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Improving Usage of the Korea Meteorological Administration's Digital Forecasts in Agriculture: I. Correction for Local Temperature under the Inversion Condition (기상청 동네예보의 영농활용도 증진을 위한 방안: I. 기온역전조건의 국지기온 보정)

  • Kim, Soo-Ock;Kim, Dae-Jun;Kim, Jin-Hee;Yun, Jin I.
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.15 no.2
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    • pp.76-84
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    • 2013
  • An adequate downscaling of the official forecasts of Korea Meteorological Administration (KMA) is a prerequisite to improving the value and utility of agrometeorological information in rural areas, where complex terrain and small farms constitute major features of the landscape. In this study, we suggest a simple correction scheme for scaling down the KMA temperature forecasts from mesoscale (5 km by 5 km) to the local scale (30 m by 30 m) across a rural catchment, especially under temperature inversion conditions. The study area is a rural catchment of $50km^2$ area with complex terrain and located on a southern slope of Mountain Jiri National Park. Temperature forecasts for 0600 LST on 62 days with temperature inversion were selected from the fall 2011-spring 2012 KMA data archive. A geospatial correction scheme which can simulate both cold air drainage and the so-called 'thermal belt' was used to derive the site-specific temperature deviation across the study area at a 30 m by 30 m resolution from the original 5 km by 5 km forecast grids. The observed temperature data at 12 validation sites within the study area showed a substantial reduction in forecast error: from ${\pm}2^{\circ}C$ to ${\pm}1^{\circ}C$ in the mean error range and from $1.9^{\circ}C$ to $1.6^{\circ}C$ in the root mean square error. Improvement was most remarkable at low lying locations showing frequent cold pooling events. Temperature prediction error was less than $2^{\circ}C$ for more than 80% of the observed inversion cases and less than $1^{\circ}C$ for half of the cases. Temperature forecasts corrected by this scheme may accelerate implementation of the freeze and frost early warning service for major fruits growing regions in Korea.

Highly Doped Nano-crystal Embedded Polymorphous Silicon Thin Film Deposited by Using Neutral Beam Assisted CVD at Room Temperature

  • Jang, Jin-Nyeong;Lee, Dong-Hyeok;So, Hyeon-Uk;Hong, Mun-Pyo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.154-155
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    • 2012
  • The promise of nano-crystalites (nc) as a technological material, for applications including display backplane, and solar cells, may ultimately depend on tailoring their behavior through doping and crystallinity. Impurities can strongly modify electronic and optical properties of bulk and nc semiconductors. Highly doped dopant also effect structural properties (both grain size, crystal fraction) of nc-Si thin film. As discussed in several literatures, P atoms or radicals have the tendency to reside on the surface of nc. The P-radical segregation on the nano-grain surfaces that called self-purification may reduce the possibility of new nucleation because of the five-coordination of P. In addition, the P doping levels of ${\sim}2{\times}10^{21}\;at/cm^3$ is the solubility limitation of P in Si; the solubility of nc thin film should be smaller. Therefore, the non-activated P tends to segregate on the grain boundaries and the surface of nc. These mechanisms could prevent new nucleation on the existing grain surface. Therefore, most researches shown that highly doped nc-thin film by using conventional PECVD deposition system tended to have low crystallinity, where the formation energy of nucleation should be higher than the nc surface in the intrinsic materials. If the deposition technology that can make highly doped and simultaneously highly crystallized nc at low temperature, it can lead processes of next generation flexible devices. Recently, we are developing a novel CVD technology with a neutral particle beam (NPB) source, named as neutral beam assisted CVD (NBaCVD), which controls the energy of incident neutral particles in the range of 1~300eV in order to enhance the atomic activation and crystalline of thin films at low temperatures. During the formation of the nc-/pm-Si thin films by the NBaCVD with various process conditions, NPB energy directly controlled by the reflector bias and effectively increased crystal fraction (~80%) by uniformly distributed nc grains with 3~10 nm size. In the case of phosphorous doped Si thin films, the doping efficiency also increased as increasing the reflector bias (i.e. increasing NPB energy). At 330V of reflector bias, activation energy of the doped nc-Si thin film reduced as low as 0.001 eV. This means dopants are fully occupied as substitutional site, even though the Si thin film has nano-sized grain structure. And activated dopant concentration is recorded as high as up to 1020 #/$cm^3$ at very low process temperature (< $80^{\circ}C$) process without any post annealing. Theoretical solubility for the higher dopant concentration in Si thin film for order of 1020 #/$cm^3$ can be done only high temperature process or post annealing over $650^{\circ}C$. In general, as decreasing the grain size, the dopant binding energy increases as ratio of 1 of diameter of grain and the dopant hardly be activated. The highly doped nc-Si thin film by low-temperature NBaCVD process had smaller average grain size under 10 nm (measured by GIWAXS, GISAXS and TEM analysis), but achieved very higher activation of phosphorous dopant; NB energy sufficiently transports its energy to doping and crystallization even though without supplying additional thermal energy. TEM image shows that incubation layer does not formed between nc-Si film and SiO2 under later and highly crystallized nc-Si film is constructed with uniformly distributed nano-grains in polymorphous tissues. The nucleation should be start at the first layer on the SiO2 later, but it hardly growth to be cone-shaped micro-size grains. The nc-grain evenly embedded pm-Si thin film can be formatted by competition of the nucleation and the crystal growing, which depend on the NPB energies. In the evaluation of the light soaking degradation of photoconductivity, while conventional intrinsic and n-type doped a-Si thin films appeared typical degradation of photoconductivity, all of the nc-Si thin films processed by the NBaCVD show only a few % of degradation of it. From FTIR and RAMAN spectra, the energetic hydrogen NB atoms passivate nano-grain boundaries during the NBaCVD process because of the high diffusivity and chemical potential of hydrogen atoms.

