• Phonetics and Speech Sciences
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• v.8 no.3
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• pp.11-20
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• 2016

It is well known that vowels are shorter before voiceless consonants than voiced ones in English, as in many other languages. Research has shown that the ratio of vowel durations in voiced and voiceless contexts in English is in the range of 0.6~0.8. However, little work has been done as to whether the ratio of vowel durations varies depending on English variety. In the production experiment in this paper, seven speakers from three varieties of English, New Zealand, British, and American English, read 30 pairs of (C)VC monosyllabic words which differ in coda voicing (e.g. beat-bead). Vowel height, phonemic vowel length, and consonant manner were varied as well. As expected, vowel-shortening effects were found in all varieties: vowels were shorter before voiceless than before voiced codas. Overall vowel duration was the longest in American English and the shortest in New Zealand (NZ) English. In particular, vowel duration before voiceless codas is the shortest in New Zealand English, indicating the most radical degree of shortening in this variety. As a result, the ratio of vowel durations in varying voicing contexts is the lowest in NZ English, while American and British English do not show a significant difference each other. In addition, consonant closure duration was examined. Whereas NZ speakers show the shortest vowel duration before a voiceless coda, their voiceless consonants have the longest closure duration, which suggest an inverse relationship between vowel duration and closure duration.

• The Plant Pathology Journal
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• v.15 no.4
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• pp.236-241
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• 1999

Sclerotinia twig blight on trees and cottony rot on fruits of Satsuma mandarin were observed in Cheju, Korea in 1996 and 1997. The causal fungus causing citrus twig blight and cottony rot was identified as Sclerotinia sclerotiorum which had cup-shaped apothecia bearing hyaline and clavate asci and periphyses on sclerotium. Symptoms were produced on twigs, developing young leaves, fully developed new leaves, and fruits 2-9 days after wound inoculation, but only on twigs with young lateral buds and developing young leaves by unwound inoculation. The fungus grew well between 10 and $27^{\circ}$, but optimum temperature was $24^{\circ}$ on potato dextrose agar. Most varieties were highly susceptible to S. sclerotiorum, whereas some varieties such as Ichinan were relatively resistant among twelve Satsuma mandarin varieties in the field. This is the first record of Scledrotinia twig blight on trees and cottony rot on stored fruits of Satsuma mandarin in Korea.

• Journal of Korean Medical classics
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• v.26 no.4
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• pp.1-21
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• 2013

Objective : This study is about how theory on seven kinds of prescriptions in Yellow Emperor's Cannon of Internal Medicine(黃帝內經) had been developed and how it had been applied for in prescription books or clinical texts. Method : I made a comparison of this theory between prescription books and clinical texts. After it, I investigated the change or development of it. Result : The first explanation about this was made by Wang Bing(王氷). Yu Wanso(劉完素) made up several varieties and meanings of it, Jang Jahwa(張子和) corrected what Yu Wanso added. Besides, someone for example, Wang Hogo(王好古), Yi Cheon(李梴), and so on added new varieties and meanings of odd prescription and even prescription. Conclusion : Theory on seven kinds of prescriptions in Yellow Emperor's Cannon of Internal Medicine had been constantly changed and developed in prescription books or clinical texts.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.24 no.1
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• pp.1-10
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• 1979

In order to investigate the causes of epidemic out break of rice blast disease in 1978, investigations were undertaken in respect of climatic conditions, variety, cultural practice and plant pathology. During 1978, especially in August at heading time, it was higher temperature and humidity, higher frequency and amount of rainfall, lower amount of sunshine and solar radiation than less blast infested years. Nitrogen content in rice plant was higher than previous years. Acreage increase of semi-dwarf varieties brought about a result of proportional increase of new blast races which are able to infect the semi-dwarf varieties. It was concluded that those conditions mentioned above might have caused the result of severe neck blast disease in rice varieties in Korea, 1978.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.12a
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• pp.80-80
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• 2020

