• Natural Product Sciences
• /
• v.17 no.4
• /
• pp.337-341
• /
• 2011

An HPLC (high-performance liquid chromatography)-PDA (photodiode array) detection method was established for the determination of naringin, hesperidin and neohesperidin in the fruit of Citrus paradisi and C. grandis. The flavonoids were separated in less than 20 min using an YMC RP 18 column with isocratic elution using acetonitrile and water (23 : 77, v/v) at a flow rate of 1 ml/min, and a PDA detector. The levels of naringin, hesperidin and neohesperidin were 1345.92, 950.62, and 2078.82 ${\mu}g/g$, respectively, in the peel, and 102.43, 59.13, and 86.68 ${\mu}g/g$, respectively, in the flesh of C. paradisi. In C. grandis, the levels of naringin, hesperidin and neohesperidin were 3530.56, 80.00, and 5.26 ${\mu}g/g$, respectively, in the peel, and 59.59, 7.43, and 38.41 ${\mu}g/g$, respectively, in the flesh. The total content was highest in the peel, reaching 0.44% and 0.36% in C. paradisi and C. grandis, respectively, while the flesh contained only 0.025% and 0.011%, respectively. Therefore, the peels of C. paradisi and C. grandis are necessary for the processing and utilization of flavonoids.

• Natural Product Sciences
• /
• v.17 no.4
• /
• pp.321-327
• /
• 2011

In this study, quantitative analysis was developed using HPLC/UVD for the quality evaluation of Scutellariae Radix. For quantitative analysis, six major bioactive compounds were assessed. The separation conditions employed for HPLC/UVD were optimized using Phenomenex $C_{18}$ column ($250{\times}4.6$ mm, 5 ${\mu}m$) with a gradient of solvent A (1% acetic acid of $H_2O$) and solvent B (acetonitrile : methanol : acetic acid = 70 : 30 : 1) as the mobile phase at a flow rate of 1.0 mL/min and a detection wavelength of 275 nm. These methods were fully validated with respect to linearity, accuracy, precision and recovery. The HPLC/UVD method was applied successfully to the quantification of six major compounds in the extract of Scutellariae Radix. The results indicate that the established HPLC/UVD method is suitable for the quantitative analysis and quality control of multicomponents in Scutellariae Radix.

• The Journal of Korea Robotics Society
• /
• v.10 no.3
• /
• pp.171-177
• /
• 2015

A telerobot offers a more engaging and enjoyable interaction with people at a distance by communicating via audio, video, expressive gestures, body pose and proxemics. To provide its potential benefits at a reasonable cost, this paper presents a telepresence robot system for video communication which can deliver speaker's head motion through its display stanchion. Head gestures such as nodding and head-shaking can give crucial information during conversation. We also can assume a speaker's eye-gaze, which is known as one of the key non-verbal signals for interaction, from his/her head pose. In order to develop an efficient head tracking method, a 3D cylinder-like head model is employed and the Harris corner detector is combined with the Lucas-Kanade optical flow that is known to be suitable for extracting 3D motion information of the model. Especially, a skin color-based face detection algorithm is proposed to achieve robust performance upon variant directions while maintaining reasonable computational cost. The performance of the proposed head tracking algorithm is verified through the experiments using BU's standard data sets. A design of robot platform is also described as well as the design of supporting systems such as video transmission and robot control interfaces.

• Analytical Science and Technology
• /
• v.30 no.2
• /
• pp.82-88
• /
• 2017

Adenophorae Radix (AR) is a frequently used medicinal herb; because of its popularity, products containing similar herbal products are often sold as substitutes, especially if their morphology is similar. However, any analytical method to identify AR based on quantitative analysis is not registered in Korea, Japan and China Pharmacopoeias. This study developed a simple HPLC method to discriminate between authentic AR and substitutes. Linoleic acid was used as a marker compound of AR. Our optimized HPLC-UV conditions included a mobile phase of 90 % acetonitrile under isocratic condition, and a flow rate of 1.0 mL/min at room temperature. Detection wavelength was set at 205 nm. Linoleic acid was detected at 13.5 minutes for a total analysis time of 20 minutes. The standard herb of AR contained 0.025 % of linoleic acid, while four authentic AR samples and eight substitutes contained 0.040~0.071 % and 0.004~0.014 %, respectively. Comparison of the linoleic acid concentrations of the sample types to reference AR showed that among 12 samples, only the four samples were authentic. Thus, our HPLC-UV method, along with our suggested content criterion for linoleic acid concentration, can be used for the quick and accurate determination whether the herbal products are authentic AR or substitute.

