• Journal of the Society of Naval Architects of Korea
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• v.44 no.2 s.152
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• pp.166-173
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• 2007

Collision analysis problems between ship to ship can be generally classified into the external mechanics(outer dynamics) and internal mechanics(inner dynamics). The former can be also dealt with the concept of fluid-structure interaction and the use of rigid body dynamic program, depending on the ways handling the hydrodynamic pressure due to surrounding water. In this study, full scale ship collision simulation was carried out, such as a DWT 75,000 ton striking ship collided at right angle to the middle of a DWT 150,000 struck ship with 10 knots velocity, coupling MCOL, a rigid body mechanics program for modeling the dynamics of ships, to hydrocode LS-DYNA. It could be confirmed that more suitable damage estimation would be performed in the case of the collision simulations with consideration of surrounding water through the comparison with the collision simulation results of fixed struck ships without it. Through this study, the opportunity could be obtained to establish a more effective ship collision simulation technique between ship to ship.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.1-6
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• 2008

This paper proposes a game controller that provides user motion input and tactile feedback display, in addition to the traditional button-type input. The device utilizes both an accelerometer and an infrared camera in order to estimate 3D position and to recognize user motion. The information from the accelerometer and the camera are integrated for better performance. Various tactile sensations are presented using a voice-coil type vibrator. We apply the proposed controller to a motion-based game and validate its usability.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.9 s.174
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• pp.85-92
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• 2005

This paper describes the recognition method of small-obstacles using a camera for a mobile robot in indoor environment. The technique of image processing using a camera has been widely used for an automaton of industrial system, an inspection of inferior goods, a lookout of an invader, and a vision sensor of intelligent robot. Mobile robot could meet small-obstacles such as a small plastic bottle of about 0.5 l in quantity, a small box of $7{\times}7{\times}7cm^3$ in volume, and so on in its designated path, and could be disturbed by them in the locomotion of a mobile robot. So, it is necessary to research on the recognition of small-obstacles using a camera and program. In this paper, 2-D image processing algorism and method fur recognition of small-obstacles using a camera for a mobile robot in indoor environment was developed. The characteristic test of the developed program to confirm the recognition of small-obstacles was performed. It is shown that the developed program could judge the size and the position of small-obstacles accurately.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.9 s.174
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• pp.147-154
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• 2005

A precision hi-directional actuator for a high precision leveling system with $Z{\Theta}_x{\Theta}_y$ motions is proposed and designed in this paper. The actuator is composed of a force generation structure, a guide mechanism, and a symmetric structure. At first, its driving force is generated by a change of flux in air gaps by permanent and changeable flux. The permanent flux is generated by a permanent magnet. The changeable flux is created by variable current flowing through coil. The combination of permanent and changeable flux makes various flux densities in air gaps between moving part and fixed yokes. And then, the difference between flux densities in lower and upper gaps creates forces fur the $bi-direction({\pm}z)$ motion. The guide mechanism of this actuator is composed of two circular plates and one shaft. Reducing motions generated by forces except z-motion, these circular plates endow the actuator with high stiffness for fast settling time. And the function of the shaft is to transfer motion to an object. At last, total body has a symmetric structure to be stable on thermal error. The actuator is designed by MAXWELL 2D and ProMECHANICA. The designed actuator is evaluated by 8nm laser doppler vibrometer, dynamic signal analyzer, and simple PID controller.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.396-401
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• 2009

This paper describes the improvements made on hardware and software of the remote controller for realistic contents. The controller can provide vibrotactile feedback which uses both of a voice-coil actuator and a vibration motor. A vision tracking system for the 3D position of the controller is optimized with respect to the marker size and the camera parameters. We also present the improvements of motion recognition due to the effective motion segmentation and the fusion of vision and acceleration data. We apply the developed controller to realistic contents and validate its usability.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.521-524
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• 2009

This study describes aerodynamic noise of high speed wind turbine system, which is invented as a new concept in order to reduce the torque of main shaft, for design parameters of the rotor blade. For parametric study of high speed rotor aerodynamic noise, Unsteady Vortex Lattice Method with Nonlinear Vortex Correction Method is used for analysis of wind turbine blade aerodynamic and Farassat1A and Semi-Empirical are used for low frequency noise and airfoil self noise. Parameters are chord length, twist and rotational speed for this parametric research. In the low frequency range, the change of noise is predicted the same level as each parameters varies. However, in case of broadband noise of blade, the change of rotational speed makes more variation of noise than other parameters. When the geometric angles of attack are fixed, as the rotational speed is increased by 5RPM, the noise level is increased by 4dB.

