• Korean Journal of Animal Reproduction
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• v.23 no.2
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• pp.141-148
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• 1999

This study was to test whether the viability of bovine hatched blastocysts (HBs) can be maintained after vitrification and thawing. The HBs were produced in vitro at Day 9 and Day 10 after IVF, and they were classified to small (S-HBs; ø$\leq$300 ${\mu}{\textrm}{m}$) and large(L-HBs; ø＞300 ${\mu}{\textrm}{m}$) on the basis of embryo diameter using eyepiece micrometer. As freezing solution, we used EFS35 which consisted of 35% ethylene glycol (EG), 18% ficoll, 0.3 M sucrose and 10% FBS added in mDPBS. Vitrification was taken by two-step method, the HBs were equilibrated in 10% EG for 5 minutes and then shortly exposed in EFS35 and plunged into L$N_2$for 30~45 sec. After thawing, the survival rates were assessed by the re-expansion of the blastocoel during 2 h and 16 h of culture. The results obtained in these experiments were summarized as follows; 1) When the blastocysts(40.8%) recovered at Day 8 after IVF were further cultured for 24 h(Day 9 after IVF) and 48 h(Day 10 after IVF), the rates of HBs were 20.5% and 6.7%, respectively. Also, the total cell number of HBs on Day 9 was significantly higher than that of HBs on Day 10 (p＜0.01). 2) When the effects of freezing solution to the survival of Day 9 L-HBs were examined, the rate of vitrified group (75.7%) was significantly lower than 100% of control and exposed group(p＜0.05). 3) When the survival rates of vitrified HBs according to size and developmental age were examined, the data of L-HBs (75.5%) and S-HBs(63.6%) on Day 9 were slightly higher than those of L-HBs(64.3%) and S-HBs(60.7%) on Day 10. 4) Also, when the in vitro survival of Day 9 HBs was evaluated under different culture condition after thawing, the result in culture medium only (79.3%) was significantly higher than 43.2% in co-culture group (p＜0.05). These results demonstrated that bovine HBs can be successfully cryopreserved by two-step vitrification method using EFS35.

• Journal of Bio-Environment Control
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• v.32 no.2
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• pp.165-171
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• 2023

Potato dry rot is one of the potato storage diseases caused by Fusarium species and is a representative pathological disorder that induced post-harvest loss during storage. Chlorpropham treatment for sprouting inhibition is mainly used for room temperature storage of potatoes for processing. In this study, the inhibitory effect of chlorpropham on Fusarium-induced dry rot of potato 'Dano'. To investigate the mycelial growth rate of the dry rot fungus (Fusarium solani Appel & Wollenw), mycelial growth was investigated in a chlorpropham (5.0, 50.4, 503.8, and 5,038 ppm) and prochloraz (0.1, 1.0, 10.0, and 100.0 ppm) medium containing F. oxysporum mycelia. Mycelia were more inhibited as the concentration of chlorpropham and prochloraz increased during incubation at 20℃, and the inhibition rate was 98.2% and 100% when treated with 503.8 ppm of chlorpropham and 10ppm of prochloraz in 14 days, respectively. Potato Dano tubers inoculated with F. oxysporum were dipped in chlorpropham (5.0, 50.4, and 503.8 ppm) and prochloraz (100 ppm) to investigate the effect of preventing dry rot during cold storage at 20℃ and 4℃ in vivo. The disease diameter of potatoes stored at room temperature (about 20℃) was reduced to 13.0 mm in the prochloraz 100 ppm teatment, and 10.7 mm in the chlorpropham 50.4 ppm treatment compared to 13.7 mm in the control tuber at 70 days of storage. The disease progression in all treatments including control was similar with no statistically significant difference at 4℃ air temperature. From the results of this study, it is considered that treatment with 50.4 ppm of chlorpropham after harvest will be useful for suppressing dry rot of stored potatoes.

• Knowledge Management Research
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• v.23 no.4
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• pp.315-338
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• 2022

In 1986, Korea established legal systems to support small and medium-sized start-ups, which becomes the main pillars of national development. The legal systems have stimulated start-up ecosystems to have more than 1 million new start-up companies founded every year during the past 30 years. To analyze the trend of Korea's start-up ecosystem, in this study, we collected 1.18 million news articles from 1991 to 2020. Then, we extracted news articles that have the keywords "start-up", "venture", and "start-up". We employed network analysis and topic modeling to analyze collected news articles. Our analysis can contribute to analyzing the government policy direction shown in the history of start-up support policy. Specifically, our analysis identifies the dynamic characteristics of government influenced by external environmental factors (e.g., society, economy, and culture). The results of our analysis suggest that the start-up ecosystems in Korea have changed and developed mainly by the government policies for corporation governance, industrial development planning, deregulation, and economic prosperity plan. Our frequency keyword analysis contributes to understanding entrepreneurial productivity attributed to activities among the networked components in industrial ecosystems. Our analyses and results provide practitioners and researchers with practical and academic implications that can help to establish dedicated support policies through forecast tasks of the economic environment surrounding the start-ups. Korean entrepreneurial productivity has been empowered by growing numbers of large companies in the mobile phone industry. The spectrum of large companies incorporates content startups, platform providers, online shopping malls, and youth-oriented start-ups. In addition, economic situational factors contribute to the growth of Korean entrepreneurial productivity the economic, which are related to the global expansions of the mobile industry, and government efforts to foster start-ups. Our research is methodologically implicative. We employ natural language processes for 30 years of media articles, which enables more rigorous analysis compared to the existing studies which only observe changes in government and policy based on a qualitative manner.

