oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2020 ( 1 )

2019 ( 245 )

2018 ( 1790 )

2017 ( 1701 )

Custom range...

Search Results: 1 - 10 of 104250 matches for " Xiaoting Zhang "
All listed articles are free for downloading (OA Articles)
Page 1 /104250
Display every page Item
Prediction of Rural Residents’ Consumption Expenditure Based on Lasso and Adaptive Lasso Methods  [PDF]
Xiaoting Tao, Haomin Zhang
Open Journal of Statistics (OJS) , 2016, DOI: 10.4236/ojs.2016.66094
Abstract: When the variable of model is large, the Lasso method and the Adaptive Lasso method can effectively select variables. This paper prediction the rural residents’ consumption expenditure in China, based on respectively using the Lasso method and the Adaptive Lasso method. The results showed that both can effectively and accurately choose the appropriate variable, but the Adaptive Lasso method is better than the Lasso method in prediction accuracy and prediction error. It shows that in variable selection and parameter estimation, Adaptive Lasso method is better than the Lasso method.
Duflo involutions for 2-categories associated to tree quivers
Xiaoting Zhang
Mathematics , 2015,
Abstract: Motivated by the definition of Duflo involution for fiat $2$-categories, we define certain analogues of Duflo involution for arbitrary finitary $2$-categories and show that such Duflo involutions exist for two classes of finitary $2$-categories associated with tree path algebras. Additionally, we describe the quiver for the algebra underlying the principal $2$-representation for these two classes of finitary $2$-categories.
Simple transitive $2$-representations and Drinfeld center for some finitary $2$-categories
Xiaoting Zhang
Mathematics , 2015,
Abstract: We classify all simple transitive $2$-representations for two classes of finitary $2$-categories associated with tree path algebras and also for one class of fiat $2$-categories associated with truncated polynomial rings. Additionally, we compute the Drinfeld centers for all these $2$-categories.
Characteristics Analysis on Short-Time Heavy Rainfall during the Flood Season in Shanxi Province, China  [PDF]
Xiaoting Tian, Dongliang Li, Jinhong Zhou, Yaqing Zhou, Zexiu Zhang
Journal of Geoscience and Environment Protection (GEP) , 2019, DOI: 10.4236/gep.2019.73011
Abstract: In order to provide a reference for the correct forecasting of short-term heavy rainfall and better disaster prevention and mitigation services in Shanxi Province, China, it is very important to carry out systematic research on short-term heavy precipitation events in Shanxi Province. Based on hourly precipitation data during the flood season (May to September) from 109 meteorological stations in Shanxi, China in 1980-2015, the temporal and spatial variation characteristics of short-time heavy rainfall during the flood season are analyzed by using wavelet analysis and Mann-Kendall test. The results show that the short-time heavy rainfall in the flood season in Shanxi Province is mainly at the grade of 20 - 30 mm/h, with an average of 97 stations having short-time heavy rainfall each year, accounting for 89% of the total stations. The short-time heavy rainfall mainly concentrated in July and August, and the maximal rain intensity in history appeared at 23 - 24 on June 17, 1991 in Yongji, Shanxi is 91.7 mm/h. During the flood season, the short-time heavy rainfalls always occur at 16 - 18 pm, and have slightly different concentrated time in different months. The main peaks of June, July and August are at 16, 17 and 18 respectively, postponed for one hour. Short-time heavy rainfall overall has the distribution that the south is more than the north and the east less than the west in Shanxi area. In the last 36 years, short-time heavy rainfall has a slight increasing trend in Shanxi, but not significant. There is a clear 4-year period of oscillation and inter-decadal variation. It has a good correlation between the total precipitation and times of short-time heavy rainfall during the flood season.
Research on Customer Geographic Proximity and Inventory Management—Empirical Evidence from Chinese Manufacturing Listed Companies  [PDF]
Xiaoting Hu
American Journal of Industrial and Business Management (AJIBM) , 2019, DOI: 10.4236/ajibm.2019.91001
