一种基于学分制排课系统的Z规格说明

运用形式化方法建模在软件开发过程中可提高目标系统的正确性和可靠性,在此提出了一种利用Z语言进行语义分析的方法。该方法在序列图Z规范的基础上,用属性集表示对象状态,并将序列图的上下文表示为Z形式约束,通过检查上下文约束与对象状态间的一致性对序列图进行语义分析。在此以一个基于学分制的排课系统为例,使用面向对象的形式规格说明语言Z,描述了一个精确、完整的高校排课系统的形式化数学模型。过程显示,该方法具有精确的描述性和很强的抽象性,能为软件系统的开发和验证提供科学的框架。     

安全协议的形式化规范

该文给出用PVS(Prototype Verification System)对安全协议进行形式化规范的一种方 法。该方法以高阶逻辑为规范语言,利用trace模型来描述协议的行为,并假设系统中存在强攻击者和理想 加密系统。重要的结构如消息、事件、协议规则等都通过语义编码方式定义.     

Interference coordination method based on graph theory in two-tier cellular networks

This paper studies an interference coordination method by means of spectrum allocation in Long-Term Evolution (LTE) multi-cell scenario that comprises of macrocells and femtocells. The purpose is to maximize the total throughput of femtocells while ensuring the Signal-to-Interference plus Noise Ratio (SINR) of the edge macro mobile stations (mMSs) and the edge femtocell Mobile Stations (fMSs). A new spectrum allocation algorithm based on graph theory is proposed to reduce the interference. Firstly, the ratio of Resource Blocks (RBs) that mMSs occupy is obtained by genetic algorithm. Then, after considering the impact of the macro Base Stations (mBSs) and small scale fading to the fMS on different RBs, multi-interference graphs are established and the spectrum is allocated dynamically. The simulation results show that the proposed algorithm can meet the Quality of Service (QoS) requirements of the mMSs. It can strike a balance between the edge fMSs’ throughput and the whole fMSs’ throughput.     

Robust tracking based on local structural cell graph

Structure information has been increasingly incorporated into computer vision, however most trackers have ignored the inner spatial structure of the object. In this paper, we develop a simple yet robust tracking algorithm based on local structural cell graph (LSCG). This approach exploits both partial and spatial information of the target via representing the object with local structural cells (LSCs) and constructing a graph to model the spatial structure between the inner parts of the object. The tracking is formulated as matching LSCG, whose nodes are target parts and edges are the interaction between two parts. Within the Bayesian framework, we achieve object tracking by matching graphs between the reference and candidates. Eventually, the candidate with the highest similarity is the target. In addition, an updating strategy is adopted to help our tracker adapt to the fast time-varying object appearance. Experimental results demonstrate that the proposed method outperforms several state-of-the-art trackers.     

Semantic loop closure detection based on graph matching in multi-objects scenes

Robust loop-closure detection is essential for visual SLAM. Traditional methods often focus on the geometric and visual features in most scenes but ignore the semantic information provided by objects. Based on this consideration, we present a strategy that models the visual scene as semantic sub-graph by only preserving the semantic and geometric information from object detection. To align two sub-graphs efficiently, we use a sparse Kuhn–Munkres algorithm to speed up the search for correspondence among nodes. The shape similarity and the Euclidean distance between objects in the 3-D space are leveraged unitedly to measure the image similarity through graph matching. Furthermore, the proposed approach has been analyzed and compared with the state-of-the-art algorithms at several datasets as well as two indoor real scenes, where the results indicate that our semantic graph-based representation without extracting visual features is feasible for loop-closure detection at potential and competitive precision.     

基于图卷积半监督学习的论文作者同名消歧方法研究

为解决学者与成果的精确匹配问题,该文提出了一种基于图卷积半监督学习的论文作者同名消歧方法。该方法使用SciBERT预训练语言模型计算论文题目、关键字获得论文节点语义表示向量,利用论文的作者和机构信息获得论文的合作网络和机构关联网络邻接矩阵,并从论文合作网络中采集伪标签获得正样本集和负样本集,将这些作为输入利用图卷积神经网络进行半监督学习,获得论文节点嵌入表示进行论文节点向量聚类,实现对论文作者同名消歧。实验结果表明,与其他消歧方法相比,该方法在实验数据集上取得了更好的效果。     

Dependence analysis for UML class diagrams

Though Unified Modeling Language (UML) has been widely used in software development, the major problems confronted lie in comprehension and testing. Dependence analysis is an important approach to analyze, understand, test and maintain programs. A new kind of dependence analysis method for UML class diagrams is developed. A set of dependence relations is definedcorresponding to the relations among classes. Thus, the dependence graph of UML class diagram can be constructed from these dependence relations. Based on this model, both slicing and measurement coupling are further given as its two applications.     

