A presentation of hyperbolic unitary group is an important part in the unitary group. The group KG 2,n (R) plays an elementary role in presentation of unitary group. It is proved that KG 2,n(R)=1 for n≥2 over a...A presentation of hyperbolic unitary group is an important part in the unitary group. The group KG 2,n (R) plays an elementary role in presentation of unitary group. It is proved that KG 2,n(R)=1 for n≥2 over a ring R with division ring of quotients, using a new method, and a presentation of GE n(R) is given.展开更多
A presentation of hyperbolic unitary group is an important part in the unitary group. The group KG 2,n (R) plays an elementary role in presentation of unitary group. It is proved that KG 2,n(R)=1 for n≥2 over a...A presentation of hyperbolic unitary group is an important part in the unitary group. The group KG 2,n (R) plays an elementary role in presentation of unitary group. It is proved that KG 2,n(R)=1 for n≥2 over a ring R with division ring of quotients, using a new method, and a presentation of GE n(R) is given.展开更多
This article investigates the time-varying output group formation tracking control(GFTC)problem for heterogeneous multi-agent systems(HMASs)under switching topologies.The objective is to design a distributed control s...This article investigates the time-varying output group formation tracking control(GFTC)problem for heterogeneous multi-agent systems(HMASs)under switching topologies.The objective is to design a distributed control strategy that enables the outputs of the followers to form the desired sub-formations and track the outputs of the leader in each subgroup.Firstly,novel distributed observers are developed to estimate the states of the leaders under switching topologies.Then,GFTC protocols are designed based on the proposed observers.It is shown that with the distributed protocol,the GFTC problem for HMASs under switching topologies is solved if the average dwell time associated with the switching topologies is larger than a fixed threshold.Finally,an example is provided to illustrate the effectiveness of the proposed control strategy.展开更多
IEEE 802.11ax,which is an emerging WLAN standard,aims at providing highly efficient communication in ultra-dense wireless networks.However,due to a large number of stations(STAs)in the ultra-dense device deployment sc...IEEE 802.11ax,which is an emerging WLAN standard,aims at providing highly efficient communication in ultra-dense wireless networks.However,due to a large number of stations(STAs)in the ultra-dense device deployment scenarios,the potentially high packet collision rate significantly decreases the communication efficiency of WLAN.In this paper,we propose an adaptive STA grouping scheme to overcome this dense network challenge in IEEE 802.11ax by using Buffer State Report(BSR)based Two-stage Mechanism(BTM).In order to achieve the optimal efficiency of BSR delivery,we analyze the functional relationship between STA number in group and Resource Unit(RU)efficiency.Based on this analysis results,an adaptive STA grouping algorithm with variable group size is proposed to achieve efficient grouping in BTM.The numerical results demonstrate that the proposed adaptive BTM grouping algorithm significantly improves the BSR delivery efficiency and the throughput of overall system and each STA in the ultra-dense wireless network.展开更多
In this paper, we prove that if a torsion nilpotent group G is a weak semi-radicable group, then every Sylow p-group Gp is a central-by-finite p-group, and moreover Gp's center ζ(GP) satisfies |ζ(GP) : (ζ(GP))P...In this paper, we prove that if a torsion nilpotent group G is a weak semi-radicable group, then every Sylow p-group Gp is a central-by-finite p-group, and moreover Gp's center ζ(GP) satisfies |ζ(GP) : (ζ(GP))P| <∞, that is, ζ(GP) = D×F, where D is a divisible Abelian group, and F is a finite Abelian group.展开更多
