• Title/Summary/Keyword: Focused wave

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Analysis of Construction Procedure of Breakwater in consideration of Harbor Siltation (항내매몰을 고려한 방파제의 시공순서 검토)

  • Yoon, Seong-Jin;Kim, Kyu-Han
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.19 no.1
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    • pp.73-80
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    • 2007
  • The predominant factor considered in the design of harbors in the East Coast of Korea is wave propagating onshore. Also, the strong wave induced current on the east coast have the biggest influence on sediment transport around the harbor structure. Therefore, a consideration of wave induced current due to waves should take place on design when constructing a harbor on east coast. In this study, we studied on the influences of construction procedure on harbor siltation using annual coastal line data and bathymetry data near breakwater. And, this study focused on investigation of the construction procedure for the best way to decrease harbor siltation.

Pressure pain threshold and visual analogue scale changes in the high and low energy extracorporeal shock wave

  • Yang, You-Jin;Lee, Seung-Joon;Choi, Matthew
    • Physical Therapy Rehabilitation Science
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    • v.3 no.2
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    • pp.142-147
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    • 2014
  • Objective: This study aims to investigate high energy and low energy extracorporeal shockwave therapy (ESWT) and which one is more effective for shoulder pain. Design: Single blind randomized controlled trial. Methods: Fifty two subjects with upper trapezius (UT) trigger point (TrP) participated in this study. They were allocated to high energy (n=26) and low energy group (n=26). This study applies ESWT and investigates the changes of pressure pain threshold (PPT) and visual analogue scale (VAS). The high and low energy groups received focused piezo electric type ESWT 4 Hz, 1,000 pulses and 0.351 and $0.092mJ/mm^2$ respectively. Outcome measures of PPT and pain was measured by algometer and pain VAS. These measurements were performed before and after treatment. Results: The PPT value was significantly increased in both groups after treatment (p<0.05) and VAS scores were significantly decreased after treatment in both groups (p<0.05). However, there were no significant differences between groups. Conclusions: ESWT is an effective treatment for the application of the UT TrP. Although there were significant effects of extracorporeal shock wave therapy on PPT and VAS scores, there were no signficant differences between high and low energy extracorporeal shock wave therapy.

The study on Focused Extracorporeal Shock Wave Prostate Therapy Apparatus using MCU and Spiral Coil (MCU와 나선형 코일을 이용한 촛점식 체외 충격파 전립선 치료 장치에 관한 연구)

  • Ryoo, Hee-Soo;Son, Byeong-Rae
    • The Journal of the Korea institute of electronic communication sciences
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    • v.16 no.1
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    • pp.203-210
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    • 2021
  • Difficulties in treating chronic prostatitis cause physical pain and mental problems not only for the treating doctor, but also for the patient. Accordingly, the device of the present research was developed to help patients suffering from prostate symptoms due to the vibration effect of shock wave energy caused by thermal and mechanical interaction of the external shock wave. The purpose of this study is to provide an effective treatment means for prostatitis and BPH(Benign prostatic hyperplasia) by devising an extracorporeal shockwave therapy device that effectively applies the heat and vibration effects of concentrated energy by MCU and spiral coil module.

Aerodynamics of a wing section along an entry path in Mars atmosphere

  • Zuppardi, Gennaro;Mongelluzzo, Giuseppe
    • Advances in aircraft and spacecraft science
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    • v.8 no.1
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    • pp.53-67
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    • 2021
  • The increasing interest in the exploration of Mars stimulated the authors to study aerodynamic problems linked to space vehicles. The aim of this paper is to evaluate the aerodynamic effects of a flapped wing in collaborating with parachutes and retro-rockets to reduce velocity and with thrusters to control the spacecraft attitude. 3-D computations on a preliminary configuration of a blunt-cylinder, provided with flapped fins, quantified the beneficial influence of the fins. The present paper is focused on Aerodynamics of a wing section (NACA-0010) provided with a trailing edge flap. The influence of the flap deflection was evaluated by the increments of aerodynamic force and leading edge pitching moment coefficients with respect to the coefficients in clean configuration. The study was carried out by means of two Direct Simulation Monte Carlo (DSMC) codes (DS2V/3V solving 2-D/3-D flow fields, respectively). A DSMC code is indispensable to simulate complex flow fields on a wing generated by Shock Wave-Shock Wave Interaction (SWSWI) due to the flap deflection. The flap angle has to be a compromise between the aerodynamic effectiveness and the increases of aerodynamic load and heat flux on the wing section lower surface.