信息物理系统技术现状分析与趋势综述

随着国民经济中各个产业信息化程度的提升和产业间深度交叉融合,信息物理系统(Cyber-Physical System, CPS)正成为支撑这一发展的关键技术,也被誉为是引领全球新一轮产业技术变革的核心体系。通过将客观物理世界中实体、行为以及交互环境等精准映射至信息空间,进行实时处理并反馈回物理空间,CPS能够从系统视角和不同层面解决复杂系统的分析建模、决策优化、不确定处理等难题。该文从CPS的体系架构和设计开发流程分析了其关键技术和难点瓶颈,探讨了CPS与边云协同计算、数字孪生、人工智能和区块链等前沿技术间相互支撑关系,综述了CPS在工业生产、能源电力、交通驾驶和医疗健康4个应用领域研究现状。最后,对CPS未来的技术发展进行了展望。以希望为信息物理系统及相关研究领域的专家和学者提供参考,为我国产业科技变革和智能化转型提供技术支持。     

基于多变异位自适应遗传算法的CPS任务调度

针对信息物理融合系统典型的分布式异构并行计算结构存在的任务调度问题,以有向无环图为调度模型,最小化任务完成时间为目标,采用多变异位自适应遗传算法,通过依赖矩阵、改进的交叉和变异算子确保基因个体的有效性,同时采用多变异位和自适应的方法保证基因个体的多样性和算法的收敛性。仿真结果显示,该算法比基于任务表的启发式调度算法更有效。     

基于异质图表达学习的跨境电商推荐模型

跨境电商产品推荐已经成为电子商务领域新兴的研究议题之一。由于电商产品信息复杂多样、“用户-产品”关联矩阵极为稀疏并且冷启动问题突出,因此传统的协同过滤推荐模型很难奏效。而改进的深度协同过滤模型,只考虑了用户对产品的“显式”和“隐式”的反馈信息,忽视了由用户与项目组成的图结构信息,推荐性能很难满足平台和用户的要求。为了解决这些难题,该文提出基于异质图表达学习的图神经网络模型(HGNR)用于个性化的跨境电商产品推荐,该模型具有2个显著的优势：(1) 构造“用户-产品-主题”3部图作为模型的输入,通过图卷积神经网络(GCN)在异质图上进行高质量信息传播和聚合;(2)能够获取高质量的用户和产品表征向量,实现了用户和产品复杂交互关系的建模。在真实的跨境电商订单数据集上的实验结果表明,HGNR模型不仅在推荐性能上表现出色,还能有效提升冷启动用户的推荐准确率,与9种推荐基准算法相比,HGNR在评价指标HitRate@10, Item-coverage@10, MRR@10上至少提升了3.33%, 0.91%, 0.54%。     

基于虚拟仪器的自动测试系统设计

为满足接收机的自动化检测需求,提出了一种基于虚拟仪器技术的接收机测试系统方案。介绍了测试系统原理,其硬件部分主要用来模拟接收机的各种输入信号,对输出信号进行测量,软件部分采用ATLAS语言进行编程,实现了对接收机的自动测试功能。实际应用表明,该系统操作简便、测试准确,满足接收机测试要求。     

An object oriented model scheduling for media-SoC

This paper proposes an object oriented model scheduling for parallel computing in media MultiProcessors System on Chip (MPSoC). Firstly, the Coarse Grain Data Flow Graph (CGDFG) parallel programming model is used in this approach. Secondly, this approach has the feature of unified abstraction for software objects implementing in processor and hardware objects implementing in ASICs, easy for mapping CGDFG programming on MPSoC. This approach cuts down the kernel overhead and reduces the code size effectively. The principle of the oriented object model, the method of scheduling, and how to map a parallel programming through CGDFG to the MPSoC are analyzed in this approach. This approach also compares the code size and execution cycles with conventional control flow scheduling, and presents respective management overhead for one application in media-SoC.     

