• Journal of the Society of Disaster Information
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• v.9 no.3
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• pp.249-258
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• 2013

Recieved Mar. 06, 2013 Revised Mar. 29, 2013 Accepted Sep. 11, 2013In this study, we evaluated the method performance and the optimum sample injection method of the portable GC/MS(HAPSITE) which were designed to operate on scene of chemical accidents. Chemicals used for performance test were vinyl chloride(VC), methyl chloride(MC), benzene(Bz), toluene(Tol). CRM(Certified Reference Material) Manufactured by KRISS(Korea Research Institute of Standards and Science) was used as the standard gas. The results showed that 1) Among three sample injection methods(Cylinder, Silico canister, and Bag), bag was identified as the most appropriate sample injection method. Bag material and capacity did not significantly affect the results. The most ideal reproducibility occurred at the 2-minute point of the purge time in the loop and tenax methods. 2) Performance evaluation of HAPSITE was conducted. Evaluation items were reproducibility, linearity, method detection limit, etc. Tenax concentration method was appropriate for larger molecules and Carbopack concentration method was suitable for smaller molecules.

• The Korean Journal of Food And Nutrition
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• v.17 no.4
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• pp.412-419
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• 2004

In odor to select optimum extraction methods of volatile compounds in beef extract powder(BEP) as basic data for the development of a new detection method of irradiated BEP, four extraction methods, such as solid phase microextraction with polar fiber(S-PD) and non-polar fiber(S-CD), purge and trap(P&T) and liquid liquid continuous extraction(LLCE) methods, were tested with gas chromatography/mass spectrometry method. A total of 106 volatile compounds including 22 hydrocarbons, 7 aldehydes, 6 ketones, 13 alcohols, 6 sulfur-containing compounds, 19 nitrogen-containing compounds, 6 aromatic compounds, 17 terpenes, 8 furans and 2 miscellaneous compounds were detected in BEP by four detection methods. The most compounds(62 compounds) were detected by S-PD method, followed by P&T(43), LLCE(38) and S-CD method(30). Among these methods, S-PD and P&T methods showed a complementary interrelationship to detect volatile compounds as S-PD method showed high detectabiltiy to all compound groups except hydrocarbons and ketones, which had high volatility and low molecular weight(less than RI 1200), but P&T method showed the contrary pattern to that of S-PD method. Moreover, the most of volatile compounds detected by S-CD and LLCE methods were also detectable by S-PD or/and P&T methods. Therefore, the simultaneous application of S-PD and P&T methods were selected as the optimum volatile extraction methods of BEP.

• Korean Journal of Food Science and Technology
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• v.32 no.5
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• pp.1029-1034
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• 2000

A suitable method of sample treatments to minimize the analytical interferences was presented in order to determine bisphenols [bisphenol F (BPF), bisphenol A (BPA), bisphenol F diglycidyl ether (BFDGE), and bisphenol A diglycidyl ether (BADGE)] in various canned beverages coated with epoxy resin by the reversephase high performance liquid chromatography (RP-HPLC) equipped with a fluorescence detector and the gas chromatography with mass selective detection. The recovery test of bisphenols was performed using 1, 5, and 10 ${\mu}g/L$ bisphenols spiked beverages with the combined technique of the solid-phase extraction (SPE) and the liquid-phase extraction (LPE). Both BPA and BADGE showed quite adequate resolutions in HPLC-chromatograms. The recoveries of BPA obtained by LPE with diethyl ether were higher than those obtaind with methylene chloride on coffee, shikhye and fruit juice. For cola and tea, the recoveries of BPA obtaind by SPE were higher than those by LPE with diethyl ether. The recoveries of BADGE were less than those of BPA for all beverage samples treated by either SPE or LPE method. In survey of bisphenols for eighteen commercial canned beverage samples, BPA contents of coffee, cola, tea, shikhye, and fruit juice were in the range of $1.3{\sim}11.6,\;0.5{\sim}0.9,\;1.0{\sim}1.3,\;2.4{\sim}7.9$, and $3.0{\sim}3.4\;{\mu}g/L$, respectively, but there was no detection of BPA in beer sample.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.42.1-42.1
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• 2019

