• Korean Journal of Plant Taxonomy
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• v.50 no.3
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• pp.318-326
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• 2020

We found an unrecorded species, Carex molestiformis Reznicek & Rothrock, in Byeokparyeong, Daehwa-myeon, Pyeongchang-gun, Gangwon-do, South Korea. This species is native to southern parts of the United States (ca. 11 states, including Arkansas, Missouri, and Oklahoma). These plants are usually distributed densely in stream flood plains, bottomlands, stream banks, and along roadsides. Belonging to section Ovales Kunth, perennial herbs with gynecandrous spikes, C. molestiformis is closely related to C. maackii Maxim. and C. scoparia Willd. and is distinguished from them by the number (2-4) of spikes in each inflorescence and the width (2.63.4 mm) and number (69) of veins of perigynia. A new Korean name of C. molestiformis 'Ga-Neun-Ta-Rae-Sa-Cho' was given, as it has slender overall appearance compared with C. maackii (Ta-Rae-Sa-Cho). We also provide a description, illustrations, photographs and a key of related taxa in Korea. We compared three DNA barcode region (chloroplast DNA matK, ndhF and nuclear ribosomal DNA internal transcribed spacer) sequences from C. molestiformis with those of C. maackii and C. scoparia, determining eight species-specific single nucleotide polymorphism sites for C. molestiformis.

• Korean Journal of Weed Science
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• v.6 no.1
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• pp.1-6
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• 1986

The growth, development, and morphological characteristics of Echinochtoa colons (L.) Link were determined through one life cycle. E. colons emerged 2 to 3 days after seeding (DAS) and reached the two leaf stage by 8 DAS. During the early growth stages, root length was greater than plant height, but the relationship was reversed from 4 weeks after seeding (WAS). Tillering started from the third leaf of the main culm as the sixth leaf on the main calm emerged. The unfolding of the leaves and tillering followed a regular pattern during the vegetative growth period. This resulted in the production of 19 tillers (5 primary, 12 secondary, 1 tertiary, and I nodal) at the 14-leaf stage. Shoot-root weight ratio was highest just before panicle initiation. The second spike from the top of the panicle was the shortest and produced the fewest seeds. Thereafter, spike length and the number of seeds per spike generally increased, the lower the position of the spike on the panicle. Seeds on the lower spikes weighed less and had lower germination ability than those from the upper spikes. Adventitious roots arose from the leaf sheath bases of a flowering stalk. The ability to produce adventitious roots was greater in a younger stalls than in an older stalk.

• Korean Journal of Materials Research
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• v.5 no.1
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• pp.87-95
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• 1995

The effect of stuffing of TiN on the diffusion barrier property between A1 and Si was investigated. The stuffing of TiN was performed by annealing in a Nz ambient at $450^{\circ}C$ for 30min. By TEM analysis, it is identified that there are solid-free or open spaces of a b u t 10-20$\AA$ between the grains of asdeposited TiN. In the case of stuffed TiN, the width of solid-free or open spaces has been reduced to about 10$\AA$ or below. The combination of RBS and AES analyses showed that the asdeposited TiN had about 7at.% of oxygen, and that the stuffed TiN had about 10-15at.% of oxygen. The diffusion barrier test result shows that after annealing at $650^{\circ}C$ for lhour, the asdeposited TiN fails due to the formation of A1 spikes and Si pits in the Si substrate. However, in the case of stuffed TiN, there is no indication of Al spikes and Si pits at the same annealing condition. Thus, it is concluded that this stuffing of TiN significantly improves the diffusion barrier property of TiN between A1 and Si. It is considered that the stuffing effect results from the reduced diffusion through grain boundaries due to the reduced spacing of grain boundaries.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.1
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• pp.78-85
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• 1987

