• Communications for Statistical Applications and Methods
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• 제6권1호
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• pp.107-116
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• 1999

We propose a sample design which minimize Bayes risk for cluster smpling in sampling inspection. We treat a pilot sample and an additional sample size as random variable. In addition we compute an appropriate cluster size for handling over-dispersion.

• Communications for Statistical Applications and Methods
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• 제25권4호
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• pp.373-383
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• 2018

The spatial scan statistic is a widely used method to detect spatial clusters. The method imposes a large number of scanning windows with pre-defined shapes and varying sizes on the entire study region. The likelihood ratio test statistic comparing inside versus outside each window is then calculated and the window with the maximum value of test statistic becomes the most likely cluster. The results of cluster detection respond sensitively to the shape and the maximum size of scanning windows. The shape of scanning window has been extensively studied; however, there has been relatively little attention on the maximum scanning window size (MSWS) or maximum reported cluster size (MRCS). The Gini coefficient has recently been proposed by Han et al. (International Journal of Health Geographics, 15, 27, 2016) as a powerful tool to determine the optimal value of MRCS for the Poisson-based spatial scan statistic. In this paper, we apply the Gini coefficient to normal-based spatial scan statistics. Through a simulation study, we evaluate the performance of the proposed method. We illustrate the method using a real data example of female colorectal cancer incidence rates in South Korea for the year 2009.

• 한국통신학회논문지
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• 제35권8B호
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• pp.1211-1216
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• 2010

임베디드 SW는 제품 내장형 SW라는 특징으로 인해 임베디드 SW를 탑재한 제품의 시장 규모가 아닌 임베디드 SW 만의 시장을 명확히 파악한 자료는 거의 없다. 본 논문에서는 임베디드 SW만의 시장규모를 최대한 정확히 알아내기 위해 생산액 규모를 추정하는 방법을 사용하였다. 임베디드 SW 시장규모 추정에 적합한 산업분류체계를 도출하였고 이에 따른 산업 분류별 시장 규모를 추정하였다. 또한, 임베디드 SW의 산업 분류별 비중을 산출하고 최종적으로 임베디드 S/W의 시장 규모를 추정하였다. 임베디드 산업 분류별 SW의 시장 규모를 추정한 결과 산업자동화, 군사, 항공, 우주, 사무자동화 순으로 추정되었고, 임베디드 SW의 부가가치는 약 27조로 나타났다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(2)
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• pp.306-309
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• 2000

In this work, we investigated A1 cluster deposition on Al (100) surface using molecular dynamics simulation. A result of simulations showed that large cluster with low energy was proper for good surfaced-films without craters at the low temperatures. We investigated the maximum substrate temperature and the time taken for substrate temperature to reach its maximum as a function of cluster size in the case of the same total energy and in the case of the same energy Per atom. The correlated collisions play an important role in interaction between energetic cluster and surface, and as cluster size and cluster energy increases, the correlated collisions effect affects interaction between energetic cluster and surface.

• 응용통계연구
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• 제24권2호
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• pp.393-400
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• 2011

조사비용과 시간과 같은 현실적인 제약하에서 관측단위 (observation unit)의 집합인 집락(cluster)율 추출하는 집락추출법은 대부분의 대형조사(large scale survey) 에서 흔히 사용된다. 특별히 집락내의 관측단위가 매우 유사한 경우, 집락 내의 모든 관측치를 조사하는 대신 일부를 추출하여 조사하는 이단계 집락 추출법이 선호된다. 이단계 집락추출법의 적용시 집락인 1차추출단위 (Primary Sampling Unit; PSU)와 관측단위인 2차추출단위(Secondary Sampling Unit; SSU)의 표본수 결정은 주어진 비용과 표본으로부터 계산되어지는 통계량의 정도에 의존한다. 본 연구에서는 기존의 1차추출단위의 크기가 동일하다는 가정하에서 유도된 최적 PSU와 SSU 표본크기 산출과정을 일반화하여 1차추출단위의 크기가 같지 않을 경우의 최적 표본크기를 유도하고 그 결과를 제 4차 퇴원환자조사를 위한 표본추출 방안에 적용하여 기존방법과 비교하였으며 이를 바탕으로 제 7차 퇴원환자조사를 위한 표본크기를 제안하였다.

• 센서학회지
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• 제19권5호
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• pp.342-348
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• 2010

The wireless sensor networks have been extensively researched. One of the issues in wireless sensor networks is a developing energy-efficient clustering protocol. Clustering algorithm provides an effective way to extend the lifetime of a wireless sensor networks. In this paper, we proposed an energy efficient clustering scheme by adjusting group size. In sensor network, the power consumption in data transmission between sensor nodes is strongly influenced by the distance of two nodes. And cluster size, that is the number of cluster member nodes, is also effected on energy consumption. Therefore we proposed the clustering scheme for high energy efficiency of entire sensor network by controlling cluster size according to the distance between cluster header and sink.

