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Semantic Remote Attestation  A Virtual Machine directed approach to Trusted Computing
 USENIX Virtual Machine Research and Technology Symposium
, 2004
"... Remote attestation is one of the core functionalities provided by trusted computing platforms. It holds the promise of enabling a variety of novel applications. However, current techniques for remote attestation are static, inexpressive and fundamentally incompatible with today's heterogeneous distr ..."
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Cited by 57 (3 self)
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Remote attestation is one of the core functionalities provided by trusted computing platforms. It holds the promise of enabling a variety of novel applications. However, current techniques for remote attestation are static, inexpressive and fundamentally incompatible with today's heterogeneous distributed computing environments and commodity open systems. Using languagebased virtual machines enables the remote attestation of complex, dynamic, and highlevel program properties  in a platformindependent way. We call this semantic remote attestation. This enables a number of novel applications that distribute trust dynamically. We have implemented a prototype framework for semantic remote attestation, and present two example applications built on it  a peertopeer network protocol, and a distributed computing application.
The Symmetric Table Addition Method for Accurate Function Approximation
 Journal of VLSI Signal Processing
, 1999
"... . This paper presents a highspeed method for computing elementary functions using parallel table lookups and multioperand addition. Increasing the number of tables and inputs to the multioperand adder significantly reduces the amount of memory required. Symmetry and leading zeros in the table co ..."
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Cited by 33 (2 self)
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. This paper presents a highspeed method for computing elementary functions using parallel table lookups and multioperand addition. Increasing the number of tables and inputs to the multioperand adder significantly reduces the amount of memory required. Symmetry and leading zeros in the table coefficients are used to reduce the amount of memory even further. This method has a closedform solution for the table entries and can be applied to any differentiable function. For 24bit operands, this method requires two to three orders of magnitude less memory than conventional table lookups. Keywords: Elementary functions, table lookups, approximations, multioperand addition, computer arithmetic, hardware design. 1. Introduction Elementary function approximations are important in scientific computing, computer graphics, and digital signal processing applications. In the systolic array implementation of Cholesky decomposition, presented in [1], 30% of the cells approximate reciprocals...
FaultBased Testing Without the Need of Oracles
 Information and Software Technology
, 2003
"... There are two fundamental limitations in software testing, known as the reliable test set problem and the oracle problem. Faultbased testing is an attempt by Morell to alleviate the reliable test set problem. In this paper, we propose to enhance faultbased testing to alleviate the oracle problem a ..."
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Cited by 31 (11 self)
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There are two fundamental limitations in software testing, known as the reliable test set problem and the oracle problem. Faultbased testing is an attempt by Morell to alleviate the reliable test set problem. In this paper, we propose to enhance faultbased testing to alleviate the oracle problem as well. We present an integrated method that combines metamorphic testing with faultbased testing using real and symbolic inputs.
Symmetric Bipartite Tables for Accurate Function Approximation
 Proceedings of the 13th IEEE Symposium on Computer Arithmetic. IEEE Computer
, 1997
"... This paper presents a methodology for designing bipartite tables for accurate function approximation. Bipartite tables use two parallel table lookups to obtain a carrysave (borrowsave) function approximation. A carry propagate adder can then convert this approximation to a two's complement number ..."
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Cited by 24 (2 self)
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This paper presents a methodology for designing bipartite tables for accurate function approximation. Bipartite tables use two parallel table lookups to obtain a carrysave (borrowsave) function approximation. A carry propagate adder can then convert this approximation to a two's complement number or the approximation can be directly Booth encoded. Our method for designing bipartite tables, called the Symmetric Bipartite Table Method, utilizes symmetry in the table entries to reduce the overall memory requirements. It has several advantages over previous bipartite table methods in that it (1) provides a closed form solution for the table entries, (2) has tight bounds on the maximum absolute error, (3) requires smaller table lookups to achieve a given accuracy, and (4) can be applied to a wide range of functions. Compared to conventional table lookups, the symmetric bipartite tables presented in this paper are 15.0 to 41.7 times smaller when the operand size is 16 bits and 99.1 to 273....
Numerical Evaluation of Special Functions
 In W. Gautschi (Ed.), AMS Proceedings of Symposia in Applied Mathematics 48
, 1994
"... . This document is an excerpt from the current hypertext version of an article that appeared in Walter Gautschi (ed.), Mathematics of Computation 19431993: A HalfCentury of Computational Mathematics, Proceedings of Symposia in Applied Mathematics 48, American Mathematical Society, Providence, ..."
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Cited by 21 (0 self)
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. This document is an excerpt from the current hypertext version of an article that appeared in Walter Gautschi (ed.), Mathematics of Computation 19431993: A HalfCentury of Computational Mathematics, Proceedings of Symposia in Applied Mathematics 48, American Mathematical Society, Providence, RI 02940, 1994. The symposium was held at the University of British Columbia August 913, 1993, in honor of the fiftieth anniversary of the journal Mathematics of Computation. The original abstract follows. Higher transcendental functions continue to play varied and important roles in investigations by engineers, mathematicians, scientists and statisticians. The purpose of this paper is to assist in locating useful approximations and software for the numerical generation of these functions, and to offer some suggestions for future developments in this field. 5.9. Mathieu, Lam'e, and Spheroidal Wave Functions. 5.9.1. Characteristic Values of Mathieu's Equation. Software Packages:...