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Seasonal Occurrences and Chemical Control of Oyster Scale, Psuedaulacaspis cockerelli (Hemiptera: Diaspididae) in Sweet Persimmon Orchards in Korea (국내 단감원에서 식나무깍지벌레의 계절적 발생과 화학적 방제)

  • Chung, Bu-Keun;Lee, Heung-Su;Kang, Dong-Wan;Kwon, Jin-Hyeuk
    • Korean journal of applied entomology
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    • v.56 no.2
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    • pp.97-105
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    • 2017
  • An investigation was conducted to determine the characteristics of seasonal occurrences and effective insecticides for minimizing the occurrence of Pseudaulacaspis cockerelli in sweet persimmon orchards. Most of the nymphs or female scales that mated in mid-September overwintered on twigs, matured to lay eggs in the next spring in accordance with temperature increase, and survived till mid to late May to lay all of their eggs. Males mostly died after mating by the end of September, while the males on the fallen leaves died during the hibernating period. Egg laying in P. cockerelli showed differences in accordance with the weather conditions in each year. They laid eggs from mid-April to mid- or late May, with a peak in early or mid-May. A female was estimated to lay 160 eggs; eggs hatched a week later from the peak period of egg laying. In summer, egg laying started in early or mid-July and ended in mid- or late August, with a peak in late July or early August; a female laid approximately 130 eggs in summer. The estimated egg period was 4 days. The first generation nymph that hatched from the eggs laid by the overwintered female on twigs showed 10% occurrence on twigs and 90% on leaves. The first generation nymphs on twigs mostly developed into female scales. The occurrence of the second generation nymphs reached a peak on July 27, 2009; they lived on the twigs as their overwintering site from mid- or late August. The female and male scales on leaves developed at the similar rate as the first generation nymphs up to August. The occurrence of male scales indicated that the peak occurrence of nymphs was on August 12, 2009, male scales on August 27, and adults approximately on September 14, which showed steady relationship in the sequence of development from nymphs to adult males. Among the nymphs that occurred on the leaves on August 12, 75% of them emerged into male adults, mated, and died. Buprofezine+dinotefurn (20+15) WP treatment on June 9 and 16 resulted in 90.6% control of P. cockerelli, when mortality was checked 7 weeks after treatment.

A Study on the Acculturation of Guǐmok(槐木) Plantings through the Remaining Species of Guǐjeong(槐亭) (괴정(槐亭)의 잔존 수종을 통해 본 괴목(槐木) 식재의 문화변용)

