• Journal of the Korean Society for Nondestructive Testing
• /
• v.24 no.6
• /
• pp.597-602
• /
• 2004

In practical applications of guided wave techniques, it is very important but also difficult to identify the propagating modes, and it is preferred to generate and detect a single or less dispersive mode. Also the noncontact method is required in the automated field application. So this paper considers a non-contact guided wave technique with enhanced mode-selectivity, where a laser beam illuminated through arrayed line slits is used as the transmitter and the air-coupled transducer is used as the receiver. The line arrayed laser illumination is a wavelength matching technique that ran generate only a few modes. The air-coupled transducer detects the leaky wave of the propagated guided wave, and by tuning its detection angle we ran detect the selected single mode. Experimental results for a 1mm thick aluminum plate proved the usefulness of the proposed method, and especially it was shown that this method was powerful in the generation and detection of the $a_0$ mode.

• Proceedings of the IEEK Conference
• /
• 1999.11a
• /
• pp.917-920
• /
• 1999

Modal transmission-line theory is described for guided electron waves in quantum-well structures. To demonstrate the validity and usefulness of this approach, we evaluate the propagation characteristics and the coupling properties of electron guiding couplers consisting of double quantum-wells (DQWs).

• Journal of the Korea Society of Computer and Information
• /
• v.8 no.1
• /
• pp.13-19
• /
• 2003

There are active researches on automated guided vehicles(AGV) generally used in flexible manufacturing system(FMS) or automated warehouse systems(AWS). Because existing AGV uses magnetic tapes, electric wire, RF or laser as guidelines, its installation and modification require a lot of money and time. The present study implemented AGV that detects paths marked with 50mm Yellow tape using a mono-color CCD camera. Because it uses color tape, it is easy and inexpensive to install and change lines. This study presented the structure of the developed AGV, the image Processing technique for detecting guidelines by ing the characteristics of color, and the result of operating AGV.

• Proceedings of the KIEE Conference
• /
• 1997.11a
• /
• pp.95-97
• /
• 1997

This paper deals with design and implementation of the controller for optically guided AGV. When AGV has only three photo sensors in front of body, AGV doesn't know how much the entry angle to guide line is. In this case, it is difficult to compensate the tracking error. To make sure that the AGV does not secede the guide line in tracking, PI controller and fuzzy logic controller is proposed. The proposed controller was verified and experienced through real AGV system.

• Archives of Pharmacal Research
• /
• v.21 no.1
• /
• pp.67-69
• /
• 1998

Three TNF-$\alpha$inhibitory lignans were isolated from the flower buds of Magnolia fargesii through bioassay-guided isolation. They were identified as eudesmin, magnolin and lirioresinol-B dimethylether on the basis of their spectroscopic data. All three lignans showed inhibitory effects on TNF-$\alpha$ production in LPS-stimulated murine macrophage cell line, RAW264.7 and eudesmin showed the strongest activity ($IC_{50}=51{\mu}M)$.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.13 no.4
• /
• pp.642-649
• /
• 2010

LOS analysis is used for optimal deployment of mid-range guided weapon system or system engagement effectiveness simulation. Comparing to real-world, LOS analysis includes error sources such as coarse terrain data resolution, refraction of radio waves, and several ideal assumptions. In this research, exact LOS algorithm under assumption of constant earth curvature and error analysis of that is investigated. It proved that LOS algorithm under assumption of constant earth curvature has negligible error in mid-range guidance weapon system's scope.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.31 no.4
• /
• pp.367-373
• /
• 2011

Guided waves inspection techniques that are different with inspection technique by bulk waves are widely used in pipe line evaluation due to advantages of long distance inspection. However, most of pipe lines at industrial fields are buried and/or coated. In this case, due to the attenuation effect from soil and/or coating material, there are a lot of difficulty on inspection by conventional ultrasonic technique. In this paper, guided waves propagating patterns are calculated with respect to excitation mode by Normal Mode Expansion(NME). Guided waves patterns based on excited by single transducer and guided wave focusing technique have employed to analyze focusing pattern on a pipe. A longitudinal mode and high order flexural modes are used with various number of transducers to determine sensitivity. Guided waves energy excited by multi transducer with focusing algorithm was successfully focused at a desired point.

• Proceedings of the KIEE Conference
• /
• 2009.07a
• /
• pp.1195_1196
• /
• 2009

Light rail transit is classified to rubber-tired LRT, lear induction motor LRT, steel wheel LRT, monorail and tramway. LRT except for tramway are usually operated without driver and tramway are driven depending on driver's sight like usual car. LRT, which is one type of urban guided transit, shall be operated according to domestic "Operational Regulation for Urban Guided Transit" but existing regulation does not contain the safety related codes for driverless operation. In this paper, we investigate "IEC 62267 : Railway Application-Safety Requirements for Automated Urban Guided Transit" and compensate for existing operational regulation by referring to international standard and operational rule of commercial line.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2000.04a
• /
• pp.56-63
• /
• 2000

Abstract - In this paper, an adaptive mechanism based on immune algorithm is designed and it is applied for the autonomous guided vehicle(AGV) driving. When the immune algorithm is applied to the PID controller, there exists the case that the plant is damaged due to the abrupt change of PID parameters since the parameters are adjusted almost randomly. To solve this problem, a neural network is used to model the plant and the parameter tuning of the model is performed by the immune algorithm. After the PID parameters are determined in this off-line manner, these gains are then applied to the plant for the on-line control using immune adaptive algorithm. Moreover, even though the neural network model may not be accurate enough intially, the weighting parameters are adjusted to be accurate through the on-line fine tuning. The computer simulation for the control of steering and speed of AGV is performed. The results show that the proposed controller has better performances than other conventional controllers.

• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.49 no.4
• /
• pp.201-212
• /
• 2000

In this paper, an adaptive mechanism based on immune algorithm is designed and it is applied for the autonomous guided vehicle(AGV) driving. When the immune algorithm is applied to the PID controller, there exists the cast that the plant is damaged due to the abrupt change of PID parameters since the parameters are adjusted almost randomly. To solve this problem, a neural network is used to model the plant and the parameter tuning of the model is performed by the immune algorithm. After the PID parameters are determined in this off-line manner, these gains are then applied to the plant for the on-line control using immune adaptive algorithm. Moreover, even though the neural network model may not be accurate enough intially, the weighting parameters are adjusted to be accurate through the on-line fine tuning. The computer simulation for the control of steering and speed of AGV is performed. The results show that the proposed controller has better performances than other conventional controllers.