• International Journal of Contents
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• v.16 no.4
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• pp.16-25
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• 2020

The size of observation data in astronomy has been increasing exponentially with the advents of wide-field optical telescopes. This means the needs of changes to the way used for large-scale astronomy data analysis. The complexity of analysis tools and the lack of extensibility of computing environments, however, lead to the difficulty and inefficiency of dealing with the huge observation data. To address this problem, this paper proposes a workflow execution system for analyzing large-scale astronomy data efficiently. The proposed system is composed of two parts: 1) a workflow execution manager and its RESTful endpoints that can automate and control data analysis tasks based on workflow templates and 2) an elastic resource manager as an underlying mechanism that can dynamically add/remove virtualized computing resources (i.e., virtual machines) according to the analysis requests. To realize our workflow execution system, we implement it on a testbed using OpenStack IaaS (Infrastructure as a Service) toolkit and HTCondor workload manager. We also exhaustively perform a broad range of experiments with different resource allocation patterns, system loads, etc. to show the effectiveness of the proposed system. The results show that the resource allocation mechanism works properly according to the number of queued and running tasks, resulting in improving resource utilization, and the workflow execution manager can handle more than 1,000 concurrent requests within a second with reasonable average response times. We finally describe a case study of data reduction system as an example application of our workflow execution system.

• Journal of Korean Society for Atmospheric Environment
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• v.26 no.2
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• pp.177-189
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• 2010

In order to incorporate correctly the large or local scale circulation in an atmospheric model, a nudging term is introduced into the equation of motion. The MM5 model was used to assess the meteorological values differences in each case, during ozone episode days in Gwangyang bay. The main objective of this study is to investigate the effect of horizontal and vertical flow fields according to the surface and vertical observation data assimilation by upper wind conditions. Therefore, we carried out several numerical experiments with various parameterization methods for nudging coefficient considering the upper wind conditions (synoptic or asynoptic condition). Nudging considering the synoptic and asynoptic nudging coefficient does have a clear advantage over dynamic initialization, therefore appropriate limitation of these nudging coefficient values on its upper wind conditions is necessary before making an assessment. Obviously, under the weak synoptic wind, there was apparent advantage associated with nudging coefficient by the regional difference. The accuracy for the prediction of the meteorological values has been improved by applying the appropriate PBL (Planetary Boundary Layer) limitation of circulation.

• Atmosphere
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• v.20 no.1
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• pp.13-26
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• 2010

The Urban Canopy Model (UCM) implemented in WRF model is applied to improve urban meteorological forecast for fine-scale (about 1-km horizontal grid spacing) simulations over the city of Seoul. The results of the surface air temperature and wind speed predicted by WRF-UCM model is compared with those of the standard WRF model. The 2-m air temperature and wind speed of the standard WRF are found to be lower than observation, while the nocturnal urban canopy temperature from the WRF-UCM is superior to the surface air temperature from the standard WRF. Although urban canopy temperature (TC) is found to be lower at industrial sites, TC in high-intensity residential areas compares better with surface observation than 2-m temperature. 10-m wind speed is overestimated in urban area, while urban canopy wind (UC) is weaker than observation by the drag effect of the building. The coupled WRF-UCM represents the increase of urban heat from urban effects such as anthropogenic heat and buildings, etc. The study indicates that the WRF-UCM contributes for the improvement of urban weather forecast such nocturnal heat island, especially when an accurate urban information dataset is provided.

• Bulletin of the Korean Space Science Society
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• 2008.10a
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• pp.31.1-31.1
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• 2008

While some observations in the geomagnetic tail region supported electrons could be accelerated by reconnection processes, we still need more observation data to confirm electron acceleration in this region. Because most acceleration processes accompany strong pitch angle diffusion, if the electrons were accelerated in this region, strong energetic electron precipitation should be observed near earth on aurora oval. Even though there are several low altitude satellites observing electron precipitation, intense and small scale precipitation events have not been identified successfully. In this presentation, we will show an observation of strong energetic electron precipitation that might be analyzed by relativistic electron acceleration in the confined region. This event was observed by low altitude Korean STSAT-1, where intense several hundred keV electron precipitation was seen simultaneously with 10 keV electrons during storm time. In addition, we observed large magnetic field fluctuations and an ionospheric plasma depletion with FUV aurora emissions. Our observation implies relativistic electrons can be generated in the small area where Fermi acceleration might work.

• Journal of Korean Association for Spatial Structures
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• v.6 no.2 s.20
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• pp.61-68
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• 2006

In this thesis, a full-scale K shape damper test model was constructed in which a passive vibration control system. This passive vibration control system was incorporated with the use of a newly developed turbulent flow damper sealed by viscoelastic material. A series of tests and earthquake observation has been conducted in this test model. The purpose of the present thesis is to investigate the vibration response characteristics of the building and to verify the effectiveness of the vibration control system. By the static loading test, it was recognized that incorporation of the dampers had little influence on static horizontal stiffness of the building. Free vibration tests revealed that the dampers incorporated increased the damping ratio of the building up to 3 times compared with the undamped case. The effectiveness of the developed vibration control system was confirmed based on the excitation tests and earthquake response observation.

