期刊文献+
共找到451篇文章
< 1 2 23 >
每页显示 20 50 100
基于hops的Internet复杂网络分割度分析 被引量:6
1
作者 苏威积 赵海 +1 位作者 徐野 张文波 《通信学报》 EI CSCD 北大核心 2005年第9期1-8,共8页
首先讨论了相同分割度对不同网络传播行为的影响,并以小世界网络为例讨论了不同分割度对相同网络传播行为的影响;定义了基于hops的Internet分割度,根据CAIDA提供的全球范围30个主要monitor5年以来采集的数据,对Internethops进行统计分析... 首先讨论了相同分割度对不同网络传播行为的影响,并以小世界网络为例讨论了不同分割度对相同网络传播行为的影响;定义了基于hops的Internet分割度,根据CAIDA提供的全球范围30个主要monitor5年以来采集的数据,对Internethops进行统计分析,并计算出Internet分割度,与国际该领域研究成果进行相比,更进一步揭示了Internet小世界效应的规律;针对hops与RTT进行了10种模型的回归分析,得出hops与RTT更符合幂函数关系及其关键参数,从统计上证明了Internet复杂网络传播行为的幂率关系,并以此建立了Internet分割度时间敏感性模型(ISTSDM);建立了针对Internet分割度的时间序列随机过程模型(MTSSPISD),并以此讨论了Internet分割度的时间演化规律;最后利用模型ISTSDM和模型MTSSPISD对2008年北京奥运期间Internet分割度和IP层数据平均传播时间进行了预测。 展开更多
关键词 分割度 集群度 特征路径长度 hops RTT 复杂网络 小世界效应
下载PDF
Optimizing Packet Generation Rate for Multiple Hops WBAN with CSMA/CA Based on IEEE802.15.6
2
作者 Pham Thanh Hiep Ryuji Kohno 《Communications and Network》 2014年第2期112-123,共12页
Wireless Body Area Network (WBAN) is considered to apply to both medical healthcare and entertainment applications. A requirement for each application is different, i.e. high reliability for medical healthcare whereas... Wireless Body Area Network (WBAN) is considered to apply to both medical healthcare and entertainment applications. A requirement for each application is different, i.e. high reliability for medical healthcare whereas high throughput for entertainment application. However, for both applications, low energy consumption is requested. Multiple hops technics have been researching in many fields of wireless system, e.g., ad hod, mobile, ITS etc. and its energy-efficiency is reported to be high. We propose the multiple hops technic for WBAN, however, WBAN is different to another systems, almost sensors forward the vital data packet of another sensors while sensing and generating the data packet of itself. Therefore, according to a packet generation rate of all sensors, probabilities of successful transmission and packet loss because of collision, timeout and overflow, are changed. It means that the vital data is lost and the transmit power is wasted due to packet loss. In order to obtain the highest throughput and save the power, the successful transmission probability is analyzed and the packet generation rate is optimized for multiple hops WBAN that using CSMA/CA based on IEEE802.15.6. The numerical calculation result indicates that the optimized packet generation rate depends on the system model. Moreover, the relation between the system model, the optimized packet generation rate and the throughput is discussed in the paper. 展开更多
关键词 Multiple hops Body Area Network Optimal PACKET Generation Rate Successful PROBABILITY COLLISION PROBABILITY CSMA/CA of IEEE802.15.6
下载PDF
Study on Brewing Characteristics of High α-acid and High β-acid Hops
3
作者 Yanwei GUO Cong NIE +2 位作者 Xueqin GUAN Jie ZHANG Guiheng YANG 《Agricultural Biotechnology》 CAS 2019年第2期185-187,190,共4页
[Objectives] Columbus and Tsingtao Flower were selected to brew Ale beer, thereby studying the brewing characteristics of high α-acid and high β-acid content hops. [Methods] The content of diacetyl and bitterness in... [Objectives] Columbus and Tsingtao Flower were selected to brew Ale beer, thereby studying the brewing characteristics of high α-acid and high β-acid content hops. [Methods] The content of diacetyl and bitterness in beer were determined by a spectrophotometer at 335 and 275 nm, respectively. With pH=8.2 as the end point of potentiometric titration, the total acid content in beer was calculated by acid-base titration method, and sensory evaluation