• 제목/요약/키워드: Symmetry Index

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인코더를 이용한 2축 각도 기반 보행 불균형 평가 시스템 연구 (A Study on Gait Imbalance Evaluation System based on Two-axis Angle using Encoder)

  • 심현민;김유현;조우형;권장우;이상민
    • 제어로봇시스템학회논문지
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    • 제21권5호
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    • pp.401-406
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    • 2015
  • In this study, the gait imbalance evaluation algorithm based on two axes angle using encoder is proposed. This experiment was carried out to experiment with a healthy adult male to 10 people. The device is attached to the hip and knee joint in order to measure the angle during the gait. Normal and imbalance gait angle data were measured using an encoder attached to the hip and knee joints. Also, in order to verify the reliability of estimation of asymmetrical gait using hip and knee angle, it was compared with the result of asymmetrical gait estimation using foot pressure. SI (Symmetry Index) was used as an index for determining the gait imbalance. As a result, normal gait and 1.5cm imbalance gait were evaluation as normal gait through SI using an encoder. And imbalance gait of 3cm, 4cm, and 6cm were judge by imbalance gait. Whereas all gait experiments except normal gait were evaluation as imbalance gait through SI using the pressure. It was possible to determine both the normal gait and imbalance gait through measurement for the angle and the pressure.

전신진동(Whole body vibration)운동훈련을 통한 육상 투척선수의 하지관절 근육 기능변화에 관한 분석 (Analysis on the Changes in Muscle Function of the Leg Joint in Athletics Athletes Through by Whole Body Vibration Exercise Training)

  • 이영선;윤창선;한기훈;김진현;하종규;박준성;김종빈
    • 융합정보논문지
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    • 제11권3호
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    • pp.250-260
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    • 2021
  • 본 연구는 투척 선수의 하지 훈련 자세를 이용한 전신진동 운동 훈련 시 근육 변화와 대칭 지수를 살펴보는데 목적이 있다. 20 대 10 명(남성 6명 여성 4명, 나이:24.60±0.92세, 신장:177.90±7.40cm, 체중:92.90±22.97kg)의 투척 선수를 대상으로 스쿼트, 카프 레이즈, 런지 동작으로 하지 훈련 자세를 이용한 전신진동 운동 훈련을 실시하였다. 하지 관절 근육(대퇴이두근, 비복근 외측, 비복근 내측, 대퇴직근, 전경골근, 외측광근, 내측광근) 부위를 Tensiomyography(TMG) 변인 Time Delay(Td), Time Contraction(Tc), Time Sustain(Ts), Time Relaxation(Tr), Displacement Maximumal(Dm)을 통해 측정하여 근 활성도, 근 피로도, 좌우 대칭을 Wilconxon의 순위 검사로 비교하였고, 이때 유의수준은 α= .05로 분석하였다. 연구결과는 Td에서 왼쪽 RF, VL, 오른쪽 VM(p<.05), Tc에서는 VM(p<.05), Ts 에서는 GM(p<.05), Tr 에서는 왼쪽 RF, 오른쪽 TA(p<.05)에서 변화를 보였다. 따라서 스쿼트, 카프 레이즈, 런지 동작의 전신진동 운동 훈련이 근 수축 변화가 있는 효과적인 운동임을 입증되었고, 좌·우 근육 대칭으로 코어의 안정성이 확보되었다. 이로 인해 전신진동운동은 재활훈련 긍정적인 영향을 미칠 것이고, 경기력 향상을 도모할 수 있을 것으로 판단된다.

A Study on the Computation of the Number of Equivalence Classes and Its applications

  • Yoo, Wonsok
    • 통합자연과학논문집
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    • 제13권1호
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    • pp.19-26
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    • 2020
  • In this paper, we study on the reinterpretation of Burnside's theorem that is a tool to compute the number of equivalence classes of a group action on a set, and by applying it, we find out the numbers of different patterns in coloring problems of various types of figures with symmetry and use them for computing the numbers of different kinds of chemical compounds.

