• Tunnel and Underground Space
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• v.16 no.5 s.64
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• pp.422-431
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• 2006

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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• pp.448-453
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• 2005

For under-water communication system, due to limit of bandwidth and reflect of under-water wave, it is difficult to implement high-reliability high-speed digital communication system. To apply high-reliability and high-speed communication system for under-water system, the efficient combine the channel design with the use of multiple transmit and/or receive antennas. Therefore this paper analyze the space time coded system for under-water communication environment.

• Proceedings of the Korean Society of Crop Science Conference
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• 2004.04a
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• pp.102-103
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• 2004

[ $\bigcirc$ ] In the growth simulation without changing of module with ORYZA2000, dry matter, LAI and leaf nitrogen content(FNLV) were estimated well under high nitrogen applicated condition, but overestimated under low nitrogen applicated condition. $\bigcirc$ Nitrogen stress factor on the SLA was introduced into ORYZA2000 because especially overestimated LAI under low nitrogen applicated condition was originated from SLA decrease with leaf nitrogen(FNLV) decrease. $\bigcirc$ In the growth simulation with modified SLA modified module, LAI was estimated well under even low nitrogen applicated condition, but dry matter was hardly changed compared with default. $\bigcirc$ Simulated plant nitrogen content and dry matter have no clear difference between modules, but compared with observed values, panicle weight(WSO) and rough rice yield(WRR14) were overestimated under high nitrogen applicated because of lodging, pest, disease and low nitrogen use efficiency.

• Clinical and Experimental Pediatrics
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• v.61 no.12
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• pp.381-386
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• 2018

Purpose: The use of proper safety restraint systems by children is vital for the reduction of traffic accident-related injury and death. This study evaluated the rates of use of safety restraint systems and front seats by Korean children. Methods: Based on data from the National Health and Nutrition Examination Survey from 2008 to 2015, I investigated the frequencies of safety restraint systems and front seat use by children under six and 12 years of age, respectively. Results: The percentage of respondents who said they always use safety restraint systems increased from 17.7% in 2008 to 45.0% in 2015. The rate of children who did not use the front seats at all was 47.3 % in 2008 compared to 33.4% in 2015. Multivariate logistic regression analysis showed a decrease in safety-restraint-system use as age increased (odds ratio, 0.63; 95% confidence interval [CI], 0.51-0.77). The use rate of front-passenger seat belts by the mother is significantly correlated with the safety-restraint-system use rate by children (odds ratio, 2.14; 95% CI, 1.12-4.06). Conclusion: Although the rate of safety-restraint-system use for children is increasing annually, it remains low. Additionally, the use rate of front passenger seats for children is high. To reduce the rates of injury and death of children from traffic accidents, it is necessary to educate on the appropriate use of safety restraint systems according to age and body size and to develop stronger regulations.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.231-231
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• 2017

Drought limits rice production under upland condition. This study quantified the effect of rhizobacteria inoculation on rice root system developmental response to drought and its role in maintaining high soil water use, and dry matter production under drought using NSIC Rc192 (rainfed lowland rice variety). The source of inoculant was Streptomyces mutabilis, a recently isolated rhizobacteria containing plant growth promoting compounds such as ACC deaminase, indole-3-acetic acid and phosphatase (Cruz et al., 2014, 2015). In the first experiment, pre-germination inoculation of seeds with S. mutabilis significantly increased the shoot and root (radicle) length as well as root hair lengths, relative to the non-inoculated control. In the second experiment, rice plants inoculated with S. mutabilis and grown in rootbox with soil generally had greater total root length under drought regardless of the timing of inoculations, relative to the non-inoculated control. Consequently, improved root system development contributed to the increase in soil water uptake under drought and thus, dry matter production. Among inoculation treatments, one-time inoculation of S. mutabilis either at pre-germination or pre-drought stress at 14 days after sowing (DAS), had significantly greater shoot dry matter production than three-time inoculation at pre-germination, at thinning (3 DAS) and at pre-drought (14 DAS). This study demonstrated the effectiveness of rhizobacteria (S. mutabilis) containing growth promoting compounds for enhancing drought dehydration avoidance root traits and improving the growth of rice plants under drought condition.

• Journal of Communications and Networks
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• v.8 no.2
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• pp.144-150
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• 2006

A serious problem with traditional 'command & control' spectrum management techniques is that they do not easily accommodate new technologies and new services. This paper describes the necessary principles of flexible-use spectrum rights which may allow a wide variety of spectrum uses in a single general-purpose band. Based on the electrospace description of the radio spectrum, these principles allow general aggregation or division of licensed electrospace regions via secondary markets, providing rules for how regulatory limits change under aggregation or division. These flexible-use principles limit transmitter behaviors that tend to create a more difficult operating environment for receivers, while making receivers responsible for handling any remaining interference. The author shows how flexible-use principles could provide a basis for real-world flexible-use frequency bands.

