• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.12
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• pp.935-943
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• 2015

This paper presents a method for early fire detection and fire position determination inside the nacelle of wind turbine generator system. The rising temperature and obscuration rates inside the nacelle were used as parameters for fire detection, which can minimize the possibility of a fire detection malfunction because these rising rates do not depend on the absolute values of temperature and obscuration. The fire position was determined using the time difference among various sensor positions for fire detection. The performance of the method was tasted using sets of experiments in a nacelle simulator.

• Journal of Pharmaceutical Investigation
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• v.16 no.4
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• pp.139-147
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• 1986

A singly charged methyl orange(MO) anion was found to be extracted with chlorpheniramine maleate(CPM) as a 1 : 1 complex in chloroform. Of various solvents, MO-chloroform system gave a yellow color for CPM, while in the absence of CPM, an organic phase showed almost no color. In this way, the spectrophotometric method was investigated for the determination of CPM by solvent extraction. The addition of alcoholic bolic acid solution to the solvent extract gave a higher color stability and transparency at least 5 days, but the extract alone lost its color intensity significantly. CPM is determined by measuring the absorbance of the extracts over a range of $1{\sim}7{\times}10^{-4}M\;(39{\sim}273\;{\mu}g/ml)$ in aqueous solution at 423 nm. The molar absorptivity was $2.26{\times}10^3\;l,\;mol^{-1},\;cm^{-1}$. The absorbance of the extract was constant in the range of pH $3.7{\sim}4.6$. This novel method was applied for the determination of CPM in artificial and commercial preparations in comparison with the analytical method of CPM tablets in K.P.IV. The results obtained showed that the former was better in accuracy and time consumption than the latter.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.6
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• pp.38-46
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• 2012

In this paper, the necessity for the identification of the absolute phase value is introduced and analyzed for a particular conductor line of a 3-phase type distribution network and the recent methods are also introduced. For the determination of the exact phase value for a specific point in the line, as compared with the phase reference point, the measured phase value must be within a range of ${\pm}60[^{\circ}]$. However, the phase of a particular point can fluctuate depending on the line constant, transformer wiring method, line length, line amperage, etc. A theoretical formulation such as Simulink modeling and analysis for a distribution network are conducted for the identification of phase at a specific point in the line. In particular, through evaluating the effects of unbalanced current loads at the time of determination of the phase value, the limitations of the present method for the determination of phases is described.

• Analytical Science and Technology
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• v.11 no.5
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• pp.400-403
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• 1998

The germanium content of the cultivated Korean medicinal herbs in several growing district was determined by adsorption stripping voltammetry. The optimum conditions in germanium determination were as following: deposition time; 120 sec, deposition potential; -0.9 volts vs. Ag/AgCl, and frequency; 100 Hz in $5.0{\times}10^{-2}M$ perchloric acid supporting electrolyte solution containing $8.0{\times}10^{-2}M$ catechol. Calibration curve was shown a good lineality in the range of 0.4 ppb to 2.0 ppm and the detection limit was 0.08 ppb. There was a large difference in content of the cultivated hermit leaf according to growing district such as 29.7~385.7 ppm and the content of nontreated hermit leaf was higher than the processed health foodstuffs. The content of the Korean ginseng (5 years) was 83 ppm while the Korean herb of life was 214 ppm.

• Journal of Astronomy and Space Sciences
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• v.28 no.1
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• pp.63-70
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• 2011

The needs for satellite formation flying are gradually increasing to perform the advanced space missions in remote sensing and observation of the space or Earth. Formation flying in low Earth orbit can perform the scientific missions that cannot be realized with a single spacecraft. One of the various techniques of satellite formation flying is the determination of the precise baselines between the satellites within the formation, which has to be in company with the precision validation. In this paper, the baseline of Gravity Recovery and Climate Experiment (GRACE) A and B was determined with the real global positioning system (GPS) measurements of GRACE satellites. And baseline precision was validated with the batch and sequential processing methods using K/Ka-band ranging system (KBR) biased range measurements. Because the proposed sequential method validate the baseline precision, removing the KBR bias with the epoch difference instead of its estimation, the validating data (KBR biased range) are independent of the data validated (GPS-baseline) and this method can be applied to the real-time precision validation. The result of sequential precision validation was 1.5~3.0 mm which is similar to the batch precision validation.

