• Journal of the Korea Convergence Society
• /
• v.12 no.8
• /
• pp.267-277
• /
• 2021

This study was done with collected and analyzed data using the convenient sampling method on 349 middle school students located in the metropolitan area in order to verify the effect of instructors verbal and nonverbal communications on instructor trust and class commitment in middle school sports clubs. As a result of analyzing the collected data, First, as a result of correlation analysis using the total number of items between sub-factors of latent variables, all correlation coefficients showed a positive (+) significant relationship. Second, as a result of the effect of verbal and nonverbal communications on instructor trust, it was found that the influence of spatial language, appearance language, body language, and linguistic factors were significantly explained in order. Third, as a result of the effect of verbal and nonverbal communications on class flow, it was found that class commitment was significantly explained in the order of appearance language, spatial language, and linguistic factors. Fourth, as a result of the influence of instructor's trust on class commitment, it was found that only the exercise capacity factor significantly explained class commitment. This study provides basic academic data to plan and create interactions with school sports club instructors and students.

• Animal Bioscience
• /
• v.35 no.7
• /
• pp.989-998
• /
• 2022

Objective: This study investigated the effects of intrauterine growth restriction (IUGR) during late pregnancy on the cell growth, proliferation, and differentiation in ovine fetal thymuses. Methods: Eighteen time-mated Mongolian ewes with singleton fetuses were allocated to three groups at d 90 of pregnancy: restricted group 1 (RG1, 0.18 MJ ME/body weight [BW]^0.75/d, n = 6), restricted group 2 (RG2, 0.33 MJ ME/BW^0.75/d, n = 6) and control group (CG, ad libitum, 0.67 MJ ME/BW^0.75/d, n = 6). Fetuses were recovered at slaughter on d 140. Results: The G0/G1 phase cell number in fetal thymus of the RG1 group was increased but the proliferation index and the expression of proliferating cell nuclear antigen (PCNA) were reduced compared with the CG group (p<0.05). Fetuses in the RG1 group exhibited decreased growth hormone receptor (GHR), insulin-like growth factor 2 receptor (IGF-2R), and their mRNA expressions (p<0.05). For the RG2 fetuses, there were no differences in the proliferation index and PCNA expression (p>0.05), but growth hormone (GH) and the mRNA expression of GHR were lower than those of the CG group (p<0.05). The thymic mRNA expressions of cyclin-dependent protein kinases (CDKs including CDK1, CDK2, and CDK4), CCNE, E2-factors (E2F1, E2F2, and E2F5) were reduced in the RG1 and RG2 groups (p<0.05), and decreased mRNA expressions of E2F4, CCNA, CCNB, and CCND were occurred in the RG1 fetuses (p<0.05). The decreased E-cadherin (E-cad) as a marker for epithelial-mesenchymal transition (EMT) was found in the RG1 and RG2 groups (p<0.05), but the OB-cadherin which is a marker for activated fibroblasts was increased in fetal thymus of the RG1 group (p<0.05). Conclusion: These results indicate that weakened GH/IGF signaling system repressed the cell cycle progression in G0/G1 phase in IUGR fetal thymus, but the switch from reduced E-cad to increased OB-cadherin suggests that transdifferentiation process of EMT associated with fibrogenesis was strengthened. The impaired cell growth, retarded proliferation and modified differentiation were responsible for impaired maturation of IUGR fetal thymus.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.21 no.2
• /
• pp.62-73
• /
• 2022

As the competition among the autonomous vehicle (AV, here after) developers are getting fierce, Korean government has been supporting developers by deregulating safety standards and providing financial subsidies. Recently, some OEMs announced their plans to market Lv3 and Lv4 automated driving systems. However, these market changes raised concern among public road management sectors for monitoring road conditions and alleviating hazardous conditions for AVs and human drivers. In this regards, the authors proposed a methodology for monitoring road infrastructure to identify hazardous factors for AVs and categorizing the hazards based on their level of impact. To evaluate the degrees of the harm on AVs, the authors suggested a methodology for managing road hazard factors based on vehicle performance features including vehicle body, sensors, and algorithms. Furthermore, they proposed a method providing AVs and road management authorities with potential risk information on road by delivering them on the monitoring map with node and link structure.

