• Journal of Life Science
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• v.34 no.2
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• pp.128-137
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• 2024

This review discusses the pivotal role of vascular endothelial growth factors (VEGF) in angiogenesis and lymphangiogenesis, vital processes influencing vascular permeability, endothelial cell recruitment, and the maintenance of tumor-associated blood and lymphatic vessels. VEGF exerts its effects through tyrosine-kinase receptors, VEGFR-1, VEGFR-2, and VEGFR-3. This VEGF-VEGFR system is central not only to cancer but also to diseases arising from abnormal blood vessel and lymphatic vessel formation. In the context of cancer, VEGF and its receptors are essential for the development of tumor-associated vessels, making them attractive targets for therapeutic intervention. Various approaches, such as anti-VEGF antibodies, receptor antagonists, and VEGF receptor function inhibitors, are being explored to interfere with tumor growth. However, the clinical efficacy of anti-angiogenic agents remains uncertain and necessitates further refinement. The article also highlights the physiological role of VEGFs, emphasizing their involvement in endothelial cell functions, survival, and vascular permeability. The identification of five distinct VEGFs in humans (VEGF-A, VEGF-B, VEGF-C, VEGF-D, and PLGF) is discussed, along with the classification of VEGFRs as typical receptor tyrosine kinases with distinct signaling systems. The family includes VEGFR-1 and VEGFR-2, crucial in tumor biology and angiogenesis, and VEGFR-3, specifically involved in lymphangiogenesis. Overall, this review has provided a comprehensive overview of VEGF and VEGFR, detailing their roles in various diseases, including cancer. This is expected to further facilitate the utilization of VEGF and VEGFR as therapeutic targets.

• Journal of Venture Innovation
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• v.7 no.1
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• pp.201-223
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• 2024

This study undertook an empirical analysis to examine the impact of various factors on entrepreneurial intention among young people, with a particular focus on the role of startup mentoring. Employing a survey distributed nationwide, data from 250 valid respondents were subjected to structural equation modeling to investigate these dynamics. The analysis uncovered that workplace stress, subjective norms, and perceived behavioral control positively influence the entrepreneurial intentions of youth. Meanwhile, technological constraints negatively affected these intentions. The study did not explore the potential effects of future uncertainty and the burden of failure. Significantly, it was found that startup mentoring plays a crucial role in mitigating the negative impacts that may deter young individuals from pursuing entrepreneurship. Mentoring was instrumental in reducing negative influences, thereby fostering a more conducive environment for entrepreneurial ambition. By integrating the Push-Pull-Mooring (PPM) and Theory of Planned Behavior (TPB) models, this research not only validates these frameworks within the context of youth entrepreneurship but also underscores the essential function of startup mentoring in enhancing entrepreneurial intentions. The insights from this study highlight the importance of mentoring programs in nurturing the entrepreneurial spirit among the youth, suggesting that targeted mentoring support can play a pivotal role in overcoming barriers to entrepreneurship.

• The Journal of the Acoustical Society of Korea
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• v.43 no.3
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• pp.314-323
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• 2024

Recently, a score-penalty method has been used for the acoustic passive tracking of marine mammals. The interesting aspect of this technique lies in the loss function, which has a penalty term representing the mismatch between the measured signal and the modeled signal, while the traditional time-domain matched-field processing is positively considering the match between them. In this study, we apply the score-penalty method into the depth estimation of a passive target with a known source waveform. Assuming deep ocean environments with uncertainties in the sound speed profile, we evaluate the score-penalty method, comparing it with the time-domain matched field processing method. We shows that the score-penalty method is more accurate than the time-domain matched field processing method in the ocean environment with weak mismatch of sound speed profile, and has better efficiency. However, in the ocean enviroment with strong mismatch of the sound speed profile, the score-penalty method also fails in the depth estimation of a target, similar to the time-domain matched-field processing method.

