• Bulletin of the Korean Chemical Society
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• v.31 no.11
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• pp.3228-3232
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• 2010

Malachite green (MG) has been used world-widely in aquaculture as a parasiticide or fungicide. Although MG performed successfully, it has not been permitted for use in aquaculture from European Union, USA, and Canada because of its carcinogenicity and mutagenicity. We developed a sensitive and specific method to determine MG and its principal metabolite, leucomalachite green (LMG), respectively by isotope dilution liquid chromatography mass spectrometry (ID-LC/MS). To enhance the extraction recovery of MG and LMG from fish tissue, an additional step, saponification, was introduced in sample preparation process to remove fat in sample extract, which hampered the performance of SPE columns. The residue of MG and LMG in fish was analyzed using liquid chromatography mass spectrometry in the selected ion monitoring (SIM) mode by monitoring at m/z 329 and 334 for MG and $d_5$-MG and at m/z 331 and 337 for LMG and $^{13}C_6$-LMG, respectively. This method was validated by comparing with the value of the reference material provided by Laboratory Government Chemistry (LGC). The results agreed within the measurement uncertainty and the accuracy was much improved than the provided reference value by LGC.

• Clean Technology
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• v.8 no.2
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• pp.101-110
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• 2002

Concurrent development system which includes design, analysis, basic experiment and performance test procedure for rotary atomizing painting equipment was established. Basic design specifications of the equipment parts were determined according to the overall design requirements of painting equipment using conceptual design model. On the basis of derived design specifications, design and analysis procedures was proposed for developing each equipment part. Also proposed are experiment and test methods to investigate the spray and transfer characteristics of designed painting equipment, and their measurement variable, process and evaluation criteria are constructed. The present development system was validated by applying its entire processes to the actual painting equipment.

• Wind and Structures
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• v.20 no.1
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• pp.75-93
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• 2015

This work is focused on a parametric numerical study of the barrier's bar inclination shelter effect in crosswind scenario. The parametric study combines mesh morphing and design of experiments in automated manner. Radial Basis Functions (RBF) method is used for mesh morphing and Ansys Workbench is used as an automation platform. Wind barrier consists of five bars where each bar angle is parameterized. Design points are defined using the design of experiments (DOE) technique to accurately represent the entire design space. Three-dimensional RANS numerical simulation was utilized with commercial software Ansys Fluent 14.5. In addition to the numerical study, experimental measurement of the aerodynamic forces acting on a vehicle is performed in order to define the critical wind disturbance scenario. The wind barrier optimization method combines morphing, an advanced CFD solver, high performance computing, and process automaters. The goal is to present a parametric aerodynamic simulation methodology for the wind barrier shelter that integrates accuracy and an extended design space in an automated manner. In addition, goal driven optimization is conducted for the most influential parameters for the wind barrier shelter.

• Proceedings of the Optical Society of Korea Conference
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• 2006.07a
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• pp.39-40
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• 2006

Digital image-projection and several modifications are the classical applications of Digital Micromirror Devices (DMD), however further applications in the field of optical metrology are also available. Operated with certain patterns, a DMD can function, for instance, as an array of pinholes that may substitute the Galvanic mirror or the stage scanning system presently used for 2 dimensional scanning in confocal microscopes. The various process parameters that influence the result of measurement (e.g. pinhole size, lateral scanning pitch and the number of pinholes used simultaneously, etc.) should be configured precisely for individual measurements by appropriately operating the DMD. This paper presents suitable conditions for the diffraction limited analysis between DMD-optics-CCD to achieve the best performance. Also sampling theorem that is necessary for the image acquisition by scanning system is simulated with OPTISCAN which is the simulator based on the diffraction theory.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.813-818
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• 2007

Construction productivity is a key factor for efficiency evaluation of construction work process, project performance measurement, and basic data of work plan in construction industry. However, although construction productivity is important in construction industry, gathering methodology and analyzing methodology of productivity data are not well-organized therefore productivity data is not utilized in the construction industry The purpose of this study is to develop productivity prediction system using data mining technology based on activities and to suggest frameworks about productivity data collection, accumulation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.10C
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• pp.987-992
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• 2002

