东平湖老湖调整为综合利用水库的可行性——南水北调东线通水后

东平湖作为蓄滞洪区对当地生活和生产经济带来一定限制,但南水北调东线工程通水、京杭运河复航又为东平湖创造机遇,从而对东平湖老湖区功能需要调整提出要求。通过分析蓄滞洪区与水库的差异、东平湖蓄滞洪区运用机率以及模拟运行水位、实际运行水位等,探讨了东平湖老湖调整为综合利用水库的可能性和可行性,并认为把东平湖老湖调整为防洪、调蓄、航运、生态景观旅游、养殖等多种功能综合利用的水库,对当地经济发展也有促进作用。     

Cluster-based multicore real-time mixed-criticality scheduling

Cluster-based scheduling is recently gaining importance to be applied to mixed-criticality real-time systems on multicore processors platform. In this approach, the cores are grouped into clusters, and tasks that are partitioned among different clusters are scheduled by global scheduler in each cluster. This research work introduces a new cluster-based task allocation scheme for the mixed-criticality real-time task sets on multicore processors. For task allocation, smaller clusters sizes (sub-clusters) are used for mixed-criticality tasks in low criticality mode, while relatively larger cluster sizes are used for high criticality tasks in high criticality mode. In this research paper, the mixed-criticality task set is allocated to clusters using worst-fit heuristic. The tasks from each cluster are also allocated to its sub-clusters, using the same worst-fit heuristic. A fixed-priority response time analysis approach based on Audsley’s approach is used for the schedulability analysis of tasks in each cluster and sub-cluster. If the high criticality job is not completed after its worst case execution time in low mode, then the system is switched to high criticality mode. After mode switch, all the low criticalities tasks are discarded and only high criticality tasks are further executed in high criticality mode. Simulation results indicate that the percentage of schedulable task sets significantly increases under cluster scheduling as compared to partitioned and global mixed-criticality scheduling schemes.     

Parallel custom instruction identification for extensible processors

With the ability of customization for an application domain, extensible processors have been used more and more in embedded systems in recent years. Extensible processors customize an application domain by executing parts of application code in hardware instead of software. Determining parts of application code as custom instruction generally requires subgraph enumeration and subgraph selection. Both subgraph enumeration problem and subgraph selection problem are computationally difficult problems. Most of previous works focus on sequential algorithms for these two problems. In this paper, we present a parallel implementation of a latest subgraph enumeration algorithm based on a computer cluster. A standard ant colony optimization algorithm (ACO), a modified version of ACO with local optimum search and a parallel ACO algorithm are also proposed to solve the subgraph selection problem in this work. Experimental results show that the parallel algorithms outperform the sequential algorithms in terms of runtime or (and) quality of results. In addition, we have formally proved the upper bound on the number of feasible solutions in subgraph selection problem with or without the overlapping constraint.     

生活水源的稳定氢氧同位素和水化学特征 —— 以天津市为例

通过稳定氢氧同位素结合水化学的方法, 在 2017 年采集天津市主要区( 县) 自来水的基础上, 于 2019 年重点收集中心城区和西青区的直接供水和二次供水的自来水, 分析水样中的稳定氢氧同位素组分和主要阴阳离子质量 浓度。自来水中稳定氧同位素∮18 O 的范围为- 4.41 ‰~ - 10.06 ‰ , 氢同位素∮D 的范围为- 52. 4 ‰ ~ - 74. 4‰ 。 引江水为水源的自来水中的同位素位于全球大气降水线附近, 水库蓄存会导致水中同位素富集; 深层地下水为水源的稳定同位素贫化。天津市中心城区、西青、津南、北辰、武清和蓟州的自来水水化学类型为 Ca·Mg-HCO3 , 滨海新区和宝坻的水化学类型为 Na· Mg-SO4 , 宁河的水化学类型为 Na-HCO3。天津市自来水的主要阴阳离子质量浓度都符合国家饮用水标准, 二次供水对水化学组成无显著影响。引江水的自来水水质较地下水为水源的水质好; 滨海新区 由于水库蓄存, 自来水中 Na+ 和 SO4 2- 的离子质量浓度高; 宁河区的 Na+ 和蓟州区的 NO3- 质量浓度高。     

水电厂高压气系统关联监测方法研究

辅助系统运行可靠性将直接影响水电厂的安全经济运行,因而有必要对辅助系统的运行状态进行实时在线监测.在介绍水电厂高压气系统工作原理基础上,总结了水电厂高压气机异常启、停与相应故障对应关系,提出了高压气系统关联监测模型,并利用梯级水电厂群远程集控系统提供的海量数据源,建立了水电厂高压气系统的远程分析与故障诊断平台,目前,该...     

Determination of maintenance floats using Buzen's algorithm

This paper applies Buzen's algorithm to the problem of determining the maintenance float needed to support an operating system with N circulating units. A maintenance network with load-independent servers is assumed. The operating system availability and maintenance floats are obtained using this iterative algorithm. It is shown that the normalizing constant used in the algorithm can easily be computed for the maintenance float problem by using geometric series. This result is further used to obtain a simple model for the expected number of operating units, thus making it easy to compute the operating system availability for any given N. Buzen's algorithm therefore provides a simple solution to the maintenance float problem.     

Does it pay to be green?

This paper examines the relationships between the environmental performances and financial performances of large U.S. companies. The environmental performance is measured in pollution in pounds per sales revenue and financial performance in profit margins and stock market values. An analysis of more than 230 companies shows that lower pollution per sales revenue has a positive impact on the profit margins and stock market values. Pollution is also found to have a direct impact on environmental compliance, spills and various other legal infractions.     

Environmental regulations and innovation activities — a view point

The impact of environmental regulations on innovative activity is explored in this paper using state‐level and company level data on patents, new product introductions, emissions, and penalties. A significant effect of environmental regulations on corporate innovative activity is found. In addition, excellence in environmental performance appears to have an indirect effect on innovation performance of companies.