• Journal of Microbiology
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• 제42권1호
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• pp.9-13
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• 2004

Culture-independent approaches, based on 16S rDNA sequences, are extensively used in modern microbial ecology. Sequencing of the clone library generated from environmental DNA has advantages over fingerprint-based methods, such as denaturing gradient gel electrophoresis, as it provides precise identification and quantification of the phylotypes present in samples. However, to date, no method exists for comparing multiple bacterial community structures using clone library sequences. In this study, an automated method to achieve this has been developed, by applying pair wise alignment, hierarchical clustering and principle component analysis. The method has been demonstrated to be successful in comparing samples from various environments. The program, named CommCluster, was written in JAVA, and is now freely available, at http://chunlab.snu.ac.kr/commcluster/.

• Mycobiology
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• 제42권3호
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• pp.215-220
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• 2014

Mushrooms are a recognized component of the human diet, with versatile medicinal properties. Some mushrooms are popular worldwide for their nutritional and therapeutic properties. However, some species are dangerous because they cause toxicity. There are many reports explaining the medicinal and/or toxic effects of these fungal species. Cases of serious human poisoning generally caused by the improper identification of toxic mushroom species are reported every year. Different substances responsible for the fatal signs and symptoms of mushroom toxicity have been identified from various poisonous mushrooms. Toxicity studies of mushroom species have demonstrated that mushroom poisoning can cause adverse effects such as liver failure, bradycardia, chest pain, seizures, gastroenteritis, intestinal fibrosis, renal failure, erythromelalgia, and rhabdomyolysis. Correct categorization and better understanding are essential for the safe and healthy consumption of mushrooms as functional foods as well as for their medicinal use.

• BMB Reports
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• 제45권11호
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• pp.604-611
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• 2012

Recent advances in genome and transcriptome analysis have enabled identification of numerous members of a new class of noncoding RNA, long noncoding RNA (lncRNA). lncRNAs are broadly defined as RNA molecules greater than 200 nt in length and lacking an open reading frame. Recent studies provide evidence that lncRNAs play central roles in a wide range of cellular processes through interaction with key component proteins in the gene regulatory system, and that alteration of their cell- or tissue-specific expression and/or their primary or secondary structures is thought to promote cell proliferation, invasion and metastasis. The biological and molecular characteristics of the large majority of lncRNAs remains unknown, and it is anticipated that improved understanding of the roles played by lncRNAs in cancer will lead to the development of novel biomarkers and effective therapeutic strategies.

• 생약학회지
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• 제20권4호
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• pp.227-232
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• 1989

As a part of studies on the quality control of crude drug preparation (So-Shi-Ho-Tang), index components of Glycyrrhizae Radix were identified by TLC and quantified by HPLC. Specific red spot (Rf=0.47) was identified in acid hydrolysate of glycosidic fraction on silica gel plate with benzene/ethyl acetate (1 : 1, v/v). The content of glycyrrhizin was determined by quantification of glycyrrhetinic acid by HPLC on ${\mu}-Bondapak\;C_{18}$ column with $MeOH/H_2O/HAc$ (78 : 19 : 3, v/v). Its recovery rate in the extract granules, compared to the content in the Glycyrrhizae Radix, was $83.3{\pm}0.7%$.

• International Journal of Aeronautical and Space Sciences
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• 제7권2호
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• pp.86-103
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• 2006

Using a combination of force transducer measurement to quantify net lift force, high frame rate camera to quantify and subtract inertial contributions, and Digital Particle Image Velocimetry (DPIV) to calculate aerodynamic contributions in the spanwise plane, the contribution of spanwise flow to the generation of lift force in wings undergoing a pure flapping motion in hover is shown as a function of flapping angle throughout the flapping cycle. These experiments were repeated at various flapping frequencies and for various wing planform sizes for flat plate and span wise cambered wings. Despite the previous identification of the importance of span wise fluid structures in the generation of lift force in flapping wings throughout the existing body of literature, the direct contribution of spanwise flow to lift force generated has not previously been quantified. Therefore, in the same manner as commonly applied to investigate the chordwise lift distribution across an airfoil in flapping wings, spanwise flow due to bulk flow and rotational fluid dynamic mechanisms will be investigated to validate the existence of a direct component of the lift force originating from the flapping motion in the spanwise plane instead.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2002년도 제18회 학술발표대회 논문초록집
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• pp.25-26
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• 2002

