• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.29 no.1
• /
• pp.98-101
• /
• 1984

Endorcarp inhibited the embryo growth of ginseng seeds. This inhibition is not due to impermeability to water, but is probably caused by mechanical resistance. The embryo growth rate was enhanced by endocarp injury by soaking for 10 to 30 minutes in 2.5% solution of sodium hydroxide. But sulfuric acid did not affect on the embryo growth of ginseng seed.

• Journal of Korean Society on Water Environment
• /
• v.35 no.1
• /
• pp.28-34
• /
• 2019

This study analyzed the occurrence pattern of Dolichospermum (= Anabaena) in the Bukhan river from March 2012 to December 2014 in order to identify the genotypes of Dolichospermum. Furthermore, 16S rRNA were analyzed to identify the genotypes of Dolichospermum that occurred in 2015 which were then compared to the reference sequence deposited at NCBI. During this period, the occurrence of Dolichospermum was highly correlated to water temperature. In the year 2012 and 2013, Dolichospermum appeared in Lake Cheongpyeong (CP), Sambong (SB), and Lake Paldang (P2) between July and August. However, in 2014, it appeared in SB and P2, but not in CP. This reduction in appearance was attributed to the decreased inflow to Lake Uiam as a result of low rainfall in 2014 as compared to 2012. In July 2015, the Dolichospermum 16S rRNA genotype was confirmed in five locations; Lake Cheongpyeong (CP), Seojong (SJ), Songchon Sewage Treatment Plant (SC), Joan (P4), and Lake Paldang (PD). Anabaena crassa of spiral clone, A. planctonica of linear clone, and A. circinalis of spiral clone exhibited high genetic similarity with the reference sequence. The 16r RNA genotype showed approximately 3 % sequence variation between the locations and were more similar to each other in locations that were closer.

• Progress in Superconductivity and Cryogenics
• /
• v.8 no.1
• /
• pp.65-70
• /
• 2006

Transient heat transfer caused by an impulsive heating in subcooled liquid nitrogen is investigated experimentally. This study is part of out ongoing efforts directed to a stable cryogenic cooling system lot superconducting fault current limiters (SFCL). A thin heater attached by epoxy on one surface of a GFRP plate is immersed in liquid-nitrogen bath at temperatures between 77 K and 55 K. A strong heat flux up to $150W/cm^2$ is generated lot 100 ms, and the temperature of the heater sulfate is measured as a function of time. The behavior of bubbles on the heating surface can be explained by comparing the measured temperature history for vertical and two horizontal (up and down) orientations. It is concluded that the subcooling of liquid nitrogen below 70 K is very effective in suppressing bubbles, resulting in better thermal protection and faster recovery from an impulsive heat.

• Journal of the Korean Society for Precision Engineering
• /
• v.13 no.7
• /
• pp.115-121
• /
• 1996

Multi-axes driving system is more suitable for FMS(Flexible Manufacturing System) compared with a conventional single-azis driving system. It has some merits such as flexibility in operation, improvement of net working rate, maintenance free because of no gear train, etc. However, studies on position synchronous control for high precision in the multi-axes driving system are not enough. In this paper, a new method of position synchronous control is suggested in order to apply to the multi- axes driving system. The proposed method is structured very simply using speed and position controller based on PID control law. Especially, the position controller is designed to keep position error to minimize by controlling either speed of two motors. The effectiveness of the proposed method is successfully confirmed through several experiments.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.30 no.3
• /
• pp.310-313
• /
• 1985

Seven years data on the yield of ginseng seedling were investigated to define the relations between meteorological conditions and yield of ginseng seedling. Variation of meteorological factors by years are showed in the order precipitation, hours of sunshine and temperature. The variation of temperature by years was biggest in June, whereas smallest figure in April. Variation of yield of ginseng seedling in different quality by years was biggest in number of short weighted seedling and least in that of usable seedling. Highly significant correlations were confirmed between number of usable seedling and number of total seedling, and between number of total seedling and precipitation from January to March, respectively. A significant negative correlation was recognized between the number of usable seedling and temperature in July but correlation between number of usable seedling and precipitation in May was positive. It suggests that water management in seedbed have to be started from May.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.31 no.1
• /
• pp.19-23
• /
• 1986

To get the basic information about ginseng seed production, yield of seed and seed quality in 27 fields were investigated. Yield of seed ranged from 4 to 10 litres per 100 kan (180cm x 90cm). Ratio of under 4mm seed is 12%, 66% for 4 to 5mm and 22% for over 5mm. Seed weight and ratio of over 4mm seed showed the decreasing tendency with the increase of seed yield per unit area. The seed yield harvested from the selected mother plants was lower than that from all plants, but seed weight and ratio of over 4mm seed were high in fields using the selected mother plants. It showed a positive correlation between length and width of seed, but no correlation between thickness and length or width. Optimum yield for high quality seed appeared under the 7 to 8 litres per 100 kan.

