• 한국전자파학회논문지
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• 제16권11호
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• pp.1147-1154
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• 2005

본 논문에서는 OFDM(Orthogonal Frequency Division Multiplexing) 시스템에서 다중 케리 어(multi carrier) 변조에 의해 크게 발생되는 PAPR(Peak to Average Power Ratio)을 저감하기 위한 방법으로 WHT(Walsh Hadamard Transform)를 이용한 PAPR 저감 기법들을 제안한다. 제안하는 방법은 기본적으로 WHT를 기존의 PAPR 저감 기법들과 혼합하여 추가적인 대역 손실 및 큰 복잡도의 증가 없이 추가적인 PAPR저감 성능을 나타내도록 하는 방법으로, 본 논문에서는 SLM(Selective Mapping) 및 DSI(Dummy Sequence Insertion) 방법을 WHT와 결합한 방법을 제시하며, 시뮬레이션 결과로부터, WHT를 이용한 PAPR 저감 기법들이 기존의 PAPR 저감 기법보다 항상 약 1 dB 가량의 더 나은 PAPR 저감 효과를 나타냄을 확인하였다. 또한 제안된 방법은 PAPR저감뿐만 아니라 주파수 다이버시티(diversity) 효과를 얻을 수 있기 때문에 비선형 증폭기에 의한 비선형 왜곡뿐만 아니라 다중 경로 페이딩(multipath lading)이 심하게 일어나는 무선 채널 환경에서 보다 안정된 데이터 전송을 가능케 할 것으로 기대된다.

• 한국콘텐츠학회논문지
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• 제19권11호
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• pp.262-269
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• 2019

학술논문의 말미에 기재하는 참고문헌은 저자가 연구윤리를 준수하고 독자들이 관련 선행연구를 참고할 수 있도록 돕는 정보이자 논문간의 인용과 피인용 관계를 연결시키는 데 유용한 정보이다. 계량서지학이 발전하면서 참고문헌 데이터는 국가, 기관, 개인의 학술 영향력을 평가하는 중요한 데이터로 활용되고 있다. 하지만 참고문헌 형식의 다양성, 학술지명과 저자명 축약 기재로 인한 정보 손실, 저자들의 오타 등으로 인해 참고문헌을 식별하여 연결하는 것은 쉽지 않다. 본 연구에서는 학술논문 참고문헌 데이터를 구축하고 매핑하는 과정에서 발생한 오류 사례를 분석함으로써 참고문헌 데이터 매핑율 제고 방안을 고찰하였다. 연구결과 참고문헌 식별 실패의 주요 원인은 유사 학술지명 식별 문제로 밝혀졌으며 식별과 매핑율 향상을 위한 방안으로 학술지명 전거파일 활용, 논문 DOI 등록율 제고를 제시하였다. 본 연구는 연구 대상 데이터에서 차별성이 있다. 국내에서 주로 구독, 이용, 출판, 인용되는 국내 및 해외 학술지 통합 데이터베이스를 대상으로 참고문헌 매핑을 시도하였다. 참고문헌 구축량 및 매핑율 향상을 통해 해외 인용색인 데이터베이스와는 차별화된 국내 상황을 반영한 인용 분석 및 서비스 기반 데이터베이스로 활용이 가능하다.

• Genes and Genomics
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• 제40권12호
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• pp.1319-1329
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• 2018

