• Title, Summary, Keyword: non-symmetry

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FULL NON-RIGID GROUP OF 2,3,5,6-TETRAMETHYLEPYRAZINE AS WREATH PRODUCT AND ITS SYMMETRY

  • Arezoomand, Majid;Taeri, Bijan
    • Journal of applied mathematics & informatics
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    • v.27 no.3_4
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    • pp.915-931
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    • 2009
  • The non-rigid molecule group theory in which the dynamical symmetry operations are defined as physical operations is applied to deduce the character table of the full non-rigid molecule group (f-NRG) of 2,3,5,6-Tetramethylpyrazine The f-NRG of this molecule is seen to be isomorphic to the group $\mathbb{Z}_3{\wr}(\mathbb{Z}_2{\times}\mathbb{Z}_2)$, where $\mathbb{Z}_n$ is the cyclic group of order n, of order 324 which has 45 conjugacy classes. We determine the some properties and relations between characters of the group. Also, we examine the symmetry group of this molecule and show that its symmetry group is $\mathbb{Z}_2{\times}\mathbb{Z}_2$.

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Effects of Performing Dual Task on Temporospatial Gait Variables in Subjects With Subacute Stroke (아급성기 뇌졸중 환자의 이중 과제 수행이 보행의 시·공간적 변수에 미치는 영향)

  • Jang, Young-Min
    • PNF and Movement
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    • v.15 no.3
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    • pp.361-371
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    • 2017
  • Purpose: The purpose of this study was to examine the effects of performing a dual task on gait velocity, temporospatial variables, and symmetry in subjects with subacute stroke. Methods: The study included 14 independent community ambulators with gait velocity of 0.8m/s. The Korean mini-mental state examination, the Berg balance scale, the Trunk impairment scale, and the Fugl-Meyer assessment scale were used to recruit homogeneous subjects. Subjects performed a single task (10m ambulation at a comfortable speed) and a dual task (10m ambulation at a comfortable speed while carrying a water-filled glass). Gait variables were examined with the OptoGait system. Results: The findings of this study were as follows: 1) Gait velocity decreased significantly in the dual-task condition as compared to the single task condition. 2) There were no significant differences between the paretic and non-paretic stances. 3) Paretic swing decreased significantly in the dual-task condition as compared to the single task condition. 4) The non-paretic, double-limb support phase increased significantly in the dual-task condition as compared to the single- task condition. 5) There was no significant difference in temporal symmetry. 6) Non-paretic step length decreased significantly in the dual-task condition as compared to the single-task condition. 7) There was no significant difference in spatial symmetry. Conclusion: Performing dual tasks decreases gait velocity, paretic swing phase, and non-paretic step length, while it increases non-paretic double limb support. In addition, although there is no difference in temporospatial symmetry, there is high inter-subject variability in temporospatial symmetry. Thus, dual tasks should be selected in accordance with the functional level of the hemiplegic patient, and inter-subject variability of the individual should be considered when dual tasks are considered for gait-training of hemiplegic patients.

Tabbed Tissue Expanders Improve Breast Symmetry Scores in Breast Reconstruction

  • Khavanin, Nima;Gust, Madeleine J.;Grant, David W.;Nguyen, Khang T.;Kim, John Y.S.
    • Archives of Plastic Surgery
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    • v.41 no.1
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    • pp.57-62
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    • 2014
  • Background Achieving symmetry is a key goal in breast reconstruction. Anatomically shaped tabbed expanders are a new tool in the armamentarium of the breast reconstruction surgeon. Suture tabs allow for full control over the expander position and thus inframammary fold position, and, in theory, tabbed expanders mitigate many factors responsible for poor symmetry. The impact of a tabbed expander on breast symmetry, however, has not been formally reported. This study aims to evaluate breast symmetry following expander-implant reconstruction using tabbed and non-tabbed tissue expanders. Methods A chart review was performed of 188 consecutive expander-implant reconstructions that met the inclusion criteria of adequate follow-up data and postoperative photographs. Demographic, oncologic, postoperative complication, and photographic data was obtained for each patient. The photographic data was scored using a 4-point scale assessing breast symmetry by three blinded, independent reviewers. Results Of the 188 patients, 74 underwent reconstruction with tabbed expanders and 114 with non-tabbed expanders. The tabbed cohort had significantly higher symmetry scores than the non-tabbed cohort ($2.82/4{\pm}0.86$ vs. $2.55/4{\pm}0.92$, P=0.034). Conclusions The use of tabbed tissue expanders improves breast symmetry in tissue expander-implant-based breast reconstruction. Fixation of the expander to the chest wall allows for more precise control over its location and counteracts the day-to-day translational forces that may influence the shape and location of the expander pocket, mitigating many factors responsible for breast asymmetry.

Reflection Symmetry of PALSAR Quad-Pol Imagery in the Amazon Rainforest (아마존 지역 PALSAR 다중편파 자료의 반사대칭성 특성)

  • Kim, Jae-Hun;Yoon, Sun Yong;Won, Joong-Sun
    • Korean Journal of Remote Sensing
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    • v.34 no.6_1
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    • pp.969-979
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    • 2018
  • This paper presents reflection symmetry of polarimetric SAR over the Amazon rainforest in terms of correlation coefficients between the pairs of HH- and HV-pol and VV- and VH-pol data by ALOS PALSAR. The reflection symmetry is defined as a non-zero correlation between HH- and HV-pol and VV- and VH-pol over natural distributed targets, and is a fundamental assumption for cross-talk calibration coefficient computation and for three-component decomposition for polarimetric SAR data. The Amazon rainforest is especially one of the common global reference sites for the reflection symmetry. The correlation coefficients for the pairs of reflection symmetry obtained in this study range from 0.018 to 0.097. The results imply that there exists a non-negligible dependency between co-pol and cross-pol in the distributed natural targets, and consequently the non-zero correlation must be considered as a potential contribution to errors of spaceborne SAR polarimetry to some extent.

