙恢10号(Oryzasativa)诱变群体,暂被命名为degrade dhull2(dh2)。表型分析发现突变体小花第1轮内稃或外稃横向细胞数目减少,导致内稃或外稃变窄而不能正常勾合,从而呈现开裂现象,其内3轮花器官均无明显变化。遗传分析表明该突变性状受1个隐性单基因控制。利用群体分离分析法(bulked segregation analysis,BSA),将DH2基因定位在第3染色体的IND-5和IND-14之间,遗传距离分别为0.99cM和1.49cM。该研究结果为DH2基因的图位克隆奠定了基础。

基于Hull-White模型的债券市场利率期限结构研究

现代利率研究中有许多理论和模型对利率期限结构问题进行探索,但是在中国还没有一种公认的理论或方法能够完全解决中国债券市场利率期限结构问题。本文尝试寻找一种更多的利用市场即时信息的定价方法对利率期限结构进行研究,应用三叉树模拟技术构建Hull-White模型,并对当前中国债券市场上几种常用利率进行比较分析。研究发现银行间质押式回购收益率具有较好的动态运动性质,比样本国债和政策性银行金融债更适宜作为短期金融产品定价的基础。

基于重构级别辨识的主配协同鲁棒供电恢复方法

传统配电网供电恢复策略大多先进行孤岛划分、后进行动态重构,缺少对二者的共同考虑,而全局重构又存在经济性差、操作难度大等问题。为此,提出基于重构级别辨识的主配协同鲁棒供电恢复方法。首先,根据配电系统的故障情况,按照局部自治、低级别优先重构的原则,快速确定主(变电站层级)、配(配电线路层级)多级重构需求。然后,对不同级别的区域进行孤岛划分与重构。接着,针对描述分布式光伏出力不确定性的凸包多面体集合存在放缩过程中保守性大的问题,采用超平面方法切割凸包集合并建立改进凸包集合模型。进一步,构建了配电网鲁棒供电恢复模型,并采用列与约束生成算法对鲁棒供电恢复模型进行求解。最后,通过改进的78节点系统进行仿真验证。结果表明,基于重构级别辨识的主配协同鲁棒供电恢复方法可以降低保守性,提高供电恢复结果的鲁棒性。

基于正则化方法的Hull-White短期利率模型参数估计

基于市场债券价格,应用正则化方法对Hull-White短期利率模型中时间变量参数进行估计.通过变分原理,证明了该正则化方法具有稳定性和收敛性.最后,数值模拟确认该方法的有效性并给出实证结果.

无氰亚铜体系电镀铜−锡合金工艺

[目的]开发了以氧化亚铜和氯化亚锡为主盐的无氰电镀铜−锡(Cu–Sn)合金体系。[方法]通过阴极极化曲线测试,研究了体系中亚锡离子和亚铜离子的电化学还原行为,并通过霍尔槽试验、扫描电子显微镜和能谱仪考察了镀液组成和电流密度对Cu–Sn合金镀层外观、形貌和元素组成的影响。[结果]在无氰亚铜电镀Cu–Sn合金体系中,亚铜离子的还原电位比亚锡离子的还原电位更负,且锡的电沉积更容易受到传质过程控制。当镀液中含有硫脲(作为亚铜离子配位剂)80 g/L、氧化亚铜16 g/L、酒石酸钾钠(作为锡离子配位剂)20 g/L及无水氯化亚锡8 g/L时,高电流密度和低电流密度下所得的Cu–Sn合金镀层都呈均匀的银灰色,结晶细致,并且Sn的质量分数稳定在35%左右。[结论]采用无氰亚铜体系可以电镀得到成分可控的Cu–Sn合金镀层。

混合分数维Hull-White利率模型下幂型期权的定价

文章假定原生资产的价格和利率的随机过程服从混合分数维布朗运动,利用风险对冲技术和偏微分方程方法得到了混合分数维Hull-White利率模型下幂型期权的定价公式,推广了相应基于几何布朗运动驱动的幂型期权定价公式和基于分数维布朗运动驱动的幂型期权定价公式。

分数维Hull-White利率模型下欧式期权的定价

假定原生资产的价格和利率的随机过程服从分数维布朗运动,利用风险对冲技巧和偏微分方程方法,得到分数维Hull-White利率模型下的欧式期权以及降低权利金权证的定价公式,推广了分数维BlackScholes期权定价公式.