企业RFID模块应用研究与实现

物联网在全球发展迅速,而射频识别技术是物联网感知层的核心技术之一.RFID作为一项新兴的自动识别技术,已广泛应用于生产制造和装配、图书管理、身份标示、运动计时、智能交通、门禁系统、航空行李处理、文档追踪、物流与供应链管理等众多领域中.显然RFID技术将会被越来越多的企业采纳,而在原有系统中扩展出RFID功能亦或是构建全新的RFID系统,将会是一个比较漫长的过程,降缓了一些企业信息化建设的步伐.RFID的发卡和读取,将会是每一个未来信息化系统所必须实现的功能,针对RFID基本概念进行了分析,以在J2EE系统中扩展出RFID模块为例,详细论述了RFID模块解决方案的设计流程,并给出了相应代码实现.     

Querying distributed multimedia databases and data sources for sensor data fusion

Sensor data fusion imposes a number of novel requirements on query languages and query processing techniques. A spatial/temporal query language called /spl Sigma/QL has been proposed to support the retrieval and fusion of multimedia information from multiple sources and databases. In this paper we investigate fusion techniques, multimedia data transformations and /spl Sigma/QL query processing techniques for sensor data fusion. Fusion techniques including fusion by the merge operation, the detection of moving objects, and the incorporation of belief values, have been developed. An experimental prototype has been implemented and tested to demonstrate the feasibility of these techniques.     

不确定数据库中概率top-k和排序查询算法

传感器网络等技术的广泛应用产生了大量不确定数据。近年来,对于不确定数据的处理和查询成为数据库和数据挖掘领域研究的热点。其中,传统关系数据库中的top-k查询和排序查询怎样拓展到不确定数据是其中的焦点之一。研究近年来提出的不确定数据库上top-k查询和排序查询算法,归纳和比较目前各种不同查询算法所适应的语义世界和应用场景,并详细分析各种算法的执行效率和算法复杂度。另外,对于不确定数据top-k查询和排序查询所面临的挑战和可能的研究方向进行了总结。     

Technology, Standards, and Real-World Deployments of the EPC Network

The EPC Network is a global RFID data sharing infrastructure based on standards that are built around the Electronic Product Code (EPC), an unambiguous numbering scheme for the designation of physical goods. The authors present the fundamental concepts and applications of the EPC Network, its integration with enterprise systems, and its functionality for data exchange between organizations in the supply chain.     

A visual tool for ontology alignment to enable geospatial interoperability

In distributed geospatial applications with heterogeneous databases, an ontology-driven approach to data integration relies on the alignment of the concepts of a global ontology that describe the domain, with the concepts of the ontologies that describe the data in the distributed databases. Once the alignment between the global ontology and each distributed ontology is established, agreements that encode a variety of mappings between concepts are derived. In this way, users can potentially query hundreds of geospatial databases using a single query. Using our approach, querying can be easily extended to new data sources and, therefore, to new regions. In this paper, we describe the AgreementMaker, a tool that displays the ontologies, supports several mapping layers visually, presents automatically generated mappings, and finally produces the agreements.     

基于XML的企业信息交换

由于XML固有的优点 ,现在已逐渐成为Internet上数据表示与交换的标准。从企业对外界信息的及时需求的角度出发 ,分析了传统的EDI技术的不足之处 ,讨论了XML在企业信息交换中的应用 ,给出了目前应用XML进行企业信息交换的两种方案 ,并提出一种基于XML的企业信息交换的实现方式。     

Semantic query optimization for query plans of heterogeneousmultidatabase systems

