• Proceedings of the Botanical Society of Korea Conference
• /
• 1999.07a
• /
• pp.85-89
• /
• 1999

Somatic embryogendesis is one of good examples of the basic research for plant embryo development as well as an important technique for plant biotechnology. This paper describes the direct somatic embryogenesis from zygotic embryos of Panax ginseng is reversely related to normal axis growth of zygotic embryos by the experiment of various chemical treatments. Under the normal growth condition, the apical tips of embryo axis produced an agar-diffusible substance, which suppressed somatic embryo development from cotyledons. Although the cells of zygotic embryos were released from the restraint of embryo axis, various factors were still involved for somatic embryo development. Electron microscopic observation revealed that the ultrastructure of cells of cotyledon epidermis markedly changed before initiation of embryonic cell division, probably indicating reprogramming events into the cells embryogenically determined state. Polar accumulation of endogenous auxin or cell-cell isolation by plasmolysis pre-treatment is the strong inducer for the somatic embryo development. The cells for the process of somatic embryogenesis might be determined by the physiological conditions fo explants and medium compositions. Direct somatic embryos from cotyledons fo ginseng were originated eithrer from single or multiple cells. The different cellular origin of somatic embryos was originated either from single or multiple cell. The different cellular origin of somatic embryos was depended on various developmental stages of cotyledons. Immature meristematic cotyledons produced multiple cell-derived somatic embryos, which developed into multiple embryos. While fully mature cotyledons produced single cell-derived single embryos with independent state. Plasmolysis pretreatment of cotyledons strongly enhanced single cell-derived somatic embryogenesis. Single embryos were converted into normal plantlets with shoot and roots, while multiple embryos were converted into only multiple shoots. GA3 or a chilling treatment was prerequisite for germination and plant conversion. Low concentration of ammonium ion in medium was necessary for balanced growth of root and shoot of plantlets. Therefore, using above procedures, successful plant regeneration of ginseng was accomplished through direct single embryogenesis, which makes it possible to produce genetically transformed ginseng efficently.

• Publications of The Korean Astronomical Society
• /
• v.29 no.3
• /
• pp.45-52
• /
• 2014

This paper describes the development of algorithm for direct data transmission between Raw VLBI Data Buffer (RVDB) and Huge Capacity Data Server (HCDS) operated in Korea-Japan Correlation Center (KJCC). The transmitted data is the VLBI observation data, which is recorded at each radio telescope site, and the data transmitting rate is varying from 1 Gbps, in usual case, upto 8 Gbps. The developed algorithm for data transmission enables the direct data transmission between RVDB and HCDS through 10 Gbps optical network using VLBI Data Interchange Format (VDIF). Proposed method adopts the conventional UDP/IP protocol, but in order to prevent the loss of data during data transmission, the packet error monitoring and data re-transmission functions are newly designed. The VDIF specification and VDIFCP (VDIF Control Protocol) are used for the direct data transmission between RVDB and HCDS. To validate the developed algorithm for data transmission, we conducted the data transmission from RVDB to HCDS, and compared to the transmitted data with the original data bit by bit. We confirmed that the transmitted data is identical to the original data without any loss and it has been recovered well even if there were some packet losses.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.23 no.2
• /
• pp.134-140
• /
• 2021

Global solar radiation consists of direct and diffuse radiations. Both components are necessary for not only atmospheric science and solar energy domains but also agricultural applications. In this study, the data of direct and diffuse radiations are uploaded to Github. It was observed in Naju during May 2019 to November 2020. Using this data, the previous empirical equations using the relation between clearness index and diffuse ratio were validated. All coefficients of determination (R²) and RMSE were similar as 0.79~0.80 and 0.13~0.15. However, to get the lower RMSE, other non-linear approaches will be required with more observation data.

• The Bulletin of The Korean Astronomical Society
• /
• v.38 no.2
• /
• pp.40.2-40.2
• /
• 2013

Although galaxy mergers are thought to play an important role in forming elliptical galaxies, mergers in galaxy clusters have drawn less attention compared to mergers in field environments because galaxies with high peculiar velocities are unlikely to merge with each other. However, comparable fractions of merger features in cluster galaxies have been reported from deep imaging of Abell clusters, suggesting the relevance of mergers in the transformation of cluster early-type galaxies (Sheen et al. 2012). As a more direct approach to understanding the origin of tidal features in clusters, we perform hydrodynamic re-simulations on a cluster of galaxies. Based on mock observation images of the simulated cluster galaxies, we construct and analyze the cluster early-type galaxy sample in a consistent manner with Sheen et al. 2012. We find that the fraction of tidal feature from the simulated cluster is comparable to that of the observation. Evolutionary history of the galaxies with merger features shows that most of the mergers responsible for the merger features in the present originate from outside the cluster more than 2Gyrs ago. We also find that many of the galaxies with tidal features show correlations with subgroups in the cluster. All these results suggest that merger features in the cluster are due to preprocessing before accretion into the cluster.