정렬된 단축이방성 분자들의 질서변수와 상대 복굴절간 준선형 관계식의 보편성 (Universality of the Quasi-linear Relation Between the Order Parameter and the Normalized Birefringence of Aligned Uniaxially Anisotropic Molecules)

  • 김상열
    • 한국광학회지
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    • 제28권1호
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    • pp.33-38
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    • 2017
  • 액정과 같은 단축 이방성 분자들의 상대 복굴절 ${\Delta}n_{rel}$과 질서변수 S가 만족하는 준선형 관계식인 $S=(1+a){\Delta}n_{rel}-a{\Delta}n^2_{rel}$이 보편적인 관계식임을 확인하였다. 액정분자들이 정다면체 대칭분포를 할 경우 굴절률은 등방적이며 $\frac{1}{n^2_{av}}=\frac{1}{3}\(\frac{1}{n^2_e}+\frac{2}{n^2_o}\)$와 같이 구해짐을 확인하였다. 정다면체 대칭성을 가지는 액정의 기본 분포에 분포함수 가중치를 가하여 액정의 정렬정도를 바꾸며 ${\Delta}n_{rel}$과 S를 수치계산 하였다. 또한 액정이 z축 주위 회전대칭성을 가지는 깔때기 모양으로 분포하고 있을 때 깔때기의 중심각을 변화시키며 ${\Delta}n_{rel}$과 S를 수치계산 하였다. 이로부터 S와 ${\Delta}n_{rel}$의 준선형 관계식이 액정의 분포형태와는 무관한 보편적인 관계식임을 보였다.

Effects of Ankle Control Training Using Neuromuscular Electrical Stimulation on Leg Muscle Activation and Balance in Patients with Stroke

  • Soo-Yong Lee;Hyo-Jung Park;Yu-Sik Choi
    • The Journal of Korean Physical Therapy
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    • 제35권5호
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    • pp.145-150
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    • 2023
  • Purpose: This study examined the effects of ankle control training using neuromuscular electrical stimulation (NMES), leg muscle activation, and balance in stroke patients. Methods: Thirty-one stroke patients diagnosed with cerebral infarction and cerebral hemorrhage were selected for the study. The experimental group underwent ankle control training using NMES, while the control group applied NMES to the paretic tibialis anterior muscle for 30 minutes per session, five times a week for four weeks. The muscle activity changes were measured using surface electromyography, and balance parameters were evaluated using a functional reach test (FRT). Results: The intra-group comparison of the concentric muscle activity revealed improvements in the experimental group, including paretic tibialis anterior (TA) muscle (p<0.05), medial gastrocnemius muscle (MG) (p<0.01), and lateral gastrocnemius muscle (LG) (p<0.05), as well as MG (p<0.05), LG (p<0.05), soleus muscle (p<0.05) of the non-paretic side, and soleus muscle symmetry index (p<0.05). The intra-group comparison of the eccentric muscle activity showed improvements in the experimental group, including MG (p<0.01) and LG (p<0.01) of the paretic side, as well as MG (p<0.01), LG (p<0.01) of the non-paretic side, and LG symmetry index (p<0.01). The intra-group comparison of the functional reach test revealed significant differences in the test results in the experimental and control groups (p<0.05). Conclusion: Ankle control training using NMES had a positive effect on the changes in muscle activation and improved balance in patients with stroke.

A Finger Dermatoglyphics of the New Zealand-Samoans

  • Cho, Ching
    • Animal cells and systems
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    • 제2권4호
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    • pp.507-511
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    • 1998
  • Fingerprints of 100 New Zealand-Samoan males and 93 females have been analyzed. Whorls are more numerous in fingerprint females (65.6%) than in males (55.6%). The index of pattern intensity displays a higher value in females (16.49) than in males (15.48). The bimanual differences both in males and females are not statistically significant for the occurrence of patterns on the digits of the right and left hands. Also the difference between both sexes for the occurrence of patterns is not statistically significant. Incidences of actual symmetry on homologous digits represented 78.2% in males and 85.8% in females. The mean total ridge counts showed $175.7{\pm}54.6$ ($M{\pm}SD$) in males and $171.6\{pm}49.8$ ($M{\pm}SD$) in females, respectively. Conclusively, this study shows that the New Zealand-Samoans are closely related to the Mongoloids in quantitative dermatoglyphics.

