149 research outputs found

    A Simulation Model of New Product Diffusion Based on Small World Network

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    This paper studies the impact of consumer network structure on the diffusion of new products. Taking a communication product for example, we study its diffusion through simulation based on small world network. We find that the greater the proportion of initial adopters is, the faster the new products diffuses, and it’s marginal benefit is decreasing. The social network’s connection can be divided into weak links and strong links with different functions. The more the weak links are, the faster the new products diffuse. For the rise in marketing costs, enterprises need to improve the possibility of the success of new product diffusion with comprehensive consideration

    Optimized design for micro Wankel compressor used in space-borne vapor compression heat pump

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    For aerospace applications, vapor compression heat pump can be used as thermal control system to collect the heat from electronic devices and transport heat to radiator by which heat can be rejected to space. Heat pumps can be used in two cases. The first consists of raising the temperature of heat energy so that the amount of radiator surface required is reduced. The second involves situations where heat cannot be directly rejected by radiators, because the heat sink temperature is higher than that of the heat source. However, the key problem is to make a small and lightweight refrigeration compressor. In order to meet the need for aerospace applications, an innovative miniature hermetic Wankel compressor was proposed and designed in this paper. We fabricated the components such as shell, cylinder, rotor, piston gear, stationary gear, rotor and stator of motor. A compressor prototype was manufactured by integrating these components. The experimental system was built to test the performances of compressor prototype. The effects of condensing temperature, compressor rotation speed and refrigerant charge on the compressor performance were obtained. The influences of tilt angle on the performances of compressor were also investigated. The results indicated that the prototype have good performance, reliability and micro-gravity adaptability

    Cooperative Advertising in a Supply Chain with Horizontal Competition

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    Cooperative advertising programs are usually provided by manufacturers to stimulate retailers investing more in local advertising to increase the sales of their products or services. While previous literature on cooperative advertising mainly focuses on a “single-manufacturer single-retailer” framework, the decision-making framework with “multiple-manufacturer single-retailer” becomes more realistic because of the increasing power of retailers as well as the increased competition among the manufacturers. In view of this, in this paper we investigate the cooperative advertising program in a “two-manufacturer single-retailer” supply chain in three different scenarios; that is, (i) each channel member makes decisions independently; (ii) the retailer is vertically integrated with one manufacturer; (iii) two manufacturers are horizontally integrated. Utilizing differential game theory, the open-loop equilibrium-advertising strategies of each channel member are obtained and compared. Also, we investigate the effects of competitive intensity on the firm’s profit in three different scenarios by using the numerical analysis

    Cooperative Advertising in a Supply Chain with Horizontal Competition

    Get PDF
    Cooperative advertising programs are usually provided by manufacturers to stimulate retailers investing more in local advertising to increase the sales of their products or services. While previous literature on cooperative advertising mainly focuses on a "singlemanufacturer single-retailer" framework, the decision-making framework with "multiple-manufacturer single-retailer" becomes more realistic because of the increasing power of retailers as well as the increased competition among the manufacturers. In view of this, in this paper we investigate the cooperative advertising program in a "two-manufacturer single-retailer" supply chain in three different scenarios; that is, (i) each channel member makes decisions independently; (ii) the retailer is vertically integrated with one manufacturer; (iii) two manufacturers are horizontally integrated. Utilizing differential game theory, the open-loop equilibriumadvertising strategies of each channel member are obtained and compared. Also, we investigate the effects of competitive intensity on the firm's profit in three different scenarios by using the numerical analysis

    A Simple Low-Cost Shared-Aperture Dual-Band Dual-Polarized High Gain Antenna for Synthetic Aperture Radars

