• Journal of the Korean Regional Science Association
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• 제34권2호
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• pp.65-77
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• 2018

The purpose of this study is to compare and analyze factors in country risk between Cambodia and Vietnam. OECD and the Export-Import Ban of Korea assess country risk of Cambodia more highly than Vietnam. As results of the parametric tests for evaluation factors on the basis of country risk classification, the economic growth rate, the foreign trade index, and the foreign exchange reserves among the economic risks with the corruption index as the political and social risk have statistically significant effect on the difference between country risks of two countries. However, discriminant factor analysis indicates that the economic growth rate, the foreign exchange reserves, and the corruption index are key variables, which represent the difference between country risks of Cambodia and Vietnam. Consequently, the government of Cambodia needs to try to root out the corruption and to expand trade through increasing export for lowering the country risk to the level of Vietnam. Vietnam would also need to focus on attaining the sustainable high economic growth rate and increasing the foreign exchange reserves.

• Journal of the Korean Society of Clothing and Textiles
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• 제28권7호
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• pp.983-994
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• 2004

The aim of this study is to provide fundamental data on the development of ready-to-wear clothes appropriate for the body types of elderly women. The study was conducted targeting 318 elderly women over 60 years of age whose fields of action were colleges for the elderly, sports centers, or business sites in Seoul and the neighboring districts. A total of 44 features in the upper body were used for the anthropometric measurement and analysis using anthropometry and photometry. The results of the study are as follows: 1. Somatotypes were classified into three types according to a cluster analysis using height and weight indices. Type 1 is the group with long and undersized upper body and straight body type since the face of the upper body is long relative to height and width, girth and depth are the smallest relative to weight, the breasts are somewhat fat, with a small extent of drooping and a straight back. Type 2 is the group that is considered fat relative to the body, has broad shoulders, drooping breasts with a wide space between them, and a back-bent upper body. Type 3 is the group that has a bent shape, the shortest upper body relative to height, and showing average obesity factors. 2. Indices of height and weight were used for factor analysis, cluster analysis, and discriminant analysis in order to classify upper body somatotype according to shape while excluding size factors of elderly women＇s upper body somatotype. The same method was used to compare and verify the result according to the absolute measurement and height index. Classification based on height and weight indices demonstrate that such somatotype classification minimizes the personal equation of body shape and it induces better classification based on shape as the results showed the highest cumulative sum of square(CUSUM) at 78.38% while six factors showed the smallest result and the hit rate for the classified three groups showed the highest result at 95.30%.

• Journal of the Korea Society of Computer and Information
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• 제18권4호
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• pp.123-129
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• 2013

The performance and practicality of cryptosystem for encryption, decryption, and primality test are primarily determined by the implementation efficiency of the modular exponentiation of $a^b$ (mod m). To compute $a^b$ (mod m), the standard binary squaring (square-and-multiply) still seems to be the best choice. However, in large b bits, the preprocessed n-ary, ($n{\geq}2$ method could be more efficient than binary squaring method. This paper proposes a square-and-divide and unpreprocessed n-ary square-and-divide modular exponentiation method. Results confirmed that the square-and-divide method is the most efficient of trial number in a case where the value of b is adjacent to $2^k+2^{k-1}$ or to. $2^{k+1}$. It was also proved that for b out of the beforementioned range, the unpreprocessed n-ary square-and-divide method yields higher efficiency of trial number than the general preprocessed n-ary method.

• Journal of the Korean Geotechnical Society
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• 제28권5호
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• pp.41-54
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• 2012

The weathering process of rocks leads to the reduction of geotechnical bearing capacity. The weathering of granite is frequently used to refer to the degradation of geotechnical property in the design and construction of infra-structure. In this study, the range of values of CIA (chemical index of alteration) and the change of mineral compositions by weathering have been analysed with igneous rock, which covers 45.5% in South Korean territory. Several weathering indices were studied for various rocks found in Korea and significant relationships between different indices were delineated via statistical analysis. The applicability of CIA was found to be the most significant among all weathering indicies. The composition of illite, the secondary weathering residual, generally increases for the felsic rock, and swelling clay material is not included. The weathering of felsic rock will follow a sequential process, starting from bed rock, illite, and chlorite to kaoline. The mafic rock will show weathering process, from bed rock, smectite, and chlorite to kaoline. The intermediate rocks such as andesite and tuff will show similar weathering procedure and the composition of kaoline, chlorite, and smectite tends to increase more than that of illite when the mafic rock is dominated. This means the increase of rock material which has high CEC (cation exchange capacity) during secondary weathering process. However, the characteristics of a specific rock cannot be completely analyzed using merely CIA, since it is exclusively based on chemical composition and corresponding alteration. The CIA can be used to quantify the weathering process in a limited range, and further considerations such as rock composition, strength characteristics will be required to configure the comprehensive weathering impact on any specific region.

