• Korean Journal of Soil Science and Fertilizer
• /
• v.50 no.3
• /
• pp.150-161
• /
• 2017

This study was conducted with the data of monitoring on soil chemical properties of rice paddy soils in Gyeongbuk Province. The selected soil chemical properties were analyzed every 4 year from 1999 to 2015. The soil pH measured in 2015 was higher than pH 6.0, which was 0.3-0.4 pH unit higher than data until 2007 survey year. The mean content of organic matter was greater than $24g\;kg^{-1}$ since 2003, but 35% of soil samples remained below the recommended level ($20-30g\;kg^{-1}$) in 2015. The mean concentration of available phosphate was maintained at $40mg\;kg^{-1}$ higher than the upper recommendation level ($80-120mg\;kg^{-1}$), and more than 40% of paddy soils tested were found to have less than the recommendation level during the survey period. The exchangeable K concentration ranged from 0.25 to $0.39cmol_c\;kg^{-1}$. Exchangeable Ca showed an average at the optimum range ($5.0-6.0cmol_c\;kg^{-1}$) during the monitoring period. Exchangeable Mg decreased linearly ($0.02cmol_c\;kg^{-1}\;year^{-1}$) from $1.55cmol_c\;kg^{-1}$ as of 1999 to below the lower level of the recommendation range ($1.5-2.0cmol_c\;kg^{-1}$). The amount of available $SiO_2$ was increased significantly from 2011 to over the recommendation level (${\geq}157mg\;kg^{-1}$). It was revealed that the soil chemical properties of rice paddy fields was influenced by topology, soil texture, type and region as result of principal component analysis or cluster analysis. Therefore, an assessment on chemical properties of rice paddy soils should be performed to consider various soil physical conditions and agronomic practices such as fertilization, cropping system, and so on. Because of the high variability of nutrient levels across Gyeongbuk Province, nutrient management based on soil fertility test is required by respective farm land unit.

• Journal of the Korea Society of Computer and Information
• /
• v.25 no.8
• /
• pp.73-79
• /
• 2020

Since the start of the 4th industrial revolution, technologies have been developed in the Internet of Things (IoT), artificial intelligence (AI), virtual reality (VR), and 5G. Compared to other technologies IoT is currently being commercialized more than other technologies where the numbers of connected things are increases every year. The IoT has a huge advantage to provide convenience and lots of information to users, but security cannot keep up with the speed of development. IoT services continue to provide services for related devices, but at present, more and more types of new services are being combined with other technologies by utilizing the services of devices. This paper reviews and analyzes research on security issues and services related to the Internet of Things to explore how security trends and service delivery will develop in the future.

• Korean Journal of Breeding Science
• /
• v.41 no.1
• /
• pp.36-39
• /
• 2009

A new mungbean cultivar "Dahyeon" (Vigna radiata (L.) Wilczek) was derived from the cross between Jeonnam11 and AV-1-3-34-204 at National Institute Crop Science (NICS) and Jeollanamdo Agricultural Research & Extension Services (JARES) in 2006. "ahyeon" has erect growth habit, heart leaflet, green hypocotyl, black and straight pod when matured, and dull green seed surface. The pods number per plant was 21.0, which was 4.0 more than check cultivar "wool" The plant height and thousand seed weight were 57cm and 48 g respectively. The sprout yield was up to 5% more than that of the check cultivar. It was field resistance to mungbean mottle virus, cercospora leaf spot, and powdery mildew. The average yield was 1.90 ton/ha, which was 17% more than the check cultivar.

