能耗式加载试验台的原理及应用

能耗式加载试验台运用水力测功器消耗被试减速箱的输出功,在工控机的控制下,加载载荷连续可调,适用于大功率减速箱的载荷加载试验。该试验台经实际试验,系统运行可靠、性能稳定。

基于ARM处理器的嵌入式软件能耗统计模型

提出了一种嵌入式软件能耗的统计模型,包括处理器、存储器和I/O控制器等硬件单元产生的能耗,然后通过分析ARM指令周期数的规律,设计了指令周期数的相应计算方法,该方法能够快速地计算软件运行时处理器产生的能耗。在高精度指令级嵌入式软件能耗模拟器HMSim中进行了模型实现。实验结果表明,该模型的能耗计算结果与实际仪器测量结果的误差在10%以内,可较准确地反映软件实现方式对系统能耗的影响程度。

低能耗嵌入式系统的设计

能量消耗问题是近几年来人们在嵌入式系统设计中普遍关注的难点与热点 ,它严重制约着嵌入式系统的应用及发展。以减少嵌入式系统所耗电能为目标 ,总结了当前国际上所采用的几种主要的优化措施。

嵌入式软件体系结构级能耗建模方法

从软件体系结构层面出发,假设体系结构级软件特征量与嵌入式软件能耗之间存在非线性函数关系(线性函数关系可被认为是一种特殊的非线性函数关系),并以此假设为基础,提出了一种利用BP神经网络在体系结构级估算软件能耗的模型.能耗模型对5个体系结构级软件特征量进行度量,使用BP神经网络拟合出软件特征量与嵌入式软件能耗的非线性函数关系,并通过实验验证了模型的有效性和假设的合理性.

基于马尔科夫链的构件化嵌入式软件能耗估算模型

在目前全球倡导"低碳经济"的背景下,嵌入式软件能耗已成为嵌入式系统设计的重要考量因素,一种快速有效的软件能耗估算模型对于嵌入式软件早期开发具有重要的意义.本文着眼于构件化嵌入式软件,从基于状态的角度出发,将嵌入式软件系统的运行过程视为一个状态的集合,提出了一种基于马尔科夫链的嵌入式软件能耗估算模型.然后,通过使用状态转移概率矩阵获得嵌入式软件构件的稳定状态分布,再结合构件的能耗测量值,实现嵌入式软件的能耗估算,并通过实验验证了该模型的有效性.

EOS系统IO能耗评估与优化

由于环境压力和自身发展的要求,EOS系统对能耗控制的要求越来越高,人们对低能耗技术的研究越来越重视,一系列的研究成果纷纷出现,针对软硬件的低能耗技术都取得长足进步。本文主要从数理逻辑层面分析能耗评估与优化技术。

基于灰色层次模型的嵌入式软件能耗优化方法评价研究

随着可移动嵌入式系统大量而广泛的使用,嵌入式软件能耗已成为嵌入式系统设计的一个重要因素,而如何评价嵌入式软件能耗优化方法的综合效果是一项重要工作.针对评价过程中信息不完备性和不确切性的问题,采用基于层次灰色评价理论建立的评价模型,通过仿真实验数据分析在源程序结构级的优化方法对嵌入式软件三项指标(包括能耗、运行时间以及指令数目)的影响程度,进而评价优化方法取得的效果和所属等级,并考虑了能耗与运行时间的负相关情况.实验结果表明,此评价方法是有效的,根据评价的反馈结果,可进一步指导并完善相应的嵌入式软件能耗优化方法.

