• Journal of Astronomy and Space Sciences
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• v.22 no.3
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• pp.273-282
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• 2005

A star sensor daytime observation model is developed in order to test the performance of the star sensor useful for daylight application. The centroid errors of the star sensor in the day time application are computed by using the model. The standard atmospheric model (LOWTRAN7) is utilized to calculate the physical quantities of the daylight atmospheric environments where the star sensor is immersed. This observation model takes the separation angles between the sun and star, the centroid algorithm and the various system specifications of the star sensor into the account. The developed star sensor model will provide more realistic measurement errors in estimating the performance of the attitude determination from the vector observations.

• Korea Real Estate Review
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• v.24 no.1
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• pp.7-14
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• 2014

This study, as the temporal and spatial data for the real price apartment in Seoul from January 2006 to June 2013, empirically compared and analyzed the estimation result of apartment price using OLS by hedonic price model for the problem of space-time correlation, temporal autoregressive model (TAR) considering temporal effect, spatial autoregressive model (SAR) spatial effect and spatiotemporal autoregressive model (STAR) spatiotemporal effect. As a result, the adjusted R-square of STAR model was increased by 10% compared that of OLS model while the root mean squares error (RMSE) was decreased by 18%. Considering temporal and spatial effect, it is observed that the estimation of apartment price is more correct than the existing model. As the result of analyzing STAR model, the apartment price is affected as follows; area for apartment(-), years of apartment(-), dummy of low-rise(-), individual heating (-), city gas(-), dummy of reconstruction(+), stairs(+), size of complex(+). The results of other analysis method were the same. When estimating the price of real estate using STAR model, the government officials can improve policy efficiency and make reasonable investment based on the objective information by grasping trend of real estate market accurately.

• Environmental and Resource Economics Review
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• v.17 no.1
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• pp.3-22
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• 2008

We study nonlinearities of $CO_2$ emissions and economic growth m Korea using the Smooth Transition Autoregressive (or STAR) model. We find evidence for nonlinearities and cyclical regime changes of both time series. In the extended nonlinear empirical work, we characterize dynamic properties of the two time series and then find mutually significant Granger causality between $CO_2$ emissions and economic growth. All these empirical evidences together reinforce long standing concern that economy-wide restrictions on $CO_2$ emissions would hurt economic growth for Korean styled medium industrialized countries.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.4
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• pp.213-218
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• 2010

In this study, a star screen model was constructed to predict the dynamic characteristics of interactive waste particles and to simulate separation capability of the particle using geared type screen(star screen). In order to approach this model, it is necessary to determine the design parameters of the screen such as driving torque, percentage of open space, and capability. Thus, a dynamic star screen model was developed with a total of 32 columns of geared assembly including screen part, wastes guide, and extra joints to rotate the screen using ADAMS. Each parameter was simulated to predict the screening capability for particle size, rotating speed, and particle condition. From the results, separation ability was predicted according to the affecting variables by using the dynamic star screen model.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.74.1-74.1
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• 2010

Using two-dimensional numerical hydrodynamic simulations, we investigate the regulation of star ormation rates in turbulent, multiphase, galactic gaseous disks. Our simulation domain is xisymmetric, and local in the radial direction and global in the vertical direction. Our models nclude galactic rotation, vertical stratification, self-gravity, heating and cooling, and thermal onduction. Turbulence in our models is driven by momentum feedback from supernova events ccurring in localized dense regions formed by thermal and gravitational instabilities. Self-onsistent radiative heating, representing enhanced/reduced FUV photons from the star formation, s also taken into account. Evolution of our model disks is highly dynamic, but reaches a quasi-teady state. The disks are overall in effective hydrostatic equilibrium with the midplane thermal ressure set by the vertical gravity. The star formation rate is found to be proportional pproximately linearly to the midplane thermal pressure. These results are in good agreement with the predictions of a recent theory by Ostriker, McKee, and Leroy (2010) for the thermal/dynamic equilibrium model of star formation regulation.

