• 천문학논총
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• 제27권5호
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• pp.399-409
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• 2012

NGC 6871을 중심으로 시계열 관측한 Cyg OB3 성협영역에서 모두 15개의 단주기 변광성을 찾았다. 이들은 모두 국부나선팔에 속한 ${\delta}$ Scuti 형 변광성으로 보인다. 그림 5의 영연령주계열 상에서 밝은쪽에 속한 V1-V4는 분광형이 모두 A, F 형으로서 Cyg OB3 성협보다 먼 거리에 있는 ${\beta}$ Cephei 형 변광성이라기 보다는 국부나선팔의 앞쪽에 놓인 ${\delta}$ Scuti 형 변광성이었다. 15개의 ${\delta}$ Scuti 형 변광성 중에는 2개(V1과 V3)는 GCVS에 ${\delta}$ Scuti 형 변광성으로 분류되어 이미 알려진 변광성이고, 나머지는 모두 새로 발견한 것이다. 새로 발견한 변광성 중에는 한 개의 이중모드 ${\delta}$ Scuti 형 변광성(V3)과 2개의 HADS 변광성(V13과 V14)이 포함되었다. 시계열 관측과는 별도로 표준화 관측을 수행하여 관측 영역의 색-등급도를 얻었는데 그림 6에서 Massey etal.(1995)의 결과와 잘 맞았다.

• 한국조경학회지
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• 제52권1호
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• pp.1-16
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• 2024

앨빈토플러는 미래사회가 속도를 맞추는 동시화가 중요하다고 언급하면서 시간의 편차가 사회 발전을 저해할 수 있다고 했다. 우리는 언택트라는 뉴노멀 시대를 겪으면서 비대면 접촉의 증가와 디지털 전환 가속화를 경험했다. 이러한 빠른 변화 속에서 공간에도 동시화 즉 변화의 필요성을 견지해볼 수 있다. 이에 사람들이 어떤 정주지를 만들고 선택하는지에 대해서 연구해 보고자 한다. 이를 간접적으로 나마 알아볼 수 있는 대상으로 메타버스를 살펴보았다. 메타버스 공간 형태와 관련된 자료를 수집하기 위해 "동물의 숲"이라는 콘텐츠를 활용했다. 표본추출은 비확률적 표본추출 중 판단추출 방법을 활용하여 게임의 진행에 따른 차이를 완화하였다. 수집한 자료들을 평면 형태와 입지 형태에 따라 분류하고, 기술 통계를 통해 간략하게 정리했다. 각 시설들을 용도별로 매칭한 후 군집별로 좌표를 설정하여 목록화하여 데이터를 구축했다. 이 데이터를 군집별로 좌표평면상에 그래픽으로 나타내어 해석하고, 유클리디안 분석을 실시해 군집별 관계와 거주지 선택에 관해 유클리디안 행렬로 분석했다. 분석결과 유사 기능을 근접배치해 효율성을 추구하는 것으로 해석할 수 있었으며, 그럼에도 불구하고 거주지 선택에 있어서는 효율성이나 편리함이 아닌 주민들과의 인접 배치를 통해 커뮤니티를 이루고자 하는 것으로 해석되었다. 메타버스와 현실세계의 다름으로 인해 이를 현실과 동일시하기에는 한계가 있을 것으로 예상한다. 그러나 현실의 제약에서 멀어진 사람들이 가상세계에 표출한 공간을 통해 우리가 인지하지 못함으로 인해 명시하지 못한 바람을 간접적으로 알 수 있다.

• 정보관리학회지
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• 제30권4호
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• pp.31-59
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• 2013

본 연구는 저자서지결합분석을 사용하여 한국 문헌정보학의 1990년대와 2000년대 지적구조와 그 변화를 분석하는데 목적을 두고 있다. 이를 위해 첫째, 군집분석, 다차원척도법을 통하여 시기별 세부 주제 영역을 밝혔다. 둘째, 네트워크 분석을 통해 세부 주제 영역 간 관계를 시각화하고 전역 중심성이 높은 주제 영역을 확인하였다. 셋째, 1990년대와 2000년대 지적구조 비교를 통해 시간의 경과에 따른 주제 영역의 흐름을 규명하였다.

