• Korean Journal of Breeding Science
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• v.40 no.3
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• pp.352-355
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• 2008

"Unmi" is a new japonica rice variety developed by the rice breeding team of Honam Agricultural Research Institute, NICS, RDA in 2007. This variety was developed from a across between Samcheonbyeo with lodging and cold tolerance and HR17870 derived from the cross of Iksan435 (Sobibyeo) and Sangju17 with resistance to diseases and good quality. This variety has about 110 days of growth duration from transplanting to harvesting in northern plain, northern and southern mid-mountainous areas of South Korea. It is about 68 cm in culm length and tolerant to lodging. In reaction to biotic and abiotic stresses, it shows moderate resistance to blast, and to bacterial blight pathogen races from $K_1$ to $K_3$, but susceptible to other major diseases and insect pests. The milled rice of "Unmi" is translucent and has relatively clear non-glutinous endosperm and medium short grain. It has about 17.3% amylose content and 6.3% of protein and similar palatability of cooked rice compared with Odaebyeo. The milled rice yield performance of this variety is about 5.16 MT/ha under the standard fertilizer level of the ordinary transplanting cultivation. "Unmi" would be adaptable for ordinary transplanting in the northern plain, northern and southern mid-mountainous area of South Korea.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.649-653
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• 2009

"Cheongan" is a new japonica rice variety developed from a cross between SR15225-B-22-1-2-1 and Iksan431 in summer season, 1997 by National Institute of Crop Science, RDA. The line SR15225-B-22-1-2-1 has good canopy architecture and multi-disease and insect resistance, and Iksan431 has translucent milled rice and good eating-quality. Heading date of Cheongan is August 13 in central lowland and mid-mountainous areas. "Cheongan" having culm length of 84 cm shows relatively semi-erect pubescent leaf blade and rigid culm, tolerance to lodging with and good canopy architecture. This variety has 14 tillers per hill and 126 spikelets per panicle. It shows tolerance to heading delay and spikelet sterility comparable to Hwaseongbyeo when exposed to cold stress. Leaf senescence of Cheongan progresses slowly during the ripening stage and the viviparous germination ratio was 59 %, similar to that of Hwaseongbyo. "Cheongan" shows moderately resistance to blast disease, but susceptible to stripe virus and brown planthopper. The milled rice of "Cheongan" exhibits translucent, clear non-glutinous endosperm and medium short grain. It shows similar amylose content of 18.7%, gelatinization temperature, and similar palatability of cooked rice compared to Hwaseongbyeo. The milled rice yield of this cultivar is about 5.54 MT/ha at ordinary season culture in local adaptability test for three years. Especially, "Cheongan" has better milling properties of higher 98.4% and 73.9% in the percentage of head rice in milled rice and milling recovery of head rice, respectively, than those of Hwaseongbyeo. "Cheongan" could be adaptable to the central and mid-southern plain area, and mid-western coastal area of Korea.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.4
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• pp.264-273
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• 2020

'Ilpum', a Korean short-grain mid-late maturing rice cultivar, was developed in 1990, more than 30 years ago. Despite its age, it has been the most widely grown cultivar in the Gyeongbuk province of South Korea for more than 25 years, making it the most important rice cultivar for the people of the Gyeongbuk province. The aim of this study was to analyze the relationship between the rice yield of "Ilpum', the main rice cultivar in the Gyeongbuk province, and climate elements in the Daegu (southern plain area) and the Andong (inland mountainous area) regions in Gyeongbuk, South Korea. The rice yield over the past five years increased by about 13% and 24%, compared to that produced in the late 1990s in Daegu and the early 2000s in the Andong region, respectively. The number of panicles per hill and the grain ripening rate significantly affected rice yield in the 'Ilpum' cultivars in the Daegu region. The faster heading was a factor in the increase in 'Ilpum' rice yield in the Andong region. The air temperature has been rising and sunshine duration has been increasing from the late 1990s to present in both regions. Rice yield was evaluated to understand the effect of climate factors. The rice yields increased owing to the long sunshine duration during the grain-filling stage in both regions. In Andong, increasing the maximum temperature during the vegetative stage increased rice yield. Rising air temperature during the reproductive stage also increased rice yield. In particular, long sunshine hours throughout the whole rice growing period increased the rice yield of this cultivar in the Andong region.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.1
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• pp.27-37
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• 1994

