• Journal of The Korean Astronomical Society
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• v.35 no.2
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• pp.87-95
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• 2002

We have conducted VI CCD photometry of the open cluster NGC 6819 in order to understand the effects of dynamical evolution in old open clusters. Our photometry covers 18' $\times$ 18' on the sky, centered on the cluster, which seems to cover the whole cluster field. Our photometry reaches down to V $\approx$ 20.5, which allows us to analyze the luminosity function and spatial distribution of stars brighter than Mv $\approx$ 8.5. There is a clear evidence for mass segregation in NGC 6819, i.e., the giants and upper main-sequence stars are concentrated in the inner regions, whereas the lower main-sequence stars distribute almost uniformly throughout the cluster. The luminosity function of the main-sequence stars of NGC 6819 is almost flat. The flat luminosity function indicates that a large number of low mass stars has escaped from the cluster unless its initial mass function is much different from the Salpeter type (${\phi}(m){\propto} m^{-(1+x)},x = 1.35$).

• Journal of the Korea Computer Industry Society
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• v.5 no.4
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• pp.461-470
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• 2004

This paper is to design the user interface of the groundwater well based on an object oriented. In order to implementation geographic data base of the an complex geo-object of the real world, this paper is the study of analysis pattern at the level By specifying the pattern appropriate to the application domain and designing the analysis pattern using the UML based on the object oriented methodology, this paper shall contribute to enhance the reuse of components that can develop and distribute a large scale open system.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1140-1142
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• 2003

Imagery and gridded data can be used as the sources of extracting important information and data layers in utilizing GIS. The existing metadata standard to distribute and to utilize the geographic information are mainly concentrated at the vector data and do not provide metadata components for imagery and gridded data. In this study, metadata components for imagery and gridded data have been investigated. Firstly, existing international metadata standards such as ISO and domestic standards of TTA have been analyzed. Based on th results, the draft metadata for imagery and gridded data have been proposed as the extensions of domestic metadata standard distribution. The draft metadata could contribute to build the basic standards to access and utilize proper imagery and gridded data fit to various application field, and this will be fundamental bases for activating GIS in public and private sectors.

• KIPS Transactions on Software and Data Engineering
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• v.3 no.10
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• pp.397-406
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• 2014

In order to answer the questions successfully on behalf of the human in DeepQA environments such as Jeopardy! of the American quiz show, the computer is required to have the capability of fast temporal and spatial reasoning on a large-scale commonsense knowledge base. In this paper, we present a scalable spatial reasoning algorithm for deriving efficiently new directional and topological relations using the MapReduce framework, one of well-known parallel distributed computing environments. The proposed reasoning algorithm assumes as input a large-scale spatial knowledge base including CSD-9 directional relations and RCC-8 topological relations. To infer new directional and topological relations from the given spatial knowledge base, it performs the cross-consistency checks as well as the path-consistency checks on the knowledge base. To maximize the parallelism of reasoning computations according to the principle of the MapReduce framework, we design the algorithm to partition effectively the large knowledge base into smaller ones and distribute them over multiple computing nodes at the map phase. And then, at the reduce phase, the algorithm infers the new knowledge from distributed spatial knowledge bases. Through experiments performed on the sample knowledge base with the MapReduce-based implementation of our algorithm, we proved the high performance of our large-scale spatial reasoner.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.119-124
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• 2010

The MAC layer in ad-hoc network which makes network of nodes without infrastructure for a time has became an issue to reduce delay, allocate fairly bandwidth, control TX/RX power and improve throughput. Specially, the problem to reduce power consumption in ad-hoc network is very important part as ad-hoc devices use the limited battery. For solution of the problem, many power control algorithms, such as distribute power control, PCM (Power Control MAC) and F-PCF (Fragmentation based PCM), are proposed to limit power consumption until now. Although the algorithms are designed to minimize power consumption, the latency communication zone is generated by power control of RX/TX nodes. However the algorithms don't suitably reuse the space. In this paper proposes the algorithm to improve data throughput through Spatial Reuse based on a power control method.