• Journal of Korea Multimedia Society
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• v.22 no.3
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• pp.395-402
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• 2019

Star characters play a key role in the background of contents that secure global competitiveness. In this study, we study the growth factors and transitional forms of Nintendo Super Mario Bros. and suggest the direction of nurturing Korean star characters. As a result of the analysis of Super Mario Bros., it was possible to derive the growth factors of Originality, repeatability, Continuity, Pertain, and Star Fame and the transition result of step development method. Robot Taekwon V was presented as a reference model while Korean game characters with global competitiveness were excavated. Robot Taekwon V, which combines the features of friendly, unique, symbolism, and narrative, could be used to present a development model of the type of jump development. In the jump development model, character development and Upbringing, diversification of genre, pioneering of new markets combined with new technology, and fostering of characters through linkage with other industries were presented.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.1
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• pp.52.3-53
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• 2021

It is yet to be understood what controls the star formation activity in high-redshift galaxy clusters. One recently proposed mechanism is that the star formation activity in galaxy clusters are fed by gas and galaxies in large-scale structures surrounding them, which we call as "web feeding model". Using galaxies in the COSMOS2015 catalog, with mass completeness at log(M/M_⦿)≥9.54 and reliable photometric redshift data (σ_Δz/(1+z) ≲ 0.01), we study the star formation activities of galaxy clusters and their surrounding environment to test the web feeding model. We first identify the overdense regions with number density exceeding the 4σ-level from photometric redshift data as galaxy clusters, and we find that they are well matched with clusters identified in the X-ray extended source catalog. Furthermore, we identify galaxy large scale structures, and will present the correlation or anti-correlation between quiescent galaxy fraction, an indicator of star-forming activity, and the prevalence of galaxy large scale structures.

• Journal of Distribution Science
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• v.20 no.4
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• pp.21-31
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• 2022

Purpose: The study focuses on the distribution of brand love on customers' behavioral intention at five-star hotels in Vietnam. Furthermore, the study also assesses the role of mediating variables and moderating variable involved in the research model. Research design, data and methodology This research surveys 458 customers using the services of five-star hotels in Vietnam through questionnaires on online platforms. Data cleaning and data analysis using SPSS 25.0 software combined with Smart-PLS 3.0 software were used in the research to evaluate the measurement model and structural model. Results: From the results of the structural model evaluation, it shows the positive distribution of brand love on customers' behavioral intentions towards five-star hotels in Vietnam. The mediating roles of brand engagement, brand equity, customer motivation, and the participation of the moderating variable, customer expectations, are determined by this research model. Conclusions: Based on the study results, the distribution of brand love positively affects customers' behavioral intention at five-star hotels in Vietnam, giving recommendations that have a positive impact on customer behavioral intention. In addition, the study shows the role of mediating variables as well as exploring the moderator's (customer expectations) in the distribution of relationships between customer motivation and customer behavioral intention.

• Knowledge Management Research
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• v.23 no.1
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• pp.187-201
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• 2022

Online reviews written by tourists provide important information for the management and operation of the tourism industry. The star rating of online reviews is a simple quantitative evaluation of a product or service, but it is difficult to reflect the sincere attitude of tourists. There is also an issue; the star rating and review content are not matched. In this study, a star rating prediction model based on online review content was proposed to solve the discrepancy problem. We compared the differences in star ratings and sentiment by continent through sentiment analysis on tourist attractions and hotels written by foreign tourists who visited Korea. Variables were selected through TF-IDF vectorization and sentiment analysis results. Logit, artificial neural network, and SVM(Support Vector Machine) were used for the classification model, and artificial neural network and SVR(Support Vector regression) were applied for the rating prediction model. The online review rating prediction model proposed in this study could solve inconsistency problems and also could be applied even if when there is no star rating.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.9
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• pp.89-96
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• 2005

This paper discusses the daytime atmospheric conditions and the possibility of daytime star detection with the purpose of practical use of the star sensor for daylight navigation. In order to estimate the daytime atmospheric data, we use the standard atmospheric model (LOWTRAN 7), from which atmospheric transmittance and radiance from background sky are calculated. Assuming the star sensor with an optical filter to reduce background radiation, different separation angles between the star sensor and the sun are set up to express the effect of the solar radiation. As considerations of field of view (FOV) of the star sensor, the variation of the sky background radiation and the star density of the detectable star are analyzed. In addition, the integration time to achieve a required signal-to-noise ratio and the number of the radiation-caused electrons of the charge coupled detector(CCD) working as the limit to daylight application of the star sensor are calculated.