for beer was conducted. [Results] The results show that α-acid is an important factor affecting the production and reduction rate of diacetyl in beer. The production and reduction rate of diacetyl in high α-acid hops were lower than those in high β-acid hops; iso-α-acid was the main source of bitterness in beer, and high α-acid hops had more significant bitter value than high β-acid hops; and malt acid compounds and fermentation production were the main source of total acid in beer, and high α-acid and high β-acid hops had a little effect on total acid in beer. In sensory evaluation, high α-acid hops were more effective than high β-acid hops in terms of zest of the mouthfeel, foaming retention and alcohol fragrance, while in clarity, high α-acid hops were lower than high β-acid hops. [Conclusions] Therefore, we can draw a conclusion that the brewing characteristics of high α-acid hops are better than those of high β-acid hops. 展开更多
关键词 hops HIGH ɑ-acid HIGH β-acid DIACETYL
下载PDF
CONVERSE HOPS MID世纪球魂
4
作者 许大维 《中国服装(北京)》 2008年第8期42-43,共2页
1908年MILLS CONVERSE先生在北卡罗来纳州创立CONVERSE橡胶公司,1910年时胶鞋的日产量已经可以达到4000双,是最畅销休闲鞋。随着篮球运动的发展,1917年CONVERSE公司推出了ALL STAR帆布鞋,标志着专业篮球鞋的诞生,在此后的几十年里... 1908年MILLS CONVERSE先生在北卡罗来纳州创立CONVERSE橡胶公司,1910年时胶鞋的日产量已经可以达到4000双,是最畅销休闲鞋。随着篮球运动的发展,1917年CONVERSE公司推出了ALL STAR帆布鞋,标志着专业篮球鞋的诞生,在此后的几十年里,“ALL STAR”一直是篮球鞋的代名词,广泛活跃在全世界的篮球场上。 展开更多
关键词 hops MID 北卡罗来纳州 STAR 篮球运动 SE公司 篮球鞋 日产量
下载PDF
Analysis of Hops Length in Wireless Sensor Networks 被引量:4
5
作者 Mekkaoui Kheireddine Rahmoun Abdellatif 《Wireless Sensor Network》 2014年第6期109-117,共9页
Wireless sensor networks are provided with a limited source of power. The lifetime of such networks is an overwhelming matter in most network applications. This lifetime depends strongly on how efficiently such energy... Wireless sensor networks are provided with a limited source of power. The lifetime of such networks is an overwhelming matter in most network applications. This lifetime depends strongly on how efficiently such energy is distributed over the nodes especially during transmitting and receiving data. Each node may route messages to destination nodes either through short hops or long hops. Optimizing the length of these hops may save energy, and therefore extend the lifetime of WSNs. In this paper, we propose a theorem to optimize the hop’s length so to make WSN power consumption minimal. The theorem establishes a simple condition on hop’s length range. Computer simulation when performing such condition on Mica2 sensors and Mica2dot sensors reveals good performance regarding WSNs energy consumption. 展开更多
关键词 Wireless Sensor NETWORKS Energy Efficiency MULTI-HOP ROUTING HOP LENGTH Network’s Life Time
下载PDF
HOPS复合体蛋白在细胞自噬过程中的功能研究 被引量:1
6
作者 胡晚秋 林志祥 +2 位作者 陈丽莲 晏向华 陈放 《中国细胞生物学学报》 CAS CSCD 2011年第8期855-860,共6页
自噬(autophagy)是一种溶酶体依赖性的细胞内降解途径,其主要功能是将生物大分子(蛋白质、多糖等)或细胞器(线粒体等)回收至溶酶体中并将其降解为单糖、氨基酸等小分子以重复利用。发现HOPS复合体中的两个基因vps39和vps41的缺失会导致... 自噬(autophagy)是一种溶酶体依赖性的细胞内降解途径,其主要功能是将生物大分子(蛋白质、多糖等)或细胞器(线粒体等)回收至溶酶体中并将其降解为单糖、氨基酸等小分子以重复利用。发现HOPS复合体中的两个基因vps39和vps41的缺失会导致酵母内GFP-ATG8大量积累。进一步研究表明,积累的原因是GFP-ATG8与液泡不能发生融合。而在HOPS复合体中的另外两个基因vps16和vps18缺失的情况下,自噬融合没有受到影响;在vps16和vps18双敲除的菌株中,自噬融合同样没有受到影响。该实验结果为理解HOPS复合体的功能和自噬体与液泡融合的过程提供了新的线索。 展开更多
关键词 自噬 膜泡融合 hops复合体
原文传递
Quantum correlations and entanglement in coupled optomechanical resonators with photon hopping via Gaussian interferometric power analysis
7
作者 Y.Lahlou B.Maroufi M.Daoud 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期204-211,共8页
