基于RS232C的即插拔多主通信协议

研究了RS232C接口电气特性和DCS系统网络的工作特性，分析了并发帧碰撞发生机理及其导致的帧错误类型，定义了多主通信的帧格式和纠错方法，完成了并发帧碰撞侦听和纠错机制设计，实现了DCS系统中的即插拔和多主通信。     

让照片即拍即打

即拍即打技术对我们而言并不陌生，Canon以及Epson此前已经推出了多款内置闪存卡读卡器的照片打印机。由于成本过高等原因,那些高端产品并不受到青睐而低端产品在兼容性方面又令人难以满意。作为业界最具实力的两大厂商,Canon与Epson都相当看好数码影像输出市场,这一由打印机与数码相机所带来的联动产业具有极大的开发价值。     

即拍即打，即刻精彩——体验“即拍即打”

在数码风尚一夜之间席卷全球之后,人们的生活也迅速为之而改变。作为这场数码革命的先行者,数码相机在今天这个数字化信息时代里已经担当起了非常重要的角色。但在它将我们身边一幕幕的“精彩”化成永恒之余,如何对这些数字化的“精彩”随时随地进行快捷、高效地照片输出,也逐渐成为时尚人士开始思考的又一新课题,这就促成了今天悄然兴起的“即拍即打”。     

LON网节点的即装即用

介绍实现ＬＯＮ网节点即装即用的一种程序设计方法,从一个典型的例子出发介绍了设计的整个过程。     

用Authorware中的“即点即输”方法制作多空填空题

该文介绍了在Authorware中用2种"即点即输"方法制作多空填空题。     

IaaS环境下虚拟机无代理通信加密机制*

云计算被广泛的用于管理IT基础设施,然而,用户在使用过程中依然面临着不同的安全威胁。针对IaaS(Infrastructure as a Service)环境下虚拟机通信数据在共享网络基础设施中的安全性问题,提出了一种虚拟机无代理通信加密机制。该机制通过加载于虚拟化节点内的加密模块与平台统一加密控制器间的协作,实现了IaaS环境下虚拟机通信无代理按需加密;同时,引入通信加密策略有效性保障机制,保障了虚拟机全生命周期内的通信加密策略有效性。实验结果表明,该机制在引入较小性能开销的前提下,可以有效实现虚拟机通信加密,并保障虚拟机全生命周期内加密策略的有效性。     

区块链即服务的发展现状与展望

论述区块链即服务研究现状,通过云计算和区块链技术结合方式介绍区块链即服务工作原理,根据区块链即服务面向的服务对象论述基础设计原则,以主流的区块链即服务平台分析研究基本架构。区块链即服务作为一种云服务,是区块链服务设施的云端出租网络平台,依照其租户特点使计算资源、平台资源、软件资源、硬件资源得到最大程度的共享。区块链即服务通过大容量的资源池,保障租户的业务规模可灵活弹性伸缩,租用设施可共享和独享,安全可靠运行。针对区块链即服务风险监管、技术难点、性能等问题对当前研究的不足和未来的研究方向进行分析和展望。     

基于Myrinet/GM的多通道通信

通信子系统对并行系统的计算效率有重要影响,大规模应用对并行平台的通信性能和可用性提出了挑战性的要求.多通道通信技术通过并行采用多路网络链路互连来提高并行系统通信性能和可用性.首先分析了多进程复用网络对通信性能的影响,然后以Myrinet/GM网络平台为基础,提出了基于网络接口层的通信链路动态选择与分配策略,设计和实现了支持多路Myrinet网络并行通信的协议层MNC.MNC支持通信进程平等,充分地利用多路Myrinet网络链路资源.在使用2路Myrinet互连的PC机群平台上,MNC进程间通信带宽相对于单链路提高了约34%,有效地提高了应用层通信性能.     

消息传递型MPSoC通信过程分析及其优化设计

通过分析消息传递型MPSoC通信过程,总结出提高通信性能的有效途径——降低一对多消息发送延迟和提高多条消息并发接收效率.从减少数据拷贝延迟的角度提出了基于硬件抽象层广播优化策略,有效地降低了一对多消息发送延迟;针对并发接收瓶颈,充分考虑减少交互次数和提高长消息通信效率,提出一种基于查找表和DMA模式相结合的接收策略.实验结果表明,广播优化策略及接收策略均能明显提高性能;在64×64的矩阵乘法中,采用优化策略整体性能提高接近1.5倍.     