• Herbal Formula Science
• /
• v.18 no.1
• /
• pp.95-103
• /
• 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 Korean Society for Atmospheric Environment
• /
• v.21 no.6
• /
• pp.593-603
• /
• 2005

Passive sampler using 4-amino-3-hydrazino-5-mercapto-1, 2, 4-triazole (AHMT) was developed to determine formaldehyde in indoor environment. The chromatography paper cleaned by $3\%$ hydrogen peroxide solution was experimently determined as a optimum absorbtion filter for the collection of formaldehyde. The passive sampler with a broad cross-sectional area and a short diffusion length was quite good in sensitivity. The passive sampler and the active sampling method with an impinger were strongly correlated with a correlation coefficient of 0.9848. The limits of detection and quantification of the passive sampler for the measurement of formaldehyde in the indoor environment were 7.5 and 10.2 ppb, respectively. Temperature ($19\∼28^{circ}C$) and relative humidity ($30\∼90\%$) had slight influence on the sampling rate of the passive sampler. However, the increase of flow velocity on the surface of sampler resulted in the increase of sampling rate.

• Journal of Korea Multimedia Society
• /
• v.14 no.12
• /
• pp.1536-1543
• /
• 2011

Video stabilization is a very important step for vision based applications in the vehicular technology because the accuracy of these applications such as obstacle distance estimation, lane detection and tracking can be affected by bumpy roads and oscillation of vehicle. Conventional methods suffer from either the zooming effect which caused by a camera movement or some motion of surrounding vehicles. In order to overcome this problem, we propose a novel video stabilization method using FOE(Focus of Expansion). When a vehicle moves, optical flow diffuses from the FOE and the FOE is equal to an epipole. If a vehicle moves with vibration, the position of the epipole in the two consecutive frames is changed by oscillation of the vehicle. Therefore, we carry out video stabilization using motion vector estimated from the amount of change of the epipoles. Experiment results show that the proposed method is more efficient than conventional methods.

• Proceedings of the KIEE Conference
• /
• 2005.07a
• /
• pp.310-312
• /
• 2005

An out-of-step condition results from the loss of the synchronism of the generators. A disturbance in a power system causes the generator angle to oscillate. When there is a severe disturbance such as a heavy current fault loss of major generation or loss of a large block of load the oscillation can be severe and even increase largely and finally the out-of-step condition may occur During the power swing and out-of-step conditions, the a apparent impedance at a relay location changes, and the power flow also changes as the angle difference is varied. This paper presents a method to analyze the trajectory of complex power during a power swing and out-of-step condition. The trajectory of the complex power is analyzed when a power swings and a fault occurs. Moreover, the complex power is analyzed when the ratios between the voltages at both sides and the line impedances are changed. These methods are verified through simulation using the ATP/EMTP MODELS.

• Proceedings of the KSR Conference
• /
• 2004.06a
• /
• pp.1297-1302
• /
• 2004

In DC power distribution system for urban rail transits potential relay, 64P, is used to detect the ground faults. The problem with this 64P is that though it detects the ground fault it cannot identify the faulted region. Therefore the faulted region cannot be isolated properly. It could results in power loss of the trains on the healthy regions and the safety of the passengers in the trains could be affected adversely. A new ground fault protective relaying scheme that can identify the faulted region is presented in this paper. The new concept uses the current differential scheme and the permissive scheme to identify the faulted region correctly. A device with similar characteristic to the arrestor is adapted to use the current relay for the ground fault detection. The role of the device is to block the ground leakage current in normal operating condition and enable the ground fault current to flow in ground fault condition. The algorithm of the new relay and the effect of the newly adapted device in the new relaying scheme are discussed.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.1594-1597
• /
• 2005

A rapid development and a wide use of the Internet have expanded a network environment. Further, the network environment has become more complex due to a simple and convenient network connection and various services of the Internet. However, the Internet has been constantly exposed to the danger of various network attacks such as a virus, a hacking, a system intrusion, a system manager authority acquisition, an intrusion cover-up and the like. As a result, a network security technology such as a virus vaccine, a firewall, an integrated security management, an intrusion detection system, and the like are required in order to handle the security problems of Internet. Accordingly, a router, which is a key component of the Internet, controls a data packet flow in a network and determines an optimal path thereof so as to reach an appropriate destination. An error of the router or an attack against the router can damage an entire network. This paper relates to a method for RSMS (router security management system) for secure networking based on a security policy. Security router provides functions of a packet filtering, an authentication, an access control, an intrusion analysis and an audit trail in a kernel region. Security policy has the definition of security function against a network intrusion.