• Korean Journal of Environmental Biology
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• v.41 no.3
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• pp.179-192
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• 2023

In this study, changes in the microbial ecosystem of the Yeongheungdo island coastal waters were investigated for five years to collect basic data. To evaluate the influence of distance from the coast on the microbial ecosystem, four sites, coastal Site (S1) and 0.75, 1.5, and 3 km away from the coast, were set up and the changes in physicochemical and biological factors were monitored. The results showed seasonal changes in water temperature, dissolved oxygen, salinity, and pH but with no significant differences between sites. For nutrients, the concentration of dissolved inorganic nitrogen increased from 6.4 μM in April-June to 16.4 μM in July-November, while that of phosphorus and silicon phosphate increased from 0.4 μM and 2.5 μM in April-June to 1.1 μM and 12.0 μM in July-November, respectively. Notably, phosphorus phosphate concentrations were lower in 2014-2015 (up to 0.2 μM) compared to 2016-2018 (up to 2.2 μM), indicating phosphorus limitation during this period. However, there were no differences in nutrients with distance from the coast, indicating that there was no effect of distance on nutrients. Phytoplankton (average 511 cells mL^-1) showed relatively high biomass (up to 3,370 cells mL^-1) in 2014-2015 when phosphorus phosphate was limited. Notably, at that time, the concentration of dissolved organic carbon was not high, with concentrations ranging from 1.1-2.3 mg L^-1. However, no significant differences in biological factors were observed between the sites. Although this study revealed that there was no disturbance of the ecosystem, further research and more basic data on the microecosystem are necessary to understand the ecosystem of the Incheon.

• Korean Journal of Heritage: History & Science
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• v.56 no.3
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• pp.158-171
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• 2023

Pottery filled with organic materials was excavated from the G-2 building site of Yongjangseong Fortress, Jingo, a relic of the Goryeo Dynasty. In this study, the characteristics of organic material were confirmed by a scientific analysis of organic material in pottery found at the palace in Yongjangseong, Jindo. In addition, it was intended to review the analysis method to identify the natural resin and to secure characteristic components(biomarkers) for each natural resin and use them as basic data in the future. The organic materials in the pottery were analyzed using attenuated total reflectance Fourier-transformed infrared spectroscopy(ATR-FTIR) and gas chromatography mass spectrometry(GC-MS). The infrared spectral characteristics were estimated to be natural resin, and biomarkers of organic materials were identified as sesquiterpene-based compounds(C₁₅H₂₄, MW 204) and derivatives. The lacquer(T.vemicifluum) is composed mainly of alkenes, alkanes, and catechol. Pine resin(P.densiflora), on the other hand, is primarily composed of diterpenoid(abietic acid, pimaric acid) and Whangchil(yellow lacquer) is identified to have sesquiterpenes(such as selinene, muurolene, calamenene) as its main components. So, the organic material in the pottery can be identified as Whangchil by comparing their compounds with modern resin materials from Dendropanax. morbifera that correspond with the results. Whangchil, which is exuded from the Dendropanax. morbifera, has been used as a natural coating materials since ancient times, and it has been confirmed that the characteristic components are well preserved even 700 years later. It can be assumed that the interior Whangchil was stored not for use as a coating, but rather for ritual purposes when the building was constructed, because the pottery was found near the cornerstone. Furthermore, based on simplified sample preparation using pyrolysis-gas chromatography mass spectrometry(Py-GC-MS), the thermal decomposition products were found to be similar to the characteristic components, suggesting that this method can be applied to the identification of natural resins used in historic artifacts.

• Journal of Korea Water Resources Association
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• v.56 no.12
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• pp.993-1003
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• 2023

