• 대한물리의학회지
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• 제7권2호
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• pp.205-212
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• 2012

Purpose : The aim of this study was to investigate the relationship between weight-supporting asymmetry and gait symmetry in patients with stroke. Methods : Sixty two stroke patients with hemiplegia stood quietly with eye opens on a force platform to calculate weight-supporting asymmetry from vertical reaction force. The GAITRite was used to evaluate their gait parameters. The data were analyzed using Pearson correlation. Results : The results of this study was showed that the medio-lateral index (ML) was correlated with symmetry rate (SR), symmetry index (SI), and Gait asymmetry (GA) of step time and length but stronger correlation with spatial gait symmetry than temporal symmetry. In gait symmetry, step length has stronger correlation with weight-supporting asymmetry than step time. Conclusions : The results of this study shows weight-supporting asymmetry was correlated with more spatial gait symmetry than temporal symmetry.

• Current Optics and Photonics
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• 제7권5호
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• pp.574-581
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• 2023

A scheme is proposed to generate triangular waveforms with alterable symmetry. The key component is a cascaded single-drive Mach-Zehnder modulator (SD-MZM) and optical polarization beam splitter-combiner architecture. In this triangular waveform generator, the bias-induced phase shift, modulation index and controllable delay difference are changeable. To generate triangular waveform signals with different symmetry indexes, different combinations of these variables are selected. Compared with the previous schemes, this generator just contains one SD-MZM and the balanced photodetector (BPD) is not needed, which means the costs and energy consumption are significantly reduced. The operation principle of this triangular waveform generator has been theoretically analyzed, and the corresponding simulation is conducted. Based on the theoretical and simulated results, some experiments are demonstrated to prove the validity of the scheme. The triangular waveform signals with a symmetry factor range of 20-80% are generated. Both experiment and theory prove the feasibility of this method.

• 한국융합학회논문지
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• 제9권10호
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• pp.423-432
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• 2018

본 연구는 볼링 선수의 상해 경험과 유형에 따라 상 하지 근력과 좌우 비대칭 차이를 살펴보고자 하였다. 본 연구 대상자는 상지 상해 경험 집단(upper body injury group, [UG], n=16)과 하지 상해 경험 집단(low body injury group, [LG], n=8), 상해 미경험 집단(non injury group, [NG], n=15)으로 선정하였다. 볼링 선수의 상 하지 근력은 Manual Muscle Tester 01165 (Lafayette Instrument Company, USA)로 등척성 최대 근력(Isometric strength)을 측정하였으며, 비대칭 지수(symmetry index, [SI])를 산출하였다. 그 결과는 다음과 같다. 하지 근력의 좌우 비대칭 지수는 엉덩관절의 신전과 외측회전 최대근력에서 상해 무경험 집단이 하지 상해 경험 집단에 비하여 통계적으로 크게 나타났다(p<.05). 위 결과를 통하여 하지 근력의 좌우 대칭이 하지 상해와 밀접한 관련이 있다고 판단되며, 상해 예방을 위해 하지 근력의 좌우 대칭 훈련이 필요할 것으로 판단된다.

• 한국과학교육학회지
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• 제15권1호
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• pp.1-5
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• 1995

One of the problem of science education in terms of its status as a unique discipline is the tendency of qualitative, rather than quantitative, arguments and judgements on research activities. In this study, a model called "Diamond Model" and an index formula for the balance of researches are suggested for achieving more pictoricaI and quantitative understandings on the distribution of researches in science education. Diamond Model is consisted of two dimensions corresponding to two main long-debated issues in science education, i.e. the dimension of cognitive-affective and the dimension of concept-process. In Diamond Model the geometrical symmetry represents the the balance of researches. An index formula for the balance was developed in order to ensure that the value of the index is between 0 to 1 and the numerical values of the index corresponds to the geometrical symmetry of the diamond. Then, in order to check their utility, the model and the index formula were applied to analyze the research papers appeared in JKARSE for the last 10 years.

• The Journal of Korean Physical Therapy
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• 제29권1호
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• pp.33-38
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• 2017

Purpose: This study was conducted to investigate the effects of variations in arm swing during gait on movement of the trunk and pelvis. During the gait task, the angle of the trunk and pelvic rotation were analyzed according to arm swing conditions. Methods: Seventeen healthy males participated in this study. All subjects were analyzed for gait on a treadmill three times each under three different types of arm swing conditions - natural arm swing, restricted arm swing using a phone, restricted swing in both arms. 3-D motion analysis systems were used to collect and analyze the kinematic data of trunk and pelvic movements, and repeated one-way ANOVA was used to compare the trunk and pelvic kinematic data and symmetry index. The level of significance was ${\alpha}=0.05$. Results: The results showed kinematic differences in trunk and pelvic during gait based on the arm swing conditions. Specifically, there were significant differences in trunk rotation, left and right trunk rotation and symmetry index of trunk rotation during gait among the three arm swing conditions. ROM was used to calculate a symmetry index (SI) based on the average left and right trunk rotation in which a value closer to zero indicated better balance. The SI obtained for arm swing restricted with the phone was closer to -1 than the other conditions. Conclusion: Restricted arm swing due to use of a phone had the possibility to induce instability of postural control while walking, which could be seen to suggest a risk of falling during gait.

