• The Bulletin of The Korean Astronomical Society
• /
• v.39 no.1
• /
• pp.70.2-70.2
• /
• 2014

We developed a three-dimensional (3D) magnetohydrodynamic (MHD) simulation code to reproduce the structure of a solar wind and the propagation of a coronal mass ejection (CME) through it. This code is constructed by a finite volume method based on a total variation diminishing (TVD) scheme using an unstructured grid system (Tanaka 1994). The grid system can avoid the singularity arising in the spherical coordinate system. In this study, we made an improvement of the code focused on the propagation of a CME through a solar wind, which extends a previous work done by Nakamizo et al. (2009). We first reconstructed a solar wind in a steady state from physical values obtained at 50 solar radii away from the Sun via an MHD tomography applied to interplanetary scintillation (IPS) data (Hayashi et al. 2003). We selected CR2057 and inserted a spheromak-type CME (Kataoka et al. 2009) into a reconstructed solar wind. As a result, we found that our simulation well captures the velocity, temperature and density profiles of an observed solar wind. Furthermore, we successfully reproduce the general characteristics of an interplanetary coronal mass ejection (ICME) obtained by the Helios 1/2 spacecraft (R. J. FORSYTH et al. 2006).

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.37 no.1
• /
• pp.143-151
• /
• 2017

Recently Korea has presented carbon emission reduce goal of 37% compare to BAU until 2030 according to Paris Agreement in order to correspond to climate change. For this, researchers need to study positively on construction industry that emit $CO_2$ of $3^{rd}$ volume of 28 industry classification. This study calculated environmental load by LCA using the road part except tunnel and bridge among national road cases completed already. After selecting representative type of large construction type based on environmental emission, earth works, drainage works and paving works took up 84%. And this study analyzed the environmental emission feature of each detail construction type after selecting representative type each detail construction type. Utilization of each construction type emission attribute to environmental load during national road construction, will be helpful in making decision of eco-friendly national road construction based on environmental emission.

• 한국지구물리탐사학회:학술대회논문집
• /
• 2001.09a
• /
• pp.104-121
• /
• 2001

Recently, the pollution of soil and groundwater becomes a serious social problem, and geophysical exploration methods have been introduced as a remedial investigation method of subsurface. Digital technologies such as personal computer have revolutionized our ability to acquire large volume of data in a short term, and to produce more reliable results for subsurface image. Also, color graphics easily visualizes the survey results in a more understandable manner, and it is widely used for not only characterizing the contaminated subsurface but also monitoring contaminant and remedial process. In this paper, electrical resistivity and electromagnetic (EM) surveys were carried out in order to understand characteristics of waste landfills, and the applicability of geophysical prospecting to site assessment of waste landfill was also tested. According to the result, electrical resistivity and electromagnetic (EM) surveys were effective in estimating distribution of the leachate plume.

• The Journal of the Petrological Society of Korea
• /
• v.18 no.3
• /
• pp.181-194
• /
• 2009

The Cheongryangsan Formation was reported to stratigraphically overlie the Gasongdong Formation and underlie the Dogyedong Formation in the northern part of the Yeongyang subbasin, and be divided into the lower Cheongryangsan Member and the Osipbong Member. But the members have more widely called as the Cheongryangsan Conglomerate and the Osipbong Basalt, because the latter have initially meant that thin basalt flows several times intercalate sedimentary rocks in the northern part but later must consider that they have a very dominant volume in the eastern one. Both formations are based on classifying the stratigraphy and play a role of an excellent key bed for stratigraphic correlation between local spaces in the subbasin dominant absolutely for reddish beds. Both formations play a role of excellent key bed in the northern and northwestern areas of the subbasin; the Osipbong Basalt, the midwestern, eastern and southern ones; the Cheongryangsan Conglomerate, the southeastern one.

• The Journal of the Petrological Society of Korea
• /
• v.6 no.1
• /
• pp.52-64
• /
• 1997

Pelitic rocks of southwestern Nova Scotia have been affected by widespread contact metamorphism due to the intrusion of the Shellburne Pluton, with aureole up to 15 km wide. Well-preserved pseudomorphic textures indicate that common staurolite and andalusite metacrysts formed at the expense only of plagioclase, muscovite and biotite. Excess components (K, Na and Ca) from such replacement reactions imply extensive metasomatism throughout the contact aureole. Modal analysis of a typical andalusite-bearing rock indicates a one-to-one volume ratio of product to reactant. However the products of the replacement reactions contain approximately three times more aluminum than the reactants, indicating that the regional metasomatism also involved aluminum.

