• Title/Summary/Keyword: difference tensor

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The Effect of Tensor Fasciea Latae Length on the Rotation of Pelvic during One Leg Stance (대퇴근막장근의 길이가 한발서기 시 골반의 회전에 미치는 영향)

  • Kim, Byoung-Kon;Son, Jung-Hee
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.15 no.2
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    • pp.63-68
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    • 2009
  • Purpose : The purpose of this study was to investigate the effect of tensor fasciae latae length on the rotation of pelvis during one leg stance. Methods : 41 healthy adults participated in this study. The movement of the pelvis and trunk was measured using 3-dimensional motion analyzer, during one leg stance. The movement of the pelvis and trunk was collected lateral shift, rotation, side bending, and flexion-extension. Tensor fasciae latae length of subjects was measured in sidelying positon with neutral position of hip joint and flexion $90^{\circ}$ of knee. Also, the range of motion of hip exteral and interal rotaion were measured in prone position wih lexion $90^{\circ}$ of knee. The subjects were separated 2 groups that more pelvic rotation group(n=15) and less pelvic rotation group(n=15) according to the degree of pelvic rotation. Results : The more pelvic rotation group was showed significantly higher in the ROM of hip external rotation than less pelvic rotation group(p<0.05). The difference of tensor fasciae latae length not showed significant difference between groups. During one leg stance, The movement of the shifting and flexion-extension of trunk and pelvis were not showed significant difference. But the side bending and the rotation of pelvis and trunk showed significant difference between groups. Conclusion : The difference of tensor fasciae latae length not showed significantly in more pelvic rotation group and less pelvic rotation group. But, this study suggests that the pelvis instability brings the instability of the trunk during one leg stance.

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Recovering Incomplete Data using Tucker Model for Tensor with Low-n-rank

  • Thieu, Thao Nguyen;Yang, Hyung-Jeong;Vu, Tien Duong;Kim, Sun-Hee
    • International Journal of Contents
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    • v.12 no.3
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    • pp.22-28
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    • 2016
  • Tensor with missing or incomplete values is a ubiquitous problem in various fields such as biomedical signal processing, image processing, and social network analysis. In this paper, we considered how to reconstruct a dataset with missing values by using tensor form which is called tensor completion process. We applied Tucker factorization to solve tensor completion which was built base on optimization problem. We formulated the optimization objective function using components of Tucker model after decomposing. The weighted least square matric contained only known values of the tensor with low rank in its modes. A first order optimization method, namely Nonlinear Conjugated Gradient, was applied to solve the optimization problem. We demonstrated the effectiveness of the proposed method in EEG signals with about 70% missing entries compared to other algorithms. The relative error was proposed to compare the difference between original tensor and the process output.

Effect of Various Leg-Crossing Positions on Muscle Activities of Rectus Femoris, Tensor Fascia Latae, and Hamstring in Healthy 20's Adults

  • Lee, Won-Hwee;Kang, Tae-Hee;Kim, Jeong-Ha;suryanti, Tri
    • The Journal of Korean Physical Therapy
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    • v.27 no.5
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    • pp.315-319
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    • 2015
  • Purpose: The purpose of this study was to investigate the effect of leg-crossing positions on muscle activities of rectus femoris, tensor fascia latae, and hamstring in healthy 20's adults. Methods: Twenty healthy subjects were asked to perform three leg-crossing positions, leg crossing (LC), tailor crossing (TC), and ankle crossing (AC). Surface electromyography (EMG) was used to evaluate the activities of rectus femoris, tensor fascia latae, and hamstring during upright sit posture (UP) and three leg-crossing positions and UP was compared to three leg-crossing positions. Repeated one way ANOVA was used for data analysis. The alpha level was set at 0.05. Results: The results showed significant difference in the muscle activities of rectus femoris, tensor fascia latae, and hamstring among leg-crossing positions. The muscle activity of the rectus femoris was significantly lower in LC and TC positions than UP. The muscle activity of tensor fascia latae was significantly higher in LC position than UP and other leg-crossing positions. The muscle activity of hamstring was significantly higher in LC and TC positions and significantly lower in AC position than in UP. Conclusion: Our study suggests that the activity of hip muscles was affected by pelvic and knee alignment in various leg-crossing positions.