• Journal of the Korean Home Economics Association
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• v.42 no.8
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• pp.65-76
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• 2004

The purpose of this study is to offer essential information related to early childhood education and care policy. Using the Korea Labor and Income Panel Study(KLIPS) Vol.5., this study analyzed sociodemographic factors that decide the use and type of institute for early childhood education and care. The following results are obtained： First, it is not easy for young children under three years old to use education and care institutes because of their preference for home care. Second, the mother's job status affects the child's use of child care centers and private institutes for education except for the using of early child education centers. Third, the affecting main factors for the use of child care centers are quite similar to critical factors for use of the private institute for education. Thus, young children using the private institute for education could be interpreted as coming from a low-income class compared with the children using the early child education centers.

• Educational Technology International
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• v.22 no.1
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• pp.23-55
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• 2021

Under the context of the recent curriculum reform in Mongolia emphasizing technology integration in schools, the main purpose of this study was to examine external and internal factors that influence teachers' use of technology. This study aimed to investigate structural relationships between school support, technology use, and TPACK (Technological Pedagogical and Content Knowledge) among Mongolian secondary school teachers. This study was conducted with 208 secondary school teachers in Ulaanbaatar, Mongolia. Data were collected through an instrument that measures three factors: teachers' use of technology, TPACK, and school support. The results indicate that TPACK has a partial mediation effect on the relationship between school support and the use of technology. The contribution of this study lies that it examines the complex relationships between internal and external factors affecting teachers' technology integration, especially among Mongolian teachers who are less researched in the existing literature.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.120-120
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• 2022

Agrivoltaic System (AVS) was introduced with the concept that it could generate electricity by using the extra light remain after crops use for photosynthesis in farm, which can earn additional income. However, crop yield was declined under the AVS condition due to the decrease in light energy. In the past, many researchers have been studied about crop states under shading conditions. However, the phenomenon of partial shading such as under the AVS is not well studied. In this study, to figure out the response of crop under the different light conditions, the electron transport rate (ETR) and non-photochemical quenching (NPQ) of rice was investigated using the chlorophyll fluorescence measurement. Also, physiological changes of crops under the shading conditions were investigated. The growth experiment under partial shading under AVS and overall shading which made of 35% shade cloth was conducted to understand the eco-physiological responses of rice to light in terms of the photosynthesis. Under the shading conditions, SPAD value and chlorophyll contents were higher, but the leaf thickness was lower than control. The overall shading condition show lower ETR than others during the growing season. In contrast, NPQ was higher than other treatments. This means the available light energy cannot contribute to photosynthesis under the shading condition.

• Journal of Korean society of Dental Hygiene
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• v.10 no.4
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• pp.635-644
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• 2010

Objectives : The purpose of this study was to analyze and investigate the effecting factors on the actual condition of dental clinic use of the out patient. Methods : In oder to achieve this purpose, A survey for 302 patients in 6 participating dental clinics located in Daejeon metropolitan city from May 01 to May 30, 2010. The result of this study was as follows. Results : 1. The duration of dental clinic use was reflected in 36.1% of the under 1 year, 34.1% of over 2 years, and 29.8% of over 1 ~ under 2 years in order. Especially, the higher the duration of over 2 years the higher the age was, on married group had a significance. 2. The type of medical examination for samples was 27.6% of periodontal, 26.5% of conservative, 17.2% of prosthodontics, 10.9% of implant, and 7.9% of preventive in order. Especially, the male group the more the prosthodontics, implant had a significance. the higher the monthly income, on married group, the more the periodontal, prosthodontics and implant had a significance. 3. The motive of dental clinic selection was 38.4% of acquaintances' inducement, 33.4% of the superb treatment, 15.6% of easy convenience, and 7.0% of friendliness staff in order. Especially, male group the more the easy convenience, superb treatment, friendliness staff had a significance. 4. The mean of transportation in order to visit a dental clinic was 38.7% of public transportation, 37.5% of the own car, 23.8% of others in order. Especially, there was a highly significant difference on the public transportation in female, the lower education level, lower monthly income, and medical protection group. 5. The duration of time required of dental clinic reflected in 80.1% of the under 30 minute, 16.3% of over 30 minute~under 1 hour, and 3.6% of over 1 hour in order. Especially, the higher the treatment satisfaction, the dissatisfaction the higher the duration of time required under 30 minute had a significance. Conclusions : These results indicate that as medical services upgrade and get more varied, the expectation of medical quality also increases. It is thus considered that the revitalization of this hospital's management strategy can be achieved by providing highly developed medical services, and, more importantly, by better understanding the actual conditions of dental clinic use by the patients themselves.