• Journal of Industrial Technology
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• v.29 no.B
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• pp.65-72
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• 2009

In this paper centrifuge model tests and numerical analysis on the coastal structure on the marine deposits of sand were performed to investigate the behavior of structure and foundation under the condition of wave action in field. In centrifuge model experiments, construction sequence of coastal structure such as preparation of sand deposit, excavation replacement, rubble mound with crushed stones and installment of coastal structure was reconstructed and the behavior of ground settlement during stage of construction was observed during tests. For the final stage of simulating the horizontal movement of coastal structure due to wave force, horizontal load was applied by horizontal loading apparatus being specially designed so that horizontal displacement of structure could be observed. Numerical analysis were also carried out and its results were compared with test results to assess the property of centrifuge mode experiments with respect to the behavior of structure as well as ground.

• International Journal of Aeronautical and Space Sciences
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• v.14 no.3
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• pp.272-281
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• 2013

Traffic Collision Avoidance System (TCAS) is designed to enhance safety in aircraft operations, by reducing the incidences of mid-air collision between aircraft. The current version of TCAS provides only vertical resolution advisory to the pilots, if an aircraft's collision with another is predicted to be imminent, while efforts to include horizontal resolution advisory have been made, as well. This paper introduces a collision resolution algorithm, which includes both vertical and horizontal avoidance maneuvers of aircraft. Also, the paper compares between the performance of the proposed algorithm and that of algorithms with only vertical or horizontal avoidance maneuver of aircraft.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1998.10a
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• pp.489-496
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• 1998

The single layer latticed domes have various behaviors with each geometrical shape and scale, and they are affected by vertical component as well as horizontal component of the dynamic load. And they represent ye different earthquake responses under each ground acceleration compared with another structural systems. Generally, all of the members of latticed domes undergo three dimensional deflections if they are subjected to arbitrary one dimensional horizontal load under earthquake motions. And their response characteristics are very different to their shapes, rise/span ratios, and damping mechanisms. In this study, the earthquake response behavior is verified according to the factor of each shape, rise/span ratio, and damping ratio of latticed domes, which undergo horizontal and vertical earthquake motions by numerical approaches.

• Journal of Industrial Technology
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• v.32 no.A
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• pp.79-86
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• 2012

In this paper, centrifuge model tests and numerical analysis on the breakwater structure were performed to investigate the stability and behavior of breakwater in field. In centrifuge model tests, construction sequence of breakwater structure such as preparation of weathered rock and sand deposit, construction of D.C.M, rubble mound with crushed stones and installment of breakwater structure was reconstructed like field condition and the behavior of ground settlement and breakwater displacement during stage of construction was observed during tests. For the final stage of simulating the horizontal movement of breakwater due to wave force, horizontal load was applied by horizontal loading apparatus being specially designed so that horizontal displacement of structure could be observed. Numerical analysis were also carried out and its results were compared with test results to assess the property of centrifuge model tests with respect to the behavior of structure as well as ground.

• The Journal of the Korean dental association
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• v.58 no.8
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• pp.486-494
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• 2020

Objectives: Management of a horizontal root fracture of an anterior teeth is challenging and often requires multiple approaches for improving the functional and esthetic outcomes. This case report describes the treatment and 2-yr follow up of 3 maxillary incisors with horizontal root fracture. Two maxillary central incisors were treated with Mineral Trioxide Aggregate (ProRoot MTA, Dentsply, Tulsa, OK, USA). Left maxillary lateral incisors were treated with endodontic treatment and submerged. During 2-yr of follow-up evaluation, the root-fractured teeth of the present patients were well retained in the arch, showing periodontal healing even after endodontic treatment.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.03a
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• pp.557-564
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• 2002

Discharge capacity test is carried out to find out influencing factors on discharge capacity of prefabricated horizontal drains to improve weak dredged clay. Four representative prefabricated horizontal drains are selected based on the size of drain as well as the shape of core. Test is carried out for 10 days at each three level of confining pressure for all drains. Effects of elapsed time, confining pressure, hydraulic gradient and strength of filter and core on discharge capacities are examined. It is found that discharge capacity of drain, which has deformable core or has a possibility of squeezing filter into core, decreases more with time due to its low strength. As confining pressure increases, discharge capacity decreases due to the squeezing of filter into core.

