• Title/Summary/Keyword: dynamic symmetry

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The Effect of Gluteal Taping on Posture and Balance During Standing in Children with Hemiplegic Cerebral Palsy (경직성 편마비 아동의 둔부 테이핑 적용이 선 자세에서 자세 및 균형에 미치는 영향)

  • Seo, Hye-Jung;Kim, Joong-Hwi;Son, Kuk-Kyung;Jeon, Je-Gyu
    • Journal of the Korean Society of Physical Medicine
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    • v.9 no.4
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    • pp.391-398
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    • 2014
  • PURPOSE: The purpose of the present study was to examine the effect of gluteal taping on posture and balance during standing in children with hemiplegic cerebral palsy (CP). METHODS: The subjects of this study were 13 children (six females, seven males; mean aged 8.5) with hemiplegic CP who were gross motor function classification system (GMFCS) level I. The change of posture and balance during standing before and after gluteal taping were measured using inclinometer, gross motor function measure, and functional reaching test. The collected data were analyzed using the paired t-test. RESULTS: The results of this study were as follows : 1) There were statistically significant decrease in the ant. tilt angle of pelvis after gluteal taping in children with hemiplegic CP (p<.05). 2) There were statistically significant increase in functional reaching test after gluteal taping (p<.05). 3) There was no statistically significant difference in gross motor function measure, but significant increase in one leg standing was observed (p<.05). CONCLUSION: As the above results, we suggest that gluteal taping could be effective on improving body alignment and dynamic balance ability during standing in children with hemiplegic CP. Further studies will be required for the short and long term effects of gluteal taping on improving postural symmetry and balance.

An Improved Active Damping Method with Capacitor Current Feedback

  • Geng, Yi-Wen;Qi, Ya-Wen;Liu, Hai-Wei;Guo, Fei;Zheng, Peng-Fei;Li, Yong-Gang;Dong, Wen-Ming
    • Journal of Power Electronics
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    • v.18 no.2
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    • pp.511-521
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    • 2018
  • Proportional capacitor current feedback active damping (CCFAD) has a limited valid damping region in the discrete time domain as (0, $f_s/6$. However, the resonance frequency ($f_r$) of an LCL-type filter is usually designed to be less than half the sampling frequency ($f_s$) with the symmetry regular sampling method. Therefore, ($f_s/6$, $f_s/2$) becomes an invalid damping region. This paper proposes an improved CCFAD method to extend the valid damping region from (0, $f_s/6$ to (0, $f_s/2$), which covers all of the possible resonance frequencies in the design procedure. The full-valid damping region is obtained and the stability margin of the system is analyzed in the discrete time domain with the Nyquist criterion. Results show that the system can operate stably with the proposed CCFAD method when the resonance frequency is in the region (0, $f_s/2$). The performances at the steady and dynamic state are enhanced by the selected feedback coefficient H and controller gain $K_p$. Finally, the feasibility and effectiveness of the proposed CCFAD method are verified by simulation and experimental results.

A study on expression methods for structural aesthetics in modern fashion design - Focus on the architectural characteristics of Santiago Calatrava - (현대 구조적 패션디자인에 나타난 구조미의 표현방식에 대한 연구 - 산티아고 칼라뜨라바의 건축특성을 중심으로 -)

  • Lee, Yeonji;Um, Sohee
    • The Research Journal of the Costume Culture
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    • v.23 no.5
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    • pp.737-754
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    • 2015
  • The structural aesthetics of architecture are becoming an inspirational source for many fashion designers and have been reborn in structural fashion. This study planned to analyze the method of expression of structural aesthetics expressed in modern structural fashion design and the construction method to maximize such an effect on the basis of the construction characteristic of Santiago Calatrava as the representative architect of the structural aesthetic. According to the study, the structural aesthetics expressed in modern structural fashion design are as follows: 1) The symbolical formative aesthetic expressed by symbolical inference and analyzation; 2) the dynamic beauty of physic expressed by visual emphasis and dynamics; and 3) the asymmetric beauty of symmetry expressed by metastasis toward the boundary between balance and imbalance. In addition, to maximize structural aesthetics, we used repetition and a progressive technique based on rhythm, asymmetry, and incision-based variances, such as balance, polygon flux, and inference, and analyzation-based distortion as the structuring principle. The following expression methods for maximizing structural aesthetics were found: 1) symbolical and structural exaggeration of appearance; 2) detail technique expansion and material property diversification; and 3) the three-dimensional transformation of structure and shell expression. Structural fashion design was found to have maximized structural aesthetics by using such expression methods to secure artistic esthetics, destroy existing shapes and patterns, and create unique shapes.