• Analyses & Alternatives
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• v.8 no.2
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• pp.87-115
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• 2024

This study examines the effect of R&D investment on firm performance and value of Chinese private firms. Through R&D investment, firms aim to acquire knowledge and technological resources to create innovation and competitive advantage, which ultimately enhances firm performance and value. However, unlike other investments, R&D investments are characterized by high adjustment costs and risks, uncertainty and asymmetric information. In addition, the effect of R&D investment on firm performance and value has been shown to be mixed results due to various internal and external contextual factors. Therefore, this study intends to consider how the ESG activities of firms, which have recently attracted attention, act as a contextual factor in the results of R&D investment. This is because interaction with stakeholders through ESG activities is considered to be an important factor in securing competitive advantages and sustainable growth. In this context, this study measures the effect of a firm's R&D investment on its business performance by dividing it into financial performance and value, respectively, and examines the moderating effect of ESG score on the relationship. Based on empirical analysis of all Chinese private firms from 2010 to 2019, the results show that a firm's R&D investment has a negative impact on performance and a positive impact on value. Furthermore, a high ESG score of private firms positively moderates each relationship, emphasizing the importance of ESG activities.

• Journal of Korea Port Economic Association
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• v.39 no.4
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• pp.205-222
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• 2023

This study examines the impact of the changes to the port logistics before and after the COVID-19 pandemic. Specifically, the study focuses on analyzing the changes to Korea's container ports network. Furthermore, this study examines the influence of the ports in the container port network before and after the COVID-19 Pandemic using the network analysis method such as centrality indexes (degree centrality, closeness centrality, and betweenness centrality) to identify changes in the structure and properties of the networks between 2018 and 2021. In this study, We analyzes the changes in the container port networks of Busan, Gwangyang, Incheon, Ulsan, and Pyeongtaek-Dangjin, the five largest ports in Korea. As a result, in case of the Busan port, Singapore port plays an important role, while Busan port plays key roles in ports of Gwangyang, Incheon, and Ulsan. In case of the Gwangyang port, Port Kelang in Malaysia has become increasingly influential as a result of the Malaysian government's policies to overcome the pandemic. In the Incheon port, Japanese ports are playing intermediary roles between their ports and those in the Incheon port network. In the case of Ulsan port, the influence of Korean ports is high, and in the case of Pyeongtaek-Dangjin port, Southeast Asian ports play a role as intermediaries between ports. By analyzing the changes in Korea's port logistics networks, this study can be used as a reference point when responding to uncertainty situations that cause changes to port logistics, such as the COVID-19 pandemic, in the future.

• Journal of Korea Port Economic Association
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• v.39 no.4
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• pp.243-254
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• 2023

This study investigates the factors contributing to price fluctuations in the shipscrapping market, the final stage in a vessel's life cycle. Shipping companies make decisions on ship dismantling based on factors such as declining freight rates, increasing vessel age leading to higher costs, or compliance with new environmental regulations. Utilizing the FMOLS (Fully Modified Ordinary Least Squares) and VECM (Vector Error Correction Model) methodologies, the research explores the long-term elasticities of factors influencing shipscrapping prices and examines short-term causal relationships. Using a time series dataset spanning from December 2015 to April 2023, covering a total of 90 months, the study focuses on the shipscrapping prices of Capesize vessels in India and Bangladesh, which constitute a significant portion of the shipbreaking market. The findings indicate that, in the long term, shipscrapping prices are closely related to global scrap prices, 20-year-old secondhand Capesize vessel prices, newbuilding prices, and exchange rates. In terms of short-term causal relationships, an increase in global scrap prices induces a rise in shipscrapping prices, while the remaining variables do not contribute to such increases. Specifically, an escalation in shipscrapping prices is associated with increased prices of 20-year-old secondhand vessels, newbuilding prices, and exchange rates. However, the other variables do not show a significant influence on short-term increases in shipscrapping prices.

• The Journal of Bigdata
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• v.9 no.1
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• pp.31-47
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• 2024

With the advancement of artificial intelligence, the travel and hospitality industry is also adopting AI and machine learning technologies for various purposes. In the tourism industry, demand forecasting is recognized as a very important factor, as it directly impacts service efficiency and revenue maximization. Demand forecasting requires the consideration of time-varying data flows, which is why statistical techniques and machine learning models are used. In recent years, variations and integration of existing models have been studied to account for the diversity of demand forecasting data and the complexity of the natural world, which have been reported to improve forecasting performance concerning uncertainty and variability. This study also proposes a new model that integrates various machine-learning approaches to improve the accuracy of hotel sales demand forecasting. Specifically, this study proposes a new time series forecasting model based on XGBoost that selectively utilizes a local model by clustering with DTW K-means and a global model using the entire data to improve forecasting performance. The hotel demand forecasting model that selectively utilizes global and regional models proposed in this study is expected to impact the growth of the hotel and travel industry positively and can be applied to forecasting in other business fields in the future.

