• Animal Systematics, Evolution and Diversity
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• 제16권2호
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• pp.203-211
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• 2000

한국에서 양식되어지고 있는 한국산 굴류 4종, 굴(Crassostrea gigas Thunberg), 바위굴(C. nippona Seki), 강굴(C. ariakensis Fujita et Wakiya), 토굴(Ostrea denselamellosa Lischke)의 유전적 근연관계를 조사하고자 미토콘드리아 DNA의 16S rDNA와 cytochrome c oxidase I (COI) 유전자 일부분의 염기서열을 분석하였다. 16S rDNA의 319 bp와 COI유전자의 710 bp를 PCR 증폭하여 염기서열을 결정하였으며, 염기서열과 아미노산서열을 자료로 하여 UPGMA와 neighbor-joining 방법으로 계통수를 작성하고, 종간 유연관계를 확인하였다. Crassostrea 속과 Ostrea 속간 비교에서는 뚜렷한 유전적 분화를 나타내었으며 계통분석 결과, neighbor-joining 방법에 의한 COI의 아미노산 서열분석에서는 굴과 강굴이 자매군을 형성하는 양상을 보였으나 두 유전자의 염기서열과 A+T 비율 비교에서는 굴과 바위굴이 자매군을 형성하는 것으로 나타났다.

• Bulletin of the Korean Chemical Society
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• 제12권6호
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• pp.644-649
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• 1991

The approximate rates and stoichiometry of the reaction of excess lithium tris(dibutylamino)aluminum hydride (LT-DBA) with selected organic compounds containing representative functional groups under standardized conditions (tetrahydrofuran, $0^{\circ}C$) were studied in order to characterize the reducing characteristics of the reagent for selective reductions. The reducing ability of LTDBA was also compared with those of the parent lithium aluminum hydride and the alkoxy derivatives. The reagent appears to be much milder than the parent reagent, but stronger than lithium tri-t-butoxyaluminohydride in reducing strength. LTDBA shows a unique reducing characteristics. Thus, the reagent reduces aldehydes, ketones, esters, acid chlorides, epoxides, and amides readily. In addition to that, ${\alpha},{\beta}$-unsaturated aldehyde is reduced to ${\alpha},{\beta}$-unsaturated alcohol. Quinones are reduced to the corresponding diols without evolution of hydrogen. Tertiary amides and aromatic nitriles are converted to aldehydes with a limiting amount of LTDBA. Finally, disulfides and sulfoxides are readily reduced to thiols and sulfides, respectively, without hydrogen evolution.

• Animal Systematics, Evolution and Diversity
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• 제9권2호
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• pp.151-170
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• 1993

한국산 기름종개 3 아종의 분류학적 의문점을 해결하기 위하여 전국 23개 집단을 대상으로 체측반문을 비롯한 형태형질 분석과 전기영동법에 의한 유전자 분석을 실시하였다. 3 아종의 체측반문 변이 분석 결과 기름종개와 점줄종개에서는 각 아종 의 특정인 점열형 (A, B type: 14.5%)의 개체보다 중간형 (C, D type: 51.0%)의 빈도가 월등히 높았다. 기름종개 3 아종은 모두 암수간 체측반문 형태가 달리 발현되는 성적이형 현상이 뚜렷하였다. 형태계측 및 집단 판별분석에서 집단간 및 아종간의 뚜렷한 차이는 발견되지 않았다. 전기영동법에 의한 유전자 분석결과 3 아종중 줄종개 5개 집단의 평균 유전적 변이가 A=1.48. P=31.2%. HD= 0.082 및 HQ=0.099로서 기름종개(A=1.37. P=24.7%. HD=0.058 및 HQ = =0.065) 및 점줄종개(A=1.43, P=27,0%. 매=0.066 및 HQ=0.079)에 비하여 높은 변이를 나타내었다 각 아종의 유전적 근연관계에 있어 기름종개와 줄종개 및 점줄종개의 평균 유전적 근연치는 S = O.64로서 일반적인 담수어류의 종간차이를 보였고, 줄종개와 점줄종개간은 S=0.82로서 아종 수준의 유전적 근연관계를 나타내었다. 체측반문 변이, 형태분석 결과 및 유전자 분석결과 기름종개는 타 두 아종과 약 200만년전에 분화된 별종으로 사료된다. 기름종개 (C. t. taenia)의 학명사용에 있어 이미 보고된 자료(핵형, 형태, 분포 등)들을 비교할 때 중국산 C. Sinensis와 많은 차이가 있어 한국산 기름종개를 중국산 C. sinensis Sauvage a and Dabry 의 synonym으로 보는 것은 타당성이 없다. 그러나 줄종개와 점줄종 개는 형태 및 유전적 특정등을 고려할 때 아종으로 취급하는 것이 타당하리라 여겨 지며 앞으로 이들에 대한 학명의 재검토가 요구된다.

