• Title/Summary/Keyword: dynamic movement

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Static and dynamic responses of a tied-arch railway bridge under train load

  • Gou, Hongye;Yang, Biao;Guo, Wei;Bao, Yi
    • Structural Engineering and Mechanics
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    • v.71 no.1
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    • pp.13-22
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    • 2019
  • In this paper, the static and dynamic responses of a tied-arch railway bridge under train load were studied through field tests. The deflection and stresses of the bridge were measured in different static loading scenarios. The dynamic load test of the bridge was carried out under the excitation of running train at different speeds. The dynamic properties of the bridge were investigated in terms of the free vibration characteristics, dynamic coefficients, accelerations, displacements and derailment coefficients. The results indicate that the tie of the measuring point has a significant effect on the vertical movement of the test section. The dynamic responses of arch bridge are insensitive to the number of trains. The derailment coefficients of locomotive and carriage increase with the train speed and symmetrically distributed double-line loads reduce the train derailment probability.

A study on the space kineticism (공간의 키네티시즘에 관한 연구)

  • 임혜선;김주연
    • Korean Institute of Interior Design Journal
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    • no.30
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    • pp.28-34
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    • 2002
  • We need to think that space is not static but dynamic because it becomes wide and narrow, newly appears and disappears by human's behavior. Generally such movement in a space is a thing of feeling and dynamic about movement. But it is extending the experience of the subject by scientific technique's development and anticipation about the feature. The practical movement is actively introduced into architecture and interior design scope and occurs a trial about this movement. By using four elements -a form, hue, movement, light- kineticism becomes visual arts united with art and science. It recovers the art's sociality and arises participation of spectators. In the environment and art field kineticism is not simple ostentation but a current trial for human's mind and sensitivility. Kineticism is four-dimensional space considered by human's experience and is related to an observer, or experiential subject of space. Now the space except human's mind feature re-illuminates kineticism, that is, the field of the formative arts in the early part of the 20th century and gets to be 'the consensus space'.

A Co-movement Analysis of Housing Purchase Price of Capital and Non-Capital Area (수도권과 지방 주택매매가격의 동조화 변화 분석)

  • Jang, Han Ik
    • Land and Housing Review
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    • v.10 no.1
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    • pp.9-18
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    • 2019
  • This study examined the dynamic change in the co-movement between the house price rates with the network methods of Mantegna (1999). First, Capital area and non-capital area form independent clusters which have the heterogeneous co-movement pattern. In other words, Capital and non-capital areas have low connectivity in the housing market. Also, if the co-movement between capital areas have been strengthened, the co-movement between non-capital areas have been weakened. The results of the dynamic analysis show that the degree of the co-movement in the housing market is continuously increased. The members of the co-movement group in the capital area are strongly steadied by all periods. However, the members in the non-capital area have been changed according to the period. Accordingly, it is necessary to establish policies based on various information for the housing market of the non-capital area rather than policies targeting the capital area. In addition, Apartments in Korea are more likely to be used as investment or speculative assets than other types of houses. It has been confirmed that this is Gangbuk, which is locatied in the northern part of Seoul, appears to be a region where the Spillover Effects of price fluctuation can be triggered in the housing and apartment market. However, the housing market in Gangnam, which is locatied in the southern part of Seoul, was divided into low systematic risk.

The Effect of Rhythmic Dance Movement Training on the Gait Length, Dynamic Valance, Depression, Quality of Life (비디오를 통한 율동적 동작훈련이 노인의 보장, 보행속도, 동적균형, 우울 및 삶의 질에 미치는 효과)

  • Roh, Kook-Hee
    • The Korean Journal of Rehabilitation Nursing
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    • v.6 no.1
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    • pp.70-78
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    • 2003
  • This study was a quasi-experimental study of nonequivalent control group pretest-posttest design to investigate the effect of rhythmic dance movement training on the physical and psychological functions of the elderly. The data were collected from November, 2001 to February, 2002. The subjects for this study were 34 elderly who was over 65 years old and was living in J city. The elderly selected for this study were: free from heart and pulmonary disease and not regular exercise. The rhythmic dance movement training in watching video tape was rhythmic dance movement and education and supportive care. The rhythmic dance movement was 40-60 intensity, 8 weeks' period, three times a week, 60 minutes a day. The data were analysed by $X^2$-test, paired t-test and unpaired t-test and ANCOVA through SAS/PC program. The results of the study were as follows: 1. There was insignificant difference in the gait length experimental and control group. 2. There was significant difference in the gait speed between the two groups. 3. There was significant difference in the dynamic valance between the two groups. 4. There was no significant difference in the depression between the two groups. 5. There was no significant difference in the Quality of life between the two groups. As shown above, the results of the 8 weeks' rhythmic movement program for the elderly produced positive effects on gait speed, dynamic valance. And this program was expected that it was more effective in different intervention period, verified program. Also it was needed follow study.

