• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.61.2-61.2
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• 2014

We present a set of fiducial sequences of horizontal-branch stars in bright Galactic globular clusters, which have previously been observed in the Sloan Digital Sky Survey (SDSS). We derive fiducial lines on color-magnitude diagrams in multiple color indices (g - r, g - i, g - z, and u - g), after rejecting foreground and background objects as well as RR Lyrae variables utilizing these color indices. We compare our fiducial sequences with model predictions from Yonsei-Yale evolutionary tracks and BaSel spectral libraries, and find a satisfactory agreement between them in terms of their color-magnitude relations, except in u - g. We also compare theoretical models to color-magnitude diagrams of two open clusters (M67 and NGC 6791). Based on our best available cluster distance and reddening, we find that the mass of red clump (RC) stars in NGC 6791 is about a factor of two smaller than an earlier estimate from the application of asteroseismic scaling relations for solar-like oscillations. The smaller RC mass implies an enhanced mass loss along the red giant branch, which is in accordance with other compelling evidences found in this metal-rich system. Our estimated luminosity of RC stars in NGC 6791 is about 0.2 mag fainter than in earlier investigations based on solar-metallicity calibrations, and results in ~10% reduction in the RC-based distance estimation, when applied to metal-rich systems such as in the Galactic bulge.

• Journal of Digital Contents Society
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• v.16 no.1
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• pp.33-41
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• 2015

Since bitmap indices are useful for OLAP queries over low-cardinality data columns, they are frequently used in data warehouses. In many data warehouse applications, the domain of a column tends to be hierarchical, such as categorical data and geographical data. When the domain of a column is hierarchical, hierarchical bitmap index is able to significantly improve the performance of queries with conditions on that column. This strategy, however, has a limitation in that when a large scale hierarchy is used, building a bimamp for each distinct node leads to a large space overhead. Thus, in this paper, we introduce the way to build hierarchical bitmap index on an attribute whose domain is organized into a large-scale hierarchy in space-constrained environments. Especially, in order to figure out space overhead of hierarchical bitmap indices, we propose the cut-selection strategy which divides the entire hierarchy into two exclusive regions.

• Journal of Digital Convergence
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• v.13 no.5
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• pp.329-336
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• 2015

The purpose of this study was to develop and manage fitness management class by experimenting effects of fitness management class on obese indices, metabolic syndrome risk factors and health and skill-related fitness in university students. Progress of fitness management class by exercise prescription program according to level of students health and fitness. Comparison of obesity indices, metabolic syndrome risk factors and health and skill-related fitness between fitness management class group and control(physical education class) group in before- and after-16week exercise prescription program. Decision of class contents and establishment of fitness management class. The effects of fitness management class appeared to higher than control group on obese indices, metabolic syndrome risk factors and health and skill-related fitness. In conclusions, we suggest that fitness management class for wellness convergence is effective for health promotion of students.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.375-381
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• 2022

Safety accidents are of concern during construction projects, even given the recent innovations in digital technologies. These projects remain focused on overcoming specific and limited applications on construction sites. For this reason, the development of an inclusive safety management system has become crucial. This study aims to build a Big Data platform to inform decisions on how to proactively eliminate worker hazards on construction sites. The platform consists of about 100,000 real records and a real-time monitored database featuring various safety indices, such as workers' altitudes, heart rates, and fatigability during construction, which are determined through various wearable devices. The data types are customized and integrated by a research team in accordance with the characteristics of a specific project using hypertext transfer protocol (HTTP). The results can be helpful as efficient tools to ensure successful safety management in complex construction situations. This study is expected to provide three significant contributions to the field, including real-time fatigability analysis and tracking of workers on-site; providing early GPS-based warnings to workers who might be accessing dangerous spaces or places; and monitoring the workers' health indices, based on details from 100,000 cases.

• Proceedings of the Korea Contents Association Conference
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• 2006.05a
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• pp.43-46
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• 2006

This study examined the stock return co-movement among Korean digital contents industry, American NASDAQ, and Japanese NIKKEI225. This is to identify the reaction of Korean digital contents industry on the movement of foreign stock market. To investigate the co-movements, during the period of 1999 to 2005, daily logarithm difference returns of each stock market indices are tested by the methodology of Granger(1963, 1969)'s causality test. The positive influence from NASDAQ index to Korean digital contents industry index are found, but not vice versa. It means that the market value of firms in Korean digital contents industry affected by the movement of American NASDAQ market which composite with digital IT firms. However, the co-movements with NIKKEI225 did not found.

• Journal of Environmental Impact Assessment
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• v.9 no.4
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• pp.349-362
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• 2000

In the study, the feasibility of landscape ecological measures as indices system for interpretation and evaluation of regional ecosystem was investigated through the application to Yongin City. Each patch metrics well showed the class structure and supplemented the class metrics, and class metrics also showed well the landscape structure and supplemented the landscape metrics. And the change analysis through subtraction of two set of landscape ecological measurement in two point of time showed the dynamic trends very well. One of the dynamic trends in Yongin City was the rapid fragmentation. While there was no landcover data on Yongin City, using Landsat data and remote sensing techniques were proved to be efficient and effective to produce the digital landcover data.

• Structural Monitoring and Maintenance
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• v.9 no.4
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• pp.373-388
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• 2022

A USW based diagnostic procedure is presented for estimating the depth of surface-breaking cracks. The diagnosis is demonstrated on seven lab-scale SFRC beam specimens, which are subjected to the CMOD controlled three-point bending test to create real bending cracks. Then, the recorded multiple ultrasonic signals are examined with the signal processing techniques, including wavelet transform and two-dimensional Fourier transform, to investigate the relationships between the crack depth and two diagnostic indices, namely the attenuation coefficient and dispersion index (DI). Finally, the reliabilities of these indices for depth estimation are verified with the visually measured crack depths as well as the crack features obtained with a digital image processing algorithm. It is found that the DI outperforms the attenuation coefficient in depth estimation, where this index displays good agreement with the visual inspection for 86% of the inspected specimens.

• Smart Structures and Systems
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• v.24 no.5
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• pp.597-606
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• 2019

Damage detection based on dynamic characteristics of a structure is one of important roles in structural damage identification. It is difficult to detect local structural damage using traditional dynamic experimental methods due to a limited number of sensors used in an experiment. In this work, a non-contact test stand of fan blades is established, and a full-field noncontact test method, combined with three-dimensional digital image correlation, Bayesian operational modal analysis, and damage indices, is used to detect local damage of a fan blade under ambient excitation without use of baseline information before structural damage. The methodology is applied to detect invisible local damage on the fan blade. Such a method has a seemingly high potential as an alternative to detect local damage of blades with complex high-precision surfaces under extreme working conditions because it is a noncontact test method and can be used under ambient excitation without human participation.

• 전기의세계
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• v.25 no.6
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• pp.89-96
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• 1976

In this paper we deal with that the performance indices by the three adaptive sampling control laws are computed and compared. It shows that the most effective control law is the integral input difference method. The techniques of simulation by Analog/Hybrid computer are presented and the results of the output illustrate that the maximum and minimum sampling interval can be applied to the time sharing of digital controller or computer.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.147.1-147.1
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• 2012

We present empirical fiducial sequences for horizontal-branch (HB) stars in a set of bright Galactic globular clusters previously observed in SDSS (An et al. 2008). Mean loci of HB stars are derived on color-magnitude diagrams with multiple color indices (u - g, g - r, g - i, and g - z ) in order to identify foreground/background objects as well as cluster RR Lyrae variables. We compare our fiducial sequences to the model predictions from Yonsei-Yale isochrones and test the accuracy of the stellar evolution models.