Effects of Pruning Methods on the Growth and Development of New Shoots and Fruit Yield and Quality of Walnut

[Objectives]This study was conducted to screen out reasonable pruning methods of walnut,and provide practical guidance for high-yield cultivation of walnut.[Methods]Xinfeng and Xinguang were used to study the effects of mechanical and artificial pruning methods on shoot growth,chlorophyll content in leaves,net photosynthetic rate and fruit quality.[Results]The results showed that:①the pruning method had a significant impact on the number of new shoots,and the number of new shoots of mechanical pruning was significantly higher than that of manual pruning;②the pruning method had a significant impact on the chlorophyll content,and the chlorophyll content of Xinguang of mechanical pruning was significantly higher than that of manual pruning;③the pruning method had a significant impact on the net photosynthetic rate of leaves,and the net photosynthetic rate of manual pruning was significantly higher than that of manual pruning;④Pruning methods had a significant effect on the number of walnut fruit,and the fruit trees pruned manually were significantly higher than those pruned mechanically;⑤the pruning method had no significant impact on the single fruit weight;⑥Pruning methods had a significant effect on the shell yield of a single walnut plant.The shell yield of single walnut plant pruned manually was significantly higher than that pruned mechanically;⑦pruning mode had a significant impact on the yield of walnut per plant,and the yield of artificially pruned walnut per plant was significantly higher than that of mechanical pruning;and⑧Xinfeng s chlorophyll content,net photosynthetic rate,fruit number,shell yield per plant and kernel yield per plant were all better than that of Xinguang,in addition,the growth and development of new shoots,the fruit quantity and quality of fruit also were affected by the interaction effect of genotype and pruning mode×variety.[Conclusions]It can be seen that different pruning methods have significant effects on the growth and development of new shoots and fruit yield and quality of walnut.Artificial pruning is more suitable for walnut cultivation by adjusting photosynthesis and improving the yield and quality of walnut;and Xinfeng is more suitable for popularization and production.

MW-OBS:An Improved Pruning Method for Topology Design of Neural Networks

Topology design of artificial neural networks （ANNs） is an important problem for large scale applications. This paper describes a new efficient pruning method, the multi-weight optimal brain surgeon （MWOBS） method, to optimize neural network topologies. The advantages and disadvantages of the OBS and unit-OBS were analyzed to develop the method. Actually, optimized topologies are difficult to get within reasonable times for complex problems. Motivating by the mechanism of natural neurons, the MW-OBS method balances the accuracy and the time complexity to achieve better neural network performance. The method will delete multiple connections among neurons according to the second derivative of the error function, so the arithmetic converges rapidly while the accuracy of the neural network remains high. The stability and generalization ability of the method are illustrated in a Java program. The results show that the MWOBS method has the same accuracy as OBS, but time is similar to that of unit-OBS. Therefore, the MWOBS method can be used to efficiently optimize structures of neural networks for large scale applications.

Decoding on Adaptively Pruned Trellis for Correcting Synchronization Errors

Forward-backward algorithm, used by watermark decoder for correcting non-binary synchronization errors, requires to traverse a very large scale trellis in order to achieve the proper posterior probability, leading to high computational complexity. In order to reduce the number of the states involved in the computation, an adaptive pruning method for the trellis is proposed. In this scheme, we prune the states which have the low forward-backward quantities below a carefully-chosen threshold. Thus, a wandering trellis with much less states is achieved, which contains most of the states with quite high probability. Simulation results reveal that, with the proper scaling factor, significant complexity reduction in the forward-backward algorithm is achieved at the expense of slight performance degradation.

LEO constellation design methodology for observing multi-targets

This paper is based on the second problem of the 8th China Space Trajectory Design Competition(CTOC8).The background is LEO constellation design strategy for monitoring discrete multi-targets with small stellite under J model.The difculty is that the small satellite is equipped with low-cost cameras with limited coverage ability and the targets are distributed separately in a key area,which result in long revisit time or large pumber of satelites based on traditional design method.In this paper,a speciflc LEO consellation design method is proposed to cope with the problems.First,grid search and numerical method are performed to construct a database consisting of repeating ground track orbits.Then several orbits are carefully selected by pruning method to visit each target.Finally,repeating ground track costellation is constructed to meet the maximun revisit time constraint.The present method provides a systematic constellation design methodology of remote sensing observation with limited coverage ability,and demonstrates the resulting constellation can obtain rapid revisit frequency over discrete multi-targets with the least number of satellites.

Comprehensive and efficient discovery of time series motifs

Time series motifs are previously unknown,frequently occurring patterns in time series or approximately repeated subsequences that are very similar to each other.There are two issues in time series motifs discovery,the deficiency of the definition of K-motifs given by Lin et al.(2002) and the large computation time for extracting motifs.In this paper,we propose a relatively comprehensive definition of K-motifs to obtain more valuable motifs.Tominimize the computation time as much as possible,we extend the triangular inequality pruning method to avoid unnecessary operations and calculations,and propose an optimized matrix structure to produce the candidate motifs almost immediately.Results of two experiments on three time series datasets show that our motifs discovery algorithm is feasible and efficient.