APPLICATION OF DIGITAL WATERMARKING
Galina T. Bogdanova, Todor J. Todorov
Institute of Mathematics and Informatics,
BAS, Veliko Tarnovo
Received: 25.09.05; Cited:
28.01.06
Abstract:
We present
some basic methods for image and text securing to embed
watermarks in the demo version of the WEB-based Database of
Folklore documents. Interest in digital watermarks has grown out
of an increasing interest in intellectual property and copyright
protection. A digital watermark is a visible or perfectly
invisible, identification code that is permanently embedded in
the data and remains present within the data after any
decryption process. Requirements and design of watermarking
techniques are impacted by the different types of content in two
major ways: imperceptibility and robustness requirements.
Key words:
Computer systems and Web technologies, Steganography, Folklore,
Databases, PHP
Pages 1-12
MODELING AND EXPERIMENTAL INVESTIGATION OF EFFECT
OF STEERING
ANGLE ON BRAKING FORCE
Recai Kusa, Ugur Taskiran,
Huseyin Bayrakceken
Selcuk, University, Technical Education Faculty, Campus, Konya/TURKEY
Afyon Kocatepe University, Technical Education Faculty, Afyon/TURKEY
Received: 25.02.06;
Cited: 14.03.06
Abstract:
The numbers of variables which affect the movement of the
vehicle during the braking are many. To extract the state of
braking system, different brake tests are applied and
mathematical models are derived. In this study, a TOFAS 1993
model Sahin brand automobile is used. The variations of braking
force are investigated for different steering angles
(0-3-6-9-12-15) and different pedal forces experimentally and a
simple mathematical model is derived. Experimental results and
mathematical model results are compared and approximately an
error of 5.8% is calculated.
Key words:
Braking, braking force, vehicle safety, mathematical model,
braking test.
Pages 13-23
SYNTHESIS OF COBALT TITANATES AND THEIR STABILITY
IN SULPHATE
SOLUTIONS
Plamen D. Tsokov, Vladimir N. Blaskov, Yavor
Sv. Stefanov, Tsvetan M. Dobrev
Institute of General and Inorganic
Chemistry, BAS,
Acad.G.Bonchev str., bl. 11, 1113, Sofia,
Bulgaria
Institute of Physical Chemistry, BAS, Acad.G.Bonchev str.,bl 11,1113, Sofia, Bulgaria
Received: 25.02.06;
Cited: 14.03.06
Abstract:
A powder polycrystalline CoTiO3
has been synthesized by the sol-gel method using CîCl2.6H2O
and TiCl4 .The obtained samples are characterized by
XRD and IR spectroscopy. The investigations on the stability of
CoTiO3 in sulphate electrolytes for
electroextraction of Zn give grounds to ascertain that this
compound is a promising one in application as
anodic
material.
Key words:
CoTiO3,
sol-gel,
stability, sulphate solutions
Pages 24-33
INVESTIGATIONS ON THE CONTACT ZONE OF
HIGH-PERFORMANCE
FINE-GRAINED SLAG CONCRETE
Violeta J.
Petkova-Ruseva*,
Evelina M. Simeonova - Ivanova
Central Laboratory of Physico-Chemical Mechnics,
BAS, 1113 Sofia, Bulgaria
Received: 25.02.06;
Cited: 14.03.06
Abstract:
Phase composition, grain size
and filler surface are very important for the formation of a
contact zone with good adhesive strength and micro hardness. The
desired properties of a new high-performance slag concrete for
construction purposes were achieved using a binding substance
and fine-grained
filler with similar chemical nature. The initial components
were: slag Portland cement, artificial fine-grained aggregate
materials and a new active additive, modifying the concrete mix
consistence.
X-ray powder diffraction and scanning
electron microscopy were used to determine the kind, composition
and morphology of the hydrate phases in granulated acidic slag
and hydrated slag Portland cement stone as well as of the same
samples in the contact zone. The presence of a diffuse
intermediate layer of tobermorite products in the contact zone
was proved. The contribution of each phase to the structure
density and the high strengths of the new fine-grained slag
concrete are analyzed separately.
Key
words:
New Active Additive,
Contact Zone, Hydration Phases, Tobermorite Products
Pages 34-45
NUMERICAL ANALYSIS OF FLOWS NEAR LOCAL VENTILATION EXHAUSTS
ON
THE BASIS OF METHOD OF DISCRETE VORTEXES
Konstantin I. Logachev, Alexei I. Puzanok, Elena
V. Selivanova
Belgorod state technological university named
after V.G. Shukhov,
Russia, 308012, Belgorod, Kostyukova St., 46
Received: 25.02.06;
Cited: 19.03.06
Abstract:
The algorithm of numerical analysis of
vortex-type flows in ventilation streams on the basis of method
of discrete vortexes is stated. With use of the computer
program, developed on the basis of method of discrete vortexes,
the outlines of the first vortex zone at the entrance to
slit-like and round exhausts with flanges were calculated and
the formula describing them was found. Profiling exhausts with
flanges by the found outlines decreases power-consuming of an
exhaust due to lowering its aerodynamic resistance.
Air flow near an exhaust with flanges,
shielded by round stream flowing from the end of the flange, was
analyzed. Use of energy of the returned flow of such a stream,
flowing onto impermeable plain, allows to increase pivotal speed
of air near the exhaust by dozens of times, and as a consequence
considerably increase its effectiveness of catching pollutants.
The received results can be
used in design of effective energy-efficient systems of local
exhaust ventilation.
Key
words:
aspiration, local exhaust, method of discrete vortexes.