Performance analysis of U-vertical direct-expansion ground-source heat pump

The performance of a direct-expansion ground-source heat pump（DX GSHP）system is theoretically analyzed.Compared with the conventional ground-source heat pump（GSHP）,the DX GSHP has a lower condensing temperature in the cooling mode and a higher evaporating temperature in the heating mode,and the ground heat exchanger（GHE）in the DX GSHP has a low thermal resistance.Therefore,the coefficient of performance（COP）of the DX GSHP is higher than that of the GSHP.In addition,the system performance of the DX GSHP system is higher than that of the conventional GSHP system because there are no secondary solution loops and water circulating pumps in the DX GSHP system.The experimental energy performance of the DX GSHP system is also investigated based on the actual operational data.The tested DX GSHP system is installed in Xiangtan,China.The U-vertical GHE of the DX GSHP is buried in a water well.The length and the outside nominal diameter of the GHE are 42 m and 12.7 mm,respectively.The experimental results show that the maximum（COP）and the average COP of the DX GSHP system in the heating mode are 5.95 and 4.72,respectively.

Mechanical and energy dissipation characteristics of granite under cyclic impact loading

This study investigated the effect of repeated blasting on the stability of surrounding rock during the construction of a tunnel or city underground engineering.The split Hopkinson pressure bar(SHPB)was used to carry out cyclic impact tests on granite samples,each having a circular hole,under different axial pressures,and the cumulative specific energy was proposed to characterize the damage characteristics of the rock during the cyclic impact.The mechanical properties and the energy absorbed by the granite samples under cyclic impact loads were analyzed.The results showed that under different axial pressures,the reflected waveform from the samples was characterized by“double-peak”phenomenon,which gradually changed to“single-peak”wi th the increase in damage value.The dynamic peak stress of the sample first increased and then decreased with an increase in impact times.The damage value criterion established based on the energy dissipation could well characterize the relationship between the damage and the number of impacts,which showed a slow increase,steady increase,and high-speed increase,and the damage value depended mainly on the last impact.Under the action of different axial pressures,all the failure modes of the samples were axial splitting failures.As the strain rate increased,with an increase in the dimension of the block,the sizes of the rock fragments decreased,and the fragmentation became more severe.

Energy consumption in rock fragmentation at intermediate strain rate

In order to determine the relationship among energy consumption of rock and its fragmentation, dynamic strength and strain rate, granite, sandstone and limestone specimens were chosen and tested on large-diameter split Hopkinson pressure bar (SHPB) equipment with half-sine waveform loading at the strain rates ranging from 40 to 150 s- 1. With recorded signals, the energy consumption, strain rate and dynamic strength were analyzed. And the fragmentation behaviors of specimens were investigated. The experimental results show that the energy consumption density of rock increases linearly with the total incident energy. The energy consumption density is of an exponent relationship with the average size of rock fragments. The higher the energy consumption density, the more serious the fragmentation, and the better the gradation of fragments. The energy consumption density takes a good logarithm relationship with the dynamic strength of rock. The dynamic strength of rock increases with the increase of strain rate, indicating higher strain rate sensitivity.

Energy optimization of representative barrier algorithms

Too high energy consumption is widely recognized to be a critical problem in large-scale parallel computing systems.The LogP-based energy-saving model and the frequency scaling method were proposed to reduce energy consumption analytically and systematically for other two representative barrier algorithms:tournament barrier and central counter barrier.Furthermore,energy optimization methods of these two barrier algorithms were implemented on parallel computing platform.The experimental results validate the effectiveness of the energy optimization methods.67.12% and 70.95% energy savings are obtained respectively for tournament barrier and central counter barrier on platforms with 2048 processes with 1.55%?8.80% performance loss.Furthermore,LogP-based energy-saving analytical model for these two barrier algorithms is highly accurate as the predicted energy savings are within 9.67% of the results obtained by simulation.

Research on the Effects of Train Operation Mode for Vehicle Energy Consumption

The research background is based on great consumption of urban rail transit energy, through summarizing the research of scholars at home and abroad, the comprehensive research including train operation pattern, the train traction characteristics and optimization design of integrated research has carried out in this paper, by using OPENTRACK software simulation to verify the optimization results according to different line features finally. The aim of this paper is to explore ways and methods of traction strategy optimization under the condition of trains timing energy saving. The main research contents of this paper are based on the research status at home and abroad, first of all, the different operating modes of the train running on the line are analysed, including the time saving mode, the energy saving mode and timing energy saving mode, and quantitative analysed the influence of different operation modes on vehicle energy consumption. The influence factors and traction calculation method of energy consumption of train running are studied. Firstly, the factors that affect the energy consumption of the train are analysed, including the basic facilities and transport organization mode. On the basis of this, the train load and running status of the train are analysed, and the model of the train movement and energy consumption are calculated. The OPENTRACK software is used to establish the actual circuit model, and the simulation is verified. The results show that the reasonable operation mode of the train operation mode can greatly reduce the energy consumption.

