• The Journal of the Korea Contents Association
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• v.12 no.7
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• pp.425-436
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• 2012

This research aims to investigate the life-style and types of leisure experienced among airline flight attendants during temporary stays abroad. In this study 2 hypotheses based on literature reviews were employed. Questionnaires were also developed based on data collected from previous studies. Subjects of the study were focused on flight attendants in Legacy Airlines. Factor analysis and reliability coefficients were used to examine the internal consistency among variables. Seven dimensions of leisure, which are cultural experience, pursuit of success, social orientation, humanity, pursuit of fashion, shopping preferences and health-orientation were identified from factor analysis. Three dimensions of leisure, which include type of rest, type of sports, and activity of tourists, were identified from factor analysis accordingly. Lifestyle factors were extracted from a result of cluster analysis, cluster 1- Passive lifestyle, Active lifestyle community type 2, and Cluster 3 analyzed Self-satisfied lifestyle types. Airline cabin crew workers involved in the life style analysis can make good use of leisure time.

• Journal of The Korean Astronomical Society
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• v.35 no.2
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• pp.87-95
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• 2002

We have conducted VI CCD photometry of the open cluster NGC 6819 in order to understand the effects of dynamical evolution in old open clusters. Our photometry covers 18' $\times$ 18' on the sky, centered on the cluster, which seems to cover the whole cluster field. Our photometry reaches down to V $\approx$ 20.5, which allows us to analyze the luminosity function and spatial distribution of stars brighter than Mv $\approx$ 8.5. There is a clear evidence for mass segregation in NGC 6819, i.e., the giants and upper main-sequence stars are concentrated in the inner regions, whereas the lower main-sequence stars distribute almost uniformly throughout the cluster. The luminosity function of the main-sequence stars of NGC 6819 is almost flat. The flat luminosity function indicates that a large number of low mass stars has escaped from the cluster unless its initial mass function is much different from the Salpeter type (${\phi}(m){\propto} m^{-(1+x)},x = 1.35$).

• The Bulletin of The Korean Astronomical Society
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• v.40 no.2
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• pp.49.3-50
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• 2015

Early-type dwarf galaxy (ETDG), the most abundant galaxy type in clusters, were recently shown to exhibit a wide variety in their properties. Particularly, the presence of blue cores in some ETDGs supports the scenario of late-type galaxy infall and subsequent transformation into red, quiescent ETDGs. While several transformation mechanisms for these ETDGs with blue core within cluster environment have been proposed, all these processes are able to explain only some of the observational properties of ETDGs such as stellar populations and structural parameters. In this context, internal kinematic properties of blue-cored ETDGs provide the most crucial evidence to discriminate different processes for the formation of these galaxies. We present a kinematic analysis of two blue-cored ETDGs in the Virgo cluster based on long-slit data obtained from Gemini Multi-Object Spectrographs (GMOS) observations. We find that the observed galaxies show kinematically decoupled sub-components in the velocity profile such as discontinuity or counter-rotating component. We discuss possible scenarios of formation of these transitional galaxies.

• The Journal of the Korea Contents Association
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• v.20 no.8
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• pp.637-644
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• 2020

VANET (Vehicular Ad Hoc Networks) is a network between vehicles and between vehicles and infrastructure. VANET-specific characteristics such as high mobility, movement limitation, and signal interference by obstacles make it difficult to provide stable VANET services. To solve this problem, this paper proposes a vehicle type-based priority clustering method that improves the existing bus-based clustering. The proposed algorithm constructs a cluster by evaluating the priority, link quality, and connectivity based on the vehicle type, expected communication lifetime, and link degree of neighbor nodes. It tries to simplify the process of selecting a cluster head and increase cluster coverage by utilizing a predetermined priority based on the type of vehicle. The proposed algorithm is expected to become the basis for activating various services by contributing to providing stable services in a connected car environment.

• Journal of the Korean Society of Safety
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• v.22 no.6
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• pp.81-86
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• 2007

The purpose of this study is to provide foot classification on 30 generation young men and women by factor analysis and cluster analysis. The sample for this work was chosen from data which were collected and measured by Size Korea during two years($2003{\sim}2004$). In order to analyze and compare features of the foot of men and women, analysis was performed about 871 subjects(male: 422, female: 449) on 24 body parts including height, width, thickness, circumference, length and angle. According to the result of factor analysis about measured data, there were seven factors and six factors for men and women respectively. After cluster analysis, data for men and women were commonly divided by three types for utilization of research results. Type 1 and type 3 had wide distribution about men. Type 2 had wide distribution about women. The results of this study can be applied in manufacturing and design of comfortable shoes and socks.

