期刊文献+
共找到5,006篇文章
< 1 2 250 >
每页显示 20 50 100
Hash折叠寻址模型的研究
1
作者 庞志赟 萧琳 《现代信息科技》 2025年第5期184-186,192,共4页
在大数据背景下,研究大数据存储及寻址对大数据管理具有重要的数据经济意义。文章从数据存储物理结构和逻辑结构分析了数据存储的架构化现状,以准实时或实时为数据查询需求,在传统的主键索引查询技术基础上,对数据存储结构进行重组,关... 在大数据背景下,研究大数据存储及寻址对大数据管理具有重要的数据经济意义。文章从数据存储物理结构和逻辑结构分析了数据存储的架构化现状,以准实时或实时为数据查询需求,在传统的主键索引查询技术基础上,对数据存储结构进行重组,关心数据模型原型、数据存储规律与调用、数据Hash检索计算策略、结果存储和分发、折叠寻址结构模型,以及提升数据处理速度和数据查询处理能力等。应用Hash折叠检索策略和折叠函数原型构建折叠寻址思想模型,并将该思想应用于折叠寻址用例,对数据快速查询的Hash折叠寻址模型的研究具有重要意义。 展开更多
关键词 hash 折叠寻址 存储结构 折叠检索策略 寻址模型
在线阅读 下载PDF
基于Python语言和Hash算法的双关键字查找算法应用研究
2
作者 卢志刚 陈平 《安徽水利水电职业技术学院学报》 2025年第1期43-48,共6页
大数据量环境下,在2个二维表之间进行双关键字等值查找是一项挑战。传统的顺序查找算法在这种情况下效率较低。二分查找算法虽然更高效,但在处理大规模及非排序数据时仍有局限性。针对这一问题,文章提出了一种基于Hash算法的查找方法,... 大数据量环境下,在2个二维表之间进行双关键字等值查找是一项挑战。传统的顺序查找算法在这种情况下效率较低。二分查找算法虽然更高效,但在处理大规模及非排序数据时仍有局限性。针对这一问题,文章提出了一种基于Hash算法的查找方法,并使用Python语言开发了使用该算法的软件。对比分析结果表明,该方法在处理大规模数据时,相比传统顺序查找和二分查找,不仅简化了实现过程,而且显著提高了查找效率。 展开更多
关键词 二维表 hash table 查找算法
在线阅读 下载PDF
Quantum-Resistant Cryptographic Primitives Using Modular Hash Learning Algorithms for Enhanced SCADA System Security
3
作者 Sunil K.Singh Sudhakar Kumar +5 位作者 Manraj Singh Savita Gupta Razaz Waheeb Attar Varsha Arya Ahmed Alhomoud Brij B.Gupta 《Computers, Materials & Continua》 2025年第8期3927-3941,共15页
As quantum computing continues to advance,traditional cryptographic methods are increasingly challenged,particularly when it comes to securing critical systems like Supervisory Control andData Acquisition(SCADA)system... As quantum computing continues to advance,traditional cryptographic methods are increasingly challenged,particularly when it comes to securing critical systems like Supervisory Control andData Acquisition(SCADA)systems.These systems are essential for monitoring and controlling industrial operations,making their security paramount.A key threat arises from Shor’s algorithm,a powerful quantum computing tool that can compromise current hash functions,leading to significant concerns about data integrity and confidentiality.To tackle these issues,this article introduces a novel Quantum-Resistant Hash Algorithm(QRHA)known as the Modular Hash Learning Algorithm(MHLA).This algorithm is meticulously crafted to withstand potential quantum attacks by incorporating advanced mathematical and algorithmic techniques,enhancing its overall security framework.Our research delves into the effectiveness ofMHLA in defending against both traditional and quantum-based threats,with a particular emphasis on its resilience to Shor’s algorithm.The findings from our study demonstrate that MHLA significantly enhances the security of SCADA systems in the context of quantum technology.By ensuring that sensitive data remains protected and confidential,MHLA not only fortifies individual systems but also contributes to the broader efforts of safeguarding industrial and infrastructure control systems against future quantumthreats.Our evaluation demonstrates that MHLA improves security by 38%against quantumattack simulations compared to