• Title/Summary/Keyword: wave barriers

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Screening of Rayleigh Waves by Composite Barriers (복합방진벽에 의한 Rayleigh파의 차단)

  • 이종세
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1997.10a
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    • pp.133-140
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    • 1997
  • Based on the Green's function technique, an analytical approach is developed to examine the surface wave screening effectiveness of composite wave barriers. The composite barrier consists of a high velocity layer sandwiched between two thin layers of low shear velocity materials. The high velocity layer is represented by differential matrix operators which relate the wave fields on each side of the layer. The low velocity layers are modeled by non-rigid contact conditions which allow partial sliding at the interfaces. Screening ratio of barriers with various combination of material, geometric, and non-rigidness parameters are compared and discussed in some detail.

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A Study on Screening of Surface Waves by Wave Barriers (방진구조물에 의한 표면파 산란해석)

  • Lee, Jong-Seh;Kim, Hee-Seok
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.11a
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    • pp.578-581
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    • 2004
  • In this paper numerical and experimental studies are conducted to examine the wave screening effectiveness of wave barriers. The numerical study is based on a finite element model of a 'sandbox' with Lysmer-Kuhlemeyer-type absorbing boundaries. Using the model, the screening effectiveness of wave barriers is studied for different barrier dimensions and distances between the source/receiver and the wave barrier. The results of the numerical modeling are compared with those of the ultrasonic experiment which is performed on an acrylic block with a drilled rectangular cut. Finally, the problem of ground transmitting vibration from a traveling train is numerically treated as a real-world application and the results are discussed in some detail.

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The Effects of Korean Wave and Heuristic on Shopping Behavioral Intention of Chinese Consumers

  • Kim, Soon-Hong;Yoo, Byong-Kook
    • Journal of Distribution Science
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    • v.15 no.9
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    • pp.53-62
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    • 2017
  • Purpose - This study aims to analyze the effects of preference for Korean Wave and heuristic on shopping satisfaction and switching barriers of Chinese people visiting Korea, and also their positive effects on consumers' behavioral intention with these variables as mediating variables by using the structural equation model. Research design, data, and Methodology - For this study, we collected 264 questionnaires of Chinese consumers' who have experienced tourism and shopping in Korea after excluding questionnaires that were not proper to be analyzed. The residence of Chinese visiter was Shandong Province, Beijing, Shanghai, Shenyang. The data of this study was analyzed using SPSS 23 statistics to verify the reliability and discriminant validity. Structural equation method was used to test the hypotheses in this study. Results - The effects of heuristic variable on shopping satisfaction and the switching barriers variable were statistically significant. The effects variables of Korean Wave effect variable were statistically significant only on the switching barriers variable. However, the Korean Wave effect variable did not have a statistically significant effect on the shopping satisfaction. Conclusions - The shopping satisfaction and Korean Wave effect variables had statistically significant effects on the behavioral intention variable. In the result of indirect analysis, only the heuristic effect had indirect effects on consumers' behavior intention.

Effects of floating wave barriers on wave-induced forces exerted to offshore-jacket structure

  • Osgouei, Arash Dalili;Poursorkhabi, Ramin Vafaei;Hosseini, Hamed;Qader, Diyar N.;Maleki, Ahmad;Ahmadi, Hamid
    • Structural Engineering and Mechanics
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    • v.83 no.1
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    • pp.53-66
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    • 2022
  • The main objective of the present research was investigating the effects of a floating wave barrier installed in front of an offshore jacket structure on the wave height, base shear, and overturning moment. A jacket model with the height of 4.55 m was fabricated and tested in the 402 m-long wave flume of NIMALA marine laboratory. The jacket was tested at the water depth of 4 m subjected to the random waves with a JONSWAP energy spectrum. Three input wave heights were chosen for the tests: 20 cm, 23 cm, and 28 cm. Two different cross sections with the same area were selected for the wave barrier: square and rhombus. Results showed that the average decrease in the jacket's base shear due to the presence of a floating wave barrier with square and rhombus cross section was 24.67% and 34.29%, respectively. The use of wave barriers with square and rhombus cross sections also resulted in 19.78% and 33.11% decrease in the jacket's overturning moment, respectively. Hence, it can be concluded that a floating wave barrier can significantly reduce the base shear and overturning moment in an offshore jacket structure; and a rhombus cross section is more effective than an equivalent square section.