• Journal of Space Technology and Applications
• /
• v.1 no.1
• /
• pp.23-32
• /
• 2021

The high-level Space Situational Awareness (SSA) objective is to provide to the users dependable, accurate and timely information in order to support risk management on orbit and during re-entry and support safe and secure operation of space assets and related services. Therefore the risk assessment for the re-entry of space objects should be managed nationally. In this research, the Software for Re-Entry Prediction of space objects (SREP) was developed for national SSA system. In particular, the rate of change of the drag coefficient is estimated through a newly proposed Drag Scale Factor Estimation (DSFE), and is used for high-precision orbit propagator (HPOP) up to an altitude of 100 km to predict the re-entry time and position of the space object. The effectiveness of this re-entry prediction is shown through the re-entry time window and ground track of space objects falling in real events, Grace-1, Grace-2, Tiangong-1, and Chang Zheng-5B Rocket body. As a result, through analysis 12 hours before the final re-entry time, it is shown that the re-entry time window and crash time can be accurately predicted with an error of less than 20 minutes.

• Korean Journal of Food Science and Technology
• /
• v.54 no.2
• /
• pp.155-162
• /
• 2022

This study investigated the immunostimulatory effect of enzymatic porcine placental hydrolyzate (EPPH) in cyclophosphamide (Cy)-treated rats. This effect of EPPH prevented Cy-induced decreases in body, spleen, and thymus weights and natural killer (NK) cell activity. The numbers of immune cells, such as white blood cells, granulocytes, and lymphocytes, and mid-range absolute counts were significantly higher compared to the control group. The levels of tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β, IL-2, IL-12, and immunoglobulin G (IgG) were notably reduced by Cy, while EPPH prevented these effects. Histopathological analysis of spleen samples revealed the protective effect of EPPH against Cy-induced immunosuppression. The findings demonstrate that EPPH can alleviate immunosuppression by cell viability, tissue damage, and regulation of the levels of cytokines. EPPH may have value as a component of immunostimulatory agents or an ingredient in functional foods.

• Smart Media Journal
• /
• v.11 no.5
• /
• pp.75-81
• /
• 2022

In order to respond to carbon neutrality and climate change in agriculture, agricultural machinery, which has been developed centered on internal combustion engines, needs to be converted to an electric-based technology that does not emit greenhouse gases. In this study, simulations for electric UTV suspension design were performed to reduce vibration and shock of electric UTV for agricultural use and to improve driving stability and control performance of the vehicle. The simulation was performed by dividing the tolerance load of the vehicle body and the loaded load state. The range of motion of the suspension spring of UTV is within 30% of the range of motion under condition B under tolerance, the displacement of the UTV suspension with full load is reduced from 264mm to 121mm, and the damping speed is 260mm/s to 300mm/s that it can be seen that the range of motion is within 60%. Suspension design of electric UTV for multi-purpose agricultural work is a very important factor for maintaining agricultural work ability in towing work such as tillage as well as driving and terrain adaptation. The results of this study can be usefully used to determine the spring parameters with the appropriate damping range so that the electric UTV can be used for various agricultural tasks.

• Journal of Korea Entertainment Industry Association
• /
• v.15 no.3
• /
• pp.269-278
• /
• 2021

This study was inteded to include online social relations and ability use information and communication devices to analyze the elderly's participation in volunteer activities and provide basic data to identify the elderly's participation in volunteer activities. The statistical data of the 2017 National survey of Senior Citizen, only 10,073 people aged 65 or older were sampled out of 10,299 people. The participation rate of volunteering was frequently analyzed, and the difference in participation in volunteer according to the factors was Chi-square analysis and One-way variance analysis. A polynomial regression analysis was conducted to identify the effect factors of participation in volunteering. As a results. 3.9% of older adults are volunteering and 11.5% are experienced in the past. Participation in volunteer activity differed significantly depending on age, education level, economic level, subjective health, body function, ability use information and communication devices, social networks, frequency of face-to-face contact and frequency of non face contact. In the regression analysis, utilization of communication and device, social networking, face to face contact frequency were show to be the effect factors. In order to promote elderly's participation in volunteer activities, consideration of related resources reported in prior studies, social relations, frequency of face-to-face contact and ability to use information and communication devices is considered important.

