The asymptotic relation between the first crossing point and the last exit time of Gaussian order statistics sequences

In this paper,we study the asymptotic relation between the first crossing point and the last exit time for Gaussian order statistics which are generated by stationary weakly and strongly dependent Gaussian sequences.It is shown that the first crossing point and the last exit time are asymptotically independent and dependent for weakly and strongly dependent cases,respectively.The asymptotic relations between the first crossing point and the last exit time for stationary weakly and strongly dependent Gaussian sequences are also obtained.

AN ESTIMATE ON THE DISTRIBUTION AND MOMENTS OF THE LAST EXIT TIME OF AN ELLIPTIC DIFFUSION PROCESS

Let Ls be the last exit time from a compact set B of an elliptic diffusion process X. A moderate estimate for the distribution of Ls is obtained, and the sufficient and necessary condition for E^x（L^κB） 〈∞ is proved.

Manpower Systems Operating under Heavy and Light Tailed Inter-Exit Time Distributions

This paper considers a Manpower system where “exits” of employed personnel produce some wastage or loss. This system monitors these wastages over the sequence of exit epochs {t0 = 0 and tk;k = 1, 2,…} that form a recurrent process and admit recruitment when the cumulative loss of man hours crosses a threshold level Y, which is also called the breakdown level. It is assumed that the inter-exit times Tk = tk-1 - tk, k = 1, 2,… are independent and identically distributed random variables with a common cumulative distribution function (CDF) B(t) = P(Tk t) which has a tail 1 – B(t) behaving like t-v with 1 v as t → ∞. The amounts {Xk} of wastages incurred during these inter-exit times {Tk} are independent and identically distributed random variables with CDF P(Xk X) = G(x) and Y is distributed, independently of {Xk} and {tk}, as an exponentiated exponential law with CDF H(y) = P(Y y) = (1 - e-λy)n. The mean waiting time to break down of the system has been obtained assuming B(t) to be heavy tailed and as well as light tailed. For the exponential case of G(x), a comparative study has also been made between heavy tailed mean waiting time to break down and light tailed mean waiting time to break down values. The recruitment policy operating under the heavy tailed case is shown to be more economical in all types of manpower systems.

Portfolio Optimization with Uncertain Exit Time in Infinite-Time Horizon

In this paper, we study infinite-period mean-variance formulations for portfolio selections with an uncertain exit time. We employ the convergence control method together with the dynamic programming algorithm to derive analytical expressions for the optimal portfolio policy and the mean-variance efficient frontier under certain conditions. We illustrate these results by an numerical example.

On the Mean Exit Time for Compact Symmetric Spaces

Given a compact symmetric space, M, we obtain the mean exit time function from a principal orbit, for a Brownian particle starting and moving in a generalized ball whose boundary is the principal orbit. We also obtain the mean exit time flmction of a tube of radius r around special totally geodesic submanifolds P of M. Finally we give a comparison result for the mean exit time function of tubes around submanifolds in Riemannian manifolds, using these totally geodesic submanifolds in compact symmetric spaces as a model.

On Exit Time from Balls of Jump-type Symmetric Markov Processes

We obtain upper and lower bounds of the exit times from balls of a jump-type symmetric Markov process. The proofs are delivered separately. The upper bounds are obtained by using the Levy system corresponding to the process, while the precise expression of the （L^2-）generator of the Dirichlet form associated with the process is used to obtain the lower bounds.

On First Returning Time and Last Exit Time of a Class of Markov Chain

Let {Xn} be a Markov chain with transition probability pij =： aj-（i-1）＋,i,j ≥ 0, where aj=0 providedj 〈 0, a0 〉 0, a0＋a1〈 1 and ∑∞n=0 an= 1. Let μ∑∞n=1nan. It is known that {Xn} is positive recurrent when μ 〈 1; is null recurrent when μ= 1; and is transient when μ 〉 1. In this paper, the integrability of the first returning time and the last exit time are discussed. Keywords Geom/G/1 queuing model, first returning time, last exit time, Markov chain

Potentials and the Distributions of the Last Exit Times of Birth and Death Processes

0 .Introduction The mathematical eqnivalenoe of Brownian切otion and olaosioal poten七ialtheory has great imPulsed the study of Potentials of Markov Prooesse

Performance and EXIT analysis of parallel concatenated space time trellis codes

Space time trellis coding （STTC） techniques have been proposed to achieve both diversity and coding gains in multiple input multiple output （MIMO） fading channels. But with more transmit antennas STTCs suffer from the design dificulty and complexity increasing. This paper proposes a scheme, named parallel concatenated space time trellis codes （PC-STTC）, to achieve the tradeoff between the performances and complexity of STTCs for a large number of transmit antennas. Simulation results and complexity comparison are provided to demonstrate the performance and superiority of the proposed scheme over conventional schemes in fast fading channels in low signal-to-noise ratio （SNR） regions. And an EXIT （extrinsic information transform） chart is given to analyze the iterative convergence of the proposed scheme. It shows that PC-STTC has better iterative convergence in low SNR regions.

