• Journal of the Korea Society of Computer and Information
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• v.13 no.7
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• pp.173-180
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• 2008

In this paper, we proposed an algorithm for an effective public key and private key generation to implement a secure asymmetric watermarking system against the public key attack. The public key and private key generation is based on the linear transformation using a special matrix and the keys are designed to be able to have high correlation value. We also proposed a counter plan of public key attack. This method uses a multiple public key generation and distribution. As the results, the correlation value between the public key and the private key is high in the watermarked image. After the public key attack. this can detect the correlation by using other public key.

• Journal of Electrical Engineering and Technology
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• v.8 no.4
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• pp.719-728
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• 2013

Probabilistic assessment of voltage stability margin (VSM) with existence of correlated wind speeds is investigated. Nataf transformation is adopted to establish wind speed correlation (WSC) model. Based on the saddle-node bifurcation transversality condition equations and Monte Carlo simulation technique, probability distribution of VSM is determined. With correlation coefficients range low to high value, the effect of WSC on VSM is studied. In addition, two risk indexes are proposed and the possible threat caused by WSC is evaluated from the viewpoint of risk analysis. Experimental results show that the presence of correlated wind speeds is harmful to safe and stable operation of a power system as far as voltage stability is concerned. The achievement of this paper gives a detailed elaboration about the influence of WSC on voltage stability and provides a potentially effective analytical tool for modern power system with large-scale wind power sources integration.

• Annals of Clinical Neurophysiology
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• v.8 no.2
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• pp.135-145
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• 2006

Background: Parkinson's disease is movement disorder due to dopaminergic deficiency. It has been noted that cognitive dysfunction also presented on Parkinson's disease patients. But, it is not clear whether such a cognitive dysfunction was a dopaminergic dysfunction or cholinergic dysfunction. Using linear and non-linear analyses, we analysed the effect of cognitive and motor symptom on EEG change. Methods: EEGs were recorded from patients with Parkinson's disease and essential tremor, and normal controls during rest. We calculated the power spectrum, correlation dimension and Lyapunov exponent by using 'Complexity'program. The power spectrum, correlation dimension, and Lyapunov exponent were compared between Parkinson's disease patients and essential tremor patients. Results: Theta power was increased in Parkinson's disease patient group. Correlation dimension was increased in Parkinson's disease patients. Positive correlation was noted between MMSE and correlation dimension, and negative correlation was noted between MMSE and Lyapunov exponent. Lyapunov exponent was decreased in Parkinson's disease patient. Conclusions: We conclude that the state of Parkinson's disease patient is characterized by increased correlation dimension and decreased Lyapunov exponent.

• Journal of Photoscience
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• v.9 no.2
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• pp.524-526
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• 2002

Hypericin was found to exhibit the highest antitumoral activity in treating EAT by photodynamic therapy (PDT): Hypericin>HPde>PII>TPPS$_4$>ALA. Moreover, 25% of mice after Hyp-based PDT survived 4 months, if compare with control group. Antitumor activity of these photosensitizers was in rather clear correlation with accumulation potential.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.64-64
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• 2019

Screening and identification of genetic resources based on their phytoconstituents and morphological characters potentially provide baseline data for researchers, breeders, and nutraceutical companies who wish to formulate a nutrient-dense diet and health beneficial supplement. Thus, we evaluated the amount of total phenolic content and major phenolic compounds; examined if phenolic compounds could be used as distinguishing factors for perilla genetic resources; and investigated the relation between some quantitative and qualitative morphological characters with the contents of phenolic compounds in 360 accessions obtained from National Agrobiodiversity Center gene bank, Jeonju, Korea. Total phenolic content (TPC) was estimated using Folin-Ciocalteu colorimetric assay. Individual phenolic compounds were determined using an Ultra-High Performance Liquid Chromatography system equipped with Photodiode Array detector. Considerable variations were observed in TPC (7.99 to 117.47 mg GAE/g DE), rosmarinic acid (RA) (ND to 19.19 mg/g DE), caffeic acid (CA) (ND to 0.72 mg/g DE), apigenin-7-O-diglucuronide (ADG) (ND to 1.24 mg luteolin equivalent (LUE)/g DE), scutellarein-7-O-glucuronide (SG) (ND to 4.32 mg LUE/g DE), and apigenin-7-O-glucuronide (AG) (ND to 1.60 mg LUE/g DE). RA was the most dominant phenolic compound in most accessions (95.3%) followed by SG. The adaxial leaf color was light green, green and dark green in 13.8%, 65.0%, and 21.1 % of the accessions, respectively. 78.8% of the accessions had light green color at the abaxial side with the remaining being described as green. Most of the accessions (96.9%) were cordate shape, the remaining being eclipse. Intensities of green pigment at abaxial and adaxial leaf surfaces were correlated with contents of individual phenolic compounds and TPC whereas leaf length and width had no correlation with TPC, CA and RA, and negatively correlated with ADG, AG, and SG. Leaf shape was not related with content of phenolic compounds, color of leaves, or the length or width of leaves. Accessions IT57426, IT157434, IT267710, and IT267712 which contained relatively high contents of TPC and major phenolic compounds (RA and SG) could be used for further research in breeding and bioassay test. Our study result showed the contents of total phenolics and individual phenolic compounds along with the morphological characters could be useful distinguishing factors for perilla genetic resources.