traditional hash functionswhilemaintaining a computational efficiency ofO(m⋅n⋅k+v+n).The algorithm achieved a 98%success rate in detecting data tampering during integrity testing.These findings underline MHLA’s effectiveness in enhancing SCADA system security amidst evolving quantum technologies.This research represents a crucial step toward developing more secure cryptographic systems that can adapt to the rapidly changing technological landscape,ultimately ensuring the reliability and integrity of critical infrastructure in an era where quantum computing poses a growing risk. 展开更多
关键词 hash functions post-quantum cryptography quantum-resistant hash functions network security supervisory control and data acquisition(SCADA)
在线阅读 下载PDF
基于线性同态hash和秘密分享的高效可验证聚合方案
4
作者 高琦 孙奕 +1 位作者 王友贺 李宇杰 《计算机应用研究》 北大核心 2025年第2期599-605,共7页
针对目前联邦学习可验证聚合方案存在用户通信开销过大、无法容忍用户退出以及用户退出导致验证效率降低的问题,提出了一种基于线性同态hash和秘密分享的高效可验证聚合方案(LHSSEVA)。首先,采用线性同态hash和同态承诺实现聚合结果的... 针对目前联邦学习可验证聚合方案存在用户通信开销过大、无法容忍用户退出以及用户退出导致验证效率降低的问题,提出了一种基于线性同态hash和秘密分享的高效可验证聚合方案(LHSSEVA)。首先,采用线性同态hash和同态承诺实现聚合结果的可验证性,保证验证信息通信开销与模型维度无关,同时防止服务器通过伪造聚合hash欺骗用户接受错误聚合结果;然后基于椭圆曲线离散对数问题及其同态性保护输入的隐私,同时保证验证的正确性;接着通过融入秘密分享使验证过程可以容忍用户随时退出,并确保用户退出不会导致验证效率降低;最后理论分析证明了方案的正确性、可靠性和隐私性。仿真实验结果表明了方案的可行性和高效性,与VeriFL方案相比,具有更低的计算和通信开销,特别是存在用户退出时,显著提高了验证效率,具有更强的退出容忍性。 展开更多
关键词 联邦学习 隐私保护 可验证 线性同态hash 秘密分享 容忍退出
在线阅读 下载PDF
Dynamically redactable blockchain based on decentralized Chameleon hash
5
作者 Xinzhe Huang Yujue Wang +3 位作者 Yong Ding Qianhong Wu Changsong Yang Hai Liang 《Digital Communications and Networks》 2025年第3期757-767,共11页
The immutability is a crucial property for blockchain applications,however,it also leads to problems such as the inability to revise illegal data on the blockchain and delete private data.Although redactable blockchai... The immutability is a crucial property for blockchain applications,however,it also leads to problems such as the inability to revise illegal data on the blockchain and delete private data.Although redactable blockchains enable on-chain modification,they suffer from inefficiency and excessive centralization,the majority of redactable blockchain schemes ignore the difficult problems of traceability and consistency check.In this paper,we present a Dynamically Redactable Blockchain based on decentralized Chameleon hash(DRBC).Specifically,we propose an Identity-Based Decentralized Chameleon Hash(IDCH)and a Version-Based Transaction structure(VT)to realize the traceability of transaction modifications in a decentralized environment.Then,we propose an efficient block consistency check protocol based on the Bloom filter tree,which can realize the consistency check of transactions with extremely low time and space cost.Security analysis and experiment results demonstrate the reliability of DRBC and its significant advantages in a decentralized environment. 展开更多
关键词 Privacy protection Redactable blockchain Chameleon hash Consistency check SCALABILITY
在线阅读 下载PDF
