• 제목/요약/키워드: wave treatment

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Quasi-steady Wave Propagation 알고리듬을 이용한 2차원 수치모형의 하상경사항 처리 (Treatment of the Bed Slope Source Term for 2-Dimensional Numerical Model Using Quasi-steady Wave Propagation Algorithm)

  • 김태형;한건연;김병현
    • 한국수자원학회논문집
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    • 제44권2호
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    • pp.145-156
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    • 2011
  • 본 연구에서는 자연하천의 흐름에서 흔히 발생하는 천이류, 불연속류, 마른하도로의 파의 전파 등을 포함하는 복잡한 흐름을 해석하기 위한 고정확도 2차원 수치모형을 개발하였다. 하상경사항을 효율적으로 처리하기 위해 quasi-steady wave propagation 기법을 적용하여 해당 격자에 대한 생성항의 영향을 효율적으로 반영함으로써 쌍곡선형 적분 보존형의 2차원 천수방정식을 해석하였다. Fractional Step Method를 적용한 유한체적기법의 사용을 위해 HLL Riemann 해법을 이용하여 흐름률을 계산하였고, 시간 및 공간에 대한 2차 정확도를 만족하기 위해 MUSCL 기법을 적용하였다. 2차 정확도의 사용으로 불연속지점에서 발생하는 수치진동은 TVD 기법 적용을통해 제어하였다. 개발된모형은 2차원 제방 붕괴 및 댐하류부에 구조물이 존재하는 경우의댐 붕괴 모의를 통해실측치와의 검증을 실시하였다. 또한 하류부에 역경사가 존재하는 경우의 댐 붕괴 모의를 통해 실측치와 비교함으로써 생성항의 영향에 대한 모형의 적용성을 검증하였다.

전자파가 인체에 미치는 영향 - 전자파 차폐소재와 청각자극에 나타난 뇌파전위의 변화 - (A Study on the Effects of Electromagnetic Wave on Human Body - The Variation of Electroencephalogram by Blocking Electromagnetic Wave Materials and Aural Stimuli -)

  • 이수정;이태일
    • 한국의류산업학회지
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    • 제6권4호
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    • pp.503-510
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    • 2004
  • The study is one of fundamental researches for the development of future smart clothing and textile products with blocking properties from electromagnetic waves by analyzing human physical symptoms in using electromagnetic products in such an environments. Among various textiles in the experiment, nano silver has shown the best blocking performance from electromagnetic waves, which decreases depending on the distance. The power spectrum distribution and the incidence of electroencephalogram between blocking materials and aural stimuli has shown that, ${\beta}$, wave appeared to be active in all channels except for $T_4$, whereas all waves appeared with processed materials and especially with nano silver silk(NSS), ${\alpha}$, ${\beta}$, ${\theta}$, ${\gamma}$ waves appeared active in all regions. As for the brain mapping of ${\alpha}$ wave according to time, there found a strong activity in $P_3$, $P_4$ of the parietal lobe, with all materials on all time regions. With silk nylon metal(SNM) and NSS, it appeared strong in $F_3$, $F_4$ as well. As for ${\beta}$, wave, the activity appeared strong in frontal lobe before 7min. 30sec, where it tends to diminish abruptly in 7min. 30sec. to 13min. 30sec. region. After 13min., it regained gradually. With NSS, it appeared strong in all areas except for the farthest $T_4$. The appearance of ${\nu}$ wave can be deduced as it can affect human body with its toxic property while the silver particles become nano-sized. Therefore, the study conducted with human participants requires a proper particle size of it which would not penetrate cellular tissues and a proper binder and binding treatment for it, to prevent the physical fatigues and the potential diseases. However, it is highly required for back-up researches to verify various aspects in applying nano silver to textile products.

