• Archives of Pharmacal Research
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• 제22권4호
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• pp.335-339
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• 1999

The oxidation-reduction potentials of cosmetic raw materials, showing tyrosinase inhibitory action, and phenolic compounds structurally similar to L-tyrosine were determined by cylcic voltammetry. The voltammograms obtained could be classified ito 4 patterns (patterns 1-4). Patterns 1, characterized by oxidation and reduction peaks as a pair, was observed with catechol, hydroquinone or phenol, and pattern 2 exhibiting another oxidation peak in addition to oxidation and reduction peaks as a pair was found with arbutin, kojic acid, resorcinol, methyl p-hydroxybenzoate and L-tyrosine as the substrate of tyrosinase. Pattern 3 with an independent oxidation peak only was expressed by L-ascorbic acid, and pattern 4 with a reduction peak only at high potentials, by hinokitiol. The tyrosinase inhibitory activity of these compounds was also evaluated using the 50% inhibitory concentration ($IC_{50}$) and the inhibition constant (Ki) as parameters. Hinokitiol, classified as patterns 4, showed the highest inhibitory activity (lowest $IC_{50}$ and Ki). Hydroquinone showing the second highest activity belonged to pattern 1, which also included compounds exhibiting pattern 2 was relatively low with Ki values being in the order of 10-4 M. Although there was no consistent relationship between oxidation-reduction potentials and tyrosinase inhibitory action, the voltammetry data can be used as an additional index to establish the relationship between the structure and the tyrosine inhibitory activity.

• Journal of Ecology and Environment
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• 제43권4호
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• pp.332-340
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• 2019

Background: Studies of morphological variation within and among populations provide an opportunity to understand local adaptation and potential patterns of gene flow. To study the evolutionary divergence patterns of Schlegel's Japanese gecko (Gekko japonicus) across its distribution, we analyzed data for 15 morphological characters of 324 individuals across 11 populations (2 in China, 4 in Japan, and 5 in Korea). Results: Among-population morphological variation was smaller than within-population variation, which was primarily explained by variation in axilla-groin length, number of infralabials, number of scansors on toe IV, and head-related variables such as head height and width. The population discrimination power was 32.4% and in cluster analysis, populations from the three countries tended to intermix in two major groups. Conclusion: Our results indicate that morphological differentiation among the studied populations is scarce, suggesting short history for some populations after their establishment, frequent migration of individuals among the populations, and/or local morphological differentiation in similar urban habitats. Nevertheless, we detected interesting phenetic patterns that may predict consistent linkage of particular populations that are independent of national borders. Additional sampling across the range and inclusion of genetic data could give further clue for the historical relationship among Chinese, Japanese, and Korean populations of G. japonicus.

• 정보처리학회논문지D
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• 제8D권6호
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• pp.753-760
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• 2001

디자인패턴은 어플리케이션 개발 시에 고려된 문제들로부터 독립적이며 확장성과 유지보수성에 대한 문제를 해결하기 위한 디자인 지식이며 현재 광범위하게 이용되고있는 분야이다. 그러나 이러한 광범위한 디자인패턴의 활용에도 불구하고 디자인 패턴에 명세와 활용은 주로 개발자의 수작업에 의존하고 있다. 그 결과 일관된 형태의 분석과 활용이 어렵고 오류 발생 빈도를 높일 뿐 아니라 프로그램 개발에 많은 시간을 필요로 한다. 따라서 이러한 문제를 해결하기 위해 본 논문에서는 디자인 패턴을 구조화하기 위해 XML을 사용한 표현방법, 이를 이용한 디자인 패턴 활용시스템 구조를 제시한다. 또한 이러한 표기법과 활용구조를 통해 소스코드 자동생성 지원 시스템을 제시하고 적용 예를 보이고자한다. XML을 이용한 구조화된 문서활용은 소스코드 생성시 사용자들에게 더 작은 코드를 작성하게 만들고, 더 안정된 시스템을 구축할 수 있게 한다.