Due to the increasing greenhouse gas emissions, the global mean temperature has risen by 1.1℃ compared to pre-industrial levels, and significant changes are expected in functioning of water supply systems. In this study, we assessed impacts of climate change and instreamflow management on water supply reliability in the Geum River basin, Korea. We proposed univariate climate response functions, where mean precipitation and potential evaporation were coupled as an explanatory variable, to assess impacts of climate stress on multiple water supply reliabilities. To this end, natural streamflows were generated in the 19 sub-basins with the conceptual GR6J model. Then, the simulated streamflows were input into the Water Evaluation And Planning (WEAP) model. The dynamic optimization by WEAP allowed us to assess water supply reliability against the 2020 water demand projections. Results showed that when minimizing the water shortage of the entire river basin under the 1991-2020 climate, water supply reliability was lowest in the Bocheongcheon among the sub-basins. In a scenario where the priority of instreamflow maintenance is adjusted to be the same as municipal and industrial water use, water supply reliability in the Bocheongcheon, Chogang, and Nonsancheon sub-basins significantly decreased. The stress tests with 325 sets of climate perturbations showed that water supply reliability in the three sub-basins considerably decreased under all the climate stresses, while the sub-basins connected to large infrastructures did not change significantly. When using the 2021-2050 climate projections with the stress test results, water supply reliability in the Geum River basin was expected to generally improve, but if the priority of instreamflow maintenance is increased, water shortage is expected to worsen in geographically isolated sub-basins. Here, we suggest that the climate response function can be established by a single explanatory variable to assess climate change impacts of many sub-basin's performance simultaneously.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.4
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• pp.17-30
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• 2022

The purpose of this study is to analyze the impact of the characteristics of start-up CEOs on the performance of investment attraction from the perspective of Series A investment. The results of the study are as follows. First, when the educational level of start-up CEOs was high and startup CEOs had start-up experience and investment attraction experience, venture investors such as venture capital had a significantly positive (+) effect on the investment for start-ups. This was systematically significantly positive even when control variables were introduced. When start-up CEOs had work experiences, there was no significantly positive effect on the total investment amount for start-ups but a significantly positive (+) effect on the average investment amount. Second, the standardization coefficient of total investment amount was larger in the case of start-up experience than that in the case of investment attraction experience while the standardization coefficient of average investment amount was larger in the case of investment attraction experience than that in the case of start-up experience. This suggests that the start-up experience is important for the total investment amount while the investment attraction experience is important for the average investment amount. Third, when the sales of start-ups were high at the time of Series A investment, the total investment amount and the average investment amount were also significantly high. Even if early start-ups are less profitable or have losses, the start-ups with a certain level of sales seem to be attractive investment targets for venture capital. The results of this study are useful for the investment decisions of venture capital and the financing strategies of start-ups. The implications for pre-CEOs preparing for start-ups art that the total amount of investment will increase if they have expertise through degree acquisition, challenge start-ups, gain start-up experience and implement investment attraction. Even if CEOs of start-ups do not have start-up experience, the average amount of investment for start-ups can increase if they have work experience in related industries.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.41 no.4
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• pp.8-20
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• 2023

Although the landscape architectural facilities need to be repaired according to historical and authentic techniques, the repair criteria of the standard specification for repairing cultural heritages still remain at a theoretical level, and there are little research analyzing detailed techniques from specific cases. This study discussed the repair techniques based on historical facts, around terraced flower beds, ponds, waterways and pavement in the government-managed spaces in the Joseon Dynasty. It analyzed the materials and finish of stone wall elements, the structural reinforcement and backfill materials, and topsoil surface protection measures, and drew out stones for foundation reinforcement, plastering material for agglutination, and stone processing techniques for the terraced flower beds. It examined the materials and structures of the rock revetment, foundation reinforcement and waterproofing techniques and drew out the outstanding characteristics of the foundation work, the recycle of used elements and the management of water quality, for the ponds. It primarily investigated the materials, foundation reinforcement and waterproofing techniques and discovered the repair techniques such as cover stone finishing methods, foundation and backfill materials, and flow reduction methods, for the waterways. Finally, it provided actual cases of the foundation composition, auxiliary materials and tools, and the use of cyperaceae and highlighted the existence of professional craftsmen called Bangjeonjang(方磚匠), for the pavement. This study is expected to be a staring point for discovering the repair techniques for landscape architectural facilities and used as basic data for revising specifications in the future.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.1
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• pp.13-28
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• 2022

