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排序方式: 共有456条查询结果,搜索用时 15 毫秒
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考虑二重预想事故的在线电压稳定预防控制 总被引:3,自引:3,他引:0
提出了一种基于原对偶内点算法的安全约束最优潮流的数学模型,以控制代价最小化为目标,不仅考虑了正常状态下的安全约束,还同时考虑到了预想事故后的安全约束以及电压稳定裕度的约束。在线电压稳定评估系统中,同时考虑单重预想事故及其引发的继发性二重预想事故,分别进行筛选和排序,综合形成预想事故集。根据预想事故集,基于上述模型依次对其中每一预想事故进行预防控制,构建在线电压稳定预防控制模块,当系统处于不安全状态时,能够及时提供合理的预防控制策略,保证系统安全运行。以IEEE 118节点测试系统为算例,验证了所提出模型的正确性。 相似文献
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In this article, a Bayesian model selection approach is introduced that can select the best of a set of inequality and equality constrained hypotheses for contingency tables. The hypotheses are presented in terms of cell probabilities allowing researchers to test (in)equality constrained hypotheses in a format that is directly related to the data. The proposed method is investigated by several simulation studies and shows good performance. Software that allows researchers to apply the Bayesian approach to their own data is also provided. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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This paper proposes an optimal dynamic reserve activation plan after the occurrence of an emergency situation (generator/transmission line outage, load increase or both). An optimal plan is developed to handle the emergency, using the coordinated action of fast and slow reserves, for secure operation with minimum overall cost. It considers the reserves supplied by the conventional thermal generators (spinning reserves), hydro power units and load demands (demand-side reserves). The optimal backing down of costly/fast reserves and bringing up of slow reserves in each sub-interval in an integrated manner is proposed. The proposed reserve activation approaches are solved using the genetic algorithm, and some of the simulation results are also compared using the Matlab optimization toolbox and the general algebraic modeling system (GAMS) software. The simulation studies are performed on the IEEE 30, 57 and 300 bus test systems. These results demonstrate the advantage of the proposed integrated/dynamic reserve activation plan over the conventional/sequential approach. 相似文献
76.
As the American population ages, older adults are accounting for a larger percentage of the drug-abusing population, but little attention has been given to this age group especially in regards to evaluating responsivity to different treatment modalities. Contingency management (CM) is a highly effective behavioral treatment that provides positive tangible reinforcers for objective evidence of behavior change. The purpose of this study was to examine main and interactive effects of age on outcomes in cocaine-dependent patients receiving CM with standard care (SC) or SC alone. Patients (N = 393) participating in 1 of 3 randomized trials of CM for cocaine dependence were divided into young, middle, and older age cohorts. Baseline characteristics and outcomes were compared across the age groups. The oldest age group had more medical problems than the youngest and middle age groups but had fewer legal difficulties and psychiatric symptoms. The oldest age group remained in treatment significantly longer than the other age groups, regardless of the type of treatment received. Although all age groups benefited from CM in terms of retention and longest duration of abstinence achieved, a significant age by treatment interaction effect emerged, with the older cohort improving relatively less from CM than the younger age groups. These findings demonstrate that age may play a role in moderating intervention outcomes, and tailoring CM to the needs of older and middle-aged substance abusers may be important for improving outcomes in this growing population. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
77.
Higham James P.; Barr Christina S.; Hoffman Christy L.; Mandalaywala Tara M.; Parker Karen J.; Maestripieri Dario 《Canadian Metallurgical Quarterly》2011,125(2):131
Understanding the genetic and neuroendocrine basis of the mother-infant bond is critical to understanding mammalian affiliation and attachment. Functionally similar nonsynonymous mu-opioid receptor (OPRM1) SNPs have arisen and been maintained in humans (A118G) and rhesus macaques Macaca mulatta (C77G). In rhesus macaques, variation in OPRM1 predicts individual differences in infant affiliation for mothers. Specifically, infants carrying the G allele show increased distress on separation from their mothers, and spend more time with them upon reunion, than individuals homozygous for the C allele. In humans, individuals possessing the G allele report higher perceptions of emotional pain on receiving rejection by social partners. We studied maternal behavior over the course of a year among free-ranging female rhesus macaques on Cayo Santiago, Puerto Rico. We then trapped females and collected blood samples from which we assessed OPRM1 genotype; we also collected cerebrospinal fluid samples from which we measured oxytocin (OT) levels. We show that females possessing the G allele restrain their infants more (i.e., prevent infants from separating from them by pulling them back) than females homozygous for the C allele. Females possessing the G allele also show higher OT levels when lactating, and lower OT levels when neither lactating nor pregnant, than females homozygous for the C allele. This is the first study to demonstrate an association between OPRM1 genotype and maternal attachment for infants, and is one of the first studies of any free-ranging primate population to link functional genetic variation to behavior via potentially related neuroendocrine mechanisms. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
78.
Deligianni Fani; Senju Atsushi; Gergely Gy?rgy; Csibra Gergely 《Canadian Metallurgical Quarterly》2011,47(6):1499
The current study tested whether the purely amodal cue of contingency elicits orientation following behavior in 8-month-old infants. We presented 8-month-old infants with automated objects without human features that did or did not react contingently to the infants' fixations recorded by an eye tracker. We found that an object's occasional orientation toward peripheral targets was reciprocated by a congruent visual orientation following response by infants only when it had displayed gaze-contingent interactivity. Our finding demonstrates that infants' gaze-following behavior does not depend on the presence of a human being. The results are consistent with the idea that, in 8-month-old infants, the detection of contingent reactivity, like other communicative signals, can itself elicit the illusion of being addressed. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
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为评估失稳故障支路的严重程度及解决故障后系统失去潮流可行解的问题,提出了失稳故障支路拟裕度评估及控制的虚拟支路法。该方法将待切除的故障支路用一条含参数的虚拟支路置换,使虚拟支路开断问题转换为故障支路两端点注入功率增长的裕度问题,并用拟裕度大小评估故障支路的严重程度。算法利用最小控制代价的过程控制法,使虚拟支路完全切除后系统获得可行潮流解;故障后优化控制是在可行解上优化系统,以满足稳定裕度要求。通过IEEE算例验证了方法的可行性和有效性。 相似文献