• The Korean Journal of Mycology
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• v.37 no.1
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• pp.108-110
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• 2009

The composition of endophytic fungal species from Pinus koraiensis was studied in two areas (Yeongwol and Jincheon), Korea. To identify 113 isolates, rDNA ITS regions were sequenced. On the basis of the ITS sequence, Pestalotiopsis sp. was the most frequently isolated species in both areas. Pestalotiopsis sp. (68.5%) and Lambertella sp. (12.4%) were isolated frequently in Yeongwol, whereas Pestalotiopsis sp. (41.7%), Hypoxylon sp. (20.8%) and Phomopsis sp. (12.4%) were dominant in Jincheon. Hypoxylon sp. and Phomopsis sp. were not found in Yeongwol.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1100-1107
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• 2012

Bacterial endophytes may be important factors in plant growth and ecologically relevant functions in rice. Using pyrosequencing technology, we analyzed the composition of endophytic bacterial communities that colonized the roots of rice cultivated in long-term fertilized (APK) and non-fertilized (NF) paddy soils. A total of 1,900 reads were obtained from 2 samples. All sequences were classified into 177 OTUs (APK sample) or 72 OTUs (NF sample) at a 97% similarity cut-off. Twenty-two OTUs were shared between the 2 samples, and these were also the most dominant OTUs in both samples. Proteobacteria was the most dominant phylum with 90.2%, followed by Actinobacteria (7.1%) and Bacteroidetes (1.1%). Furthermore, Pseudomonas was the most abundant genus in both samples. We observed clear differences in the structure of the endophytic bacterial community structure between the 2 samples. Notably, the distributions of Alphaproteobacteria and Gammaproteobacteria were markedly different. The diversity index of the APK sample was higher than that of the NF sample. These findings showed that the endophytic bacterial community of rice roots was affected by the presence of fertilizers in the rice field soil.

• Journal of Life Science
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• v.22 no.10
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• pp.1384-1391
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• 2012

Five coastal plant species, Artemisia fukudo, Aster sphathulifolius, Plantago camtschatica, Sedum oryzifolium, and Setaria viridis, were collected from the coastal region of Ulleung Island (Ulleung-Do, South Korea). Thirty-six endophytic fungi were isolated from the roots of these plants, and all were identified by using PCR with the following specifications: internal transcribed spacer 1 (ITS1), 5.8S rRNA, and ITS2 regions. Phylogenetic analysis indicated that all fungal strains belong to the phylum Ascomycota and comprise four orders (Capnodiales, Eurotiales, Hypocreales, and Pleosporales). Among all the identified species, the Eurotiales species were more abundant than species in the other orders. Nine different genera (Alternaria, Aspergillus, Cladosporium, Exserohilum, Fusarium, Neosartorya, Penicillium, Phoma, and Pyrenochaeta) in the four orders were confirmed. Penicillium and Aspergillus species were the most dominant species among the endophytic fungi isolated from the coastal plants. Shannon's diversity index (H') ranged from 0.684 to 1.609, and the endophytic fungi in S. oryzifolium was more diverse compared to the endophytic fungi in the other plants.

• The Korean Journal of Mycology
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• v.42 no.1
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• pp.79-85
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• 2014

Forty-two endophytic fungi were isolated from the roots of coastal plants, such as Aster sphathulifolius Maxim., Aster tripolium L., Phragmites australis, and Puccinellia nipponica Ohwi, naturally growing in Taean peninsula. The identity of the endophytic fungal strains was analyzed using the sequence of internal transcribed spacer regions. All fungi belonged to the phylum Ascomycota, and they were classified into eight orders (Botryosphaeriales, Capnodiales, Diaporthales, Dothideales, Eurotiales, Helotiales, Hypocreales, and Pleosporales) and thirteen genera (Alternaria, Aureobasidium, Cadophora, Cladosporium, Davidiella, Diaporthe, Fusarium, Gibberella, Macrophomina, Metarhizium, Neosartorya, Penicillium, and Phoma). Among the analyzed fungi, the fungi belonging to the genus Penicillium in Eurotiales were the most widely distributed. The host plant Aster tripolium L. was found to contain the most diverse endophytic fungal species among the coastal plants.

