• Title/Summary/Keyword: 동요속도

Search Result 50, Processing Time 0.023 seconds

Roll Damping Moment of a Small Fishing Vessel by Free Rolling Test in Waves (파랑중 자유 횡동요 시험에 의한 소형어선의 횡동요 감쇠모멘트에 관한 연구)

  • H.H. Chun;S.H. Chun;S.Y. Kim
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.37 no.2
    • /
    • pp.30-37
    • /
    • 2000
  • The roll damping characteristics of the three models of a 3ton class fishing vessel, that is the bare hull, hull with bilge keels, and hull with bilge keels and a central wing are investigated by the free roll tests in head waves in a towing tank with the variations of the forward speed, initial angle and OG. The wave length variations are also included. The experimental results are compared with the numerical results of mathematical modellings by the energy method for these three models and the energy dissipation patterns are also compared. The roll damping speed increases, the effect of the waves on the roll damping of the models with the additional devices is negligible due to the much increased damping caused by the lift increase.

  • PDF

The effect of ankle joint mobilization technique on equilibrium ability in the individuals with supinated foot (회외발에 대한 족관절 관절가동술이 균형능력에 미치는 영향)

  • Gong, Won-Tae;Ma, Sang-Yeol;Kim, Tae-Ho
    • Journal of the Korean Data and Information Science Society
    • /
    • v.20 no.3
    • /
    • pp.527-539
    • /
    • 2009
  • The purpose of this study was to evaluate the influence of ankle joint mobilization on equilibrium ability of supinated foot. Both Joint mobilization group(n=20) and control group(n=20) were measured an equilibrium ability by Balance performance monitor at pre-test, post-test in 2 weeks, post-test in 4 weeks and follow-up test in 2 weeks. The sway area, sway path length and sway maximum velocity of the joint mobilization group were significantly reduced among the experimental period (p<.05). The reduction of sway area, sway path length and sway maximum velocity were significantly different between the joint mobilization group and the control group at in 2 weeks, 4 weeks and follow-up test(p<.05). In conclusion, we were found that ankle joint mobilization could reduce sway area, sway path length and sway max velocity and improve a balance for the individuals with supinated foot.

  • PDF

Effect of Balance Ability and Walking in the Elderly by Taekwon-do Program (태권도 프로그램이 노인의 체중심 동요와 보행에 미치는 영향)

  • Kim, Jun-Hyun;Park, Sung-Jin
    • Journal of the Korean Society of Physical Medicine
    • /
    • v.7 no.3
    • /
    • pp.379-385
    • /
    • 2012
  • 연구목적 : 본 연구의 목적은 태권도 프로그램이 노인의 균형능력에 어떠한 영향을 미치는지에 대해 알아보는 것이다. 연구방법 : 대상자는 본 연구에 대해 설명을 들은 후 자원한자로서 65세 이상의 노인이었다. 실험군은 태권도 프로그램 그룹으로서 17명이었다. 태권도 프로그램을 주3회씩 6주간 시행하였고 모든 대상자의 균형능력을 평가하기 위하여 BPM, GAITrite, Berg 균형척도를 실험전후로 평가하여 자료를 수집하였다. 수집된 자료는 SPSS 14.0으로 대응표본 t-test를 사용하여 유의수준 ${\alpha}$=.05에서 통계 처리 하였다. 연구결과 : 태권도 프로그램을 시행한 결과 프로그램 실행 전에 비해 오른쪽 활보폭, 왼쪽 보폭, 왼쪽 활보폭, 버그 균형척도에서 통계적으로 유의한 증가를 나타내었다. 그리고 최대 동요속도, 동요거리, 오른쪽 기저 지지면, 오른쪽 양하지 지지기, 왼쪽 기저지지면, 왼쪽 양하지 지지기에서 통계적으로 유의한 감소가 있었다. 결론 : 태권도 프로그램을 시행한 결과 오른쪽 활보폭, 왼쪽 보폭, 왼쪽 활보폭, 버그 균형척도에서 유의한 증가와 최대 동요속도, 동요거리, 오른쪽 기저 지지면, 오른쪽 양하지 지지기, 왼쪽 기저지지면, 왼쪽 양하지 지지기에서 유의한 감소는 균형 제어에 긍정적인 영향을 미칠 것으로 판단된다. 따라서 이러한 균형 제어 능력의 향상은 노인의 보행에 있어서의 낙상 예방에 효과적일 것으로 사료된다.

