• 한국전기전자재료학회논문지
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• 제34권5호
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• pp.382-385
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• 2021

Electrical poling is a crucial step to convert ferroelectrics to piezoelectrics. Nevertheless, no systematic investigation on the effect of poling has been reported. Given that the poling involves an alignment of spontaneous polarization, the condition for poling should be different when a material has an internal bias field that influences the domain stability. Here, we present the effect of poling profile on the dielectric and piezoelectric properties in Mn-doped Pb(Mg_1/3Nb_2/3)O₃-29 mol%PbTiO₃ single crystal with an internal bias field. We showed that both the dielectric permittivity and the piezoelectric coefficient were further enhanced when the poling procedure ends with a field application along the opposite direction to the internal bias field. We expect that the current finding would give a clue to understanding the true mechanism for the electrical poling.

• 한국의류학회지
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• 제45권2호
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• pp.217-232
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• 2021

This study analyzed the characteristics of generation Z leading the trend of the fashion industry through the creative activity of Virgil Abloh. A literature review and case study were conducted together with detailing the research methodology. As a result of research, generation Z is conceptualized as a "digital native" who grows in digital technology environment with excellent visual sense. They are "SNS creators" who have influence on Social Networking Services (SNS). They are also characterized as "social activists" who reject social conventions and prejudices. They are a "leading creators" who seek to differentiate with creativity. The characteristics of generation Z in the creative activities of Virgil Abloh have a feature of digital native in that they seek visual originality. In terms of communicating with generation Z through SNS and influencer marketing, it has the characteristics of SNS creators. It expresses social activists in providing consumers with diversity, and social perceptions of differentiation. In terms of providing content that encourages consumers to express their personality, it has a feature of leading creators. It is meaningful in that it contributes to the understanding of the market change and marketing strategy according to the consumer development and the activity of the fashion designer.

• ETRI Journal
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• 제45권2호
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• pp.267-276
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• 2023

R&D strategies of companies with low and high technological levels are discussed based on the concept of technology convergence and divergence. However, empirically detecting enterprise technology convergence in the distribution of enterprise technology (total productivity increase) over time and identifying key change factors are challenging. This study used a novel statistical indicator that captures the internal technology distribution change with a single number to clearly measure the technology distribution peak as a change in critical bandwidth for enterprise technology convergence and presented it as evidence of each technology convergence or divergence. Furthermore, this study applied the quantitative technology convergence identification method. Technology convergence appeared from the separation of total corporate productivity distribution of 69 IT companies in Korea in 2019-2020 rather than in 2015-2016. Results indicated that when the total technological level was separated from the technology leading and technology catch-up, IT companies were found to be pursuing R&D strategies for technology catch-up.

• Journal of Veterinary Science
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• 제24권3호
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• pp.42.1-42.6
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• 2023

Lumpy skin disease (LSD) is one of the most important emerging transboundary diseases. Recently, LSD has emerged in many countries in the northern hemisphere. The LSD virus has a huge genome and is highly resistant to environmental conditions. The virus is also host-specific and large ruminants, such as cattle and domestic water buffalo, are particularly susceptible. In addition, wild ruminants can serve as potential reservoirs for spreading the LSD virus. The emergence might be related to climate change in various regions because LSD is an arthropod-borne infectious disease. This disease causes enormous economic losses, such as leather damage, decreased milk production, abortion, and death in infected ruminants. The economic importance of LSD in the bovine industry has forced countries to develop and implement control strategies against the disease. With the recent global spread and the economic impact, LSD will be discussed intensively. In addition, effective preventive measures are suggested based on the presence or absence of LSD outbreaks.

• 한국유기농업학회지
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• 제31권4호
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• pp.357-380
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• 2023

This study analyzed the management efficiency of jujube, bitter persimmon, and chestnut farms using data envelopment analysis (DEA). And this study analyzed causes affecting management inefficiency of those farms using the two-step method. The main findings are as follows. First, as self and employment labor costs are increased, it is important to reduce labor costs which account for 60~70% of the total production cost. Second, efforts to improve management efficiency are needed as overall efficiency of farms were decreased. Third, a pesticide cost per 10a representing a level of pesticide had a negative effect or did not have a statistically significant effect on the management efficiency. This implies that expanding environment-friendly production by reducing pesticides is effective for improving the management efficiency. Fourth, as leading farms were more efficient than general farms, technology dissemination and education through leading farms are important for improving efficiency, and efforts are needed to promote exchange between leading and general farms.

