• Journal of Korea Multimedia Society
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• v.22 no.10
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• pp.1142-1148
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• 2019

Reconstruction of the three-dimensional (3D) environment is a key aspect of augmented reality and augmented virtuality, which utilize and incorporate a user's surroundings. Such reconstruction can be easily realized by employing a Kinect device. However, multiple Kinect devices are required for enhancing the reconstruction density and for spatial expansion. While employing multiple Kinect devices, they must be calibrated with respect to each other in advance, and a marker is often used for this purpose. However, a marker needs to be placed at each calibration, and the result of marker detection significantly affects the calibration accuracy. Therefore, a user-friendly, efficient, accurate, and marker-less method for calibrating multiple Kinect devices is proposed in this study. The proposed method includes a joint tracking algorithm for approximate calibration, and the obtained result is further refined by applying the iterative closest point algorithm. Experimental results indicate that the proposed method is a convenient alternative to conventional marker-based methods for calibrating multiple Kinect devices. Hence, the proposed method can be incorporated in various applications of augmented reality and augmented virtuality that require 3D environment reconstruction by employing multiple Kinect devices.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.4
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• pp.24-32
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• 2012

Of many approaches to reduce motion analysis errors, the compensation method of anatomical landmarks estimates the position of anatomical landmarks during motion. The method models the position of anatomical landmarks with joint angle or skin marker displacement using the data of the so-called dynamic calibration in which anatomical landmark positions are calibrated in ad hoc motions. Then the anatomical landmark positions are calibrated in target motions using the model. This study applies the compensation methods with joint angle and skin marker displacement to three lower extremity motions (walking, sit-to-stand/stand-to-sit, and step up/down) in ten healthy males and compares their performance. To compare the performance of the methods, two sets of kinematic variables were calculated using different two marker clusters, and the difference was obtained. Results showed that the compensation method with skin marker displacement had less differences by 30~60% compared to without compensation. And, it had significantly less difference in some kinematic variables (7 of 18) by 25~40% compared to the compensation method with joint angle. This study supports that compensation with skin marker displacement reduced the motion analysis STA errors more reliably than with joint angle in lower extremity motion analysis.

• The Journal of Korean Medicine
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• v.31 no.6
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• pp.8-15
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• 2010

Objectives: We investigated to develop and validate HPLC-PDA methods for simultaneous determination of eight constituents in Galgeun-tang (GGT). Methods: Reverse-phase chromatography using a Gemini C18 column operating at $40^{\circ}C$, and photodiode array (PDA) detection at 230 nm, 254 nm, and 280 nm, were used for quantification of the eight marker components of GGT. The mobile phase using a gradient flow consisted of two solvent systems. Solvent A was 1.0% (v/v) aqueous acetic acid and solvent B was acetonitrile with 1.0% (v/v) acetic acid. Results: Calibration curves were acquired with $r^2$ > 0.9999, and the relative standard deviation (RSD) values (%) for intra- and inter-day precision were less than 3.0%. The recovery rate of each component was in the range of 87.33-101.38%, with an RSD less than 7.0%. The contents of the eight components in GGT were 1.98-12.17 mg/g. Conclusions: The established method will be applied for the quantification of marker components in GGT.

• Herbal Formula Science
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• v.18 no.2
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• pp.251-257
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• 2010

Objectives : To develop and validate High-performance liquid chromatography-photodiode array methods for simultaneous determination of two constituents in Oryeong-san(ORS). Methods : Reverse-phase chromatography using a Gemini C18 column operating at $40^{\circ}C$, and photodiode array(PDA) detection at 280 nm, were used for quantification of the two marker components of ORS. The mobile phase using a gradient flow consisted of two solvent systems. Solvent A was $H_2O$ and solvent B was acetonitrile. Results : Calibration curves were acquired with correlation coefficient ($r^2$)>0.9999, and the relative standard deviation(RSD) values(%) for intra- and inter-day precision were not exceed 1.0%. The recovery rate of each compound was in the range of 93.01-104.16%, with an RSD less than 2.0%. The contents of two compounds in ORS were 1.10-3.72 mg/g. Conclusions : The established HPLC method will be helpful to improve quality control of ORS.

