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Deep Q-Learning Based Optimal Query Routing Approach for Unstructured P2P Network 被引量:2
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作者 Mohammad Shoab Abdullah Shawan Alotaibi 《Computers, Materials & Continua》 SCIE EI 2022年第3期5765-5781,共17页
Deep Reinforcement Learning(DRL)is a class of Machine Learning(ML)that combines Deep Learning with Reinforcement Learning and provides a framework by which a system can learn from its previous actions in an environmen... Deep Reinforcement Learning(DRL)is a class of Machine Learning(ML)that combines Deep Learning with Reinforcement Learning and provides a framework by which a system can learn from its previous actions in an environment to select its efforts in the future efficiently.DRL has been used in many application fields,including games,robots,networks,etc.for creating autonomous systems that improve themselves with experience.It is well acknowledged that DRL is well suited to solve optimization problems in distributed systems in general and network routing especially.Therefore,a novel query routing approach called Deep Reinforcement Learning based Route Selection(DRLRS)is proposed for unstructured P2P networks based on a Deep Q-Learning algorithm.The main objective of this approach is to achieve better retrieval effectiveness with reduced searching cost by less number of connected peers,exchangedmessages,and reduced time.The simulation results shows a significantly improve searching a resource with compression to k-Random Walker and Directed BFS.Here,retrieval effectiveness,search cost in terms of connected peers,and average overhead are 1.28,106,149,respectively. 展开更多
关键词 Reinforcement learning deep q-learning unstructured p2p network query routing
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A Routing Algorithm for Risk-Scanning Agents Using Ant Colony Algorithm in P2P Network
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作者 TANG Zhuo LU Zhengding LI Ruixuan 《Wuhan University Journal of Natural Sciences》 CAS 2006年第5期1097-1103,共7页
This paper describes a routing algorithm for risk scanning agents using ant colony algorithm in P2P(peerto peer) network. Every peer in the P2P network is capable of updating its routing table in a real-time way, wh... This paper describes a routing algorithm for risk scanning agents using ant colony algorithm in P2P(peerto peer) network. Every peer in the P2P network is capable of updating its routing table in a real-time way, which enables agents to dynamically and automatically select, according to current traffic condition of the network, the global optimal traversal path. An adjusting mechanism is given to adjust the routing table when peers join or leave. By means of exchanging pheromone intensity of part of paths, the algorithm provides agents with more choices as to which one to move and avoids prematurely reaching local optimal path. And parameters of the algorithm are determined by lots of simulation testing. And we also compare with other routing algorithms in unstructured P2P network in the end. 展开更多
关键词 RISK ant colony algorithm p2p
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Bidirectional Clone Node Model of Optimizing Performance of Structured P2P Overlay Network 被引量:1
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作者 Zhang Yu Hao Ying +1 位作者 Ye Xinxin Li Yongzhen 《China Communications》 SCIE CSCD 2012年第4期123-129,共7页