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    This paper presents a novel shared-aperture dual-band dual-polarized high-gain antenna for potential applications in synthetic aperture radars (SAR). To reduce the complexity of SAR antennas, a dual-band dual-polarized high gain antenna based on the concept of Fabry-Perot resonant cavity is designed. This antenna operates in both C and X bands with a frequency ratio of 1:1.8. To form two separate resonant cavities, two frequency selective surface (FSS) layers are employed, leading to high flexibility in choosing desired frequencies for each band. The beam scanning capability of this proposed antenna is also investigated, where a beam scanning angle range of ±15o is achieved in two orthogonal polarizations. To verify this design concept, three passive antenna prototypes were designed, fabricated and measured. One prototype has broadside radiation patterns whilst the other two prototypes have frozen beam scanned to +15o. The measured results agree well with the simulated ones, showing that high gain, high port isolation, and low cross cross-polarization levels are obtained in both bands. Compared to the conventional high gain dual-band dual-polarized SAR antennas, the proposed antenna has achieved a significant reduction in the complexity, mass, size, loss and cost of the feed network

    HO-1 Is Essential for Tetrahydroxystilbene Glucoside Mediated Mitochondrial Biogenesis and Anti-Inflammation Process in LPS-Treated RAW264.7 Macrophages

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    2,3,5,4′-Tetrahydroxystilbene-2-O-β-D-glucoside (TSG), an important monomer extracted from Polygonum multiflorum, can prevent a number of inflammation associated chronic diseases. However, the mechanism involved in TSG inducing anti-inflammatory role remains unclear. As an inducible antioxidant enzyme, Heme oxygenase-1 (HO-1), is crucial for protecting the mammalian cells against adverse stimuli. Here, we found that the TSG treatment strongly induces the expression of HO-1 in an NRF2-depended manner. Meanwhile, TSG increased the mitochondrial mass through upregulation of the mitochondrial biogenesis activators (PGC-1α, NRF1, and TFAM) as well as the mitochondrial complex IV. Furthermore, TSG attenuated Lipopolysaccharide (LPS) mediated RAW264.7 cells activation and secretion of proinflammatory cytokines, including interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). Zinc Protoporphyrin (ZnPP), a selective inhibitor of HO-1 activity, was able to attenuate TSG mediated mitochondrial biogenesis and anti-inflammatory process. Finally, we observed that LPS induced obvious mtDNA depletion and ATP deficiency, which indicated a severe damage of mitochondria. TSG restored the LPS induced mitochondrial dysfunction via activation of the mitochondrial biogenesis. ZnPP treatment markedly reversed the inhibitory effects of TSG on mitochondrial damage and oxidative stress in LPS stimulated macrophages. Taken together, these findings suggest that TSG enhances mitochondrial biogenesis and function mainly via activation the HO-1. TSG can be developed as a potential drug for treatment of inflammatory diseases

    A Tri-Band Low-Profile High-Gain Planar Antenna Using Fabry-Perot Cavity

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    A tri-band high-gain antenna with a planar structure and low profile is proposed. The principle of operation is explained. It is based on Fary-Perot cavity antenna (FPCA) with two frequency selective surface (FSS) layers. Two different resonant frequencies are generated by the two resonant cavities formed by the ground plane and each of the two FSS layers, respectively. A third resonant frequency is produced by combining the two FSS layers together. Advantages of this tri-band antenna includes low profile, high gain, easy fabrication and low cost. Low profile is achieved by designing the combined FSS layers as an artificial magnetic conductor (AMC) with a reflection coefficient having 0o phase shift and high magnitude. In addition, a large frequency ratio, which is often a problem for multiband array antennas, can be achieved here. To verify this concept, a C/X/Ku band FPCA is designed and one prototype is fabricated and tested. Experimental results agree well with the simulated results. High gain performance with good impedance matching in three bands is obtained, which reaches a peak gain of 14.2 dBi at 5.2 GHz, 18.9 dBi at 9.6 GHz and 19.8 dBi at 14.7 GHz, respectively. The overall height of antenna is only 20.2 mm, which is about 1/3 wavelength at its lowest operating frequency, which means a reduction of 30% compared to the height of traditional FPCA antenna
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