• Korean Journal of Animal Reproduction
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• v.23 no.4
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• pp.337-345
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• 1999

The present study was conducted to investigate the effects of various co-culture systems and supplemented protein sources on the in vitro development of bovine IVF embryos. Bovine cumulus oocyte complexes (COCs) were matured and fertilized in vitro. Presumptive zygotes with cumulus cells were transferred to TCM-199 or CRlaa containing 10% FBS or 3mg/$m\ell$ BSA, and cultured for 36~40 hr. After primary culture, cleaved embryos were co-cultured with cumulus cells(CC), bovine oviduct epithelial cells(BOEC) or Buffalo rat liver cells (BRLC) in TCM-199 or CRlaa supplemented with FBS or BSA respectively, for further 6 days. Cleavage rate increased with BSA(P＜0.01) in the both TCM-199(79%) or CRlaa(74%) When embryos were co-cultured with CC or BOEC in TCM-199, blastocyst development was enhanced with BSA(40% and 43%) compared to FBS (22% and 29%) , whereas in CRlaa no difference observed between BSA(40% and 39%) and FBS (40% and 42%). When embryos were co-cultured with BRLC monolayer, FBS enhanced the blastocyst development (P＜0.05) compared to BSA in both TCM-199(41% vs 31%) and CRlaa (44% vs 37%). The result of the present study showed that the cleavage rate of bovine IVF embryos increased with BSA, The result also showed that BSA can enhance the development of IVF embryos in co-culture with CC or BOEC in TCM-199, suggesting the in vitro development is affected by the medium and supplemented protein sources in co-culture with somatic cells.

• Journal of Intelligence and Information Systems
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• v.28 no.1
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• pp.69-88
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• 2022

One of the characteristics of South Korea's economic structure is that it is highly dependent on exports. Thus, many businesses are closely related to the global economy and diplomatic situation. In addition, small and medium-sized enterprises(SMEs) specialized in exporting are struggling due to the spread of COVID-19. Therefore, this study aimed to develop a model to forecast exports for next year to support SMEs' export strategy and decision making. Also, this study proposed a strategy to recommend promising export countries of each item based on the forecasting model. We analyzed important variables used in previous studies such as country-specific, item-specific, and macro-economic variables and collected those variables to train our prediction model. Next, through the exploratory data analysis(EDA) it was found that exports, which is a target variable, have a highly skewed distribution. To deal with this issue and improve predictive performance, we suggest a separated learning method. In a separated learning method, the whole dataset is divided into homogeneous subgroups and a prediction algorithm is applied to each group. Thus, characteristics of each group can be more precisely trained using different input variables and algorithms. In this study, we divided the dataset into five subgroups based on the exports to decrease skewness of the target variable. After the separation, we found that each group has different characteristics in countries and goods. For example, In Group 1, most of the exporting countries are developing countries and the majority of exporting goods are low value products such as glass and prints. On the other hand, major exporting countries of South Korea such as China, USA, and Vietnam are included in Group 4 and Group 5 and most exporting goods in these groups are high value products. Then we used LightGBM(LGBM) and Exponential Moving Average(EMA) for prediction. Considering the characteristics of each group, models were built using LGBM for Group 1 to 4 and EMA for Group 5. To evaluate the performance of the model, we compare different model structures and algorithms. As a result, it was found that the separated learning model had best performance compared to other models. After the model was built, we also provided variable importance of each group using SHAP-value to add explainability of our model. Based on the prediction model, we proposed a second-stage recommendation strategy for potential export countries. In the first phase, BCG matrix was used to find Star and Question Mark markets that are expected to grow rapidly. In the second phase, we calculated scores for each country and recommendations were made according to ranking. Using this recommendation framework, potential export countries were selected and information about those countries for each item was presented. There are several implications of this study. First of all, most of the preceding studies have conducted research on the specific situation or country. However, this study use various variables and develops a machine learning model for a wide range of countries and items. Second, as to our knowledge, it is the first attempt to adopt a separated learning method for exports prediction. By separating the dataset into 5 homogeneous subgroups, we could enhance the predictive performance of the model. Also, more detailed explanation of models by group is provided using SHAP values. Lastly, this study has several practical implications. There are some platforms which serve trade information including KOTRA, but most of them are based on past data. Therefore, it is not easy for companies to predict future trends. By utilizing the model and recommendation strategy in this research, trade related services in each platform can be improved so that companies including SMEs can fully utilize the service when making strategies and decisions for exports.