In order to reduce the maintenance cost of structured Peer-to-Peer (P2P),Clone Node Protocol (CNP) based on user behavior is proposed.CNP considers the regularity of user behavior and uses the method of clone node.A B... In order to reduce the maintenance cost of structured Peer-to-Peer (P2P),Clone Node Protocol (CNP) based on user behavior is proposed.CNP considers the regularity of user behavior and uses the method of clone node.A Bidirectional Clone Node Chord model (BCNChord) based on CNP protocol is designed and realized.In BCNChord,Anticlockwise Searching Algorithm,Difference Push Synchronize Algorithm and Optimal Maintenance Algorithm are put forward to increase the performances.In experiments,according to the frequency of nodes,the maintenance cost of BCNChord can be 3.5%~32.5% lower than that of Chord.In the network of 212 nodes,the logic path hop is steady at 6,which is much more prior to 12 of Chord and 10 of CNChord.Theoretical analysis and experimental results show that BCNChord can effectively reduce the maintenance cost of its structure and simultaneously improve the query efficiency up to (1/4)O(logN).BCNChord is more suitable for highly dynamic environment and higher real-time system. 展开更多
关键词 structured p2p user behavior clone node protocol maintenance cost
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HDNBS: An approach for search in decentralized and unstructured P2P
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作者 贾兆庆 尤晋元 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2007年第5期629-633,共5页
Decentralized and unstructured peer-to-peer applications such as Gnutella are attractive because they require no centralized directories and no precise control over network topology or data placement. Search algorithm... Decentralized and unstructured peer-to-peer applications such as Gnutella are attractive because they require no centralized directories and no precise control over network topology or data placement. Search algorithm is the major component of the distributed system and its efficiency also does influence the systems performance. However the flooding-based query algorithm used in Gnutella produces huge traffic and does not scale well. Gnutella-like P2P topology has power-law characteristic, so a search algorithm was proposed based on high degree nodes of power-law network, High Degree Nodes-Based Search (HDNBS). Extensive simulation results show that this algorithm performs on power-law networks very well, achieves almost 100% success rates, produces O(logN) messages per query and can locate target file within O(lagN) hops. 展开更多
关键词 unstructured p2p search algorithm high degree walk power-law network
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Study on the Distributed Routing Algorithm and Its Security for Peer-to-Peer Computing
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作者 ZHOUShi-jie 《Journal of Electronic Science and Technology of China》 2005年第2期187-188,共2页
关键词 peer-to-peer computing p2p distributed computing information security distributed routing algorithm bidding-electing algorithm one-way accumulator
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Hybrid ants-like search algorithms for P2P media streaming distribution in ad hoc networks
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作者 ZUO Dong-hong DU Xu YANG Zong-kai 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2007年第8期1191-1198,共8页
Media streaming delivery in wireless ad hoc networks is challenging due to the stringent resource restrictions,po-tential high loss rate and the decentralized architecture. To support long and high-quality streams,one... Media streaming delivery in wireless ad hoc networks is challenging due to the stringent resource restrictions,po-tential high loss rate and the decentralized architecture. To support long and high-quality streams,one viable approach is that a media stream is partitioned into segments,and then the segments are replicated in a network and served in a peer-to-peer(P2P) fashion. However,the searching strategy for segments is one key problem with the approach. This paper proposes a hybrid ants-like search algorithm(HASA) for P2P media streaming distribution in ad hoc networks. It takes the advantages of random walks and ants-like algorithms for searching in unstructured P2P networks,such as low transmitting latency,less jitter times,and low unnecessary traffic. We quantify the performance of our scheme in terms of response time,jitter times,and network messages for media streaming distribution. Simulation results showed that it can effectively improve the search efficiency for P2P media streaming distribution in ad hoc networks. 展开更多