• Molecular & Cellular Toxicology
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• v.5 no.1
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• pp.88-92
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• 2009

The effect of Chlorella vulgaris (CV) on the urinary excretion of di-ortho PCB congeners (PCB-138, -153) was investigated. Sprague-Dawley rats (6-weeks-old, n=10 rats/group) were randomly divided into one control (0CV) or 2% CV (2CV) or 5% CV (5CV) or 10% CV (10CV) groups, respectively. Composition of normal and chlorella meal-based diet were made up of 30% casein, 15% cornstarch, 50% sucrose, 5% cellulose, 5% coconut oil, 3.5% mineral mixture, 1 % vitamin mixture. All rats had free access to water and diet for 4 weeks. A significant increase in both PCB 138 and 153 in urinary level was detected in CV fed groups, 540% and 167% for 2CV, 155% and 89% for 5CV, 114% and 144% for 10CV group, respectively, when compared with their controls. These findings suggest that CV may have potential to eliminate body burden levels of dioxin-like PCB compounds.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.9
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• pp.821-829
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• 2014

This paper describes the development of a wireless communication controller of gripper contact signal for industrial robot. The wireless communication gripper controller is composed of a robot wireless communication controller and a gripper wireless transmitting/receiving controller. The robot wireless communication controller transmits the data of gripper sensors, and the gripper wireless communication controller receives the data. And the controller sends the data to the robot controller of industrial robot. As a result of the characteristics test of the wireless communication gripper controller, it is thought that the robot wireless communication controller A transmits and receives three gripper wireless transmitting/receiving controller A1, A2, A3 another. Thus, the developed wireless communication gripper controller can be used for transmitting/ receiving the data of gripper sensors for industrial robot.

• Journal of the East Asian Society of Dietary Life
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• v.17 no.5
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• pp.696-702
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• 2007

The purpose of this paper is to describe the differences in mineral, ascorbic acid, and total polyphenol content, and also the relationship between polyphenol content and antioxidant activity(DPPH radical scavenging, FTC, and TBA methods) in three sizes of Cudrania tricuspidata leaves. For the mineral contents of the leaves, Ca was highest(17.26 mg/g.d.w.), followed by K(15.53 mg), P(2.61 mg), and Mg(1.99 mg). Ascorbic acid was found to be slightly higher(43.4 mg/100g.f.w.) in the basal parts of the medium size leaves and lowest in the whole parts(9.9 mg) of the small size leaves. Total polyphenol content was highest($1,384{\sim}1,258mg/100g.f.w.$) in the leaves, for all sizes, when extracted with 80% ethanol, followed by the stem bark(543 mg%), roots(369 mg%), stems(243 mg%), and thorns(223 g%). By determining DPPH activity, we found that antioxidant activity was higher in the ethanol extracts of the leaves than in the ethanol extracts of the thorns, stems, roots, and stem bark. While in the tea, no differences were found between the ethanol and water extracts.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.2
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• pp.139-149
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• 2013

As the importance of technology forecasting while countries and companies manage the R&D project is growing bigger, the methodology of technology forecasting has been diversified. One of the forecasting method is patent analysis. This research proposes quick forecasting process of emerging technology based on keyword approach using text mining. The forecasting process is following: First, the term-document matrix is extracted from patent documents by using text mining. Second, emerging technology keyword are extracted by analyzing the importance of word from utilizing mean values and standard deviation values of the term and the emerging trend of word discovered from time series information of the term. Next, association between terms is measured by using cosine similarity. finally, the keyword of emerging technology is selected in consequence of the synthesized result and we forecast the emerging technology according to the results. The technology forecasting process described in this paper can be applied to developing computerized technology forecasting system integrated with various results of other patent analysis for decision maker of company and country.