• Wind and Structures
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• v.36 no.6
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• pp.367-377
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• 2023

This study proposes a few-shot learning model for extrapolating the wind pressure of scaled experiments to full-scale measurements. The proposed ML model can use scaled experimental data and a few full-scale tests to accurately predict the remaining full-scale data points (for new specimens). This model focuses on extrapolating the prediction to different scales while existing approaches are not capable of accurately extrapolating from scaled data to full-scale data in the wind engineering domain. Also, the scaling issue observed in wind tunnel tests can be partially resolved via the proposed approach. The proposed model obtained a low mean-squared error and a high coefficient of determination for the mean and standard deviation wind pressure coefficients of the full-scale dataset. A parametric study is carried out to investigate the influence of the number of selected shots. This technique is the first of its kind as it is the first time an ML model has been used in the wind engineering field to deal with extrapolation in wind performance prediction. With the advantages of the few-shot learning model, physical wind tunnel experiments can be reduced to a great extent. The few-shot learning model yields a robust, efficient, and accurate alternative to extrapolating the prediction performance of structures from various model scales to full-scale.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.117-124
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• 2000

As the reinforced earth wall is constructed with step by step backfill compaction method, the accumulative horizontal deformation is inevitable. It has been reported that about 80% of horizontal deformation is occurred during the construction stage of reinforced earth retaining wall. To reduce the horizontal deformation, an isolated-reinforced earth wall method(KOESWall system) was newly developed. In this system, the reinforced earth is constructed first with reinforcements and backfills only, and then facing blocks are installed after the horizontal displacement of reinforced earth is fully occurred. To evaluate the effect of a construction method and the performance of KOESWall system, two cases of full scale field performance was monitored during and after the construction stages.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.301-305
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• 2007

The performance of the railway bogie is classified into the stability and the steering performance. Testing for the bogie stability is conducted on the roller rig. But testing for the bogie steering performance on test facility is very difficult, so the testing for the vehicle curving performance is conducted on the real curve track. And it is desirable to test on the full scale test rig, but it caused many problems relating to test costs, test time. To overcome these problems, the small scale test rig is actively used in the field of bogie stability. Thus, in this paper, we have studied the scale track to test the bogie steering performance. For this, we designed the 1/5 scale test track equivalent to radius 200 curve and confirmed the validity of the testing for the bogie steering performance on the scale curve track through the testing using 1/5 scale bogie.

• Journal of the Society of Naval Architects of Korea
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• v.47 no.2
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• pp.150-162
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• 2010

Assessment of hydrodynamic performance of a ship hull has been focused on a model ship rather than a full-scale ship. In order to design the propeller of a ship, model-scale wake is often extended to full-scale based upon an empirical method or designer's experience, since wake measurement data for a full-scale ship is very rare. Recently modern CFD tools made some success in reproducing wake field of a model ship, which implicates that there are some possibilities of the accurate prediction of full-scale wakes. In this paper firstly the evaluation of model-scale wake obtained by Fluent package was performed. It was found that CFD calculation with the Reynolds-stress model (RSM) provided much better agreement with wake measurement in the towing tank than with the realizable k-$\varepsilon$ model (RKE). In the next full-scale wake was calculated using the same package to find out the difference between model and full-scale wakes. Three hull forms of KLNG, KCS, KVLCC2 having measurement data open for the public, were chosen for the comparison of resistance, form factor, and propeller plane wake between model ships and full-scale ships.

• Wind and Structures
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• v.20 no.6
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• pp.719-737
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• 2015

Full scale measurement on the structural dynamic characteristics and Vortex-induced Vibrations (VIV) of a long-span suspension bridge with a central span of 1650 m were conducted. Different Finite Element (FE) modeling principles for the separated twin-box girder were compared and evaluated with the field vibration test results, and the double-spine model was determined to be the best simulation model, but certain modification still needs to be made which will affect the basic modeling parameters and the dynamic response prediction values of corresponding wind tunnel tests. Based on the FE modal analysis results, small-scaled and large-scaled sectional model tests were both carried out to investigate the VIV responses, and probable Reynolds Number effects or scale effect on VIV responses were presented. Based on the observed VIV modes in the field measurement, the VIV results obtained from sectional model tests were converted into those of the three-dimensional (3D) full-scale bridge and subsequently compared with field measurement results. It is indicated that the large-scaled sectional model test can probably provide a reasonable and effective prediction on VIV response.

