• Journal of Astronomy and Space Sciences
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• 제35권1호
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• pp.31-37
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• 2018

Pc1 pulsations are geomagnetic fluctuations in the frequency range of 0.2 to 5 Hz. There have been several observations of Pc1 pulsations in low earth orbit by MAGSAT, DE-2, Viking, Freja, CHAMP, and SWARM satellites. However, there has been a clear limitation in resolving the spatial and temporal variations of the pulsation by using a single-point observation by a single satellite. To overcome such limitations of previous observations, a new space mission was recently initiated, using the concept of multi-satellites, named the Small scale magNetospheric and Ionospheric Plasma Experiments (SNIPE). The SNIPE mission consists of four nanosatellites (~10 kg), which will be launched into a polar orbit at an altitude of 600 km (TBD) in 2020. Four satellites will be deployed in orbit, and the distances between each satellite will be controlled from 10 to 1,000 km by a high-end formation-flying algorithm. One of the possible science targets of the SNIPE mission is observing electromagnetic ion cyclotron (EMIC) waves. In this paper, we report on examples of observations, showing the limitations of previous EMIC observations in low earth orbit, and suggest possibilities to overcome those limitations through a new mission.

• 대한공간정보학회지
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• 제2권1호
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• pp.141-153
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• 1994

본 연구는 지리정보체계를 이용하여 도시계획의 결정, 도시계획의 제한, 또는 도시계획의 사업을 수행하는 데 활용할 수 있는 지역환경 관리체계를 구축하는 데 일차적인 목적이 있으며, 구축된 정보를 이용하여 실제 성남시의 지역환경을 분석하고 문제점을 도출하였다. 또한 이와 같은 지역환경정보를 활용하여 주거환경분석 및 평가에 적용하기 위한 주거환경관리모형 개발시에 필요한 지표의 종류를 토지이용, 교통 및 환경의 상호관계를 고려하여 결정하고 관리모형에서 고려되어야 할 기법 등을 고찰하였다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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• pp.1324-1329
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• 2009

Needs for underground space development and utilization have been increasing in urban area. The conventional strutting method in excavation is effective to restrain the ground movements and displacements of earth structures but inefficient for workers because of small working space. The conventional earth reinforcement methods such as earth-anchor and soil-nailing also have limitation to apply in urban area due to threats to stability of adjacent buildings around excavation boundaries. Recently, many types of earth retaining structures are being developed to overcome disadvantages of conventional excavation methods in urban area. In this study, a series of numerical analyses were performed with MIDAS GTS, geotechnical analysis program and MIDAS Civil, structural analysis design program to evaluate behavior and stability of the new type of non-supporting earth retaining structure, called Temporary Tower System (TTS), consisting of tower truss structures with much economical and spatial advantage.

• 건축역사연구
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• 제24권1호
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• pp.7-16
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• 2015

The purpose of this study is to identify ways of remodeling from the traditional hanok to the modern local governmental facility in 1910s. Analysing architectural drawings in the National Archives of Korea, 58 hanok remodeling cases of 52 facilities were verified like the provincial office, county office, county court from 1907 to 1910s. Using hanok as the local governmental building, exterior walls were all changed to the scaled-wooden wall like one of western-wooden building in 1910s and the western-style entrance was set. Change of the plan caused by remodeling interior walls had an intention of the centralized closed plan. Remodeled semi-outer corridor using the space of the eave became changed to the inner corridor with expansion of space. Expansion of hanok for spatial demand was in three ways. First was the expansion towards the eave space, second was direct extension from hanok, and last was the use of external corridor to the new building. Using the eave space was simple but had limitation of space, it was planed with other expansion ways. The way of direct extension was usually used than the one with the corridor, because it was more economical way.

• 한국환경과학회지
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• 제1권1호
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• pp.19-33
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• 1992

The high oxidants, which occur the daily maximum concentrations in the afternoon, are transported into the other region via long range transport mechanisms or trapped within the shallow mixing boundary layer and then removed physically (deposition, transport by mountain wind, etc.) and chemically (reaction with local sources). Therefore, modeling formation of photochemical oxidants requires a complex description of both chemical and meteorolog ital processecs . In this study, as a part of air quality studies, we reviewed various aspects of photochemical modeling on the basis of currently available literature. The result of the review shows that the model is based on a set of coupled continuity equations describing advection, diffusion, transport, deposition, chemistry, emission. Also photochemical oxidant models require a large amount of input data concerned with all aspects of the ozone life cycle. First, emission inventories of hydrocarbon and nitrogen oxides, with appropriate spatial and temporal resolution. Second, chemical and photochemical data allowing the quantitative description of the formation of ozone and other photochemically-generated secondary pollutants. Third, dry deposition mechanisms particularly for ozone, PAN and hydrogen peroxide to account for their removal by absorption on the ground, crops, natural vegetation, man-made and water surfaces. Finally, meteorological data describing the transport of primary pollutants away from their sources and of secondary pollutants towards the sensitive receptors where environmental damage may occur. In order to improve our present study, shortcomings and limitation of existing models are pointed out and verification Process through observation is emphasized.

