• Journal of the Korean Society for Nondestructive Testing
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• v.15 no.2
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• pp.395-406
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• 1995

Classification of flaws in weldments from their ultrasonic scattering signals is very important in quantitative nondestructive evaluation. This problem is ideally suited to a modern ultrasonic pattern recognition technique. Here brief discussion on systematic approach to this methodology is presented including ultrasonic feature extraction, feature selection and classification. A stronger emphasis is placed on probabilistic neural networks as efficient classifiers for many practical classification problems. In an example probabilistic neural networks are applied to classify flaws in weldments into 3 classes such as cracks, porosity and slag inclusions. Probabilistic nets are shown to be able to exhibit high performance of other classifiers without any training time overhead. In addition, forward selection scheme for sensitive features is addressed to enhance network performance.

• International Journal of Internet, Broadcasting and Communication
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• v.10 no.2
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• pp.45-50
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• 2018

Recently the water management department advised the water treatment industry to focus on deploy the chemical free and the environmentally responsible process to adopt on water treatment plants in every country. In this objective, water treatment process started using ultrasonic based phycocyanin extraction with fluorescence measurement techniques to detect the change in the yield of phycocyanin. This paper propose the design of optical filter model for fluorescence technique based immersive optical phycocyanin measurement sensor design. The proposed design uses the multi-wavelength sensor module for irradiating part, and this plays a role of removing a wavelength band other than 590 ~ 620 nm. The preliminary study on immersed phycocyanin sensor, the fluorescence value of picocyanin according to the ultrasonic intensity, treatment time and number of cells was measured using JM phycocyanin module to emulate the proposed design, and were compared performance of the proposed sensor emulation. In this design, the phycocyanin fluorescence value increased about 2.1 ~ 4.7 times as the ultrasonic treatment time increased as compared with JM phycocyanin module, and the phycocyanin fluorescence value within the analysis range was obtained by ultrasonic treatment within one minute.

• KSBB Journal
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• v.24 no.2
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• pp.189-194
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• 2009

In this work, antioxidant substance homoorientin from Pseudosasa japonica and Phyllostachys bambusoides leaves wereextracted using ultrasonic system, and analyzed by reversed-phase high performance liquid chromatography (RP-HPLC) on-line ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) antioxidant screening method. Also, the various experimental variables were the frequency and time of ultrasonic system. From the results, homoorientin was high extracted at the experimental condition of low frequency 35 kHz and time 60 min. And the content of homoorientin in Phyllostachys bambusoides was remarkably higher than that in the Pseudosasa japonica extract.

• Korean Journal of Plant Resources
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• v.31 no.4
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• pp.330-341
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• 2018

This study was performed to investigate and measure the antimicrobial activity of evergreen woody species extracts on Trichophyton mentagrophytes. To do this, leaves and stems were collected from Wando and Jeju islands, and were used for the extraction with different solvents (i.e., distilled water, 80% ethanol, and 100% methanol), and at different ultrasonic extracting times (i.e., 15, 30, and 45 minutes). The experiment was conducted by using the agar diffusion method. The clear zone was measured after incubating the paper disc containing the plant extract in a bacterial culture medium. The controls were synthetic antimicrobials, methylparaben and phenoxyethanol, at concentrations of 0.4, 1, 2, and 4 mg/disc. Altogether, extracts of 56 out of 64 species used in this study had inhibitory activity, which confirmed their antimicrobial activity against Athlete's foot. Among them, the crude ethanolic extract of Elaeocarpus sylvestris in 45 min showed a zone of inhibition < 20.2 mm, while the clear zone of Actinodaphne lancifolia ethanolic extraction for 30 min was 23.5 mm. Also, Quercus acuta, Dendropanax morbiferus and Daphne odora showed clear zones of 28.0 mm (45 minutes ethanolic extraction), 20.5 mm (45 minutes crude methanolic extraction) and 19.7 mm (45 minutes methanolic extraction), respectively. Thus, these results confirm that the extracts of evergreen woody species have therapeutic potential against Athlete's foot, and suggest that in order to extract adequate amounts of antimicrobial substance from the plant sources, ideal extraction condition has to be considered.

• Journal of IKEEE
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• v.2 no.1 s.2
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• pp.139-149
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• 1998

There are some problems in robot navigations with a single kind of sensor. We propose a system that takes advantages of both CCD camera and ultrasonic sensors for the concerning matter. A coordinate extraction algorithm to avoid obstacles during the navigation is also proposed. We implemented a CCD based vision system at the front part of the vehicle and did experiments to verify the suggested algorithm's availability. From experimental results, the error rate was reduced when a CCD camera was used rather than when only ultrasonic sensors were used. Also we can generate path to avoid those obstacles using the measured values.

