This paper examines the concrete impact of digital publishing upon print publishing. The remarkable growth of the Internet is at the core of this impact, as the Internet forms the backbone for much of the digitization of print publishing, from commercial promotional efforts to e-book readers to alliances with education. Additionally, this paper offers short-term speculations-grounded in specific current developments-of the continuing effects of digital publishing on print publishing.

A new method of computing the glottal pulse period of voiced speech is given. This algorithm is based on the mathematically derived fact that the amplitudes of the odd harmonics of a periodic function with period P are zero when the function is expanded in a Fourier series whose coefficients are determined by integrating over 2P instead of the usual P. It is shown that such a glottal pulse tracker is extremely sensitive to sudden short-lived shifts in the apparent frequency of the glottal pulse that circumscribe certain consonants in the speech stream. This method may therefore be used to segment these consonants for various analytical purposes. 1.

The maximum likelihood voting (MLV) strategy was recently proposed as one of the most reliable voting methods. The strategy determines the most likely correct result based on the reliability history of each software version. However, the theoretical results were obtained under the assumption that inter-version failures are not correlated by common cause faults. We first discuss the issues that arise in practical implementation of MLV, and present an extended version of the MLV algorithm that uses component reliability estimates to break voting ties. We then empirically evaluate the implemented MLV strategy in a situation where the inter-version failures are highly correlated. Our results show that, although in real situations MLV carries no reliability guarantees, it tends to be statistically more reliable, even under high inter-version correlation conditions, than other voting strategies that we have examined. We also compare implemented MLV performance with that of Recovery Block and hybrid Consensus Recovery Block approaches. Our results show that MLV often outperforms Recovery Block and that it can successfully compete with more elaborate Consensus Recovery Block. To the best of our knowledge, this is the first empirical evaluation of the MLV strategy.

A cost model determines system costs for fault-tolerant software systems. The model finds the optimal number of program versions to achieve minimum system cost of the fault-tolerant software techniques: N-version programming, recovery block, and consensus recovery block. In this case, all versions, the voter, and the acceptance test have the same reliability. When the parameters for the versions, acceptance test, and voter in the cost function are all equal, the cost of a 3-version system is always optimal, Cost(CRB)/spl Lt/Cost(RB)/spl Lt/Cost(NVP) for each target reliability differing by as much as two orders of magnitude in some cases. The cost functions were increasing functions of N. When the parameters are not equal, optimality occurred for other values of N. This was especially the case when the cost exponent for version-1 was larger than the exponents for the other versions and the acceptance test or voter. As the values of the cost exponents for the version reliabilities become larger, a smaller difference was required between the version-1 exponent and the others to produce alternate optima.

The strategy of using multiple versions of independently developed software as a means to tolerate residual software design faults is discussed. The effectiveness of multiversion software is studied by comparing estimates of the failure probabilities of these systems with the failure probabilities of single versions. The estimates are obtained under a model of dependent failures and compared with estimates obtained when failures are assumed to be independent. The experimental results are based on 20 versions of an aerospace application developed and independently validated by 60 programmers from 4 universities. Descriptions of the application and development process are given, together with an analysis of the 20 versions.>

The timing performance of N-version multi-stage software is analyzed for a strategy called expedient voting. In expedient voting the voting takes place as soon as an adequate number of components have finished the stage. The concept of a 'runahead' is introduced: the faster versions are allowed to run ahead of the rest of the slower versions by one or more stages, with synchronized re-start in the event of a failure. If the versions are highly reliable, inter-version failure dependence is small, and the difference between the fastest and the slowest successful components in each stage is large, then the execution speed-up through expedient voting may be substantial. Runaheads exceeding three stages offer diminishing returns. Speed-up deteriorates with reduction in the version reliability and independence.>

A fault-tolerant system architecture for medical applications in which the processors and software interactions are treated in a unified manner is proposed. An overview of the requirements of such a system, which includes fully testable processors that are self-checking and which can execute multiversion software in parallel, is provided. The system will facilitate the interactions and provide for performance and fault monitoring, adjudication of outputs, and dynamic system reconfiguration. An implementation plan for the processor is presented.>

In situations in which computers are used to manage life-critical situations, software errors that could arise due to inadequate or incomplete testing cannot be tolerated. This paper examines three methods of creating fault-tolerant software systems, Recovery Block, N-Version Programming, and Consensus Recovery Block, and it presents reliability models for each. The models are used to show that one method, the Consensus Recovery Block, is more reliable than the other two.

An algorithm is presented for calculating an osculatory quadratm sphne that preserves the monotonmlty and convexity of the data when consmtent with the given derivatives at the data points A method is also presented for calculatmn of an mterpolatory quadratm sphne with monotonicity and convexity consistent with that of the data Included is a discussion of pathologms that can occur when these algorithms are maplemented.Examples are given that illustrate the dependence of the method on only local informatmn and its usefulness m geometrm design.

This algorithm is a FORTRAN implementation for the procedure developed in [3].Let n data points {(x,, y,)} n.1 and n first derivatives {rn,),"-1 at these data points be given, with x, <_-X,+l, 1 __ i __.n -1.The algorithm constructs a smooth osculatory quadratic spline S, which satisfies (1) S(x,) = y,, 1 <_ i <_ n;(2) S'(xi) = m,, 1 <_ i <_ n;(3) S preserves monotonicity and convexity in the case that the slopes rn, are consistent with the shape of the data; (4) the knots of the spiine S include the data points and at most two additional knots between adjacent data points.The spline S is a piecewise quadratic Bernstein polynomial with a continuous first derivative.

The Integrated Photogrammetric Instrument Network (IPIN) is being designed and developed by the Defense Mapping Agency Aerospace Center in St. Louis, Mo. to meet database demands for terrain elevation information. IPIN is a network of computers and instrumentation dedicated to digitizing and editing photo-source terrain data [1]. Editing procedures are required because of digitizing errors inherent in the data-collection process. Some of these errors are random; others are systematic and predictable.