The central air conditioning system in an intelligent building (IB) was analyzed and modeled in order to perform the optimization scheduling strategy of the central air conditioning system. A set of models proposed ...The central air conditioning system in an intelligent building (IB) was analyzed and modeled in order to perform the optimization scheduling strategy of the central air conditioning system. A set of models proposed and a type of periodically autoregressive model (PAR) based on the improved genetic algorithms (IGA) were used to perform the optimum energy saving scheduling. The example of the Liangmahe Plaza was taken to show the effectiveness of the methods.展开更多
Background Studies have shown that staged percutaneous coronary intervention （PCI） for non-culprit lesions is beneficial for prog- nosis of ST-segment elevation myocardial infarction （STEMI） patients with multives...Background Studies have shown that staged percutaneous coronary intervention （PCI） for non-culprit lesions is beneficial for prog- nosis of ST-segment elevation myocardial infarction （STEMI） patients with multivessel disease. However, the optimal timing of staged re- vascularization is still controversial. This study aimed to find the optimal timing of staged revascularization. Methods A total of 428 STEMI patients with multivessel disease who underwent primary PCI and staged PCI were included. According to the time interval between primary and staged PCI, patients were divided into three groups （〈 1 week, 1- weeks, and 2-12 weeks after primary PCI）. The primary endpoint was major adverse cardiovascular events （MACE）, a composite of all-cause death, non-fatal re-infarction, repeat revascularization, and stroke. Cox regression model was used to assess the association between staged PCI timing and risk of MACE. Results During the follow-up, 119 participants had MACEs. There was statistical difference in MACE incidence among the three groups （〈 1 week： 23.0%; 1-2 weeks： 33.0%; 2-12 weeks： 40.0%; P = 0.001）. In the multivariable adjustment model, the timing interval of staged PCI ≤ 1 week and l-2 weeks were both significantly associated with a lower risk of MACE [hazard ratio （HR）： 0.40, 95% confidence intervals （CI）： 0.24-4）.65; HR： 0.54, 95% CI： 0.3 lq3.93, respectively], mainly attributed to a lower risk of repeat revascularization （HR： 0.41, 95% CI： 0.24-0.70; HR： 0.36, 95% CI： 0.18-0.7）, compared with a strategy of 2-12 weeks later of primary PCI. Conclusions The optimal timing of staged PCI for non-culprit vessels should be within two weeks after primary PCI for STEMI patients.展开更多
When it comes to evaluating the effectiveness of interventions, the random experiment is considered the ＂gold standard＂. Randomization is considered the gold standard because it provides a way of decreasing the chan...When it comes to evaluating the effectiveness of interventions, the random experiment is considered the ＂gold standard＂. Randomization is considered the gold standard because it provides a way of decreasing the chance that systematic differences, other than type of intervention, will be obtained between treatment and control groups. What has received little attention in the literature, however, is the fact that even with random assignment researchers may end up facing problems similar to those faced with data from a study that did not use randomization. This is because attrition may result in the values of potentially confounding variables no longer being ＂balanced＂ between （or among） the groups under investigation. This means that in order to estimate the effect of the treatment, one must find some way of adjusting for these potential confounders. Although multiple regression modeling is the way social science researchers typically control for the effects of potentially confounding variables, this paper argues that a modification of multiple regression modeling that uses propensity scores, under some conditions, may provide more parsimonious and better fitting models.展开更多
The paper uses the proportion of zero-return days model to analyze stock market synchronous behaviors for 11 sample counties. It is found that the zero-return measure of stock synchronicity is higher for some emerging...The paper uses the proportion of zero-return days model to analyze stock market synchronous behaviors for 11 sample counties. It is found that the zero-return measure of stock synchronicity is higher for some emerging economies than the developed economies though the result is not statistically significant. In addition, panel data analysis indicates somewhat positive and negative correlation between the zero-return measures with the explanatory variables. The findings raise question about the reliability of the proportion of zero-return days measure and its capability to capture stock market synchronous behavior.展开更多
