This paper describes the principles underlying an efficient implementation of a lazy functional language, compiling to code for ordinary computers. It is baaed on combinator-like graph reduction: the user defined func...
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The NBS Data Encryption Standard may be integrated into computer networks to protect personal (nonshared) files, to communicate securely both on- and off-line with local and remote users, to protect against key substi...
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The NBS Data Encryption Standard may be integrated into computer networks to protect personal (nonshared) files, to communicate securely both on- and off-line with local and remote users, to protect against key substitution, to authenticate system users, to authenticate data, and to provide digital signatures using a nonpublic key encryption algorithm. Key notarization facilities give users the capability of exercising a set of commands for key management as well as for data encryption functions. The facilities perform notarization which, upon encryption, seals a key or password with the identities of the transmitter and intended receiver. Thus, in order to decrypt a message, the receiver must authenticate himself and supply the correct identity of the transmitter. This feature eliminates the threat of key substitution which must be protected against to attain a high level of security.
This paper defines and demonstrates four philosophies for processing queries on tree structures; shows that the data semantics of queries shuld be described by designating sets of nodes from which v values for attnbut...
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This paper defines and demonstrates four philosophies for processing queries on tree structures; shows that the data semantics of queries shuld be described by designating sets of nodes from which v values for attnbutes may be returned to the data consumer; shows that the data semantics of database processing can be specified totally independent of any madhine, file structure, or implementation; shows that set theory is a natural and effective vehicle for analyzing the semantics of queries on tree structures; and finally, shows that Bolts is an adequate formalism for conveying the semantics of tree structure processing.
This paper explores the concept of an underwater robot manipulator mounted on an unmanned submersible for the purpose of doing some undersea tasks of interest to the U.S. Navy. The robot concept is compared with other...
An optimization technique known as inline substitution is analyzed. The optimization consists of replacing a procedure invocation by a modified copy of the procedure body. The general problem of using inline substitut...
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This paper discusses a technique in computer system simulation that uses models as effective tools for the study of new software technologies. This model development technique, called representative modelling, and its...
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This open access book presents the outcomes of the “Design for Future – Managed Software Evolution” priority program 1593, which was launched by the German Research Foundation (“Deutsche Forschungsgemeinschaft (D...
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ISBN:
(数字)9783030134990
ISBN:
(纸本)9783030134983;9783030135010
This open access book presents the outcomes of the “Design for Future – Managed Software Evolution” priority program 1593, which was launched by the German Research Foundation (“Deutsche Forschungsgemeinschaft (DFG)”) to develop new approaches to software engineering with a specific focus on long-lived software systems. The different lifecycles of software and hardware platforms lead to interoperability problems in such systems. Instead of separating the development, adaptation and evolution of software and its platforms, as well as aspects like operation, monitoring and maintenance, they should all be integrated into one overarching process.;Accordingly, the book is split into three major parts, the first of which includes an introduction to the nature of software evolution, followed by an overview of the specific challenges and a general introduction to the case studies used in the project. The second part of the book consists of the main chapters on knowledge carrying software, and cover tacit knowledge in software evolution, continuous design decision support, model-based round-trip engineering for software product lines, performance analysis strategies, maintaining security in software evolution, learning from evolution for evolution, and formal verification of evolutionary changes. In turn, the last part of the book presents key findings and spin-offs. The individual chapters there describe various case studies, along with their benefits, deliverables and the respective lessons learned. An overview of future research topics rounds out the coverage.;The book was mainly written for scientific researchers and advanced professionals with an academic background. They will benefit from its comprehensive treatment of various topics related to problems that are now gaining in importance, given the higher costs for maintenance and evolution in comparison to the initial development, and the fact that today, most software is not developed from scratch, but as part of a c
This book discusses physical and mathematical models, numerical methods, computational algorithms and software complexes, which allow high-precision mathematical modeling in fluid, gas, and plasma mechanics; general m...
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ISBN:
(数字)9789811526008
ISBN:
(纸本)9789811525995;9789811526022
This book discusses physical and mathematical models, numerical methods, computational algorithms and software complexes, which allow high-precision mathematical modeling in fluid, gas, and plasma mechanics; general mechanics; deformable solid mechanics; and strength, destruction and safety of structures. These proceedings focus on smart technologies and software systems that provide effective solutions to real-world problems in applied mechanics at various multi-scale levels. Highlighting the training of specialists for the aviation and space industry, it is a valuable resource for experts in the field of applied mathematics and mechanics, mathematical modeling and information technologies, as well as developers of smart applied software systems.
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