A Study on Polyamide-6 Sintering and Effect by $CO_2$ Laser ($CO_2$ Laser에 의한 Polyamide-6 소결과 그 영향에 관한 연구)

  • Bae S.W.;Kim D.S.;Ahn Y.J.;Kim H.I.;Choi K.S.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2006.05a
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    • pp.197-198
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    • 2006
  • In the solid freeform fabrication (SFF) system using selective laser sintering (SLS), polyamide-12 powder is currently recognized as general material. In this study, some kinds of polyamide-6 powders with different shape and particlesize were fabricated to investigate the formability, the microstructure and mechanical properties. Also, to develop a more elaborate and rapid system, this study employs a new SLS device with a 3-axis dynamic focusing scanner system instead of the existing fe lens used in commercial SLS. Polyamide-6 powders having the average size of 100 m were treated thermally in order to keep the spherical symmetry in shape. These polyamide-6 powders were mixed with polyamide-12 powders having the average size of 50 m to give the bimodal distribution of size. These mixed powders showed the better fabrication in the selective laser sintering process because the smaller particles of polyamide-11 played an important role in the compact packing of powders by filling the void space between the large particles of polyamide-6. Also, Experiments have performed to evaluate the effect of a scanning path and sintering parameters by fabricating the various 3D objects.

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Assessment of the Counter-Flow Thrust Vector Control in a Three-Dimensional Rectangular Nozzle (3차원 직사각형 노즐에서 역유동 추력벡터 제어 평가)

  • Wu, Kexin;Kim, Tae Ho;Kochupulickal, James Jintu;Kim, Heuy Dong
    • Journal of the Korean Society of Propulsion Engineers
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    • v.24 no.1
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    • pp.34-46
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    • 2020
  • Computational assessment of gas-dynamic characteristics is explored for a three-dimensional counter-flow thrust vector control system in a rectangular supersonic nozzle. This convergent-divergent nozzle is designed by Method of Characteristics and its design Mach number is specially set as 2.5. Performance variations of the counter-flow vector system are illustrated by varying the gap height of the secondary flow duct. Key parameters are quantitatively analyzed, such as static pressure distribution along the centerline of the upper suction collar, deflection angle, secondary mass flow ratio, and resultant thrust coefficient. Additionally, the streamline on the symmetry plane, three-dimensional iso-Mach number surface contour, and three-dimensional turbulent kinetic energy contour are presented to reveal overall flow-field characteristics in detail.

Correction of Asymmetric Crying Facies with Botulinum Toxin A Injection: A Case Report (비대칭 우는 얼굴에서 보툴리눔 독소 A를 이용한 치험례)

  • Park, Seong Oh;Kim, Min Ho;Song, Jung Yoon;Park, Ji Ung;Yun, Byung Min;Choi, Tae Hyun;Kim, Sukwha
    • Archives of Craniofacial Surgery
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    • v.12 no.2
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    • pp.125-128
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    • 2011
  • Purpose: Asymmetric crying facies is caused by agenesis or hypoplasia of the depressor anguli oris muscle and is often associated various anomalies. Several static and dynamic surgical interventions have been reported, but their effects are unreliable. We report on the successful use of botulinum toxin A in an asymmetric crying facies patient. Methods: A 4-year-old girl presented with a facial asymmetry on crying or smiling. Physical examination revealed that her face had no asymmetry at rest. However, the patient showed characteristic asymmetry when smiling, crying, and with other normal facial movements. Asymmetric crying facies was clinically suspected and the weakness of left depressor anguli oris was present on electrophysiology study. Fifteen units of botulinum toxin type A were injected to the right depressor anguli oris muscle. Results: The patient showed the prominent improvement in the facial symmetry without significant complication and the effect persisted until 3 months post injection. Conclusion: Asymmetric crying facies was treated successfully with botulinum toxin A and this method was easy and noninvasive.