• 암석학회지
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• 제2권1호
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• pp.9-18
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• 1993

The high-P metamorphic belt in central China, between the Sino-Korean and the Yangtze continental plates, is composed of the low-T and high-P metamorphic belt on the south and the high-T and high-P metamorphic belt on the north. The low-T and high-P metamorphic belt consists predominantly of bimodal metamorphic volcano-sedimentary sequences of Middle to Upper Proterozoic, characterized by the occurrences of blueschists, which have undergone a progressive metamorphism from blueschist through greenschist to epidote amphibolite facies with metamorphic conditions of 7~14 kb and 350~$560^{\circ}C$. The high-T and high-P and high-P metamorphic belt mainly consists of the Upper Archean to Lower Proterozoic crystalline basement characterized by the aboundant occurrences of eclogites formed at 12~28 kb and 620~$840^{\circ}C$. The formation of high-P metamorphic belt is related to the collision between the Sino-Korean and the Yangtze continental plates during Indosinian orogeny. The two belts may extend to central Korean Peninsula correlating respectively to the Okchon belt and the Kyonggi massif based on comparative studies of geography, tectonics and petrology. Therefore, much attention should be paid to search for such high-P metamorphic rocks as blueschists or eclogites in those two areas, which can play a key role for understanding the tectonic evolution of the Korean Peninsula.

• 한국재료학회지
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• 제27권7호
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• pp.359-363
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• 2017

The resistance of metallic materials to ballistic penetration generally depends on a number of parameters related to projectile, impact, and armor plate. Recently, armor materials have been required to have various properties such as hardness, strength, and impact toughness in order to maintain an excellent ballistic resistance even after impact. In the present study, the influence of tempering on the microstructure and mechanical properties of an ARMOX 500T armor steel plate was investigated and then compared with those of S45C and SCM440 steels. As the tempering temperature increased, the hardness and strength gradually decreased, whereas the ductility and impact toughness clearly increased because the hardness, tensile, and impact properties were affected by the microstructural evolution and precipitation occurring during tempering. On the other hand, temper embrittlement appeared at tempering temperatures of 300 to $400^{\circ}C$ for the impact specimens tested at low temperature.

• Animal Systematics, Evolution and Diversity
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• 제11권1호
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• pp.115-124
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• 1995

Twenty-two species of Echinodermata collected from 11 localities in Chindo Island, Korea in September, 1990 and July, 1994 are recorded. One asteroids, Luidia quinaria, five ophiudoids such as Astrocladus coniferus coniferus, A.c.dofleini, Ophicatis affinis, Stegophiura sladeni, Amphipholis sp., four echinoids such as Temnopleurus toreumaticus, T. hardwicki, Hemicentrotus pulcherrimus, anthoicidaris crassispina and two holothuroids such as Protankyra bidentata, Stichopus japonicus are unrecorded species by this time in Chindo Is. One asteroid species, Asterina minor is newly recorded in Korea water and its taxonomic characteristics are redescribed.

