• ANNALS OF ANIMAL RESOURCE SCIENCES
• /
• v.29 no.4
• /
• pp.158-165
• /
• 2018

The present study was undertaken to investigate the reproductive performance of the female breeding pigs after artificial insemination (AI) using the frozen boar semen imported from Canada, thereby finding insights into improving the efficiency of AI using the frozen semen (FSAI). Analyzed in the present study were the records of a total of 626 FSAI in a great grandparent (GGP) farm beginning from May through November of the year of 2016 (Farm A) and 2,024 FSAI beginning from 2015 through 2017 from a second GGP farm (Farm B). Both the total number of piglets born (TNB) and the number born alive (NBA) were greater during May than during September within FSAI (p<0.05) in Farm A (p<0.01 for the effect of the month). In Farm B, no difference was detected between the years in any of the farrowing rate, TNB, and NBA. When the records from Farm A and Farm B were pooled, the farrowing rate was greater for Farm A vs. Farm B (p<0.01), with no difference between the two farms in TNB and NBA. Moreover, TNB and NBA were less for FSAI than for AI using the liquid semen (LSAI; $10.9{\pm}0.3$ vs. $13.4{\pm}0.1$ and $10.0{\pm}0.3$ vs. $12.0{\pm}0.1$ piglets, respectively, for FSAI vs. LSAI in TNB and NBA, respectively; p<0.01). In conclusion, these results suggest that the reproduction efficiency for FSAI, which is lower than that for LSAI, could be improved by selecting an optimal period of the year for the use of the former.

• Journal of Embryo Transfer
• /
• v.33 no.4
• /
• pp.265-270
• /
• 2018

Up-to-date artificial insemination (AI) using frozen sperm consider as the most widely using technology for improvement of Korean Native Cow (Hanwoo) embryo production. However, it is time consuming, required at least 15~20 years to make more than 6 generations, and their offspring number is limited. To overcome such limitations, superovulation and in vitro fertilization have been developed. For superovulation, the number of produced embryos are not enough for commercialization and donor cows need rest period. This led to use of slaughterhouse ovary for in vitro fertilization, but it is impossible to repeat the collection from the same individual and it only can improve the genetic merits of offspring for one generation. Production of embryos using Ovum Pick-Up (OPU) technique, where oocytes can be repeatedly collected from living elite donor, might overcome these limitations. In this study, we investigated the possibility of using OPU technique from donors at different age and different session periods for mass-embryo-production. Oocytes were collected from 26 donor cows twice per week, 3 - 4 months per year, between 2013 and 2016. Results showed that, the average number of embryo produced in first year used donor was significantly higher than that in second year used donor ($3.89{\pm}2.85$ vs $3.29{\pm}2.70$), however, there was no significant difference between third year used donor ($3.51{\pm}3.32$) and other groups. Taken together, our data showed that repeated using of donor up to three years is possible for in vitro embryo mass-production. Moreover, OPU can be used as suitable embryo producing technique for livestock breed improvement.

• Asian Journal of Turfgrass Science
• /
• v.15 no.2
• /
• pp.87-104
• /
• 2001

This Study was carried out to investigate on the environmental effects of golf courses and to find a solution to the negative effects in Korea. The results were ai follows. 1. There were 152 golf courses opened in December 2000. 113 golf courses were member-ship and 39 golf courses were public. Users (golfer) were over 12,000,000 in 2000. 2. Total area of golf courses was 0.8% as compared with total area of farmland in 1999. Total amount of agricultural chemicals used in golf courses was 0.3% of total amount of agricultural chemicals used in Korea. The remaining amount of agricultural chemicals in golf courses tested were almost below the permitted limits. 3. Recently, total amount of fertilizers in green decreased 5~7g/$m^2$/year as compared with the recommended. 4. The control by antagonistic microorganisms and the fertilizing of the organic matter or the organic fertilizer were effective to decrease the amount of agricultural chemicals used. To success the control of microorganisms, active antagonistic microorganisms had to be applied over the recommended dose eve교day. Though fertilizing of organic fertilizer, slow release fertilizer, was effective to suppress dollar spot, necrotic ring spot. fungicides were required as a supplementary means when disease symptom was very heavy. 5. Zoysiagrass was fertilized intensively from May to August. Cool-season grasses were fertilized intensively from March to May and September to October. The fall fertilizing of Zoysiagrass was carried out to the begining of October. The fall fertilizing of cool-season grasses were carried out to the end of November or the begining of December. The fertilizing amount of Zoysiagrass was 10g/$m^2$/year. The fertilizing amount of bentgrass was 25~27g/$m^2$/year.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.8
• /
• pp.3961-3965
• /
• 2012