  • Rho, Jae-Hyun;Han, Sang-Yub;Choe, Seung-Heuy
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.37 no.4
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    • pp.81-97
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    • 2019
  • The purpose of this study is to examine what people in Korea recognize the cultural symbolism and the planting patterns of 'Guǐmok', pagoda tree(Sophora japonica). The species planted in the 'Guǐjeong' was empirically investigated and analyzed to determine which species of pagoda tree or Zelkova tree(Zelkova serrata) was taken through literature surveys, field surveys, and interviews with persons. This 'Guǐjeong' was combined to track how the culture of the 'Guǐmok' planting introduced in China was ultimately accepted and transformed in Korea. In this study, we tried to analyze the meaning implicit in the mystery while checking the distribution of the mystery and the form of the mystery, the name of the pavilion and its relevance to the contrast medium. Essentially, the trees that govern the characterization of the nectar plant, regardless of the region, are considered to be a pagoda tree, which is considered an internal factor in which the pagoda tree culture was not completely transformed into a zelkova tree. It was recognized throughout the Joseon Dynasty that the species representing 'Prime ministers(三公)' was judged from all the Joseon Dynasty periods, based on the builder of Guǐjeong's Aho(雅號) and Dangho(堂號). It was confirmed that the tree was very likely to be planted in place of the painting tree. But now is selectively zelkova tree is in accordance with the preparation of planting site conditions and areas on behalf of the Change is very high probability that is planted. Cultural variables that led to the cultural transformation of the 'Guǐmok' seem to have been deeply involved in the geographical space of China and Korea, Confucian practices of the Choson society, comings and goings and letter bridge, and network strength with China through the book spread. In addition, the culture of 'Guǐmok' is presumed to have led to cultural custom of the upper class, not the whole class, in the Yeongnam region, it can be said that the independent adaptation to act to recognize 'Guǐmok' as a pagoda tree, that is a Sophora japonica, has occurred very strongly. The difference between the cultural areas of Yeongnam and non-Yeongnam is also considered to be an internal factor that has played a major role in the cultural transformation of planting of 'Guǐmok'.

A Study on the Design & Construction Method of Traditional Landscape Space through the 『Imwongyeongjeji』 「Seomyongji」 and the 'Standard Specification for Repairing Cultural Heritages' (『임원경제지』 「섬용지」와 문화재수리 표준시방서를 통해 본 전통조경공간 설계 시공방법)

  • Lee, Jung-Han
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.37 no.4
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    • pp.1-10
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    • 2019
  • The purpose of this study is to examine the design & construction methods of the traditional landscape space of the past and the repair and maintenance of cultural heritages to maintain it today. To this end, the method of narrative description, process extraction and construction related to traditional landscaping were compared to each other based on the 『Imwongyeongjeji』 「Seomyongji」 and 'Standard Specification for Repairing Cultural Heritages'. The results are as follows; First, to analyze at the description methods of the 『Imwongyeongjeji』 「Seomyongji」 and 'Standard Specification for Repairing Cultural Heritages' and related processes in the field of traditional landscaping. 『Imwongyeongjeji』 「Seomyongji」 was an encyclopedia of the overall construction method of the living space, describing the location, effect, and advantages and disadvantages of each component and presenting quantitative figures to institutionalize the construction of traditional landscaping spaces. 'Standard Specification for Repairing Cultural Heritages' presented the entire process of repairing cultural heritages, and it is becoming a kind of guide for reference at the site. Among them, foundation construction, roof construction, landscape construction, and fence construction were drawn as items that could be applied to traditional landscaping areas. Second, the traditional landscape space construction method was divided into the processes of foundation construction, roof construction, landscaping construction, and fence construction. Foundation construction is a way of repeating the process of land-tramping. During the construction of the roof, the tile-roofed building was built on top of the rafters and roofed with tiles. And thatched roof was made to a number of rice straws bundles to cover the roof one after the other. Instead of tiles, the stone roof was made of thin and wide stones, and the wooden boards were used for the single roof and the bark roof were constructed with many layers of dried corrugations. Landscape construction mainly consists of the Paving technique through tramping rubble and the construction of terraced flower by planting stone, plants, and shrubs on the top. According to the building materials, the wall construction was derived from the earth-stacked earthen wall, stone walls using stone and clay, marble walls made of tile patterns, and the construction of a board wall using a wood board as a wall. Third, comparing the construction methods of the 『Imwongyeongjeji』 「Seomyongji」 and 'Standard Specification for Repairing Cultural Heritages', 『Imwongyeongjeji』 「Seomyongji」 focuses on standardizing the construction methods to create a new traditional space. There is a difference in the setting of the scope of the 『Imwongyeongjeji』 「Seomyongji」 and the construction because 'Standard Specification for Repairing Cultural Heritages' provides the overall construction procedure considering the diversity of the cultural heritages. In addition, the traditional landscape space used to be a residential space in the past, but today, the maintenance process of the already established facilities as designated cultural heritages has been carried out, and construction methods have been added to create viewing conditions. In terms of the succession of traditional knowledge, some similar methods were found in the repair of cultural assets today, and some cases were also confirmed in the reconstruction of traditional technologies such as application of some materials or mix, separation of added facilities and introduction of efficient construction methods.

