In the paper, an algorithm is presented for solving two-level programming problems. This algorithm combines direction finding problem with a regularization of the lower level problem. The upper level objective functio...
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In the paper, an algorithm is presented for solving two-level programming problems. This algorithm combines direction finding problem with a regularization of the lower level problem. The upper level objective function is included in the regularization to yield uniqueness of the follower's solution set. This is possible if the problem functions are convex and the upper level objective function has a positive definite Hessian. The computation of a direction of descent and of the step size is discussed in more detail. Afterwards the convergence proof is given. Last but not least some remarks and examples describing the difficulty of the inclusion of upper-level constraints also depending on the variables of the lower level are added.
Chip multiprocessors are of increasing importance due to recent difficulties in achieving higher clock frequencies in uniprocessors, but their success depends on finding useful work for the processor cores. This paper...
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Chip multiprocessors are of increasing importance due to recent difficulties in achieving higher clock frequencies in uniprocessors, but their success depends on finding useful work for the processor cores. This paper addresses this challenge by presenting a simple compiler approach that extracts non-speculative thread-level parallelism from sequential codes. We present initial results from this technique targeting a validated dual-core processor model, achieving speedups ranging from 948% with an average of 25% for important benchmark loops over their single-threaded versions. We also identify important next steps found during our, pursuit of higher degrees of automatic threading.
The occur-check problem arises from the omission of the ``occur-check'' test in the implementation of the unification algorithm in the PROLOG interpreters. This may cause loops or unsound successes. Even an un...
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ISBN:
(纸本)0262691477
The occur-check problem arises from the omission of the ``occur-check'' test in the implementation of the unification algorithm in the PROLOG interpreters. This may cause loops or unsound successes. Even an unification algorithm of rational infinite terms may cause unsound success (with regards to the classical logic). Many works have been devoted to methods for finding statically in which points in a program an occur check has to be performed, taking advantage of the knowledge about the strategy to find a minimal set of such points. But the method depends on a fixed strategy and it is a limitation (for example strategy may be dynamically defined as in interpreters with delaying primitives). We tackle the problem in another way: We define the property NSTO for a program: ``all unifications are Not Subject To Occur-check in any step of any resolution scheme''. The NSTO property itself is undecidable. Therefore the paper is devoted to the elaboration of sufficient conditions for a program to be NSTO. An originality of our approach is that it can be applied not only to all computation rules in SLD resolution but more generally to all resolution strategies. This presentation clarifies and develops some results already known about this problem.
We consider end-to-end latency specifications for hard real-time embedded systems. We introduce a discrete-event programming model generalizing such specifications, and address its schedulability problem for uniproces...
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ISBN:
(纸本)9781479914432
We consider end-to-end latency specifications for hard real-time embedded systems. We introduce a discrete-event programming model generalizing such specifications, and address its schedulability problem for uniprocessor systems. This turns out to be rather idiosyncratic, involving complex, time-dependent release predicates and precedence constraints, quite unlike anything we have seen in the hard realtime computing literature. We prove the optimality of the earliest-deadline-first scheduling policy, and provide an algorithmic solution, reducing the schedulability problem to a reachability problem for timed automata.
Many computer programs today show skills that appear to rival those of outstanding human consultants. However, while each such program does certain things well, it is helpless at doing anything else. Why do our presen...
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ISBN:
(纸本)9783540699118
Many computer programs today show skills that appear to rival those of outstanding human consultants. However, while each such program does certain things well, it is helpless at doing anything else. Why do our present-day programs lack the versatility and resourcefulness that a typical person shows? Clearly, those programs are deficient in both commonsense knowledge and commonsense reasoning. I’ll argue that this has happened because the field of AI has evolved in a backwards direction, as compared with how a typical person develops-and that this is because our AI programmers have not appreciated the importance of making their system able to use more ’reflective’ ways to think.
With the transferring and development of the application of computer operating system from desktop to network, in the next generation of internet operating system, it is more and more important to consider the securit...
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ISBN:
(纸本)076952432X
With the transferring and development of the application of computer operating system from desktop to network, in the next generation of internet operating system, it is more and more important to consider the security of creating, running and exiting a thread on remote computer. This paper put forward the conceptions of "WorkerApplet", and designs a new running mechanism of thread that is implemented in Elastos. We change the object of thread for running from a "code of function" to a "WorkerApplet object". This work gives a new way to create, run, and exit a thread in remote system, especially which can be used to improve the security of system and data in the internet environment. And it perfects the running mechanism of thread in traditional operating system on the aspects of both the management of security and programming model.
In this paper we provide answers to the following problems. 1. Given a data flow graph and a performance constraint, determine a lower-bound on the storage area required for executing the data flow graph while satisfy...
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ISBN:
(纸本)0818665653
In this paper we provide answers to the following problems. 1. Given a data flow graph and a performance constraint, determine a lower-bound on the storage area required for executing the data flow graph while satisfying the performance constraint. 2. Determine a lower-bound on performance for executing a data flow graph under fixed storage area constraints. The results demonstrate that our approach produces solutions which are very close to the optimal.
In the case of imperfect loop nests, some researchers suggested to first use Abu-Sufah's Non-Basic-to-Basic-loop transformation to convert them into perfect loop nests and then apply the unimodular transformation ...
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ISBN:
(纸本)0780335295
In the case of imperfect loop nests, some researchers suggested to first use Abu-Sufah's Non-Basic-to-Basic-loop transformation to convert them into perfect loop nests and then apply the unimodular transformation approach. This paper identifies some limitations of this approach, describes some improvements, and provides some insights into the problem of restructuring imperfect loop nests.
A procedure that constructs mechanically the appropriate lemmas for proving assertions about programs with arrays is described. A certain subclass of formulas for which the procedure is guaranteed to terminate and thu...
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ISBN:
(纸本)0818627352
A procedure that constructs mechanically the appropriate lemmas for proving assertions about programs with arrays is described. A certain subclass of formulas for which the procedure is guaranteed to terminate and thus constitutes a decision procedure is exhibited. This subclass allows for ordering over integers but not for incrementation. A more general subclass that allows for incrementation, but without the termination property, is considered. It is also indicated how to apply the method to a still more general subclass that allows for full arithmetic. These results are extended to the case in which predicates have more than one list argument.
In this paper we give a topological proof of the following result. There exist 2(N0) lambda theories of the untyped lambda calculus without a model in any semantics based on Scott's view of models as partially ord...
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ISBN:
(纸本)076951281X
In this paper we give a topological proof of the following result. There exist 2(N0) lambda theories of the untyped lambda calculus without a model in any semantics based on Scott's view of models as partially ordered sets and of functions as monotonic functions. As a consequence of this result, we positively solve the conjecture, stated by Bastonero-Gouy [6, 7] and by Berline [10], that the strongly stable semantics is incomplete.
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