• Journal of The Korean Society of Grassland and Forage Science
• /
• v.24 no.2
• /
• pp.123-128
• /
• 2004

This study was conducted to investigate the effects of bulb size (10, 15, 20, 25 cm) on growth and yield characteristics of edible canna in Jeju region from 20 May to 24 Nov. 2003. The results obtained were summarized as follows; Plant height grew big 78.8~129.1 cm as bulb size increased 10~25 cm. Leaf length, leaf width, number of leaves, tillers and bulb per plant and stem diameter were the same trend with plant height response. Fresh matter yield increased 29.0~91.1 MT/ha as bulb size increased from 10 to 25 cm. Fresh weight of above-ground part and bulb yield were the same trend with fresh matter yield.

• Korean Journal of Plant Resources
• /
• v.22 no.1
• /
• pp.71-77
• /
• 2009

Antioxidative activity and ${\alpha}$-amylase inhibitory activity were investigated in the methanol extracts of 289 species of angiosperm plants native to Jeju Island in order to select the plant species containing bioactive materials for functional foods or medicines. The antioxidative activity, estimated by the DPPH radical scavenging capacity, was high in the galla of Rhus chinensis, the fruit of Platycarya strobilacea, and the stem of Cedrela sinensis. Particularly, the antioxidative activity of Rhus chinensis galla (94.2${\pm}$0.8%) was very high even though compared to those of BHA (61.7${\pm}$0.6%) and ascorbic acid (53.6${\pm}$0.7%). The ${\alpha}$-amylase inhibitory activity was 80% or above in 9 species including Cornus macrophylla (stem, leaf), Distylium racemosum (leaf) and Vaccinium oldhami (leaf). These results suggest that these plants could be potentially utilizable to develop bioactive materials for functional foods or medicines.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.34 no.3
• /
• pp.201-207
• /
• 2008

In this study, we investigated the antimicrobial and antifungal activity from the wild seaweeds of Jeju island. The active ingredients of the seaweeds were prepared by 80% methanol extraction. Antimicrobial and antifungal activity of seaweed extracts was examined. We found that 6 plant extracts among 45 plants, namely, Codium contractum, Undaria pinnatifida, Ishige sinicola, Ishige okamurai, Ishige okamuriai, Ecklonia cava, Hizikia fusiformis, Ulva fasciata, Ulva pertusa, Sargassum siliquastrum, Ecklonia kurome, Gracilaria textorii, significantly inhibited growth of harmful microorganisms. Additionally, according to DPPH assay. 2 plant extracts were found to have antioxidant activities. Taken together, these results suggest the possibility that 11 plant extracts can be utilized as an antimicrobial agent.

• Journal of Fisheries and Marine Sciences Education
• /
• v.11 no.1
• /
• pp.59-68
• /
• 1999

The effectiveness of fishery resources enhancement of artificial reef settled in the coast of Cheju Island was determined by using the samples collected by scuaba and caught by the trammel net. The obtained results are summarized as follows; 1. Six types of shellfish were found in the artificial reef area, and the amount of shellfish living in that area was $490{\sim}3,483g/m^2$ according to our research. This shows a high density of shellfish in that area. 2. Ten types of seaweeds were found in the artificial reef area, and the reef living in that area was abundant, with $3,556{\sim}10,550g/m^2$. 3. The amount of a catch of fish in the artificial reef area was 3.5~21.4 times more than in the control area. This result shows the high productivity in that area.

• The Journal of the Korea Contents Association
• /
• v.19 no.3
• /
• pp.649-658
• /
• 2019

The purpose of this study was to investigate the current status of postpartum depression intervention program performed in Korea and to evaluate its effectiveness. Of the Korean academic journals reported until November 2018, 13 experimental studies were selected and used for final analysis. The average age of the subjects was 26.9 to 34.4 years, and subjects were puerperal women or couples. The sample size was 6~39 (mean: 20.4) in the experimental group, 5~40 in the control group (mean: 20.0), and the intervention program consisted of 0.5~12 weeks/2~14 sessions/10~120 minutes per session. The design of all the studies was a non-equivalent control group pre-post test design. The main dependent variables, postpartum depression, fatigue, and maternal role self-confidence, were all found to have a statistically significant median level of effect size in the meta-analysis. This study confirms the composition and effects of various experimental studies used to mediate postpartum depression in Korea. This could be used as specific evidence-based data to form an optimal postpartum intervention program.

• New Physics: Sae Mulli
• /
• v.68 no.11
• /
• pp.1249-1261
• /
• 2018

The quantitative representation for the magnetic force of a cylindrical permanent magnet acting on a ferromagnetic cylindrical object was derived on the basis of magnetization theories, and the Gilbert and Ampere models of magnetism. The magnetic force derived in this study is directly proportional to the remanent magnetization magnetic field, the cross-sectional area of the permanent magnet, the saturation magnetic field, and the cross-sectional area of the ferromagnetic object and is inversely proportional to the square of the quantity related to the distance between the permanent magnet and the ferromagnetic object. The magnetic forces of an AlNiCoV cylindrical permanent magnet and a Ferrite cylindrical permanent magnet, both with a radius of 0.4 cm and a length of 7 cm, acting on ferromagnetic objects at distances farther than the radius were calculated to be less than 3.6711 N and 0.1857 N, respectively.

