• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 ICEIC The International Conference on Electronics Informations and Communications
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• pp.447-450
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• 2004

This paper proposes remotely sensed image classification method by fuzzy c-means clustering algorithm using average intra-cluster distance. The average intra-cluster distance acquires an average of the vector set belong to each cluster and proportionates to its size and density. We perform classification according to pixel's membership grade by cluster center of fuzzy c-means clustering using the mean-values of training data about each class. Fuzzy c-means algorithm considered membership degree for inter-cluster of each class. And then, we validate degree of overlap between clusters. A pixel which has a high degree of overlap applies to the maximum likelihood classification method. Finally, we decide category by comparing with fuzzy membership degree and likelihood rate. The proposed method is applied to IKONOS remote sensing satellite image for the verifying test.

• 한국진공학회지
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• 제9권3호
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• pp.273-278
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• 2000

본 연구에서는 분자동력학 방법을 사용하여 알루미늄 덩어리 증착에 관하여 연구하였다. 다양한 크기의 덩어리 충돌에서 기판의 온도와 비정렬 원자수 변화를 관찰하여 알루미늄 덩어리 증착시 덩어리내의 원자들 상호간의 상관충돌이 기판으로의 에너지전달과 원자 재배열과정에 큰 영향을 미치는 것을 발견하였다. 덩어리 크기가 클수록 상관충돌 효과는 커지는 것을 알 수 있었다.

• 스마트미디어저널
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• 제8권4호
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• pp.46-52
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• 2019

산업 현장과 공공 기관에서 생성 및 수집되는 데이터의 크기가 빠르게 증가하고 있다. 기존의 데이터 처리 서버는 스케일업 방식으로 성능을 높여 증가하는 데이터를 처리하였다. 그러나 데이터의 생성 속도가 폭증하는 빅데이터 시대에는 기존 방식의 서버로는 데이터 처리에 한계가 있다. 이러한 한계를 극복하기 위해 스케일 아웃 방식으로 데이터를 분산 처리하는 분산 클러스터 컴퓨팅 시스템이 등장하게 되었다. 그러나 분산 클러스터 컴퓨팅 시스템은 데이터를 분산 처리하기 때문에 네트워크 대역폭을 비효율적으로 사용할 경우 클러스터 전체의 성능을 하락시킬 수 있다. 본 논문에서는 네트워크 대역폭을 고려하여 하둡 클러스터에서 데이터 전송 시 데이터를 압축 전송하는 기법을 제안한다. 제안 기법은 네트워크 대역폭과 압축 알고리즘의 특징을 고려하여 최적의 압축 전송 기법을 선정 후 전송한다. 실험 결과는 제안 기법을 사용할 경우 데이터 전송 시간과 크기를 감소시킨 것을 보여준다.

• Asian Journal of Atmospheric Environment
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• 제4권1호
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• pp.9-19
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• 2010

The size distribution of airborne particulate matter (PM) and the concentrations of associated metallic elements were investigated in a busy urban region of a typical Korean industrial city. The PM concentrations measured during the spring, except for those in the size range of 1.1 to 2.1 ${\mu}m$, were slightly higher than the PM concentrations in the summer. Coarse particles contributed greatly to the variation in PM concentrations in the spring, while fine and submicron particles contributed largely to the variation in PM concentrations in the summer. The difference in size modes of the PM concentrations between spring and summer may be explained by the Asian dust effect and its accompanying wind direction and speed. Extremely high enrichment factors (EFs) values (6,971 to 60,966) for all of the size distributions in PM were identified for cadmium (Cd). High EFs values (12 to 907) were also identified for other heavy metals including Cr, Cu, Ni, Pb, Zn and Mn. Low EF values (0.29 to 8.61) were identified for Ca, K, Mg and Na. These results support the common hypothesis that most heavy metals in ambient PM have anthropogenic sources and most light metals have crustal sources. The results of principal components analyses and cluster analyses for heavy metals indicate that the principal sources of PM and metals were emissions from non-ferrous metal smelters, oil combustion, incinerators, vehicular traffic and road dust.

• 응용통계연구
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• 제20권3호
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• pp.605-618
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• 2007

모집단 단위들이 희박하게 존재하고 접근하기 어려운 경우에 적용하는 적응추출설계에서의 추출과정은 관심변수의 관측값에 의존한다. 동일한 표본크기에서 적응집락추출의 추정량은 단순임의추출의 추정량에 비해 효율이 더 좋다 적응추출에서 Rao-blackwell의 정리를 적용하여 Murthy의 추정량의 형태로 수정한 한센-휴비_(HH) 추정량과 호르비_-톰슨 (HT) 추정량은 기존의 추정량에 비해 작은 분산을 가진다. 본 연구는 초기표본을 바꿔가면서 기대표본크기와 적응추출의 표본크기 하의 단순임의추출의 추정량과 적응추출의 추정량의 효율을 비교하였다.

