Ontological reasoning in the design space exploration of advanced cyber–physical systems

Cyber–physical systems are becoming increasingly complex. In these advanced systems, the different engineering domains involved in the design process become more and more intertwined. Therefore, a traditional (sequential) design process becomes inefficient in finding good design options. Instead, an integrated approach is needed where parameters in multiple different engineering domains can be chosen, evaluated, and optimized to achieve a good overall solution. However, in such an approach, the combined design space becomes vast. As such, methods are needed to mitigate this problem.In this paper, we show a method for systematically capturing and updating domain knowledge in the context of a co-design process involving different engineering domains, i.e. control and embedded. We rely on ontologies to reason about the relationships between parameters in the different domains. This allows us to derive a stepwise design space exploration workflow where this domain knowledge is used to quickly reduce the design space to a subset of likely good candidates. We illustrate our approach by applying it to the design space exploration process for an advanced electric motor control system and its deployment on embedded hardware.     

萃取预分离法分离富铕中钇矿新工艺

采用一种新的串级萃取方式--萃取预分离法分离富铕中钇矿的新工艺.原料首先流入十几的三出口预先粗分离工艺,其萃余液La～Gd(TbDy)直接流入Nd/Sm工艺;中间出口流入(Gd)Tb～HoY(Er)Gd～Dy/Ho～LuY细分离工艺;出口负载有机相(Ho)Er～LuY流入Gd～Dy/Ho～LuY的洗涤段.结果表明,新工艺的粗分离工艺将占原料约70%的La～Gd(TbDy)预分离掉,使流入Gd～Dy/Ho～LuY工艺的稀土量减少约70%;由于Gd～Dy/Ho～LuY分组的萃余液GdTbDy含Ho2O3小于0.03%,省去原工艺的GdTbDy/HoY分离;新工艺的处理能力提高30%,酸碱消耗减少20%以上,贵重稀土元素Eu和Tb的存槽量大大减少.     

A comparison of the performance of N simulation models in the prediction of Nmin on farmers' fields in the spring

The performance of three different models, which simulate changes in the inorganic N content of the soil, was evaluated in respect of their ability to predict N_min content in the spring under cereal crops. The models of British, Dutch and German origin, were tested using data from farmers' fields supplied by 70 farmers over two growing seasons in FRG. The models were run between harvest of the previous crop and spring of the following year, and predictions of N_min in the spring compared to soil measurements. The performance of the models was assessed by counting the number of cases in which predictions agreed within 10 or 20 kg (N) ha^–1 of the measurements. Predictions were less than ± 10 kg (N) ha^–1 of measured values in only 30–44% and 28–55% of cases in 1988 and 1989, respectively. Predictions were less than ± 20 kg (N) ha^–1 of measured values in 62–70% and 68–82% of cases in 1988 and 1989, respectively. Predictions in 1989 were better because the initial N_min content in the autumn was included in the model input. None of the models tested had been designed to use input data of the type available to farmers. It is concluded that, at present, the results are too variable for any of the models to be used with confidence as tools to aid in N fertilizer recommendations.     

Chlorosis in sugarcane: Associated soil properties,leaf mineral composition,and crop response to iron and manganese

Attempts were made to find out the nature and cause of a widespread sugarcane chlorosis in a cane growing area. Soils from chlorotic and nonchlorotic fields did not differ markedly in pH, CaCO₃, electrical conductivity, organic C, and soil test P, Zn, Cu, and Mn levels, but the chlorotic field soils had relatively more NH₄OAc-extractable K and less clay and DTPA-extractable Fe. Chlorotic and green leaf blades contained about the same concentration of P, S, Mg, Fe, Zn, Cu, and Mo, but the former leaf blades had more K and less Ca and HCl soluble Fe than the green ones. Green leaves of plants that seemed to have naturally recovered in chlorotic fields were higher in Mn. A foliage spray with 2.5% FeSO₄.7H₂O solution resulted in greening of leaves and a field experiment showed marked crop response to Fe and some response to Mn. The results thus suggest that the chlorosis is due to a lime-induced Fe-deficiency with the possibility of some role of Mn in Fe nutrition in calcareous soil conditions.Deceased 22 September 1988     

混合材对碱—碳酸盐反应的影响

利用快速测长法研究了混合材对碱—碳酸盐反应的影响。通过试验证明混合材能减缓碱—碳酸盐反应的速度,但不能有效地抑制碱—碳酸盐反应,并初步探讨了混合材不能有效地抑制碱—碳酸盐反应的机理。     

Coupling geometric analysis and viability theory for system exploration: Application to a living food system

This paper addresses the issue of studying a food complex system in a reverse engineering manner with the aim of identifying the set of all possible actions that makes it reach a quality target with respect to manufacturing constraints. Once the set of actions is identified, several criteria can be considered to identify interesting trajectories and control policies. A viability approach, coupling the viability theory and a geometric approach of robustness, is proposed to study complex dynamical systems. It can be implemented for several types of systems, from linear to non linear or hybrid systems. The proposed framework was adapted to a living food system: a ripening model of Camembert cheese to identify the set of states and actions (capture basin) from which it is possible to reach a predefined quality target. Within the set of viable trajectories, particular trajectories that improve the Camembert cheese ripening process are identified using the proposed approach. The results are applied at a pilot scale and are discussed in this paper.     

