• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.343-345
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• 2003

This paper describes the system development for the Ground Control Point collection and management through the major coastline region in KOREA, which will collect and manage the ground control point based on high resolution satellite image database. The module of this system is following 1) GCP/Coarstline research plan module 2) GCP/Coarstline ground collection module 3) GCP/Coarstline post processing module Our team developed the core components of ‘High Resolution Satellite Image Processing Technique’ project, and this system, among applications of our project, is constructed to apply to practical use. In this application, you will also see how to apply core components of our project.

• Journal of Korean Port Research
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• v.10 no.2
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• pp.69-90
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• 1996

This study is related to save the bearing capacity from using Meyerhof formula namely, static mechanics formula with the S.P.T(N value) of the soft ground and is to choose the soft ground improvement method by the using of total load for the proper method of the pile foundation and then to design the most suitable pile foundation to fit the actual circumstance. The purpose of this study is calculating the diameter of the pile foundation by static mechanics formula and introducing the optimum design condition from the result of the bearing capacity for using N value of the S.P.T obtained from the deep soft ground about the piles such as P.H.C pile, pipe and cast-in-place pile of big diameter, etc. As above-mentioned, it is considered that the use of P.H.C pile or pipe pile is advisable on the synthetical investigation and that the selection of cast-in-place pile method is desirable in terms of the constructive safety and durability.

• Land and Housing Review
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• v.6 no.4
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• pp.221-229
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• 2015

Large trees in the apartment complex are playing an important role to decide the quality of external environment. They are planted with the object of utilizing themselves as a landmark of the complex and enhancing space symbolism. Since planting large trees would require high maintenance costs and generate defect, it would cause decline in quality of external environment. This study researches on large trees in artificial ground of the apartment complex. This study analyzes actual condition of planting and tries to provide improvement direction of planting. In order to conduct this research, three target areas (over R30) and 265 trees are selected. Based on the drawings and specifications this study researches on the plan of landscape design, changes of field design, actual condition of completion, present condition of planting, minimum soil depth of growth and development and types of extra action for soil depth. The result shows that 85% of drawings and specifications for large trees in the apartment complex are deep-rooted tree species. On average large trees with R 35 are planted in artificial ground and there is lack of on average 65cm minimum soil depth of growth and development. Reviewing changes of field design is conducted in such limited size as mainly R30 and R40 and there is no extra plan for lack of soil depth. The plan for securing additional soil depth is done by 85% of mounding. However, since there is only 10% of satisfaction, the inappropriateness in securing additional soil is pointed out. This research also points out that the size of large trees, root characteristics and location-allocation for planting are pivotal factors for securing minimum soil depth of growth and development. This research also provides improvement direction in case of planning planting.

• Earthquakes and Structures
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• v.20 no.3
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• pp.239-260
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• 2021

Torsional response of buildings is attributed to poor structural configurations in plan, which arises due to two factors - torsional eccentricity and torsional flexibility. Usually, building codes address effects due to the former. This study examines both of these effects. Buildings with torsional eccentricity (e.g., those with large eccentricity) and with torsional flexibility (those with torsional mode as a fundamental mode) demand large deformations of vertical elements resisting lateral loads, especially those along the building perimeter in plan. Lateral-torsional responses are studied of unsymmetrical buildings through elastic and inelastic analyses using idealised single-storey building models (with two degrees of freedom). Displacement demands on vertical elements distributed in plan are non-uniform and sensitive to characteristics of both structure and earthquake ground motion. Limits are proposed to mitigate lateral-torsional effects, which guides in proportioning vertical elements and restricts amplification of lateral displacement in them and to avoid torsional mode as the first mode. Nonlinear static and dynamic analyses of multi-storey buildings are used to validate the limits proposed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.1
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• pp.436-440
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• 2014

To verity the effect of PCB plane layer to the output characteristics of the Switched Mode Power Supply (SMPS), this paper compared with a generic one-layer PCB and a double-side PCB. This paper specially focused on the voltage, the current and the high frequency noise of the output characteristic of the SMPS, using a double-side PCB which has same layout and was installed a ground plane on the opposite side. This double-side PCB was assembled by all same components which used on the SMPS using the single-side PCB. The experiment results show the SMPS using the ground plan PCB can efficiently reduce the high frequency noise to 50mV at 100MHz from 150mV in the single-side PCB. And the results also show the high harmonics frequency was reduced as well.

