• Title/Summary/Keyword: chi Method

Search Result 2,815, Processing Time 0.032 seconds

A Rao-Robson Chi-Square Test for Multivariate Normality Based on the Mahalanobis Distances

  • Park, Cheolyong
    • Communications for Statistical Applications and Methods
    • /
    • v.7 no.2
    • /
    • pp.385-392
    • /
    • 2000
  • Many tests for multivariate normality are based on the spherical coordinates of the scaled residuals of multivariate observations. Moore and Stubblebine's (1981) Pearson chi-square test is based on the radii of the scaled residuals, or equivalently the sample Mahalanobis distances of the observations from the sample mean vector. The chi-square statistic does not have a limiting chi-square distribution since the unknown parameters are estimated from ungrouped data. We will derive a simple closed form of the Rao-Robson chi-square test statistic and provide a self-contained proof that it has a limiting chi-square distribution. We then provide an illustrative example of application to a real data with a simulation study to show the accuracy in finite sample of the limiting distribution.

  • PDF

Effects of a 8-week Tai Chi Exercise Program on the Risk Factors for Falls in the Elderly with Osteoarthritis (8주간의 타이치 운동 프로그램이 골관절염 노인환자의 낙상 위험요인에 미치는 효과)

  • Lee, Eun-Nam;Yoo, Young-Won
    • Journal of muscle and joint health
    • /
    • v.11 no.1
    • /
    • pp.61-73
    • /
    • 2004
  • Purpose: The purpose of this study was to determine the effects of a 8- week Tai Chi exercise program on improving the risk factors for falls in the older adults with chronic arthritis pain. Method: Fifteen subjects were assigned for experimental group and thirteen were assigned for control group. The subjects of the experimental group participated in a 8 -week program of Tai Chi exercise. In order to evaluate the effects of Tai Chi program, pain intensity, postural stability, balance, gait, and flexibility of knees and ankles were measured before the first and after the 8th session Result: After a 8-week Tai Chi program, there were significant improvement in single-leg stance time with eyes open(left: p=.000, right: p=.003), total scores of balance(p=.004), total scores of gait(p=.005), and the angle of ankle dorsiflexion(p=.008) in the experimental group when compared to the control group. However, there was no significant difference in pain intensity between Tai Chi group and control group(p=.054). Conclusion: These results suggest that a 8-week Tai Chi exercise program can be utilized as a safe and effective nursing program to improve on improving the risk factors for falls in the older adults with osteoarthritis.

  • PDF

Improving Utilization of GPS Data for Urban Traffic Applications

  • Nguyen, Duc Hai;Nguyen, Tan Phuc;Doan, Khue;Ta, Ho Thai Hai;Pham, Tran Vu;Huynh, Nam;Le, Thanh Van
    • International Journal of Internet, Broadcasting and Communication
    • /
    • v.7 no.1
    • /
    • pp.6-9
    • /
    • 2015
  • The use of Intelligent Transportation System (ITS) is promising to bring better solutions for managing and handling the city traffic. This system combines many fields in advanced technology such as Global Positioning System (GPS), Geographic Information System (GIS) and so on. The basement of applications in ITS is the effective collections and data integration tools. The purpose of our research is to propose solutions which involve the use of GPS time series data collected from GPS devices in order to improve the quality of output traffic data. In this study, GPS data is collected from devices attached to vehicles travelling on routes in Ho Chi Minh City (HCMC). Then, GPS data is stored in database system to serve in many transportation applications. The proposed method combines the data usage level and data coverage to improve the quality of traffic data.

Effect of Tai Chi Exercise on Fatigue, Stress, and Quality of Life in Middle Aged Women (타이치 운동이 중년여성의 피로, 스트레스 및 삶의 질에 미치는 효과)

