Automatic abstraction controller in reinforcement learning agent via automata

Reinforcement learning (RL) for solving large and complex problems faces the curse of dimensions problem. To overcome this problem, frameworks based on the temporal abstraction have been presented; each having their advantages and disadvantages. This paper proposes a new method like the strategies introduced in the hierarchical abstract machines (HAMs) to create a high-level controller layer of reinforcement learning which uses options. The proposed framework considers a non-deterministic automata as a controller to make a more effective use of temporally extended actions and state space clustering. This method can be viewed as a bridge between option and HAM frameworks, which tries to suggest a new framework to decrease the disadvantage of both by creating connection structures between them and at the same time takes advantages of them. Experimental results on different test environments show significant efficiency of the proposed method.     

气动潜孔锤跟管钻进技术在岩土工程勘察施工中的应用

以渤船重工新型总装生产线工程岩土工程勘察项目为依托，应用KG940 A型高风压履带式潜孔钻车﹑采用气动潜孔锤跟管钻进工艺，结合空气正循环排渣方式，摸索总结出一套针对复杂破碎覆盖层的干式成孔新方法，钻进效率及钻孔质量显著提高，为岩土工程勘察勘探孔施工增添了一种新的思路。     

A MapReduce-based scalable discovery and indexing of structured big data

Various methods and techniques have been proposed in past for improving performance of queries on structured and unstructured data. The paper proposes a parallel B-Tree index in the MapReduce framework for improving efficiency of random reads over the existing approaches. The benefit of using the MapReduce framework is that it encapsulates the complexity of implementing parallelism and fault tolerance from users and presents these in a user friendly way. The proposed index reduces the number of data accesses for range queries and thus improves efficiency. The B-Tree index on MapReduce is implemented in a chained-MapReduce process that reduces intermediate data access time between successive map and reduce functions, and improves efficiency. Finally, five performance metrics have been used to validate the performance of proposed index for range search query in MapReduce, such as, varying cluster size and, size of range search query coverage on execution time, the number of map tasks and size of Input/Output (I/O) data. The effect of varying Hadoop Distributed File System (HDFS) block size and, analysis of the size of heap memory and intermediate data generated during map and reduce functions also shows the superiority of the proposed index. It is observed through experimental results that the parallel B-Tree index along with a chained-MapReduce environment performs better than default non-indexed dataset of the Hadoop and B-Tree like Global Index (Zhao et al., 2012) in MapReduce.     

Evaluation of the genetic algorithm performance for the optimization of the grand potential in the cluster variation method

Due to the importance of phase diagrams in a wide range of material based industries, additional efforts should be dedicated to their elaboration techniques. The cluster variation method is a promising technique to model the entropy within different plane lattices and is recognized by the materials physics community as a powerful modeling framework. Motivated by the efficiency of genetic algorithms in solving numerous types of optimization problems, our aim in this work is to investigate their performance in minimizing the grand potential in the context of the cluster variation method. A comparison is conducted with respect to numerical iterative techniques namely the Newton-Raphson and natural iteration methods, where many performance criteria are computed and compared. The obtained results allow the ranking of the considered approaches according to their performance measures and suggest a more profound investigation of metaheuristics particularly for complicated cluster structures in the future.     

A theoretical study on different cluster configurations of the 9Be nucleus by using a simple cluster model

In this study,a comprehensive investigation on different cluster configurations of the ~9Be nucleus is performed with a simple cluster approach.With this goal,the elastic scattering angular distributions of ~9Be by ~(27)A1,~(28)Si,~(64)Zn,~(144)Sm,~(208)Pb,and ~(209)Bi target nuclei are reanalyzed for α + α + n,d + ~7Li,~3H + ~6Li,~3He + ~6He and n + ~8Be cluster configurations of the ~9Be projectile within the framework of the optical model.The theoretical results are compared with each other as well as the experimental data.The results provide an opportunity for a test of different cluster configurations in explaining the elastic scattering of~9Be nucleus.     

