• Title, Summary, Keyword: non-symmetry

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The Effects of Rhythmic Auditory Stimulation on the Gait Symmetry in the Chronic Stroke Patients (리듬청각자극이 만성 뇌졸중 환자의 보행대칭성에 미치는 효과)

  • Lee, Sun-Hyun;Lee, Kyoung-Jin;Ha, Gwee-Hyun;In, Tae-Sung;Song, Chang-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.5
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    • pp.2187-2196
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    • 2011
  • The objective of this study was to investigate the effect of gait training using rhythmic auditory stimulation on gait symmetry of stroke patients. Forty chronic stroke patients were divided into four groups by intervention. Group A and B received auditory stimulation when they walk with comfortable gait speed. Group A received auditory stimulation to paralyzed side while group B to non-paralyzed side. Group C and D received auditory stimulation with 10% faster gait speed than their comfortable gait speed. Group C received auditory stimulation to paralyzed side while group D to non-paralyzed side. Gait training using auditory stimulation was done in each group during five minutes. Gait symmetry was evaluated by formula and temporal variables of gait were measured by gait analysis system. Step time was decreased significantly in all groups except group A (P<.05), and gait symmetry was also improved significantly in all groups except group A (P<.05). Cadence was increased significantly in all groups except group A (p<.05), but velocity was not increased in all groups. Therefore we conclude that RAS gait training is effective in improving gait symmetry and can be useful to stroke patient's gait training.

Effects of Real-time Visual Feedback Gait Training on Gait Stability in Older Adults (실시간 시각적 피드백 보행 훈련이 노인들의 보행 안정성에 미치는 영향)

  • Byun, Kyungseok;Han, Sooji;Bhang, Dawon;Seo, Hyundam;Lee, Hyo Keun
    • Korean Journal of Sport Biomechanics
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    • v.30 no.3
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    • pp.247-253
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    • 2020
  • Objective: This study aimed to examine the effects of real-time visual feedback gait training on gait stability in older adults. Method: Twelve older adults participated in this study, being divided into 2 groups including a) visual feedback (VF) and b) non-visual feedback (NVF) groups. For 4 weeks, VF performed a treadmill walking training with real-time visual feedback about their postural information while NVF performed a normal treadmill walking training. For evaluations of gait stability, kinematic data of 15-minute treadmill walking were collected from depth-based motion capture system (30 Hz, exbody, Korea). Given that step lengths in both right and left sides were determined based on kinematic data, three variables including step difference, coefficient of variation, approximate entropy were calculated to evaluate gait symmetry, variability and complexity, respectively. Results: For research findings, VF exhibited significant improvements in gait stability after 4-week training in comparison to NVF, particularly in gait symmetry and complexity measures. However, greater improvement in gait variability was observed in NVF than VF. Conclusion: Given that visual feedback walking gives potential effectiveness on gait stability in older adults, gait training with visual feedback may be a robust therapeutic intervention in people with gait disturbances like instability or falls.

The Relationship between Grip Strength and Ground Reaction Force by Change of Position when Lifting Tasks (들기 작업할 때 자세의 변화에 따른 악력과 지면 반발력의 상관관계)

  • Jung, Sang-Yong;Gang, Jin-Woo;Koo, Jung-Wan
    • Journal of the Ergonomics Society of Korea
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    • v.28 no.3
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    • pp.41-47
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    • 2009
  • The purpose of this study, during the lifting task was researching the difference and a relationship between the ground reaction force and the grip strength by change of position. After grip strength has measured in symmetry position and asymmetry position at 45cm and 75cm of height of hand, ground reaction force was measured by same attitude lifting wooden box. We analyzed the difference of grip strength and ground reaction force in each position change. The results of grip strength, the grip strength of both hand were significant difference that in study subject symmetry and asymmetry position (p<0.01). The results of symmetry lifting task, the study subjects was significant difference of the ground reaction force difference by height (p<0.05). Asymmetry lifting task was significant difference of ground reaction force difference by direction of rotation was changed (p<0.01). The result of it will rotate with non-dominant hand side of lifting tasks from height 75cm where it easily maintains a balance possibility and decreasing the load of the hand. Therefore, from the workshop in the work people, it will be between the height 75cm and non-dominant hand side of trunk rotatory direction in the lifting tasks. Future study is necessary researched about the change of grip strength when the height of the hand is higher, and the difference of the ground reaction force when the change of weight.

