• Journal of Korean Physical Therapy Science
• /
• v.29 no.3
• /
• pp.63-74
• /
• 2022

Purpose: The purpose of this study is to examine the mediating effect of children's perceived peer attachment on children's subjective well-being and the effects of self-esteem, one of the variables of individual personality characteristics, on peer attachment and subjective well-being. Design: Data from the 2018 Panel Study on Korean Children were used. Methods: The survey method was conducted by the investigator, and the total number of cases was 1,434 people. Results: First, the higher the child's peer attachment leads to higher subjective well-being and self-esteem, and the higher the self-esteem leads to higher subjective well-being. Second, in the relationship between peer attachment and subjective well-being, self-esteem acts as a mediator variable. Third, children's peer attachment affects subjective well-being and self-esteem, and self-esteem affects subjective well-being. The results explain that the degree of children's peer attachment itself affects subjective well-being and self-esteem, and self-esteem also affects children's subjective well-being. Conclusion: Self-esteem is an important factor influencing subjective well-being and has a mediating effect on the relationship between peer attachment and subjective well-being. In other words, it can be understood that children feel subjective well-being through positive interactions with peers, not only in parent relationships. Based on these results, it is necessary to suggest practical interventions to enhance children's subjective sense of well-being and to develop various programs that can strengthen the sub-factors of peer attachment.

• Journal of the Korea Society of Computer and Information
• /
• v.28 no.9
• /
• pp.9-15
• /
• 2023

Metaverse is a modern new technology that is advancing quickly. The goal of this study is to investigate this technique from the perspective of computer vision as well as general perspective. A thorough analysis of computer vision related Metaverse topics has been done in this study. Its history, method, architecture, benefits, and drawbacks are all covered. The Metaverse's future and the steps that must be taken to adapt to this technology are described. The concepts of Mixed Reality (MR), Augmented Reality (AR), Extended Reality (XR) and Virtual Reality (VR) are briefly discussed. The role of computer vision and its application, advantages and disadvantages and the future research areas are discussed.

• Journal of Creative Information Culture
• /
• v.3 no.1
• /
• pp.29-36
• /
• 2017

The Ministry of Education announced plans to introduce SW education to elementary and secondary schools in the 2015 curriculum. However, if we examine major foreign countries where SW education strongly implemented it is found that they stress not only coding education but also real life SW education. Especially they emphasized convergence with other different fields. Therefore, it can be concluded SW education in Korea should be differentiated based on levels of students. For the common basic curriculum, it is needed basic concepts and thinking skills of SW development, but for the enriched curriculum, it should be emphasized SW development education that can be applied to real life experiences and other difference fields as well. Therefore, it is necessary to plan SW intensive education to develop programs for the enriched program. In this study, I explored how virtual reality programming education can be applied to the level of elementary and secondary school students as an enrichment program.

• Journal of Korean Physical Therapy Science
• /
• v.30 no.3
• /
• pp.91-104
• /
• 2023

Background: The purpose of this study is to investigate whether peer attachment serves as a positive emotional resource for children who have experienced school violence and cyber violence victimization. In addition, we aim to present alternative programs to reduce school violence and promote positive peer attachment among children. Design: We utilized data from the 13th year(2020) of the Panel Study on Korean Children for this study. Methods: The survey was conducted through a questionnaire administered by surveyors, and the total number of cases was 1,357. Results: First, the effects of school violence and cyber violence victimization experiences were confirmed. Second, it can be inferred that children with isolation in peer relationships may ultimately be more vulnerable to cyber violence victimization, as their interactions in cyberspace may also be undermined, highlighting the potential impact of social relationships on cyber violence victimization. Third, it can be observed that children with high levels of peer attachment are emotionally stable, even when exposed to school violence and cyberviolence victimization, which may enable them to regulate the degree of victimization they experience. Conclusion: School violence experience and cyber violence experience interact with each other, and in this relationship, positive peer attachment is a positive resource. Therefore, it emphasizes the importance of the relationship between friends in preventing and overcoming school violence and provides suggestions for solutions based on this understanding.

