• The Journal of the Korea Contents Association
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• v.10 no.10
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• pp.68-77
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• 2010

In the case of operating steam generators for long periods in nuclear power plants, sludge is accumulated inside the steam generator. This phenomenon could adversely affect the operation of the steam generator. This paper is about the design of a sludge washing apparatus which can remove the sludge efficiently and the control methods of the apparatus. In this paper, to design the sludge washing apparatus, firstly, we design nozzles for spraying high-pressure water through applying mathematical models and lab tests. Secondly, we establish the mathematical theory for performance parameters required to drive the sludge washing apparatus. Thirdly, we design physical structures of the apparatus based on the established performance parameters. Finally, we present the control methods of the apparatus. The sludge washing apparatus presented in this paper moves along the walls of the steam generator according to cracks in the tube array, and spray the high pressure water to remove the sludge. By this way, a relatively large amount of sludge formed in the inner surfaces can be washed very effectively.

• Journal of the Korean institute of surface engineering
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• v.53 no.3
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• pp.116-123
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• 2020

Ion beam irradiation induces self-organization of nanostructure on the surface of polymer film. We show that the incident angle of Ar ions on polyethylene naphthalate(PEN) film changes self-organized nanostructure. PEN film was irradiated by argon ion beams with the ion incident angle of 0°, 30°, 45°, 60°, and 80°. Nanostructure was altered from dimple to ripple structure as the angle increases. The ripple structure changed to pillar structure after 60°due to that the shallow incident angle increased the ion energy transfer per depth up to 50 eV/Å, which value could induce excessive surface heating and oligomer formation reacting as a physical mask for anisotropic etching. And quantitative analysis of the nanostructures was adapted by using ABC model and fractal dimension theory.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.1_2
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• pp.119-127
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• 2006

Real-time animation of human figures in virtual environments is an important problem in the context of computer games and virtual environments. Recently, the use of large collections of captured motion data have added increased realism in character animation. However, assuming that the virtual environment is large and complex, the effort of capturing motion data in a physical environment and adapting them to an extended virtual environment is the bottleneck for achieving interactive character animation and control. We present a new technique for allowing our animated characters to navigate through a large virtual environment, which is constructed using a small set of building blocks. The building blocks can be tiled or aligned with a repeating pattern to create a large environment. We annotate each block with a motion patch, which informs what motions are available for animated characters within the block. We demonstrate the versatility and flexibility of our approach through examples in which multiple characters are animated and controlled at interactive rates in large, complex virtual environments.

• The Journal of the Korea Contents Association
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• v.12 no.7
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• pp.183-193
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• 2012

The purpose of the formation of the regional community is to draw community formation strategy for effective resolve the conflicts. Along with thesis of the regional community theory, this study sought strategy plan through cheonan regional people investigate. Feeling of satisfaction, sense of common bonds, sense of belonging could showed relation of high existence, and know that duplex sense of belonging acts greatly in desire of social activities in interrelationship study finding, regional community and participation of resident. Essential factor of regional community formation is as following. First, it is application to the strategy of the formation of the regional community that can correspond to special quality of various area and request of inhabitantses. Second, the regional community's formation needs the local governments' active support, the cooperation, comprehension and voluntary effort of the regional people. Ideal regional community that we think gets joined conclude the relation as well as physical plenty and equality realization of social structure that is matured because awakening of conduced wholesome accident.

• Smart Structures and Systems
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• v.18 no.1
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• pp.139-154
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• 2016

This paper is concerned with the dynamics of hyperelastic solids and structures. We seek for a smart control actuation that produces a desired (prescribed) displacement field in the presence of transient imposed forces. In the literature, this problem is denoted as displacement tracking, or also as shape morphing problem. One talks about shape control, when the displacements to be tracked do vanish. In the present paper, it is assumed that the control actuation is provided by imposed eigenstrains, e.g., by the electric field in piezoelectric actuators, or by thermal actuators, or via analogous physical effects, such as magneto-striction or pre-stress. Structures with a controlled eigenstrain-type actuation belong to the class of smart structures. The action of the eigenstrains can be conveniently characterized by actuation stresses. Our theoretical derivations are performed in the framework of the theory of small incremental dynamic deformations superimposed upon a statically pre-deformed configuration of a hyperelastic solid or structure. We particularly ask for a distribution of incremental actuation stresses, such that the incremental displacements follow exactly a prescribed trajectory field, despite the imposed incremental forces are present. An exact solution of this problem is presented under the assumption that the actuation stresses can be tailored freely and applied everywhere within the body. Extending a Neumann-type solution strategy, it is shown that the actuation stresses due to the distributed control eigenstrains must satisfy certain quasi-static equilibrium conditions, where auxiliary body-forces and auxiliary surface tractions are to be taken into account. The latter auxiliary loading can be directly computed from the imposed forces and from the desired displacement field to be tracked. Hence, despite the problem is a dynamic one, a straightforward computation of proper actuator distributions can be obtained in the framework of quasi-static equilibrium conditions. Necessary conditions for the functioning of this concept are presented. Particularly, it must be required that the intermediate configuration is infinitesimally superstable. Previous results of our group for the case of shape control and displacement tracking in linear elastic structures are included as special cases. The high potential of the solution is demonstrated via Finite Element computations for an irregularly shaped four-corner plate in a state of plain strain.

