• Advances in aircraft and spacecraft science
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• v.9 no.5
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• pp.449-462
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• 2022

Space-telescopes placed in the Sun-Earth second Lagrange point (L2) observe the sky following a scan strategy that is usually based on a spin-precession motion. Knowing which regions of the sky will be more observed by the instrument is important for the science operations and the instrument calibration. Computing sky observation parameters numerically (discretizing time and the sky) can consume large amounts of time and computational resources, especially when high resolution isrequired.This problem becomesmore critical if quantities are evaluated at detector level instead of considering the instrument entire Field of View (FoV). In previous studies, the authors have derived analytic solutions for quantities that characterize the observation of each point in the sky in terms of observation time according to the scan strategy parameters and the instrument FoV. Analytic solutions allow to obtain results faster than using numerical methods as well as capture detailed characteristics which can be overseen due to discretization limitations. The original approach is based on the analytic expression of the instrument trace over the sky. Such equations are implicit and thusrequiresthe use of numeric solversto compute the quantities.In this work, a new and simpler approach for computing one ofsuch quantities(mean observation time) is presented.The quantity is first computed for pure spin motion and then the effect of the spin axis precession is incorporated under the assumption that the precession motion is slow compared to the spin motion.In this sense, this new approach further simplifies the analytic approach, sparing the use of numeric solvers, which reduces the complexity of the implementation and the computing time.

• KOMUNHWA
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• no.70
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• pp.35-62
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• 2007

Songguk-ri site gained academic recognition by the excavation of stone coffin tomb with a bronze dagger in 1974. And it is confirmed that this site is epoch-making in Korean bronze age through the following excavation started in 1975. But the excavation reports published until now do not have even overall view of this site, thus it is difficult to get the whole picture of this site. Thus, in this paper the author reexamined all reports on this site and by making the map of overall view and distribution of archaeological features as a basic research. Moreover, I analyzed also artifacts from this site, and compared with the recent papers written by other researchers about the chronology and character. Songguk-ri site has livelihood domain which consists of dwelling pits, attached features, storage pits, pot-firing features, wood fence, abatises, buildings above ground, as well as cemetery which consists of stone-coffins, jar-coffins, pit tombs. Trace of making large terrace was also excavated. These features seem to belong to the same archaeological stage, dated about B.C.850-550, according to C14 dating. On the other hand, the intensification of wet-rice cultivation made this group more productive. Based on this financial strength, some influential group emerged they constructed defensive settlement to protect their products safely. Besides it seems that there were frequent occurrence of conflicts. However, we can know that they kept their stable life, through the expansion of living space. Consequently, Songguk-ri site played a role of the summit among some settlement in this area.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.28 no.1
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• pp.49-58
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• 2010

This study is attempted to establish the concept of Byeulseo Scenic Spot that the definitions of Byeulseo and Scenic Spot would be presented first followed by clarifying the basis, reason and justification that Byeulseo would be called as Byeulseo Scenic Spot that the following is the major results formulated herein. First, the concept of scenic spot under the Cultural Property Act is the reference to the famous site with the building improvement well known for its great scenery or the point where splendid scenery is viewed that has the artistic value along with the trace of human lives in this cultural heritage that, although the scenery is important but the attention has to be on discovery of historic resources with the story telling in the subject site. Second, the criteria of designation on the Scenic Spot in Korea would be natural scenery, animal and plant site with well-known scenery, view point of scenery, famous building or garden and important places with legend that there lacks diversification. In this aspect, the intent of the concept of Scenic Spot would be facilitated to expand the designation of the Byeulseo Scenic Spot as the Scenic Spot of living style. Third, from the foreign cases, particularly, in Japan, it is needed to note that Byeulseos and housing gardens are designated for 196 places of Scenic Spot, reaching 55.4% of entire Scenic Spots. Laws, regulations, systems and designated criteria on the cases of designating the foreign Scenic Spots would be studied and quoted. Fourth, the classification work for each type to designate as cultural heritage has to be continued as the Scenic Spot of subject site with even more emerged for the value as the Scenic Spot in garden, original site and the like classified as historic site, important folk data and the like. Fifth, the designation of Scenic Spot of Byeulseo garden with splendid scenery as the living Scenic Spot has to be expanded. The pavilion existed now nationwide would be approximately 1,500, and these pavilions are the place where the scholars stay in the famous site, and this is the central space of Byeulseo to study, and if there is clear one that has written and record of deed to create the stories to people with the value for publicity campaign, it would be the subject of Scenic Spot. And sixth, for the case of view point with splendid scenery in Byeulseo Garden, it cannot be the subject of designation that the designation of Scenic Spot has to be expanded. In the event of the Byeulseo garden in Korea, there are many cases of having outstanding view points, and there is a few case of designating the subject site with great view point as a Scenic Spot.