• Journal of the Korea Institute of Information Security & Cryptology
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• 제24권6호
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• pp.1055-1063
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• 2014

Recently, various methods have been proposed for improving the performance of the side channel analysis using the power consumption. Of those method, waveform compression method applies to reduce the noise component in pre-processing step. In this paper, we propose the new LDA(Linear Discriminant Analysis)-based signal compression method finding unique feature vector. Through experimentations, we are comparing the proposed method with the PCA(Principal Component Analysis)-based method which has known for the best performance among existing signal compression methods.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• 제29권1호
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• pp.29-37
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• 2011

The purpose of this research is to measure Quality of Life indices using Factor Analysis and Principle Component Analysis and to analyze the spatial patterns of Quality of life distribution in the Seoul Metropolitan Area in terms of spatial association using spatial statistics and spatial exploratory technique. In order to check the degree of clustering, this study used spatial autocorrelation indices, global Moran's I index. In addition, local scale analysis was conducted using Moran Scatterplot and Local Moran's I to identify the spatial association pattern and the high Quality of life. The analysis based on global statics showed that, in the Seoul Metropolitan Area, QoL Indices had been distributed with positive spatial association. According to the local spatial statistics, the general tendency of clustering H-H clusters which were mainly concentrated on the Seoul, L-H clusters were concentrated on the Kyunggi-Do and L-L Clusters showed the regional extent of lagging behind. However, in case of H-H, L-H Clusters they had been spread out in the Newtown as population increase.

• The Journal of the Korea Contents Association
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• 제12권3호
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• pp.161-170
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• 2012

Based on the qualitative analysis, 4 factors of dance giftedness were operationally defined and test items were initially developed accordingly. The preliminary test data obtained from 206 dancers was analyzed, using item analysis and a series of reliability analyses. In order to dancer the construct validity, four exploratory factor analyses were conducted for 54 items, resulting in 20 items of 4 factors; physique, dance attitude Expressiveness and creativity, movement ability. A confirmatory factor analysis conducted for 292 dancers to test the goodness-of-fit of 4 factor model revealed a satisfactory level of $x^2$, Q, root mean square residual(RMR), goodness of fit index(GFI), Tucker-Lewis index(TLI), comparative fit index(CFI), root mean square error of approximation(RMSEA). The concurrent and cross validity indices proved the validity of 20 items of 4 factors.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 한국정보통신학회 2017년도 추계학술대회
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• pp.170-172
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• 2017

Due to the technological advances in modern society, the distinction between mask and authenticity is becoming very difficult. to solve these problems, this paper describes a high-level improvement of the image processing technique of the code authentication system which discriminates the good and the bad by using the color information and the dot information. Labels were given to each genuine article and the article, which can not be distinguished from each other. In the proposed method, image matching of labels is performed using the opencv library, and genuine and good products are discriminated by using the halftone dots and w dot dots of each label. In this paper, the proposed method stores genuine and good labels on the server and compares them with the user's labels to determine genuine products.

• Communications of Mathematical Education
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• 제37권1호
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• pp.21-45
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• 2023

This study presents a machine learning program designed to identify impactful papers in the field of mathematics education. To achieve this objective, we examined the impact of papers from a scientific econometrics perspective, developed a mathematics education research network, and defined the impact of mathematics education research using PageRank, a network centrality index. We developed a machine learning model to determine the impact of mathematics education research and identified the journals with the highest percentage of impactful articles to be the Journal for Research in Mathematics Education (25.66%), Educational Studies in Mathematics (22.12%), Zentralblatt für Didaktik der Mathematik (8.46%), Journal of Mathematics Teacher Education (5.8%), and Journal of Mathematical Behaviour (5.51%). The results of the machine learning program were similar to the findings of previous studies that were read and evaluated qualitatively by experts in mathematics education. Significantly, the AI-assisted impact evaluation of mathematics education research, which typically requires significant human resources and time, was carried out efficiently in this study.

• Journal of the Korea institute for structural maintenance and inspection
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• 제18권3호
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• pp.101-107
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• 2014

Damage location and extent of structure could be detected by the inverse analysis on dynamic response properties such as frequencies and mode shapes. The dynamic response of building structures has many noise and affected by nonstructural members and, above all, the behavior of building structure is more complex than civil structure and this makes the damage detection difficult. In recent researches the damage is detected by the indirect index such as sensitivity or assumed values. However, for the more reasonable damage detection, it needs to use the damage index directly induced from dynamic equation. The purpose of this study is to provide the damage detection method on shear building structures by the damage index directly induced from dynamic equation. The provided damage index could be estimated from measured mode shape of undamaged structure and frequency difference between undamaged and damaged structure. The damage detection method is applied to numerical analysis model such as MATLAB and MIDAS GENw for the verification. The damage index at damaged story represents (-) sign and 15 times than other undamaged sories.