• 아동학회지
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• 제34권1호
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• pp.175-189
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• 2013

The purpose of this study was to investigate the differences in children's play behaviors in terms of their levels of playfulness, leadership and communicative ability. The subjects were 152 children aged between 3 and 4, and their 20 teachers at 10 child care centers in the Seoul and Gyeonggi area. The results of this study suggested that play behaviors were related to the level of playfulness, leadership and communicative ability in 3 and 4 years old children. Among these children, those who scored highly in terms of their playfulness, leadership and communicative ability were involved more frequently in both 'group play' and 'symbolic play' whereas those who achieved lower scores were more frequently involved in 'solitary play' and 'functional play'. However, in case of 'constructive play', significant results were not found in relation to the independent variables named in this study. 'Parallel play' and 'games with rules' were the only categories within which the findings revealed that children's play behaviors have shown different patterns according to the age of the child and to the levels of those three independent variables mentioned above.

• ALGAE
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• 제22권2호
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• pp.107-116
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• 2007

Annual growth segments of Ascophyllum nodosum (L.) Le Jolis (Fucales, Fucaceae) are denoted by air bladders that form each spring. By examining annual growth segments, it may be possible to infer information about the physical conditions during the growth period; however, it is uncertain whether the annual segments will expand in size after the initial growth. We examined A. nodosum segments from three populations in Nova Scotia, and statistically evaluated whether the annual growth (length, mass, and maximum diameter) of segments was independent of the age of the frond, whether the segments increased in size after the initial growth, and whether the segment lengths were correlated with mean water temperatures and mean air temperatures when the segments were formed. We found that the growth in length of A. nodosum is dependent on the age of the frond, but frond age explained less than 12 % of the overall variation in length. However, the mass and maximum diameter of segments were independent of the age of the frond. Differences occurred between the lengths of segments formed in different years, but there was no significant correlation with regional mean water or air temperatures. This study indicates that the length of A. nodosum segments may be an indicator of the annual physical characteristics of a site, but future studies are needed to identify which factors have the strongest influence on growth patterns.

• 전자공학회논문지CI
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• 제39권2호
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• pp.10-20
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• 2002

여러 가지의 독립성분분석 및 암묵신호분리 알고리즘들이 개발되었지만, 아직 이러한 알고리즘들의 성능비교가 철저히 이루어지지는 못 하였다. 이 논문은 이 알고리즘들 중에서 뛰어난 알고리즘들을 센서 잡음에 대한 강인성, 계산 복잡도, 혼합 행렬의 조건, 센서 수, 학습패턴 수 등 여러 측면에서 비교한다. 또한, 알고리즘들의 성능 비교에 유용한 문제들도 제시한다. 이 비교결과는 이 알고리즘들의 EEG/MEG 분석, 음성신호분리 등과 같은 실질적 응용에 큰 도움이 될 것이다.

• BMB Reports
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• 제51권1호
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• pp.1-2
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• 2018

Positive selection on a new beneficial mutation generates a characteristic pattern of DNA sequence polymorphism when it reaches an intermediate allele frequency. On genome sequences of African Drosophila melanogaster, we detected such signatures of selection at 37 candidate loci and identified "sweeping haplotypes (SHs)" that are increasing or have increased rapidly in frequency due to hitchhiking. Based on geographic distribution of SH frequencies, we could infer whether selective sweeps occurred starting from de novo beneficial mutants under simple constant selective pressure. Single SHs were identified at more than half of loci. However, at many other loci, we observed multiple independent SHs, implying soft selective sweeps due to a high beneficial mutation rate or parallel evolution across space. Interestingly, SH frequencies were intermediate across multiple populations at about a quarter of the loci despite relatively low migration rates inferred between African populations. This invokes a certain form of frequency-dependent selection such as heterozygote advantage. At one locus, we observed a complex pattern of multiple independent that was compatible with recurrent frequency-dependent positive selection on new variants. In conclusion, genomic patterns of positive selection are very diverse, with equal contributions of hard and soft sweeps and a surprisingly large proportion of frequency-dependent selection in D. melanogaster populations.

