检索结果-南通市图书馆

On the parameterized complexity of minimum/maximum degree vertex deletion on several special graphs

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2023年第4期17卷 97-107页

作者： Jia LI wenjun LI Yongjie yang Xueying yang School of Information Engineering Hunan Industry PolytechnicChangsha 410036China Hunan Provincial Key Laboratory of Intelligent Processing of Big Data on Transportation School of Computer and Communication EngineeringChangsha University of Science and TechnologyChangsha 410015China Chair of Economic Theory Saarland UniversitySaarbrücken 66123Germany

In the minimum degree vertex deletion problem,we are given a graph,a distinguished vertex in the graph,and an integer κ,and the question is whether we can delete at most κ vertices from the graph so that the distinguished vertex has the unique minimum degree.The maximum degree vertex deletion problem is defined analogously but here we want the distinguished vertex to have the unique maximum degree.It is known that both problems areΨ-hard and fixed-parameter intractable with respect to some natural parameters.In this paper,we study the(parameterized)complexity of these two problems restricted to split graphs,p-degenerate graphs,and planar graphs.Our study provides a comprehensive complexity landscape of the two problems restricted to these special graphs.

关键词： minimum degree maximum degree vertex deletion split graphs planar graphs parameterized complexity

A Fast Cartesian Grid-Based Integral Equation Method for Unbounded Interface Problems with Non-Homogeneous Source Terms

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Computational Physics 2023年第6期33卷 208-234页

作者： Jiahe yang wenjun Ying School of Mathematical Sciences Shanghai Jiao Tong UniversityMinhangShanghai 200240P.R.China Department of Mathematics MOE-LSC and Institute of Natural SciencesShanghai Jiao Tong UniversityMinhangShanghai 200240P.R.China

This work presents a fast Cartesian grid-based integral equation method for unbounded interface problems with non-homogeneous source terms.The unbounded interface problem is solved with boundary integral equation methods such that infinite boundary conditions are satisfied naturally.This work overcomes two difficulties.The first difficulty is the evaluation of singular integrals.Boundary and volume integrals are transformed into equivalent but much simpler bounded interface problems on rectangular domains,which are solved with FFT-based finite difference solvers.The second one is the expensive computational cost for volume integrals.Despite the use of efficient interface problem solvers,the evaluation for volume integrals is still expensive due to the evaluation of boundary conditions for the simple interface problem.The problem is alleviated by introducing an auxiliary circle as a bridge to indirectly evaluate boundary conditions.Since solving boundary integral equations on a circular boundary is so accurate,one only needs to select a fixed number of points for the discretization of the circle to reduce the computational cost.Numerical examples are presented to demonstrate the efficiency and the second-order accuracy of the proposed numerical method.

关键词： Interface problem unbounded domain boundary integral equation kernel-free method auxiliary circle Cartesian grid method fast algorithm

Sustained delivery of vascular endothelial growth factor mediated by bioactive methacrylic anhydride hydrogel accelerates peripheral nerve regeneration after crush injury

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2022年第9期17卷 2064-2071页

作者： Wanlin Xu Yifan Wu Hao Lu Yun Zhu Jinhai Ye Wenjun Yang Department of Oral and Maxillofacial-Head and Neck Oncology Shanghai Ninth People’s HospitalShanghai Jiao Tong University School of MedicineCollege of StomatologyShanghai Jiao Tong UniversityNational Center for StomatologyNational Clinical Research Center for Oral DiseasesShanghai Key Laboratory of StomatologyShanghaiChina Jiangsu Key Laboratory of Oral Diseases Department of Oral and Maxillofacial SurgeryThe Affiliated Stomatological Hospital of Nanjing Medical UniversityNanjingJiangsu ProvinceChina

Neurotrophic factors,currently administered orally or by intravenous drip or intramuscular injection,are the main method for the treatment of peripheral nerve crush injury.However,the low effective drug concentration arriving at the injury site results in unsatisfactory outcomes.Therefore,there is an urgent need for a treatment method that can increase the effective drug concentration in the injured area.In this study,we first fabricated a gelatin modified by methacrylic anhydride hydrogel and loaded it with vascular endothelial growth factor that allowed the controlled release of the neurotrophic factor.This modified gelatin exhibited good physical and chemical properties,biocompatibility and supported the adhesion and proliferation of RSC96 cells and human umbilical vein endothelial cells.When injected into the epineurium of crushed nerves,the composite hydrogel in the rat sciatic nerve crush injury model promoted nerve regeneration,functional recovery and vascularization.The results showed that the modified gelatin gave sustained delivery of vascular endothelial growth factors and accelerated the repair of crushed peripheral nerves.