• Korean Journal of Child Studies
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• v.28 no.6
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• pp.169-182
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• 2007

Creative problem solving skills in mathematics were measured by fluency, flexibility, and originality; cognitive strategies were measured by rehearsal, elaboration, organization, planning, monitoring, and regulating. The Creative Problem Solving Test in Mathematics developed at the Korea Educational Development Institute(Kim et al., 1997) and the Motivated Strategies for Learning Questionnaire(Pintrich & DeGroot, 1990) were administered to 84 subjects in grade 5(45 girls, 39 boys). Data were analyzed by Pearson's correlation, multiple regression analysis, and canonical correlation analysis. Results indicated that positive regulating predicted total score and fluency, flexibility, and originality scores of creative problem solving skills. Elaboration, rehearsal, organization, regulating, monitoring, and planning positively contributed to the fluency and flexibility scores of creative problem solving skills.

• Journal of Korean Elementary Science Education
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• v.26 no.3
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• pp.286-294
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• 2007

This study investigated the relationship between elementary school students' creative problem solving skills in terms of science and cognitive strategies. Creative problem solving in science was measured by 4 variables; appropriateness, scientific ability, concreteness, and originality. Cognitive strategies were measured by 6 variables; surface(rehearsal), deep(elaboration and organization), and metacognitive strategies(planning, monitoring, and regulating). The KEDI Creative Problems Solving Test in Science(Cho et al., 1997) and the Motivated Strategies for Learning Questionnaire(Pintrich & DeGroot, 1990) were administered to 72 subjects. Data were analyzed by means of Pearson's correlation and multiple regression analysis. Our findings indicated a positive correlation between creative problem solving in science and cognitive strategies. The surface cognitive strategy (rehearsal) positively predicted the total score, the scientific ability's score, the concrete score, and the original score of creative problem solving in science. The deep cognitive strategy(organization) positively predicted the appropriate score and the metacognitive strategy(planning) positively predicted the original score of scientific creative problem solving skills.

• Korean Journal of Child Studies
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• v.29 no.3
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• pp.273-288
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• 2008

Types of motivation for self-determination studied in the current research included intrinsic motivation (IM) to know, IM to accomplish, IM to experience stimulation; external, introjected, identified regulation; and amotivation as related to children's self-regulated learning strategies (use of cognitive strategy and self-regulation). The Motivated Strategies for Learning Questionnaire (Pintrich & DeGroot, 1990) and the Academic Motivation Scale (Vallerand et al., 1992, 1993) were administered to 123 $5^{th}$ graders (63 girls, 60 boys). Data were analyzed by Pearson's correlation, multiple regression, and canonical correlation analysis. Results indicated that IM to accomplish, IM to know, and identified regulation positively and amotivation negatively affected self-regulated learning strategies. IM to accomplish and IM to know positively and amotivation negatively contributed to use of cognitive strategy and self-regulation.

• Computational Structural Engineering : An International Journal
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• v.3 no.1
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• pp.31-37
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• 2003

A typical marine platform in the Bay of Campeche is studied from the standpoint of structural reliability, and several characteristics of its deck such as slenderness and diameter/thickness ratios of the legs and actual degree of correlation between some variables are taken into account. The global and local buckling capacities of the deck legs are compared and the correlation coefficient between the critical axial load and the critical moment is assessed in order to validate its influence on the structural reliability. In addition, the influence of the vertical load, and its uncertainty, on the variance of the decks capacity, and latter on, on the platform's failure probability is assessed. The results presented may be used in future studies to further extend and upgrade the first version of the Reference Norm (PEMEX, 2000) and, in the longer term, to improve the current practice in the Design and Requalification of Offshore Marine Platforms in the Bay of Campeche.

• 제어로봇시스템학회:학술대회논문집
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• 1998.10a
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• pp.221-225
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• 1998

This paper is to present a method for recognizing an image of a tracking object by processing the image from a camera, whose attitude is controlled in inertial space with inertial co-ordinate system. In order to recognize an object, a pseudo-random M-array is attached on the object and it is observed by the camera which is controlled on inertial coordinate basis by inertial stabilization unit. When the attitude of the camera is changed, the observed image of M-array is transformed by use of affine transformation to the image in inertial coordinate system. Taking the cross-correlation function between the affine-transformed image and the original image, we can recognize the object. As parameters of the attitude of the camera, we used the azimuth angle of camera, which is de-fected by gyroscope of an inertial sensor, and elevation an91e of camera which is calculated from the gravitational acceleration detected by servo accelerometer.