• Journal of the Korean Society of Clothing and Textiles
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• v.22 no.2
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• pp.203-214
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• 1998

The purpose of this study is to classify the upper body of women into several kinds of somatotypes, using the method of Surgical Tape and making their shells. The subjects are 53 females 30 to 39 years-old. Fifty-three anthropometric data are measured per shell of bodysurface; six somatotype factors are obtained through principal component analysis and orthogonal rotation by the method of Varimax, Somatotype of women's upper body is achieved by cluster analysis, using the standardized factor score as an independent variable and the FASTCLUS of SAS by Kmeans. The results are as follows: 1. The number of the factors which explain the somatotype is six and those factors comprise 76.12 percent of total variance. Factor 1: related to the size of shape in the front of upper body Factor S: related to the size of shape in the back of upper body Factor 3: related to the type of the upper chest over the chest circumference line Factor 4: related to the length of·the upper body Factor 5: related to the part of the neck Factor 6: related to the type of the lower chest under the chest circumference line 2. Cluster analysis results in classification of upper body into five clusters. Cluster L: the length is the largest and the circumference is small. The part of waist is the largest and widest among surface areas. Cluster 2: Slender body line from chest to waist is characteristic. The length is longer. The part of upper and lower chest is larger among surface areas. Cluster S: the circumference is the smallest and armhole is small. The length and surface area are small. Cluster 4: the circumference and armhole is the largest. The length is the smallest. Cluster 5: the circumference is average and the length is a little long. The body line(silhouette) from chest to waist is curved slightly.

• Journal of Environmental Science International
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• v.12 no.12
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• pp.1215-1225
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• 2003

The purpose of this research was to investigate the characteristics of urban ecotopes and to classify ecotopes systematically from them. Total of 15 characteristics for classification of ecotopes were selected, and there were categorized 3 factors, that is abiotic, biotic and anthropological factors. The ecotope types in the study area were classified into 67. The classification of ecotope was made with SPSS for Windows Version 10.0 on the basis of the 15 characteristics. As the results of cluster analysis using the average linkage method between groups, groups of ecotope type were divided into 15 clusters. It was known that there was not a great difference in an affinity as the result of overlapping the maps of ecotope type and land use type. This research suggested characteristics for classification of ecotopes, but there was a limit to Set the objective method for grade classification because of lacking in the basic data, the research of characteristics will be accomplished continuously.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.1
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• pp.51.4-52
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• 2017

We perform hydrodynamical simulations of a late-type galaxy experiencing frequent high-speed encounters with intruding galaxies, called "galaxy harassment". Specifically, we simulate a Milky Way-like galaxy colliding consecutively with six twice-massive early-type galaxies containing hot diffuse gas on their halos, with various impact parameters ranging from 65 kpc/h to 15 kpc/h at the relative speed of about 1500 km/s. We show that galaxy-galaxy encounters play a significant role in a cluster environment in gas stripping and star formation quenching through hydrodynamic interactions of late-type galaxies with cluster early-type galaxies.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.42.3-42.3
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• 2018

We investigate surface brightness profiles (SBPs) of dwarf galaxies in field, group, and cluster environments. Using images from the Korea Microlensing Telescope Network (KMTNet) Supernova Program (KSP) for the NGC 2784 group and SDSS for the Virgo cluster, SBP types are classified into profiles with single exponential (Type I), double exponential (Type II and Type III). Type II and Type III have smaller and larger outer sizes than inner sizes, respectively. SBP types of field dwarfs are compiled from a previous study. The distributions of SBP types are different in three environments. After comparing sizes of dwarfs in different environments, we suggest that since sizes of some dwarfs are changed due to the environmental effects, SBP types are able to be transformed. It makes that the distributions of SBP types in three environments are different.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.81-81
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• 2012

Since the ultraviolet (UV) flux of an integrated population is a good tracer of recent star formation activities, UV observations provide an important constraint on star formation history (SFH) in galaxies. We present UV color-magnitude relations (CMRs) of early-type dwarf galaxies in the Virgo cluster, based on Galaxy Evolution Explorer (GALEX) UV data and the Extended Virgo Cluster Catalog (EVCC, Kim, S. in prep.). The EVCC covers an area 5.4 times larger (750 deg2) than the footprint of the classical Virgo cluster catalog by Binggeli and collaborators. We secure 1304 galaxies as members of the Virgo cluster and 526 galaxies of them are new objects not contained in the VCC. Morphological classification of galaxies in the EVCC is based on the optical image ("Primary Classification") and spectral feature ("Secondary Classification") of the SDSS data. We find that dwarf lenticular galaxies (dS0s) show a surprisingly distinct and tight locus separated from that of ordinary dwarf elliptical galaxies (dEs), which is not clearly seen in previous CMRs. The dS0s in UV CMRs follow a steeper sequence than dEs and show bluer UV-optical color at a given magnitude. Most early type dwarf galaxies with blue UV colors (FUV-r < 6 and NUV-r < 4) are identified as those showing spectroscopic hints of recent or ongoing star formation activities. We explore the observed CMRs with population models of a luminosity-dependent delayed exponential star formation history. The observed CMR of dS0s is well matched with models with relatively long delayed star formation. Our results suggest that dS0s are most likely transitional objects at the stage of subsequent transformation of late-type progenitors to ordinary red dEs in the cluster environment. In any case, UV photometry provides a powerful tool to disentangle the diverse subpopulations of early-type dwarf galaxies and uncover their evolutionary histories.