Fashion Market Analysis and Design Development for Expansion to Southeast Asian Market of Korean Wave Fashion -Focused on Vietnam, Ho Chi Minh City- (한류 패션의 동남아시아 진출을 위한 시장 분석 및 디자인 개발 - 베트남 호치민시를 중심으로 -)

  • Choi, Hyerin;Lee, Inseong
    • Journal of the Korea Fashion and Costume Design Association
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    • v.16 no.2
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    • pp.139-150
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    • 2014
  • The purposes of this study are to analyze current situation of fashion market of Vietnam who is mainly influenced by Korean wave, analyze preferred fashion brand product and street fashion style of women in 10~20s interested in fashion so much, and develop the design suitable for Vietnamese consumers' preference so as to seek the methods domestic fashion industry can have competitive edge in emerging economic market. It's significant to suggest the direction of Korean new contents and seek the possibility of advancing new market by getting out of domestic market which is stagnated by preparing the foothold of fiber and fashion industry, beyond the first effects of Korean wave. Through this study, current situation of Korean wave which recently becomes new Korean wave based on the K-pop and futhermore, one of worldwide cultural situation could be recognized. Based on the preference of the Korean wave, current situation of Korean fashion industry spread gradually in Vietnam and design characteristics of fashion style preferred by Vietnamese consumers could be grasped. As the result, the design which can satisfy various needs of Vietnamese female consumers preferring fashion style was developed based on the characteristics by product's styles of Vietnamese fashion market. In addition, it intended to be helpful to plan the design of casual wear which is more professional so that Korean fashion industry can advance Vietnamese market through it.

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Effect of LED Light Color on Mid Beta Wave Activities of QEEG in Learning State (LED 광색이 학습상태 정량뇌파의 미드베타파 활성에 미치는 영향)

  • Lee, Ho Sung
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.29 no.3
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    • pp.29-36
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    • 2023
  • Purpose: The purpose of this study is to find out whether the color change of the LED light source has a significant effect on the beta wave activity of EEG in the learning state. Methods: The subjects of the experiment were 20 male and female college students between the ages of 19 and 25 who routinely perform their studies. In the created learning environment, the EEG change according to the change in the lighting color was measured while solving the Mensa thinking ability problem while sitting on a desk with LED lights installed on the top and a chair with a footrest to stabilize the legs. The light source consisted of 3 ready-made colors and 6 newly created colors. A total of 9 color light stimuli were given for 2 minutes each, and the EEG change of the subject was observed. After the experiment, the correlation was analyzed based on the mid-beta wave data recorded on the QEEG according to the color change of light and the Mensa problem score. Results: It was found that the activation of mid-beta waves was stimulated in the temporal lobes (T5, T3, T6, T4) and occipital lobes (O1, O2) of all subjects who focused on solving Mensa thinking problems. As a result of comparing the top 20% and the bottom 20% of problem solving scores, the upper group had no effect of lighting, while the lower group showed increased beta wave activity in response to color light stimulation in the order of T4, T6, and T5. Implications: It was confirmed that the color of light that activates the middle beta wave varies greatly depending on the subject's attention and learning ability, and it is judged that the color of light including the green wavelength is helpful in activating the middle beta wave in the group with low learning ability.

Hydrodynamic Analysis of Two-dimensional Floating Breakwater in Weakly Nonlinear Waves (약 비선형 파랑에 대한 연직 2차원 부방파제의 동수역학적 해석)

  • Lee, Jeongwoo;Cho, Woncheol
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.5B
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    • pp.539-549
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    • 2006
  • The performance of a pontoon-type floating breakwater (FB) is investigated numerically with the use of a second-order time domain model. The model has been developed based on potential theory, perturbation theory and boundary element method. This study is focused on the effects of weakly nonlinear wave on the hydrodynamic characteristics of the FB. Hydrodynamic forces, motion responses, surface elevation, and wave transmission coefficient around the floating breakwater are evaluated for various wave and geometric parameters. It is shown that the second-order wave component is of significant importance in calculating magnitudes of the hydrodynamic forces, mooring forces and the maximum response of a structure. The weak non-linearity of incident waves, however, can have little influence on the efficiency of the FB. From numerical simulations, the ratio of draft and depth, the relationship of wave number and width are presented for providing an effective means of reducing wave energy.