Roll Damping Moment of a Small Fishing Vessel by Free Rolling Test in Calm Water (평수중 자유 횡동요 시험에 의한 소형어선의 횡동요 감쇠모멘트에 관한 연구)

  • H.H. Chun;S.H. Chun;S.Y. Kim
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.37 no.1
    • /
    • pp.1-9
    • /
    • 2000
  • The roll damping characteristics of the three models of a 3 ton class fishing vessel such as the bare hull, hull with bilge keels, and hull with bilge keels and a central wing are investigated by the free roll tests in calm water in a towing tank with the variations of the forward speed, initial angle and OG. The experimental results are compared with the numerical results of mathematical modellings by the energy method for these three models and the energy dissipation patterns are also compared.

  • PDF

Comparison of Effects of Obstacle Training in Aqua and Land on the Balance of Chronic Stroke Patients (수중과 지상에서 장애물 훈련이 만성 뇌졸중 환자의 균형에 미치는 효과 비교)

  • Jung, Jae Hyun;Chung, Eun Jung;Kim, Kyoung;Lee, Ji Yeun
    • 재활복지
    • /
    • v.17 no.4
    • /
    • pp.383-399
    • /
    • 2013
  • The purpose of this study was to comparison the effects of aqua-and-land based obstacle training on balance of chronic stroke patients. Subjects were randomly divided into an aqua group(n=15) and d land group(n=15). Both group received obstacle training for 40 minutes, 3 times a week during 12 weeks. Static balance was assessed by measuring the mean velocity of mediolateral, anteroposterior and sway area with the eyes open using Good Balance System. Dynamic balance was assessed by measuring Functional Reaching Test(FRT) and the Timed Up and Go test(TUG). Following the intervention, both groups showed significant changes static balance(the mean velocity of mediolateral, anteroposterior and sway area) and dynamic balance(FRT and TUG). There were significant difference in the mean velocity of mediolateral, anteroposterior, sway area, FRT and TUG between the two groups after the interventions. The results of this study suggest that the aqua group and land group were increase balance functions of chronic stroke patients. The aqua group was significantly higher than the land group for patients with chronic stroke patients. We hope that aquatic training can be useful for patients with chronic stroke patients to improve balance functions and the aqua training research for improve balance functions will be conducted continuously.

The Effects of Home Based Exercise Program on Balance Recovery in a Post-Stroke Population (뇌졸중 환자의 균형능력 회복을 위한 가정운동프로그램 효과)

  • Jang, Sang-Hun;Bang, Hyun-Soo;Jung, Byeong-Ok
    • Journal of Digital Convergence
    • /
    • v.12 no.7
    • /
    • pp.297-304
    • /
    • 2014
  • The present study was designed to investigate the effect of home based exercise program on balance recovery of stroke patients. In total, 20 participants were assigned to a control group(n=10) or exercise group(n=10) between September 2013 and December 2013. In addition to existing physiotherapy, the exercise group received home based exercise program consisting of weight transfer, training endurance, mobility, sensory retraining, lower limb exercise for 30 minutes, 2 times a week, for 8 weeks, every time for 30 minutes. Balance ability was assessed by measuring foot pressure(FP), limit of stability(LOS) and velocity sway(VS) by using Biorescue and by using the functional reaching test(FRT). To compare the improvement level of each group's balance ability, examination of independent sample T was done. Significant differences between control group and exercise group in LOS, VS of affect side and FRT were observed. This study showed that home based exercise program application was effective strategy on balance recovery in a post stroke population.