• Journal of Bio-Environment Control
• /
• v.21 no.4
• /
• pp.419-427
• /
• 2012

This study was carried out to investigate the effect of two shading methods, shading agent spray on the glasshouse and internal shading screen treatment, on the growth and fruit quality of paprika (Capsicum annuum L. 'Cupra' and 'Coletti') in summer season cultivation. In the shading agent treatment, a commercial shading agent diluted with water at a ratio of 1 : 4 was sprayed on the roof of a glasshouse. In the internal shading screen treatment, a 10~20% shaded screen was used during the day time when the sun radiation was greater than $700W{\cdot}m^{-2}$. Compared to the unshaded control, photosynthetic photon flux density (PPFD) decreased in the greenhouse in the shading agent (SA) and shading screen (SS) treatments by 20% and 30%, respectively. Lower air temperatures and higher relative humidities were observed in the SA than in both the control and the SS treatment. Time to reach the break point of humidity deficit $8g{\cdot}m^{-3}$ was 2 hours late in the SA than in both the control and the SS treatment. Compared to control, both the SA and the SS treatments showed lower instantaneous temperatures of leaf, fruit, and flower by $2^{\circ}C$, $5^{\circ}C$ and $3^{\circ}C$, respectively. There were no differences in number of branches, stem diameter, and leaf size among treatments although both shading treatments promoted plant height in both cultivars. Botrytis infection ratio declined with the SA treatment by 14.7% in 'Cupra' and 22.1% in 'Coletti' as compared to that in the control. Shading increased fruit size in both cultivars, whereas no differences were observed in the number of locules and thickness of fruit tissue among treatments. Shading treatment increased mean fruit weight by a range of 10 to 15 g per fruit, while it decreased soluble solids contents as compared to that in the control. Similar Hunter values were observed among treatments, while fruit firmness increased slightly in shading treatments. Compared to the control, shading treatments improved marketable fruits by 11.7~22.6% and increased the number of fruits per plant by 4~9.2 in both 'Cupra' and 'Coletti'. The results of this study indicate that shading agent application on the roof of glasshouse would be one of the most effective options to reduce heat stress imposed on the paprika crop in summer cultivation, resulting in improved crop growth and fruit yield.

• Korean Journal of Soil Science and Fertilizer
• /
• v.49 no.5
• /
• pp.577-583
• /
• 2016

Small-sized persimmons produced by high crop load are better accepted in the export markets. However, maintaining high crop load frequently results in weakness of tree vigor, deterioration of fruit quality, and increase of the risks for alternate bearing. This experiment was conducted to determine the combined effects of fertilization rate and leaf-fruit (L/F) ratio on container-grown 3-year-old 'Fuyu' persimmon trees. Application of 3.6-g N, 2.1-g $P_2O_5$, 2.7-g $K_2O$, 2.7-g CaO, and 0.6-g MgO was for the control fertilization rate (CF) and that of a 3-fold CF was for the high fertilization rate (HF). Commercial fertilizers were surface-applied to a container on July 6, July 17, and August 10 in three equal aliquots. Single tree for each fertilization rate was assigned for 12 L/F ratios (5, 6.3, 7.7, 9, 10.4, 13, 15.5, 18, 21, 24, 27, and 33) mostly by fruit thinning or rarely by defoliation on July 1. HF did not affect the yield, weight and soluble solids of the fruits but decreased skin color. As L/F ratio increased, yield decreased but average weight, skin color, and soluble solids of fruits increased. With HF, N and K concentrations in leaves, fruits, and shoots increased to some extent but soluble sugars in dormant shoots decreased. Many shoots were cold-injured with low L/F ratio especially at the HF. HF did not increase number of flower buds the next spring either on a shoot or on a tree basis but increased shoot length, compared with the CF. Increasing L/F ratio markedly increased number of flower buds and shoot growth the following year at both fertilization rates. Therefore, an appropriate combination of fertilization rate and L/F ratio should be necessary to maintain stable fruit production and tree vigor at high crop load.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2011.10a
• /
• pp.291-294
• /
• 2011

4G WiBro service in Korea, the world's fourth-generation communication is standardized. VoIP service has been activated one of the application in WiBro communications infrastructure. When using VoIP in the WiBro service, complementing the existing VoIP vulnerabilities in the encryption and authentication technology is a need for research. In this paper, fourth-generation WiBro, LTE, and the definition, 1G, 2G, 3G and 4G compares. And, WiBro service in the VoIP edaehan technical, administrative, physical, and hacker attacks and vulnerability analysis is the study of security measures. Enhanced security measures for the WiBro service to VoIP security through encryption and authentication technologies are studied.

• Korean Journal of Soil Science and Fertilizer
• /
• v.44 no.3
• /
• pp.492-497
• /
• 2011

Soil management for orchard depends on the effects of soil microbial activities. The present study evaluated the soil microbial community of 25 orchard in Gyeongnam Province by fatty acid methyl ester (FAME) method. The average concentrations in the orchard soils were $332nmol\;g^{-1}$ of total FAMEs, $94nmol\;g^{-1}$ of bacteria, $46nmol\;g^{-1}$ of Gram-negative bacteria, $42nmol\;g^{-1}$ of Gram-positive bacteria, $4.8nmol\;g^{-1}$ of actinomycetes, $54nmol\;g^{-1}$ of fungi, and $9.1nmol\;g^{-1}$ of arbuscular mycorrhizal fungi. In addition, sandy loam soils had significantly low ratio of cy19:0 to 18:$1{\omega}7c$ compared with that of loam soils (p<0.05), indicating that microbial stress decreased. The average soil microbial communities in the orchard soils were 28.1% of bacteria, 15.9% of fungi, 13.6% of Gram-negative bacteria, 12.5% of Gram-positive bacteria, 2.8% of arbuscular mycorrhizal fungi, and 1.4% of actinomycetes. The soil microbial community of Gram-negative bacteria in peach cultivating soils was significantly higher than that of pear cultivating soils (p<0.05).

