检索结果-南通市图书馆

Capacity analysis of based-regular-topologies cognitive wireless mesh networks with power control

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2013年第5期20卷 71-78页

作者： KOU Ke-hao TANG Bi-hua LIU kai-ming MA Tao School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing Key Laboratory of Work Safety Intelligent Monitoring Beijing University of Posts and Telecommunications

Capacity analysis is a fundamental and essential work for evaluating the performance of cognitive wireless mesh network （CWMN） which is considered a promising option for the future network. Power control is an efficient way to avoid interference and improve capacity of wireless mesh networks. In this paper, a quantitative result of the per-node average throughput capacity of CWMN with power control is deduced for the first time, which is much helpful for understanding the limitations of CWMN. Firstly, under the large-scale channel fading model and protocol interference model, a closed-form expression for the maximum channel capacity of each node with power control is presented, under the constraint that the interference tolerated by the primary users （PUs） does not exceed a threshold. And then, with the deduced channel capacity result, the per-node average throughput capacity of CWMN is derived based on two regular topologies, i.e. square topology and triangle topology. The simulation results indicate that the capacity is effectively improved with power control, and affected by topology, tolerated interference threshold, the number of cognitive users （CUs） and primary users （PUs）.

关键词： capacity cognitive wireless mesh networks power control regular topologies

Is it necessary to use the entire root as a donor when transferring contralateral C7 nerve to repair median nerve？

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2018年第1期13卷 94-99页

作者： kai-ming Gao Jie Lao Wen-jie Guan Jing-jing Hu Department of Hand Surgery Huashan Hospital Fudan University Shanghai China Key Laboratory of Hand Reconstruction Ministry of Health Shanghai China Shanghai Key Laboratory of Peripheral Nerve and Microsurgery Shanghai China Nursing Department Huashan Hospital Fudan University Shanghai China

If a partial contralateral C7 nerve is transferred to a recipient injured nerve, results are not satisfactory. However, if an entire contralateral C7 nerve is used to repair two nerves, both recipient nerves show good recovery. These findings seem contradictory, as the above two methods use the same donor nerve, only the cutting method of the contralateral C7 nerve is different. To verify whether this can actually result in different repair effects, we divided rats with right total brachial plexus injury into three groups. In the entire root group, the entire contralateral C7 root was transected and transferred to the median nerve of the affected limb. In the posterior division group, only the posterior division of the contralateral C7 root was transected and transferred to the median nerve. In the entire root ＋ posterior division group, the entire contralateral C7 root was transected but only the posterior division was transferred to the median nerve. After neurectomy,the median nerve was repaired on the affected side in the three groups. At 8, 12, and 16 weeks postoperatively, electrophysiological examination showed that maximum amplitude, latency, muscle tetanic contraction force, and muscle fiber cross-sectional area of the flexor digitorum superficialis muscle were significantly better in the entire root and entire root ＋ posterior division groups than in the posterior division group. No significant difference was found between the entire root and entire root ＋ posterior division groups. Counts of myelinated axons in the median nerve were greater in the entire root group than in the entire root ＋ posterior division group, which were greater than the posterior division group. We conclude that for the same recipient nerve, harvesting of the entire contralateral C7 root achieved significantly better recovery than partial harvesting, even if only part of the entire root was used for transfer. This result indicates that the entire root should be used as a dono

关键词： nerve regeneration peripheral nerve injury brachial plexus injury avulsion injury contralateral C7 transfer nerve root entire root partial root median nerve ulnar nerve animal experiment neural regeneration

Intelligent geochemical interpretation of mass chromatograms:Based on convolution neural network

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第2期21卷 752-764页

作者： kai-ming Su Jun-Gang Lu Jian Yu Zi-Xing Lu Shi-Jia Chen Hubei Key Laboratory of Petroleum Geochemistry and Environment Wuhan430100HubeiChina College of Resources and Environment Yangtze UniversityWuhan430100HubeiChina School of Geoscience and Technology Southwest Petroleum UniversityChengdu610500SichuanChina Changqing Oilfield Company PetroChinaXi'an710021ShaanxiChina

Gas chromatography-mass spectrometry(GC-MS)is an extremely important analytical technique that is widely used in organic *** is the only approach to capture biomarker features of organic matter and provides the key evidence for oil-source correlation and thermal maturity ***,the conventional way of processing and interpreting the mass chromatogram is both timeconsuming and labor-intensive,which increases the research cost and restrains extensive applications of this *** overcome this limitation,a correlation model is developed based on the convolution neural network(CNN)to link the mass chromatogram and biomarker features of samples from the Triassic Yanchang Formation,Ordos Basin,*** this way,the mass chromatogram can be automatically *** research first performs dimensionality reduction for 15 biomarker parameters via the factor analysis and then quantifies the biomarker features using two indexes(*** and PMI)that represent the organic matter thermal maturity and parent material type,***,training,interpretation,and validation are performed multiple times using different CNN models to optimize the model structure and hyper-parameter setting,with the mass chromatogram used as the input and the obtained MI and PMI values for supervision(label).The optimized model presents high accuracy in automatically interpreting the mass chromatogram,with R2values typically above 0.85 and0.80 for the thermal maturity and parent material interpretation results,*** significance of this research is twofold:(i)developing an efficient technique for geochemical research;(ii)more importantly,demonstrating the potential of artificial intelligence in organic geochemistry and providing vital references for future related studies.

