Bohmian trajectories and Klein's paradox

We compute the Bohmian trajectories of the incoming scattering plane waves for Klein's potential step in explicit form. For finite norm incoming scattering solutions we derive their asymptotic space-time localization and we compute some Bohmian trajectories numerically. The paradox, which appears in the traditional treatments of the problem based on the outgoing scattering asymptotics, is absent.Comment: 14 pages, 3 figures; minor format change

Research and Design of a Routing Protocol in Large-Scale Wireless Sensor Networks

无线传感器网络，作为全球未来十大技术之一，集成了传感器技术、嵌入式计算技术、分布式信息处理和自组织网技术，可实时感知、采集、处理、传输网络分布区域内的各种信息数据，在军事国防、生物医疗、环境监测、抢险救灾、防恐反恐、危险区域远程控制等领域具有十分广阔的应用前景。 本文研究分析了无线传感器网络的已有路由协议，并针对大规模的无线传感器网络设计了一种树状路由协议，它根据节点地址信息来形成路由，从而简化了复杂繁冗的路由表查找和维护，节省了不必要的开销，提高了路由效率，实现了快速有效的数据传输。 为支持此路由协议本文提出了一种自适应动态地址分配算——ADAR（AdaptiveDynamicAddre...As one of the ten high technologies in the future, wireless sensor network, which is the integration of micro-sensors, embedded computing, modern network and Ad Hoc technologies, can apperceive, collect, process and transmit various information data within the region. It can be used in military defense, biomedical, environmental monitoring, disaster relief, counter-terrorism, remote control of haz...学位：工学硕士院系专业：信息科学与技术学院通信工程系_通信与信息系统学号：2332007115216

PROSPECTS AND BARRIERS FOR UP-FRONT CAE-SIMULATION IN THE AUTOMOTIVE DEVELOPMENT PROSPECTS AND BARRIERS FOR UP-FRONT CAE- SIMULATION IN THE AUTOMOTIVE DEVELOPMENT SUMMARY

identification of the best practicing and breakthrough technologies to support the European automotive industry. This three year project is coordinated by NAFEMS, the International Association for the Engineering Analysis Community. The author of this article holds the role of the technology leadership steering the project aim to identify the most promising potential breakthrough technologies of the future for the integration of simulation into the automotive development process. Breakthrough technologies in the context of AutoSIM project are novel or revolutionary technologies and procedures required to offer successful solutions to solve the engineering problems in the coming century. The project consortium – representatives of 32 Europe's leading automotive companies – was defining important technology topics with potential to become breakthrough technologies. After a brief introduction of topics which will battle challenges as forthcoming basic tendencies for CAE-simulation within the next years, some priorities for integration of CAE-simulation into the development process will picked out and are discussed in detail. Especially the early concept and layout phases in the product development process will be discussed in this context. The reason is seen that from today’s point of view several particular bottlenecks are evident during these phases. The purpose of these remarks is to address to the most effective methods, tools and techniques to support the integration of analysis into the development process in early phases the reader. Furthermore an elaboration of essential and specific consolidated terms and concepts is visualised. In connection with the description of the priorities, which can be localised on account of available bottlenecks at the same time, technological as well as organizational and methodical barriers become recognizable