• ALGAE
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• 제17권3호
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• pp.135-144
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• 2002

Scytosiphonaceae is an acetocarpalean brown algal family, that is a recent focus of synstematics and marine biodiversity. We describe Petalonia zosterifolia and Scytosiphon gracilis from Korea for the first time. P. zosterifolia occurred on the East coast, and had flat, linear and solid thalli. S. gracilis was found in Jeju, and had cylindircal to flat and hol-low thalli. However, these two species are so similar that it is difficult to identify by morphology alone. In order to determine if the nuclear DNA reveals the distinctness of both species and to know their phylogenies, the ITS region sequences were newly detrmined in 22 samples of P. zosterifolia, Scytosiphon gracilis, and other three members of the genera from Korea. We found 0.12% variation among samples of P. zosterifolia from different locations, and no variation between S. gracilis samples from diferent years, but extensive interspecific divergences (13.62-22.83%) of each species to other members in Petalonia and Scytosiphon . The ITS sequence dta consistently showed a close relationship between P. zosterifolia and S. gracilis. This result is congruent with morphology and with the published data of plastid rbc and partial nrDNA large subunit gene sequences, and suggests that P. zosterifolia and S. gracilis might have diverged from the most recent common ancestor.

• Journal of Species Research
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• 제1권2호
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• pp.224-231
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• 2012

To assess the genetic diversity of Aconitum coreanum (Ranunculaceae) populations in Korea, we have amplified and sequenced eight organellar marker regions, and developed and analyzed microsatellite markers. No sequence variation was detected from the eight organellar markers. Ten microsatellites were developed using Next Generation Sequencing and two microsatellite markers, AK_CA03 and AK_CT07, were identified polymorphic and applied for 143 individuals of twelve A. coreanum populations. Four and five alleles were detected for the two microsatellite loci, respectively, and number of migrants ($N_m$) was estimated as 1.12586. Two microsatellite marker loci showed $F_{ST}$ of 0.205 and 0.275, respectively. The heterozygosity deficit, low level of among-population differentiation, small size of gene flow, and lack of sequence variation of the organellar markers suggest that A. coreanum is reproductively isolated from other Aconitum species and there has been continuous gene flow among the populations of A. coreanum or it has dispersed relatively recently after speciation. Though population pairwise $F_{ST}$'s presented significant geographic structure, further sampling and study will be necessary to confirm this.

• Plant Resources
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• 제3권3호
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• pp.211-218
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• 2000

Intraspecific genetic relationship of 19 variation types of the Yam (Dioscorea alata) classified by their external morphological characteristics such as leaf and tuber shape were assessed by DNA using random and specific primer. Twenty two out of 113 primers (100 random[10-mer] primers, two 15 mer [M13 core sequence, and (GGAT)$_4$ sequence]) had been used in PCR-amplification. Only 12 primers, however, were success in DNA amplification in all of the analyzed plants, resulting in 93 randomly and specifically amplified DNA fragments. The analyzed taxa showed very high polymorphisms(69 bands, 71.0 %), allowing individual taxon to be identified based on DNA fingerprinting. Monomorphic bands among total amplified DNA bands of each primer was low under the 50%. Similarity indices between accessions were computed from PCR(polymerase chain reaction) data, and genetic relationships among intraspecific variations were closely related at the levels ranging from 0.66 to 0.90. These DNA data were not matched well with those of morphological characters since they were divided into two major groups at the similarity coefficient value of 0.70. Therefore, Grouping of species into variation types by mainly morphological charactistics was suggested unreasonable.

• 한국육종학회지
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• 제43권4호
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• pp.273-281
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• 2011