Hash-based FDI attack-resilient distributed self-triggered secondary frequency control for islanded microgrids
6
作者 Xing Huang Yulin Chen +4 位作者 Donglian Qi Yunfeng Yan Shaohua Yang Ying Weng Xianbo Wang 《Global Energy Interconnection》 2025年第1期1-12,共12页
Given the rapid development of advanced information systems,microgrids(MGs)suffer from more potential attacks that affect their operational performance.Conventional distributed secondary control with a small,fixed sam... Given the rapid development of advanced information systems,microgrids(MGs)suffer from more potential attacks that affect their operational performance.Conventional distributed secondary control with a small,fixed sampling time period inevitably causes the wasteful use of communication resources.This paper proposes a self-triggered secondary control scheme under perturbations from false data injection(FDI)attacks.We designed a linear clock for each DG to trigger its controller at aperiodic and intermittent instants.Sub-sequently,a hash-based defense mechanism(HDM)is designed for detecting and eliminating malicious data infiltrated in the MGs.With the aid of HDM,a self-triggered control scheme achieves the secondary control objectives even in the presence of FDI attacks.Rigorous theoretical analyses and simulation results indicate that the introduced secondary control scheme significantly reduces communication costs and enhances the resilience of MGs under FDI attacks. 展开更多
关键词 MICROGRIDS Distributed secondary control Self-triggered control hash algorithms False data injection attack
在线阅读 下载PDF
Secure Medical Image Retrieval Based on Multi-Attention Mechanism and Triplet Deep Hashing
7
作者 Shaozheng Zhang Qiuyu Zhang +1 位作者 Jiahui Tang Ruihua Xu 《Computers, Materials & Continua》 2025年第2期2137-2158,共22页
Medical institutions frequently utilize cloud servers for storing digital medical imaging data, aiming to lower both storage expenses and computational expenses. Nevertheless, the reliability of cloud servers as third... Medical institutions frequently utilize cloud servers for storing digital medical imaging data, aiming to lower both storage expenses and computational expenses. Nevertheless, the reliability of cloud servers as third-party providers is not always guaranteed. To safeguard against the exposure and misuse of personal privacy information, and achieve secure and efficient retrieval, a secure medical image retrieval based on a multi-attention mechanism and triplet deep hashing is proposed in this paper (abbreviated as MATDH). Specifically, this method first utilizes the contrast-limited adaptive histogram equalization method applicable to color images to enhance chest X-ray images. Next, a designed multi-attention mechanism focuses on important local features during the feature extraction stage. Moreover, a triplet loss function is utilized to learn discriminative hash codes to construct a compact and efficient triplet deep hashing. Finally, upsampling is used to restore the original resolution of the images