• KIEAE Journal
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• 제10권1호
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• pp.109-116
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• 2010

The city means not only a geographical area as a role of the spatial boundary, but also a socio-economic place to communicate with each area. It requires various functions to get the income and economic-activities. But city has a limitation of a available land to provide the required functions and a sufficient space to supply the urban activity. Therefore, the development trend of city has not been to spread to the horizontal area any more and considered the vertical area. In addition, various functions put into a massive building because many people want to solve the daily requirements without spending time and cost in outer area. In this paper, it aimed at classifying the mixed-use building into function, circulation, relation according to the public and private space and the building shape to provide the design information such as land area, functional complex, accessibility, etc.. The classification of the mixed-use buildings is divided into four areas. The data are collected with foreign countries in Japan, Europe and US. Results of the study are as follows; First, the commercial function is mainly centered with other functions. Second, after studied the development scale, accessibility, building form, the commercial and residential area overwhelmly share at the total area.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제50권6호
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• pp.281-287
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• 2001

In order to obtain guidelines for design and operation of a new plasma source by a magnetic neutral loop discharge(NLD), the electron behavior was studied experimentally and numerically. Experimentally, the magnetic field gradient was changed over a wide range, and it was found that there existed an optimum value for efficient plasma production. Analyses of the electron behavior were performed using a model that included effects of a three dimensional electromagnetic field configuration considering the spatial decay of the electric field, and the limitation to the motion of electron caused by the existence of walls and thus electron loss at wall surfaces. These three dimensional factors were found to explain the existence of the optimum magnetic field gradient. It was shown that the L dependence of the plasma production efficiency was firstly decided by the finite decay length of the electric field strength, which was further modified by electron elastic collisions with neutral atoms which drove the electron to walls. The latter effect tends to reduce the optimum value of L.

• Journal of Information Processing Systems
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• 제8권4호
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• pp.653-668
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• 2012

In this study, an improved HMM based recognition model is proposed for online English and Korean handwritten characters. The pattern elements of the handwriting model are sub character strokes and ligatures. To deal with the problem of handwriting style variations, a modified Hierarchical Clustering approach is introduced to partition different writing styles into several classes. For each of the English letters and each primitive grapheme in Korean characters, one HMM that models the temporal and spatial variability of the handwriting is constructed based on each class. Then the HMMs of Korean graphemes are concatenated to form the Korean character models. The recognition of handwritten characters is implemented by a modified level building algorithm, which incorporates the Korean character combination rules within the efficient network search procedure. Due to the limitation of the HMM based method, a post-processing procedure that takes the global and structural features into account is proposed. Experiments showed that the proposed recognition system achieved a high writer independent recognition rate on unconstrained samples of both English and Korean characters. The comparison with other schemes of HMM-based recognition was also performed to evaluate the system.

• Journal of Electrical Engineering and Technology
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• 제9권2호
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• pp.762-770
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• 2014

Tangible Space Initiative (TSI) is a new framework that can provide a more natural and intuitive Human Computer Interface for users. This is composed of three cooperative components: a Tangible Interface, Responsive Cyber Space, and Tangible Agent. In this paper we present a Tangible Tele-Meeting system in TSI, which allows people to communicate with each other without any spatial limitation. In addition, we introduce a method for registering a Tangible Avatar with a Tangible Agent. The suggested method is based on relative pose estimation between the user and the Tangible Agent. Experimental results show that the user can experience an interaction environment that is more natural and intelligent than that provided by conventional tele-meeting systems.

• Korean Journal of Geomatics
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• 제2권1호
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• pp.17-24
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• 2002

The Global Positioning System technology has been widely used in positioning and attitude determination. It is well known that the accuracy, availability and reliability of the positioning results are heavily dependent on the number and geometric distribution of tracked GPS satellites. Because of this limitation, in some situations, such as in urban canyons, underground or inside of buildings, it is difficult to navigate with GPS receiver. Therefore, in order to improve the performance of satellite-based positioning, the integration of GPS with the pseudolite technology has been proposed. With this pseudolite technology, it is expected that seamless positioning service can be provided in a wider area without replacing existing GPS receivers. On the other hand, to adopt pseudolites on a larger scale, it is necessary to verify how the pseudolites may complement the existing GPS-based positioning. In this paper the authors present the details of the experiments and the results of the fundamental verification for seamless positioning using integration of GPS and pseudolite. This paper shows that the accuracy and efficiency of integrating GPS and pseudolite through the dynamic and static positioning experiment. The influence of pseudolite signal on GPS receiver is also discussed. The experimental results indicate that the accuracy of the height component can indeed be significantly improved, to approximately the same level as the horizontal component.