• Title/Summary/Keyword: asymmetric methods

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Support Vector Quantile Regression Using Asymmetric e-Insensitive Loss Function

  • Shim, Joo-Yong;Seok, Kyung-Ha;Hwang, Chang-Ha;Cho, Dae-Hyeon
    • Communications for Statistical Applications and Methods
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    • 제18권2호
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    • pp.165-170
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    • 2011
  • Support vector quantile regression(SVQR) is capable of providing a good description of the linear and nonlinear relationships among random variables. In this paper we propose a sparse SVQR to overcome a limitation of SVQR, nonsparsity. The asymmetric e-insensitive loss function is used to efficiently provide sparsity. The experimental results are presented to illustrate the performance of the proposed method by comparing it with nonsparse SVQR.

뇌졸중 환자의 낙상 예방을 위한 체중부하 비대칭과 자세 동요와의 관련성 (The Relation Between Postural Sway and Asymmetric Weight-bearing for Fall Prevention in Patients with Stroke)

  • 송창호;이규창;유재호;이경진;이승원
    • 대한물리의학회지
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    • 제5권1호
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    • pp.81-88
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    • 2010
  • Purpose : The purpose of this study was to investigate the relationship between postural sway and asymmetric weight-bearing for fall prevention in patients with stroke. Methods : Fifty-three individuals with hemiplegic stroke and 57 healthy older adults c

Threshold-asymmetric volatility models for integer-valued time series

  • Kim, Deok Ryun;Yoon, Jae Eun;Hwang, Sun Young
    • Communications for Statistical Applications and Methods
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    • 제26권3호
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    • pp.295-304
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    • 2019
  • This article deals with threshold-asymmetric volatility models for over-dispersed and zero-inflated time series of count data. We introduce various threshold integer-valued autoregressive conditional heteroscedasticity (ARCH) models as incorporating over-dispersion and zero-inflation via conditional Poisson and negative binomial distributions. EM-algorithm is used to estimate parameters. The cholera data from Kolkata in India from 2006 to 2011 is analyzed as a real application. In order to construct the threshold-variable, both local constant mean which is time-varying and grand mean are adopted. It is noted via a data application that threshold model as an asymmetric version is useful in modelling count time series volatility.

방사선사진과 안모사진을 이용한 하악 비대칭의 평가 (Evaluation of the mandibular asymmetry using the facial photographs and the radiographs)

  • 이설미
    • Imaging Science in Dentistry
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    • 제31권4호
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    • pp.199-204
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    • 2001
  • Purpose : To assess the relationship between soft tissue asymmetry and bone tissue asymmetry using the standardized photographs and the posteroanterior (PA) cephalometric radiographs in mandibular asymmetric patients. And to clarify that the lack of morphologic balance among different skeletal components can often be masked by compensatory soft tissue contributions. Methods: Experimental group consisted of 58 patients whose chief complaints were facial asymmetry, they were taken with standardized facial photographs and PA cephalometric radiographs. Control group consisted of 30 persons in the normal occlusion. The reproducibility of the facial photograph was confirmed by model test. The differences of fractional vertical heightand horizontal width from standardized facial photographs and PA cephalometric radiographs were compared and analyzed. Results: The difference of fractional vertical bone height was 0.63 and fractional vertical soft height was 0.58 in control group, 3.10 and 2.01 in asymmetric group, respectively. The difference of fractional horizontal bone width was 0.52 and fractional horizontal soft width was 0.70 in control group, 2.51 and 1.70 in asymmetric group, respectively. Both soft and bone tissue showed significant difference between control and asymmetric group (p<0.05). The difference of bone tissue was greater than that of soft tissue (p<0.05) in the experimental group but, not in control group. Conclusions: Soft tissue components may compensate for underlying skeletal imbalances.