In this paper, we research on the Shaanxi urbanization and agricultural modernization coordinated development pattern based on the game theory. At present, the industrialization and the urbanization, agricultural mode...In this paper, we research on the Shaanxi urbanization and agricultural modernization coordinated development pattern based on the game theory. At present, the industrialization and the urbanization, agricultural modernization in our country obviously lags behind, which hindered the synchronous development of them. Therefore, with the internal relations between the empirical researches, we explore influence of industrialization and urbanization of agricultural modernization and path, to promote three synchronous developments which have important practical significance. Based on vector autoregressive model and game thinking, at the same time, we analysis the influence degree of the industrialization and urbanization of agricultural modernization and path in order to provide experience for the synchronous development of reference.展开更多
The multivariate linear errors-in-variables model when the regressors are missing at random in the sense of Rubin （1976） is considered in this paper. A constrained empirical likelihood confidence region for a parame...The multivariate linear errors-in-variables model when the regressors are missing at random in the sense of Rubin （1976） is considered in this paper. A constrained empirical likelihood confidence region for a parameter β0 in this model is proposed, which is constructed by combining the score function corresponding to the weighted squared orthogonal distance based on inverse probability with a constrained region of β0. It is shown that the empirical log-likelihood ratio at the true parameter converges to the standard chi-square distribution. Simulations show that the coverage rate of the proposed confidence region is closer to the nominal level and the length of confidence interval is narrower than those of the normal approximation of inverse probability weighted adjusted least square estimator in most cases. A real example is studied and the result supports the theory and simulation＇s conclusion.展开更多
This paper employs the SCAD-penalized least squares method to simultaneously select variables and estimate the coefficients for high-dimensional covariate adjusted linear regression models.The distorted variables are ...This paper employs the SCAD-penalized least squares method to simultaneously select variables and estimate the coefficients for high-dimensional covariate adjusted linear regression models.The distorted variables are assumed to be contaminated with a multiplicative factor that is determined by the value of an unknown function of an observable covariate.The authors show that under some appropriate conditions,the SCAD-penalized least squares estimator has the so called "oracle property".In addition,the authors also suggest a BIC criterion to select the tuning parameter,and show that BIC criterion is able to identify the true model consistently for the covariate adjusted linear regression models.Simulation studies and a real data are used to illustrate the efficiency of the proposed estimation algorithm.展开更多
文摘The central air conditioning system in an intelligent building (IB) was analyzed and modeled in order to perform the optimization scheduling strategy of the central air conditioning system. A set of models proposed and a type of periodically autoregressive model (PAR) based on the improved genetic algorithms (IGA) were used to perform the optimum energy saving scheduling. The example of the Liangmahe Plaza was taken to show the effectiveness of the methods.
文摘Background Studies have shown that staged percutaneous coronary intervention （PCI） for non-culprit lesions is beneficial for prog- nosis of ST-segment elevation myocardial infarction （STEMI） patients with multivessel disease. However, the optimal timing of staged re- vascularization is still controversial. This study aimed to find the optimal timing of staged revascularization. Methods A total of 428 STEMI patients with multivessel disease who underwent primary PCI and staged PCI were included. According to the time interval between primary and staged PCI, patients were divided into three groups （〈 1 week, 1- weeks, and 2-12 weeks after primary PCI）. The primary endpoint was major adverse cardiovascular events （MACE）, a composite of all-cause death, non-fatal re-infarction, repeat revascularization, and stroke. Cox regression model was used to assess the association between staged PCI timing and risk of MACE. Results During the follow-up, 119 participants had MACEs. There was statistical difference in MACE incidence among the three groups （〈 1 week： 23.0%; 1-2 weeks： 33.0%; 2-12 weeks： 40.0%; P = 0.001）. In the multivariable adjustment model, the timing interval of staged PCI ≤ 1 week and l-2 weeks were both significantly associated with a lower risk of MACE [hazard ratio （HR）： 0.40, 95% confidence intervals （CI）： 0.24-4）.65; HR： 0.54, 95% CI： 0.3 lq3.93, respectively], mainly attributed to a lower risk of repeat revascularization （HR： 0.41, 95% CI： 0.24-0.70; HR： 0.36, 95% CI： 0.18-0.7）, compared with a strategy of 2-12 weeks later of primary PCI. Conclusions The optimal timing of staged PCI for non-culprit vessels should be within two weeks after primary PCI for STEMI patients.
