• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1333-1337
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• 2000

The flexural vibration of laminated composite beams with active and passive constrained-layer damping has been investigated to design structure with maximum possible damping capacity. The equations of motion are derived for flexural vibrations of symmetrical, multi-layer laminated beams. The damping ratio and modal damping of the first bending mode are calculated by means of iterative complex eigensolution method. This paper addresses a design strategy of laminated composite under flexural vibrations with active control.

• Journal of Korea Technology Innovation Society
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• v.14 no.2
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• pp.343-372
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• 2011

Since the introduction of motion picture in the early 20th century, Korean motion picture industry has gradually evolved as one of the world leaders. However, due to the rapid technological change as exemplified by the emergence of the new digital and 3D cinema technologies, there is a need to re-consider the existing technology policy and strategy designed for the adoption and effective use of new technologies. In this paper, the authors address this issue by emphasizing the technological development side rather than the use/adoption side. In order to provide policy makers with critical information on the current status of the sector, we analyzed the sectoral innovation system of the Korean motion picture industry. In order to conduct this analysis, we re-visited previous literature and interviewed experts in the motion picture sector. Then, the authors attempted to identify the characteristics and problems of the current Korean motion picture industry. Based on the insights gained from this research, we draw policy implications for technological innovation in this sector. However, the implications from this paper are not limited to the motion picture industry. As the motion picture industry is a new case for innovation studies, our paper may provide new research opportunities to the academia.

• The KIPS Transactions:PartB
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• v.16B no.2
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• pp.123-130
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• 2009

Motion estimation (ME) plays an important role in digital video compression. But it limits the performance of image quality and encoding speed and is computational demanding part of the encoder. To reduce computational time and maintain the image quality, integer pel and fractional pel ME methods are proposed in this paper. The proposed method for integer pel ME uses a hierarchical search strategy. This strategy method consists of symmetrical cross-X pattern, multi square grid pattern, diamond patterns. These search patterns places search points symmetrically and evenly that can cover the overall search area not to fall into the local minimum and to reduce the computational time. The proposed method for fractional pel uses full search pattern, center biased fractional pel search pattern and the proposed search pattern. According to block sizes, the proposed method for fractional pel decides the search pattern adaptively. Experiment results show that the speedup improvement of the proposed method over Unsymmetrical cross Multi Hexagon grid Search (UMHexagonS) and Full Search (FS) can be up to around $1.2{\sim}5.2$ times faster. Compared to image quality of FS, the proposed method shows an average PSNR drop of 0.01 dB while showing an average PSNR gain of 0.02 dB in comparison to that of UMHexagonS.

• Physical Therapy Korea
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• v.11 no.1
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• pp.53-67
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• 2004

This simulation study investigated the characteristics of normal gait, $30^{\circ}$ crouch gait, $30^{\circ}$ crouch/equinus gait, $45^{\circ}$ crouch gait, $45^{\circ}$ crouch/equinus gait. The knee flexion angles were restricted using a specially designed orthosis. This study was carried out in a motion analysis laboratory of the National Rehabilitation Center. Fifteen healthy male subjects were recruited for the study. The purposes of this study were (1) to compare spatiotemporal parameters, kinematics, and kinetic variables in the sagittal plane among the different gait, (2) to investigate the secondary compensatory strategy, and (3) to suggest biomechanical physical therapy treatment methods. The pattern and magnitude observed in each condition were similar to those of normal gait, except the peak knee extension moment of the unrestricted ankle motion-crouch gait. However, the speed of the $45^{\circ}$ crouch gait was half that of a normal gait. The ankle joint moment in the crouch/equinus gait showed the double-bump pattern commonly observed in children with spastic cerebral palsy, and there was no significant difference in gait speed as compared with normal gait. The peak ankle plantar-flexor moment and ankle power generated during the terminal stance in the crouch/equinus conditions were reduced as compared with normal and $45^{\circ}$ crouch gaits (p<.05). The crouch/equinus gait at the ankle joint was an effective compensatory mechanism. Since ankle plantarflexion contracture can be exacerbated secondary to the ankle compensatory strategy in the crouch/equinus gait, it is necessary to increase the range of ankle dorsiflexion and the strength of plantarflexion simultaneously to decrease the abnormal biomechanical advantages of the ankle joint.

