SITH耐压容量的控制和调节

分析了SITH结构的掺杂电阻率、N－基区厚度、沟道尺寸以及终端结构对正向阻断电压的影响，分析了其横向自掺杂、沟道尺寸、外延层以及相关因素对栅－阴极击穿电压的影响，讨论了如何进行正向阻断电压和栅－阴极击穿电压的控制和调节。     

Decompositions of graphs of functions and fast iterations of lookup tables

We show that every function f implemented as a lookup table can be implemented such that the computational complexity of evaluating f^m(x) is small, independently of m and x. The implementation only increases the storage space by a small constant factor.     

非线性薛定谔方程的几种差分格式

在满足一定的初值、边值条件下,结合不同的差分格式对非线性薛定谔(NLS)方程进行数值求解.分别利用经典的向前差分算子、二阶中心差分算子、Crank-Nicolson方法和紧致差分算子构造向前Euler格式、Crank-Nicolson格式和紧致差分格式,并证明Crank-Nicolson格式和紧致差分格式精确保持离散质量守恒和能量守恒.利用数学软件MATLAB进行实验计算,结果表明:所构造的3种格式具有合理性及有效性.     

稳压二极管的非线性伏安特性研究

用FD-UI-A非线性元件伏安特性实验仪测量了稳压二极管的正向和反向伏安特性,研究结果表明,稳压二极管的正向和反向伏安特性都呈现出非线性,但其正向和反向的lnI-Ud呈良好的线性关系,其斜率反映了二极管材料的导电特性.     

无感知音频信号数字水印技术

 从时域统计的音频信号数字水印技术出发,提出一种无感知音频信号数字水印方法,该方法以ISO/IEC11172-3(MPEG-Audio)中定义的心理声学模型作为数字水印产生的模型,使嵌入到音频信号中的水印信息最大可能地被掩蔽,保证声信号的质量.根据统计模型,检测时可在不需要原声信号的情况下对数字水印的有无作出判决.     

一种基于检测转发方式的酉空时协作分集技术

对一种基于检测转发方式的酉空时协作分集技术进行了研究,该技术可以在发送端和接收端都不知道信道信息的情况下使数据可靠地传输.在该协作分集技术下,通过对2个用户协作系统进行仿真分析,结果表明,其误码率性能与每个用户的信道和用户间的信道相关.     

Light-extraction efficiency and forward voltage in GaN-based light-emitting diodes with different patterns of V-shaped pits

We present a new method of making a textured V-pit surface for improving the light extraction efficiency in GaN- based light-emitting diodes and compare it with the usual low-temperature method for p-GaN V-pits. Three types of GaNbased light-emitting diodes （LEDs） with surface V-pits in different densities and regions were grown by metal-organic chemical vapor deposition. We achieved the highest output power and lowest forward voltage values with the p-InGaN V-pit LED. The V-pits enhanced the light output power values by 1.45 times the values of the conventional LED owing to an enhancement of the light scattering probability and an effective reduction of Mg-acceptor activation energy. Moreover, this new technique effectively solved the higher forward voltage problem of the usual V-pit LED.     

Vasicek利率模型下具有随机障碍的动态保障年金的定价

带有动态保障的投资连接基金在整个投资期间提供了一些安全保障.文章考虑了随机利率环境下,具有随机障碍水平的动态保障年金的价格.当障碍水平设为某个零息债券的函数时,可以给出具有动态保障年金的价格.     

Hitting time and time change

This paper determines first‐passage time distributions with a twofold emphasis on the dynamics of the state variables and interest rate uncertainty. Underlyings follow two‐dimensional geometric Brownian motions, Ornstein–Uhlenbeck processes or Poisson jump‐diffusion processes, and boundaries are either fixed or indexed on risk‐free bonds. Forward‐neutral changes of numeraire enable one to derive generic valuation expressions, while changing time allows one to determine closed‐form solutions for geometric Brownian motions and moving barriers. In turn, the latter formulas are used to reduce the variance of Monte Carlo simulations in the case of jump‐diffusion processes, by means of the control variate method.     

Real-World Scenarios With Negative Interest Rates Based on the LIBOR Market Model

ABSTRACT

In this article, we present a methodology to simulate the evolution of interest rates under real-world probability measure. More precisely, using the multidimensional Shifted Lognormal LIBOR market model and a specification of the market price of risk vector process, we explain how to perform simulations of the real-world forward rates in the future, using the Euler?Maruyama scheme with a predictor?corrector strategy. The proposed methodology allows for the presence of negative interest rates as currently observed in the markets.