• Journal of Korea Spatial Information System Society
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• v.9 no.3
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• pp.35-50
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• 2007

In a data centric sensor network, a sensor node to store data is determined by the measured data value of each sensor node. Therefore, if the same data occur frequently, the energy of the sensor node to store the data is exhausted quickly due to the concentration of loads. And if the sensor network is extended, the communication cost for storing data and processing queries is increased, since the length of the routing path for them is usually in the distance. However, the existing researches that generally focus on the efficient management of data storing can not solve these problems efficiently. In this paper, we propose a NUNS(Non-Uniform Network Split) method that can distribute loads of sensor nodes and decrease the communication cost caused by the sensor network extension. By dividing the sensor network into non-uniform partitions that have the minimum difference in the number of sensor nodes and the splitted area size and storing the data which is occurred in a partition at the sensor nodes within the partition, the NUNS can distribute loads of sensor nodes and decrease the communication cost efficiently. In addition, by dividing each partition into non-uniform zones that have the minimum difference in the splitted area size as many as the number of the sensor nodes in the partition and allocating each of them as the processing area of each sensor node, the NUNS can protect a specific sensor node from the load concentration and decrease the unnecessary routing cost.

• Journal of the Korean Institute of Rural Architecture
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• v.5 no.1
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• pp.32-41
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• 2003

After the 1988 Seoul Olympics, a lot of Culture & Arts Centers have been built in Korea. There have been raised questions on the frequency of room use and the occupancy of seats, but there are not enough architectural data for the Culture & Arts Centers in Korea. This paper focuses on the investigation of the architectural features of the Culture & Art Centers, such as the spatial sizes, the composition ratio of the performing art hall area to the overall facility area, the sizes and proportions of seat zone to stage zone, the average area per one person at the seat zone, the wide and the height of the procenium, the height of fly loft, and the number of users per one program. We could find out some meaning results. The composition ratios of the performing art hall area to the overall area of the facilities distribute with a wide range. The floor areas of 1500 through 2000 seat performing art halls are larger than $13,000m^2$. The average area per one person for seat zone and stage zone is approximately $0.8m^2$. All facilities we investigated have the types of the procenium stage. Almost all of the facilities have high quality stage conditions and equipments, but few programs use the various stage equipments and all of the main, side, and rear stages. To resolve this problems, various programs have to be developed for encouraging more people to use the Culture & Art Centers.

• Journal of Korea Spatial Information System Society
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• v.11 no.4
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• pp.33-38
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• 2009

Since the beginning of 2000, the ubiquitous technology rapidly has been at center of public concerns, and application of the ubiquitous technology is expanding in Korea with U-City as the center. U-City is currently planned and built by local governments, but the applicable range of the ubiquitous technology should be expanded in the future to build U-Territory and U-Land projects. As a part of this, U-forest should also be implemented, and that now is the time to gain support in policy and systematic initiative. Therefore, this study defines U-Forest concept to implement valuable national resources, healthy land environment, and pleasant green space by using ubiquitous technology as an effective way to produce, manage, use, and distribute the forest. In order to establish strategy for U-Forest, it has considered basic forest plan, k-Forest, and FGIS projects, and has drawn a service model pertaining to them. Also, it has proposed the need to establish the basic plan for U-Forest, and suggested details to include in the plan.

• Journal of Korean Association for Spatial Structures
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• v.7 no.5
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• pp.39-48
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• 2007

Recently, the trend of construction has been concentrated on the development of structural systems improved economically. As a result, the usage of High Performance Steel which simplifies the girder structures and shortens the construction time is increasing. Also the interest in Longitudinally Profiled(LP) plate as a structural element for girders has been increased. The LP can distribute efficiently the sectional force applied to the structure, and also reduce the self-weight and the number of welding points. The LP plate was developed in Europe originally and its application has been increased rapidly on steel structures in Korea. Though it is used widely and internationally, the study for the LP plate application is rarely performed. In this paper, sectional stress and deflections were analyzed in the different section types by solid element in the finite element method; finally the workability, as well as economical efficiency of the LP plate produced in Korea was evaluated.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.4
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• pp.1-11
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• 2019

The purpose of this study is to determine urban walking tourists' spatiotemporal movement densities and the stopping characteristics by season. With the Bukchon Hanok Village in Seoul, as the study site, a GPS-based smartphone application collected spatiotemporal data, and GIS and statistical methods were used to analyze the urban walking tourists' spatiotemporal activities in the spring and summer. The results show that the moving and staying variables of urban walking tourists differ significantly by season. In addition, spatiotemporal movement densities and stopping characteristics using ArcGIS's tools show clear spatial and temporal concentrations along the main access roads and commercial areas of the study site in the spring and summer. Policy-makers and developers of urban walking tours should use these spatiotemporal concentrations of walking tourists to define policies that would control the capacities of urban walking areas and distribute tourists spatially and temporally.