• The Korean Journal of Mycology
• /
• v.47 no.2
• /
• pp.173-179
• /
• 2019

Sawdust cultivation of Lentinula edodes has been increasing in Korea. Fourteen strains were used to develop the best varieties of L. edodes, and hybridization was carried out by monohybrid cross. The number of hybridized strains was 1,638 among 3,100 combinations. They were cultivated on sawdust medium, and fruiting bodies were formed in 364 strains. Among them, 65 strains were selected as superior candidate strains based on the shape and size of the fruiting bodies. Forty strains formed fruiting bodies without lamellae structure. The shape of the stipe was cylindrical (255 strains), thick to lower part (15 strains), and thick to upper part (94 strains). By the combinations of 2462 n1-10 and 3420 n1-10, 2462 n1, 2462 n2, 2462 n10, and 3420 n3 were selected as excellent monokaryotic strains. These strains were considered to be superior monokaryotic strains that could be used for hybrid breeding.

• Journal of The Korean Association of Information Education
• /
• v.25 no.5
• /
• pp.733-740
• /
• 2021

The purpose of this study is to present the direction of elementary school AI education by analyzing cases of classes related to AI education in actual school settings. For this purpose, 19 classes were collected as elementary school class cases based on AI education. According to the result of analyzing the class case, it was confirmed that the class was designed in a hybrid aspect of learning content and method using AI. As a result of analyzing the achievement standards and learning goals, action verbs related to memory, understanding, and application were found in 8 classes using AI from a tool perspective. When class was divided into introduction, development, and rearrangement stages, the AI education element appeared the most in the development stage. On the other hand, when looking at the ratio of learning content and learning method of AI education elements in the development stage, the learning time for approaching AI education as a learning method was overwhelmingly high. Based on this, the following implications were derived. First, when designing the curriculum for schools and grades, it should be designed to comprehensively deal with AI as a learning content and method. Second, to supplement the understanding of AI, in the short term, it is necessary to secure the number of hours in practical subjects or creative experience activities, and in the long term, it is necessary to secure information subjects.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.3
• /
• pp.643-650
• /
• 2021

The purpose of this study was to evaluate the impact of lecture content on the overall academic satisfaction in non-contact online classes. The study was conducted using an online survey of 107 university students attending metropolitan, local and foreign universities for a week from August 25th, 2020 to September 2nd, 2020. The analysis methods used included descriptive statistics and chi-square distribution, Fisher's exact test, linear by linear association, and logistic regression. The result of the study showed a significant decrease in Junior by 0.025 times compared to Senior (p<.05). Furthermore, a significant decrease in the impact of recorded lectures by 0.036 times compared to a hybrid of face-to-face and online lectures (p<.05). Compared to the response 'No', the number of student's responses of 'Yes' increased significantly by 31.358 times (p<.05). Additionally, a significant increase was seen in teaching methods by 19.709 times, and academic satisfaction by 7.989 times(p<.05). In conclusion, the results imply that the quality of lecture content is also important to improve the student's satisfaction with school life, but overall management is required in the areas of appropriate teaching methods, appropriate tuition, and evaluation methods.

• Journal of Environmental Health Sciences
• /
• v.47 no.6
• /
• pp.540-547
• /
• 2021

Background: Indoor air pollutants are caused by a number of factors, such as coming in from the outside or being generated by internal activities. Typical indoor air pollutants include nitrogen dioxide and carbon monoxide from household items such as heating appliances and volatile organic compounds from building materials. In addition there is carbon dioxide from human breathing and bacteria from speaking, coughing, and sneezing. Objectives: According to recent research results, most indoor air pollution is known to be greatly affected by internal factors such as burning (biomass for cooking) and various pollutants. These pollutants can have a fatal effect on the human body due to a lack of ventilation facilities. Methods: We fabricated a polydopamine (PDA) layer with Ti substrates as a coating on supported glass fiber fabric to enhance its photo-activity. The PDA layer with TiO₂ was covalently attached to glass fiber fabric using the drop-casting method. The roughness and functional groups of the surface of the Ti substrate/PDA coated glass fiber fabric were verified through infrared imaging microscopy and field emission scanning electron microscopy (FE-SEM). The obtained hybrid Ti substrate/PDA coated glass fiber fabric was investigated for photocatalytic activity by the removal of ammonia and an epidermal Staphylococcus aureus reduction test with lamp (250 nm, 405 nm wavelength) at 24℃. Results: Antibacterial properties were found to reduce epidermal staphylococcus aureus in the Ti substrate/PDA coated glass fiber fabric under 405 nm after three hours. In addition, the Ti substrate/PDA coated glass fiber fabric of VOC reduction rate for ammonia was 50% under 405 nm after 30 min. Conclusions: An electron-hole pair due to photoexcitation is generated in the PDA layer and transferred to the conduction band of TiO₂. This generates a superoxide radical that degrades ammonia and removes epidermal Staphylococcus aureus.

