• Journal of Biosystems Engineering
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• v.15 no.3
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• pp.219-229
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• 1990

The compression creep behavior of grains when loaded depends not only on load but also on duration of load application. The most common methods of studying the load-time characteristics of agricultural products is by employing rheological models such as Burger's model. However it is sometimes not sufficient to describe the viscoelastic behavior of grains to be Burger's model. For this reason, this study was conducted to develop the rheological model which represented the creep compliance response of the rough rice kernel and was a function of initial stress applied and time. The effects of the initial stress applied and the moisture content on the compression creep behavior of the rough rice kernel were analyzed. The results were obtained from the study as follows: 1. Since the viscoelastic behavior of the rough rice kernel was nonlinear, the transient and steady state creep compliance was satisfactorily modelled as follows: $$J({\sigma},t)=A{\sigma}^B[C+Dt-exp(-Ft)]$$ But, for the every stress applied, the compression creep behavior of the samples tested can be well described by Burger's model respectively. 2. The creep compliance, the instantaneous elastic strain, the retarded elastic strain and the viscous strain of the sample tested generally increased in magnitude with increasing the applied initial stress and the moisture content used in the tests. At low moisture content, the creep compliance for the Japonica-type rough rice kernel Was a little higher than those for Indica-type and at high moisture content, vice versa at high moisture content. 3. The retardation times of the samples had not an uniform tendency by the initial stress and the moisture content. The retardation times ranged from 0.66 to 6.76 seconds, and the creep progressed from transient to steady state at a relatively high rate. 4. The less viscous strain than the instantaneous elastic strain for the samples tested indicated that rough rice kernel behaved as a viscoelastic body characterized by elasticity than viscosity.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.3
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• pp.252-258
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• 1985

An experiment was conducted at the Yeongnam Crop Experiment Station to obtain basic informations about cultural techniques for high yielding by manipulating plant spacing using two rice cultivars, Samgangbyeo (Indica/Japonica type) and Nakdongbyeo (Japonica type), and four plant spacings, 10${\times}$10cm, 20${\times}$20cm 30${\times}$30cm and 40${\times}$40cm, with 4 kinds of seedling number per hill, 1,3,5 and 7, respectively. High photosynthetic efficiency (Eu) exhibited at the Samgangbyeo compared to Nakdongbyeo regardless of plant spacings and seedling numbers. For Samgangbyeo, Eu value was the highest at the 20${\times}$20cm plant spacing and five seedlings and seven seedlings per hill showed high Eu values at 10${\times}$10cm plant spacing and 20${\times}$20cm plant spacing, respectively, while other plant spacings were not significantly differed among seedling numbers. For Nakdongbyeo, however, one seedling plot obtained high Eu value at the 10${\times}$10cm plant spacing while this Eu value increased as the seedling number per hill increased in other plant spacings. There was a high positive correlation between rice grain yield and total competition index for both cultivars while kind of relationships differed in these two cultivars; linear relationship for Samgangbyeo and exponential relationship for Nakdongbyeo, respectively. Competition index between rice hill was more significant than within rice hill for Samgangbyeo while both competition indexs were important for Nakdongbyeo to increase rice yield.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.15 no.4
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• pp.23-40
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• 2012

