• YAKHAK HOEJI
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• v.24 no.2
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• pp.117-122
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• 1980

A new application of high pressure liquid chromatography for the determination of fenitrothion and cis- and trans-neopynamin in insecticidal preparations was investigated. Optimum conditions for a good separation and determination were determined; solvent system: dichloromethane + n-hexane = 17 + 83; Bow rate: 0.5ml/min; column: u-porasil ($4mm{\times}3Ocm$); absorbance wavelength: 254nm; 0.05 AUFS and sample size: 30 ul. Recovery of fenicrothion, cis- and trans-neopynamin from mixed artificial preparations was 99.6%, 99.7% and 99.8% respectively. Also reproducibility tests showed that the coefficient of variation was 0.89% for fenitrothion, 0.74% cis-neopynamin and 1.1% for trans-neopynamin. There was no interference with insecticidal preparation containing DDVP, allethrin, S-421 and kerosene. HPLC method was rapid, accurate and it gave better reproducibility and higher sensitivity than any other analytical method. It was considered that HPLC could be greatly applied to the analysis of fenitrothion and neopynamin in insecticidal preparations.

• The Korean Journal of Applied Statistics
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• v.32 no.4
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• pp.643-652
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• 2019

We propose a method for sample size determination using design effect formulas when a sample is resigned for a repeated survey. The proposed method enables the determination of the sample size by incorporating the impact of various design components to the sampling error through design effect formulas that are applicable under multistage sampling design and stratified multistage sampling designs.

• Journal of Korean Society of Transportation
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• v.31 no.2
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• pp.60-68
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• 2013

This study developed plural gravity models and their application method in order to increase the accuracy of trip distribution estimation. The developed method initially involves utilizing the coefficient of determination ($R^2$) to set the target level. Afterwards, the gravity model is created, and if the gravity model's coefficient of determination is satisfactory in regards to the target level, the model creation is complete and future trip distribution estimation is calculated. If the coefficient of determination is not on par with the target level, the zone pair with the largest standardized residual is removed from the model until the target level is obtained. In respect to the model, the removed zone pairs are divided into positive(+) and negative(-) sides. In each of these sides, gravity models are made until the target level is reached. If there are no more zone pairs to remove, the model making process concludes, and future trip distribution estimation is calculated. The newly developed plural gravity model and application method was adopted for 42 zone pairs as a case study. The existing method of utilizing only one gravity model exhibited a coefficient of determination value ($R^2$) of 51.3%, however, the newly developed method produced three gravity models, and exhibited a coefficient of determination value ($R^2$) of over 90%. Also, the accuracy of the future trip distribution estimation was found to be higher than the existing method.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.4
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• pp.69-75
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• 2003

The ideal thrust function is used to determine the local thrust of supersonic combustor. Method of thrust determination from measured pressures are applied to the Mach 2.5 model supersonic combustor. In this application, measured pressures from the experiments in the University of Michigan are used to determine the local thrust of supersonic combustor. Marginal results of local thrust are obtained and discussed. Combustion and wedge affect thrust distributions in the upstream region significantly. The thrust determination from pressure measurements can be a simple, feasible and applicable method, especially when thrust stand is not available.

• Journal of Oral Medicine and Pain
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• v.20 no.2
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• pp.497-513
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• 1995

Human genomic Deoxyribonucleic acid(DNA) was extracted from teeth by boiling, salting-out, phenol, boiling-phenol methods. The author compared DNA concentration and its purity, the accuracy of sex determination and the results of the D1S80 locus detection among above 4 methods. The following results were obtained : 1. DNA concentration was the highest in pulp with salting-out method and DNA purity was higher in pulp with salting-out and phenol methods than other 2 methods. 2. Sex determination was possible using of the pulp and the dentin of the teeth with four methods but, it was impossible in the enamel and some pulp with boiling method. 3. Amplification of D1S80 locus occurred from pulp and dentin with salting-out, phenol, and boiling-phenol methods. 4. There are no differences among the amplification of X-Y homologus amelogenin gene by application of 4 methods and salting-out, phenol methods efficiently makes available to amplification of D1S80 locus. From the investigation DNA extraction, sex determination, amplification of D1S80 locus was successfully accomplished with salting-out, phenol, boiling-phenol methods Therefore above 3 methods are available and applicable as forensic odontology for individual identification.

• The Journal of the Korea institute of electronic communication sciences
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• v.3 no.4
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• pp.260-265
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• 2008

The arc-fault occurring in the customer system becomes the direct cause of electric fire. However, it is very difficult to identify the arc-fault using the existing fault detection mechanism because the magnitude of the fault current is very small. Accordingly, this paper analyzes the causes of arc fault and designs the basic detection mechanism of arc fault. And then, it proposes an signal processing-based arc-fault determination methodology which can enhance the of accuracy of the arc-fault determination by applying DFT/DWT to the voltage and current waveform. Finally, this paper showed the application methodology of the proposed signal processing based fault determination method by applying and analyzing DFT/DWT to an high voltage in-rush current waveform.

