• Archives of Plastic Surgery
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• v.34 no.6
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• pp.796-798
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• 2007

Purpose: Giant cell tumor is the second most common benign neoplasm in upper extremity. Unlike usual chief complaint of painless mass, an atypical case with giant cell tumor presented a distinguishing characteristics of which accompany pain and tenderness and is histologically giant-cell free. Methods: A 31-year-old male patient complained of a rapid growing painful mass on the proximal phalanx of the left ring finger. Under microscopic operation, a $1.6{\times}1.3cm$ sized mass was found to be surrounded by areolar tissue and attached to a tendon sheath, encircling the digital nerve and artery. Diagnostic confirmation was assisted by positive finding in histologic immunohistochemical stain-CD68. Characteristic pathologic finding is an atypical distribution of spindle cells & histiocytes without giant cells in fascicular pattern. Results: Giant cell tumor was carefully removed under microscopic approach, while preserving digital nerve & artery. In postoperative 13th month, the patient presented with a 6mm of static two-point discrimination test, similar to that of the adjacent fingers. Conclusion: We report an atypical case with painful mass on tendon sheath, surrounding the digital nerve and artery that was diagnosed of giant cell tumor, but without giant cells on pathology. This case provides broader understanding of the giant cell tumor that should not only rely its typical findings of the painless mass and positive sign on H&E stain.

• Water for future
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• v.28 no.2
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• pp.125-136
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• 1995

The propose of this study is improve the uncertainty of parameter choice of tank model by the trials and errors method. The real time prediction of parameter by using the Kalman filter is practiced to get the effective prediction algorithm of low flow runoff. Even though the total discharge of runoff through the orifice of each tank should be similar to the observed discharge, the tank model which can show the various basin characteristic is influenced by the runoff circumstances. As a result of the real-time estimation of the tank model parameter by the state-space type of Kalman filter, the variation of runoff circumstances is static when the convergence of observed value and estimated value keeps the ficed high point. The parameter of tank model which is estimated by Kalman filter shows good result for low flow and reasonable adaptability where flow change abruptly. The Kalman filter method is proved to give better result than Automatic structure estimation method.

• Journal of the Institute of Convergence Signal Processing
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• v.12 no.3
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• pp.204-211
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• 2011

Embedded systems require intensively complex and high power dissipating modules that have the capability of real-time high performance data processing, wide bandwidth communication, and low power consumption. However, the current battery technology has not been developed as much as meeting the requirements of portable embedded systems for long system lifetime. In this paper, new approach that operates with low energy consumption is proposed to overcome the situation while guaranteeing detection accuracy. The designed method associates a variety of detection algorithms hierarchically to detect events happening around the system. The Change for energy consumption characteristics is shown with change for probabilistic characteristics and those relationships are analytically explained from experiments. Furthermore, several techniques to consume low energy and achieve high detection accuracy are described, depending on the event static or dynamic characteristics.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.5
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• pp.359-365
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• 2004

To study the lipid adsorption characteristic of chitosans with different molecular weights and the degrees of deacetylation, in vitro test and near-infrared (NIR) spectroscopic analysis have been performed for the measurement of lipid adsorption characteristics of chitosan. The degrees of deacetylation in chitosans were $70{\%},\;85{\%}\;and\;92{\%}$ at different deacetylation times (1 hr, 2 hrs, 3 hrs), respectively. The molecular weight of each chitosan was controlled by enzymatic hydrolysis, and then the molecular weight of the chitosan was 4 kDa. The bulk density, water holding capacity and fat binding capacity of each chitosan powder were $96.2-504.0{\%},\;374.4-1217.9{\%},\;and\;307.0-659.3{\%}$, respectively. The higher molecular weight of chitosan was exhibited the lower bulk density and the higher water and fat binding capacities. Bindinf capacities of chitosan powders to bile salts, cholesterol and linoleic acid were $41.2-63.3{\%},\;40.8-67.4{\%},\;42.6-72.6{\%}$, respectively. In NIR spectrum of lipid adsorbed chitosan the occurrence static eletronical binding between chitosan and lipid was identified by NIR spectrum peak induced from combination of carboxylic group in lipid and amino group in chitosan. In conclusion, the higher degree of deacetylation and molecular weight of chitosan showed the higher lipid binding capacity and the lipid adsorption of chitosan were occurred by combination of carboxylic group in lipids and amino group in chitosan.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2002.05a
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• pp.134-139
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• 2002

Fracture behaviors of pipes with local wall thinning are very important for the integrity of nuclear power plant. However, effects of local wall thinning on strength and fracture behaviors of piping system were not well studied. Acoustic emission(AE) has been widely used in various fields because of its extreme sensitivity, dynamic detection ability and location of growing defects. In this study, we investigated failure modes of locally wall thinned pipes and AE signals by bending test. From test results, we could be divided four types of failure modes of ovalization, crack initiation after ovalization, local buckling and crack initiation after local buckling. And fracture behaviors such as elastic region, yielding range, plastic deformation range and crack progress could be evaluated by AE counts, accumulative counts and time-frequency analysis during bending test. It is expected to be basic data that can protect a risk according to local wall thinning of pipes, as a real time test of AE.

