Some results on discrete mean residual life

Mean residual life (MRL) is important in reliability studies; it provides the engineer with an idea of how long a device of any particular age can be expected to survive. Components and systems are frequently characterized as having increasing or decreasing MRL. Over the past 10-15 years, several authors have discussed MRL for components or systems whose lifetimes are measured in discrete units (number of trials until failure). This paper establishes some simple bounds for residual life when the device has a monotonic hazard rate sequence (either increasing or decreasing) and provides examples. MRL is obtained in closed form for a particular family of decreasing failure-rate models     

Power spectral density of unevenly sampled data by least-squareanalysis: performance and application to heart rate signals

This work studies the frequency behavior of a least-square method to estimate the power spectral density of unevenly sampled signals. When the uneven sampling can be modeled as uniform sampling plus a stationary random deviation, this spectrum results in a periodic repetition of the original continuous time spectrum at the mean Nyquist frequency, with a low-pass effect affecting upper frequency bands that depends on the sampling dispersion. If the dispersion is small compared with the mean sampling period, the estimation at the base band is unbiased with practically no dispersion. When uneven sampling is modeled by a deterministic sinusoidal variation respect to the uniform sampling the obtained results are in agreement with those obtained for small random deviation. This approximation is usually well satisfied in signals like heart rate (HR) series. The theoretically predicted performance has been tested and corroborated with simulated and real HR signals. The Lomb method has been compared with the classical power spectral density (PSD) estimators that include resampling to get uniform sampling. The authors have found that the Lomb method avoids the major problem of classical methods: the low-pass effect of the resampling. Also only frequencies up to the mean Nyquist frequency should be considered (lower than 0.5 Hz if the HR is lower than 60 bpm). It is concluded that for PSD estimation of unevenly sampled signals the Lomb method is more suitable than fast Fourier transform or autoregressive estimate with linear or cubic interpolation. In extreme situations (low-HR or high-frequency components) the Lomb estimate still introduces high-frequency contamination that suggest further studies of superior performance interpolators. In the case of HR signals the authors have also marked the convenience of selecting a stationary heart rate period to carry out a heart rate variability analysis     

Multidimensional circuit synthesis and multivariable dilation theory

Holomorphic contractive matrix- or operator-valued functions on the unit disk and their counterparts under double Cayley transform, namely holomorphic functions with positive real part on the right half plane, have been a fundamental object of study in both the mathematics and engineering communities. We discuss recent extensions of these notions to multivariable settings.     

Mean residual life and its association with failure rate

The life time distributions having decreasing, increasing, or upside-down bathtub shaped MRL (mean residual life) are used as models in many applications. Mi (1995) has shown that if a component has a bathtub shape failure rate function, then the MRL is unimodal but the converse does not hold. This paper develops sufficient conditions for the unimodal MRL to imply that the failure rate function has a bathtub shape     

Fault Models for Quantum Mechanical Switching Networks

In classical test and verification one develops a test set separating a correct circuit from a circuit containing any considered fault. Classical faults are modelled at the logical level by fault models that act on classical states. The stuck fault model, thought of as a lead connected to a power rail or to a ground, is most typically considered. A classical test set complete for the stuck fault model propagates both binary basis states, 0 and 1, through all nodes in a network and is known to detect many physical faults. A classical test set complete for the stuck fault model allows all circuit nodes to be completely tested and verifies the function of many gates. It is natural to ask if one may adapt any of the known classical methods to test quantum circuits. Of course, classical fault models do not capture all the logical failures found in quantum circuits. The first obstacle faced when using methods from classical test is developing a set of realistic quantum-logical fault models (a question which we address, but will likely remain largely open until the advent of the first quantum computer). Developing fault models to abstract the test problem away from the device level motivated our study. Several results are established. First, we describe typical modes of failure present in the physical design of quantum circuits. From this we develop fault models for quantum binary quantum circuits that enable testing at the logical level. The application of these fault models is shown by adapting the classical test set generation technique known as constructing a fault table to generate quantum test sets. A test set developed using this method will detect each of the considered faults.     