To catch the relative importance of varietal and environmental variation in various grain quality components associated with palatability of cooked rice, grain appearance, milling recovery, several physicochemical properties of milled rice and texture or eating quality of cooked rice for rice materials of five japonica cultivars, produced at four locations of the mid-mountainous and alpine area of Korea in 1989, were evaluated and analyzed the obtained data. Highly significant varietal and locational variations were detected in 1000-grain weight, amylose content, K/Mg ratio, gelatinization temperature, peak viscosity, breakdown and setback viscosities as compared with variety x location interaction variation. Also, marked locational variations were recongnized in milling recovery from rough to brwon rice, alkali digestibility and protein content, and significant varietal variation was caught in stickiness /hardness ratio of cooked rice. The variety x location interaction variation was especially large in quality components of grain appearance and ripening, palatability of cooked rice and consistency viscosity. One thousand kernel weight was heaviest in Jinbuolbyeo and Odaebyeo, and the unfilled grain ratio was lowest in Jinbuolbyeo. Odaebyeo showed slightly' lower ratio of intact and clear milled rice because of more chalky rice kernels compared with other cultivars. Amylose content of Jinbuolbyeo and Sobaegbyeo was about 1% lower than that of others and K/Mg ratio of Odaebyeo was the lowest one among rice materials. Odaebyeo, Sobaegbyeo and Jinbuolbyeo revealed significantly low gelatinization temperature and setback viscosity while high peak and breakdown viscosities. Cholwon rice showed the greatest kernel weight, good grain filling but lowest ratio of intact and clear milled rice while Jinbu rices exhibited the highest milling recovery from rough to brown rice and ratio of sound milled rice. Amylose content of milled rice in Jinbu rices was about 2-3% lower than those in other locations. Protein content of polished rice was about 1% lower in rice materials of middle zone than those of southern part of Korea. K/Mg ratio of milled rice was highest in Jinbu rice and potassium content was slightly higher in the rice materials of middle region than in those of southern region. Alkali digestion value and gelatinization temperature of polished rice was markedly high in Jinbu rices as compared with other locations. Breakdown viscosity was hightest in Chlown rices and next higher with the order of Hwaso>Unbong>Jinbu rices, and setback viscosity was the quite contrary tendency with breakdown. The stickiness /hardness ratio of cooked rice was relatively higher value in Cholwon rices than in the others and the palatability of cooked rice was a little better in Unbong and Cholwon rices than in Jinbu and Hwaso rices, although variety x location interaction variation was large. The rice materials can be classified largely into two groups of Jinbu and the others by the distribution on the plane of 1st and 2nd principal components (about 60% of total informations) contracted from twelve grain quality properties closely associated with eating quality of cooked rice. Also, Jinbu and the other rices were divided into two and three rice groups respectively. Varietal variation of overall rice quality was smallest in Hwaso. The most superior rice group in overall quality evaluation included Odaebyeo produced at Cholwon, Unbong and Hwaso, and Sobaegbyeo grown at Unbong

• Korean Journal of Breeding Science
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• v.42 no.6
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• pp.632-637
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• 2010

'Hanseol' is a new very early-maturing, cold tolerant and high quality japonica rice variety developed from a cross of 'Jinbu24' and 'Jinbu25' by the rice breeding team of National Institute of Crop Science (NICS), Rural Development Administration (RDA) in 2009. The heading date of this variety is July 25, which is four days earlier than check variety, 'Jinbubyeo'. 'Hanseol' has 65 cm of culm length, 99 spikelets per panicle, 82.9% of ripened grain rate, and 21.5 g of 1,000 grain-weight of brown rice. This variety shows susceptibility to bacterial leaf blight and virus diseases, and insect pests. It is tolerant to cold stress in terms of less heading delay and high fertility in cold water irrigated cultivation. This variety shows delayed leaf senescence and considerable tolerance to viviparous germination at ripening stage. The milled rice of this variety exhibits translucent, clear non-glutinous endosperm and medium-short grain. 'Hanseol' showed low gelatinization temperature and 6.1% protein content, 19.1% amylose content and good palatability of cooked rice. The milled rice yield of this variety is about 5.43 MT/ha at ordinary culture in local adaptability test for three years. 'Hanseol' would be highly adaptable to mid-north and mid-mountainous areas, and mid-northern alpine area in Korea.

• The Korean Journal of Quaternary Research
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• v.17 no.2
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• pp.145-148
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• 2003