• 복식문화연구
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• 제13권4호
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• pp.564-575
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• 2005

The purposes of this study were to investigate the effects of shopping orientation on fashion shopping mall environments and purchase intention in internet fashion shopping mall. Data were obtained from 423 internet fashion shopping mall consumers who have experiences of buying products or visiting to internet fashion shopping mall in Busan, and were analyzed using by factor analysis, Cronbach's alpha, cluster analysis, ANOVA and Duncan test. The results showed shopping orientation perceived by Internet fashion shopping mall consumers were consisted five factors: Brand loyalty orientation, Economical orientation, Fashion orientation, Time saving orientation and Internet shopping orientation. Internet fashion shopping mall environments were composed of Visual information, Loading speed, Space composition, Product assortment, Checkout service, and Help desk. Consumers were classified by the shopping orientation into the Economical shopper, Fashion/brand shopper, and Convenience shopper. Economical shopper and Fashion/brand shopper rise in the estimation of Visual information, Product assortment, and Checkout service of shopping mall environment. Additionally, they were likely to have more intentions to purchase than the other types of shoppers in internet fashion shopping mall.

• 한국측량학회지
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• 제38권5호
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• pp.487-496
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• 2020

This study introduces how GISs (Geographic Information Systems) are used to assess spatial disparities in urban green spaces in the Chicago. Green spaces provide us with a variety of benefits, namely environmental, economic, and physical benefits. This study seeks to explore socioeconomic relationships between green spaces and their surrounding communities and to evaluate spatial disparities from a variety of perspectives, such as health-related, socioeconomic, and physical environment factors. To achieve this goal, this study used spatial statistics, such as optimized hotspot analysis, network analysis, and space-time cluster analysis, which enable conclusions to be drawn from the geographic data. In particular, 12 variables within the three factors are used to assess spatial disparities in the benefits of the use of green spaces. Finally, the variables are standardized to rank the community areas and identify where the most vulnerable community areas or parks are. To evaluate the benefits given to the community areas, this study used the z- and composite scores, which are compared in the three different combinations. After identifying the most vulnerable community area, crime data is used to spatially understand when and where crimes occur near the parks selected. This work contributes to the work of urban planners who need to spatially evaluate community areas in considering the benefits of the uses of green spaces.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1996년도 추계학술대회
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• pp.118-121
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• 1996

This paper describes ECG signal labeling based on Fuzzy clustering, which is necessary at automated ECG diagnosis. The NPPA(Non parametric partitioning algorithm) compares the correlations of wave forms, which tends to recognize the same wave forms as different when the wave forms have a little morphological variation. We propose to apply Fuzzy clustering to ECG QRS Complex labeling, which prevents the errors to mistake by using If-then comparision. The process is divided into two parts. The first part is a parameters extraction process from ECG signal, which is composed of filtering, QRS detection by mapping to a phase space by time delay coordinates and generation of characteristic vectors. The second is fuzzy clustering by FCM(Fuzzy c-means), which is composed of a clustering, an assessment of cluster validity and labeling.

• Journal of Information Processing Systems
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• 제14권1호
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• pp.140-149
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• 2018

Social data such as users' comments are unstructured in nature and up-to-date technologies for analyzing such data are constrained by the available storage space and processing time when fast storing and processing is required. On the other hand, it is even difficult in using a huge amount of dynamically generated social data to analyze the user features in a high speed. To solve this problem, we design and implement a topic association analysis system based on the latent Dirichlet allocation (LDA) model. The LDA does not require the training process and thus can analyze the social users' hourly interests on different topics in an easy way. The proposed system is constructed based on the Spark framework that is located on top of Hadoop cluster. It is advantageous of high-speed processing owing to that minimized access to hard disk is required and all the intermediately generated data are processed in the main memory. In the performance evaluation, it requires about 5 hours to analyze the topics for about 1 TB test social data (SNS comments). Moreover, through analyzing the association among topics, we can track the hourly change of social users' interests on different topics.

