Seventy-eight patients underwent coronary angiography and submaximal tre-admill exercise test to evaluate the Q-Tc,Q-Tr and ΔQ-Tc criteria for predicting co-ronary artery disease(CAD).The sensitivity,specificity,pred...Seventy-eight patients underwent coronary angiography and submaximal tre-admill exercise test to evaluate the Q-Tc,Q-Tr and ΔQ-Tc criteria for predicting co-ronary artery disease(CAD).The sensitivity,specificity,predicting value and correctdiagnostic rate of the Q-Tc and Q-Tr criteria were 84,76,83,81 percent and 69,88,89,77 percent,respectively,which had no significant differences when compared with ST de-pression.The Q-Tc had higher specificity(94%)than that of ST depression but less sen-sitivity(58%).These criteria could reflect the severity of coronary artery disease identi-fied with coronary angiography.Therefore,these criteria are usefel to interpret the resultsof stress test.展开更多
Chaos theory has taught us that a system which has both nonlinearity and random input will most likely produce irregular data. If random errors are irregular data, then random error process will raise nonlinearity (K...Chaos theory has taught us that a system which has both nonlinearity and random input will most likely produce irregular data. If random errors are irregular data, then random error process will raise nonlinearity (Kantz and Schreiber (1997)). Tsai (1986) introduced a composite test for autocorrelation and heteroscedasticity in linear models with AR(1) errors. Liu (2003) introduced a composite test for correlation and heteroscedasticity in nonlinear models with DBL(p, 0, 1) errors. Therefore, the important problems in regression model axe detections of bilinearity, correlation and heteroscedasticity. In this article, the authors discuss more general case of nonlinear models with DBL(p, q, 1) random errors by score test. Several statistics for the test of bilinearity, correlation, and heteroscedasticity are obtained, and expressed in simple matrix formulas. The results of regression models with linear errors are extended to those with bilinear errors. The simulation study is carried out to investigate the powers of the test statistics. All results of this article extend and develop results of Tsai (1986), Wei, et al (1995), and Liu, et al (2003).展开更多
G-DINA(the generalizeddeterministic input,noisy and gate)模型限制条件少,应用范围广,满足大量心理与教育评估测验数据的要求。研究提出一种适用于G-DINA等模型的同时标定新题Q矩阵与项目参数的认知诊断计算机化自适应测验(CD-CAT)...G-DINA(the generalizeddeterministic input,noisy and gate)模型限制条件少,应用范围广,满足大量心理与教育评估测验数据的要求。研究提出一种适用于G-DINA等模型的同时标定新题Q矩阵与项目参数的认知诊断计算机化自适应测验(CD-CAT)在线标定新方法SCADOCM,以期促进CD-CAT在实践中的推广与应用。本研究分别基于模拟题库以及真实题库进行研究,结果表明:相比传统的SIE方法,SCADOCM在各实验条件下均具有较为理想的标定精度与标定效率,应用前景较好;SIE方法不适用于饱和的G-DINA等模型,其各实验条件下的Q矩阵标定精度均较低。展开更多
文摘Seventy-eight patients underwent coronary angiography and submaximal tre-admill exercise test to evaluate the Q-Tc,Q-Tr and ΔQ-Tc criteria for predicting co-ronary artery disease(CAD).The sensitivity,specificity,predicting value and correctdiagnostic rate of the Q-Tc and Q-Tr criteria were 84,76,83,81 percent and 69,88,89,77 percent,respectively,which had no significant differences when compared with ST de-pression.The Q-Tc had higher specificity(94%)than that of ST depression but less sen-sitivity(58%).These criteria could reflect the severity of coronary artery disease identi-fied with coronary angiography.Therefore,these criteria are usefel to interpret the resultsof stress test.
文摘Chaos theory has taught us that a system which has both nonlinearity and random input will most likely produce irregular data. If random errors are irregular data, then random error process will raise nonlinearity (Kantz and Schreiber (1997)). Tsai (1986) introduced a composite test for autocorrelation and heteroscedasticity in linear models with AR(1) errors. Liu (2003) introduced a composite test for correlation and heteroscedasticity in nonlinear models with DBL(p, 0, 1) errors. Therefore, the important problems in regression model axe detections of bilinearity, correlation and heteroscedasticity. In this article, the authors discuss more general case of nonlinear models with DBL(p, q, 1) random errors by score test. Several statistics for the test of bilinearity, correlation, and heteroscedasticity are obtained, and expressed in simple matrix formulas. The results of regression models with linear errors are extended to those with bilinear errors. The simulation study is carried out to investigate the powers of the test statistics. All results of this article extend and develop results of Tsai (1986), Wei, et al (1995), and Liu, et al (2003).
文摘G-DINA(the generalizeddeterministic input,noisy and gate)模型限制条件少,应用范围广,满足大量心理与教育评估测验数据的要求。研究提出一种适用于G-DINA等模型的同时标定新题Q矩阵与项目参数的认知诊断计算机化自适应测验(CD-CAT)在线标定新方法SCADOCM,以期促进CD-CAT在实践中的推广与应用。本研究分别基于模拟题库以及真实题库进行研究,结果表明:相比传统的SIE方法,SCADOCM在各实验条件下均具有较为理想的标定精度与标定效率,应用前景较好;SIE方法不适用于饱和的G-DINA等模型,其各实验条件下的Q矩阵标定精度均较低。