• Tunnel and Underground Space
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• v.33 no.5
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• pp.414-424
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• 2023

In this study, a total of 326 data on a variety of geometric parameters of pick cutters and the corresponding cuttable rock conditions were collected and built as a database. Statistical analysis of the database showed that there is a significant positive correlation between the parameters that define the geometry of a pick cutter, especially between the parameters related to the length of a pick cutter and the geometry of a tungsten carbide insert. The diameter of a pick cutter shaft was also strongly correlated with the geometry of the inserts. On the other hand, it was difficult to find a clear correlation between the parameters for the rock conditions defined by the four conditions and the geometric parameters of pick cutters, which may be due to the uncertainty of the rock mass and the fact that the application of a pick cutter is presented as a range rather than a numerical single value. However, the mean values of geometric parameters of pick cutters tend to increase as a rock mass becomes harder. However, the pick length parameters are found to decrease as a rock mass becomes harder, which may be a way to reduce the moments that can occur when using long pick cutters in a hard rock condition.

• The Journal of the Convergence on Culture Technology
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• v.9 no.5
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• pp.935-940
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• 2023

Digital-twin technology is emerging as an innovative solution for all industries, including manufacturing and production lines. Therefore, this paper optimizes all the energy used in a biomass plant based on unused resources. We will then implement a digital-twin prototype for biomass plants and evaluate its performance in order to improve the efficiency of plant operations. The proposed digital-twin prototype applies a standard communication platform between the framework and the gateway and is implemented to enable real-time collaboration. and, define the message sequence between the client server and the gateway. Therefore, an interface is implemented to enable communication with the host server. In order to verify the performance of the proposed prototype, we set up a virtual environment to collect data from the server and perform a data collection evaluation. As a result, it was confirmed that the proposed framework can contribute to energy optimization and improvement of operational efficiency when applied to biomass plants.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.1
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• pp.63-77
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• 2022

The importance of start-ups and venture companies in the Korean economy is growing. However, the successful growth of startups and venture companies are still challenging as 70% of startups fail within 5 years. A new perspective on innovation is essential to overcome the liability of newness and the liability of smallness in the existing market and obtain the competitive advantage. Recent phenomenon in the Korean startups ecosystem is the remarkable growth of unicorns and future unicorns. Their business models, types of business, and success cases serve as a good example. Neverthless, the process of unicorn and future unicorn startups making new industries and innovative business has poorly understood. In this paper, we first define 175 unicorns and future unicorn startups participating in the K-unicorn project as a unicorn group and analyze current trends of the group. Then the in-depth analyses of industry sectors are conducted. Specifically, focusing on the unicorn forming the new market, we examine the unicorn making the processes of industry category innovation through the business innovation model. Lastly, broadening the scope of the analysis to the unicorn group, policy implications in startups and venture ecosystem are suggested.

• Journal of Korean Society of Forest Science
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• v.113 no.2
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• pp.239-258
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• 2024

In the face of complex crises such as a shrinking society, regional imbalance, and climate change, there is a need to seek sustainable development in local communities. In the forest sector, attempts are being made to link forest resources with local industries. However, the current support system, which is centered on the central government, has limitations in achieving sustainable forest management. On the other hand, the international community is actively promoting a shift in systems by introducing the concept of local forestry, which emphasizes local initiatives to achieve sustainable forest management. However, in the Republic of Korea, the concept of local forestry is still unclear, which hinders the promotion of a paradigm shift. In this paper, we applied the Delphi technique to conduct three surveys of 29 academics, administrators, and field experts in the Republic of Korea. The aim was to define the concept of local forestry that is suitable for domestic conditions and identify institutional measures to establish and revitalize it. The results showed that local forestry can be defined as a broad concept that is both consultative and systemic in nature and that an institutional approach that supports actors and their activities is necessary to revitalize local forestry.

• Journal of The Korean Association For Science Education
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• v.28 no.4
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• pp.316-330
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• 2008

During the past two decades or so, science (or scientific or scientific & technological) culture has become one of the main themes not only of policy makers but also of science educators. Although, the idea of science culture has been taken as a desirable goal, there is little agreement about what it means and how to measure it. Particularly in Korea, there has been a rapid growth of science culture projects and programs, either by governmental or non-governmental, but with little systemic monitoring and evaluation for its practice. The purpose of this study is, thus, to explore a model of measuring science culture and develop a comprehensive indicator system for it. We reviewed many literatures on definitions of science culture and the surveys for related terms, particularly, of recent national and international surveys (e.g. US Science and Engineering Indicators, Eurobarometer, Japanese Science and Technology Indicators). Based on this review, a model for science culture is proposed and then used to define the Science Culture Indicators (SCI). This model encompasses two dimensions(i.e. individual and social), which are further divided into two aspects (i.e. potential and practice). Each dimension is expected to represent citizen literacy of and national infrastructure of science culture respectively. Each category in this $2{\times}2$ matrix is further divided into several sub-categories. The discussion concerning how the model and the indicators can be used to check the states of science culture at social as well as individual levels will be given with some concrete examples, such as indicators particularly related to science education.

• Journal of The Korean Association For Science Education
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• v.27 no.1
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• pp.70-83
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• 2007

Reflection in teacher education is one reform effort that has taken hold in many teacher preparation programs. However, how to define it and how to foster it in a teacher's education are problematic issues. In this study, on the basis of literature review, science teachers' reflective thinking is defined as a process of thinking that deliberates on alternatives to solve conflict between one's previous knowledge/belief/practice and internal/external factors in science teaching context. Based on this definition, three types of science teachers' reflective thinking (i.e. technical reflection, professional reflection and critical reflection) were proposed. In addition, a framework of classifying the reflective thinking's types was also developed. To investigate science teachers' reflective thinking, two pre-service science teachers who majored in physics education participated in this study. The participants presented the monthly report on reflective practice, pre/post questionnaire, and education practicum journals. Individual interviews with them were conducted before and after their teaching activities. From the analysis of the data, it was possible to categorize the reflective thinking of the participants into three types. The major type of their reflective thinking was the technical reflection. However, it was difficult to find examples of the critical reflection.