Glycyrrhizae Radix (GR), commomly known as liquorice, is a medicinal and edible plant widely used in East Asia with its pharmacological properties. Currently, Glycyrrhiza uralensis, G. glabra and G. inflata are used for pharmaceutical purposes in Korea and then the improved Glycyrrhiza varieties, WON-GAM (WG) has been developed by Korea Rural Development Administration. To evaluate equivalence of efficacy, several comparative studies between already-registered species and new cultivars have been conducted. To evaluate equivalence of efficacy, several comparative studies between already-registered species and new cultivars have been conducted. The aim of this study was to evaluate the effect of WG on fecal microbiota in DSS-induced colitis model. Fecal microbiota was analyzed by terminal restriction fragment length polymorphism (T-RFLP). The composition of the fecal microbiota did not show a specific pattern based on experimental groups; however, a tendency toward an increase in the proportion of Lactobacillales was observed. Glycyrrhiza varieties could change composition of fecal microbiota in DSS-induced colitis model. This work was carried out with the support of "Cooperative Research Program for Agriculture Science and Technology Development (Project No. PJ014246022020)" Rural Development Administration.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.51-51
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• 2022

Water dropwort (Oenanthe stolonifera DC.) is a perennial herbaceous plant that grows wild throughout Korea. As of 2020, 24,819 tons (51.7% of open field, 48.3% of facility) are produced in 1,278 ha (59.9% of open field, 40.1% of facility) nationwide. Water dropwort, which is rich in nutrients such as vitamins and iron, is mainly cultivated by vegetative propagation method using local traditional species, however, seed propagation and breeding of cultivars are insufficient so far. Since securing, propagating and continuous characterization of various genetic resources are required to breed new cultivars, this study was conducted to compare the main characteristics of domestic genetic resources and to improve their utilization. Growth characteristics such as plant height, fresh weight, plant type, and flowering date were investigated for the 89 varieties of genetic resources owned by Jeollabuk-do Agricultural Research and Extension Services after vegetative propagation in the individual pots. Also, the morphological image information of leaves and flowers was constructed. Genetic resources were collected nationwide and originated in 30 regions including Hwaseong, Siheung and Jeju. Their plant types could be classified into straight, intermediate and creeping types according to their morphological characteristics, and at this time, the number of intermediate types accounted for the largest proportion. Flowering was carried out under high-temperature and long-day conditions in summer. According to the flowering date, they could be classified into early, middle and late flowering varieties, and at this time, the middle flowering varieties occupied the largest proportion. As a result of the investigation of vegetative growth characteristics, varieties with long plant height, heavy fresh weight and thick stem thickness were identified. Along with this result, it is thought that classification and selection of genetic resources for various purposes will be possible through additional investigations such as analysis of components and antioxidant activity. Moreover, it is judged that such results can be used as basic data for breeding new water dropwort cultivars in the future.

• Weed & Turfgrass Science
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• v.6 no.4
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• pp.283-291
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• 2017

Zoysiagrass has been used in Korea as a native grass. Informations on distributions, classifications, breeding efforts and outputs, current production and uses of zoysiagrasses in Korea are summarized. During past a few decades, collection of naturally growing zoysiagrass ecotypes has been continued, followed by evaluation, selection and cross-pollination. Classification efforts using important morphological, biochemical traits and DNA polymorphisms resulted in the several suggestions of grouping zoysiagrass species and varieties. Zoysia japonica consistently form separate group, while Zoysia sinica and Zoysia macrostackya have been separately or inter-mixed. Z. matrella with some variations frequently grouped separately but with some similarity with Z. tenuifolia, which was recently renamed as Z. pacifica. Hybrid types of zoysiagrasses were frequently found in Korea. New varieties such as 'Kunhee' and 'Green Ever' etc. were bred by ecotype selections, while 'Senock', 'Semil', 'Millock' were bred through pollination. Molecular approaches were also used to introduce beneficial genes into zoysiagrasses with no practical outputs by legal regulations. Currently popular varieties are inter-specific hybrid types such as 'Anyang' and other local zoysiagrasses as well as common zoysiagrass (Zoysia japonica) Production area in Korea was estimated as 2,947 ha with increasing problems of mixed or contaminated species and varieties.