during retrieval, thereby enabling more accurate matching. To ensure the security of medical image data, a lightweight image encryption method based on frequency domain encryption is designed to encrypt the chest X-ray images. The findings of the experiment indicate that, in comparison to various advanced image retrieval techniques, the suggested approach improves the precision of feature extraction and retrieval using the COVIDx dataset. Additionally, it offers enhanced protection for the confidentiality of medical images stored in cloud settings and demonstrates strong practicality. 展开更多
关键词 Secure medical image retrieval multi-attention mechanism triplet deep hashing image enhancement lightweight image encryption
在线阅读 下载PDF
A Review of Image Steganography Based on Multiple Hashing Algorithm 被引量:1
8
作者 Abdullah Alenizi Mohammad Sajid Mohammadi +1 位作者 Ahmad A.Al-Hajji Arshiya Sajid Ansari 《Computers, Materials & Continua》 SCIE EI 2024年第8期2463-2494,共32页
Steganography is a technique for hiding secret messages while sending and receiving communications through a cover item.From ancient times to the present,the security of secret or vital information has always been a s... Steganography is a technique for hiding secret messages while sending and receiving communications through a cover item.From ancient times to the present,the security of secret or vital information has always been a significant problem.The development of secure communication methods that keep recipient-only data transmissions secret has always been an area of interest.Therefore,several approaches,including steganography,have been developed by researchers over time to enable safe data transit.In this review,we have discussed image steganography based on Discrete Cosine Transform(DCT)algorithm,etc.We have also discussed image steganography based on multiple hashing algorithms like the Rivest–Shamir–Adleman(RSA)method,the Blowfish technique,and the hash-least significant bit(LSB)approach.In this review,a novel method of hiding information in images has been developed with minimal variance in image bits,making our method secure and effective.A cryptography mechanism was also used in this strategy.Before encoding the data and embedding it into a carry image,this review verifies that it has been encrypted.Usually,embedded text in photos conveys crucial signals about the content.This review employs hash table encryption on the message before hiding it within the picture to provide a more secure method of data transport.If the message is ever intercepted by a third party,there are several ways to stop this operation.A second level of security process implementation involves encrypting and decrypting steganography images using different hashing algorithms. 展开更多
关键词 Image steganography multiple hashing algorithms hash-LSB approach RSA algorithm discrete cosine transform(DCT)algorithm blowfish algorithm
在线阅读 下载PDF
适用于高速检索的完美Hash函数 被引量:3
9
作者 王兴 鲍志伟 《计算机系统应用》 2016年第2期250-256,共7页