• 한국정밀공학회지
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• 제29권11호
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• pp.1199-1206
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• 2012

Recently, technologies to help the elderly or disabled people who have difficulty in walking are being developed. In order to develop these technologies, it is necessary to construct a system that gathers the gait data of people and analysis of these data is also important. In this research, we constructed the development of sensor system which consists of pressure sensor, three-axis accelerometer and two-axis gyro sensor. We used k-means clustering algorithm to classify the data for characterization, and then calculated the symmetry index with histogram which was produced from each cluster. We collected gait data from sensors attached on two subjects. The experiment was conducted for two kinds of gait status. One is walking with normal gait; the other is walking with abnormal gait (abnormal gait means that the subject walks by dragging the right leg intentionally). With the result from the analysis of acceleration component, we were able to confirm that the analysis technique of this data could be used to determine gait symmetry. In addition, by adding gyro components in the analysis, we could find that the symmetry index was appropriate to express symmetry better.

• Journal of the Korean Statistical Society
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• 제33권1호
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• pp.129-147
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• 2004

For square contingency tables with nominal categories, this paper proposes a measure to represent the degree of departure from the quasi-symmetry (QS) model and the Bradley-Terry (BT) model. The measure proposed is expressed by using the Cressie and Read (1984)'s power-divergence or Patil and Taillie (1982)'s diversity index. The measure lies between 0 and 1, and it is useful for comparing the degree of departure from QS or BT in several tables.

• Journal of the Korean Statistical Society
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• 제27권3호
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• pp.289-303
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• 1998

For square contingency tables with ordered categories, Tomizawa (1995) considered two kinds of measures to represent the degree of departure from global symmetry, which means that the probability that an observation will fall in one of cells in the upper-right triangle of square table is equal to the probability that the observation falls in one of cells in the lower-left triangle of it. This paper proposes a generalization of those measures. The proposed measure is expressed by using Cressie and Read's (1984) power divergence or Patil and Taillie's (1982) diversity index. Special cases of the proposed measure include TomiBawa's measures. The proposed measure would be useful for comparing the degree of departure from global symmetry in several tables.

• 한국운동역학회지
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• 제24권4호
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• pp.391-397
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• 2014

The purpose of this work is to biomechanically study the effect of the one leg standing pose in yoga.. The work have been done through the evaluation for the left and right symmetry ability of one leg standing pose in the before and after yoga training for the 14 female yoga subject group (height: $164.3{\pm}4.4cm$, mass: $53.4{\pm}6.4kg$, year: $20.0{\pm}0.49yrs$) participated in this experiment. The motions of one leg standing pose were captured with Vicon system and the parameters were calculated with Visual-3D and Ground reaction force system. The results were as followed; - Front and backward COPsd did not show the significant difference, compared the before training with the after. - Left and right COPsd showed the significant difference (p<0.05), compared the before training with the after. - COP distance showed the significant difference (p<0.01), compared the before training with the after. - The asymmetry index of front and backward COPsd did not show the significant difference, compared the before training with the after. - The asymmetry index of left and right COPsd did not show the significant difference, compared the before training with the after. - The asymmetry index of COP distance showed the significant difference (p<0.01), compared the before training with the after. Therefore, the yoga training demonstrated the stable improvement in the one leg standing pose of inferior feet and the positive effect to the left and right symmetry ability.

• 한국운동역학회지
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• 제26권4호
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• pp.383-390
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• 2016

Objective: Gymnastics on rings needs a high level of muscle strength with balance ability for controlling the body. A study on a new balance training program is necessary for elite gymnasts. Therefore, the purpose of this study was to investigate the effects of an 8-week pilates core-muscle training on balance ability and asymmetry index of the L-sit on the rings in male elite gymnasts. Method: Ten elite gymnasts (age: $20.6{\pm}0.7years$, height: $169.9{\pm}4.9cm$, weight: $65.4{\pm}5.6kg$, career duration: $20.6{\pm}0.7years$), who are students at K-university, participated in this study. Results: First, the range of the COM tended to decrease in the anterior-posterior direction. Second, the left hip joint angle and knee extension and ankle dorsiflexion angles significantly increased after the pilates training. Third, the ROM also increased. Fourth, the symmetry value increased in the hip angle, while the symmetry index in all joints of the ROM decreased. As a result, the pilates core-muscle training influenced the static balance ability during the L-sit on the rings. Conclusion: Accordingly, the pilates core-muscle training is suitable in enhancing the basic balance ability in gymnastics on rings.