Metrics to identify meaningful downscaling skill in WRF simulations of intense rainfall events

Dynamical downscaling attempts to provide regional detail to climate change projections that subsequently can be used as input to climate change impact models. However, unlike forecasts by numerical weather prediction models, downscaled projections cannot be tested for skill because the future of interest is decades away. Nevertheless, models can be tested in terms of how well they simulate current weather or climate, thus giving an indication of skill in representing the process of interest. Here, six configurations using different combinations of three microphysics and two planetary boundary layer schemes are assessed on their skill to simulate desired characteristics in daily rainfall fields from three two week simulations in southeast Australia; ‘desired’ meaning desirable in relation to the intended application. Of different metrics and analysis assessed, a metric based on variography analysis, summarising characteristics about spatial variability and dissimilarity, is shown to provide the most informative guidance relative to the desirable characteristics.     

Vibration component separation by iteratively using stochastic resonance with different frequency-scale ratios

It is well-known that stochastic resonance (SR) is mainly used for signal denoising and weak signal detection. In this paper, we firstly find the frequency range selection characteristic (filtering characteristic) of re-scaling frequency SR (RFSR) caused by the driving frequency limitation of bistable SR. It then follows that a novel approach to separate vibration components with different frequencies by iteratively using SR is explored. The frequencies of most vibration signals exceed the driving frequency limitation, thus by use of different frequency-scale ratios, the vibration signals with different frequency range can be extracted by RFSR. Firstly, a small frequency-scale ratio is used to obtain the vibration signal with a narrow frequency range, i.e. low frequency vibration. As the output of SR may have a phase lag, a simple phase-shift correction method is proposed to improve the accuracy of signal component separation. The phase-shift corrected signal of RFSR output is separated from the original vibration signal and the residue is treated as the new vibration signal. Then, increasing the frequency-scale ratio according to a searching algorithm, the vibration signal with higher frequency can be obtained by RFSR. Through this iterative process, several harmonic vibration components can be separated from the original noisy vibration signal. The proposed method, empirical mode decomposition (EMD) and Hilbert vibration decomposition (HVD) are respectively applied to analyzing a simulated vibration signal and extracting the fault feature of a rotor system. The contrastive results show that this proposed method has good frequency resolution and can successfully separate monocomponent harmonic signals from a strongly noisy multicomponent harmonic vibration signal while EMD and HVD cannot.     

An improved ultrasonic method for lubricant-film thickness measurement in cylindrical roller bearings under light radial load

Focusing on measuring the oil-film thickness with ultrasonic approaches in roller bearings, a new feasible method is proposed to improve the measuring accuracy. The spatial resolution, which has great influence on the measuring accuracy, is mainly determined by the focus size of the ultrasound transducer. Under the light load conditions, the width of the Hertz contact area is smaller than the focus size, which results in overlapping measurement regions by the high pulse-repetition frequency and then brings about large measurement errors. By introducing reflection coefficients of sound pressure in the non-overlapping areas, the new method improves the measuring accuracy successfully. The experimental results are achieved from the real-time lubricant-film thickness monitoring system for cylindrical roller bearings, which show good agreement with the theoretical solutions.     

Collaborative negotiation for ontology-driven enterprise businesses

The requirements from a globalised world demand that enterprises not only shift their paradigm from product-centrism to component-centrism on integrated products, potentiating the need for tight interoperability dependencies, but also that the product specifications and concepts are fully understood by customers and providers in a transparent manner that surpasses the barriers of language, culture and technology. This paper presents the NEGOSEIO framework, which enables service-based interoperability between parties, closely integrated with semantics and business understanding via the use of reference ontologies in the quest for achieving a stronger interoperability liaison. The paper's validation and discussion is performed in its application on the ontology negotiation of business environments in the scope of the EU-funded FP7 project TIMBUS for digital preservation of resources and enduring business continuity.     

水溶液中Np、Pu、Am和Cm同时电沉积制备α测量源

为制备高分辨率Np、Pu、Am和Cm的α混合测量源,研究了电沉积液介质浓度、pH值、电流密度、电沉积时间等条件对电沉积效率及沉积源质量的影响。结果表明,在pH为2.0~2.5的0.2mol/L硫酸铵介质中,电流密度为0.40~0.50A/cm2,室温条件下电沉积60min,~(237)Np、~(238)Pu、~(243)Am和~(244)Cm在阴极不锈钢片上的电沉积效率均大于96%,制备的α测量源能量分辨率较好。     

高分辨率卫星遥感影像立体像对量测的实验——精度统计、分析总结和可行性分析

对0.31 m分辨率Worldview3立体像对带RPC参数的立体量测实验,采用不同的作业平台对立体像对进行量测实验,进行精度统计、分析总结和可行性分析。最终得出0.31 m分辨率Worldview3立体像对在1∶2 000比例尺3D产品生产的可行性,为生产服务打下基础和实践。