A differential game model research on dynamic pricing and coordination of fresh agricultural products supply chain based on freshness

For the problem of optimal dynamic pricing and coordination of fresh agricultural products supply chain, the differential equations related to freshness and market needs are constructed, and the optimal control theory is used to solve the optimal strategy under centralized and decentralized decision-making, i.e., optimal selling price and optimal preservation input. The equilibrium results under the two scenarios are also compared. The comparison finds that the decentralized scenario leads to low overall supply chain profits, based on which a two-part pricing contract is proposed to coordinate the supply chain operating companies. The results show that freshness effectiveness directly impacts pricing, and the centralized scenario does not necessarily lead to high prices for fresh produce due to the ‘double marginal effect’. the two pricing contracts can successfully coordinate the supply chain. The freshness effectiveness increases the supply chain coordination ability of fresh produce suppliers, while operational inefficiencies, on the contrary, decrease the coordination abilit

A New Single-blade Based Hybrid CFD Method for Hovering and Forward-flight Rotor Computation

AbstractA hybrid Euler/full potential/Lagrangian wake method, based on single-blade simulation, for predicting unsteady aerodynamic flow around helicopter rotors in hover and forward flight has been developed. In this method, an Euler solver is used to model the near wake evolution and transonic flow phenomena in the vicinity of the blade, and a full potential equation (FPE) is used to model the isentropic potential flow region far away from the rotor, while the wake effects of other blades and the far wake are incorporated into the flow solution as an induced inflow distribution using a Lagrangian based wake analysis. To further reduce the execution time, the computational fluid dynamics (CFD) solution and rotor wake analysis (including induced velocity update) are conducted parallelly, and a load balancing strategy is employed to account for the information exchange between two solvers. By the developed method, several hover and forward-flight cases on Caradonna-Tung and Helishape 7A rotors are performed. Good agreements of the loadings on blade surface with available measured data demonstrate the validation of the method. Also, the CPU time required for different computation runs is compared in the paper, and the results show that the present hybrid method is superior to conventional CFD method in time cost, and will be more efficient with the number of blades increasing

Two NHX-type transporters from Helianthus tuberosus improve the tolerance of rice to salinity and nutrient deficiency stress.

The NHX-type cation/H+ transporters in plants have been shown to mediate Na+ (K+ )/H+ exchange for salinity tolerance and K+ homoeostasis. In this study, we identified and characterized two NHX homologues, HtNHX1 and HtNHX2 from an infertile and salinity tolerant species Helianthus tuberosus (cv. Nanyu No. 1). HtNHX1 and HtNHX2 share identical 5'- and 3'-UTR and coding regions, except for a 342-bp segment encoding 114 amino acids (L272 to Q385 ) which is absent in HtNHX2. Both hydroponics and soil culture experiments showed that the expression of HtNHX1 or HtNHX2 improved the rice tolerance to salinity. Expression of HtNHX2, but not HtNHX1, increased rice grain yield, harvest index, total nutrient uptake under K+ -limited salt-stress or general nutrient deficiency conditions. The results provide a novel insight into NHX function in plant mineral nutrition

Cooperative Acoustic Navigation Scheme for Heterogenous Autonomous Underwater Vehicles

International audienceCooperative Acoustic Navigation Scheme for Heterogenous Autonomous Underwater Vehicle

Underwater dual manipulators-Part I: Hydrodynamics analysis and computation

1098-1103This paper introduces two 4-DOF underwater manipulators mounted on autonomous underwater vehicle (AUV) with grasping claws, such that the AUV can accomplish the underwater task by using dual manipulators. Mechanical design of the manipulator is briefly presented and the feature of the simple structure of dual manipulators is simulated by using Solid Works. In addition, the hydrodynamics of the manipulator is analyzed, considering drag force, added mass and buoyancy. Then, hydrodynamic simulations of the manipulator are conducted by using 3-D model with Adams software, from which the torque of each joint is calculated. This paper presents an integrated result of computed torques by combining the theoretical calculation and simulation results, which is instrumental in determining the driving torque of the manipulators

Optimizing plant transporter expression in Xenopus oocytes

BACKGROUND: Rapid improvements in DNA synthesis technology are revolutionizing gene cloning and the characterization of their encoded proteins. Xenopus laevis oocytes are a commonly used heterologous system for the expression and functional characterization of membrane proteins. For many plant proteins, particularly transporters, low levels of expression can limit functional activity in these cells making it difficult to characterize the protein. Improvements in synthetic DNA technology now make it quick, easy and relatively cheap to optimize the codon usage of plant cDNAs for Xenopus. We have tested if this optimization process can improve the functional activity of a two-component plant nitrate transporter assayed in oocytes. RESULTS: We used the generally available software (http://www.kazusa.or.jp/codon/; http://genomes.urv.es/OPTIMIZER/) to predict a DNA sequence for the plant gene that is better suited for Xenopus laevis. Rice OsNAR2.1 and OsNRT2.3a DNA optimized sequences were commercially synthesized for Xenopus expression. The template DNA was used to synthesize cRNA using a commercially available kit. Oocytes were injected with cRNA mixture of optimized and original OsNAR2.1 and OsNRT2.3a. Oocytes injected with cRNA obtained from using the optimized DNA template could accumulate significantly more NO(3)(-) than the original genes after 16 h incubation in 0.5 mM Na(15)NO(3). Two-electrode voltage clamp analysis of the oocytes confirmed that the codon optimized template resulted in significantly larger currents when compared with the original rice cDNA. CONCLUSION: The functional activity of a rice high affinity nitrate transporter in oocytes was improved by DNA codon optimization of the genes. This methodology offers the prospect for improved expression and better subsequent functional characterization of plant proteins in the Xenopus oocyte system

A Hybrid Wireless Image Transmission Scheme with Diffusion

We propose a hybrid joint source-channel coding (JSCC) scheme, in which the conventional digital communication scheme is complemented with a generative refinement component to improve the perceptual quality of the reconstruction. The input image is decomposed into two components: the first is a coarse compressed version, and is transmitted following the conventional separation based approach. An additional component is obtained through the diffusion process by adding independent Gaussian noise to the input image, and is transmitted using DeepJSCC. The decoder combines the two signals to produce a high quality reconstruction of the source. Experimental results show that the hybrid design provides bandwidth savings and enables graceful performance improvement as the channel quality improves