의류무역회사의 해외생산공장 현황과 소싱지역의 한류 영향에 대한 연구 - 베트남과 인도네시아를 중심으로 - (A Study of Overseas Manufacturing Factories of Garment Vendors and the Influence of Korean Wave over the Sourcing Area - Focused on Vietnam and Indonesia -)

  • 최혜선;이은영;김지은
    • 복식
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    • 제62권4호
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    • pp.149-163
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    • 2012
  • This study reviewed current facts on overseas manufacturing factories of garment vendors that were launched in the countries that have a great influence of the Korean Wave, and investigated the influence of Korean Wave in its sourcing area. By doing so, this study aims to present basic data in order to help fabric and garment vendors to enter into the fashion markets of different countries through a local network. For data collection and analysis, Windows SPSS 19.0 was used for frequency analysis of the facts and figures of the local manufacturing factories. In-depth interviews regarding the current facts on local manufacturing factories and the influence of Korean Wave were conducted with 16 Korean garment manufacturing factories in Vietnam and 9 in Indonesia among the overseas garment companies that were registered in the Korean Apparel Industry Association. Through the interview, it was found that new companies should investigate custom tariffs, salary level of the local employees, and infrastructure prior to launching above all. Also, as a result of analyzing competitors and competitive advantages, good treatment of local employees and a good labor environment were noted the most. As for the influence of the Korean Wave, the image of Korea was positive and favorable, but it did not directly affect the preference for Korean companies. After investigating the obstacles that prevented the entrance into local markets, it was found that the rise in the salary level was the biggest hindrance.

스펙트랄요소법(SEM)을 이용한 파랑-조류 상호작용 현상 수치해석 연구 (Numerical Analysis of Wave-Current Interaction Phenomenon Using the Spectral Element Method)

  • 성홍근;홍기용;경조현;홍사영
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2006년도 추계학술대회 논문집(제1권)
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    • pp.181-186
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    • 2006
  • 본 논문에서는 Freak Wave의 생성원인에 대하여 간략히 논의하였으며, 이 중 파랑-조류 비선형 상호작용에 대한 이론 및 수치적 해석기법의 역사와 장단점 등을 기술한다. 본 연구에서는 파랑-조류 상호작용에 대한 수치모델링 및 해석 기법을 개발하고 있다. 개발 중인 수치해석 기법은 공간적으로 불균일한 조류와 파랑의 비선형 상호작용을 해석하기 위하여 Navier-Stokes 방정식을 이용하여 유동현상을 모델링하였으며, 이산화를 위하여 스펙트랄요소법(Spectral Element Method; SEM)을 이용하였다. 또한 자유표면의 운동을 효과적으로 기술하기 위하여 ALE(Arbitrary Lagrangian-Eulerian)기법을 사용하였다. 본 연구의 유동 모델과 수치해석기법의 과정과 특성, 그리고 장점 등에 대하여 논의하였으며, 초기적인 수치해석 결과를 제시하였다. 이를 바탕으로 개발된 수치해석기법의 정확성 및 수렴성을 확인할 수 있다.

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세장선 이론에 의한 조파저항의 수치 해석 (Numerical Analysis on the Wave Resistance by the Theory of Slender Ships)

  • 김인철
    • 수산해양기술연구
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    • 제23권3호
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    • pp.1-1
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    • 1987
  • 이상으로부터 다음의 결론을 얻는다. 조파저항 이론의 전개에서 Michell 적분보다 더욱 정밀한 Neumann-Kelvin 문제가 복잡한 kernel 함수 때문에 많은 시간과 노력이 필요하지만, 원점 부근에서 Kelvin 소오스의 점근거동을 조사하여 세장체 근사를 행함으로 N-K 문제의 kernel 함수에 대한 근사와 동등하게 처리될 수 있었다. 조파저항의 계산 결과가 Michell 적분과 비슷한 경향을 보이나, 실험치와의 정확한 비교를 할 수 없었다. 그러나 세장선 이론을 적용함으로써 훨씬 복잡하고 지루한 작업을 들 수 있었다. 전진 속도를 갖는 경우에는 수정된 Green정리를 이용하면 될 것으로 기대된다.

