• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.1275-1282
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• 2009

The tunnel excavations are used for construction of common utility tunnel, electric tunnel, communication line tunnel, water supply and public sewerage pile line in urban area. The trench cut methods were mainly used in the past, but now, tunneling method is more being used. The tunnel excavation method like as NATM, Messer-Shield, Semi-Shield Methods are being applied to small section tunnel in Korea. The actual construction results of seme-shield method are increasing due to simplified construction process and reduced noise and vibration. And also this method is being used frequently in waterway tunnel and construction of prevention flooding recently. The seme-shield method design guideline is absence except for electric line tunnel construction in Korea, because of the semi-shield method was developed in Europe and Japan. In the prescriptive design, engineer's subjects are tending to intervene, because of absence of standard and specification for details. Therefore, Design and Construction Problems of Semi-Shield Method were described and construction trouble was introduced for exam. These problem and construction troubles have to be examined thoroughly in advance.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.03a
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• pp.323-330
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• 1999

Daylight collapse have been occurred by about 5.0m deep at ground surface and collapse of the crown head part of the tunnel have connected to the ground surface during first step of shotcrete work after blasting of upper half section of the tunnel driving at two-way double track tunnel face section on highway construction. This study is for a successful illustration case for the earth improvement method through applying such strengthening methods as cement milk grouting, S.G.R grouting,, steel pipe reinforced multi-step grouting etc. for the purpose of earth strengthening of loosened earth block occurred by tunnel collapse.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.2
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• pp.27.4-28
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• 2015

The GMT-Consortium Large Earth Finder (G-CLEF) is an optical band echelle spectrograph that has been selected as the first light instrument for the Giant Magellan Telescope (GMT). G-CLEF is a general purpose high dispersion instrument that is fiber-fed and capable of extremely precise radial velocity measurements. G-CLEF has undergone a preliminary design review in April 2015 and is now entering final design phase and construction. G-CLEF has been designed to measure the mass of Earth-analogue exoplanets and to make critical observations in near-field and high-Z cosmology. We describe the G-CLEF instrument and several key science missions that shaped the development of G-CLEF. First light on the GMT is scheduled for late 2020.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.308-311
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• 2002

Radar interferometric phase is sensitive to both ground topography and coherent surface displacement. The basic tactics of differential interferometric synthetic aperture radar (DInSAR) technique are to separate the two effects. Applications of DInSAR to Duk-Po area in Busan were studied. In the study area, an abrupt subsidence, possibly caused by sub-way construction, was observed by JERS-1 SAR interferometry. Differential interferograms were generated using twenty-three JERS-1 SAR data acquired between April 24, 1992, and August 7, 1998. Because the area is relatively flat with little topographic relief the topographic effects were not removed. A phase filtering and interferogram techniques were applied to increase fringe clarity as well as to decrease decorrelation error. The stacking improves the quality of interferograms especially when the displacement is discontinuous. The interferograms clearly show the evidence of subsidence along Duk-Po subway railroad. These results demonstrate that the interferogram stacking technique can improve the detectability of radar interferometry to an abrupt displacement and DInSAR is useful to geological engineering applications.

• Journal of Magnetics
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• v.1 no.2
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• pp.94-100
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• 1996

A hysteresis loop tracer using a pulsed high magnetic field of 113.4 kOe, which is suitable for rare earth based permanent magnets, is constructed. The high pulsed magnetic field is generated by discharging a large capacitance charge (5 mF) with a voltage of 600 V into an air solenoid with the inner diameter of 14 mm, outer diameter of 36 mm and the lingth of 34 mm. A computer simulation method is used for the construction of an electromagnet to optimize the many parameters such as the discharge current, generated pulsed magnetic field intensity, thermal dissipation, capacitance, charged voltage, period of damping oscillation and solenoid geometry. By using the hysteresis loop tracer constructed in this work, we are able to measure hystersis loops of several rare earth based permanent magnets with large values of the remanent magnetization, coercvity and energy product.

