BNCT物理剂量Monte Carlo程序系统——MCDB及算法

硼中子俘获治疗(BNCT,boron neutron capture therapy)规划软件系统MCDB(Monte Carlo dosimetry inbrain),包括医学前处理、Monte Carlo物理剂量计算和后处理。采用中心点方法确定网格的材料和密度,并自动生成Monte Carlo输入文件。MCDB借鉴并发展了一套网格几何下的快速粒子径迹算法,取得了与MCNP程序一致的剂量计算结果,计算速度较MCNP程序提高2.7~3.5倍。MCDB可进行并行计算,具有线性加速比,能够满足BNCT临床对计算时间和精度的要求。     

Avoiding obstacles by using a proximity infrared sensor skin

Placement and wiring of vast amount of sensor elements on the 3-dimensionally configured robot surface to form soft sensor skin is very difficult with the traditional technology. In this paper we propose a new method to realize such a skin. By implanting infrared sensors array in an elastic body, we obtain an elastic and tough sensor skin that can be shaped freely. The developed sensor skin is a large-area, flexible array of infrared sensors with data processing capabilities. Depending on the skin electronics, it endows its carrier with an ability to sense its surroundings. The structure, the method of infrared sensor signal processing, and basic experiments of sensor skin are presented. The validity of the infrared sensor skin is investigated by preliminary obstacle avoidance trial.     

区间精细算法与长效精细算法的对比研究

如何应用精细算法求解非齐次或非线性问题是计算力学中的热点问题，通常采用区间精细算法，但这一方法的精细传递矩阵与t步长的区间有关，计算量很大．能否设计出“一次计算，终生使用”的长效精细算法是一个倍受关注的问题，尤其是针对非线性的情况．以Burgers方程为模型设计出一种能解决二次非线性困难的长效精细算法．这类技巧不难推广至一般的二次非线性PDE（偏微分方程），且有广泛的应用，还建立了相应算法的基础理论与误差分杯两个算例表明，计算结果十分令人满意．     

泰山日出的气象条件及气候慨率

描述了泰山日出的壮丽景观，根据泰山日出的气象条件及气候概率，指出了泰山日出的最佳观赏时机。     

VB上机操作题自动判分程序的设计

介绍了VB上机操作题的自动判分程序的主要算法，对上机操作题的评分标准格式进行了描述，阐述如何提取考生提交的答案并使用评分标：簋进行自动判分，并给出判分过程记录。     

Provable Efficient Certificateless Group Key Exchange Protocol

Certificateless public key cryptography （CL-PKC） avoids the inherent escrow of identity-based cryptography and does not require certificates to guarantee the authenticity of public keys. Based on CL-PKC, we present an efficient constant-round group key exchange protocol, which is provably secure under the intractability of computation Diffie-Hellman problem. Our protocol is a contributory key exchange with perfect forward secrecy and has only two communication rounds. So it is more efficient than other protocols. Moreover, our protocol provides a method to design efficient constant-round group key exchange protocols and most secret sharing schemes could be adopted to construct our protocol.     

Escrow-Free Certificate-Based Authenticated Key Agreement Protocol from Pairings

Key agreement protocols are essential for secure communications. In this paper, to solve the inherent key escrow problem of identity-based cryptography, an escrow-free certificate-based authenticated key agreement （CB-AK） protocol with perfect forward secrecy is proposed. Our protocol makes use of pairings on elliptic curves. The protocol is described and its properties are discussed though comparison with Smart＇s protocol.     

A Weighted Algorithm for Watermarking Relational Databases

0 Introduction Watermarking relational database become a hotspot in recent years, it aims to protect copyrights by intro- ducing small errors into the original content without af- fecting the usability for intended purpose. Although some pioneer efforts h…     

蒙特卡洛法在油气储量估算中的应用

详细论述了蒙特卡洛法的数学原理及其在油气储量估算中的具体使用方法 ,并通过应用实例说明在油气田的不同勘探开发阶段 ,根据拥有资料的多少选用适当的数学模型 ,利用蒙特卡洛法都可以估算出一个具有一定可信度的比较合理的油气储量数值。当一个区块勘探程度较高 ,拥有资料较多时 ,用蒙特卡洛法估算的储量与用容积法估算的储量比较接近。     

支持移动IP的无线接入点研究与设计

分析了现行无线局域网的不足和应采取的相应对策，给出了支持移动IP的无线局域网基本体系结构。研究了支持移动IP的无线接入点的扩展功能和协议栈，提出了新的子层－IP关口层。分析无线接入点在IP关口层和数据链路层对移动IP的支持，并给出了支持移动IP的无线接入点软件设计方案。