Scattering Analysis of Electromagnetic Materials Using Fast Dipole Method Based on Volume Integral Equation

The fast dipole method (FDM) is extended to analyze the scattering of dielectric and magnetic materials by solving the volume integral equation (VIE). The FDM is based on the equivalent dipole method (EDM) and can achieve the separation of the field dipole and source dipole, which reduces the complexity of interactions between two far groups (such as group i and group j) from O(NiNj) to O(Ni+Nj), where Ni and Nj are the numbers of dipoles in group i and group j, respectively. Targets including left-handed materials (LHMs), which are a kind of dielectric and magnetic materials, are calculated to demonstrate the merits of the FDM. Furthermore, in this study we find that the convergence may become much slower when the targets include LHMs compared with conventional electromagnetic materials. Numerical results about convergence characteristics are presented to show this property

Three-fund constant proportion portfolio insurance strategy

Specific purpose guarantee funds (SPGFs) such as pension guarantee funds are becoming much popular among loss averse investors with common peculiar investment purpose, but receive few academic attention regarding to its investment strategy, hedging technique and performance. In this paper we propose a more practical constant proportion portfolio insurance (CPPI) strategy, three-fund CPPI (hereafter 3F-CPPI) strategy, which optimally allocates its assets in three funds: a risk-free fund, a stock-index fund and a purpose-related stock fund, to maximize the loss averse investor’s utility and to control the downside risk as well. Closed-form solutions of the optimal allocations of 3F-CPPI and its outcome distribution have been derived first under the continuous time case, followed by an extensive Monte Carlo simulation under the discrete time case to compare 3F-CPPI with other benchmark strategies such as CPPI. Our simulation results show that the proposed 3F-CPPI dominates other benchmark strategies in almost all the aspects such as the mean return, downside risk control and loss averse utility

Toward Sustainable Development: Unleashing the Mechanism Among International Technology Spillover, Institutional Quality, and Green Innovation Capability

Under the background of sustainable development, China’s economic growth engine becomes innovation-driven, and it is an important way for China to rapidly improve its green innovation capability by opening up to the outside world and utilizing the spillover effect of international technology. In this article, the system quality evaluation system is reconstructed by the method of fully arranged polygonal graphical indicators, and the provincial system quality in China is measured and added into the model as a regulating variable. The dynamic panel method and the dynamic threshold panel method are used to test the direct effects of foreign direct investment (FDI) and foreign trade on green innovation capability, the interaction effect of institutional quality, and the threshold effect. Empirical results show that the three technology spillovers have significantly promoted China’s green innovation capability. System quality will affect the determining coefficient of international technology spillovers on China’s green innovation capability. The positive promoting effects of FDI and foreign trade on China’s green innovation capability, all increase with the improvement of China’s system quality. Therefore, when utilizing FDI and foreign trade to promote green innovation in each region, each region should consider creating a good institutional environment for the emergence of international technological effects

Financial Literacy Confidence and Retirement Planning: Evidence from China

Though ample empirical evidence demonstrates the relationship between objective financial literacy and retirement planning, we have a limited understanding of the role of individuals’ subjective financial literacy in their retirement planning. In this study, we examine how individuals’ financial literacy confidence bias affects their retirement planning behaviors using survey data in China. Based on the difference between respondents’ subjective and objective financial literacy from survey data, we construct measures of individuals’ financial literacy overconfidence and underconfidence for empirical analysis. Our results document the critical role of individuals’ assessment of financial literacy in their retirement planning. We find that individuals’ financial literacy overconfidence (underconfidence) significantly promotes (demotes) their retirement planning behaviors

Hedge inflation risk of specific purpose guarantee funds

Specific purpose guarantee funds (SPGFs) such as pension guarantee funds are popular among investors with both specific investment purpose and guaranteed return requirement, but receive little academic attention. We propose a practical purpose-oriented constant proportion portfolio insurance (PO-CPPI) strategy that optimally allocates its assets into a risk-free fund (floor) and a purpose-related portfolio (cushion) to maximize prospect theory investors' utility with consideration of their purpose-related inflation risk. Our closed-form solution of optimal PO-CPPI allocation derived in the continuous time case and Monte-Carlo simulations in the discrete-time and dynamic cases prove the superiority of PO-CPPI over general portfolio insurance strategies