• The Journal of the Korea Contents Association
• /
• v.22 no.7
• /
• pp.55-62
• /
• 2022

The perovskite solar cell is an active part of research in renewable energy fields such as solar energy, wind, hydroelectric power, marine energy, bioenergy, and hydrogen energy to replace fossil fuels such as oil, coal, and natural gas, which will gradually disappear as power demand increases due to the increase in use of the Internet of Things and Virtual environments due to the 4th industrial revolution. The perovskite solar cell is a solar cell device using an organic-inorganic hybrid material having a perovskite structure, and has advantages of replacing existing silicon solar cells with high efficiency, low cost solutions, and low temperature processes. In order to optimize the light absorption layer thin film predicted by the existing empirical method, reliability must be verified through device characteristics evaluation. However, since it costs a lot to evaluate the characteristics of the light-absorbing layer thin film device, the number of tests is limited. In order to solve this problem, the development and applicability of a clear and valid model using machine learning or artificial intelligence model as an auxiliary means for optimizing the light absorption layer thin film are considered infinite. In this study, to estimate the light absorption layer thin-film optimization of perovskite solar cells, the regression models of the support vector machine's linear kernel, R.B.F kernel, polynomial kernel, and sigmoid kernel were compared to verify the accuracy difference for each kernel function.

• Journal of Mushroom
• /
• v.20 no.2
• /
• pp.50-54
• /
• 2022

This study was conducted to reduce the phenomenon of the biased cultivation of certain mushroom varieties and to develop a competitive variety of Grifola frondosa. We developed the first Korean white commercial mushroom strain, 'Bakyeon', by crossing monokaryons derived from brown strains. We have collected and tested the characteristics of mushrooms from domestic and international genetic resources since 2018. We bred the unique domestic variety, 'Bakyeon', which has the following characteristics. The optimal temperature for mycelial growth was 25~28℃ and the optimal temperature for fruit body growth was 16~18℃. The new variety was similar to the control variety (Daebak) in terms of the pileus, which formed a pine cone shape, and the number of days of cultivation. The yield was 94.1 g/bottle, which was 23% lower than the 108.5 g/bottle yield of the control variety. When incubating the parent and control varieties, the replacement line was clear. Moreover, polymerase chain reaction analysis of mycelial DNA resulted in different band patterns between the parent and control varieties, confirming the hybrid species.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.34 no.3
• /
• pp.280-287
• /
• 1989

In order to know growing habit of the maize bearing tillers, IK//IRI/B68 with tillers was grown and compared with Jinjoo Ok which is not tillering, and several parameters were measured for analysis. The results obtained were summarized as follows. 1. The plant height and fresh weight of IK//IRI/B68 were lower than those of Jinjoo Ok until the tasseling stage of IK/ /IRI/B68, while then plant height and fresh weight of IK//IRI/B68 were higher than those of Jinjoo Ok after the tasseling stage of IK//IRI/B68. 2. The average number of tillers per plant of IK//IRI/B68 at maturity was 3.7 and the average tiller height of IK//IRI/B68 was almost the same as the height of the main stem. 3. The dry weight of IK//IRI/B68 at the early growing stage was lower than the check hybrid Jinjoo Ok, while it was higher than Jinjoo Ok at the later growing stage. 4. The LAI of IK//IRI/B68 after full expansion of the leaves was greater than that of Jinjoo Ok The LAIs of IK//IRI/B68 and Jinjoo Ok were 12.6 and 5.8, respectively. 5. The CGR of Jinjoo Ok was greater than that of IK//IRI/B68 until earey July while the CGR of Jinjoo Ok was lower than that of IK//IRI/B68 as the tillers of IK//IRI/B68 were fully developed. 6. The LAR and RGR of IK//IRI/B68 were greater than those of Jinjoo Ok until mid-July. The RGR of IK//IRI/B68 seemed to be affected by both NAR and LAR. The RGR of Jinjoo Ok seemed to be affected by LAR.

