• Title/Summary/Keyword: Test For Asymmetry

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The Effects of Breathing Retraining on Asymmetry of Diaphragm Thickness in Stroke Patients (호흡훈련이 뇌졸중 환자의 횡격막 비대칭에 미치는 영향)

  • Kim, Nan-Soo;Jung, Ju-Hyeon
    • Journal of the Korean Society of Physical Medicine
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    • v.8 no.2
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    • pp.263-269
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    • 2013
  • PURPOSE: The purpose of this study was to examine the effects of breathing retraining on asymmetry of diaphragm thickness in stroke patients. METHODS: This study was nonequivalent control group pre-post test design. Subjects were assigned to two different groups(intervention group=10, control group=12). Intervention group conducted breathing retraining program for six-week. Diaphragm thickness was assessed by ultrasound in B-mode with a 7.5 MHz linea probe. The collected data analyzed by Wilcoxon signed rank test and Mann-Whitney U test. RESULTS: The intervention group significantly increased diaphragm thickness ratio on paretic side but the control group showed no significant difference in diaphragm thickness ratio. The control group significantly increased asymmetry of diaphragm thickness, but intervention group showed no significant difference in asymmetry of diaphragm thickness. CONCLUSION: This study showed that breathing retraining increased diaphragm thickness ratio in stroke patients and prevent the increase of asymmetry in diaphragm thickness with stroke patients.

Tests for Asymmetry and Structure Changes in Retail Price Volatility of Fresh Common Squid in the Republic of Korea (신선 물오징어 소매가격 변동성의 구조변화와 비대칭성 검증)

  • Nam, Jongoh;Sim, Seonghyun
    • Ocean and Polar Research
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    • v.37 no.4
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    • pp.357-368
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    • 2015
  • This study analyzed structural changes and asymmetry of price volatility during the period before and after a point of structural change in price volatility, using the Korean fresh common squid daily retail price data from January 1, 2004 to September 30, 2015. This study utilized the following analytical methods: the unit-root test was applied to ensure the stability of the data, the Quandt-Andrews breakpoint test was applied to find the point of structural change, and the Glosten-Jagannathan-Runkle GARCH and EGARCH models were applied to investigate the asymmetry of price volatility. The empirical results of this study are as follows. First, ADF, PP, KPSS and Zivot-Andrews tests showed that the daily retail price change rate of the Korean fresh common squid differentiated by logarithm was stable. Secondly, the ARIMA (2,1,2) model was selected by information criteria such as AIC, SC, and HQ. Thirdly, the Quandt-Andrews breakpoint test found that a single structural change in price volatility occurred on June 11, 2009. Fourthly, the Glosten-Jagannathan-Runkle GARCH and EGARCH models showed that estimates of coefficients within the models were statistically significant before and after structural change and also that asymmetry as a leverage effect existed before and after structural change.

Identification of Asymmetry in General Rotors from Directional Frequency Response Functions (방향성 주파수 응답 함수를 이용한 일반 회전체의 비대칭성 규명)

  • Seo, Yun-Ho;Kang, Sung-Woo;Lee, Chong-Won
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.05a
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    • pp.941-944
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    • 2005
  • Asymmetry of rotor systems is an important factor for identification of dynamic characteristics including the stability and response of rotors and for condition monitoring. In this work, asymmetry of rotors is identified by applying curve-fitting method to the directional frequency response functions (dFRFs), which are known as a powerful tool for detecting the presence and degree of asymmetry. This method minimizes least square error between analytical and measured dFRFs by iteratively updating physical parameters associated with rotor asymmetry. The effectiveness of the identification method is demonstrated by experiments with a laboratory test rotor.

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The Influences of Participatory Management and Corporate Governance on the Reduction of Financial Information Asymmetry: Evidence from Thailand

  • LATA, Pannarai
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.11
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    • pp.853-866
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    • 2020
  • The purposes of this research were: 1) to investigate the effect of participatory management on financial information asymmetry, 2) to investigate the effect of corporate governance on financial information asymmetry, 3) to examine the influences of benefits incentives on financial information asymmetry, and 4) to test the mediating effects of benefits incentive that influences the relationship between participatory management, corporate governance, and financial information asymmetry. The research sample consisted of 388 Thai-listed firms. Data were collected through a survey questionnaire. Descriptive analysis, Multiple Regression Analysis, and Structural Equation Modeling were used for the data analysis. The results revealed: 1) participatory management and participation in evaluation had a negative influence on financial information asymmetry. 2) Corporate governance and the rights of shareholders had a negative influence on financial information asymmetry. 3) Benefits incentive was negatively associated with financial information asymmetry. 4) The model's influences of participatory management, corporate governance on the reduction of financial information asymmetry through benefits incentive as mediator fit the empirical data (Chi-square = 104.459, df = 84, p = 0.065, GFI = 0.967, RMSEA = 0.025). The variables in the model explained 78.00% and 4.70 % of the variance of benefits incentive and financial information asymmetry, respectively.