关键词 Ad hoc networks Media streaming distribution Search algorithms Peer to peer p2p
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INCENTIVE MECHANISMS FOR TRUSTWORTHY ROUTING BASED ON GAME MODEL OF THE STRATEGIES OF NODES IN P2P NETWORKS
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作者 Wang Haoyun Zhang Shunyi +1 位作者 Li Jun Chen Zhixian 《Journal of Electronics(China)》 2009年第6期842-852,共11页
The trustworthiness and security of routing in the existing Peer-to-Peer (P2P) networks can not be ensured because of the diversity of the strategies of P2P nodes. This paper firstly uses game theory to establish game... The trustworthiness and security of routing in the existing Peer-to-Peer (P2P) networks can not be ensured because of the diversity of the strategies of P2P nodes. This paper firstly uses game theory to establish game model of the strategies and profits of various types of routing nodes. Then,two incentive mechanisms for the corresponding stages of P2P trustworthy routing are proposed,namely trust associated mechanism and trust compensated mechanism. Simulation results show that the incentive mechanisms proposed in this paper will encourage cooperation actions of good nodes and restrain malicious actions of bad nodes,which ensure the trustworthiness of routing consequently. 展开更多
关键词 Peer-to-Peer p2p network routing Node GAME Strategy
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A P2P Approach to Routing in Hierarchical MANETs
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作者 Thomas Kunz Silas Echegini Babak Esfandiari 《Communications and Network》 2020年第3期99-121,共23页
We present an effective routing solution for the backbone of hierarchical MANETs. </span></span><span><span><span style="font-family:""><span style="font-family:Ver... We present an effective routing solution for the backbone of hierarchical MANETs. </span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">Our solution leverages the storage and retrieval mechanisms of a Distributed Hash Table (DHT) common to many (structured) P2P overlays. Th</span><span style="font-family:Verdana;">e DHT provides routing information in a decentralized fash</span><span style="font-family:Verdana;">ion, while supporting different forms of node and network mobility. We split a flat network into clusters, each having a gateway who participates in a DHT overlay. These g</span><span style="font-family:Verdana;">ateways interconnect the clusters in a backbone network. Two routing </span><span style="font-family:Verdana;">approaches for the backbone are explore</span><span style="font-family:Verdana;">d: floodi</span><span style="font-family:Verdana;">ng and a new solution exploit</span><span style="font-family:Verdana;">ing the storage and retrieval capabilities of a P2P overlay based on a DHT.</span><span style="font-family:Verdana;"> We </span><span style="font-family:Verdana;">implement both approaches in a net</span><span style="font-family:Verdana;">work simulator and thoroughly evaluate th</span><span style="font-family:Verdana;">e performance of the proposed scheme using a range of stati</span><span style="font-family:Verdana;">c and mobile scenarios. We also compare our solution against flooding. The simulation results show that our solution, even in the presence of mobility, achieved well abo</span><span style="font-family:Verdana;">ve 90% success rates and maintained very low and constant round tr</span><span style="font-family:Verdana;">ip times, unlike the flooding approach. In fact, the performance of the proposed </span><span style="font-family:Verdana;">inter-cluster routing solution, in many cases, is comparable to the perfo</span><span style="font-family:Verdana;">rma</span><span style="font-family:Verdana;">nce of the intra-cluster routing case. The advantage of our proposed ap</span><span style="font-family:Verdana;">proach compared to flooding increases as the number of clusters increases, demonstrating the superior scalability of our proposed approach. 展开更多
