Validation of vessel seakeeping model tuning algorithm based on measurements at model scale

Wave-induced vessel motion prediction plays a critical role in ensuring safe marine operations. The operational limiting criteria can usually be calculated by applying presumed linearized vessel motion transfer functions based on the specified vessel loading condition, which may deviate from the real vessel condition when the operation is executed. Reducing the uncertainties of the onboard vessel loading condition can therefore improve the accuracy of vessel motion prediction and hence improve the safety and cost-efficiency for marine operations. However, parameters related to the onboard vessel loading condition can be difficult to measure directly, such as the center of gravity and moments of inertia. In addition, the hydrodynamic viscous damping terms are always subject to significant uncertainties and sometimes become critical for accurate vessel motion predictions. A very promising algorithm for the tuning of these important uncertain vessel parameters based on the unscented Kalman filter (UKF) that uses onboard vessel motion measurements and synchronous wave information was proposed and demonstrated previously by application to synthetic data. The present paper validates the UKF-based vessel seakeeping model tuning algorithm by considering measurements from model-scale seakeeping tests. Validation analyses demonstrate rational tuning results. The observed random errors and bias in relation to the measurement functions due to the applied simplification and linearization in the seakeeping simulations can lead to biased tuning. The importance of designing the state space and the measurement space is demonstrated by case studies. Due to the nonlinear relationship between the uncertain vessel parameters and the vessel motions, the tuning is shown to be sensitive to the mean state vector and selection of the surrounding sigma points.     

Ti-Ni-Hf基合金薄带的相变行为分析

利用DSC系统研究Cu含量、退火温度、退火时间对Ti-Ni-Hf基薄带相变行为的影响。Cu含量的少量增加仅仅会略微降低Ti—NiHf合金的马氏体相变温度,不改变其相变顺序。退火处理后的Ti35Ni41Hf15Cu8合金薄带中存在2种尺寸差巨大的的晶粒,且在经较高温度退火的薄带中会有明显的（Ti,Hf）2Ni析出相,这些组织的存在对薄带的马氏体相变行为产生影响。     

城市交通发展模式转型研究

随着国家经济和社会的快速发展,我国很多城市也经历了数十年的建设黄金时期,相继而来的问题是城市人口增加,机动车数量超出城市路网承受能力,城市交通拥堵问题日益严峻。通过研究和分析国内外城市的交通发展历程和交通模式,探寻不同阶段合理的城市交通发展模式,并通过分析成功的城市交通发展经验,提出城市交通发展模式转型战略、未来发展走向和交通导控策略,为缓解城市交通拥堵、指明城市交通未来发展方向提供了科学借鉴。     

铁路10kV配电所运营改造中常见问题及对策

通过对铁路10kV配电所运营改造中出现的线路励磁涌流、母线互感器柜"虚幻接地"、TA饱和、断路器分合闸线圈容易烧毁4个常见问题的分析,提出了相应的解决方法.     

中等职业教育学校创新经营思路探索

近年来中等职业教育发展面临重重困难,本文介绍了职业教育学校创新经营方面的四条理念和实施方法,并对其理念进行综合思考与探索.     

加强政府职能转变 提高海上搜救水平

海上搜救作为一种国家组织实施的公益性事业．是国家应急管理体系的重要组成部分，体现政府的应急处理能力，我国正在积极构建社会主义和谐社会，对海上搜救工作提出了更高的要求。目前我国海上搜救工作在取得明显成效的同时，存在立法滞后、设施设备不成系统、公共服务产品缺乏等诸多问题。“必须按照政府职能转变的要求，从加快立法进度、推广宣传教育、完善基础设施、发挥海事主导作用等方面，努力提供人民群众满意的海上搜救公共服务产品。     

中国的社会转型与经济伦理的主体困境

中国的社会转型致使社会价值取向上出现了两种强势价值观并存的状况。一方面，经济体制的转变使得经济至上主义在商业技术社会中得以确立。另一方面，传统的官本位思想并没有因此受到根本性的冲击。受这两种价值观的影响，中国社会的经济伦理在道德主体层面遭遇了困境。劳动者职业道德观念淡漠，企业责任意识缺失，政府不能有效履行其职能。惟有破除经济至上主义和官本位思想，摆脱这些困境，中国的市场经济才能持续、快速、健康地发展。     

回旋线一般表达式的推导及应用

推导回旋曲线及其特殊形式的坐标计算公式的一般表达式,并由此给出通常能满足工程精度要求的回旋曲线坐标计算公式的固定表达式     

Transformation and Expression of Choline Monooxygenase(CMO) Gene in Embryogenic Tissue of White Pine(Pinus strobus)

Many plants can accumulate glycine betaine(GlyBet, N, N, N-trimethylglycine), an non-toxic or osmo-protectant in response to salinity anddrought stress. Numerous experiments in vitrohave indicated that betaine acts as an osmoprotec-tant by stabilizing both the quaternary structure ofproteins and the highly ordered structure of mem-branes against the adverse effects of high salinityand extreme temperatures. Exogenous applicationof betaine to leaves or roots has been shown to in-crease the tol…     

京津客运专线协议转换平台子系统的研究

本文阐述了京津客运专线CTC系统的结构、功能、处理流程及接1：2等。该系统实现了Siemens协议、铁道部标准协议以及其他协议间的相互转换，完成京津客运专线系统数据转入输出平台的功能。