Fusarium head blight (FHB), also known as scab, caused mainly by Fusarium graminearum is a devastating disease of wheat in regions that are warm and humid during flowering. In addition to significant yield and quality losses, the mycotoxin deoxynivalenol produced by the pathogen in infected wheat kernels is a serious problem for food and feed safety. Twenty- three Korean cultivars and "Sumai 3", which is a FHB-resistant Chinese cultivar were tested for Type I, Type II resistances of FHB. Three cultivars were identified as resistant in Type I assessment, and two cultivars were resistant in Type II assessment. Genetic variation and relationship among the cultivars were evaluated on the basis of 11 Simple Sequence Repeat (SSR) and 29 Sequence Tagged Site (STS) markers that were linked to FHB resistance Quantitative Trait Loci (QTL) on chromosome 3BS. One SSR and 7 STS markers detected polymorphisms. Especially, using a STS marker (XSTS3B-57), 32.4% of the variation for Type II FHB resistance could be explained. Genetic relationship among Korean wheat cultivars was generally consistent with their released year. These markers on chromosome 3BS have the potential for accelerating the development of Korean wheat cultivars with improved Fusarium head blight resistance through the use of marker-assisted selection.

• 한국응용곤충학회지
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• 제58권2호
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• pp.133-142
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• 2019

본 연구는 국내 금지급 과실파리인 오리엔탈과실파리(Bactrocera dorsalis)에 대한 유전적 변이를 분석하였다. 이를 위해 오리엔탈과실파리가 자생하는 대만 지역을 대상으로 2019년 동일한 시기(3일간: 7월 30일~8월 1일)에 서로 다른 세 지역(타이페이, 타이중, 카오슝)에서 과실파리류를 채집하여 나이 변이 및 미토콘드리아 서열 변이를 각각 비교하였다. 세 지역에서 채집된 오리엔탈과실파리는 1,085마리로서 메틸유제놀 유인제에 모두 유인되었으며, 큐루어 유인제에는 30마리의 오이과실파리(Zeugodacus cucurbitae) 및 1마리의 타우과실파리(Bactrocera tau)만 채집되었다. 단백질먹이 유인제에는 총 6마리가 포획되었으며 이 가운데 오리엔탈과실파리는 1마리가 포함되었으며 나머지는 오이과실파리였다. 오리엔탈과실파리 수컷의 머리에는 테린이 포함되었으며 나이가 증가함에 따라 각 머리에는 $32{\mu}g$에서 $59{\mu}g$까지 테린 함량이 증가하였다. 대만 세 지역의 수컷 집단들은 테린 양에 차이를 나타냈으며, 카오슝 집단이 타이페이와 타이중 집단에 비해 적은 테린 양을 보유하였다. 이들 세 지역 사이에 유전적 거리가 RAPD (random amplified polymorphic DNA)를 이용하여 분석되었으며 타이페이 집단이 타이중 및 카오슝 집단들과 차이를 나타내는 것으로 나타났다. 유전적 변이는 미토콘드리아의 cytochrome oxidase I (CO-I)과 NADH dehydrogenase I (ND-I)을 각각 비교하였다. CO-I 영역 가운데 360개 염기서열을 비교한 결과 7.8%의 염기서열 변이를 나타냈다. ND-I 영역을 비교한 결과 213개 염기서열 가운데 6.6%의 염기서열 변이를 보였다. 이들 변이 서열을 대만 지역에 발생하는 오리엔탈과실파리의 특이적 SNP (single nucleotide polymorphism) 마커로 개발하는 데 추천한다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제4권4호
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• pp.269-274
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• 2004

Current delivery system, in which the analog current produced by a unique DAC circuit is stored into a current-memory circuit and delivered in a time-divided sequence, shows variation of output current as low as 4% in a current source data-driver IC for AM-OLED driven by a current-programmed method without any fuse repairing after fabrication. This driver IC has 54 outputs and can sink constant current as low as 3 ${\mu}A$ with 6-bit analog levels. Such a low current level without variation can hardly be obtained by an ordinary MOS transistor because the current level is in the sub-threshold region and changes exponentially with threshold voltage variation. Thus we adopted a current mirror circuit composed of bipolar transistors to supply well-controlled current within a nano-ampere range.

• Structural Engineering and Mechanics
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• 제58권6호
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• pp.1001-1020
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• 2016

The study is to investigate the free vibration of antisymmetric angle-ply conical shells having non-uniform sinusoidal thickness variation. The arbitrarily varying thickness is considered in the axial direction of the shell. The vibrational behavior of shear deformable conical shells is analyzed for three different support conditions. The coupled differential equations in terms displacement and rotational functions are obtained. These displacement and rotational functions are invariantly approximated using cubic spline. A generalized eigenvalue problem is obtained and solved numerically for an eigenfrequency parameter and an associated eigenvector of spline coefficients. The vibration characteristic of the shells is examined for cone angle, aspect ratio, sinusoidal thickness variation, layer number, stacking sequence, and boundary conditions.