关键词 MANET routing Hierarchical Networks DHT p2p CHORD OLSR OMNET++
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基于Space P和K-means的货运航司航线网络特征分析研究
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作者 罗凤娥 卫昌波 +1 位作者 韩晓彤 郭玲玉 《现代电子技术》 北大核心 2026年第1期102-107,共6页
针对航空货运行业的迅速扩张,航空货运网络结构变得更加复杂,文中通过Space P建模方法构建了货运航空公司航线网络模型,并运用K-means聚类算法对网络进行了深入分析。选取度、平均路径长度、聚类系数和中间度等关键网络特性指标对航线... 针对航空货运行业的迅速扩张,航空货运网络结构变得更加复杂,文中通过Space P建模方法构建了货运航空公司航线网络模型,并运用K-means聚类算法对网络进行了深入分析。选取度、平均路径长度、聚类系数和中间度等关键网络特性指标对航线网络进行层次化分类,揭示了网络的复杂特征和层次结构。通过仿真实验评估了网络的小世界特性,并利用轮廓系数得到不同K值下的聚类结果,进而确定最优聚类结果。同时,模拟了航线网络在遭受攻击时的鲁棒性,实验结果表明:在航线网络较为脆弱的情况下,该方法为货运航司航线网络的优化和抗风险能力的提升提供了重要参考。 展开更多
关键词 航空货运 Space P 航线网络 复杂网络 聚类算法 网络特征
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融合组织型P系统与自适应遗传算法的车辆路径优化
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作者 王婷婷 许家昌 《宁夏师范大学学报》 2026年第1期69-84,共16页
针对传统遗传算法在求解带时间窗的车辆路径问题时容易陷入局部最优解和收敛速度慢等问题,提出一种融合组织型P系统与自适应遗传算法的车辆路径优化方法.该算法借鉴组织型P系统的结构特点,设计多个进化膜与指导膜协同进化结构,显著提升... 针对传统遗传算法在求解带时间窗的车辆路径问题时容易陷入局部最优解和收敛速度慢等问题,提出一种融合组织型P系统与自适应遗传算法的车辆路径优化方法.该算法借鉴组织型P系统的结构特点,设计多个进化膜与指导膜协同进化结构,显著提升算法的局部和全局收敛能力.在此基础上,提出自适应交叉变异算子、基于破坏-修复算子的自适应局部搜索策略及精英保留策略以改进遗传算法,有效增强了算法的全局搜索能力.最后,在Solomon数据集上进行实验.实验结果表明,所提算法在大多数算例中优于9种最先进的优化算法,验证了其在解决带时间窗的车辆路径问题中的有效性和应用潜力. 展开更多
关键词 组织型P系统 带时间窗的车辆路径问题 自适应遗传算法 自适应局部搜索策略
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Raft Consensus Algorithm Based on Credit Model in Consortium Blockchain 被引量:5
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作者 CHEN Yunfang LIU Ping ZHANG Wei 《Wuhan University Journal of Natural Sciences》 CAS CSCD 2020年第2期146-154,共9页
As one of the underlying technologies of the blockchain,the consensus algorithm plays a vital role in ensuring security and efficiency.As a consensus algorithm for the private blockchain,Raft has better performance th... As one of the underlying technologies of the blockchain,the consensus algorithm plays a vital role in ensuring security and efficiency.As a consensus algorithm for the private blockchain,Raft has better performance than the rest of the consensus algorithms,and it does not cause problems such as the concentrated hashing power,resource waste and fork.However,Raft can only be used in a non-byzantine environment with a small network size.In order to enable Raft to be used in a large-scale network with a certain number of byzantine nodes,this paper combines Raft and credit model to propose a Raft blockchain consensus algorithm based on credit model CRaft.In the node credit evaluation phase,RBF-based support vector machine is used as the anomaly detection method,and the node credit evaluation model is constructed.Then the Trust Nodes List(TNL)mechanism is introduced to make the consensus phase in a creditable network environment.Finally,the common node is synchronized to the consensus node to update the blockchain of the entire network.Experiments show that CRaft has better throughput and lower latency than the commonly used consortium blockchain consensus algorithm PBFT(Practical Byzantine Fault Tolerance). 展开更多
关键词 credit model consensus algorithm consortium blockchain p2p network
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A Hierarchical P2P Model and a Data Fusion Method for Network Security Situation Awareness System 被引量:5
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作者 GUO Fangfang HU Yibing +2 位作者 XIU Longting FENG Guangsheng WANG Shuaishuai 《Wuhan University Journal of Natural Sciences》 CAS CSCD 2016年第2期126-132,共7页
