检索结果-南通市图书馆

Behaviors analysis of on-coming cluster based on knowledge under cluster security requirements

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第9期37卷 448-462页

作者： Huixia ZHANG Yan LIANG Ying shi Yuedong WANG Chaoxiong MA ran WANG School of Automation Northwestern Polytechnical UniversityXi'an 710129China Key Laboratory of Information Fusion Technology Ministry of EducationXi'an 710129China

Analysis of cluster behaviors of the on-coming cluster is an essential measure for high value locations on the *** target tracking and clustering analysis,cluster behaviors analysis under cluster security requirements remains an open issue,which is a joint analysis of clus-tering,intent reasoning and activity *** address this issue,a framework for cluster behav-iors analysis is proposed by incorporating expert knowledge and domain knowledge,and a knowledge-assisted score function with is designed to improve the accuracy of intent reasoning net-work,overcoming the effects of possible knowledge *** framework consists of three mod-ules for cluster analysis,intent reasoning and activity region analysis for typical tasks,in which an intent reasoning network is constructed to obtain cluster intents by using a hybrid knowledge and data driven ***,considering the complexity of the battlefield environment,dif-ferent tasks and corresponding activity region optimization functions are designed for cluster activ-ity region analysis,which are vital elements of cluster behaviors *** demonstrate the effectiveness of the proposed cluster behaviors analysis framework.

关键词： Cluster analysis Intent reasoning,Activity region analysis Cluster behavior Battlefield environment

Pressure transient characteristics of non-uniform conductivity fractured wells in viscoelasticity polymer flooding based on oil-water two-phase flow

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum Science 2024年第1期21卷 343-351页

作者： Yang Wang jia Zhang shi-Long Yang Ze-Xuan Xu shi-Qing Cheng National Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing102249China

Polymer flooding in fractured wells has been extensively applied in oilfields to enhance oil *** contrast to water,polymer solution exhibits non-Newtonian and nonlinear behavior such as effects of shear thinning and shear thickening,polymer convection,diffusion,adsorption retention,inaccessible pore volume and reduced effective ***,the flux density and fracture conductivity along the hydraulic fracture are generally non-uniform due to the effects of pressure distribution,formation damage,and proppant *** this paper,we present an oil-water two-phase flow model that captures these complex non-Newtonian and nonlinear behavior,and non-uniform fracture characteristics in fractured polymer *** hydraulic fracture is firstly divided into two parts:high-conductivity fracture near the wellbore and low-conductivity fracture in the far-wellbore section.A hybrid grid system,including perpendicular bisection(PEBI)and Cartesian grid,is applied to discrete the partial differential flow equations,and the local grid refinement method is applied in the near-wellbore region to accurately calculate the pressure distribution and shear rate of polymer *** combination of polymer behavior characterizations and numerical flow simulations are applied,resulting in the calculation for the distribution of water saturation,polymer concentration and reservoir *** with the polymer flooding well with uniform fracture conductivity,this non-uniform fracture conductivity model exhibits the larger pressure difference,and the shorter bilinear flow period due to the decrease of fracture flow ability in the far-wellbore *** field case of the fall-off test demonstrates that the proposed method characterizes fracture characteristics more accurately,and yields fracture half-lengths that better match engineering reality,enabling a quantitative segmented characterization of the near-wellbore section with high fracture conductivity and th

关键词： Polymer flooding Non-Newtonian fluid Non-uniform fracture conductivity Two-phase flow Pressure transient analysis

Higher palaeoelevation in the Baoshan Basin:Implications for landscape evolution at the southeastern margin of the Tibetan Plateau

在线全文

学校读者我要写书评

暂无评论

Journal of Palaeogeography 2024年第3期13卷 563-580页

作者： Yong-jiang Huang Hao-ran Zong shi-Tao Zhang Arata Momohara Jin-Jin Hu Lin-Bo jia Yun-Heng Ji Zhe-Kun Zhou Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of BotanyChinese Academy of SciencesKunming 650201Yunnan ProvinceChina College of Forestry Shandong Agricultural UniversityTai'an 271018Shandong ProvinceChina Faculty of Land Resource Engineering Kunming University of Science and TechnologyKunming 650093Yunnan ProvinceChina Graduate School of Horticulture Chiba UniversityChiba 271-8510Japan Key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMengla 666303Yunnan ProvinceChina