Quantum correlations that surpass entanglement are of great importance in the realms of quantum information processing and quantum computation.Essentially,for quantum systems prepared in pure states,it is difficult to... Quantum correlations that surpass entanglement are of great importance in the realms of quantum information processing and quantum computation.Essentially,for quantum systems prepared in pure states,it is difficult to differentiate between quantum entanglement and quantum correlation.Nonetheless,this indistinguishability is no longer holds for mixed states.To contribute to a better understanding of this differentiation,we have explored a simple model for both generating and measuring these quantum correlations.Our study concerns two macroscopic mechanical resonators placed in separate Fabry–Pérot cavities,coupled through the photon hopping process.this system offers a comprehensively way to investigate and quantify quantum correlations beyond entanglement between these mechanical modes.The key ingredient in analyzing quantum correlation in this system is the global covariance matrix.It forms the basis for computing two essential metrics:the logarithmic negativity(E_(N)^(m))and the Gaussian interferometric power(P_(G)^(m)).These metrics provide the tools to measure the degree of quantum entanglement and quantum correlations,respectively.Our study reveals that the Gaussian interferometric power(P_(G)^(m))proves to be a more suitable metric for characterizing quantum correlations among the mechanical modes in an optomechanical quantum system,particularly in scenarios featuring resilient photon hopping. 展开更多
关键词 quantum correlations ENTANGLEMENT Gaussian interferometric power logarithmic negativity optomechanics photon hopping
下载PDF
Elevating Localization Accuracy in Wireless Sensor Networks:A Refined DV-Hop Approach
8
作者 Muhammad Aamer Ejaz Kamalrulnizam Abu Bakar +4 位作者 Ismail Fauzi Bin Isnin Babangida Isyaku Taiseer Abdalla Elfadil Eisa Abdelzahir Abdelmaboud Asma Abbas Hassan Elnour 《Computers, Materials & Continua》 SCIE EI 2024年第10期1511-1528,共18页
Localization is crucial in wireless sensor networks for various applications,such as tracking objects in outdoor environments where GPS(Global Positioning System)or prior installed infrastructure is unavailable.Howeve... Localization is crucial in wireless sensor networks for various applications,such as tracking objects in outdoor environments where GPS(Global Positioning System)or prior installed infrastructure is unavailable.However,traditional techniques involve many anchor nodes,increasing costs and reducing accuracy.Existing solutions do not address the selection of appropriate anchor nodes and selecting localized nodes as assistant anchor nodes for the localization process,which is a critical element in the localization process.Furthermore,an inaccurate average hop distance significantly affects localization accuracy.We propose an improved DV-Hop algorithm based on anchor sets(AS-IDV-Hop)to improve the localization accuracy.Through simulation analysis,we validated that the ASIDV-Hop proposed algorithm is more efficient in minimizing localization errors than existing studies.The ASIDV-Hop algorithm provides an efficient and cost-effective solution for localization in Wireless Sensor Networks.By strategically selecting anchor and assistant anchor nodes and rectifying the average hop distance,AS-IDV-Hop demonstrated superior performance,achieving a mean accuracy of approximately 1.59,which represents about 25.44%,38.28%,and 73.00%improvement over other algorithms,respectively.The estimated localization error is approximately 0.345,highlighting AS-IDV-Hop’s effectiveness.This substantial reduction in localization error underscores the advantages of implementing AS-IDV-Hop,particularly in complex scenarios requiring precise node localization. 展开更多
