检索结果-南通市图书馆

Optimal power allocation for multi-user OFDM and distributed antenna cognitive radio with RoF

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 2010年第6期17卷 41-46,71页

作者： ge wen-dong JI Hong SI Peng-bo LI Yi School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing 100876 China School of Electronics Information and Control Engineering Beijing University of Technology Beijing 100022 China

In cognitive radio （CR）,power allocation plays an important role in protecting primary user from disturbance of secondary user. Some existing studies about power allocation in CR utilize ＇interference temperature＇ to achieve this protection,which might not be suitable for the OFDM-based CR. Thus in this paper,power allocation problem in multi-user orthogonal frequency division multiplexing （OFDM） and distributed antenna cognitive radio with radio over fiber （RoF） is firstly modeled as an optimization problem,where the limitation on secondary user is not ＇interference temperature＇,but that total throughput of primary user in all the resource units （RUs） must be beyond the given threshold. Moreover,based on the theorem about maximizing the total throughput of secondary user,equal power allocation algorithm is introduced. Furthermore,as the optimization problem for power allocation is not convex,it is transformed to be a convex one with geometric programming,where the solution can be obtained using duality and Karush-Kuhn-Tucker （KKT） conditions to form the optimal power allocation algorithm. Finally,extensive simulation results illustrate the significant performance improvement of the optimal algorithm compared to the existing algorithm and equal power allocation algorithm.

关键词： cognitive radio power allocation OFDM distributed antenna convex optimization radio over fiber (RoF)

Distribution of gamasid mites on small mammals in Yunnan Province, China

在线全文

学校读者我要写书评

暂无评论

Insect Science 2007年第1期14卷 71-78页

作者： LI-PU LUO XIAN-GUO GUO TI-JUN QIAN DIAN WU XING-YUANMEN wen-ge dong Institute of Pathogens and Vectors Dali University Dali Yunnan China

An investigation of gamasid mites on the body surface of small mammals was carried out in Yunnan Province of China from 1990 to 2004. The small mammal hosts were captured from 25 counties which represent five geographical subregions, namely Middle Subregion of Hengduan Mountains, Southern Subregion of Hengduan Mountains, Eastern Plateau Subregion of Yunnan, Western Plateau Subregion of Yunnan and Southern Moun- tainous Subregion of Yunnan. The captured 10 803 small mammal hosts belong to nine families, 29 genera and 52 species in four orders （Rodentia, Insectivora, Scandentia and Lagomorpha）. A total of 68 571 gamasid mites were collected from the body surface of the captured small mammal hosts and all the gamasid mites were identified to 10 families, 33 genera and 112 species. This paper lists all the mite species, together with their taxonomic position （genera and families） and their corresponding hosts. Much more mite species were found in the Middle Subregion of Hengduan Mountains than in other geographical subregions. The total individuals of mites and small mammals in the Middle Subregion of Hengduan Mountains are also the most plentiful in the five geographical subregions. Three dominant mite species and three dominant small mammal hosts were determined as the dominant species in the investigated areas of Yunnan Province. The dominant hosts are Rattus flavipectus （which accounts for 34.85% of the total individuals）, Apodemus chevrieri （13.43%） and Rattus norvegicus （10.40%） while the dominant gamasid mite species are Laelaps nuttalli （Hirst, 1915）（27.84%）, Laelaps echidninus （Berlese, 1887）（18.38%） and Laelaps guizhouensis （Gu et Wang, 1981）（14.79%）. The results showed the high species diversity of gamasid mites in Yunnan Province and the uneven distribution feature in different subregions.

关键词： Arachnida China fauna gamasid mites small mammal Yunnan

Carbonic anhydrase-like enzymes in the formation of Lycopodium alkaloid

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

Chinese Journal of Natural Medicines 2024年第3期22卷 193-194页

作者： dong Huiwen ge Huiming State key Laboratory of Pharmaceutical Biotechnology Institute of Functional BiomoleculesSchool of Life SciencesNanjing UniversityNanjing 210023China

Plant alkaloids,renowned for their structural diversity and bioactivity,are prominent in both modern and traditional medicine[1].Unraveling the intricacies of plant alkaloid biosynthesis could pave the way for the discovery of new natural products and *** may also shed light on the roles of existing pathways in host biology and provide valuable tools for metabolic engineering in plants and microbes[2].Unlike other major classes of plant natural products,such as terpenoids and polyketides,the formation of alkaloid scaffolds does not conform to a uniform chemical theme or depend on a singular enzyme class[3].A case in point is the Lycopodium alkaloids in the Lycopodiaceae family,where the enzymes responsible for their core scaffold construction remain unidentified[4].

