To take advantage of existing order in a sequence when sorting, we evaluate the quantity of this information by the minimal size of decomposition of the input sequence, particularly the minimal size of chain and of mo...
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To take advantage of existing order in a sequence when sorting, we evaluate the quantity of this information by the minimal size of decomposition of the input sequence, particularly the minimal size of chain and of monotonic partitions. Some sorting strategies that are optimal with respect to these measures of presortedness are presented. The relationships between these new measures of presortedness and other known measures have also been explored. As an application, we carry out the optimality of an adaptive sorting algorithm Skiena's Melsort. For some special partitioning strategies, we present two sorting algorithms based on Dijkstra's Smoothsort. Moreover, the optimalities of these two algorithms are demonstrated. By examining the optimalities of sorting algorithms with respect to certain measures of presortedness, we also propose some optimal sorting strategies for one class of measures. Finally, we discuss other types of sorting problems, such as sorting multisets and topological sorting. In particular, we derive an optimal algorithm for sorting multisets and for finding the multiset sizes as well.
BOTTOM-UP HEAPSORT is a variant of HEAPSORT which beats on average even the clever variants of QUICKSORT, if n is not very small. Up to now, the worst case complexity of BOTTOM-UP HEAPSORT has been able to be estimate...
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BOTTOM-UP HEAPSORT is a variant of HEAPSORT which beats on average even the clever variants of QUICKSORT, if n is not very small. Up to now, the worst case complexity of BOTTOM-UP HEAPSORT has been able to be estimated only by 1.5n log n. McDiarmid and Reed (1989) have presented a variant of BOTTOM-UP HEAPSORT which needs extra storage for n bits. The worst case number of comparisons of this (almost internal) sorting algorithm is estimated by n log n + 1.1 n. It is discussed how many comparisons can be saved on average.
Order-sorted specifications (i.e. many-sorted specifications with subsort relations) have been proved to be a useful tool for the description of partially defined functions and error handling in abstract data types. S...
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Order-sorted specifications (i.e. many-sorted specifications with subsort relations) have been proved to be a useful tool for the description of partially defined functions and error handling in abstract data types. Several definitions for order-sorted algebras have been proposed. In some papers an operator symbol, which may be multiply declared, is interpreted by a family of functions ("over-loaded" algebras). In other papers it is always interpreted by a single function ("non-overloaded" algebras). On the one hand, we try to demonstrate the differences between these two approaches with respect to equality, rewriting and completion;on the other hand, we prove that in fact both theories can be studied in parallel provided that certain notions are suitably defined. The overloaded approach differs from the many-sorted and the nonoverloaded one in that the overloaded term algebra is not necessarily initial. We give a decidable sufficient criterion for the initiality of the term algebra, which is less restrictive than GJM-regularity as proposed by Goguen, Jouannaud and Meseguer. Sort-decreasingness is an important property of rewrite systems since it ensures that confluence and Church-Rosser property are equivalent, that the overloaded and nonoverloaded rewrite relations agree, and that variable overlaps do not yield critical pairs. We prove that it is decidable whether or not a rewrite rule is sort-decreasing, even if the signature is not regular. Finally, we demonstrate that every overloaded completion procedure may also be used in the nonoverloaded world, but not conversely, and that specifications exist that can only be completed using the nonoverloaded semantics.
HyperNet is an authoring and browsing system facilitating creation and navigation of multimedia documents. It is conceived and designed to provide a mechanism for very fast choreographing and configurating of hypermed...
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HyperNet is an authoring and browsing system facilitating creation and navigation of multimedia documents. It is conceived and designed to provide a mechanism for very fast choreographing and configurating of hypermedia documents. This system provides to the users a hypermedia integration and browsing environment to document component databases distributed across the world, provided they have access to the Internet network and are valid HyperNet sites. The intention was for users to be able to search for and retrieve documents stored locally and/or remotely, while the access mechanism being completely transparent. This system was implemented and tested with a suite of hypermedia document components which were distributed over southern California and Europe.
One common job scheduling objective is to minimize makespan. The problem can be modeled as integer linear programming (ILP) and will often have multiple alternative optimal solutions. However, secondary considerations...
