• 천문학논총
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• 제30권2호
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• pp.267-268
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• 2015

One of the long-standing problems in modern astronomy is the curious division of globular clusters (GCs) into two groups, according to the mean period (<$P_{ab}$>) of type ab RR Lyrae variables. In light of the recent discovery of multiple populations in GCs, we suggest a new model explaining the origin of the Sandage period-shift and the difference in mean period of type ab RR Lyrae variables between the two Oosterhoff groups. In our models, the instability strip in the metal-poor group II clusters, such as M15, is populated by second generation stars (G2) with enhanced helium and CNO abundances, while the RR Lyraes in the relatively metal-rich group I clusters like M3 are mostly produced by first generation stars (G1) without these enhancements. This population shift within the instability strip with metallicity can create the observed period-shift between the two groups, since both helium and CNO abundances play a role in increasing the period of RR Lyrae variables. The presence of more metal-rich clusters having Oosterhoff-intermediate characteristics, such as NGC 1851, as well as of most metal-rich clusters having RR Lyraes with the longest periods (group III) can also be reproduced, as more helium-rich third and later generations of stars (G3) penetrate into the instability strip with further increase in metallicity. Therefore, although there are systems where the suggested population shift cannot be a viable explanation, for the most general cases, our models predict that RR Lyraes are produced mostly by G1, G2, and G3, respectively, for the Oosterhoff groups I, II, and III.

• 복식
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• 제26권
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• pp.279-288
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• 1995

The objective of the study was to provide fun-damental data on somatotype for elderly women by classifying the somatotype and analyzing the characteristics of their somatotype. The subjects were 368 women ages of 60∼84, they were measured direct anthropometry. In or-der to find out differences among the age groups, the 368 subjects were grouped into two age groups(Group 1 aged 60 to 69, Group 2 ; aged 70 to 84) Data were analyzed using Factor analysis, Cluster analysis, Duncan test and Analysis of variance. The results of this study were as follows. 1. The characteristics of Elderly women's somatotype were bending of the upper-torso, fat-ness of the waist and abdomen, drooping of the bust and shoulder and hip. In addition, height, girth, depth and width items were decreased in their sizes respectively. 2. Through the factor analysis, we extracted 5 factors from anthropometric measurements. Factor components were obesity, height, girth of the leg and arm, length of the upper-torso except the center front length, the center front length, we categorized by 4 clusters using 5 factor scores. And after the cluster analysis using 5 factor scores, 4 clusters were categorized. The characteristics of clusters were as follows. Type 1 was characterized by short, obesity type, and droopy bust. Type 2 was characterized by short and slender type, dropped bust, and bending somatotype from the lateral view. Type 3 was characterized by middle sized and straight somatotype from the lateral view. Type 4 was characterized by tall and obese type from the lateral view.

• 한국멀티미디어학회논문지
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• 제14권9호
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• pp.1182-1189
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• 2011

본 논문에서는 대상자의 체력상태에 따른 군집과 운동처방 과정 전반을 시각화 하는 방법을 비쥬얼패스맵이라 명명하고, 비쥬얼패스맵을 이용하여 운동처방사의 처방과정을 시각화하는 것을 목표로 한다. 비쥬얼패스맵은 대상자의 체력상태에 따른 군집 분포, 대상자의 현재 상태와 목표 상태, 운동처방에 따라 어떤 군집에 속하게 될지를 보여준다. 그래서 비쥬얼패스맵은 운동처방 안에 따라 현재 상태에서 목표 상태에 이르기까지의 경로를 나타내게 된다. 비쥬얼패스맵에서 대상자의 특성 간 군집을 표현하기 위해 인공신경망 SOM을 이용했고, 일반인 1,500명의 체력검사 결과값, 비만도, 나이 정보를 학습하여 군집형태를 시각화했다. 또한 운동처방사의 운동처방 자료를 이용하여 운동처방 과정을 비쥬얼패스맵으로 시각화했다.

• Journal of Communications and Networks
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• 제13권6호
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• pp.655-663
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• 2011

Diffuse optical wireless (DOW) systems have the advantage that they do not require point-to-point siting so one transmitter can communicate with several receivers. In this paper, we investigate multiple access scheduling methods for downlink orthogonal frequency division multiplexing (OFDM) in diffuse optical wireless networks. Unlike the radio frequency (RF) channel, the DOW channel has low-pass filter characteristics and so requires different scheduling methods than those developed for the RF channel. Multi-user diversity orthogonal frequency division multiple access (OFDMA) systems nominate a cluster of subcarriers with the largest signal-to-noise-ratio for transmission. However, in a DOW channel, most users would choose the lowest frequency clusters of subcarriers. To remedy this problem, we make two proposals. The first is to use a variable cluster size across the subcarriers; the lower frequency clusters will have fewer subcarriers while the higher frequency clusters will have more subcarriers. This will equalize the capacity of the clusters. The second proposal is to randomize a user's cluster selection from a group of clusters satisfying a minimum threshold. Through simulation it is shown that combining these strategies can increase the throughput while ensuring a fair distribution of the available spectrum.