Radiation, Energy, and Entropy Exchange in an Irrigated-Maize Agroecosystem in Nebraska, USA (미국 네브라스카의 관개된 옥수수 농업생태계의 복사, 에너지 및 엔트로피의 교환)

  • Yang, Hyunyoung;Indriwati, Yohana Maria;Suyker, Andrew E.;Lee, Jihye;Lee, Kyung-do;Kim, Joon
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.22 no.1
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    • pp.26-46
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    • 2020
  • An irrigated-maize agroecosystem is viewed as an open thermodynamic system upon which solar radiation impresses a large gradient that moves the system away from equilibrium. Following the imperative of the second law of thermodynamics, such agroecosystem resists and reduces the externally applied gradient by using all means of this nature-human coupled system acting together as a nonequilibrium dissipative process. The ultimate purpose of our study is to test this hypothesis by examining the energetics of agroecosystem growth and development. As a first step toward this test, we employed the eddy covariance flux data from 2003 to 2014 at the AmeriFlux NE1 irrigated-maize site at Mead, Nebraska, USA, and analyzed the energetics of this agroecosystem by scrutinizing its radiation, energy and entropy exchange. Our results showed: (1) more energy capture during growing season than non-growing season, and increasing energy capture through growing season until senescence; (2) more energy flow activity within and through the system, providing greater potential for degradation; (3) higher efficiency in terms of carbon uptake and water use through growing season until senescence; and (4) the resulting energy degradation occurred at the expense of increasing net entropy accumulation within the system as well as net entropy transfer out to the surrounding environment. Under the drought conditions in 2012, the increased entropy production within the system was accompanied by the enhanced entropy transfer out of the system, resulting in insignificant net entropy change. Drought mitigation with more frequent irrigation shifted the main route of entropy transfer from sensible to latent heat fluxes, yielding the production and carbon uptake exceeding the 12-year mean values at the cost of less efficient use of water and light.

Enjoyment Culture of Garden through Poet(詩) and Text(書), Painting(畵) in the 18·19th Century, Hanyang(漢陽) (시(詩)·서(書)·화(畵)를 통해 본 18·19세기 한양(漢陽)의 원림 향유문화)

  • Kim, Dong-Hyun;Choi, Jong-Hee
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.33 no.2
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    • pp.36-48
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    • 2015
  • This study aims to contemplated the enjoying culture of Gyeonghwasejok's garden in late Joseon dynasty. It was track down the behavior from cultural perspective by using recorded in literature. The results were as follows. First, Gyeonghwasejok was the main principal of the garden at Hanyang in Joseon Dynasty. There are established residence in the downtown and make a garden. Garden organizer recognized to fine conditions of residences even crowded downtown. As a result people tried to include habitation and garden culture for preserve their cultural benefit. Secondly, Seongsisanrim culture has appeared of common in site selection of garden for occupies the scenic beauty. Garden was surrounded by scenic beauty. Garden organizer was formed archival culture for owning the beautiful landscape through creation of guguk(九曲), designation of space and lettering on rocks. Thirdly, Formation of the collection culture was placed of various ornaments inside garden. A behaviour of landscape view and ornaments appreciation led to the archival culture such as Won-rim-gi(園林記) and essay(小品文). Moreover, hold a friendship meeting for sharing garden culture. Fourthly, Attention of flowering plants was extended to development of gardening hobby such as fashion of pot-planting, planted to exotic tree. It was know that the plants are recognized as favorite elements by target of appreciation according to introduction of plants inside garden. In addition, facility of horticulture and kitchen garden were placed inside garden. Fifth, Influx of chinese garden culture influenced construction of garden space in late Joseon dynasty. Garden organizer recognizes garden as a ideal space by garden aesthetics that Hojungcheonji(壺中天地). And the imitation of Chinese garden culture such as collecting of Chinese's ornaments has become a high-level culture.

Dendrochronological Analysis of Abies koreana W. at Mt. Halla, Korea: Effects of Climate Change on the Growths (한라산 구상나무(Abies koreana W.)의 연륜연대학적 연구 - 기후변화에 따른 생장변동 분석 -)