In order for Paldanghomil (winter rye) to be investigated if its grain yield is able to be produced after clipping just before winter season for forage utilization this experiment was carried out under the four sowing dates of four locations in Korea (Chunchon, Suwon, Hwasung and Chungju). In rye clipping plot earlier sowing showed taller plant height, more number of tillers/㎡ and higher forage yield before winter season, indicating the highest forage yield (1803 kg/10a) in Chunchon by sowing of September II. Forage yield of rye before winter season was mainly influenced by plant height and number of tillers/㎡, showing more effect of plant height. Rye plants were more or less affected on winter damages, late heading and short culm by clipping before winter season. Analysis of variance indicated that only number of spikes/㎡ among grain yield components showed the high significance according to the clipping method, and that there showed little variation for other yield components due to the sowing date and clipping method. There showed more grain yield in non-clipping rather than that of clipping plot, indicating the difference of 46kg/10a. This was resulted from short culm and severe winter damages caused by clipping before winter season. Of the grain yield components, number of spikes/㎡ was greatly influenced for grain yield by analysis of stepwise regression. Therefore, grain yield of rye was able to produce after forage utilization before winter season due to the appropriate crop and soil managements, by resulting from the little variation in grain yield between clipping or non-clipping plots and from the higher grain yield by the early sowing.

• Korean Journal of Applied Biomechanics
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• v.26 no.3
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• pp.315-321
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• 2016

Objective: The aim of this study was to analyze effects of the toe-spring angle of bobsleigh shoes on start speed lap time to develop Korean-specific bobsled shoes suitable for winter environments and for domestic players on the basis of sports science and optimized biomechanical performance. Method: Seven Korean bobsleigh athletes participated in this study, with three pairs of sprint spikes from three companies (Type A, Type B, Type C). To analyze sprint lap time and forefoot bending angle for each shoe, participants were instructed to drag a sled 15 meters from the start line at a maximum sprint. forefoot bending angle was collected by a high speed camera, and lap time speed was measured. Results: Lap time for type B shoes was $3.52{\pm}0.17sec$, type A was $3.55{\pm}0.19sec$, and type C was $3.56{\pm}0.18sec$. Forefoot bending angles were: angle 1, $6.88{\pm}5.55^{\circ}$; angle 2, $9.23{\pm}6.38^{\circ}$; angle 3, $15.56{\pm}5.39^{\circ}$; angle 4, $9.54{\pm}3.85^{\circ}$; angle 5, $9.22{\pm}5.08^{\circ}$; angle 6, $7.66{\pm}6.44^{\circ}$; and angle 7, $4.30{\pm}6.24^{\circ}$ (p<.001). Forefoot bending in angle 3 was as follows: type A, $16.47{\pm}6.01^{\circ}$; type B, $14.30{\pm}4.96^{\circ}$; and type C, $15.90{\pm}5.17^{\circ}$. Conclusion: Hard outsoles and midsoles are better than soft type for reduced start lap time when developing a prototype Korean bobsled shoe.

• Korean Journal of Medicinal Crop Science
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• v.11 no.2
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• pp.109-114
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• 2003

To determine the optimum N rate m Jeju island for utricle and root production of Achyranthes japonica Nakai, a medicinal plant, the plants were grown at two plant densities $(50\;and\;100\;hills/m^2$, two plants per hill; mall plots) at six N application rates (0, 6, 12, 18, 24, and 30 kg/10a; split plots) in 2001. There was no significant interaction between plant density and N application rate for all measured agronomic characters. Main root length and roots per hill were 5 and 52% greater, respectively, but N content of stover was lower under lower plant density compared to higher plant density. The other characters were not affected by plant density. N application rate did not significantly affect mall stem diameter, spikes per hill, spike length, utricles per spike, mall root length and diameter, and utricle N content. As N rate increased from 0 to 30 kg/10a, SPAD values and stover N content increased linearly from 35.0 to 40.5 and 1.09 to 1.38%, respectively, and plant height, branches per hill, stover, utricle and root dry matter yields, roots per hill, and top N yield increased quadratically. Spikes per hill were increased in a cubic manner with increased N application rates. N application rate for the maximum dry matter yield of utricle and root in A. japonica was estimated to be 21 kg N/10a.

• Publications of The Korean Astronomical Society
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• v.17 no.1
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• pp.23-40
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• 2002

The spatial distribution of meteoroids or cometary debris along the orbit of the Earth is investigated by analyzing the meteoric records in the Chronicle of the Koryo dynasty (918-1392) which is called Koryosa. Sporadic meteors in this period show the seasonal variation in number, which is similar to the current meteors. We also found that there are a few spikes showing large accumulation of records around the same dates. We regard these spikes as meteor showers in the Koryo period. We compared the dates of meteor showers with those compiled from the historical records around the world including Korea, Japan, China, Arab, and European countries. We discovered three prominent showers and four weak showers. The prominent ones are the Leonids, the Perseids, and the Aquarids and the Orionids pair. The last pair is the remnants of Halley's comet. The astronomical records written in the history book of the Koryo dynasty are turned out to be accurate and written in a steady manner. We can also see that those records can be useful to contribute the development of modern astronomy and astrophysics.