• Journal of Korean Elementary Science Education
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• v.43 no.2
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• pp.233-251
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• 2024

Meaningful learning occurs through an active process of engaging with the content in a lively interaction between teacher and student. In this study, we explored teachers' learning, challenges, and changes as they learned and practiced responsive teaching (RT), a practice that supports students to put their ideas at the center of their lessons. As a result, we found that teachers initially embraced RT from different perspectives and struggled to implement it in ways they understood. We then explored RT more deeply by focusing on the case of a teacher who was teaching science herself, and found that her experience was both rewarding and confusing. However, by the end of the learning process, the teachers were able to define RT in their own ways, which strengthened their commitment to implementing RT in elementary science education. Based on this teacher learning process, it was suggested that teachers should be viewed as curriculum experts, that they should learn and explore collaboratively through a community of teachers, and that they should be researchers who continue to explore various practices in the field.

• Journal of Wetlands Research
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• v.26 no.1
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• pp.82-91
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• 2024

In this study, research cases related to blue carbon storage were collected and analyzed, and various definitions of blue carbon were considered in terms of spatiotemporal scope and scientific aspect. 444 papers were selected as research cases related to blue carbon storage, and analysis of the number of papers published by year/country and keywords was performed. Publication of papers related to blue carbon storage has continued to increase since 2011, and more than 50 papers have been published annually since 2018. The most publications by country were in Australia with more than 100 papers, and the United States and China also published more than 60 papers. Key terms related to "natural environment" and "storage characteristics" were analyzed in the sentences defined in the 23 papers that presented the definition of blue carbon. The natural environments where blue carbon was stored were mostly mangroves, salt marshes, and seagrass beds, and blue carbon repository included sediments and even plants themselves. The existing definition of blue carbon focused on the vegetation environment as the storage environment for blue carbon. However, since blue carbon is stored in the sediments of coastal wetlands, it would be appropriate to define the coastal ecosystem, including non-vegetated mudflats, as the storage environment for blue carbon.

• The Journal of the Acoustical Society of Korea
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• v.28 no.2
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• pp.155-163
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• 2009

In text-to-speech systems, the conversion of text into prosodic parameters is necessarily composed of three steps. These are the placement of prosodic boundaries. the determination of segmental durations, and the specification of fundamental frequency contours. Prosodic boundaries. as the most important and basic parameter. affect the estimation of durations and fundamental frequency. Break prediction is an important step in text-to-speech systems as break indices (BIs) have a great influence on how to correctly represent prosodic phrase boundaries, However. an accurate prediction is difficult since BIs are often chosen according to the meaning of a sentence or the reading style of the speaker. In Japanese, the prediction of an accentual phrase boundary (APB) and major phrase boundary (MPB) is particularly difficult. Thus, this paper presents a method to complement the prediction errors of an APB and MPB. First, we define a subtle BI in which it is difficult to decide between an APB and MPB clearly as a variable break (VB), and an explicit BI as a fixed break (FB). The VB is chosen using the classification and regression tree, and multiple prosodic targets in relation to the pith and duration are then generated. Finally. unit-selection is conducted using multiple prosodic targets. In the MOS test result. the original speech scored a 4,99. while proposed method scored a 4.25 and conventional method scored a 4.01. The experimental results show that the proposed method improves the naturalness of synthesized speech.

• IMMUNE NETWORK
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• v.23 no.2
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• pp.17.1-17.16
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• 2023

Latent membrane protein 2A (LMP2A), a latent Ag commonly expressed in Epstein-Barr virus (EBV)-infected host cells, is a target for adoptive T cell therapy in EBV-associated malignancies. To define whether individual human leukocyte antigen (HLA) allotypes are used preferentially in EBV-specific T lymphocyte responses, LMP2A-specific CD8⁺ and CD4⁺ T cell responses in 50 healthy donors were analyzed by ELISPOT assay using artificial Ag-presenting cells expressing a single allotype. CD8⁺ T cell responses were significantly higher than CD4⁺ T cell responses. CD8⁺ T cell responses were ranked from highest to lowest in the order HLA-A, HLA-B, and HLA-C loci, and CD4⁺ T cell responses were ranked in the order HLA-DR, HLA-DP, and HLA-DQ loci. Among the 32 HLA class I and 56 HLA class II allotypes, 6 HLA-A, 7 HLA-B, 5 HLA-C, 10 HLA-DR, 2 HLA-DQ, and 2 HLA-DP allotypes showed T cell responses higher than 50 spot-forming cells (SFCs)/5×105 CD8⁺ or CD4⁺ T cells. Twenty-nine donors (58%) showed a high T cell response to at least one allotype of HLA class I or class II, and 4 donors (8%) had a high response to both HLA class I and class II allotypes. Interestingly, we observed an inverse correlation between the proportion of LMP2A-specific T cell responses and the frequency of HLA class I and II allotypes. These data demonstrate the allele dominance of LMP2A-specific T cell responses among HLA allotypes and their intra-individual dominance in response to only a few allotypes in an individual, which may provide useful information for genetic, pathogenic, and immunotherapeutic approaches to EBV-associated diseases.