In this paper, we propose a multi-expert seal imprint verification system. The system has been specifically designed for applications in the Japanese bankcheck processing. A difficult problem encountered in automatic ...
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In this paper, a novel construction of a pseudo random binary sequence generator based on the shrinking generator concept is presented. This new generator is the shrink-swell generator and is an irregular combination ...
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In this paper, a novel construction of a pseudo random binary sequence generator based on the shrinking generator concept is presented. This new generator is the shrink-swell generator and is an irregular combination of two shrinking generators. It is shown that the shrink-swell generator exhibits good randomness properties by means of statistical testing and that the generator has additional favourable properties such as long period and high linear complexity. A formal proof is provided illustrating a means of period control. Results are presented indicating that both period and linear complexity exponentially grow with an increase in the length of the generator.
The rapidly increasing complexity of systems is driving the movement towards autonomic systems that are capable of managing themselves without the need for human intervention. Without autonomic technologies, many conv...
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ISBN:
(纸本)0769523560
The rapidly increasing complexity of systems is driving the movement towards autonomic systems that are capable of managing themselves without the need for human intervention. Without autonomic technologies, many conventional systems suffer reliability degradation due to the accumulation of errors. The autonomic management techniques break the traditional reliability degradation trend. This paper comprehensively describes the roles and functions of various autonomic components, and systematically reviews past and current technologies that have been developed to address the specific areas of the autonomic computing environment. A new mechanism of model-driven autonomic management is further presented, which is more intelligent and efficient.
Scavenging (or resource borrowing) is a common approach used to harness unused resources to perform useful calculations. Since these are volunteer contributions from resource owners, it is vital to reduce the impact o...
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ISBN:
(纸本)0769522769
Scavenging (or resource borrowing) is a common approach used to harness unused resources to perform useful calculations. Since these are volunteer contributions from resource owners, it is vital to reduce the impact of scavenging activities on their native workload to a minimum. To this end, existing impact control systems are either overly conservative in stopping scavenging altogether or inflexible and lack user autonomy to regulate resource usage as in some priority-based techniques. In this paper, we propose a systematic impact control framework for resource scavenging, by quantifying the performance impact a scavenging application incurs on a set of tasks stressing different system resources. For a user-configurable impact threshold, the framework monitors the native workload, determines the dominating native task, and autonomically and adoptively throttles the scavenging application, to bring the impact below target levels. This novel approach has unique benefits of 1) making impact control explicit to resource owners and an easy-to-tune "knob," and 2) adapting to different scavenging applications and native workloads. Our experiments with two scavenging applications, which use resources in very different ways, demonstrate that this framework allows both more aggressive resource scavenging and less impact on native workloads at the same time, compared to a priority-based method. Finally, the framework itself is a lightweight user-level process whose monitoring overhead on native workloads averages as low as 1%.
We propose preventing format-string attacks with a combination of static dataflow analysis and dynamic white-lists of safe address ranges. The dynamic nature of our white-lists provides the flexibility necessary to en...
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ISBN:
(纸本)1595932267
We propose preventing format-string attacks with a combination of static dataflow analysis and dynamic white-lists of safe address ranges. The dynamic nature of our white-lists provides the flexibility necessary to encode a very precise security policy - namely, that %n-specifiers in printf-style functions should modify a memory location x only if the programmer explicitly passes a pointer to x. Our static dataflow analysis and source transformations let us automatically maintain and check the white-list without any programmer effort - they merely need to change the Make-file. Our analysis also detects pointers passed to vprintf-style functions through (possibly multiple layers of) wrapper functions. Our results establish that our approach provides better protection than previous work and incurs little performance overhead. Copyright 2005 ACM.
This study examines the potential of an evolutionary automatic programming methodology to uncover a series of useful technical trading rules for the US S&P stock index. Index values for the period 01/01/1991 to 01...
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ISBN:
(纸本)3540441840
This study examines the potential of an evolutionary automatic programming methodology to uncover a series of useful technical trading rules for the US S&P stock index. Index values for the period 01/01/1991 to 01/10/1997 are used to train and test the evolved rules. A number of replacement strategies, and a novel approach to constant evolution are investigated. The findings indicate that the automatic programming methodology has much potential with the evolved rules making gains of approximately 13% over a 6 year test period.
When automatically synthesizing big programs, it is important to consider the combinatorial properties of the program transformations that are employed. In this paper, we show how to effectively generate transformatio...
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When automatically synthesizing big programs, it is important to consider the combinatorial properties of the program transformations that are employed. In this paper, we show how to effectively generate transformation sequences representing incremental changes to a given program. In order to cover combinations of transformations, we use so-called covering arrays in which each line is a transformation sequence to be translated into a program. Covering and orthogonal arrays are standard tools from combinatorial design theory to guarantee coverage of all pair-wise parameter combinations, for example. We equipped the ADATE automatic programming system with our new covering array (CA) transformation and conducted a series of 18 experiments which show that the CA transformation is a highly useful supplement to the old ADATE transformations.
We show how to write surjective random generators for several different classes of inductively defined types in dependent type theory. We discuss both non-indexed (simple) types and indexed families of types. In parti...
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The manual application of formal methods in system specification has produced successes, but in the end, despite any claims and assertions by practitioners, there is no provable relationship between a manually derived...
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The manual application of formal methods in system specification has produced successes, but in the end, despite any claims and assertions by practitioners, there is no provable relationship between a manually derived system specification or formal model and the customer's original requirements. Complex parallel and distributed systems present the worst case implications for today's dearth of viable approaches for achieving system dependability. No avenue other than formal methods constitutes a serious contender for resolving the problem, and so recognition of requirements-based programming has come at a critical juncture. We describe a new, NASA-developed automated requirements-based programming method that can be applied to certain classes of systems, including complex parallel and distributed systems, to achieve a high degree of dependability.
We consider the subset sum pseudorandom generator, introduced by Rueppel and Massey in 1985 and given by a linearly recurrent bit sequence u0, u1, ... of order n over 2, and weights w = (w 0,..., wn-1) ∈. Rn for some...
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