• Journal of Environmental Health Sciences
• /
• v.48 no.2
• /
• pp.116-122
• /
• 2022

Background: The recent COVID-19 pandemic is one of the worst disease outbreaks of the 21th century. Due to a lack of reliable antiviral therapeutics, wearing face masks is recommended to prevent airborne infection originating from virus-contaminated bioaerosols. Objectives: The aim of this study was to evaluate the filtration efficiencies of face masks that are commercially available in South Korea for a biological aerosol of Staphylococcus aureus (S. aureus) and murine coronavirus, a well-known surrogate for human coronaviruses. Methods: We collected six different kinds of commercial masks: two Korea Filter (KF)94 (KF94-1, KF94-2) masks, one surgical (Surgical-1) mask, one anti-droplet (KF-AD-1) mask, and two dust (Dust-1, Dust-2) face masks. S. aureus (ATCC 6538), a well-performing test bacteria and murine coronavirus (ATCC VR-764) were prepared under a suitable culture condition. Then, a mask biological filtration tester was used to examine the microbial filtration efficiencies of masks. Test microorganisms were quantitatively measured via cultivation methods and microbial filtration efficiencies were calculated appropriately. Results: All face masks showed over 99.6% filtration efficiency for S. aureus or murine coronavirus. There were no significant differences among the bacterial filtration efficiencies of the face masks. KF94-1 (99.97±0.08%) and Dust-1 mask (99.97±0.07%) showed the highest (over 99.9%) filtration efficiency for murine coronavirus. KF94-1 or Dust-1 masks showed a significant virus filtration efficiency compared to Surgical-1 mask (p<0.05; Mann-Whitney U test). Conclusions: All the commercially available face masks used in this study can filter S. aureus or murine coronavirus in bioaerosols efficiently, regardless of the mask type. Therefore, our results suggest that wearing a certified face mask is a reliable means to prevent the transmission of infectious airborne diseases via biological aerosols.

• Korean Journal Plant Pathology
• /
• v.1 no.2
• /
• pp.136-140
• /
• 1985

The studies were conducted to test for combining ability and to evaluate resistance to maize dwarf mosaic virus (MDMV) by diallel crosses of corn inbreds. For the genetic analysis of the resistance, a diallel set of crosses without reciprocals was made using the eight corn inbreds which had different degrees of resistance to MDMV. Twenty eight $F_1$ hybrids showed different symtom severity. the highest value is 3.63 and the lowest value is 1.87 in disease ratings (1-4). General combining ability (GCA) for resistance to MDMV was highly significant, but specific combining ability (SCA) was not significant. Two inbreds, A632 and KS15 showed negative GCA effects, indicating that these parents were good general combiners and that resistance to MDMV increased in hybrid combinations. Hyrid A632 x KS5, showed the highest negative SCA effect and several combinations showed negative SCA effects. The analysis of parent-offspring covariance (Wr) and array variance (Vr), suggest that there may be many dominant genes in the resistant inbreds and many recessive genes in the susceptible inbreds.

• Journal of Korea Port Economic Association
• /
• v.24 no.4
• /
• pp.25-46
• /
• 2008

By using data envelopment analysis(DEA) this research measures the efficiency of Korea's five seaports and their Malmquist productivity from 1997 to 2006. Under the assumption of CRS(constant returns to scale) and VRS(various returns to scale), seaports' rankings of efficiency are measured. Busan port is confirmed as a best-performed port in the various measurements. Important finding facts are as follows. 1)Busan, lncheon and Ulsan seaports are efficient ports under the assumption of CRS and VRS. 2)Gwangyang port shows 4.3% lower efficiency level compared with efficient ports. 3)Pohang port shows 27.3% lower efficiency level compared with efficient ports. 4)Average total factor productivity of Korea's five ports has been lower at the rate of 3.1% during the period from 1997 to 2006. Main policy implications are 1)Busan port is more efficient than Gwangyang port, which reflects the difference of economic activities between two regional econmies. 2)During the period 1997-2006, Korea's five largest ports has experienced lower efficiency levels in the first half period because of the 1997 Korean Financial Crisis, but higher efficiency levels in the second half period because of economic recovery. In future research the more and better data will be expected to improve the understanding of Korean seaports' efficiency characteristics.

• Asian-Australasian Journal of Animal Sciences
• /
• v.15 no.12
• /
• pp.1695-1701
• /
• 2002