石油勘探电磁层析成像在复杂岩层的应用仿真

对石油岩层进行勘探时,是通过电磁波形成稳定图像,对石油岩层进行勘探.由于石油区域的岩层结构密集和稀松部分分布不均匀,电磁层析成像在分布不均匀的岩石结构中,电磁波回波过程发生不定衰减,导致电磁析图像发生局部变异.传统的石油勘探电磁层析成像技术在图像局部变异下,会严重影响后期的成像效果,成像信息失真明显.提出采用加权小波分析的石油勘探中电磁层析成像复杂结构声波过滤方法.用非线性方程描述所有的石油勘探中电磁层析成像结构声波,选取一组成像信号作为样本数据,计算成像信号的权重,获取所有成像信号在声波过滤过程中的重要程度.针对上述结果进行小波变换处理,完成成像信号的分解,将所有的因子进行重构,实现声波过滤.实验结果表明,利用改进算法进行石油勘探中电磁层析成像复杂结构声波过滤,能够极大的提高过滤准确性,得到清晰的成像信号.     

An algorithm and observability research of autonomous navigation and joint attitude determination in asteroid exploration descent stage

In this paper, an autonomous relative navigation and joint attitude determination algorithm in asteroid exploration descent stage is researched based on feature point information of perpendicular asteroid surface image observed by optical navigation camera, distance vectors from spacecraft to asteroid measured by three angled installed lidars and relative velocity increment measured by accelerometer when the relative distance vector to the centroid of asteroid can not be obtained. The inertial attitude of spacecraft is determined by sun vector, star vectors and inertial angular velocity respectively measured by sun sensor, star trackers and inertial reference unit. Also, in order to obtain measurement error model transferred from sensor noise, a covariance matrix solver considering error correlation is presented via the error model of normalized vector to first order. Numerical simulation and improved observability evaluation of filtering are undertaken to discuss the results of complete sensor observation and weak observation of lidars, and verify the effectiveness of the presented relative navigation and attitude determination algorithm.     

无人机群目标搜索的主动感知方法

为提升蚁群搜索算法在规模大的栅格环境中对未知目标的搜索效率,提出基于蚁群算法的主动感知搜索框架。该框架通过应用历史环境信息来选择无人机的运动方式,并由无人机运动方式和感知域信息得到新的环境信息,从而实现无人机群的智能自动化搜索功能。新方法计算出一种具有探索偏好的未搜索概率,可使无人机搜索时偏向未搜索程度高的栅格,以此来提高算法的搜索能力。同时,以未搜索概率和信息素作为运动方式决策的依据来建立一种新的运动方式选择机制。该机制不仅考虑了目标可能出现的区域,又可兼顾未知区域,从而可实现无目标先验信息条件下的搜索过程。仿真结果表明,此算法在规模大的栅格环境中,与现有算法相比具有更高的搜索效率,并且得到的目标分布信息将更加全面。     

鄂尔多斯盆地下古生界构造-沉积演化、古地理重建及有利成藏区带划分

鄂尔多斯盆地下古生界是重要的天然气勘探层位,相继发现了奥陶系顶部风化壳、古隆起周缘中组合和马家沟组盐下等多套含气层系,证明了盆地下古生界具有良好的勘探开发潜力,也揭示出深化古地理重建工作的急迫性。在分析鄂尔多斯盆地构造-沉积演化过程的基础上,对早古生代重点时期的古地理进行了重建,进而提出了成藏区带划分的新思路。研究表明,鄂尔多斯盆地经历了太古宙—元古宙裂陷沉积、寒武纪—奥陶纪沉积-剥蚀、石炭纪—三叠纪拗陷稳定沉积、侏罗纪—白垩纪挤压成藏和晚白垩纪—现今调整定型等5大阶段。盆地下古生界古地理格局经历了早-中寒武世的古陆消减、沉积增长、边缘裂陷阶段和早奥陶世的隆-坳相间阶段,并控制了优质成藏区带的分布。结合近期勘探研究进展,依据源-储组合和空间分布,划分出了基于主控因素的4类成藏区带：潮缘滩白云岩成藏区、奥陶系盐下台内丘滩成藏区、西部双滩带白云岩和页岩成藏区以及岩溶-滩相白云岩成藏区。不同区带显示出了不同的成藏条件和主控因素,需要选择针对性的勘探策略。