Objective: To compare the clinical effects of concurrent radiochemotherapy with those of radiotherapy in treating locally advanced nasopharyngeal carcinoma (Stage III~IVa). Methods: A total of 95 patients suffering from nasopharyngeal carcinoma (Stage III~IVa) were divided into two groups: concurrent radiochemotherapy (Group CCRT, n=49) and radiotherapy (Group RT, n=46). The two groups were both delivered conventional fractionated radiotherapy, while Group CCRT also received three cycles of PF (DDP+5-Fu) or PLF (DDP+5-Fu+CF) chemotherapy. Results: The complete remission rate and total remission rate of Group CCRT were higher than those of Group RT ($X^2$=4.72~7.19, P<0.05). The one-year overall survival (OS) rate calculated by the life table method, was also higher than that of Group RT ($X^2$=4.24, P<0.05) as well as the 3-year OS rate, nasopharyngeal control rate and cervical lymph nodes' control rate ($X^2$=4.28~4.40, P<0.05). In addition, the 5-year OS and metastasis-free rates of Group CCRT were higher than those of Group RT and the differences were of statistical importance ($X^2$=3.96~8.26, P<0.05). However, acute toxicity was also obviously higher, the difference in gastrointestinal reactions being statistically significant ($X^2$=11.70, P<0.05). Conclusion: This study demonstrated that concurrent radiochemotherapy could improve the remission rate, overall survival rate and locally control rate. The toxicity of concurrent radiochemotherapy could be tolerated by the patients.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.06a
• /
• pp.536-537
• /
• 2007

From the standpoint that the life of conductor is influenced by softening of AI wire, the life assessment of conductor was carried out. As a result, it was found that the estimated life of conductor was 45.2 year. The detailed description will be presented in the text.

• Journal of Astronomy and Space Sciences
• /
• v.29 no.2
• /
• pp.221-232
• /
• 2012

We analyzed the manufacturing procedure, specifications, repair history, and details of celestial movements of the water-hammering type $Honsang$ (celestial globe). Results from our study on the remaining $Honsangs$ in China and Japan and on the reconstruction models in Korea were applied to our conceptual design of the water-hammering type $Honsang$. A $Honui$ (armillary sphere) and $Honsang$ using the water-hammering method were manufactured in $Joseon$ in 1435 (the 17th year of King $Sejong$). $Jang$ $Yeong-Sil$ developed the $Honsang$ system based on the water-operation method of $Shui$ $y{\ddot{u}}n$ $i$ $hsiang$ $t'ai$ in China. Water-operation means driving water wheels using a water flow. The most important factor in this type of operation is the precision of the water clock and the control of the water wheel movement. The water-hammering type $Honsang$ in $Joseon$ probably adopted the $Cheonhyeong$ (天衡; oriental escapement device) system of $Shui$ $y{\ddot{u}}n$ $i$ $hsiang$ $t'ai$ in China and the overflow mechanism of $Jagyeongnu$ (striking clepsydra) in $Joseon$, etc. In addition to the $Cheonryun$ system, more gear instruments were needed to stage the rotation of the $Honsang$ globe and the sun's movement. In this study, the water-hammering mechanism is analyzed in the structure of a water clock, a water wheel, the $Cheonhyeong$ system, and the $Giryun$ system, as an organically working operation mechanism. We expect that this study will serve as an essential basis for studies on $Heumgyeonggaknu$, the water-operating astronomical clock, and other astronomical clocks in the middle and latter parts of the $Joseon$ dynasty.