New applications of information systems need to integrate a large number of heterogeneous databases over computer networks. Answering a query in these applications usually involves selecting relevant information sources and generating a query plan to combine the data automatically. As significant progress has been made in source selection and plan generation, the critical issue has been shifting to query optimization. This paper presents a semantic query optimization (SQO) approach to optimizing query plans of heterogeneous multidatabase systems. This approach provides global optimization for query plans as well as local optimization for subqueries that retrieve data from individual database sources. An important feature of our local optimization algorithm is that we prove necessary and sufficient conditions to eliminate an unnecessary join in a conjunctive query of arbitrary join topology. This feature allows our optimizer to utilize more expressive relational rules to provide a wider range of possible optimizations than previous work in SQO. The local optimization algorithm also features a new data structure called AND-OR implication graphs to facilitate the search for optimal queries. These features allow the global optimization to effectively use semantic knowledge to reduce the data transmission cost. We have implemented this approach in the PESTO (Plan Enhancement by SemanTic Optimization) query plan optimizer as a part of the SIMS information mediator. Experimental results demonstrate that PESTO can provide significant savings in query execution cost over query plan execution without optimization     

An Object Algebra Approach to Multidatabase Query Decomposition in Donají

This paper presents an approach to query decomposition in a multidatabase environment. The unique aspect of this approach is that it is based on performing transformations over an object algebra that can be used as the basis for a global query language. In the paper, we first present our multidatabase environment and semantic framework, where a global conceptual schema based on the Object Data Management Group standard encompasses the information from heterogeneous data sources that include relational databases as well as object-oriented databases and flat file sources. The meta-data about the global schema is enhanced with information about virtual classes as well as virtual relationships and inheritance hierarchies that exist between multiple sources. The AQUA object algebra is used as the formal foundation for manipulation of the query expression over the multidatabase. AQUA is enhanced with distribution operators for dealing with data distribution issues. During query decomposition we perform an extensive analysis of traversals for path expressions that involve virtual relationships and hierarchies for access to several heterogeneous sources. The distribution operators defined in algebraic terms enhance the global algebra expression with semantic information about the structure, distribution, and localization of the data sources relevant to the solution of the query. By using an object algebra as the basis for query processing, we are able to define algebraic transformations and exploit rewriting techniques during the decomposition phase. Our use of an object algebra also provides a formal and uniform representation for dealing with an object-oriented approach to multidatabase query processing. As part of our query processing discussion, we include an overview of a global object identification approach for relating semantically equivalent objects from diverse data sources, illustrating how knowledge about global object identity is used in the decomposition and assembly processes.     

支持位置追溯的射频识别移动对象索引机制

随着射频通信技术的不断成熟及硬件制造成本的不断降低,射频识别(RFID)技术已开始应用于物品实时监控、跟踪与追溯领域。在供应链应用中,RFID对象数量繁多而且位置经常发生变化,如何从海量数据中查询标签对象的位置及其变化历史已成为供应链追溯亟须解决的问题。针对RFID移动对象特征及追溯查询需求,提出了一种有效的时空索引机制CR-L,并详细讨论了CR-L的结构及维护算法,包括插入、删除、二分裂及惰性分裂算法等。针对对象查询,CR-L利用读写器、时间及对象等三维信息设计了新的最小外界矩形(MBR)值计算原则,将相同读写器在相近时间内探测到的轨迹尽可能聚集于相同或相邻节点。对于轨迹查询,采用单链表将相同对象的轨迹链接起来。实验结果表明,所提索引机制具有较好的查询效率和较低的空间占用率。     

Building an E-Business from Enterprise Systems

Building their companies into successful e-businesses has become an important objective for today's enterprises. Conceptually, it embodies the enabling of the business with such capabilities as global networking, streamlining business processes, sharing information, agility in responding to the market, and intelligent decision making. But how can these concepts be implemented in actual enterprises? Why do these desirable attributes of business systems suddenly become the definition of competency of companies large and small? This paper describes the framework for building an e-business from the enterprise information systems' perspective. Increasingly enterprise systems have extended beyond the traditional business functions and include such new features as supply-chain management, customer relationship management and electronic commerce. The shifting focus is driven by the adoption of the Web as a new channel for product distribution, marketing, and interacting with customers. The integration of the traditional as well as the Web-oriented functions is the cornerstone for a successful e-business. This paper presents a framework for e-businesses that on one hand build on the enterprise systems but on the other hand encompasses the new e-business dimensions.     

