• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.2
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• pp.75-83
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• 2005

NASA/DLR Gravity Recovery and Climate Experiment (GRACE) mission, which consists of two co-orbiting low altitude satellites, is to measure the Earth gravity field with unprecedented accuracy. Its key instruments include inter-satellite ranging systems and three-axis accelerometers. For the preliminary design and requirements analysis, extensive instrument simulation models are developed. These modeling techniques and orbit-gravity field estimation techniques are described.

• Journal of the Korean earth science society
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• v.34 no.6
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• pp.550-560
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• 2013

In this study, the variations of geoid measured by GRACE satellite are investigated in the 20 volcanic areas erupted since 2005, and it is recognized that a detailed geological study is necessary in using geoid data for a research of the magmatic activities under the volcano. Therefore, the relationship between the regional geoid variation obtained by GRACE satellite and the change of magma activity, is studied in Japan's Shinmoedake volcano in the Kirishima volcanic complex whose eruption in 2011 was studied in detail geologically. Throughout this study the increase of geoid from 2002 in the Shinmoedake volcanic area is confirmed to be caused by the increase of gravity under the volcano, which is well matched with geological interpretation of the continuous intrusion of basaltic magma into magma chamber during several years before the 2011 eruption. The result indicates that information of the geoid variation measured by GRACE satellite is useful for monitoring the possibility of volcanic eruption although there is a need to more study to be able to confirm the possibility.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.17 no.1
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• pp.52-57
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• 2009

One of the error sources for microwave ranging is the instability of the oscillator that drives the microwave signals. Dual one-way ranging (DOWR) minimizes the oscillator effect by combining two one-way carrier phase signals from two transmitter/receiver instrument. The DOWR is first implemented in the GRACE (Gravity Recovery and Climate Experiment) satellites. Direct evaluation of the DOWR is not possible due to its extremely high accuracy. The flight performance of the GRACE DOWR is analyzed by applying several indirect methods. Comparison with the design noise level is discussed.

• 발명특허
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• v.28 no.9 s.327
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• pp.64-69
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• 2003

• Journal of Korea Multimedia Society
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• v.8 no.4
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• pp.502-508
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• 2005

This paper proposes a dynamic hybrid patching technique that can improve the performance of VOD systems by adopting the advantages of both greedy patching and grace patching to use a VOD server's limited network-I/O bandwidth. The proposed technique uses grace patching to the requests for the videos, arrival intervals of which are smaller than the size of patching window, and uses greedy patching to the rest requests. In addition, proposed patching technique expands the latest particular patching multicast into a regular multicast for a new request. In result, the patching multicast data for the new request can be the data from the beginning to the skew point of the video and the holding time of a dispatched channel can exceedingly decrease. Simulation results confirm that the proposed technique is better than grace patching in terms of defection rate and average service latency.

• Journal of the Korean Society of Costume
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• v.23
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• pp.197-209
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• 1994

The purpose of this study is to present a way to analyze and review the subjective view of the aesthetic for dress based on the framework of the aesthetic categories suggested by aesthetics. In order to define objectivism and subjectivism of the aesthetic of dress, theoretical studies on the aesthetic categories of dress were precded. And empirical studies on the aethetic categories of dress for selected period, the Renaissance (16th century) and the Baroque(17 th century). The results were follows : The objectivism of the aesthetic is the point of that an object causes human to feel and judge aesthetically, that is that of dress means judge aesthetically, that is that of dress means formal characteristic of dress and pervasive ideology expressed in dress. the subjectivism of the aesthetic is the point that the aesthetic is ruted in human, that is that of dress has been studied in relation to the image, the aesthetic consciousness m, or the aesthetic categories of dress. Especially, the aesthetic category is one of the universal and valid methods for the analysis of subjectivism of the aesthetic for dress. This study includes beauty, grace, elegance , the sublime, the tragic , the comic, aptness, ugliness as aesthetic categories of dress . Beauty is perfection and rule. Grace pleases human by sense. Elegance comes from the harmony of sense and spirit. the sublime comes into existence that human feels pleasure as well as displeasure simultaneously when human is overehelmed by objects. The tragic is the sense of the present of something valuable even if there is suffering. The comic is the sense of the presence of something amusing even if there is displeasure caused by contradiction. Apteness means utility in terms of the objectivism and , formality in terms of the subejctivism. Ugliness is opposite to beauty. As the result of emperical studies, the aesthetic categories of the Renaissance dress showed harmonious, balanced, and symmetrical beauty, and the magnificent, and enlarged sublime. In addition to these , grace and elegance were also found to some extent. Aesthetic categories of the Baroque dress show feminie, soft, cheerful, and fantastic grace, asymmetric , disarmonious, and extraordinary uglinesss, and the magnificient , grave, and dignified sublime.

