Pliska Studia Mathematica Bulgarica

Volume 16, 2004



Study on Robustness of Strehler-Mildvan Model
Dimitar Atanasov

2000 AMS Subject Classification: 62F35, 62F15
Key words: robust statistics

Probabilistic Models in Cryptography and Coding Theory
Verica Bakeva

2000 AMS Subject Classification: 94A29, 94B70
Key words: quasigroups, stream cypher, tests for pseudo-random number generators, error-correcting codes.

Total Progeny in a Subcritical Branching Process with Two Types of Immigration
Maroussia Slavtchova-Bojkova
P. Becker-Kern
Kosto V. Mitov

2000 AMS Subject Classification: 60J80, 60F05
Key words: central limit theorem, total progeny, Bellman-Harris branching processes, law of large numbers, renewal processes.

On Some Concepts of Residuals
Georgi N. Boshnakov

2000 AMS Subject Classification: 60E10, 62G15, 62M20
Key words: concentration function, confidence density, confidence residual highest density region

Application of the d-fullness Technique for Breakdown Point Study of the Trimmed Likelihood Estimator to a Generalized Logistic Model
Rositsa Dimova
Neyko Neykov

2000 AMS Subject Classification: 62J12, 62F35
Key words: Breakdown Point, Subcompact Function, d-fullness, Robustness, Trimmed Likelihood Estimator, generalized logistic model.

A Statistical Approach for Multilingual Document Clustering and Topic Extraction from Clusters
Joaquim Silva
Joao Mexia
Carlos A. Coelho
Gabriel Lopes

2000 AMS Subject Classification: 62H30
Key words: cluster analysis, applied statistics, document clustering, text mining, topics extraction.

Recent Results for Supercritical Controlled Branching Processes with Control Random Functions
Miguel Gonzalez
Manuel Molina
Ines del Puerto

2000 AMS Subject Classification: 60J80, 60F05
Key words: controlled branching process, extinction problem, limiting behaviour.

Monte Carlo Method for Reconstruction of the Densities
Sofiya Ivanovska

2000 AMS Subject Classification: 65C05
Key words: Monte Carlo algorithms

Estimation of the Offspring Mean in a General Single-Type Size-Dependent branching process
Christine Jacob
Nadia Lalam

2000 AMS Subject Classification: 60J80,62F12, 62P10
Key words: Size-dependent branching process, Controlled branching process.

On the fractal Burgers equation with a stochastic noisy term
Ekaterina T. Kolkovska

2000 AMS Subject Classification: 60H15, 60H40
Key words: Burgers equation, white noise, weak and strong solutions, Hilbert space regularity.

Branching Particle Representations of a Class of Semilinear Equations
Jose Alfredo Lopez-Mimbela

2000 AMS Subject Classification: 60J80, 60J85
Key words: Markov branching process, semilinear partial differential equation, global and nonglobal solutions, mild solutions

Gait Measurments and Motor Recovery After Stroke
P. Mateev
E. Titianova
I. Tarkka

2000 AMS Subject Classification: 62P10, 92C20
Key words: gait analysis, recovery after stroke.

A Modified Model of Risk Business
Leda D. Minkova

2000 AMS Subject Classification: 60K10, 62P05
Key words: Pуlya - Aeppli risk model, ruin probability, Cramйr - Lundberg approximation.

Limiting Distributions for Lifetimes in Alternating Renewal Processes
Kosto V. Mitov
Nickolay M. Yanev

2000 AMS Subject Classification: 60K05
Key words: alternating renewal processes, spent working time, spent waiting time, residual working time, limiting disributions, infinite mean renewal periods.

Discrete Time Bisexual Branching Processes in Varying Environments
Manuel Molina
Manuel Mota
Alfonso Ramos

2000 AMS Subject Classification: 60J80
Key words: discrete time branching processes, bisexual processes, branching processes in varying environments.

An Estimate of the Probability Pr (X < Y)
Saralees Nadarajah
Georgi K. Mitov
Kosto V. Mitov

2000 AMS Subject Classification: 33C90, 62E99
Key words: beta distribution, bootstrap confidence intervals, exponential distribution, gamma distribution, normal distribution, stress-strength, uniform disribution.

A Stochastic Approach for Finding of Semantically Related Words
Veska Noncheva
Pablo Gamallo
Alexandre Agustini

2000 AMS Subject Classification: 62P99, 68T50
Key words: syntatic context, semantic preferences, c2 goodness of fit test.

On the Equality of Sharp and Germ s -fields for Gaussian Processes and Fields
Loren D. Pitt
Raina S. Robeva

2000 AMS Subject Classification: 60G15, 60G60
Key words: Gaussian processes, Gaussian fields, germ fields, sharp Markov property, spectral syntesis.

Application of Two-phase Regression to Geotechnical Data
Eugenia Stoimenova
Maria Datcheva
Tom Schanz

2000 AMS Subject Classification: 62F10, 62J05, 62P30
Key words: two-phase regression, transition point,air entry value.

Simulation and Robust Modifications of Estimates in Branching Processes
Vessela Stoimenova
D. Atanasova
Nickolay Yanev

Multiple Dipole Source Models for Scalp-Recorded Event-Related Potentials: Example from Complex Visual Processing in the Human Brain

2000 AMS Subject Classification: 62P10, 92C20
Key words: electroencephalography, source modelling, visual recignition.

Classification of Chenopodium Genus Populations and Species Based on Continuous and Categorical Variables
Yanka Tsvetanova
Neli Grozeva

2000 AMS Subject Classification: 62P10, 62H30
Key words: distance between populations based on continuous and discrete variables, genus Ghenopodium, cluster analysis.

Interactive Discriminant Analysis in MATLAB
Dimitar Vandev

Key words: stepwise discriminant analysis linear quadratic MATLAB.

Comparing Several Methods of Discriminant Analysis on the Case of Wine Data
Dimitar Vandev
Ute Romisch

2000 AMS Subject Classification: 62H30, 62J20, 62P12, 68T99
Key words: application linear quadratic discriminant analysis SVM.

Quality Improvement through Experiments with Mixtures