• The Korean Journal of Food & Health Convergence
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• v.7 no.6
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• pp.1-8
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• 2021

Premna foetida is a woody plant with short and twisted trunk. P. foetida is a scandent, erect shrub or small tree, thorny on the trunk and large branches. Leaves are opposite or whorled and entire or serrate. Premna foetida is a wild plant locally known as "Daun Sebuas". P. foetida is used for it nutritive and as traditional treatment. The fruit and leaves of P. foetida are prepared for salad. The study aimed at the hydrodistillation and antioxidant activity of leaves, stem-bark and fruits essential oil from Premna foetida Linn, they were analysed by capillary GC and GC-MS. Ninety eight compounds representing 81.68±0.02, 37.31±0.05 and 93.45±0.03 of the isolates of leaves, stem-bark and fruits respectively were identified, the most abundant were α -Duprezianene (77.27±0.03, leaves, α-Gurjunene (36.06±0.05) fruits and Hinesol acetate (77.19±0.03) stem-bark. Components among which sesquiterpenoids dominated. The total volatiles were assayed for antioxidant potentials using 2, 2-diphenyl-1-picrylhydrazyl (DPPH). The total volatiles showed strong activity with IC₅₀ of 11.74±0.82㎍/ml, 9.63±0.34 ㎍/ml and 49.73±1.12 ㎍/ml for leaves fruits and stem-bark respectively.

• Smart Structures and Systems
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• v.31 no.4
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• pp.383-392
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• 2023

Post-earthquake building condition assessment is crucial for subsequent rescue and remediation and can be automated by emerging computer vision and deep learning technologies. This study is based on an endeavour for the 2nd International Competition of Structural Health Monitoring (IC-SHM 2021). The task package includes five image segmentation objectives - defects (crack/spall/rebar exposure), structural component, and damage state. The structural component and damage state tasks are identified as the priority that can form actionable decisions. A multi-task Convolutional Neural Network (CNN) is proposed to conduct the two major tasks simultaneously. The rest 3 sub-tasks (spall/crack/rebar exposure) were incorporated as auxiliary tasks. By synchronously learning defect information (spall/crack/rebar exposure), the multi-task CNN model outperforms the counterpart single-task models in recognizing structural components and estimating damage states. Particularly, the pixel-level damage state estimation witnesses a mIoU (mean intersection over union) improvement from 0.5855 to 0.6374. For the defect detection tasks, rebar exposure is omitted due to the extremely biased sample distribution. The segmentations of crack and spall are automated by single-task U-Net but with extra efforts to resample the provided data. The segmentation of small objects (spall and crack) benefits from the resampling method, with a substantial IoU increment of nearly 10%.

• International journal of advanced smart convergence
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• v.12 no.2
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• pp.47-55
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• 2023

The automotive industry is undergoing a paradigm shift due to the convergence of IT and rapid digital transformation. Various components, including embedded structures and systems with complex architectures that incorporate IC semiconductors, are being integrated and modularized. As a result, there has been a significant increase in vehicle defects, raising expectations for the quality of automotive parts. As more and more data is being accumulated, there is an active effort to go beyond traditional reliability analysis methods and apply machine learning models based on the accumulated big data. However, there are still not many cases where machine learning is used in product development to identify factors of defects in performance and durability of products and incorporate feedback into the design to improve product quality. In this paper, we applied a prediction algorithm to the defects of automotive door devices equipped with automatic responsive sensors, which are commonly installed in recent electric and hydrogen vehicles. To do so, we selected test items, built a measurement emulation system for data acquisition, and conducted comparative evaluations by applying different machine learning algorithms to the measured data. The results in terms of R² score were as follows: Ordinary multiple regression 0.96, Ridge regression 0.95, Lasso regression 0.89, Elastic regression 0.91.

• Journal of Sensor Science and Technology
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• v.32 no.6
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• pp.432-440
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• 2023

This study introduces an efficient readout circuit designed for two-electrode electrocardiogram (ECG) recording, characterized by its low-noise and low-power consumption attributes. Unlike its three-electrode counterpart, the two-electrode ECG is susceptible to common-mode interference (CMI), causing signal distortion. To counter this, the proposed circuit integrates a common-mode charge pump (CMCP) with a window comparator, allowing for a CMI tolerance of up to 20 V_PP. The CMCP design prevents the activation of electrostatic discharge (ESD) diodes and becomes operational only when CMI surpasses the predetermined range set by the window comparator. This ensures power efficiency and minimizes intermodulation distortion (IMD) arising from switching noise. To maintain ECG signal accuracy, the circuit employs a chopper-stabilized instrumentation amplifier (IA) for low-noise attributes, and to achieve high input impedance, it incorporates a floating high-pass filter (HPF) and a current-feedback instrumentation amplifier (CFIA). This comprehensive design integrates various components, including a QRS peak detector and serial peripheral interface (SPI), into a single 0.18-㎛ CMOS chip occupying 0.54 mm². Experimental evaluations showed a 0.59 µV_RMS noise level within a 1-100 Hz bandwidth and a power draw of 23.83 µW at 1.8 V.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.10
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• pp.1361-1370
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• 2011

