• Korean journal of applied entomology
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• v.61 no.1
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• pp.197-210
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• 2022

Entomopathogenic fungi can be used to control a variety of sucking and chewing insects, with little effect on beneficial insects and natural enemies. Approximately 170 entomopathogenic fungal insecticides have been registered and used worldwide, with the recent focus being on the mode of action and mechanism of insect-fungal interactions. During the initial period of research and development, the industrialization of entomopathogenic fungi focused on the selection of strains with high virulence. However, improvement in productivity, including securing resistance to environmental stressors, is a major issue that needs to be solved. Although conidia are the primary application propagules, efforts are being made to overcome the limitations of blastospores to improve the economic feasibility of the production procedure. Fungal transformation is also being conducted to enhance insecticidal activity, and molecular biology is being used to investigate functions of various genes. In the fungi-based pest management market, global companies are setting up cooperative platforms with specialized biological companies in the form of M&As or partnerships with the aim of implementing a tank-mix strategy by combining chemical pesticides and entomopathogenic fungi. In this regard, understanding insect ecology in the field helps in providing more effective fungal applications in pest management, which can be used complementary to chemicals. In the future, when fungal applications are combined with digital farming technology, above-ground applications to control leaf-dwelling pests will be more effective. Therefore, for practical industrialization, it is necessary to secure clear research data on intellectual property rights.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.92-92
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• 2022

In preparation for the ever-changing climate and unification of North Korea and South Korea, it is necessary to increase the grain self-sufficiency rate by selecting crops with good utilization in high-altitude regions. The principle is to sow pastures at the end of August. However, sowing occurs in spring because the sowing period is missed when the weather is bad or when the workforce is insufficient. Sometimes when the grassland is completely devastated, it is frequently sowed in spring. In addition, North Korea consists of a high-altitude regions, and has been devastated in a general mountainous region. As a result, the landscape is not good and it is vulnerable to natural disasters such as landslides. Therefore, to prevent this, pasture must be sowed in the high-altitude regions. The goal of this study was to evaluate and compare yield and feed value of pasture species and varieties by spring sowing in high-latitude regions. The study was conducted in Pyeongchang, Gangwon-do, which is 700m height above sea level. The pasture species and varieties was sown on April 24, 2022. Each treatment was carried out by sowing 30 kg/ha, the experiment field size was 1 m²(1m×1m), and randomized block design with tri-repeat. The total of 14 varieties was used in the study, 6 varieties of Orchardgrass (OG), 6 varieties of Tall fescue (TF) and 2 varieties of Perennial ryegrass (PRG). The grassland composition fertilization using (N:P₂O₅:K₂O at 80:200:70 kg/ha) was conducted and management fertilizer was N:P₂O₅:K₂O at 210:150:180 kg/ha. The first harvest was June 26,2022 and the second harvest was on August 16, 2022. For statistical analysis of the data, an Analysis of Variance (ANOVA) was performed using the R3.6.3 software program, and all data was subjected to analysis using Duncan's multiple range test. Significance was set at the 5% level. The dry matter yield at the first harvest was the highest in PRG, and second harvest was the highest in TF (p < 0.05). Overall, PRG showed a trend of gradually decreasing growth, OG and TF showed a trend of gradually improving growth. This showed that PRG was considerably weaker to summer depression than other pasture species. Comparing the total dry matter yield, TF was the highest (4,565.45 kg/ha), but there was no significance difference with PRG (4,487.24 kg/ha) (p < 0.05). In addition, comparing the total TDN (total digestible nutrient) yield, TF was the highest (3147.33 kg/ha), second in PRG (2975.67 kg/ha) and third in OG (2052.33 kg/ha). Since this result is the data of the second harvests, if the result is derived by the end of next year, it will be provided as basic data for selection of pasture species and varieties suitable for spring seeding in high-altitude regions.

