• Title, Summary, Keyword: Korean Wave

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Electromagnetic Wave Shield Characteristics of Thermal Sprayed Ferrite Coatings (자성 페라이트 용사피막의 전자파 차폐 특성)

  • 정태식;김태형;박경채
    • Journal of Welding and Joining
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    • v.20 no.1
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    • pp.76-82
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    • 2002
  • In these days, many advanced nations have enforced import restrictions against things emitting electromagnetic wave which has report that it is so harmful. In general, electromagnetic wave is composed of electric wave and magnetic wave. The reflection of electromagnetic wave is mainly reflected by conductive materials and the magnetism loss is generated by magnetic ferrite. The magnetism loss of ferrite is separated by eddy current loss, residual magnetism loss and hysteresis loss. Thermal sprayed coating is intended to manufacture because of simple processes and high efficient electromagnetic wave shielding. The high efficient thermal sprayed coatings were made from the magnetic ferrite materials that characterizes absorption of electromagnetic wave, and the electric conductive materials that characterize emitting of electromagnetic wave. This study was manufactured thermal sprayed coatings to improve absorption-efficiency, and measured the electromagnetic wave shielding efficiency. As the experimental results, high electromagnetic wave shield efficiency was obtained at wave frequency 2GHz to thermal sprayed ferrite coatings manufactured by size distribution range of spray powders, $38~88\mu\textrm{m}$.

Wave Properties in the Sea Area of Mara-do in ′98 and ′99 (′98-′99 마라도해역에서의 파랑의 특성)

  • 안용호;정진영;류황진;김도영
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • pp.108-116
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    • 2001
  • In this paper, statistical properties of waves in the sea area of Mara-do, Korea are examined based on 1998-1999's wave data from a directional wave buoy which is located in Mara-do. Wave data aquisition rate, monthly maximium, minimum and mean wave heights, frequency of wave direction are summarized. Wave height and period scatter diagrams and n-year return period wave heights are estimated. Wave periods of maximum wave heights are also estimated.

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A Study on the Determination of Wave Load Acting on Offshore Structures (해저 석유개발을 위한 해양구조물의 기본 설계/해석 및 실험기법 개발 -해양구조물에 작용하는 파랑하중 산정에 관한 연구)

  • 이근무
    • Journal of Ocean Engineering and Technology
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    • v.14 no.1
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    • pp.6-10
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    • 2000
  • In this paper various methods of determining of wave loads acting ofshore structures including impact load due to breaking wave are studied and corresponding model test was performed. In the theoretical approach wave load by nonbreaking wave and impact load by breaking wave is determined by Morrison's equation Goda's equation and impact wave equation, In the experimental approach wave load by nonbreaking wave acting on cylindrical pile used in offshore structures is determined by measuring the strain on a cylindrical pile and compared with theoretical calue. in the numerical approach impact load by breaking wave acting on a modeled cylindrical pile is calculated by usign ANSYS FEM program and compared with theoretical value. It is found that the experimental and numerical results are comparable to theoretical results, Thus the determination of wave load acting on offshore structures can be obtained by a proposed methods and it acceptable.

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Study on Mobile Wave Energy Harvesting System Utilizing Wave Glider Mechanism (웨이브 글라이더 메커니즘을 이용한 이동형 파력발전 시스템의 성능 테스트와 최적 설계에 관한 연구)

  • Joe, Hangil;Yu, Son-Cheol
    • Journal of Ocean Engineering and Technology
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    • v.32 no.5
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    • pp.393-401
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    • 2018
  • This paper reports a novel mobile-type wave energy harvesting system. The proposed system adopts a wave glider's propulsion mechanism. A wave glider's blades were mounted on a circular layout and generated a rotational motion. Combining the wave converting system with the wave glider, a mobile floating-type robotic buoy system was developed. It enabled the relocation of the buoy position, as well as station-keeping for long term operation. It had a small size and could efficiently harvest wave energy. A feasibility study and modeling were carried out, and a prototype system was constructed. Various tank tests were performed to optimize the proposed wave energy harvesting system.