  • Koo, Kyung-Ah;Park, Won-Kyu;Kong, Woo-Seok
    • The Korean Journal of Ecology
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    • v.24 no.5
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    • pp.281-288
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    • 2001
  • The relationships between the growths of Abies koreana W. and climatic factors were analyzed by the use of tree-ring analysis at the subalpine belt of Mt. Halla National Park. The four cores were extracted from each 21 trees at north-facing slope (1,900m a.s.1.). The site chronology was established on the periods from 1912 to 1999. The growth of A. koreana was very poor, in particular in the years of 1982, 1988 and 1996. Simple correlation was employed to analyze the relationship between the growth of A. koreana and climatic factors. The result of simple correlation indicates that the growth of A. koreana represent positive correlations both with the mean temperatures of April and previous November, and the precipitation of previous December and January. The presence of large number of frost-damaged scars in the individual trees of A. koreana implies that local freezing temperature conditions at Mt. Halla have occurred in 1964, 1965 and 1966. The correlations between the fir chronology SOI(Southern Oscillation Index) of previous January, February and November were significantly positive. The growth ratio of A. koreana demonstrates that this species is sensitive to seasonal variations. As the winter temperature rises, the growth ratio of A. koreana decreases, on the other hand, the increase of autumn temperature accelerates the growth ratio of A. koreana. The growth decline of A. koreana was observed from 51 cores out of the 54 cores, and the overall growth declines have initiated at 1978, 1982 and 1988. Distinct growth decline of A. koreana in the range of 70% is noticed at 34 cores out of the 51 cores. The decline of, A. koreana growth appears to be related to the winter temperature which has increased since mid-1970s.

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Geochemical Characteristics of Soil Solution from the Soil Near Mine Tailing Dumps and the Contamination Assessment in Duckum Mine (토양수의 자구화학특성에 따른 금속폐광산 광미야적장주변 토양오염평가: 덕음광산)

  • 이상훈;정주연
    • Economic and Environmental Geology
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    • v.37 no.1
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    • pp.61-72
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    • 2004
  • The soil samples were collected from the paddy field near the mine tailing dumps in the abandoned Duckum mine in Korea. In the laboratory, the soil solution was extracted from the soil using centrifuge, and analysed for the chemical composition. Physical and chemical soil properties were also analysed. Kaolinite is the main clay minerals in the paddy soil and the CEC value is therefore relatively low. Nearly all soil samples show enrichment in their trace elemental concentrations(Cd, Cu, Pb and Zn) compared with natural background level. Some soil samples exceed the soil remediation intervention values for Cd, Pb and Zn and target value for Cu, when compared with Dutch standard, whereas As, Ni and Cr are in normal range. Lead concentrations in some samples near the mine tailing dumps also exceed the standard for remediation act for agricultural area set by Korean soil conservation law. The trace elemental concentrations are higher in the paddy soil nearer the mine tailing dumps and lower for the samples from distance. Similar trend with distance is found for the soil solution chemistry but the decrease with distance from the mine tailing dumps are sharper than the changes in soil chemistry. Cadmium, Cu and Pb concentrations in the soil solution are very low, ranging from a tenth and hundredths to a maximum of several mg/l, whereas their concentrations in soils are highly enriched for natural background. Most of the trace elements are thought to be either removed by reduced iron sulphides or iron oxides, depending on the redox changes. Geochemical equilibrium modelling indicate the presence of solubility controlling solid phases for Cd and Pb, whereas Zn and Cu might have been controlled by adsorption/desorption processes. Although pollutants migration through solution phase are thought to be limited by adsorption onto various Fe, Mn solid phases, the pollutants exist as easily releasable fractions such as exchangeable site. In this case, the paddy soil would act as pollutant pool, which will supply to plants in situ. whenever the geochemical conditions favour.

Germination Characteristics of Chinese Milk Vetch(Astragalus sinicus L.) Seeds Produced in China and Korea (수입 및 국내 채종 자운영 종자의 발아 특성)

  • Kim, Sang-Yeol;Oh, Seong-Hwan;Choi, Kyung-Jin;Park, Sung-Tae;Kim, Jeong-Il;Yeo, Un-Sang;Kang, Hang-Won
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.54 no.4
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    • pp.384-389
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    • 2009
  • Germination characteristics of Chinese milk vetch(CMV) seeds produced from Hanam Province, China and Milyang, Korea were investigated to give basic information on the stability of seedling establishment in the CMV cultivation. The germination percentage of the imported CMV seed from China varied according to importation year and seed collection site ranging from 79~95%. The germination of black colored seed coat was lower than the light green colored ones and germination by seed weight was not significantly different. Although the seed germination was lower under dark than in the presence of light, it was not significantly different. The germination of the imported CMV seed slightly declined to only less than 6% after one-year of storage under natural environment conditions but it significantly decreased after two years. However, when the seed was stored at the $5^{\circ}C$, the seed germination was the same as after two years of storage. On the other hand, fresh CMV seed produced in Milyang, Korea had only 8% germination due to seed coat dormancy but the germination increased to 73~85% after breaking seed dormancy after a year of storage. The high germination percentage of 72~82% was still maintained even after 27 months of seed storage unlike the CMV seed produced from China. These results indicate that CMV seeds do not require light for germination and the seed from China should be used within one-year after importation while the seeds produced from Korea can be used even after two years from harvest for stable CMV seedling establishment in the CMV-rice cropping system.