The Effect of Cane Height on Walking and Balance for Stroke Patients (뇌졸중 환자의 지팡이 높이에 따른 보행과 균형에 미치는 영향)

  • Seo, Tae-Hwa;Doo, Young-Taek;Jung, Dae-In
    • Journal of agricultural medicine and community health
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    • v.43 no.4
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    • pp.250-257
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    • 2018
  • Objecctives: This study investigates the effects of using customized walking aids individualized for stroke patients by measuring the effects of different cane lengths to determine the ideal length of walking aids for stroke patients. Methods: Cane lengths were determined from the greater trochanter with walking aids measured 5cm below, at the greater trochanter and 5cm above. All patients walked for ten meters with each cane length to measure speed. Then, we measured the opto gait, timed up go test, and electromyography three times each. Statistical analysis was performed using a linear mixed model, and in the case of significance, the p-value was corrected using the Bonferroni method. Results: There was a statistically significant differences in time up and go test(TUGT), 10m walking, stride and speed between the groups. Conclusions: Long cane length increases body symmetry, stride, increasing muscle activity, and short cane length increases balance and walking.

Customer Acceptance Procedure for Clinac (21EX-Platinum)

  • Hong, Dong-Ki;Lee, Woo-Seok;Kwon, Kyung-Tae;Park, Kwang-Ho;Kim, Chung-Man
    • The Journal of Korean Society for Radiation Therapy
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    • v.16 no.2
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    • pp.43-61
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    • 2004
  • Purpose : For qualify improvement in radiotherapy, it is important to set up and evaluate equipment (linac) accurately. In addition, technicians are needed to be fully aware of the equipment's detailed quality and its manual. Therefore, the result of ATP is evaluated and introduced, in order that the technicians are skilled by participating in quality assurance (QA) and understanding the quality of the equipment before clinical use. Method and Material : QA for LINAC 21EX (Varian, US) was done with suppliers its procedure was divided into radiation survey, mechanical test, radiation isocenter test, bean performance, dosimetry, and enhanced dynamic wedge and using X-omat film (Kodak), multidata, densitometer, and electrometer. QA of MLC (Millennium, 120 leaf) attached to LINAC and EPID (Portal vision) were done separately. Result : The leakage dose by survey meter was below the tolerance. In mechanical test, collimater, gantry, and couch rotation were less than 1mm, and the angles were ${\pm}0.1^{\circ}$ for digital and ${\pm}0.5^{\circ}$ for mechanical. The alignment test of the light field and crosshair were evaluated less than 1mm. The (a)symmetrical jaw field was less than ${\pm}0.5mm$. The radiation isocenter test using X-mat film was less than 1mm. The consistency of light field and radiation field was less than ${\pm}0.1mm$. PDD for photon energy was less than ${\pm}1\%$ and for electron energy of $90\%,\;80\%,\;50\%,\;and\;30\%$ were evaluated within the tolerance. Flatness for photon and electron energy was evaluated $2.3\%$ (tolerance $3\%$) and $3\%$ (tolerance $4.5\%$), respectively, and symmetry was $0.45\%$ (tolerance $2\%$) and $0.3\%$ (tolerance $2\%$), respectively. Dosimetry test for short term, MU setting, rep rate, and dose rate accuracy of photon and electron energy was within the tolerance depending on energy, MU, and gantry angle. Conclusion : Accuracy and safety for clinical use of Clinac 21EX was verified through customer acceptance procedure and the quality of the equipment was found out. These can reduce the difficulties in using the equipment. Furthermore, it is useful for clinically treatment of patients by technicians' active participations.