• Journal of architectural history
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• v.23 no.2
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• pp.39-52
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• 2014

This study researched changes over time regarding the location and spatial characteristics of modern meteorological stations, and examined the characteristics of modern meteorological station construction using the location and spatial characteristics of the Busan Meteorological Station. First, meteorological stations were located in port areas, and then moved to high altitude areas for stable meteorological observation beginning in the transition phase. Here, office buildings and residences were joined, but were separated due to the increase in functions from the stabilization phase. Second, as for spatial composition, in the establishment phase, existing buildings were used, and the scale of newly constructed buildings differed according to time and area. However, after the Japan-Korea Annexation, with increased funds and increased observation equipment, floor plans subdivided by function started to appear. In the stabilization phase, space was subdivided with redundancy due to the increase in functions. In the wartime transition phase, '一' shaped floor plans with redundancy became the norm. Meanwhile, the location of the maritime customs where the first meteorological observations took place after the opening of the ports, and the location and construction of the Busan Temporary Observatory built in the meteorological observation transition phase (1905) were investigated. Also, through the investigation of the Busan Meteorological Observatory, newly constructed before 1934, the location and spatial characteristics of modern era meteorological observatories were studied.

• Current Industrial and Technological Trends in Aerospace
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• v.9 no.1
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• pp.45-54
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• 2011

Earth observation satellites data apply to various fields and global satellite imagery market continues to expand with increasing the scale according to the developed satellites. Sudden natural disasters frequently have occurred in Japan. ALOS satellite data support to repair the damaged area and mitigate the disasters in Japan as well as all around the world. In this paper, the status of remote sensing and data policy in Japan are described. In addition, satellite-based remote sensing technology effectively contribute to the public sector and related support to establish the infra system of satellite application promotion has been investigated.

• Journal of the Korean Institute of Landscape Architecture
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• v.25 no.1
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• pp.112-123
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• 1997

This study investigated the effect of high-rise buildings on the preference for rural landscapes. The study site was a Seoul suburban, Yong-in, which showed typical scenes of rural development. Slides used in the study were taken in Young-in along the national road 45(north-south) and national road 42(east-west). Forty slides reflecting typical characters of Young-in were selected. Among them, ten slides which were selected through factor analysis based on “ruralits”score were used as original slides. They represent ten landscape types. The simulation of original slides was based on the following aspects: a observation distance. number of buildings and landscape types. The preferences for the landscapes were tested by 200 respondents on 40 slides: Distance(2) ${\times}$ Landscape type(10) = 20 slides, Number of buildings(2) ${\times}$ Landscape type(10) = 20 slides. The following results are found: 1) When high-rise buildings are introduced into rural scenes, there are some vulnerable landscape types: the landscape with high “rurality”, the landscape with background skyline and the focal landscape. 2) The observation distance affects landscape preference. The hypothesis that the nearer the distance the lower the preferences, is accepted. However, there are some exceptions in 3 landscape types. 3) The hypothesis that the more the number of buildings, the lower the preferences, is rejected. The result is quite unexpected one. When a single building is introduced in natural scene, it draws more attention as a focal point than a group of buildings, and subsequently the visual impact is stronger.

• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.6
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• pp.13-23
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• 2022

The purpose of this study was to analyze the impact of greenhouse cultivation area and groundwater level changes due to the water curtain cultivation in the greenhouse complexes, which are mainly situated along rivers where water resources are easy to secure. The groundwater observation network in Miryang, Gyeongsangnam-do, located downstream of the Nakdong River, was selected for the study area. We classified the groundwater monitoring well into the greenhouse (riverside) and field cultivation areas (plain and mountain) to compare the groundwater impact of water curtain cultivation in the greenhouse complex. The characteristics of groundwater level changes classified by terrain type were analyzed using the observed data. Riverside wells have significant permeability coefficients and are close to rivers, so they are greatly affected by river flow and precipitation changes so that water level shows a specific pattern of annual changes. Most plain wells do not show a constant annual change, but observation wells near small rivers and small-scale greenhouse cultivation areas sometimes show annual and daily changes in which the water level drops during winter. Compared to other observation wells, mountain wells do not show significant yearly changes in water level and show general characteristics of bedrock aquifer well with a low permeability coefficient.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2006.04a
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• pp.133-138
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• 2006

Currently high resolution satellite imagery has been used in lots of fields of terrain analysis, ocean development, change detection, cartography, classification, environmental monitoring, earth resource observation, meteorological observation as well as military The accuracy of the 3-D modeling of SPOT-5 stereopair images using these ground control points is about 5m in planimetric distance error and about 2m in height error. This study demonstrates the available ground control points for North Korea, of which accuracy is as good as to generate the digital map at the scale of 1:25,000.