SA based software deployment reliability estimation considering component dependence

Reliability is one of the most critical properties of software system. System deployment architecture is the allocation of system software components on host nodes. Software Architecture (SA) based software deployment models help to analyze reliability of different deployments. Though many approaches for architecture-based reliability estimation exist, little work has incorporated the influence of system deployment and hardware resources into reliability estimation. There are many factors in-fluencing system deployment. By translating the multi-dimension factors into degree matrix of com-ponent dependence, we provide the definition of component dependence and propose a method of calculating system reliability of deployments. Additionally, the parameters that influence the optimal deployment may change during system execution. The existing software deployment architecture may be ill-suited for the given environment, and the system needs to be redeployed to improve reliability. An approximate algorithm, A*_D, to increase system reliability is presented. When the number of components and host nodes is relative large, experimental results show that this algorithm can obtain better deployment than stochastic and greedy algorithms.     

用可编程器件实现ISD4004级联工作设计

分析了ISD（Information Storage Device）4004芯片的录放音控制方法,用ISP（In-System Programmable digital Circuits）在系统编程器件M4-32／32实现了对4片ISD4004语音芯片的录放音控制设计,使录放时间达64min。与其它控制方法相比是一种新方法。     

SCA配置文件自动生成工具的设计

软件通信体系结构（SCA）提供了一种标准、开放、可互操作无线电通信软件平台，是联合战术无线电系统（JTRS）的顶层设计规范。SCA核心框架中的XML描述文件描述了SCA系统域中的硬件设备和软件组件的属性，在SCA的波形开发中占有非常重要的位置。“SCA配置文件自动生成工具”能够方便高效地自动生成和维护配置文件，提高开发效率，缩短开发时间。以软件组合描述符文件为例，说明了SCA配置文件自动生成工具的设计思想和实现过程。     

两种先进的封装技术--SOC和SOP

为了能够实现通过集成所获得的优点,像高性能、低价格、较小的接触面、电源管理和缩短产品进入市场的时间,出现了针对晶圆级的系统级芯片(system on a chip简称SOC)和针对组件级的系统级组件(system on a pakage简称SOP)。本文介绍了SOC和SOP的益处、功能和优点。     

The transmission capacity of MANET based on conflict graph

The transmission capacity of Mobile Ad Hoc Networking (MANET) is constrained by the mutual interference of concurrent transmissions between nodes. First, the transmission capacity of MANET is studied by the view of information flow between nodes. At the same time, the problem that the interference between nodes affects the transmission capacity of MANET is also studied by the tool of the event conflict graph. Secondly, the paper presents the method to compute the maximum ex- pectant achievable capacity for the given conflict graph, and concludes and proves an sufficient con- dition that the information flow transmit successfully between nodes. At last, the results are simulated and a fitting equation of transmission capacity between nodes is given.     

基于PC/ 104 的GPS 车辆定位系统设计

PC／104嵌入式计算机模块系列为系统设计者提供了一整套低成本，高可靠性，能迅速配置成产品的结构化模块，本文给出其应用在GPS车辆定位系统中的设计方案，讨论了该系统的软硬件设计。     

PLC在全自动太阳能制绒清洗设备中的应用

随着太阳能行业的高速发展,设备的自动化已成为太阳能硅片清洗设备的发展趋势。以全自动太阳能制绒清洗设备工艺流程为基础,介绍了欧姆龙PLC在全自动硅片清洗设备中的应用过程。     

基于属性攻击图的网络动态威胁分析技术研究

该文首先利用属性攻击图理论构建了网络动态威胁分析属性攻击图(DT-AAG)模型,该模型在全面刻画系统漏洞和网络服务导致的威胁转移关系的基础上,结合通用漏洞评分标准(CVSS)和贝叶斯概率转移计算方法设计了威胁转移概率度量算法;其次基于构建的DT-AAG模型,利用威胁与漏洞、服务间的关联关系,设计了动态威胁属性攻击图生成算法(DT-AAG-A),并针对生成的属性攻击图存在的威胁传递环路问题,设计了环路消解机制;最后通过实验验证了该模型和算法的有效性。