1
Report of three presentations on graduate
seminar
Fenye Bao
Abstract—This report concluded three presentations on the
graduate seminar of Department of CS, Virginia Tech (NVC).
Index Terms—summary, seminar, Virginia Tech
I. SUMMARIES
A. Spatial Computing for Supporting Geographic Science
This presentation was given by Professor Chaowei Yang on
September 4, 2009.
In geographic information science, the analysis and
simulations are computing intensive, which is hardly to be
supported by single computer. During this talk, Prof. Yang
introduced the spatial computing and its objective. Spatial
computing refers to the computing that utilizes the spatial
principles and distributed computers for enabling the
advancements of geographic sciences. The hardware
infrastructure they built for spatial computing is a distributed
computing environment among several universities and
institutions in the United States. He also presented three
research examples in geographic sciences which are supported
by spatial computing. The first application example is the
geographic data and service discovery and access. The second
example is utilizing HPC (High Performance Computing) in
the distributed environment to support the computing in
geographic applications. The third example is the geospatial
data visualization supported by spatial computing. He demoed
the projects of data and service discovery and geospatial data
visualization.
The infrastructure for spatial computing is mainly supported
by high performance computing and grid computing
technologies which heavily depend on the network routing and
transactions and the granularity of the grid. Prof. Yang also
demonstrated that how the performance of the system is
affected by the network routing and the size of the grid. Best
on their evaluation to the system, the optimal grid size can be
found.
Some of their work can be found at: [1-2].
B. Adiabatic Quantum Computation
This presentation was given by Professor Vicky Choi on
September 25, 2009.
Quantum Computation can be utilized to solve NP-hard
problems by designing quantum algorithms. Adiabatic
Quantum Computation (AQC) is a quantum model which has
been proven to be equivalent to conventional quantum
computation. Prof. Vicky Choi presented the maximum
independent set problem (MIS, which is a maximum problem),
the Ising Problem (which is a minimum problem), and the
correspondence of solving the Max problem by Min problem.
She briefly introduced the Quantum Computation. A classical
bit is 0 or 1, which a Qubit (quantum bit) is a superposition of
the quantum |x> = C0|0> + C1|1>, |C0|2 + |C1|2 = 1. The
measurement of |x> is 0 with the probability of |C0|2 and 1 with
the probability of |C1|2. The classical computation is discrete,
which the Adiabatic Quantum Computation is continuous. The
Adiabatic Quantum Computation utilizes Hamiltonian which is
a 2n by 2n complex matrix. The MIS problem and factoring
problem can be solved in polynomial time with AQC
algorithm, causing the widely used encryption methods, like
RAS etc. to be broken. There are also fundamental issues of
AQC to be solved in analysis and design of AQC algorithms,
How to design a “good” initial Hamiltonian? How to design a
best encoded final Hamiltonian? How to design the evolution
path?
Her work on this topic can be found in paper [3]. She also
has a US patent[4] in this field.
C. From Atoms to Material Properties: Basic Physics in the
Development of New Nano-materials
This presentation was given by Professor Diana Farkas on
October 9, 2009.
Materials are mostly designed by nature. The physics and
material science development bring the concept of “materials
by design”. Prof. Farkas firstly introduced the multiscale
physics in the dimensions of time and length. Their research
focuses on the scale between Quantum mechanics (QC) and
Molecular Dynamic (MD). The basic concept is the
interatomic potential. The interatomic potential will increase
when the distance between atoms is either too far or too close.
Their research includes the visualization and simulation of
material properties with the clustering computing environment
in Virginia Tech. They simulated and visualized the material
cracks in 3-dimensions with different structures. Their
experiments illustrate that the path of material crack follows
some patterns formed by the defects in nano-scale inside the
material and the material becomes harder when increasing the
stress, but not hard again if the stress beyond a certain
threshold. Finally, she concluded that the current computing
power allows the simulation of material properties and the
2
simulation can reach smallness as tested in the real materials.
Prof. Farkas also pointed that the computer clusters at Virginia
Tech is very powerful and convenient to use. Today, there are
many software libraries available for simulation in this area.
It’s easier than years ago to conduct the experiments even for
new researchers.
II. QUESTION DISCUSSION
Question: How far is the applicable quantum computation
from us?
Answer: There was a quantum computing talked with title
“Quantum Computing – how far have we come, and where will
we end?” We may still have image of the appearance of the
first real quantum computer which depends on physics,
computer science, electronic engineering, etc.
REFERENCES
[1] AAG
Cyberinfrastructure
Specialty
Group.
Available:
http://cisg.gmu.edu/
[2] Joint Center for Intelligent Spatial Computing at George Mason
University. Available: http://www.cisc.gmu.edu/
[3] V. Choi, "Minor-embedding in adiabatic quantum computation: I. The
parameter setting problem," Quantum Information Processing, vol. 7,
2008.
[4] G. Rose, et al., "SYSTEMS, DEVICES, AND METHODS FOR
INTERCONNECTED PROCESSOR TOPOLOGY," US Patent, 2008.