근조직 재활치료를 위한 자계신경 자극시스템의 설계 및 구현 (Research about design and manufacture of Crossing High-Amplitude Magneto-Therapy own nerve system for Muscuoskeltal tissue rehalibitation treatment)

  • 김휘영
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2006년도 하계종합학술대회
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    • pp.855-856
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    • 2006
  • Magnetic nerve stimulation treatment is much backward real condition than other field. Specially, successful medical treatment introduction of magnetic field (MF) can was refered long ago in Avicenna's work, and is thought as age of medicine magnetology development recently. These development is achieved through biologist and biophysicist and clinician's joint effort, but, new mountings and relationship air tassel are developed steadily. Magnetic nerve stimulation treatment field designs treatment system by each function during long wave high-amplitude (traditional magneto therapy of greatly great that strong that) short time that CMF, VMF, PMF field etc. are representative but are HPMT technology in this research and manufacture and special quality did comparative analysis.

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아크 금속 용사 표면 처리 방법에 따른 Zn-Al 금속 용사 피막의 물리적 특성 평가 (Evaluation of physical properties of Zn-Al metal coating according to arc metal spray surface treatment method)

  • 장종민;김영관;이한승
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2022년도 가을 학술논문 발표대회
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    • pp.89-90
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    • 2022
  • Arc metal spraying is a widely used method for improving the performance of construction structures such as corrosion resistance and electromagnetic wave shielding. However, when arc metal spraying is applied to a concrete structure, adhesion performance may deteriorate. Therefore, the effect of each surface treatment method on the physical properties between the arc metal spray coating and concrete was reviewed by evaluating the deposition efficiency and adhesion performance according to the arc metal spray surface treatment method (surface reinforcing agent, roughening agent, and sealing agent). As a result, it is suggested as an optimal surface treatment condition to induce non-interface failure by using a roughening agent and to improve the properties of concrete and metal coatings by applying a surface reinforcing agent and sealing agent.

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진동, 파동치료에 관한 국내 연구 동향 (An Overview on Vibration or Wave Therapy in Korea)

  • 이재흥;백지유;장성진;필감매
    • 대한의료기공학회지
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    • 제20권1호
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    • pp.15-67
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    • 2020
  • Objective : The purpose of this study is to identify the trends of vibration(or wave) therapy in Korea, to actively utilize vibration(or wave) therapy, and to help research activities of vibration therapy in Korean Medicine. Methods : The following Korean words "진동기", "진동요법", "진동운동", "진동치료", "파동요법", "파동운동", "파동치료" were searched on three specialized search sites (RISS, NAL, DBpia). Trends of vibration therapy were analyzed through the selected researches suitable for this study among these searched researches in an overview format. Results : 1. A total of 8,116 studies were searched and a total of 365 studies were finally selected 2. From 2000 to 2019, when research began to increase in earnest, there were 17.45±10.28 studies per year, and the AGR(Average Annual Growth Rate) was 11.92%. 3. In the main field of research, the 'Medicine and Pharmacy' was the largest with 147(40.16%) studies. In the Middle Field, the 'Kinesiology' was the largest with 99(27.05%) studies. In the study design, 'RCT(Randomized Controlled trial)' was the largest with 138(47.75%) studies. In the Age Group, 'Youth' was the largest with 126(48.84%) studies. 4. The average of the number of participants was 24.90±17.44. 5. The most used Intervention was the 'WBV(Whole Body Vibration)' with 177(61.25%) studies. 6. The average of Intervention Period was 5.99±4.14 weeks, while the maximum was 36 weeks. 7. The journal that published the most research papers is 'K. J. of Sports Science(체육과학연구;13)', and the society is 'Rehabilitation Engineering And Assistive Technology Society of Korea(한국재활복지공학회; 14)'. The University that published the most dissertations is 'Sahmyook University(11)'. 8. The authors who published the most studies are Ju-Hwan O(8) as the main author and Tae Kyu Kwon(18) as the co-author (including the thesis Director). In an integrated analysis of the authors and co-authors, Tae Kyu Kwon published the most numerous studies(19) Conclusions : 1. The study of vibration or wave therapy has been increasing noticeably every year. 2. The major academic Fields studying vibration or wave therapy are the 'Kinesiologic Field', 'Physical Therapy Field', and 'Biomedical Engineering Field'. 3. The most chosen method of study design on vibration or wave treatment was 'RCT', and there was no significant change in the annual presentation rate. 4. Types of vibration or wave therapy could be classified as 'LVS(Local Vibration Stimulation)', 'WBV(Whole Body Vibration)', 'MV(Micro Vibration)', 'BV(Bio Vibration)' and 'SWV(Sound Wave Vibration)', and the study on Whole Body Vibration is most active. 5. Most of the studies of vibration or wave therapy were on musculoskeletal systems, but there were very few studies on internal diseases.

