bell northern research

About: bell northern research is a based out in . It is known for research contribution in the topics: Semiconductor laser theory & Laser. The organization has 1473 authors who have published 1339 publications receiving 36442 citations.

Comparison of parametric representations for monosyllabic word recognition in continuously spoken sentences

Abstract: Several parametric representations of the acoustic signal were compared with regard to word recognition performance in a syllable-oriented continuous speech recognition system. The vocabulary included many phonetically similar monosyllabic words, therefore the emphasis was on the ability to retain phonetically significant acoustic information in the face of syntactic and duration variations. For each parameter set (based on a mel-frequency cepstrum, a linear frequency cepstrum, a linear prediction cepstrum, a linear prediction spectrum, or a set of reflection coefficients), word templates were generated using an efficient dynamic warping method, and test data were time registered with the templates. A set of ten mel-frequency cepstrum coefficients computed every 6.4 ms resulted in the best performance, namely 96.5 percent and 95.0 percent recognition with each of two speakers. The superior performance of the mel-frequency cepstrum coefficients may be attributed to the fact that they better represent the perceptually relevant aspects of the short-term speech spectrum.

Authentication and authenticated key exchanges

Abstract: We discuss two-party mutual authentication protocols providing authenticated key exchange, focusing on those using asymmetric techniques. A simple, efficient protocol referred to as the station-to-station (STS) protocol is introduced, examined in detail, and considered in relation to existing protocols. The definition of a secure protocol is considered, and desirable characteristics of secure protocols are discussed.

Force-directed scheduling for the behavioral synthesis of ASICs

Abstract: A general scheduling methodology is presented that can be integrated into specialized or general-purpose high-level synthesis systems. An initial version of the force-directed scheduling algorithm at the heart of this methodology was originally presented by the authors in 1987. The latest implementation of the logarithm introduced here reduces the number of functional units, storage units, and buses required by balancing the concurrency of operations assigned to them. The algorithm supports a comprehensive set of constraint types and scheduling modes. These include multicycle and chained operations; mutually exclusive operations; scheduling under fixed global timing constraints with minimization of functional unit costs, minimization of register costs, and minimization of global interconnect requirements; scheduling with local time constraints (on operation pairs); scheduling under fixed hardware resource constraints; functional pipelining; and structural pipeline (use of pipeline functional units). Examples from current literature, one of which was chosen as a benchmark for the 1988 High-Level Synthesis Workshop, are used to illustrate the effectiveness of the approach. >

Cryptanalysis of short RSA secret exponents

Abstract: A cryptanalytic attack on the use of short RSA secret exponents is described. The attack makes use of an algorithm based on continued fractions that finds the numerator and denominator of a fraction in polynomial time when a close enough estimate of the fraction is known. The public exponent e and the modulus pq can be used to create an estimate of a fraction that involves the secret exponent d. The algorithm based on continued fractions uses this estimate to discover sufficiently short secret exponents. For a typical case where e>pq, GCD(p-1, q-1) is small, and p and q have approximately the same number of bits, this attack will discover secret exponents with up to approximately one-quarter as may bits as the modulus. Ways to combat this attack, ways to improve it, and two open problems are described. This attack poses no threat to the normal case of RSA where the secret exponent is approximately the same size as the modulus. This is because the attack uses information provided by the public exponent and, in the normal case, the public exponent can be chosen almost independently of the modulus. >

Registering multiview range data to create 3D computer objects

Abstract: Concerns the problem of range image registration for the purpose of building surface models of 3D objects. The registration task involves finding the translation and rotation parameters which properly align overlapping views of the object so as to reconstruct from these partial surfaces, an integrated surface representation of the object. The registration task is expressed as an optimization problem. We define a function which measures the quality of the alignment between the partial surfaces contained in two range images as produced by a set of motion parameters. This function computes a sum of Euclidean distances from control points on one surfaces to corresponding points on the other. The strength of this approach is in the method used to determine point correspondences. It reverses the rangefinder calibration process, resulting in equations which can be used to directly compute the location of a point in a range image corresponding to an arbitrary point in 3D space. A stochastic optimization technique, very fast simulated reannealing (VFSR), is used to minimize the cost function. Dual-view registration experiments yielded excellent results in very reasonable time. A multiview registration experiment took a long time. A complete surface model was then constructed from the integration of multiple partial views. The effectiveness with which registration of range images can be accomplished makes this method attractive for many practical applications where surface models of 3D objects must be constructed. >