• Herbal Formula Science
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• v.18 no.1
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• pp.95-103
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• 2010

Objectives : To develop and validate HPLC-PDA methods for simultaneous determination of seven constituents in Samsoeum(SSE). Methods : Reverse-phase chromatography using a Gemini C18 column operating at $40^{\circ}C$, and photodiode array(PDA) detection at 254 and 280 nm, were used for quantification of the seven marker components of SSE. The mobile phase using a gradient flow consisted of two solvent systems. Solvent A was 1.0% (v/v) aqueous acetic acid and solvent B was acetonitrile with 1.0% (v/v) acetic acid. Results : Calibration curves were acquired with $r^2$>0.9997, and the relative standard deviation (RSD) values (%) for intra- and inter-day precision were less than 3.0%. The recovery rate of each compound was in the range of 100.07-112.65%, with an RSD less than 4.0%. The contents of seven compounds in SSE were 1.24-10.53 mg/g. Conclusions : The established method will be helpful to improve quality control of SSE.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.11
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• pp.1682-1686
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• 2015

This study was conducted to establish an HPLC analysis method for determination of marker compounds as part of materials standardization for development of health functional food materials from pear pomace. The quantitative determination method of caffeic acid and chlorogenic acid as marker compounds of pear pomace extract (PPE) was optimized by HPLC analysis using a C18 column ($5{\times}250mm$, $5{\mu}m$) with a 0.2% elution gradient of acetic acid and methanol as the mobile phase at a flow rate of 0.8 mL/min and detection wavelength of 330 nm. The HPLC/UV method was applied successfully to the quantification of marker compounds in PPE after validation of the method with linearity, accuracy, and precision. The method showed high linearity of the calibration curve with a coefficient of correlation ($R^2$) of 0.9999, and limit of detection and limit of quantification were $1.14{\mu}g/mL$ (caffeic acid) and $1.61{\mu}g/mL$ (chlorogenic acid) as well as $4.9{\mu}g/mL$ (caffeic acid) and $4.9{\mu}g/mL$ (chlorogenic acid), respectively. Relative standard deviation values from intra- and inter-day precision were less than 3.1% (caffeic acid) and 4.0% (chlorogenic acid), respectively. Recovery rates of caffeic acid and chlorogenic acid at 12.5, 25, and $50{\mu}g/mL$ were 93.66~106.32% and 97.33~105.68%, respectively. An optimized method for extraction of caffeic acid and chlorogenic acid in PPE was established through diverse extraction conditions, and the validation indicated that the method is very useful for evaluation of marker compounds in PPE to develop a health functional food material.

• Korean Journal of Pharmacognosy
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• v.40 no.4
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• pp.298-302
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• 2009

Samultang is one of traditional medicine composed of Paeonia lactiflora, Angelica gigas, Rehmannia glutinosa and Cnidium officinale. To develop simultaneous determination of paeoniflorin, decursin and 5-HMF in Samultang, a high performance liquid chromatography with diode array detector was used. To separate three marker components, Dionex $C_{18}$ column (5 ${\mu}m$, 120 ${\AA}$, 4.6 mm${\times}$150 mm) was used with a gradient elution system of water and methanol. UV wavelength of detector set at 230 nm and 280 nm. This method was validated by linearity, precision test and recovery test. Calibration curves of three standard components were showed good linear regression ($R^2$>0.9973). LOD and LOQ ranged from 0.08 ${\mu}g$/ml to 0.38 ${\mu}g$/ml and 0.25 ${\mu}g$/ml to 1.16 ${\mu}g$/ml, respectively. The relative standard deviations (RSDs) of data of the inter-day and intra-day experiments were less than 0.54% and 0.89%, respectively. The measured results of recovery test were varied from 93.36 to 107.79 with RSD values 0.01~1.45%. The established method was applied for separation of bio-conversion Samultang sample and compared with control sample.

