• 한국신뢰성학회지:신뢰성응용연구
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• 제15권4호
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• pp.262-269
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• 2015

Accelerated degradation mechanism of the heat-resistant steel for high temperature plant was analysed in terms of microstructure and hardness. In order to simulate the microstructure of the steel actually used at $540^{\circ}C$ in the field, isothermal exposure was carried out at $630^{\circ}C$ up to 4,800 hours. The artificial degradation mechanism was comparatively verified to successfully simulate degradation of the long-time used field material. For the artificially degraded specimens, databases including size and aspect ratio of carbide, chemical composition (i.e., Cr/Mo ratio) of grain boundary carbide were built up. These degradation parameters were suggested as fingerprints for PHM (i.e., prognostics health management) of power plants.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.133.2-134
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• 2003

Cedar-apple rust fungi had been collected at 36 sites throughout the country from 1984 to 2001 and deposited at the Herbarium of Korea Forest Research Institute (HKFRI). We conducted the morphological examination on the dried specimens by light and scanning electron microscopy and as results six Gymnosporangium species were identified. Three species, G. asiaticum, G. clavaritforme and G. yamadae, were previously described in Korea, while the other three species, G. cornutum, G. globosum, and G. japonicum were new to Korea. Here we present the detailed morphological descriptions, distribution, host ranges and keys to species in both aecial and telial stages of each species. Some morphological characteristics related with telial formation on trees were newly identified; witches brooms for G. asiaticum, small galls for G. yamadae and telial formations on trunk for G. japonicun Geographically G. asiaticum and G. yamadae distributed widely throughout Korea, while the others were collected only at the limited locations. Eight Juniperus species as telial hosts and fifteen Rosaceous plants as aecial hosts were confirmed to be new in Korea.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1349-1352
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• 2005

This paper is to investigate a defect for thermal barrier coating layers by acoustic emission method in 4-point bending test. The two-layer thermal barrier coating is composed of $150\mu{m}\;CoNiCrAlY\;bond\;coating\;by\;vacuum\;plasma\;spray(VPS)\;process\;and\;250\mu{m}\;ZrO_2-8wt%Y_2O_3$ ceramic coating layer by air plasma spray(APS) process on Inconel-718. The specimen prepared by cyclic thermal test(500, 1000, 2000cycle) at $1050^{\circ}C$ The AE monitoring system is composed of PICO type sensor, a wide band pre-amplifier(40dB), PC and AE DSP(16/32 PAC) board. The AE event, amplitude, Cumulative energy and count of coating specimens is evaluated according to cyclic thermal test.

• 식물분류학회지
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• 제41권3호
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• pp.287-297
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• 2011

The objective of this study was to discuss the characteristics of the moss flora of Mt. Deogyu located on the border of the Jeonbuk and Kyungnam provinces in Korea. A total of 21 field surveys were carried out at various sites in the mountain area from August 2007 to September 2008. All the collected materials were processed into voucher specimens and were currently deposited in the herbarium at Chonbuk National University (JNU). In this study, we collected and identified 158 moss taxa, which included 156 species, 1 subsp. and 1 var. of 96 genera and 37 families. Unconfirmed taxa in this study, but previously recorded, belonged to 25 taxa, which included 13 families, 19 genera and 25 species. In addition, 183 taxa were found on Mt. Dreogyu, which belonged to 37 families, 101 genera, 1 subsp. and 1 var. The habitat of each collection was examined and the classification system of Ignatov et al. (2006) was used. New vernacular names of 6 families and 11 genera were then determined. Six species, formerly thought be only in North Korea, were shown to be present on Mt. Deogyu, which included Bucklandiella laeta, Anomobryum filiforme var. concinnatum, Herzogiella turfacea, Brachythecium rutabulum, Eurhynchium angustirete and Campylidium hispidulum.

• 식물분류학회지
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• 제41권1호
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• pp.1-9
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• 2011

사철쑥(Artemisia capillaris Thunb.)과 비쑥(A. scoparia Waldst. & Kit.)의 분류형질인 뿌리 형태, 잎 크기, 두상화서 크기는 사철쑥의 연속변이에 포함되어 두 분류군을 구분하는 유용한 형질이 아니며, 다른 분류학적 중요형질인 생육형에 있어서 관찰된 국내의 모든 표본과 생체들은 반관목 또는 다년초로서, 비쑥의 형질인 1, 2년초는 없는 것으로 확인되었다. 따라서 국내에 분포하는 개체 중 기존에 비쑥으로 알려진 다년초의 개체들은 사철쑥의 변이이며, 1, 2년초인 비쑥은 국내에 분포하지 않는 것으로 판단된다.