关键词 LOCALIZATION anchor nodes COLLINEARITY CONNECTIVITY hop based
下载PDF
Moisture‑Electric–Moisture‑Sensitive Heterostructure Triggered Proton Hopping for Quality‑Enhancing Moist‑Electric Generator
9
作者 Ya’nan Yang Jiaqi Wang +11 位作者 Zhe Wang Changxiang Shao Yuyang Han Ying Wang Xiaoting Liu Xiaotong Sun Liru Wang Yuanyuan Li Qiang Guo Wenpeng Wu Nan Chen Liangti Qu 《Nano-Micro Letters》 SCIE EI CSCD 2024年第3期351-366,共16页
Moisture-enabled electricity(ME)is a method of converting the potential energy of water in the external environment into electrical energy through the interaction of functional materials with water molecules and can b... Moisture-enabled electricity(ME)is a method of converting the potential energy of water in the external environment into electrical energy through the interaction of functional materials with water molecules and can be directly applied to energy harvesting and signal expression.However,ME can be unreliable in numerous applications due to its sluggish response to moisture,thus sacrificing the value of fast energy harvesting and highly accurate information representation.Here,by constructing a moisture-electric-moisture-sensitive(ME-MS)heterostructure,we develop an efficient ME generator with ultra-fast electric response to moisture achieved by triggering Grotthuss protons hopping in the sensitized ZnO,which modulates the heterostructure built-in interfacial potential,enables quick response(0.435 s),an unprecedented ultra-fast response rate of 972.4 mV s^(−1),and a durable electrical signal output for 8 h without any attenuation.Our research provides an efficient way to generate electricity and important insight for a deeper understanding of the mechanisms of moisture-generated carrier migration in ME generator,which has a more comprehensive working scene and can serve as a typical model for human health monitoring and smart medical electronics design. 展开更多
关键词 Moist-electric generators Grotthuss proton hopping Fast response Durable electrical output Personal health monitoring
下载PDF
Edge modes in finite-size systems with different edge terminals
10
作者 Huiping Wang Li Ren +1 位作者 Xiuli Zhang Liguo Qin 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第10期381-387,共7页
We investigate the behavior of edge modes in the presence of different edge terminations and long-range(LR)hopping.Here,we mainly focus on such model crystals with two different types of structures(type I:“…-P-Q-P-Q... We investigate the behavior of edge modes in the presence of different edge terminations and long-range(LR)hopping.Here,we mainly focus on such model crystals with two different types of structures(type I:“…-P-Q-P-Q-…”and type II:“…=P-Q=P-Q=…”),where P and Q represent crystal lines(CLs),while the symbols“-”and“=”denote the distance between the nearest neighbor(NN)CLs.Based on the lattice model Hamiltonian with LR hopping,the existence of edge modes is determined analytically by using the transfer matrix method(TMM)when different edge terminals are taken into consideration.Our findings are consistent with the numerical results obtained by the exact diagonalization method.We also notice that edge modes can exhibit different behaviors under different edge terminals.Our result is helpful in solving novel edge modes in honeycomb crystalline graphene and transition metal dichalcogenides with different edge terminals. 展开更多
关键词 edge modes long-range hopping different edge terminals