SSRs were successfully isolated from the Perilla crop in our current study, and used to analyze Perilla accessions from East Asia. Analyses of the clear genetic diversity and relationship for Perilla crop still remain insufficient. In this study, 40 new simple sequence repeat (SSR) primer sets were developed from RNA sequences using transcriptome analysis. These new SSR markers were applied to analyze the diversity, relationships, and population structure among 35 accessions of the two cultivated types of Perilla crop and their weedy types. A total of 220 alleles were identified at all loci, with an average of 5.5 alleles per locus and a range between 2 and 10 alleles per locus. The MAF (major allele frequency) per locus varied from 0.229 to 0.943, with an average of 0.466. The average polymorphic information content (PIC) value was 0.603, ranging from 0.102 to 0.837. The genetic diversity (GD) ranged from 0.108 to 0.854, with an average of 0.654. Based on population structure analysis, all accessions were divided into three groups: Group I, Group II and the admixed group. This study demonstrated the utility of new SSR analysis for the study of genetic diversity and population structure among 35 Perilla accessions. The GD of each locus for accessions of cultivated var. frutescens, weedy var. frutescens, cultivated var. crispa, and weedy var. crispa were 0.415, 0.606, 0.308, and 0.480, respectively. Both weedy accessions exhibited higher GD and PIC values than their cultivated types in East Asia. The new SSR primers of Perilla species reported in this study may provide potential genetic markers for population genetics to enhance our understanding of the genetic diversity, genetic relationship and population structure of the cultivated and weedy types of P. frutescens in East Asia. In addition, new Perilla SSR primers developed from RNA-seq can be used in the future for cultivar identification, conservation of Perilla germplasm resources, genome mapping and tagging of important genes/QTLs for Perilla breeding programs.

• 한국작물학회지
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• 제59권2호
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• pp.109-127
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• 2014

Maize is one of the most important food and feed crops in the world including Southeast Asia. In spite of numberous efforts with conventional breeding, the maize productions remain low and the loss of yields by drought and downy mildew are still severe in Asia. Genetic improvement of maize has been performed with molecular marker and genetic engineering. Because maize is one of the most widely studied crop for its own genome and has tremendous diversity and variant, maize is considered as a forefront crop in development and estimation of molecular markers for agricultural useful trait in genetics and breeding. Using QTL (Quantitative Trait Loci) and MAS (Marker Assisted Breeding), molecular breeders are able to accelerate the development of drought tolerance or downy mildew resistance maize genotype. The present paper overviews QTL/MAS approaches towards improvement of maize production against drought and downy mildew. We also discuss here the trends and importance of molecular marker and mapping population in maize breeding.

• 한국산림과학회지
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• 제96권5호
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• pp.567-571
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• 2007

This study was conducted to clarify the differences in breeding bird communities between deciduous forests of Gwangneung and Mt. Namsan areas from April to August 2006. Two 10ha area were selected for territory mapping of breeding bird community in both study area. The DBH distribution of trees and average foliage profiles were significantly different between study areas. Also, breeding bird communities were different. Number of breeding species and pairs, breeding density, and bird species diversity were higher in Gwangneung area than in Mt. Namsan area. When examining relationship between forest habitat structure and bird community, Number of bird species and breeding pairs belonged to hole and canopy guild were increase as the increase of coverstory coverage and number of large trees. Therefore, it is necessary to make vertical structure more various to plant bushes, and to make DBH distribution more diverse for enhancing bird species diversity in the degraded ecosystem.

• 한국토양비료학회지
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• 제43권6호
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• pp.995-1001
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• 2010

농경지 토양미생물상의 생물지리학적으로 특성을 보고자 우리나라 농경지 토양 미생물의 다양성을 지도화 하였다. 1999년부터 2007년까지 조사되어 농업환경변동조사로 구축된 미생물 균수 및 미생물체량 자료를 DB화하여 세균, 사상균, 바실러스, 그람음성균 및 미생물체량을 분포도 작성에 이용하였다. 세균, 사상균, 바실러스 및 그람음성균의 분포상은 농경지별로 상이한 경향을 보였다. 토양에 서식하는 미생물의 생체중인 미생물체량은 바실러스와 사상균 수처럼 증가하는 경향을 보였다.