• KDI Journal of Economic Policy
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• v.34 no.2
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• pp.139-171
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• 2012

This paper examines the effect of private tutoring expenditures on academic performance of middle school students in South Korea, using data from "Analysis of the Level of School Education and Its Actual condition: Middle School". In the face of endogeneity of private tutoring expenditures, the paper employs an instrumental variable (IV) method and a nonparametric bounding method. Using both methods we show that the true effect of private tutoring on middle school students remains at most modest in Korea. The IV results suggest that a 10 percent increase in tutoring expenditure for Korean, English and math raises a student's test score of the subject at the largest by 1.24, 1.28, and 0.75 percent, respectively. The bounding results also fail to show evidence that an increase in tutoring expenditure leads to economically and statistically significant improvements in test score.

• International Area Studies Review
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• v.13 no.3
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• pp.213-238
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• 2009

This paper empirically examines effects of exporting on employment over the period 2000-2007 for Korean listed and non-listed manufacturing firms. The paper employs the dynamic panel model of labor demand and controls for simultaneity of the exports and real wages using a two step random effect Tobit-DPD (Dynamic Panel Data) procedure. Our empirical results suggest that surprisingly, there is no robust evidence for employment effects of exporting of Korea's large firms and small-medium sized firms during the sample period after Korean financial crisis. This implies that Korean exporting patterns have been changed in a way that exporting highly capital intensive goods leads to importing more intermediate goods and thus to countervailing the employment effects of exporting. This suggests that expansion of exporting by lowering exporting prices through the bilateral FTA might not be helpful to enhancing employment in Korea.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.10-10
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• 2020

전 지구적으로 생물다양성의 지속적인 감소 추세에 따른 생물자원의 중요성이 증가하는 시점에서, 식물 유전자원의 종 다양성 보존과 지속가능한 이용을 위한 체계적이고 현실적인 방안 마련이 절실한 실정이다. 국내에서도 2017년에 유전자원 접근 및 이익 공유에 대한 나고야 의정서가 발효됨에 따라 식물유래 BT산업 소재의 국내 자급이 불가피해진 상황이며, 더불어 국토의 생태복원에 적합한 식물 소재 개발의 중요성이 대두되면서 자생식물의 종자 수급기반 대책은 국가적 차원에서 중대한 과제라 할 수 있다. 우리나라는 면적 대비 높은 식물 종 다양성을 보이며, 이는 종자의 휴면유형 또한 다양하고 복잡할 수 있다는 것을 의미한다. 따라서 식물유전자원으로써의 보존 및 국가 경제적 이익을 위한 종자 활용, 산업화를 위해서는 종자의 생리적 특성에 기반 한 데이터베이스의 축적과 효과적인 활용을 위한 종자 휴면유형 분류 및 적정 휴면타파 조건을 확립할 필요가 있다. 현재까지 다양한 식물종에서 종자 휴면의 하위 카테고리가 계속적으로 세부 분류되고 있으나, 아직까지 밝혀지지 않은 세부 휴면유형에 의해 많은 유용 식물자원의 활용이 제한적이다. 종자의 휴면유형은 크게 외생휴면(Exogenous dormancy)과 내생휴면(Endogenous dormancy)으로 분류되며, 국내에서는 내생휴면에 대한 연구가 주를 이루고 있다. 한편 외생휴면은 물리적 휴면(Physical dormancy), 기계적 휴면(Mechanical dormancy) 및 화학적 휴면(Chemical dormancy)으로 세부 분류되며, 기계적 휴면과 화학적 휴면은 내생휴면인 생리적 휴면(Physiological dormancy)에 포함되어야 한다는 의견도 있다. 물리적 휴면 종자에서는 water-gap 복합체의 존재 등에서 원인을 찾을 수 있으나, 발아억제 호르몬에 기인하는 화학적 휴면 및 종(과)피 또는 배유에 의한 기계적 휴면은 배의 성장잠재력과 발달에 의해 타파될 수 있다. 이와 같이 실제로 많은 식물 종에서 다양하게 존재하는 외생휴면 유형에 대해 내생휴면과는 명확히 다른 방식으로 접근되어야 하므로, 다년간의 체계적 연구를 통해 미흡한 종자생리 연구 분야를 보완하고 자생식물의 종자 활용도를 높일 수 있을 것으로 기대한다.

