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21.
Luis Garcés-Erice 《Parallel Computing》2011,37(8):379-391
The software in modern systems has become too complex to make accurate predictions about their performance under different configurations. Real-time or even responsiveness requirements cannot be met because it is not possible to perform admission control for new or changing tasks if we cannot tell how their execution affects the other tasks already running. Previously, we proposed a resource-allocation middleware that manages the execution of tasks in a complex distributed system with real-time requirements. The middleware behavior can be modeled depending on the configuration of the tasks running, so that the performance of any given configuration can be calculated. This makes it possible to have admission control in such a system, but the model requires knowledge of run-time parameters. We propose the utilization of machine-learning algorithms to obtain the model parameters, and be able to predict the system performance under any configuration, so that we can provide a full admission control mechanism for complex software systems. In this paper, we present such an admission control mechanism, we measure its accuracy in estimating the parameters of the model, and we evaluate its performance to determine its suitability for a real-time or responsive system. 相似文献
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23.
Prediction-based Iterative Learning Control (PILC) is proposed in this paper for a class of time varying nonlinear uncertain systems. Convergence of PILC is analyzed and the uniform boundedness of tracking error is obtained in the presence of uncertainty and disturbances. It is shown that the learning algorithm not only guarantees the robustness, but also improves the learning rate despite the presence of disturbances and slowly varying desired trajectories in succeeding iterations. The effectiveness of the proposed PILC is presented by simulations. 相似文献
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25.
我国多数油田经过一次、二次采油后,仅能采出地下总储量的30%左右,这意味着有60%~70%的剩余石油仍然残留在地下成为剩余油。加强剩余油分布规律研究、提高石油采收率不仅有着可观的经济效应,而且关系到国家石油战略的安全。本研究应用神经网络的原理,基于BP网络使用MATLAB语言建立一个剩余油分布的预测系统。该系统通过学习在地理坐标和孔隙度之间建立一个非线性函数关系,以此来预测任何区域的孔隙度,再通过孔隙度与剩余油饱和度之间的关系达到剩余油分布预测的目的。 相似文献
26.
The parallelism attained by the use of Field Programmable Gate Arrays (FPGAs) has shown remarkable potential for accelerating control systems applications. This comes at a time when well established methods based on inherited serial Central Processor Units (CPUs) cannot guarantee solutions for the increasing execution speed demands. However, the transition from serial to parallel architectures represents a tremendous challenge due to overwhelming numbers of unexplored options and conflicting factors. The work presented achieves a parallelisation characterisation for generic MIMO systems using stand-alone FPGA implementations. The main contribution is that a very fine subset of possible serial/parallel implementations is obtained. This is used to achieve a flexible trade-off between cost and performance. Automatic optimisation of latency, occupied FPGA area and execution speed is attained and justified in respect to most of the feasible scenarios. 相似文献
27.
《Ergonomics》2012,55(12):1996-2015
Experiments were designed to investigate the effects of control type and display location, relative to the operator, on the strength of control/display stereotypes. The Worringham and Beringer Visual Field principle and an extension of this principle for rotary controls (Hoffmann E.R., and Chan A.H.S. 2013). “The Worringham and Beringer ‘Visual Field’ Principle for Rotary Controls. Ergonomics.” 56 (10): 1620–1624) indicated that, for a number of different control types (rotary and lever) on different planes, there should be no significant effect of the display location relative to the seated operator. Past data were surveyed and stereotype strengths listed. Experiments filled gaps where data are not available. Six different control types and seven display locations were used, as in the Frame of Reference Transformation Tool (FORT) model of Wickens et al. (Wickens, C.D., Keller, J.W., and Small, R.L. (2010). “Left. No, Right! Development of the Frame of Reference Transformation Tool (FORT).” Proceedings of the Human Factors and Ergonomics Society 54th Annual Meeting September 2010, 54: 1022–1026). Control/display arrangements with high stereotype strengths were evaluated yielding data for designers of complex control/display arrangements where the control and display are in different planes and for where the operator is moving. It was found possible to predict display/control arrangements with high stereotype strength, based on past data.Practitioner Summary: Controls and displays in complex arrangements need to have high compatibility. These experiments provide arrangements for six different controls (rotary and translational) and seven different display locations relative to the operator. 相似文献
28.
沧州市区关停深层自备井后,深层地下水恢复取得了明显的效果。本文采用色系统中GM(1,1)模型对第Ⅴ含水组地下水埋深进行预测。 相似文献
29.
《Ergonomics》2012,55(3):398-406
This article describes the development and validation of a model for predicting multi-finger movements in grasping activities. The model builds upon a newly proposed approach that incorporates forward dynamics and a system identification procedure, and is amenable to empirical tests. A database of multi-fingered grasping movements performed by 28 subjects was established and divided into four sets, one for model development and three for model validation. In the development phase, model parameter values were estimated by the iterative system identification procedure through a physics-based heuristic algorithm. The estimated parameter values were then statistically synthesised and integrated into the prediction model. In the validation phase, the model was applied to three novel datasets containing different grasping movements involving objects of varied sizes and different subjects. The results demonstrated the model's ability to predict hand prehensile movements with error magnitudes comparable to the inter-person variability in performing such movements. New insights into the control of multi-fingered hand prehensile movements at the systems and joint levels emerged from the model development and validation process. The current study contributes to building a foundation for long-term development of realistic biodynamic simulation of multi-finger hand movements. Such simulation capabilities will aid in design of hand-operated tools, devices or hand-intensive work for proactive ergonomics and in evaluation as well as treatment of functional impairment of the hand. 相似文献
30.
在施工建设中,实时准确地观测、分析和预报建筑物的沉降变形对最后施工的成功与否有着很大的影响。在变形监测中经常遇到数据信息不完备的情况,而灰色系统理论则是用来解决此问题的有效方法。建立了灰色预测模型,并将其应用于苏南运河整治工程中新建驳岸的沉降监测分析和预测中,预测效果较好。 相似文献