关键词： Organic geochemistry Biomarker Mass chromatographic analysis Automated interpretation Convolution neural network Machine learning

Surface Temperature Changes Projected by FGOALS Models under Low Warming Scenarios in CMIP5 and CMIP6

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2021年第2期38卷 203-220页

作者： Shang-Min LONG kai-ming HU Gen LI Gang HUANG Xia QU Key Laboratory of Marine Hazards Forecasting Ministry of Natural ResourcesHohai UniversityNanjing 210098China College of Oceanography Hohai UniversityNanjing 210098China State key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics and Center for Monsoon System Research Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China

To meet the low warming targets proposed in the 2015 Paris Agreement,substantial reduction in carbon emissions is needed in the *** is important to know how surface climates respond under low warming *** present study investigates the surface temperature changes under the low-forcing scenario of Representative Concentration Pathways(RCP2.6)and its updated version(Shared Socioeconomic Pathways,SSP1-2.6)by the Flexible Global Ocean-Atmosphere-Land System(FGOALS)models participating in phases 5 and 6 of the Coupled Model Intercomparison Project(CMIP5 and CMIP6,respectively).In both scenarios,radiative forcing(RF)first increases to a peak of 3 W m^−2 around 2045 and then decreases to 2.6 W m^−2 by *** mean surface air temperature rises in all FGOALS models when RF increases(RF increasing stage)and declines or holds nearly constant when RF decreases(RF decreasing stage).The surface temperature change is distinct in its sign and magnitude between the RF increasing and decreasing stages over the land,Arctic,North Atlantic subpolar region,and Southern ***,the regional surface temperature change pattern displays pronounced model-to-model spread during both the RF increasing and decreasing stages,mainly due to large intermodel differences in climatological surface temperature,ice-albedo feedback,natural variability,and Atlantic Meridional Overturning Circulation *** pattern of tropical precipitation change is generally anchored by the spatial variations of relative surface temperature change(deviations from the tropical mean value)in the FGOALS ***,the projected changes in the updated FGOALS models are closer to the multi-model ensemble mean results than their predecessors,suggesting that there are noticeable improvements in the future projections of FGOALS models from CMIP5 to CMIP6.

关键词： surface temperature low warming targets Arctic amplification AMOC Southern Ocean

Synthesis of a new aromatic dianhydride monomer and related polyimide

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2009年第2期20卷 229-230页

作者： Yun Xia Wei ming Guang Ma Guo Hu Zhao Sheng Ying Li ming kai Chen College of Chemistry and Environmental Science Lanzhou City University Lanzhou 730070 China Department of Chemistry Lanzhou University Lanzhou 730000 China

A novel aromatic dianhydride monomer, 3,3′-oxybis[（3,4-dicarboxyphenoxy）phenol] dianhydride, was successfully synthe- sized in three steps using 3,3′-oxybis（phenol） as starting material, which was reacted with 4,4′-oxydianiline （ODA） via a conventional thermal or chemical imidization method to produce a new polyimide. The resulting polyimide exhibited excellent solubility, and film-forming capability.

关键词： Polyimidc Dianhydridc Solubility

Microstructure recognition of steels by machine learning based on visual attention mechanism

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第4期31卷 909-923页

作者： Xing-yu Chen Lin Cheng Cheng-yang Hu Yu-peng Zhang kai-ming Wu The State Key Laboratory of Refractories and Metallurgy Hubei Province Key Laboratory of Systems Science on Metallurgical ProcessingInternational Research Institute for Steel TechnologyCollaborative Center on Advanced SteelsWuhan University of Science and TechnologyWuhan 430081HubeiChina Metals Valley and Band(Foshan)Metallic Composite Materials Co. Ltd.Foshan 528000GuangdongChina

U-Net has achieved good performance with the small-scale datasets through skip connections to merge the features of the low-level layers and high-level layers and has been widely utilized in biomedical image segmentation as well as recent microstructure image segregation of the *** representative visual attention mechanism modules,named as squeeze-and-excitation networks,convolutional block attention module,and extended calibration algorithm,were intro-duced into the traditional U-Net architecture to further improve the prediction *** is found that compared with the original U-Net architecture,the evaluation index of the improved U-Net architecture has been significantly improved for the microstructure segmentation of the steels with the ferrite/martensite composite microstructure and pearlite/ferrite composite microstructure and the complex martensite/austenite island/bainite microstructure,which demonstrates the advantages of the utilization of the visual attention mechanism in the microstructure *** reasons for the accuracy improvement were discussed based on the feature maps analysis.