• YAKHAK HOEJI
• /
• v.42 no.5
• /
• pp.473-479
• /
• 1998

Lovastatin (LOVA), a fungal metabolite isolated from cultures of Aspergillus terreus, is a competitive HMG-CoA reductase inhibitor used for the treatment of primary hyper cholesterolemia, and has also been shown to suppress growth in a variety of non-glioma tumor cell lines. A sensitive reversed-phase high-perfonnance liquid chromatographic method with ultraviolet (UV) absorbance detection has been developed to quantitate LOVA in human plasma and urine samples using liquid-liquid extraction procedure. Baseline separation of LOVA and internal standard, simvastatin was achieved on a Novapak $C_{18}$ analytical column with a mobile phase containing 0.025M $NaH_2PO_4$: CAN (35:65, v/v%), adjusted pH to 4.5. The flow rate was set at 1.5ml/min, and the column effluent was monitored by a UV detection at 238nm. The limit of quantification was determined to be 0.5${\mu}$g/ml while extraction efficiency of LOVA ranged from 73.4-82.9% at LOVA concentrations of 0.5 to 10${\mu}$g/ml. Good linearity with correlation coefficients greater than 0.999 was obtained in the range of LOVA concentrations from 0.5 to 10${\mu}$g/ml. The accuracy and the precision were proven excellent with relative standard deviation (RSD, %) and relative error (RE, %) of less than 4.2 and 4.0, respectively. Intraday precision, evaluated at five LOVA concentrations (0.5, 1, 2, 5, 10${\mu}$g/ml) and expressed as RSD ranged from 0-1.82% while the interday precision at the same concentrations ranged from 0.7-10.5%. The analytical method described was then successfully employed for the determination of LOVA concentrations in plasma samples obtained during a phase II clinical trial using high doses of LOVA (30-40mg/kg/day). This method could be further utilized for the ongoing pharmacolkinetic studies and therapeutic drug monitoring of the high-dose LOVA therapy in adenocarcinoma patients.

• Journal of the Korean BIBLIA Society for library and Information Science
• /
• v.31 no.4
• /
• pp.95-119
• /
• 2020

The study examined the behavior of infant's caregivers using public libraries, measured the level of awareness of infant and toddler services in the library to determine the factors affecting their revisit or recommendation of use to others, and examined the impact of such recognition on the use behavior, revisit and willingness to recommend others. The study surveyed 146 caregivers of infants who use four public libraries in Gwangju Metropolitan City on demographic characteristics, library use behavior, level of awareness of library services, library revisit and recommendation to others. Analysis of this survey shows that the factors that influence the caregivers' revisit of the library or their desire to recommend to others through their caregivers' use of the library are the factors that influence the expansion of information data, the stability of space facilities, the accessibility of space facilities, and the ease of participation in programs among the various service factors provided by the library rather than the personal factors of infants and toddlers' caregivers.

• Journal of Mushroom
• /
• v.16 no.3
• /
• pp.192-197
• /
• 2018

A new blackish-brown variety of Flammulina velutipes, 'Yeoreumhyang2ho,' which was bred by crossing two monokaryons isolated from the 'Heukhyang' and 'Garlmoe' varieties, showed adaptability to high temperature. During bottle cultivation, the temperature was maintained at $16^{\circ}C$ and the variety displayed good productivity compared to the control ('Heukhyang'), without necessitating low temperature ($4^{\circ}C$) treatment. The period necessary for mycelial and fruit body growth, and primordia formation was 24 days, 8 days, and 8 days, respectively. The total cultivation period was 40 days, which was 3 days shorter than that of the control. Particularly, primordia formation took 2 days less than the control and showed initial uniformity. The yield of 'Yeoreumhyang2ho' was 154 g per 850 ml bottle, which was 8% higher than the control yield. The ${\beta}-glucan$ content was 67.9 g per 100 g dry weight, which is approximately 1.1-2.2 times the amount of ${\beta}-glucan$ in control, the golden and white mushrooms that are available in the market.