无线传感器网络数据库的研究

本文根据应用需要,讨论了构建无线传感器网络数据库的必要性,分析了它与传统数据库管理系统在功能上的差别,以及在实现上面临的问题;详细分析了系统的体系结构,主要包括数据库前端和网络节点上的功能组成,以及节点之间协同完成查询请求的关键技术。     

RFID数据仓库上的多时空粒度近似聚集查询

随着物联网的发展,以RFID为代表的物联网传感器数据的存储、查询、处理等课题正成为研究的热点。结合数据仓库时空维度和列存储的思想,建立了一种列式RFID数据仓库,并根据RFID的时空特性,设计了一种支持连续聚集查询的多时空粒度数据结构和快速更新算法。它去除了传统聚集查询的部分冗余操作,适合处理大规模RFID数据仓库上的连续实时聚集查询。通过实验证明,该模型与算法在一些典型的物联网应用中取得了较高的效率,可广泛地适用于海量RFID数据仓库上的OLAP分析。     

A market mechanism for participatory global query: A first step of enterprise resources self-allocation

The problem of Database Query has always been considered from the user’s side. That is, the databases are always treated merely as the object of search, rather than being a subject or willing participants of an information exchange. This paradigm works when all participating databases belong to a single authority (such as a company) under which their participation is definitive and their contents completely open for the querying. Traditional single databases, federated databases, and even the new XML-based Internet databases subscribe to this user-oriented paradigm. However, emerging information enterprises are increasingly collaborative in nature, since they tend to involve, on a real-time and on-demand basis, a large number of databases belonging to many different organizations whose participation is conditional and case-by-case; e.g., drilling through supply chains. These collaborative queries deserve a new paradigm that equally account for the provider side. Research has shown that market-style self-allocation of users to providers is a promising approach to support such a paradigm. However, previous results of artificial markets are insufficient for global database query. Therefore, we develop an artificial market model to provide a Two-Stage Collaboration solution, where the first stage establishes optimal participation of databases for a search task, and the second executes the task in a traditional database query manner. The proposed model employs a new agent-based, peer-to-peer publish and subscribe approach to self-allocating database resources in an information enterprise. This approach promises to lead eventually to allocating other classes of information resources, as well. New results include (1) an agent model using a Metadatabase and an Agent-Base to create and manage large number of custom agents, (2) a peer-to-peer negotiation method, and (3) an open common schema design. The paper also provides an implementation scheme for developing the artificial market. Laboratory tests show that such a mechanism is feasible for large scale matching and negotiation as required by the first stage. The second stage employs mainly previous results established in the field.     

基于CNN特征加权和区域整合的图像检索

相比传统特征,卷积神经网络提取的特征对图像具有更强的描述能力,其卷积层比全连接层更适合用来检索图像。然而卷积特征是高维特征,若直接用来匹配图像会消耗大量的时间和内存。提出了一种新的改善和整合卷积特征,形成单维特征向量,再将其用于图像匹配的方法。首先,提取最后一个卷积层的三维特征,再对该卷积特征重新加权,突显图像的边缘信息和位置信息;其次,用滑动窗口进行处理,形成多个区域特征向量,再相加整合成全局特征向量;最后,用余弦距离衡量查询图和测试图的相似性得出检索的初始排名,并且用拓展查询方法进行重排得出最终的平均精度均值mAP。分别在Paris6k和Oxford5k数据库以及用100k张图扩展的Paris106k和Oxford105k数据库上进行测试。相对于CroW方法在Paris数据库上获得的mAP性能指标,本文方法提升了约3个百分点;在Oxford数据库上提升了约1个百分点。实验结果表明,新方法提取的全局特征能够更好地描述图像。     