• Analytical Science and Technology
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• v.24 no.3
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• pp.231-235
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• 2011

A spectrofluorimetric method for the determination of EDTA in real samples such as mayonnaise, powder detergent and cleansing cream with tiron (4,5-dihydroxy-1,3-benzenedisulfonic acid) as a fluorimetric reporter was developed. When tiron is chelated with Cu(II), the fluorescent intensity is decreased by a quenching effect. However, when Cu(II)-tiron chelate reacts with EDTA, fluorescent intensity is increased as tiron is released. Several experimental conditions such as pH of the sample solution, the amount of Cu(II), the amount of tiron, heating temperature and heating time were optimized. Fe(III) interfered more seriously than any other ions, interference of Fe(III) could be disregarded, because Fe(III) was scarcely contained in selected real samples. The linear range of EDTA was from $8.0{\times}106{-8}\;M$ to $2.0{\times}10^{-6}\;M$. With this proposed method, the detection limit of Fe(III) was $5.2{\times}10^{-8}\;M$. Recovery yields of 92.7~99.3% were obtained. Based on experimental results, it is proposed that this technique can be applied to the practical determination of EDTA.

• Archives of Pharmacal Research
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• v.26 no.2
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• pp.114-119
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• 2003

A high performance liquid chromatographic (HPLC) method was developed for the qualitative and quantitative determination of benzophenanthridine alkaloids from the methanol extracts of Hylomecon hylomeconoides and H. vernale (Papaveraceae). Achiral and chiral methods were adapted for the separation of 6-methoxydihydrosanguinarine (1), 6-acetonyldihydrosanguinarine (2) and dihydrosanguinarine (3). The achiral reversed phase HPLC method made it possible the simultaneous separation and determination of 1, 2 and 3 within 20 min on ODS column using acetonitrile-phosphate buffer (50 mM, pH 7.0) (50 : 50, v/v). The separation and determination of 1 and 2 enantiomers was available using chiral columns. The same amount of (+) and (-)-enantiomers of 1 was found from the methanol extract of specimen, indicated that 1 could be the artifact produced by the reaction of sanguinarine with methanol. H. hylomeconoides showed higher level of 1 and 3 in compared with H. vernale, especially in root samples permitting the possibility of chemical discrimination between two species.

• Bulletin of the Korean Chemical Society
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• v.25 no.8
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• pp.1137-1142
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• 2004

A spectrophotometric and first derivative spectrophotometric method was developed in aquatic Tween 80 micellar solutions for selective determination of nickel without using any pre-separation step. 1-(2-Pyridylazo)-2-naphthol (PAN), as a sensitive chromogenic complexing agent formed a red-colored Ni(II)-PAN complex in Tween 80 media with satisfactory solubility and stability. Conditions such as pH, PAN concentration, type and concentration of micellizing agent were optimized. Molar absorptivity of Ni-PAN complex was found $4.62\;{\times}\;10^4L\;cm^{?1}\;mol^{?1}$ at 569 nm, under the optimum condition. Calibration graphs were derived by zero, first and second derivative spectrophotometry at maximum wavelengths of 569, 578 and 571 nm with linear ranges of 30-1800, 20-2500 and 30-2000 ng $mL^{?1}$ , respectively. Precision as standard deviation as well as accuracy as recovery percent were in the range of 1-20 ng $mL^{?1}$, and 93.3-103.3%, respectively, for the entire of the linear ranges. Spectrophotometric detection limit was 3 ng $mL^{?1}$ and effects of diverse ions on the first derivative determination of nickel were studied to investigate selectivity of the method. Interferences of cobalt and copper on the nickel determination were prevented using o-phenanthroline as masking agent. The recommended procedures were applied to the various synthetic and stainless steel alloys, tea leaves and human hair, with satisfactory results.

• KSBB Journal
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• v.30 no.4
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• pp.141-147
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• 2015

The convenient determination of methylsulfonylmethane (MSM) for a commercially available dietary supplement was developed using gas chromatography (GC)-flame ionization detector (FID). Chromatography was performed on a capillary column ($0.32mm\;I.D{\times}30m$, $0.25{\mu}m$) coated with dimethylpolysiloxane using diethylene glycol methyl ether as an internal standard. The performance characteristics of GC were evaluated in terms of selectivity, linearity, precision, accuracy, recovery, limit of detection (LOD) and limit of quantification (LOQ). The calibration curve was highly linear (the coefficient of determination: 0.9979) within the concentration range of $10.0{\sim}800.0{\mu}g/mL$ for MSM. The recoveries for three fortified concentrations were 96.7~97.1%, 96.6~97.3% and 96.8~97.2%, respectively. The LOD and LOQ of the method were $0.29{\mu}g/mL$ and $0.97{\mu}g/mL$, respectively. All obtained results were acceptable according to the guidelines of the Association of Official Analytical Chemists for dietary supplements. Thus, the validated analytical method using the GC-FID system is suitable for the determination of MSM in dietary supplement formulations for quality control.