• The Korea Journal of Herbology
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• v.30 no.3
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• pp.19-24
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• 2015

Objectives : HPL-1, a novel herbal medicine which is composed of five herbs such as Kalopanacis Cortex, Chaenomelis Fructus, Raphani Semen, Atractylodis Rhizoma and Pulvis Aconiti Tuberis Purificatum, was developed for treatment of osteoarthritis. This study is aimed to develop analytical method for consistent quality control of HPL-1 and validate chromatographic method. Methods : Chromatographic analysis was performed using ultra-high performance liquid chromatography - diode array detector (UHPLC-DAD) equipped with RP-amide column, column oven, and auto sampler. Marker compounds [protocatechuic acid, chlorogenic acid, liriodendrin, 3,5-dicaffeoylquinic acid, ${\beta}$-D-(3-O-sinapoyl)-fructofuranosyl-$\alpha$-D-(6-O-sinapoyl)glucopyranoside and benzoylmesaconine] were separated by step gradient elution of acetonitrile and 0.1% phosphoric acid/water. The method validation was evaluated by quantitative validation parameters of linearity, accuracy, precision, limit of detection (LOD) and limit of quantification (LOQ) according to KFDA guideline.Results : An optimized method for six marker compounds in HPL-1 was established by UHPLC-DAD. The correlation coefficient (R²) with each calibration curve was greater than 0.99. The LOD and LOQ were within the range of 0.008-0.090 and $0.023-0.274{\mu}g/mL$, respectively. The relative standard deviation (RSD) of intra- and inter-day variability were less than 4.0%. The result of recovery test was range from 93.3-106.3% with RSD < 4.0%.Conclusions : These results suggest that the quantitative UHPLC method is precise, accurate, effective for quality evaluation of HPL-1. The method may also contribute to improve quality of crude drug preparations used for treatment of various diseases.

• Korean Journal of Pharmacognosy
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• v.40 no.3
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• pp.224-228
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• 2009

For the quality control of traditional herbal medicine, Galgeun tang, simultaneous determination of glycyrrhizin, paeoniflorin, puerarin, 6-gingerol was established by using a high performance liquid chromatographic (HPLC) method with diode array detector. To separate five four constituents, DIONEX $C_{18}$ column ($5{\mu}m$, $120{\AA}$, $4.6\;mm{\times}150\;mm$) was used with gradient elution system of water and methanol. Validation of the chromatography method was evaluated by linearity, recovery, and precision test. Calibration curve of standard components showed excellent linearity ($R^2$>0.9906). Limits of detection (LOD) and limits of quantification (LOQ) varied from 0.15 to $0.52{\mu}g$/ml and 0.27 to $0.80{\mu}mg$/ml, respectively. The relative standard deviations (RSDs) of data of the intra-day and inter-day experiments were less than 2.88% and 1.21%, respectively. The results of recovery test were ranged from 96.71 to 106.29% with RSD values 0.01-0.80%.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.100-100
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• 2019

This study attempted to establish a High Performance Liquid Chromatography (HPLC) analysis method for the determination of (-)-epicatechin gallate as a part of the quality control for the development of functional cosmetic materials from Penthorum chinense Pursh extracts. HPLC was performed on a Unison US-C18 column ($4.6{\times}250mm$, $5{\mu}m$) with a gradient elution of 0.05% (v/v) trifluoroacetic acid (TFA) and methyl alcohol at a flow rate of 1.0 mL/min at $30^{\circ}C$. The analyte was detected at 280 nm. The HPLC method was performed in accordance with the International Conference on Harmonization (ICH) guideline (version 4, 2005) of analytical procedures with respect to specificity, precision, accuracy, and linearity. The limits of detection and quantitation were 0.11 and 0.33 mg/mL, respectively. Calibration curves showed good linearity (r2 > 0.9999), and the precision of analysis was satisfied (less than 0.6%). Recoveries of quantified compounds ranged from 99.51 to 101.92%. This result indicates that the established HPLC method is very useful for the determination of marker compound in P. chinense Pursh extracts.