• Journal of The Korean Association For Science Education
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• v.32 no.4
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• pp.671-685
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• 2012

In this study, we developed an analogical experimental design strategy emphasizing understanding and checking stages and applied it to four groups consisting of 7th grade science-gifted students. We classified the patterns of experimental design processes and analyzed the verbal interactions among the science-gifted students at the levels of turn and interaction unit. The analyses of the results reveled that three groups were relevant to reinitiated motion and the other to backward-divergent motion. In the analyses of turn and interaction unit, the frequencies of the statements related to the task were high, especially 'making suggestion' and 'elaborated symmetrical interaction'. The analyses for each stage of strategy indicated that the frequencies of 'explain', 'question', and 'cumulative interaction' at understanding stage were high. At designing stage, the frequencies of 'making suggestion', 'cumulative interaction', and 'disputative interaction' were found to be high. At checking stage, 'making suggestion', 'receiving opinion', and 'disputative interaction' were high. In the comparison of the patterns, the qualitative differences among interaction unit were found at all the stages, whereas there were differences only between designing and checking stages in the turn cases. Educational implications of these findings are discussed.

• Journal of Korea Game Society
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• v.12 no.3
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• pp.25-36
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• 2012

Cross-Media Storytelling(CMS) is the new method of media representation. It picks the features and the elements in one media, and uses them in another media. 'Remediation' in digital era uses the content of old media in new form based on new technology. But 'CMS' represents the basic elements of the media experience in each unique style of media. It changes the focus from the technology to experience. So CMS is the new strategy of the media not based on the new technology. Adam PESapane's (2006) is a example for this strategy. It takes the game media as a subject matter. But it expresses the meta-representation of game experience in the "stop motion animation" Especially it emphasizes the narrative chain between the usual phenomenon and the visual imagination. And it shows the possibility of representation of new media experience in the old media genre. So it suggests the conditions of CMS.

• The Transactions of the Korean Institute of Power Electronics
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• v.7 no.5
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• pp.427-436
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• 2002

This paper presents an implementation of high-dynamic performance of position sensorless motion control system of Reluctance Synchronous Motor(RSM) drives for an industrial servo system with direct torque control(DTC). The problems of high-dynamic performance and maximum efficiency RSM drives controlled by DTC are saturation of stator linkage flux and nonlinear inductance characteristics with various load currents. The accurate estimation of the stator flux and torque are obtained using stator flux observer of which a saturated inductance $L_d$ and $L_q$ can be compensated by adapting from measurable the modulus of the stator current and rotor position. To obtain fast torque response and maximum torque/current with varying load current, the reference command flux is ensured by imposing $I_{ds} = I_{qs}$. This control strategy is proposed to achieve fast response and optimal efficiency for RSM drive. In order to prove rightness of the suggested control algorithm, the actual experiment carried out at $\pm$20 and $\pm$1500 rpm. The developed digitally high-performance motion control system shown good response characteristic of control results and high performance features using 1.0kW RSM which has 2.57 Ld/Lq salient ratio.

• International Journal of Naval Architecture and Ocean Engineering
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• v.12 no.1
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• pp.376-386
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• 2020

