Parallelizing Dijkstra\u27s Algorithm

Dijkstra’s algorithm is an algorithm for finding the shortest path between nodes in a graph. The algorithm published in 1959 by Dutch computer scientist Edsger W. Dijkstra, can be applied on a weighted graph. Dijkstra’s original algorithm runtime is a quadratic function of the number of vertices. In this paper, I will investigate the parallel formulation of Dijkstra’s algorithm and its speedup against the sequential one. The implementation of the parallel formulation will be performed by Message Passing Interface (MPI) and Open Multi-Processing (OpenMP). The results gained indicated that the performance of MPI and OpenMP to be significantly better than sequential for a higher number of input data scale. And the smaller number of processors/threads give the fastest result for MPI and OpenMP implementation. However, the results show that the average speedup achieved by parallelization is not satisfied. The parallel implementation of Dijkstra’s algorithm may not be the best option

Species of Chrysotus Meigen in Palaearctic China (Diptera: Dolichopodidae)

The species of the genus Chrysotus from Palaearctic China are reviewed and keyed. The following 5 species are described as new to science: Chrysotus bifurcatus sp. n., C. brevicercus sp. n., C. luoyangensis sp. n., C. sinuolatus sp. n., and C. xinjiangensis sp. n. Three species are recorded from China for the first time: C. gramineus (Fallén), C. suavis Loew, and C. pennatus Lichtwardt. Information on their distribution is also given or updated

Descriptions of four new species of Chrysotimus Loew from Tibet (Diptera: Dolichopodidae)

The occurrence of the genus Chrysotimus Loew, 1857 in Tibet is confirmed for the first time. The following four species are described as new to science: Chrysotimus bifurcatus sp. n., C. grandis sp. n., C. lii sp. n. and C. linzhiensis sp. n. A key is given to distinguish the Chinese species of the genus

Two new species of the genus Nepalomyia, with a key to species from China (Diptera: Dolichopodidae)

The species of the genus Nepalomyia Hollis, 1964 from China are reviewed and keyed. The following two species are described as new to science: Nepalomyia beijingensis sp. n. and N. ruiliensis sp. n. The distribution of the genus in China is discussed

Two new species of the genus Teuchophorus (Diptera: Dolichopodidae) from Taiwan

Two species are described as new to science from Taiwan: Teuchophorus elongatus sp. n. and T. taiwanensis sp. n. Currently three Teuchophorus species are known from Taiwan. A key is given to help identify the Chinese species

Residual Attention Network for Image Classification

In this work, we propose "Residual Attention Network", a convolutional neural network using attention mechanism which can incorporate with state-of-art feed forward network architecture in an end-to-end training fashion. Our Residual Attention Network is built by stacking Attention Modules which generate attention-aware features. The attention-aware features from different modules change adaptively as layers going deeper. Inside each Attention Module, bottom-up top-down feedforward structure is used to unfold the feedforward and feedback attention process into a single feedforward process. Importantly, we propose attention residual learning to train very deep Residual Attention Networks which can be easily scaled up to hundreds of layers. Extensive analyses are conducted on CIFAR-10 and CIFAR-100 datasets to verify the effectiveness of every module mentioned above. Our Residual Attention Network achieves state-of-the-art object recognition performance on three benchmark datasets including CIFAR-10 (3.90% error), CIFAR-100 (20.45% error) and ImageNet (4.8% single model and single crop, top-5 error). Note that, our method achieves 0.6% top-1 accuracy improvement with 46% trunk depth and 69% forward FLOPs comparing to ResNet-200. The experiment also demonstrates that our network is robust against noisy labels.Comment: accepted to CVPR201

Effects of Different Dietary Lipid Sources on Spawning Performance, Egg and Larval Quality, and Egg Fatty Acid Composition in Tongue Sole Cynoglossus semilaevis

A 60-day feeding experiment was conducted to investigate the effects of dietary lipid sources on reproduction of Cynoglossus semilaevis. Experimental diets were formulated with similar proximate compositions but different lipid sources (6.5%): fish oil (FO), soybean oil (SO) and olive oil (OO). The results showed that the relative fecundity in group FO and OO was significantly higher than that in group SO. Group OO showed a significantly higher buoyant egg rate than group FO and SO. The hatching rate and larval survival rate at 7 days post hatching were the highest in group FO, followed by group OO, and group SO recorded the lowest values. Group FO showed significantly higher egg diameter and larval survival activity index (SAI) and significantly lower larval deformity rate compared to group SO and OO. Fatty acid compositions of eggs reflected closely those of the diets. These results showed that the olive oil supplement in diets for tongue sole positively influenced the broodstock fecundity and buoyant egg rate though fish oil resulted in the highest hatching rate and best larval quality among the tested oils. The dietary soybean oil supplement reduced the spawning performance, and egg and larval quality

Dynamic flows and stocks of plastics in the United States and pathways towards zero plastic pollution by 2050

The United States (U.S.) is the second-largest national consumer of plastics in the world, which directly leads to a large amount of plastic waste. Due to low recycling and incineration rates in the U.S., 53% of plastic waste was discarded (landfilled or mismanaged) in 2018. Scientific studies have proved that pollution from discarded plastics has a significant negative impact on the environment. This study aims to explore feasible pathways for the U.S. to achieve zero plastic pollution by 2050. This study first developed a dynamic material flow analysis (MFA) model to assess flows and stocks of nine commonly used plastic polymers in seven commodity sectors with five end-of-life pathways in the U.S. for almost seven decades (1950 – 2018). The results show that national plastic pollution increased from 176 thousand metric tons in 1950 to 34,393 thousand metric tons in 2018. Plastic packaging contributed the most to plastic pollution because it has a shorter lifespan and a higher discard rate compared with plastics in other sectors. This study also developed six scenarios to explore pathways of plastic pollution reduction from 2019 to 2050 through seven strategies including 1) adapting a national plastic grocery bag ban, 2) reducing plastic consumption, 3) improving the lifespan of plastic products, 4) increasing waste recycling rate, 5) abandoning waste export, 6) avoiding mismanaged waste leakage, and 7) increasing waste incineration rate to utilize waste resources. Even though each strategy can reduce plastic pollution to different extents, the U.S. cannot achieve the zero plastic pollution target by 2050 through implementing one strategy solely. Thus, a combined scenario that implementing multiple strategies would help the U.S. to achieve zero plastic pollution.Master of ScienceSchool for Environment and SustainabilityUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/167299/1/Kan_Mengqing_Master's thesis.pd