Effect of Lumbar Mobilization Combined with Dual Task Training on Balance in Patients with Chronic Stroke (이중과제훈련을 결합한 허리 관절가동술이 만성 뇌졸중 환자의 균형에 미치는 영향)

  • Kim, Tae Young;Lee, Sang Bin;Ryu, Byeong Ho;Kim, Ji Hong
    • Journal of Convergence for Information Technology
    • /
    • v.9 no.12
    • /
    • pp.264-270
    • /
    • 2019
  • The purpose of this study was to evaluate the effect of lumbar mobilization combined with dual task training on balance ability in patients with chronic stroke. In this study, 30 adults who were diagnosed with a stroke were divided into 15 groups, each with a dual task training group, a dual task training group applying joint mobilization to the lumbar from July 1, 2019 to August 31, 2019, it was held for 30 minutes a day for two months, three times a week for a total of eight weeks. The clinical balance evaluation index was measured by K-BBS, and the surface area, step length and average speed were measured using Bioresque. In K-BBS, scores were increased in all groups, and the balance ability was increased in the surface area, step length and average speed using Bioresque. Therefore, the combination of dual task training for the lumbar was thought to have an effect on increasing the balance ability of chronic stroke patients.

KVLCC2의 천수역에서의 자세변화에 대한 실험적 연구

  • Yun, Geun-Hang;Yeo, Dong-Jin;Park, Byeong-Jae
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
    • /
    • 2013.10a
    • /
    • pp.85-87
    • /
    • 2013
  • 깊이가 제한된 천수역을 운항하는 선박의 경우, 선저면의 동유체력변화로 인해 선박의 흘수가 증가하는 스쿼트 현상이 나타난다. 본 연구에서는 KVLCC2선형을 대상으로 H/T(Depth/Draft) = 2.0, 1.5, 1.2의 천수조건에서 모형선의 속도변화, 프로펠러 유무에 따른 모형선박의 상하동요, 종동요 자세변화를 계측하였다. 또한 계측된 모형선의 상하동요변화는 Tuck/Huuska, Barrass 2, Eryuzlu 등의 경험식에 따른 결과와 비교하여 그 유효성을 검증하였다.

  • PDF

Surface-Tension Effects on the Flow Caused by a Two-Dimensional Pulsating Source Moving with a Constant Speed beneath the Free Surface (전진하며 동요하는 2차원 특이점에 의하여 발생되는 자유표면파에 미치는 표면장력의 영향)

  • Hang-S.,Choi;Jae-S.,Choi
    • Bulletin of the Society of Naval Architects of Korea
    • /
    • v.27 no.1
    • /
    • pp.57-62
    • /
    • 1990
  • This paper deals with the flow caused by a two-dimensional pulsating source, which moves with a constant horizontal speed beneath the free surface. The analysis is based on lincar potential theory including surface tension effects. In the case of subcritical reduced frequencies $\tau<1/4(\tau=U_{\omega}/g$, U=constant speed, $\omega$=circular frequency, g=gravitational acceleration), six wave components arc found. Two of them are largely affected by surface tension, which propagate ahead of the source in the direction of and opposite to the steady translation, respectively. The rest are almost identical with those found by Haskind(1954), i.e. for which the surface tension effect is negligible. For low oscillation frequencies, the resonant frequency still exists at $\tau$ only slightly greater than 1/4. For oscillation frequencies greater than $\nu(={\omega}^2/g)>20$, the surface tension effect is so significant that it disperses generated waves and consequently the singular phenomenon is removed. However, in addition to the gravity breaking, capillary breakings occur when the translation speed coincides with the minimum capillary celerity.

  • PDF

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
    • /
    • v.38 no.2
    • /
    • pp.97-103
    • /
    • 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.