Pages 46-60
Digital Art and Design
Khaled Batiha, Safwan Al-Salaimeh,
Khaldoun A.A. Besoul
Irbid National University, Faculty of information
technology
Irbid, The
Hashemite Kingdom of Jordan
Received: 25.02.06; Cited: 19.03.06
Abstract:
The desire to create
unique things and give free rain to one's imagination served as
a powerful impetus to the development of digital art and design
software. The commoner was the use of computers the wider
variety of professional software was developed. Nowadays the
creators and computer designers are receiving more and more new
and advanced programs that allow their ideas becoming virtual
reality. This research paper looks at the history of the
development of graphic editors from the simplest to the most
modern and advanced. This brief survey includes the history of
different graphic editors’ creation, their features and
abilities. This paper highlights the two basic branches of
graphic editors – these that are in free use and commercial
graphic editors design software. The researcher selected the
most powerful and influential graphic editors design software
brands like Paint.NET and GIMP among free software and
commercial Adobe Photoshop. This paper also dwells upon the way
digital art transferred from the exclusively professional
business into the hobby for ordinary users. This research paper
bears implications for those who are interested in features and
potentiality of most popular graphic editors design software.
Key words:
Digital Art, Graphic information,
Dpaint, Image Manipulation
Program, Paint Shop Pro, Photopaint,
Photoshop.
Pages
61-70
PRINCIPLES OF INSTRUCTIONAL DESIGN AND
THEIR IMPLEMENTATION
IN LEARNING CONTENT CREATION
Korneliya
Todorova Yordanova
Faculty of
Mathematics and Informatics , James Bauchier Str. 3, Sofia,
Bulgaria
Received: 25.02.06; Cited: 19.03.06
Abstract:
Implementation of main principles of
instructional design in e-learning content design and
development is presented in this paper. Phases and rules for
systematic process of design of
instruction
are discussed. It is described how they are applied in a course
in the field of e-learning.
One of the most important problems in the
field of e-learning is development of high quality and effective
learning content. For this purpose principles for design of
learning content have been developed. In this paper these
principles have been overviewed, discussed and applied.
Learning content in the field of e-learning
was created to demonstrate the discussed principles and rules.
Needs analysis and assessment, tasks analysis, and learner
analysis has been done and instructional strategies for
instruction of different types of learning goals have been
applied. The categories defined by Gagne taxonomy for learning
outcomes have been used – declarative knowledge, psychomotor and
intellectual skills (concepts, principles, domain-specific
problems) and attitudes and cognitive theories.
They have been illustrated by several
diagrams for information-processing analysis and prerequisite
analysis.
The developed materials are evaluated and
their quality has been discussed and assessed.
Key words:
Instructional Design (ID) analysis,
instructional strategies, evaluation, learning outcomes,
declarative knowledge, psychomotor and intellectual skills,
attitudes, cognitive theories
Pages
71-85
SWITCHING EFFECTS IN OXIDES OF VANADIUM,
NICKEL AND ZINC
Alexander
Pergament, Genrikh Stefanovich, Andrey Velichko,
Ilya
Melnichenok, Elena Kotsuba, Victor Romanov
Petrozavodsk State University, 185910, Petrozavodsk, Russia
Received: 25.02.06; Cited: 19.03.06
Abstract:
The results
on electroforming and switching in thin-film MOM structures with
oxides of V, Ni, and Zn are presented. It is shown that
the switching mechanism in transition
metal oxides (VO2, NiO) is caused by the
electronically-induced Mott metal-insulator transition. Memory
switching in the vanadium, nickel, and zinc oxide based MOM
structures is also studied, and possible mechanisms of this
effect are discussed.
Key words: switching,
metal-insulator transition, thin films, metal oxides
Pages
86-100
Finite element modeling for interpretation
of orthotropic polymeric
composites mechanical tests results
Alexander V. Fomin, Olga D. Pahanyan,
Barbara S. Shevtsova2, Maria S. Shevtsova
1
Department of Aviation
Engineering,
Don State Technical
University,
Rostov-on-Don,
Russia
2
Department of Mechanics
& Applied Mathematics,
Rostov State University,
Russia.
Received: 25.02.06; Cited:
19.03.06
Abstract:
The fast development of
high-strength composites structures and technologies require to
operatively modernize the experimental techniques for its
mechanical characteristics test. The specific feature of such
materials is that often the specimens can be received only by
cutting out them from a finished product - material properties
of specially worked sample can differ from properties of
finished product material sufficiently. In this case, saving
working zone geometry of defined by standards (ASTM, SACMA,
Agate etc.) specimens it is necessary to change a design of
grabs. Such modernization of a technique inevitably makes
modifications in stress-strain distribution into a specimen. The
satisfactory solution of a problem can be obtained by use of
finite element calculations initially utilizing results of other
independent physical tests. To agree the calculations results
and experimental data obtained with modernized specimens the
iterative technique is applied. Effectiveness of this technique
is illustrated on example of orthotropic polymeric composite
elastic constants determination.
Key words:
polymeric composite, elastic constant,
mechanical tests, finite element modelling
Pages
101-121
Antonios Papadopoulos, Ioannis Takos and
Dimitrios Emmanouloudis
Technological Educational
Institute of Kavala, Department of
Forestry and Management of
Natural Environment, 66100, Drama, Greece
Received: 21.12.06; Cited: 22.12.06
Abstract:
Elm wood was esterified with acetic and maleic anhydride and
studied for moisture adsorption behaviour. The sorption
isotherms for untreated and chemically modified wood were
analysed using the Hailwood-Horrobin model. The experimental
analysis of the sorption isotherms showed that esterification
affects total, polymolecular, and monomol-ecular sorption.
Acetic anhydride treatment was found more effective in reducing
the hygroscopicity of wood compared to maleic anhydride
treatment at comparable weight percentage gain.
Keywords:
Chemical modification, Acetic anhydride, Maleic anhydride,
Sorption, Hailwood-Horrobin model
Pages
122-133