软件实现的Hash函数在当前检索领域应用非常广泛,但是由于处理速度不高,很难满足骨干网以及服务器海量数据的高速实时查找要求.硬件Hash函数处理速度快,但普遍存在设计电路复杂、存储空间利用率不高以及无法支持数据集动态更新等问题.... 软件实现的Hash函数在当前检索领域应用非常广泛,但是由于处理速度不高,很难满足骨干网以及服务器海量数据的高速实时查找要求.硬件Hash函数处理速度快,但普遍存在设计电路复杂、存储空间利用率不高以及无法支持数据集动态更新等问题.基于位提取(Bit-extraction)算法,利用位选择(Bit-Selection)操作与位逻辑运算在FPGA上仿真实现一种Hash函数,可生成负载因子(Load factor)接近于1的近似最小完美Hash表.仿真结果表明,该Hash函数中每个24 bits长度Key的存储空间只要2.8-5.6 bits,系统时钟频率可以达到300MHz左右(吞吐率超过14Gbps).可以应用于IP地址查找、数据包分类、字符串匹配以及入侵检测等需要实时高速表查找的场景. 展开更多
关键词 硬件hash 完美hash函数 高速搜索 最小完美hash
在线阅读 下载PDF
Second-Order Side-Channel Attacks on Kyber: Targeting the Masked Hash Function 被引量:2
10
作者 WANG Ya-Qi HUANG Fan +1 位作者 DUAN Xiao-Lin HU Hong-Gang 《密码学报(中英文)》 CSCD 北大核心 2024年第6期1415-1436,共22页
Recently,several PC oracle based side-channel attacks have been proposed against Kyber.However,most of them focus on unprotected implementations and masking is considered as a counter-measure.In this study,we extend P... Recently,several PC oracle based side-channel attacks have been proposed against Kyber.However,most of them focus on unprotected implementations and masking is considered as a counter-measure.In this study,we extend PC oracle based side-channel attacks to the second-order scenario and successfully conduct key-recovery attacks on the first-order masked Kyber.Firstly,we analyze the potential joint information leakage.Inspired by the binary PC oracle based attack proposed by Qin et al.at Asiacrypt 2021,we identify the 1-bit leakage scenario in the masked Keccak implementation.Moreover,we modify the ciphertexts construction described by Tanaka et al.at CHES 2023,extending the leakage scenario from 1-bit to 32-bit.With the assistance of TVLA,we validate these leakages through experiments.Secondly,for these two scenarios,we construct a binary PC oracle based on t-test and a multiple-valued PC oracle based on neural networks.Furthermore,we conduct practical side-channel attacks on masked Kyber by utilizing our oracles,with the implementation running on an ARM Cortex-M4 microcontroller.The demonstrated attacks require a minimum of 15788 and 648 traces to fully recover the key of Kyber768 in the 1-bit leakage scenario and the 32-bit leakage scenario,respectively.Our analysis may also be extended to attack other post-quantum schemes that use the same masked hash function.Finally,we apply the shuffling strategy to the first-order masked imple-mentation of the Kyber and perform leakage tests.Experimental results show that the combination strategy of shuffling and masking can effectively resist our proposed attacks. 展开更多
关键词 side-channel attack plaintext-checking oracle post-quantum cryptography masked Kyber masked hash function
在线阅读 下载PDF
基于Hash编码的多目标航迹重合度算法研究
11
作者 李高云 雷陈奕 +2 位作者 李福林 张伟 吴腾亚 《舰船电子对抗》 2024年第6期65-69,83,共6页
未来战争是体系化的群体博弈,因而对多目标协同关系的挖掘成为了厘清战场的重要研究方向。剖析了传统空间航迹关系分析算法,以及其面临航迹点要求插值平滑、积分运算量大、点迹对齐困难等挑战。同时鉴于大数据时代,海量数据挖掘算法的... 未来战争是体系化的群体博弈,因而对多目标协同关系的挖掘成为了厘清战场的重要研究方向。剖析了传统空间航迹关系分析算法,以及其面临航迹点要求插值平滑、积分运算量大、点迹对齐困难等挑战。同时鉴于大数据时代,海量数据挖掘算法的复杂度直接关系到能否工程化应用,提出了基于Hash编码的多目标航迹重合度算法,仅需剖分编码和代数简便运算即可。在工程实践中检验了该算法的可行性和有效性,旨在为电磁大数据挖掘算法研究提供技术参考。 展开更多
