• Journal of Navigation and Port Research
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• v.48 no.3
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• pp.192-199
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• 2024

Wave overtopping is a significant natural hazard that occurs in coastal areas, primarily driven by high waves, particularly those generated during typhoons, which can cause coastal flooding. The development of residential and commercial areas along the coast, driven by increasing social and economic demands, has led to a concentration of people and assets in these vulnerable areas. This, coupled with long-term sea level rise and an increase in typhoon frequency, has heightened the risk of coastal hazards. Traditionally, the evaluation of wave overtopping volumes has relied on directly measuring the collected volume of water that exceeds the crest height of structures through hydraulic model experiments. These experiments are averaged over a specific measurement period. However, in this study, we propose a new method for estimating individual wave overtopping volumes. We utilize the temporal variation of wave overtopping heights to develop an observation system that can quantitatively assess wave overtopping volumes in actual coastal areas. To test our method, we conducted hydraulic model experiments on rubble mound breakwaters, which are commonly installed along the Korean coast. We introduce wave overtopping discharge coefficients, assuming that the inundation velocity from the structure's crest is the long-wave velocity. We then predict overtopping volumes based on wave overtopping heights and compare and review the results with experimental data. The findings of our study confirm the feasibility of estimating wave overtopping volumes by applying the overtopping discharge coefficients derived in this study to wave overtopping heights.

• Bulletin of the Korean Mathematical Society
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• v.17 no.1
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• pp.21-24
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• 1980

• The Pure and Applied Mathematics
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• v.10 no.5
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• pp.5-53
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• 2003

• Communications of the Korean Mathematical Society
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• v.6 no.2
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• pp.167-175
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• 1991

• Proceedings of the Korean Magnestics Society Conference
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• 2001.04a
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• pp.18-19
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• 2001

• Bulletin of the Korean Chemical Society
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• v.1 no.4
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• pp.131-138
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• 1980

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2012.10a
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• pp.325-326
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• 2012

• Korean Journal of Computational Design and Engineering
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• v.15 no.2
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• pp.106-114
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• 2010

The swept volume, the region of a moving object, is applied in many fields such as valid paths for motions of tools, visualization in robot paths and interference tests for parts assembling or disjointing. The shape of a swept volume depends on an generators computed with normal vectors of an object and velocity vectors of a motion. Although free-from surfaces are widely used to represent geometric models in CAD, computing the generators for a free-form object is a formidable task. Previous approaches exploit the closed form expressions of generators but limited to planer or quadric faces. In this paper, we propose the algorithm to compute swept volumes generated by free-form objects in screw motions. For the algorithm a tracing method is applied to the computation of generators. It considers curvatures of surfaces of an object to increase the computational accuracy. We implemented our algorithm in the CATIA V.5 environment to test the validity of our algorithm and to generate examples.

• The Journal of Fisheries Business Administration
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• v.41 no.2
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• pp.45-60
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• 2010

The objective of this article was to estimate the market size of recreational fishing in Korea. Data were collected through sample surveys of 3,081 households nationwide in 2008. The number of anglers was directly estimated by applying weights expressed as the ratio of population to the sample. Yields and expenditures were estimated based on modules developed. On the basis of the results, a total of 6,524 thousand anglers caught an estimated 643,343 thousand fish, divided 65.2% on inland lake and 34.8% on saltwater. An angler caught about 98 fish on average in 2008. A typical angler went fishing 9.6 times, divided 8.4 times on inland lake and 5.5 times on sea. An annual expenditure of 5,233.6 billion won was estimated. The total was divided 2,851.4 billion won on inland lake(54.5%) and 2,382.2billion won on saltwater(45.5%). An average angler spent 802 thousand won a year. This study also estimated volumes by various types of fish.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1689-1693
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• 2004

This paper proposes a vehicle detector with a magnetoresistive (MR) sensor. The detector consists of a MR sensor and mechanical and electronic apparatuses. Composed of six magnetically variable resistors, the MR sensor senses disturbance of the earth's magnetic field caused by a moving vehicle over itself and then produces an output indicative of the moving vehicle. Experiments have been carried out with three stages. At the first stage, the outputs of the sensor have been analyzed to show the validity of the detector's circuit and the detecting method. At the second stage, the detector has been tested on a local highway in Korea. Through the field tests, the outputs of the detector in response to various kinds of moving vehicles have been collected and analyzed. At the final stage, to verify the performance of the detector, traffic volumes on the highway have been measured with the detector and compared with the exact traffic volumes in a highly congested traffic.