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The Minimum Stretch Spanning Tree Problem for Typical Graphs

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Acta Mathematicae Applicatae Sinica 2021年第3期37卷 510-522页

作者： Lan lin yi-xun lin School of Electronics and Information Engineering Tongji UniversityShanghai 200092China School of Mathematics and Statistics Zhengzhou UniversityZhengzhou 450001China

With applications in communication networks,the minimum stretch spanning tree problem is to find a spanning tree T of a graph G such that the maximum distance in T between two adjacent vertices is *** problem has been proved NP-hard and fixed-parameter polynomial algorithms have been obtained for some special families of *** this paper,we concentrate on the optimality characterizations for typical classes of *** determine the exact formulae for the complete k-partite graphs,split graphs,generalized convex graphs,and several planar grids,including rectangular grids,triangular grids,and triangulated-rectangular grids.

关键词： communication network spanning tree optimization tree spanner max-stretch congestion

The Early X-ray Afterglows of Optically Bright and Dark Gamma-Ray Bursts

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Chinese Journal of Astronomy and Astrophysics 2006年第5期6卷 555-560页

作者： yi-Qing lin Astronomy Department Nanjing University Nanjing 210093

A systematic study on the early X-ray afterglows of both optically bright and dark gamma-ray bursts （B-GRBs and D-GRBs） observed by Swift is presented. Our sample includes 25 GRBs of which 13 are B-GRBs and 12 are D-GRBs. Our results show that the distributions of the X-ray afterglow fluxes （Fx）, the gamma-ray fluxes （Sγ）, and the ratio （Rγ,x） are similar for the two kinds of GRBs, that any observed differences should be simply statistical fluctuation. These results indicate that the progenitors of the two kinds of GRBs are of the same population with comparable total energies of explosion. The suppression of optical emission in the D-GRBs should result from circumburst but not from their central engine.

关键词： gamma rays bursts

Relativistic Filamentation of Intense Laser Beam in Inhomogeneous Plasma

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Plasma Science and Technology 2012年第12期14卷 1054-1058页

作者： XIA Xiongping yi lin Department of Physics Huazhong University of Science and Technology Wuhan 430074China Department of Science Guilin University of Technology Guilin 541004 China

In the paper, relativistic filamentation of intense laser beam in inhomogeneous plasma is investigated based on the nonparaxial region theory. The results show that, relativistic nonlinearity plays a main role in beam filamentation, and plasma inhomogeneity further reinforces the beam filamentation. The combination effects of relativistic nonlinearity and plasma inhomogeneity can generate particularly intense and short pulse laser. However, plasma inhomogeneity leads to obvious filamentation instability.

关键词： relativistic filamentation relativistic nonlinearity plasma inhomoheneous

Phase separation in RNA biology

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Journal of Genetics and Genomics 2021年第10期48卷 872-880页

作者： yi lin Xiaofeng Fang School of Life Sciences Tsinghua UniversityBeijing 100084China

The formation of biomolecular condensates via liquid-liquid phase separation(LLPS)is an advantageous strategy for cells to organize subcellular compartments for diverse *** involvement of LLPS is more widespread and overrepresented in RNA-related biological *** is in part because that RNAs are intrinsically multivalent macromolecules,and the presence of RNAs affects the formation,dissolution,and biophysical properties of biomolecular condensates formed by *** studies have illustrated how LLPS participates in RNA transcription,splicing,processing,quality control,translation,and *** interconnected regulation between LLPS and RNAs ensures tight control of RNA-related cellular functions.

关键词： Phase separation RNA biology Condensates Membrane-less organelle

Comparison between Swift and pre-Swift gamma-ray bursts

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Research in Astronomy and Astrophysics 2009年第6期9卷 682-686页

作者： yi-Qing lin Department of Mathematics and Physics Xiamen University of Technology Xiamen 361024 China

The gamma-ray burst （GRB） mission Swift has made a much deeper GRB survey than any previous one. I present a systematical comparison between GRB samples detected with pre-Swift missions and those from Swift, in order to investigate whether they show any statistical difference. Our Swift GRB sample includes the bursts detected by Swift/BAT before 2007 September. With both flux-limited surveys and redshift-known GRB samples, I show that, apparently, the observed distributions of the redshifts, T90, and log N- log P are significantly different, but not for the spectral hardness ratio, fluence and Eiso. The redshifts of the Swift GRB sample are statistically larger than those of pre-Swift GRBs, with a mean of 1.95±0.17 compared to ～ 1 for pre-Swift GRBs. The cosmological effect on the observables is thus considerable. This effect on the spectral hardness ratio, fluence and Eiso is cancelled out, and the distributions of these quantities indeed do not show significant differences between the Swift and pre-Sw/ft GRBs. Taking this effect into account, I found that the corrected distributions of T90 for long GRBs and log N - log P observed with Swift/BAT are also consistent with those observed with CGRO/BATSE. These results indicate that the Swift and pre-Swift GRBs are from the same population.