• 식물분류학회지
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• 제42권4호
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• pp.324-329
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• 2012

한국산 쑥속 식물 중 큰외잎쑥(A. integrifolia L.)의 분포와 실체를 교토대학(KYO)에 소장되어 있는 함경북도 온성군 북창평과 함경북도 경흥군 함림산, 성균관대학교(SKK)에 소장되어 있는 강원도 회양군에서 수집된 표본을 바탕으로 재검토하였다. 큰외잎쑥은 중부 잎의 형태가 타원상 피침형이고 엽연의 형태가 1-3쌍의 큰 결각이 있는 특징으로 형태가 유사한 분류군들인 외잎쑥(A. viridissima (Kom.) Pamp.), 가는잎쑥(A. subulata Nakai)과 뚜렷하게 구분된다. 이에 분류군의 형질기재 및 도해, 근연종과의 검색표를 작성하였다.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2018년도 추계학술대회
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• pp.42-42
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• 2018

Two unrecognized species of Sparganium of Korea were found during the our field expeditions and phylogenetic analyses of specimens deposited in the Herbarium of Korea National Arboretum (KH). S. coreanum H. $L{\acute{e}}v$. was first reported as a new species based on the specimen (Taquet, 2150) collected from Jeju Island. It has been recognized as synonym or infraspecific taxa of S. stoloniferum and S. eurycarpum or even never recognized recently. However, phylogenetic tree showed that S. coreanum is monophyletic and has sister relationship with S. eurycarpum. Furthermore, additional distribution localities were also found by herbarium survey. Morphological characteristics and distribution information of S. coreanum will be discussed. Another Sparganium species found from Mt. Daeam is occurring either as floating or emergent. Although we could not identify this species since lack of any flowers or fruits for two year surveys, phylogenetic analyses results showed that this species belong to the clade of S. glomeratum, which is distributed in high elevation lakes and marshes of Europe, Asia, and North America. Additional survey of morphology and report will be needed.

• 한국응용곤충학회지
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• 제20권4호
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• pp.196-206
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• 1981

국립식물검역소 인천지소에 소장중인 수입원목해충 중 나무좀류를 동정한 결과 다음과 같이 나무좀과에서 2 아과 6속 14종이 긴 나무좀에서 2아과 2속 11종이 확인되었다. Scolytidae Ipinae Arixyleborus granulifer A. rugosipes Xyleborus posticepilosus X. similis X. subcostatus Ips pini I. plastographus I. tridens Trypodendron lineatum Hylesininae Dendroctonus adjunctus D. brevicomis D. frontalis D. ponderosae Hylurgops porosus Platypodidae Platypodinae Platypus agnatus P. biuncus P. curtus P. geminatus P. jansoni P. maritimus P. pseudocupulatus pseudocupulatus P. shoreanus bifurcus P. solidus Diaporinae Diapus pendleburyi D. pusillimus.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집A
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• pp.37-42
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• 2000

The boiler tubes and steam Pipes operating both at high temperature and pressure for a long period of time in a power plant are degraded by creep because of internal pressure. So, the remaining life of a component is evaluated by the creep rupture strength. Although the conventional method to evaluate the creep damage is widely used, it has some disadvantages such as requires large size specimen and long employed to evaluate the correlation between fracture toughness and evaluation time. Recently, new method so called "small lunch test' is used to evaluate degradation of creep. In this study, a conventional creep test and a small punch test are conducted using 2.25Cr-1Mo steel which is mainly used for the boiler tubes and steam pipes in power plant. The creep life, approximately 1,500 hrs, is determined by conventional method under a severe condition then specimens for a small Punch test are obtained after certain time intervals such as 1/4, 1/2 and 3/4 of final rupture time, respectively.

• 품질경영학회지
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• 제45권4호
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• pp.969-980
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• 2017

Purpose: The purpose of this study was to estimate the lifetime, and verify the target lifetime at steady state temperature, of communication cable jackets used in nuclear power plants. Method: This study was completed according to test and analysis methods required by international standards. After measuring the residual elongation(%) of specimens at specific points in time with the accelerated degradation test, average failure time of each temperature was computed. Thus, the activation energy could be derived by applying the temperature-Arrhenius law to estimate cable jacket lifetime at steady state temperature. Results: The cable jacket lifetime was estimated as 363.8 years assuming a normal nuclear power plant operating temperature of $90^{\circ}C$. Conclusion: To ascertain stable operating conditions for a nuclear power plant, accelerated degradation tests were performed according to the Arrhenius law for components of the nuclear power plants. The lifetime was estimated from the degradation data collected during the accelerated degradation test.