Sparse field level set method for non-convex Hamiltonians in 3D plasma etching profile simulations

Level set method [S. Osher, J. Sethian, J. Comput. Phys. 79 (1988) 12] is a highly robust and accurate computational technique for tracking moving interfaces in various application domains. It originates from the idea to view the moving front as a particular level set of a higher dimensional function, so the topological merging and breaking, sharp gradients and cusps can form naturally, and the effects of curvature can be easily incorporated. The resulting equations, describing interface surface evolution, are of Hamilton-Jacobi type and they are solved using techniques developed for hyperbolic equations. In this paper we describe an extension of the sparse field method for solving level set equations in the case of non-convex Hamiltonians, which are common in the simulations of the profile surface evolution during plasma etching and deposition processes. Sparse field method itself, developed by Whitaker [R. Whitaker, Internat. J. Comput. Vision 29 (3) (1998) 203] and broadly used in image processing community, is an alternative to the usual combination of narrow band and fast marching procedures for the computationally effective solving of level set equations. The developed procedure is applied to the simulations of 3D feature profile surface evolution during plasma etching process, that include the effects of ion enhanced chemical etching and physical sputtering, which are the primary causes of the Hamiltonian non-convexity.     

WCDMA系统接口信令消息的描述与实现

WCDMA作为第三代移动通信系统的主流标准，能够提供多种类型的多媒体服务。为了实现各种用户平面数据的传输，系统会提前通过控制平面对所需的无线资源进行分配。由于配置过程是通过接口之间发送控制平面应用协议消息来实现的，因此能否正确有效地对信令消息进行编解码成为保证系统稳定工作的关键因素。3GPP标准中，ASN．1语言被用来描述接口信令消息。首先简要介绍了WCDMA系统结构以及主要接口协议，重点描述了ASN．1存在的意义及其编解码规则，最后给出了基于ASN．1的开发环境下应用层网络协议的开发流程。     

Fracture toughness of PAN-based carbon fibers estimated from strength-mirror size relation

Fracture toughness (K_IC) of representative high-strength type PAN (polyacrylonitrile)-based carbon fibers, Torayca™ T300 and T800H, with or without artificial surface defects, were estimated to be ca. 1 MPam^1/2 from the tensile strength vs. fracture mirror size relation, assuming a constant crack-to-mirror size ratio. The corresponding critical energy release rate (Γ) was ca. 7.4 J m⁻², which was close to the value derived from the reported surface energies for a graphite crystal. Similar K_IC values were obtained for the old-type PAN-based carbon fibers from the reported data by the use of the present estimation procedure.     

基于B/S架构的口岸管理信息系统设计与实现

为了对口岸管理进行微机化，以微软、NET和水晶报表为开发工具，设计并实现了口岸管理信息系统，同时对实现过程中所遇到的关键技术进行了探讨。运行证明：该系统界面美观简洁，方便易用，客户端只需通过浏览器就可以访问服务器，不需要安装其它软件。加强各执法部门间的业务衔接，减少业务脱节现象，简化查验手续，促进查验工作的快速完成，也减轻了查验工作人员的劳动强度，提高口岸工作的效率，有利于发挥口岸工作的综合管理职能和整体功能。     

提高托盘利用效率的重要手段——电子信息化管理

托盘能否有效运用对物流的畅通与否关系重大,这已经引起了国内外专家和学者们的重视,并就此制定了托盘电子信息化管理系统,旨在更合理地使用托盘,推进托盘一体化和共用系统的建立。而RFID技术在托盘的电子信息化管理的应用更将大大提高物流的效率与准确性,托盘电子信息化管理将成为今后托盘管理的趋势。     

基于FPGA的CAVLC编解码器设计与实现

H．264标准在基本档次和扩展档次中采用CAVLC熵编码，完成对变换系数残差块的编码。提出一种基于FPGA的H．264标准的CAVLC编解码器，程序代码用verilog硬件描述语言编写，并在QuartusⅡ中进行了仿真验证，可以实现对每个残差块数据的编解码并将其按照宏块光栅扫描的顺序输出到存储器，因此适合于嵌入在最终的码流中。仿真结果表明此CAVLC编解码器达到H．264标准中基本档次和扩展档次level3．0的性能要求。     

SIP协议在VoIP终端的设计和实现

SIP是下一代网络中的重要协议,而基于SIP协议的VoIP业务已经对传统话音业务形成了重要的威胁,并成为各大运营商竞争的重点业务之一.概述了VoIP业务的发展现状,介绍了SIP协议的实体、消息机制以及它所提供的业务,通过对SIP协议的原理及工作流程的分析,论证了其在实现一个VoIP系统中的优势,在此基础上设计并实现了一个基于SIP协议的VoIP终端.     

陆东凹陷油气藏烃类组成非均质性及其意义

陆东凹陷原油和油砂抽提物中烃类的宏观组成存在着明显的非均质性。在高孔隙度(>15%)储层单元中,饱和烃的含量高,占总组成的含量均大于40%,而极性化合物则相对较低,一般不足40%;相反,在低孔隙度(<15%)储层单元中,饱和烃的含量明显降低,而极性化合物则显著增加。此外,陆东凹陷原油和油砂抽提物中烃类成熟度亦存在着非均质性:在高孔隙度储层中,原油和油砂烃类的成熟度参数高,而在低孔隙度储层中原油和油砂烃类的成熟度参数低。根据原油和油砂抽提物中烃类的宏观组成特征和成熟度参数的变化规律,提出了陆东凹陷油气聚集模式。     

蓝牙与IEEE802.11g系统的共存

蓝牙与IEEE802.11g无线局域网(Wireless Local Area Network,WLAN)都工作在2.4GHz频段上,因此它们之间存在一定的干扰。分析了蓝牙与IEEE802.11g通信系统之间的干扰,并提出了解决这一问题的两种方法:自适应跳频和删除标记法,并对两种方法的性能做了比较。