【目的】对广西玉米种质材料进行类群结构分析和核心种质构建,为广西玉米种质资源的高效利用、多样性保护及品种改良提供参考依据。【方法】利用SNP分子标记对523份具有重要育种价值的玉米种质材料进行遗传多样性分析,基于主成分判别分...【目的】对广西玉米种质材料进行类群结构分析和核心种质构建,为广西玉米种质资源的高效利用、多样性保护及品种改良提供参考依据。【方法】利用SNP分子标记对523份具有重要育种价值的玉米种质材料进行遗传多样性分析,基于主成分判别分析(Discriminant analysis of principal components,DAPC)法、K-means聚类法和系谱关系分析材料的群体结构和遗传差异;采用模拟退火算法,在30.00%~10.00%取样范围内,以5.00%梯度取样比例逐级探索构建广西玉米核心种质。【结果】通过7888个SNP分子标记分析发现,523份玉米种质材料的基因多样性(Genetic diversity,GD)平均值为0.391,多态信息含量(Polymorphism information content,PIC)平均值为0.309,遗传多样性总体上处于中度多态。基于DAPC法和K-means聚类法,可将523份玉米种质材料划分为4个类群,分别为Suwan群、墨黄群、Reid群和Non-Reid群,其遗传多态性排序为Suwan群<墨黄群<Non-Reid群<Reid群,其中,Reid群的遗传多样性最高(GD=0.398,PIC=0.313),Suwan群的多态性最低(GD=0.280,PIC=0.226)。分子方差分析结果表明,4个类群内的遗传变异差异显著,占总遗传变异的83.1%,类群间的遗传变异为16.9%,Suwan群与Non-Reid群的遗传距离最大,其次是Suwan群与Reid群,Suwan群与墨黄群的遗传距离最小。按照30.00%~10.00%的取样比例,采取模拟退火算法逐级构建核心种质,经遗传多样性分析及不同取样比例t检验,最终确定取样比例为17.20%,筛选出90份核心种质并构建形成核心种质库。【结论】利用SNP分子标记可将523份广西玉米种质材料划分为Suwan群、墨黄群、Reid群和Non-Reid群4个类群,且各类群间存在显著遗传差异,能代表广西玉米主要杂种优势类群;以17.20%的取样比例筛选形成的90份玉米核心种质库,其遗传多样性评价结果与523份玉米种质材料聚类的4个类群保持一致,具有较好的代表性。展开更多
Neuroscience (also known as neurobiology) is a science that studies the structure, function, development, pharmacology and pathology of the nervous system. In recent years, C. Cotardo has introduced coding theory into...Neuroscience (also known as neurobiology) is a science that studies the structure, function, development, pharmacology and pathology of the nervous system. In recent years, C. Cotardo has introduced coding theory into neuroscience, proposing the concept of combinatorial neural codes. And it was further studied in depth using algebraic methods by C. Curto. In this paper, we construct a class of combinatorial neural codes with special properties based on classical combinatorial structures such as orthogonal Latin rectangle, disjoint Steiner systems, groupable designs and transversal designs. These neural codes have significant weight distribution properties and large minimum distances, and are thus valuable for potential applications in information representation and neuroscience. This study provides new ideas for the construction method and property analysis of combinatorial neural codes, and enriches the study of algebraic coding theory.展开更多
文摘A presentation of hyperbolic unitary group is an important part in the unitary group. The group KG 2,n (R) plays an elementary role in presentation of unitary group. It is proved that KG 2,n(R)=1 for n≥2 over a ring R with division ring of quotients, using a new method, and a presentation of GE n(R) is given.
文摘A presentation of hyperbolic unitary group is an important part in the unitary group. The group KG 2,n (R) plays an elementary role in presentation of unitary group. It is proved that KG 2,n(R)=1 for n≥2 over a ring R with division ring of quotients, using a new method, and a presentation of GE n(R) is given.
文摘This article investigates the time-varying output group formation tracking control(GFTC)problem for heterogeneous multi-agent systems(HMASs)under switching topologies.The objective is to design a distributed control strategy that enables the outputs of the followers to form the desired sub-formations and track the outputs of the leader in each subgroup.Firstly,novel distributed observers are developed to estimate the states of the leaders under switching topologies.Then,GFTC protocols are designed based on the proposed observers.It is shown that with the distributed protocol,the GFTC problem for HMASs under switching topologies is solved if the average dwell time associated with the switching topologies is larger than a fixed threshold.Finally,an example is provided to illustrate the effectiveness of the proposed control strategy.
