• Journal of Plant Biology
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• v.27 no.2
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• pp.81-94
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• 1984

Anatomical features and cell dimensions of the secondary xylem in the stem of the korean Lauraceas including 6 genera and 12 species were investigated under a light microscope and scanning electron microscope. Key to identification among genera or species was made from the anatomical features and systematic correlation investigated. The stem woods of Lauraceae exhibit the following characters: (1) quite evenly distributed pores (diffuse-porous wood) (2) perforation plates simple or occasionally scalariform in the latewood vessels (3) almostly 2-seriate and heterocellular rays (4) abundant paratracheal-vasicentric parenchyma (5) oil cells. Especially, the appearance of simple perforation plates suggest the Lauraceae to be more or less advanced. It is considered that the series of specialization in the Lauraceae from the perforation plates and the height of rays is as LinderalongrightarrowNeolitsealongrightarrow(Machilus, Litsea, Iozoste)longrightarrowCinnamomum, and Lindera sericea is the most pribitive in the Lauraceae.

• Earthquakes and Structures
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• v.16 no.3
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• pp.321-327
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• 2019

This study investigated the possibility of using the recorded micro tremor data on ground level as ambient vibration input excitation data for investigation and application Operational Modal Analysis (OMA) on the bench-scale earthquake simulator (The Quanser Shake Table) for model chimney. As known OMA methods (such as EFDD, SSI and so on) are supposed to deal with the ambient responses. For this purpose, analytical and experimental modal analysis of a model chimney for dynamic characteristics was performed. 3D Finite element model of the chimney was evaluated based on the design drawing. Ambient excitation was provided by shake table from the recorded micro tremor ambient vibration data on ground level. Enhanced Frequency Domain Decomposition is used for the output only modal identification. From this study, best correlation is found between mode shapes. Natural frequencies and analytical frequencies in average (only) 1.996% are different.

• Journal of IKEEE
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• v.25 no.1
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• pp.32-36
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• 2021

This paper presents a novel collided tag signals's periodic characteristic based radio frequency identification (RFID) tag collision detection method for the ultra high frequency (UHF) RFID. The proposed method utilizes that periodicity of tag signals is maintained even under tag collision. In the proposed method, the correlation between received signal and reference edge signal is used. Simulation result shows that the detection performance using the proposed method is about 10 dB better than that of existing method. In addition, the detection performances with different magnitude difference, phase difference, delay, number of tags are analyzed.

• Advances in nano research
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• v.11 no.6
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• pp.641-648
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• 2021

In this article, the dynamic parameters (frequencies, mode shapes, damping ratios) of the scaled concrete structure and the dynamic parameters (frequencies, mode shapes, damping ratios) of the entire outer surface of titanium dioxide, 80 micron in thickness are compared using operational modal analysis method. Ambient excitation was provided from micro tremor ambient vibration data on ground level. Enhanced Frequency Domain Decomposition (EFDD) was used for the output only modal identification. From this study, a good correlation between mode shapes was found. Titanium dioxide applied to the entire outer surface of the scaled concrete structure has an average of 11.78% difference in frequency values and 10.15% in damping ratios, proving that nanomaterials can be used to increase rigidity in structures, in other words, for reinforcement. Another important result determined in the study was the observation of the adherence of titanium dioxide and similar nanomaterials mentioned in the introduction to concrete structure surfaces was at the highest level.

• Advances in nano research
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• v.12 no.1
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• pp.65-72
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• 2022

The dynamic properties (frequencies, mode shapes, damping ratios) of the scaled WPC warehouse are compared using the operational modal analysis approach to the dynamic parameters (frequencies, mode shapes, damping ratios) of the full outer surface of titanium dioxide, 70 micron in thickness. Micro tremor ambient vibration data on ground level was used to provide ambient excitation. For the output-only modal identification, Enhanced Frequency Domain Decomposition (EFDD) was used. This study discovered a strong correlation between mode shapes. Titanium dioxide applied to the entire outer surface of the scaled WPC warehouse results in an average 14.05 percent difference in frequency values and 7.61 percent difference in damping ratios, demonstrating that nanomaterials can be used to increase rigidity in structures, or for reinforcement. Another significant finding in the study was the highest level of adherence of titanium dioxide and similar nanomaterials mentioned in the introduction to WPC structure surfaces.