• Journal of the Korean Society of Groundwater Environment
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• v.4 no.1
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• pp.5-13
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• 1997

The Island of Cheju plans massive ground water development to meet predicted water demand. Effective management of ground water resources requires impact assessment study. Due to the nature of the island, effects of sea water must be considered. In this work, salt water intrusion, due to hypothetical ground water development in Eastern and Central Cheju Watersheds, is predicted using a sharp-interface model. The model considers simultaneously hydrodynamics of both freshwater and saltwater. The hypothetical ground water development was designed such that it follows closely the regional ground water development plan. The numerical model predicted that the saltwater wedge may intude over 1km depending on the location. This observation leaves doubt on impact assement studies based on freshwater-flow only modeling.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.13 no.2
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• pp.9-15
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• 2017

When applying geothermal systems in cities such as seoul where high density development prevails, the selection of geothermal system capable of obtaining a large capacity in the limited grounds is necessary. In this study, an easy-to-use design tool is developed in the form of spreadsheet by applying the calculation theory of existing closed-loop vertical ground heat exchanger that can be used in the early design stage of the open-loop ground heat exchanger. By only using the maximum cooling and heating load, it is possible to calculate optimal design open-loop ground heat exchanger. Further research is needed, we are plan to improve the program considering the heat loss of groundwater flowing in the inner casing, G-Function for Open-Loop, and verification by applying actual projects.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.1060-1064
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• 2010

Ground anchors are mostly used to improve the resistance capacity of retaining walls. The end of the anchor is connected to retaining wall through tendons and the forces in tendons are transferred to ground. In this study, we plan that the new anchor system increases the tension force in tendons and improves the pullout resistance characteristics of the system. In order to increase the pullout resistance capacity of existing anchor system, the new anchor system is made by attaching four steel sticks to the tip of anchor end. So the field test results showed that the pullout resistance capacity of the wedge-shaped ground anchor was acceptable to elastic displacement range.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.660-670
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• 2009

Neighboring construction becomes mainstream of Ground excavation in downtown area. This causes the displacement, deformation, stress condition, etc of the ground surroundings. Therefore Neighboring construction have an effect on Neighboring structure. All these years a lot of Neighboring construction carried out, and the accumulation of technology also get accomplished. But earth retaining structure collapse happens yet. Types of earth retaining structure collapse are 12. 1. Failure of anchor or strut system, 2. Insufficiency of penetration, 3. H-pile Failure on excessive bending moment, 4. Slope sliding failure, 5. Excessive settlement of the back, 6. Deflection of H-pile, 7. Joint failure of coupled H-pile, 8. Rock failure when H-pile penetration is rock mass, 9. Plane arrangement of support systems are mechanically weak, 10. Boiling, 11. Heaving, 12. Over excavation. But field collapses are difficult for classification according to the type, because collapse process are complex with various types. When we consider the 12 collapse field, insufficient recognition of ground condition is 4 case. Thorough construction management prevents from fault construction. For limitations of soil survey, It is difficult to estimate ground condition exactly. Therefore, it should estimate the safety of earth retaining system, plan for necessary reinforcement, according to measurement and observation continuously.

• Earthquakes and Structures
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• v.8 no.1
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• pp.185-204
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• 2015

This study investigates the impact of the earthquake incident angle on the structural demand and the influence of ground motion selection and scaling methods on seismic directionality effects. The structural demand produced by Non-Linear Time-History Analyses (NLTHA) varies with the seismic input incidence angle. The seismic directionality effects are evaluated by subjecting four three-dimensional reinforced concrete structures to different scaled and un-scaled records oriented along nine incidence angles, whose values range between 0 and 180 degrees, with an increment of 22.5 degrees. The results show that NLTHAs performed applying the ground motion records along the principal axes underestimate the structural demand prediction, especially when plan-irregular structures are analyzed. The ground motion records generate the highest demand when applied along the lowest strength structural direction and a high energy content of the records increases the structural demand corresponding to this direction. The seismic directionality impact on structural demand is particularly important for irregular buildings subjected to un-scaled accelerograms. However, the orientation effects are much lower if spectrum-compatible combinations of scaled records are used. In both cases, irregular structures should be analyzed first with pushover analyses in order to identify the weaker structural directions and then with NLTHAs for different incidence angles.