关键词 电磁大数据 hash编码 重合度 航迹挖掘
在线阅读 下载PDF
基于Simhash算法的题库查重系统的设计与实现
12
作者 熊良钰 邓伦丹 《科学技术创新》 2024年第9期91-94,共4页
Simhash算法是一种基于局部敏感哈希(LSH)的技术,以其快速的计算速度和高度的查重准确性而知名。该算法通过将文本特征转换为二进制码,进而通过计算这些二进制码之间的汉明距离来评估文本的相似度。在文本去重和重复文档检测等多个领域,... Simhash算法是一种基于局部敏感哈希(LSH)的技术,以其快速的计算速度和高度的查重准确性而知名。该算法通过将文本特征转换为二进制码,进而通过计算这些二进制码之间的汉明距离来评估文本的相似度。在文本去重和重复文档检测等多个领域,Simhash算法已经展现出了显著的效果。鉴于此,将Simhash算法应用于题库查重具有很高的可行性和实际应用价值。 展开更多
关键词 Simhash算法 汉明距离 题库查重系统 文本相似度计算 哈希函数
在线阅读 下载PDF
Underwater Pulse Waveform Recognition Based on Hash Aggregate Discriminant Network
13
作者 WANG Fangchen ZHONG Guoqiang WANG Liang 《Journal of Ocean University of China》 SCIE CAS CSCD 2024年第3期654-660,共7页
Underwater pulse waveform recognition is an important method for underwater object detection.Most existing works focus on the application of traditional pattern recognition methods,which ignore the time-and space-vary... Underwater pulse waveform recognition is an important method for underwater object detection.Most existing works focus on the application of traditional pattern recognition methods,which ignore the time-and space-varying characteristics in sound propagation channels and cannot easily extract valuable waveform features.Sound propagation channels in seawater are time-and space-varying convolutional channels.In the extraction of the waveform features of underwater acoustic signals,the effect of high-accuracy underwater acoustic signal recognition is identified by eliminating the influence of time-and space-varying convolutional channels to the greatest extent possible.We propose a hash aggregate discriminative network(HADN),which combines hash learning and deep learning to minimize the time-and space-varying effects on convolutional channels and adaptively learns effective underwater waveform features to achieve high-accuracy underwater pulse waveform recognition.In the extraction of the hash features of acoustic signals,a discrete constraint between clusters within a hash feature class is introduced.This constraint can ensure that the influence of convolutional channels on hash features is minimized.In addition,we design a new loss function called aggregate discriminative loss(AD-loss).The use of AD-loss and softmax-loss can increase the discriminativeness of the learned hash features.Experimental results show that on pool and ocean datasets,which were collected in pools and oceans,respectively,by using acoustic collectors,the proposed HADN performs better than other comparative models in terms of accuracy and mAP. 展开更多
关键词 convolutional channel hash aggregate discriminative network aggregate discriminant loss waveform recognition
在线阅读 下载PDF
基于双向Hash链的无线传感网络通信节点自愈算法
14
作者 李晓薇 李翔宇 《传感技术学报》 CSCD 北大核心 2024年第12期2119-2124,共6页