In this paper, a new clock and data recovery circuit is proposed for the application of data communication systems requiring ㎓-range clock signals. The circuit is suitable for recovering NRZ data which is widely used for high speed data transmission in ㎓ ranges. The high frequency jitter is one of major performance-limiting factors in PLL, particularly when NRZ data patterns are used. A novel phase detector is able to suppress this noise, and stable clock generation is achieved. Futhermore, the phase detector has an adaptive delay cell removing the dead zone problem and has the optimal characteristics for fast locking. The proposed circuit has a convenience structure that can be easily extended to multi-channels. The circuit is designed based on CMOS 0.25㎛ fabrication process and verified by measurement result.

• Journal of information and communication convergence engineering
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• v.13 no.2
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• pp.81-85
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• 2015

A 94-GHz phased array antenna using a log-periodic antenna has been developed on a GaAs substrate. The developed phased array antenna comprises four log-periodic antennas, a phase shifter, and a Wilkinson power divider. This antenna was fabricated using the standard microwave monolithic integrated circuit (MMIC) process including an air bridge for unipolar circuit implementations on the same GaAs substrate. The total chip size of the fabricated phased array antenna is 4.8 mm × 4.5 mm. Measurement results showed that the fabricated phased array antenna had a very wide band performance from 80 GHz to 110 GHz with return loss characteristics better than -10 dB. In the center frequency of 94 GHz, the fabricated phased array antenna showed a return loss of -16 dB and a gain of 4.43 dBi. The developed antenna is expected to be widely applied in many applications at W-band frequency.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.12
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• pp.627-632
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• 2001

There are claims that ESE(Early streamer emission) Air terminals offer a vastly increased zone of protection over that of traditional lightning rods by causing the emission of an upward streamer/leader that will propagate towards the tip of downward leader at an early stage in the attachment process than would occur for a simple rod in the same geometrical configurations. This paper shows the results of comparing test a particular type of ESE air terminals with a simple rod conducted in the KEH HV laboratory, which are lightning impulse voltage test, flashover direction test and corona emission current measurement. The results from this test show a completely random scattering of flashovers to the conventional and ESE air terminals under identical electrics] and geometrical conditions, and thus shows no advantage of one terminal over the other.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.05
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• pp.22-26
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• 1996

In this paper, we designed 4-channel electrolyte analyzer that can measure simultaneousely the 4 electrolytes - pH, $pNa^{+}$, $pCa^{2+}$, and $pK^{+}-$ using 2-point calibration and implemented it. Developed electrolyte analyzer consists of singal processing part, actuator part and control unit for sample flow system. To implement reliable instrument, design considerations are emphasized on flow system and sample chamber that requires small sample volume and prevent air contact with sample solution. In addition to the hardware design, we developed system software which controls full measuring process. After system developed, we verified the system performance by the test measurement for pH, $pNa^{+}$, $pCa^{2+}$, and $pK^{+}$ value.

• Journal of Power System Engineering
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• v.18 no.6
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• pp.21-28
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• 2014

The studies of the spray characteristics for a CRDI engine had been advancing by many researchers, because the performance and exhaust emission were significantly affected with the spray characteristics. But most experiments of the studies would be done at low ambient pressure conditions under 2MPa. In this study, injection rates were measured with Zeuch's method at various ambient pressures to 5MPa and a constant injection pressure of 130MPa. On the same conditions, non-evaporating spray images were taken with a high speed camera and analyzed carefully with Adobe Photoshop CS3. Macroscopic spray characteristics and breakup processes in the spray could be found from the examined and analyzed data. The initial injection rate, penetration, angle, velocity and breakup of the spray were practically affected with a variation of the ambient pressure, but the injection start time and injection period were scarcely affected. As the ambient pressure was higher, the breakup of a high density droplet region in the spray was happened slowly and the main position of breakup was shifted from a front of the spray to a upstream around a nozzle. The results and techniques of spray visualization and injection rate measurement in this study would be practically effective to study a high pressure diesel spray for a CRDI.