关键词： Lycopodium alkaloid Carbonic anhydrase-like enzymes Biosynthesis

EG-STC: An Efficient Secure Two-Party Computation Scheme Based on Embedded GPU for Artificial Intelligence Systems

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第6期79卷 4021-4044页

作者： Zhenjiang dong Xin ge Yuehua Huang Jiankuo dong Jiang Xu School of Computer Science Nanjing University of Posts and TelecommunicationsNanjing210023China School of Computer Nanjing University of Information Science and TechnologyNanjing210044China

This paper presents a comprehensive exploration into the integration of Internet of Things(IoT),big data analysis,cloud computing,and Artificial Intelligence(AI),which has led to an unprecedented era of *** delve into the emerging trend of machine learning on embedded devices,enabling tasks in resource-limited ***,the widespread adoption of machine learning raises significant privacy concerns,necessitating the development of privacy-preserving *** such technique,secure multi-party computation(MPC),allows collaborative computations without exposing private *** its potential,complex protocols and communication interactions hinder performance,especially on resource-constrained *** to enhance efficiency have been made,but scalability remains a *** the success of GPUs in deep learning,lever-aging embedded GPUs,such as those offered by NVIDIA,emerges as a promising ***,we propose an Embedded GPU-based Secure Two-party Computation(EG-STC)framework for Artificial Intelligence(AI)*** the best of our knowledge,this work represents the first endeavor to fully implement machine learning model training based on secure two-party computing on the Embedded GPU *** experimental results demonstrate the effectiveness of *** an embedded GPU with a power draw of 5 W,our implementation achieved a secure two-party matrix multiplication throughput of 5881.5 kilo-operations per millisecond(kops/ms),with an energy efficiency ratio of 1176.3 kops/ms/***,leveraging our EG-STC framework,we achieved an overall time acceleration ratio of 5–6 times compared to solutions running on server-grade *** solution also exhibited a reduced runtime,requiring only 60%to 70%of the runtime of previously best-known methods on the same *** summary,our research contributes to the advancement of secure and efficient machine learning implementations on resource-constrained embedded

关键词： Secure two-party computation embedded GPU acceleration privacy-preserving machine learning edge computing

Carbon efficiency modeling and optimization of solar-powered cellular networks

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

Science China(Information Sciences) 2024年第5期67卷 228-243页

作者： Yuxi ZHAO Xiaohu ge wen YAN Tao HAN Yi ZHONG School of Electronic Information and Communications Huazhong University of Science and Technology Huawei Technology Co. Ltd.

As wireless communication traffic experiences rapid growth, the carbon emissions caused by the communication industry are also on the rise. To achieve “carbon neutrality”, researchers are considering the use of renewable energy sources to power cellular networks, thereby reducing carbon emissions. However, a challenge arises when using renewable energy, specifically owing to the unpredictable nature of both the energy consumption of the cellular network and the power generation from renewable sources. This inconsistency results in low renewable energy utilization and reduced carbon efficiency. Herein, we construct a carbon efficiency model of solar-powered cellular networks using practical data from solar radiation. We propose a mechanism that alternately optimizes the performance of the renewable energy network and the cellular network. This approach is based on convex optimization theory and the Dinkelback algorithm, and it leads to the design of a carbon efficiency optimization algorithm. This algorithm aims to improve the carbon efficiency of cellular networks and reduce their carbon emissions. Simulation results demonstrate that our optimization scheme yields a maximum improvement of 2.56 × 108bps/g in the carbon efficiency of the cellular network as compared to conventional power allocation schemes such as the traditional water filling method and heuristic energy sharing and charge/discharge algorithms.

关键词： cellular networks renewable energy carbon efficiency convex optimization theory dinkelbach

Resource allocation for cognitive WLAN over fiber

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Harbin Institute of Technology(New Series) 2011年第5期18卷 119-122页

作者：葛文栋纪红司鹏搏李曦 Key Laboratory of Universal Wireless Communication Ministry of EducationBeijing University of Posts and Telecommunications College of Electronics Information and Control Engineering Beijing University of Technology

In this paper,a novel WLAN system,Cognitive WLAN over Fiber (CWLANoF),is introduced in the first ***,when CWLANoF has more channels than STAs,a new channel allocation scheme is proposed using the Hungarian algorithm,which is demonstrated to be the optimal ***,when CWLANoF has fewer channels than STAs,it is possible for more than one STA to share the same channel simultaneously based on the new features of *** the power control scheme is proposed for this kind of sharing,considering efficiency and ***,extensive simulation results illustrate the significant performance improvement of the proposed channel allocation scheme and power control scheme.

