Lempel–Ziv Welch (LZW) algorithm is a well-known powerful data compression algorithm created by Abraham Lempel, Jacob Ziv, and Terry Welch. The algorithm is designed to be fast to implement but is not usually optimal because it performs only limited analysis of the data. A modified LZW algorithm on source coding will be proposed in this paper to improve the compression efficiency of the existin...

In part of speech tagging by Hidden Markov Model, a statistical model is used to assign grammatical categories to words in a text. Early work in the field relied on a corpus which had been tagged by a human annotator to train the model. More recently, Cutt ing et al. (1992) suggest that training can be achieved with a minimal lexicon and a limited amount of a priori information about probabilit...

Hidden Markov models (HMM’s) are popular in many applications, such as automatic speech recognition, control theory, biology, communication theory over channels with bursts of errors, queueing theory, and many others. Therefore, it is important to have robust and fast methods for fitting HMM’s to experimental data (training). Standard statistical methods of maximum likelihood parameter estimati...

Total Variability Model Conventionally formulated as generative model over features Assumes that feature vector distribution is a GMM Distribution Free Formulation Follows from asymptotic normality of Baum-Welch statistics Connections to probabilistic PCA, matrix completion Leads to a stochastic subgradient descent based estimation algorithm Conventional Formulation Collection of feature vector...

The Welch map x → g is similar to the discrete exponential map x → gx, which is used in many cryptographic applications including the ElGamal signature scheme. This paper analyzes the number of solutions to the Welch equation: g ≡ x (mod pe) where p is a prime and g is a unit modulo p, and looks at other patterns of the equation that could possibly be exploited in a similar cryptographic system...

-This paper describes a technique for on-line signature verification using Hidden Markov Models (HMMs). Signatures are captured and digitized in real-time using a graphic tablet. For each signature a HMM is constructed using a set of sample signatures described by the normalized directional angle function of the distance along the signature trajectory. The Baum-Welch algorithm is used for both ...

In this paper we present a statistical model with a nonsymmetric half-plane (NSHP) region of support for twodimensional continuous-valued vector fields. It has the simplicity, efficiency, and ease of use of the well-known hidden Markov model (HMM) and associated Baum-Welch algorithms for time-series and other one-dimensional problems. At the same time, it is able to learn textures on a twodimen...