The aim of this study was to develop a new efficient strategy that uses the Vector form Intrinsic Finite-element (VFIFE) method to conduct the static and dynamic analyses of marine pipes. Nonlinear problems, such as large displacement, small strain, and contact and collision, can be analyzed using a unified calculation process in the VFIFE method according to the fundamental theories of point value description, path element, and reverse motion. This method enables analysis without the need to integrate the stiffness matrix of the structure, because only motion equations of particles established according to Newton's second law are required. These characteristics of the VFIFE facilitate the modeling and computation efficiencies in analyzing the nonlinear dynamic problem of flexible pipe with large deflections. In this study, a three-dimensional (3-D) dynamical model based on 3-D beam element was established according to the VFIFE method. The deep-sea flexible pipe was described by a set of spatial mass particles linked by 3-D beam element. The motion and configuration of the pipe are determined by these spatial particles. Based on this model, a simulation procedure to predict the 3-D dynamical behavior of flexible pipe was developed and verified. It was found that the spatial configuration and static internal force of the mining pipe can be obtained by calculating the stationary state of pipe motion. Using this simulation procedure, an analysis was conducted on the static and dynamic behaviors of the flexible mining pipe based on a 1000-m sea trial system. The results of the analysis proved that the VFIFE method can be efficiently applied to the static and dynamic analyses of marine pipes.

• Physical Therapy Rehabilitation Science
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• v.13 no.3
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• pp.294-303
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• 2024

Objective: The objective of this study is to evaluate the effects of radial shock wave therapy (RSWT) targeting multiple myofascial trigger points (MTrPs) along myofascial chains on shoulder pain, function, range of motion, and muscle strength in patients with bicipital tendinopathy. While traditional treatments primarily focus on a single MTrP, this study aims to achieve better clinical improvement by simultaneously treating multiple MTrPs along the myofascial chains. Design: A randomized controlled trial. Methods: Twenty-eight patients with bicipital tendinopathy were randomly assigned to either an experimental group (n=14) or a control group (n=14). The experimental group received RSWT targeting multiple MTrPs along myofascial chains, while the control group received RSWT focused on a single MTrP in the biceps brachii. Both groups underwent three treatment sessions over a nine-day period, with one session every three days. Outcomes, including shoulder pain, function, range of motion, and muscle strength, were measured before and after treatment to assess therapeutic effects. Results: Both groups showed significant improvements in shoulder pain, function, range of motion, and muscle strength (p<0.05). However, the experimental group demonstrated significantly greater improvements in all outcome measures compared to the control group (p<0.05). Conclusions: RSWT targeting multiple MTrPs along myofascial chains showed significantly greater effects in relieving shoulder pain, improving function, enhancing range of motion, and strengthening muscles in patients with bicipital tendinopathy compared to treatment targeting a single MTrP. Therefore, this study proposes that a comprehensive treatment strategy considering the entire myofascial pathway may be more effective in the rehabilitation of patients with bicipital tendinopathy.

• Korean Journal of Applied Biomechanics
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• v.27 no.2
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• pp.141-147
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• 2017

Objective: We obtained force-displacement curves for countermovement jumps of multiple heights and examined the effect of an arm swing on changes in vertical jumping strategy. Countermovement jumps with hands on hips (Condition 1) and with an arm swing (Condition 2) were evaluated to investigate the mechanical effect of the arm movement on standing vertical jumps. We hypothesized that the ground reaction force (GRF) and/or center of mass (CoM) motion resulting from the countermovement action would significantly change depending on the use of an arm swing. Method: Eight healthy young subjects jumped straight up to five different levels ranging from approximately 10% (~25 cm) to 35% (~55 cm) of their body heights. Each subject performed five sets of jumps to five randomly ordered vertical elevations in each condition. For comparison of the two jumping strategies, the characteristics of the boundary point on the force-displacement curve, corresponding to the vertical GRF and the CoM displacement at the end of the countermovement action, were investigated to understand the role of arm movement. Results: Based on the comparison between the two conditions (with and without an arm swing), the subjects were grouped into type A and type B depending on the change observed in the boundary point across the five different jump heights. For both types (type A and type B) of vertical jumps, the initial vertical force at the start of push-off significantly changed when the subjects employed arm movement. Conclusion: The findings may imply that the jumping strategy does change with the inclusion of an arm swing, predominantly to modulate the vertical force advantage (i.e., the difference between the vertical force at the start of push-off and the body weight).