下载PDF
Joint Beam Scheduling and Power Optimization for Beam Hopping LEO Satellite Systems
11
作者 Zheng Shuang Zhang Xing +1 位作者 Wang Peng Wang Wenbo 《China Communications》 SCIE CSCD 2024年第10期226-239,共14页
Low earth orbit(LEO) satellite communications can provide ubiquitous and reliable services,making it an essential part of the Internet of Everything network. Beam hopping(BH) is an emerging technology for effectively ... Low earth orbit(LEO) satellite communications can provide ubiquitous and reliable services,making it an essential part of the Internet of Everything network. Beam hopping(BH) is an emerging technology for effectively addressing the issue of low resource utilization caused by the non-uniform spatio-temporal distribution of traffic demands. However, how to allocate multi-dimensional resources in a timely and efficient way for the highly dynamic LEO satellite systems remains a challenge. This paper proposes a joint beam scheduling and power optimization beam hopping(JBSPO-BH) algorithm considering the differences in the geographic distribution of sink nodes. The JBSPO-BH algorithm decouples the original problem into two sub-problems. The beam scheduling problem is modelled as a potential game,and the Nash equilibrium(NE) point is obtained as the beam scheduling strategy. Moreover, the penalty function interior point method is applied to optimize the power allocation. Simulation results show that the JBSPO-BH algorithm has low time complexity and fast convergence and achieves better performance both in throughput and fairness. Compared with greedybased BH, greedy-based BH with the power optimization, round-robin BH, Max-SINR BH and satellite resource allocation algorithm, the throughput of the proposed algorithm is improved by 44.99%, 20.79%,156.06%, 15.39% and 8.17%, respectively. 展开更多
关键词 beam hopping interior point method potential game resource allocation
下载PDF
Core-level spectroscopy of the photodissociation process of BrCN molecule
12
作者 周坤 王涵 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期176-182,共7页
Fewest-switches surfacing hopping(FSSH) simulations have been performed with the high-level multi-reference electronic structure method to explore the coupled electronic and nuclear dynamics upon photoexcitation of cy... Fewest-switches surfacing hopping(FSSH) simulations have been performed with the high-level multi-reference electronic structure method to explore the coupled electronic and nuclear dynamics upon photoexcitation of cyanogen bromide(BrCN). The potential energy surfaces(PES) of BrCN are charted as functions of the Jacobi coordinates(R, θ). An indepth examination of the FSSH trajectories reveals the temporal dynamics of the molecule and the population changes of the lowest twelve states during BrCN's photodissociation process, which presents a rich tapestry of dynamical information.Furthermore, the carbon K-edge x-ray absorption spectroscopy(XAS) is calculated with multi-reference inner-shell spectral simulations. The rotation of the CN fragment and the elongation of the C–Br bond are found to be the reason for the peak shifting in the XAS. Our findings offer a nuanced interpretation for inner-shell probe investigations of BrCN, setting the stage for a deeper understanding of the photodissociation process of cyanogen halides molecules. 展开更多
关键词 x-ray absorption spectroscopy PHOTODISSOCIATION fewest-switches surface hopping
下载PDF
A Synchronization Acquisition Algorithm Based on the Frequency Hopping Pulses Combining
13