The purposes of this study were to optimize the in vitro maturation (IVM) and culture (IVC) systems of rabbit oocytes. Cytoskeletal structures in the germinal vesicle stage (GV) and during IVM are also investigated. Ovaries were transported from local slaughterhouses and the cumulus-oocyte complexes (COCs) were collected from ovarian follicles (${\geq}1mm$). COCs were randomly allocated to TCM199-based medium ($T_1$, TCM-199) supplemented with $NaHCO_3$, glucose, sodium pyruvate and FSH ($T_2$), $T_2+E_2+LH$ ($T_3$), $T_3+FBS$ ($T_4$), or $T_1+E_2+LH+FSH+FBS$ ($T_5$), for IVM. In Experiment 1, COCs were retrieved from the follicles and 51 GV oocytes were fixed in the fixative (MTSB-XF) for nuclear and cytoplasmic examinations. In Experiment 2, progressive changes of both the nucleus and the cytoskeleton were examined at 0, 6, 16, and 20 h after IVM. Maturation (MR) and developmental rates were assessed in Experiment 3. Cytoplasmic microtubules (MT) were clearly observed in rabbit GV oocytes. To our knowledge, this is the first report that describes the appearance of MT structures in the GV stage ooplasm. Tremendous variations in cytoskeletal alterations were observed among treatments with the exception of the vitelline ring (VR), which is constantly visible and unchanged during maturation. Germinal vesicle breakdown (GVBD) does not occur at 6 h after onset of maturation culture. When the oocytes for IVM were collected within 2 h, results from Experiment 3 showed that rates of nuclear maturation were 42, 8, 42, 37 and 65% at 16 h of IVM for $T_1$ through $T_5$, respectively, in which $T_1$, $T_4$ and $T_5$ had significantly greater MR than those in other groups (p<0.05). Morula/blastocyst development after parthenogenetic activation ranged from 20 to 63% with significantly greater rates in $T_3$, $T_4$ and $T_5$ (p<0.05). These results suggested that oocytes recovered from slaughterhouse ovaries can be matured and parthenogenetically activated in vitro, but the MR remained low in this study. Addition of $E_2$ and LH in the medium may be beneficial for cytoplasmic maturation, but FBS exerts a nega- tive role in the subsequent development of parthenogenetic embryos when energy substrates are provided in the IVC media. More studies are required for improving the MR and further development of the GV stage rabbit oocytes.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.32 no.2
• /
• pp.208-214
• /
• 1987

A genetic study on the panicle characters in Oryza sativa was carried out by means of a 5 x 5 diallel cross. The five parental varieties were Raekyung, Yeongnamjosaeng, Nongbaek, Yushin and Honenwase. All characters were correlated positively each other, except number of kernels per primary branch. The number of secondary branches per primary branch.was the most effective factor in determining the number of kernels per panicle, the next being the number of primary branches per panicle. Regression analyses of the data of Vr/Wr indicated the presence of non-allelic gene interactions for all characters. Overdominant characters were the number of kernels per panicle, the number of primary branches per panicle, the number of secondary branches per primary branch, the number of kernels per primary branch and sum of kernels on all the tertiary branches per panicle, suggesting that the characters were more influenced by dominant effect than additive effect. However, the number of kernels per secondary branch was partially dominant where the genetic variation was due more to additive effect than to dominance effect. But after omitting the parent which had non-allelic interaction gene, the characters; the number of kernels per panicle, the number of secondary branches per primary branch, and the number of kernels per secondary branch, were partially dominant. Narrow sense heritabilities(h$^2$ N) in number of kernels per panicle and number of secondary branches were high and moderate, respectively, but those of the rest were lower. Mean squares of GCA and SCA of all characters, except SCA of the number of kernels per secondary branch, were highly significant. Effects of GCA were larger than SCA effects in all characters. Raekyung, Yushin and Nongbaek had highly positive GCA, and the best positive SCA was observed in crosses of Nongbaek x Tongillines (Raekyung, Yushin, and Yeongnamjosaeng) in all characters.

• The Journal of Korean Society for Radiation Therapy
• /
• v.33
• /
• pp.71-78
• /
• 2021

Purpose: To evaluate the inter-fractional position and respiratory reproducibility of lung and liver tumors using pressure conserving type(P-type) abdominal compressor in volumetric modulated arc therapy(VMAT). Materials and methods: Six lung cancer patients and three liver cancer patients who underwent VMAT using a P-type abdominal compressor were included in this study. Cone-beam computed tomography(CBCT) images were acquired before each treatment and compared with planning CT images to evaluate the inter-fractional position reproducibility. The position variation was defined as the difference of position shift values between target matching and bone matching. 4-dimensional cone-beam computed tomography(4D CBCT) images were acquired weekly before treatment and compared with planning 4DCT images to evaluate the inter-fractional respiratory reproducibility. The respiratory variation was calculated by the magnitude of excursions by breathing. Results: The mean ± standard deviation(SD) of overall position variation values, 3D vector in the three translational directions were 1.1 ± 1.4 mm and 4.5 ± 2.8 mm for the lung and liver, respectively. The mean ± SD of respiratory variation values were 0.7 ± 3.4 mm (p = 0.195) in the lung and 3.6 ± 2.6 mm (p < 0.05) in the liver. Conclusion: The use of P-type compressor in lung and liver VMAT was effective for stable control of inter-fractional position and respiratory variation by reproduction of abdominal compression. Appropriate PTV margin must be considered in treatment planning, and image guidance before each treatment are required in order to obtain more stable reproducibility