• Korean Journal of Mineralogy and Petrology
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• v.34 no.3
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• pp.157-167
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• 2021

Lead (Pb) is one of the key trace elements, exhibiting a peculiar partitioning behavior into silicate melts in contact with minerals. Partitioning behaviors of Pb between silicate mineral and melt have been known to depend on melt composition and thus, the atomic structures of corresponding silicate liquids. Despite the importance, detailed structural studies of Pb-bearing silicate melts are still lacking due to experimental difficulties. Here, we explored the effect of lead content on the atomic structures, particularly the evolution of silicate networks in Pb-bearing sodium metasilicate ([(PbO)_x(Na₂O)_1-x]·SiO₂) glasses as a model system for trace metal bearing natural silicate melts, using ²⁹Si solid-state nuclear magnetic resonance (NMR) spectroscopy. As the PbO content increases, the ²⁹Si peak widths increase, and the maximum peak positions shift from -76.2, -77.8, -80.3, -81.5, -84.6, to -87.7 ppm with increasing PbO contents of 0, 0.25, 0.5, 0.67, 0.86, and 1, respectively. The ²⁹Si MAS NMR spectra for the glasses were simulated with Gaussian functions for Qⁿ species (SiO₄ tetrahedra with n BOs) for providing quantitative resolution. The simulation results reveal the evolution of each Qⁿ species with varying PbO content. Na-endmember Na₂SiO₃ glass consists of predominant Q² species together with equal proportions of Q¹ and Q³. As Pb replaces Na, the fraction of Q² species tends to decrease, while those for Q¹ and Q³ species increase indicating an increase in disproportionation among Qⁿ species. Simulation results on the ²⁹Si NMR spectrum showed increases in structural disorder and chemical disorder as evidenced by an increase in disproportionation factor with an increase in average cation field strengths of the network modifying cations. Changes in the topological and configurational disorder of the model silicate melt by Pb imply an intrinsic origin of macroscopic properties such as element partitioning behavior.

• Korean Journal of Environmental Agriculture
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• v.16 no.2
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• pp.199-205
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• 1997

Water quality of streams and ground water from areas of different agricultural practices in the small catchments of the Han River basin was investigated. Water samples were collected from upper, middle and lower reaches of the Han River Basin where three types of agricultural management have been practiced : (1) highland agriculture and livestocks in Daegwanryung area, (2) typical upland and paddy farmings in Dunnae (Jucheon River) and Chuncheon (Soyang River) areas, and (3) intensive farming in the plastic film house in Guri area (Wangsuk stream). Water quality was monitored for EC, pH, COD, TSS, N, rations and anions. Concentrations of N, especially nitrate, and phosphorus in both stream and ground water exceeded the standard water quality criteria in many cases, but those of heavy metals were non-detectable or trace in most cases, except for Wangsuk stream where a high level was detected in a specific sampling time. Chemical criteria such as pH, EC and COD of the stream were suitable for irrigation purpose, but nitrate concentrations in ground water used in the intensive plastic film house were high enough to require a special management consideration. A model on the irrigation water quality incorporating EC and nitrate concentrations was suggested in view of fertilizer management and environmental quality.

• The KIPS Transactions:PartA
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• v.16A no.6
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• pp.419-426
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• 2009

To realistically simulate fluid, the Navier-Stokes equations are generally used. Solving these Navier-Stokes equations on the Eulerian framework, the non-linear advection terms invoke heavy computation and thus Semi-Lagrangian methods are used as an approximated way of solving them. In the Semi-Lagrangian methods, the locations of advection sources are traced and the physical values at the traced locations are interpolated. In the case of Stam's method, there are relatively many chances of numerical losses, and thus there have been efforts to correct these numerical errors. In most cases, they have focused on the numerical interpolation processes, even simultaneously using particle-based methods. In this paper, we propose a new approach to reduce the numerical losses, through improving the tracing method during the advection calculations, without any modifications on the Eulerian framework itself. In our method, we trace the grids with the velocities which will let themselves to be moved to the current target position, differently from the previous approaches, where velocities of the current target positions are used. From the intuitive point of view, we adopted the simple physical observation: the physical quantities at a specific position will be moved to the new location due to the current velocity. Our method shows reasonable reduction on the numerical losses during the smoke simulations, finally to achieve real-time processing even with enhanced realities.