• Molecules and Cells
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• 제28권2호
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• pp.111-117
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• 2009

The CHRM3 gene is a member of the muscarinic acetylcholine receptor family that plays important roles in the regulation of fundamental physiological functions. The evolutionary mechanism of exon-acquisition and alternative splicing of the CHRM3 gene in relation to transposable elements (TEs) were analyzed using experimental approaches and in silico analysis. Five different transcript variants (T1, T2, T3, T3-1, and T4) derived from three distinct promoter regions (T1: L1HS, T2, T4: original, T3, T3-1: THE1C) were identified. A placenta (T1) and testis (T3 and T3-1)-dominated expression pattern appeared to be controlled by different TEs (L1HS and THE1C) that were integrated into the common ancestor genome during primate evolution. Remarkably, the T1 transcript was formed by the integration event of the human specific L1HS element. Among the 12 different brain regions, the brain stem, olfactory region, and cerebellum showed decreased expression patterns. Evolutionary analysis of splicing sites and alternative splicing suggested that the exon-acquisition event was determined by a selection and conservation mechanism. Furthermore, continuous integration events of transposable elements could produce lineage specific alternative transcripts by providing novel promoters and splicing sites. Taken together, exon-acquisition and alternative splicing events of CHRM3 genes were shown to have occurred through the continuous integration of transposable elements following conservation.

• Genomics & Informatics
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• 제3권2호
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• pp.61-65
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• 2005

Comparing 231 genes on chimpanzee chromosome 22 with their orthologous on human chromosome 21, we have found that 15 orthologs have indels within their coding sequences. It was rather surprising that significant number of genes have changed by indel, despite the shorter time since their divergence and led us hypothesize that indels and structural changes may represent one of the major mechanism of proteome evolution in the higher primates. Human T-complex protein 10 like (TCP 10L) is a representative having indel within its coding sequence. Gene structure of human TCP10L compared with chimpanzee TCP10L gene showed 16 base pair difference in genomic DNA. As a result of the indel, frame shift mutation occurs in coding sequence (CDS) and human TCP10L express longer polypeptide of 21 amino acid residues than that of chimpanzee. Our prediction found that the indel may affect to dramatic change of secondary protein structure between human and chimpanzee TCP10L. Especially, the structural changes in the C-terminal region of TCP10L protein may affect on the interacting potential to other proteins rather than DNA binding function of the protein. Through these changes, TCP10L might influence gene expression profiles in liver and testis and subsequently influence the physiological changes required in primate evolution.

• 전자통신동향분석
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• 제35권6호
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• pp.78-87
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• 2020

With the evolution of the Internet of Things (IoT), a computing paradigm shift from cloud to edge computing is rapidly taking place to effectively manage the rapidly increasing volume of data generated by various IoT devices. Edge computing is computing that occurs at or near the physical location of a user or data source. Placing computing services closer to these locations allows users to benefit from faster and more reliable services, and enterprises can take advantage of the flexibility of hybrid cloud computing. This paper describes the concept and main benefits of edge computing and presents the trends and future prospects for edge computing technology.

• 소성∙가공
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• 제18권6호
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• pp.448-452
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• 2009

Superplastic deformation behavior and texture evolution after equal channel angular pressing (ECAP) of Zn-0.3Wt%Al alloy were investigated in this study. ECAP was conducted at temperatures from $60^{\circ}C$ to $160^{\circ}C$ on the plate type specimens of 5 mm thickness and 20 mm width. The specimens obtained by ECAP showed typical texture with basal poles tilted away from the ND toward ED, which is called shear texture. Tensile tests were carried out at $100^{\circ}C$ for ECAPed specimens under the strain rate of 0.0002/s. After ECAP of the Zn-0.3Wt%Al alloy, elongation was dramatically increased up to 500% at $100^{\circ}C$. The effect of ECAP on the anisotropy in the superplastic deformation behavior was negligible.