  • Park, Young-Ju;Park, In-Hyae
    • Journal of muscle and joint health
    • /
    • v.13 no.1
    • /
    • pp.20-30
    • /
    • 2006
  • Purpose: To determine the effect of Tai Chi exercise program on fatigue, stress, and quality of life in middle aged women. Method: The study was designed as a nonequivalent control group pretest-posttest quasi-experimental study. Thirty subjects were assigned for experimental group and thirty four subjects were assigned for control group. The subjects in the experimental group were participated in Tai Chi exercise program for 60 minutes per session 3 times a week for 8weeks. Tai Chi exercise program consists of 10 minutes warm-up, 45 minutes main, and 5 minutes cooling down exercises. In order to evaluate the effect of Tai Chi exercise program, fatigue, stress, and qualify of life were assessed by measuring the condition of the participants in respect of fatigue, stress, and qualify of life with questionnaire. The data were analyzed by using $x^2-test$, Fisher's exact test, t-test by a SAS-pc+ 8.12 program. Result: After 8 weeks Tai Chi exercise program, there were significant improvement in fatigue, stress, and quality of life in middle aged women. Conclusion: Tai Chi exercise program can be an effective nursing intervention to improve fatigue, stress, and quality of life in middle aged women.

  • PDF

Nonlinear bending analysis of porous sigmoid FGM nanoplate via IGA and nonlocal strain gradient theory

  • Cuong-Le, Thanh;Nguyen, Khuong D.;Le-Minh, Hoang;Phan-Vu, Phuong;Nguyen-Trong, Phuoc;Tounsi, Abdelouahed
    • Advances in nano research
    • /
    • v.12 no.5
    • /
    • pp.441-455
    • /
    • 2022
  • This study explores the linear and nonlinear solutions of sigmoid functionally graded material (S-FGM) nanoplate with porous effects. A size-dependent numerical solution is established using the strain gradient theory and isogeometric finite element formulation. The nonlinear nonlocal strain gradient is developed based on the Reissner-Mindlin plate theory and the Von-Karman strain assumption. The sigmoid function is utilized to modify the classical functionally graded material to ensure the constituent volume distribution. Two different patterns of porosity distribution are investigated, viz. pattern A and pattern B, in which the porosities are symmetric and asymmetric varied across the plate's thickness, respectively. The nonlinear finite element governing equations are established for bending analysis of S-FGM nanoplates, and the Newton-Raphson iteration technique is derived from the nonlinear responses. The isogeometric finite element method is the most suitable numerical method because it can satisfy a higher-order derivative requirement of the nonlocal strain gradient theory. Several numerical results are presented to investigate the influences of porosity distributions, power indexes, aspect ratios, nonlocal and strain gradient parameters on the porous S-FGM nanoplate's linear and nonlinear bending responses.

The Impact of Human Resource Management Activities on the Compatibility and Work Results

  • NGUYEN, Duc Trung;HA, Van Dung;DANG, Truong Thanh Nhan
    • The Journal of Asian Finance, Economics and Business
    • /
    • v.7 no.9
    • /
    • pp.621-629
    • /
    • 2020
  • This research focuses on determining the impact of human resource management activities on the compatibility and work results of employees of Ho Chi Minh Stock Exchange (HOSE) listed companies. The paper includes five parts: introduction, literature review, research methodology, research results, and conclusion and policy implications. The data are collected from the survey of 350 listed companies in HOSE, in which 315 survey notes filled with sufficient information are used for analysis. The paper employs both qualitative method and quantitative method. Group discussion of 10 experts is for qualitative research. Quantitative method performs analysis of Statistics, Cronbach's Alpha, EFA analysis, CFA analysis and SEM model. The results of the research clearly indicate that human resource management (HRM) activities are measured through improving the ability, improving the motivation and improving the opportunity. While compatibility is measured through suitability, connection and sacrifice; whereby HRM activities of ability improvement have a positive effect on the job suitability and connection; HRM activities of motivation improvement have a positive effect on the job suitability, connection and sacrifice; and HRM activities of opportunity improvement have a positive effect on the job suitability, sacrifice and connection; Finally, the job suitability, sacrifice and connection positively affect the work results of employees.