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Direct construction of a four-dimensional mesh model from a three-dimensional object with continuous rigid body movement

  • Otomo, Ikuru;Onosato, Masahiko;Tanaka, Fumiki
    • Journal of Computational Design and Engineering
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    • v.1 no.2
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    • pp.96-102
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    • 2014
  • In the field of design and manufacturing, there are many problems with managing dynamic states of three-dimensional (3D) objects. In order to solve these problems, the four-dimensional (4D) mesh model and its modeling system have been proposed. The 4D mesh model is defined as a 4D object model that is bounded by tetrahedral cells, and can represent spatio-temporal changes of a 3D object continuously. The 4D mesh model helps to solve dynamic problems of 3D models as geometric problems. However, the construction of the 4D mesh model is limited on the time-series 3D voxel data based method. This method is memory-hogging and requires much computing time. In this research, we propose a new method of constructing the 4D mesh model that derives from the 3D mesh model with continuous rigid body movement. This method is realized by making a swept shape of a 3D mesh model in the fourth dimension and its tetrahedralization. Here, the rigid body movement is a screwed movement, which is a combination of translational and rotational movement.

Robust background acquisition and moving object detection from dynamic scene caused by a moving camera (움직이는 카메라에 의한 변화하는 환경하의 강인한 배경 획득 및 유동체 검출)

  • Kim, Tae-Ho;Jo, Kang-Hyun
    • Proceedings of the Korean Information Science Society Conference
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    • 2007.06c
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    • pp.477-481
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    • 2007
  • A background is a part where do not vary too much or frequently change in an image sequence. Using this assumption, it is presented a background acquisition algorithm for not only static but also dynamic view in this paper. For generating background, we detect a region, where has high correlation rate compared within selected region in the prior pyramid image, from the searching region in the current image. Between a detected region in the current image and a selected region in the prior image, we calculate movement vector for each regions in time sequence. After we calculate whole movement vectors for two successive images, vector histogram is used to determine the camera movement. The vector which has the highest density in the histogram is determined a camera movement. Using determined camera movement, we classify clusters based on pixel intensities which pixels are matched with prior pixels following camera movement. Finally we eliminate clusters which have lower weight than threshold, and combine remained clusters for each pixel to generate multiple background clusters. Experimental results show that we can automatically detect background whether camera move or not.

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A Study of Dynamic Motion Analysis Device for Free Weight Exercise (프리웨이트운동의 동적 동작분석장치에 관한 연구)

  • Rahman, Mustafizur;Park, Ju-hoon;Kim, Ji-won;Jeong, Byeong-Ho
    • Journal of the Korea Convergence Society
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    • v.11 no.2
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    • pp.271-279
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    • 2020
  • Squats and lunges are important exercises for strengthening the trunk and lower body among various free weight exercises. It should be achieved safe and effective excise through establishing of theoretical basis for exercise posture and standard movement. Therefore, it's necessary to develop the exercise model in order to prepare the scientific countermeasures for the prevent injuries and error movement through optimal exercise movement. For this purpose, it is effective to use appropriate instruments for motion compensation according to the optical motion and error motion. In this paper, we develop a motion model analysis system based on dynamic motion through the four-point load cell for dynamic motion analysis. Proposed analytical method, the optimal and the error motion numerical data is obtained through the dynamic motion analysis. And we verified that dynamic movement is simplified to establish the motion modeling according to the classification motion and the numerical quantification data for analyzing.