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Simplistic QA for an Enhanced Dynamic Wedge using the Reversed Wedge Pair Method (역방향 조사방식을 통한 동적쐐기의 품질관리)

  • Lee Jeong Woo;Hong Semie;Suh Tae Suk
    • Progress in Medical Physics
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    • v.15 no.3
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    • pp.161-166
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    • 2004
  • A simplistic quality assurance (QA) method was designed for a Linac built-in enhanced dynamic wedge (EDW), which can be utilized to make wedged beam distributions. For the purpose of implementing the EDW symmetry QA, a film dosimetry system, low speedy dosimetry film, film densitometer and 3D RTP system were used, and the films irradiated by means of a 60$^{\circ}$ Reversed wedge pair (REWP) method. The profiles were then analyzed in terms of their symmetries, including partial treatment, which is the case of stopping it abruptly during EDW irradiation, and the measured and calculated values compared using the Cad Plan Golden Segmented Treatment Table (Golden STT). The result of this experiment was in good agreement, within 1 %, of the 'reversed wedge pair counterbalance effect'. For the QA of the effective wedge factor (EWF), the authors measured EWFs in relation to the 10$^{\circ}$, 15$^{\circ}$, 20$^{\circ}$, 25$^{\circ}$, 30$^{\circ}$, 45$^{\circ}$ and 60$^{\circ}$ EDW, which were compared with the calculated values using the correction factor derived from the Golden STT and the log files produced automatically during the process of EDW irradiation. By means of this method it was capable of check up the safety of effective wedge factor without any other dosimetry system. The EDW QA was able to be completed within 1 hour from irradiation to analysis as a consequence of the simplified QA procedure, with maximized effectiveness. Unlike the metal wedge system, the EDW system was heavily dependent on the dose rates and jaw movements; therefore, its features could potentially cause inaccuracy. The frequent simplistic QA for the EDW is essential, and could secure against the flaw of dynamic treatment that uses the EDW.

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Static and dynamic elastic properties of the Iksan Jurassic Granite, Korea (익산 쥬라기 화강암의 정 및 동탄성학적 특성)

  • Kang, Dong-Hyo;Jung, Tae-Jong;Lee, Jung-Mo
    • Journal of the Korean Geophysical Society
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    • v.3 no.2
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    • pp.99-112
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    • 2000
  • The Iksan Jurassic Granite shows relatively less fractures and homogeneous rock fabrics, and is one of the most popular stone materials for architectures and sculptures. Almost mutually perpendicular rift, grain, and halfway in the Iksan Jurassic Granite are well known to quarrymen based on its splitting directions, and therefore it should exhibit orthorhombic symmetry. Theoretically, there are 9 independent elastic stiffness coefficients $(C_{1111},\;C_{2222},\;C_{3333},\;C_{2323},\;C_{1313},\;C_{1212},\;C_{1122},\;C_{2233},\;and\;C_{1133})$ for orthorhombic anisotropy. In order to characterize the static and dynamic elastic properties of the Iksan Jurassic Granite, triaxial strains under uniaxial compressive stresses and ultrasonic velocities of elastic waves in three different polarizations are measured. Both experiments are carried out with six directional core samples from massive rock body. Using the results of experiments and the densities measured independently, the static and dynamic elastic coefficients are computed by simple mathematical manipulation derived from the governing equations for general anisotropic media. The static elastic coefficients increase ar uniaxial compressive stress rises. Among those, the static elastic coefficients at uniaxial compressive stress of a 24.5 MPa appear to be similar to the dynamic elastic coefficients under ambient condition. Although some deviations are observed, the preferred orientations of microcracks appear to be parallel or subparallel to the rift, the grain, and the hardway from microscopic observation of thin sections. This indicates that the preferred orientations of microcracks cause the elastic anisotropy of the Iksan Jurassic Granite. The results are to be applied to the effective use of the Iksan Jurassic Granite as stone materials, and can be used for the non-destructive safety test.

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