• Journal of The Korean Association For Science Education
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• v.44 no.4
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• pp.343-360
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• 2024

The purpose of this study is to analyze the difficulties with scientific research faced by leading Korean scientists and suggest implications for science education. Data were collected through semi-structured interviews with 13 leading Korean scientists and were qualitatively analyzed using constructivist grounded theory. The results of the study showed that the leading scientists encountered 11 subcategories of difficulties, which were grouped into three main categories: uncharted territory, unexpected situations, and a lack of resources in domestic research environments. 'Uncharted territory' comprised anxiety due to uncertainty about research performance, insufficient knowledge accumulation in the field of research, and the burden of maintaining research influence as an academic leader. 'Unexpected situations' included encountering new phenomena that cannot be explained by existing theories, an inability to utilize research results, and repeated failures. 'A lack of resources in domestic research environments' included inadequate research funding support systems, a shortage of expert networks, limitations on employment and career opportunities for students, poor research equipment, and insufficient support policies for retired researchers. This study provides science educators with implications for the direction of science education and R&E. For students, it can serve as career education material, their attitudes towards science and their understanding of its nature. Lastly, the study may contribute to finding ways to improve scientific research policies and to developing a culture that fosters expertise in science.

• Korean Journal of Remote Sensing
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• v.40 no.4
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• pp.377-385
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• 2024

We investigated the effect of spectral fitting wavelength interval variations and selection of absorption cross-section on the sulfur dioxide slant column density (SCD) retrievals from the scattered sunlight observation using a UV-Vis hyperspectral instrument. The sulfur dioxide slant column densities were retrieved from the combinations of multiple spectral fitting intervals and absorption cross-sections. The observation was carried out at the site 0.53 km away from a combustion site located in Gimhae from December 1, 2023, to January 23, 2024. The radiances were obtained on the line of measurement sight toward the stack of the combustion facility. The best spectral fitting intervals were found to be from 305.7 to 321.1 nm. In terms of the absorption cross-section dependency, the SO₂ (293 K), O₃ (223 K, 243 K) show the best spectral fitting for the observed radiances with both the smallest fitting residual and SCD error. The effects of the fitting interval and cross sections found in this study can be useful information for improving SO₂ retrievals based on UV hyperspectral measurements.

• Journal of Service Research and Studies
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• v.14 no.3
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• pp.79-101
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• 2024

This study aims to investigate the impact of hotel marketing agility on employee job crafting and service innovative behavior in the context of the uncertainties faced by the Korean hotel industry amidst a rapidly changing business environment. In the post-COVID era, hotel companies need to quickly detect market trends and respond flexibly to secure a competitive advantage and promote sustainable growth. Given the high proportion of face-to-face services in the hotel industry, marketing agility is emerging as a core competency to effectively cope with changing customer demands and market dynamics. However, an organization's agile marketing capabilities only take on true meaning when frontline employees voluntarily redesign their jobs and lead service process innovations. In this regard, job crafting, which refers to employees' active redefinition and modification of their job boundaries, can serve as a link between organizational agility and individual innovative behavior. By empirically analyzing the structural relationship between marketing agility, job crafting, and service innovative behavior in the hotel context, this study applies the concept of agility to the field of human resource management and provides new insights into the antecedents and outcomes of job crafting. The results show that hotel responsiveness has a significant positive impact on all three dimensions of job crafting. In the case of speed and flexibility, they had a significant positive effect on task and relational crafting, but the effect of speed on cognitive crafting was not significant. The implications of the study suggest that hotels' rapid decision-making and execution may actually constrain employees' cognitive crafting activities, such as reflecting on and reinterpreting the meaning and identity of their work. Furthermore, it is expected to provide meaningful insights for hotel managers facing environmental upheavals to seek practical measures to enhance agility and innovativeness.