• Korea Science and Art Forum
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• v.20
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• pp.147-158
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• 2015

This study made an approach to the industrial exhibition space, which is a medium of marketing communication, from the position of an enterprise and consumers through the output of Space Design, and conducted it with focus on B2B transactions among specialized exhibitions. In addition, this study inquired into what factors should be considered along with space design by interpreting the purpose of participating in the exhibition and space design of the enterprise which supply capital goods, elements, related technologies and materials, etc. This study aimed at drawing the direct/indirect effect, produced by space design, on the marketing by analyzing correlation between space design and participating enterprises' marketing. Despite the marketing effect of the exhibition, which was proved by preceding research results, the reality is that exhibition-participating expenses work as considerable burden on enterprises. Particularly, booth design, which is forming the most proportion among the participating expenses, was found to have insufficient influence on visitors due to the decline in its importance among diverse factors influencing visitor's decision to visit a booth. Regardless of the business category of participating enterprises in the exhibition, the standard of exhibits was ranked as the most important consideration factor in visiting a booth. Even by business category, the standard of booth design rarely had an influence on booth visit. Booth design had an affirmative influence on participating enterprise's preference, but its influence on product purchase or business talk & contact with a participating enterprise or price was found to be extremely low. It's difficult to judge marketing success or failure of an exhibition by the form and standard of booth design. Preferably, this study infers that it's necessary to put much weight on qualitative excellence of an exhibition, which consists of participation of an enterprise in possession of excellent technologies, exhibits with higher standards and high-quality visitors with purchasing power. This study suggests that it's more effective to set up the plan for expansion of participation in exhibition by optimally regulating the proportion of space design in participating expense to increase marketing effectiveness of an exhibition. The limitations of this study, analysis of which based on the visitors to an exhibition only, requires supplementation through the follow-up research work on participating enterprises in the exhibition.

• Korean Journal of Heritage: History & Science
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• v.56 no.2
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• pp.264-279
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• 2023

The 50th anniversary of the UNESCO World Heritage Convention was in 2022. In order to reflect on the present and future of the meaning of World Heritage, this paper examines the development and changes of the UNESCO World Heritage system. After promulgating the convention in 1972, the UNESCO World Heritage system prioritized the protection of heritage sites in the world that were at risk due to armed conflicts and natural disasters to bequeath heritage to the next generation. In addition, the UNESCO World Heritage's emphasis on Outstanding Universal Value represents the particular culture of human beings formed during a certain period of time, and acts as a significant source of soft power in public diplomacy. The UNESCO World Heritage might be perceived as a shared heritage that has not only become a channel to understand various national values, but also an effective medium to convey one of UNESCO's main principles, that is, peacebuilding. However, the UNESCO World Heritage is now at the center of conflicts of heritage interpretation between many stakeholders related to invisible wars, such as cultural wars, memory wars, and history wars as the social, political, and cultural contexts concerning World Heritage have dramatically shifted with the passing of time. Paying attention to such changing contexts, this paper seeks to understand the main developments in UNESCO World Heritage's discourse concerning changes to the World Heritage Operation Guidelines and heritage experts' meetings by dividing its 50-year history into five phases. Next, this paper analyzes the main shifts in keywords related to UNESCO World Heritage through UNESDOC, which is a platform on which all UNESCO publications are available. Finally, this paper discusses three main changes of UNESCO World Heritage: 1) changes in focus in World Heritage inscriptions, 2) changes in perception of World Heritage protection, and 3) changes of view on the role of the stakeholders in World Heritage. It suggests new emerging issues regarding heritage interpretation and ethics, climate change, and human rights.

• Korean Journal of Heritage: History & Science
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• v.56 no.1
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• pp.182-205
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• 2023