关键词： bioactive material controlled release crush injury hydrogel muscle function nerve regeneration peripheral nerve sciatic function index vascular endothelial growth factor vascularization

The Stability of Imitation Dynamics with Continuously Distributed Delays

在线全文

学校读者我要写书评

暂无评论

系统科学与复杂性学报:英文版 2023年第5期36卷 2067-2081页

作者： FANG Caiya yang Hui PI Jinxiu WU wenjun School of Mathematics and Statistics Guizhou UniversityGuizhou 550025China Guizhou Provincial Key Laboratory for Games Decision Making and Control SystemsGuiyang 550025China

This paper investigates imitation dynamics with continuously distributed delay.In realistic technological,economic,and social environments,individuals are involved in strategic interactions simultaneously while the influences of their decision-making may not be observable instantaneously.It shows that there exists a time delay effect.Different distributions of delay are further considered to efficiently lucubrate the stability of interior equilibrium in the imitation dynamics with continuous distributions of delay in the two-strategy game contexts.Precisely,when the delay follows the uniform distributions and Gamma distributions,the authors present that interior equilibrium can be asymptotically stable.Furthermore,when the probability density of the delay is general density,the authors also determine a sufficient condition for stability derived from the expected delay.Last but not least,the interested but uncomplicated Snowdrift game is utilized to demonstrate our theoretical results.

关键词： Continuous distributed delay evolutionary games imitation dynamics stability

Power generation maximization of distributed photovoltaic systems using dynamic topology reconfiguration

在线全文

学校读者我要写书评

暂无评论

Protection and Control of Modern Power Systems 2022年第1期7卷 508-522页

作者： Xiaolun Fang Qiang yang wenjun Yan College of Electrical Engineering Zhejiang UniversityHangzhou 310027China Zhejiang Lab Hangzhou 310000China

The‘mismatch losses’problem is commonly encountered in distributed photovoltaic(PV)power generation systems.It can directly reduce power generation.Hence,PV array reconfiguration techniques have become highly popular to minimize the mismatch losses.In this paper,a dynamical array reconfiguration method for Total-Cross-Ties(TCT)and Series-Parallel(SP)interconnected PV arrays is proposed.The method aims to improve the maximum power output generation of a distributed PV array in different mismatch conditions through a set of inverters and a switching matrix that is controlled by a dynamic and scalable reconfiguration optimization algorithm.The structures of the switching matrix for both TCT-based and SP-based PV arrays are designed to enable flexible alteration of the electrical connections between PV strings and inverters.Also,the proposed reconfiguration solution is scalable,because the size of the switching matrix deployed in the proposed solution is only determined by the numbers of the PV strings and the inverters,and is not related to the number of PV modules in a string.The performance of the proposed method is assessed for PV arrays with both TCT and SP interconnections in different mismatch conditions,including different partial shading and random PV module failure.The average optimization time for TCT and SP interconnected PV arrays is 0.02 and 3 s,respectively.The effectiveness of the proposed dynamical reconfiguration is confirmed,with the aver-age maximum power generation improved by 8.56%for the TCT-based PV array and 6.43%for the SP-based PV array compared to a fixed topology scheme.

关键词： Dynamical reconfiguration Inverter Switching matrix Mismatch losses

Bacterial inactivation,DNA damage,and faster ATP degradation induced by ultraviolet disinfection

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2020年第1期14卷 153-162页

作者： Chao yang wenjun Sun Xiuwei Ao School of Environment Tsinghua UniversityBeijing 100084China

The efficacy of ultraviolet(UV)disinfection has been validated in numerous studies by using culturebased methods.However,the discovery of viable but non-culturable bacteria has necessitated the investigation of UV disinfection based on bacterial viability parameters.We used quantitative polymerase chain reaction(qPCR)to investigate DNA damage and evaluated adenosine triphosphate(ATP)to indicate bacterial viability.The results of qPCR effectively showed the DNA damage induced by UV when using longer gene amplicons,in that sufficiently long amplicons of both 16S and gadA indicated that the UV induced DNA damages.The copy concentrations of the long amplicons of 16S and gadA decreased by 2.38 log/mL and 1.88 log/mL,respectively,after exposure to 40 mJ/cm^2 lowpressure UV.After UV exposure,the ATP level in the bacteria did not decrease instantly.Instead it decreased gradually at a rate that was positively related to the UV fluence.For low-pressure UV,this rate of decrease was slow,but for medium pressure UV,this rate of decrease was relatively high when the UV fluence reached 40 mJ/cm^2.At the same UV fluence,the ATP level in the bacteria decreased at a faster rate after exposure to medium-pressure UV.

