• Bulletin of the Korean Chemical Society
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• 제16권11호
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• pp.1060-1064
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• 1995

The reactivity of superoxide ion (O2-.) with halogenated substrates is investigated by cyclic voltammetry and rotated ring-disk electrode method in aprotic solvents. The more positive the reduction potential of the substituted nitrile, the more facile is nucleophilic displacement by O2-.. The reaction rates of halogenonitriles with O2-. vary according to the leaving-group propensity of halide (Br > Cl > F). The relative reaction rates of other substituted nitriles are in the order of electron-withdrawing propensity of the substituent group (CN > C(O)NH2 > Ph ≒ CH2CN). The reaction of O2-. with dihalocarbons indicates that five-membered rings can be rapidly formed by the cyclization of substrate and O2-., and the relative rates of cyclization depend on the number of methylenic carbons {Br(CH2)nBr, [n=1 < 2 < 3 > 4 > 5]}. Mechanisms are proposed for the reaction of O2-. with halogenated substrates.

• 한국경영공학회지
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• 제23권4호
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• pp.105-123
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• 2018

The purpose of this study is to verify whether the technology grade, which is the result of technology appraisal by Technology Credit Bureau, can be extended and applied to the venture certification system. We confirmed that there was a significant difference in the average financial performance for three years after the certification and appraisal of the two groups after matching the venture certification enterprise group and the technology appraisal enterprise group in 2015 through the propensity score matching method. As a result, there was no significant difference in the financial performance of venture certified firms and technology appraisal firms, so we confirmed that the technology grade can be expanded and applied to the venture certification system. As a result of estimating the technology grade conforming to the venture certification system, it was concluded that technology outstanding firm(T1-T4) is a technology grade suitable for the venture certification system.

• Communications for Statistical Applications and Methods
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• 제27권6호
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• pp.675-688
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• 2020

In survival analysis of observational data, the inverse probability weighting method and the Cox proportional hazards model are widely used when estimating the causal effects of multiple-valued treatment. In this paper, the two kinds of weights have been examined in the inverse probability weighting method. We explain the reason why the stabilized weight is more appropriate when an inverse probability weighting method using the generalized propensity score is applied. We also emphasize that a marginal hazard ratio and the conditional hazard ratio should be distinguished when defining the hazard ratio as a treatment effect under the Cox proportional hazards model. A simulation study based on real data is conducted to provide concrete numerical evidence.

• 한국멀티미디어학회논문지
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• 제24권2호
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• pp.336-343
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• 2021

AI technology is spreading not only to industrial fields, but also to culture, art, and content fields. In this paper, we proposed a system based on AI technology that can automate the process of reproducing contents using characters for movie contents. After creating the basic appearance of the character by using the StyleGAN2 model from the video extracted from the movie contents, analyzing the character's personality and propensity using the extracted dialogue data, it was determined from the contemplative appearance based on the yin-yang and five elements to the character's propensity. Accordingly, the external characteristics are reflected in the character. Using the OpenPose model, a character's motion is created, and the finally generated data is integrated to reproduce the content. It is expected that many movie contents can be reproduced through the study of the proposed system.

• 패션비즈니스
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• 제26권6호
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• pp.64-81
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• 2022

Many fashion brands provide sophisticated customization services with advanced technology. Previous studies have revealed that a high level of customization aided by technology positively influences purchase intention. However, since fashion products are society-approved symbols, brand prestige and consumer propensity are expected to affect purchase behavior of customized products. This study aims to identify the purchase decision mechanism of customized products by identifying the relationships among self-expression, brand prestige, narcissistic disposition, and purchase intention. An online survey was conducted on 220 Korean women in their 20s and 30s with customization experience. The results of the data analysis showed that the affluent customization area and narcissistic disposition positively affected purchase intention. Surprisingly, when brand prestige was high and narcissistic disposition was low, the more affluent the customization area, the higher the purchase intention. However, for higher narcissistic disposition, no significant relationship was found between the customization area and purchase intention. This study provides insights into discriminatory customization strategies based on consumer propensity and the brand prestige level when providing customization services in fashion brands.

• 한국자기공명학회논문지
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• 제27권1호
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• pp.1-4
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• 2023

Transthyretin (TTR) is an indispensable transporter protein of thyroxine and a retinol molecule in humans. TTR has a stable homo-tetrameric structure in its native state, while upon dissociation into monomers, it becomes aggregation-prone and can form an amyloid fibril. Although the amyloidogenic propensity of TTR has been known and investigated since the late 1990s, the structural information regarding TTR's amyloidogenic species is still elusive. Here, we employed high-pressure nuclear magnetic resonance (HP-NMR) approaches on the monomeric variant of TTR (TTR[F87M/L110M]; M-TTR) and observed that it experiences a two-step transition in response to the pressurized condition. Our study demonstrated that M-TTR in an ambient condition has heterogeneous structural features, which is likely related to the amyloidogenic propensity of TTR.

• Communications for Statistical Applications and Methods
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• 제29권2호
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• pp.263-275
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• 2022

Use of appropriate technique for non-response occurring in sample survey improves the accuracy of the estimation. Many studies have been conducted for handling non-ignorable non-response and commonly the response probability is estimated using the propensity score method. Recently, post-stratification method to obtain the response probability proposed by Chung and Shin (2017) reduces the effect of bias and gives a good performance in terms of the MSE. In this study, we propose a new response probability estimation method by combining the propensity score adjustment method using the logistic regression model with post-stratification method used in Chung and Shin (2017). The superiority of the proposed method is confirmed through simulation.

• 무역학회지
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• 제46권2호
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• pp.323-335
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• 2021

With the advent of the 4th Industrial Revolution, there is a rising interest in the impact of these changes on Korea's trade. While the previous studies related to the 4th Industrial Revolution are very limited in the field of trade research, this study attempts an empirical analysis regarding the effect of the use of the 4th Industrial Revolution technology on the performance of exporters, based on the data of the Survey of Business Activities during 2017-2019 by the Korean government statistical office. Through the empirical analysis in combination with the propensity score matching (PSM) and the difference-in-difference (DID) analysis, this research confirms that the use of the 4th Industrial Revolution technology has a positive effect on the export performance of Korean exporters.

• 한국벤처창업학회:학술대회논문집
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• 한국벤처창업학회 2021년도 추계학술대회
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• pp.113-117
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• 2021

Due to the recent COVID-19 pandemic, SMEs are forced to converge themselves into online business to cope with the rapidly changing business environment. However, due to various difficulties of becoming an online business, most SMEs choose to use services provided by the online sales platform. These platforms offer valuable support such as DSS in return for the high amount of commission fee. We analyze a novel data set from Naver Corporation's 'Smart Store' platform with the quasi-experimental method (propensity score matching technique combined with the difference in differences analysis) to analyze DSS usage and SME's performance empirically. Our results suggest that DSS usage leads to an increase in SME's sales performance in means of sales frequency and sales amount. Additionally, we have found weak support that DSS usage enables SMEs to attract customers better than those not using DSS.

• 교통기술과정책
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• 제9권2호
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• pp.13-18
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• 2012