• Journal of Practical Engineering Education
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• v.15 no.1
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• pp.73-80
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• 2023

The advancement of online technology in the 21st century has increased online courses and web-based communication in higher education. This type of education is not limited by time or location and has made it possible to expand university campuses globally and broaden the reach of university education to the general public and students from other universities. Changes such as a decrease in the school-age population and a reorganization of the university structure have also created an opportunity to change the perception of online education. In this paper, we conducted surveys on K University students, high school seniors, and the general public to assess their satisfaction with online courses, identify areas that require massive online courses, and determine students' needs for the operation of massive online courses. The survey showed that K University students are generally satisfied with online courses. However, improvements are needed to ensure a smooth online course-taking environment, increase system uniformity, and enhance the overall online course environment. High school students have a strong preference for natural science and should be offered online courses in subjects such as mathematics and physics as prerequisites to prepare for their major classes. The general public prefers the humanities, which is evident in the purpose of the liberal arts lectures.

• KIPS Transactions on Software and Data Engineering
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• v.12 no.10
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• pp.455-460
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• 2023

Text augmentation is a methodology that creates new augmented texts by transforming or generating original texts for the purpose of improving the performance of NLP models. However existing text augmentation techniques have limitations such as lack of expressive diversity semantic distortion and limited number of augmented texts. Recently text augmentation using large language models and few-shot learning can overcome these limitations but there is also a risk of noise generation due to incorrect generation. In this paper, we propose a text augmentation method called TAGS that generates multiple candidate texts and selects the appropriate text as the augmented text. TAGS generates various expressions using few-shot learning while effectively selecting suitable data even with a small amount of original text by using contrastive learning and similarity comparison. We applied this method to task-oriented chatbot data and achieved more than sixty times quantitative improvement. We also analyzed the generated texts to confirm that they produced semantically and expressively diverse texts compared to the original texts. Moreover, we trained and evaluated a classification model using the augmented texts and showed that it improved the performance by more than 0.1915, confirming that it helps to improve the actual model performance.

• Tunnel and Underground Space
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• v.33 no.6
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• pp.445-471
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• 2023

Long-term safety over millennia is the top priority consideration in the construction of disposal sites. However, ensuring the mechanical stability of deep geological repositories for spent fuel, a.k.a. radwaste, disposal during construction and operation is also crucial for safe operation of the repository. Imposing restrictions or limitations on tunnel support and lining materials such as shotcrete, concrete, grouting, which might compromise the sealing performance of backfill and buffer materials which are essential elements for the long-term safety of disposal sites, presents a highly challenging task for rock engineers and tunnelling experts. In this study, as part of an extensive exploration to aid in the proper selection of disposal sites, the anticipation of constructing a deep geological repository at a depth of 500 meters in an unknown state has been carried out. Through a review of 2D and 3D numerical analyses, the study aimed to explore the range of properties that ensure stability. Preliminary findings identified the potential range of rock properties that secure the stability of central and disposal tunnels, while the stability of the vertical tunnel network was confirmed through 3D analysis, outlining fundamental rock conditions necessary for the construction of disposal sites.

• Journal of the Korean Association of Geographic Information Studies
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• v.26 no.4
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• pp.80-96
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• 2023

The expansion of human activities and road development has led to the loss and fragmentation of ecological spaces, which is a negative factor for biodiversity. In particular, urban areas where land use and land cover have rapidly changed into urbanization zones are regions where ecological spaces are lost and isolated, making it difficult for wildlife to inhabit. Furthermore, the loss and fragmentation of ecological spaces due to urbanization can have a negative impact on ecosystem services. Therefore, to enhance biodiversity and ecosystem services in urban and national land, it is necessary to establish a practical ecological axis that reflects the current status of the city. Thus, this study analyzed the connectivity of ecological spaces and forest axis that can be used for spatial planning related to urban ecological axis of local governments in Daegu and Gyeongsangbuk-do. The ecological connectivity was analyzed by dividing the Daegu-Gyeongbuk region into 31 local government units, distinguishing between forests and natural areas using land cover data. Subsequently, the study area was divided into 20,483 hexagonal grids of 1 square kilometer each, and the restoration effects for ecological fragmentation within 100 meters were spatially clustered to visualize priority restoration areas. The forest axis was derived by considering regional conditions such as land cover, building area, slope, and others to connect 1,534 forests of 100 hectares or more. The research results are expected to be used as fundamental data for spatial planning, goal setting, and the selection of restoration areas for improving ecological connectivity.