• Journal of the Korean Professional Engineers Association
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• v.10 no.3
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• pp.8-16
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• 1977

The pbjective of this study to clarify the varietal resistance to green leaf-and planthopper and the evaluate the nature of the resistance to the insects in connection with the Antibiosis. this study was investigated the reaction of the varieties to insects with 46 rice varieties including recommended varieties of korea, At seedling stage they were in fested with second of third inster nymphs. the results were as follows. 1. Most of the rice vari eties tested showed highly susceptible reaction to Brown planthopper except Mudgo, KR 108-143- and HR529-41-3-2 as resistance, and Akamoch, Satominori, IR 24 and IR 8 asmoderately suscptible. 2. In the test of varietal resistance to white backed planthopper Mudgo, KR 108-243-1, KR 109-154-2 and HR 529-45-3-2 were resistance, and Suweon 82, Tongil, IR 8 palkeum, Iri 309, Hokwang and Chuhoku #31 were Moderatly susceptible. 3. Most of the varieties tested were observed highly resistance to green leafhopper, but Tongil, Suweon 82, IR 24, Milsung and Chuhoku #31 were Moderatly susceptible. 4. the new bred lines HR 108-243-1 are multiple resistance of Brown planthopper, green leafhopper and white babked planthopper, and some others showed moderatly susceptible as. IR 8: Brown planthopper, white backed planthopper. IR 24: Brown poanthopper, green leafhopper. Tongil: suweon #82, Chukoku #31, whist backed planthopper, Green leafhopper.

• Journal of Korea Foresty Energy
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• v.22 no.2
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• pp.1-17
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• 2003

Populus species have been as a model species in tree breeding and we have enormous varieties resulting from the poplar breeding because of their fast growth performance and short rotation age. New varieties developed in Korea are common italian poplar(P euramericana, I-214, I-476), P euramericana“Eco 28”(Italian poplar No.1) and p. deltoides“Lux”(Italian poplar No.2), which were introduced from foreign countries. As hybrid polars, Hyun-Sasi(p. alba ${\times}$ P. glandulosa No.1, No.2, No.3, No4.), P. nigra x P. maximowiczii and P. koreana x P. nigra val. italica, were developed, and P. davidiana was selected as the result of selection breeding The total plantation areas covered with the new varieties are 935,162ha that include 745,773ha of P. euramericana, 184,636ha of P. alba x P. glandulosa, and other new varieties are 4,735ha. The new poplars are contributed to increase farmer's income as well as bare land tree-planting in Korea. The technologies associated with the poplar species were developed, such as the determination of optimum site for new the poplar species, the crossing method between incompatible poplar species, and the vegetative mass propagation. In the future, poplar species will be considered for phytoremediation species at contaminated areas such as landfill sites or with lives stock's waste water as well as wood production, a shade tree like road-side tree and public park tree.

• Korean Journal of Plant Resources
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• v.32 no.6
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• pp.683-688
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• 2019

This study was conducted to determine the number of days required to break a plant's dormancy and promote subsequent crop growth in new varieties of Gomchwi through the 4℃ treatment. Three new varieties of Gomchwi namely, 'Sammany', 'Gommany', and 'Damogy' were observed in this study. The rate of leaf emergence of 'Sammany' after 15-day of 4℃ treatment was 100%, while 'Gommany', and 'Damogy' took 20-days and 10-days, respectively to reach to 97.9% rate of leaf emergence. After 10-days of 4℃ treatment, 'Damogy' grew faster than the other varieties. and Harvest time for 'Damogy' was on January 18^th, after 5-days of 4℃ treatment and yield was observed to be the highest at 15-days of 4℃ treatment. 'Sammany' was next with a minimum of 10-days of 4℃ treatment, although 15-days is more preferred for better harvest. 'Gommany' on the other hand, did not grow enough for harvest by January 18^th, and its harvest time was delayed to January 31^st. It needed a minimum of 15-days and preferentially 20-days of 4℃ treatment to grow normally and be ready for harvest. The plant height, leaf length and leaf petiole length appeared to grow better by extending duration of the 4℃ treatment. The number of leaves of 'Sammany' and 'Gommany' varieties was three leaves for the 5-days treatment which may be due to the incomplete breaking of dormancy. Regarding the yield per plant, 'Sammany' yielded 112.3 grams (g) in 15-days treatment, and 'Gommany' yielded 106.5 g in 25-days treatment. In the case of 'Damogy', it yielded 123.5 g and 183 g in the 10-days and 25-days treatment respectively. It is concluded that 'Damogy', 'Sammany' and 'Gommany requires 10, 15, and 20 days of 4℃ treatment to break the plant's dormancy and promote better plant growth.