• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1098-1100
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• 2005

This paper presents a position control system for a linear induction motor(LIM) with cage-type secondary using direct thrust control(DTC). Also it presents a virtual instrumentation(VI) system for LIMs performance monitoring. The VI is designed using the graphical programming language LabVIEW and is capable of performing measurement functions, including data acquisition, display, and analyses at the same time. This paper reports the LIM's responses of the thrust, current, speed, and flux measured by the proposed monitoring system.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.1
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• pp.145-151
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• 2004

This paper proposes the calculation method of magnetic coupling coefficient of contact-less power supply by the 3D finite element method with a variation of the secondary core position. The primary, secondary self and leakage inductances and the capacitances of a resonant circuit are calculated by the finite element analysis results. The magnetic coupling coefficients are obtained also. The power factors are obtained by simulation for the magnetic coupling coefficients and compared.

• Journal of Advanced Navigation Technology
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• v.21 no.2
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• pp.163-170
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• 2017

MLAT which is an independent cooperative surveillance system is applied to increase the positon resoultin of secondary survelliance radar. MLAT uses the hyperboic or hyperboloid position mesurement algorithm. Central processing unit of MLAT calculates target position using time difference of arrival (TDOA) which can be solved from time of arrival (TOA) information of each receivers (at least 4 receivers). To increase position resolution of MLAT which use TDOA, TOA which is transfer time from tranmitter to receiver shold be calculated with precision time resolution in receiver. This paper explained the MLAT system briefly and explained ATD which is one of means of calcuating pulse position. ATD is applied to solve the deviation of pulse position due to different amplitude of signals in mulitiple receivers. In this paper, to analysis the performance of ATD, the simulation result of LAS and CDS was compared with the simulation result of basic threshold method.

• Nuclear Engineering and Technology
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• v.48 no.6
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• pp.1291-1302
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• 2016

This paper presents a new and efficient scheme to determine the optimal neutron source position in a model near-equilibrium pressurized water reactor, which is based on the OPR1000 Hanul Unit 3 Cycle 7 configuration. The proposed scheme particularly assigns importance of source positions according to the local adjoint flux distribution. In this research, detailed pin-by-pin reactor adjoint fluxes are determined by using the Monte Carlo KENO-VI code from solutions of the reactor homogeneous critical adjoint transport equations. The adjoint fluxes at each allowable source position are subsequently ranked to yield four candidate positions with the four highest adjoint fluxes. The study next simulates ex-core detector responses using the Monte Carlo MAVRIC code by assuming a neutron source is installed in one of the four candidate positions. The calculation is repeated for all positions. These detector responses are later converted into an inverse count rate ratio curve for each candidate source position. The study confirms that the optimal source position is the one with very high adjoint fluxes and detector responses, which is interestingly the original source position in the OPR1000 core, as it yields an inverse count rate ratio curve closest to the traditional 1/M line. The current work also clearly demonstrates that the proposed adjoint flux-based approach can be used to efficiently determine the optimal geometry for a neutron source and a detector in a modern pressurized water reactor core.

• Journal of Industrial Technology
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• v.36
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• pp.3-7
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• 2016

The change of flue gas residence time with the location of air inlet in an incinerator is analysed. An independent numerical variable is the location of air inlet and dependant is the residence time of flue gas. The mean value of turbulence energy in a primary combustion chamber is also analysed. The flow field and the distribution of turbulence energy are investigated to evaluate their influence on the residence time of flue gas and the turbulence energy. As the position of secondary air inlet approaches to the top of primary combustion chamber, the residence time of gas and the turbulence energy become longer and larger respectively.

• Proceedings of the KSME Conference
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• 2000.11b
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• pp.698-703
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• 2000

The characteristics of NOx emission in reburning process have been experimentally studied. The design point of burner is creative of three distinct reaction zones; a primary flame zone that NOx producted, reburn zone to reduce the primary zone NOx and burnout zone. Liquefied Petroleum Gas(LPG) was used as main and reburn fuels. Process parameters investigated included main/reburn fuel ratio, primary/secondary air ratio, reborn fuel injector position and different designed quarl. The NOx emission characteristic of aerodynamic designed burner relied on reborn fuel ratio and was slightly affected by a reburn fuel injector position and quarl shape.

• Journal of Ginseng Research
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• v.22 no.3
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• pp.205-210
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• 1998

Glucosidic bonds at the C20 position of the sapogenins were hydrolyzed easily in the lower pH, higher temperatures and longer times to give prosapogenins and sugars. The glucosidic bond of saponin at the C3 of ginsenoside-Rb1, which is secondary carbon, was relatively stable due to the low electron density of -0.2. But the bond of saponin at the C20 position, which is tertiary carbon with the relatively high electron density of -0.3, was liable to be hydrolyzed even in weakly acidic solution by the increase of heating time. On the other hand, red ginseng contained 13.34 mg/g of citric acid, 8.78 mg/g of malonic acid, 3.70 mg/g of oxalic acid, 2.13 mg/g of malic acid and 0.44 mg/g of succinct acid. Ginseng saponins were very stable in ginseng extract neutralized with sodium carbonate or sodium bicarbonate corresponding to the equivalent amount of the total organic acid in the red ginseng.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.1
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• pp.36-41
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• 2002

The cause and the elimination method for the chattering phenomena were investigated in a check valve attached to the exit of an auxiliary cooling water pump in a Korean nuclear powerplant. From the site experiment and the numerical calculation, the incident angle of the disk was so small that it was not able to produce the sufficient lifting force to overcome the gravitational component of the disk weight. Moreover, it turned out that the installation position was not symmetric for the secondary vortical flow generated inside the elbow so that the flow structure had strongly unstable flow characteristics. From this study, the tapping noise and the chattering phenomena were eliminated exactly by changing the incidence angle of the valve disk and the installation position of the calve body.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1848-1853
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• 2000

Cause and the elimination method for the chattering phenomena were investigated the check valve attached exit of the auxiliary cooling water pump at a korean nuclear powerplant. From the site experiment and numerical calculation the incident angle of the disk was so small that it was not able to produce the lifting force to overcome the component of disk weight. Moreover, it turned out that the installed position was not symmetric for the secondary vortical flow generated inside the elbow, so that the flow structure had strongly unstable flow characteristics. From this technical support, the tapping noise and the chattering phenomena were eliminated exactly by changing the incidence angle of the valve disk and installed position of the check valve.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.12
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• pp.1216-1222
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• 2010

Based on the MacDonald's analytic model for the diffracted sound field of a semi-infinite noise barrier, computer simulations were performed for various positions of error microphones for an active noise barrier system. The simulation process also included the effects of floor reflections on both sides of the barrier. The results were also compared with Niu's simulation results and showed a straight line arrangement of sensors and actuators, in the order of primary source, secondary source and error microphone is better than over the top arrangement of the error microphones.