关键词： WLANs cognitive radio channel allocation power control Hungarian algorithm

Association between central serous chorioretinopathy and Helicobacter pylori infection: a systematic review and Meta-analysis

在线全文

学校读者我要写书评

暂无评论

International Journal of Ophthalmology(English edition) 2024年第6期17卷 1120-1127页

作者： Da-wen Wu Fei-Peng Jiang ge ge Mei-Xia Zhang Department of Ophthalmology West China HospitalSichuan UniversityChengdu 610041Sichuan ProvinceChina Research Laboratory of Macular Disease West China HospitalSichuan UniversityChengdu 610041Sichuan ProvinceChina

AIM:To investigate the association between central serous chorioretinopathy(CSC)and Helicobacter pylori(Hp)by summarizing all available ***:The Scopus,Embase,EBSCO,PubMed,Web of Science,and Cochrane Library databases for all relevant studies published from inception to October 2022 were searched,and manually searched for relevant reference lists as a *** investigating the association between CSC and Hp infection were ***,8 case-control studies were included in the Meta-analysis after study ***:The results showed no significant correlation between Hp infection and CSC[odds ratio(OR)1.89,95%confidential interval(CI)0.58–6.15,I2=96%,P=0.29].After subgroup analysis based on the degree of development of the study(developing/developed countries),it was found that the results of the two subgroups were the same as the whole,and no significant difference between the two subgroups ***-regression showed that the effect of sample size on heterogeneity among studies was more prominent(P<0.01,adjusted R^(2)=89.72%),which can explain 89.72%of the sources of ***:This Meta-analysis reveals no significant correlation between Hp infection and CSC,which still warrants further well-designed extensive sample studies to reach a more reliable conclusion and promote a better understanding of the treatment of CSC.

关键词： central serous chorioretinopathy Helicobacter pylori infection retinal diseases Meta-analysis

Reinforcement learning based adaptive control for uncertain mechanical systems with asymptotic tracking

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

Defence Technology（防务技术） 2024年第4期34卷 19-28页

作者： Xiang-long Liang Zhi-kai Yao Yao-wen ge Jian-yong Yao School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing210094China College of Automation&College of Artificial Intelligence Nanjing University of Post and TelecommunicationNanjing210023China

This paper mainly focuses on the development of a learning-based controller for a class of uncertain mechanical systems modeled by the Euler-Lagrange *** considered system can depict the behavior of a large class of engineering systems,such as vehicular systems,robot manipulators and *** these systems are often characterized by highly nonlinear characteristics,heavy modeling uncertainties and unknown perturbations,therefore,accurate-model-based nonlinear control approaches become *** by the challenge,a reinforcement learning(RL)adaptive control methodology based on the actor-critic framework is investigated to compensate the uncertain mechanical *** approximation inaccuracies caused by RL and the exogenous unknown disturbances are circumvented via a continuous robust integral of the sign of the error(RISE)control *** from a classical RISE control law,a tanh(·)function is utilized instead of a sign(·)function to acquire a more smooth control *** developed controller requires very little prior knowledge of the dynamic model,is robust to unknown dynamics and exogenous disturbances,and can achieve asymptotic output ***,co-simulations through ADAMS and MATLAB/Simulink on a three degrees-of-freedom(3-DOF)manipulator and experiments on a real-time electromechanical servo system are performed to verify the performance of the proposed approach.

关键词： Adaptive control Reinforcement learning Uncertain mechanical systems Asymptotic tracking

Immune regulation of the gut-brain axis and lung-brain axis involved in ischemic stroke

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第3期19卷 519-528页

作者： Xiaodi Xie Lei Wang Shanshan dong ShanChun ge Ting Zhu Institute of Neuroregeneration&Neurorehabilitation Department of PathophysiologySchool of Basic MedicineQingdao UniversityQingdaoShandong ProvinceChina School of Traditional Chinese Pharmacy China Pharmaceutical UniversityNanjingJiangsu ProvinceChina Department of Rehabilitation Medicine The Affiliated Hospital of Qingdao UniversityQingdaoShandong ProvinceChina

Local ischemia often causes a series of inflammatory reactions when both brain immune cells and the peripheral immune response are *** the human body,the gut and lung are regarded as the key reactional targets that are initiated by brain ischemic *** microorganisms play an important role in immune regulation and metabolism and affect blood-brain barrier *** addition to the relationship between peripheral organs and central areas and the intestine and lung also interact among each ***,we review the molecular and cellular immune mechanisms involved in the pathways of inflammation across the gut-brain axis and lung-brain *** found that abnormal intestinal flora,the intestinal microenvironment,lung infection,chronic diseases,and mechanical ventilation can worsen the outcome of ischemic *** review also introduces the influence of the brain on the gut and lungs after stroke,highlighting the bidirectional feedback effect among the gut,lungs,and brain.

关键词： enteric glia cells gut microbiota gut-brain axis immune response inflammation ischemic stroke lung-brain axis microglia