The Influence of Electromyographic Activation on Gluteus Medius and Tensor Fascia Lata by Functional Leg Length Discrepancy in Women's University Students During Lunge (여대생의 기능적 다리길이 차이가 런지 자세에서 중간볼기근, 넙다리근막긴장근의 근활성도에 미치는 영향)

  • Kim, Hae-Ree;Song, Ye-Jin;Moon, Sung-Gi;Jang, Hyun-Jeong
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.19 no.2
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    • pp.39-46
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    • 2013
  • Background: The purpose of this study was to realize the relations between gluteus medius, tensor fascia lata of pelvic muscles and functional leg length in women's university students. This study is examined the change of electromyographic activation on gluteus medius and tensor fascia lata according to the leg length discrepancy. Methods: All of the female of freshman and sophomore in 'D'college were gathered and separated fourteen of healthy women in two groups by functional leg length discrepancy. and The subjects divided into two groups that the difference with less than 2cm or more would have structural defects by tapeline. The electromyographic activation on the gluteus medius and tensor fascia lata muscles were recorded by surface electrodes at maximal voluntary isometric contraction (MVIC) during lunge posture. The collected datas were analyzed using Independent t-test with SPSS win19.0. Results: In intergroup comparison of electromyographic activation levels for gluteus medius and tensor fascia lata in short or long leg, the influence of electromyographic activation on tensor fascia lata is shown to be more statically higher than gluteus medius according to functional leg length discrepancy in coeds. Even though both muscles are shown to be statistically higher in comparison of electoromyographic activation levels for tensor fascia lata and gluteus medius between short leg and long leg in Group I, Differences of electoromyographic activation levels for tensor fascia lata is shown to be statistically higher than gluteus medius. Conclusion: Through this study, we realized that tensor fascia lata than the long leg, and also, tensor fascia lata is significantly effective for functional leg length discrepancy than gluteus medius. It leads to pelvic lateral instability. This means that cause tensor fascia lata to have a leg length discrepancy.

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Conformal transformations of difference tensors of Finsler space with an $(alpha,beta)$-metric

  • Lee, Yong-Duk
    • Communications of the Korean Mathematical Society
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    • v.12 no.4
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    • pp.975-984
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    • 1997
  • In the Finsler space with an $(\alpha, \beta)$-metric, we can consider the difference tensors of the Finsler connection. The properties of the conformal transformation of these difference tensors are investigated in the present paper. Some conformal invariant tensors are formed in the Finsler space with an $(\alpha, \beta)$-metric related with the difference tensors.

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Distribution of the Reynolds Stress Tensor Inside Tip Leakage Vortex of a Linear Compressor Cascade (I) - Effect of Inlet Flow Angle - (선형 압축기 익렬에서 발생하는 익단 누설 와류내의 레이놀즈 응력 분포 (I) -입구 유동각 변화의 영향-)

  • Lee, Gong-Hee;Park, Jong-Il;Baek, Je-Hyun
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.28 no.8 s.227
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    • pp.902-909
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    • 2004
  • A steady-state Reynolds averaged Navier-Stokes simulation was conducted to investigate the distribution of the Reynolds stress tensor inside tip leakage vortex of a linear compressor cascade. Two different inlet flow angles ${\beta}=29.3^{\circ}$(design condition) and $36.5^{\circ}$(off-design condition) at a constant tip clearance size of $1\%$ blade span were considered. Classical methods of solid mechanics, applied to view the Reynolds stress tensor in the principal direction system, clearly showed that the high anisotropic feature of turbulent flow field was dominant at the outer part of tip leakage vortex near the suction side of the blade and endwall flow separation region, whereas a nearly isotropic turbulence was found at the center of tip leakage vortex. There was no significant difference in the anisotropy of the Reynolds normal stresses inside tip leakage vortex between the design and off-design condition.

Constitutive Equations for Dilute Bubble Suspensions and Rheological Behavior in Simple Shear and Uniaxial Elongational Flow Fields

  • Seo Dongjin;Youn Jae Ryoun
    • Fibers and Polymers
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    • v.6 no.2
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    • pp.131-138
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    • 2005
  • A theoretical model is proposed in order to investigate rheological behavior of bubble suspension with large deformation. Theoretical constitutive equations for dilute bubble suspensions are derived by applying a deformation theory of ellipsoidal droplet [1] to a phenomenological suspension theory [2]. The rate of deformation tensor within the bubble and the time evolution of interface tensor are predicted by applying the proposed constitutive equations, which have two free fitting parameters. The transient and steady rheological properties of dilute bubble suspensions are studied for several capillary numbers (Ca) under simple shear flow and uniaxial elongational flow fields. The retraction force of the bubble caused by the interfacial tension increases as bubbles undergo deformation. The transient and steady relative viscosity decreases as Ca increases. The normal stress difference (NSD) under the simple shear has the largest value when Ca is around 1 and the ratio Of the first NSD to the second NSD has the value of 3/4 for large Ca but 2 for small Ca. In the uniaxial elongational flow, the elongational viscosity is three times as large as the shear viscosity like the Newtonian fluid.

