This study presented a simulation-based two-stage interval-stochastic programming （STIP） model to support water resources management in the Kaidu-Konqi watershed in Northwest China. The modeling system coupled a dis...This study presented a simulation-based two-stage interval-stochastic programming （STIP） model to support water resources management in the Kaidu-Konqi watershed in Northwest China. The modeling system coupled a distributed hydrological model with an interval two-stage stochastic programing （ITSP）. The distributed hydrological model was used for establishing a rainfall-runoff forecast system, while random parameters were pro- vided by the statistical analysis of simulation outcomes water resources management planning in Kaidu-Konqi The developed STIP model was applied to a real case of watershed, where three scenarios with different water re- sources management policies were analyzed. The results indicated that water shortage mainly occurred in agri- culture, ecology and forestry sectors. In comparison, the water demand from municipality, industry and stock- breeding sectors can be satisfied due to their lower consumptions and higher economic values. Different policies for ecological water allocation can result in varied system benefits, and can help to identify desired water allocation plans with a maximum economic benefit and a minimum risk of system disruption under uncertainty.展开更多
The degradation process modeling is one of research hotspots of prognostic and health management(PHM),which can be used to estimate system reliability and remaining useful life(RUL).In order to study system degradatio...The degradation process modeling is one of research hotspots of prognostic and health management(PHM),which can be used to estimate system reliability and remaining useful life(RUL).In order to study system degradation process,cumulative damage model is used for degradation modeling.Assuming that damage increment is Gamma distribution,shock counting subjects to a homogeneous Poisson process(HPP)when degradation process is linear,and shock counting is a non-homogeneous Poisson process(NHPP)when degradation process is nonlinear.A two-stage degradation system is considered in this paper,for which the degradation process is linear in the first stage and the degradation process is nonlinear in the second stage.A nonlinear modeling method for considered system is put forward,and reliability model and remaining useful life model are established.A case study is given to validate the veracities of established models.展开更多
AIM: To assess the cost-effectiveness of two populationbased hepatocellular carcinoma(HCC) screening programs, two-stage biomarker-ultrasound method and mass screening using abdominal ultrasonography(AUS).METHODS: In ...AIM: To assess the cost-effectiveness of two populationbased hepatocellular carcinoma(HCC) screening programs, two-stage biomarker-ultrasound method and mass screening using abdominal ultrasonography(AUS).METHODS: In this study, we applied a Markov decision model with a societal perspective and a lifetime horizon for the general population-based cohorts in an area with high HCC incidence, such as Taiwan. The accuracy of biomarkers and ultrasonography was estimated from published meta-analyses. The costs of surveillance, diagnosis, and treatment were based on a combination of published literature, Medicare payments, and medical expenditure at the National Taiwan University Hospital. The main outcome measure was cost per lifeyear gained with a 3% annual discount rate. RESULTS: The results show that the mass screening using AUS was associated with an incremental costeffectiveness ratio of USD39825 per life-year gained, whereas two-stage screening was associated with an incremental cost-effectiveness ratio of USD49733 per life-year gained, as compared with no screening. Screening programs with an initial screening age of 50 years old and biennial screening interval were the most cost-effective. These findings were sensitive to the costs of screening tools and the specificity of biomarker screening.CONCLUSION: Mass screening using AUS is more cost effective than two-stage biomarker-ultrasound screening. The most optimal strategy is an initial screening age at 50 years old with a 2-year inter-screening interval.展开更多
The optimal conditions for two-stage Kalman estimator with random bias of anARMA model is considered in this paper.First,the optimal augmented state Kalman fil-ter and the two-stage Kalman estimator are given.Second,u...The optimal conditions for two-stage Kalman estimator with random bias of anARMA model is considered in this paper.First,the optimal augmented state Kalman fil-ter and the two-stage Kalman estimator are given.Second,under an algebraic constraint,the equivalence between the two-stage Kalman estimator and the optimal augmented stateKalman filter is proved.Finally,because the given algebraic constraint are restrictive inpractice,the results thus obtained implies that two-stage Kalman estimator is suboptimal.展开更多
