• 한국물환경학회지
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• 제27권6호
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• pp.905-913
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• 2011

This study was conducted to characterize the discharge feature of pollutant load from the upper and lower watershed influencing on the water quality of South Han River using the empirical equation and Factor Analysis. The results of regression analysis between flow rate and pollutant load were as follows. In the streams of the upper watershed of South Han river, $BOD_5$ and $COD_{Mn}$ were increased as the flow rate was increased. Also, steep increases in SS and TP were observed with positive correlation with the flow rate while change in TN was slightly shown. On the other hand, in the streams of the lower watershed of South Han river, $BOD_5$ was negatively correlated with the flow rate, being decreased with the increase in the flow rate. However, changes in $COD_{Mn}$, TN, SS, and TP showed a similar trend with those observed in the upper watershed. With Factor Analysis of the water quality and various components, it was appeared that the flow rate, SS, and TP were significantly correlated each other and they were indicated as the principal component influencing on water quality in the streams of the upper watershed. In contrast, $BOD_5$, $COD_{Mn}$ and TOC were significantly correlated each other and they were included as the principal pollution component of the streams in the lower watershed. From these results, it was conclusive that the upper watershed of South Han River was mainly affected by non point source pollutants while the lower watershed was influenced by point source pollutants from the developed areas.

• 응용통계연구
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• 제26권2호
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• pp.335-347
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• 2013

다양한 분야에서 시그널(signal) 형태로 자료들이 표현된다. 예를 들면 심전도(electrocardiogram)는 심근에서 발생하는 활동 전류를 나타내는데, 심장의 박동에 따라 수축과 이완을 반복하는 과정을 시간에 따른 활동 전류량의 변동으로 나타낸다. 현실세계에서 측정하거나 관찰되는 시그널에는 다양한 형태의 시그널들이 혼합되어 있는 경우가 흔하다. 예를 들어 오케스트라 연주의 아름다운 선율은 고유한 주파수(frequency)를 지닌 악기들의 다양한 소리로 구성되어 있으며, 각기 다른 음조(note)가 하나로 모여 완벽한 하모니를 형성하게 된다. 시그널이 정상인(stationary) 경우에 혼합된 시그널들을 분해하여 분석하는 방법에 대해 현재까지 다양하게 연구되어 왔다. 자료가 비정상(non-stationary)일 경우에는 기존의 방법론들을 적용시키기에는 한계가 있다. 비정상성 자료를 다루기 위해 Huang 등 (1998)은 경험적 모드분해법(empirical mode decomposition)이라는 방법을 제안하였다. 자료에 내포되어 있는 국소적인 파동(oscillation)을 국소 극값들(local extrema)을 식별하여 자료 적응적으로 추출한다. 경험적 모드분해법은 잡음(error)에 의해 자료가 오염되어 있는 경우에는 국소 극값들을 통하여 국소적인 파동을 추정하기 어려우며, 자료의 크기가 커짐에 따라 계산량도 크게 늘어나는 단점 등이 있다. 본 연구에서는 이차 미분을 이용하여 국소적인 파동을 식별하고 추정하는 새로운 방법론을 제시하고자 한다.

• Journal of Multimedia Information System
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• 제6권4호
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• pp.309-316
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• 2019

Virtual Reality is broadly recognized as an "empathy machine". This reputation is due to the feeling of 'presence' that it provides to users, which is the sensation of being bodily present in a space, even when that space is virtual. The possibility of complete immersion attracts many creators looking to induce empathy and awareness about the most diverse subjects. One of the first types of VR non-fiction productions to be released was in the morally sensitive humanitarian documentary genre. This research aims to explore how VR productions differ from non-VR productions with a focus on humanitarian communication. Rather than targeting mechanical aspects of VR technology, this article compares the visual and narrative storytelling characteristics in VR and non-VR media. First, humanitarian communication and its nuances are explained. Then, 360° video filming characteristics are analyzed, followed by a comparison table contrasting VR and non-VR non-fiction. After evaluating VR non-fiction empirical studies, a discussion is initiated over the betterment of VR non-fiction storytelling in a way that could help it generate more empathy, since many productions seem to purely rely on the technology as a production novelty, and end up lacking emotional depth and audience engagement through story.