Reciprocation, Square Root, Inverse Square Root, and Some Elementary Functions Using Small Multipliers
, 1997
"... This paper deals with the computation of reciprocals, square roots, inverse square roots, and some elementary functions using small tables, small multipliers, and for some functions, a final "large" (almost fulllength) multiplication. We propose a method that allows fast evaluation of these functio ..."
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Cited by 17 (5 self)
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This paper deals with the computation of reciprocals, square roots, inverse square roots, and some elementary functions using small tables, small multipliers, and for some functions, a final "large" (almost fulllength) multiplication. We propose a method that allows fast evaluation of these functions in double precision arithmetic. The strength of this method is that the same scheme allows the computation of all these functions. Our method is mainly interesting for designing special purpose circuits, since it does not allow a simple implementation of the four rounding modes required by the IEEE754 standard for floatingpoint arithmetic.
Argument reduction for huge arguments: Good to the last bit (can be obtained by sending an email to the author: kwok.ng@eng.sun.com
, 1992
"... It is not uncommon to encounter trigonometric functions of huge argument.Consider a simple spring problem, under no damping conditions, the motion can be described ..."
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Cited by 14 (0 self)
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It is not uncommon to encounter trigonometric functions of huge argument.Consider a simple spring problem, under no damping conditions, the motion can be described
Highspeed function approximation using a minimax quadratic interpolator
 IEEE TRANSACTIONS ON COMPUTERS
, 2005
"... A tablebased method for highspeed function approximation in singleprecision floatingpoint format is presented in this paper. Our focus is the approximation of reciprocal, square root, square root reciprocal, exponentials, logarithms, trigonometric functions, powering (with a fixed exponent p), ..."
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Cited by 13 (1 self)
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A tablebased method for highspeed function approximation in singleprecision floatingpoint format is presented in this paper. Our focus is the approximation of reciprocal, square root, square root reciprocal, exponentials, logarithms, trigonometric functions, powering (with a fixed exponent p), or special functions. The algorithm presented here combines table lookup, an enhanced minimax quadratic approximation, and an efficient evaluation of the seconddegree polynomial (using a specialized squaring unit, redundant arithmetic, and multioperand addition). The execution times and area costs of an architecture implementing our method are estimated, showing the achievement of the fast execution times of linear approximation methods and the reduced area requirements of other seconddegree interpolation algorithms. Moreover, the use of an enhanced minimax approximation which, through an iterative process, takes into account the effect of rounding the polynomial coefficients to a finite size allows for a further reduction in the size of the lookup tables to be used, making our method very suitable for the implementation of an elementary function generator in stateoftheart DSPs or graphics processing units (GPUs).
Case Studies on the Selection of Useful Relations in Metamorphic Testing
 Proceedings of the 4th IberoAmerican Symposium on Software Engineering and Knowledge Engineering (JIISIC 2004)
, 2004
"... An oracle is a mechanism against which the tester can decide whether the outputs of the program for the executed test cases are correct. A fundamental problem of software testing is that, in many situations, the oracle is not available or too difficult to apply. A metamorphic testing (MT) method has ..."
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Cited by 12 (4 self)
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An oracle is a mechanism against which the tester can decide whether the outputs of the program for the executed test cases are correct. A fundamental problem of software testing is that, in many situations, the oracle is not available or too difficult to apply. A metamorphic testing (MT) method has been proposed to alleviate the oracle problem. MT is an automated testing method that employs expected properties of the target functions to test programs without human involvement. These properties are called metamorphic relations (MR). For a given problem, usually more than one MR can be identified. It is therefore interesting and very useful for practitioners to know how to select effective MRs that are good at detecting program defects. This article proposes a guideline for the selection of good MRs for automated testing. The effectiveness of our strategy has been investigated through case studies.
Properties of Machine Learning Applications for Use in Metamorphic Testing
"... It is challenging to test machine learning (ML) applications, which are intended to learn properties of data sets where the correct answers are not already known. In the absence of a test oracle, one approach to testing these applications is to use metamorphic testing, in which properties of the app ..."
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Cited by 11 (8 self)
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It is challenging to test machine learning (ML) applications, which are intended to learn properties of data sets where the correct answers are not already known. In the absence of a test oracle, one approach to testing these applications is to use metamorphic testing, in which properties of the application are exploited to define transformation functions on the input, such that the new output will be unchanged or can easily be predicted based on the original output; if the output is not as expected, then a defect must exist in the application. Here, we seek to enumerate and classify the metamorphic properties of some machine learning algorithms, and demonstrate how these can be applied to reveal defects in the applications of interest. In addition to the results of our testing, we present a set of properties that can be used to define these metamorphic relationships so that metamorphic testing can be used as a general approach to testing machine learning applications. 1