• Journal of the Korean Solar Energy Society
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• v.30 no.2
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• pp.81-86
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• 2010

Since the solar energy resource is the main input for sizing any solar photovoltaic system and solar thermal power system, it is essential to utilize the solar radiation data as a application and development of solar energy system increase. It will be necessary to understand and evaluate the insolation data. The Korea Institute of Energy Research(KIER) has begun collecting horizontal global insolation data since May, 1982 and direct normal insolation data since December 1992 at 16 different locations in Korea. Because of a poor reliability of existing data, KIER's new data will be extensively used by solar energy system users as well as by research institutes. From the results, the yearly averaged horizontal global insolation was turned out 3.60kWh/$m^2$/day and a significant difference of horizontal global insolation is observed between 1982~1990 and 1991~1999, 2000~2008 through 16 different cities in Korea.

• Geotechnical Engineering
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• v.10 no.3
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• pp.33-40
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• 1994

The effects of smear and well resistance should be taken into account for the design of sand drains. Practically, simple design, which employs the method using 112 reduced diameter of drains or assuming the coefficient of consolidation in horizontal direction equals to that in vertical direction, based on the theory neglecting these effects, has been used. In this study, the reliability of existing simple design methods as well as the influences of smear and well resistance was investigated with the equations proposed by Hansbo and Onoue. It is shown that the consolidation time is chiefly governed by the effect of smear for drains with highly permeable sands. For general soil condition and placing type of sand drain, consolidation time is underestimated for simple design wi어. 1/2 reduced diameter of drains, and it is overestimated for that with the assumption that the coefficient of consolidation in horizontal direction equals to that in vertical direction. Through the investigations on different reduced diameter, it was shown that simple design with 1/4 reduced diameter of drains yielded the reliable results with errors less than 6%.

• Geophysics and Geophysical Exploration
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• v.7 no.4
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• pp.245-250
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• 2004

Horizontal-axes on the seismic section have been represented in a distance unit by applying horizontal-distance correction transformation on a 2-D seismic section of single channel marine seismic data. By drawing horizontal-axes in a distance unit, distortion of horizontal distances shown on the seismic section when the ship speed varies during a survey can be diminished considerably. Position information obtained by GPS and stored in each trace of seismic data as well as data collection windows were used for horizontal distance correction. The minimum window length was decided by considering ship speed and shot interval, and the maximum window length wat determined by reflecting radius of the 1st Fresnel zone. In choosing an optimum window length, horizontal resolution and stacking effect were considered simultaneously. By applying horizontal distance correction we could get a 2-D seismic section which is considered at reflecting the real subsurface structure analogously.

• Atmosphere
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• v.21 no.4
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• pp.391-404
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• 2011

This study investigates the impact of cumulus parameterization scheme (CPS) with different horizontal grid sizes on the simulation of the local heavy rainfall case over the Korean Peninsula. The Weather Research and Forecasting (WRF)-based real-time forecast system of the Joint Center for High-impact Weather and Climate Research (JHWC) is used. Three CPSs are used for sensitivity experiments: the BMJ (Betts-Miller-Janjic), GD (Grell-Devenyi ensemble), and KF (Kain-Fritsch) CPSs. The heavy rainfall case selected in this study is characterized by low-level jet and low-level transport of warm and moist air. In 27-km simulations (DM1), simulated precipitation is overestimated in the experiment with BMJ scheme, and it is underestimated with GD scheme. The experiment with KF scheme shows well-developed precipitation cells in the southern and the central region of the Korean Peninsula, which are similar to the observations. All schemes show wet bias and cold bias in the lower troposphere. The simulated rainfall in 27-km horizontal resolution has influence on rainfall forecast in 9-km horizontal resolution, so the statements on 27-km horizontal resolution can be applied to 9-km horizontal resolution. In the sensitivity experiments of CPS for DM3 (3-km resolution), the experiment with BMJ scheme shows better heavy rainfall forecast than the other experiments. The experiments with CPS in 3-km horizontal resolution improve rainfall forecasts compared to the experiments without CPS, especially in rainfall distribution. The experiments with CPS show lower LCL(Lifted Condensation Level) than those without CPS at the maximum rainfall point, and weaker vertical velocity is simulated in the experiments with CPS compared to the experiments without CPS. It means that CPS suppresses convective instability and influences mainly convective rainfall. Consequently, heavy rainfall simulation with BMJ CPS is better than the other CPSs, and even in 3-km horizontal resolution, CPS should be applied to control convective instability. This conclusion can be generalized by conducting more experiments for a variety of cases over the Korean Peninsula.