作者 She Honghan Cheng Yufan +4 位作者 Zhang Wenzihan Zhang Yaohui Zhao Yuheng Shen Haoran Mou Ying 《China Communications》 SCIE CSCD 2024年第4期74-87,共14页
As modern electromagnetic environments are more and more complex,the anti-interference performance of the synchronization acquisition is becoming vital in wireless communications.With the rapid development of the digi... As modern electromagnetic environments are more and more complex,the anti-interference performance of the synchronization acquisition is becoming vital in wireless communications.With the rapid development of the digital signal processing technologies,some synchronization acquisition algorithms for hybrid direct-sequence(DS)/frequency hopping(FH)spread spectrum communications have been proposed.However,these algorithms do not focus on the analysis and the design of the synchronization acquisition under typical interferences.In this paper,a synchronization acquisition algorithm based on the frequency hopping pulses combining(FHPC)is proposed.Specifically,the proposed algorithm is composed of two modules:an adaptive interference suppression(IS)module and an adaptive combining decision module.The adaptive IS module mitigates the effect of the interfered samples in the time-domain or the frequencydomain,and the adaptive combining decision module can utilize each frequency hopping pulse to construct an anti-interference decision metric and generate an adaptive acquisition decision threshold to complete the acquisition.Theory and simulation demonstrate that the proposed algorithm significantly enhances the antiinterference and anti-noise performances of the synchronization acquisition for hybrid DS/FH communications. 展开更多
关键词 adaptive anti-interference frequency hopping synchronization acquisition
下载PDF
Gigahertz frequency hopping in an optical phase-locked loop for Raman lasers
14
作者 毛德凯 税鸿冕 +3 位作者 殷国玲 彭鹏 王春唯 周小计 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第2期60-65,共6页
Raman lasers are essential in atomic physics,and the development of portable devices has posed requirements for time-division multiplexing of Raman lasers.We demonstrate an innovative gigahertz frequency hopping appro... Raman lasers are essential in atomic physics,and the development of portable devices has posed requirements for time-division multiplexing of Raman lasers.We demonstrate an innovative gigahertz frequency hopping approach of a slave Raman laser within an optical phase-locked loop(OPLL),which finds practical application in an atomic gravimeter,where the OPLL frequently switches between near-resonance lasers and significantly detuned Raman lasers.The method merges the advantages of rapid and extensive frequency hopping with the OPLL’s inherent low phase noise,and exhibits a versatile range of applications in compact laser systems,promising advancements in portable instruments. 展开更多
关键词 Raman lasers optical phase-locked loop frequency hopping
下载PDF
Solid-state synthesis and ion transport characteristics of the β-KSbF_(4) for all-solid-state fluoride-ion batteries
15
作者 Jiali Liu Huahui Zhao +8 位作者 Jingcheng Xia Lingguang Yi Xiaoyi Chen Dongdu Li Shuhan Ni Xinyi Su Yixuan Chen Min Liu Xianyou Wang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第7期758-767,共10页