• Journal of the Korean Chemical Society
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• v.59 no.5
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• pp.407-412
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• 2015

A preconcentration procedure for determination of palladium by laser thermal lens spectrometry (TLS) is proposed. It is based on cloud point extraction of palladium(II) ions as 2-(3,5-dichloro-2-pyridylazo)-5-dimethylaminoaniline (3,5-diCl-PADMA) complexes using octylphenoxypolyethoxyethanol (Triton X-114) as surfactant. The effects of various experimental conditions such as pH, concentration of ligand and surfactant, equilibration temperature and time on cloud point extraction were studied. Under the optimized conditions, the calibration graph was linear in the range of 0.15~6 ng mL⁻¹, and the detection limit was 0.04 ng mL⁻¹ with an enrichment factor of 22. The sensitivity was enhanced by 846 times when compared with the conventional spectrophotometric method. The recovery of palladium was in the range of 96.6%~104.0%. The proposed method was applied to the determination of palladium in water samples.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.122-124
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• 2010

WPS(Wifi Positioning System) is a location determination technique that utilizes AP information scattered all over the real world. In general, the finger print technique is used for location calculations in WPS. However the finger print technique is a location determination technique that utilizes average values and has problems in the accuracy of the location determination. It also shows low performance of the system due to arithmetic operations. In this paper, the MSS(Max Signal Strength) method is proposed to resolve the existing problems in the finger print technique. The proposed method can reduce the operation time and improve the accuracy of the system under the same conditions. Test environments of the system is presented and the performance of the system is analyzed to verify the methods.

• Journal of Aerospace System Engineering
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• v.10 no.1
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• pp.21-28
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• 2016

Orbit determination problems have been interest of many researchers for long time. Due to the high nonlinearity of the equation of motion and the measurement model, it is necessary to linearize the both equations. To avoid linearization, the filter based on Fokker-Planck equation is designed. with the extended Kalman filter update mechanism, in which the associated Fokker-Planck equation was solved efficiently and accurately via discrete quadrature and the measurement update was done through the extended Kalman filter update mechanism. This filter based on the DQMOM and the EKF update is applied to the orbit determination problem with appropriate modification to mitigate the filter smugness. Unlike the extended Kalman filter, the hybrid filter based on the DQMOM and the EKF update does not require the burdensome evaluation of the Jacobian matrix and Gaussian assumption for the system, and can still provide more accurate estimations of the state than those of the extended Kalman filter especially when measurements are sparse. Simulation results indicate that the advantages of the hybrid filter based on the DQMOM and the EKF update make it a promising alternative to the extended Kalman filter for orbit estimation problems.

• Preventive Nutrition and Food Science
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• v.4 no.1
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• pp.79-83
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• 1999

A potentiometric biosensor employing a CO3-2 ion-selective electrode(ISE) and malic enzyme immobilization in al flow injection analysis (FIA) system was constructed. Analytical parameters were optimized for L-malate determination . The CO3-2 -ISE-FIA system was composed of a pump, an injector, a malic enzyme (EC1.1.1.40) reactor, a CO3-2 ion-selective electrode, a pH/mV meter and a recorder. Cofactor NADP was also injected with substrate for theenzyme reaction into the system. Optimized analytical parameters for L-malate determination in the CO3-2 ISE-FIA system were as follows ; flow rate, 14.5ml/hr ; sample injection volume, 100ul; enzyme loading in the reactor, 20 units ; length of the enzyme reactor , 7 cm ; tubing length form the enzyme reactor to the detector as a geometric factor in FIA, 15 cm . The response time for measuring the entire L-malate concentration range (10-2 ~10-5 mol/L ; 4 injections )was <15minutes . In this CO3-2 -ISE-FIA system, the potential differences due to th eformation of CO3-2 by the reaction of malic enzyme on L-malate were correlated to L-malate concentration in the range of 10-2 ~10-5mol/L ; the detection limit was 10-5 mol/L. This potentionmetric CO3-2 ISE--FIA system was found to be useful for L-malate measurement.

• Analytical Science and Technology
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• v.8 no.1
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• pp.25-32
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• 1995

Determination method of trace thioglycolate has been studied by adsorptive stripping voltammetry. Copper(II)-thioglycolate complex is adsorbed at the hanging mercury drop electrode and stripped during cathodic scan. Electrolyte was used pH 6.5 phosphate and pH 9.5 borate buffer solutions. Optimal conditions were a copper(II) concentration $1{\times}10^{-4}M$, an adsorption accumulation potential -0.2V, an adsorption accumulation time 60 sec and a scan rate 20mV/sec. A detection limit of $1{\times}10^{-9}M$ thioglycolate was obtained. The method was applied to the determination of thioglycolate in cold wave fluids and depilating creams.