Comparison Analysis of Muscle Strength and Asymmetry according to Bowler Injury Experience and Type (볼링 선수 상해 경험과 유형에 따른 근력과 비대칭 비교 분석)

  • Byun, Ho-Jin
    • Journal of the Korea Convergence Society
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    • v.9 no.10
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    • pp.423-432
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    • 2018
  • The purpose of this study was to investigate the differences in upper and lower strengths and symmetry between upper body injury group, lower body injury group and non-injury group of bowling athletes. The subjects were the upper body injury group (UG), n = 16, the low body injury group (LG), n = 8, the non injury group, [NG], n = 15). The isometric strength of the bowler was measured using Manual Muscle Tester 01165 (Lafayette Instrument Company, USA) and the symmetry index (SI) was calculated. The results were as follow. The symmetry index of hip extension strength and hip external rotation strength was statistically larger in NG than LG (p <.05). The above results suggest that lower body strength and bilateral symmetry was closely related to injuries of the lower body. In order to prevent injury of the bowler, strengthening of lower body strength and symmetrical training are needed.

A study on the drawing of spline shaped section with non-rotary symmetry (비회전 대칭 단면 형상의 스플라인 인발 공정에 관한 연구)

  • Choi, B.H.;Han, S.S.;Han, C.H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • pp.450-453
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    • 2008
  • During the drawing of reentrant section like a spline, the unfilled in the corner of dies or the bended product emerges from the large reduction of area, the complex shaped sections and other nonuniform properties in material and lubrication conditions. In this study, the drawing of the spline section with the non-rotary symmetry from a circular aluminum billet has been analyzed by using commercial code DEFORM-3D. A new die construction method preventing the spline from the drawback of bending and the unfilled defect has been suggested and verified through the analysis using centroid shift method and the hybrid construction between converged and diverged profile.

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Neutrino Oscillation and S4 Flavor Symmetry

  • Park, Jong-Chul
    • Applied Science and Convergence Technology
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    • v.27 no.5
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    • pp.86-89
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    • 2018
  • Observations of neutrino oscillations are very strong evidence for the existence of neutrino masses and mixing. From recent experimental results on neutrino oscillation, we find that neutrino mixing angles are quite consistent with the so-called tri-bi-maximal mixing pattern, but the deviation from observational results is non-negligible. However, the tri-bi-maximal mixing pattern is still useful as a leading order approximation and provides a good guideline to search for the flavor symmetry in the neutrino sector. We introduce the $S_4$ permutation symmetry as a flavor symmetry to the standard model of particle physics with additional particle contents of heavy right-handed neutrinos and scalar fields. Finally, we obtain the tri-bi-maximal mixing pattern as a mixing matrix in the lepton sector within the suggested model. To derive the required unitary mixing matrix for the neutrino sector, the double seesaw mechanism is utilized.

Comparison of Both Legs EMG Symmetry during Over-Ground Walking and Stair Walking in Stroke Patients

  • Jeong, Mu-Geun;Kim, Joong-Hwi
    • The Journal of Korean Physical Therapy
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    • v.27 no.4
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    • pp.228-233
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    • 2015
  • Purpose: Gait is the most basic element when evaluating the quality of life with activities of daily living under ordinary life circumstances. Symmetrical use of the lower extremities requires complicated coordination of all limbs. Thus, this study examined asymmetry of muscle activity quadriceps femoris and tibialis anterior as a baseline for training during over-ground walking and stair walking of stroke patients. Methods: Subjects were 14 stroke patients included as one experimental group. Gait speed used in this study was determined by the subject. Low extremity paretic and non-paretic EMG was compared using the surface EMG system. Results: The low extremity EMG difference was statistically significant during over-ground walking and stair walking (p<0.05). The result of low extremity EMG substituted symmetry ratio formula was compared to EMG symmetry ratio in both legs during over-ground walking and stair walking. The average symmetry ratio of quadriceps femoris during over-ground walking was 0.65, and average symmetry ratio of quadriceps femoris during stair walking was 0.47, with significant difference (p<0.05). Conclusion: EMG data was higher in stair walking than over-ground walking. However, in the comparison of symmetry ratio, asymmetric EMG of quadriceps femoris was significantly increased during stair walking. These findings suggested that application of stair walking for strengthening of both legs can be positive, but the key factor is maintaining asymmetrical posture of both legs. Therefore, physical therapists should make an effort to reduce asymmetry of quadriceps femoris power during stair walking by stroke patients.

A New Vehicle Detection Method based on Color Integral Histogram

  • Hwang, Jae-Pil;Ryu, Kyung-Jin;Park, Seong-Keun;Kim, Eun-Tai;Kang, Hyung-Jin
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.8 no.4
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    • pp.248-253
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    • 2008
  • In this paper, a novel vehicle detection algorithm is proposed that utilizes the color histogram of the image. The color histogram is used to search the image for regions with shadow, block symmetry, and block non-homogeneity, thereby detecting the vehicle region. First, an integral histogram of the input image is computed to decrease the amount of required computation time for the block color histograms. Then, shadow detection is performed and the block symmetry and block non-homogeneity are checked in a cascade manner to detect the vehicle in the image. Finally, the proposed scheme is applied to both still images taken in a parking lot and an on-road video sequence to demonstrate its effectiveness.