• Korean Institute of Interior Design Journal
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• v.19 no.6
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• pp.112-120
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• 2010

Human can recognize the environment by detecting spatial perception, and most of environmental perception depends on visual perception. In view that the acquisition of spatial information is accomplished through visual recognition, analysis of visual structure contained in the space is thought to be very important sector in studying the characteristic of the space. The history of studies on visual structure of space, however, wasn't too long, and furthermore most of the theories up to now focused on static and planar principles. Under this circumstance, this study is intended to suggest new theory by combining Isovist theory and VGA theory that have been actively discussed as the theory on visual perception-based spatial structure and supplementing them between each other to expand into 3-dimensional model. The suggested theory is a complex principle in dimensional and dynamic form in consideration of visual direction, which forms 3-dimentional virtual model that enables visualization of the property of spatial structure as the routine discriminating whether visual connection is made between viewing point and target point, and the target point is included in the visual field quadrangular pyramid or not. Such model was built up by an analysis application where four probe paths were applied to simulate the visual structure that occurs in virtual space, and then the characteristics were analyzed through quantification. In result, in spite of the path with equal space and equal length, significant difference in the acquired quantity of spatial information could be found depending on the probe sequence. On the contrary, it was found that probe direction may not affect the acquired quantity of information and visual property of the space.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.12
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• pp.2226-2240
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• 1992

This paper studies the applicability of the method of caustics into anisotropic materials under mode I and mixed static loading conditions and introduces the procedure to obtain stress intensity factors(S.I.F.) in anisotropic materials by the method of caustics. The mapping equations for initial and caustic curves in anisotropic materials were introduced and their computer graphical images were compared to the experimental ones to check the validity of the mapping equations proposed in this paper. The agreement between them was found to satisfactory. Two kinds of method to determine S.I.F. in anisotropic materials by the method of caustics were proposed in this paper and applied into the orthotropic materials under various loading conditions. In the case of mode I loading condition, the S.I.F.'s obtained by this paper's methods were found to be quite similar to the results by other method, boundary element method(B.E.M) and in the case of mixed loading condtion, the S.I.F's by this paper and B.E.M. showed a little differences(2.2-24.4%) with respect to the slanted angle of crack.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.8
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• pp.80-87
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• 2006

This paper analyzed the characteristics of the claw pole PM stewing motor by using 3D FEM. As the magnetization occurs along the z-axis of the motor, it is necessary to apply 3D FEM for analysis of the claw pole PM stewing motor. Considering the computation time, reducing the number of the analysis model is effective method of the methods of the reducing analysis time. By using the "Design Of Experiments(DOE)", efficient analysis was able to be done. To see the effects of the design factors, the 3D FEM is applied only to the selected models. As the design factors, the teeth selected models, the number of turns and the permanent magnet overhang was selected.

• Structural Engineering and Mechanics
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• v.75 no.4
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• pp.487-496
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• 2020

Most of the previous works on numerical analysis of galloping of transmission lines are generally based on the quasisteady theory. However, some wind tunnel tests of the rectangular section or hangers of suspension bridges have shown that the galloping phenomenon has a strong unsteady characteristic and the test results are quite different from the quasi-steady calculation results. Therefore, it is necessary to check the applicability of the quasi-static theory in galloping analysis of the ice-covered transmission line. Although some limited unsteady simulation researches have been conducted on the variation of parameters such as aerodynamic damping, aerodynamic coefficients with wind speed or wind attack angle, there is a need to investigate the numerical simulation of unsteady galloping of two-dimensional iced transmission line with comparison to wind tunnel test results. In this paper, it is proposed to conduct a two dimensional (2-D) unsteady numerical analysis of ice-covered transmission line galloping. First, wind tunnel tests of a typical crescent-shapes iced conductor are conducted firstly to check the subsequent quasisteady and unsteady numerical analysis results. Then, a numerical simulation model consistent with the aeroelastic model in the wind tunnel test is established. The weak coupling methodology is used to consider the fluid-structure interaction in investigating a two-dimension numerical simulation of unsteady galloping of the iced conductor. First, the flow field is simulated to obtain the pressure and velocity distribution of the flow field. The fluid action on the iced conduct at the coupling interface is treated as an external load to the conductor. Then, the movement of the conduct is analyzed separately. The software ANSYS FLUENT is employed and redeveloped to numerically analyze the model responses based on fluid-structure interaction theory. The numerical simulation results of unsteady galloping of the iced conduct are compared with the measured responses of wind tunnel tests and the numerical results by the conventional quasi-steady theory, respectively.

• Journal of Korean Ophthalmic Optics Society
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• v.6 no.2
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• pp.31-35
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• 2001

The anti-reflective anti-static(ARAS) optical film Was designed using conducting layer $TiN_x$ by Essential Macleod program. From this results, [air ${TiN_x{\mid}SiO_2{\mid}$ glass] two layer shows wide-band AR coating in the wavelength range of 450~700 nm. The $TiN_x$ thin films were prepared on the glass substrate by RF(radio-freqency) magnetron sputtering apparatus from a Ti target in agaseous mixture of argon and nitrogen with the thickness of 7~10 nm. For the films obtained, the chemical binding energy of the films was investigated by x-ray photoelectron spectroscopy(XPS) in order to analyze the chemical nature and composition of the films. In addition, we investigated the relationship between the surface resistance and the chemical nature the sheet resistance and XPS depth profiling the chemical binding of the films.