Query optimization in multidatabase systems considering schemaconflicts

In a multidatabase system, the participating databases are autonomous. The schemas of these databases may be different in various ways, while the same information is represented. A global query issued against the global database needs to be translated to a proper form before it can be executed in a local database. Since data requested by a query (or a part of a query) is sometimes available in multiple sites, the site (database) that processes the query with the least cost is the desired query processing site. The authors study the effect of differences in schemas on the cost of query processing in a multidatabase environment. They first classify schema conflicts to different types. For each type of conflict, they show how much more or less complex a translated query can become in comparison with the originally user-issued global query. Based on this observation, they propose an analytical method that considers the conflicts between local databases and finds the database(s) that renders the least execution cost in processing a global query. This research introduces a new level of query optimization (termed the schema-level optimization) in multidatabase environments. The results provide a new dimension of enhancement for the capability of a query optimizer in multidatabase systems     

Answering Queries Addressed to Several Databases According to a Majority Merging Approach

The general context of this work is the problem of merging data provided by several sources which can be contradictory. Focusing on the case when the information sources do not contain any disjunction, this paper first defines a propositional modal logic for reasoning with data obtained by merging several information sources according to a majority approach. Then it defines a theorem prover to automatically deduce these merged data. Finally, it shows how to use this prover to implement a query evaluator which answers queries addressed to several databases. This evaluator is such that the answer to a query is the one that could be computed by a classical evaluator if the query was addressed to the merged databases. The databases we consider are made of an extensional part, i.e. a set of positive or negative ground literals, and an intensional part i.e. a set of first order function-free clauses. A restriction is imposed to these databases in order to avoid disjunctive data.     

基于语义协作的RFID应用集成框架

本文指出了RFID在企业应用中的应用集成技术,提出了基于复杂事件和语义事件的集成框架,并对语义协作技术进行了具体的分析,提出了一套可以简化RFID应用集成的解决方案。     

Information extraction from sensor networks using the Watershed transform algorithm

Wireless sensor networks are an effective tool to provide fine resolution monitoring of the physical environment. Sensors generate continuous streams of data, which leads to several computational challenges. As sensor nodes become increasingly active devices, with more processing and communication resources, various methods of distributed data processing and sharing become feasible. The challenge is to extract information from the gathered sensory data with a specified level of accuracy in a timely and power-efficient approach. This paper presents a new solution to distributed information extraction that makes use of the morphological Watershed algorithm. The Watershed algorithm dynamically groups sensor nodes into homogeneous network segments with respect to their topological relationships and their sensing-states. This setting allows network programmers to manipulate groups of spatially distributed data streams instead of individual nodes. This is achieved by using network segments as programming abstractions on which various query processes can be executed. Aiming at this purpose, we present a reformulation of the global Watershed algorithm. The modified Watershed algorithm is fully asynchronous, where sensor nodes can autonomously process their local data in parallel and in collaboration with neighbouring nodes. Experimental evaluation shows that the presented solution is able to considerably reduce query resolution cost without scarifying the quality of the returned results. When compared to similar purpose schemes, such as “Logical Neighborhood”, the proposed approach reduces the total query resolution overhead by up to 57.5%, reduces the number of nodes involved in query resolution by up to 59%, and reduces the setup convergence time by up to 65.1%.     

数据源集成系统中动态字典构造方法研究

本文从异构数据源集成系统的角度出发,引入模板和动态字典的概念,统一描述各种数据源数据的模式。动态字典不仅能描述对象的结构特征,还能描述对象的行为特征,完全符合面向对象特点。除此以外,本文还引入五种模板操作的定义,并证明ＯＩＭ对象操作的模板可由相应的模板操作构成,从而给出不通过扫描数据库,而是利用局部动态字典的模板操作构造集成系统全局动态字典的方法。