Abstract: Using the hand collected data of the top five clients of manufacturing enterprises in China, this paper examines the effect of customer geographic proximity on the inventory management level of manufacturing enterprises. The results show that there is a positive relation between the geographic proximity and inventory management level: the greater the geography proximity of customers, the lower the proportion of inventory, the higher the inventory turnover rate. This paper not only contributes to the literature on the factors affecting the level of inventory management and the supply chain management, but also provides reference on how the manufacturing enterprises can maintain the relationship with customers better, and improve inventory management efficiency.
Transfer Matrix Method for Natural Vibration Analysis of Tree System
Bin He,Xiaoting Rui,Huiling Zhang
Mathematical Problems in Engineering , 2012, DOI: 10.1155/2012/393204
Abstract: The application of Transfer matrix method (TMM) ranges from linear/nonlinear vibration, composite structure, and multibody system to calculating static deformation, natural vibration, dynamical response, and damage identification. Generally TMM has two characteristics: (1) the TMM formulae share similarity to the chain mechanics model in terms of topology structure; then TMM often is selected as a powerful tool to analyze the chain system. (2) TMM is adopted to deal with the problems of the discrete system, continuous system, and especial discrete/continuous coupling system with the uniform matrix form. In this investigation, a novel TMM is proposed to analyze the natural vibration of the tree system. In order to make the TMM of the tree system have the two above advantages of the TMM of the chain system, the suitable state vectors and transfer matrices of the typical components of the tree system are constructed. Then the topology comparability between the mechanics model and its corresponding formulae of TMM can be adopted to assembling the transfer matrices and transfer equations of the global tree system. Two examples of natural vibration problems validating the method are given. The formulation of the proposed TMM is mathematically intuitive and can be held and applied by the engineers easily.
Statistical and Probability Quantification of Hydrologic Dynamics in the Lake Tuscaloosa Watershed, Alabama, USA  [PDF]
Shawn Dawley, Yong Zhang, Xiaoting Liu, Peng Jiang, Lin Yuan, Hongguang Sun
Journal of Geoscience and Environment Protection (GEP) , 2018, DOI: 10.4236/gep.2018.65008
Abstract:
Interconnected components of water cycle, including surface water, groundwater, and precipitation, can exhibit complex hydrologic dynamics. This study investigates dynamics embedded in surface water, groundwater, and precipitation time series data in the Lake Tuscaloosa watershed located in northern Alabama, using standard statistics and non-stationarity analysis. Standard statistics analysis shows that less water is available in this watershed over time. A significant correlation between different data sets is found, and groundwater is found to be slower evolving than its nearby surface systems. Non-stationarity analysis based on time scale-local Hurst exponents calculated by the multifractal detrended fluctuation approach shows that, on one hand, the stream system exhibits non-stationarity properties similar to precipitation, as expected. On the other hand, groundwater and lake stage non-stationarity is found to be influenced by the seasonal variation in rainfall and the long-term anthropogenic factors. Therefore, sustainability of surface water and aquifer may be affected by natural input and/or anthropogenic activity, both of which can evolve non-stationary in different time scales.
Selective Synthesis and Luminescence Properties of Nanocrystalline GdF3:Eu3+ with Hexagonal and Orthorhombic Structures
Xiaoting Zhang,Tomokatsu Hayakawa,Masayuki Nogami,Yukari Ishikawa
Journal of Nanomaterials , 2010, DOI: 10.1155/2010/651326
Abstract: GdF3:Eu3+ nanophosphors with hexagonal or orthorhombic structure have been succeeded to be selectively synthesized at room temperature for the first time via a simple soft chemical route. The structure and morphology of GdF3:Eu3+ nanophosphors were controlled by using different fluoride precursors. Hexagonal GdF3:Eu3+ nanocrystals were formed when NaBF4 was used as a fluoride precursor, while orthorhombic GdF3:Eu3+ nanocrystals were obtained with NaF or NH4F fluoride precursor. It was also experimentally revealed that hexagonal GdF3:Eu3+ nanophosphors emitted essentially stronger Eu3+ luminescence than orthorhombic ones did. The formation mechanism of GdF3 nanocrystals and the possible reasons of the strong PL in hexagonal were discussed. 