基于关系数据库的时态XML存取研究

时间是自然界无所不在的客观属性,更是信息的重要属性。能够根据时序进行访问的XML文档称之为时态XML。针对时态XML文档这种特殊的文档,应用一种数据模型进行时态的扩展并在此数据模型的基础上研究基于关系数据库时态XML数据的存储和查询方法。该方法使时态XML的查询变成可以在关系数据库里使用SQL语句的一般查询。     

基于云存储的医院PACS系统存储研究

做为医院数字化建设的重要系统PACS(医学影像存储与传输系统)目前在许多大医院都完成初步建设,对于PACS系统来说,存储的图像数据信息量大,现有的存储技术都不能很好的解决这一需求,需要一种新的信息系统存储架构,完成数据的集中存储、备份,并保证数据安全性和共享,提出云存储的概念,分析云存储的优越性,为PACS系统存储提供新的存储系统架构模型。     

初探网格数据库的访问与查询技术

针对高度异构的网格环境,研究网格数据库访问与查询的设计与实现,使用户可以更方便、更高效的使用网格中的数据库资源。     

计算机网络设计中关系数据库技术的应用探析

随着现代信息技术的飞速发展,计算机网络已成为人们工作、生活不可缺少的现代技术手段。因此,计算机网络设计也成为了时下一项热门的研究课题。计算机网络设计工序复杂,需要构建相关的数据库对整个设计起到保障作用。关系数据库技术的应用就在很大程度上便捷了计算机的网络设计过程。本文通过对关系数据库技术的分析,探讨了其在计算机网络设计中的巨大优势。希望能够进一步促进计算机网络技术与关系数据库技术的结合应用。     

存储虚拟化技术的研究

存储虚拟化技术是基于网络的存储管理技术,它屏蔽大量异构设备的差异性,向用户提供简单的逻辑存储访问接口;它简化了存储管理,优化了系统性能,提高了存储设备的利用率。本文从存储虚拟化的概念入手,详细分析了存储虚拟化的使用优点、实现方式、关键技术等方面的问题。     

基于HDFS存储服务系统的研究和应用

本文研究对象是云计算的分布式存储技术,通过构建基于HDFS的云存储服务系统来解决海量数据的存储难题,降低实施分布式存储系统的成本。     

基于高速总线的实时图象采集和存储

基于目前的计算机体系结构,为解决图象的实时采集和记录问题,引入高性能总线是一项有效的解决办法,详细阐述了利用PCI总线和SCSI设备对高速CCD图象数据的实时采集和存储,并给出了硬件实现和软件流程。     

基于关系数据库的工艺尺寸链解算

针对在计算机中描述工艺尺寸链的方法,研究利用关系数据库技术来解算位置尺寸较多、工序较长、多次转换基准时的工艺尺寸链.使数据的独立性、完整性、安全性、及数据的有效使用、共享得到提高.联系工艺过程,对工艺尺寸链的计算机解算进行研究,给出工序中各表面的编码规则及建立尺寸链的程序流程,并给出易于计算机处理的增环、减环的判据和关系数据库存储结构.     

Java数据库访问技术研究

Java具有健壮、安全、易于使用、易于理解和支持从网络自动下载等特性,是编写数据库应用程序的杰出语言。JDBC正是实现Java应用程序同各种各样数据库连接的关键。对Java数据库访问机制进行分析,提出优化措施。     

ADO技术访问数据库的研究

当今社会数据库几乎触及人类社会生活的所有方面,数据库是计算机编程中应用最广泛的领域.而数据库应用的一个最基本、最重要的方面就是对数据库的访问.介绍ADO等这种数据库访问技术,叙述这些技术的典型特征和结构体系.并从其对数据源的操作方式、面向对象特性等几个方面进行深入分析,最后给出使用ADO编程模型的一般步骤与实例.     

Hybrid Flexible Resistive Random Access Memory‐Gated Transistor for Novel Nonvolatile Data Storage

Here, a single‐device demonstration of novel hybrid architecture is reported to achieve programmable transistor nodes which have analogies to flash memory by incorporating a resistive switching random access memory (RRAM) device as a resistive switch gate for field effect transistor (FET) on a flexible substrate. A high performance flexible RRAM with a three‐layered structure is fabricated by utilizing solution‐processed MoS₂ nanosheets sandwiched between poly(methyl methacrylate) polymer layers. Gate coupling with the pentacene‐based transistor can be controlled by the RRAM memory state to produce a nonprogrammed state (inactive) and a programmed state (active) with a well‐defined memory window. Compared to the reference flash memory device based on the MoS₂ floating gate, the hybrid device presents robust access speed and retention ability. Furthermore, the hybrid RRAM‐gated FET is used to build an integrated logic circuit and a wide logic window in inverter logic is achieved. The controllable, well‐defined memory window, long retention time, and fast access speed of this novel hybrid device may open up new possibilities of realizing fully functional nonvolatile memory for high‐performance flexible electronics.     