• 대한의용생체공학회:의공학회지
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• 제27권4호
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• pp.170-179
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• 2006

The purpose of this study was to investigate the spatiotemporal cortical activation pattern and functional connectivity during visual perception of words. 61 channel recordings of electroencephalogram were obtained from 15 subjects while they were judging the meaning of Korean, English, and Chinese words with concrete meanings. We examined event-related potentials (ERP) and applied independent component analysis (ICA) to find and separate simultaneously activated neural sources. Spectral analysis was also performed to investigate the gamma-band activity (GBA, 30-50 Hz) which is known to reflect feature binding. Five significant ERP components were identified and left hemispheric dominance was observed for most sites. Meaningful differences of amplitudes and latencies among languages were observed. It seemed that familiarity with each language and orthographic characteristics affected the characteristics of ERP components. ICA helped confirm several prominent sources corresponding to some ERP components. The results of spectral and time-frequency analyses showed distinct GBAs at prefrontal, frontal, and temporal sites. The GBAs at prefrontal and temporal sites were significantly correlated with the LPC amplitude and response time. The differences in spatiotemporal patterns of GBA among languages were not prominent compared to the inter-individual differences. The gamma-band coherence revealed short-range connectivity within frontal region and long-range connectivity between frontal, posterior, and temporal sites.

• 디지털콘텐츠학회 논문지
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• 제9권2호
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• pp.251-260
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• 2008

인터넷의 전자상거래에서 대규모 정보 저장소에 있는 원하는 정보를 신속하게 검색하기란 어렵다. 대부분의 전자상거래 사이트에 있어서 정보를 제공하는 방법으로는 통계적 분석이나 분류별 지향의 간단한 과정을 통해 생성된다. 그러나 이러한 것은 생성 정보들 사이의 다양한 상호관계를 표현할 수 없고 사용자의 정확한 구매 패턴을 반영하기 어렵다. 본 논문에서는 전자상거래에서 효과적인 클러스터링을 이용한 다양한 관심정보 추출을 위한 효율적인 웹 마이닝을 제안한다. 이러한 방법은 분류별 항목에서 순차 패턴과 상관 규칙을 이용하여 생성 정보들 사이의 보다 적합한 상관관계를 구성하고 제안된 방법을 통해 효율적인 실험 결과를 나타낸다. 그리고 효과적인 클러스터링을 이용하여 신속한 검색을 제안한다.

• 한국정보과학회논문지:소프트웨어및응용
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• 제30권1_2호
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• pp.1-18
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• 2003

객체 지향 모델링의 결과를 소스 코드로 매핑 할 때 구현 플랫폼에 맞는 정확하고 체계적인 매핑 기법이 요구된다. 또한, 모델링 자체는 구현 언어나 특정 플랫폼에 종속적이지 않기 때문에 특정 플랫폼이나 언어에 맞게 구현할 수 있는 효율적이며 순차적인 접근법이 필요하다. 모델링한 결과는 구현상의 소스 코드로 정확하게 나타나야 하며 정확한 매핑을 위해서 본 논문에서는 EJB(Enterprise Java Beans) 2.0을 기준으로 하여 구현하고자 할 때, 모델링 단계에서 도출된 각 클래스가 가지는 비즈니스 오퍼레이션들이 EJB 2.0에서 지원하는 여러 가지 구현 가능한 장치들을 통해서 어떻게 나타날 수 있는지에 대한 절차적이며 구체적인 방법 및 디자인 패턴을 제시한다. 따라서 개발자로 하여금 이러한 기법들을 이용하여 비즈니스 오퍼레이션을 좀 더 체계적이며 정확하게 EJB 2.0 플랫폼에 맞도록 구현하여 설계 내용이 구현 소스 코드 상에 정확히 대응되어 나타날 수 있도록 지침을 제시한다.