• 한국공작기계학회논문집
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• 제14권6호
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• pp.68-73
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• 2005

Tire manufactures have dealt with noise problem by varying the pitch of the tread. The various formulas for the variations are generally determined differently, however. Often these variations are based on a combination of trial and error, intuition, and economics. Some manufactures have models and analogs to test tread patterns and their variations. These efforts, however practical, do not determine the best variation beforehand or guarantee the best results. For this reason it was felt that a general mathematical approach fur determining the best variation was needed. Moreover, the method should be completely general, easy to use, and sufficiently accurate. This paper discusses a mathematical method called Mechanical Frequency Modulation(MFM) which meets the above requirements. Thus, MFM pertains to computing an irregular time sequence of events so that the resulting excitation spectrum is shaped to a preferred form. The first part of this paper treats the theoretical basis for computing an optimum variation ; the second part discusses experimental results and simulation program which corroborate the theory.

• 대한전자공학회논문지SP
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• 제41권5호
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• pp.35-44
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• 2004

디지털 미디어 데이터의 증가에 따라 디지털 미디어를 효과적으로 관리하고 사용하기 위하여 다양한 비디오 색인 및 비디오 시퀀스 정합 알고리즘이 제안되었다. 본 논문에서는 급격한 밝기 변화를 가지는 비디오 시퀀스에 대해서 효율적인 비디오 색인 알고리즘과 비디오 시퀀스 질의에 대한 비디오 시퀀스 정합 알고리즘을 제안한다. 급격한 밝기 변화를 고려한 비디오 색인의 정확도를 향상시키고 계산량을 줄이기 위해 제안한 알고리즘은 칼라 특성뿐만 아니라 에지 특성도 함께 사용하였으며 기존의 알고리즘에 비해 현저한 성능 향상을 보였다. 제안한 알고리즘은 먼저 칼라 히스토그램을 사용하여 후보 샷경계 지점을 추출하고 에지 정합과 밝기 보상을 이용하여 후보점들이 샷경계인지 밝기 변화인지를 결정한다 장면내의 밝기 변화가 작은 경우 에지 정합과 밝기 보상은 샷경계에서만 일어난다. 실험 결과 제안한 방법은 기존의 방법에 비해 비슷한 계산량으로 현저히 향상된 성능과 효율을 보였다.

• 대한의생명과학회지
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• 제17권2호
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• pp.151-155
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• 2011

Short tandem repeats (STRs) loci are the genetic markers used for forensic human identity test. With multiplex polymerase chain reaction (PCR) assays, STRs are examined and measured PCR product length relative to sequenced allelic ladders. In the repeat region and the flanking region of the commonly-used STR may have DNA sequence variation. A mismatch due to sequence variation in the DNA template may cause allele drop-out (i.e., a "null" or "silent" allele) when it falls within PCR primer binding sites. The STR markers were co-amplified in a single reaction by using commercial PowerPlex$^{(R)}$ 16 system and AmpFlSTR$^{(R)}$ Identifiler$^{(R)}$ PCR amplification kits. Separation of the PCR products and fluorescence detection were performed by ABI PRISM$^{(R)}$ 3100 Genetic Analyzer with capillary electrophoresis. The GeneMapper$^{TM}$ ID software were used for size calling and analysis of STR profiles. Here, this study described a forensic human identity test in which allelic drop-out occurred in the STR system D18S51. During the course of human identity test, two samples with a homozygous (16, 16 and 21, 21) genotype at D18S51 locus were discovered using the PowerPlex$^{(R)}$ 16 system. The loss of alleles was confirmed when the samples were amplified using AmpFlSTR$^{(R)}$ Identifiler$^{(R)}$ PCR amplification kit and resulted in a heterozygous (16, 20 and 20, 21) genotype at this locus each other. This discrepancy results suggest that appropriate measures should be taken for database comparisons and that allele should be further investigated by sequence analysis and be reported to the forensic community.