• Animal Bioscience
• /
• v.35 no.1
• /
• pp.87-95
• /
• 2022

Objective: This study was conducted to investigate the effect of associating calcium butyrate with tannin extract, compared to an antimicrobial on the growth performance, incidence of diarrhea, intestinal histology, immune-expression of cyclooxygenase-2 (COX-2) and tumor necrosis factor α (TNF-α) in piglets. Methods: Seventy-two piglets (36 barrows and 36 gilts) weaned at 28±2 d and initial body weight of 7.17±1.07 kg were allocated to 3 treatments in a randomized complete block design with 8 replicates per treatment and 3 animals per experimental unit. Treatments were composed of NC, negative control: basal diet without additives; PC, positive control: basal diet + 40 mg/kg of colistin sulfate; or BT, basal diet + calcium butyrate + tannin extract. The butyrate and tannin inclusion levels were 0.15% in the pre-starter phase and 0.075% in the starter phase. Incidence of diarrhea was monitored daily, and on d 14 and 35 of experiment, 1 animal from each experimental unit was slaughtered to collect intestinal samples. Results: No significant differences were observed for growth performance. The butyrate-and tannin-based additive resulted in reduced (p<0.05) incidence of diarrhea in piglets during d 1 to 14 and d 1 to 35 in comparison with the other treatments. Piglets that consumed the diet containing the calcium-butyrate and tannin showed a lower (p<0.05) crypt depth in the duodenum than those receiving the NC treatment at 14 d of experimentation. The BT treatment provided a lower (p<0.05) immune-expression of COX-2 at 14 d and TNF-α at 35 d in the duodenum. Conclusion: Association between calcium butyrate and tannin extract resulted in a significant decrease in the incidence of diarrhea and inflammatory process in the duodenum of piglets. Therefore, calcium-butyrate combined with tannin could be a part of an alternative program to reduce the use of antimicrobials in the diet of weaned piglets.

• Journal of the Korean Applied Science and Technology
• /
• v.38 no.2
• /
• pp.465-475
• /
• 2021

This study conducted an online and offline survey of 210 people from March 11 to 27, 2021 for the purpose of investigating and analyzing the current status of skin stress recognition and beauty care behavior due to wearing masks. The collected data were analyzed using SPSS 25.0 with Cronbach's α, Frequency Analysis, Chi-square test, and One way Anova. The average daily mask wearing time of more than 7 hours during the Covid-19 period was 43.8%, and skin stress recognition by wearing masks was highest among those in their 30s (M=4.27) and service workers (M=4.64), and those with acne and skin troubles (M=4.47) perceived high stress. The most important factor for home care treatment was cleansing(67.6%) and for beauty care was skin care(36.7%). Considerations factors on beauty care were 54.3% for service and customer care capabilities, and on body shape management method 45.7% for exercise. According to this study, respondents are recognizing skin stress due to the long-term use of masks, and home care treatment has been increasing as the esthetic salon has become unstable to visit due to the Covid-19 epidemic.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.49 no.2
• /
• pp.180-187
• /
• 2022

The aim of this study was to investigate the risk factors associated with sleep disordered breathing (SDB) by comparing intraoral factors, body mass index (BMI), and medical history with pediatric sleep questionnaire (PSQ) findings. Seven hundred eighty-seven subjects aged between 7 to 11 years old were included. Their caregivers were asked to complete questionnaires. Oral manifestations including Angle's classification, overjet, and Brodsky tonsil grade were examined. Children with PSQ scores of more than 0.33 points were classified into the SDB high-risk group. Among the 787 subjects, 34 (4.3%) were classified into the SDB high-risk group. Children with allergic rhinitis, atopic dermatitis, excessive overjet, or large tonsil size had a significantly higher risk for SDB versus those without. Also, there was a significant difference in SDB risk according to BMI status. Gender, gestational age, breastfeeding, and Angle's classification were not associated with SDB. Children at high risk for SDB were predisposed to tonsillar hypertrophy, allergic rhinitis, obesity, and atopic dermatitis. Children with these factors could be candidates for early intervention to prevent the progression of SDB.