We propose the test statistic to check whether the nonpararnetric functions in two partially linear models are equality or not in this paper. We estimate the nonparametric function both in null hypothesis and the alte...We propose the test statistic to check whether the nonpararnetric functions in two partially linear models are equality or not in this paper. We estimate the nonparametric function both in null hypothesis and the alternative by the local linear method, where we ignore the parametric components, and then estimate the parameters by the two stage method. The test statistic is derived, and it is shown to be asymptotically normal under the null hypothesis.展开更多
空调负荷规模大且具备灵活的可控性,同时储能的充放电行为与其寿命紧密相关,针对配电网多主体如何实现在互动博弈中共赢的问题,提出了一种计及空调负荷和储能寿命衰减的配电网两阶段鲁棒博弈调控方法。首先考虑墙体与外部环境的热交换,...空调负荷规模大且具备灵活的可控性,同时储能的充放电行为与其寿命紧密相关,针对配电网多主体如何实现在互动博弈中共赢的问题,提出了一种计及空调负荷和储能寿命衰减的配电网两阶段鲁棒博弈调控方法。首先考虑墙体与外部环境的热交换,采用两参数热模型建立空调负荷热力学模型;其次,考虑放电深度、电池循环次数和温度对电池寿命的影响,建立储能寿命衰减模型;然后,基于配电网运行模型、空调负荷聚合商模型和储能寿命衰减模型,构建各主体收益最大的双层互动博弈模型;接着采用(Karush-KuhnTucker,KKT)条件将其转化为单层混合整数二阶锥问题,针对分布式光伏出力的不确定性,建立钻石型切割凸包不确定集合,并采用列与约束生成(column and constraint generation,C&CG)算法对两阶段鲁棒博弈问题进行求解;最后,在52节点的实际算例上进行仿真分析,验证了所提的计及空调负荷和储能寿命衰减的配电网两阶段鲁棒博弈调控方法的有效性。展开更多
Data Envelopment Analysis （DEA） is a mathematical tech- nique to assess relative efficiencies of decision making units （DMUs）. The efficiency of 14 Iranian forest companies and forest management units was investig...Data Envelopment Analysis （DEA） is a mathematical tech- nique to assess relative efficiencies of decision making units （DMUs）. The efficiency of 14 Iranian forest companies and forest management units was investigated in 2010. Efficiency of the companies was esti- mated by using a traditional DEA model and a two-stage DEA model. Traditional DEA models consider all DMU activities as a black box and ignore the intermediate products, while two-stage models address inter- mediate processes. LINGO software was used for analysis. Overall pro- duction was divided into to processes for analyses by the two-stage model, timber harvest and marketing. Wilcoxon＇s signed-rank test was used to identify the differences of average efficiency in the harvesting and marketing sub-process. Weak performance in the harvesting sub-process was the cause of low efficiency in 2010. Companies such as Neka Chob and Kelardasht proved efficient at timber harvest, and Neka Chob forest company scored highest in overall efficiency. Finally, the reference units identified according to the results of two-stage DEA analysis.展开更多
基金supported by the National Basic Research Program of China(2010CB951002)the Dr.Western-funded Project of Chinese Academy of Science(XBBS201010 and XBBS201005)+1 种基金the National Natural Sciences Foundation of China (51190095)the Open Research Fund Program of State Key Laboratory of Hydro-science and Engineering(sklhse-2012-A03)
文摘This study presented a simulation-based two-stage interval-stochastic programming （STIP） model to support water resources management in the Kaidu-Konqi watershed in Northwest China. The modeling system coupled a distributed hydrological model with an interval two-stage stochastic programing （ITSP）. The distributed hydrological model was used for establishing a rainfall-runoff forecast system, while random parameters were pro- vided by the statistical analysis of simulation outcomes water resources management planning in Kaidu-Konqi The developed STIP model was applied to a real case of watershed, where three scenarios with different water re- sources management policies were analyzed. The results indicated that water shortage mainly occurred in agri- culture, ecology and forestry sectors. In comparison, the water demand from municipality, industry and stock- breeding sectors can be satisfied due to their lower consumptions and higher economic values. Different policies for ecological water allocation can result in varied system benefits, and can help to identify desired water allocation plans with a maximum economic benefit and a minimum risk of system disruption under uncertainty.
基金National Outstanding Youth Science Fund Project,China(No.71401173)
文摘The degradation process modeling is one of research hotspots of prognostic and health management(PHM),which can be used to estimate system reliability and remaining useful life(RUL).In order to study system degradation process,cumulative damage model is used for degradation modeling.Assuming that damage increment is Gamma distribution,shock counting subjects to a homogeneous Poisson process(HPP)when degradation process is linear,and shock counting is a non-homogeneous Poisson process(NHPP)when degradation process is nonlinear.A two-stage degradation system is considered in this paper,for which the degradation process is linear in the first stage and the degradation process is nonlinear in the second stage.A nonlinear modeling method for considered system is put forward,and reliability model and remaining useful life model are established.A case study is given to validate the veracities of established models.