A hierarchical peer-to-peer(P2P)model and a data fusion method for network security situation awareness system are proposed to improve the efficiency of distributed security behavior monitoring network.The single po... A hierarchical peer-to-peer(P2P)model and a data fusion method for network security situation awareness system are proposed to improve the efficiency of distributed security behavior monitoring network.The single point failure of data analysis nodes is avoided by this P2P model,in which a greedy data forwarding method based on node priority and link delay is devised to promote the efficiency of data analysis nodes.And the data fusion method based on repulsive theory-Dumpster/Shafer(PSORT-DS)is used to deal with the challenge of multi-source alarm information.This data fusion method debases the false alarm rate.Compared with improved Dumpster/Shafer(DS)theoretical method based on particle swarm optimization(PSO)and classical DS evidence theoretical method,the proposed model reduces false alarm rate by 3%and 7%,respectively,whereas their detection rate increases by 4%and 16%,respectively. 展开更多
关键词 distributed security behavior monitoring peer-to- peer p2p data fusion DS evidence theory PSO algorithm
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Analytical Comparison of Resource Search Algorithms in Non-DHT Mobile Peer-to-Peer Networks 被引量:1
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作者 Ajay Arunachalam Vinayakumar Ravi +2 位作者 Moez Krichen Roobaea Alroobaea Jehad Saad Alqurni 《Computers, Materials & Continua》 SCIE EI 2021年第7期983-1001,共19页
One of the key challenges in ad-hoc networks is the resource discovery problem.How efciently&quickly the queried resource/object can be resolved in such a highly dynamic self-evolving network is the underlying que... One of the key challenges in ad-hoc networks is the resource discovery problem.How efciently&quickly the queried resource/object can be resolved in such a highly dynamic self-evolving network is the underlying question?Broadcasting is a basic technique in the Mobile Ad-hoc Networks(MANETs),and it refers to sending a packet from one node to every other node within the transmission range.Flooding is a type of broadcast where the received packet is retransmitted once by every node.The naive ooding technique oods the network with query messages,while the random walk scheme operates by contacting subsets of each node’s neighbors at every step,thereby restricting the search space.Many earlier works have mainly focused on the simulation-based analysis of ooding technique,and its variants,in a wired network scenario.Although,there have been some empirical studies in peer-to-peer(P2P)networks,the analytical results are still lacking,especially in the context of mobile P2P networks.In this article,we mathematically model different widely used existing search techniques,and compare with the proposed improved random walk method,a simple lightweight approach suitable for the non-DHT architecture.We provide analytical expressions to measure the performance of the different ooding-based search techniques,and our proposed technique.We analytically derive 3 relevant key performance measures,i.e.,the avg.number of steps needed to nd a resource,the probability of locating a resource,and the avg.number of messages generated during the entire search process. 展开更多
关键词 Mathematical model MANET p2p networks p2p MANET UNstructured search algorithms Peer-to-Peer AD-HOC ooding random walk resource discovery content discovery mobile peer-to-peer broadcast PEER
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GRADE: Deep learning and garlic routing-based secure data sharing framework for IIoT beyond 5G
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作者 Nilesh Kumar Jadav Riya Kakkar +4 位作者 Harsh Mankodiya Rajesh Gupta Sudeep Tanwar Smita Agrawal Ravi Sharma 《Digital Communications and Networks》 SCIE CSCD 2023年第2期422-435,共14页
