高效、准确地为用户选择满足其需求的软件服务一直是近年来的研究热点。服务质量(Quality of Service,QoS)是衡量软件服务性能的关键指标之一,考虑到同一服务在不同网络环境下QoS值的动态性,提出一种面向用户需求的动态QoS服务选择方法...高效、准确地为用户选择满足其需求的软件服务一直是近年来的研究热点。服务质量(Quality of Service,QoS)是衡量软件服务性能的关键指标之一,考虑到同一服务在不同网络环境下QoS值的动态性,提出一种面向用户需求的动态QoS服务选择方法,简称URDQ方法。URDQ方法采用区间数的形式记录动态环境下候选服务的属性值范围,并基于用户需求对候选服务进行初步过滤;通过区间数模型对候选服务属性区间和用户需求区间进行相对优势度计算,将属性区间数转化为易于计算的实数;使用Skyline方法对候选服务集进行过滤,减小搜索空间;根据熵权法得到的客观权重并结合用户给定的主观权重,使用TOPSIS方法对Skyline服务集进行排序。仿真实验和对比实验验证了URDQ方法在动态网络环境下的可行性和有效性。展开更多
In the model of geometric programming, values of parameters cannot be gotten owing to data fluctuation and incompletion. But reasonable bounds of these parameters can be attained. This is to say, parameters of this mo...In the model of geometric programming, values of parameters cannot be gotten owing to data fluctuation and incompletion. But reasonable bounds of these parameters can be attained. This is to say, parameters of this model can be regarded as interval grey numbers. When the model contains grey numbers, it is hard for common programming method to solve them. By combining the common programming model with the grey system theory, and using some analysis strategies, a model of grey polynomial geometric programming, a model of θ positioned geometric programming and their quasi-optimum solution or optimum solution are put forward. At the same time, we also developed an algorithm for the problem. This approach brings a new way for the application research of geometric programming. An example at the end of this paper shows the rationality and feasibility of the algorithm.展开更多
In city planning managing, the third dimension is becoming a necessity. Using 3D GIS modeling offers a flexible interactive system while providing one of the best visual interpretation of data which supports planning ...In city planning managing, the third dimension is becoming a necessity. Using 3D GIS modeling offers a flexible interactive system while providing one of the best visual interpretation of data which supports planning and decision processes for city planners. As a result, 3D GIS model expresses terrain features in an intuitive way which enhances the management and analysis of a proposed project through 3D visualization. This paper discusses the concept of 3D GIS modeling techniques using a simple procedure to generate a university campus model （real 3D GIS model） which will show the effectiveness of this approach. The 3D GIS model provides access to mapping data to support planning, design and data management. Intelligent GIS models and GIS tools help community planning and apply regional and discipline-specific standards. Integration of GIS spatial data with campus organization helps to improve quality, productivity and asset management. The following study built 3D GIS map and all utility information for AI al-Bayt University campus as an example. The primary objective is to improve data management （e.g., maps, plans, usage of facilities and services） and to develop methods using 3D spatial analysis for specific applications at the university.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
Empirical likelihood has been found very useful in many different occasions. It usually runs into serious computational difficulties while jackknife empirical likelihood （JEL） is shown to be effective when applied t...Empirical likelihood has been found very useful in many different occasions. It usually runs into serious computational difficulties while jackknife empirical likelihood （JEL） is shown to be effective when applied to some complicated statistics. In this paper, to test the difference between coefficients of two linear regression models, the authors apply JEL to construct the confidence regions. Based on the 3EL ratio test, a version of Wilks＇ theorem is developed. Furthermore, to improve the coverage accuracy of confidence regions, a Bartlett correction is applied. Simulation studies are carried out to show the effectiveness of the proposed method in aspects of coverage accuracy. A real data set is analyzed with the proposed method as an example.展开更多
This paper considers the problem of change point in single index models.In order to obtain asymptotically valid confidence intervals for the estimation of the change point,the convergence rate and asymptotic distribut...This paper considers the problem of change point in single index models.In order to obtain asymptotically valid confidence intervals for the estimation of the change point,the convergence rate and asymptotic distribution of the change point estimate is studied.Some simulation results are presented which show that the numerical performance of our estimator is satisfactory.展开更多