The use of royal artificial flowers was finally found through schematics and records in Wonhaeng Eulmyojeongri Uigwe, which organized the procession to Hwaseong in 1795. The results of classifying the uses of artificial flowers in the brthday banquet at Bongsudang Hall in 1795 and considering the shape, user, and usage are as follows. According to literature records, artificial flowers were made with high-quality materials such as gold, silver, and silk thread in the early period, but were mainly made of paper in the later period. Artificial flowers were used for decorating official hats, Bongsudang Hall, and banquet tables. The Sagwonhwa was used for decoration of the official hats of members of the royal family, and the one on the top was called Eosam-Sagwonhwa. At the birthday banquet inBongsudang Hall, King Jeongjo and Hyegyeonggung used the Eosam-Sagwonhwa and put it on the right side of the official hats. Officials put peach blossom with two petals on the left side of the official hats for decoration. The artificial flowers for decoration of the official hats of musicians and dancers were more expensive and flashier than the officials' ones. Depending on the dance, several artificial flowers were inserted into the official hats. When measuring the size of artificial flowers, the scale used was when making a ceremonial article. For artificial flowers for decoration of the banquet hall, red and white peach blossoms were placed in two jars with dragons painted on them and them placed on two red-painted tables, respectively. The table and jar with flowers were tied together with a red cotton string and fixed so as not to fall over. The artificial flowers for decoration of the banquet table of King Jeongjo, Hyegyeonggung, and the king's sisters were a large lotus, medium-sized lotus, peony, rose, and specially made peach flowers. The artificial flowers for decoration of the banquet table of guests and officials were small lotuses and peach blossoms. The artificial flowers used in the birthday banquet at Bongsudang Hall the most were peach blossoms, and peaches had the meaning of longevity and exorcism. It is expected that the above research results will be helpful in understanding the characteristics and usage of artificial flowers in the period of King Jeongjo and use in reproducing royal feasts and producing traditional cultural contents.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.3B
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• pp.303-310
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• 2009

Natural zeolite is widely used as sorbents and bio-media materials because it is cheap as well as it has efficient porous structures and large cation exchange. In this study, the effect of metal cations $(Na^+,\;Ca^{2+},\;Mg^{2+},\;Al^{3+})$ adsorbed to natural zeolite on the microorganism attachment was investigated. Metal-modified zeolites (MMZ) were prepared with 0.01 M, 0.02 M and 0.1 M NaCl, $CaCl_2$, $MgCl_2$ and $AlCl_3$ solutions respectively, which concentrations were equivalent to 10%, 20% and 100% of cation exchange capacity (CEC) of natural zeolite. Pseudomonas putida was used as microorganism which was cultivated in Beef Extract Medium at $26^{\circ}C$. The microorganism attachment to MMZ was increased more than natural zeolite. The amount of bacterial adhesion to MMZ and natural zeolite were $Mg^{2+}>natural>Na^+>Al^{3+}>Ca^{2+}$ under 10% of CEC, $Mg^{2+}>Ca^{2+}>Al^{3+}>natural>Na^+$ under 20% of CEC and $Ca^{2+}>Mg^{2+}>natural>Al^{3+}>Na^+$ under 100% of CEC. Especially, Mg-modified zeolite (Mg-MZ) showed the highest amount of bacterial adhesion, which increased the microorganism attachment 60% higher than natural zeolite under 10% of CEC. However, the amount of bacterial adhesion was decreased as the concentration of metal cations modified to zeolite were increased, showing that the increased amounts were 60% under 10% of CEC, 50% under 20% of CEC and 10% under 100% of CEC in Mg-MZ. Additionally, the effect of $Mg^{2+}$ in solution on the bacterial adhesion was investigated in order to compare it with the effect of $Mg^{2+}$ adsorbed to zeolite. The maximum quantity of bacterial adhesion to Mg-MZ was not different from the amount of microorganism attachment to the natural zeolite when $Mg^{2+}$ solution was added.

• Journal of the Korean Society for information Management
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• v.39 no.4
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• pp.191-213
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• 2022

With a view to providing a high-quality policy information service beyond the existing national task service of the national policy information portal (POINT) of the National Library of Korea Sejong, it would be necessary to effectively provide the policy data needed for the implementation of the new national tasks. Accordingly, in this study, an attempt has been made to find a way to connect and develop the BRM-based national tasks and the policy information contents. Towards this end, first, the types of national tasks and the contents of each field and area of the government function's classification system were analyzed, with a focus placed on the 120 national tasks of the new administration. Furthermore, by comparing and analyzing the national tasks of the previous administration and the current information, the contents ought to be reflected for the development of contents related to the national tasks identified. Second, the method for linking and collecting the policy information was sought based on the analysis of the current status of policy information and the national information portal. As a result of the study, first, examining the 1st stage BRM of the national tasks, it turned out that there were 21 tasks for social welfare, 14 for unification and diplomacy, 17 for small and medium-sized businesses in industry and trade, 12 for general public administration, 8 for the economy, taxation and finance, 6 for culture, sports and tourism, science and technology, and education each, 5 for communication, public order and safety each, 4 for health, transportation and logistics, and environment each, 3 for agriculture and forestry, 2 for national defense and regional development each, and 1 for maritime and fisheries each, among others. As for the new administration, it is apparent that science technology and IT are important, and hence, it is necessary to consider such when developing the information services for the core national tasks. Second, to link the database with external organizations, it would be necessary to form a linked operation council, link and collect the information on the national tasks, and link and provide the national task-related information for the POINTs.