• Environmental Analysis Health and Toxicology
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• v.16 no.3
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• pp.121-126
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• 2001

Analytical method of benzophenone (BP) in sediment and soil was developed by gas chromatography/mass selective detector/selected ion monitoring (GC/MSD/SIM). The ultrasonic extraction of US EPA (method 3550B) method and liquid-liquid extraction for sediment and soil samples were used for the analysis of BP from sediment and soil. BP was extracted with n-hexane. Organic layer was washed with 5% sodium chloride solution. 1∼2 l of the concentrated solution of organic layer was applied to GC/MSD. The retention time of BP peak was 11.10 min. Recovery (％) of BP by ultrasonication from sediment and soil samples was 96.0∼100.6％ and 40.0∼83.0％, respectively. Recovery of BP by liquid-liquid extraction was 51∼59％ in soil samples. The detection limit of BP in sediment and soil samples were determined to 0.1 ng/g.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.304-309
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• 2003

In this study, natural flaws in welding parts are classified using the signal pattern classification method. The storage digital oscilloscope including FFT function and enveloped waveform generator is used and the signal pattern recognition procedure is made up the digital signal processing, feature extraction, feature selection and classifier design. It is composed with and discussed using the distance classifier that is based on euclidean distance the empirical Bayesian classifier. Feature extraction is performed using the class-mean scatter criteria. The signal pattern classification method is applied to the signal pattern recognition of natural flaws.

• Journal of the Korean Society of Safety
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• v.26 no.5
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• pp.17-22
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• 2011

This study proposes feature extraction method of pattern recognition by evaluation of weld defects in weld zone of titanium. For this purpose, analysis objectives in this study are features of attractor quadrant and fractal dimension. Trajectory changes in the attractor indicated a substantial difference in fractal characteristics resulting from distance shifts such as porosity of weld zone. These differences in characteristics of weld defects enables the evaluation of unique characteristics of defects in the weld zone. In quantitative fractal feature extraction, feature values of 0.87 and 1.00 in the case of part of 0.5 skip distance and 0.72 and 0.93 in the case of part of 1.0 skip distance were proposed on the basis of fractal dimensions. Attractor quadrant point, feature values of 1.322 and 1.172 in the case of ${\phi}1{\times}3mm$ porosity and 2.264 and 307 in the case of ${\phi}3{\times}3mm$ porosity were proposed on the basis of distribution value. The Proposed feature extraction of pattern recognition in this study can be used for safety evaluation of weld zone in titanium.

• Applied Chemistry for Engineering
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• v.29 no.5
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• pp.565-570
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• 2018

In this study, the antioxidant was extracted from Broussonetia kazinokii using ultrasound-assisted extraction (UAE) and optimized by using a response surface methodology. The response value of the central composite design model establishes the extraction yield and the DPPH radical scavenging activity. The extraction time and temperature and volume ratio of ethanol/ultrapure water were selected as quantitative factors. When considering both the main and interaction effects, the factor having the greatest influence on the extraction yield and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity was the volume ratio of ethanol/ultrapure water. The results of optimal extraction conditions were the extraction time (19.92 min), volume ratio of ethanol/ultrapure water (54.23%), and ultrasonic irradiation power (557.65 W). We could also obtained expected results of the yield = 38.93 wt% and DPPH radical scavenging activity = 55.33% under these conditions.

• Korean Journal of Agricultural Science
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• v.46 no.1
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• pp.85-92
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• 2019

This study was intended to provide basic data for a health functional food study by exploring antioxidant activity of reflux extract according to the concentration of ethanol and the extract of ultrasonic waves extracted and reflux extracted under the same solvent conditions. In the same solvent condition, the reflux extract ($75.10{\pm}1.99mg$) showed a higher total phenol content than the ultrasonic wave extract ($51.74{\pm}2.28mg$). Flavonoids also had a higher reflux extract ($25.05{\pm}1.53mg$) than did ultrasonic extracts ($16.23{\pm}1.95mg$). Reflux extract according to ethanol concentration was found to have a higher phenol content than the 70% ethanol extract ($40.60{\pm}1.49mg$) in 60% ethanol extract. Flavonoid content was also similar to phenol content in reflux extract as determined by ethanol concentration from 60% ethanol ($25.05{\pm}1.53mg$) to 70% ethanol extract ($6.60{\pm}0.46mg$). In addition, the antioxidant activity (DPPH, TEAC, FRAP, ORAC) of the reflux extract in the same solvent conditions tended to be higher than that of ultrasonic extracts. Also, 60% ethanol extract had better antioxidant activity than 70% ethanol extract. However, an analysis of phenolic acid content through HPLC showed that the ultrasonic extract had a higher content in the same solvent condition than did the reflux extract. Not only the presence of phenolic acid, but also those of other compounds are believed to be attributed to the activity of antioxidants. Therefore, further studies are needed to clarify this phenomenon.