Professor 
Visiting Researcher 
Visiting Researcher 
The Computer Graphics Lab conducts research into physicsbased modeling of different
phenomena, their visualization and animation. Innovative approaches to graphical
user interfaces and direct interaction methods, modeling, rendering, simulation and scientific
visualization are under development. Created mathematical models are used for
graphical representation of natural processes.

[jhpark01:2008] 
Jai Hak Park, Kyu In Shin, Chi Yong Park, and Sung Ho Lee. Allowable
local thickness of wallthinned straight pipes in ASME Code Case N5972.
Int. J. of Pressure Vessels and Piping, 85:620–627, 2008. 
In Code Case N5972, the allowable local thickness of a thinned straight pipe is given
through three different methods. Because of different technical bases, each method
gives different thickness values and sometimes gives contradictory values. So in this
paper attempts were made in order to propose a unified rule for the allowable local
thickness and in order to remove or relax the restrictions on the application of the
code case. For this purpose elastic stress analyses were made using the finite element
method and the stress results were examined. Based on the obtained bending stress
results, a very simple procedure was proposed to obtain the consistent allowable local
thickness for the thinned straight pipes. 

[jhpark02:2008] 
S.H. Lee, J.K. Lee, and J.H. Park. Failure behavior of elbows with local
wall thinning. Modern Physics Letters B, 22(11):845–850, 2008. 
Wall thinning defect due to corrosion is one of major aging phenomena in carbon
steel pipes in most plant industries, and it results in reducing load carrying capacity
of the piping components. A failure test system was set up for real scale elbows
containing various simulated wall thinning defects, and monotonic inplane bending
tests were performed under internal pressure to find out the failure behavior of them.
The failure behavior of wallthinned elbows was characterized by the circumferential
angle of thinned region and the loading conditions to the piping system. 

[niki01:2008] 
Y.Nishidate and G.P.Nikishkov. Atomicscale modeling of selfpositioning
nanostructures. Computer Modeling in Engineering and Sciences, 26:91–1006,
2008. 
Atomicscale finite element procedure for modeling of selfpositioning nanostructures
is developed. Our variant of the atomicscale finite element method is based on a
meshless approach and on the Tersoff interatomic potential function. The developed
algorithm is used for determination of equilibrium configuration of atoms after nanostructure
selfpositioning. Dependency of the curvature radius of nanostructures on
their thickness is investigated. It is found that for thin nanostructures the curvature
radius is considerably smaller than predicted by continuum mechanics equations.
Curvature radius variation with varying orientation of crystallographic axes is also
modeled and results are compared to finite element continuum anisotropic solution. 

[niki02:2008] 
Y.Nishidate and G.P.Nikishkov. Atomicscale analysis of selfpositioning
nanostructures. eJournal of Surface Science and Nanotechnology, 6:301–306,
2008. 
An atomicscale analysis of selfpositioning nanostructures using the atomicscale finite
element method (AFEM) and Kriging interpolation technique is reported. Equilibrium
atomic configurations are modeled for varying nanostructure thicknesses and
results are compared with the plane strain continuum mechanics solution. Significant
decrease of equilibrium curvature radius is observed for thin structures. Large
compressive strains near the free surface have been found. 
[jhpark03:2008] 
Jae Bong Lee, Jai Hak Park, Hong Deok Kim, and Han Sub Chung.
Evaluation of ECT reliability for axial ODSCC in steam generator tubes. In
Proceedings of the 7th ASINCO Workshop, pages 125–134, July 2008. 
In this paper the reliability of ECT inspection system is analyzed quantitatively.
The reliability of ECT is subdivided into the reliability of size and the reliability
of detection. The reliability of size is often characterized as the simplest form of a
linear or linearized regression model with the measured one versus true size data.
The reliability of detection is characterized in terms of the probability of detection
(POD) as a function of flaw size. POD of ECT inspection system for Axial ODSCC
in steam generator tubes is evaluated. Using the loglogistic regression method, POD
is evaluated from hit (detection) and miss (no detection) binary data obtained from
destructive and nondestructive inspection of the cracked tubes. Length and depth
of cracks are considered as variables in multivariate loglogistic regression and their
effects on detection capacity are assessed. The detail method of loglogistic regression
and some cautions that can be introduced in the calculation of the likelihood
estimator are also mentioned. 

[niki03:2008] 
G.P.Nikishkov and Y.Nishidate. Atomicscale modeling of anisotropy effects
in nanostructures. , A2. In Symposium on Surface and Nano Science
SSNS9, pages A–2, Shizukuishi, Iwate, Japan, 27–30 January 2009. 
Effect of material anisotropy on the curvature radius of rolledup nanostructures is
investigated using the finite element method with appropriate transformation of the
elasticity tensor. For bilayer GaAsInAs nanostructures, dependency of the curvature
radius on the material orientation angle follows periodic curve with the maximum curvature
at material orientation angle 45 and 135 degrees. Direct modeling of material
anisotropic effects is performed with the atomicscale finite element (AFEM) method
based on the Tersoff interatomic potential. The AFEM modeling of anisotropy effects
is based on changing orientation of atomic planes during creation of atomic
models. The developed AFEM code is applied to modeling of GaAsInAs bilayer
selfpositioning nanostructures with different orientation of crystallographic axes. 

