“奥圣65”轮沉船打捞方案和施工技术

"奥圣65"轮于2008年12月21日在天津港外锚地沉没。上海打捞局组织专业船舶经过52天的施工,圆满完成整体打捞任务。天津海事局给予了"沉船扳正起浮安全协调工作都十分圆满"的评价,交通运输部领导亲笔批示并对工程技术人员表示感谢。本文从该工程的技术难点和工程特点进行了分析总结,以期为技术人员从事救助打捞或相关工作提供借鉴。     

Construction of Pure Mendelsohn Triple Systems

This paper determined the existence of λ-fold pure Mendelsohn triple system of order υ satisfying λυ(υ-1)≡0 (mod 3) and υ≥4λ 5, or υ=2λ 2, and in the case of λ=4,5,6, which completely settled their existence.     

Cryptanalysis of One Fair E-cash System

Introduction The concept of group signature was intro-duced by Chaum and Heyst[1], which allows indi-vidual members to make signatures on behalf of thegroup. More formally, a secure group signaturescheme must satisfy such properties as unforgeabil-ity, anonymity, traceability, coalition-resistance,unlinkability, exculpability[2,3]. An important application of group signature isto construct fair e-cash systems. A fair electroniccash system is a system that allows customers tomake payments anon…     

FURTHER RESULTS ON THE EXISTENCE OF LABELED RESOLVABLE BLOCK DESIGNS

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