数据库大数据量存储结构的设计研究

针对电网公司信息化建设的发展而业务数据库性能水平却显得相对滞后的问题,提出了在电力系统营销数据库设计过程中解决数据量庞大而数据库效率较低的一种解决办法,即通过分析数据流向、数据访问特点、数据量、数据增长量和数据生命周期,对数据进行分类,从而达到提升数据库的性能的目的.     

Secure and Efficient Data Storage and Sharing Scheme Based on Double Blockchain

In the digital era, electronic medical record (EMR) has been a major way for hospitals to store patients’ medical data. The traditional centralized medical system and semi-trusted cloud storage are difficult to achieve dynamic balance between privacy protection and data sharing. The storage capacity of blockchain is limited and single blockchain schemes have poor scalability and low throughput. To address these issues, we propose a secure and efficient medical data storage and sharing scheme based on double blockchain. In our scheme, we encrypt the original EMR and store it in the cloud. The storage blockchain stores the index of the complete EMR, and the shared blockchain stores the index of the shared part of the EMR. Users with different attributes can make requests to different blockchains to share different parts according to their own permissions. Through experiments, it was found that cloud storage combined with blockchain not only solved the problem of limited storage capacity of blockchain, but also greatly reduced the risk of leakage of the original EMR. Content Extraction Signature (CES) combined with the double blockchain technology realized the separation of the privacy part and the shared part of the original EMR. The symmetric encryption technology combined with Ciphertext-Policy Attribute-Based Encryption (CP–ABE) not only ensures the safe storage of data in the cloud, but also achieves the consistency and convenience of data update, avoiding redundant backup of data. Safety analysis and performance analysis verified the feasibility and effectiveness of our scheme.     

Data Security Storage Mechanism Based on Blockchain Network

With the rapid development of information technology, the development of blockchain technology has also been deeply impacted. When performing block verification in the blockchain network, if all transactions are verified on the chain, this will cause the accumulation of data on the chain, resulting in data storage problems. At the same time, the security of data is also challenged, which will put enormous pressure on the block, resulting in extremely low communication efficiency of the block. The traditional blockchain system uses the Merkle Tree method to store data. While verifying the integrity and correctness of the data, the amount of proof is large, and it is impossible to verify the data in batches. A large amount of data proof will greatly impact the verification efficiency, which will cause end-to-end communication delays and seriously affect the blockchain system’s stability, efficiency, and security. In order to solve this problem, this paper proposes to replace the Merkle tree with polynomial commitments, which take advantage of the properties of polynomials to reduce the proof size and communication consumption. By realizing the ingenious use of aggregated proof and smart contracts, the verification efficiency of blocks is improved, and the pressure of node communication is reduced.     

Security and Privacy Frameworks for Access Control Big Data Systems

In the security and privacy fields, Access Control (AC) systems are viewed as the fundamental aspects of networking security mechanisms. Enforcing AC becomes even more challenging when researchers and data analysts have to analyze complex and distributed Big Data (BD) processing cluster frameworks, which are adopted to manage yottabyte of unstructured sensitive data. For instance, Big Data systems’ privacy and security restrictions are most likely to failure due to the malformed AC policy configurations. Furthermore, BD systems were initially developed toped to take care of some of the DB issues to address BD challenges and many of these dealt with the “three Vs” (Velocity, Volume, and Variety) attributes, without planning security consideration, which are considered to be patch work. Some of the BD “three Vs” characteristics, such as distributed computing, fragment, redundant data and node-to node communication, each with its own security challenges, complicate even more the applicability of AC in BD.
This paper gives an overview of the latest security and privacy challenges in BD AC systems. Furthermore, it analyzes and compares some of the latest AC research frameworks to reduce privacy and security issues in distributed BD systems, which very few enforce AC in a cost-effective and in a timely manner. Moreover, this work discusses some of the future research methodologies and improvements for BD AC systems. This study is valuable asset for Artificial Intelligence (AI) researchers, DB developers and DB analysts who need the latest AC security and privacy research perspective before using and/or improving a current BD AC framework.     

上海地区典型数据中心错峰蓄冷方案探讨

介绍了上海地区典型数据中心的错峰蓄冷技术选择,并对蓄冷方案进行了详细的设计,讨论分析了在不同电价下数据中心不同错峰蓄冷方案的经济性。为上海地区类似数据中心项目采用错峰蓄冷技术提供参考。     

用航空航天影像更新地形图地物要素的栅格化方法

文章针对当前我国1:5和1:1万地形图更新的大规模生产的迫切需求,提出在原有地形图栅格式数字化的基础上,叠加经过精密纠正配准的航空或卫星遥感影像,以栅格方式更新地物要素的全过程方法。文中特别阐述了：1）地形图栅格数字化不同于矢量数字化的扫描采样分辨率问题;2）区别于传统的"针孔式"控制点概念的图像图形阵列控制点技术;3）由于DEM（数字高程模型）数据缺乏或精度不足引起的航空航天影像与地形图图形配准误差的局部纠正方法;4）定性指导定量的影像判读方法;5）从遥感影像提取地物结构信息的半自动化方法。文章最后列出