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科学技术的日新月异发展,推进了素质教育的进程,多媒体技术已经走进了课堂,为教师教学开辟了广阔空间。多媒体技术激发了学生浓厚的学习兴趣,化解了教学难点,创设了丰富的教学情境,有效地进行了德育渗透,突出了学生主体地位,提高了课堂教学效率。本文试就小学语文教学运用多媒体技术问题进行了探讨。 相似文献
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科学技术的日新月异发展,多媒体技术已经进入了课堂,优化了课堂教学,提高了教学效率,突出了学生主体地位,激发了学生学习欲望,调动了学生学习的积极性、主动性、创造性,扩大了知识容量,促进了学生想象思维的发展,实现了课堂教学过程的最优化。本文试就多媒体技术在小学语文教学中的应用进行了探讨。 相似文献
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科学技术的日新月异发展,推动了素质教育的进程,多媒体技术已经走进了课堂,本文阐述了小学数学教学应用多媒体技术,激发了学生浓厚的学习兴趣,化解了教学重点难点,营造了良好的氛围,优化了课堂教学,提高了课堂教学效率。 相似文献
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分析了软件工程课程的教学特点,结合遵义师范学院学生学习现状,整合了教学内容、组建了多种教学方式、进行了教学评价改革与实践,提高了学生学习主动性和积极性,培养了学生分析问题、解决问题的能力,提高了教学质量。 相似文献
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地震震动了人心,奥运鼓舞了人心,金融海啸席卷了人心。
失业了,郁闷;降息了,还银行贷款少了,高兴。人们在悲喜交织中动荡着。 相似文献
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炼油企业生产调度的优化因能提高资源利用效率、增加生产收率、满足需求和最大化利润而成为近年来的研究热点。本文以生产调度中的油品调和为例,分析和描述了调度过程建模所需的模型元素及其数学表达,其中涉及炼油企业典型的物料平衡及物性计算方法。针对生产操作规则对汽油和柴油的调和分别进行建模,求得在经济效益最大时各调和组分的质量以及主要性能指标,由此提出了一种针对成品油调和的优化方法。 相似文献
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为了研制油污染传感器,首先要配置不同污染度的油液,并用颗粒计数器对所配置的油液进行实验标定,本文以矿山机械减速器常用的N320润滑油为对象,首先讨论了新油的过滤以及注意事项;其次按照NAS1638污染度等级标准配置了不同污染度等级的油样,本文总共配置了污染度等级从10级到22级共13油样,叙述了配制油液的方法和具体步骤,最后对所配置的油液进行了试验标定,详细介绍了标定前的准备工作、标定的方法和标定的步骤,最后通过实验数据,进一步确定了我们所配油液的污染度,从而为下一步标定传感器做了前期准备工作。 相似文献
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Heping Pan Imad Haidar Siddhivinayak Kulkarni 《Frontiers of Computer Science in China》2009,3(2):177-191
This paper documents a systematic investigation on the predictability of short-term trends of crude oil prices on a daily
basis. In stark contrast with longer-term predictions of crude oil prices, short-term prediction with time horizons of 1–3
days posits an important problem that is quite different from what has been studied in the literature. The problem of such
short-term predicability is tackled through two aspects. The first is to examine the existence of linear or nonlinear dynamic
processes in crude oil prices. This sub-problem is addressed with statistical analysis involving the Brock-Dechert-Scheinkman
test for nonlinearity. The second aspect is to test the capability of artificial neural networks (ANN) for modeling the implicit
nonlinearity for prediction. Four experimental models are designed and tested with historical data: (1) using only the lagged
returns of filtered crude oil prices as input to predict the returns of the next days; this is used as the benchmark, (2)
using only the information set of filtered crude oil futures price as input, (3) combining the inputs from the benchmark and
second models, and (4) combing the inputs from the benchmark model and the intermarket information. In order to filter out
the noise in the original price data, the moving averages of prices are used for all the experiments. The results provided
sufficient evidence to the predictability of crude oil prices using ANN with an out-of-sample hit rate of 80%, 70%, and 61%
for each of the next three days’ trends. 相似文献
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This paper documents a systematic investigation on the predictability of short-term trends of crude oil prices on a daily basis. In stark contrast with longer-term predictions of crude oil prices, short-term prediction with time horizons of 1-3 days posits an important problem that is quite different from what has been studied in the literature. The problem of such short-term predicability is tackled through two aspects. The first is to examine the existence of linear or nonlinear dynamic processes in crude oil prices. This sub-problem is addressed with statistical analysis involving the Brock-Dechert-Scheinkman test for nonlinearity. The second aspect is to test the capability of artificial neural networks (ANN) for modeling the implicit nonlinearity for prediction. Four experimental models are designed and tested with historical data: (1) using only the lagged returns of filtered crude oil prices as input to predict the returns of the next days; this is used as the benchmark, (2) using only the information set of filtered crude oil futures price as input, (3) combining the inputs from the benchmark and second models, and (4) combing the inputs from the benchmark model and the intermarket information. In order to filter out the noise in the original price data, the moving averages of prices are used for all the experiments. The results provided sufficient evidence to the predictability of crude oil prices using ANN with an out-of-sample hit rate of 80%, 70%, and 61% for each of the next three days’ trends. 相似文献
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本体论与各个领域计算机技术的发展结合产生了所谓的“领域本体”的构建及应用研究, 首先介绍了计算机本体理论的基本概念, 接着给出石油勘探开发知识管理系统的框架设计, 然后提出基于多层次业务流程的石油勘探和开发领域知识本体库的构建方法, 把石油勘探开发领域所涉及方面分为多级业务活动层次, 并以采油工程方案为例列出了对应的知识本体库构建方法的探讨. 相似文献
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对某厂重催装置汽压机组汽轮机控制油系统进行了阐述,分析速关油内漏故障引发原因,最后给出详细的故障排查和处理方法。 相似文献
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Roberto Iachan 《International Transactions in Operational Research》2009,16(5):585-593
Petrobras was created as an integrated company to operate in oil and oil byproduct exploration, production, refining, marketing, and transportation. Petrobras is now the biggest Brazilian company, operating in a number of areas in the energy sector and currently present in 27 countries. This article describes the evolution of the activities and the achievements of its Operations Research group, created in the 1960s, and its work offering decision support to the most diverse segments of the company. 相似文献