“即装即用”的轧制力遥测系统设计

为解决轧制力检测系统安装困难、调试繁琐问题,将智能信号调理电路、无线收发模块与附着式传感器集成;附着式传感器可方便、快捷地安装在换辊侧(传动侧)机架外侧,通过测取机架变形间接测取该侧分轧制力;由X9241、AD623、ADC、MCU等组成的智能信号调理电路,通过分析所采集信号的特征,将漂移信号分离,并将量化后的分轧制力信息送基于nRF401的无线收发模块发送,从而既保证了系统的测量精度,又实现了传感器的快速安装和"即装即用".在无线信号接收端,采用两块同样基于nRF401的无线收发模块,利用该模块拥有两个工作频道这一特点,与(集成)传感器进行点对点的无线数传,使系统获取总轧制力信息的速率达到19.2 kbit/s.     

A mid-ranging control strategy for non-stationary processes and its application to dissolved oxygen control in a bioprocess

In this study a modified mid-ranging strategy is proposed where the controller for the secondary manipulated variable uses its own output as its setpoint, possibly with an offset and/or re-scaling. This modification allows the manipulated variables to increase in unison so that the mid-ranging advantage of utilizing the fast dynamics of the primary controller to regulate the process can be achieved also in non-stationary processes, while not adding complexity to the controller. The proposed control strategy has been implemented in pilot-scale (500 l) industrial bioprocesses where it is used to control the dissolved oxygen level by manipulating agitator speed and aeration rate. The controller is demonstrated to perform well in these, outperforming a reference controller which has previously been shown to give satisfactory control performance. It is also shown in similar experiments that the strategy can easily be adapted to control dissolved oxygen in bioprocesses where the feed rate is controlled using an extremum-seeking controller. The proposed strategy is generally applicable to non-stationary processes where a mid-ranging approach is suitable.     

Some Practical Approaches to Pursuit-Evasion Dynamic Games

For problems of realistic dynamic games, some practical approaches are proposed to the construction of suboptimal strategies of the behavior of players for different data on the choice of controls by their opponents. All the approaches proposed employ only solvers of one-sided nonlinear optimal control problems and simulation programs. The approaches are as follows: (i) give both players some suboptimal feedback strategies and conduct a great number of Monte Carlo simulations, (ii) give one player a suboptimal feedback strategy and the other player an exact one-sided nonlinear optimal control, (iii) give both players suboptimal feedback strategies dependent on parameters. Each player tries to optimize his parameters with respect to the one-sided nonlinear optimal control of the opponent. Methods (i) and (ii) can be used to solve multi-player problems. The efficiency of the method of choice of a suboptimal strategy is illustrated by examples important for actual practice.     

An Intensity-Based,Coarse-to-Fine Approach to Reliably Measure Binocular Disparity

Disparity estimation is an ill-conditioned problem: at certain locations, the disparity vectors cannot be estimated solely using local intensity patterns. According to the strategy they use to solve this problem, the algorithms to estimate disparity vectors can be divided into two classes: the feature-based and intensity-based algorithms. In this paper, a new strategy is proposed. First, the disparity vectors are estimated, and then the unreliable and unfeasible vectors are eliminated. The method bears some resemblance with methods of both classes. In principle, the new approach is intensity-based, but it will be proved that because of the elimination process it determines the features on a binocular basis: the binocular raw primal sketch is constructed. A computational technique is developed for this new strategy. This technique is based on the simplex algorithm and its associated sensitivity analysis. Methods to reduce the required storage space and computation time are discussed. Numerical results are given for a random dot stereogram and an artificially generated stereo pair. Qualitative results are given for natural stereo pairs.     

A combined in silico strategy to describe the variation of some 3D molecular properties of beta-cyclodextrin due to the formation of inclusion complexes

A powerful in silico strategy based on the combined use of two computational tools (MLP and MIFs) able to calculate and visualize 3D molecular fields can give useful information about surface properties of macromolecules involved in the mechanisms of formation of complexes. In particular, this study investigated the variation in polar/hydrophobic pattern induced on the beta-CD alone (i.e. =without the ligand) by the inclusion of four ligands having different lipophilicities and small size. Results indicate that, in the presence of guests with P>0, the hydrophobicity of beta-CD increases in the cavity and its surroundings on the primary face.     