• 품질경영학회지
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• 제51권3호
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• pp.363-379
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• 2023

Purpose: The main objective of this research is to construct an AI-based Composite Supplementary Index (ACSI) model to achieve accurate predictions of the Composite Index of Business Indicators. By incorporating various economic indicators as independent variables, the ACSI model enables the prediction and analysis of both the leading index (CLI) and coincident index (CCI). Methods: This study proposes an AI-based Composite Supplementary Index (ACSI) model that leverages diverse economic indicators as independent variables to forecast leading and coincident economic indicators. To evaluate the model's performance, advanced machine learning techniques including MLP, RNN, LSTM, and GRU were employed. Furthermore, the study explores the potential of employing deep learning models to train the weights associated with the independent variables that constitute the composite supplementary index. Results: The experimental results demonstrate the superior accuracy of the proposed composite supple- mentary index model in predicting leading and coincident economic indicators. Consequently, this model proves to be highly effective in forecasting economic cycles. Conclusion: In conclusion, the developed AI-based Composite Supplementary Index (ACSI) model successfully predicts the Composite Index of Business Indicators. Apart from its utility in management, economics, and investment domains, this model serves as a valuable indicator supporting policy-making and decision-making processes related to the economy.

• Kyungpook Mathematical Journal
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• 제12권1호
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• pp.129-135
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• 1972

• 드라이브 ㆍ 컨트롤
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• 제18권1호
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• pp.40-44
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• 2021

• 대한기계학회논문집B
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• 제30권2호
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• pp.126-135
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• 2006

The pressure drop characteristics in a rotating two-pass duct with rib turbulators are investigated in the present study. The square duct has a hydraulic diameter $(D_h)$ of 26.7 mm, and $1.5mm{\times}1.5mm$ square $90^{\circ}-rib$ turbulators are attached on the leading and trailing walls. The pitch-to-rib height ratio (p/e) is 10. The distance between the tip of the divider and the outer wall of the duct is $1.0D_h$ and the width of divider wall is 6.0mm or $0.225D_h$. The Reynolds number (Re) based on the hydraulic diameter is kept constant at 10,000 to exclude the Reynolds effect, and the rotation number (Ro) is varied from 0.0 to 0.20. The pressure drop distribution, the friction factor and thermal performance are presented for the leading, trailing and the outer surfaces. It is found that the curvature of the $180^{\circ}$-turn produces Dean vortices that cause high pressure drop in the turn. The channel rotation results in pressure drop discrepancy between leading and trailing surfaces so that non-dimensional pressure drops are higher on the trailing surface in the first-pass and on the leading and side surfaces in the second-pass. In the turning region, Dean vortices shown in the stationary case transform into one large asymmetric vortex cell, and subsequent pressure drop characteristics also change. As the rotation number increases, the pressure drop discrepancy enlarges.

• 통상정보연구
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• 제13권2호
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• pp.27-48
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• 2011

싱글 윈도우는 무역 촉진의 중요한 부분으로 세계 각국 특히 무역 의존도가 높은 아시아 국가들이 적극적으로 참여하고 있다. 한국은 지난 1990년대 무역자동화를 시작으로 2007년 한국형 싱글윈도우인 uTradeHub를 오픈했고 2010년에는 uTradeHub상의 전자네고시스템을 개발, 인터넷에서도 신용장 네고가 실현되었다. 특히 통관 부분에 국한된 많은 나라들의 싱글윈도우와 달리 한국의 uTraHub는 세계 최초의 웹 기반 싱글 윈도우로 바이어나 셀러를 찾는 단계에서부터 최종 결제까지 인터넷에서 이루어지는 것이 특징이다. 현재까지는 국내에서만 한해 이와 같은 싱글 윈도우서비스가 가능하지만 외국 싱글윈도우와의 연계를 통해 단절없는 싱글 윈도우 서비스를 제공한다는 목표이다. 중국은 싱글윈도우 구축에 있어서 여타 아시아 국가에 비해서 다소 늦게 출발했다. 골든게이트 프로젝트로 시작된 무역 자동화가 E-port 프로젝트를 통해서 전자 통판서비스로 이어졌다. 현재중국에서 싱글윈도우의 주체로 고려되는 대상은 전자통관시스템주체인 '차이나 E포트'와 한국의 KTNET과 유사한 CIECC, 싱글 윈도우를 운영하는 각 지방 정부 등이다. 싱글윈도우의 성공 조건인 적극적인 정부 지원, 법적 기반의 마련, 관련 기관간의 협조, 적절한 기술 조화 등을 고려했을 때 법적 기반이 다소 미흡하긴 하지만 중국은 이미 성공을 위한 요건은 대부분 갖추었다고 볼 수 있다. 중국의 싱글 윈도우를 이끄는 주체로는 경쟁 체제인 지방 정부보다는 중앙 정부의 적극적인 지원을 전제로 해서 기업인 CIECC가 진행하는 형태가 바람직할 것으로 생각한다, 특히 향후 외국 싱글윈도우와의 원활한 연계를 위해서도 기업이 비즈니스 파트너로서 나서는 것이 바람직하다고 분석되어진다.