无线传感网络中节点数量突增,增大了出现失效节点的概率,会影响数据传输效率,导致次级节点出现失效现象,为此提出基于双向hash链的无线传感网络通信节点自愈算法。分析无线传感网络节点流量过载现象,构建节点失效裁决模型,找出网络中失... 无线传感网络中节点数量突增,增大了出现失效节点的概率,会影响数据传输效率,导致次级节点出现失效现象,为此提出基于双向hash链的无线传感网络通信节点自愈算法。分析无线传感网络节点流量过载现象,构建节点失效裁决模型,找出网络中失效节点;利用质心算法确定失效节点具体位置,将双向hash链和节点失效裁决模型结合起来,实现对失效节点的自愈修复。构建WSN拓扑结构,对所提方法展开仿真测试,对比结果表明所提方法的节点拓扑移动距离平均值为63.5 m,网络流量出口带宽值平均值为583 Mbyte/s,节点自愈耗时平均值为14.2 s,证明该方法具有较高的自愈效率,保证了失效节点自愈效果最优、自愈能力最强。 展开更多
关键词 网络通信 通信节点自愈 双向hsh链 节点失效 质心算法 流量过载
在线阅读 下载PDF
基于DCT特征点的感知图像Hash函数 被引量:3
15
作者 唐振军 戴玉敏 +1 位作者 张显全 张师超 《广西师范大学学报(自然科学版)》 CAS 北大核心 2012年第3期135-141,共7页
本文提出一种基于离散余弦变换(DCT)特征点的感知图像Hash函数算法。具体地说,先对输入图像预处理,生成规范化图像。在此基础上,将规范化图像分块并进行二维DCT处理,利用DCT交流系数构造特征点。最后计算特征点的重心,用特征点与重心的... 本文提出一种基于离散余弦变换(DCT)特征点的感知图像Hash函数算法。具体地说,先对输入图像预处理,生成规范化图像。在此基础上,将规范化图像分块并进行二维DCT处理,利用DCT交流系数构造特征点。最后计算特征点的重心,用特征点与重心的欧氏距离生成Hash。实验结果表明本文算法对正常数字处理稳健并具有良好的唯一性。接收机操作特性曲线对比发现,本文算法性能优于3种现有的算法。 展开更多
关键词 图像hash hash函数 图像检索 拷贝检测 接收机操作特性
在线阅读 下载PDF
二维hash链在Payword中的应用 被引量:3
16
作者 刘忆宁 李宏伟 田金兵 《计算机工程》 CAS CSCD 北大核心 2006年第23期34-35,39,共3页
由于hash函数的高效安全性,利用hash链构造微支付方案已经成为一个研究热点。在WCC’2005会议上,Quan Son Nguyen提出了基于RSA的多维hash链模型。该文指出了该方案的不可行之处,并对该方案进行了改进,使之满足PayWord的要求。
关键词 微支付 hash函数 hash 结点
在线阅读 下载PDF
命名数据网络中基于Hash映射的命名检索 被引量:3
17
作者 张良 刘敬浩 李卓 《计算机工程》 CAS CSCD 2014年第4期108-111,115,共5页
命名数据网络(NDN)是一种以内容为中心的新型网络架构,可有效提高网络资源的共享利用率。但与传统的IPv4、IPv6相比,NDN命名的长度更长且具有可变性,因此实现NDN中命名的快速检索对提高网络性能具有重要作用。为此,提出一种基于Hash映... 命名数据网络(NDN)是一种以内容为中心的新型网络架构,可有效提高网络资源的共享利用率。但与传统的IPv4、IPv6相比,NDN命名的长度更长且具有可变性,因此实现NDN中命名的快速检索对提高网络性能具有重要作用。为此,提出一种基于Hash映射的分治命名检索方法,将命名分解为组件并进行CRC32映射后分别存储在相应的Hash表中,对Hash表中的数据进行快速排序后使用二分查找定位Hash值,并利用排序后Hash表的递增数据结构进行Hash冲突的快速检测,通过对Hash值添加标志位的方法解决冲突问题。实验结果表明,相比建立命名前缀树的检索方法,该分治命名检索方法可将NDN命名的存储空间压缩近65%,并且大幅提升了检索速度。 展开更多
关键词 命名检索 命名数据网络 前缀匹配 hash映射 hash冲突检测 最长匹配原则
在线阅读 下载PDF
可扩展Hash方法的一种改进算法 被引量:3
18
作者 徐凤刚 许俊奎 潘清 《计算机工程与应用》 CSCD 北大核心 2006年第4期95-97,共3页
文章介绍了可扩展Hash方法,并提出了改进的缓存算法,该算法可以避免因为伪键分布异常而出现频繁的桶分裂及Hash表更新操作,从而提高空间和时间效率,有效地利用服务器资源。
关键词 hash 可扩展hash方法 缓存算法
在线阅读 下载PDF
基于多重熵Hash及Box-Cox蓄电池续航时长分析与仿真
19
作者 邓翠艳 齐小刚 +1 位作者 姚旭清 李青云 《通信与信息技术》 2024年第4期18-22,共5页
现代工业生产中,蓄电池是市电停电后通信网络业务能够持续运行的重要保障,是化解网络风险发生的重要一环。针对目前通信行业蓄电池智能化管理水平不高,尤其对于蓄电池的剩余寿命及续航时长无法测算,导致通信机房停电后无法准确预估蓄电... 现代工业生产中,蓄电池是市电停电后通信网络业务能够持续运行的重要保障,是化解网络风险发生的重要一环。针对目前通信行业蓄电池智能化管理水平不高,尤其对于蓄电池的剩余寿命及续航时长无法测算,导致通信机房停电后无法准确预估蓄电池的续航时长。针对该问题,首先设计了一种基于信息熵的多重哈希(Hash)查询方法,然后提出了一种基于对数似然函数优化方法的Box-Cox算法,实现蓄电池时序运维数据续航时长的平稳化处理。实验结果表明对于大量的通信机房运维数据,通过基于熵的多重哈希(Hash)方法进行数据查询结构设计并使用最优化参数的Box-Cox算法可以有效计算得到蓄电池的续航时长。该方法能够将蓄电池机房运维数据转化为蓄电池续航时长生产知识数据,实现通信机房蓄电池能耗的有效管理运营,实际生产实践也证明了该方法的可行性。 展开更多
关键词 多重hash Box-Cox 对数似然函数 蓄电池 续航时长 剩余寿命
在线阅读 下载PDF
时态数据的可变Hash索引 被引量:1
20
作者 蒋夏军 吴慧中 李蔚清 《计算机科学》 CSCD 北大核心 2006年第1期130-133,242,共5页
索引技术是时态数据库查询优化的重要方法之一。本文提出的可变 Hash(VH)索引是建立在时间属性上的一种新的动态索引技术,主要目的是提高时态数据库快照查询的效率。由于时间的不确定性,在时态数据的时间属性上建立 Hash 索引比较困难。... 索引技术是时态数据库查询优化的重要方法之一。本文提出的可变 Hash(VH)索引是建立在时间属性上的一种新的动态索引技术,主要目的是提高时态数据库快照查询的效率。由于时间的不确定性,在时态数据的时间属性上建立 Hash 索引比较困难。VH 索引克服了 Hash 索引这一难点,提出了索引参数可变的思想,并应用 B^+-树对Hash 参数进行组织。查询时由时间值在 B^+-树上获得 Hash 参数,进而确定数据的存储地址。通过对其时间复杂度和空间复杂度的理论分析以及实验验证,表明该索引技术可以减少索引查找以及读取数据的 I/O 次数,并具有理想的空间利用率。 展开更多
关键词 时态数据库 可变hash索引 快照查询 时间复杂度 索引技术 hash 可变 时间属性 查询优化 空间复杂度
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部