Comparision of Mandible Changes on Three-Dimensional Computed Tomography image After Mandibular Surgery in Facial Asymmetry Patients (안면 비대칭 환자의 하악골 수술 후 하악골 변화에 대한 3차원 CT 영상 비교)

  • Kim, Mi-Ryoung;Chin, Byung-Rho
    • Journal of Yeungnam Medical Science
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    • v.25 no.2
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    • pp.108-116
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    • 2008
  • Background : When surgeons plan mandible ortho surgery for patients with skeletal class III facial asymmetry, they must be consider the exact method of surgery for correction of the facial asymmetry. Three-dimensional (3D) CT imaging is efficient in depicting specific structures in the craniofacial area. It reproduces actual measurements by minimizing errors from patient movement and allows for image magnification. Due to the rapid development of digital image technology and the expansion of treatment range, rapid progress has been made in the study of three-dimensional facial skeleton analysis. The purpose of this study was to conduct 3D CT image comparisons of mandible changes after mandibular surgery in facial asymmetry patients. Materials & methods : This study included 7 patients who underwent 3D CT before and after correction of facial asymmetry in the oral and maxillofacial surgery department of Yeungnam University Hospital between August 2002 and November 2005. Patients included 2 males and 5 females, with ages ranging from 16 years to 30 years (average 21.4 years). Frontal CT images were obtained before and after surgery, and changes in mandible angle and length were measured. Results : When we compared the measurements obtained before and after mandibular surgery in facial asymmetry patients, correction of facial asymmetry was identified on the "after" images. The mean difference between the right and left mandibular angles before mandibular surgery was $7^{\circ}$, whereas after mandibular surgery it was $1.5^{\circ}$. The right and left mandibular length ratios subtracted from 1 was 0.114 before mandibular surgery, while it was 0.036 after mandibular surgery. The differences were analyzed using the nonparametric test and the Wilcoxon signed ranks test (p<0.05). Conclusion: The system that has been developed produces an accurate three-dimensional representation of the skull, upon which individualized surgery of the skull and jaws is easily performed. The system also permits accurate measurement and monitoring of postsurgical changes to the face and jaws through reproducible and noninvasive means.

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News Impact Curve and Test for Asymmetric Volatility

  • Park, J.A.;Choi, M.S.;Kim, K.K.;Hwang, S.Y.
    • Journal of the Korean Data and Information Science Society
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    • v.18 no.3
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    • pp.697-704
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    • 2007
  • It is common in financial time series that volatility(conditional variance) as a measure of risk exhibits asymmetry in such a manner that positive and negative values of return rates of the series tend to provide different contributions to the volatility. We are concerned with asymmetric conditional variances for Korean financial time series especially during the time span of 2000-2001. Notice that these periods suffer from 9-11 disaster in US and collapses of stock prices of dot-companies in Korea. Threshold-ARCH models are considered and a Wald test of asymmetry is suggested. News impact curves are illustrated for graphical representations of leverage effects inherent in various Korean financial time series.

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Repeatability Test for the Asymmetry Measurement of Human Appearance using General-purpose Depth Cameras (범용 깊이 카메라를 이용한 인체 외형 비대칭 측정의 반복성 평가)

  • Jang, Jun-Su
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.30 no.3
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    • pp.184-189
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    • 2016
  • Human appearance analysis is an important part of both eastern and western medicine fields, such as Sasang constitutional medicine, rehabilitation medicine, dental medicine, and etc. By the rapid growing of depth camera technology, 3D measuring becomes popular in many applications including medical area. In this study, the possibility of using depth cameras in asymmetry analysis of human appearance is examined. We introduce the development of 3D measurement system using 2 Microsoft Kinect depth cameras and fully automated asymmetry analysis algorithms based on computer vision technology. We compare the proposed automated method to the manual method, which is usually used in asymmetry analysis. As a measure of repeatability, standard deviations of asymmetry indices are examined by 10 times repeated experiments. Experimental results show that the standard deviation of the automated method (1.00mm for face, 1.22mm for body) is better than that of the manual method (2.06mm for face, 3.44mm for body) for the same 3D measurement. We conclude that the automated method using depth cameras can be successfully applicable to practical asymmetry analysis and contribute to reliable human appearance analysis.

