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排序方式: 共有266条查询结果,搜索用时 15 毫秒
61.
Iranian Polymer Journal - This study presents the tribological behavior of epoxy matrix composites containing two different fillers. The composites contain fillers with different particle sizes... 相似文献
62.
Ruminant diseases are strictly connected to pH and temperature values of the rumen. Therefore, the attenuation to dynamic measurement and tracking of both pH and temperature values through animal rumen has grown rapidly for decades. Reading performance of RFID tags depends on signal quality and signal level, and this can be understood by means of wave attenuation through tissue. In this article, attenuation through cow body is investigated for improving reading performance and battery life. Number of receiving antennas will be used in the system, their location and heights are critical for this aim. Signals from different points of animals' body are measured and compared with the signals spread just out of RFID tags. Equivalent dielectric constants of tissue between RFID tag and receiving antenna is modeled by using literature data, and finally simulation and analytical results are verified by measurement results. Measured value of attenuation through the cow body is varying between 25 dB and 87 dB for RFID tags operating at 434 MHz. Within the 30 m radius, the strongest signal is obtained at 50 cm height and taken from the left side of the animal body, which is offered as optimum communication position. 相似文献
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Yaman Ay?e; Mesman Judi; van IJzendoorn Marinus H.; Bakermans-Kranenburg Marian J. 《Canadian Metallurgical Quarterly》2010,24(2):208
We investigated the influence of parenting practices in the prediction of child physical aggression in 94 second-generation Turkish immigrant families with 2-year-old toddlers, and the moderating role of child temperament. In a longitudinal study we tested both a dual-risk model and a differential susceptibility model. Observational data were obtained for mothers’ positive parenting and authoritarian discipline, and maternal reports for child temperament and physical aggression. All measures were repeated 1 year later. Child temperament at age 2 years was a significant predictor of child aggression 1 year later. We found no main effects of positive parenting or of authoritarian discipline for the prediction of child aggression. However, we found support for the dual-risk hypothesis: Toddlers with difficult temperaments were more adversely affected by a lack of positive parenting than other children, but they did not benefit more from high levels of positive parenting than toddlers with more easy temperaments. We found no interaction effects with child temperament for authoritarian discipline. These findings provide support for the generalizability of the dual-risk model of parenting and temperament to non-Western immigrant families with young children. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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Serdar Yaman Ayşegül Ersoy-Mericboyu Sadriye Küçükbayrak 《Petroleum Science and Technology》2013,31(1):49-58
Abstract A number of methods have been developed which are used to remove the sulphur present in coal before combustion. The physical removal of pyritic sulphur by coal cleaning has been commercial practice for a number of years, but these methods do not remove organically bound sulphur, they can be applied effectively only to a limited number of coals. However, the removal of both pyritic and organically bound sulphur from coal can be effectively achieved by applying the chemical desulphurization methods. This paper gives a general review on the chemical desulphurization studies, including carbonization in different atmospheres, air oxidation, wet oxidation, Meyers Process, chlorination and extraction with the solutions of NaOH, CuCl2 and C2H5OH, which were carried out using different Turkish lignites. 相似文献
67.
Prediction of earthquake damage to urban water distribution systems: a case study for Denizli,Turkey
Selcuk Toprak Filiz Taskin A. Cem Koc 《Bulletin of Engineering Geology and the Environment》2009,68(4):499-510
Prediction of damage to water supply lines during an earthquake is a critical part of seismic planning. This study evaluates
the performance of the water supply system in Denizli, Turkey, in the event of an M6, M6.3, M6.5 and M7 earthquake associated with the Pamukkale and Karakova-Akhan Faults. The relative effects of transient ground deformations
and permanent ground deformations based on maps of liquefiable soil and zones of predicted lateral ground displacements are
compared. The relative effects of the different magnitude earthquakes and pipeline damage relationships on the pipeline performance
following a seismic event are assessed. 相似文献
68.
In this paper, we propose and compare single- and multi-objective programming (MOP) approaches to the language model (LM)
adaptation that require the optimization of a number of competing objectives. In LM adaptation, an adapted LM is found so
that it is as close as possible to two independently trained LMs. The LM adaptation approach developed in this paper is based
on reformulating the training objective of a maximum a posteriori (MAP) method as an MOP problem. We extract the individual
at least partially conflicting objective functions, which yields a problem with four objectives for a bigram LM: The first two objectives are concerned
with the best fit to the adaptation data while the remaining two objectives are concerned with the best prior information
obtained from a general domain corpus. Solving this problem in an iterative manner such that each objective is optimized one
after another with constraints on the rest, we obtain a target LM that is a log-linear interpolation of the component LMs.
The LM weights are found such that all the (at least partially conflicting) objectives are optimized simultaneously. We compare
the performance of the SOP- and MOP-based solutions. Our experimental results demonstrate that the ICO method achieves a better
balance among the design objectives. Furthermore, the ICO method gives an improved system performance. 相似文献
69.
Yaman S. Chin-Hui Lee 《IEEE transactions on audio, speech, and language processing》2008,16(4):779-789
We propose a multiobjective programming (MOP) framework for finding compromise solutions that are satisfactory for each of multiple competing performance criteria in a pattern classification task. The fundamental idea for our formulation of classifier learning, which we refer to as iterative constrained optimization (ICO), evolves around improving one objective while allowing the rest to degrade. This is achieved by the optimization of individual objectives with proper constraints on the remaining competing objectives. The constraint bounds are adjusted based on the objective functions obtained in the most recent iteration. An aggregated utility function is used to evaluate the acceptability of local changes in competing criteria, i.e., changes from one iteration to the next. Although many MOP approaches developed so far are formal and extensible to large number of competing objectives, their capabilities are examined only with two or three objectives. This is mainly because practical problems become significantly harder to manage when the number of objectives gets larger. We, however, illustrate the proposed framework in the context of automatic language identification (LID) of 12 languages and three dialects. This LID task requires the simultaneous minimization of the false-acceptance and false-rejection rates for each of the 15 languages/dialects, and, hence, is an MOP problem with a total of 30 competing objectives. In our experiments, we observed that the ICO-trained classifiers result in not only reduced error rates but also a good balance among the many competing objectives when compared to those classifiers that minimize an overall objective. We interpret our experimental findings as evidence for ICO offering a greater degree of freedom for classifier design. 相似文献
70.