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武钢制氧空压机组差动保护包括对启动用自耦变压器和空压机主电机的保护,是反应电机柜、自耦变压器及主电机三端电流互感器二次电流流入差动继电器的电流差而动作的。在保护范围内无故障时,差动继电器内不平衡电流接近于零。但在某些情况下,保护范围内无故障时差动继电器内仍有较大的不平衡电流。本文对武钢制氧空压机组差动保护的这个特点进行了介绍,分析了该机组差动保护可能误动作的原因,并对差动保护整定值的确定及保护的灵敏度做了简单分析。 相似文献
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In testing the factorial invariance of a measure across groups, the groups are often of different sizes. Large imbalances in group size might affect the results of factorial invariance studies and lead to incorrect conclusions of invariance because the fit function in multiple-group factor analysis includes a weighting by group sample size. The implication is that violations of invariance might not be detected if the sample sizes of the 2 groups are severely unbalanced. In this study, we examined the effects of group size differences on results of factorial invariance tests, proposed a subsampling method to address unbalanced sample size issue in factorial invariance studies, and evaluated the proposed approach in various simulation conditions. Our findings confirm that violations of invariance might be masked in the case of severely unbalanced group size conditions and support the use of the proposed subsampling method to obtain accurate results for invariance studies. 相似文献
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无论是在任何时候,收入分配问题都是社会关注的重点,尤其近些年来,这一关注重点成为了焦点。当前我国收入分配结构不合理,收入分配关系失衡。其根本原因是由于分配不公和侵害他人的权益造成的。分配公平不仅仅是单纯的经济利益调节问题,也是关系社会和谐稳定的重大社会问题。我国收入分配格局失衡已经产生了许多不良后果,导致内需不足特别是消费不振,影响社会和谐稳定。因此,要加快收入分配制度改革,调整收入分配结构,理顺收入分配关系,逐步形成中等收入占多数的"橄榄型"分配格局。 相似文献
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周珍 《新乡师范高等专科学校学报》2004,18(6):96-98
当前我国税收征管的完善面临的突出问题是税源监控手段落后,征管内部监控弱化,税收立法层次较低,税制结构不合理以及税务队伍综合素质偏低,导致了"征收、管理、稽查、监控"四环节的信息不对称,从而造成大量税收流失,税制僵化,征管成本过高。因此,若要做到地方税收征管的完善,首先要实现税源监控转移,强化征管内部的监控体系,提升税收立法层次,并要多途径地推动税务队伍综合素质的提高。 相似文献
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Spyros Konstantopoulos 《Journal of Experimental Education》2013,81(3):291-317
Previous work on statistical power has discussed mainly single-level designs or 2-level balanced designs with random effects. Although balanced experiments are common, in practice balance cannot always be achieved. Work on class size is one example of unbalanced designs. This study provides methods for power analysis in 2-level unbalanced designs with random effects. Overall, the nesting affects power negatively, the treatment affects power positively, and the Level-2 units affect power more than Level-1 units. Computing power assuming balanced designs provides reasonable estimates only when imbalance is mild or moderate. When imbalance is large or extreme, computing power assuming balanced designs produces larger estimates of power. The use of the harmonic mean provides accurate estimates of power in unbalanced 2-level designs even when imbalance is large. 相似文献
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在远程教育飞速发展的过程中,暴露出了东西部远程教育发展不平衡、盲目扩张、技术力量薄弱、管理不力、教育方法跟不上教学手段、教学质量不能保证等问题。分析远程教育存的这些问题,旨在为远程教育的健康、可持续发展找出一条道路。 相似文献
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采用文献资料法、数理统计法和对比分析法,定性和定量分析相结合,对我国经济和社会发展水平与群众体育发展程度进行相关分析研究.结果表明:经济发展状况、社会发展水平、教育水平、人口结构以及社会非均衡发展均会对我国群众体育的发展产生重大的影响,而且我国群众体育发展与经济和社会发展一样,都具有很大的区域差异性. 相似文献