• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.8 no.2
• /
• pp.509-515
• /
• 2004

Pulmonary function tests are widely used to diagnose and determine patients' therapy in clinic. And it was also applied in the research of the physiology and dynamics for lung disease. Among the pulmonary function tests, spirometry is the most easy and economic test. Spirometers are medical instruments that measure the instantaneous rate of volume flow of respired Bas. The mechanical spirometer was mostly used in the past. Up to the present, the most popular method of spirometer is the differential pressure technique with which change in the volume of flow are transferred to change in pressure. This kind of instrument suffers from several limitations, pressure drop, difficulty in maintenance and short period of calibration. Therefore, this study has begun to implement ultrasound spirometer, which is free of pressure loss and has wide range, focusing on the flow measurement technique and diagnostic algorithm.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2014.05a
• /
• pp.695-698
• /
• 2014

As most the scanning systems developed until now provide radiation scan plane images of the inspected objects, there has been a limitation in judging exactly the shape of the objects inside a logistics container exactly with only 2-D radiation image information. Two 2-dimensional radiation images which have different disparity values are acquired from a newly designed stereo image acquisition system which has one additional line sensor to the conventional system. Using a matching algorithm the 3D reconstruction process which find the correspondence between the images is progressed. In this paper, we proposed a new volume based 3D reconstruction algorithm and experimental results show the proposed new volume based reconstruction technique can provide more efficient visualization for cargo inspection. The proposed technique can be used for the development of the high speed and more efficient non-destructive auto inspection system.

• Journal of the Society of Disaster Information
• /
• v.19 no.1
• /
• pp.184-194
• /
• 2023

Purpose: The purpose of this study is to identify the characteristics of C02 emissions by road before establishing a policy to reduce greenhouse gas emissions. Method: As for the analysis method, the traffic volume and speed of the road were estimated using the traffic Assignment model targeting 27 arterial road axes in Incheon Metropolitan City. And, after estimating CO2 emissions by road axis by applying this, the characteristics of each group were analyzed through cluster analysis. Result: As a result of cluster analysis using total CO2 emissions, CO2 emissions by truck vehicles, and the ratio of truck vehicle emissions to total carbon dioxide emissions, four clusters were classified. When examining the characteristics of each road included in each group, it was analyzed that the characteristics of each group appeared according to the level of impact by CO2 emissions and truck vehicles. Conclusion: It is judged that it is necessary to establish a plan in consideration of CO2 emission characteristics for road CO2 management for greenhouse gas reduction.

• Geomechanics and Engineering
• /
• v.34 no.5
• /
• pp.577-595
• /
• 2023

A dynamic triaxial discrete element numerical model of lightweight soil was established using the discrete element method to study the microscopic mechanism of expanded polystyrene (EPS) particles in the soil under cyclic loading. The microscopic parameters of the discrete element model of the lightweight soil were calibrated depending on the dynamic triaxial test hysteresis curves. Based on the calibration results, the effects of the EPS particles volume ratio and amplitude on the contact force, displacement field, and velocity field of the lightweight soil under different accumulated strains were studied. The results showed that the hysteresis curves of lightweight soil exhibit nonlinearity, hysteresis, and strain accumulation. The strain accumulated in remolded soil is mainly tensile strain, and that in lightweight soil is mainly compressive strain. As the volume ratio of EPS particles increased, the contact force first increased and then decreased, and the displacement and velocity of the particles increased accordingly. With an increase in amplitude, the dynamic stress of the particle system increased, and the accumulation rate of the dynamic strain of the samples also increased. At 5% compressive strain, the contact force of the particles changed significantly and the number of particles deflected in the direction of velocity also increased considerably. These results indicated that the cemented structure of the lightweight soil began to fail at a compressive strain of 5%. Thus, a compressive strain of 5% is more reasonable than the dynamic strength failure standard of lightweight soil.

• The Korean Journal of Pesticide Science
• /
• v.19 no.4
• /
• pp.370-393
• /
• 2015

This study was conducted to compare STQ method, multi-residue method in Korean food code and QuEChERS method for validated selected and accuracy, reproducibility and efficiency. A total of 45 selected and targeted pesticides were the analyzed by GC and 5 of them were crops (apple, potato, green pepper, rice, soy bean). $R^2$ values were calculated in the standard calibration curve was over 0.990. Recovery tests were performed by three replications in two levels and the relative standard deviation of the repeated experiments was less than 30%. The average percentage of recoveries in the multi-residue method in Korean food code was 89.13%, QuEChERS method was 92.45% and STQ method was 85.28%. In addition, matrix effects in multi-residue method in Korean food code was 24.61%, QuEChERS method was 23.98% and STQ method showed 11.24%. The STQ method is easy and showed high clean-up effect in extracting the sample solution than the QuEChERS method and clean-up with C18, PLS, PSA cartridge columns. A large volume of the sample was injected in order to compensable for the problem, that occurred due to high detection limit in the analyser. When the STQ method was applied using a large volume injector, the standard calibration curve showed a higher linearity $R^2=0.990$, and method detection limit was 0.01 mg/kg. It showed an average recovery of 91.84% and the relative standard deviations of three replications repeated in two level process was less than 30% and had an average matrix effect of 17.90%.