• 한국생활과학회지
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• 제8권2호
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• pp.313-325
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• 1999

This study aimed to classify the data of children's bodies into several clusters by principal component scores that were extracted through the factor analysis in the former study, and to describe the distribution and body characteristics of the clusters. The sample was 308 elementary school children aged from 6 to 8 and the anthropometric measurements were performed indirectly from the photographs of the subjects, which was the same as the first analysis. The data were analysed statistically using SPSSWIN Ver. 8.0. Through the statistical analysis, 3 clusters were obtained from the data. The first cluster distributed more in the children aged 7 and 8 than in the children aged 6. The somatotype of this group was the tallest among the three groups, and they were the most developed group compared to the two other groups in lateral component as well as in linear component. The second cluster group wasn't well developed in lateral components, and had lowest level in Rohrer Index, so this group had thin figures compared to the other groups. The third cluster revealed dominant distribution in the group aged 6, and the group had the least developed linear components but higher level in Rohrer Index. Each cluster group revealed peculiar somatotype that was dominant in one group but rarely in other cluster groups. Lateral views of these characteristics were showed using the average of the measurements of clusters.

• 한국주거학회논문집
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• 제26권6호
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• pp.43-52
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• 2015

The purpose of this study was to explore housing value clusters of young renters in South Korea and their relationships to household and housing characteristics reflected in the 2012 Korea Housing Survey (KHS). The 2012 KHS microdata was used as secondary data. Among the households included in the microdata, 1,196,144 young renter households (between 20 and 34 years of age) in private rental units were analyzed. The main findings are as follows. Ten rating scale items measured housing values. Eight of them were grouped into three value factors: Investment, Affordability and Cost Increase. Using these three value factors and perception of homeownership, households were classified into four clusters: Prospective Home Investor, Settled Renter, Homeowner Wannabe, and Support Needed. The current tenure types, income and expectation for next tenure types of four housing value clusters of young renters reflected Korea's tenure ladder which has home ownership at top followed by Jeon-se rental, monthly rental with deposit and monthly rental without deposit. The households in Prospective Home Investor and Homeowner Wannabe clusters would consider home purchase in the near future. Finally, households in Support Needed Cluster would be the main target to consider in development and implementation of housing welfare policies and programs to resolve housing problems of young renters, including beginning-stage professionals.

• 한국산학기술학회논문지
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• 제19권12호
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• pp.416-431
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• 2018

본 연구의 목적은 간호사들의 병원 근무 경험과 경력단절 영향요인을 심층적으로 분석하기 위해 시도되었다. 이를 위해 26-55세 경력단절 간호사 20명을 대상으로 간호사로서의 경험, 간호 일의 특성과 퇴직사유의 내용을 인터뷰하였으며 현상학적 방법 중 꼴라쥐(Colaizzi)의 분석방법을 적용하였다. 분석결과 104개의 주요 진술과 17개의 구성된 의미, 6개의 공통 주제군, 2개의 범주가 도출되었다. 2개의 범주는 간호 업무 특성과 근무 환경 특성이며 간호 업무 특성에서는 '시간 압박', '자율성 부재', '신체 감정 노동', '낮은 임금 상승률'의 4가지 공통 주제군이, 근무 환경 특성에서는 '물리적 환경', '인적 환경'의 2가지 공통 주제군이 각각 도출되었다. 따라서 간호사의 경력단절 현상을 개선하기 위해서는 과도한 업무강도를 완화하고 적정수준의 임금인상과 안전한 근무환경을 제공하려는 노력이 필요하다.

• 토지주택연구
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• 제11권2호
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• pp.25-32
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• 2020

This study classified and analyzed characteristics of residents in public rental housing based on data from the 2018 Housing Survey. First, in order to classify the type of public rental housing resident, the criteria were derived through factor analysis based on the satisfaction evaluation index. Next, based on the factor value, the group was classified by type through cluster analysis, and the satisfaction, characteristics of residential households, and characteristics of rental housing types were analyzed for each cluster. As a result of factor analysis, evaluation of housing facilities, accessibility, and residential comfort was selected as the cluster classification criteria, and a total of four clusters were derived through cluster analysis. As a result of analyzing the characteristics of each cluster, it was found that there was a statistically significant difference in the level of residential satisfaction, characteristics of residents, and detailed types of rental housing. The results of this analysis are expected to be used to improve existing public rental housing or develop new types of rental housing to match the characteristics of residential housing for public rental housing. In addition, in the type integration of rental housing currently being promoted, it is necessary to develop a method of providing differentiated services in consideration of the characteristics of tenants as well as the integration of physical housing types.