Performance of Oscillating Water Column type Wave Energy Converter in Oblique Waves (사파중 진동수주형 파력발전장치의 성능평가)

  • Jin, Jiyuan;Hyun, Beom-Soo;Hong, Keyyong;Liu, Zhen
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.17 no.3
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    • pp.182-188
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    • 2014
  • In an oscillating water column (OWC)-type wave energy conversion system, the performance of the OWC chamber depends on the chamber shape, as well as the incident wave direction and pressure drop produced by the turbine. Although the previous studies on OWC chambers have focused on wave absorbing performance in ideal operating conditions, incident waves do not always arrive normally to the OWC chamber in real sea conditions, especially in fixed devices. The present study deals with experiments and numerical calculations to investigate the effects of wave direction on the performance of the OWC chamber. The experiments were carried out in a three-dimensional wave basin for five different wave directions, including the effect of turbine using the corresponding orifice. The wave elevation inside the chamber was measured at the center point under various incident wave conditions. The numerical study was conducted by using a numerical wave tank-based volume-of-fluid model to compare the results with experimental data and to reveal the detailed flows around the chamber.

Korean Fashion Brand Purchasing Behavior by Fashion Leadership and Korean Wave of College Women Students in China (중국 여자대학생의 유행선도력과 한류 선호에 따른 한국 패션브랜드 구매행동)

  • Hong, Keum-Hee;Liu, Jing
    • Journal of the Korean Society of Clothing and Textiles
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    • v.33 no.4
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    • pp.655-665
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    • 2009
  • The purpose of this study is to find out the Korean fashion brand purchasing behavior of Chinese woman college students who would be the one of major customers in Chinese market along with their preferences of Korean wave and fashion leadership. The data was collected from 379 Chinese female college students on Qingdao, China. The results based on the data analysis were as follows. 1. The students's preferences for Korean wave about Korean drama, popular song, films were relatively high. 2. Chinese female college students's evaluation of Korean fashion brand was high, especially, for the fashion trend, design/style, color, cutting and sewing, fitting, and material. However, they valued that its price was expensive. 3. The fashion leadership was classified as fashion innovation or fashion opinion leadership. 9.0% of the respondents were fashion dual leaders who were fashion innovator and fashion opinion leader. 4. The higher family income of the respondents was the better fashion leadership, preferences for Korean wave, perceived quality and attitude toward Korean fashion brand. The results showed that promotion strategy focused on keeping the Korean wave through drama, films, and popular song. And the development of high fashion brand and the word of mouth marketing through fashion dual leader were also needed in order to make inroads into China market.

Numerical Simulation of Jet-like Currents Influenced by Irregular Waves (불규칙 파랑의 영향을 받는 유사제트류의 수치모의)

  • Choi, Jun-Woo;Park, Won-Kyung;Bae, Jae-Seok;Yoon, Sung-Bum
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.20 no.5
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    • pp.491-497
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    • 2008
  • The effect of wave and current interactions on jet-like current flowing against waves was investigated based on numerical simulations. The numerical simulations were conducted using a model system of REF/DIF(a wave model) and SHORECIRC(a current model). In the simulations, irregular waves refracted due to the jet-like opposing current were focused along the centerline of current, and the jet-like current was spreaded earlier when the wave heights become larger. The numerical results show that the rapid change of wave height distribution in transverse direction near current inlet plays a significant role to spread the jet-like current. In other words, the radiation stress gradients acting in transverse direction have a more significant effect on the jet-like current than its gradients acting in flowing direction which tend to accelerate the current do. In conclusion, it is indispensible to take into account the interaction between waves and current when the jet-like current such as river mouth meets opposing waves.