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1.
We examine two criteria for balance of a gain graph, one based on binary cycles and one on circles. The graphs for which each criterion is valid depend on the set of allowed gain groups. The binary cycle test is invalid, except for forests, if any possible gain group has an element of odd order. Assuming all groups are allowed, or all abelian groups, or merely the cyclic group of order 3, we characterize, both constructively and by forbidden minors, the graphs for which the circle test is valid. It turns out that these three classes of groups have the same set of forbidden minors. The exact reason for the importance of the ternary cyclic group is not clear. © 2005 Wiley Periodicals, Inc. J Graph Theory 相似文献
2.
Miklos Kassai 《实验传热》2018,31(2):106-120
The object of this research was to investigate the effectiveness of sorption energy exchanger and the impact of the operational and thermal environmental conditions on their efficiency under steady-state conditions. To achieve this object, a test facility was installed into the Indoor Air Quality and Thermal Comfort Laboratory of BUTE University. A molecular 3Å sieve sorption wheel with high latent effectiveness is integrated into the experimental setup. In this study, the correlation between the sensible, latent, total effectiveness under different ambient air temperature and humidity values and different rotational speeds of the wheel is investigated in detailed by experimental tests. 相似文献
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The working performance of agricultural machinery is largely determined by the walking performance of the wheel when driving in complex unstructured soil. However, the driving performance of existing wheels is not satisfactory for paddy field with muddy soil. The purpose of the current study is therefore to propose a novel rigid wheel for agricultural machinery which is applicable to paddy field with muddy soil. Firstly, a novel arc edge shaped wheel was designed based on the principles of mechanics on the ground. Then the driving performance of this arc edge shaped wheel was evaluated using FE modeling of interaction between rigid wheel and soil. Finally, the structure originally designed arc edge shaped wheel was improved according to FE modeling results, and this improved design was further evaluated by both FE simulation and prototype experiments. Both FE modeling and experimental results indicate that the improved arc edge shaped wheel proposed in this study has a good driving performance with regarding to wheel sinkage and soil reaction force. The proposed arc edge shaped wheel could be used as an effective component of rice harvester for paddy field with muddy soil. 相似文献
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In this paper, we study the multi-machine scheduling problem with earliness and tardiness penalties and sequence dependent
setup times. This problem can be decomposed into two subproblems—sequencing and timetabling. Sequencing focuses on assigning
each job to a fixed machine and determine the job sequence on each machine. We call such assignment a semi-schedule. Timetabling
focuses on finding an executable schedule from the semi-schedule via idle-time insertion. Sequencing is strongly NP-hard in
general. Although timetabling is polynomial-time solvable, it can become a computational bottleneck if the procedure is executed
many times within a larger framework. This paper makes two contributions. We first propose a quantum improvement to the computational
efficiency of the timetabling algorithm. We then apply it within a squeaky wheel optimization framework to solve the sequencing
and overall problem. Finally, we demonstrate the strength of our proposed algorithms by experiments. 相似文献
9.
多模跟踪技术在轮式侦察车图像处理器的应用 总被引:1,自引:0,他引:1
为解决目标旋转形变、遮挡、光照变化等目标跟踪的难题,对粒子滤波和尺度不变特征变换(SIFT)算法进行了改进,结合两种算法提出了决策主导模式的多模跟踪技术。该技术采用粒子滤波预测目标位置进行粗定位,SIFT特征匹配进行精定位的方法,在解决上述难题上有很好的鲁棒性。将该技术应用于轮式侦察车图像处理器,并进行了各种实验验证,结果证明了提出算法的有效性。 相似文献
10.
This paper deals with the mechanics involved in a spinning wheel of which the pivot is not fixed as usual but is forced to rotate along the circumference of a circle on the horizontal plane. The usual Euler equations are extended so that, in addition to the three well-known rotations (Euler angles), they also include a fourth one related to the rotation of the motor that induces the forced precession. This study aims at offering a first insight in one of the renowned Laithwaite's experiments. The derived theoretical expressions are accompanied by computer simulation. 相似文献