All-solid-state fluoride ion batteries(FIBs)have been recently considered as a post-lithium-ion battery system due to their high safety and high energy density.Just like all solid-state lithium batteries,the key to th... All-solid-state fluoride ion batteries(FIBs)have been recently considered as a post-lithium-ion battery system due to their high safety and high energy density.Just like all solid-state lithium batteries,the key to the development of FIBs lies in room-temperature electrolytes with high ionic conductivity.β-KSbF_(4) is a kind of promising solid-state electrolyte for FIBs owing to its rational ionic conductivity and relatively wide electrochemical stability window at room temperature.However,the previous synthesis routes ofβ-KSbF_(4) required the use of highly toxic hydrofluoric acid and the ionic conductivity of as-prepared product needs to be further improved.Herein,the β-KSbF_(4) sample with an ionic conductivity of 1.04×10^(-4)s cm^(-1)(30°C)is synthesized through the simple solid-state route.In order to account for the high ionic conductivity of the as-synthesizedβ-KSbF_(4),X-ray diffraction(XRD),scanning electron microscopy(SEM),and energy dispersive X-ray spectroscopy(EDS)are used to characterize the physic-ochemical properties.The results show that the as-synthesizedβ-KSbF_(4) exhibits higher carrier concentra-tion of 1.0×10^(-6)S cm-Hz^(-1)K and hopping frequency of 1.31×10^(6)Hz at 30°C due to the formation of the fluorine vacancies.Meanwhile,the hopping frequency shows the same trend as the changes of ionic conductivity with the changes of temperature,while the carrier concentration is found to be almost con-stant.The two different trends indicate the hopping frequency is mainly responsible for the ionic conduc-tion behavior withinβ-KSbF_(4).Furthermore,the all-solid-state FIBs,in which Ag and Pb+PbF_(2) are adopted as cathode and anode,andβ-KSbF_(4) as fluoride ion conductor,are capable of reversible charge and discharge.The assembled FIBs show a discharge capacity of 108.4 mA h g^(-1) at 1st cycle and 74.2 mA h g^(-1) at 50th cycle.Based on an examination of the capacity decay mechanism,it has been found that deterioration of the electrolyte/electrode interface is an important reason for hindering the commer-cial application of FIBs.Hence,the in-depth comprehension of the ion transport characteristics inβ-KSbF_(4) and the interpretation of the capacity fading mechanism will be conducive to promoting development of high-performanceFIBs. 展开更多
关键词 Solid-state electrolyte Carrier concentration Hopping frequency β-KSbF_(4) All-solid-state fluoride ion batteries
下载PDF
Securing Forwarding Layers from Eavesdropping Attacks Using Proactive Approaches
16
作者 Jiajun Yan Ying Zhou +1 位作者 Anchen Dai Tao Wang 《Computers, Materials & Continua》 SCIE EI 2024年第4期563-580,共18页
As an emerging network paradigm,the software-defined network(SDN)finds extensive application in areas such as smart grids,the Internet of Things(IoT),and edge computing.The forwarding layer in software-defined network... As an emerging network paradigm,the software-defined network(SDN)finds extensive application in areas such as smart grids,the Internet of Things(IoT),and edge computing.The forwarding layer in software-defined networks is susceptible to eavesdropping attacks.Route hopping is amoving target defense(MTD)technology that is frequently employed to resist eavesdropping attacks.In the traditional route hopping technology,both request and reply packets use the same hopping path.If an eavesdropping attacker monitors the nodes along this path,the risk of 100%data leakage becomes substantial.In this paper,we present an effective route hopping approach,called two-day different path(TDP),that turns communication paths into untraceable moving targets.This technology minimizes the probability of data leakage by transmitting request data and reply data through different paths.Firstly,a brief introduction to the network model and attack model involved in this paper is given.Secondly,the algorithm and processingmethod of the TDP are proposed.Thirdly,the paper proposes three differentmetrics tomeasure the effectiveness of the proposed approach.Finally,theoretical analysis and simulation results show that the TDP can effectively reduce the percentage of data exposure,decrease eavesdropping attack success probability,and improve the unpredictability of the path. 展开更多