The vascular plants of major sites in Changwon-si were listed 456 taxa (9.3% of all 4,881 taxa of vascular plants); 112 families, 293 genera, 371 species, 2 subspecies, 66 varieties and 17 forms. The vascular plants of Changwon-cheon were listed 133 taxa, Junam reservoir were listed 90 taxa, Seongju-sa were listed 293 taxa, and Yungji park were listed 164 taxa. Divided into 456 taxa; woody plants were 160 taxa (35.1%) and herbaceous plants were 296 taxa (64.9%). Furthermore, therophytes (Th) were 111 taxa (24.3%), hemicryptophytes (H) were 75 taxa (16.4%), megaphanerophytes (MM) were 63 taxa (13.8%) showed high proportional ratio in life form. Based on the list of rare plants by the Korea Forest Service and Korea National Arboretum, 10 taxa (1.8% of all 571 taxa of rare plants); Aristolochia contorta (LC), Euryale ferox (VU), Melothrua japonica (LC), Utricularia pilosa (CR), Hydrocharis dubia (LC), Carex idzuroei (DD), Acorus calamus var. angustatus (LC), etc. Based on the list of endemic plants by the Korea National Arboretum, 10 taxa (3.0% of all 328 taxa of endemic plants); Salix pseudolasiogyne, Philadelphus incanus, Indigofera koreana, Lespedeza ${\times}$ maritima, Stewartia pseudocamellia, Weigela subsessilis, Carex okamotoi, etc. Based on the list of specific plants by floral region were total 43 taxa (4.0% of all 1,071 taxa of specific plants); 4 taxa (Euryale ferox, Hydrocharis dubia, Carex idzuroei, etc.) in class IV, 9 taxa (Ilex crenata, Acer palmatum, Stewartia pseudocamellia, Melothria japonica, Fatsia japonica, etc.) in class III, 3 taxa (Caltha palustris var. membranacea, Nymphoides indica, etc.) in class II, 26 taxa (Cyrtomium fortunei, Chloranthus japonicus, Quercus variabilis, Ulmus parvifolia, Aphananthe aspera, etc.) in class I. Based on the list of naturalized plants, 48 taxa (Rumex crispus, Chenopodium album var. album, Amaranthus patulus, Phytolacca american, Brassica juncea var. integrifolia, Potentilla paradoxa, Robinia pseudoacacia, Euphorbia maculata, Oenothera odorata, Cuscuta pentagona, Veronica persica, Plantago lanceolata, Diodia teres, Helianthus tuberosus, Dactylis glomerata, etc.), naturalization rate was 10.5% of all 456 taxa of vascular plants and urbanization index was 15.0% of all 321 taxa of naturalized plants. Ecosystem disturbing wild plants were 3 taxa (Rumex acetocella, Solanum carolinense, Ambrosia artemisiifolia).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.6
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• pp.833-840
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• 1997

Differentiation and degeneration of spikelets in paddy rice has been studied in high yielding Indica$\times$Japonica hybrid cultivar, Milyang 23 and a Japonica type cultivar, Koshihikari. Germinated seeds planted in 5000$^{-1}$ a pots filled with submerged soil and cultured under natural conditions. The young panicles of main stem were continuously dissected and observered by Cryo-SEM from the panicle initiation stage, and investigated about formation position of the differentiation and degeneration spikelet within a panicle of 7 days after heading. The degeneration of spikelet appeared simultaneously throughout panicle just after closure of spikelet by the palea and lemma. Differentiated and degenerated spikelets per panicle were about 240, 80 for Milyang 23 and 87, 6 for Koshihikari, respectively. The spikelets degeneration in Milyang 23 was mainly on the secondary and tertiary branch which were developed from primary branch of middle-basal panicle node and hardly not the spikelets of primary branch, and degeneration rate of secondary and tertiary rachis branch and spikelets for Milyang 23 were 2.5 times greater than those of Koshihikari. The proper relation equation between total differentiation or normal spikelets number per panicle(Y) and each rachis branch number were different between cultivars, Le., Y=5.5X$_1$＋3.0X$_2$ for Koshihikari as previously proposed, but those of Milyang 23, Y=5.7X$_1$＋3.5X$_2$＋2.8X$_3$ for total differentiation spikelets and Y=5.6X$_1$＋3.2X$_2$＋2.4X$_3$ for normally developed spikelets, where X$_1$, X$_2$, X$_3$ are number of primary, secondary, tertiary rachis branch, respectively.

• Journal of Life Science
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• v.15 no.1 s.68
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• pp.61-65
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• 2005

Using two japonica rice cultivars (Ilpumbyeo and Sanghaehyanghyella), which are distinguishable by the brown planthopper (BHP) resistance maker (R208), a relationship between the BPH resistance gene (Os-Bil) and salt-tolerance was investigated. To do this, changes in the expression level of Os-Bil by the salt stress were quantified by the real-time PCR in the two cultivars, and compared with those in other two indica rice cultivars (Pokkali and IR29). In Ilpumbyeo, the expression level of Os-Bil decreased by the treatments of 50 and 200 mM NaCl in a concentration-dependent manner, and in Sanghaehyanghyella it rather increased slightly at 50 mM but decreased drastically at 200 mM. Comparably, IR29, a salt-sensitive cultivar, showed a reduction of the Os-Bil gene expression after the treatment of 100 mM NaCl, but Pokkali, a salt-tolerance cultivar, rather increased about two times in the level of Os-Bil transcripts. These results suggest that the BPH resistance gene may involve in the difference in the salt-tolerance at least between the two indica rice cultivars.