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편측성 운동이 축구선수의 척추 변형과 체중 지지에 미치는 영향 (Effect of asymmetric exercise to soccer player's spinal deformity and weight bearing)

  • 엄요한;박승규;양대중
    • 대한임상전기생리학회지
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    • 제10권1호
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    • pp.45-52
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    • 2012
  • Purpose : This study is carried out to investigate the effect of asymmetric exercises on soccer players' vertebral abnormality and weight bearing. Methods : A total of 40 soccer players were divided into either a group of 20 players who use a unilateral foot or a group of 20 players who use both feet. 3-dimensional spine structure analyzer was used to analyze body inclination, pelvic inclination, pelvic torsion, turning of spinal segment, spinal curvature, thoracic kyphosis curvature, lumbar lordosis curvature, left/right weight distribution, and front/back weight distribution. Results : The result of the two groups showed that there were significant differences (p<0.05) for every item except turning of spinal segment and lumbar lordosis curvature. Conclusion : From this result, we can find that spinal and pelvic deformity and body weight are unilaterally supported for soccer players with asymmetric exercises.

자이로스코픽 효과와 유체 동압 베어링에 의한 비대칭성을 고려한 회전 유연 디스크-스핀들 시스템의 유한요소 강제 진동 해석 (Finite Element Forced Response of a Spinning Flexible HDD Disk-spindle System Considering the Asymmetry Originating from Gyroscopic Effect and Fluid Dynamic Bearings)

  • 박기용;장건희;서찬희
    • 한국소음진동공학회논문집
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    • 제20권10호
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    • pp.915-922
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    • 2010
  • This paper presents an efficient method for determining the forced response of a spinning flexible disk-spindle system supported by fluid dynamic bearings(FDBs) in a computer hard disk drive(HDD). The spinning flexible disk-spindle system is represented by the asymmetric finite element equations of motion originating from the asymmetric dynamic coefficients of the FDBs and the gyroscopic moment of a spinning disk-spindle system. The proposed method utilizes only the right eigenvectors of the eigenvalue problem to transform the large asymmetric finite element equations of motion into a small number of coupled equations, guaranteeing the accuracy of their numerical integration. The results are then back-substituted into the equations of motion to determine the forced response. The effectiveness of the proposed method was verified by comparing it with the responses from the classical methods of mode superposition with the general eigenvalue problems, and mode superposition with modal approximation. The proposed method was shown to be effective in determining the forced response represented by the asymmetric finite element equations of motion of a spinning flexible disk-spindle system supported by FDBs.

Asymmetric Flankers in Comodulation Masking Release

  • Pourbakht, Akram;Faraji, Leila
    • Journal of Audiology & Otology
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    • 제23권1호
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    • pp.27-32
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    • 2019
  • Background and Objectives: Detection of auditory signals may be improved when maskers far from the frequency of the target signal are coherently amplitude-modulated. This improvement of signal detection is called comodulation masking release (CMR). In the CMR experiments, flankers have been usually arranged symmetrically. In practice, we will be confronted with a problem by using symmetric flankers due to the limited output of clinical audiometers, especially at high-frequency. We aimed to check whether flanker arrangement has any effect on the amount of CMR, especially when there is no flankers with a frequency higher than the signal. Subjects and Methods: Eighteen normal hearing listeners ranging in age from 20 to 46 years old participated. Symmetric (2-2) and asymmetric (3-1 and 4-0) flankers were used and then the amount of CMR compared among them. Results: Our results showed in the same numbers of flankers, there were no statistically CMR differences between symmetric and asymmetric arrangement. Also when we did not have a flanker at a frequency higher than the signal and all flankers were placed below the signal, there was no statistically difference with the symmetric arrangement. Conclusions: The asymmetry of the flankers and also omitting the flankers with a frequency higher than the signal, have no effect on CMR results. We concluded that CMR can be considered by using clinical audiometer.

Three-dimensional evaluation of mandibular width after mandibular asymmetric setback surgery using sagittal split ramus osteotomy

  • Seong-Sik Kim;Sung-Hun Kim;Yong-Il Kim;Soo-Byung Park
    • 대한치과교정학회지
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    • 제53권2호
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    • pp.99-105
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    • 2023
  • Objective: The study aimed to evaluate the changes in mandibular width after sagittal split ramus osteotomy (SSRO) in patients with mandibular asymmetric prognathism using cone-beam computed tomography (CBCT). Methods: Seventy patients who underwent SSRO for mandibular setback surgery were included in two groups, symmetric (n = 35) and asymmetric (n = 35), which were divided according to the differences in their right and left setback amounts. The mandibular width was evaluated three-dimensionally using CBCT images taken immediately before surgery (T1), 3 days after surgery (T2), and 6 months after surgery (T3). Repeated measures analysis of variance was applied to verify the differences in mandibular width statistically. Results: Both groups showed a significant increase in the mandibular width at T2, followed by a significant decrease at T3. No significant difference was observed between T1 and T3 in any of the measurements. No significant differences were found between the two groups (p > 0.05). Conclusions: After mandibular asymmetric setback surgery using SSRO, the mandibular width increased immediately but returned to its original width 6 months after surgery.

