多节点部分充电模型下的充电调度优化

在无线可充电传感器网络中,针对移动充电车采用多节点部分充电模型在充电调度过程中往复行驶,导致充电时间增加的问题进行了研究。提出一种新颖的多节点部分充电模型,从全局优化移动充电车在每个充电位置的充电时间,保证每个能量临界的传感器被充满电。同时提出AlgMinTime算法进行路径规划,确定移动充电车的充电环路以及对应位置的充电时间,使得环路上总充电调度时间最小化。最终通过仿真实验评估所提出算法的性能。实验结果表明,所提算法的充电调度平均环路时间相较于SOTA算法缩短9.8%。     

基于时空协作的多移动充电器充电路径规划的研究

为解决大型无线可充电传感器网络中节点的实时充电问题,对具有多个移动充电器的网络进行了研究。在将网络公平划分为多个簇的基础上提出一种基于时空协作的多移动充电器实时充电算法STMA：通过联合考虑节点的空间位置和截止充电时间要求规划移动充电器的充电路径,在充电过程中及时获取最新的充电请求,并按照充电请求的紧急程度及时调整充电路径。仿真结果表明,采用STMA算法比单纯考虑时空要求的算法的能量利用率提高约14%,节点存活率提高约9%,更加适应节点的实时充电需求。     

一种累计多路径的移动自组网络路由策略

描述了一种基于多路径移动自组网络按需路由策略.在移动自组网络,由于网络节点的移动性及拓扑结构的易变性,路由成为最受关注的问题.在以前的移动自组网络路由算法中,主要采用的是传统的单路径方式.最近,多路径方式也逐渐出现,因为相对单路径路由而言,多路径为移动自组网络提供的QoS支持更可行、更高效.鉴于现有的移动自组网络多路径策略未能为源节点提供充分的信息,提出了一种新型的移动自组网络多路径路由算法.该算法可以将路由信息保存在源节点中,并依此在源节点中采用替换路径或多路径并发的方式进行数据传输.     

WRSN中多MC协同的一对多能量补充策略

无线可充电传感网络(Wireless Rechargeable Sensor Networks, WRSN)由于受到传感器有限的电池容量限制,所面临的一项重要挑战是如何调度移动充电器MC(Mobile Charger)及时为传感器进行充电,避免传感器由于能量过低而失效。然而现有的充电策略中单MC充电策略难以满足大规模WRSNs的电量需求,多MC充电策略常忽略充电的均衡性。针对WRSN中多MC协同充电问题,提出一种多MC协同的一对多能量补充策略(MTORN)。首先通过相交圆算法将网络中的传感器节点划分为若干个节点簇,MC根据节点簇的平均剩余能量以及距离划分簇的优先级,每个MC前往不同的节点簇进行一对多充电从而提高充电效率。仿真结果表明,与现有的算法相比,MTORN能够有效降低网络中传感器节点失效数量和MC的移动成本,延长网络生存时间。     

基于移动代理的无线传感器网络多路径路由算法研究

无线传感器网络中路由算法最重要的设计目标是减少传感器节点的能量消耗,避免节点过早死亡,延长网络生存时间。在原有多路径路由算法的基础上,提出一种新的ABMR（Agent Baseon Multipath Router）路由算法,在这种算法中引入了移动Agent技术,避免了大量的感知数据在网络中传输,由移动Agent移动到感知节点进行本地处理。充分考虑节点的能量、线道的可靠性和跳数,建立从源节点到目标节点的多条可靠路径。仿真实验表明,ABMR算法比原有多路径路由算法在降低节点能耗、丢包率等方面上有显著提高。     

无线可充电传感器网络高效在线充电算法

在无线可充电传感器网络中,传感器节点的电池寿命是决定整个传感器网络生命周期的重要因素之一,而移动充电车可有效地为传感器节点提供电量补给。在动态请求(On-Demand)的无线可充电传感器网络中,研究充电车移动耗能和充电周期内总电量两个约束条件下的充电传感器数量最大化问题。针对该问题建立非线性整型数学模型,并提出一个基于贪心策略的在线算法。该算法在每个充电周期内,充电车依次选择距离最近的传感器节点进行充电。基于聚类思想,提出另一个在线算法。该在线聚类算法利用解决旅行商问题的最小生成树算法,使得充电车在每一个类中的充电路径构成一条回路的同时,减少移动耗能。实验结果表明,在线贪心算法、在线聚类算法得出的充电传感器数量分别占充电请求总数的67%与76%。     

移动自组网中基于相关因子的多路径节能路由算法

一方面,由于移动自组网节点的能量由电池供应,一旦能量耗尽,不能继续充电,使用多路径可以节省能源;另一方面,使用多路径即便是节点不相交多路径,由于移动自组网的无线多播特性,仍存在严重的冲突问题。综合这两方面因素,提出了冲突受限的节能路由算法。该算法引入相关因子来衡量多路径同时进行数据传输时发生冲突的可能性,然后根据特定应用对传输性能的要求,得到一个冲突上限,即相关因子的最大值,最后找到能满足冲突上限的最节能的一组节点不相交多路径。仿真结果表明,该算法与单纯的节能路由算法——源传输功率选择算法（STPS）相比,可显著降低数据传输时的丢包率,且没有明显增加能量消耗和寻路时间。     

基于网格划分的井下无线充电装置部署算法

针对利用无线充电装置为井下无线可充电传感器网络进行能量传输的场景,将充电装置的部署转化为充电覆盖问题,并结合充电模型建立了最优充电覆盖模型。为求得最优充电覆盖模型的近似最优解,提出了一种基于网格划分的无线充电装置部署算法。该算法通过网格划分及扫描的方式确定充电装置的最优位置,在满足所有传感器节点充电覆盖的同时,最小化充电装置的数量。仿真结果表明,传感器节点数量较少时,网格大小对充电覆盖的影响不大,但充电半径对充电装置数量的影响较大;传感器节点数量较多时,网格大小对充电覆盖有一定的影响,但充电半径对充电装置数量的影响不大,当充电半径超过一定范围时,所需充电装置数量几乎不变。     

基于蝙蝠优化器的三维无线传感器网络节能覆盖增强策略

针对三维无线传感器网络在传感器节点重新部署时,由于复杂和恶劣环境导致的传感器节点电池充电和恢复困难的问题,提出了一种基于蝙蝠优化器的三维无线传感器网络节能覆盖增强策略.首先,利用截角八面体对三维环境进行无缝叠加,将覆盖增强和能量优化问题转化为将节点移动到截角八面体的任务分配问题;其次,基于蝙蝠优化器实现无线传感器网络的...     

一种基于非均匀分簇的实时充电算法

针对具有实时性要求的无线可充电传感器网络,使用移动充电器及时为网络中的节点补充能量,提出一种基于非均匀分簇的实时充电算法(nUCRC):首先采用非均匀分簇的方法,将网络划分为大小不等的多个簇,通过研究簇内节点的能量状态和充电截止时间决定簇头的选举和轮换;采用动态规划算法得出移动充电器的簇间最短移动路径,并根据簇内节点的时间和空间的混合优先级决定充电顺序,遍历完所有簇后,返回基站结束当前充电周期.仿真结果表明采用nUCRC算法比采用目前最新的按需充电算法的节点存活率提高约10％,平均充电时延提升约20％,更加适用于具有实时性要求的网络.     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.