• Journal of The Korean Society of Grassland and Forage Science
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• v.31 no.4
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• pp.345-352
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• 2011

Soil fertility different depend on application rate of manure and compost for many years. While each crop has different adaptability depend on soil fertility, crop and species or varieties should be chosen depending on the adaptability and productivity. These experiments were carried out to compare the five winter cereal crops for whole crop silage on growth, yield and feed value as affected by soil organic content. The rate of increase on no. of spikes at high fertile soil compared with medium fertile soil was sequently high Samhan (Oat's variety) > Cheongwoo (Wheat) > Gogu (Rye) > Youngyang (Barley) > Shinyoung (Triticale). The rate of decrease at low fertile soil compared with medium fertile soil was sequently high Youngyang > Gogu > Cheongwoo > Shinyoung > Samhan. The triticale was lower variation of no. of spikes as affected by soil organic content than that of other winter cereals. The variations of dry matter yield as affected by soil fertility was higher oat and barley and lower triticale. Forage yield of triticale was higher about 69 percent than that of barley at low fertile soil. Forage yield was the highest in triticale and the lowest in rye in all soil fertility. In high fertile soil, rate of increasing digestible dry matter (DDM) yield compared with medium fertile was high in Samhan and Youngyang. Rate of reduced DDM yield in low fertile soil compared with medium fertile was low in Shinyoung and Cheongwoo.

• Conservation Science in Museum
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• v.3
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• pp.65-69
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• 2001

Scientific analysis are carried on gilded ornamental shoes, which have been excavated from tomb No 1. and No 4. in Beopcheon-ri, Wonju dated from Baekje Period. This object is a very important because it provides valuable information on the development of metal-making techniques of that period. Thus, this article illustrates the investigation conducted to reveal how the object was created using what materials and techniques. Instead of the spikes-attached to the bottom plate of the object-that couldn't be sampled, a sample of a decorative rivet showing a similar structure to the spikes-attached to the other parts of the shoes-was prepared for a cross-section examination. Using radiography and microscopes, it was found that the head of a spike was placed and then punched to the gilded plate, so it can be held to the shoes. Under the SEM-EDS, the cross-section of the rivet shows that the gilding layer was applied before the attachment of the rivets. It also shows that the gilding layer is distributed unevenly and there are empty spaces indicating amalgam gilding was employed. This was confirmed as Mercury was detected on the SEM-EDS analysis of the object. The examination of the microstructure of the plate using the SEM-EDS revealed that the object is made of a single copper alloy plate with recrystallized twining and non-metallic white inclusions, which found to be lead in this case.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.3
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• pp.263-269
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• 1997

To cope with increasing importance of water stress in food crop production, some physiological characteristics, their cultivar-differences and grain yield of winter barley cultivars in response to water stress during reproductive stages were studied employing three covered-barley cultivars, Milyang 12, Durubori, and Olbori, one naked-barley cultivar, Baegdong, and one two-row malting-barley cultivar, Hyangmaeg. The barley grown in pot-soil was conditioned for 10 days under water stress, varying the time of water stress : 20 days before heading, 10 days before heading and the time of heading. The decrease in growth due to water stress varied greatly with the cultivars and time of water stress. The greatest injury occurred when water stress was imposed for 10 days from 10 days before heading : the culm length of water-stressed plants have shown reduced by 85∼98％ of the non-stressed; the number of spikes per plant by 52∼83%; the number of grains per spike by 71∼86%; 1,000-grain weight by 80∼84%; yield per pot by 60∼94%. The number of spikes per plant as one of yield components was most sensitively affected. As a whole, the drought resistance of cultivars was high in the order of Olbori> Milyang 12 and Durubori> Hyangmaeg>Baegdong. On rewatering the plants after termination of the water stress treatment the recovery rate of free proline content and relative turgidity of flag leaf were higher in 3 covered-barley cultivars, and lower in cultivars Baegdong and Hyangmaeg.