• Korean Journal of Acupuncture
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• v.32 no.3
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• pp.81-89
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• 2015

Objectives : The purpose of this study is to explore the trends of acupoints used for lumbar HIVD(Herniated Intervertebral Disc) and treatment and anatomical location of Hwatahyeopcheock. Methods : We searched the latest clinical studies on acupuncture treatment for lumbar HIVD(Herniated Intervertebral Disc) through domestic studies search. To analyze the data, we categorized them by year and article types of literatures and investigated often-used acupoints and acupuncture types for treatment by reading treatment part of every paper searched. Domestic and Chinese literatures related to Hwatahyeopcheock were also studied for its anatomical location. Results : Total 50 articles are searched and local points are more used than distant points for lumbar HIVD(Herniated Intervertebral Disc) and most of them showed curative effects. Back-su points were used the most and Hwatahyeopcheock use accounted for one-third of the articles. In the articles of Hwatahyeopcheock use, except for one, patients complained of both low back pain and radiating pain, and all of them showed positive results after treatment. Conclusions : Back su point is considered to have its meaning as physical region where patients feel pain including herniated disc level rather than the effect meridian system makes. Through document research and meridian muscle theory, we found that Hwatahyeopcheock means vertebral facet joint, intervertebral foramen and surrounding muscle, nerve, blood vessel and related spinal nerves.

• Journal of Music and Human Behavior
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• v.9 no.2
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• pp.19-34
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• 2012

The purpose of this study was to investigate the empirical elements of non-Korean traditional musicians in the process of Pansori music listening. 5 non-Korean traditional musicians who are not professionally trained Korean music were participated in this study. The data were collected in depth interviews and analyzed from modified ground theory method. The findings showed that the elements of performer's voice, Chang-bub, contents, Gosu's buk sound and Gosu's role evoked various physical, emotional reponses and thoughts in all listeners. Through these responses the listeners awared internal issues related to inner problems and positive intervention aroused inner feelings. Also, emotional responses and awareness were reorganized their negative emotion and resolved through the different dimension of Pansori music.

• Journal of KIISE:Computer Systems and Theory
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• v.28 no.12
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• pp.620-631
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• 2001

In interactive environments including computer games and virtual reality applications, we have increased need for interactive control of articulated body motions. Recently, physically based methods including constrained dynamics techniques are introduced to this area, in order to produce more realistic animation sequences. However, they are hard to achieve real-time control of articulated bodies, due to their heavy computations. In this paper, we present a procedural method for interactive animation of articulated bodies. In our method, each object of the constrained body is first moved according to their physical properties and external forces, without considering any constraints. Then, the locations of objects are adjusted to satisfy given constraints. Through adapting this two-stage approach, we have avoided the solving of large linear systems of equations, to finally achieve the interactive animation of articulated bodies. We also present a few example sequences of animations, which are interactively generated on PC platforms. This method can be easily applied to character animations in virtual environments.

• Journal of Information Processing Systems
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• v.15 no.6
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• pp.1350-1364
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• 2019

The ice damage occurs frequently in cold and dry region of western China in winter ice period and spring thaw period. In the drift ice condition, it is easy to form different extrusion force or impact force to damage tunnel lining, causing project failure. The failure project could not arrive the original planning and construction goal, giving rise to the water allocation pressure which influences diversion irrigation and farming production in spring. This study conducts the theoretical study on contact-impact algorithm of drift ices crashing diversion tunnel based on the symmetric penalty function in finite element theory. ANSYS/LS-DYNA is adopted as the platform to establish tunnel model and drift ice model. LS-DYNA SOLVER is used as the solver and LS-PREPOST is used to do post-processing, analyzing the damage degrees of drift ices on tunnel. Constructing physical model in the experiment to verify and reveal the impact damage mechanism of drift ices on diversion tunnel. The software simulation results and the experiment results show that tunnel lining surface will form varying degree deformation and failure when drift ices crash tunnel lining on different velocity, different plan size and different thickness of drift ice. The researches also show that there are damages of drift ice impact force on tunnel lining in the thawing period in cold and dry region. By long time water scouring, the tunnel lining surfaces are broken and falling off which breaks the strength and stability of the structure.

• Elastomers and Composites
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• v.22 no.3
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• pp.195-203
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• 1987

In this study, as one of the developing ways of the functional elastomer, improvement of the functionality of CB-BR was attempted through moisture curing reaction. The curing reaction of CB-BR was determined with an use of 3-aminopropyltriethoxysilane(APS) as a crosslinking agent, also a solution reaction with an active chlorine of CB-BR was elucidated by using a reaction kinetics theory and a study of physical property was made through moisture curing on the compound of 3-aminopropyltriethoxysilane and CB-BR The results of this study obtained are as follows : 1) CB-BR reacted easily with APS in the liquid state and the reaction rate coefficient and activation energy were as follows : 2) Optimum pressure condition of moisture cured elastomer(CB-BR+APS) was 20 minutes at $150^{\circ}C$, and the crosslinked elastomer was close to the theoretical value (q=1) for Flory's equation($\frac{\alpha}{\alpha-1}=q{\nu}RT$)