• Fisheries and Aquatic Sciences
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• 제25권3호
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• pp.158-166
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• 2022

The complete mitochondrial genome of Tremoctopus violaceus was sequenced to analyze its organization and phylogenetic status within the order Octopoda. The mitochondrial genome of T. violaceus had a structure and organization similar to that of other Octopoda. The content of the nucleotides A, C, G, and T was 31.68 %, 7.71 %, 20.02 %, and 40.58 %, respectively. All protein-coding genes (PCG) began with the ATG codon, excluding ND4 and ATP6, which began with ATC and ATT, respectively, and terminated with TAG, TAA, TA, or T. Codons for isoleucine were the most used codons, whereas those for arginine were used the least. Two extra tRNAs, trnN and trnL, were found in the control region. These tRNAs have a D-armless structure. The control region had excess A + T content (83.16 %) and a stem-loop structure with two elements, which is reported for the first time in Octopoda by our study. Bayesian inference using 13 PCG revealed that Octopus and Octopodidae were polyphyletic, and that Tremoctopodidae diverged relatively earlier within Octopoda. The mitochondrial genome of T. violaceus and its characteristics may help to understand the evolutionary history of Octopoda and establish a marine biodiversity conservation strategy.

• 생명과학회지
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• 제21권9호
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• pp.1329-1335
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• 2011

한국재래염소는 흑모색의 특징을 나타내며, 유일한 염소 품종으로서 오랫동안 한반도에서 사육되어 왔다. 하지만 이들에 대한 유전적 다양성, 계통유전학적 분석 등을 통한 기원 추정 등에 대한 연구는 미비한 실정이다. 본 연구에서 한국재래염소 5개 집단, 60두를 대상으로 mtDNA D-loop 영역 중 HVI 영역의 서열을 이용하여 유전적 다양성 및 계통유전학적 분석을 실시하였다. 한국재래염소는 다른 나라 염소들에 비해서 haplotype 다양성 지수가 낮게 나타났다. 또한 본 연구에서 분류된 한국재래염소 10개 haplotype 중 현재까지 보고되지 않은 6개의 새로운 haplotype이 확인되었다. 계통유전학적 분석 결과, 분석에 사용된 모든 한국재래염소는 mtDNA 모계혈통 A에 속하였다. 10개의 haplotype 중 8개는 베트남, 일부 중국 염소와 함께 subgroup을 형성하였다. 그러나 나머지 2개 haplotype은 각각 서로 독립적인 계통유전학적 위치를 보였다. 이런 결과들을 토대로 한국재래염소는 상대적으로 높은 근친상황으로 외부 유전자 유입이 적었을 것이라고 추정된다. 한국재래염소의 새로운 mtDNA haplotype의 발견 및 유전자원 보존 및 평가를 위해서 더 많은 분석집단 및 개체를 수집하고, MS 마커를 이용한 추가분석이 필요하다고 사료된다.

• Molecules and Cells
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• 제28권5호
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• pp.423-430
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• 2009

In order to elucidate the precise phylogenetic relationships of Korean wild boar (Sus scrofa coreanus), a partial mtDNA D-loop region (1,274 bp, NC_000845 nucleotide positions 16576-1236) was sequenced among 56 Korean wild boars. In total, 25 haplotypes were identified and classified into four distinct subgroups (K1 to K4) based on Bayesian phylogenetic analysis using Markov chain Monte Carlo methods. An extended analysis, adding 139 wild boars sampled worldwide, confirmed that Korean wild boars clearly belong to the Asian wild boar cluster. Unexpectedly, the Myanmarese/Thai wild boar population was detected on the same branch as Korean wild boar subgroups K3 and K4. A parsimonious median-joining network analysis including all Asian wild boar haplotypes again revealed four maternal lineages of Korean wild boars, which corresponded to the four Korean wild boar subgroups identified previously. In an additional analysis, we supplemented the Asian wild boar network with 34 Korean and Chinese domestic pig haplotypes. We found only one haplotype, C31, that was shared by Chinese wild, Chinese domestic and Korean domestic pigs. In contrast to our expectation that Korean wild boars contributed to the gene pool of Korean native pigs, these data clearly suggest that Korean native pigs would be introduced from China after domestication from Chinese wild boars.