• 천문학회보
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• 제45권1호
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• pp.31.2-31.2
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• 2020

Mass segregation, a tendency of more massive galaxies being distributed closer to the cluster center, is naturally expected from dynamical friction, but its presence is still controversial. Using deep optical observations of 14 Abell clusters (KYDISC) and a set of hydrodynamic simulations (YZiCS), we find in some cases a hint of mass segregation inside the virial radius. Segregation is visible more clearly when the massive galaxy fraction is used instead of mean stellar mass. The trend is more significant in the simulations than in the observations. To find out the mechanisms working on mass segregation, we look into the evolution of individual clusters simulated. We find that the degree of mass segregation is different for different clusters: the trend is visible only for low-mass clusters. We compare the masses of galaxies and their dark haloes at the time of infall and at the present epoch to quantify the amount of tidal stripping. We then conclude that satellites that get accreted at earlier epochs, or galaxies in more massive clusters go through more tidal stripping. These effects in combination result in a correlation between the host halo mass and the degree of stellar mass segregation. This is a work submitted to The Astrophysical Journal (under review).

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2018년도 학술발표회
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• pp.154-154
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• 2018

To interpret the climate projections for the future as well as present, recognition of the consequences of the climate internal variability and quantification its uncertainty play a vital role. The Korean Peninsula belongs to the Far East Asian Monsoon region and its rainfall characteristics are very complex from time and space perspective. Its internal variability is expected to be large, but this variability has not been completely investigated to date especially using models of high temporal resolutions. Due to coarse spatial and temporal resolutions of General Circulation Models (GCM) projections, several studies adopted dynamic and statistical downscaling approaches to infer meterological forcing from climate change projections at local spatial scales and fine temporal resolutions. In this study, stochastic downscaling methodology was adopted to downscale daily GCM resolutions to hourly time scale using an hourly weather generator, the Advanced WEather GENerator (AWE-GEN). After extracting factors of change from the GCM realizations, these were applied to the climatic statistics inferred from historical observations to re-evaluate parameters of the weather generator. The re-parameterized generator yields hourly time series which can be considered to be representative of future climate conditions. Further, 30 ensemble members of hourly precipitation were generated for each selected station to quantify uncertainty. Spatial map was generated to visualize as separated zones formed through K-means cluster algorithm which region is more inconsistent as compared to the climatological norm or in which region the probability of occurrence of the extremes event is high. The results showed that the stations located near the coastal regions are more uncertain as compared to inland regions. Such information will be ultimately helpful for planning future adaptation and mitigation measures against extreme events.

• 한국멀티미디어학회논문지
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• 제14권6호
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• pp.742-751
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• 2011

본 논문에서는 형상 특징자인 열 커널 인증 (Heat Kernel Signature, HKS)를 기반으로 강인한 3D 모델 해싱을 제안한다. 키와 매개변수에 의존한 형상 특징자 기반 3D 모델 해싱을 제안한다. 제안한 방법에서는 Mesh Laplace 연산자의 고유치와 고유벡터에 의하여 각 꼭지점에 대한 전역 및 국부 타임 HKS 계수를 구한 다음, 이 계수들을 정방형 2D 셀로 군집화한다. 그리고 각 셀에 할당된 HKS 계수 쌍의 거리 가중치 기반으로 정의된 특징계수와 랜덤 계수 키와의 조합에 의하여 중간 해쉬 계수를 생성한 다음, 이진화 과정에 의하여 최종 이진 해쉬를 생성한다. 본 실험에서는 3D 범용 툴을 이용한 다양한 기하하적 공격과 위상학적 공격을 통하여 강인성을 평가하였고, 모델과 키 조합에 대한 해쉬의 유일성을 평가하였다. 또한 인증 범위를 만족히는 공격 세기를 측정함으로써 모델 공간성을 평가하였다. 실험결과로부터 제안한 3D 모델 해싱이 기존 해싱에 비하여 강인성 모델 공간성 및 유일성이 우수함을 확인하였다.