关键词： UV disinfection DNA damage qPCR ATP

A multiple-target mRNA-LNP vaccine induces protective immunity against experimental multi-serotype DENV in mice

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Virologica Sinica 2022年第5期37卷 746-757页

作者： Lihong He Wenqiang Sun Limin yang wenjun Liu Jing Li CAS Key Laboratory of Pathogenic Microbiology and Immunology Institute of MicrobiologyChinese Academy of SciencesBeijing100101China Institute of Infectious Diseases Shenzhen Bay LaboratoryShenzhenGuangdong518000China University of Chinese Academy of Sciences Beijing100049China Institute of Microbiology Center for Biosafety Mega-ScienceChinese Academy of SciencesBeijing100101China

Dengue virus(DENV)is a mosquito-borne virus with a rapid spread to humans,causing mild to potentially fatal illness in hundreds of millions of people each year.Due to the large number of serotypes of the virus,there remains an unmet need to develop protective vaccines for a broad spectrum of the virus.Here,we constructed a modified mRNA vaccine containing envelope domain III(E-DIII)and non-structural protein 1(NS1)coated with lipid nanoparticles.This multi-target vaccine induced a robust antiviral immune response and increased neutralizing antibody titers that blocked all four types of DENV infection in vitro without significant antibodydependent enhancement(ADE).In addition,there was more bias for Th1 than Th2 in the exact E-DIII and NS1-specific T cell responses after a single injection.Importantly,intramuscular immunization limited DENV transmission in vivo and eliminated vascular leakage.Our findings highlight that chimeric allogeneic structural and non-structural proteins can be effective targets for DENV vaccine and that they can prevent the further development of congenital DENV syndrome.

关键词： Dengue virus(DENV) mRNA vaccine Envelope domain III(E-DIII) Non-structural protein 1(NS1) Multi-serotype Immune response

Robust Nonsingular Fixed Time Terminal Sliding Mode Control for Atmospheric Pollution Detection Lidar Scanning Mechanism

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2023年第2期36卷 500-523页

作者： KANG Yu yang Yuxiao CHEN Cai Lüwenjun ZHAO Yunbo Department of Automation University of Science and Technology of ChinaHefei 230027China Institute of Advanced Technology University of Science and Technology of ChinaHefei 230027China State Key Laboratory of Fire Science University of Science and Technology of ChinaHefei 230027China

A robust nonsingular fixed time terminal sliding mode control scheme with a time delay disturbance observer is proposed for atmospheric pollution detection lidar scanning mechanism(APDL-SM)system.Distinguished from the conventional terminal sliding mode control methods,the authors design a novel fixed-time terminal sliding surface,the convergence time of sliding mode phase of which has a constant upper bound that is designable by adjusting only one parameter.Moreover,in order to overcome the problem of unknown upper bound of lumped uncertainty including model uncertainty,friction effect and external disturbances from the port environment,the authors propose a time delay disturbance observer to provide an estimation for the system lumped uncertainty.By using the Lyapunov synthesis,the explicit analysis of the convergence time upper bound are performed.Finally,simulation studies are conducted on the APDL-SM system to show the fast convergence rate and strong robustness of the proposed control scheme.

关键词： Atmospheric pollution detection lidar fixed time terminal sliding mode time delay disturbance observer tracking control

Analysis and Optimization of Validation Procedure in Blockchain-Enhanced Wireless Resource Sharing and Transactions

在线全文

学校读者我要写书评

暂无评论

中国通信:英文版 2023年第10期20卷 245-261页

作者： Enyu Du yang Gao wenjun Wu Zhaoxin yang Yufeng Yin Pengbo Si Faculty of Information Technology Beijing University of TechnologyBeijing 100124China

To ensure the security of resource and intelligence sharing in 6G,blockchain has been widely adopted in wireless communications and applications.Although blockchain can ensure the traceability and non-tamperability of data in the concatenated blocks,it cannot guarantee the honest behaviors of users in the application before the generation of transactions.Thus,additional technologies are required to ensure that the source of blockchain data is reliable.In this paper,the detailed procedure is designed for the application-oriented task validation in the blockchainenhanced computing resource sharing and transactions in ultra dense networks(UDN).The corresponding queuing model is built and analyzed with the consideration of the wireless re-transmission and the probability of malicious deception by users.Based on the analysis results,the UDN deployment is optimized to save network cost while ensuring latency performance.Numerical results verify our analysis,and the optimized system deployment including the number and service capacities of both base stations and mobile edge computing(MEC)servers are also given with various system settings.

关键词： blockchain queuing theory wireless resource sharing validation procedure