• Journal of Forest and Environmental Science
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• 제28권4호
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• pp.278-281
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• 2012

Comparative sequence analyses were conducted on complete mtDNA sequences from four small mammal species in Korea and revealed the presence of 30 well conserved sequences in various regions of the complete mtDNA sequences. The conserved sequences were found in 9 regions in protein coding genes, 10 regions in tRNA genes, 10 in rRNA genes, one region in replication origin and 2 regions in D loop. They could be used to design primers for amplifying complete mtDNA sequences of small mammals.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2004년도 춘계 학술대회논문집
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• pp.9-16
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• 2004

This study presents results of aerodynamic wing optimization under uncertainties. To consider uncertainties, an alternative strategy for reliability-based design optimization(RBDO) is developed. The strategy utilizes a single loop algorithm and a sequential approximation optimization(SAO) technique. The SAO strategy relies on the trust region-SQP framework which validates approximated functions at every iteration. Further improvement in computational efficiency is achieved by applying the same sensitivity of limit state functions in the reliability analysis and in the equivalent deterministic constraint calculation. The framework is examined by solving an analytical test problem to show that the proposed framework has the computational efficiency over existing methods. The proposed strategy enables exploiting the RBDO technique in aerodynamic design. For the aerodynamic wing design problem, the solution converges to the reliable point satisfying the probabilistic constraints.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 E
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• pp.2161-2163
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• 1999

Generally, ZnO varistors have dynamic characteristics that the cut-off voltage increases as the time to crest of the varistor current decreases. Dynamic characteristics of ZnO varistor are the most important factor in region of the steep front discharge current particularly. Also, V-I characteristics of ZnO varistor have hysterisis loop in time domain and frequency dependency. This paper deals with ZnO varistor numerical equation and modeling method which takes the behavior of varying clamping voltage into consideration during the time to crest, in range of $1{\mu}m{\sim}50{\mu}m$, of impulse current applied to a ZnO varistor. The simulated results by the proposed model are compared with experimental results for each of the impulse current.

• Animal cells and systems
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• 제8권4호
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• pp.235-245
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• 2004

Numerous specimens of adults and juveniles of Draconema japonicum Kito, 1976 have been found in intertidal and subtidal sediments and various algae around coast of South Korea. Draconema japonicum is recognized by the following characteristics: having an elongated loop-shaped amphideal fovea in male and horseshoe-shaped amphideal fovea in female, two pairs of uniformly tapered sublateral anal setae and two pairs of unevenly tapered subventral anal setae in male, eight to ten pairs in male and 13 to 15 pairs in female of posterior sublateral adhesion tubes, and five to six pairs of somatic setae on non-striated tail region. Scanning electron photomicrographs of the species are presented with a detailed morphological description and a key to the species of the genus Draconema Cobb, 1913. This is the first discovery of D. japonicum outside the Japanese waters.

• 천문학회보
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• 제30권1호
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• pp.31.2-31.2
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• 2005

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2000년도 International Symposium on Magnetics The 2000 Fall Conference
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• pp.369-376
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• 2000

Change of magnetic properties in CoCrPt/Ti perpendicular media with varying CoCrPt films thickness has been studied. As CoCrPt films thickness increase, the Ms(magnetization saturation) drastically increases at thinner thickness and gradually increases with further increase in thickness from 25nm. This Ms behaviour is associated with primarily the formation of "amorphous-like" reacted layer by intermixing of CoCrPt and Ti at CoCrPt/Ti interface and secondarily change of Cr segregation mode with varying the CoCrPt films thickness. Magnetic domain structure distinctively changes with increasing CoCrPt magnetic layer(ML) thickness. Also the strength of exchange coupling measured from the slope in demagnetizing region in M-H loop changes with ML thickness. Details of the above magnetic properties will be discussed. The expansion of lattice parameters a and c at thinner thickness suggests that Cr segregation mode may be connected with the residual stress of the films. Finally, negative nucleation field(Hn) behaviour with the exchange slope will be reported.

• 대한기계학회논문집
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• 제15권2호
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• pp.497-506
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• 1991

In this paper, a new construction for training simulator of R/C helicopter based on two types of servo controller is proposed. Two modified algorithms (algorithm I and II) for servo controller design are presented. Algorithm I is developed by adopting Davison's method in the case that the expressions for the homogeneous differential equations of reference input and disturbance are different types, and algorithm II is done by considering error weighting function for the servo controller of algorithm I . The linear fractional transformation method is incorporated in both design methods in order to assign the closed loop poles of the servo system in a specified region. The helicopter simulator is composed by the gimbals with two freedom of rolling and pitching. The reliability and validity for the design methods of the proposed servo controller are investigated through the practical experiment for the simulator by using 16bits micro-computer with A/D and D/A converters. It can be observered from the experimental results that the proposed servo controller is applicable to practical plants since the simulator is robust for the arbitrary disturbance and it follows to the given reference input without significant steady state error.