• Smart Structures and Systems
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• v.13 no.5
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• pp.849-868
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• 2014

An indirect approach is explored for structural health bridge monitoring allowing for wide, yet cost-effective, bridge stock coverage. The detection capability of the approach is tested in a laboratory setting for three different reversible proxy types of damage scenarios: changes in the support conditions (rotational restraint), additional damping, and an added mass at the midspan. A set of frequency features is used in conjunction with a support vector machine classifier on data measured from a passing vehicle at the wheel and suspension levels, and directly from the bridge structure for comparison. For each type of damage, four levels of severity were explored. The results show that for each damage type, the classification accuracy based on data measured from the passing vehicle is, on average, as good as or better than the classification accuracy based on data measured from the bridge. Classification accuracy showed a steady trend for low (1-1.75 m/s) and high vehicle speeds (2-2.75 m/s), with a decrease of about 7% for the latter. These results show promise towards a highly mobile structural health bridge monitoring system for wide and cost-effective bridge stock coverage.

• Journal of Environmental Health Sciences
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• v.47 no.6
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• pp.521-529
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• 2021

Background: The coronavirus disease (COVID-19) has caused changes in human activity, and these changes may possibly increase or decrease exposure to fine dust (PM_2.5). Therefore, it is necessary to evaluate the exposure to PM_2.5 in relation to the outbreak of COVID-19. Objectives: The purpose of this study was to compare and evaluate the exposure to PM_2.5 concentrations by the variation of dynamic populations before and after the outbreak of COVID-19. Methods: This study evaluated exposure to PM_2.5 concentrations by changes in the dynamic population distribution in Guro-gu, Seoul, before and after the outbreak of COVID-19 between Jan and Feb, 2020. Gurogu was divided into 2,204 scale standard grids of 100 m×100 m. Hourly PM_2.5 concentrations were modeled by the inverse distance weight method using 24 sensor-based air monitoring instruments. Hourly dynamic population distribution was evaluated according to gender and age using mobile phone network data and time-activity patterns. Results: Compared to before, the population exposure to PM_2.5 decreased after the outbreak of COVID-19. The concentration of PM_2.5 after the outbreak of COVID-19 decreased by about 41% on average. The variation of dynamic population before and after the outbreak of COVID-19 decreased by about 18% on average. Conclusions: Comparing before and after the outbreak of COVID-19, the population exposures to PM_2.5 decreased by about 40%. This can be explained to suggest that changes in people's activity patterns due to the outbreak of COVID-19 resulted in a decrease in exposure to PM_2.5.

• Journal of environmental and Sanitary engineering
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• v.22 no.3
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• pp.89-96
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• 2007

To determine 8 anti-impotence drug/drug-like compounds such as sildenafil, vardenafil, tadalafil, homosildenafil, hydroxyhomosildenafil, aminotadalafil, pseudovardenafil and hongdenafil in foods, simultaneously, high performance liquid chromatography(HPLC) and liquid chromatography-mass spectrometry (LC/MS) were used. The HPLC/UV analysis was performed on a column of capcellpak $C_{18}$ with 0.1% sodium-1-hexansulfonate in 0.2M ammonium formate/acetonitrile as a mobile phase. Mass spectra of the compounds by LC/MS were investigated with SCAN mode(Mass range and Fragment voltage) and SIM(Selected Ion Monitoring) mode (Ion target and Fragment voltage). The results follow as; 1. The HPLC/UV analysis was detected from 5 out of 63 samples. The content of sildenafil was in the range of 32.80 ppm ${\sim}$ 60.13 ppm from 4 out of 5 samples. The contents of sildenafil, vardenafil, homosildenafil were in the range 47.14 ppm from 1 out of 5 samples. 2. The conformed result of LC/MS was equal of detected from 5 out of 63 samples in HPLC/UV analysis. An easily available, simultaneous determination of 8 standards in adulterated health related foods was established by using a combination of LC/MS methods.

• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.480-481
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• 2008

본 논문은 U-Health 장치 인터페이싱을 위하여 표면 근전도를 이용한 손동작 특징들의 모델링 알고리즘에 대하여 제안하였다. 지금까지 연구에서는 표면 근전도를 측정하기 위하여 전완의 여러 부위에서 신호를 측정하였지만 휴대용 U-Health 장치들의 특성상 센서를 부착 할 수 있는 공간이 한정 되어있기 때문에 한 채널당 손동작의 인식률이 높아야하고 착용하기 편한 위치예서 신호를 측정해야 한다. 따라서 본 논문에서는 손목 근처의 수지신근(finger extensor)과 소지신근(extensor digiti minimi) 사이에 생체신호 센서를 부착하는 것을 제안했으며, 적은 수의 센서에서도 손동작에 따른 충분한 근전도 패턴을 구분해 내기 위하여 3차원 공간상에서 시간과 스케일 정보를 분석할 수 있는 다해상도 웨이블릿을 이용하였다. 정밀한 근전도 분석을 위하여 모 웨이블릿을 신경 신호의 활동전위(action potential)와 가장 유사한 형태를 가지고 있는 Daubechies 4 (db4)로 선택하였고, 이렇게 웨이블릿 분석을 통하여 1차원 신호를 16레벨로 나누어 각 신호에 대하여 에너지를 200 ms 간격으로 평가함으로서 7가지 손동작 인식을 위한 패턴 모델을 구하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.10a
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• pp.874-875
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• 2016

This paper proposes the architecture and major functionalities of IT converged smart outdoor exercise equipment and health cashback system. It provides basic information such as date, time, weather information, and display the amount of exercise, thermal images for monitoring the change of user's body temperature and health cashback point. The amount of exercise is transferred to a health cashback server via mobile communication network and the server provides the exercise history and health cashback point. Also, as additional public services, a fine dust alarm light and an emergency alarm function are embedded. The proposed IT converged smart outdoor exercise equipment will be a reference model for studying and commercializing the next generation product.

