The characteristics of a new wave power generating system have been proposed by installing a piezoelectric sensor to the seaward position of an existing coastal structure. By installing the sensor to the structure, waves will hit the piezoelectric sensor to generate wave energy; at the same time, the structure acts as a wave breaker. This technique can be applied to various coastal structures to converge the functions of renewable energy generator and the wave reducing structure. This technique of using piezoelectric sensor is relatively inexpensive that can be used for economic purposes as well. Throughout the study, usability of the existing coastal structure and characteristics of current research trend in the ocean wave energy retrieval of the wave power generators have been analyzed. Hydrographic analysis of this technique has been conducted by hydraulic model experiment using 2D wave flume and confirmed that the wave pressure and voltages maximize when higher wave with longer period of wave induces. Throughout the experiment, correlations of generation volume and wave conditions have been found.

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A physical model test was carried out to evaluate a measure of reducing sediment transport in a condition of erosive wave incidence. The erosion trend was analyzed in a beach profile consisting of 0.1 mm sand, and a scenario in which 1 mm and 5 mm materials were applied to the erosion section was conducted. The effects of beach nourishment profiles with different sand diameters were verified by comparing the results when the submerged breakwater was installed. In addition, because high waves are usually accompanied with strong wind, to determine the wind effect, morphological change was examined under waves only and the coexistence of waves and wind together. The experimental results showed that sediment transport around the shoreline decreased in a condition of nourishment with 1 mm grains, and the total amount of morphological change was similar to the case in which the submerged breakwater was installed. The results illustrated that a change in wind velocity increased the wave energy density, as well as the range of morphological change.

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The construction of large-scale coastal structures in any coastal area may not only have direct effects on the coastal environment in that vicinity but also cause severe property damage. In order to prevent this problem, probable effects should be appreciated before any construction and the mechanism that may cause any probable damage must be accurately analyzed along with the plans to minimize damage. This study sought to analyze the cause and mechanism of damage inflicted on coasts by artificial structures through reviewing beach erosions that have occurred on beaches on the east coast of Korea after the large-scale construction of artificial structures, for which wave heights were measured in the vicinity of those structures, and the correlation between the measurements and the analysis data of waves and coastal erosion on the surrounding beach was analyzed. In addition, the correlation between coastal erosion and wave data was applied in order to understand what impact large waves have in relation to sand loss. Accordingly, a movable-bed physical model test was employed to appraise the factors that cause coastal erosion to take place.