基金Supported by Kaohsiung Municipal Min-Seng Hospital(KMSH 9702)
文摘AIM: To assess the cost-effectiveness of two populationbased hepatocellular carcinoma(HCC) screening programs, two-stage biomarker-ultrasound method and mass screening using abdominal ultrasonography(AUS).METHODS: In this study, we applied a Markov decision model with a societal perspective and a lifetime horizon for the general population-based cohorts in an area with high HCC incidence, such as Taiwan. The accuracy of biomarkers and ultrasonography was estimated from published meta-analyses. The costs of surveillance, diagnosis, and treatment were based on a combination of published literature, Medicare payments, and medical expenditure at the National Taiwan University Hospital. The main outcome measure was cost per lifeyear gained with a 3% annual discount rate. RESULTS: The results show that the mass screening using AUS was associated with an incremental costeffectiveness ratio of USD39825 per life-year gained, whereas two-stage screening was associated with an incremental cost-effectiveness ratio of USD49733 per life-year gained, as compared with no screening. Screening programs with an initial screening age of 50 years old and biennial screening interval were the most cost-effective. These findings were sensitive to the costs of screening tools and the specificity of biomarker screening.CONCLUSION: Mass screening using AUS is more cost effective than two-stage biomarker-ultrasound screening. The most optimal strategy is an initial screening age at 50 years old with a 2-year inter-screening interval.
文摘The optimal conditions for two-stage Kalman estimator with random bias of anARMA model is considered in this paper.First,the optimal augmented state Kalman fil-ter and the two-stage Kalman estimator are given.Second,under an algebraic constraint,the equivalence between the two-stage Kalman estimator and the optimal augmented stateKalman filter is proved.Finally,because the given algebraic constraint are restrictive inpractice,the results thus obtained implies that two-stage Kalman estimator is suboptimal.
文摘We propose the test statistic to check whether the nonpararnetric functions in two partially linear models are equality or not in this paper. We estimate the nonparametric function both in null hypothesis and the alternative by the local linear method, where we ignore the parametric components, and then estimate the parameters by the two stage method. The test statistic is derived, and it is shown to be asymptotically normal under the null hypothesis.
文摘空调负荷规模大且具备灵活的可控性,同时储能的充放电行为与其寿命紧密相关,针对配电网多主体如何实现在互动博弈中共赢的问题,提出了一种计及空调负荷和储能寿命衰减的配电网两阶段鲁棒博弈调控方法。首先考虑墙体与外部环境的热交换,采用两参数热模型建立空调负荷热力学模型;其次,考虑放电深度、电池循环次数和温度对电池寿命的影响,建立储能寿命衰减模型;然后,基于配电网运行模型、空调负荷聚合商模型和储能寿命衰减模型,构建各主体收益最大的双层互动博弈模型;接着采用(Karush-KuhnTucker,KKT)条件将其转化为单层混合整数二阶锥问题,针对分布式光伏出力的不确定性,建立钻石型切割凸包不确定集合,并采用列与约束生成(column and constraint generation,C&CG)算法对两阶段鲁棒博弈问题进行求解;最后,在52节点的实际算例上进行仿真分析,验证了所提的计及空调负荷和储能寿命衰减的配电网两阶段鲁棒博弈调控方法的有效性。
文摘Data Envelopment Analysis （DEA） is a mathematical tech- nique to assess relative efficiencies of decision making units （DMUs）. The efficiency of 14 Iranian forest companies and forest management units was investigated in 2010. Efficiency of the companies was esti- mated by using a traditional DEA model and a two-stage DEA model. Traditional DEA models consider all DMU activities as a black box and ignore the intermediate products, while two-stage models address inter- mediate processes. LINGO software was used for analysis. Overall pro- duction was divided into to processes for analyses by the two-stage model, timber harvest and marketing. Wilcoxon＇s signed-rank test was used to identify the differences of average efficiency in the harvesting and marketing sub-process. Weak performance in the harvesting sub-process was the cause of low efficiency in 2010. Companies such as Neka Chob and Kelardasht proved efficient at timber harvest, and Neka Chob forest company scored highest in overall efficiency. Finally, the reference units identified according to the results of two-stage DEA analysis.