Asymmetric Flankers in Comodulation Masking Release

  • Pourbakht, Akram;Faraji, Leila
    • 대한청각학회지
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    • 제23권1호
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    • pp.27-32
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    • 2019
  • Background and Objectives: Detection of auditory signals may be improved when maskers far from the frequency of the target signal are coherently amplitude-modulated. This improvement of signal detection is called comodulation masking release (CMR). In the CMR experiments, flankers have been usually arranged symmetrically. In practice, we will be confronted with a problem by using symmetric flankers due to the limited output of clinical audiometers, especially at high-frequency. We aimed to check whether flanker arrangement has any effect on the amount of CMR, especially when there is no flankers with a frequency higher than the signal. Subjects and Methods: Eighteen normal hearing listeners ranging in age from 20 to 46 years old participated. Symmetric (2-2) and asymmetric (3-1 and 4-0) flankers were used and then the amount of CMR compared among them. Results: Our results showed in the same numbers of flankers, there were no statistically CMR differences between symmetric and asymmetric arrangement. Also when we did not have a flanker at a frequency higher than the signal and all flankers were placed below the signal, there was no statistically difference with the symmetric arrangement. Conclusions: The asymmetry of the flankers and also omitting the flankers with a frequency higher than the signal, have no effect on CMR results. We concluded that CMR can be considered by using clinical audiometer.

중량물 들기 작업시 물체 무게중심 및 발의 위치가 허리 근육의 최대 EMG 진폭에 미치는 영향 (Effects of Load Center of Gravity and Feet Positions on Peak EMG Amplitude at Low Back Muscles While Lifting Heavy Materials)

  • 김선욱;한승조
    • 한국산업보건학회지
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    • 제22권3호
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    • pp.257-264
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    • 2012
  • Objectives: This study's aims were to evaluate the effects of load center of gravity within an object lifted and feet placements on peak EMG amplitude acting on bilateral low back muscle groups, and to suggest adequate foot strategies with an aim to reducing low back pain incidence while lifting asymmetric load. Methods: The hypotheses that asymmetric load imposes more peak EMG amplitude on low back muscles contralateral to load center of gravity than symmetric load and maximum peak EMG amplitude out of bilateral ones can be relieved by locating one foot close to load center of gravity in front of the other were established based on biomechanics including safety margin model and previous researches. 11 male subjects were required to lift symmetrically a 15.8kg object during 2sec according to each conditions; symmetric load-parallel feet (SP), asymmetric load-parallel feet (AP), asymmetric load-one foot contralateral to load center of gravity in front of the other (AL), and asymmetric load-one foot ipsilateral to load center of gravity in front of the other (AR). Bilateral longissimus, iliocostalis, and multifidus on right and left low back area were selected as target muscles, and asymmetric load had load center of gravity 10cm deviated to the right from the center in the frontal plane. Results: Greater peak EMG amplitude in left muscle group than in right one was observed due to the effect of load center of gravity, and mean peak EMG amplitudes on both sides was not affected by load center of gravity because of EMG balancing effect. However, the difference of peak EMG amplitudes between both sides was significantly affected by it. Maximum peak EMG amplitude out of both sides and the difference of peak EMG amplitude between both sides could be reduced with keeping one foot ipsilateral to load center of gravity in front of the other while lifting asymmetric load. Conclusions: It was likely that asymmetric load lead to the elevated incidence of low back pain in comparison with symmetric load based on maximum peak EMG amplitude occurrence and greater imbalanced peak EMG amplitude between both sides. Changing feet positions according to the location of load center of gravity was suggested as one intervention able to reduce the low back pain incidence.