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One common job scheduling objective is to minimize makespan. The problem can be modeled as integer linear programming (ILP) and will often have multiple alternative optimal solutions. However, secondary considerations, e.g. minimizing the second latest completion time, may very well dictate a preference between solutions with identical makespans. Because of the nature of the primary objective, standard approaches for optimizing a prioritized set of multiple objectives will not work. In this paper we prove that for unit time problems, an appropriate objective function can be formulated, which, when optimized, satisfies both the primary and secondary objectives. Moreover, the new formulation can be modeled as a classical assignment problem (AP). This has the added advantage of efficiency of solution and availability of software. Applications to computer processor scheduling and the military are presented.
A semantic algebra construction is introduced to model the stepwise behavior of synchronous systems in an arbitrary pointed algebraic theory T The theory T is extended to a feedback theory F(infinity)T in which the bo...
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A semantic algebra construction is introduced to model the stepwise behavior of synchronous systems in an arbitrary pointed algebraic theory T The theory T is extended to a feedback theory F(infinity)T in which the bottom morphism is the designated point of T The feedback theory F(infinity)T is obtained as the inverse limit of the theories n-res T that describe the stepwise behavior of systems in T restricted to the first n clock cycles. It is shown that in F(infinity)T, iteration satisfies the functorial dagger condition. Some suggestions are made about how to generalize the construction to handle infinite systems.
We present a cost-optimal parallel algorithm for traversing a general tree in breadth-first fashion. For a tree with n nodes, this algorithm requires O(n/p + log n) time employing p processors on the EREW PRAM model. ...
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We present a cost-optimal parallel algorithm for traversing a general tree in breadth-first fashion. For a tree with n nodes, this algorithm requires O(n/p + log n) time employing p processors on the EREW PRAM model. To the best of our knowledge, it is the first parallel algorithm for breadth-first tree-traversal, which has O(log n) time complexity and yet being cost-optimal for p = O(n/log n) on the EREW PRAM. Our approach is based on a novel idea which converts the breadth-first traversal problem into a parentheses matching problem. As an application of this technique, we design a simple but elegant parallel algorithm for sorting a special class of integers in which elements in any two consecutive places of the input sequence differ at most by unity. The proposed sorting algorithm is stable and it achieves the same performance as that of our breadth-first traversal algorithm.
To date the necessary rationalization procedures in the manufacturing environment to achieve competitive advantage have taken place mostly from a high level, centralized point of view within organizations. Additional ...
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To date the necessary rationalization procedures in the manufacturing environment to achieve competitive advantage have taken place mostly from a high level, centralized point of view within organizations. Additional competitive success can only be achieved through consequential shop floor orientation. Existing resources at the shop floor level, for example, processing proximity and manufacturing know-how can be used to an advantage. In this paper, a shop floor oriented approach is presented using the example of reduction of the run-in time of CNC-Programmes. A computer aided method for the run-in of CNC-Programmes is presented. Up to now this task has been undertaken empirically. The result is a transparent, well structured and thus target oriented run-in system which assists the production planning process and which leads to significant time saving.
In recent years many prototype systems have been developed for graphically visualizing program execution in an attempt to create a better interface between software engineers and their programs. Several classification...
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In recent years many prototype systems have been developed for graphically visualizing program execution in an attempt to create a better interface between software engineers and their programs. Several classification based taxonomies have been proposed to describe computer program visualization systems and general frameworks have been suggested for implementation. In this paper we provide a framework for both describing existing systems and implementing new ones. We demonstrate the utility of automatic program visualization by re-implementing a number of classic systems using this framework.
Assembler language has traditionally been the choice for systemsprogramming. In this paper, the author will share his experience using the C language to develop major systems software in an MVS ISPF environment. This...
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Assembler language has traditionally been the choice for systemsprogramming. In this paper, the author will share his experience using the C language to develop major systems software in an MVS ISPF environment. This paper will present the following technical issues with using such a high-level language as C in systemsprogramming: supervisor services, low-level I/O, inter-language communication and run-time environment considerations. By using a high-level language, we were able to program at a conceptual level rather than the machine's direct level of comprehension. The improved productivity and the ease of maintainability of C far outweighted any perceived benefits of a comparable assembler program.
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