A functional central limit theorem for Markov additive processes with an application to the closed Lu–Kumar network

A functional central limit theorem for a class of time-homogeneous continuous-time Markov processes (X,Y) is proved. The process X is a positive recurrent Markov process on a countable-state space and the process Y has conditionally independent increments given X. The pair (X,Y) is called a Markov additive process. This paper unifies and generalizes several functional central limit theorems for Markov additive processes. An explicit expression for the variance parameter of the limit process is calculated using the local characteristics of the X process. The functional central limit theorem is then used to prove a heavy traffic limit theorem for the closed Lu–Kumar network.     

POLLING SYSTEMS WITH SIMULTANEOUS BATCH ARRIVALS

We study the delay in polling systems with simultaneous batch arrivals. Arrival epochs are generated according to a Poisson process. At any arrival epoch, batches of customers may arrive simultaneously at the different queues, according to a general joint batch-size distribution. The server visits the queues in cyclic order, the service times and the switch-over times are generally distributed, and the service disciplines are general mixtures of gated and exhaustive service. We derive closed-form expressions for the expected delay at each of the queues when the load tends to unity (under proper scalings), in a general parameter setting. The results are strikingly simple and reveal explicitly how the expected delay depends on the system parameters, and in particular, on the batch-size distributions and the simultaneity of the batch arrivals. Moreover, the results suggest simple and fast-to-evaluate approximations for the expected delay in heavily loaded polling systems. Numerical experiments demonstrate that the approximations are highly accurate in medium and heavily loaded systems.     

ON THE INFINITE SERVER SHORTEST QUEUE PROBLEM: SYMMETRIC CASE

Abstract

We consider two identical parallel M/M/∞ queues. A new arrival is routed to the queue with the smaller number of customers. If both systems have equal occupancy, the arrival joins either with probability 1/2. These types of models have been used to describe CDMA (Code Division Multiple Access) cellular systems. We analyze this model both numerically and asymptotically. For the latter, we consider the limit ρ = λ/μ → ∞, where λ (resp., μ) is the arrival (resp., service) rate. An efficient numerical method is developed for computing the joint steady-state distribution of the number of customers in the two queues. We give several asymptotic formulas, valid for different ranges of the state variables, which show the qualitative structure of the joint distribution. The numerical accuracy of the asymptotic results is tested.     

Block bootstrap testing for changes in persistence with heavy-tailed innovations

This article considers the detection of changes in persistence in heavy-tailed series. We adopt a Dickey–Fuller-type ratio statistic and derive its null asymptotic distribution of test statistic. We find that the asymptotic distribution depends on the stable index, which is often typically unknown and difficult to estimate. Therefore, the block bootstrap method is proposed to detect changes without estimating κ. The empirical sizes and power values are investigated to show that the block bootstrap test is valid. Finally, the validity of the method is demonstrated by analyzing the exchange rate of RMB and US dollars.     

企业文化创新与企业价值观实现——内蒙古北方重型汽车股份有限公司实证分析

在社会主义市场经济激烈的竞争中,企业必须构建和创新企业文化。有特色的企业文化是企业的生命。内蒙古北方重汽在"产业报国"价值观的指导下,创新有特色的企业文化,盘活了国有资产、增强了企业竞争力和员工的凝聚力。由此可见,企业文化创新对实现企业价值观有重要作用。     

论罪刑法定视野下的“轻重”刑事政策

"轻重"刑事政策是是基于对特定法益保护的要求而对符合一定条件的重罪减轻或免除处罚的政策,是宽严相济刑事政策的贯彻和体现,实行这一政策也有助于起到特殊预防的目的,能更好的保护法益.基于罪刑法定原则的考虑,轻重刑事政策应该实现法定化,在刑法分则条文中明确规定下来.就绑架罪而言,应该一方面降低绑架罪的起刑点,以求取得罪与罪之间的平衡;另一方面从保护被绑架人的生命安全出发,设定对主动或者应要求释放人质的行为减轻或者免予处罚条款,以更为有效地实现刑法保护法益的目的.     

指数测度技术在“江南重工”财务分析中的应用

财务预警可以帮助企业经营者及时发现企业运行中存在的财务危机并适时调控。基于财务预警指数测度技术,以江南重工股份有限公司为对象,计算并分析了其预警结果,结果表明"江南重工"2006年总体财务状况较好,属于无警状态。     

深郁悲怆 简淡古朴：陆游诗艺术风格论

陆游是我国古代诗歌史上创作数量最繁富的诗人,也是一位杰出的爱国诗人.在艺术风格上,其诗呈现出不同他人的三种特征,一是以最广泛的题材、最为多样的风格、各体精工的特点体现出一种丰富的集大成性;二是以爱国诗篇为代表的高度抒情的艺术风格,它吸收了杜甫的对民族国家的深切热爱和对理想至死靡它的执著精神,也吸收了李白慷慨激昂、意气风发的抒情手段,最终形成了既沉郁顿挫又豪气冲霄的抒情特色;三是以闲适的农村咏物诗为代表的清新流丽、简淡古朴的艺术风格,表现出陆诗艺术的别一面目与复杂性.     

Extreme Value Distributions for the Skew-Symmetric Family of Distributions

We derive the extreme value distribution of the skew-symmetric family, the probability density function of the latter being defined as twice the product of a symmetric density and a skewing function. We show that, under certain conditions on the skewing function, this extreme value distribution is the same as that for the symmetric density. We illustrate our results using various examples of skew-symmetric distributions as well as two data sets.     

敦煌本《大方等大集经》残卷缀合研究

《大方等大集经》是大乘佛教大集部经典的汇编,由北凉昙无谶、北齐那连提耶舍、隋那连耶舍等数代经师接续翻译而成。在现已刊布的敦煌文献中,该经共有171号,除4号某一卷首尾完整外,其余167号均为残卷或残片,其中不乏原属同一写卷而被撕裂为数号者。依据内容前后相承、残卷断痕或残字相互契合、乌丝栏等行款相同、书写风格或笔迹相近以及背面内容相合等因素,可将其中的38号残卷或残片缀合为13组。敦煌残卷的缀合是进一步整理研究的基础。通过缀合,除使原本身首异处的残卷或残片重聚之外,还纠正了《国家图书馆藏敦煌遗书》或《英国国家图书馆藏敦煌遗书》条记目录对北敦9793号、北敦11119号、斯627号等残卷著录信息的错误,更为进一步定名、断代及校理创造了条件。