• Journal of Information Processing Systems
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• v.20 no.3
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• pp.399-408
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• 2024

The moisture content of crude oil notably affects various aspects of oil production, storage, transportation, and exploration. However, accurately measuring this moisture content is challenging because of numerous influencing factors, leading to a lack of precision in existing detection methods. This inadequacy hinders the progress of China's petroleum industry. To overcome these challenges, this paper proposes a conductivity-based method for measuring crude oil moisture content. By employing an embedded system, we designed a sensor comprising five electrodes. Additionally, we developed signal excitation and signal processing circuits. Moreover, a software program was designed to analyze and compute the output signal using fast Fourier transform operations. This facilitated the identification of flow patterns, computation of relevant flow rates, and establishment of correlation rates based on frequency spectral characteristics. Based on experimental results, we established a functional relationship between measurement parameters and crude oil moisture content. This study enhanced the precision of moisture content measurement, thereby addressing existing limitations and fostering the advancement of China's petroleum industry.

• Food Science and Preservation
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• v.31 no.3
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• pp.374-384
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• 2024

Soybean paste is a staple food used to make doenjang (DE), cheonggukjang (CGJ), and miso (MI). In this study, solid-phase microextraction followed by gas chromatography-mass spectrometry was used to identify volatile components in DE, CGJ, and MI, and principal component analysis (PCA) was performed to determine their correlation between soybean pastes. Esters and hydrocarbons accounted for more than 55% of the total volatile components. PCA showed that esters were highly correlated with DE; pyrazines were correlated with CGJ; and alcohols were highly correlated with MI. Because DE, CGJ, and MI are made of the same material, their overall volatile content tended to be similar. However, the main volatile components and fragrances were different. These findings will be used as basic research data to promote quality improvement of soybean-based fermented foods in Korea and Japan.

• The Journal of the Korean dental association
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• v.51 no.6
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• pp.346-354
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• 2013

Early identification of maxillary canine impaction is very important, because of treatment duration time. Analysis used by 3-dimensional computed tomography is more important than before in treatment planning. The aim of this study was to analysis of factors associated with the treatment during time of forced eruption of the impacted maxillary canine using 3-dimensional computed tomography. 17 patients were analysed in Daejeon dental hospital of Wonkwang university(16 patients with unilateral impactions and 1 patient with bilateral impaction). In total, 18 maxillary impacted cannines were analysed by 3-dimensional computed tomography. The results obtained were as follow; 1. There was positive correlation between the age of patient and treatment duration time. 2. There was positive correlation between the distance of occlusal plane to cusp of maxillary impacted canine and treatment duration time, and negative correlation between the length of maxillary impacted canine and treatment duration time. 3. There was positive correlation between the angulation of midsagittal plane to axis of maxillary impacted canine and treatment duration time, and negative correlation between occlusal plane to axis of maxillary impacted canine and treatment duration time. In conclusion, age, tooth length, distance from the canine cusp tip to the occlusal plane, angulation of tooth axis to occlusal plane and midsagittal plane allow that we can predict treatment duration time.

• Journal of the Korean Chemical Society
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• v.52 no.3
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• pp.295-302
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• 2008

In this study, the test that were used in entrance examination for chemistry class in a Science-Gifted Education Center for middle school students were analyzed by using criteria for identification and measurement of scientific giftedness and a classical test theory. The result of analysis exhibited that most of problems measured more than two elements of scientific giftedness and required applications of scientific knowledge of middle school level to solve problems. In the analysis of sub-elements of scientific giftedness, originality, fluency in creativity and finding problems/formulating hypothesis, planning inquiry, interpreting data in science process skills were dominant while drawing conclusion and generalization processes were lacking. In correlation analysis between total score and each type of problems, total score was most influenced by the problems measuring science inquiry linked with scientific knowledge. Item difficulty is moderately high and item discrimination is moderate.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.6
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• pp.491-499
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• 2001

In this paper, the scheme of an efficient fuzzy rule generation and fuzzy system construction using GA(genetic algorithm) and FCM(fuzzy c-means) clustering algorithm is proposed for TSK(Takagi-Sugeno-Kang) type fuzzy system. In the structure identification, input data is transformed by PCA(Principal Component Analysis) to reduce the correlation among input data components. And then, a set fuzzy rules are generated for a given criterion by FCM clustering algorithm . In the parameter identification premise parameters are optimally searched by GA. On the other hand, the consequent parameters are estimated by RLSE(Recursive Least Square Estimate) to reduce the search space. From this one can systematically obtain the valid number of fuzzy rules which shows satisfying performance for the given problem. Finally, we applied the proposed method to the Box-Jenkins data and rice taste data modeling problems and obtained a better performance than previous works.