正弦变换与Bézier曲线的参数化

通过对Bernstein基函数实施正弦变换,给出了Bézier曲线的一类重新参数化方法。基于Bernstein基函数,导出了正弦—Bernstein-Bézier类(Sine Bernstein-Bézier Class-SBBC)函数,定义了SBBC曲线,讨论了SBBC曲线和Bézier曲线的关系,提供了Bézier曲线重新参数化的一种有效方法。

Sine Transformation and the Reparametrization of Bézier Curves

A solution to the reparametrization of Bézier curves by sine transformation of Bemstein basis is presented. The new effective reparametrization method is given through the following procedures： educing Sine Bemstein-Bézier Class-SBBC function, defining SBBC curve and discussing the relation between SBBC and Bézier curve.

策略与计费控制技术及标准进展

介绍了基于策略与计费控制的基本架构(包括PCC和SBBC),比较了两者的不同;阐述了PCC相关的国际、国内标准及进展情况,并提出了策略与计费控制的发展方向。

IMS网络中的QoS策略控制机制

以PCC为主体介绍策略控制的系统架构,PCC规则,PCC系统的相关实体功能;通过比较PCC与SBBC的异同,PCC与RACS的异同,阐述了未来QoS策略控制系统的发展趋势。

一种PCC对CDMA2000 HRPD网络进行QoS策略控制的方案

3GPP与3GPP2针对各自主要的承载网络提出了不同的策略控制架构,分别是PCC与SBBC。由于两者QoS策略控制的基本原理相同,所以SBBC将和PCC一起完成其标准的研究和制定。本文总结并比较了PCC与SBBC的架构及实体接口功能;然后基于已提出的E-UTRAN与eHRPD互操作规范基础设计出一种PCC对CDMA2000 HRPD网络进行QoS策略控制的方案,建立QoS来实现承载资源的分配。

Optimizing Adjuvant Radiation Planning Outcomes in Patients with Synchronous Bilateral Breast Cancer

Background: Breast cancer is the most common cancer diagnosed worldwide, synchronous bilateral breast cancer accounts for unique entity of the disease, particularly post-operative radiotherapy for Synchronous Bilateral Breast Cancer (SBBC) is challenging with lack of evidence about the best irradiation technique. In this study, we tried to explore the optimum radiotherapy technique regarding the dosimetric parameters. Methods: We recruited 15 SBBC patients in whom post-operative radiotherapy was indicated and we established three plans for each patient using 3DCRT, IMRT and VMAT, and then we compared the three plans as regard target volume coverage parameters and organs at risk (OAR) doses. Results: We found that PTV coverage parameter was superior with IMRT compared with 3DCRT and VMAT in terms of Dmean (p = 0.001), D95% (p = 0.001), Dmax (p = 0.0001), conformity index (p = 0.0001) and HI (p = 0.0001). Doses to OAR were not significantly different between the three techniques in cardiac dose and LAD maximum dose, but 3DCRT was superior in LAD mean dose (p = 0.03) and lung volume receiving 20 Gy (V20) and 10 Gy (V10) (p = 0.0001), but this difference was non-significant between 3DCRT and IMRT (p = 0.4 and 0.06 respectively), while VMAT led to the highest doses to LAD and lung. Conclusions: IMRT showed the best target coverage parameters in post-operative radiotherapy for SBBC compared with 3DCRT and VMAT. For OAR doses IMRT showed comparable results with 3DCRT, while VMAT delivered a significantly higher dose to OAR.