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61.
综述了近年来基于智能方法的非线性系统滤波器和观测器的设计方法.关于滤波器,一方面介绍了基于智能方法辨识系统模型而设计的间接滤波器,分析了模型偏差修正的重要性;另一方面探讨了基于智能方法设计的直接滤波器的研究进展.关于观测器,重点介绍了基于神经网络的广义Luenberger观测器的设计方法,总结了该观测器稳定性和鲁棒性的理论分析结果,并进一步介绍了适用范围更广的智能自适应鲁棒观测器的设计方法.最后,对非线性估计问题的进一步研究提出了几点展望.  相似文献   
62.
照金-焦坪一带位于鄂尔多斯盆地南缘东部,处于渭北隆起与陕北斜坡过渡区域,周边分布有店头铀矿床。笔者通过典型矿床分析,结合成矿地质条件、航空放射性异常查证结果,总结砂岩型铀矿找矿标志,建立数学-物理找矿模型,并用俄罗斯半定量成矿预测技术对该研究区进行了成矿预测,新划定铀成矿远景区2片,推进了该地区铀矿资源勘查。  相似文献   
63.
Evidence has begun to accumulate showing that successful performance of event-based prospective memory (PM) comes at a cost to other ongoing activities. The current study builds on previous work by examining the cost associated with PM when the target event is salient. Target salience is among the criteria for automatic retrieval of intentions according to the multiprocess view of PM. An alternative theory, the preparatory attentional and memory processes theory, argues that PM performance, including retrieval of the intent, is never automatic and successful performance always will come at a cost to other ongoing activity. The 4 experiments reported here used a salient PM target event. In addition, Experiments 3 and 4 were designed to meet the stringent criteria proposed for automatic retrieval of intentions by multiprocess theory, and, yet, in all 4 experiments, delayed intentions interfered with ongoing task performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
64.
预测21世纪后期世界石油资源将面临枯竭,而天然气具有成因类型多、分布广泛,与石油相比深埋后也很稳定等特点,因此人类第四代能源的选择将是天然气。生物成因和非生物成因的各种类型天然气在我国大、中型含油气盆地中广泛分布,远景资源量比较丰富,具备了在我国东部、中部和西部地区创建8个天然气生产基地的地质条件。笔者认为本世纪末到下个世纪早期是我国逐步开展油气勘探战略转移的大好时机。  相似文献   
65.
The length of hospital stay is considered to influence hospital readmission in general. The Dialysis Outcomes and Practice Patterns Study (DOPPS), an international prospective observational study undertaken to establish a relationship between facility practices and dialysis outcomes, started in 1996. Results suggest that the duration of hospital stay is significantly correlated with the probability of early readmission in dialysis patients. Thus, early hospital readmission was observed to be less likely for hemodialysis patients from facilities with longer median length of stay. The lengths of hospital stay for hemodialysis patients differed in the three continents studied. Although socioeconomic pressures may drive the lengths of hospital stay, the duration of hospitalization should be determined keeping in mind the safety of clinical course for each disease. In this forum, a 47-year-old female hemodialysis patient with severe secondary hyperparathyroidism, who had been treated with hemodialysis for 21 years, was hospitalized with severe clinical symptoms. Although the clinical symptoms disappeared 10 days after total parathyroidectomy with autotransplantation, severe hypocalcemia persisted despite large amounts of intravenous calcium gluconate. This patient was hospitalized for a long duration owing to the large calcium deficit in her body. Had the length of her hospital stay been shortened, either she could have needed rehospitalization or her condition could have worsened.  相似文献   
66.
确定预期瞬态恢复电压的低压模拟装置   总被引:1,自引:1,他引:1  
瞬态恢复电压(TRV)是电力网络中存在的固有特性之一,是影响断路器开断性能的重要因素,因此在IEC、GB以及DL的相关标准中都对此做出了明确的规定。为了获得满足标准要求的试验回路预期参数,需要采用低压模拟的方法来测取TRV波形,因此参照相关标准中推荐的直接短路开断法、工频电流注入法、电容电流注入法等几种方法,经过分析比较,选定基于“电容电流注入法”的原理研制出了一套操作简便的低压模拟装置,使用该装置可快速实施对试验回路预期TRV波形的测取。装置研制成功后已投入课题的调试工作,进行了数百次低压模拟试验,取得了很好的预期效果。  相似文献   
67.
Several theories of event-based prospective memory were evaluated in 3 experiments. The results depended on the association between the target event and the intended action. For associated target-action pairs (a) preexposure of nontargets did not reduce prospective memory, (b) divided attention did not reduce prospective memory, (c) prospective memory was better than when the target event and intended action were not associated, and (d) prospective memory was characterized by retrieval of the precise intended action. These results converge on the view that retrieval is mediated by a reflexive-associative process. In contrast, for unassociated pairs (a) preexposure of nontargets reduced prospective memory, and (b) divided attention reduced prospective memory. These results implicate cue-focused retrieval processes and are most consistent with a discrepancy-plus-search model. The entire pattern implicates both cue-focused and reflexive-associative processes and more generally supports a multiprocess framework of prospective memory (M. A. McDaniel & G. O. Einstein, 2000). (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
68.
Interference is reduced in mostly incongruent relative to mostly congruent lists. Classic accounts of this list-wide proportion congruence effect assume that list-level control processes strategically modulate word reading. Contemporary accounts posit that reliance on the word is modulated poststimulus onset by item-specific information (e.g., proportion congruency of the word). To adjudicate between these accounts, we used novel designs featuring neutral trials. In two experiments, we showed that the list-wide proportion congruence effect is accompanied by a change in neutral trial color-naming performance. Because neutral words have no item-specific bias, this pattern can be attributed to list-level control. Additionally, we showed that list-level attenuation of word reading led to a cost to performance on a secondary prospective memory task but only when that task required processing of the irrelevant, neutral word. These findings indicate that the list-wide proportion congruence effect at least partially reflects list-level control and challenge purely item-specific accounts of this effect. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   
69.
任务驱动教学是将所讲授的课程内容与实际生产任务相结合。通过具体的工作任务进行教学,减少传统教学中局限于概念的理论课时。在生产项目的实施过程讲解所涉及到的知识点,完成生产施工任务,并探寻一种基于任务驱动的教学方式,达到提高教学质量的目的。  相似文献   
70.
Objective: The aim of this prospective study was to investigate the reciprocal nature of the physical activity-depressive symptoms relationship in 17,593 older adults from 11 European countries older adults (M age = 64.07, SD = 9.58) across two-year follow-up. Also, gender and age were examined as potential moderators of this relation. Method: A two-wave cross-lagged panel design and latent change score models with structural equation modeling was used to analyze data. Depressive symptoms were measured at baseline (T1) and follow-up (T2) using the EURO-D scale, capturing the two factors of affective suffering and motivation. Physical activity was measured at T1 and T2 as frequency of moderate physical activity and vigorous physical activity. Results: Cross-sectional latent variable analyses revealed that higher levels of physical activity at T1 and T2 were associated with lower levels of affective suffering and motivation at T1 and T2. Physical activity at T1 was significantly associated with affective suffering and motivation at T2. The relations of depressive symptoms at T1 with physical activity at T2 were not significant. However, a cross-lagged model showed best model fit, supporting a reciprocal prospective relationship between physical activity and depressive symptoms in older adults. Latent change in depressive symptoms factors was related to latent change in physical activity indicating complex and dynamic associations across time. Conclusions: Regular physical activity may be a valuable tool in the prevention of future depressive symptoms in older adults, and depressive symptoms may also prevent older adults from engaging in regular physical activity. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   
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