Korean Government Budget Supports for startups have been spiked and resulted in increasing the number and scaling up Startup Accelerating managers. It have skyrocketed the strong demand for their qualified roles. However, unclear role description and gap between required role and their capability have discouraged startup manager's self-efficacy resulted in declining their full commitment and causing poor role performance. The focus of this research falls on empirical analysis to the effect of startup accelerating manager's capability characteristics on their full commitment and performance to start-up support groups. This research is expected to deliver diverse policy alternatives to build up manager's core competencies to accelerate their self-efficacy leading their full role commitments and finally pushing up policy performance. In addition, this research will found more strong literature review for the following researches in this emerging fields. This research is brought four highlighting results with respect to four research problems. First, it propose proper concept of startup accelerating manager based upon its legal entitlement. Second, it drive required core competencies of manager for successful their accountability. Third, it analyze the unique features of startup accelerating manger's capabilities against business incubation manger. Fourth, it empirically analyze in coming with government startup funding, the effect of self-efficacy including employment status, job environment, etc. on their organizational commitment and job performance. This research reveal the required unique core competencies of manger into founder sourcing ability, project managing ability, startup proving and pivoting ability, consulting ability for successful investment raising. As of this empirical research results, First, manager's ability have positively effect on their job performance, full commitment, and self-efficacy. Second, self-efficacy have a mediating effect on manager's ability, job performance, full commitment. This research derive key policy implication of requiring to build up more accelerating ability, of manager from the basics to advance level by customized and algorithm based traing program. This accelerating ability buildup program will not only surge self-efficacy of manger resulting in making full commitment and better job performance, but also devote to categorizing the unique new feature and position of manger as seed investment and supporter.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.2
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• pp.33-51
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• 2022

This study analyzes newly listed companies on KOSDAQ from 2011 to 2020 for both firms having experience in attracting venture investment before listing (VI) and those without having experience in attracting venture investment (NVI) by examining differences between two groups (VI and NVI) with respect to both the level of listing performance and that of firm performance (growth) after the listing. This paper conducts descriptive statistics, mean difference, and multiple regression analysis. Independent variables for regression models include VC investment, firm age at the time of listing, firm type, firm location, firm size, the age of VC, the level of expertise of VC, and the level of fitness of VC with investment company. Throughout this paper, results suggest that listing performance and post-listed growth are better for VI than NVI. VC investment shows a negative effect on the listing period and a positive effect on the sales growth rate. Also, the amount of VC investment has negative effects on the listing period and positive effects on the market capitalization at the time of IPO and on sales growth among growth indicators. Our evidence also implies a significantly positive effect on growth after listing for firms which belong to R&D specialized industries. In addition, it is statistically significant for several years that the firm age has a positive effect on the market capitalization growth rate. This shows that market seems to put the utmost importance on a long-term stability of management capability. Finally, among the VC characteristics such as the age of VC, the level of expertise of VC, and the level of fitness of VC with investment company, we point out that a higher market capitalization tends to be observed at the time of IPO when the level of expertise of anchor VC is high. Our paper differs from prior research in that we reexamine the venture ecosystem under the outbreak of coronavirus disease 2019 which stimulates the degradation of the business environment. In addition, we introduce more effective variables such as VC investment amount when examining the effect of firm type. It enables us to indirectly evaluate the validity of technology exception policy. Although our findings suggest that related policies such as the technology special listing system or the injection of funds into the venture ecosystem are still helpful, those related systems should be updated in a more timely fashion in order to support growth power of firms due to the rapid technological development. Furthermore, industry specialization is essential to achieve regional development, and the growth of the recovery market is also urgent.

• Health Policy and Management
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• v.34 no.1
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• pp.78-86
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• 2024

Background: The purpose of this study was to determine the effectiveness of the specialty hospital system by comparing the medical use of inpatients who had artificial joint replacement surgery in specialty hospitals and non-specialty hospitals. Methods: This study utilized 2021-2022 healthcare benefit claims data provided by the Health Insurance Review and Assessment Service. The dependent variable is inpatient medical use which is measured in terms of charges per case and length of stay. The independent variable was whether the hospital was designated as a specialty hospital, and the control variables were patient-level variables (age, gender, insurer type, surgery type, and Charlson comorbidity index) and medical institution-level variables (establishment type, classification, location, number of orthopedic surgeons, and number of nurses). Results: The results of the multiple regression analysis between charges per case and whether a hospital is designated as a specialty hospital showed a statistically significant negative relationship between charges per case and whether a hospital is designated as a specialty hospital. This suggests a significant low in charges per case when a hospital is designated as a specialty hospital compared to a non-specialty hospital, indicating that there is a difference in medical use outcomes between specialty hospitals and non-specialty hospitals inpatients. Conclusion: The practical implications of this study are as follows. First, the criteria for designating specialty hospitals should be alleviated. In our study, the results show that specialty hospitals have significantly lower per-case costs than non-specialty hospitals. Despite the cost-effectiveness of specialty hospitals, the high barriers to be designated for specialty hospitals have gathered the specialty hospitals in metropolitan and major cities. To address the regional imbalance of specialty hospitals, it is believed that ease the criteria for designating specialty hospitals in non-metropolitan areas, such as introducing "semi-specialty hospitals (tentative name)," will lead to a reduction in health disparities between regions and reduce medical costs. Second, it is necessary to determine the appropriateness of the size of hospitals' medical staff. The study found that the number of orthopedic surgeons and nurses varied in charges per case. Therefore, it is believed that appropriately allocating hospital medical staff can maximize the cost-effectiveness of medical services and ultimately reduce medical costs.