• Applied Biological Chemistry
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• v.34 no.4
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• pp.360-365
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• 1991

Rheological properties of Shinsunchalbyeo(Japonica) and $Hangangchalbyeo(J{\times}Indica)$ waxy-rice starches gelatinized with thermal or alkali solutions were investigated with rotational viscometer(Brabender Viscotron). The two starches showed Bingham pseudoplastics behavior in $4{\sim}8%$ thermal or alkali gelatinized starch solutions. The shear stress of Hangangchalbyeo starch solution gelatinized with thermal or alkali showed higher values than that of Shinsunchalbyeo starch and the difference of the two varieties gelatinized with alkali showed higher values than that gelatinized with thermal. Consistency index and yield stress values of Hangangchalbyeo starch showed higher than that of Shinsunchalbyeo starch in the two gelatinized methods and the difference of the two varieties gelatinized with alkali showed higher values. And it was higher that the deffendence of consistency index on starch concentration and initial starch concentration of yield stress in the alkali gelatinized samples than those of in the thermal gelatinized ones.

• Korean Journal of Weed Science
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• v.2 no.1
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• pp.20-30
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• 1982

A field experiment was conducted in 1981 at the Crop Experiment Station, Suweon, Korea, in machine transplanted paddy rice field, to study the effectiveness of single herbicide, mixture, and systematic application of herbicides on diversity of weed control spectrum. The rice variety planted was Taebaegbyeo, Indica ${\times}$ Japonica cross bred. Experimental field was dominated by Echinochtoa crusgalli, Eleocharis kuroguwai, and Scirpus hotarui, and importance values based on dry weight of these weeds were 89%, 5%, and 3%, respectively. The mixture or systematic treatments of herbicide were generally more effective than single herbicide applications on weed control. Coefficients of similarity based on floristic composition after herbicide application between Perfluidone (5G) and Chloromethoxynil (7G), and between Pertluidone (5G) and Bifenox (7G), and between Perfluidone (5G) and three types of Butachlor (6G) were low, and these sets seemed to be a good mixture herbicide in paddy fields. While, Perfluidone (5G) had low coefficient of similarity with other single herbicides tested. The information on coefficient of similarity could be used as parameter for selecting herbicides to increase the efficiency of herbicidal performance. Simpson's indices from Butachlor (3.5G)/SL-49 (7G), Butachlor (3.5G)/Pyrazolate (6G), and Perfluidone (5G) treatments were high, and these herbicide treatments tended to the weed community type simplified, while the indices from Perfluidone (5G) + Chloromethoxynil (7G), Butachlor (6G) fb Perftuidone (5G), and Butachlor (4G)/Naproanilide (6G) treatments were low, and these herbicide treatments caused to the community type diversified in terms of floristic composition.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.34 no.1
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• pp.83-96
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• 2016