关键词： gamma-rays bursts

Geometrically modeling 2D scattered points: a review of the potential for methodologically improving mobile laser scanning in data processing

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International Journal of Digital Earth 2014年第6期7卷 432-449页

作者： yi lin Juha Hyyppa Department of Remote Sensing and Photogrammetry Finnish Geodetic Institute MasalaFinland

As a state-of-the-art mapping technology,mobile laser scanning(MLS)is increasingly applied to fields such as digital presentations of city ***,its application has recently met a bottleneck in data *** has been found that conventional methods for geometrically modeling 3D scattered points are inadequate when dealing with large volumes of MLS *** fact,this is a challenge that has already been noted in the MLS-relevant fields,*** sensing,robot perception,and pattern recognition.A variety of algorithms under the schematic frame of analysis,modeling and synthesis(AMS)have been developed in these *** AMS paradigm is to first extract the implicit geometric primitives within each scan profile by geometrically modeling its 2D scattered points(GM2P).The resultant 2D geometric primitives are then integrated to restore the real 3D geometrical *** this process,GM2P is a kernel procedure whereby a review of the GM2P algorithms is assumed to be of significance for developing new efficient algorithms for geometrically modeling 3D scattered *** idea is supported by MLS sampling often being executed via parallel scan ***,the results of the literature review indicate an avenue for methodologically improving MLS in data processing.

关键词： MLS geometrically modeling scattered points GM2P AMS scan profile

SYSTEM RELIABILITY OF ASSURED ACCURACY RATE FOR MULTI-STATE COMPUTER NETWORKS FROM SERVICE LEVEL AGREEMENTS VIEWPOINT

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Journal of Systems Science and Systems Engineering 2014年第2期23卷 196-211页

作者： yi-Kuei lin Cheng Fu Huang Department of Industrial Management National Taiwan University of Science & Technology

From the viewpoint of service level agreements, the transmission accuracy rate is one of critical performance indicators to assess internet quality for system managers and customers. Under the assumption that each arc＇s capacity is deterministic, the quickest path problem is to find a path sending a specific of data such that the transmission time is minimized. However, in many real-life networks such as computer networks, each arc has stochastic capacity, lead time and accuracy rate. Such a network is named a multi-state computer network. Under both assured accuracy rate and time constraints, we extend the quickest path problem to compute the probability that d units of data can be sent through multiple minimal paths simultaneously. Such a probability named system reliability is a performance indicator to provide to managers for understanding the ability of system and improvement. An efficient algorithm is proposed to evaluate the system reliability in terms of the approach of minimal paths.

关键词： Assured accuracy rate service level agreement (SLA) transmission time multi-state computer network (MSCN) system reliability

Adsorption and Decomposition of NH3 on Ni/Pt（111） and Ni/WC（001） Surfaces： A First-Principles Study

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Chinese Journal of Chemical Physics 2016年第6期29卷 710-716,I0002页

作者： Ai-ai Shen yi-lin Cao Schoolof:ChemistryandChemicalEnEineerin~.HenanNormalUniversity.Xinxi~n~453007.China

Density functional theory was used to study the NH3 behavior on Ni monolayer covered Pt（111） and WC（001）. The electronic structure of the surfaces, and the adsorption and decomposition of NH3 were calculated and compared. Ni atoms in the monolayer behave different from that in Ni（111）. More dz2 electrons of Ni in monolayer covered systems were shifted to other regions compared to Ni（111）, charge density depletion on this orbital is crucial to NH3 adsorption. NH3 binds more stable on Ni/Pt（lll） and Ni/WC（001） than on Ni（111）, the energy barriers of the first N-H bond scission were evidently lower on Ni/Pt（111） and Ni/WC（001） than on Ni（111）, these are significant to NH3 decomposition. N recombination is the rate-limiting step, high reaction barrier implies that N2 is produced only at high temperatures. Although WC has similar properties to Pt, differences of the electronic structure and catalytic activities are observed for Ni/Pt（111） and Ni/WC （001）, the energy barrier for the rate-determined step increases on Ni/WC（001） instead of decreasing on Ni/Pt（lll） when compared to Ni（111）. the N recombination barrier by modifying To design cheaper and better catalysts, reducing Ni/WC（001） is a critical question to be solved.

关键词： Ni monolayer Electronic structure NH3 decomposition Density functionaltheory

ESTIMATED AND EXACT SYSTEM RELIABILITIES OF A MAINTAINABLE COMPUTER NETWORK

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Journal of Systems Science and Systems Engineering 2011年第2期20卷 229-248页

作者： yi-Kuei lin Ping-Chen CHANG Department of Industrial Management National Taiwan University of Science & Technology Taipei 106 Taiwan China

This paper presents an algorithm to evaluate estimated and exact system reliabilities for a computer network in the cloud computing *** the quality of service（QOS） viewpoint,the computer network should be maintained when falling to a specific state such that it cannot afford enough capacity to satisfy ***,the transmission time should be concerned as ***,the data can be sent through several disjoint minimal paths simultaneously to shorten the transmission *** the maintenance budget B and time constraint T,we evaluate the system reliability that d units of data can be sent from the cloud to the client through multiple *** procedures are integrated in the proposed algorithm-an estimation procedure for estimated system reliability and an adjusting procedure utilizing the branch-and-bound approach for exact system ***,the estimated system reliability with lower bound and upper bound,and exact system reliability are computed by applying the recursive sum of disjoint products（RSDP） algorithm.

关键词： System reliability maintenance network flows branch-and-bound approach estimation