• Journal of the Korean Geophysical Society
• /
• v.4 no.3
• /
• pp.197-203
• /
• 2001

The vertical distribution of pore water pressure in the highly saturated sand layer under the oscillating water pressure (water wave) us studied theoretically and experimentally. By the experiments it is shown that the water pressure acting on the sand surface propagates into the sand layer with the damping in amplitude and the lag in phase, and that the liquefaction, the state that the effective stress become zero, occurs under certain conditions. These experimental results are explained fairly well by the same theoretical tearment as for ground water problems in the elastic aquifer. The main characteristics of liquefaction clarified by the analysis are as follows: 1) The depth of the liquified layer increases with the increase of the amplitude and the frequency of the oscillating water pressure. 2) The increase of the volume of the air in the layer increases the liquified depth. Especially the very small amount of the air affects the liquefaction significantly. 3) The liquefied depth decrese rapidly with the increase of the compressibility coefficient of the sand. 4) In the range beyond a certain value of the permeability coefficient the liquified depth decrease with the increase of the coefficient.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.21 no.4
• /
• pp.293-299
• /
• 2003

In the future, the design of road should be convenient in using of high-technology information and it needs the design of alignment that is able to make the maximum vehicles inducement function appropriated for CNS(Car Navigation System). So it needs to analysis appropriately the alignment of road for the improvement design of road which is established and to make the design of road and the coordinate of the main points. Therefore, this research had acquired the road data by RTK-GPS to accurate the analysis of road alignment and compared with Total Station. As the result, we could acquire the design source of the road alignment using RTK-GPS. Also, it was estimated the accuracy after comparing the design with RTK-GPS coordinates. We made an analysis of the degree of slant or the ups and downs of surface. We made an analysis of three dimensional visual information which was included in GSIS concept and estimated the accuracy. Finally, we analyzed the earth volume calculation by comparing with Total Station.

• Journal of Korean Society of Environmental Engineers
• /
• v.31 no.1
• /
• pp.64-69
• /
• 2009

Musty and earth odors caused by geosmin and 2-MIB are the major complaints from the drinking water consumers. Therefore, early detection of geosmin and 2-MIB is the key to prevent off-flavor occurrence. In this study, a rapid method using stir bar sorptive extraction (SBSE) in combination with the GC/MS was investigated to analyze geosmin and 2-MIB in water. The SBSE method, a solventless extraction technique, was optimized and then applied to the analysis of geosmin and 2-MIB in water. The SBSE technique was found to be a simple and fast procedure that allows many samples to be extracted simultaneously using very small volume (10~20 mL). In addition, the SBSE method offered high recovery and good linear regression coefficient for the geosmin and 2-MIB. The good repeatability of this method can be deduced from the low RSD (7.2~7.6%) at 10 ng/L for geosmin and 2-MIB. The limit of detection was determined 1~2 ng/L and the limit of quantitation was 3~6 ng/L. Above all, the SBSE method proved to be a very practical technique for the analysis of geosmin and 2-MIB in water.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.23 no.2
• /
• pp.117-128
• /
• 2005

This study presented the route location method by applying AHP and evaluating quantitatively. This study developed the program that can be easily applied to this kind of road design, and built the decision support system fur route location. The study results are summarized as follows : We could quantitatively evaluate the appropriateness of exiting routes by applying the AHP based on GIS. If we apply this to the roads that will be newly constructed, we can make the objective and reliable route location when making road plans and basic designs. We improved the technique of route location by applying the decision support system with third-dimensional data, which considers even the vertical alignment plan, to the existing decision support system with second-dimensional data. had, since we call set those data such as vertical slope, earth-volume, structure size, location and construction cost to independent variables, we can make road designs more scientifically and reasonably.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2008.03a
• /
• pp.330-339
• /
• 2008

Ground-based interceptors(GBI) comprise a major element of the strategic defense against hostile targets like Intercontinental Ballistic Missiles(ICBM) and reentry vehicles(RV) dispersed from them. An optimum design of the subsystems is required to increase the performance and reliability of these GBI. Propulsion subsystem design and optimization is the motivation for this effort. This paper describes an effort in which an entire GBI missile system, including a multi-stage solid rocket booster, is considered simultaneously in a Genetic Algorithm(GA) performance optimization process. Single goal, constrained optimization is performed. For specified payload and miss distance, time of flight, the most important component in the optimization process is the booster, for its takeoff weight, time of flight, or a combination of the two. The GBI is assumed to be a multistage missile that uses target location data provided by two ground based RF radar sensors and two low earth orbit(LEO) IR sensors. 3Dimensional model is developed for a multistage target with a boost phase acceleration profile that depends on total mass, propellant mass and the specific impulse in the gravity field. The monostatic radar cross section (RCS) data of a three stage ICBM is used. For preliminary design, GBI is assumed to have a fixed initial position from the target launch point and zero launch delay. GBI carries the Kill Vehicle(KV) to an optimal position in space to allow it to complete the intercept. The objective is to design and optimize the propulsion system for the GBI that will fulfill mission requirements and objectives. The KV weight and volume requirements are specified in the problem definition before the optimization is computed. We have considered only continuous design variables, while considering discrete variables as input. Though the number of stages should also be one of the design variables, however, in this paper it is fixed as three. The elite solution from GA is passed on to(Sequential Quadratic Programming) SQP as near optimal guess. The SQP then performs local convergence to identify the minimum mass of the GBI. The performance of the three staged GBI is validated using a ballistic missile intercept scenario modeled in Matlab/SIMULINK.