전자기식 체외충격파쇄석술시 하부요관 결석 환자에 대해 적합한 충격강도와 C-arm 총 가동시간 (The Optimal Shock Intensity and C-arm Total Running Time in Patients with Inferior Ureter Stones during Electromagnetic of ESWL)

  • 박정규;조의현
    • 한국방사선학회논문지
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    • 제8권7호
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    • pp.461-466
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    • 2014
  • 체외 충격파 쇄석술시 쇄석기종에 따라 각각 장단점이 있으며, 전 처치로 인한 여러 가지 부작용이 보고되고 있다. 이에 전자기식 ESWL시 하부결석환자에서 적합한 충격파의 강도를 찾아보고, C-arm의 총 가동시간을 측정해 보았다. 본 연구는 2014년 1월부터 6월까지 경북지역 일개시의 C대학병원에서 전 처치를 시행하지 않고 ESWL을 받은 65명의 환자를 대상으로 하였다. 성비는 남자가 48명, 여자가 17명으로 남자가 더 많았으며, 연령은 50대가 가장 많았다. 하부요로결석의 발생은 왼쪽이 더 많았으며, 결석의 크기는 5mm 이하가 39명으로 가장 많았다. 적합한 충격강도는 1의 강도이며 통증을 호소하는 경우 C의 강도로 전환하여 충격을 가할 수 있다. 또한 C-arm의 총 가동시간은 $241.73{\pm}30.37$초로 나타났으며, 이것은 하부요로결석의 크기와 유의한 차이를 보였다(p<0.05). 따라서, ESWL시 전처치를 시행하지 않고 시술을 할 경우 요관 결석의 부위에 따라 적합한 충격강도와 충격빈도의 기준이 필요로 하며, C-arm 총 가동시간도 요관 결석의 발생부위에 따라 방사선으로 인한 피폭을 최소화하기 위한 총 가동시간에 대한 기준이 필요할 것으로 사료된다.

초음파를 이용한 만성 부비동염의 치료연구 (The Effects of the Ultrasound on Treatment of Chronic Sinusitis)

  • 허성귀;임원식;배성수
    • The Journal of Korean Physical Therapy
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    • 제14권1호
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    • pp.55-62
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    • 2002
  • The purpose of this study was to determine the effects of the ultrasound on treatment of chronic sinusitis. 24 persons of men and women with chronic sinusitis divided into three groups of each 8 persons randomly and when were they were treated with the medication, the ultrasound(1MHz continuous wave, 1W/$cm^2$ intensity, three times per a week and once of three minutes circular stroke method) and the medication+ultrasound for 2, 4, 6 and 8 weeks. The results of this study were ad follows. 1. There was not statistical significant differences between the effects of treatment until two weeks(P>.05). 2. There was statistical difference between the effects of treatment after 4 weeks, 6 weeks and 8 weeks(P<.05). There was statistical significant difference between the group with ultrasound treatment and the group with ultrasound+medication treatment and there was statistical significant difference between the group with medication treatment and the group with ultrasound+medication treatment but there was not statistical significant between the group with ultrasound treatment and the group with medication treatment. 3. After 4 weeks, the highest effect for chronic sinusitis was group

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