DFT simulations and microkinetic modelling of 1-pentyne hydrogenation on Cu20 model catalysts

Adsorption and dissociation of H₂ and hydrogenation of 1-pentyne on neutral and anionic Cu₂₀ clusters have been investigated using the density functional theory and microkinetic modelling. Molecular adsorption of H₂ is found to occur strictly at atop sites. The H₂ dimer is activated upon adsorption, and the dissociation occurs with moderate energy barriers. The dissociated H atoms reside preferentially on 3-fold face and 2-fold edge sites. Based on these results, the reaction paths leading to the partial and total hydrogenation of 1-pentyne have been studied step-by-step. The results suggest that copper clusters can display selective activity on the hydrogenation of alkyne and alkene molecules. The hydrogenated products are more stable than the corresponding initial reactants following an energetic staircase with the number of added H atoms. Stable semi-hydrogenated intermediates are formed before the partial (1-pentene) and total (pentane) hydrogenation stages of 1-pentyne. The microkinetic model analysis shows that C₅H₁₀ is the dominant product. Increasing the reactants (C₅H₈/H₂) ratio enhances the formation of products (C₅H₁₀ and C₅H₁₂).     

气动潜孔锤跟管钻进技术在岩土工程勘察施工中的应用

以渤船重工新型总装生产线工程岩土工程勘察项目为依托,应用KG940A型高风压履带式潜孔钻车﹑采用气动潜孔锤跟管钻进工艺,结合空气正循环排渣方式,摸索总结出一套针对复杂破碎覆盖层的干式成孔新方法,钻进效率及钻孔质量显著提高,为岩土工程勘察勘探孔施工增添了一种新的思路。     

Application of multivariate statistical analyses in the differentiation between two phosphate ores from the Nuba Mountains,Sudan

In previously published research, uranium abundance and major and trace element content were determined in phosphate ore samples from the Kurun and Uro areas of the Nuba Mountains in Sudan. The current work aims to characterise and differentiate between the phosphate ores from these two areas by subjecting the obtained geochemical data to quantitative and qualitative statistical analyses. Multivariate statistical analyses and correlation studies show several geochemical differences in the occurrence of uranium in Kurun and Uro phosphate ores. Uranium in Uro phosphate ore shows a higher degree of mobility coefficient of variability (CV%?=?91) than that in Kurun phosphate ore (CV%?=?48). Kurun and Uro phosphate ores are found to be good sources of titanium and strontium. The average concentrations of Ti and Sr in Uro phosphate ore are 4880 and 2780?mg?kg^–1, respectively. The corresponding values in Kurun phosphate ore are 7300 and 2630?mg?kg^–1, respectively. A cluster analysis of trace elements demonstrates that both Ti and Sr, which are the most abundant trace elements, appear in individual groups or in sub-groups. Uranium behaves in the same manner in both phosphate ores in that it associates in groups containing all the transition metals except for the most abundant trace element, titanium.     

Granulometry,cluster analysis and spatial distribution of manganese contaminated soils,Kgwakgwe, southeastern Botswana

The particle size distribution (PSD) of 400 Mn contaminated soil samples was established, and generated data were statistically analysed and spatially presented. The PSD for the 53 µm – 4 µm size fraction soil samples ranged from 11.05 to 100 wt %, whereas that for < 4 µm was from 0.3 to 30 wt %. Texturally, samples were dominantly silt loam, although silt and sandy loam were also present, as well as loam, loamy sand and clay classes. Six clusters were identified with cluster one being the most dominant occurring in sandy loam, silt loam and loamy sand. The < 53 µm fraction had three dominant areas, and the < 4 µm fraction had several unevenly presented populations as reflected in the maps. Because of its spatial distribution, the < 4 µm fraction may pose hazards to human health. Furthermore, predominance of Mn limits land use to subsistence agriculture with possibly low crop yield.     

Urbanization Effect on Floristic and Landscape Patterns of Green Spaces

The study explored the effects of intensive urbanization on urban plant diversity and landscape pattern. An inventory of plant species in managed green spaces in the nine urban districts of Guangzhou (south China) with varied development history was conducted. The relationships among species richness, diversity and urban development were analysed by community ecology attributes, cluster analysis, growth-form differentiation and district fidelity indices, and statistical tests. The 1055 vascular species were dominated by a small number of common evergreen species, accompanied by many rare species. By species richness, tree was the dominant growth form, followed by herb and shrub. Species richness and diversity were slightly below urban-fringe secondary forests. Old and young districts offered disparate conditions for species enrichment to establish urban landscape patterns with divergent floristic and growth-form assemblages. Urban species profile and vegetation landscapes were mainly influenced by planning and management of the urban landscape and changing landscape fashion.