• 대한화학회지
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• 제62권1호
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• pp.36-42
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• 2018

이 연구에서는 중학교 학생들이 생성한 비유의 특징을 비유의 개수와 대응 관계 이해도, 소재의 다양성과 독창성의 측면에서 조사하고, 이 결과를 학생들의 과학적 창의성과 장독립성 장의존성, 학습접근양식에 따라 비교하였다. 서울특별시에 소재한 2개 중학교에 재학 중인 3학년 학생 250명이 연구에 참여하였다. 연구 결과, 과학적 창의성이 높은 학생이 많은 수의 비유를 생성하고, 대응 관계 이해도가 높았으며, 다양하고 독창적인 소재를 활용하였다. 장독립적인 학생이 대응 관계 이해도가 높은 것으로 나타났으나 나머지 특징은 장독립성 장의존성과 관련이 없는 것으로 나타났다. 유의미 학습접근양식은 모든 특징과 관련이 있었으나 기계적 학습접근양식은 모든 특징과 관련이 없었다. 연구 결과를 바탕으로 교육적 함의를 논의하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권9호
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• pp.4389-4411
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• 2018

High dynamic range (HDR) images are becoming pervasive due to capturing or rendering of a wider range of luminance, but their special display equipment is difficult to be popularized because of high cost and technological problem. Thus, HDR images must be adapted to the conventional display devices by applying tone mapping (TM) operation, which puts forward higher requirements for intellectual property protection of HDR images. As the robustness presents regional diversity in the low dynamic range (LDR) watermarked image after TM, which is different from the traditional watermarking technologies, a concept of watermarking activity is defined and used to distinguish the essential distinction of watermarking between LDR image and HDR image in this paper. Then, a novel robust HDR image watermarking algorithm is proposed against TM operations. Firstly, based on the hybrid processing of redundant discrete wavelet transform and singular value decomposition, the watermark is embedded by modifying the structure information of the HDR image. Distinguished from LDR image watermarking, the high embedding strength can cause more obvious distortion in the high brightness regions of HDR image than the low brightness regions. Thus, a perceptual brightness mask with low complexity is designed to improve the imperceptibility further. Experimental results show that the proposed algorithm is robust to the existing TM operations, with taking into account the imperceptibility and embedded capacity, which is superior to the current state-of-art HDR image watermarking algorithms.

• Journal of Microbiology and Biotechnology
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• 제21권10호
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• pp.1001-1011
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• 2011

To explore bacterial diversity for elucidating genetic variability in acylhomoserine lactone (AHL) lactonase structure, we screened 800 bacterial strains. It revealed the presence of a quorum quenching (QQ) AHL-lactonase gene (aiiA) in 42 strains. These 42 strains were identified using rrs (16S rDNA) sequencing as Bacillus strains, predominantly B. cereus. An in silico restriction endonuclease (RE) digestion of 22 AHL lactonase gene (aiiA) sequences (from NCBI database) belonging to 9 different genera, along with 42 aiiA gene sequences from different Bacillus spp. (isolated here) with 14 type II REs, revealed distinct patterns of fragments (nucleotide length and order) with four REs; AluI, DpnII, RsaI, and Tru9I. Our study reflects on the biodiversity of aiiA among Bacillus species. Bacillus sp. strain MBG11 with polymorphism (115Alanine > Valine) may confer increased stability to AHL lactonase, and can be a potential candidate for heterologous expression and mass production. Microbes with ability to produce AHL-lactonases degrade quorum sensing signals such as AHL by opening of the lactone ring. The naturally occurring diversity of QQ molecules provides opportunities to use them for preventing bacterial infections, spoilage of food, and bioremediation.

• 로봇학회논문지
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• 제4권2호
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• pp.97-104
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• 2009

Recently, simultaneous localization and mapping (SLAM) approaches employing Rao-Blackwellized particle filter (RBPF) have shown good results. However, due to the usage of the accurate sensors, distinct particles which compensate one another are attenuated as the RBPF-SLAM continues. To avoid this particle depletion, we propose the strategic games to assign the particle's payoff which replaces the importance weight in the current RBPF-SLAM framework. From simulation works, we show that RBPF-SLAM with the strategic games is inconsistent in the pessimistic way, which is different from the existing optimistic RBPF-SLAM. In addition, first, the estimation errors with applying the strategic games are much less than those of the standard RBPF-SLAM, and second, the particle depletion is alleviated.