关于一类二阶共轭矩阵方程的解

考虑一类二阶共轭短阵方程BXAXB＋BXC＋CXB＋D＝0其中，B∈C^p*m,A∈C^n*n,C∈Cn*m,D∈Cm*m,在A＞O及A大于等于O，C或B为列满秩阵两种情况下，此方程可解的充分必要条件，并在有解的情况下，给出了妥的显式表示。     

矩阵方程AX+XB=D的最优解

考虑如下问题问题1.给定A∈SRm×m,B∈SRn×n,D∈Rm×n.记S1={X|X∈Rm×n,‖AX+XB-D‖=min},求∈S1,使得‖‖=min.问题2.给定A∈SRm×m,B∈SRn×n,D∈Rm×n.记S2={X|Xm×n,AX+BX=D},求∈S2,使得‖‖=min.借助于矩阵分解得出了问题2有解的充分必要条件,给出了问题1与问题2的解的表示.     

一类广义亚半正定矩阵反问题有解的条件

考虑如下问题 问题P 给定G∈Rn×m,设X∈Rn×k,B∈Rm×k,求A∈GRm×n≥O,使得AX=B其中,GRm×n≥O={A∈Rm×n|GA∈Rn×n≥O}. 本文讨论了问题P有解的充分必要条件,并在有解的情况下,给出了问题P的解的表示.     

一类广义中心对称矩阵的Procrustes问题

设R∈(C)n×n为广义反射矩阵满足R=RH=R-1≠±In.若G∈(C)n×n满足RGR=G,则称G为广义中心对称矩阵.所有n×n阶广义中心对称矩阵的全体记为GCS(C)n×n.考虑问题Ⅰ给定X,Y,D∈(C)n×p,求A,B∈GCS(C) n×n,使得‖AX-BY-D‖=min.问题Ⅱ给定,∈(C)n×n,求((A),(B))∈ψ(X,Y,D)使得‖(A,B)-((A),(B))‖=min(A,B)∈φ(X,Y,D)‖(A,B)-((A),(B))‖(ψ(X,Y,D)是问题Ⅰ的解集合).文中给出了问题Ⅰ的通解表示及问题Ⅱ的唯一解,的表达式.     

关于一类特殊形状线性方程组的可解性条件

在许多领域中,常需要解下列形状的线性方程组ABTB-Dxy=fg其中,A∈Rn×n,B∈Rm×n,D∈Rm×m,且A、D对称非负定.本文讨论此种特殊方程组的可解性及有唯一解的充分必要条件,并通过A、B、D、f、g表示出来.     

线性流形上对称正交对称矩阵反问题的最小二乘解

研究了以下问题问题Ⅰ给定X,B∈Rn×m,求A∈S,使得f(A)=‖AX-B ‖=min,其中S={A∈SRn×nP| AY=C,Y,C∈Rn×m}为非空流形.问题Ⅱ给定(A)∈Rn×n,求(A)∈SE,使得‖(A)-(A)‖=min ‖A-(A)‖,其中SE是问题Ⅰ的解集.A∈SE首先讨论了S非空的充要条件,并给出了其显式表示;其次研究了在线性流形S上反问题的最小二乘解及其最佳逼近,得到了问题Ⅰ的解和问题Ⅱ的唯一解.     

线性流形上广义反自反矩阵反问题的最小二乘解

设P∈C m×m、Q∈C n×n 是广义反射矩阵,若A∈C m×n满足A=-PAQ,则称A为关于矩阵对(P,Q)的广义反自反矩阵; 所有m×n阶关于矩阵对(P,Q)的广义反自反矩阵的全体记为Cam×n (P,Q). 设S={A∈Cam×n(P,Q)(|AZ-Y)=min,Z∈C n×k,Y∈C m×k}, 考虑问题Ⅰ给定X∈C n×p,B∈C m×p,求A∈S,使得(AX-B)=min,考虑问题Ⅱ给定(~A)∈C m×n,求(A)∈SE,使得(~A-~A)=infA∈SE(~A-A),其中SE是问题Ⅰ的解集合.首先讨论C m×na (P,Q)中元素的结构,然后给出问题Ⅰ解集合SE的通式,最后证明问题Ⅱ的解存在唯一,并给出解的表达式.     