Antioxidant and anti-inflammatory activities of eugenol and its derivatives from clove (Eugenia caryophyllata Thunb.) were evaluated using in vitro assay systems by measuring 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, cyclooxygenase-2 (COX-2), and 15-lipoxygenase (15-LOX). Among eight different crude medicinal drugs tested, volatile extracts of clove extracted by steam distillation extraction (SDE) showed potent DPPH radical scavenging activity ($IC_{50}$=8.85 ${\mu}g/mL$) as well as strong inhibitory activity against COX-2 (58.15%) and 15-LOX (86.15%) at 10 ${\mu}g/mL$ and 25 ${\mu}g/mL$, respectively. Major volatile components of clove were identified as eugenol, trans-caryophyllene, and acetyleugenol by GC-MS analysis. Out of three eugenol derivatives, eugenol, methyl eugenol, and acetyl eugenol, eugenol showed the strongest DPPH radical scavenging activity and COX-2 inhibitory activity, whereas methyl eugenol exhibited the strongest 15-LOX inhibitory activity. Finally, the contents of the three eugenol derivatives in clove were quantified by analytical HPLC. Contents of eugenol and acetyl eugenol in clove were 6.95% and 1.85% per dry weight, respectively. These results suggest that eugenol and its derivatives in steam distilled extract of clove may be useful as potential antioxidant and anti-inflammatory agents.

• Korean Journal of Plant Resources
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• v.30 no.4
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• pp.335-342
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• 2017

Spiraea prunifolia Sieb. et Zucc. var. simpliciflora Nakai (SSN) has been used for the anti-inflammation in traditional folk medicine. To compare water and methanol extracts of SSN, we analyzed major components using LC IT TOF MS. The major components of hot water extract were identified as caffeic acid and p-coumaric acid, but methanol extract was not well established. However, methanol extract was detected with less polarity compounds compared to hot water extract. Next, we investigated the inhibitory effects of SSN water extract on the lipopolysaccharide (LPS)-induced inflammatory response or $H_2O_2-induced$ oxidative stress in Raw 264.7 macrophage cells. SSN strongly suppressed the production of nitric oxide in LPS-induced inflammatory response without cytotoxcity. The SSN possessed free radical scavenging activities such as DPPH ($IC_{50}=320.2{\mu}g/m{\ell}$), ABTS ($IC_{50}=124.0{\mu}g/m{\ell}$), and superoxide anion radical ($IC_{50}=122.6{\mu}g/m{\ell}$). The total phenol and flavonoid content of SSN was 56.7 mg/g, and 15.1 mg/g, respectively. Furthermore, SSN decreased the $H_2O_2-induced$ cytotoxicity by enhancing the cell viability, and SSN significantly reduced the intracellular reactive oxygen species (ROS) level. Therefore, SSN may be recommended as an effective strategy to prevent and/or treat various inflammation and ROS-induced diseases.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.5
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• pp.1981-1987
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• 2013

$CO_2$ emissions of vehicles vary with vehicle's speeds. In addition, the speeds vary with road type, location, time and traffic volume. In this paper, the section in which a large quantity of $CO_2$ emissions per vehicle is exhausted is determined and analyzed with principal component analysis(PCA). In results of analysis, the principal components analysis were divided into two principal components. It had been identified that the main component was the time zone one which is able to explain each components' role. The first principal component could explain the role of a major component on $CO_2$ emissions per vehicle in the early morning and afternoon hour, respectively. The second principal component could explain the role of the component on $CO_2$ emissions per vehicle in the morning and afternoon peak hours, respectively. Therefore, the section in which a large quantity of $CO_2$ emissions per vehicle could be deterimined by PCA scores.