Exit Probability and First Passage Time of a Lazy Pearson Walker: Scaling Behaviour

The motion of a lazy Pearson walker is studied with different probability (p) of jump in two and three dimensions. The probability of exit ( ) from a zone of radius is studied as a function of with different values of jump probability p. The exit probability is found to scale as , which is obtained by method of data collapse. The first passage time ( ) i.e., the time required for first exit from a zone is studied. The probability distribution of first passage time was studied for different values of jump probability (p). The probability distribution of first passage time was found to scale as . Where, F and G are two scaling functions and a, b, g and d are some exponents. In both the dimensions, it is found that, , , and .

ABSOLUTE CONTINUITIES OF EXIT MEASURES AND TOTAL WEIGHTED OCCUPATION TIME MEASURES FOR SUPER-α-STABLE PROCESSES

Suppose X is a super-α-stable process in R^d, （0 〈 α〈 2）, whose branching rate function is dr, and branching mechanism is of the form ψ（z） = z^1＋β （0 〈0 〈β ≤1）. Let Xγ and Yγ denote the exit measure and the total weighted occupation time measure of X in a bounded smooth domain D, respectively. The absolute continuities of Xγ and Yγ are discussed.

两种级联空时格码方案的EXIT分析

级联空时格码方案可以有效地提高空时格码系统的性能。研究了两种级联空时格码方案:PC-STTC和ST-Turbo-TC。由于两种级联方案都使用了迭代译码方法,而外信息转移(EXIT)图是分析迭代译码性能的有利工具,主要分析比较了PC-STTC和ST-Turbo-TC的EXIT性能,比较了不同信噪比和编码多项式对于译码外信息转移特性的影响。研究结果显示,PC-STTC方案比ST-Turbo-TC方案有着更好的迭代收敛性能,同时给出了BER仿真图证明了EXIT图的分析结论。

进出境大中动物中单核细胞增生李斯特氏菌检验方法的研究

为快速检测进出境大中动物中的单核细胞增生李斯特氏菌,将细菌学方法和实时荧光PCR检测方法相结,利用叠氮溴化丙锭(PMA)抑制死菌核酸扩增的特性,对样品进行前处理,构建一套针对进出境大中动物中具有传染性的单核细胞增生李斯特氏菌PMA-qPCR实时荧光快速检测方法。

Two-Sided First Exit Problem for Jump Diffusion Distribution Processes Having Jumps with a Mixture of Erlang

In this paper, we consider the two-sided first exit problem for jump diffusion processes having jumps with rational Laplace transforms. We investigate the probabilistic property of conditional memorylessness, and drive the joint distribution of the first exit time from an interval and the overshoot over the boundary at the exit time.

Analysis of Residence Time in the Measurement of Radon Activity by Passive Diffusion in an Open Volume: A Micro-Statistical Approach

Residence time in a flow measurement of radioactivity is the time spent by a pre-determined quantity of radioactive sample in the flow cell. In a recent report of the measurement of indoor radon by passive diffusion in an open volume (i.e. no flow cell or control volume), the concept of residence time was generalized to apply to measurement conditions with random, rather than directed, flow. The generalization, leading to a quantity Δtr, involved use of a) a phenomenological alpha-particle range function to calculate the effective detection volume, and b) a phenomenological description of diffusion by Fick’s law to determine the effective flow velocity. This paper examines the residence time in passive diffusion from the micro-statistical perspective of single-particle continuous Brownian motion. The statistical quantity “mean residence time” Tr is derived from the Green’s function for unbiased single-particle diffusion and is shown to be consistent with Δtr. The finite statistical lifetime of the randomly moving radioactive atom plays an essential part. For stable particles, Tr is of infinite duration, whereas for an unstable particle (such as 222Rn), with diffusivity D and decay rate λ, Tr is approximately the effective size of the detection region divided by the characteristic diffusion velocity . Comparison of the mean residence time with the time of first passage (or exit time) in the theory of stochastic processes shows the conditions under which the two measures of time are equivalent and helps elucidate the connection between the phenomenological and statistical descriptions of radon diffusion.