• 한국의류학회지
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• 제10권3호
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• pp.37-48
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• 1986

The purpose of this study was to analyze 'the natural groupings' of subjects in order to classify highly similar somatotype for clothing construction. The sample for the study was drawn randomly out of senior high school boys in Seoul urban area. The sample size was 425 boys between age 16 and 18. Cluster analysis was more concerned with finding the hierarchical structure of subjects by three dimensional distance of stature. bust girth and sleeve length. The groups forming a partition can be subdivided into 5 and 6 sets by the hierarchical tree of the given subjects. Ward's Minimum Variance Method was applied after extraction of distance matrix by the Standardized Euclidean Distance. All of the above data was analyzed by the computer installed at Korea Advanced Institute of Science and Technology. The major findings, take for instance, of 16 age group can be summarized as follows. The results of cluster analysis of this study: 1. Cluster 1 (32 persons means $18.29\%$ of the total) is characterized with smaller bust girth than that of cluster 5, but stature and sleeve length of the cluster 1 are the largest group. 2. Cluster 2 (18 Persons means $10.29\%$ of the total) is characterized with the group of the smallest stature and sleeve length, but bust girth larger than that of cluster 3. 3. Cluster 3(35persons means $20\%$ of the total) is classified with the smallest group of all the stature, bust girth and sleeve length. 4. Cluster 4(60 persons means $34.29\%$ of the total) is grouped with the same value of sleeve length with the mean value of 16 age group, but the stature and bust girth is smaller than the mean value of this age group. 5. Cluster 5(30 persons means $17.14\%$ of the total) is characterized with smaller stature than that of cluster 1, and with larger bust girth than that of cluster 1, but with the same value of the sleeve length with the mean value of the 16 age group.

• 한국생활과학회지
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• 제12권4호
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• pp.553-558
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• 2003

The purpose of this paper was to design the sizing system of the head gears which would be a guide of men for selecting their head gears of suitable size. This study was carried out on 214 men and was done by cluster analysis with two variables(head circumference and bitragus to vertex arc length). The results were as follows : First, most of measurements were larger in men than in women. Second, the suitable numbers of size were found that 5 sizes were proper by cluster analysis with two variables. After the design of sizing system, the cover ratio was investigated in order to decide whether it is proper or not. Third, in the cover ratio, the 5 sizes were the highest in all of them.

• 응용통계연구
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• 제25권5호
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• pp.733-741
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• 2012

The successful launch of Arirang satellites allow the acquisition of high resolution satellite imagery of Korean territory and enables the transition from the conventional cultivation area survey method to new image based methods adopted in advanced nations. In this study, we suggested reasonable sizes of the primary sampling unit and the secondary sampling unit for the satellite imagery based sampling design in 8 provinces preselected for this research. The PSU size was determined mainly in consideration of intracorrelation that shows the degree of homogeneity within each cluster and the efficiency of the image process. For the SSU size, we considered the relative standard error and the differences between the land cover maps produced by the Ministry of Environment and the satellite imagery processed by the National Statistical Office.

• 융합경영연구
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• 제10권6호
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• pp.9-16
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• 2022

Purpose: This research investigates the differences in knowledge exchange activities and performances between startups and large companies in software industry clusters. Research design, data, and methodology: Six independent factors of human resource information, R&D and technology, marketing knowledge, government support information, strategic knowledge, and cooperation information were extracted to test the firm size effect in the relationships with two performance factors such as satisfaction with industry cluster location and satisfaction with financial performances. Data were collected through a survey of entrepreneurs, managers, and employees and tested by statistical analysis methodologies. Results: Three independent factors of human resource information, R&D and technology, and cooperation information were particularly significant in the relationship with both dependent factors. Strategic knowledge significantly affected financial performance. Knowledge exchange activities were more important in startups than in large companies for all eight factors. Conclusion: Policies for software industry clusters need a different approach for startups and large companies.

• 한국통신학회논문지
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• 제41권12호
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• pp.1801-1810
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• 2016

본 논문에서는 최근 많은 관심과 집중을 받고 있는 SDN 분야 오픈 소스 프레임워크인 오픈데이라이트 컨트롤러를 중심으로 컨트롤러 클러스터 구조 및 동작방식에 대하여 분석한다. 오픈데이라이트 컨트롤러 클러스터에서는 컨트롤러 간 데이터 스토어의 동기화를 위하여 분산 샤드 구조 및 샤드 리더 선정을 위한 Raft 알고리즘을 적용하고 있다. 성능 분석에서는 컨트롤러 클러스터 크기, 샤드 역할, 샤드 정책에 따른 CRUD, Routed RPC 지연시간 및 리더 재선정 지연시간 등을 분석함으로써, 오픈데이라이트 컨트롤러 클러스터 운영 시의 최적 운영 방안을 논의한다.