Through the research and analysis on the vegetation environment, flora of habitats through documentary and field studies over 14 habitats of Euryale ferox Salisbury within Jeollabukdo, with the objective of acquiring the basic data for forming an environment based on plantation of reservoirs that are composed with Euryale ferox, the following results were obtained. 1. The entire flora of the 14 habitats appeared to be 79 families, 211 genus, 298 species, two subspecies, 30 varieties and six forma, thus, a total of 336 taxa was confirmed. Among these, emergent water plants appeared to compose 17 taxa, floating-leaved plants to compose seven taxa including Euryale ferox floating plants to compose five taxa and submerged water plants to compose two taxa. As a result of analyzing the similarity only over the water plants. The lowest similarity rate appeared between Gamdong Reservoir and Aedang Reservoir, as the similarity rate between the two regions appeared to be 0% as a result of the analysis. Floating-leaved plants, lotuses and caltrops, appeared to be equally inhabiting in Hanseongji at Jeongeup and Seoknam Reservoir at Gochang, which showed the highest similarity rate, in addition to Euryale ferox. 2. When examining the appearance frequency of aquatic plants per growth type, Actinostemma lobatum and Phragmites communis, in addition to Euryale ferox each appeared 11 times, showing a high frequency of 78.6% and Trapa japonica, which is a floating-leaved water plant, appeared ten times(71.4%) and Zizania latifolia appeared eight times(57.1%). In addition, the appearance rate appeared to be high in the order of Persicaria thunbergii, Leersia sayanuka, Ceratophyllum demersum, Echinochloa crusgalli var. oryzicola, Scirpus maritimus, and Nelumbo nucifera. 3. The rare plants discovered in the Euryale ferox habitats pursuant to the IUCN evaluation standards was confirmed to be composed of five taxa, with three taxa including the least concerned species(LC), Melothria japonica at Yanggok Reservoir, Hydrocharis dubia at Myeongdeokji and Ottelia alismoides at Daewi Reservoir, in addition to vulnerable species(VU), Utricularia vulgaris at Sangpyeong Reservoir, along with Euryale ferox. 4. Most of the group or community types of the natural habitats of Euryale ferox appeared to be the Euryale ferix community' and the Daewi Reservoir of Gunsan was defined as caltrop + Euryale ferox + Nymphoides indica community. The green coverage ratio of Euryale ferox per natural habitats showed a considerably huge deviation from 0.03 to 36.50 and as the average green coverage ratio was appropriated as 9.8, it can be considered that maintaining the green coverage ratio of Euryale ferox in a 10% level would be advisable when forming a reservoir with Euryale ferox as the key composition species. 5. The vegetation community nearby the natural habitats of Euryale ferox per research subject area appeared to be composed of three Leersia japonica communities, two communities each for Zizania latifolia community and Trapa japonica community and one community each for Nelumbo nucifera community, Nymphoides peltata + Typha orientalis community, Trapa japonica + Nelumbo nucifera community, Hydrocharis dubia community, Leersia japnica + Paspalum distichum var. indutum community and Euryale ferox + Trapa japonica community, showing a slight difference depending on the location conditions of each reservoir. Thus, this result may be suggested as a guideline to apply when allocating the vegetation ratio and the types of floating-leaved plants upon planting plants in reservoirs with Euryale ferox as the main companion species.

• Korean Journal of Soil Science and Fertilizer
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• v.15 no.4
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• pp.221-225
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• 1982

Soil and water temperature were measured at different distances from the irrigation inlet of a Paddy land supplied with $16^{\circ}C$ water. The rice growth and yields of Nongbaek variety (Japonica) and Milyang 23 variety (Indica${\times}$Japonica)were interrelated with average soil and water temperature from tillering to heading stage. Water temperature was asymtotically increased to $21^{\circ}C$ as cold water forwarded, while the distribution of soil temperature showed linear shape with distance overall, water temperature was 1 to $2^{\circ}C$ higher than soil temperature. Cold soil and water temperature shorterned culm length and panicle exertion and retarded heading date resulting in yield reduction, Response of rice growth and yield to water temperature was apparently different between two varieties. Nongbaek variety produced no grains below $17^{\circ}C$, but it's reproductive growth was possible from 17 to $20^{\circ}C$. A normal yield could be obtained at $21^{\circ}C$. Comparatively, no reproductive growth of Milyang 23 variety was Possible even at $19^{\circ}C$.

• Journal of Bio-Environment Control
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• v.15 no.4
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• pp.421-427
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• 2006

To investigate the relationships among the traits related seed dormancy in rice, viviparous germination, dry-heat tolerance and seed longevity were tested using 164 M/G RILs ($F_{17}$) derived from the cross between Milyang 23 (Indica/Japonica) and Gihobyeo (Japonica). At 40 days after heading, the viviparous germination rates of Milyang 23 and Gihobyeo were 0.0 and 7.0%, respectively. The averaged viviparous germination rate of 164 MIG RILs was 3.2%, and their range was from 0.0 to 50.9%. In dry-heat treatment at $90^{\circ}C$ for 24 h followed by the pre-drying at $40^{\circ}C$ for 2 days, Milyang 23 showed higher germinability (98.6%,2.7 days to $T_{50}$) than Gihobyeo (37.6%, 12.9 days to $T_{50}$), and the mean germination rate of 164 M/G RILs was 72.4%. In 54 months after harvest, the germinability in Milyang 23 and Gihobyeo were 90% and 0%, and 71 lines among 164 M/G RILs showed the germinability over 90%. The relationship between seed longevity and dry-heat tolerance was linearly correlated with high positive correlation coefficient. The relationships between seed longevity and viviparous germination, and viviparous germination and dry-heat tolerance were linearly correlated with high negative correlation coefficient. Milyang 23 had higher tolerance against high dry-heat, viviparous germination and long-term storage than Gihobyeo, and 164 M/G RILs showed the medium values of parents.