QoS‐Guaranteed Slot Allocation Algorithm for Efficient Medium Access in HR‐WPAN

It is very important to provide a parameterized quality of service (QoS) using traffic specification (TSPEC), such as mean data rate, maximum burst size, and peak data rate, when packets from the application layer need to be transmitted with guaranteed services in a high‐rate wireless personal area network (HR‐WPAN). As medium resources are limited, the optimal medium time required for each device needs to be estimated to share the resources efficiently among devices. This paper proposes a variable‐service interval‐based resource allocation algorithm to efficiently make a reservation of medium resources based on a parameterized QoS. In other words, the proposed algorithm calculates the number of medium access slots (MASs) based on TSPEC, local resources, and local conditions and determines suitable locations for the MASs within a superframe to accommodate more devices. The simulation results show that the proposed algorithm can accommodate more devices and has greater than 10% resource allocation efficiency in an HR‐WPAN compared to existing schemes.     

High-performance three-layer 1.3-/spl mu/m InAs-GaAs quantum-dot lasers with very low continuous-wave room-temperature threshold currents

The combination of high-growth-temperature GaAs spacer layers and high-reflectivity (HR)-coated facets has been utilized to obtain low threshold currents and threshold current densities for 1.3-/spl mu/m multilayer InAs-GaAs quantum-dot lasers. A very low continuous-wave (CW) room-temperature threshold current of 1.5 mA and a threshold current density of 18.8 A/cm/sup 2/ are achieved for a three-layer device with a 1-mm HR/HR cavity. For a 2-mm cavity, the CW threshold current density is as low as 17 A/cm/sup 2/ for an HR/HR device. An output power as high as 100 mW is obtained for a device with HR/cleaved facets.     

Do the high-frequency indexes of HRV provide a faithful assessment of cardiac vagal tone? A critical theoretical evaluation

When spectral analysis of the heart rate (HR) signal is performed, it is quite common to attribute the HF indexes of heart rate variability (HRV) to cardiac vagal control. The paradigm underlying this attribution states that changes in cardiac vagal outflow correspond to a proportional change in respiratory sinus arrhythmia (RSA). However, recent studies have demonstrated that variations in these indexes do not necessarily reflect proportional changes in vagal tone. The current study provides a theoretical evaluation of the relationship between mean HR, RSA, and cardiac vagal tone. This evaluation is based on a theoretical model, which quantifies the differential effects of vagal blockade by a competitive muscarinic antagonist on the HF indexes of HRV. The model relies on several assumptions that reflect the basic physiology of the sinoatrial (SA) node, as well as pharmacological relations that describe agonist/antagonist equilibrium at the SA receptors. The mathematical framework of this model is the integral-pulse-frequency-modulation (IPFM) process, and its derivations lead to a specific expressions for the dependence of HF and mean HR on the level of vagal blockade. These expressions provide a new insight into the relationship between mean HR, RSA, and vagal tone, and explain conflicting experimental results previously published.     

基于模糊综合函数的航迹关联算法

本文运用现代数学中的综合分析方法,提出了模糊综合航迹关联算法,文中详细讨论了状态估计向量间模糊综合相似度的计算和评价方法,导出了三种典型模糊综合函数的递推式,研究了模糊综合航迹关联准则,并通过仿真将它与两种经典方法进行了比较。仿真结果表明,在密集目标环境下和/或交叉、分岔和机动航迹较多的场合,模糊航迹关联算法的性能明显优于传统方法,其正确关联率比传统方法提高了大约40％。     

分布式多传感器数据融合中的双门限航迹相关算法

本文提出两种适合于分布式多传感器数据融合的双门限航迹相关算法.文中对这两种双门限航迹相关准则进行了详细的描述,研究了航迹相关质量设计、多义性处理和漏相关概率的估计方法,并通过仿真将它们与两个经典方法进行了比较.仿真结果表明,在密集目标环境下和/或交叉、分岔和机动航迹较多的场合,双门限航迹相关算法的性能明显优于传统方法,其正确相关率比传统方法提高了大约35％.     

