Optimal scheduling of electrical power in energy-deficient scenarios using artificial neural network and Bootstrap aggregating

In a developing country like Pakistan, where the electrical power demand is more than the generated power, maintaining the power system stability is a big challenge. In such cases it becomes, thus, essential to shed just the right amount of load to keep a power system stable. This paper presents a case study of Pakistan’s power system where the generated power, the load demand, frequency deviation and the load shed during a 24-h duration have been provided. The data have been analyzed using two techniques; the conventional artificial neural network (ANN) by implementing feed forward back propagation model and the Bootstrap aggregating or bagging algorithm. The simulation results reveal the superiority of the Bootstrap aggregating algorithm over a conventional ANN technique using feed forward back propagation model.     

一种新型自动化测试管理平台的实现

由于自动化测试有着回归测试更方便,可运行更多更繁琐的测试,执行一些手工测试困难或不可能进行的测试,更好地利用资源的一致性、可重复性,增加软件信任度的特点,故越来越多的公司和科研院所开始进行自动化测试管理平台的研究工作。但是,通常开发出来的自动化测试管理平台功能单一,缺乏灵活性、可升级性和集成性,而现代测试管理系统已经迫切需要集成自动化测试管理平台,这样,落后的测试平台设计就无法满足先进测试管理系统的需求。这里设计一种新型的自动化测试管理平台,能够很好地集成到先进测试管理系统中,并且容易维护和升级。     

The Estimation of Formation Permeability in a Carbonate Reservoir Using an Artificial Neural Network

Abstract

Reservoir permeability is an important parameter that its reliable prediction is necessary for reservoir performance assessment and management. Although many empirical formulas are derived regarding permeability and porosity in sandstone reservoirs, these correlations cannot be accurately depicted in carbonate reservoir for the wells that are not cored and for which there are no welltest data. Therefore, having a framework for estimation of these parameters in reservoirs with neither coring samples nor welltest data is crucial. Rock properties are characterized by using different well logs. However, there is no specific petrophysical log for estimating rock permeability; thus, new methods need to be developed to predict permeability from well logs. One of the most powerful tools that we applied by the authors is artificial neural network (ANN), whose advantages and disadvantages have been discussed by several authors. In particular, 767 data sets were used from five wells of Bangestan reservoir in a southwestern field of Iran. Depth, Neutron (NPHI), Density (RHOB), Sonic (DT) logs, and evaluated total porosity (PHIT) from log data were used as the input data and horizontal permeability obtained by coring was as target data. Sixty percent of these data points were used for training and the remaining for predicting the permeability (i.e., validation and testing). An appropriate ANN was developed and a correlation coefficient (R) of 0.965 was obtained by comparing permeability predictions and the actual measurements. As a result, the neural science can be used effectively to estimate formation permeability from well log data.     

车削细长轴的振动试验

针对背向力对工件的影响进行了细长轴车削实验,并且进行了仿真分析,两者都得到了车削细长轴时经常在工件的哪个范围段出现波纹振动,给实际操作者提供了很高的参考价值和指导意义。     

银冠大厦基础设计

本文通过对银冠大厦基础设计的分析，说明了高层地下室片筏基础设计应考虑的的一些问题，及施工注意事项。     

层次化IP Traceback算法研究

DDoS攻击是当今互联网最有危害的攻击之一,它具有攻击效果明显,攻击力强,攻击源难以追查等特点。本文提出层次化路径标记算法,在一定程度上解决了IP traceback问题,从而能比较有效地解决DDoS的威胁。     

关于鞍钢主干网络建设的两点建议

针对鞍钢计算机网络现状，提出了有关鞍钢主干网络建设的两点建设及未来的设想。     

引进型６００ＭＷ汽轮机组主汽门调门的阀壳加工

介绍了引进型６００ＭＷ汽轮机主汽门调门阀壳加工工艺的设计过程，并对各个加工难点的解决作了详细的说明。     

Novel Atmospheric Growth Technique to Improve Both Light Absorption and Charge Collection in ZnO/Cu2O Thin Film Solar Cells

In low temperature grown ZnO/Cu₂O solar cells, there is a discrepancy between collection length and depletion width in the Cu₂O which makes the simultaneous achievement of efficient charge collection and high open‐circuit voltage problematic. This is addressed in this study by fabricating ZnO/Cu₂O/Cu₂O⁺ back surface field devices using an atmospheric atomic layer deposition (AALD) printing method to grow a sub‐200‐nm Cu₂O⁺ film on top of electrodeposited ZnO and Cu₂O layers. The AALD Cu₂O⁺ has a carrier concentration around 2 orders of magnitude higher than the electrodeposited Cu₂O, allowing the electrodeposited Cu₂O layer thickness in a back surface field cell to be reduced from 3 μm to the approximate charge collection length, 1 μm, while still allowing a high potential to be built into the cell. The dense conformal nature of the AALD layer also blocks shunt pathways allowing the voltage enhancement to be maintained. The thinner cell design reduces recombination losses and increases charge collection from both incident light and light reflected off the back electrode. Using this design, a short circuit current density of 6.32 mA cm^?2 is achieved–the highest reported J_SC for an atmospherically deposited ZnO/Cu₂O device to date.     

有限元辅助分析在冠梁弯矩分析中的应用

采用有限元辅助计算方法对某实际深基坑工程的关键节点进行了分析,结果表明在交界位置存在弯矩突变,最后结合分析结果进行围护设计,实践证明该方法既可避免大量复杂的有限元计算,也可确保工程安全。