We observed 80 dense cores ($N(H_2)$ > $10^{22}cm^{-2}$) in the Orion molecular cloud complex which contains the Orion A (39 cores), B (26 cores), and ${\lambda}$ Orionis (15 cores) clouds. We investigate the behavior of the different molecular tracers and look for chemical variations of cores in the three clouds in order to systematically investigate the effects of stellar feedback. The most commonly detected molecular lines (with the detection rates higher than 50%) are $N_2H^+$, $HCO^+$, $H^{13}CO^+$, $C_2H$, HCN, and $H_2CO$. The detection rates of dense gas tracers, $N_2H^+$, $HCO^+$, $H^{13}CO^+$, and $C_2H$ show the lowest values in the ${\lambda}$ Orionis cloud. We find differences in the D/H ratio of $H_2CO$ and the $N_2H^+/HCO^+$ abundance ratios among the three clouds. Eight starless cores in the Orion A and B clouds exhibit high deuterium fractionations, larger than 0.10, while in the ${\lambda}$ Orionis cloud, no cores reveal the high ratio. These chemical properties could support that cores in the ${\lambda}$ Orionis cloud are affected by the photo-dissociation and external heating from the nearby H II region. An unexpected trend was found in the $[N_2H^+]/[HCO^+]$ ratio with a higher median value in the ${\lambda}$ Orionis cloud than in the Orion A/B clouds than; typically, the $[N_2H^+]/[HCO^+]$ ratio is lower in higher temperatures and lower column densities. This could be explained by a longer timescale in the prestellar stage in the ${\lambda}$ Orionis cloud, resulting in more abundant nitrogen-bearing molecules. In addition to these chemical differences, the kinematical difference was also found among the three clouds; the blue excess, which is an infall signature found in optically thick line profiles, is 0 in the ${\lambda}$ Orionis cloud while it is 0.11 and 0.16 in the Orion A and B clouds, respectively. This result could be another evidence of the negative feedback of active current star formation to the next generation of star formation.

• Journal of the Institute of Convergence Signal Processing
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• v.22 no.4
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• pp.185-192
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• 2021

Various methods have been proposed to determine the defect detection of welding bead, and recently sensor data and image data inspection have been steadily announced. There are advantages that sensor data inspection is highly accurate, and two-dimensional-based image data inspection is able to determine the position of the welding bead. However, when analyzing only with sensor data, it is difficult to determine whether the welding has been performed at the correct position. On the other hand, the image data inspection does not have high accuracy due to noise and measurement errors. In this paper, we propose a method that can complement the shortcomings of each inspection method and increase its advantages to improve accuracy and speed up inspection by fusing sensor data inspection which are average current, average volt, and mixed gas data, and image data inspection methods and is implemented as software. In addition, it is intended to allow users to conveniently and intuitively analyze and grasp the results by performing analysis using a graphical user interface(GUI) and checking the data and inspection results used for the inspection. Sensor inspection is performed using the characteristics of each sensor data, and image data is inspected by applying a morphology geodesic active contour algorithm. The experimental results showed 98% accuracy, and when performing the inspection on the four image data, and sensor data the inspection time was about 1.9 seconds, indicating the performance of software that can be used as a real-time inspector in the welding process.

• Journal of the Society of Disaster Information
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• v.19 no.3
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• pp.665-672
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• 2023

Purpose: Underground utility tunnel is facility that is jointly house infrastructure such as electricity, water and gas in city, causing condensation problems due to lack of airflow. This paper aims to prevent electricity leakage fires caused by condensation by detecting whether the control panel door in the underground utility tunnel is open using a deep learning model. Method: YOLO, a deep learning object recognition model, is trained to recognize the opening and closing of the control panel door using video data taken by a robot patrolling the underground utility tunnel. To improve the recognition rate, image augmentation is used. Result: Among the image enhancement techniques, we compared the performance of the YOLO model trained using mosaic with that of the YOLO model without mosaic, and found that the mosaic technique performed better. The mAP for all classes were 0.994, which is high evaluation result. Conclusion: It was able to detect the control panel even when there were lights off or other objects in the underground cavity. This allows you to effectively manage the underground utility tunnel and prevent disasters.

• Analytical Science and Technology
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• v.22 no.6
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• pp.514-518
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• 2009

Coenzyme $Q_{10}$($CoQ_{10}$), a vitamin E-like substance, represents a components of the complex antioxidant system of the human organism. $CoQ_{10}$ levels in human plasma were determined by high performance liquid chromatography (HPLC) with UV detection. It was dissociated from lipoproteins by methanol and extracted into n-hexane with liquid-liquid extraction procedure, after centrifugation, the supernatant was dried under nitrogen gas stream. The residue was dissolved in the absolute ethanol. Determination of $CoQ_{10}$ was performed on a $C_{18}$ reversed-phase analytical column with ultraviolet detection at 275 nm and the mobile phase containing 15% (v/v) ethanol in methanol at a flow rate of 1.7 mL/min. The low limit of quantitation was 0.02 mg/L (S/N=10), the linearity between the concentration and peak height is from 0.1 to 2.0 mg/L. Twenty-four randomly selected plasma samples from apparently healthy, 27 to 44 year old individuals (males and females) were analyzed for total $CoQ_{10}$. The average level in these subjects was $0.62{\pm}0.13mg/L$ with the range of 0.41-0.98 mg/L. This method has a specific and a sufficient limit of quantitation (LOQ) for analysis of $CoQ_{10}$ in human plasma in both a clinical study and research at laboratories.