The Kunang cave paleolithic site is located at Tanyang [$N37^{\circ}2'$, $128^{\circ}21'E$], Chungbuk Province, which is in the Central part of the Korean peninsula. The cave is developed at 312 amsl in a karstic mountainous area. The South Han River flows across this region and other caves can also be found near the river. The site was discovered in 1986 and excavated 3 times by the Chungbuk National University Museum until now. The cave was wellpreserved from modem human activities until the first discovery. The full length of the cave is estimated to be ca. 140 m. However, a spacious part up to 11 m from the entrance has been excavated. Eight lithological units are divided over the vertical profile at a depth of 5 m. Each unit is deposited in ascending order as follow: mud layer (Unit 9), lower complex (Unit 8) which is composed of angular blocks and fragments with a muddy matrix, lower travertine layer (Unit 7； flowstone), middle complex (Unit 6; cultural layer) which is composed of fragments with a muddy matrix, middle travertine layer (Unit 5； flowstone), yellowish muddy layer (Unit 4), upper complex (Unit 3； cultural layer) which has a similar composition to Unit 8. the upper travertine layer (Unit 2； flowstone), and finally surface soil layer (Unit 1). The most abundant vestiges in the cultural layers are the animal bones. They are small fractured pieces and mostly less than 3 cm in length. About 3,800 bone pieces from 25 animal species have been collected so far, 90 percent of them belonging to young deers. Previous archaeological study of these bone pieces shows thatprehistoric people occupied the cavenot for permanent dwelling but for temporary shelter during their seasonal hunting activity. More extensive studies of these bones together with pollen analysis are in progress to reconstruct the paleoenvironment of this cave. Only a single date (12,500 BP) obtained from a U-Th measurement of the upper travertine layer was previously available. In spite of the importance of the cave stratigraphy, there was no detail chronological investigation to establish the depositional process of the cultural layers and to understand the periodic structure of the cave strata, alternating travertine floor and complex layers. We have measured five 14C age dating (38900+/-1000, 36400+/-900, 40600+/-1600, more than 51000 and 52000 14C BP) using Seoul National University 14C AMS facility, conducted systematic process of the collagen extraction from bone fragments samples. From the result, we estimate that sedimentation rate of the cave earth is constant, and that the travertine layers, Unit 2 and Unit 3, was formed during MIS 5a(ca. 80 kBP) and MIS 5c (ca. 100 kBP) respectively. The Kunang Cave site is located at Yochonli of the region of Danyang in the mid-eastern part of Korea. This region is compased of limestones in which many caves were found and the Nam-han river flows meanderingly. The excavations were carried out three times in 1986, 1988, and 1998.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.11a
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• pp.177-184
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• 2003

Numerical simulation on marine wind and sea surface elevation was carried out using both three-dimensional hydrostatic and non-hydrostatic models and a simple oceanic model from 0900 LST, August 13 to 0900 LST, August 15, 1995. As daytime easterly meso-scale sea-breeze from the eastern sea penetrates Kangnung city in the center part as basin and goes up along the slope of Mt. Taegullyang in the west, it confronts synoptic-scale westerly wind blowing over the top of the mountain at the mid of the eastern slope and then the resultant wind produces an upper level westerly return flow toward the East Sea. In a narrow band of weak surface wind within 10km of the coastal sea, wind stress is generally small, less than l${\times}$10E-2 Pa and it reaches 2 ${\times}$ 10E-2 Pa to the 35 km. Positive wind stress curl of 15 $\times$ 10E-5Pa $m^{-1}$ still exists in the same band and corresponds to the ascent of 70 em from the sea level. This is due to the generation of northerly wind driven current with a speed of 11 m $S^{-1}$ along the coast under the influence of south-easterly wind and makes an intrusion of warm waters from the southern sea into the northern coast, such as the East Korea Warm Current. On the other hand, even if nighttime downslope windstorm of 14m/s associated with both mountain wind and land-breeze produces the development of internal gravity waves with a hydraulic jump motion of air near the coastal inland surface, the surface wind in the coastal sea is relatively moderate south-westerly wind, resulting in moderate wind stress. Negative wind stress curl in the coast causes the subsidence of the sea surface of 15 em along the coast and south-westerly coastal surface wind drives alongshore south-easterly wind driven current, opposite to the daytime one. Then, it causes the intrusion of cold waters like the North Korea Cold Current in the northern coastal sea into the narrow band of the southern coastal sea. However, the band of positive wind stress curl at the distance of 30km away from the coast toward further offshore area can also cause the uprising of sea waters and the intrusion of warm waters from the southern sea toward the northern sea (northerly wind driven current), resulting in a counter-clockwise wind driven current. These clockwise and counter-clockwise currents much induce the formation of low clouds containing fog and drizzle in the coastal region.