• Korean Journal of Veterinary Service
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• v.34 no.3
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• pp.285-289
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• 2011

This study was conducted to determine the content of non-steroidal anti-inflammatory drugs (NSAIDs) in meats available on the Korean markets. The analysis was carried out using following conditions; C18 column ($100{\times}2.1$ mm, 1.7 ${\mu}m$), mobile phase composed of DW (containing 0.1% formic acid): acetonitrile (containing 0.1% formic acid), binary pump at a flow rate of 0.3 ml/min and 5 ${\mu}l$ of injection volume, MS/MS detector with ESI positive mode. The calibration range of five NSAIDs showed linearity ($r^2{\geq}0.99$) at concentration range of 3.125~200 ${\mu}g$/kg. The recoveries in fortified muscle more than 78.7~100.3%. The detection limits for meloxicam, ketoprofen, flunixin, carprofen and tolfenamic acid were 3.5, 1.6, 1.7, 9.8 and 4.8 ${\mu}g$/kg, respectively. We also monitored NSAIDs residue in cattle muscle 51 samples. The test results, NSAIDs were all not founded.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.222.1-222.1
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• 2003

This study was carried out to investigate the quality control of domestic and imported Puerariae Radix. It was analyzed by HPLC using ${\mu}$-Bondapak C$\sub$18/ column with 35% MeOH containing 1% CH$_3$3CO$_2$H system as the mobile phase at UV 254nm. Good linearity showed over the range of 10 to 200$\mu\textrm{g}$/$m\ell$(r$^2$=1) for Puerarin, and 0.5 to 10$\mu\textrm{g}$/mg(r$^2$=0.9999) for Daidzein. The average contents of Puerarin and Daidzein were 5.5${\pm}$1.2%(Domestic), 5.3${\pm}$0.7%(Imported), and 0.05${\pm}$0.02%(Domestic), 0.08${\pm}$0.02%(Imported).The average recovery rates of Puerarin and Daidzein were 101.8${\pm}$1.9% and 97.2${\pm}$0.7%, respectively.

• Applied Chemistry for Engineering
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• v.9 no.3
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• pp.404-406
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• 1998

Analysis for the imidazoline type cationic surfactants was performed by the gas chromatography(GC) and high performance liquid chromatography(HPLC). The composition of the alkyl chain distribution was investigated by GC after base/Acid hydrolysis of the imidazoline ring. The distribution of total alkyl chain was separated clearly by a Bondclone C18/NOVA-Pak C18 HPLC column using 50% acetonitrile in methanol containing 0.1M sodium perchlorate as a mobile phase. Alkyl chain distribution and average molecular weight of imidazoline type cationic surfactants were obtained based on these analytical methods. The agreement of results from GC and HPLC was good. The detection limit of imidazoline by HPLC method was 10ng without pretreatment.

• The Journal of the Korea Contents Association
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• v.15 no.3
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• pp.192-198
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• 2015

Checked out by the moving vehicle health checks for patients, practitioners, and the increase in radiation dose outside the vehicle, but an investigation into the leakage of radiation can still be negligible. In this study, through experimental results were as follows: Dose that occurs most often where the leak in the right door $1.14{\pm}1.75mR/h$, X-ray generator in terms of proximity to the top $0.65{\pm}1.25mR/h$, X-ray generator and away to the bottom in terms $0.91{\pm}1.25mR/h$, the adjacent rear detector in the upper part $96.98{\pm}158.88mR/h$ dose of the leak appeared in various locations. By measuring position from the rear of the adjacent detector $67.48{\pm}97.03mR/h$ dose had the highest leakage into. Generating device for diagnosis of radiation safety regulations regarding the maximum leakage dose per week, but all met back when it is displayed in the leakage dose Hourly rates do not ignore the leakage radiation dose were measured. Therefore, a mobile health screening in a vehicle outside of the leakage radiation dose to the liver and move on we are not interested twelve barrier leakage radiation dose of defense has a chance to re-evaluate the standards required, and move the vehicle health check using the X-ray increases as the dose per hour, depending on the criteria for choosing the appropriate measures that will require effort.

• Analytical Science and Technology
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• v.32 no.3
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• pp.96-104
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• 2019

Agastache rugosa, known as Korean mint, is a medicinal plant with many beneficial health effects. In this study, a simple and reliable HPLC-UV method was proposed for the quantification of rosmarinic acid (RA) in the aqueous extracts of A. rugosa. RA was selected as a quantification marker due to its easiness in procurement and analysis. The developed method involved chromatographic separation on a $C_{18}$ column ($250{\times}4.6mm$, $5{\mu}m$) at room temperature. The mobile phase consisted of water and acetonitrile both containing 2 % acetic acid and was run at a flow rate of $1mL\;min^{-1}$. The method was validated for specificity, linearity, precision, and accuracy. It was specific to RA and linear in the range of $50-300{\mu}g\;mL^{-1}$ ($r^2=0.9994$). Intra-day, inter-day, and inter-analyst precisions were ${\leq}0.91%\;RSD$, ${\leq}1.40%\;RSD$, and 1.94 % RSD, respectively. Accuracy was 93.3-95.9 % (${\leq}1.21%\;RSD$). The method could be applied to three batches of bulk samples and three batches of lab scale samples, which were found to be $0.64({\pm}0.04)mg\;g^{-1}$ and $0.48({\pm}0.02)mg\;g^{-1}$ for the dried raw materials of A. rugosa. The results show that the proposed method can be used as a readily applicable method for QC of health functional foods containing the aqueous extracts of A. rugosa.