1. Introduction In recent years, precise architectural manipulation of lanthanide trifluorides (LnF3) nanocrystals gathers great attention because nanostructure-based properties were closely interrelated with geometrical factors such as crystal structure, shape, dimensionality, and size [1–6]. Various techniques recently used to control shape and size of lanthanide trifluorides nanoparticles were also summarized by Rahman and Green [3]. Above all, polytype control of LnF3 becomes one of the most interesting issues to improve light emitting properties as intra transitions of lanthanide ion are affected by the coordination of atoms around the lanthanide atom. Mansmann [7] pointed out that the polytypes of LnF3 (hexagonal or orthorhombic) depend on ionic radius and coordination number of the lanthanide metal. An increase in a repulsive energy between fluoride ions with a decrease in an ionic radius of lanthanide ( ) results in polytype change from hexagonal to orthorhombic. A critical ratio of was proposed to be 0.94. Taking into account the ionic radius calculated by Ahrens [8], the critical point is positioned between Sm and Eu. However, it was reported that the critical point of LnF3 polytype in an aluminosilicate was experimentally between Gd and Tb [9], which is supported on the basis of the Shannon’s table for ionic radii [10]. Resultantly, it can be known that polytype control of GdF3 is fundamentally possible and GdF3 is a proper material for investigating the influence of polytype on the light emitting properties of lanthanide activator doped such as Eu3+, Tb3+, and Sm3+. Because of its potential in optical and biological application, GdF3 has attracted much increasing attention as a good host lattice [4–6, 9], and actually polytype GdF3 crystals had been prepared [11–13]. However, they were synthesized at high
Facile Synthesis and Herbicidal Evaluation of 4H-3,1-Benzoxazin-4-ones and 3H-Quinazolin-4-ones with 2-Phenoxymethyl Substituents
Zumuretiguli Aibibuli,Yufeng Wang,Haiyang Tu,Xiaoting Huang,Aidong Zhang
Molecules , 2012, DOI: 10.3390/molecules17033181
Abstract: Series of 4H-3,1-benzoxazin-4-ones and 3H-quinazolin-4-ones with phenoxy-methyl substituents were rationally designed and easily synthesized via one-pot N-acylation/ring closure reactions of anthranilic acids with 2-phenoxyacetyl chlorides to yield the 4H-3,1-benzoxazin-4-ones, and subsequently substituted with amino derivatives to obtain the 3H-quinazolin-4-ones. The herbicidal evaluation was performed on the model plants barnyard grass (a monocotyledon) and rape (a dicotyledon), and most of the title compounds displayed high levels of phytotoxicity. The active substructure and inhibitory phenotype analysis indicated that these compounds could be attributed to the class of plant hormone inhibitors. A docking study of several representative compounds with the hormone receptor TIR1 revealed an appreciable conformational match in the active site, implicating these compounds are potential lead hits targeting this receptor.
Rough Set Approach to Multivariate Decision Trees Inducing
Dianhong Wang,Xingwen Liu,Liangxiao Jiang,Xiaoting Zhang
Journal of Computers , 2012, DOI: 10.4304/jcp.7.4.870-879
Abstract: Aimed at the problem of huge computation, large tree size and over-fitting of the testing data for multivariate decision tree (MDT) algorithms, we proposed a novel rough set-based multivariate decision trees (RSMDT) method. In this paper, the positive region degree of condition attributes with respect to decision attributes in rough set theory is used for selecting attributes in multivariate tests. And a new concept of extended generalization of one equivalence relation corresponding to another one is introduced and used for construction of multivariate tests. We experimentally test RSMDT algorithm in terms of classification accuracy, tree size and computing time, using the whole 36 UCI Machine Learning Repository data sets selected by Weka platform, and compare it with C4.5, classification and regression trees (CART), classification and regression trees with linear combinations (CART-LC), Oblique Classifier 1 (OC1), Quick Unbiased Efficient Statistical Trees (QUEST). The experimental results indicate that RSMDT algorithm significantly outperforms the comparison classification algorithms with improved classification accuracy, relatively small tree size, and shorter computing time.
Page 1 /104250
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.