消防应急照明和疏散指示系统工程验收常见问题

总结工程验收中发现的消防应急照明和疏散指示系统设计的常见问题,包括未正确应用最短路径疏散原则和避险原则、疏散标志灯被遮挡、消防应急灯具的持续工作时间不满足规范要求等;指出线缆及保护管的选择错误、消防应急照明灯具无3CF认证等施工相关的问题;对与建筑及装饰专业、智能化专业、水专业、暖通专业的配合提出建议。

替代稳态下阜康北部荒漠生态弹性的时空格局

替代稳态下的荒漠生态系统生态弹性反映了系统承受环境干扰后的恢复能力,这对认识荒漠生态系统过程具有重要的理论意义。当前研究主要集中在湖泊和森林生态系统,而有关荒漠生态系统弹性的研究普遍未考虑替代稳态,也鲜有考虑弹性的时间变化。本研究以阜康北部的古尔班通古特沙漠南缘至沙漠腹地样带为例,运用2001年1月至2020年12月的MODIS全球植被指数遥感数据,采用BFAST(Breaks for Additive Season and Trend)和状态空间建模对数据进行处理和提取,通过不同状态的退出时间量化得出不同时段替代稳态条件下的生态弹性,同时根据计算结果分析了该地区生态弹性时空演变特征及其影响机制。研究结果表明:(1)研究区弹性+和弹性-整体呈现先下降后上升的趋势,但沙漠边缘至腹地空间差异显著。(2)生态弹性对降水变化存在滞后响应。(3)降水季节变化的差异会降低降水量与生态弹性之间的相关性。综上所述,生态弹性的空间分布总体受降水格局控制,但立地条件导致的植被空间异质性增加了生态弹性空间分布的复杂性,而生态弹性与降水变化的关系取决于植被群落构成、植物对降水变化响应、降水量变化趋势和季节分布。本研究在认识荒漠生态系统功能稳定性维持机制以及荒漠生态保护和修复方面具有重要的理论与实践意义。

基于反应时间的隧道出口预告标志布设研究

针对《公路路线设计规范》(JTG D20-2017)对隧道出口与互通立交间距过短时,互通立交出口预告标志布设位置规定不明确的问题。基于UC-Win/Road软件建立出口预告标志分别布设于公路左侧、右侧和上方的3种仿真场景,并利用自主研发的动态驾驶仿真试验平台,研究3种仿真场景下左、右车道行车时对驾驶员反应时间的影响,最后基于反应时间均值、换道距离理论和驾驶员的视认特性得出预告标志的最佳布设形式和位置。研究结果表明:预告标志位于公路左侧且右车道行车时,驾驶员反应时间最长;预告标志位于公路上方且右车道行车时,驾驶员反应时间最短;驾驶员对预告标志的反应时间与预告标志在道路横断面上的布设位置显著相关;推荐在隧道入口前采用门架式支撑方式布设出口预告标志,且布设位置距隧道入口的距离不小于424~710 m。研究结果可为《公路路线设计规范》具体实施提供参考,对保障交通安全具有重要意义。

加强院前急救护理管理对院前救护效果的影响

目的探析加强院前急救护理管理对院前救护效果的影响。方法选取2020年1月—2022年8月山东省淄博市医疗急救指挥中心的10名院前急救护士为研究对象,依据抽签法将其分为两组,每组5名,对照组实施常规护理管理,观察组实施加强院前急救护理管理。对比两组管理效果。结果干预后,观察组的管理质量明显优于对照组,差异有统计学意义(P<0.05)。观察组的出车反应时间短于对照组,差异有统计学意义(P<0.05)。结论加强院前急救护理管理在院前急救工作中的应用,可以缩短出车反应时间,并减少不良事件,有助于管理质量提升。

磁阻发射器结构参数与时序控制分析

为了获得较高的弹丸出口速度,研究了磁阻发射器对弹丸的作用规律,首先通过不同长度弹丸在不同匝数线圈下的速度仿真计算,表明长度一定时弹丸出口速度和动能随线圈匝数增大先增后降,弹丸越长其最大速度对应的线圈匝数越多,匝数相同时弹丸出口动能随着弹丸长度增大而增大;接着在线圈匝数和弹丸直径和长度一定的情况下分析了弹丸出口速度与线圈放电时序、回路电阻的关系,发现放电时序一定时弹丸出口速度随回路电阻增大先增后降,并最终获得了弹丸最大出口速度时的放电时序和回路电阻;最后通过仿真计算与实验结果对比,表明二者吻合较好,验证了弹丸出口速度随放电时序的变化。