• Analytical Science and Technology
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• v.21 no.4
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• pp.316-325
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• 2008

An inductively coupled plasma mass spectrometry (ICP-MS) instrument equipped with flow injection-hydride generation system was used for the determination of trace arsenic in seawater sample. The accuracy in this method was verified by the analysis of certified reference materials (CRM) of seawater (CASS-4, NASS-5). The analytical results agreed with certified value within the range of uncertainty. The expanded uncertainties for CASS-4 and NASS-5 in this experiment were ranged from 6.2% to 6.8% obtained from repeated analyses of the CRMs (n=5). The detection limit of $As^+$ (m/z=74.9216) in this method was confirmed about 0.01 ug/kg. Linearity obtained from calibration curve of arsenic was excellent ($R^2=1$). The detection at $As^+$ (m/z=74.9216) and $AsO^+$ (m/z=90.9165) by using oxygen reaction gas in DRC mode was compared. Sensitivity at $AsO^+$ (m/z=90.9165) was decreased about 25-fold, but the analytical results are the same that at $As^+$ (m/z=74.9216).

• Journal of Food Hygiene and Safety
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• v.28 no.2
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• pp.130-137
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• 2013

In this study, we investigated the applicability of the photostimulated luminescence (PSL), thermoluminescence (TL), electron spin resonance (ESR) and gas chromatography/mass spectrometry (GC/MS) methods for 5 seeds which are not allowed to be irradiated in Korea. All 5 seeds including evening primrose seed, safflower seed, rape seed, sunflower seed and flax seed were analyzed. Samples were irradiated at 1~10 kGy using a $^{60}Co$ gamma-ray irradiator. In PSL study, the photon counts of all the unirradiated samples showed negative (lower than 700). The photon counts of irradiated (1, 5, 10 kGy) samples showed positive (higher than 5,000). In TL analysis, results showed that it is possible to apply TL method to all foods containing minerals. In ESR measurements, the ESR signal (single-line) intensity of irradiated foods was higher than non-irradiated foods. The hydrocarbons 1,7-hexadecadiene ($C_{16:2}$) and 8-heptadecene ($C_{17:1}$) from oleic acid were detected only in the irradiated samples before and after the treatment at doses ${\geq}$ 1 kGy, but they were not detected in non-irradiated samples before and after treatment. These two hydrocarbons could be used as markers to identify irradiated safflower seed, rape seed, Sunflower seed and flax seed. And then, the hydrocarbons 1,7,10-hexadecatriene ($C_{16:3}$) and 6,9-heptadecadiene ($C_{17:2}$) from linoleic acid were detected in the evening primrose seed, safflower seed and sunflower seed. According to the results, PSL, TL and GC/MS methods were successfully applied to detect the irradiated foods. It is concluded that PSL, TL and GC/MS methods are suitable for detection of irradiated samples and a combined method is recommendable for enhancing the reliability of detection results.

• Journal of Acupuncture Research
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• v.17 no.4
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• pp.79-87
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• 2000

Objectives : To evaluate the findings useful for differential diagnosis and associated abnormaiities of isthmic spondylolisthesis and degenerative spondylolisthesis on CT. Materials and methods : We reviewed retrospectively the CT images of 65 patients who were diagnosed spondylolisthesis during 3 years period. Our technique was 5mm slices at 5mm intervals with gantry angle to parallel the interspaces. Also reformatted sagittal views were taken. 41 patients were isthmic spondylolisthesis and 24 patients were degenerative spondylolisthesis. Resuits : Isthmic spondylolisthesis. 1. Isthmic type was more common at L5-S1. 2. The degree of anterior displacement was grade I and II. 3. The plane of defect was more horizontal than the usual facet joint. 4. The defect had an irregular shape. 5. Medial aspect of bone just anterior to defect had a small round prominence. 6. Anteroposterior elongation of the spinal canal was common. 7. Pseudobulging disk was common. 8. The most common associated abnormality was a HNP at the upper level of the defect. Degenerative spondylolisthesis. 1. Degenerative type was more common at L4-5. 2. The degree of anterior disptacement was grade I and II. 3. The Plane of facet joint was oriented obliquely instead of horizontally. 4. The posterior facet(inferior facet of superior vertebra) was anteriorly displaced. 5. Bony spur of the posterior portion of anterior facet was seen. 6. The facet joints often contain gas(vaccum phenomenum). 7. The most common associated abnormality was a HNP at the level of the displacement. Conclusions : CT is a highly accurate and most sensitive technique for recognition, differential diagnosis of isthmic and degenerative types and the detection of associated abnormalities.