On the robustness of longevity risk pricing

For longevity bond pricing, the most popular methods contain the risk-neutral method, the Wang transform and the Sharpe ratio rule. This paper studies robustness of these three methods and investigates connections and differences among them through theoretic analysis and numerical illustrations. We adopt the dynamic mortality models with jumps to capture the permanent effects caused by unexpected factors and allow the correlation between mortality and interest rate be nonzero. The analysis is based on four typical mortality models, including the mean-reverting models and the non mean-reverting ones. Our work may provide a guidance for participants on choice of pricing methods.Longevity risk Risk-neutral method Wang transform Sharpe ratio rule Robustness

Exosomal microRNA-Based therapies for skin diseases

Based on engineered cell/exosome technology and various skin-related animal models, exosomal microRNA (miRNA)-based therapies derived from natural exosomes have shown good therapeutic effects on nine skin diseases, including full-thickness skin defects, diabetic ulcers, skin burns, hypertrophic scars, psoriasis, systemic sclerosis, atopic dermatitis, skin aging, and hair loss. Comparative experimental research showed that the therapeutic effect of miRNA-overexpressing exosomes was better than that of their natural exosomes. Using a dual-luciferase reporter assay, the targets of all therapeutic miRNAs in skin cells have been screened and confirmed. For these nine types of skin diseases, a total of 11 animal models and 21 exosomal miRNA-based therapies have been developed. This review provides a detailed description of the animal models, miRNA therapies, disease evaluation indicators, and treatment results of exosomal miRNA therapies, with the aim of providing a reference and guidance for future clinical trials. There is currently no literature on the merits or drawbacks of miRNA therapies compared with standard treatments

High-efficiency transition between rectangular waveguide and domino plasmonic waveguide

In this work, we propose an optimized transition structure to realize smooth and high efficiency conversion from the guided wave supported by a conventional rectangular waveguide (CRW) to the domino plasmon polaritons (DPPs) supported by a domino plasmonic waveguide (DPW) and vice versa in the X-band (8.2GHz∼12.4GHz). This transition structure consists of two tapered CRWs connected by a gradient domino array with optimized gradient heights and lateral widths. Experimental results of the S-parameters show excellent agreement with the simulations and the optimization scheme can be readily extended to other bands. Furthermore, a domino plasmonic power divider is implemented to demonstrate the application of the transition structure in the integration of conventional microwave circuits with plasmonic devices

Numerical Simulation Investigation on Parameter Optimization of Deep-Sea Mining Vehicles

Abstract The four-track walking mining vehicle can better cope with the complex terrain of cobalt-rich crusts on the seabed. To explore the influence of different parameters on the obstacle-crossing ability of mining vehicles, this paper took a certain type of mine vehicle as an example and establish a mechanical model of the mine vehicle. Through this model, the vehicle’s traction coefficient variation could be analyzed during the obstacle-crossing process. It also reflected the relationship between the obstacle-crossing ability and the required traction coefficient. Many parameters were used for this analysis including the radius of the guide wheel radius, ground clearance of the driving wheel, the dip angle of the approaching angular and the position of centroid. The result showed that the ability to cross the obstacles requires adhesion coefficient as support. When the ratio between obstacle height and ground clearance of the guide wheel was greater than 0.7, the required adhesion coefficient increased sharply. The ability to cross obstacles will decrease, if the radius of the guide wheel increases, the height of the driving wheel increases or the dip angle of the approaching angular increases. It was most beneficial to cross the obstacle when the ratio of the distance between the center of mass and the front driving wheel to the wheelbase is between 0.45‒0.48. The results of this paper could provide reference for structural parameter design and performance research for mining vehicles