• The Mathematical Education
• /
• v.38 no.2
• /
• pp.145-157
• /
• 1999

Ability diagnosis is similar to medical diagnosis from a number of perspectives. However, a medical diagnosis is carried out by a direct observation through medical apparatuses, while an ability diagnosis is made by an indirect observation in the from of testing. In this respect, ability diagnosis is more difficult than medical diagnosis. Confined to middle school 1st year Mathematics, we collected survey data in 1996 from monthly tests. The data consist of student responses to diagnosis results on their abilities and of the effects of catch-up guidances for individual students which are provided based on their ability diagnosis outcomes. We analyzed the data and summarized the result in the paper. One of the main results is that the ability diagnosis as used in the paper has a very positive effect on catch-up study. But it is important to note that the effects vary across the ability groups, the effect appearing weaker in the lower ability group than in the higher ability group. This calls our attention to the need that the ability diagnosis and guidance for the catch-up study be differentiated among ability groups.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2009.05a
• /
• pp.827-831
• /
• 2009

Recently, frequency occurring flood and drought has increased the necessity of an effective water resources control and management of river flows. Therefore, the simulation of the flow distribution in natural rivers is great importance to the solution of a wide variety of practical flow problems in water resources engineering. However The serious problem facing two-dimensional hydraulic model is the treatment of wet and dry areas. The objective of this study is to investigate the wet and dry parameters that have direct relevance to model performance in situations where inundation of initially dry areas occurs. Several numerical simulations were carried out, which examined the performance of the marsh porosity method for the purpose of sensitivity analysis. Experimental channel and a variety of channel were performed for model tests. The results were compared with those of the observation data and simulation data of existing model. The RMA-2 model displayed reasonable flow distribution compare to the observation data and simulation data of existing model in dry area for application of natural river flow. As a result of this study, effectively applied marsh porosity method provide a reliable results for flow distribution of wet and dry area, it could be further developed to basis for extending to water quality and sediment transport analysis.

• Asian Journal of Atmospheric Environment
• /
• v.5 no.3
• /
• pp.172-180
• /
• 2011

The transfer of microorganisms is important process for ecosystems. Microorganisms in dryland can transport itself to wetland through atmospheric diffusion, but only few papers reported about the atmospheric bioaerosol present over dryland. We carried out the direct sampling using a tethered balloon over Dunhuang City, China's northwestern dryland. Bioaerosols were collected using a tethered balloon with a bioaerosol collector at 820 m above the ground (1,960 m above the sea level) around noon on August 17, 2007. The bioaerosols were cultured after the collection at Dunhuang Meteorological observatory. Two strains of molds were isolated using the Nutrient agar medium. About 400-bp 18S rRNA partial sequences were amplified by PCR and determined afterwards. The results of a homology search by 18S rRNA sequences of isolates in DNA databases (GenBank, DDBJ, and EMBL) and an observation of the form revealed that two bioaerosols in the convective mixed layer over Dunhuang City were Cladosporium sp. and Aspergillus sp.

• Korean Institute of Interior Design Journal
• /
• no.3
• /
• pp.33-37
• /
• 1994

Increasing interest and providing educational experience for the public have long been a major ARt Museum goal. This interest raises the question of how visitors respond to museum exhibits. Much researches have been done which indicate the newer and more interactive exhibits are indeed more didactic and enjoyable than conventional exhibits. This study examined the effectiveness of art exhibits which display information about the creative process of developing a work art along with the final work of art to test if they results in more viewer interest and greater appreciation of the final work of art than those which display only the final work of art. In the early part of the 1991 spring, a counterblancing AB/BA quasi-experiment was carried out in the Jhnson Museum of Art, Cornell University. Methods used to collect and measure visitory interest and appreciation were unobtrusive observation and survey questionnaire. As the indirect measurement of visitor interest, attracting power and holding power were measured by unobstrusive observation of visitor time spent, while the direct measurement of visitor interest and appreciation, visitor's interest, understanding , and degree of favorableness were measured by survey questinnaire. Data analysis reached conclusion that the process approach fine art exhibit designs significantly resulted in more viewer interest and greater appreciation of art work than the conventional fine art exhibit design.

• Journal of the Korean Society of Safety
• /
• v.33 no.5
• /
• pp.109-119
• /
• 2018

This study has performed to identify the effect of safety behavior, safety climate and its satisfaction through the Behavior Based Safety Program for 5 sites of the same Company. The study result indicated that the level of recognized safety behavior, climate and its satisfaction improved by conducting observation of worker behavior, jobsite feedback, displaying feedback chart, safety training, behavior modification committee. Additionally, the participation level of safety activity and conformity level of safety rule improved. The recognized level of safety climate improved together with recognized safety value by management, safety participation of direct boss, communication with each other to be dealt with safety matter, safety training material to be contained unsafe behavior and practical hazard, understanding and conducting safety standard. In addition, The recognized level of satisfaction improved together with safety behavior and climate. As a result, this program provided an opportunities to correct worker's unsafe behavior to safe behavior in conjunction with increasing number of observation, providing additional time to have a safety check, safety suggestion to improve work situation and a permit to work rule. It will be integrated into health and safety management system to be able to reduce industrial accident.

• Journal of Advanced Marine Engineering and Technology
• /
• v.20 no.5
• /
• pp.93-102
• /
• 1996

Laser-induced plume and laser-target interaction during pulsed laser deposition are demonstrated for a lead zirconate titanate (PZT). A KrF excimer laser (wavelength 248nm) was used and the laser was pulsed at 20Hz, with nominal pulse width of 20ns. The laser fluence was~$16J/cm^2,$ with 100mJ per pulse. The laser-induced plasma plume for nanosecond laser irradiation on PZT target has been investigated by optical emission spectra using an optical multichannel analyzer(OMA) and by direct observation of the plume using an ICCD high speed photography. OMA analysis showed two distinct ionic species with different expansion velocities of fast or slow according to their ionization states. The ion velocity of the front surface of the developing plume was about $10^7$cm/sec and corresponding kinetic energy was about 100eV. ICCD photograph showed another kind of even slower moving particles ejected from the target. These particles considered expelled molten parts of the target. SEM morphologies of the laser irradiated targets showed drastic melting and material removal by the laser pulse, and also showed the evidence of the molten particle ejection. The physics of the plasma(plume) formation and particle ejection has been discussed.