一类可反对称化矩阵反问题的最小二乘解

利用矩阵的奇异值分解讨论了如下问题:已知X,B∈Rn×m,S=ASRn×n,A*∈Rn×m,令L={A∈S|‖AX-B‖=min},求AL,S∈L使‖A*-AL,S‖=infA∈L‖A*-A‖,给出了问题的通解表达式.     

对称正交反对称矩阵反问题的最小二乘解

设P∈Rn×n 满足PT=P,PTP=In,即P为对称正交矩阵.若A∈Rn×n 满足AT=A,(PA)T=-(PA),则称A为n阶对称正交反对称矩阵,所有n阶对称正交反对称矩阵全体记为ASRn×nP.考虑问题Ⅰ给定X,B∈Rn×m,求A∈ASRn×nP 使得‖AX-B‖=min 及问题Ⅱ给定∈Rn×n,求∈SE 使得 ‖-‖=infA∈SE‖-A‖,其中SE是问题Ⅰ的解集合.首先讨论了对称正交反对称矩阵的结构;然后给出了问题Ⅰ解集合SE的通式,并导出AX=B有解的条件及其通解表示;最后证明问题Ⅱ的解存在唯一,并给出解的表达式.     

一类Hermitian-Hamilton矩阵的广义特征值反问题

设J=OIn-InO是单位辛矩阵,若A∈C 2n×2n满足AH=A,(JA)H=JA,则称A为Hermitian-Hamilton矩阵,所有2n×2n阶Hermitian-Hamilton矩阵的全体记为HHC2n×2n.本文考虑问题P给定X∈C 2n×p,Λ=diag(λ1,λ2,…,λp)∈Cp×p,求A,B∈HHC2n×2n使得AX=BXΛ.文中首先讨论了HHC2n×2n中元素的结构,然后给出了问题P的解的表达式.     

Errata

正In the paper"Influence of Fouling Assemblage on the Corrosion Behaviour of Mild Steel in the Coastal Waters of The Gulf of Mannar,India"in Vol.12,No.4,Page:509,References were lost,and the two authors’biographies were identical.The correct text is shown below.We apologize to the authors and our readers for any inconvenience caused by the errors.     

Journal of Marine Science and Application 2014 Sum. Contents

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33rd International Conference on Ocean,Offshore and Arctic Engineering （OMAE2014）

正San Francisco,California,June 8-13,2014.OMAE 2014 is the ideal forum for researchers,engineers,managers,technicians and students from the scientific and industrial communities from around the world to:·meet and present advances in technology and its scientific support;·to exchange ideas and experiences whilst promoting technological progress and its application in industry·to promote international cooperation in ocean,offshore and arctic engineering.In line with the tradition of excellence of previous OMAE conferences,more than 900 technical papers are planned for presentation.Outreach for Engineers Specialty Forum This Specialty Forum is designed for students and professionals who may not be familiar with the Ocean and Offshore industry,as well as those who have just recently specialized in this field.     

联合作战计划和执行系统

全球指挥控制系统(GCCS)实施当前美国海军网络中心战信息基础设施的联合计划网络。联合作战计划和执行系统(JOPES)支持GCCS实现联合计划。JOPES有两类计划：时间不限的精密预案计划生成作战计划、方案计划或职能计划；时间敏感的危机行动计划生成作战命令或战役方案。前者在和平时期创建的作战计划是后者的计划基础，加速应付危机的能力。     

Recent progress on wave induced loading measurements in warships

Recent measurements of wave induced hull strain and flexure in RN warships are presented together with the derivation of the current design criteria for extreme hull girder bending loads. The history of the development of the shipboard instrumentation used is given and recent developments to improve the quality and ease of analysis of the data are described. An unexpectedly high transverse asymmetry in the longitudinal strains measured in destroyers is shown to be the result of a combination of vertical and lateral bending in oblique seas. Finally recent theoretical comparisons between the loading of Deep-Vee hulls and conventional UK rounded bilge hulls are presented which demonstrate the higher loading experienced by this type of hull form.     