BAYESIAN INFERENCE FOR MTAR MODEL WITH INCOMPLETE DATA

  • Park, Soo-Jung;Oh, Man-Suk;Shin, Dong-Wan
    • Proceedings of the Korean Statistical Society Conference
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    • 2003.05a
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    • pp.183-189
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    • 2003
  • A momentum threshold autoregressive (MTAR) model, a nonlinear autoregressive model, is analyzed in a Bayesian framework. Parameter estimation in the presence of missing data is done by using Markov chain Monte Carlo methods. We also propose simple Bayesian test procedures for asymmetry and unit roots. The proposed method is applied to a set of Korea unemployment rate data and reveals evidence for asymmetry and a unit root.

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The Role of Remittances in Financial Development: Evidence from Nonlinear ARDL and Asymmetric Causality

  • MEHTA, Ahmed Muneeb;QAMRUZZAMAN, Md.;SERFRAZ, Ayesha;ALI, Asad
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.3
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    • pp.139-154
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    • 2021
  • This study's impetus is to explore fresh evidence to answer the question, i.e., whether remittances asymmetrically influence financial development in Bangladesh from 1975 to 2019. The study employs several tests, i.e., nonlinear unit root test, Autoregressive Distributed Lagged (ARDL), NARDL, and asymmetric causality test for establishing the pattern of association. Nonlinear unit root tests confirm that variables follow a nonlinear system of being stationary after the first difference. nonlinearity among variables is investigated by performing the BDS test and nonlinear OLS. Directional causality is investigated through both linear and nonlinear effects of remittance inflows by following the non-granger casualty test. The test statistics of Fpass and tBDM showed the Long-run cointegration in the empirical model and positive effect running from remittances inflow to financial development both in the long-run and short-run. Furthermore, the results of a standard Wald test divulge the presence of long-run and short-run asymmetry. Asymmetry causality test established unidirectional causality due to positive and negative shocks in remittances inflows to Bank-based financial development and feedback hypothesis hold for explaining causality between positive and negative shocks in remittance inflows and Stock-based financial development.

Comparative analysis of craniofacial asymmetry in subjects with and without symptoms of temporomandibular joint disorders: a cross-sectional study

  • Anita Pradhan;Preeti Bhattacharya;Shivani Singh;Anil Kumar Chandna;Ankur Gupta;Ravi Bhandari
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.49 no.3
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    • pp.125-134
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    • 2023
  • Objectives: The aim of the study was to quantify and compare craniofacial asymmetry in subjects with and without symptoms of temporomandibular joint disorders (TMDs). Materials and Methods: A total of 126 adult subjects were categorized into two groups (63 with a TMDs and 63 without a TMDs), based on detection of symptoms using the Temporomandibular Joint Disorder-Diagnostic Index (TMD-DI) questionnaire. Posteroanterior cephalograms of each subject were traced manually and 17 linear and angular measurements were analyzed. Craniofacial asymmetry was quantified by calculating the asymmetry index (AI) of bilateral parameters for both groups. Results: Intra- and intergroup comparisons were analyzed using independent t-test and Mann-Whitney U test, respectively, with a P<0.05 considered statistically significant. An AI for each linear and angular bilateral parameter was calculated; higher asymmetry was found in TMD-positive patients compared with TMD-negative patients. An intergroup comparison of AIs found highly significant differences for the parameters of antegonial notch to horizontal plane distance, jugular point to horizontal plane distance, antegonial notch to menton distance, antegonial notch to vertical plane distance, condylion to vertical plane distance, and angle formed by vertical plane, O point and antegonial notch. Significant deviation of the menton distance from the facial midline was also evident. Conclusion: Greater facial asymmetry was seen in the TMD-positive group compared with the TMD-negative group. The mandibular region was characterized by asymmetries of greater magnitude compared with the maxilla. Patients with facial asymmetry often require management of temporomandibular joint (TMJ) pathology to achieve a stable, functional, and esthetic result. Ignoring the TMJ during treatment or failing to provide proper management of the TMJ and performing only orthognathic surgery may result in worsening of TMJ-associated symptoms (jaw dysfunction and pain) and re-occurrence of asymmetry and malocclusion. Assessments of facial asymmetry should take into account TMJ disorders to improve diagnostic accuracy and treatment outcomes.