文摘IEEE 802.11ax,which is an emerging WLAN standard,aims at providing highly efficient communication in ultra-dense wireless networks.However,due to a large number of stations(STAs)in the ultra-dense device deployment scenarios,the potentially high packet collision rate significantly decreases the communication efficiency of WLAN.In this paper,we propose an adaptive STA grouping scheme to overcome this dense network challenge in IEEE 802.11ax by using Buffer State Report(BSR)based Two-stage Mechanism(BTM).In order to achieve the optimal efficiency of BSR delivery,we analyze the functional relationship between STA number in group and Resource Unit(RU)efficiency.Based on this analysis results,an adaptive STA grouping algorithm with variable group size is proposed to achieve efficient grouping in BTM.The numerical results demonstrate that the proposed adaptive BTM grouping algorithm significantly improves the BSR delivery efficiency and the throughput of overall system and each STA in the ultra-dense wireless network.
文摘In this paper, we prove that if a torsion nilpotent group G is a weak semi-radicable group, then every Sylow p-group Gp is a central-by-finite p-group, and moreover Gp's center ζ(GP) satisfies |ζ(GP) : (ζ(GP))P| <∞, that is, ζ(GP) = D×F, where D is a divisible Abelian group, and F is a finite Abelian group.
文摘【目的】对广西玉米种质材料进行类群结构分析和核心种质构建,为广西玉米种质资源的高效利用、多样性保护及品种改良提供参考依据。【方法】利用SNP分子标记对523份具有重要育种价值的玉米种质材料进行遗传多样性分析,基于主成分判别分析(Discriminant analysis of principal components,DAPC)法、K-means聚类法和系谱关系分析材料的群体结构和遗传差异;采用模拟退火算法,在30.00%~10.00%取样范围内,以5.00%梯度取样比例逐级探索构建广西玉米核心种质。【结果】通过7888个SNP分子标记分析发现,523份玉米种质材料的基因多样性(Genetic diversity,GD)平均值为0.391,多态信息含量(Polymorphism information content,PIC)平均值为0.309,遗传多样性总体上处于中度多态。基于DAPC法和K-means聚类法,可将523份玉米种质材料划分为4个类群,分别为Suwan群、墨黄群、Reid群和Non-Reid群,其遗传多态性排序为Suwan群<墨黄群<Non-Reid群<Reid群,其中,Reid群的遗传多样性最高(GD=0.398,PIC=0.313),Suwan群的多态性最低(GD=0.280,PIC=0.226)。分子方差分析结果表明,4个类群内的遗传变异差异显著,占总遗传变异的83.1%,类群间的遗传变异为16.9%,Suwan群与Non-Reid群的遗传距离最大,其次是Suwan群与Reid群,Suwan群与墨黄群的遗传距离最小。按照30.00%~10.00%的取样比例,采取模拟退火算法逐级构建核心种质,经遗传多样性分析及不同取样比例t检验,最终确定取样比例为17.20%,筛选出90份核心种质并构建形成核心种质库。【结论】利用SNP分子标记可将523份广西玉米种质材料划分为Suwan群、墨黄群、Reid群和Non-Reid群4个类群,且各类群间存在显著遗传差异,能代表广西玉米主要杂种优势类群;以17.20%的取样比例筛选形成的90份玉米核心种质库,其遗传多样性评价结果与523份玉米种质材料聚类的4个类群保持一致,具有较好的代表性。
文摘Neuroscience (also known as neurobiology) is a science that studies the structure, function, development, pharmacology and pathology of the nervous system. In recent years, C. Cotardo has introduced coding theory into neuroscience, proposing the concept of combinatorial neural codes. And it was further studied in depth using algebraic methods by C. Curto. In this paper, we construct a class of combinatorial neural codes with special properties based on classical combinatorial structures such as orthogonal Latin rectangle, disjoint Steiner systems, groupable designs and transversal designs. These neural codes have significant weight distribution properties and large minimum distances, and are thus valuable for potential applications in information representation and neuroscience. This study provides new ideas for the construction method and property analysis of combinatorial neural codes, and enriches the study of algebraic coding theory.