An Improved Nonparametric Change Detection Algorithm Using Euler Number and Structure Tensor (오일러 수와 구조 텐서를 사용한 개선된 Nonparametric 변화 검출 알고리즘)

  • 이웅희;김태희;정동석
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.10C
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    • pp.958-966
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    • 2003
  • Change detection algorithms based on frame difference are frequently used for finding moving objects in image sequences. These algorithms detect the change of frames using estimated statistical background model. But, if this estimated background model is different from the actual statistical distribution, false detections are generated. In this paper, we propose an improved change detection algorithm using euler number and structure tensor. The proposed mapping method which is based on the euler number can be used for reducing the false detections that generated by nonparametric change detection algorithm. In this paper, the change in the region of moving object also can be detected by the proposed method using structure tensor. Experimental result shows that the proposed method reduces the false detections effectively by 90% on "Weather", by 34% on "Mother & daughter" and by 43% on "Aisle" than an existing method does.

Comparison of Fractional Anisotropy Values of Corticospinal Tract and Corpus Callosum between 6- and 25-Direction Diffusion Tensor Images in Normal Subjects

  • Lee, Jeong-Hyun;Lee, Sun-Young;Kim, Hyun-Jeong;Park, Choong-Gon;Lee, Deok-Hee;Lee, Ho-Kyu;Kim, Sang-Joon;Suh, Dae-Chul
    • Proceedings of the KSMRM Conference
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    • 2003.10a
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    • pp.20-20
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    • 2003
  • Purpose: To investigate the difference of fractional anisotropy (FA) values between 6- and 25-direction diffusion tensor images (DTI) in normal adult brain. Materials and Methods: DTI was peformed in 28 normal subjects (15 subjects with 6-direction, 13 subjects with 25-direction) in a 1.5 T MR system. DTI was done with SE-EPI sequence with TR/TE/NEX 10000/84/1, 5mm slice thickness and b=1000 s/mm2. FA values were measured from 8 different anatomical locations which included both cerebral peduncles, both posterior limbs of the internal capsules, both corona radiata, genu and splenium of the corpus callosum. Statistical difference of FA was tested between 6-and 25-direction DTI.

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Estimation of South Korea Spatial Soil Moisture using TensorFlow with Terra MODIS and GPM Satellite Data (Tensorflow와 Terra MODIS, GPM 위성 자료를 활용한 우리나라 토양수분 산정 연구)

  • Jang, Won Jin;Lee, Young Gwan;Kim, Seong Joon
    • Proceedings of the Korea Water Resources Association Conference
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    • 2019.05a
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    • pp.140-140
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    • 2019
  • 본 연구에서는 Terra MODIS 위성자료와 Tensorflow를 활용해 1 km 공간 해상도의 토양수분을 산정하는 알고리즘을 개발하고, 국내 관측 자료를 활용해 검증하고자 한다. 토양수분 모의를 위한 입력 자료는 Terra MODIS NDVI(Normalized Difference Vegetation Index)와 LST(Land Surface Temperature), GPM(Global Precipitation Measurement) 강우 자료를 구축하고, 농촌진흥청에서 제공하는 1:25,000 정밀토양도를 기반으로 모의하였다. 여기서, LST와 GPM의 자료는 기상청의 종관기상관측지점의 LST, 강우 자료와 조건부합성(Conditional Merging, CM) 기법을 적용해 결측치를 보간하였고, 모든 위성 자료의 공간해상도를 1 km로 resampling하여 활용하였다. 토양수분 산정 기술은 인공 신경망(Artificial Neural Network) 모형의 딥 러닝(Deep Learning)을 적용, 기계 학습기반의 패턴학습을 사용하였다. 패턴학습에는 Python 라이브러리인 TensorFlow를 사용하였고 학습 자료로는 농촌진흥청 농업기상정보서비스에서 101개 지점의 토양수분 자료(2014 ~ 2016년)를 활용하고, 모의 결과는 2017 ~ 2018년까지의 자료로 검증하고자 한다.

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