A Study on Image of Patterns [ 1 ] - With a focus on Development on Image Positioning of Patterns - (문양 이미지에 관한 연구[ 1 ] -문양 이미지 포지셔닝 기준 개발을 중심으로-)

  • Ryu, Hyun-Jung;Kim, Min-Ja
    • Journal of the Korean Society of Costume
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    • v.59 no.2
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    • pp.29-41
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    • 2009
  • Perception between real object and recognized subject of human on objective subject is not the same. The reason Is that individual perception of visual design components are transmitted as the image of whole. It is required process of visual perception. Therefore, I developed the vision of seeing image of pattern which is based on Gestalt visual perception theory in clothes. The summary of this study's results is like followings. Extremely antagonistic terms which are specialized by formative characteristics of formative components are clearness and blur of outline/ fixed shape and non-fixed shape/ visuality and tangibility of representation/ simplicity and complexity of structure/ invariability and variability of mobility/ symmetry and asymmetry of arrangements singularity and plurality of group number. The expression of motive shows that clearness, fixed shape, visuality and simplicity pursuit Determination image, and blur, non-fixed shape, tangibility and complexity pursuit Ambiguity image. The arrangements of motive shows that invariability, symmetry and singularity pursuit Order image, and variability asymmetry and plurality pursuit Disorder image. Therefore, the standard of the coordinator of Pattern image positioning is established as Determination and Ambiguity of motive are X-axis, and Order and Disorder of pattern are Y-axis. As the frame of Pattern image positioning, four separated dimensions have made.

Aesthetic Characteristics of Grecian Style (그리스 스타일의 미적 특성)

  • Ham, Youn-Ja
    • Fashion & Textile Research Journal
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    • v.9 no.6
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    • pp.595-602
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    • 2007
  • This study examined the aesthetic characteristics of Grecian style which is being considered as the representative classic of Western fashion and the transformations of those Grecian styles on the fashion of the twentieth century. This study used positive research method using literatures on art history and clothing history, fashion related publications, and magazines and websites to understand the trend of fashion designer's collections. The study results are as follows. The aesthetic characteristics of Grecian style was considered to be the ideal beauty combined with symmetry, the functional beauty combined with non-construction, and the sensual beauty combined with natural body. The ideal beauty combined with symmetry appears as a style that shows idealistic proportion of a body emphasizing high-waist based on the golden ratio and the body as a whole rather than details. The functional beauty combined with non-construction appears as perfect recreation a body in its original and natural form. The clothing takes a form that does not have any structural design and has simplified cutting and sewing. It uses pins and strings to fix up the form of clothing which is flexible and naturally draped. The sensual beauty combined with natural body is found in natural silhouette dress alluding naked body in connection with Rousseau' naturalism in neoclassic period. Throughout the twentieth century, the desire for Grecian style was conveyed by a single detail or through an array of allusive effects.

Tomographic PIV measurement of internal complex flow of an evaporating droplet with non-uniformly receding contact lines

  • Kim, Hyoungsoo;Belmiloud, Naser;Mertens, Paul W.
    • Journal of the Korean Society of Visualization
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    • v.14 no.2
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    • pp.31-39
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    • 2016
  • We investigate an internal flow pattern of an evaporating droplet where the contact line non-uniformly recedes. By using tomographic Particle Image Velocimetry, we observe a three-dimensional azimuthal vortex pair that is maintained until the droplet is completely dried. The non-uniformly receding contact line motion breaks the flow symmetry. Finally, a simplified scaling model presents that the mechanical stress along the contact line is proportional to the vorticity magnitude, which is validated by the experimental results.

Chirality in Non-Hermitian Photonics

  • Yu, Sunkyu;Piao, Xianji;Park, Namkyoo
    • Current Optics and Photonics
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    • v.3 no.4
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    • pp.275-284
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    • 2019
  • Chirality is ubiquitous in physics and biology from microscopic to macroscopic phenomena, such as fermionic interactions and DNA duplication. In photonics, chirality has traditionally represented differentiated optical responses for right and left circular polarizations. This definition of optical chirality in the polarization domain includes handedness-dependent phase velocities or optical absorption inside chiral media, which enable polarimetry for measuring the material concentration and circular dichroism spectroscopy for sensing biological or chemical enantiomers. Recently, the emerging field of non-Hermitian photonics, which explores exotic phenomena in gain or loss media, has provided a new viewpoint on chirality in photonics that is not restricted to the traditional polarization domain but is extended to other physical quantities such as the orbital angular momentum, propagation direction, and system parameter space. Here, we introduce recent milestones in chiral light-matter interactions in non-Hermitian photonics and show an enhanced degree of design freedom in photonic devices for spin and orbital angular momenta, directionality, and asymmetric modal conversion.