Surface uplift at the southeastern margin of the Tibetan Plateau has been widely studied,but more palaeoaltimetry data are required to better understand the elevation history of this geologically complex *** this study,fossil leaves of Abies(Pinaceae),a cool-temperate element,recovered from the latest Miocene-Pliocene Yangyi Formation of the southern Baoshan Basin,were used as a proxy to estimate the local *** on the regional modern altitude range(2100-4280 m)of the genus as well as regional temperature discrepancy(1.5℃)between the past and present,the palaeoelevation of the study area was calculated to be>2360 m above sea level as compared to 1670 m at *** result suggests that the southern Baoshan Basin experienced pronounced uplift prior to the time of fossil deposition,probably as a result of crustal shortening and thickening of the northern Baoshan Terrane during the *** infer that surface growth in areas south of the Dali Basin may have been greater than previously interpreted,and that a widespread plateau or plateau patches higher than 2000 m probably extended southwards into at least the Baoshan Basin by the latest *** also infer that the elevation of the southern Baoshan Basin has decreased by at least 690 m since then,in contrast to most other scenarios in which the elevation of the southeastern margin of the Tibetan Plateau has increased or remained close to modern levels since the late *** major cause of the inferred altitude decline is likely tectonic *** a transtensional graben basin,the Baoshan Basin has experienced pull-apart and base-fall movement since the late Miocene,which would reduce the altitude of its southern part located on the hanging *** erosion associated with the increased summer rainfall might also have played a role especially in reducing the local relief,although its contribution can be *** study provides one of the few palaeoelevation

关键词： Abies Lapse rate Palaeoaltimetry Surface uplift Tectonic movement Tibetan plateau

AWeb Application Fingerprint Recognition Method Based on Machine Learning

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2024年第7期140卷 887-906页

作者： Yanmei shi Wei Yu Yanxia Zhao Yungang jia School of Integrated Circuit Science and Engineering Tianjin University of TechnologyTianjin300382China College of International Business Zhejiang Yuexiu UniversityShaoxing312030China School of Public Administration Zhejiang Gongshang UniversityHangzhou310018China Tianjin Branch of National Computer Network Emergency Response Technical Team/Coordination Center of China Tianjin300100China

Web application fingerprint recognition is an effective security technology designed to identify and classify web applications,thereby enhancing the detection of potential threats and *** fingerprint recognition methods,which rely on preannotated feature matching,face inherent limitations due to the ever-evolving nature and diverse landscape of web *** response to these challenges,this work proposes an innovative web application fingerprint recognition method founded on clustering *** method involves extensive data collection from the Tranco List,employing adjusted feature selection built upon Wappalyzer and noise reduction through truncated SVD dimensionality *** core of the methodology lies in the application of the unsupervised OPTICS clustering algorithm,eliminating the need for preannotated *** transforming web applications into feature vectors and leveraging clustering algorithms,our approach accurately categorizes diverse web applications,providing comprehensive and precise fingerprint *** experimental results,which are obtained on a dataset featuring various web application types,affirm the efficacy of the method,demonstrating its ability to achieve high accuracy and broad *** novel approach not only distinguishes between different web application types effectively but also demonstrates superiority in terms of classification accuracy and coverage,offering a robust solution to the challenges of web application fingerprint recognition.