• Nuclear Engineering and Technology
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• 제56권4호
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• pp.1347-1356
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• 2024

Measuring the residual stress in the components in nuclear power plants is crucial to their safety evaluation. The instrumented indentation technique is a minimally invasive approach that can be conveniently used to determine the residual stress in structural materials in service. Because the indentation behavior of a structure with residual stresses is closely related to the elastic-plastic behavior of the indented material, an accurate understanding of the elastic-plastic behavior of the material is essential for evaluation of the residual stresses in the structures. However, due to the analytical problems associated with solving the elastic-plastic behavior, empirical equations with limited applicability have been used. In the present study, the impact of the non-equibiaxial residual stress state on indentation behavior was investigated using finite element analysis. In addition, a new nonequibiaxial residual-stress prediction methodology is proposed using a convolutional neural network, and the performance was validated. A more accurate residual-stress measurement will be possible by applying the proposed residual-stress prediction methodology in the future.

• 한국산업정보학회논문지
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• 제27권4호
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• pp.93-104
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• 2022

최근 빠른 속도로 성장하고 있는 NFT는 점점 우리들의 삶 속에 들어오고 있다. NFT는 대체 불가 토큰(Non-Fungible Token)의 약자로 디지털 데이터에 대하여 소유권을 주장할 수 있게 해주는 기술이다. 디지털 데이터에 소유권이 생기면서 신기술의 특성과 함께 투자가치로서의 특성을 보이고 있으며 앞으로 더 발전할 것으로 전망된다. 본 연구에서는 NFT를 보유하고 있는 사용자들이 어떠한 의도를 가지고 구매하게 되는지에 대한 분석을 수행하고자 하였다. 개인적인 특성과 NFT 자체의 특성, 사회적 특성을 활용하여 구매의도에 영향을 미칠 수 있는 요인들을 선정하고 연구모형을 수립하였다. 실증연구를 수행한 결과, 개인의 혁신성과 NFT의 수익성 및 신뢰성, 그리고 FOMO 요인이 구매의도에 유의한 영향을 주는 것으로 나타났다.

• ETRI Journal
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• 제25권4호
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• pp.258-265
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• 2003

In our study, we extracted the market, finance, and government factors determining R&D investment of individual firms in the IT industry in Korea. We collected the financial data of 515 individual firms belonging to IT and non-IT industries between 1980 and 1999 from the Korea Investors Service's database and investigated the empirical relationship between the factors using an ordinary regression model, a fixed effects model, and a random effects model. The main findings of our study are as follows: i) The Herfindahl Index variable representing the degree of market concentration is statistically insignificant in explaining R&D expenditures in the IT manufacturing industry. ii) Assets, which is used as a proxy variable for firm size, have a positive and statistically significant coefficient. These two results suggest that the Schumpeterian Hypothesis may be only partially applied to the IT manufacturing industry in Korea. iii) The dividend variable has a negative value and is statistically significant, indicating that a tendency of high dividends can restrict the internal cash flow for R&D investment. iv) The sales variable representing growth potential shows a positive coefficient. v) The subsidy as a proxy variable for governmental R&D promotion policies is positively correlated with R&D expenditure. This suggests that government policy has played a significant role in promoting R&D activities of IT firms in Korea since 1980. vi) Using a dummy variable, we verified that firms reduced their R&D investments to secure sufficient liquidity under the restructuring pressure during Korea's 1998 and 1999 economic crisis.