Low energy consumption depth control method of self-sustaining intelligent buoy

Aiming at the contradiction between the depth control accuracy and the energy consumption of the self-sustaining intelligent buoy,a low energy consumption depth control method based on historical array for real-time geostrophic oceanography(Argo)data is proposed.As known from the buoy kinematic model,the volume of the external oil sac only depends on the density and temperature of seawater at hovering depth.Hence,we use historical Argo data to extract the fitting curves of density and temperature,and obtain the relationship between the hovering depth and the volume of the external oil sac.Genetic algorithm is used to carry out the optimal energy consumption motion planning for the depth control process,and the specific motion strategy of depth control process is obtained.Compared with dual closed-loop fuzzy PID control method and radial basis function(RBF)-PID method,the proposed method reduces energy consumption to 1/50 with the same accuracy.Finally,a hardware-in-the-loop simulation system was used to verify this method.When the error caused by fitting curves is not considered,the average error is 2.62 m,the energy consumption is 3.214×10^(4)J,and the error of energy consumption is only 0.65%.It shows the effectiveness and reliability of the method as well as the advantages of comprehensively considering the accuracy and energy consumption.

Energy Dissipation Within the Wave Run-Up at Stepped Revetments

To understand the processes and energy dissipation performance caused by turbulence during the wave run-up over a stepped revetment,hydraulic model tests with steady flow conditions are conducted and correlated with unsteady flow conditions of the wave run-up within a short time frame.Under irregular waves,the run-up reduction over a stepped revetment is dependent on the Iribarren number and decreases for decreasing Iribarren numbers.Velocity gradients are found to be similar in a steady and unsteady flow regime near the pseudo-bottom.

Entransy dissipation analysis and optimization of separated heat pipe system

Seperated heat pipe systems are widely used in the fields of waste heat recovery and air conditioning due to their high heat transfer capability,and optimization of heat transfer process plays an important role in high-efficiency energy utilization and energy conservation.In this paper,the entransy dissipation analysis is conducted for the separated heat pipe system,and the result indicates that minimum thermal resistance principle is applicable to the optimization of the separated heat pipe system.Whether in the applications of waste heat recovery or air conditioning,the smaller the entransy-dissipation-based thermal re-sistance of the separated heat pipe system is,the better the heat transfer performance will be.Based on the minimum thermal resistance principle,the optimal area allocation relationship between evaporator and condenser is deduced,which is numeri-cally verified in the optimation design of separated heat pipe system.

Theoretical study of electric energy consumption for self-powered chaos signal generator

Self-powered chaos signal generator is potentially useful in future medical system,such as low cost portable human healthy monitor and treatment without external power source.For both functional and power unit,the power level of electric energy generator and consumption is a key factor for self-powered system.In this paper,we have investigated the power consumption of three typical output modes of a simple chaos circuit.Analytical analysis for power consumption of fixed output mode is obtained for evaluating the power characteristics of chaos signal generator.Numerical calculations are given for predicting the power characteristics of periodical and chaotic output modes.This study is important for not only understanding the power consumption of chaos signal generator,but also guiding new self-powered chaos signal generator design.

Scientific Evaluation and Regeneration of Eco-building Experience in Traditional Dwellings

In 1996, Department of Engineering and MaterialSciences,National Natural Science Foundation (NSFC), accepted the suggestion made by some experienced members of CAS and published the key support project Green Architecture System and Dwelling Pattern in application guide for NSFC project. The project research group, led by Prof.