• Title/Summary/Keyword: 함정운동

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연중특별기획 - 의사가 따로 있나? 내몸은 내가 잘 알지! - 건강기능식품과 민간요법을 맹신하는 건 몸을 망치는 일

  • Jeong, Jong-Ho
    • 건강소식
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    • v.34 no.12
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    • pp.18-23
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    • 2010
  • 우리나라의 병원문턱이 그리 높지 않은데도 특정 건강식품을 즐겨먹거나, 주위 사람이 효과를 봤다는 비법(?)들을 따라하며 몸 망치거나, 숨겨진 병을 키우며, 헛되이 돈을 쓰는 사람들이 많다. 규칙적인 운동과 식단을 조절하려는 노력은 게을리 한 채 간편하게 건강관리를 해보겠다는 사람들이 빠질 수 있는 함정이다. 당신이 만약 내 몸은 내가 잘 안다며 무슨 의사인냥 한다면 이보다 더 큰 실수도 없다. 그 이유를 알아본다.

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Experimental Investigation on Hydrodynamic Coefficients of Submarine Model by VPMM Test (VPMM 시험을 이용한 수중 잠수함 모형의 동유체력 계수 추정에 관한 연구)

  • Jung, Jin-Woo;Jeong, Jae-Hun;Kim, In-Gyu;Lee, Seung-Keon
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2013.10a
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    • pp.117-118
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    • 2013
  • In these days, the world have been increasing navy forces such as aircraft carriers and high-tech destroyers etc. and the importance of submarines is being emphasized. Therefore, accurate values of the derivatives in equations of motion are required to control motion of the submarines. Hydrodynamic coefficients were measured by the vertical planar motion mechanism(VPMM) model test. VPMM equipment gave pure heave and pitch motion respectively to the submarine model and the forces and moments were acquired by load cells. As a result, the hydrodynamic coefficients of the submarine are provided through the fourier analysis of the forces and moments in this paper.

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Approximate Analysis of Shock Response for Ship Hull Girder (선체거더 충격응답의 근사해석)

  • Song, C.T.;Park, B.W.;An, C.W.;Cho, Y.S.
    • Journal of the Society of Naval Architects of Korea
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    • v.33 no.2
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    • pp.75-84
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    • 1996
  • The structural response of naval surface ships subjected to underwater shock loadings is a very important problem in viewpoint ship survivability. In practice, among others the case of noncontact underwater explosions is the only one shock loading considered in designing naval surface ships to resist underwater explosions. In orator to efficiently design naval surface ships and their equipment to resist such shock loadings it seems necessary to prepare theoretical analysis tools and/or empirical design criteria which can predict the three dimensional transmission of shock waves. This paper describes a simplified method to analyse shock responses for ship hull girder, which uses a loading function to approximate the shock loadings on ship structures due to noncontact underwater explosions. A couple of examples to apply this method are provided.

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Estimation of Hydrodynamic Derivatives of Submarine Model by Using VPMM Test (VPMM 시험을 이용한 잠수함 모형의 유체력 미계수 추정)

  • Jung, Jin-Woo;Jeong, Jae-Hun;Kim, In-Gyu;Lee, Seung-Keon
    • Journal of Navigation and Port Research
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    • v.38 no.2
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    • pp.97-103
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    • 2014
  • In these days, the world has been increasing navy forces such as aircraft carriers and high-tech destroyers etc. and the importance of submarines is being emphasized. Therefore, accurate values of the derivatives in equations of motion are required to control motion of the submarines. Hydrodynamic derivatives were measured by the vertical planar motion mechanism(VPMM) model test. VPMM equipment gave pure heave and pitch motion respectively to the submarine model and the forces and moments were acquired by load cells. As a result, the hydrodynamic derivatives of the submarine are provided through the Fourier analysis of the forces and moments in this paper.

A Denoising Method for the Transient Response Signal (과도응답신호의 잡음제거기법)

  • Ho-Il Ahn
    • Journal of the Society of Naval Architects of Korea
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    • v.38 no.3
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    • pp.117-122
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    • 2001
  • The shock test of shipboard equipments is performed for the evaluation of the shock-resistant. capability by analyzing the maximum acceleration, the effective time duration and the shock response spectrum, etc. But some measured signals have impulsive noise and gaussian white noise because of the ambient noise, the acquisition equipment error and the transient movement of cables during the shock test. The improved transient signal analysis method which removes the noise of measured signal using the threshold policy of the median filter and the orthogonal wavelet coefficients is proposed. It was verified that the signal-to-noise ratio was improved about 30dB by the numerical simulation. And the shock response spectrum was extracted using the denoised shock response signal which was applied by this proposed method.

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The Effect of Muscle Strength, Endurance & Flexibility on Taping and Concentric Exercise of Trunk (테이핑과 체간의 구심성 운동이 근력, 지구력 및 유연성에 미치는 영향)

  • Cho, Nam-Jung;Choi, Won-Jye;Park, Sun-Ha;Park, Hyun-Ju;Oh, Sang-Bu;Oh, Han-Suk;Ham, Jeong-Dae;Yoo, Byung-Kook;Lee, Sam-Cheol;Son, Kyung-Hyun
    • Journal of Korean Physical Therapy Science
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    • v.16 no.3
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    • pp.35-42
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    • 2009
  • Background: The purpose of this study is to measure the amount of influence of taping and a whole body balance upon muscle strength, endurance, and flexibility. Experiments were conducted by two different groups, specially designed for this study. The choice of exercise methods for each group depends on its own idiosyncratic characteristics (or Each group employs its own idiosyncratic exercise method). Methods: The first group, with taping applied, undertook exercises three times a week; second group just took exercises three times a week. These experiments show the following outcomes. Results: The first group showed a considerable amount of difference in terms of muscle strength, endurance, and flexibility. Second group also showed similar outcome. Both the first group and the second group revealed a considerable difference. But the first group showed a bigger difference than the second group. Conclusion: Thus, the result of these experiments strongly indicates that exercise, with taping applied, turns out the most effective in promoting muscle strength, endurance, and flexibility.

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An Experimental Study on the Measurement of Water Surface Discharge Temperature of High-Temperature Bubble Injected into Cylindrical Acrylic Water Tank (원통 아크릴 수조로 주입된 고온 기포의 수면 배출 온도 측정에 관한 실험적 연구)

  • SeokTae Yoon;YongJin Cho
    • Journal of Korea Society of Industrial Information Systems
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    • v.28 no.6
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    • pp.99-105
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    • 2023
  • Submarines, which require a high degree of survivability, are among the most critical combat weapon systems in military strategic assets. Conventional submarines need air to operate their propulsion systems. Exhaust gases released into the water during snorkel navigation heat the surrounding fluid, producing a temperature wake. This wake, in turn, reduces the submarine's survivability. In this study, we conducted a preliminary experiment on the temperature traces formed by an underwater submarine's waste discharge. For this purpose, we collected propulsion system and navigation condition data from domestically introduced submarines and developed an experimental system to measure the temperature traces. As a result, we observed that high-temperature bubbles injected into the tank broke down into smaller sizes, and their temperature dropped to levels similar to the surrounding fluid. This observation was confirmed using a thermocouple sensor. Consequently, the thermal imaging system designed to measure the temperature trace of the water's surface did not detect any significant temperature traces.