文摘When it comes to evaluating the effectiveness of interventions, the random experiment is considered the ＂gold standard＂. Randomization is considered the gold standard because it provides a way of decreasing the chance that systematic differences, other than type of intervention, will be obtained between treatment and control groups. What has received little attention in the literature, however, is the fact that even with random assignment researchers may end up facing problems similar to those faced with data from a study that did not use randomization. This is because attrition may result in the values of potentially confounding variables no longer being ＂balanced＂ between （or among） the groups under investigation. This means that in order to estimate the effect of the treatment, one must find some way of adjusting for these potential confounders. Although multiple regression modeling is the way social science researchers typically control for the effects of potentially confounding variables, this paper argues that a modification of multiple regression modeling that uses propensity scores, under some conditions, may provide more parsimonious and better fitting models.
文摘The paper uses the proportion of zero-return days model to analyze stock market synchronous behaviors for 11 sample counties. It is found that the zero-return measure of stock synchronicity is higher for some emerging economies than the developed economies though the result is not statistically significant. In addition, panel data analysis indicates somewhat positive and negative correlation between the zero-return measures with the explanatory variables. The findings raise question about the reliability of the proportion of zero-return days measure and its capability to capture stock market synchronous behavior.
文摘In this paper, we research on the Shaanxi urbanization and agricultural modernization coordinated development pattern based on the game theory. At present, the industrialization and the urbanization, agricultural modernization in our country obviously lags behind, which hindered the synchronous development of them. Therefore, with the internal relations between the empirical researches, we explore influence of industrialization and urbanization of agricultural modernization and path, to promote three synchronous developments which have important practical significance. Based on vector autoregressive model and game thinking, at the same time, we analysis the influence degree of the industrialization and urbanization of agricultural modernization and path in order to provide experience for the synchronous development of reference.
基金supported by the Natural Science Foundation of China under Grant Nos.10771017 and 11071022Key Project of MOE,PRC under Grant No.309007
文摘The multivariate linear errors-in-variables model when the regressors are missing at random in the sense of Rubin （1976） is considered in this paper. A constrained empirical likelihood confidence region for a parameter β0 in this model is proposed, which is constructed by combining the score function corresponding to the weighted squared orthogonal distance based on inverse probability with a constrained region of β0. It is shown that the empirical log-likelihood ratio at the true parameter converges to the standard chi-square distribution. Simulations show that the coverage rate of the proposed confidence region is closer to the nominal level and the length of confidence interval is narrower than those of the normal approximation of inverse probability weighted adjusted least square estimator in most cases. A real example is studied and the result supports the theory and simulation＇s conclusion.
基金supported by the National Natural Science Foundation of China under Grant Nos.11471029,11101014,61273221 and 11171010the Beijing Natural Science Foundation under Grant Nos.1142002 and 1112001+1 种基金the Science and Technology Project of Beijing Municipal Education Commission under Grant No.KM201410005010the Research Fund for the Doctoral Program of Beijing University of Technology under Grant No.006000543114550
文摘This paper employs the SCAD-penalized least squares method to simultaneously select variables and estimate the coefficients for high-dimensional covariate adjusted linear regression models.The distorted variables are assumed to be contaminated with a multiplicative factor that is determined by the value of an unknown function of an observable covariate.The authors show that under some appropriate conditions,the SCAD-penalized least squares estimator has the so called "oracle property".In addition,the authors also suggest a BIC criterion to select the tuning parameter,and show that BIC criterion is able to identify the true model consistently for the covariate adjusted linear regression models.Simulation studies and a real data are used to illustrate the efficiency of the proposed estimation algorithm.