• Journal of Korea Trade
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• 제23권4호
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• pp.131-148
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• 2019

Purpose - Based on the Korea-China FTA as the starting point, this paper makes an empirical analysis of the main influencing factors of the FTA utilization and performance of SMEs. Design/methodology - Taking into account the relationship between the internal and external environmental factors on FTA activities and performance of Korea's SMEs, with PLS-SEM and data obtained by the questionnaire, Smart PLS was applied for the analysis. Findings - The recognition of FTA in SMEs has a significant positive effect on FTA utilization and performance, the international marketing orientation factor only has a significant positive effect on the performance, while the inadequate improvement of non-tariff barriers has a significant negative impact on FTA utilization. In addition, FTA activity has a significant mediation effect on two paths. Originality/value - This paper is of great practical relevance as a tool to enable SMEs to make effective utilization of Korea-China FTA and improve their imports and exports. The paper helps grasp the main factors affecting the utilization and performance of FTA for SMEs, also to establish FTA Business Model and FTA utilization plans for specific industries in the future regarding tariff and non-tariffs compatibility.

• The Journal of Asian Finance, Economics and Business
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• 제9권5호
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• pp.63-73
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• 2022

In today's financial economics literature, the impact of innovative family ownership and management on firm performance is a prominent concern. In this study, the existence of family firms in the listed sector of Pakistan's economy is investigated. The objective of this study is to examine the performance-oriented relationship of family ownership and active involvement of family member at the CEO position. The theoretical perspectives that underpin this research are agency and stewardship. This analysis used a sample of 315 publicly traded companies from 2009 to 2019. The study's primary independent variables include family influence on ownership and family CEO. Financial performance is the dependent variable that is divided into accounting and market measures. The proxy for accounting measure is return on asset and proxy for market measure is Tobin's Q. This study employs univariate and balanced panel data analysis. For robustness of the analysis random-effects GLS regression is carried out. The empirical results show that that Family Firms outperform Non-Family Firms both in terms of accounting and market measures. In the later part family CEOs firms outperform the firms that have either insider or outsider non-family CEOs. This superior performance is subjected to the positive and statistically significant association between family ownership, management, and financial performance.

• 무역학회지
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• 제47권4호
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• pp.233-254
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• 2022

Although there is growing literature evidence of linkages between global value chains (GVCs) and foreign direct investment (FDI), the results are mixed and ambiguous by geographic dimension, time period and sectoral scope. Moreover, bilateral approaches on these connections have been rarely analyzed. In this context, we investigate the effect of bilateral greenfield FDI and cross-border M&A on GVC linkages between host countries and source countries. We match three-year averages of bilateral FDI and UNCTAD-Eora GVC value-added data from 2005 to 2019 between 37 OECD sources and 176 host countries (37 OECD versus 139 non-OECD countries). In the structural gravity model, the empirical specification includes bilateral and country-period fixed effects and uses a Poisson Pseudo-Maximum Likelihood (PPML) estimator. We find that greenfield and M&A FDI promote forward and backward GVC linkage for all sectors between OECD countries, whereas greenfield FDI promotes backward GVC linkage between OECD and non-OECD countries. In addition, the results indicate that the degree of influence of GVCs by FDI flows is greater for forward GVC than backward GVC among OECD countries.

• 한국의류학회지
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• 제33권9호
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• pp.1398-1408
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• 2009

This study focuses on how positive emotions form when consumers impulsively purchase fashion products. Examined are the novelty seeking situations and the fashion knowledge of consumers as influential factors that affect positive impulsive shopping emotions along with the mediating role of the perceived risk of consumers for purchase and non-purchase. An online survey was conducted for the empirical research with a questionnaire about the fashion impulsive purchases of a product within the last 2 months. A total of 555 surveys were collected from impulsive female buyers and 404 complete responses were analyzed. The results find that the perceived risk is identified into purchase and non-purchase perspectives. Purchase perceived risk influenced negatively on positive emotions of impulsive purchase and non-purchase perceived risk positively. The perceived risk for non-purchase versus purchase increased by the more fashion knowledge consumers had and the more they shopped as novelty seeking. The results imply that non-purchase perceived risk importantly mediated between the influential factors and positive affect for impulsive purchase. Based on the findings, this study proposed some marketing suggestions and thoughts about effective purchase stimulation.