• Korean Journal of Ecology and Environment
• /
• v.51 no.4
• /
• pp.299-310
• /
• 2018

Odor compounds (geosmin, 2-MIB) have been causing problems in the Bukhan River system, but the causative organisms have not been clearly identified. To evaluate the relationship between dynamics of microbial community and odor compounds, two times monthly monitoring of water quality and microbial community from the three serial lakes (Lake Uiam, Lake Cheongpyeong and Lake Paldang) in the Bukhan River system were conducted from April to October 2017. The odor compounds were analyzed by HS-SPME analysis method using GC/MS. Bacteria communities were identified at the class level by NGS analysis. Actinobacteria and Betaproteobacteria were dominant taxon in bacteria community of three serial lakes. In the case of phytoplankton communities showed that seasonal changes by Bacillariophyceae and Cryptophyceae in spring, Cyanobacteria in summer, and Bacillariophyceae and Cryptophyceae in autumn. Dominant species was Dolichospermum (=Anabaena), Microcystis and Pseudanabaena in Bukhan River system in all study period. At the same time the odors geosmin and 2-MIB were also detected at high concentration. There is a significant positive correlation between proportion of Actinobaceria and 2-MIB concentration (r=0.491, p<0.01). In addition, proportion of cyanobacteria showed a significant correlation of geosmin (r=0.381, p<0.05) and 2-MIB (r=0.386, p<0.05) concentration. In this study, odor compounds in the Bukhan River system are considered to be a direct relationship between with Actinobacteria and cyanobacteria.

• 동북아역사논총
• /
• no.60
• /
• pp.196-227
• /
• 2018

The issues of this study are as follows. First, I will examine the overall situation and transition trends of Tibetan research in Taiwan since the modern period, and examine the development and trends of Tibetan history research in Taiwan. Secondly, in order to satisfy the above, we will analyze trends of Taiwan's major Tibetan research institutes and scholars, and trace their trends and their trajectories. Third, the trend of Tibetan research in Taiwan may be a useful indicator for us to analyze research methods and trends of Taiwanese scholars. If there is a flow of features and transitions, the text will explore the reason. Fourth, one of the implications of this study is that it can trigger an understanding of locality in the structure of the central region, the Han Chinese minority, and the possession and distribution of academic reasoning. In other words, it should be noted that even though the same Tibetan research is conducted, China is in the position of the vested right to distribute 226 | 동북아역사논총 60호the central or ownership, while Taiwan has historical and territorial characteristics that deviate from such a gaze and attitude. Taiwan may be sensitive to the vertical concept understood as a change in the relationship between the state and the center, or whether it is applicable to Tibetan research. If there is such an academic climate, I would like to consider suggestions for us. This may provide a direction to view the academic issues of a few scholars, or even the domestic academic world as an independent object of more specific academic research.

• Journal of Radiation Industry
• /
• v.5 no.3
• /
• pp.203-210
• /
• 2011

To evaluate the ability of Bamboo (Phyllostachys nigra var. henenis Strapf) leaf extract (BL) to protect the skin from photodamage, the gross and microscopic changes in the skin of hairless mice and BL-treated mice exposed chronically to ultraviolet (UV) were examined. The skin of the UV-irradiated mice showed characteristic signs of photoaging, such as deep wrinkles across the back, increased epidermal thickeness, numerous cell infiltration, and many enlarged keratinizing cysts. BL-treated mice showed a significantly decreased wrinkling score and lack of proliferation of cysts. By the 22nd week, 88.9% (i.p. with saline) or 60.0% (topical administration with cream base) of the UV-irradiated mice developed at least one tumor. BL delayed tumor onset significantly. BL (i.p.) was also effective in reducing the occurrence of UV radiation-induced skin tumors and reduced the number of tumors per mouse. After 22 weeks of treatment, 37.5% (i.p.) of the mice treated with BL were tumor-free. Tumor multiplicity was reduced by 81.2% (i.p.) in the BL treated groups. It is noted that skin that is chronically exposed to UV is subject to photoaging and photocarcinogenesis and regular use of BL would prevent these photodamaging effects of UV.

• Journal of Convergence for Information Technology
• /
• v.11 no.1
• /
• pp.12-19
• /
• 2021

For strengthening the national defense, the function of tactical network is essential. tactics and strategies in wartime situations are based on numerous information. Therefore, various reconnaissance devices and resources are used to collect a huge amount of information, and they transmit the information through tactical networks. In tactical networks that which use contention based channel access scheme, high-speed nodes such as recon aircraft may have performance degradation problems due to unnecessary channel occupation. In this paper, we propose a learning-backoff method, which empirically learns the size of the contention window to determine channel access time. The proposed method shows that the network throughput can be increased up to 25% as the number of high-speed mobility nodes are increases.