• Food Science and Biotechnology
• /
• v.17 no.3
• /
• pp.508-513
• /
• 2008

Erythromycin has been used to treat Streptococosis, Edwardsiel1osis, Vibriosis, Bacterial enteritis in the cultured fish. In this study, a rapid and effective erythromycin analysis method with new sample treatment protocol and liquid chromatography/tandem mass spectrometry (LC/MS/MS) system for fish products was developed. For the erythromycin extraction from fish muscle, the solvent mixture composed of 0.2% meta-phosphoric acid and methanol (6:4) showed good recovery rate, and the optimum extraction solvent volume was 20 mL. Erythromycin detection using LC/MS/MS were carried out under electro spray ionization (ESI) positive condition and erythromycin mass value 576.2 and 157.9. And the detection limit of the established method was 0.005 mg/kg in fish products. The recovery rate of the developed method applied to the fish species were as following, olive flounder, $87.6{\pm}5.0%$; black rockfish, $87.2{\pm}6.4%$; eel, $85.2{\pm}4.8%$; and rainbow trout, $86.0{\pm}6.2%$. In the established method in this study, the correlation of coefficient values ($R^2$) of erythromycin calibration curve (n=11) was 0.9998.

• Bulletin of the Korean Chemical Society
• /
• v.27 no.6
• /
• pp.875-880
• /
• 2006

A new, simple and fast flow injection analysis (FIA) method has been developed for the indirect determination of nitrite. The proposed indirect automatic method is based on the oxidation of nitrite to nitrate using a lead(IV) dioxide oxidant microcolumn where the flow of the sample through the microcolumn reduces the $PbO_2$ solid phase reagent to Pb(II), which is measured by flame atomic absorption spectrometry. The absorbance of Pb(II) are proportional to the concentration of nitrite in the samples. The calibration curve was linear up to 30 mg $L ^{-1}$, with a detection limit of 0.11 mg $L ^{-1}$ for a 400 mL injected sample volume and a sampling rate of about 80 $h ^{-1}$. The results exhibit no interference from the presence of large amounts of ions. The developed procedure was found to be suitable for the determination of nitrite in foodstuffs and wastewaters. A relative standard deviation better than 0.9% was obtained in a repeatability study. The reliability of the method was established by parallel determination against the standard method.

• Proceedings of the KSME Conference
• /
• 2001.06e
• /
• pp.690-695
• /
• 2001

The three-dimensional spatial structures of impeller flow created by a six bladed Rushton turbine have identified based on the volumetric velocity information from multi-plane stereoscopic PIV measurements. A total of 10 planes with 2 mm space with a 50 mm by 64 mm size of the field of view were targeted. To reduce the depth of focus, we adopted an angle offset configuration which satisfied the Scheimpflug condition. The distortion compensation procedure was utilized during the in situ calibration. Phase-locked instantaneous data were ensemble averaged and interpolated in order to obtain mean 3-D, volumetric velocity fields on a 60 degree sector of a cylindrical ring volume enclosing the turbine blade. Using the equi-vorticity surface rendering, the spatial structure of the trailing vortices was clearly demonstrated. Detail flow characteristics of the radial jet reported in previous studies of mixer flows were easily identified.

• Bulletin of the Korean Chemical Society
• /
• v.25 no.7
• /
• pp.1019-1024
• /
• 2004

The present paper is focused on simultaneous sorption concentration of gold (III) and silver (I) from thiocyanate solutions using high-selective anion exchanger AN-25 and subsequent separation of these ions at various concentrations of thiocarbamide (eluent). As a result, silver (I) ions are completely eluted from AN-25 and gold (III) ions remain in the resin phase and can be determined directly in the solid phase by diffuse reflection spectroscopy. It is proposed to use the sorption-spectroscopic method for Au(III) determination in aqueous solutions. The calibration curve is linear in the concentration range of 1-19 mg/L (sample volume is 10.0 mL) and the detection limit is 0.05 ${\mu}g/mL$. The presence of Cu(II), Co(II), Fe(II) do not hinder this determination. Au(III) was determined in industrial solutions.

• Environmental Analysis Health and Toxicology
• /
• v.17 no.2
• /
• pp.95-107
• /
• 2002

This study was designed to investigate the characteristics of atmospheric concentrations of toxic volatile organic compounds (VOCs) in Korea. Target compounds included 1,3-butadiene, aromatics such as BTEX, and a number of carbonyl compounds. In this paper, as the first part of the study, the performance of sampling and analytical methods was evaluated for the measurement of selected VOCs and carbonyl compounds in the ambient air. VOCs were determined by the adsorbent tube sampling and automatic thermal desorption coupled with GC/MSD analysis, while carbonyls by the DNPH-silica cartridge sampling with HPLC analysis. The methodology was investigated with a wide range of performance criteria such as repeatability, linearity. lower detection limits, collection efficiency, thermal conditioning, breakthrough volume and calibration methods using internal standards. In addition, the sampling and analytical methods established in this study were applied to real field samples duplicately collected in various ambient environments. Precisions for the duplicate samples appeared to be comparable with the performance criteria recommended by USEPA TO-17. The overall precision of the sampling and analytical methods was estimated to be within 20 ∼ 30% for major aromatic VOCs such as BTEX, whereas the precision for major carbonyl compounds such as formaldehyde and acetaldehyde was within 10 ∼ 20% for field samples. This study demonstrated that the adsorbent sampling and thermal desorption method can be reliably applied for the measurement of BTEX in ppb levels frequently occurred in common indoor and ambient environments.