• Journal of the Korean Geographical Society
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• v.42 no.6
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• pp.863-878
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• 2007

The time-spatial distribution of Scrub typhus and its relationship with environmental ecology, such as climate, and habitat change are analyzed in respect of the geography of disease. Scrub typhus was firstly reported in 1951, and reemerged in 1986 mainly in southwestern Korea. later it has sharply increased and spreaded out toward whole country in 1998 and 2004, except mid-eastern mountainous region. Hwasung City is the typical example of sudden upsurge of Scrub typhus. High incidence of Scrub typhus patients might due to elevated temperature and decreased precipitation during the summer, as well as milder autumn. Sharp increase of Scrub typhus patients at rural area since 1980's might also be the result of the rapid changes of land use pattern, which eventually have contributed for the active development of dense vegetation and propagation of chigger mites around cultivated land.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.4
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• pp.284-293
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• 2020

Rice consumption in Korea has been decreasing as the eating habits of the Korean people have diversified with rapid economic growth. Recently, floury endosperm rice cultivars were developed to boost rice consumption and replace wheat flour consumption with rice flour, which is vulnerable to viviparity under wet weather during the grain-filling stage because of its loosely packed starch granule structures. To overcome this limitation, it is necessary to find a suitable rice transplanting date to produce high-quality rice flour by altering the heading ecology type and changing the cultivation time by region. We examined four floury endosperm rice cultivars (FERC) in the Cheongju (central plain area) and Boeun (mid-mountainous area) regions of Korea from 2017 to 2019. Of the FERCs, the mid-late maturing types (MMT) Seolgaeng (SG), Hangaru (HGR), and Shingil (SGL) exhibited high yield and yield components after transplanting May 30 in both regions; the early maturing type (EMT) Garumi 2 (GRM2) also exhibited high yield after transplanting June 20 in Cheongju. In addition, MMTs showed the same tendency as the characteristics shown in Cheongju when grown in the Boeun region, and EMT displayed high yield and yield components after transplanting June 10. The FERCs could easily present pre-harvest sprouting in the rainy season during the grain-filling stage after 20 days post-heading because the mean temperature and frequency of more three-day rainfalls have increased over the last 5 years from the previous annual averages. Viviparity of HGR and GRM2 decreased as the transplanting date was delayed, with decreases of 2.3%-4.6% in HGR and 11.9%-23.1% in GRM2 according to the region. SGL was generally resistant to viviparity because of the Tongil type. To minimize pre-harvest sprouting and produce high yield of rice flour in the Chungbuk province, the most suitable transplanting time was the end of May in MMT and the middle and end of June in EMT.

• Korean Journal of Weed Science
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• v.15 no.4
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• pp.254-261
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• 1995

The nationwide weed survey was conducted in lowland rice fields over whole country of Korea in 1992 in order to determine a change of weed community and to identify a major dominant weed species and/or problem weed. Based on morphological characteristics of weeds, population ratio of broad leaf weed was 42.6%, grasses weed-9.0%, sedges-33.4% and others were 15.0%. Annual weed was 33.4% while perennial weed was 66.6% in terms of life cycle of weeds. Meanwhile, there was different weed occurrence as affected by planting method of the rice plant. In hand transplanted paddy fields predominant weed species was Sagittaria trifolia L., Monochoria vaginalis Presl., and Aneilema japonica Kunth. In machine transplanted rice fields of infant and young rice seedling Eleocharis kuroguwai Ohwi. and S. trifolia L. were more predominant. There was high occurrence of M. vaginalis, Echinochloa crus-galli L., and Leesia japonica Makino in water seeding while E. crus-galli and Cyperus serotinus Rottb. were predominant weed species in dry seeded rice. Monoculture of the rice plant would cause to high occurrence of E. kuroguwai, S. trifolia, M. vaginalis, E. crus-galli, and Sagittaria pygmaea Miq and there was higher population of S. trifolia, S. pygmaea, M. vaginalis, E crus-galli, and E. kuroguwai in double cropping system based on rice culture. In particular, there was high different weed occurrence under different transplanting times. E. kuroguwai, S. trifolia, S. pygmaea, M. vaginalis, and C. serotinus were higher population at the transplanting of 25 May and S. trifolia, E crus-galli, C. serotinus, and M. vaginalis at 10 June and S. pygmaea, E. kuroguwai, M. vaginalis, S. trifolia, and E. crusgalli at 25 June in Korea, respectively. Autumn tillage in terms of tillage time would cause more predominant weed species such as S. trifolia, E. kuroguwai, M. vaginalis, and S. pygmaea while spring tillage was higher population of E. kuroguwai, S. trifolia, E. crusgalli, M. vaginalis, and S. pygmaea. In plain area of paddy field there was higher occurrence of E. kuroguwai, S. trifolia, M. vaginalis, E. crus-galli, and S. pygmaea and in mid-mountainous area S. trifolia, E. kuroguwai, M. vaginalis, E. crus-galli, and Ludwigia prostrate Roxb. while in mountainous area S. trifolia, M. vaginalis, Potamogeton distinctus Ben., E. kuroguwai, and E. crus-galli were. In 1992 the most ten predominant weed species at the rice field of Korea based on summed dominant ratio(SDR) were E. kuroguwai > S. trifolia > E. crus-galli > M. vaginalis > S. pygmaea > C. serotinus > L. prostrate > P. distinctus > A. japonica > Scirpus juncoides Roxb.