• Journal of Mushroom
• /
• v.21 no.3
• /
• pp.145-149
• /
• 2023

This study was conducted to reduce the phenomenon of the biased cultivation of certain mushroom varieties and to develop a competitive variety of Pleurotus nebrodensis. We have collected and tested characteristics of genetic resources from domestic and overseas varieties since 2015. We bred the domestic variety 'Boram'. The optimal temperature was 26~29℃ for mycelial growth and 15~18℃ for fruit body growth temperature. This variety was similar to the control variety (Uram) in terms of the number of cultivation days and yield per bottle. The shape of the new cultivar was round, whereas that of the control group was spatula-like. The yield was 181.1 g/bottle, which was statistically similar to that of the control variety. When incubating the parent and control varieties, the replacement line was clear. Moreover, polymerase chain reaction analysis of mycelial DNA resulted in different band patterns between the parent and control varieties, confirming the hybrid species.

• International Journal of Computer Science & Network Security
• /
• v.23 no.4
• /
• pp.55-68
• /
• 2023

In recent years, the Television White Space (TVWS) has attracted the interest of many researchers due to its propagation characteristics obtainable between 470MHz and 790MHz spectrum bands. The plenty of unused channels in the TV spectrum allows the secondary users (SUs) to use the channels for broadband services especially in rural areas. However, when the number of SUs increases in the TVWS wireless network the aggregate interference also increases. Aggregate interferences are the combined harmful interferences that can include both co-channel and adjacent interferences. The aggregate interference on the side of Primary Users (PUs) has been extensively scrutinized. Therefore, resource allocation (power and spectrum) is crucial when designing the TVWS network to avoid interferences from Secondary Users (SUs) to PUs and among SUs themselves. This paper proposes a model to improve the resource allocation for reducing the aggregate interface among SUs for broadband services in rural areas. The proposed model uses joint power and spectrum hybrid Firefly algorithm (FA), Genetic algorithm (GA), and Particle Swarm Optimization algorithm (PSO) which is considered the Co-channel interference (CCI) and Adjacent Channel Interference (ACI). The algorithm is integrated with the admission control algorithm so that; there is a possibility to remove some of the SUs in the TVWS network whenever the SINR threshold for SUs and PU are not met. We considered the infeasible system whereby all SUs and PU may not be supported simultaneously. Therefore, we proposed a joint spectrum and power allocation with an admission control algorithm whose better complexity and performance than the ones which have been proposed in the existing algorithms in the literature. The performance of the proposed algorithm is compared using the metrics such as sum throughput, PU SINR, algorithm running time and SU SINR less than threshold and the results show that the PSOFAGA with ELGR admission control algorithm has best performance compared to GA, PSO, FA, and FAGAPSO algorithms.

• 한국정보교육학회:학술대회논문집
• /
• 2021.08a
• /
• pp.377-383
• /
• 2021

The purpose of this study is to present the direction of elementary school AI education by analyzing cases of classes related to AI education in actual school settings. For this purpose, 19 classes were collected as elementary school class cases based on AI education. According to the result of analyzing the class case, it was confirmed that the class was designed in a hybrid aspect of learning content and method using AI. As a result of analyzing the achievement standards and learning goals, action verbs related to memory, understanding, and application were found in 8 classes using AI from a tool perspective. When class was divided into introduction, development, and rearrangement stages, the AI education element appeared the most in the development stage. On the other hand, when looking at the ratio of learning content and learning method of AI education elements in the development stage, the learning time for approaching AI education as a learning method was overwhelmingly high. Based on this, the following implications were derived. First, when designing the curriculum for schools and grades, it should be designed to comprehensively deal with AI as a learning content and method. Second, to supplement the understanding of AI, in the short term, it is necessary to secure the number of hours in practical subjects or creative experience activities, and in the long term, it is necessary to secure information subjects.