关键词 Route hopping moving target defense software-defined network two-way different path metrics
下载PDF
Localization effect in single crystal of RuAs_(2)
17
作者 易哲铠 刘琪 +12 位作者 光双魁 徐升 岳小宇 梁慧 李娜 周颖 吴丹丹 孙燕 李秋菊 程鹏 夏天龙 孙学峰 王义炎 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期195-200,共6页
We report the magnetotransport and thermal properties of RuAs_(2) single crystal.RuAs_(2) exhibits semiconductor behavior and localization effect.The crossover from normal state to diffusive transport in the weak loca... We report the magnetotransport and thermal properties of RuAs_(2) single crystal.RuAs_(2) exhibits semiconductor behavior and localization effect.The crossover from normal state to diffusive transport in the weak localization(WL)state and then to variable range hopping(VRH)transport in the strong localization state has been observed.The transitions can be reflected in the measurement of resistivity and Seebeck coefficient.Negative magnetoresistance(NMR)emerges with the appearance of localization effect and is gradually suppressed in high magnetic field.The temperature dependent phase coherence length extracted from the fittings of NMR also indicates the transition from WL to VRH.The measurement of Hall effect reveals an anomaly of temperature dependent carrier concentration caused by localization effect.Our findings show that RuAs_(2) is a suitable platform to study the localized state. 展开更多
关键词 weak localization variable range hopping RuAs_(2) single crystal
下载PDF
恒电位电解法制备光致发光掺钬多孔硅 被引量:1
18
作者 龚孟濂 曾春莲 +3 位作者 黄伟国 谢国伟 郑婉华 廉德亮 《中国稀土学报》 CAS CSCD 北大核心 1998年第2期126-130,共5页
研究了一种新的多孔硅掺稀土的电化学方法———恒电位电解,以及稀土硝酸盐支持电解质有机溶剂的新电解体系。这一方法和体系的特点是通过采用适当外加电压来控制电解产物,提高掺入的稀土浓度,提高发光强度,同时避免生成导致发... 研究了一种新的多孔硅掺稀土的电化学方法———恒电位电解,以及稀土硝酸盐支持电解质有机溶剂的新电解体系。这一方法和体系的特点是通过采用适当外加电压来控制电解产物,提高掺入的稀土浓度,提高发光强度,同时避免生成导致发光不稳定的产物,提高发光稳定性。优化了阳极氧化制备多孔硅的条件和阴极还原制备掺钬多孔硅的条件(钬化合物浓度、溶剂、离子强度、电解电压、时间),获得光致发光强度高于多孔硅的掺钬多孔硅。对多孔硅和掺钬多孔硅的光致发光机制进行了讨论。 展开更多
关键词 掺钬 多孔硅 恒电位电解 制备 光致发光 hops
下载PDF
基于双通信半径的传感器网络DV-Hop定位算法 被引量:45
19
作者 李娟 刘禹 +1 位作者 钱志鸿 卢长刚 《吉林大学学报(工学版)》 EI CAS CSCD 北大核心 2014年第2期502-507,共6页
为了减少传统的DV—Hop算法对未知节点定位时产生的较大误差,分析了影响传统DV—Hop算法定位精度的两个因素,继而提出了一种改进算法。改进算法在进行未知节点定位时,信标节点先后使用两个通信半径广播自身位置信息,从而获得未知节... 为了减少传统的DV—Hop算法对未知节点定位时产生的较大误差,分析了影响传统DV—Hop算法定位精度的两个因素,继而提出了一种改进算法。改进算法在进行未知节点定位时,信标节点先后使用两个通信半径广播自身位置信息,从而获得未知节点与信标节点间更精确的跳数,并计算出它们之间更精确的距离,得到未知节点更精确的坐标。仿真结果显示,改进算法相比于传统DV—Hop算法相对定位误差减少了13%~15%,并且减少了由于网络拓扑结构不同带来的定位误差的差异性。 展开更多
关键词 通信技术 无线传感器网络 节点定位 DV—Hop算法 改进算法
下载PDF
基于RSSI每跳分级和跳距修正的DV-HOP改进算法 被引量:32
20
作者 张爱清 叶新荣 +1 位作者 胡海峰 丁绪星 《仪器仪表学报》 EI CAS CSCD 北大核心 2012年第11期2552-2559,共8页
针对DV-HOP(distance vector hop)算法的定位精度对节点间跳数信息依赖性较强的特点,提出一种基于接收信号强度指示(received signal strength indicator,RSSI)每跳分级和平均跳距修正的DV-HOP改进算法RADV-HOP(RSSI and average hoppin... 针对DV-HOP(distance vector hop)算法的定位精度对节点间跳数信息依赖性较强的特点,提出一种基于接收信号强度指示(received signal strength indicator,RSSI)每跳分级和平均跳距修正的DV-HOP改进算法RADV-HOP(RSSI and average hopping distance modifying DV-HOP)。仿真结果表明:在相同的网络环境里,与传统DV-HOP算法相比,RADV-HOP定位算法仅需节点通信芯片带有RSSI指示功能及增加少量的计算和通信开销,不需要额外的硬件开销,将每跳分为3个子级时,归一化定位误差能下降65%;与其他DV-HOP修正算法相比,RADV-HOP算法以相同的通信开销和稍微增加的计算开销使定位误差下降了45%。 展开更多
关键词 无线传感器网路 DV—HOP 接收信号强度指示 每跳分级
下载PDF
上一页 1 2 23 下一页 到第
使用帮助 返回顶部