Evaluation of the Functional and Non-functional Seat Sponge Effect in Sitting Chairs

  • Min, Seung Nam;Park, Se Jin;Subramaniyam, Murali;Lee, Heeran
    • Journal of the Ergonomics Society of Korea
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    • v.33 no.4
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    • pp.255-265
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    • 2014
  • Objective: The purpose of this study was to evaluate comfort levels of functional and non-functional chairs using subjective comfort rating, interface pressure measurement, muscle activity measurement, and skin temperature measurement. Background: Chairs are used for a prolonged period of time for sitting in many places such as the office, at university, at school, in industry, and so on. Almost all people use chairs in their everyday life. The functional properties of the chair are associated with comfort. Method: The subjective evaluation contains questions regarding chair comfort which can be rated with five point scale. The body-seat interface pressure was measured using a pressure mat system. The symmetry of sitting was measured using electromyography. The change in body part (thigh and buttock) temperature before and after sitting on a chair was measured with an infrared camera. Results: Participants rated significantly (p < 0.05) higher comfort scores for the functional chair in relation to the buttock and thigh region. Also, the participants felt a better cushion effect in the functional chair. When using the functional chair, lower interface pressure, better thermal comfort, and better symmetry of erector spinae muscle activity were observed. Conclusion: Overall, interface pressure measurement, muscle activity measurement, thermal imaging and subjective comfort score results showed that the functional chair was more comfortable than the non-functional chair. Application: The adopted methodologies could be used to measure the seating comfort of train seats.

The modal characteristics of non-uniform multi-span continuous beam bridges

  • Shi, Lu-Ning;Yan, Wei-Ming;He, Hao-Xiang
    • Structural Engineering and Mechanics
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    • v.52 no.5
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    • pp.997-1017
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    • 2014
  • According to the structure characteristics of the non-uniform beam bridge, a practical model for calculating the vibration equation of the non-uniform beam bridge is given and the application scope of the model includes not only the beam bridge structure but also the non-uniform beam with added masses and elastic supports. Based on the Bernoulli-Euler beam theory, extending the application of the modal perturbation method and establishment of a semi-analytical method for solving the vibration equation of the non-uniform beam with added masses and elastic supports based is able to be made. In the modal subspace of the uniform beam with the elastic supports, the variable coefficient differential equation that describes the dynamic behavior of the non-uniform beam is converted to nonlinear algebraic equations. Extending the application of the modal perturbation method is suitable for solving the vibration equation of the simply supported and continuous non-uniform beam with its arbitrary added masses and elastic supports. The examples, that are analyzed, demonstrate the high precision and fast convergence speed of the method. Further study of the timesaving method for the dynamic characteristics of symmetrical beam and the symmetry of mode shape should be developed. Eventually, the effects of elastic supports and added masses on dynamic characteristics of the three-span non-uniform beam bridge are reported.

Shape Finding Analysis of Pneumatic Structure (공기막 구조물의 형상해석)

  • 권택진;서삼열;이장복
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.57-64
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    • 1994
  • The purpose of this paper is to find minimum surface shape of pneumatic structure using the finite element method. The pneumatic membrane structure is a kind of large deformation problem and very flexible composite material, which mean geomatric nonlinearity. It is not to resist for compression and resultant moment. As the displacement due to internal pressure is getting bigger, it should be considered the direction of forces. It becomes non-linear problem with the non-conservative force. The follower-force depends on the deformation and the direction of force is normal to each element. The solution process is obtained the new stiffness matrix (load correction matrix) depending on deformation through each iterated step. However, the stiffness matrix have not the symmetry and influence on the time of covergence. So in this paper Newton-Rhapson method for solving non-linear problem and for using symmetic matrix, the load direction is changed in each iterated step using the transformation matrix.

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