关键词： Microstructure recognition-Steel Machine learning Visual attention mechanism Visualization

Revisiting Persistent Indexing Structures on Intel Optane DCPersistent Memory

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Computer Science & Technology 2021年第1期36卷 140-157页

作者： Heng Bu ming-kai Dong Ji-Fei Yi Bin-Yu Zang Hai-Bo Chen Institute of Parallel and Distributed Systems Shanghai Jiao Tong UniversityShanghai 200240China

Persistent indexing structures are proposed in response to emerging non-volatile memory(NVM)to provide high performance yet durable ***,due to the lack of real NVM hardware,many prior persistent indexing structures were evaluated via emulation,which varies a lot across different setups and differs from the real ***,Intel has released its Optane DC Persistent Memory Module(PMM),which is the first production-ready *** this paper,we revisit popular persistent indexing structures on PMM and conduct comprehensive evaluations to study the performance differences among persistent indexing structures,including persistent hash tables and persistent *** to the evaluation results,we find that Cacheline-Conscious Extendible Hashing(CCEH)achieves the best performance among all evaluated persistent hash tables,and Failure-Atomic ShifT B+-Tree(FAST)and Write Optimal Radix Tree(WORT)perform better than other ***,we find that the insertion performance of hash tables is heavily influenced by data locality,while the insertion latency of trees is dominated by the flush *** also uncover that no existing emulation methods accurately simulate PMM for all the studied data ***,we provide three suggestions on how to fully utilize PMM for better performance,including using clflushopt/clwb with sfence instead of clflush,flushing continuous data in a batch,and avoiding data access immediately after it is flushed to PMM.

关键词： persistent memory data structure performance Intel Optane DC persistent memory module(PMM)

Calculations of the 3-D neutronics for CH HCSB TBM with 3×3 sub-modules

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

核聚变与等离子体物理 2006年第3期26卷 170-175页

作者： ZHANG Guo-shu FENG kai-ming CHEN Rong-guang YUAN Tao LI Zeng-qiang Southwestern Institute of Physics Chengdu 610041

Using three dimension MCNP code and FENDL2.0 data library, neutronics calculation for a HCSB (helium cooling solid breeder ) TBM ( test blanket module ) with 3×3 sub-modules has been performed. Local tritium breeding ratio (TBR) of 0.907, total tritium generation rate of 0.0175 g· d-1, peak power density of 9.27MW· m-3 and total power deposit of 0.422MW·m-3 are obtained under neutron wall loading of 0.78MW·m-2 and duty factor of 22%.

关键词：融化覆盖中子物理 TBR 再生区

Effects of Zr addition on microstructure and toughness of simulated CGHAZ in high-strength low-alloy steels

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2019年第10期26卷 1117-1125页

作者： Jin-wei Lei kai-ming Wu Yu Li Ting-ping Hou Xing Xie RDKMisra The State Key Laboratory of Refractories and Metallurgy Hubei Province Key Laboratory of Systems Science on Metallurgical ProcessingInternational Research Institute for Steel TechnologyWuhan University of Science and TechnologyWuhan 430081HubeiChina Wuhan Second Ship Design and Research Institute Wuhan 430064HubeiChina Department of Metallurgical and Materials Engineering University of Texas at El PasoEl PasoTX 79968USA

The effect of Zr addition(0.005,0.013,and 0.054 wt.%)on the microstructure and toughness of simulated coarse-grained heat-affected zone in high-strength low-alloy steels was revealed using a Gleeble 2000 thermal *** was observed that elongated MnS inclusions were formed in the lowest Zr-containing steel,while only pure equiaxed ZrO2 existed in the 0.054Zr steel(Zr content of 0.054 wt.%).Complex oxide-sulfide inclusions(ZrO2+MnS)with size of(1.40±0.25)μtm were formed in 0.013Zr steel(Zr content of 0.013 wt.%).The complex inclusions refined the prior austenite grain,and the nucleation of acicular ferrite was promoted compared to those of 0.005Zr steel(Zr content of 0.005 wt.%)and 0.054Zr ***,the 0.013Zr steel possessed superior low-temperature impact toughness in relation to 0.005Zr and 0.054Zr ***,moderate Zr addition can be considered as an effective method to refine the structure and improve the mechanical properties of the coarse-grained heat-affected zone.

关键词： High-strength low-alloy steel Welding Heat-affected zone Heat input Zirconium addition