基于改进的MOSSE相关滤波的目标跟踪

视频目标跟踪存在如遮挡、形变、漂移等诸多挑战。虽然研究者提出了大量的算法来解决这一问题, 但大多数不具备普适性和实时性。为了实现目标有效稳定的实时跟踪, 本文在MOSSE相关滤波算法基础上提出了一种多模式的视觉目标跟踪算法, 该算法不仅具有相关算法的实时性, 还适应跟踪目标外观大幅度变化情况。同时, 为了适应跟踪过程中目标外形的复杂变化, 提出了一个控制模式更新率的算法, 利用具有多模式的跟踪算法可以同时处理极小的运动与外形突变。对基准视频数据的仿真实验结果表明, 与对应的单模型跟踪算法相比, 本文提出的算法可以明显改善跟踪精度和稳定性。     

基于QOS的网络计费管理

In this paper we present a network accounting method based on QoS which is compared with the methods based on the length of time or the size of the stream.We give out its strategy and its main data structure when used in a wide bandwidth connection system.     

基于OpenPBS的机群作业管理系统的设计与实现

机群作业管理系统直接关系到机群性能的发挥和使用率的提高,是机群的一个重要组成部分。该文主要介绍了当前比较流行的作业管理系统OpenPBS的结构及工作过程,以及在其基础上开发的好用的web方式的作业提交系统。基于web的使用策略增加了系统的好用性。     

结合ABC算法动态分级的双蚁态蚁群算法

针对蚁群算法收敛速度慢、易陷入局部最优等问题，结合人工蜂群算法的分级思想，提出动态分级的双蚁态蚁群算法。根据适应度不同，将蚁群划分为寻优蚁和侦查蚁，并执行不同加权系数的动态信息素更新策略：寻优蚁负责较优路径的搜索，执行较大权重的信息素更新策略，以增强其导向性，提高算法收敛速度。侦查蚁则负责探索非较优路径，发现其他更优解，以保证算法多样性。然后，每次迭代结束则两类蚂蚁进行优良解交换，以提高解的质量。以旅行商问题为例，将其与经典蚁群算法、最新蚁群改进算法以及其他最新优化算法进行对比，其表现皆更优。     

非独立同分布数据下的去中心化联邦学习策略

区块链具有不可篡改性和去中心化的特点,其与联邦学习的结合成为人工智能领域的热门主题。目前去中心化联邦学习存在训练数据非独立同分布导致的性能下降问题,为了解决这个问题,提出一种模型相似度的计算方法,然后设计一种基于该模型相似度的去中心化联邦学习策略,并使用五个联邦学习任务进行测试,分别是CNN模型训练fashion-mnist数据集、alexnet模型训练cifar10数据集、TextRnn模型训练THUsnews数据集、Resnet18模型训练SVHN数据集和LSTM模型训练sentiment140数据集。实验结果表明,设计的策略在五个任务非独立同分布的数据下进行去中心化联邦学习,准确率分别提升了2.51、5.16、17.58、2.46和5.23个百分点。     

Enhancing tit-for-tat for incentive in BitTorrent networks

BitTorrent achives great success in its high performance for file distribution. It is commonly believed that this owes to Tit-for-Tat strategy adopted in choking algorithm for incentive in BitTorrent protocol. But there are still many issues in incentive mechanism in BitTorrent. In this paper, we study Tit-for-Tat strategy by constructing a game model in P2P environments and deducing the constraint under which the strict Tit-for-Tat is an equilibrium strategy. We then enhance and adapt the Tit-for-Tat strategy to the dynamic property in P2P networks, and deduce the constraint under which it is still an equilibrium strategy. We also study through simulations the performance improvement of the enhanced Tit-for-Tat, and give suggestion on how to choose proper system parameters under different network conditions. Finally, based on the enhanced Tit-for-Tat strategy, we propose a method to improve incentive in BitTorrent networks to cope with free-riding and fairness issues.