• Journal of Ecology and Environment
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• 제36권1호
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• pp.11-17
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• 2013

The life cycle of butterflies is closely related to the growth of food plants and, through a prolonged coevolutionary process, has undergone an ecological adaptation. So, it is important that control the egg-laying number and place to secure enough food plant by female adult to guarantee the survival of the larvae. To study whether oviposition control of the Luehdorfia puziloi takes into greater consideration food plant leaf biomass or leaf abundance, correlation among the egg cluster size, the leaf size, and the number of leaves around egg clusters was investigated. According to the results, the egg clusters size exhibited positive correlation with the leaf size of food plants on which eggs had been laid but did not do so with the number of surrounding leaves. In addition, the number of egg clusters laid exhibited positive correlation with the number of surrounding food plant leaves but not with the leaf size on which eggs had been laid. Consequently, for the Luehdorfia puziloi, the females' recognition of the leaf size seems to be the most important factor in the egg cluster size, and the number of egg clusters had positive correlation with food plant density per unit area.

• 한국의류학회지
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• 제28권7호
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• pp.1019-1028
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• 2004

The purpose of this study was to compare the body measurements of cyclists and non-cyclists and to classify cyclists＇ body types to offer basic information for the bicycle apparel manufacturer in Korea. The anthropometric data was collected including both direct and indirect measurements of 81 cyclists (40 female, 41 male) aged from 19 to 24. Anthropometric measurements were analyzed using percentiles, T-test, factor and cluster analysis. The results were as follows; Comparison of anthropomeoic data between cyclist and non-cyclist was to clarify that cyclists have bigger size than non-cyclists; especially the thigh circumference shows big differences. As the result of factor analysis, 5 factors, which explain 74% of variance, were extracted from all items for male and female cyclists. The results of cluster analysis classified body types into 3 groups. Cluster 1 among three female cyclist groups has biggest torso and had an erect back. Cluster 2 has small size among three female group and drooping shoulders. Cluster 3 has the bended forward shoulders and shows the protrusion back. In case of male cyclists, cluster 1 has thin body type owing to big height measurements and small girth measurements. Cluster 2 among three male groups has the biggest torso and thigh circumference. Cluster 3 has big forward angle of shoulders and shows the protrusion of the back as female cyclist.

• Animal cells and systems
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• 제2권4호
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• pp.439-449
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• 1998

To discuss the taxonomic dispositions of Korean Isopyroideae (Ranunculaceae) taxa, principal components analysis and cluster analysis were performed using quantitative and qualitative morphological characters. The principal components analysis revealed that the size and number of ovule, ovary width, ratio of style length/ovary length, filament length, sepal size, style length, leaf size, and ovary length are important characters to distinguish Korean Isopyroideae taxa. The cluster and principal components analyses based on both quantitative and quantitative characters demonstrate that lsopyrum mandshuricum is more closely related to Enemion raddeanum than to Semiaquilegia adoxoides. Even though Enemion s not separated from Isopyrum by uantitative characters, they are distinguished by qualitative characters, suggesting that our taxa, Enemion, Semiaquilegia, Isopyrum and Aquilegia, should be recognized in Korean Isopyroideae. In addition, cluster analyses suggest that S. adoxoides could be separated from Aquilegia buergeriana var, oxysepala.

• 한국비블리아학회지
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• 제31권3호
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• pp.79-99
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• 2020

이 연구의 목적은 공공도서관 그룹화를 위해 적합한 군집분석 모델을 파악하고 그 특징을 분석하는데 있다. 국가도서관통계시스템의 공공도서관 통계 데이터를 사용하였으며, 군집분석 기법의 3가지 모델을 적용하였다. 공공도서관 규모를 기준으로 군집분석을 실시한 결과 크게 2가지 군집으로 구분되었으며, 군집의 크기는 크게 한쪽으로 치우쳤다. 그룹화 모델로 도서관 규모를 기준으로 삼으면, 계층적 군집분석의 와드측정법과 k-평균군집분석 모델이 적합하였다. 공공도서관 그룹화 연구 결과에 대한 시사점은 다음과 같다. 첫째, 통계 데이터 외에 도서관 서비스 관련 다양한 데이터 수집이 진행되어야 한다. 둘째, 분석 대상이 되는 데이터 세트에 적합한 분석 모델이 적용되어야 한다. 셋째, 도서관 서비스 향상을 위해 군집분석 기법의 다양한 분야 적용 가능성에 대한 적극적인 연구가 필요가 있다.