• 벤처창업연구
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• 제18권4호
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• pp.149-163
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• 2023

혁신클러스터 정책은 특정 지역에 산업부문과 연구부문의 연계를 강화하여 산업의 경쟁력을 확보하는 것을 목적으로 한다. OECD(1997)에서 첨단 중소기업을 중심으로 산업 재구조화를 통해 지역발전을 유도하는 혁신클러스터 개념이 제시된 후 산업과 지역, 과학기술 분야에서 혁신클러스터 개념을 적용하여 적극적으로 정책을 추진하기 시작했다. 혁신클러스터 활성화 차원에서 그간의 정책 및 연구에서는 구성원 간 교류·협력에 집중하는 경향이 뚜렷했으나, 본 연구에서는 혁신클러스터를 육성하고자 하는 근본적인 이유인 산업 및 지역의 경쟁력 강화, 즉 기업의 경쟁력 강화에 집중하여 연구를 진행하였다. 이에 따라, 본 연구는 혁신클러스터 활성화 요인이 대덕연구개발구에 입주한 중소기업의 경영성과에 미치는 영향을 분석하는 것을 목적으로 진행하였다. 이를 위해 혁신클러스터가 가지는 본질적인 개념인 산업집적 요인, 네트워킹 요인, 혁신창출 요인 등 혁신클러스터 활성화 요인 도출 후 175개 기업의 설문조사 결과를 활용하여 가설을 검증하였다. 혁신클러스터 활성화 요인 중 산업집적 요인과 혁신창출 요인은 기업의 경영성과에 긍정적으로 영향을 미치는 것으로 나타났다. 그러나 네트워킹 요인은 기업의 경영성과에 유의한 영향을 미치지 않는 것으로 분석되었다. 본 연구는 이전에 수행된 사례 중심의 연구들과 달리 실증분석을 통해 혁신클러스터의 활성화 요인을 다루었다는 점에서 차별성을 가진다. 또한, 혁신클러스터에서 네트워킹 요인에 대한 직관적 판단과 실제 기업의 경영성과에 미치는 영향 간 차이를 고려하여, 보다 효과적인 혁신클러스터 정책을 위해서는 지역에 뿌리내려진 사회적·문화적 구조, 특화 산업의 특성, 구성원의 니즈 등 다각적인 관점에서 혁신클러스터에 대한 입체적 검토의 필요성을 제기했다는 측면에서 실무적인 의의도 존재한다.

• 한국콘텐츠학회논문지
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• 제19권5호
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• pp.48-63
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• 2019

본 연구는 한국기업정보(주)에서 제공받은 2015년도의 5만 여개의 최신 기업정보를 활용하여 전자업체를 중심으로 거래 네트워크를 생성하여, 사회네트워크 분석을 포함한 새로운 분석을 시도하였다. 그 결과 97개의 10개 이상 기업으로 이루어진 클러스터들이 발견되었고, 전자산업 매출의 90% 이상을 차지하는 13개의 클러스터들을 주목하게 되었다. 사회네트워크 분석에서의 클러스터들은 소속 기업들이 해당 클러스터 안에서 거래를 완결하는 특성을 가지고 있다. 13개 클러스터들을 보면, 매출액이 많은 상위 5개 클러스터에 전자매출의 83%가 집중되어 있으며, 일부 예외를 제외하고는 각각의 클러스터들은 특정업체가 매출의 대부분을 차지한다. 그렇지만 이들 이외에도 후방생산연관효과가 특별히 높은 업체들도 발견하였으며, 중소기업에 미치는 영향력이 특히 큰 전자 업체들도 눈에 뜨인다. 후방생산연관효과가 높은 업체들은 성장 정책적인 측면에서, 그리고 중소기업에 영향력을 많이 미치는 전자업체들은 중소기업 육성 정책적인 측면에서 중시되어야 할 것이다. 그리고 작은 클러스터들의 합인 마지막 기업군은 매출 대비 고용이 매우 높은 특성을 지닌다는 사실도 발견하였다. 이 기업군에 높은 생산연관효과를 보이는 기업군과 전자업체들이 발견되었으며, 이들은 고용정책적 측면에서 중시될 필요가 있다. 거래를 중계하는 네트워크 특성인 사이중심성이 매출과 비례하지 않게 특별히 높은 클러스터들도 발견하였다. 사이 중심성이 높은 이들 클러스터들은 기술 발전의 가능성이 큰 기업 그룹들이기에 주목할 필요가 있다.