The rise of automation with Machine-Type Communication(MTC)holds great potential in developing Industrial Internet of Things(IIoT)-based applications such as smart cities,Intelligent Transportation Systems(ITS),supply... The rise of automation with Machine-Type Communication(MTC)holds great potential in developing Industrial Internet of Things(IIoT)-based applications such as smart cities,Intelligent Transportation Systems(ITS),supply chains,and smart industries without any human intervention.However,MTC has to cope with significant security challenges due to heterogeneous data,public network connectivity,and inadequate security mechanism.To overcome the aforementioned issues,we have proposed a blockchain and garlic-routing-based secure data exchange framework,i.e.,GRADE,which alleviates the security constraints and maintains the stable connection in MTC.First,the Long-Short-Term Memory(LSTM)-based Nadam optimizer efficiently predicts the class label,i.e.,malicious and non-malicious,and forwards the non-malicious data requests of MTC to the Garlic Routing(GR)network.The GR network assigns a unique ElGamal encrypted session tag to each machine partaking in MTC.Then,an Advanced Encryption Standard(AES)is applied to encrypt the MTC data requests.Further,the InterPlanetary File System(IPFS)-based blockchain is employed to store the machine's session tags,which increases the scalability of the proposed GRADE framework.Additionally,the proposed framework has utilized the indispensable benefits of the 6G network to enhance the network performance of MTC.Lastly,the proposed GRADE framework is evaluated against different performance metrics such as scalability,packet loss,accuracy,and compromised rate of the MTC data request.The results show that the GRADE framework outperforms the baseline methods in terms of accuracy,i.e.,98.9%,compromised rate,i.e.,18.5%,scalability,i.e.,47.2%,and packet loss ratio,i.e.,24.3%. 展开更多
关键词 Garlic routing Blockchain I2P LSTM Artificial intelligence Onion routing
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Research on Video on Demand Based on P2P Network
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作者 Min Cui 《Intelligent Information Management》 2010年第5期338-341,共4页
A P2P approaches to extend the ability of Video on Demand systems to serve more users. In the proposed system users share with each other the media data obtained and the media server is no longer the only source to ge... A P2P approaches to extend the ability of Video on Demand systems to serve more users. In the proposed system users share with each other the media data obtained and the media server is no longer the only source to get data from, thereby, the load on the media server could be greatly alleviated and the overall system capacity increases and more users could be served. The P2P streaming system introduces efficient searching;data transfer dynamically monitoring and initial buffering to maintain a high quality of playback. Its provider selection policy helps to reduce the load of the underlying network by avoiding remote data transfer. 展开更多
关键词 p2p PEER to PEER Video on DEMAND STREAMING Media SUPER-PEER CACHE REPLACEMENT algorithm
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Detecting P2P Botnet by Analyzing Macroscopic Characteristics with Fractal and Information Fusion
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作者 SONG Yuanzhang 《China Communications》 SCIE CSCD 2015年第2期107-117,共11页
Towards the problems of existing detection methods,a novel real-time detection method(DMFIF) based on fractal and information fusion is proposed.It focuses on the intrinsic macroscopic characteristics of network,which... Towards the problems of existing detection methods,a novel real-time detection method(DMFIF) based on fractal and information fusion is proposed.It focuses on the intrinsic macroscopic characteristics of network,which reflect not the "unique" abnormalities of P2P botnets but the "common" abnormalities of them.It regards network traffic as the signal,and synthetically considers the macroscopic characteristics of network under different time scales with the fractal theory,including the self-similarity and the local singularity,which don't vary with the topology structures,the protocols and the attack types of P2P botnet.At first detect traffic abnormalities of the above characteristics with the nonparametric CUSUM algorithm,and achieve the final result by fusing the above detection results with the Dempster-Shafer evidence theory.Moreover,the side effect on detecting P2P botnet which web applications generated is considered.The experiments show that DMFIF can detect P2P botnet with a higher degree of precision. 展开更多
