• Genomics & Informatics
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• 제1권1호
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• pp.32-39
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• 2003

We present a latent variable model-based approach to the analysis of gene expression patterns, coupled with topographic clustering. Aspect model, a latent variable model for dyadic data, is applied to extract latent patterns underlying complex variations of gene expression levels. Then a topographic clustering is performed to find coherent groups of genes, based on the extracted latent patterns as well as individual gene expression behaviors. Applied to cell cycle­regulated genes of the yeast Saccharomyces cerevisiae, the proposed method could discover biologically meaningful patterns related with characteristic expression behavior in particular cell cycle phases. In addition, the display of the variation in the composition of these latent patterns on the cluster map provided more facilitated interpretation of the resulting cluster structure. From this, we argue that latent variable models, coupled with topographic clustering, are a promising tool for explorative analysis of gene expression data.

• 수면정신생리
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• 제8권1호
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• pp.30-36
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• 2001

배 경 : 주간기분변동은 주요 우울장애, 멜랑콜리아 형의 세부진단으로 포함되어 있다. 그러나 현재까지의 연구를 종합해 보면 주간기분변동은 우울증의 고유한 증상인지 수면 양상의 변화와 관련된 현상인지, 혹은 별개의 다른 기전을 갖는 현상인지에 대해서 서로 모순되는 주장들이 혼재되어 있다. 이에 본 연구에서는 우울증의 세부 진단에 따른 주간 기분변동의 유무를 조사하고, 주간기분변동의 유무에 따른 수면 양상의 차이를 비교함으로써 주간기분변동과 수면 양상 사이의 관계를 찾아 보고자 하였다. 방 법 : 입원 혹은 의뢰된 우울장애 환자 62명을 대상으로 하여 주간기분변동은 Visual Analogue Mood Scale로, 수면 양상은 Pittsburgh Sleep Quality Index, 우울증의 심각도는 Hamilton Depression Rating Scale을 이용하여 측정하였다. 주간기분변동이 있는 군과 없는 군으로 나누고 HDRS 총점과 소항목, 그리고 PSQI 총점과 소항목을 변수로 하여 통계적 분석을 시행하였다. 결 과 : 주간기분변동의 빈도는 각각의 진단별로 차이가 없었으며, 주간기분변동이 있는 군과 없는 군으로 나누었을 때 중기 불면증과 수면 시간에 있어서 유의한 차이가 있었다(p<0.05). 또한 멜랑콜리아 형만을 대상으로 주간기분변동이 있는 군과 없는 군을 비교하였을 때 중기 불면증, 수면 시간뿐만 아니라 PSQI 총점, 수면 잠복기, 수면 장애, 주간의 기능 면에서 유의한 차이를 보였다(p<0.05). 결 론 : 주간기분변동은 멜랑콜리아 형의 우울장애 뿐만 아니라, 다른 우울장애에서도 존재하기 때문에 주간기분변동이 멜랑콜리아 형 우울장애의 특유한 증상으로 보기는 어려웠다. 주간기분변동이 있는 군에서 수면의 질이 더 좋은 것으로 나타났는데 이는 수면과 관련될 가능성이 높으며 향후 심도있는 연구가 필요할 것이다. 주간 기분변동은 외부 환경의 영향을 받기 쉬움으로 신뢰성을 높이기 위해서는 측정 기간과 횟수 등의 방법론적 연구도 필요할 것으로 생각된다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2004년도 학술발표회
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• pp.124-133
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• 2004

Global climate variations are expected to affect local hydro-meteorological variables like precipitation and temperature. The Southern Oscillation (SO) is one of the major driving forces that give impact on regional and local climatic variation. The relationships between SO and local climate variation are, however, characterized by strong nonlinear variation patterns. In this paper, the nonlinear dynamic relationship between the Southern Oscillation Index (SOI), precipitation, and temperature in Fukuoka, Japan, is investigated using by a nonlinear multivariable approach. This approach is based on the joint variation of these variables in the phase space. The joint phase-space variation of SOI, precipitation, and temperature is studied with the primary objective to obtain a better understanding of the dynamical evolution of local hydro-meteorological variables affected by global atmospheric-oceanic phenomena.

• 전자공학회논문지B
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• 제29B권11호
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• pp.130-137
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• 1992

This paper presents the word recognition method using a neural-fuzzy pattern matching, in order to make a proper speech pattern for a spectrum sequence and to improve a recognition rate. In this method, a frequency variation is reduced by generating binary spectrum patterns through associative memory using a neural network, and a time variation is decreased by measuring the simillarity using a fuzzy pattern matching. For this method using binary spectrum patterns and logic algebraic operations to measure the simillarity, memory capacity and computation requirements are far less than those of DTW using a conventional distortion measure. To show the validity of the recognition performance for this method, word recognition experiments are carried out using 28 DDD city names and compared with DTW and a fuzzy pattern matching. The results show that our presented method is more excellent in the recognition performance than the other methods.