• Korean Journal of Plant Resources
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• v.37 no.2
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• pp.214-224
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• 2024

In this study, the growth, physical characteristics of fruit and soil chemistry were investigated by grouping S. thea populations. The soil for each group was sandy loam or sandy loam, and it was analyzed to be slightly acidic to neutral, with a pH ranging from 5.6 to 7.0. Additionally, the leaf size was highest in the G7 group, and overall fruit growth was highest in the G1 group, confirming differences between the groups. The sweetness ranged from 16.8° Brix to 12.3° Brix, indicating a higher sweetness compared to Vaccinium oldhamill, blueberry, and blackberry. The correlation analysis between soil chemistry and S. thea growth characteristics revealed a significant negative correlation between calcium (Ca) and fruit growth characteristics. Furthermore, a significant positive correlation was observed between sodium (Na) and fruit acidity, as well as between cation exchange capacity (CEC) and fruit hardness.

• Korean Journal of Environmental Biology
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• v.41 no.4
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• pp.370-385
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• 2023

Cyanobacterial harmful algal blooms (Cyano-HABs) are an international environmental problem that negatively affects the ecosystem as well as the safety of water resources by discharging cyanotoxins. In particular, the discharge of microcystins (MCs), a highly toxic substance, has been studied most actively, and various water treatment methods have been proposed for this purpose. In this paper, we reviewed adsorption technology, which is recognized as the most feasible, economical, and efficient method among suggested treatment methods for removing MCs. Activated carbons (AC) are widely used adsorbents for MCs removal, and excellent MCs adsorption performance has been reported. Research on alternative adsorption materials for AC such as biochar and biosorbents has been conducted, however, their performance was lower compared to activated carbon. The impacts of adsorbent properties(characteristics of pore surface chemistry) and environmental factors (solution pH, temperature, natural organic matter, and ionic strength) on the MCs adsorption performance were also discussed. In addition, toward effective control of MCs, the possibility of the direct removal of harmful cyanobacteria as well as the removal of dissolved MCs using adsorption strategy was examined. However, to fully utilize the adsorption for the removal of MCs, the application and optimization under actual environmental conditions are still required, thereby meeting the environmental and economic standards. From this study, crucial insights could be provided for the development and selection of effective adsorbent and subsequent adsorption processes for the removal of MCs from water resources.

• 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 Korean Society of Forest Science
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• v.31 no.1
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• pp.8-20
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• 1976

For study on the variation of natural stand, three populations of Pinus densiflora S. et Z. were selected at samsanri Yongogmyun Myongjugun Kangwondo (4), Hawonri seomyun Uljingun Kyongbuk (5), and Emogdong Suweon Kyongkido (6) successibely after the selection of three population in 1974. Twenty individual trees were chosen from each population and the morphological characteristics of trees, needle and wood properties were investigated on the trees. The results are summerized as follows; 1. Serration density, resin canal number in needle did not show significant differences, however stomata row number in the both sides of needle showed highly significant differences among 3 populations. But significant differences were calculated among individual trees in a population regarding any character of needles. 2. Ail population had high correlation on the stomata row between abaxial and adaxial side of needle. 3. The Myongjungun population showed the highest value of resin duct index, which means the population had the highest degree of hybrid character. 4. The ring segment width and summerwood percentage in the wood properties had significant differences, and yet specific gravity and tracheid length had not significant differences statistically among 3 populations. But all the values were significant statistically among the ring segments within population. 5. The ring segment width decreased rapidly with increasing tree age but summerwood percentage, specific gravity, tracheid length increased slowly to the middle age of tree and then decreased slowly after the age. But the patterns of decrease or increase were some different by population. 6. The values of Uljingun population were generally high in the coefficient of variation on all the needle characters. And the values of Suweon population were always the highest and those of Myongjugun population the lowest in the coefficient of variation on all the wood properties.