Development of a Wave Absorbing System Using a Liquefied Sandbed

  • Kang, Yoon-Koo;Takahashi, Shigeo
    • Journal of Ocean Engineering and Technology
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    • v.20 no.4
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    • pp.9-16
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    • 2006
  • A new wave-absorbing system, called the liquefied sandbed wave barrier (LSWB) system, is currently under development at the Port and Airport Research Institute (PARI) of Japan. The wave damping effect by the LSWB system is substantial, as confirmed by small-scale experiments and FEM numerical calculations, i.e., the wave transmission coefficient of the system is less than 0.2. Here, the results of large-scale experiments arediscussed in view of practical application. Although the LSWB system provides high wave damping, nearly equal to theoretical values, difficulty exists in obtaining a homogeneously liquefied sandbed, due to the occurrence of liquefied sandbed compaction by cyclic wave loading, which in turn, reduces excess pare pressure and the wave damping effect. These two phenomena primarily occur when the sandbed is composed of fine sand with small permeability. Based on experimental results, we propose a design method that includes countermeasures against such problems, and a prototype LSWB system is constructed in a very large wave flume at PARI. Wave damping by the prototype LSWB system is confirmed to be quite stable and high, as predicted by theoretical calculations.

Nondestructive Characterization of Materials Using Laser-Generated Ultrasound

  • Park, Sang-Woo;Lee, Joon-Hyun
    • International Journal of Reliability and Applications
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    • v.5 no.1
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    • pp.1-13
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    • 2004
  • It is recently well recognized that the technique for the one-sided stress wave velocity measurement in structural materials provides measurement in structural materials provides valuable information on the state of the material such as quality, uniformity, location of cracked or damaged area. This technique is especially effective to measure velocities of longitudinal and Rayleigh waves when access to only one surface of structure is possible. However, one of problems for one-sided stress wave velocity measurement is to get consistent and reliable source for the generation of elastic wave. In this study, the laser based surface elastic wave was used to provide consistent and reliable source for the generation of elastic wave into the materials. The velocities of creeping wave and Rayleigh wave in materials were measured by the one-sided technique using laser based surface elastic wave. These wave velocities were compared with bulk wave velocities such as longitudinal wave and shear wave velocities to certify accuracy of measurement. In addition, the mechanical properties such as poisson's ratio and specific modulus(E/p) were calculated with the velocities of surface elastic waves.

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Influence of characteristics, attachment and self congruity of Korean wave human brand on brand equity - Focused on Chinese female consumers - (한류 휴먼브랜드의 특성과 애착 및 자아일치성이 브랜드 자산에 미치는 영향 - 중국 여성 소비자를 대상으로 -)

  • Kim, Eunhye;Lee, Jin Hwa
    • The Research Journal of the Costume Culture
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    • v.27 no.5
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    • pp.479-495
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    • 2019
  • This study defines Korean wave stars as Korean wave human brands and examines the influence of the characteristics, attachment, and self-congruity of the Korean wave human brand on brand equity. For this, this study surveyed Chinese female consumers in their 20s and 30s who consume many Korean wave products from May 2018 to June 2018. First, human brand characteristics, attachment, self-congruity, Korean wave aspiration level, and brand equity according to demographic characteristics were identified. Second, characteristics, attachment, self-congruity, and the aspiration level of the Korean wave human brand showed correlations with brand equity. However, brand awareness, a sub-factor of brand equity, does not show correlations with self-congruity. Third, characteristics, attachment, self-congruity, and Korean wave aspiration level had a positively influenced brand equity. Fourth, when looking into the mediated effect of attachment on brand equity, both human brand characteristics and self-congruity showed a partially mediated effect. Fifth, when analyzing the adjustment effect in the Korean wave aspiration level, a group with higher Korean wave aspiration level showed more correlations with attachment and brand equity. This study found that attachment and self congruity are important elements in forming human brand and brand equity. This study is significant in that it verified the influence of Korean wave brand power that has been on the rise recently on brand equity and provided a theoretical basis that has allowed researchers to determine that the characteristics, attachment, and self-congruity of Korean wave human brand significantly influence brand equity.