A new gate driver integrated circuit for IGBT devices with advanced protections

The aim of this paper is to discuss new solutions in the design of insulated gate bipolar transistor (IGBT) gate drivers with advanced protections such as two-level turn-on to reduce peak current when turning on the device, two-level turn-off to limit over-voltage when the device is turned off, and an active Miller clamp function that acts against cross conduction phenomena. Afterwards, we describe a new circuit which includes a two-level turn-off driver and an active Miller clamp function. Tests and results for these advanced functions are discussed, with particular emphasis on the influence of an intermediate level in a two-level turn-off driver on overshoot across the IGBT.     

基于ARM及μC/OS-Ⅱ的RGB视频矩阵设计

RGB视频矩阵也叫RGB视频信号切换器。在多媒体视频会议、安防监控、广播电视等领域都起着非常重要的作用。随着某些场合用到切换信号源的不断增多与控制地点的灵活变化,对视频矩阵的控制方式灵活性要求也越来越强烈,一种控制方式远远不能满足人们的需求,因此多种控制方式并存,才能使RGB视频矩阵发挥更大作用空间。该设计用低成本ARM LM3S6911作为主控制芯片,配合MAX232串口收发芯片,网络变压器芯片HR601680,还有本机键盘模块和LCD模块,采用专业视频信号切换芯片ISL59530实现了RGB视频矩阵的按键、串行口、以太网口3种控制方式并存。在软件方面成功地将μC/OS-Π内核移植到微控制器LM3S6911上,保证了系统操作的实时性,并提高了切换速度     

A contrasting look at self-organization in the Internet and next-generation communication networks

This article examines contrasting notions of self-organization in the Internet and next-generation communication networks, by reviewing in some detail recent evidence regarding several of the more popular attempts to explain prominent features of Internet structure and behavior as "emergent phenomena." In these examples, what might appear to the nonexpert as "emergent self-organization" in the Internet actually results from well conceived (albeit perhaps ad hoc) design, with explanations that are mathematically rigorous, in agreement with engineering reality, and fully consistent with network measurements. These examples serve as concrete starting points from which networking researchers can assess whether or not explanations involving self-organization are relevant or appropriate in the context of next-generation communication networks, while also highlighting the main differences between approaches to self-organization that are rooted in engineering design vs. those inspired by statistical physics.     

Mechanisms determining three-dimensional SiGe lsland density on Si(001)

Thin, coherently strained, films of SiGe were deposited on Si(001) in the Stranski-Krastanow (SK) growth mode to form small, faceted, dislocation-free-three-dimensional (3D) islands. The number density of these islands was determined as functions of SiGe alloy composition, growth rate, and substrate temperature during growth. From these experiments, the classical model of 3D island nucleation and growth yields an approximate activation energy for diffusion of Ge dimers on a Ge covered Si(001) surface of 0.70 eV. The dependence of the 3D-island number density on growth rate cannot be understood without modifying the classical model to account for the wetting layer present in SK systems. Heteroepitaxial strain is not included in the classical model of island nucleation and growth. A simple linear elastic model that fits the data is developed that predicts the island number density is proportional to the inverse square of the Ge mole fraction in the alloy plus a constant.     

Characterization of Security Notions for Probabilistic Private-Key Encryption

The development of precise definitions of security for encryption, as well as a detailed understanding of their relationships, has been a major area of research in modern cryptography. Here, we focus on the case of private-key encryption. Extending security notions from the public-key setting, we define security in the sense of both indistinguishability and non-malleability against chosen-plaintext and chosen-ciphertext attacks, considering both non-adaptive (i.e., ``lunchtime') and adaptive oracle access (adaptive here refers to an adversary's ability to interact with a given oracle even after viewing the challenge ciphertext). We then characterize the 18 resulting security notions in two ways. First, we construct a complete hierarchy of security notions; that is, for every pair of definitions we show whether one definition is stronger than the other, whether the definitions are equivalent, or whether they are incomparable. Second, we partition these notions of security into two classes (computational or information-theoretic) depending on whether one-way functions are necessary in order for encryption schemes satisfying the definition to exist. Perhaps our most surprising result is that security against adaptive chosen-plaintext attack is (polynomially) equivalent to security against non-adaptive chosen-plaintext attack. On the other hand, the ability of an adversary to mount a (non-adaptive) chosen-plaintext attack is the key feature distinguishing computational and information-theoretic notions of security. These results hold for all security notions considered here.     