• Journal of agricultural medicine and community health
• /
• v.47 no.1
• /
• pp.27-39
• /
• 2022

Objectives: The purpose of this research was to explore Fall Risk Home Environment(FRHE) and to investigate the association between FRHE and fall experience among community-dwelling older adults. Methods: The data were collected from 299 older adults using FRHE through observation and interview at home of the participants and were analyzed with SPSS 22.0 applying descriptive statistics, χ²-test, t-test, and logistic regression analysis. Results: The prevalence of fall experience during the past year was 51.5%. 'No handles beside the toilet or bathtub'(73.2%) was most common FRHE factor, 'thresholds in your room or kitchen'(68.9%), 'wearing socks, outer socks, or slipper when you move in the house'(59.5%), and threshold on the gate (apartment entrance)(55.5%) were followed. The findings of logistic regression of FRHE on fall experiences showed darkness of house had the highest Odds Ratio (OR 9.83 95% CI 3.75-25.71), followed by furniture obstructs your walking in the house(OR 7.07, CI 2.88-17.36), dark kitchen (OR 5.13, CI 2.38-11.03). The group having fall experiences presented significantly higher score of FRHE than the group of non experiences of fall. Conclusion: The community dwelling older adults exposures to various FRHE factors and FRHE might increase the risk of falls. Assessing and modifying the home environment could be a good strategy to prevent fall among older adults.

• Korean journal of applied entomology
• /
• v.61 no.4
• /
• pp.623-631
• /
• 2022

The family Ptiliidae (Insecta: Coleoptera) has approximately 1,000 valid species in 100 recognized genera. Ptiliid beetles are readily collected from various habitats. They can be distinguished by feather-like hindwings and small body sizes. The genus Acrotrichis is the largest ptiliid genus. It contains almost a quarter of all ptiliids. In Korea, a single species of Acrotrichis lewisii (Matthews, 1884b) was recently reported in 2020. In this paper, we report two additional species, A. thoracica (Waltl, 1838) and A. grandicollis (Mannerheim, 1844) from the Korean Peninsula, collected during an assessment of biological variation in agricultural land of Jeju Island. Illustrations of habitus and diagnostic characters, distribution map and a key to Korean Acrotrichis species are provided.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
• /
• v.18 no.4
• /
• pp.1-11
• /
• 2022

In this study, the thermal runaway of NCM and LFP batteries were compared and analyzed through numerical analysis under various conditions. Comparing the thermal runaway of the NCM622 (18650) battery cell and the LFP (18650) battery cell through oven test simulation, the LFP battery did not show thermal runaway, whereas the NCM622 battery temperature increased to 710℃ in 12 minutes. To observe the thermal runaway and propagation of the prismatic LFP battery cell, the internal temperature was set at 200℃ and the oven test simulation was conducted. It was found that thermal runaway occurred at 391℃ after 47 minutes. As a result of observing thermal runaway propagation by placing five NCM622 and LFP battery cells, the thermal runaway propagation was clearly observed in the case of the NCM622 battery, but in the case of the LFP battery, thermal runaway was not observed after the first cell. From the third battery cell, it was confirmed that the temperature change was very insignificant, and through this, it is considered that the LFP battery is relatively safe compared to the NCM battery in terms of the thermal runaway propagation of the battery.

• Journal of Korean Dental Hygiene Science
• /
• v.1 no.1
• /
• pp.37-46
• /
• 2018

This study conducted a 'specialist tooth brushing' method against the severely disabled once every other week. The purpose of this study is to analyze and validate the effectiveness of maintaining healthy periodontal management when consistent oral hygiene lasts with minimum stimuli for 24 - months. The conclusions were as follows. Table 2 compares the difference between group 1 and 2 from the 1^st to 11th management and verifies the actual difference in measurement of each index. Group 1 used a professional tooth brush while Group 2 used a general brush. There were found many significant differences in dental index. As for PHP, Oral Malodor index and gingival bleeding, it was found that one or two times of dental care can make substantial differences in dental health condition. These results show that as the number of toothbrush method has been increased, gingival bleeding and periodontal index are significantly improved, not to mention the improvement of gingivitis and periodontal disease. This is because periodontal tissue is affected by brushing method, brushing time and consistency of dental care. During the 6-month period, 20 minutes of active periodontal care was intensively conducted, and for 18-months the effect of consistent care was verified by 10-minute periodontal care once every other week. As a result of the test, it was found that there was no complete regression in the basic periodontal treatment and the periodontal health condition had been maintained for 24 months. Also this test shows that, despite of inconsistent dental hygienic care, regular plague control can prevent dental diseases and maintain the dental health. This study proved that periodontal condition can be maintained by periodontal care once every other week as the tooth brushing properly stimulates the gums with positive effect. Therefore, professional dental healthcareworkers should be designated for each facility for the disabled, and dental health of the disabled should be professionally cared on a regular basis, and consistent and repetitive management by the dental care specialist are required.