• Korean Journal of Heritage: History & Science
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• v.57 no.2
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• pp.6-25
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• 2024

This study concentrated on a report on the results of smelting experiments conducted eight times by the Jungwon National Research Institute of Cultural Heritage, put together the goals and results of the operation, and examined changes in the content of experiments and in the experimental results. First, changes related to operation, such as the ratio of raw materials to fuel and the presence or absence of additives, were reviewed depending on the operation goal. In addition, the results of metallurgical analysis of raw materials, formations, and byproducts were summarized and reviewed by comparing them with materials excavated from the ruins. The operation method varied up to the eighth smelting experiment in terms of iron ore roasting, additives, and raw material/fuel ratio. After reviewing the results again, pure iron with a low carbon content began to be confirmed through metallurgical analysis. As a result, it was confirmed that the charging ratio of raw materials and fuel plays an important role depending on the purpose of production. In addition, most of the products are gray cast iron, and it was deemed that this is due to changes in the internal structure of the pig iron while it was left in the furnace for a long time. The iron was an ingot that was in a molten state even though the carbon content did not reach 4.3%, where the process reaction takes place, and it was deemed to have been caused by excessive operating temperature. Based on the previously reviewed results and the structure and shape of the experimental furnace used in other ironmaking technology restoration experiments, this study finally attempted to restore the structure of an ancient iron smelting furnace, including the furnace's upper structure. By comprehensively referring to the remaining conditions of the excavated iron smelting furnace and the characteristics of the blow pipe, the form of the ancient iron smelting furnace was subdivided into six categories: furnace wall thickness, furnace height, blower height, blow pipe size, furnace inner wall shape, and top shape, and a restoration plan was proposed. To improve the problems of the restoration plan and the Jungwon National Research Institute of Cultural Heritage's experiments that have been conducted through continuous trial and error, an experiment that reflects changes in operating methods by lowering the furnace height and controlling the blowing volume is necessary.

• Health Policy and Management
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• v.34 no.2
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• pp.185-195
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• 2024

Background: Disabled people have particularly restricted access to health care. In response to this, the pilot project for the general physician (GP) system for disabled people was implemented in 2018, based on the rights of people with disability to the Health Act in South Korea. However, its participants were 0.2% among the total of those with severe disabilities in 2021. Therefore, this study examined the factors related to registering with a GP and the access level to its services to suggest implications for activating the participation of disabled people. Methods: We analyzed factors affecting the registration with a GP and the number of using the services among the participants of the GP system during May 2018 and December 2021 by conducting hierarchical logistic regression and hierarchical regression. The data were linked with the national health insurance data to examine various predictors, including disability types, socioeconomic status, health status, and GP registration. Results: As a result of analyzing the factors affecting whether or not to register for the pilot project, those with disabilities (physical disabilities, brain lesions, visual, intellectual, mental, and autistic disability) eligible for disability care (odds ratio [OR], 4.157) than other disability, and those living in metropolitan (OR, 4.330) or cities (OR, 3.332) than rural residences were highly likely to enroll the pilot study. Health-related variables also predicted the registration status of the pilot project. The predictors related to GP enrollment types (membership type: general health or disability care, GP's affiliation: clinics or hospitals) significantly influenced levels of access to services. Conclusion: It is necessary to develop the GP project for disabled people by considering the variation in types of disability, residences, and health. Further study will be needed to investigate the impact of GPs on the level of participation among disabled people.