가스터빈 엔진의 성능모사는 개발단계에서의 개발위험도 감소나 개발비용 절감의 목적뿐만 아니라 운용단계에서 최적의 정비를 위한 엔진의 상태 진단을 위해서도 그 필요성이 매우 크다. 가스터빈 엔진의 성능모사를 위해서는 "각 구성품의 성능은 구성품 성능선도를 따라야 한다"는 제약조건을 만족해야 하며 이를 위해서는 구성품의 특성을 나타내는 성능선도가 매우 중요하다. 구성품 성능선도는 다양한 조건에서의 성능시험을 통해 얻는 것이 당연하나 이는 엔진 개발사에서나 가능하며 대부분 공개를 기피한다. 따라서 일반 구매자나 가스터빈 엔진의 성능을 연구하는 사람들은 일부 공개된 성능도를 축척하여 이용하고 있다.여 이용하고 있다.

• 한국대기환경학회지
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• 제18권4호
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• pp.317-325
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• 2002

An air pollution monitoring station has been operated at Tokchok Island since April 1999 to characterize the background atmosphere in the vicinity of the Yellow Sea. In this study, eight chemical species in PM$_{2.5}$ and three gaseous species were analyzed. A total of 53 samples were collected for the analysis of PM$_{2.5}$ and gaseous species from April, 1999 to April, 2001. The overall mean mass concentration of PM$_{2.5}$ was 20.8 $\mu\textrm{g}$/㎥ and the eight soluble ionic species accounted for about 46.8% of PM$_{2.5}$ mass. Approximately 80% of samples appeared to experience the chloride loss effect. Air pollutant sources of PM$_{2.5}$ measured at Tokchok Island were qualitatively identified by the principal component analysis. It was found that five principal components are secondary aerosol, soil, incineration, phase change of nitrate, and ocean.and ocean.

• 한국미생물·생명공학회지
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• 제48권3호
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• pp.322-327
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• 2020

Abortive infection systems (Abi) are phage resistance systems that can be prophage-encoded. Here, two genes encoding an Abi system were identified on a prophage sequence contained by the chromosome of the Levilactobacillus brevis strain UCCLBBS124. This Abi system is similar to the two-component AbiL system encoded by Lactococcus lactis biovar. diacetylactis LD10-1. The UCCLBBS124 prophage-derived Abi system (designated here as AbiL₁₂₄) was shown to exhibit specific activity against phages infecting L. brevis and L. lactis strains. Expression of the AbiL₁₂₄ system was shown to cause reduction in the efficiency of plaquing and cell lysis delay for phages of both species.

• 대한전기학회논문지:시스템및제어부문D
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• 제51권7호
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• pp.302-307
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• 2002

Digital watermarking is the technique, which embeds an invisible signal including signal including owner identification and copy control information into multimedia data such as audio, video, and images for copyright protection. A new MPEG watermark embedding algorithm using complex block effect based on the Human Visual System(HVS) is introduced in this paper. In this algorithm, $8{\times}8$ dark blocks are selected, and the watermark is embedded in the DC component of the discrete cosine transform(DCT) by using quantization and modulus calculation. This algorithm uses a blind watermark retrieval technique, which detects the embedded watermark without using the original image. The experimental results show that the proposed watermark technique is robust against MPEG coding, bitrate changes, and various GOP(Group of Picture) changes.

• 대한임베디드공학회논문지
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• 제5권3호
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• pp.111-117
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• 2010

The easily accessible handheld devices equipped with camera are widely available as common commodities. According to this trend, utilization of images is popular among common users for various purposes resulting in huge amount of images in local or network based storage systems. In this environment, identification of an image with a solid and effective manner is demanded in behalf of safe distribution and efficient management of images. The generated identifiers can be used as a file name in file systems or an index in image databases utilizing the uniqueness of the identifiers. In this paper, we propose a method that generates image identifiers using linear components in images. Some experiments of generation of identifiers are performed, and the results evaluate that the proposed method has feasible effectiveness.