• Korean Journal of Remote Sensing
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• v.33 no.5_3
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• pp.855-866
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• 2017

Several research cases using remote sensing methods to analyze changes of storage and dynamics of groundwater aquifer were reviewed in this paper. The status of groundwater storage, in an area with regional scale, could be qualitatively inferred from geological feature, surface water altimetry and topography, distribution of vegetation, and difference between precipitation and evapotranspiration. These qualitative indicators could be measured by geological lineament analysis, airborne magnetic survey, DEM analysis, LAI and NDVI calculation, and surface energy balance modeling. It is certain that GRACE and InSAR have received remarkable attentions as direct utilization from satellite data for quantification of groundwater storage and dynamics. GRACE, composed of twin satellites having acceleration sensors, could detect global or regional microgravity changes and transform them into mass changes of water on surface and inside of the Earth. Numerous studies in terms of groundwater storage using GRACE sensor data were performed with several merits such that (1) there is no requirement of sensor data, (2) auxiliary data for quantification of groundwater can be entirely obtained from another satellite sensors, and (3) algorithms for processing measured data have continuously progressed from designated data management center. The limitations of GRACE for groundwater storage measurement could be defined as follows: (1) In an area with small scale, mass change quantification of groundwater might be inaccurate due to detection limit of the acceleration sensor, and (2) the results would be overestimated in case of combination between sensor and field survey data. InSAR can quantify the dynamic characteristics of aquifer by measuring vertical micro displacement, using linear proportional relation between groundwater head and vertical surface movement. However, InSAR data might now constrain their application to arid or semi-arid area whose land cover appear to be simple, and are hard to apply to the area with the anticipation of loss of coherence with surface. Development of GRACE and InSAR sensor data preprocessing algorithms optimized to topography, geology, and natural conditions of Korea should be prioritized to regionally quantify the mass change and dynamics of the groundwater resources of Korea.

• Journal of Positioning, Navigation, and Timing
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• v.1 no.1
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• pp.59-64
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• 2012

Precise Point Positioning (PPP) has been widely used in navigation and orbit determination applications as we can obtain precise Global Positioning System (GPS) satellite orbit and clock products. Kinematic PPP, which is based on the GPS measurements only from the spaceborne GPS receiver, has some advantages for a simple precise orbit determination (POD). In this study, we developed kinematic PPP technique to estimate the orbits of GRACE-A satellite. The comparison of the mean position between the JPL's orbit product and our results showed the orbit differences 0.18 cm, 0.54 cm, and 0.98 cm in the Radial, in Along-track, and Cross-track direction respectively. In addition, we obtained the root mean square (rms) values of 4.06 cm, 3.90 cm, and 3.23 cm in the satellite coordinate components relative to the known coordinates.

• The Research Journal of the Costume Culture
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• v.15 no.5
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• pp.863-874
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• 2007

The propose of the study was to evaluate impression effects and likeness of clothing styles and make-up types. The stimuli were composed of 4 clothing styles(base, natural, romantic, classic) and 4 make-up types(no make-up, natural, romantic, classic). The subjects were 512 male and female university students in Daejeon and Chungnam province. The study consisted of a survey and quasi- experiment. The experimental materials used for this study were 16 stimuli, 32 hi-polar adjectives, and likeness scale were composed of 7-point Likert type scales. As a result, the clothing styles and make-up types effected on the 4 impressional dimensions: grace, evaluation, salience, and dynamism. The clothing styles effected on grace, salience and dynamism dimension and the effect of dynamism dimension was the most powerful among the dimensions. The make-up types effected on all of the 4 impression dimensions and the effect of salience dimension was the most powerful among the dimensions. The interaction effects existed between the clothing styles and make-up types in salience dimension. The likeness showed significant difference only on the make-up types. The effect of grace dimension was the most powerful among the dimensions. The main reason that make-up effect appears greatly could be analyzed into that clothes color is controlled by white. The results suggest the necessity of succession study about the effect of clothes color.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.33 no.6
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• pp.497-506
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• 2015

Gravity variations due to the 2011 Tohoku (M9.0) earthquake, which occurred at the plate boundaries near the northeastern coast of Japan, were estimated through the GRACE spherical harmonic (Stokes) coefficients derived from the CSR. About -5 μGal gravity variation by the GRACE data was found in the back-arc basin area with respect to a reference gravity model. The mean gravity variations in the back-arc basin area and the Japan Trench area were -4.4 and -3.2 μGal in order. The small negative gravity variations around the Japan Trench area can be interpreted by both crustal dilatation and the seafloor topography change in comparison with the large negative gravity variations in the back-arc basin area by co-seismic crustal dilatation of the landward plate. From the results of the gravity variations, vertical displacements generated from relatively short wavelength caused by the earthquake were estimated by use of multi-beam bathymetric measurements obtained from JAMSTEC. The maximum seafloor topography changes of about ±50 m were found at west side of the Japan Trench axis by the earthquake. The seafloor topography change by the megathrust earthquake can be considered as the results of the landslide of the seafloor throughout the landward side.