Evaluation of Static Bending Properties for Some Domestic Softwoods and Tropical Hardwoods Using Sonic Stress Wave Measurements (응력파(應力波) 측정(測定)에 의(依)한 수종(數種)의 국산(國産) 침엽수재(針葉樹材) 및 열대(熱帶) 활엽수재(闊葉樹材)의 휨성질(性質) 평가(評價))

  • Lee, Do-Sik;Jo, Jae-Sung;Kim, Gyu-Hyeok
    • Journal of the Korean Wood Science and Technology
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    • v.25 no.1
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    • pp.8-14
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    • 1997
  • Stress wave velocity, wave impedance, and stress wave elasticity of small, clear bending specimens of five domestic softwoods (Pinus densiflora, Pinus koraiensis, Chamaecyparis obtusa, Cryptomeria japonica, and Larix leptolepis) and four tropical hardwoods(Kempas, Malas, Taun, and Terminalia) were correlated with static bending modulus of elasticity(MOE) and modulus of rupture(MOR). The degree of correlation between stress wave parameters and static bending properties was dependent on wood species tested. Stress wave elasticity and wave impedance were better predictors for static bending properties than stress wave velocity for each species individually and for softwood or hardwood species taken as a group, even though elasticity and impedance were nearly equally correlated with static bending properties apparently. Based upon the correlation coefficient between stress wave parameters and static properties, stress wave elasticity and wave impedance were found as stress wave parameters which can be used for the purpose of the reliable and successful prediction of bending properties. The degree of correlation between static MOE and MOR was also different according to wood species tested. Static MOE was nearly as well correlated with MOR as was stress wave elasticity. The results of this research are encouraging and can be considered as a basis for further work using full-size lumber. From the results of this study, it was concluded that stress wave measurements could provide useful predictions of static bending properties and was a feasible method for machine stress grading of domestic softwoods and tropical hardwoods tested in this study.

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Strategy Research for the Korean Broadcasting Contents Development (한류 방송 콘텐츠 확산을 위한 방안 연구)

  • Yang, Moonhee
    • The Journal of the Korea Contents Association
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    • v.19 no.11
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    • pp.201-210
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    • 2019
  • Recently, Korean broadcasting contents experienced difficulty caused by political issues. After the decision of THAAD missiles placement by Korean Government, Chinese government adopted restriction policy of the Korean wave. This kind of political conflict can influence K-wave broadcasting contents at any time, Therefore, it is necessary to build support system for stable and sustainable K-wave growth. Through in-depth interview with ten experts from broadcasting area, this study attempted to diagnose problems of K-wave related law, system and policy, then suggest the improvement plan for K-wave. In addition, this study tried to investigate the possibility of K-wave market diversification. As potential markets for K-wave, the Southeast Asia area and western Europe were considered and the advancement plan for these area were studied. Lastly, K-wave improvement plan for China and Japan, the traditional K-wave market also considered. The research suggested the strategies and alternatives for K-wave broadcasting contents development.

Analysis of Impact Factors for the Wave Transmission in the Narrow Channel Sea (수로형 해역에서의 파랑전달에 미치는 영향인자 분석)

  • Lee, Gyong-Seon;Yoon, Han-Sam;Ryu, Cheong-Ro;Park, Jong-Hwa
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • pp.303-308
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    • 2003
  • In this paper, wave numerical modeling was experimented for the analysis of impact factors for the wave transmission as the incident wave and topographic conditions in the narrow channel sea. Recently, Although the results of many researcher for the wave modelling, numerical equations have limited to simulation of wave transformation effects. Despite of thispresent problems, the models was used to design the coastal structures in barrow channel sites. Finally, this paper estimated the wave model(mild slope eq. model) as the analysis of the wave energy transmission according to changing of impact factors(width of channel, bottom slope in channel, incident wave angle, wave period). As the results of numerical experiment, the major impact factors which influence to wave energy transmission were the width of channel and incident wave direction. But in the case that the width of channel is larger than 3L(L=Length of wave), the reduction of wave energy was small.

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