903 research outputs found

    3D GIS Modeling of Soft Geo-Objects: Taking Rainfall, Overland Flow, and Soil Erosion as an Example

    Get PDF
    In physics, objects can be divided into rigid and soft objects according to the object deformation capacity. Similarly, geo-object can also be classified into rigid geo-objects (e.g., building, urban) and soft geo-objects (e.g., mudflow, water, soil erosion). There are three types of approaches for 3D GIS modeling, i.e., surface-based, volume-based, and hybrids in terms of geometry. These approaches are suitable for representing rigid geo-objects, but they are not suitable to simulate the intrinsic properties of the soft geo-object, i.e., dynamics and deformation. And so far there are few GIS modeling methods for simulation of soft geo-objects. GIS flow elements (FEs) and GIS soft voxels (SVs) were proposed for 3D modeling of soft geo-objects. GIS flow elements can realistically represent the dynamics and stochastics of soft geo-objects, while GIS soft voxels simulate deformation of soft geo-objects. The authors discuss the implementation and computer programming of GIS flow elements and GIS soft voxels in this study. GIS FE and SV have been successfully applied in a case study toward the simulation of the process of rainfall, overland flow, and soil erosion. A software system has been designed and developed, which has the functions of data management, model computation, and 3D simulation

    How Does Suppliers’ Fairness Affect the Relationship Quality of Agricultural Product Supply Chains?

    Get PDF
    Although many studies have suggested that the relationship between different supply chain members significantly affects agricultural product quality, suppliers’ perceptions of fairness, which greatly influence their decisions on building the relationship quality, are often overlooked. Particularly, the empirical evidence to investigate the impacts of suppliers’ fairness on the relationship quality and the factors that affect the suppliers’ fairness is missing, and therefore this knowledge gap needs to be filled by new research. Herein, we conducted a survey of 450 agricultural product suppliers and systemically analyzed the impact of antecedents on fairness perception and the impact of fairness perception on relationship quality. In addition, we developed a structural equation model and found that information sharing and price satisfaction had significantly positive effects on procedural fairness and distributive fairness, respectively. Furthermore, our studies demonstrated that procedural fairness is more important in improving the relationship quality than distributive fairness. However, supplier dependence is another important impact factor, and it greatly decreases the positive effects of suppliers’ fairness on relationship quality. In summary, the study results provide several managerial implications and extend our understanding of the importance of suppliers’ fairness in the relationship quality, which involves product development with respect to the supplier’s performance

    Relationship between polymorphisms in vitamin D metabolism-related genes and the risk of rickets in Han Chinese children

    Get PDF
    BACKGROUND: Vitamin D deficiency rickets is common in China. Genetic factors may play an important role in the susceptibility to rickets. Our study aimed to identify the relationship between three vitamin D-related genes (group specific component [GC], cytochrome P450, family 2, subfamily R, polypeptide 1 (CYP2R1), and 7-dehydrocholesterol reductase/nicotinamide-adenine dinucleotide synthetase 1 (DHCR7/NADSYN1) and rickets in Han Chinese children from northeastern China. METHODS: A total of 506 Han children from northeastern China were enrolled in the current study. Twelve SNPs in three candidate genes were genotyped using the SNaPshot assay. Linear regression was used to examine the effect of 12 single-nucleotide polymorphisms (SNPs) on the risk of rickets. RESULTS: In our case–control cohort, six alleles of the 12 SNPs conferred a significantly increased risk of rickets in GC (rs4588 C, P = 0.003, OR: 0.583, 95% CI: 0.412-0.836; rs222020 C, P = 0.009, OR: 1.526, 95% CI: 1.117-2.0985; rs2282679 A, P = 0.010, OR: 0.636, 95% CI: 0.449-0.900; and rs2298849 C, P = 0.001, OR: 1.709, 95% CI: 1.250-2.338) and in CYP2R1 (rs10741657 G, P = 0.019, OR: 1.467, 95% CI: 1.070-2.011; and rs2060793 G, P = 0.023, OR: 0.689, 95% CI: 0.502-0.944). The results remained significant after adjustment for sex and body mass index. We further analyzed the effect of genotypes under three different genetic models. After using Bonferroni’s method for multiple corrections, rs4588, rs2282679, and rs2298849 of the GC gene were significantly associated with rickets under the dominant (P =0.003 for rs4588, P =0.024 for rs2282679, and P =0.005 for rs2298849) and additive models (P = 0.006 for rs4588, P = 0.024 for rs2282679, and P = 0.005 for rs2298849). Haplotype analysis showed that the CAT haplotype of the GC gene (P = 0.005) and the GAA haplotype of the CYP2R1 gene (P = 0.026) were associated with susceptibility to rickets. CONCLUSIONS: This case–control study confirmed the strong effect of GC and CYP2R1 loci on rickets in Han children from northeastern China

    Model and Frequency Control for Three-Phase Wireless Power Transfer System

    Get PDF
    In order to the eliminate the “dead spot” in the traditional three-phase wireless power transfer (WPT) system, a three-phase WPT system with an asymmetric magnetic circuit is presented in this paper. Additionally, mathematical model of the system is established and the system parameters are optimized. Based on the fact that the resonant frequency and efficiency are greatly varied with the load, a method based on impedance conversion is further proposed to improve the frequency stability and system efficiency. Finally, simulation and experimental results show that the proposed method is reliable and feasible to eliminate the “dead spot.
    • …
    corecore