Nondestructive crack detection in metal structures using impedance responses and artificial neural networks

  • Ho, Duc-Duy;Luu, Tran-Huu-Tin;Pham, Minh-Nhan
    • Structural Monitoring and Maintenance
    • /
    • v.9 no.3
    • /
    • pp.221-235
    • /
    • 2022
  • Among nondestructive damage detection methods, impedance-based methods have been recognized as an effective technique for damage identification in many kinds of structures. This paper proposes a method to detect cracks in metal structures by combining electro-mechanical impedance (EMI) responses and artificial neural networks (ANN). Firstly, the theories of EMI responses and impedance-based damage detection methods are described. Secondly, the reliability of numerical simulations for impedance responses is demonstrated by comparing to pre-published results for an aluminum beam. Thirdly, the proposed method is used to detect cracks in the beam. The RMSD (root mean square deviation) index is used to alarm the occurrence of the cracks, and the multi-layer perceptron (MLP) ANN is employed to identify the location and size of the cracks. The selection of the effective frequency range is also investigated. The analysis results reveal that the proposed method accurately detects the cracks' occurrence, location, and size in metal structures.

Fucntional Prediction Method for Proteins by using Modified Chi-square Measure (보완된 카이-제곱 기법을 이용한 단백질 기능 예측 기법)

  • Kang, Tae-Ho;Yoo, Jae-Soo;Kim, Hak-Yong
    • The Journal of the Korea Contents Association
    • /
    • v.9 no.5
    • /
    • pp.332-336
    • /
    • 2009
  • Functional prediction of unannotated proteins is one of the most important tasks in yeast genomics. Analysis of a protein-protein interaction network leads to a better understanding of the functions of unannotated proteins. A number of researches have been performed for the functional prediction of unannotated proteins from a protein-protein interaction network. A chi-square method is one of the existing methods for the functional prediction of unannotated proteins from a protein-protein interaction network. But, the method does not consider the topology of network. In this paper, we propose a novel method that is able to predict specific molecular functions for unannotated proteins from a protein-protein interaction network. To do this, we investigated all protein interaction DBs of yeast in the public sites such as MIPS, DIP, and SGD. For the prediction of unannotated proteins, we employed a modified chi-square measure based on neighborhood counting and we assess the prediction accuracy of protein function from a protein-protein interaction network.

A novel coupled finite element method for hydroelastic analysis of FG-CNTRC floating plates under moving loads

  • Nguyen, Vu X.;Lieu, Qui X.;Le, Tuan A.;Nguyen, Thao D.;Suzuki, Takayuki;Luong, Van Hai
    • Steel and Composite Structures
    • /
    • v.42 no.2
    • /
    • pp.243-256
    • /
    • 2022
  • A coupled finite element method (FEM)-boundary element method (BEM) for analyzing the hydroelastic response of functionally graded carbon nanotube-reinforced composite (FG-CNTRC) floating plates under moving loads is firstly introduced in this article. For that aim, the plate displacement field is described utilizing a generalized shear deformation theory (GSDT)-based FEM, meanwhile the linear water-wave theory (LWWT)-relied BEM is employed for the fluid hydrodynamic modeling. Both computational domains of the plate and fluid are coincidentally discretized into 4-node Hermite elements. Accordingly, the C1-continuous plate element model can be simply captured owing to the inherent feature of third-order Hermite polynomials. In addition, this model is also completely free from shear correction factors, although the shear deformation effects are still taken into account. While the fluid BEM can easily handle the free surface with a lower computational effort due to its boundary integral performance. Material properties through the plate thickness follow four specific CNT distributions. Outcomes gained by the present FEM-BEM are compared with those of previously released papers including analytical solutions and experimental data to validate its reliability. In addition, the influences of CNT volume fraction, different CNT configurations, water depth, and load speed on the hydroelastic behavior of FG-CNTRC plates are also examined.

A Study on the Reading Method of "Choi Chi-won" (수이전 일문 「최치원」의 독법(讀法)에 대한 연구)

  • Lee, Jee-sun
    • Journal of Korean Classical Literature and Education
    • /
    • no.35
    • /
    • pp.123-152
    • /
    • 2017
  • The 'Jeongi' genre is characterized by a style composed of poetry and prose. "Choi Chi-won" shows the important features of the early 'Jeongi' character. In this study, I explore the poetry-centered reading method, considering that "Choi Chi-won" is a work that contains a high proportion of poetry. In this paper, I propose a reading method that focuses on the change of 'rhyme' centering on the body. Secondly, it focuses on the 'Heung' reading method. If the readers focus on the poetry, they will concentrate more on their emotional functioning, so the lyrical characteristics can be more aesthetically captured through poetic poetry. The poetry-centered reading method can be proposed as a method to capture the multi-layered aesthetic qualities of texts with complex styles.