Mean residual life of lifetime distributions

This paper characterizes the general behaviors of the MRL (mean residual lives) for both continuous and discrete lifetime distributions, with respect to their failure rates. For the continuous lifetime distribution with failure rates with only one or two change-points, the characteristic of the MRL depends only on its mean and failure rate at time zero. For failure rates with “roller coaster” behavior, the subsequent behavior of the MRL depends on its MRL and failure-rates at the change points. Using the characterization, their behaviors for the: Weibull; lognormal; Birnbaum-Saunders; inverse Gaussian; and bathtub failure rate distributions are tabulated in terms of their shape parameters. For discrete lifetime distributions, for upside-down bathtub failure rate with only one change point, the characteristic of the MRL depends only on its mean and the probability mass function at time zero     

基于灰色关联和不确定推理的HRRP 目标识别

由于HRRP 固有的信息有损压缩,利用单帧HRRP 样本进行目标识别时, 存在经典算法识别率较低而改进后的算法一般复杂度较高的问题。为获得更加稳健、可信的识别效果,文中基于MYCIN 模型,引入灰色关联算子,构造了不确定因子,提出了一种基于HRRP 序列的雷达目标识别方法。基于五种飞机模型高分辨距离像数据的仿真实验表明:与单样本的识别算法相比,所提出的算法具有识别精度高、稳定性好、抗干扰能力强等优点,具有较好的工程应用前景。     

实时嵌入式操作系统VxWorks设备驱动程序的设计

在嵌入式实时系统中进行软硬件开发的关键是编写高效可靠的设备驱动程序,而VxWorks下END网口驱动程序是设备驱动程序中较为复杂的一类.首先从整体上分析了VxWorks操作系统的特点与结构,然后介绍了VxWorks中设备驱动程序的功能、结构和开发方法,并给出了END网口驱动程序的设计实例.该文对VxWorks设备驱动程...     

Patterning Si at the 1 nm Length Scale with Aberration‐Corrected Electron‐Beam Lithography: Tuning of Plasmonic Properties by Design

Patterning of materials at single nanometer resolution allows engineering of quantum confinement effects, as these effects are significant at these length scales, and yields direct control over electro‐optical properties. Silicon is by far the most important material in electronics, and the ability to fabricate Si‐based devices of the smallest dimensions for novel device engineering is highly desirable. The work presented here uses aberration‐corrected electron‐beam lithography combined with dry reactive ion etching to achieve both: patterning of 1 nm features and surface and volume plasmon engineering in Si. The nanofabrication technique employed here produces nanowires with a line edge roughness (LER) of 1 nm (3σ). In addition, this work demonstrates tuning of the Si volume plasmon energy by 1.2 eV from the bulk value, which is one order of magnitude higher than previous attempts of volume plasmon engineering using lithographic methods.     

Framework for TCAD augmented machine learning on multi-I-V characteristics using convolutional neural network and multiprocessing

In a world where data is increasingly important for making breakthroughs,microelectronics is a field where data is sparse and hard to acquire.Only a few entities have the infrastructure that is required to automate the fabrication and testing of semiconductor devices.This infrastructure is crucial for generating sufficient data for the use of new information technolo-gies.This situation generates a cleavage between most of the researchers and the industry.To address this issue,this paper will introduce a widely applicable approach for creating custom datasets using simulation tools and parallel computing.The multi-I-V curves that we obtained were processed simultaneously using convolutional neural networks,which gave us the abil-ity to predict a full set of device characteristics with a single inference.We prove the potential of this approach through two con-crete examples of useful deep learning models that were trained using the generated data.We believe that this work can act as a bridge between the state-of-the-art of data-driven methods and more classical semiconductor research,such as device en-gineering,yield engineering or process monitoring.Moreover,this research gives the opportunity to anybody to start experi-menting with deep neural networks and machine learning in the field of microelectronics,without the need for expensive experi-mentation infrastructure.