• Korean Journal of Food Science and Technology
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• v.33 no.1
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• pp.28-32
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• 2001

Major sensory characteristic components-salty(NaCl), sweet(free sugars), palatable tastes(MSG, IMP, GMP) and related components-in soup base of commercial ramyons(25 ramyons, 11 bowl ramyons) were investigated to estimate their use level. $Na^+$ content($18.73{\pm}3.18%$ in ramyons and $17.62{\pm}1.92%$ in bowl ramyons) was determined by IC so that NaCl values (20.90% in ramyons and 18.16% in bowl ramyons) could be calculated from it. And from the assayed results of glutamic acid($10.50{\pm}3.78%$ in ramyons and $10.47{\pm}1.68%$ in bowl ramyons) by LC, MSG values were 12.08% in ramyons and 12.04% in bowl ramyons. GMP and IMP contents were $0.15{\pm}0.06%$, $0.20{\pm}0.11%$ in ramyons and $0.14{\pm}0.03%$, $0.18{\pm}0.05%$ in bowl ramyons, respectively. In addition, free sugars contained in ramyons such as sucrose, glucose and fructose were also analyzed by LC. In order to compare the sweetness, the free sugars were multiplied by conversion factor(sucrose 1, glucose 0.7, fructose 1.1), which showed $19.85{\pm}5.68%$ in ramyons and $18.02{\pm}7.82%$ in bowl ramyons. Therefore it is concluded that the analytical method of $Na^+$, glutamic acid and free sugars can be used as a simple and exact technique for the determination of NaCl, MSG and sweetness of ramyons.

• Journal of Food Hygiene and Safety
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• v.22 no.3
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• pp.223-230
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• 2007

We have previously reported that green tea catechins(GTC) displayed potent antithrombotic effect, which was due to the antiplatelet activity. In the present study, the antiplatelet activity of each green tea catechin components was compared in vitro. Galloylated catechins including (-)-epigallocatechin gallate (EGCG), (-)-gallocatechin gallate (GCG), (-)-epicatechin gallate (ECG) and (-)-catechin gallate (CG), significantly inhibited collagen $(5{\mu}g/mL)-induced$ rabbit platelet aggregation with $IC_{50}$ values of 79.8, 63.0, 168.2 and $67.3{\mu}M$, respectively. EGCC GCG and CG also significantly inhibited arachidonic acid (AA, $100{\mu}M$)-induced rabbit platelet aggregation with $IC_{50}$ values of 98.9, 200.0 and $174.3{\mu}M$, respectively. However catechins without gallate moiety showed little inhibitory effects against rabbit platelet aggregation induced by collagen or AA compared with galloylated catechins. These observations suggest that the presence of gallate moiety at C-3 position may be essential to the antiplatelet activity of catechins and the presence of B ring galloyl structure may also contribute to the antiplatelet activity of GTC. In line with the inhibition of collagen-induced platelet aggregation, EGCG caused concentration-dependent decreases of cytosolic calcium mobilization, AA liberation and serotonin secretion. In contrast, epigallocatechin (EGC), a structural analogue of EGCG lacking a galloyl group in the 3' position, although slightly inhibited collagen-stimulated cytosolic calcium mobilization, failed to affect other signal transductions as EGCG in activated platelets. Taken together, these observations suggest that the antiplatelet activity of EGCG may be due to inhibition of arachidonic acid liberation and inhibition of $Ca^{2+}$ mobilization and that the antiplatelet of EGCG is enhanced by the presence of a gallate moiety esterified at carbon 3 on the C ring.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.8
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• pp.1214-1220
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• 2016

This study compared antioxidant compounds and antioxidant activities according to various varieties of 18 colored rice. Selected rice cultivars for this study were as follows: black rice (12 cultivars)-Heugjinjubyeo, Nunkeunheugchal, Joeunheugmi, Josaengheugchal, Heuggwang, Heugseol, Shinmyeongheugchal, Shinongheugchal, Shintoheugmi, Cheongpungheukchal, Heughyang, Boseogheugchal, red rice (four cultivars)-Jeogjinju, Jeogjinjuchal, Hongjinju, Geonganghongmi, and green rice (two cultivars)-Nogwonchal and Jungmo1020. These were transplanted on June 30th and cultivated from the Department of Southern Area Crop Science, National Institute of Crop Science in Miryang, Korea. Total polyphenol (TP) content of black rice cultivars was higher than that of red rice varieties. Heugjinjubyeo exhibited the highest TP, which was $9.55{\pm}0.05mg$ gallic acid equivalent/g sample. There were no significant differences between black rice cultivars and red rice cultivars in terms of total flavonoid (TF) level. Heugjinjubyeo and Hongjinju showed the higher TF content than any other variety. Shintoheugmi revealed the highest anthocyanin content ($194.26{\pm}0.65mg/100g$). Methanol extract of Heugjinjubyeo had the highest antioxidant activities. 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activities of Heugjinjubyeo extract were $14.70{\pm}0.62$ and $30.68{\pm}2.22{\mu}g/mL$, respectively. There were significant correlations between antioxidant compound content and antioxidant activities.