Wave Reflection and Transmission from Buoyant Flap Typed Storm Surge Barriers - Hydraulic Experiments (부유 플랩형 고조방파제의 파랑 반사 및 전달 - 수리실험)

  • Jeong, Shin-Taek;Kim, Jeong-Dae;Ko, Dong-Hui;Kim, Dong-Hyawn;Park, Woo-Sun
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.20 no.2
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    • pp.238-245
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    • 2008
  • To evaluate wave reflection and transmission from buoyant flap-typed storm surge barriers, hydraulic experiments were performed by using regular and irregular wave conditions. Buoyant flap-typed storm surge barriers consist of buoyant main body connected with foundation structure in the seabed by hinge. The characteristics of wave reflection, transmission and dynamic response of the structure were investigated for 36 regular and 4 irregular wave conditions. It was also evaluated the usage of plain plate attached on the buoyant main body as one of alternatives to control wave reflection and transmission. From the hydraulic experiments, it was found that the case of plain plate attached on the offshore side is very effective to improve the wave transmission as well as reflection. But, the effect of the case on the harbor side might be negligible.

Scattering of Surface Waves in Anisotropic Media for Applications in Wave Barriers and Non-Destructive Evaluation (방진구조물 및 비파괴 응력파 탐상의 응용을 위한 비등방성 재료의 표면파 산란에 관한 연구)

  • 이종세
    • Journal of the Earthquake Engineering Society of Korea
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    • v.2 no.2
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    • pp.77-85
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    • 1998
  • Propagation of elastic surface waves in anisotropic media is considered in this study. An analytical technique is proposed to study the scattering of surface waves at the interface between two anisotropic quarter-spaces. The Green's function technique is used to derive a system of equations which can determine the scattering coefficients at the interface. A numerical study is carried out and the trade-offs between the material anisotropy and inhomogeneity are studied.

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Wave Responses of Buoyant Flap-typed Storm Surge Barriers - Numerical Simulation (부유 플랩형 고조방파제의 파랑응답 - 수치모의)

  • Jeong, Shin-Taek;Ko, Dong-Hui;Park, Woo-Sun
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.21 no.2
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    • pp.196-208
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    • 2009
  • In this paper, wave responses of buoyant flap-typed storm surge barriers was studied numerically. Wave motions were modeled by using a linear potential wave theory, and behaviors of structures were represented as a Newton's 2nd law of motion. The near field region of the fluid was discretized as conventional quadratic iso-parametric elements, while the far field was modeled as infinite elements. Comparisons with the results from hydraulic model tests show that the present model gives good results. By using the model, the applicability of a buoyant flap-typed storm surge barrier in Masan bay was investigated considering field environmental conditions.

A Numerical Study of Surface Wave Scattering at Infilled Trenches (방진벽에 의한 표면파 산란의 수치 해석)

  • 이종세
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1998.04a
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    • pp.106-112
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    • 1998
  • A numerical experiment is conduced to study the wave screening effectiveness of wave barriers which are constructed to reduce the ground-transmitted vibration. The finite element method is used for the simulation of the wave propagation behavior. In order to reduce the computational burden the absorbing boundary's one employed. Validity of the numerical model is checked by comparing the results with the published data. The screening effectiveness of the in filled trenches is then studied for different trench dimensions and material properties.

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Vibration Isolation of Wave Barriers Constructed Near a Shallow Tunnel (저심도 터널과 인접한 방진벽의 지반진동 저감효과)

  • Yang, Sin-Chu
    • Journal of the Korean Society for Railway
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    • v.18 no.6
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    • pp.567-577
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    • 2015
  • This paper presents an assessment method of the ground vibration level with a combination of measured data and an analytic method. The basic concept of the method is similar to that in FRA(Federal Railway Administration) manual for detailed vibration analyses. However, going into detail, the assessment method was modified for a feasible evaluation of the vibration reduction effects of diverse types of wave barriers. The force density was evaluated in a vehicle-track interaction analysis and the transfer mobility of vibration was analyzed through a 2-D ground vibration analysis. The calculated 2-D transfer mobility was corrected to incorporate transfer characteristics of actual ground vibration by comparing the previously measured data and analysis results. Nine types of vibration reduction effects of wave barriers were analyzed on a shallow tunnel section of an urban railway where numerous civil complaints had actually been filed.

PIV Applications for Flow Analysis of Floating Breakwater with double barriers (이흘수판형 부소파제 주위의 유동해석을 위한 PIV 적용)

  • Kim, Ho;Cho, Dae-Hwan;Lee, Gyoung-Woo;Gim, Ok-Sok
    • Proceedings of KOSOMES biannual meeting
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    • 2006.11a
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    • pp.53-58
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    • 2006
  • Along with the development of costal engineering, various type of breakwaters have been built. The main purpose of breakwaters are to provide harbour protection against waves, to stabilize beaches against erosion due to large wave action, and to provide for temporary wave protection for installation on or under water surface. This paper an application example of PIV system for analyzing the flow of Floating Breakwater with double barriers. We introduce an analysis method to predict the characteristics of flow around the neighboring fields of Floating Breakwater with double barriers in order to develop a high performance model. Flow visualization has conducted in circulating water channel by a high speed camera and etc. Flowing phenomenon according to velocity distribution and flow separation around the breakwater with double barriers were obtained by 2-D PIV system.

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