关键词 p2p botnet fractal information fusion CUSUM algorithm
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双壳层P(MMA-MPS)/SiO_(2)/CeO_(2)核壳复合磨料制备及其抛光性能研究
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作者 贾慧灵 吕镓屹 +2 位作者 吴锦绣 李森 王少峰 《表面技术》 北大核心 2025年第24期184-194,共11页
目的针对磨料在机械耐用性和化学抛光效率两个方面的高需求制备出一种应用于KDP晶体等脆性材料抛光的新型双壳层复合磨料。方法采用沸腾体系无皂乳液聚合法合成了3-(甲基丙烯酰氧)丙基三甲氧基硅烷(MPS)修饰的P(MMA-MPS)微球作为内核,... 目的针对磨料在机械耐用性和化学抛光效率两个方面的高需求制备出一种应用于KDP晶体等脆性材料抛光的新型双壳层复合磨料。方法采用沸腾体系无皂乳液聚合法合成了3-(甲基丙烯酰氧)丙基三甲氧基硅烷(MPS)修饰的P(MMA-MPS)微球作为内核,使用溶胶-凝胶法在微球表面包覆SiO_(2)内壳层,通过均匀沉淀法沉积CeO_(2)外壳层,制备了P(MMA-MPS)/SiO_(2)/CeO_(2)双壳层核壳复合磨料用于KDP晶体抛光。用扫描电镜、透射电镜、XRD、FT-IR、X射线衍射等手段分析样品的结构和性质。结果P(MMA-MPS)微球粒径在280~320nm之间,Si—O—Si键和Ce—O键的XPS吸收峰的出现验证了SiO_(2)壳层和CeO_(2)壳层都均匀地依次包覆在P(MMA-MPS)微球上,P(MMA-MPS)/SiO_(2)/CeO_(2)磨料的单分散性良好。SiO_(2)层的引入增加了CeO_(2)层中氧空位的浓度,Ce^(3+)含量增多,抛光时的氧化还原反应活性增强;同时增强了核壳间的结合强度。相比PMMA/CeO_(2)磨料,抛光后在5μm×5μm范围内的KDP晶体表面粗糙度RMS值由(1.03±0.05)nm降至(0.51±0.03)nm。材料去除率由(268.84±7)nm/min提升至(302.26±6.6)nm/min。结论成功制备出一种克服界面结合弱和单一CeO_(2)壳活性受限,可以应用于KDP晶体等脆性材料抛光的新型双壳层复合磨料。 展开更多
关键词 双壳层 核壳结构 P(MMA-MPS)/SiO_(2)/CeO_(2)磨料 制备 抛光性能
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基于扩展型活性膜系统的彩色图像分割方法
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作者 许家昌 郭佳 苏树智 《深圳大学学报(理工版)》 北大核心 2025年第1期59-67,共9页
为克服优化算法易陷入局部最优和收敛速度慢的局限,提高扩展膜系统在图像处理领域的优化性能,提出一种基于扩展型活性膜系统(P system)的改进北方苍鹰优化(improved northern goshawk optimization,INGO)算法——PINGO.采用北方苍鹰优... 为克服优化算法易陷入局部最优和收敛速度慢的局限,提高扩展膜系统在图像处理领域的优化性能,提出一种基于扩展型活性膜系统(P system)的改进北方苍鹰优化(improved northern goshawk optimization,INGO)算法——PINGO.采用北方苍鹰优化算法作为基本膜中的进化规则,通过更新苍鹰的状态进化基本膜中的对象,将INGO算法作为局部进化规则来进化子膜中的对象.该系统根据活性膜自身的特点在基本膜中溶解或产生子膜,通信规则用于实现不同膜之间的信息交换与共享,避免算法陷入局部最优.在数据集BSD300和BSD500上,分别采用海鸥优化(seagull optimization algorithm,SOA)算法、灰狼优化(grey wolf optimizer,GWO)算法、INGO算法和PINGO算法,对不同优化阈值个数的图像进行分割.结果表明,PINGO算法在分割后的图像上的峰值信噪比均优于其他算法,特征相似度最优值也占了83%,在保持色彩与纹理的同时提高了分割的准确性.研究结果表明了所提彩色图像分割方法的有效性. 展开更多
关键词 图像处理 图像分割 P系统 活性膜结构 北方苍鹰优化算法 进化规则
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共掺杂β-Ga_(2)O_(3)导电性质第一性原理研究
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作者 王淳 王坤 +2 位作者 宋相满 任林 张浩 《人工晶体学报》 北大核心 2025年第8期1426-1432,共7页
本文基于密度泛函理论的第一性原理计算方法,研究了Mg-Al共掺杂、F-Zn共掺杂和N-Mg共掺杂β-Ga_(2)O_(3)三种体系的结构性质和电学性质,以期获得高性能共掺杂P型导电β-Ga_(2)O_(3)材料。结果表明,Mg-Al共掺杂和F-Zn共掺杂β-Ga_(2)O_(3... 本文基于密度泛函理论的第一性原理计算方法,研究了Mg-Al共掺杂、F-Zn共掺杂和N-Mg共掺杂β-Ga_(2)O_(3)三种体系的结构性质和电学性质,以期获得高性能共掺杂P型导电β-Ga_(2)O_(3)材料。结果表明,Mg-Al共掺杂和F-Zn共掺杂β-Ga_(2)O_(3)仍为直接带隙半导体材料,而N-Mg共掺杂β-Ga_(2)O_(3)为间接带隙半导体材料。三种共掺杂体系均具有较低的形成能。其中Mg-Al共掺杂β-Ga_(2)O_(3)体系形成能最低,表现出较好的热力学稳定性。该体系中,Mg-p和Al-p轨道推移价带顶向高能方向移动,并穿越费米能级,是三种掺杂体系中最有可能实现P型导电性质的材料。 展开更多
关键词 共掺杂β-Ga_(2)O_(3) 第一性原理 P型导电 电子结构 密度泛函理论 半导体
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β相氧化镓p型导电研究进展 被引量:1
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作者 查显弧 万玉喜 张道华 《人工晶体学报》 北大核心 2025年第2期177-189,共13页
β相氧化镓(β-Ga_(2)O_(3))具有超宽带隙、高击穿电场和容易制备等优势,是功率器件的理想半导体材料。但由于β-Ga_(2)O_(3)价带顶能级位置低、能带色散关系平坦,其p型掺杂目前仍具有挑战性,限制了p-n结及双极性晶体管的开发。利用尺... β相氧化镓(β-Ga_(2)O_(3))具有超宽带隙、高击穿电场和容易制备等优势,是功率器件的理想半导体材料。但由于β-Ga_(2)O_(3)价带顶能级位置低、能带色散关系平坦,其p型掺杂目前仍具有挑战性,限制了p-n结及双极性晶体管的开发。利用尺寸效应、缺陷调控、非平衡动力学及固溶提升价带顶能级等方案是目前实现β-Ga_(2)O_(3)p型掺杂的主要策略。对于β-Ga_(2)O_(3)p-n同质结和异质结,提高晶体质量、减少界面缺陷态是优化器件性能的关键问题。本文针对β-Ga_(2)O_(3)的p型导电问题,系统阐述了β-Ga_(2)O_(3)电子结构,实验表征及理论计算掺杂能级方法,p型掺杂困难原因,以及改进p型掺杂的突破性研究进展。最后简单介绍了β-Ga_(2)O_(3)p-n同质结和异质结器件的相关工作。利用复合缺陷调控、非平衡动力学、固溶等方案,以及不同方案的协同实现体相β-Ga_(2)O_(3)的p型掺杂仍需要深入探索,p-n同质及异质结的器件性能需要进一步优化。 展开更多
关键词 β-Ga_(2)O_(3) p型导电 电子结构 受主能级 固溶 P-N结
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