一种应用于移动医疗的体征参数管理软件的设计

随着通信技术的发展,移动医疗在生活中扮演着越发重要的角色。在体域网及移动健康医疗的基础上,实现一种典型的个人健康监护系统,采用Android平台作为系统协调器,设计开发一种软件可以对传感器采集的体征参数进行管理。通过编程测试证明能够实时将用户的体征参数传输进入An-droid手机并发送至远端服务器,并可保证参数在移动监护终端和远端监护设备间实时、准确地传输,这对体域网的发展有着重要的参考价值。     

社区模型机会网络路由研究

当前,基于社区的机会网络研究在模型上还有待完善,在社区间的路由算法没有考虑消息的传输效率,只采用简单的分发等待路由算法,使得路由效率较低。为此,对社区模型进行了改进,加入节点回归因素,并在此模型下提出了新的路由算法NBR。在社区内采用混合路由算法,并加入了正反馈思想重新计算节点活跃度。在社区间采用查询路由表和判断节点回归相结合的方法,利用节点回归的特性提高转发效率。仿真结果表明,在改进后的社区模型下,NBR算法使得社区间和社区内的消息传输成功率得到了提升,有效的降低了网络资源的消耗。     

基于BP神经网络算法的Ti-6Al-4V激光NiAl-VC合金化的工艺研究

为了进一步提高Ti-6Al-4V的性能,以满足其在工程中更广泛的运用,研究了在Ti-6Al-4V激光NiAl-VC合金化的工艺。以改变激光功率、激光扫描速度和粉末质量含量比例进行了工艺实验,采用BP神经网络(BP-NN)算法,建立了合金化层性能与工艺参数之间的关系模型,并通过验证实验表明预测效果良好,具有可行性。采用BP-NN算法进行了模拟实验,分析了不同工艺参数条件对合金化层深度、宽度、平均硬度、最高硬度的影响规律。本研究对Ti-6Al-4V激光NiAl-VC合金化的实践应用具有指导意义和参考价值。     

Design of reliable fiber‐based distribution networks modeled by multi‐objective combinatorial optimization

In this work, we investigate the planning of hybrid fiber/very high bit rate digital subscriber line (HFV) access networks. This HFV variant is considered as an alternative to passive optical access network. It consists of implementing optical fibers in the access network part from the central office to the street cabinets, whereas the very high bit rate digital subscriber line technology is used in the last meter part, from street cabinets to subscribers. Firstly, we discuss the different tasks of this planning problem. We model this planning problem as a multi‐objective optimization problem, where different conflicting objectives have to be optimized at the same time. We consider network costs and network reliability. This problem is solved by two different approaches: the classical single‐objective optimization (SOO) and the multi‐objective optimization (MOO), which is a recent optimization approach that is gaining an increasing interest in practical optimization problems. MOO solves the problem by searching for different optimal trade‐offs between the optimization objectives. The performances of SOO and MOO are analyzed and compared with each other using three network instances. Copyright © 2012 John Wiley & Sons, Ltd.     

Identification of preconditions for an emerging mobile LBS market

Location information has become a very important horizontal service component for a wide range of vertical mobile applications. This enabled multiple innovative mobile location-based services (LBS) that range from conventional mapping and navigation services featuring millions of points of interest (POI) to location-aware content delivery and mobile social networking. Providing a whole new world of opportunities for device and application vendors, network operators, content providers and prospective consumers, mobile LBS have potential to become one of the core businesses in today's mobile arena. However, the future of this market is not fully transparent due to several uncertainties associated with a mixture of technologies, service demand, consumer attitude, privacy aspects of using LBS and a complex value network. In this study, we identify and analyse a set of preconditions for an emerging mobile LBS market in its present evolution phase. The history of LBS motivates us to take a closer look at this emerging market and try to understand what the main reasons for LBS initial failure have been and what is still missing in this market today to emerge successfully. To focus on the most relevant issues, we construct our own research framework containing three main dimensions: technological advance and standardisation, value network and value proposition. Within these dimensions, we compare the early state of mobile LBS with the present situation and analyse the key factors presently crucial for LBS proliferation.     

Real options and technology management: Assessing technology migration options in wireless industry

The wireless industry is currently undergoing a major transition from second generation (2G) to third generation (3G) wireless technologies. The paper attempts to assess wireless technology migration options using the real options approach (ROA) to support the wireless network operators’ strategic decisions: to migrate or not, if so, which migration path to take. The preliminary result shows that the evolution of wireless network technologies between generations is desirable, but not within generations. Finally, from a strategic perspective, we should consider the possible challenges that may hinder migration. By identifying these challenges, we can be more watchful of transition pitfalls and can choose a better alternative.     

Nonlinear network coding based on multiplication and exponentiation in GF（2^m）

This article proposes a novel nonlinear network code in the GF(2m) finite field. Different from previous linear network codes that linearly mix multiple input flows, the proposed nonlinear network code mixes input flows through both multiplication and exponentiation in the GF(2m). Three relevant rules for selecting proper parameters for the proposed nonlinear network code are discussed, and the relationship between the power parameter and the coding coefficient K is explored. Further analysis shows that the proposed nonlinear network code is equivalent to a linear network code with deterministic coefficients.     

泛在网络架构的研究

结合国际主要标准组织——ITU-T的最新标准化情况,韩国、日本的一些产业化情况以及欧盟的一些研究项目,介绍了泛在网络的一些发展趋势和情况,提出了泛在网络的架构和其可能包含的内容。     

Distributed Borrowing Addressing Scheme for ZigBee/IEEE 802.15.4 Wireless Sensor Networks

This paper proposes a distributed borrowing addressing (DIBA) scheme to solve problems of failure in address assignments resulting from limited tree depth and width when the distributed address assignment mechanism is used in a ZigBee/IEEE 802.15.4 wireless sensor network. DIBA is a method of borrowing addresses from neighbor nodes for newly entering nodes and assigning the borrowed addresses. Its network or sensing coverage can increase with almost the same overhead as the existing method. DIBA is a simple and lightweight means of addressing and routing, making it suitable for wireless sensor networks. Simulations showed that DIBA is a distributed addressing scheme with consistently excellent performance.     

移动网络中数据业务关键性能指标KPI探讨

移动网络的性能评估是网络规划和优化建设的前提，数据业务的迅速发展为移动网络的性能评估提出新的课题，当前评价数据业务网络的关键性能指标主要有吞吐量、时延等，从网络的容量和质量角度出发提出每用户平均吞吐量和网络资源利用率两个关键性能指标，并分别进行理论分析，为数据业务网络的性能评估提供参考依据。