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특정 고조파 제거를 위한 Cascaded H-bridge 7레벨 인버터의 특성해석 및 시뮬레이션 (Analysis and simulation of Cascaded H-bridge 7 level inverter for eliminating typical harmonic waveforms)

  • 진선호;오진석;조관준;곽준호;임명규;김장목
    • 한국마린엔지니어링학회:학술대회논문집
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    • 한국마린엔지니어링학회 2005년도 전기학술대회논문집
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    • pp.1022-1028
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    • 2005
  • This paper is presented the analysis results and simulation results of cascaded H-bridge 7 level inverter with various modulation index. Stepped waveform having number of switching was used to eliminate harmonic components. Switching angles according to modulation index are calculated numerically. Therefore, 3 times of switching with 7 level topology and QWS(Quarter Wave Symmetry) could eliminate 5th and 7th harmonics. The harmonic characteristics are compared to those of space vector modulation method which known as common modulation method in industrial field. Stepped waveform method showed higher ability to reduce, especially lower order of harmonics.

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Finger Dermatoglyphics of Australian Aborigines in the Northern Territory of Australia

  • Cho, Ching
    • Animal cells and systems
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    • 제4권1호
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    • pp.91-94
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    • 2000
  • Fingerprints of 114 Australian Aboriginal males and 90 females have been analyzed. Whorls are more frequent in males (56.7%) than in females (51.2%) and loops are less frequent in males (42.6%) than in females (47.0%). The index of pattern intensity displays a higher value in males (15.60) than in females (14.94). The bimanual differences both in males and females ave not statistically significant for the occurrence of patterns on the digits of the right and left hands. Also the difference between both sexes for the occurrence of patterns is not statistically significant. Incidences of actual symmetry on homologous digits represented 74.0% in males and 77.3% in females. The mean total ridge counts showed 156.65 $\pm$43.32 (M$\pmSD) in males and 148.6943.64 (M$\pmSD) in females, respectively. Conclusively, this study represents that the Australian Aborigines conform closely to the Polynesians in finger dermatoglyphics.

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전기장에 의한 Bi12SiO20 단결정의 변화된 광행로길이 계산 (Calculation of Changed Optical Path Length of Bi12SiO20Single Crystal by the Electric Field)

  • 이수대
    • 한국전기전자재료학회논문지
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    • 제18권11호
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    • pp.1048-1055
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    • 2005
  • The formula to calculate a variation of optical path length of single crystal by the electric field was derived by this study. The formula was applied to $Bi_{12}SiO_{20}$ single crystal. The results are as follows. In case of the applied electric field in the body diagonal direction and the passing light along the same direction, the variation of optical path length had the largest value. The symmetry of the space distribution of optical path length satisfied $E3C_2\;8C_3$, the set of elements of the symmetry of $Bi_{12}SiO_{20}$ single crystal. The property which gave the largest influence to the variation of optical path length is the strain of length by the Inverse piezoelectric effect. The second influence, is the variation of the refractive index by the electro-optic effect. The variation of optical path length by the inverse piezoelectric effect and by the electro-optic effect have a reverse sign each other.

대퇴절단인의 보행 시 하지 내 협응성 평가 (Evaluation of Intralimb Coordination in Transfemoral Amputee during Level Walking)

  • 장윤희;정보라;강성재;류제청;문무성;고창용
    • 재활복지공학회논문지
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    • 제10권2호
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    • pp.147-153
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    • 2016
  • 본 논문의 목적은 보행 시 대퇴절단인의 엉덩관절과 무릎관절의 협응을 평가하고, 건측과 의지측의 대칭성에 대하여 평가하는 것이다. 본 연구에는 7명의 대퇴절단인($46.4{\pm}10.7$세, $174.8{\pm}3.5cm$, $78.3{\pm}9.7kg$)와 7명의 비절단인($24.0{\pm}4.5$세, $174.5{\pm}5.9cm$, $66.9{\pm}9.4kg$)가 참여하였다. 이들은 편한 속도로 10m 평지보행을 하였으며, 이때 보행 분석시스템을 이용하여 엉덩관절과 무릎관절의 각도와 각속도를 측정하였으며, 이를 기반으로 입각기와 유각기의 연속상대위상(CRP), CRP의 표준편차(CRP_SD) 및 이들의 대칭지수(SI)를 계산하였다. 그 결과 비절단인의 경우 CRP 및 CRP_SD는 좌우가 차이가 없었지만 (모두 p>0.05), 대퇴절단인의 경우는 입각기의 CRP를 제외하고는 모두 유의한 차이를 보였다 (모두 p<0.05). 또한 비절단인과 대퇴절단인간의 SI는 모두 유의한 차이를 보였다 (all p<0.05). 결론적으로 대퇴절단인의 경우 하지의 협응이 변화되며, 건측과 의지측의 좌우 비대칭이 발생하는 것을 확인하였다.