关键词： Web application fingerprint recognition unsupervised learning clustering algorithm feature extraction automated testing network security

Phosphotungstic acid immobilized on amino-functionalized TS-1 zeolite as a solid acid catalyst for the synthesis of tributyl citrate

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第6期70卷 199-210页

作者： Pei Li Bianfang shi Junyao Shen ran Cui Wenze Guo Ling Zhao Zhenhao Xi State Key Laboratory of Chemical Engineering East China University of Science and TechnologyShanghai 200237China Key Laboratory of Smart Manufacturing in Energy Chemical Process Ministry of EducationEast China University of Science and TechnologyShanghai 200237China

The amino-functionalization of TS-1 zeolite followed by immobilization of phosphotungstic acid(HPW)was presented to prepare a strong solid acid catalyst for the synthesis of bio-based tributyl citrate from the esterification of citric acid and n-butanol.γ-Aminopropyltriethoxysilane(APTES)was first grafted on the TS-1 zeolite via the condensation reactions with surface hydroxyl groups,and subsequently the HPW was immobilized via the reaction between the amino groups and the protons from HPW-forming strong ionic *** Keggin structure of HPW and MFI topology of TS-1 zeolite were well maintained after the *** amino-functionalization generated abundant uniformly distributed active sites on TS-1 for HPW immobilization,which promoted the dispersity,abundance,as well as the stability of the acid *** tetrahedrally coordinated framework titanium and non-framework titania behaved as weak Lewis acid sites,and the protons from the immobilized HPW acted as the moderate or strong Brønsted acid *** optimized TBC yield of 96.2%(mol)with a conversion of-COOH of 98.1%(mol)was achieved at 150℃for 6 h over the HPW immobilized on amino-functionalized *** catalyst exhibited good stability after four consecutive reaction runs,where the activity leveled off at still a relatively high level after somewhat deactivation possibly caused by the leaching of a small portion of weakly anchored APTES or HPW.

关键词： Amino-functionalization Phosphotungstic acid TS-1 zeolite Esterification Tributyl citrate

Microstructural characterization and mechanical properties of(TiC+TiB)/TA15 composites prepared by an in-situ synthesis method

在线全文

学校读者我要写书评

暂无评论

China Foundry 2024年第2期21卷 168-174页

作者： Zhi-yong Zhang jiao-jiao Cheng jia-qi Xie shi-bing Liu Kun shi Jun Zhao Shenyang Research Institute of Foundry Co. Ltd.CAMShenyang 110022China National Key Laboratory of Advanced Casting Technologies Shenyang 110022China

Titanium matrix composites reinforced with ceramic particles are considered a promising engineering material due to their combination of high specific strength,low density,and high *** this study,the TA15-based composites reinforced with a volume fraction of 10% to 25%(TiB+TiC)were prepared using powder metallurgy and casting *** characterization and phase constitution were examined using optical microscopy(OM),scanning electron microscopy(SEM),and X-ray diffraction(XRD).In addition,the microhardness,room temperature(RT)and high temperature(HT)tensile properties of the composites were *** revealed that the reinforcements are distributed uniformly even in the composites with a high volume of TiB and ***,as the volume fraction exceeds 15%,TiB and TiC particles become coarsening and exhibit rod-like and dendritic-like *** increases gradually from 321.2 HV for the base alloy to a maximum of 473.3 HV as the reinforcement increases to 25vol.%.Tensile test results indicate that a reinforcement volume fraction above 20% is beneficial for enhancing tensile strength and yield strength at high temperatures,but it has an adverse effect on room temperature ***,if the reinforcement volume fraction is below 20%,it can improve high-temperature elongation when the temperature exceeds 600℃.

关键词： titanium matrix composites microstucture microhardness tensile properties in-situ synthesis

Survey on performance of vertical slot and nature-like fishways at Angu hydropower station, Southwest China

在线全文

学校读者我要写书评

暂无评论

Water Science and Engineering 2024年第1期17卷 83-91页

作者： Jun-jian Sun jia-yue shi Qi Zhang Xiao-tao shi Jun-jun Tan PowerChina Huadong Engineering Corporation Limited Hangzhou 311122China Hubei International Science and Technology Cooperation Base of Fish Passage China Three Gorges UniversityYichang 443002China