• KIEAE Journal
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• v.10 no.2
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• pp.57-62
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• 2010

In case of earth-covered storage, the condensation occurs on surface of wall and stores in summer with high humidity because of low temperature of constructional mass. Therefore, the preventive plans should be considered to protect stores from the damage by corrosion in earth-covered storages. This study aims to suggest the methods of forced ventilation by the air, to solve the problems of construction's surface condensation at the Magazine of igloo type which is similar to earth-covered storages. A fan was installed at the air outlet for exhaust gas to conduct forced ventilation. The surface and indoor temperature were measured, and then the influence of those on condensation was analyzed. The results of this research are follows; 1) Forced ventilation by a fan affects the rise in surface temperature of walls and stores. 2) The condensation on surface of walls and stores was reduced after operating a fan.

• Journal of the Korean Geophysical Society
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• v.9 no.1
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• pp.7-19
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• 2006

Laser scanning is a new technology for obtaining Digital Surface Models(DSM) of the earth surface.It is a fast method for sampling the earth surface with high density and high point accuracy. This paper is for buildings extraction from LiDAR points data. The core part of building construction is based on a parameters filter for distinguishing between terrain and non-terrain laser points. The 3D geometrical properties of the building facades are obtained based on plane fitting using least-squares adjustment. The reconstruction part of the procedure is based on the adjacency among the roof facades. Primitive extraction and facade intersections are used for building reconstruction. For overcome the difficulty just reconstruct of laser points data used with digital camera images. Also, 3D buildings of city area reconstructed using digital map. Finally, In this paper show 3D building Modeling using digital map and LiDAR data.

• International Journal of Advanced Culture Technology
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• v.3 no.1
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• pp.78-85
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• 2015

In Thailand, the electricity consumption is very high with the intention of reduce high temperature in the building. Since 2000, a lot of people paying attention to Green-Building concept. A similar concept is natural building, which is usually on a smaller scale and tends to focus on the use of natural materials that are available locally. Therefore, the Earth-Block (EAB) product is appropriated approach to reduce energy consumption in the buildings. The EAB is produced with environmentally friendly process, which does not release harmful pollution and effective cost. The main significant character is durable materials for building construction. This study aims to develop the new thermal insulation by using soil-cement with vetiver grass fibre. Additionally, it describes the innovative systems used in production of EAB materials by mixing the soil-cement with vetiver grass fibre. This paper reveals lowest costs, space configurations changing and greater design flexibility for constructing the building.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2002.10a
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• pp.412-419
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• 2002

This paper presents a parametric study on the behavior of integral abutment PSC beam bridge. An integral abutment bridge is a simple span or multiple span continuous deck type bridge having the deck integral with the abutment wall. The rational structural model and design load combinations accounting for each construction stage are proposed. It can be used for defining the effect of earth pressure and temperature change in the design process including for determining maximum flexural responses. The bending moment at each response location due to the design load combination is investigated according to the change of flexural rigidity of piles and abutment height. The flexural responses of proposed model are computed for the cases of applying the Rankine passive earth pressure and the earth pressure based on the soil-structure interaction respectively, and the results are discussed.

• Journal of Positioning, Navigation, and Timing
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• v.3 no.4
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• pp.149-154
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• 2014

The BeiDou is a satellite-based positioning and navigation system, which is under construction by the China Satellite Navigation Office. Until the June of 2014, the constellation of BeiDou navigation satellite system consists of 14 satellites including five geostationary earth orbit (GEO), five inclined geosynchronous earth orbit (IGSO) and four medium earth orbit (MEO). In this paper, we present the positioning results using BeiDou B1 code measurements obtained from three GNSS reference stations (BHAO, SKMA, MKPO). Combined Beidou/GPS positioning results are also compared to BeiDou and GPS only. BeiDou-only positioning errors for the east-west and north-south direction had less than 2 meter with root mean square (RMS) value. However, the positioning error for the up-down direction had larger than 10 meter at a 95% confidence level. Our results also suggest that the position precision is improved by combined BeiDou/GPS compared to BeiDou-only.