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To Raise Safe and Economical Operation Level on Scientific and Technical Progress Basis
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《Electricity》 1997年第1期20-22,共3页
关键词 To Raise Safe and Economical operation level on Scientific and Technical Progress Basis
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工程理念的形成、操作化及其层次——再论工程理念 被引量:5
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作者 梁军 《西安交通大学学报(社会科学版)》 CSSCI 北大核心 2014年第6期91-95,共5页
工程理念是关于工程活动的顶层设计的灵魂,是人们从实践中不断总结和升华的,是关于工程存在总体性特征的理性认识和自觉追求。作为工程造物活动过程中的一种实践智慧,工程理念经历了从科学认识到工程实践的演化。工程理念操作化过程,通... 工程理念是关于工程活动的顶层设计的灵魂,是人们从实践中不断总结和升华的,是关于工程存在总体性特征的理性认识和自觉追求。作为工程造物活动过程中的一种实践智慧,工程理念经历了从科学认识到工程实践的演化。工程理念操作化过程,通常是通过实践模型的方式发生作用的。一般地,这种模型又根据工程造物的规模在宏观、中观、微观三个层次发挥引导和约束作用。 展开更多
关键词 工程理念 形成 操作化 (实践)模型 层次
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Design of secure operating systems with high security levels 被引量:5
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作者 QING SiHan1,2 & SHEN ChangXiang3 1 Institute of Software, Chinese Academy of Sciences, Beijing 100080, China 2 School of Software and Microelectronics, Peking University, Beijing 102600, China 3 Institute of Computing Technology, Navy, Beijing 100841, China 《Science in China(Series F)》 2007年第3期399-418,共20页
Numerous Internet security incidents have shown that support from secure operating systems is paramount to fighting threats posed by modern computing environments. Based on the requirements of the relevant national an... Numerous Internet security incidents have shown that support from secure operating systems is paramount to fighting threats posed by modern computing environments. Based on the requirements of the relevant national and international standards and criteria, in combination with our experience in the design and development of the ANSHENG v4.0 secure operating system with high security level (hereafter simply referred to as ANSHENG OS), this paper addresses the following key issues in the design of secure operating systems with high security levels: security architecture, security policy models, and covert channel analysis. The design principles of security architecture and three basic security models: confidentiality, integrity, and privilege control models are discussed, respectively. Three novel security models and new security architecture are proposed. The prominent features of these proposals, as well as their applications to the ANSHENG OS, are elaborated. Cover channel analysis (CCA) is a well-known hard problem in the design of secure operating systems with high security levels since to date it lacks a sound theoretical basis and systematic analysis approach. In order to resolve the fundamental difficulties of CCA, we have set up a sound theoretical basis for completeness of covert channel identification and have proposed a unified framework for covert channel identification and an efficient backward tracking search method. The successful application of our new proposals to the ANSHENG OS has shown that it can help ease and speedup the entire CCA process. 展开更多
关键词 secure operating systems with high security levels ARCHITECTURE security model covert channel analysis
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View Creation for Queriesin Object Oriented Databases
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作者 RajeshNarang K.D.Sharma 《Journal of Computer Science & Technology》 SCIE EI CSCD 1999年第4期349-362,共14页
A view in object oriented databases corresponds to virtual schemawith restructured generalization and decomposition hierarchies. Numbers of viewcreation methodologies have been proposed. A major drawback of existing m... A view in object oriented databases corresponds to virtual schemawith restructured generalization and decomposition hierarchies. Numbers of viewcreation methodologies have been proposed. A major drawback of existing method-ologies is that they do not maintain the closure property. That is, the result of aquery does not have the same semantics as embodied in the object oriented datamodel. Therefore, this paper presents a view creation methodology that derives aclass in response to a user's query, integrates derived class in global schema (i.e.,considers the problem of classes moving in class hierarchy) and selects the requiredclasses from global schema to create the view for user's query. Novel idea of viewcreation includes: (a) an object algebra for class derivation and customization (wherethe derived classes in terms of object instances and procedure/methods are studied),(b) maintenance of closure property, and (c) classification algorithm which providesmechanism to deal with the problem of a class moving in a class hierarchy. 展开更多
关键词 object manipulation type level operation instance level operation object algebra object operator operator syntax operator semantics derived class class integration view creation algorithm
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QCD factorization semi-inclusive deep inelastic scattering diffractive deep inelastic scattering
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作者 周高亮 《Communications in Theoretical Physics》 SCIE CAS CSCD 2016年第2期204-212,共9页
The operator level proof of factorization theorem exhibited in [ar Xiv:hep-ph/1307.4194] is extended to the semi-inclusive deep inelastic scattering process(SIDIS). Factorization theorem can be proved at operator l... The operator level proof of factorization theorem exhibited in [ar Xiv:hep-ph/1307.4194] is extended to the semi-inclusive deep inelastic scattering process(SIDIS). Factorization theorem can be proved at operator level if there are not detected soft hadrons. The key point is that the initial one-nucleon state is the eigenstate of QCD. 展开更多
关键词 QCD Factorization of Semi-Inclusive DIS Process at Operator level
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QCD factorization Drell–Yan process
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作者 周高亮 《Communications in Theoretical Physics》 SCIE CAS CSCD 2016年第2期193-203,共11页
An alternative proof of factorization theorem for Drell–Yan process that works at operator level is presented in this paper. Contributions of interactions after the hard collision for such inclusive processes are pro... An alternative proof of factorization theorem for Drell–Yan process that works at operator level is presented in this paper. Contributions of interactions after the hard collision for such inclusive processes are proved to be canceled at operator level according to the unitarity of time evolution operator. After this cancellation, there are no longer leading pinch singular surface in Glauber region in the time evolution of electromagnetic currents. Effects of soft gluons are absorbed into Wilson lines of scalar-polarized gluons. Cancelation of soft gluons is attribute to unitarity of time evolution operator and such Wilson lines. 展开更多
关键词 A Proof of Factorization Theorem of Drell–Yan Process at Operator level
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