To restore dam-blocked natural fish migratory passages,a growing number of artificial fishways have been built in water conservancy and hydropower projects in *** Angu hydropower station involved diverse important fish habitats in the lower reaches of the Daduhe River in Southwest ***,a vertical slot fishway(VSF)and a nature-like fishway(NLF)were built near the backwater area of the reservoir to connect the upstream and downstream *** and aquatic ecological surveys were conducted after the completion of the project to estimate the fish passing effect of the two *** results indicated that both fishways were in effective operation and could maintain the desired hydrodynamic conditions and be used by several local fish *** the survey,149 fish from 15 species and 111 fish from 17 species were captured by the traps in the VSF and NLF,respectively,while 1263 fish from 27 species were found in the downstream *** species captured in the VSF were not found in the NLF,and vice versa,which implied the different preferences of ***,3789 signals including 2099 upward ones and 1690 downward ones were monitored with an ultrasonic fish detector at the inlet of the *** findings revealed the characteristics of fish species observed in and near the fishways and provided valuable insights into the different fish passing capabilities of VSFandNLF.

关键词： Vertical slot fishway Nature-like fishway Aguatic ecological survey Fishwaymonitoring Statistical analysis

Cognitive Jammers Assisted Covert Communication in Cognitive Radio Networks

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Communications 2024年第9期21卷 75-89页

作者： Liu Changjun shi jia Tie Zhuangzhuang Wang Yongchao The State Key Laboratory of Integrated Services Networks Xidian UniversityXi’an 710071China

In this work,we investigate the covert communication in cognitive radio(CR)networks with the existence of multiple cognitive jammers(CJs).Specifically,the secondary transmitter(ST)helps the primary transmitter(PT)to relay information to primary receiver(PR),as a reward,the ST can use PT's spectrum to transmit private information against the eavesdropper(Eve)under the help of one selected cognitive jammer(CJ).Meanwhile,we propose three jammer-selection schemes,namely,link-oriented jammer selection(LJS),min-max jammer selection(MMJS)and random jammer selection(RJS).For each scheme,we analyze the average covert throughput(ACT)and covert outage probability(COP).Our simulation results show that CJ is helpful to ST's covert communication,the expected minimum detection error probability and ACT can be significantly improved with the increase of false alarm of ***,the LJS scheme achieves best performance in ACT and COP,followed by RJS scheme,and MMJS scheme shows the worst performance.

关键词： cognitive jammer cognitive radio covert communication performance analysis

An approximate analytical model for unconventional reservoir considering variable matrix blocks and simultaneous matrix depletion

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第1期21卷 352-365页

作者： Kai-Xuan Qiu jia Li Dong Feng shi-Ming Wei Gang Lei jiangmen Laboratory of Carbon Science and Technology Jiangmen529100GuangdongChina The Hong Kong University of Science and Technology(Guangzhou) Guangzhou511400GuangdongChina China University of Geosciences(Beijing) Beijing100083China China University of Petroleum(Beijing) Beijing102249China China University of Geosciences(Wuhan) Wuhan430074HubeiChina Shenzhen Research Institute China University of GeosciencesShenzhen518063GuangdongChina

In regard to unconventional oil reservoirs,the transient dual-porosity and triple-porosity models have been adopted to describe the fluid flow in the complex fracture *** has been proven to cause inaccurate production evaluations because of the absence of matrix-macrofracture *** addition,most of the existing models are solved analytically based on Laplace transform and numerical ***,an approximate analytical solution is derived directly in real-time space considering variable matrix blocks and simultaneous matrix *** simplify the derivation,the simultaneous matrix depletion is divided into two parts:one part feeding the macrofractures and the other part feeding the ***,a series of partial differential equations(PDEs)describing the transient flow and boundary conditions are constructed and solved analytically by ***,a relationship between oil rate and production time in real-time space is *** new model is verified against classical analytical *** the microfracture system and matrix-macrofracture communication is neglected,the result of the new model agrees with those obtained with the dual-porosity and triple-porosity model,***,the new model also has an excellent agreement with the numerical *** model is then applied to two actual tight oil wells completed in western Canada sedimentary *** identifying the flow regime,the solution suitably matches the field production data,and the model parameters are *** these output parameters,we can accurately forecast the production and even estimate the petrophysical properties.

关键词： Analytical solution Unconventional reservoir Variable matrix Simultaneous flow