• 한국생물정보학회:학술대회논문집
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• 한국생물정보시스템생물학회 2002년도 제1차워크샵
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• pp.139-152
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• 2002

Gene-shaving(Hastie et al, 2000) is a very useful method to identify a meaningful group of genes when the variation of expression is large. By shaving off the low-correlated genes with the leading principal component, the primary genes with the coherent expression pattern can be identified. Gene-shaving method works well If expression levels are varied enough, but it may not catch the meaningful cluster in low expression level or different expression time even with coherent patterns. The sliding window gene-shaving method which is to apply gene-shaving in each sliding window after hierarchical clustering is to compensate losing a meaningful set of genes whose variation is not large but distinct. The performance to identify expression patterns is compared for the simulated profile data by the different variance and expression level.

• 한국균학회지
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• 제27권5호
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• pp.328-336
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• 1999

Isozyme comparisons of mycelial extracts from Pleurotus ostreatus were undertaken using isoelectric focusing. Enzyme isozyme patterns were Used to describe the extent of geographical diversity and degree of intraspecific variation in these extracts. A total of 77 bands were resolved from six different enzymes. Cluster analyses were performed using the zymograms for esterase (EST), glucose phosphate isomerase (GPI), leucine aminopeptidase (LAP), malate dehydrogenase(MDH), peroxidase (POX), and phosphoglucomutase (pGM). EST gave multiple banding patterns, while less variability was observed for GPI, MDH, and PGM. Cluster analyses demonstrated that strains of P. ostreatus from geographically different origins are genetically divergent, supporting the idea that there is little or no gene flow between these geographically distant population groups.

• Earthquakes and Structures
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• 제6권4호
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• pp.437-455
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• 2014

Some conventional lateral load patterns for pushover analysis, and proposing a new accurate pattern was investigated in present research. The new proposed load pattern has load distribution according weight and stiffness variation in height and mode shape of structure. The assessment of pushover application with mentioned pattern in X type braced steel frames and steel moment resisting frames, with stiffness and mass variation in height, was studied completely and the obtained results were compared with nonlinear dynamic analysis method (including time history analysis). The methods were compared from standpoints of some basic parameters such as displacement, drift and shape of lateral load pattern. It is concluded that proposed load pattern results are closer to nonlinear dynamic analysis (NDA) compared to other pushover load patterns especially in tall and medium-rise buildings having different stiffness and mass during the height.

• 한국자원식물학회지
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• 제22권3호
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• pp.242-247
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• 2009

Randomly Amplified Polymorphic DNA (RAPD) was performed to define the genetic variation and relationships of Artemisia capillaris. Fifteen populations by the distributions and habitat were collected to conduct RAPD analysis. RAPD markers were observed mainly between 300bp and 1600bp. Total 72 scorable markers from 7 primers were applied to generate the genetic matrix, and 69 bands were polymorphic and only 3 bands were monomorphic. The genetic dissimilarity matrix by Nei's genetic distance (1972) and UPGMA phenogram were produced from the data matrix. Populations of Artemisia capillaris were clustered with high genetic affinities and cluster patterns were correlated with distributional patterns. Two big groups were clustered as southern area group and middle area group. The closest OTUs were GW2 and GG1 in middle area group, and GB1 from southern area group was clustered with OTUs in middle area group. RAPD data was useful to define the genetic variations and relationships of A. capillaris.

• 대기
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• 제20권3호
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• pp.367-377
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• 2010

Variation of tracer distribution during the vortex-breakup period in the Antarctic region was observed by the data from the Improved Limb Atmospheric Spectrometer (ILAS) and ILAS-II. All four trace species including methane, nitrous oxide, ozone, and water vapor show similar patterns of vertical gradient in spite of different structures of zonal mean mixing ratio. Timings of vortex breakup on each level are estimated by two different methods, and they are compared with zonal standard deviations following the latitude circle of each trace species. Although the tracers have different chemical life times and sink/source, the zonal standard deviation patterns show remarkable similarities. The zonal standard deviation shown here to measure the zonal asymmetry of tracer distribution is believed to diagnose the timing of the Antarctic polar-vortex breakup reasonably well.

• 한국해안해양공학회지
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• 제8권2호
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• pp.204-214
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• 1996

본 연구의 목적은 새만금해역에서 방조제 축조에 따른 토사의 이동형태변화와 토사 확산을 알아보는 데 있다. 유동은 조석잔차류와 관측된 바람, 수온, 염분자료를 이용하여 계산되었다. 유동에 의한 토입자의 3차원적 거동은 Euler-Lagrange 방법으로 추적하였다. 방조제 축조에 따른 토사확산 및 이동 형태는 금강 하구 남쪽에서 고군산군도 북쪽에 대부분의 토사를 퇴적시켰다. 이것은 잔차류의 영향으로 판단된다.