参数变量

For fitting ROC curves and getting the area under the ROC curve, we applied the parametric methods of binormal models and ordinal regression models, the semiparametric method of Cox proportional hazards model, the nonparametric methods of Hanley, Delong.

本文采用双正态模型、有序回归模型等参数法，Cox比例风险模型半参数法，Hanley、Delong非参数法拟合了ROC曲线；文中也考虑了样本量的估计、协变量的混杂效应、再抽样技术计算ROC曲线下面积的标准误与可信区间等问题；并研究了SROC分析方法。

Parametric model of brake pad and parametric design of brake shoe have been accomplished on the base of parametric method, secondary development tools on UG, the method of setting environment variables about development system and establishing method of application program, and which can provide the foundation for the development platform of automotive brake system.

对鼓式制动器的组件进行了离散化处理，在介绍了参数化方法、UG二次开发工具、开发系统环境变量的设置以及应用程序创建方法的基础上，完成了鼓式制动器垫片参数化模型的建立以及制动蹄的参数化设计，为汽车制动器专用开发平台的建立奠定了基础。

A method of determination of the base circle and offset distance was presented and a designer can ascertain the principal size parameters of disk cams correctly or take them as the original numerical values for design.

主要分析了偏置式推杆盘形凸轮机构的主要尺度参数与所给定运动参数之间的关系，并提出了基圆半径r0 ，偏距e等的取值原则与方法，从而准确无误地确定凸轮的主要参数，或是把此参数作为设计变量的初值。

Takingthe contact stress, bend stress stiffness and temperature stress as thecondition, taking the weight of the kiln tyre as optimization aim function, theredia and the width of the tyre are optimized General optimize methods justconsider the affecting of the parameters to aim function, but in fact,structural parameters(such as structure dimension, interval and so on),physics and dynamics (damp factor, conduct factor, friction factor material'selastic module strength limits and so on), which would be changed afterused.

一般的优化方法，仅仅考虑了参数对其目标函数的影响，而实际情况下有些参数是变化的，产品的结构参数、物理和力学参数如阻尼系数、传导系数、磨擦系数、材料的弹性模量和强度极限等的设计值与制造后和使用中的实际值会有差异，这种差异称为设计变量和噪声因素的变差。

If certain variables based on experience to know there is some functional relation can be used, we can find a function of some parameters to fit the observed data, which is called parametric model.

但是当我们对变量间的内在关系不太清楚时，使用参数模型会带来较大的模型偏差，所以又引入了非参数、半参数模型。

However the posterior density functions of character parameter, skew parameter and location parameter are multi-mode, so the slice sampling is used to make the algorithm more efficient.

其中辅助变量的后验密度是单峰的，因此引入自适应舍选抽样来提高效率，而特征参数、偏度参数和位置参数的后验密度是多峰的，用切片抽样来处理效果较好。

On this basis, anoptimization algorithm library named OPTLIB is formed. The study of dynamic optimization theory is followed. To solve the problem of thecoupling of the static and the dynamic parameters of the flying vehicle design, some auxiliaryvariables are introduced to deal with them together. Then the calculus of variation is adoptedand augment form of Pontryagin's Maximum Principle is derived.

研究了飞行器设计中的典型动态优化问题——轨迹优化问题及算法，针对飞行器设计中的静态参数和动态参数互相耦合的问题，引入辅助变量将静态参数和动态参数统一处理，在此基础上用变分法推导了极大值原理的增广形式，证明了单独的静态或动态最优并不等于总体最优。

Secondly by using the real parameter complex variable error model and its parameter adjusting algorithms developed in this paper, some new parameter identification methods that can be used in the variant speed driving condition are proposed.

其次，应用本文得到的实参数复变量正实误差模型条件下的参数调整算法，给出了2种新的变速驱动时感应电动机定转子参数的辨识算法，它们可以在交流传动系统的参数自适应设计问题中得到应用。

Using lumped-parameters method according to the parameters at the outlet of desuperheater and the control volume approach, the dynamic models of desuperheater were established . Enthalpy was used as the main variable in the model, thus many uncertain parameters could be avoided.

以减温器出口参数为集总参数的建模方法和分多段集总参数建模方法，分别建立了减温环节的动态数学模型，模型以焓值为主要变量，避免了大量不确定参数的引入。

The method to configure RED parameters based on network properties is also presented. Simulations show that the modified Random Early Detection algorithm really performs better than the original Random Early Detection algorithm and can work for a much wider range of traffic. Finally, whether the assured service mechanisms i. e. an edge router tags every arriving packet of a TCP flow based service profile and core router drops packets differently at congestion using active queue management scheme is possible to provide a throughput consistent with target rate, is investigated under different network scenarios. Different factors including target rate tagged algorithm, RIO algorithm and TCP congestion control mechanism how to affect the throughput of an assured service TCP flow are examined. Based on a fluid model. we then derive a model of an assured service TCP flow, which is the function of round trip delay, packet loss rate and token bucket parameters. Based on this model, we observe that in some cases it is possible to regulate the token bucket parameters to gain a consistent throughput with the target rate, while in other cases there exist ranges of values of the achieved rate for which the token parameters have no influence. With the latter, some modified TCP congestion control mechanisms to assure TCP throughput are proposed.

最后，在区别服务网络结构内，研究了当前提出的一种边缘路由器根据服务合同标记、分类数据包，结合内部路由器采用主动队列缓冲管理机制区别处理数据包的确信服务机制是否可在不同网络情况下使TCP连接获得同目标速率相一致的、公平的吞吐量问题；指出影响TCP连接获得同目标速率相一致吞吐量的主要因素是目标速率大小、标记算法参数和TCP连接的拥塞控制算法；对此，基于流模型假设，首次推导出一个以端到端时延、数据包丢失率、漏桶参数为变量的确信服务TCP连接吞吐量模型；利用这个模型进行分析，得到主要结论是在一些情况下可通过设置合适的漏桶参数得到同目标速率更一致的吞吐量，而在另一些网络情况下不管如何设置漏桶参数都不能使TCP连接获得同目标速率一致的吞叶量；对于后一些情况，还初步讨论了改进TCP拥塞控制算法来改善TCP连接性能的方法。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。