[niki04:2008] 
K. Kanev, Z. Cheng, and N. Mirenkov. Methods and Technologies for
Enhancing and Optimizing Power Plant Inspection Procedures. In Proceed
ings of the 7th IEEE International Conference on Computer and Information
Technology (CIT 2007), pages 605609, 2007. 
This paper considers different methods and approaches for improving power
plant inspection procedures through innovative technological means. Main objectives are to provide timely, context dependent assistance and advice to
human inspectors of power plant facilities, to minimize human errors and
to increase inspection efficiency and reliability. A solution based on spatial
awareness methods for inspector localization, registration and tracking
through remote sensing of RFID tags and digital codes embedded in the
surrounding environment is proposed. Possible extensions for industrial inspection
robots are briefly discussed and potential applicability in nuclear
power plant inspections is revealed. 

[niki05:2008] 
G.P.Nikishkov. SGBEMFEM modeling of stress corrosion cracking. In
16th Pacific Basin Nuclear Conference (16PBNC), pages P16P1159–1–6, Aomori,
Japan, 13–18 October 2008. 
SGBEMFEM computational procedure is used for modeling of crack growth under
stress corrosion cracking (SCC) conditions. The crack is modeled by the symmetric
Galerkin boundary element method (SGBEM). The finite element method (FEM)
is used for stress analysis of the uncracked structural component. The solution for
the structural component with the crack is obtained in an iterative procedure, which
alternates between FEM solution for the uncracked body, and the SGBEM solution
for the crack in an infinite medium. Computational procedure for SCC crack growth
is developed. Crack growth criterion in the threedimensional case is based on the
Jintegral vector. 

[niki06:2008] 
Y.Nishidate and G.P.Nikishkov. Atomicscale modeling of rolledup thin
films. In Int. Symp. on Graphene Devices: Technology, Physics and Modeling
(ISGD 2008), pages W1–4, AizuWakamatsu, Japan, 17–19 November 2008. 
Recently, we developed an atomicscale finite element (AFEM) procedure for modeling
of bilayer GaAs/InAs rolledup nanostructures. The AFEM can consider atomicscale
characteristics of the rolledup nanostructures. The developed AFEM program
has been applied for investigating dependency of curvature radius on the structure
thickness and crystal orientations. 
[niki07:2008] 
E.M.Morozov and G.P.Nikishkov. The Finite Element Method in Fracture
Mechanics. URSS, Moscow, Russia, 2008. 
The book presents finite element algorithms and their use for solution of linear and
nonlinear fracture mechanics problems. 
[niki08:2008] 
G.P.Nikishkov and Y.Nishidate. Continuum and atomicscale modeling of
selfpositioning microstructures and nanostructures, pages 271–294. Trends in
Engineering Computational Technology. SaxeCoburg, Stirlingshire, Scotland,
2008. 
This article presents investigations of selfpositioning microstructures and nanostructures
by analytical techniques, finite element analysis and atomicscale modeling.
Closedform solutions for curvature radius of selfpositioning hinge structures are obtained
for plane strain and generalized plane strain deformation. The finite element
method is used for predicting hinge curvature radius for selfpositioning structures of
variable width and anisotropic structures. An algorithm of the atomicscale finite element
method (AFEM) based on the Tersoff interatomic potential has been developed.
The AFEM is applied to modeling of GaAs and InAs bilayer selfpositioning nanostructures. 
[niki09:2008] 
Gennadiy Nikishkov. Tohoku Nuclear Cluster, 2008. 
[niki10:2008] 
Gennadiy Nikishkov, 2008. Member of the Editorial Board, International Journal ’Computer Modeling in Engineering and Sciences’. 
[niki11:2008] 
Gennadiy Nikishkov, March 2009. Member of the Program Committee, Int. Conf. on Computational and Experimental Engineering and Sciences ICCES 2009, Phuket, Thailand. 
[niki12:2008] 
Gennadiy Nikishkov, February 2009. Member of the Program Committee, Int. Conf. on Computer Graphics Theory and Applications GRAPP 2009, Lisboa, Portugal. 
[niki13:2008] 
Gennadiy Nikishkov, October 2008. Section chair, The 16th Pacific Basin Nuclear Conference (16PBNC), Aomori, Japan. 
[niki14:2008] 
Gennadiy Nikishkov, July 2008. Member of the Program Committee, IEEE 8th International Conference on Computer and Information Technology (CIT2008), Sydney, Australia. 
[niki15:2008] 
Gennadiy Nikishkov, June 2008. Member of the Program Committee, International Conference on Computational Science (ICCS’2008), Krakow, Poland. 
[niki16:2008] 
Gennadiy Nikishkov, September 2008. Member of the Editorial Board, Ninth International Conference on Computational Structures Technology CST 2008, Athens, Greece. 
[niki17:2008] 
Gennadiy Nikishkov, 2008. Reviewer, Computers and Structures. 
[niki18:2008] 
Gennadiy Nikishkov, 2008. Reviewer, Journal of ASTM International. 
[niki19:2008] 
Gennadiy Nikishkov, 2008. Reviewer, Journal of Virtual Reality and Broadcasting. 
[niki20:2008] 
Youhei Nishidate. PhD Thesis: Modeling of selfpositioning nanostructures,
University of Aizu, 2009.
Thesis Advisor: Gennadiy Nikishkovv 
[niki21:2008] 
Akiha Iwase. Master Thesis: Augmented virtuality for 3D data visualization,
University of Aizu, 2009.
Thesis Advisor: Gennadiy Nikishkov 
[niki22:2008] 
Mio Kanai. Graduation Thesis: Augmented reality for learning environment,
University of Aizu, 2009.
Thesis Advisor: Gennadiy Nikishkov 
[niki23:2008] 
Satoru Ishibashi. Graduation Thesis: Performance of 3D graphics on
mobile devices, University of Aizu, 2009.
Thesis Advisor: Gennadiy Nikishkov 