Effects of Mobilization With Movement Using Posterior Talus Glide Taping Added Myofascial Release on Kinematic Data of Dynamic Balance in Individuals With Calf Shortening (종아리근 단축 대상자에게 목말뼈 후방활주 테이핑을 이용한 관절가동술 적용과 근막이완기법의 적용이 동적 균형의 운동학적 변화에 미치는 영향)

  • Seo, Min-A;Jeong, Kyu-Na;Kim, Yu-Jin;Lee, Yu-Jin;Hwang, Young-In
    • Physical Therapy Korea
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    • v.29 no.1
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    • pp.70-78
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    • 2022
  • Background: Individuals with calf muscle shortening may have decreased dynamic balance. Objects: This study aimed to investigate the effect of mobilization with movement (MWM) and myofascial release (MFR) on kinematic changes in dynamic balance in individuals with calf muscle shortening. Methods: Thirteen participants were randomly assigned to the MWM or the mobilization with movement added myofascial release (MWM-MFR) group. The MWM group received treatment with only MWM, whereas the MWM-MFR group was treated with MWM and MFR. Pre- and post-intervention passive range of motion (PROM), maximum reaching lengths, and modified star excursion balance test (MSEBT) results were compared for all participants. Wilcoxon signed-rank test and Mann-Whitney U test were used for statistical analysis. Results: The results showed significant within-group differences in ankle PROM, but no significant between-group differences. The maximum reaching length in the MWM-MFR group in the posterolateral direction was significantly different before and after the intervention (p = 0.005). This group also showed significantly reduced ankle abduction in MSEBT during the posteromedial direction section 3 (p = 0.007) and posterolateral direction section 5 (p = 0.049) compared with the MWM group. Conclusion: Combined MWM and MFR intervention improves ankle stability in the coronal plane during the posteromedial and posterolateral forward movement in dynamic balance compared with only MWM in individuals with calf shortening.

Modeling Dynamic Behavior and Injection Characteristic of a GDI Injector (GDI 인젝터의 동적 거동과 분사 특성에 대한 모델링)

  • Lee, Kye Eun;Kim, Na Young;Cho, Young Jun;Lee, Dong Ryul;Park, Sungwook
    • Journal of ILASS-Korea
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    • v.22 no.4
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    • pp.210-217
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    • 2017
  • A gasoline direct injection engine has an intake air temperature can be lowered by the fuel vaporization in the combustion chamber increase the volume efficiency is high compression ratio. Therefore, study for injection rate and characteristics which influence mixture formation in combustion chamber is important. Movement of the injector needle has a direct effect on the injection of the fuel, such as formation of cavitation, the fuel injection rate, etc. Therefore, recent studies on the dynamic characteristics of the injector considering the movement of the needle have been reported, but it takes a lot of time and cost to experimentally confirm the movement of the needle inside the injector. In this study, AMESim, a commercial 1-D code, and Star-CCM+, a 3-D CFD code, were used to predict the dynamic performance of the injector with needle motion. In order to predict the movement of the needle under the high pressure, the result of the surface pressure distribution according to the movement of the needle was derived by using the morphing technique of flow analysis. In addition, we predicted the injection rate of the injector considering the movement of the needle in conjunction with the 1-D code. The injection rate of the injector was measured by the BOSCH's method and the results were similar to those of the simulation results. This method can predict the injection rate and injection characteristics and this result is expected to be used to predict the performance of gasoline direct injection engines with low cost and time in the future.

Investigation of dynamic response of "bridge girder-telpher-load" crane system due to telpher motion

  • Maximov, Jordan T.;Dunchev, Vladimir P.
    • Coupled systems mechanics
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    • v.7 no.4
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    • pp.485-507
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    • 2018
  • The moving load causes the occurrence of vibrations in civil engineering structures such as bridges, railway lines, bridge cranes and others. A novel engineering method for separation of the variables in the differential equation of the elastic line of Bernoulli-Euler beam has been developed. The method can be utilized in engineering structures, leading to "a beam under moving load model" with generalized boundary conditions. This method has been implemented for analytical study of the dynamic response of the metal structure of a single girder bridge crane due to the telpher movement along the bridge girder. The modeled system includes: a crane bridge girder; a telpher, moving with a constant horizontal velocity; a load, elastically fixed to the telpher. The forced vibrations with their own frequencies and with a forced frequency, due to the telpher movement, have been analyzed. The loading resulting from the telpher uniform movement along the bridge girder is cyclical, which is a prerequisite for nucleation and propagation of fatigue cracks. The concept of "dynamic coefficient" has been introduced, which is defined as a ratio of the dynamic deflection of the bridge girder due to forced vibrations, to the static one. This ratio has been compared with the known from the literature empirical dynamic coefficient, which is due to the telpher track unevenness. The introduced dynamic coefficient shows larger values and has to be taken into account for engineering calculations of the bridge crane metal structure. In order to verify the degree of approximation, the obtained results have been compared with FEM outcomes. An additional comparison has been made with the exact solution, proposed by Timoshenko, for the case of simply supported beam subjected to a moving force. The comparisons show a good agreement.