卫星分系统仿真测试平台设计与实现

卫星三级测试包括设备级测试、分系统级测试和整星级测试,测试成本较为昂贵,为了达到尽早的开展分系统级测试的目的,提出了一种数字仿真环境同单机设备相结合的分系统仿真测试平台的设计方法;通过对各单机设备进行仿真建模,并依据设备间的数据交互方式进行物理实现,为单机设备构建分系统级的测试环境;解决了在缺少单机设备时无法开展分系统级测试的难题;尽早的对单机设备进行分系统级测试,可以在早期就发现单机设备存在的缺陷并进行改正,从而达到节省测试成本的目的。     

智能分区PID控制算法在电动缸伺服系统中的研究

针对电动缸伺服系统中的非线性环节,本文采用带线性补偿的分区二级前馈PID控制算法。首先建立电动缸伺服系统的仿真模型,并采用单组控制参数的二级前馈PID控制算法,通过仿真发现系统存在着抖动、精度较低的问题。然后提出了具有线性补偿的分区二级前馈PID控制算法,改进了相应的控制器结构并实现控制器的数字离散化。最后通过线性补偿的方法整定实际系统在各分区的控制参数,计算出相应的控制量。对比分析实际系统的稳态误差,发现智能分区PID控制器在电动缸伺服系统中能够取得更好的控制效果。     

Non-cooperative implementation of the nucleolus: The 3-player case

I present a non-cooperative bargaining game, in which responders may exit at any time and have endogenous outside options. When the order of proposers corresponds to the power that players have in the underlying coalitional function, the unique Markov perfect equilibrium outcome of the game is the prenucleolus. The result holds for 3-player superadditive games. An example shows that it cannot be extented to the same class of games forn players. The mechanism is inspired by the consistency property of the prenucleolus.I am grateful to Vijay Krishna, Andreu Mas-Colell, Eric Maskin, Amy Salsbury, and an anonymous referee for helpful comments and suggestions.     

以项目驱动的化妆品与香料课程改革

The construction of application-based courses is one of the keys to the development of application-oriented universities. In this paper, the construction of the project-driven "Cosmetics and Spices" course was introduced. Its construction content from the four modules of theory, experiment, open experiment, enterprise project-oriented curriculum design and maker education was explored, and corresponding implementation plans of application-based courses were proposed.     

The GPU‐enabled divide‐expand‐consolidate RI‐MP2 method (DEC‐RI‐MP2)

We report porting of the Divide‐Expand‐Consolidate Resolution of the Identity second‐order Møller–Plesset perturbation (DEC‐RI‐MP2) method to the graphic processing units (GPUs) using OpenACC compiler directives. It is shown that the OpenACC compiler directives implementation efficiently accelerates the rate‐determining step of the DEC‐RI‐MP2 method with minor implementation effort. Moreover, the GPU acceleration results in a better load balance and thus in an overall scaling improvement of the DEC algorithm. The resulting cross‐platform hybrid MPI/OpenMP/OpenACC implementation has scalable and portable performance on heterogeneous HPC architectures. The GPU‐enabled code was benchmarked using a reduced version of the S12L test set of Stefan Grimme (Grimme, Chem. Eur. J. 2012, 18, 9955) consisting of supramolecular complexes up to 158 atoms and 4292 contracted basis functions (cc‐pVTZ). The test set results demonstrate the general applicability of the DEC‐RI‐MP2 method showing results consistent with the DEC‐RI‐MP2 introductory paper (Baudin et al., J. Chem. Phys. 2016, 144, 054102) on molecules of complicated electronic structures. © 2016 Wiley Periodicals, Inc.     

高峰体验课程的教学设计、实施及评价——《高分子合成方案设计》为例

高峰体验课程具有整合、探究及自主等特性,对提高本科教学水平和人才培养质量能发挥积极作用.但在微观落实层面存在一些问题.本文针对高峰体验课程教学从设计到实施再到评价的全过程,探讨了各环节所需要遵循的一般原则和要点,并结合中北大学设计(或开发)出的高峰体验课程——《高分子合成方案设计》为例,对高峰体验课程中项目(或任务)选...     

Implementation of ISO/IEC 17025 standard in a nuclear analytical laboratory: The KAERI experience

The practical experience on the implementation of ISO/IEC 17025 compliant quality system in a nuclear analytical laboratory of the Korea Atomic Energy Research Institute (KAERI) is described. This paper summarizes the need for a quality system and accreditation, the process of a quality system implementation, the quality system structures, and the formal accreditation of our laboratory by the Korean Laboratory Accreditation Scheme (KOLAS). Also, the improvements in the management, technical and service quality which resulted from implementation of this system are briefly reported.     

Development and implementation of a real time statistical control method to identify the start and end of the winter surge in demand for paediatric intensive care

Winter surge management in intensive care is hampered by the annual variability in the winter surge. We aimed to develop a real-time monitoring system that could promptly identify the start, and accurately predict the end, of the winter surge in a paediatric intensive care (PIC) setting. We adapted a statistical process control method from the stock market called “Bollinger bands” that compares current levels of demand for PIC services to thresholds based on the medium term average demand. Algorithms to identify the start and end of the surge were developed for a specific PIC service: the North Thames Children's Acute Transport Service (CATS) using eight winters of data (2005–12) to tune the algorithms and one winter to test the final method (2013/14). The optimal Bollinger band thresholds were 1.2 and 1 standard deviations above and below a 41-day moving average of demand respectively. A simple linear model was found to predict the end of the surge and overall demand volume as soon as the start had been identified. Applying the method to the validation winter of 2013/14 showed excellent performance, with the surge identified from 18th November 2013 to 4th January 2014.An Excel tool running the algorithms has been in use within CATS since September 2014. There were three factors which facilitated the successful implementation of this tool: the perceived problem was pressing and identified by the clinical team; there was close clinical engagement throughout and substantial effort was made to develop an easy-to-use Excel tool for sustainable use.     

Further development of multiple centrality correctors for interior point methods

This paper addresses the role of centrality in the implementation of interior point methods. We provide theoretical arguments to justify the use of a symmetric neighbourhood, and translate them into computational practice leading to a new insight into the role of re-centering in the implementation of interior point methods. Second-order correctors, such as Mehrotra’s predictor–corrector, can occasionally fail: we derive a remedy to such difficulties from a new interpretation of multiple centrality correctors. Through extensive numerical experience we show that the proposed centrality correcting scheme leads to noteworthy savings over second-order predictor–corrector technique and previous implementations of multiple centrality correctors.     

Efficient Kriging-based robust optimization of unconstrained problems

A novel methodology, based on Kriging and expected improvement, is proposed for applying robust optimization on unconstrained problems affected by implementation error. A modified expected improvement measure which reflects the need for robust instead of nominal optimization is used to provide new sampling point locations. A new sample is added at each iteration by finding the location at which the modified expected improvement measure is maximum. By means of this process, the algorithm iteratively progresses towards the robust optimum. It is demonstrated that the algorithm performs significantly better than current techniques for robust optimization using response surface modeling.