• Journal of Life Science
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• v.23 no.1
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• pp.95-101
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• 2013

In this study, plant samples of five species were collected from the Dokdo islands in South Korea. Plant samples such as Asparagus schoberioides, Corydalis platycarpa, Festuca rubra, Sedum oryzifolium, and Setaria viridis were collected from the Dongdo and Seodo. Endophytic fungal strains were isolated from the roots of five plants from the Dokdo islands. Thirty-three fungal strains were isolated from these native plants. All the endophytic fungi were analyzed by internal transcribed spacer (ITS) sequencing (ITS containing ITS1, 5.8s, and the ITS2 region). Waito-c rice seedlings were treated with fungal culture filtrates to test their plant growth-promoting activity. A bioassay of the D-So-1-1 fungal strain isolated from S. oryzifolium confirmed that it has the highest plant growth-promoting activity. All the endophytic fungi belong to four orders: Eurotiales (86%), Capnodiales (3%), Hypocreales (4%), and Incertae sedis (7%). The endophytic fungi were classified as Ascomycota, which contained Aspergillus (12%), Cladosporium (3%), Eurotium (3%), Fusarium (18%), Microsphaeropsis (6%), and Penicillium (58%) at the genus level.

• The Korean Journal of Mycology
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• v.51 no.4
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• pp.511-519
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• 2023

Red pine (Pinus densiflora) is a dominant tree species in Korean forests. The diversity of endophytic fungi was investigated by isolating fungi from different parts of a red pine tree during the fall and spring seasons. One hundred and fifty-two strains of endophytic fungi were isolated and classified into 42 species belonging to 29 genera. Among these, 74 (49%), 47 (31%) and 31 strains (20%) were isolated from branches, leaves, and stems, respectively. The most frequently isolated species were Daldinia childiae and Biscogniauxia maritima (28.9% and 9.8%, respectively). D. childiae was the dominant endophytic fungus on branches (20 strains) and leaves (19 strains). B. maritima was most frequently isolated from branches. The isolation frequencies on stems of B. maritima (6 strains) and D. childiae (5 strains) were also high. Fifty-seven isolates belonging to 19 species and 17 genera were isolated in the spring, and 95 strains belonging to 35 species and 24 genera were isolated in the fall. D. childiae was the most frequently isolated fungus in both spring and fall (21 and 23 strains, respectively). B. maritima was also frequently isolated in both spring (7 strains) and fall (8 strains).

• Journal of Technology Innovation
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• v.21 no.2
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• pp.1-24
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• 2013

In spite of the increasing importance of service sector, most previous studies on schumpeterian hypotheses originated from manufacturing firms that have the needs to invest heavily in research and development (R&D). Conversely, we investigated the relationship between technological innovation activity and size of firms using panel data. Results of the analysis, the following results were obtained. First, the details depending on the industry sector was divided into active and vigorous industry technology innovation activities did not. Second, the relationship between firm size and technological innovation activity may not be, depending on the industry, some of the U-shaped model, may be. Third, showed fewer intangible assets, more debt, larger exports which further promote the technological innovation activities in industry. Finally, the relationship is responsive depend on the firm size variable.