The 11th International Conference on Hydrodynamics (ICHD 2014)

正19–24 October 2014 SingaporeCONFERENCE THEMES The overall aim of the ICHD Conference is to provide a forum for participants from around the world to review,discuss and present the latest developments in the broad discipline of hydrodynamics and fluid mechanics.The first International Conference on Hydrodynamics(ICHD)was initiated in 1994 in Wuxi,China.Since then,9 more ICHD conferences were held subsequently in Hong Kong,Seoul,Yokohama,Tainan,Perth,Ischia,Nantes,Shanghai and St Petersburg.Evidently the ICHD conference has become an important event among academics,researchers,engineers and operators,working in the fields closely related to the science and technology of hydrodynamics.The 11th ICHD will be held in Singapore in 2014.     

第十二届深水操作会议和展览会(英文)

正November 4-6,2014Moody Gardens HotelConvention Center/Galveston,TX The Deepwater Operations Conference and Exhibition is celebrating its 12th anniversary this year.This growing event will continue the tradition of excellence in addressing operational challenges involved in developing deepwater resources.We will return to the Moody Gardens Hotel and Convention Center on November 5-7,2014 in Galveston,Texas.     

Eastbound or westbound ?

In terms of equal sailing distances, where is the inflexion when ships depart from ports in the Asian Continent to New York via Suez and/or Panama？
The answer is China South Port Group （Hong Kong, Shenzhen and Guangzhou）.     

Impact of regulation on the performances of long-distance transport services: A comparison of the different approaches in Sweden and Norway

Despite the many socio-economic similarities between Sweden and Norway, differences in jurisdiction, organisation, cooperation, and financing of long-distance passenger train and coach services have led to the development of four distinctively different ways of serving the markets. This paper describes how the train and coach markets have developed in the two countries, with emphasis on regulatory and industrial structure and a couple of performance variables.Looking at passenger rail, both countries separated infrastructure from operation over a decade ago. However, while Norwegian rail is characterised by an almost monopoly supplier, rail services in Sweden are partly decentralised to the responsibility of county authorities and are widely subjected to competitive tendering. The rest of the network is about to be opened up for on-the-track competition. Swedish Rail (SJ) has spent the last decades consolidating its core business (passenger rail) and sold out its other businesses. In contrast, the Norwegian state rail (NSB) has expanded its business to become a major bus operator and property owner, with extensions also into the Swedish market.The coach industry was more recently deregulated in both countries. The Swedish coach market is dominated by privately owned companies operating services to and from Stockholm. In Norway, state-owned NSB is a major coach operator on medium distance routes, and is also the largest partner of Nor-Way Bussekspress which totally dominates long-distance coach services. Further, the Norwegian coach market is characterised by cross-ownership and cooperation which has enabled an extensive route network which covers most of Norway.We find distinct differences in achievements in the two modes and in the two countries. Swedish rail services have succeeded in winning market shares and in renewing and developing both infrastructure and service levels to a greater extent than the Norwegian model. On the other hand, the Norwegian coach market seems to be more developed and efficient compared to its Swedish counterpart.The paper concludes with a discussion on the possible links between the different approaches and the performance observed, with the aim to stimulate further and more detailed research on some important issues.     

某海港码头的撞损修复

依据码头撞击受损区域调查检测结果,对受损构件提出合理的修复方案,为码头的安全运行提供保障。