• Journal of Korean Society for Geospatial Information Science
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• v.20 no.2
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• pp.63-71
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• 2012

Recently, web portals have been offering georeferenced SLI(Street-Level Imagery) services, such as Google Streetview. The SLI has a distinctive strength over aerial images or vector maps because it gives us the same view as we see the real world on the street. Based on the characteristic, applicability of the SLI can be increased substantially through conflation with other spatial datasets. However, spatial inconsistency between different datasets is the main reason to decrease the quality of conflation when conflating them. Therefore, this research aims to remove the spatial inconsistency to conflate an SLI with a widely used 2D vector map. The removal of the spatial inconsistency is conducted through three sub-processes of (1) road intersection matching between the SLI trace and the road layer of the vector map for detecting CPPs(Control Point Pairs), (2) inaccurate CPPs filtering by analyzing the trend of the CPPs, and (3) local alignment using accurate CPPs. In addition, we propose an evaluation method suitable for conflation result including an SLI, and verify the effect of the removal of the spatial inconsistency.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.9
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• pp.1719-1729
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• 1994

In this paper, an adaptive CAC(Connection Admission Control) method is proposed. The adaptive CAC uses traffic estimates derived from both traffic parameter specified by user and cell flow measurements. Traffic estimation using user-specified parameters is performed at every moment of connection request or connection release by recursive formula which makes real-time calculation possible. Traffic estimation using cell flow measurement is carried out when the number of connected calls does not change during a measurement reflection period-renewal period. The most import ant thing for the traffic estimation using cell flow measurement is the determination of the length of a renewal period to trace a real traffic flow with an allowable time lag and the measurement reflection ratio(MRR) both to reduce the portion of overestimation and to avoid underestimation of real traffic flow. To solve these problems, the adaptive CAC updates renewal period and MRR adaptively according to the number of connections and the elapsed time after last connection or release respectively. Performance analysis for the proposed method is evaluated in several aspects for the cases of both homogeneous and heterogeneous bursty traffic. Numerical examples show the adaptive CAC method has the better performance compared with conventional CAC method based on burst model from the both utilization and QOS point of view.

• Cartoon and Animation Studies
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• s.43
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• pp.123-150
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• 2016

There has been discussed very little about animation authorship studies, especially the themes of authors and their original animation texts since 1990s. This study is to explore the academic discourse of animation authorship studies understanding the media aesthetics of animation and the scholarly approach of animation studies about authorship. This article examines 55 articles via meta analysis about animation authorship studies drawn from the 1,516 articles on the general animation studies. The results were as follows. First, the domestic animation studies on the authorship were made about animators of Japan, US, and european countries. Second, It was dominant that scholarly interest on the screen direction and visual expression of animation texts. This shows the authorship approaches were mainly about visual aspects of animations. The domestic animation authorship studies did not trace the authorship issues on author's world view and visual style revealed in the corpus of texts. Instead, they discussed authorship issues on the characteristics of individual animation text. It has been evident that animation studies were not enthusiastic about building the independent theory on animation. Therefore, animation studies have tried theorizing the animation issues borrowing the literature and film theories. This study can contribute to increase phase of animation studies by drawing the intensive discussion of animation authors and their authorship.

• The Korean Journal of Archival Studies
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• no.65
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• pp.227-251
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• 2020

The documentation of a city can never be complete with only the documentation of the administrative domain, and requires that of its citizens, who are living in the city in different ways. This study attempts to present the documentation of the memories of the citizens, which either have never been produced or have been damaged and thus are difficult to be collected. From the Archival Activist point of view, this study suggests documentary as its research method, in order to leave trace of various experiences of Seoul, which are not recorded in document but are rooted in its people's memories and their daily lives. Documentaries are characterized by their narrative. This can be somewhat arbitrary, but it is due to their narrative that this study suggests documentaries, rather than oral statements, as a new form of method. While, due to its self-historicality, oral records are subject to producing redundant or irrelevant memories, documentaries enable the documentation of data relevant to the topic of collection. First, the study presents the narrative-based archiving, which is the same method of collection suggested by Seoul Metropolitan Archives, and then explores the role and significance of documentary archiving. It further presents the conditions in which documentary archiving is required in the context of narrative-based collection. The study presents the planning and implementation of documentary archiving and introduces one of the three documentaries produced by 2019 Seoul Archiving Project.