• International Journal of Naval Architecture and Ocean Engineering
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• v.3 no.3
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• pp.208-215
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• 2011

A full-scale field trial in ice-covered sea is one of the most important tasks in the design of icebreaking ships. The first Korean icebreaking research vessel 'ARAON', after her delivery in late 2009, had a sea ice field trial in the Arctic Sea during July-August, 2010. This paper describes the test procedures and data analysis on the icebreaking performance of the IBRV ARAON. The data gathered from the icebreaking performance test in the Chukchi Sea and the Beaufort Sea during the Arctic voyage of ARAON includes the speed and engine power of the ship as well as sea ice thickness and strength data. The air temperature, wind speed and heading of the ship were also measured during each sea ice trial. The ARAON was designed to break 1 m thick level ice with a flexural strength of 630kPa at a continuous speed of 3knots. She is registered as a KR POLAR 10 class ship. The principal dimensions of ARAON are 110 m, 19 m and 6.8 m in length, breadth and draft respectively. She is equipped with four 3,500kW diesel-electric main engines and two Azipod type propulsion motors. Four sea ice trials were carried out to understand the relationship between the engine power and the ship speed, given the Arctic ice condition. The analysis shows that the ARAON was able to operate at 1.5knots in a 2.5m thick medium ice floe condition with the engine power of 5MW, and the speed reached 3.1 knots at the same ice floe condition when the power increased to 6.6MW. She showed a good performance of speed in medium ice floe compared to the speed performance in level ice. More detailed analysis is summarized in this paper.

• Wind and Structures
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• v.4 no.3
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• pp.247-260
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• 2001

In the last three decades several comprehensive field measurement programs have produced significant insight into the wind effects on low-rise structures. The most notable and well published of these efforts are measurements being collected at the Wind Engineering Field Laboratory (WERFL) at Texas Tech University, measurements on low-rise structures in Silsoe, England and measurements on groups of low-rise structures collected in Aylesbury, England. Complementary to these efforts, an additional full-scale field investigation program has recently collected meteorological, pressure, strain and displacement data on a low-rise structure in Southern Shores, North Carolina. To date over seventy-five hundred data sets have been collected at the Southern Shores site in a variety meteorological conditions up to and including hurricane-force winds. This paper provides details of the system, its development, and preliminary assessment of its performance. A description of the field site, the instrumented structure, and the instrumentation system is provided. In addition, an example of the data collected during three hurricanes is presented. The primary goal of this paper is to provide the reader with the necessary technical details to appropriately interpret data from this experiment, which will be presented in future publications currently under development.

• Journal of information and communication convergence engineering
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• v.13 no.3
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• pp.180-188
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• 2015

As a potential alternative to the complementary metal-oxide semiconductor (CMOS) technology, many researchers are focusing on carbon-nanotube field-effect transistors (CNFETs) for future electronics. However, existing studies report the advantages of CNFETs over CMOS at the device level by using small-scale circuits, or over outdated CMOS technology. In this paper, we propose a methodology of analyzing CNFET-based circuits and study its impact at the full-chip scale. First, we design CNFET standard cells and use them to construct large-scale designs. Second, we perform parasitic extraction of CNFET devices and characterize their timing and power behaviors. Then, we perform a full-chip analysis and show the benefits of CNFET over CMOS in 45-nm and 20-nm designs. Our full-chip study shows that in the 45-nm design, CNFET circuits achieve a 5.91×/3.87× (delay/power) benefit over CMOS circuits at a density of 200 CNTs/µm. In the 20-nm design, CNFET achieves a 6.44×/3.01× (delay/power) benefit over CMOS at a density of 200 CNTs/µm.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.171-176
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• 2016

This paper proposes road safety facilities applying Hot-dip zinc-aluminum-magnesium alloy-coated steel sheets and coils to reduce the loss of function caused by the corrosion of steel in the service state. Vehicle crash simulations and full-scale crash tests were carried out to provide reliable information on evaluating the crash performance with the products of road safety facilities built with hot-dip zinc-aluminum-magnesium alloy-coated steel. From the results of the simulations and full-scale crash tests, the impact behaviors evaluated by the three-dimensional crash simulations considering the strain-rate dependency in a constitutive model were similar to those obtained from the full-scale crash test results. The full-scale crash test results met the crashworthiness evaluation criteria; hence, the proposed bridge barrier in this paper is ready for field applications.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.10a
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• pp.5-21
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• 2005

Urbanization rates of population range from about 1% in the developed countries to about 4% in developing countries. For a global population that may reach 10 billion within the next 40 years, pressure has arisen for an increase in the large-scale use of wastes and byproducts in construction. Ironically, most of the wastes that need to be recycled are generated in large cities where the need for constructed facilities to serve large population is high. Waste and recycled materials (WRM) that are used in construction are required to satisfy material strength, durability and contaminant teachability requirements. These materials exhibit a wide variety of characteristics owing to the diversity of industrial processes through which they are produced. Several laboratory-based investigations have been conducted to assess the pollution potential and load bearing capacity of materials such as petroleum-contaminated soils, coal combustion ash, flue-gas desulphurization gypsum and foundry sand. For full-scale systems, although environmental pollution potential and structural integrity of constructed facilities that incorporate WRM are interrelated, comprehensive schemes have not been developed for integrated assessment of the relevant field-scale performance factors. In this presentation, a framework for such an assessment is proposed and presented in the form of a flowchart. The proposed scheme enables economic, environmental, worker safety and engineering factors to be addressed in a number of sequential steps. Quantitative methods and test protocols that have been developed can be incorporated into the proposed scheme for assessing the feasibility of using WRM as partial or full substitutes for earthen highway materials in the field.