• The Journal of Korean Association of Computer Education
• /
• v.22 no.3
• /
• pp.67-78
• /
• 2019

The purpose of this study is to explore information ethics issues based on academic big data from Web of Science (WoS) and to provide implications for information ethics education in informatics subject. To this end, 318 published papers from WoS related to information ethics were text mined. Specifically, this paper analyzed the frequency of key-words(TF, DF, TF-IDF), information ethics issues using topic modeling, and frequency of appearances by year for each issue. This paper used 'tm', 'topicmodel' package of R for text mining. The main results are as follows. First, this paper confirmed that the words 'digital', 'student', 'software', and 'privacy' were the main key-words through TF-IDF. Second, the topic modeling analysis showed 8 issues such as 'Professional value', 'Cyber-bullying', 'AI and Social Impact' et al., and the proportion of 'Professional value' and 'Cyber-bullying' was relatively high. This study discussed the implications for information ethics education in Korea based on the results of this analysis.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.17 no.2
• /
• pp.85-101
• /
• 2021

This study aims to gain insight through understanding the Metaverse, which has recently become a hot topic. The study utilizes the methods of case study and News Bigdata Analysis Services. The Metaverse can be defined as a world with no separation between the virtual and real worlds. Currently, the Metaverse is dominated mainly by the MZ generation, but just like smartphones have quickly entered our lives, the Metaverse will soon, too, become a part of our lives. To follow up on this change, all companies, including global companies, are going after the Metaverse. Today, the Metaverse is successfully being used in all types of fields, including gaming, performing arts, business, etc., and its essential technologies include VR/AR/MR/XR and AI. This study intends to help understand the Metaverse through a case analysis of Zepeto, which has 200 million users worldwide. On Zepeto, users can decorate their own avatars, hang out with friends, go to art galleries and performances, and create and sell items. Of these users, 90% are from outside of South Korea, and 80% are teenagers. With most of the users being underage, many legal and social problems also follow. Nevertheless, who will be the first to conquer the new world of the Metaverse will continue to be a big issue. This study also analyzes domestic news articles about the Metaverse by utilizing the BigKinds system. Starting in 1996, the number of articles about the Metaverse each year remains single digit, until in 2020 when the number sharply rises to 86 news. As of June 2021, there are 1,663 articles on the Metaverse. This study suggests that the Metaverse should now be carefully examined and closely followed.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.25 no.3
• /
• pp.339-345
• /
• 2021

With the development of online education due to COVID-19, the EduTech market, which combines new technologies such as AI and AR/VR in education is rapidly growing. In addition, the children's industry is steadily growing despite the decreasing birth rate every year as more and more families with one child per household are investing in their children. However, supply of contents to EduTech market is slow compared to demands that are increasing. Therefore, the purpose of this paper is to help solve these problems by developing and supporting AR kids contents with convenience, practicality, and efficiency using AR technology. AR content for supporting vocabulary learning for infants is not just an end to watching and listening, but an observation-driven model that can manipulate content directly, which attracts children's interest and helps children learn words. This paper is intended for infants from 15 months to 36 months old when full-fledged language development occurs.

• Journal of The Korean Association of Information Education
• /
• v.25 no.6
• /
• pp.1005-1013
• /
• 2021

With the prolonged COVID-19, the existing academic gap is widening. The purpose of this study is to provide homeroom teachers with a visual confirmation of the academic achievement gap in grades and classrooms through academic achievement analysis, and to use this to help them design lessons and explore ways to improve the academic achievement gap. The data of students' Korean and math diagnostic evaluation scores at the beginning of the school year were visualized as clusters using the K-means algorithm, and as a result, it was confirmed that a meaningful clusters were formed. In addition, through the results of the teacher interview, it was confirmed that this system was meaningful in improving the academic achievement gap, such as checking the learning level and academic achievement of students, and designing classes such as individual supplementary instruction and level-specific learning. This means that this academic achievement data analysis system helps to improve the academic gap. This study provides practical help to homeroom teachers in exploring ways to improve the academic gap in grades and classes, and is expected to ultimately contribute to improving the academic gap.