Download Assignment on Principles of Visualization

Assignments - Principles of Visualization
Group-4
Khandaker Tabin Hasan, Md. Fakhrul Islam, Md. Shafiul Alam Chowdhury
Md. Mahfuz-Ur-Rahman, Muhammad Shahid Nawaz
Royal Institute of Technology (KTH)
Department of Computer and System Sciences
Forum 100, 16400 Kista, Stockholm, Sweden
[email protected], [email protected], [email protected], [email protected],
[email protected]
Abstract
This report describes two assignments named ‘Construction of
2D Data Diagrams for the Distribution, leafing period and
defoliation of five different trees in North America’ and
‘Construction of Interactive Visualization of the Life and
Death of Sun’ respectively. In the first assignment we used
different visualization techniques that enable user to retrieve
information easily from a color and grayscale map about the
distribution, leafing period and defoliation of different trees in
North America, while in the second assignment, we have
developed an interactive 3D application that visualizes the life
cycle of a medium size star.
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Balsam Flr (Abies balsamea)
White Ash (Fraxinus americana)
Quaking Aspen (Populus tremuloides)
American Beech (Fagnus grandifolia)
River Birch (Batula nigra)
Key words
Leafing period, defoliation, distribution, supernovae, black
hole.
Introduction
If our extraordinary skill in perceiving the information
inherent in the environment can be applied to data
visualization, we will have gained a truly powerful tool (Colin
Ware 2000). A 2D Diagram has been used to represent
distribution, leafing period and defoliation of five different
species in North America. In the second assignment our main
concern was to develop an application that involves user
interaction. Video animation for different phases of the life
cycle of a Star has been created using 3D Max Software and
Macromedia Flash has been used to construct interaction
between different phases from the birth to the death of a Star.
Fig: Leafing and Defoliation of different species
Description of Assignment 01 (one)
In our first assignment we have developed two topological
maps, one in multi-color format and another in grayscale
shape. Both show the distribution, leafing period and
defoliation of five different species geographically distributed
in different places of North America. It can be called
topological map since it contains visual information regarding
the mountain, river, plain land etc. In order to distinguish the
distribution and density of different species in the map, five
different symbols with different color and shape have been
used. Moreover, different patterns of symbols representing
different species enable users to differentiate them in the
grayscale map. The table below shows the seasonal
transformation of different species along with their leafing and
defoliation. We have tried to make both the maps simpler as
well as convenient for the user to visualize the information
whenever s/he goes through it. Following five species of
North America have been chosen -
Fig: 2D color representation for the distribution of different
species in North America.
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Fig: 2D Grayscale representation for the distribution of
different species in North America.
Main Sequence Phase:
Upon completion of Contraction Phase, the star becomes a
fixed star or an "adult" Star and enters the Main Sequence
Phase. In this phase, stars produce energy as the result of a
nuclear reaction that creates one helium atom from every four
hydrogen atoms. As a consequence, the amount of hydrogen in
the star gradually decreases, while the helium increases.
Fusion creates heavier elements from lighter elements and
releases energy (Photons) which travel outward from the core
of the star and eventually escape from the surface of the star
(This is the light we see from the star). It is the longest period
in a star's life, and in the case of a star with a mass similar to
that of our Sun, lasts for about 10 billion years.
Description of Assignment 02 (two)
Stars are born from nebulae and consist mostly of hydrogen
and helium gas. Surface temperatures range from 2000ºC to
above 30,000ºC, and the corresponding colors from red to
blue-white. The brightest stars have masses 100 times that of
the Sun and emit as much light as millions of Suns. They live
for less than a million years before exploding as supernovae.
Stars have a life cycle just like everything else in the universe.
Its life begins with its condensation out of the interstellar gas
and ends, sometimes catastrophically, when the star has
exhausted its nuclear fuel or can no longer adjusts itself to a
stable configuration. After a star is born, it goes through its
adolescence and adulthood until it finally gets old and dies.
The death of a star can either be quiet calm or dramatic and
violent, which is what happens when a supernova occurs.
Giant Star Phase
The helium at the center of the star continues to increase until
a helium core is formed. Nuclear reaction then begins to
spread outward. As the helium core grows heavier, the core's
temperature also increases, and the outer layers begin to
expand until the star becomes a massive red star known as a
Red Giant. Hydrogen fusion reactions become less efficient in
the core region of red giant star and with the gravitational
collapse of the core, the fusion reactions now occur in a shell
surrounding the core. This increases the luminosity of the star
enormously (up to 1000 times the Sun). In the case of a star
that is about the size of our Sun, the gases of the outer layer
are expelled, and then contract, so that the star becomes what
it known as a White dwarf. The giant star phase is about one
tenth as long as the main sequence star phase.
Phases in the life of a Star
There are mainly four phases in the life cycle of a star. Brief
description of those phases is given below:
Contraction Phase:
Outer space which is filled very thin clouds of hydrogen,
helium and dust like interstellar particles which are the raw
materials of future stars. Clusters of interstellar particles
attract more and more other particles, and gradually its size
increases. The temperature and density are the highest at the
center of the cloud, where a new star will eventually form. The
object that is formed at the centre of the collapsing cloud and
which will become a star is called a Protostar. Eventually, the
cluster begins to contract by virtue of its own gravity. At this
stage, a nuclear reaction begins when the core temperature
reaches around 10 million degrees. The period up until this
point is known as the "Contraction Phase" and, it takes about
500 million years for a star which has mass similar to that our
Sun.
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In our Interactive Visualization Assignment, We have
designed and created an application which shows the four
phases mentioned above. Tools that have been used to create
the application are 3D Studio Max for creating the animations
and Macromedia Flash for the interactive presentation of
information.
We have used a all presentations in a window and vertical
toolbar to move between different phases of sun.
In our application, both text and video animation have been
used to provide necessary information so that user can
visualize the life cycle both ways.
Supernova Phase:
A Supernova is a very massive star that explodes at the end of
its life cycle. When a star's mass is about three times that of
our Sun, after the red giant phase, it begins to collapse under
its own weight, causing a supernova explosion that scatters it
through space. Its brightness at this point will be 100 billion
times that of the Sun. When this happens, it looks as if a bright
new star has appeared in the night sky.
Conclusion
In our visualization techniques, we have considered optical
flow, surface and gradients, lightness and other techniques.
Many suggestions have been obtained during the presentation
of our work and it could be improved more comprehensively.
We tried interactive animation in our second assignment with
little success due to lack of time as we planned developing a
full application for a richer user experience.
Acknowledgement
Thanks to Lena Norberg for her hearty cooperation, guidance
and support.
Reference
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http://www.telescope.org/pparc/res8.html
http://spaceinfo.jaxa.jp/note/hoshi/e/hos01_e.html
http://www.dustbunny.com/afk/stars/lifecycle/