文摘高效、准确地为用户选择满足其需求的软件服务一直是近年来的研究热点。服务质量(Quality of Service,QoS)是衡量软件服务性能的关键指标之一,考虑到同一服务在不同网络环境下QoS值的动态性,提出一种面向用户需求的动态QoS服务选择方法,简称URDQ方法。URDQ方法采用区间数的形式记录动态环境下候选服务的属性值范围,并基于用户需求对候选服务进行初步过滤;通过区间数模型对候选服务属性区间和用户需求区间进行相对优势度计算,将属性区间数转化为易于计算的实数;使用Skyline方法对候选服务集进行过滤,减小搜索空间;根据熵权法得到的客观权重并结合用户给定的主观权重,使用TOPSIS方法对Skyline服务集进行排序。仿真实验和对比实验验证了URDQ方法在动态网络环境下的可行性和有效性。
基金Supported by the NSF Jiangsu Province(BK2003211)Supported by the NSF of Henan Province(2003120001)
文摘In the model of geometric programming, values of parameters cannot be gotten owing to data fluctuation and incompletion. But reasonable bounds of these parameters can be attained. This is to say, parameters of this model can be regarded as interval grey numbers. When the model contains grey numbers, it is hard for common programming method to solve them. By combining the common programming model with the grey system theory, and using some analysis strategies, a model of grey polynomial geometric programming, a model of θ positioned geometric programming and their quasi-optimum solution or optimum solution are put forward. At the same time, we also developed an algorithm for the problem. This approach brings a new way for the application research of geometric programming. An example at the end of this paper shows the rationality and feasibility of the algorithm.
文摘In city planning managing, the third dimension is becoming a necessity. Using 3D GIS modeling offers a flexible interactive system while providing one of the best visual interpretation of data which supports planning and decision processes for city planners. As a result, 3D GIS model expresses terrain features in an intuitive way which enhances the management and analysis of a proposed project through 3D visualization. This paper discusses the concept of 3D GIS modeling techniques using a simple procedure to generate a university campus model （real 3D GIS model） which will show the effectiveness of this approach. The 3D GIS model provides access to mapping data to support planning, design and data management. Intelligent GIS models and GIS tools help community planning and apply regional and discipline-specific standards. Integration of GIS spatial data with campus organization helps to improve quality, productivity and asset management. The following study built 3D GIS map and all utility information for AI al-Bayt University campus as an example. The primary objective is to improve data management （e.g., maps, plans, usage of facilities and services） and to develop methods using 3D spatial analysis for specific applications at the university.
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 China Postdoctoral Science Foundation under Grant No.2014M550799the National Science Foundation of China under Grant No.11401561
文摘Empirical likelihood has been found very useful in many different occasions. It usually runs into serious computational difficulties while jackknife empirical likelihood （JEL） is shown to be effective when applied to some complicated statistics. In this paper, to test the difference between coefficients of two linear regression models, the authors apply JEL to construct the confidence regions. Based on the 3EL ratio test, a version of Wilks＇ theorem is developed. Furthermore, to improve the coverage accuracy of confidence regions, a Bartlett correction is applied. Simulation studies are carried out to show the effectiveness of the proposed method in aspects of coverage accuracy. A real data set is analyzed with the proposed method as an example.
基金supported by National Natural Science Foundation for Young Scientists of China(Grant Nos.11101397,11201108)the Humanities and Social Sciences Project from Ministry of Education of China(Grant No.12YJC910007)+1 种基金Anhui Provincial Natural Science Foundation(Grant No.1208085QA12)the National Statistical Research Plan Project(Grant No.2012LZ009)
文摘This paper considers the problem of change point in single index models.In order to obtain asymptotically valid confidence intervals for the estimation of the change point,the convergence rate and asymptotic distribution of the change point estimate is studied.Some simulation results are presented which show that the numerical performance of our estimator is satisfactory.
