传感论美学：一个理论的框架分析

计算机、通信与传感是现代科技的三大支柱,它们不约而同地与美学结盟。计算机美学与信息论美学方兴未艾,传感技术亦日益成为通约计算机技术与通信技术的掮客。传感论在美学的理论框架中逐渐形成了自己的研究对象、参数内容与理论目标及学科价值,传感论美学所具有的学科理论的合法性席位昭示它自身成为技术美学新成员是可能的。同时,传感技术在信息技术中的掮客身份愈来愈抽象化与审美化,信息技术的生产主体、知识构型、商业流通、编码解读的科技化亦等同于社会风险的不断增加,这些风险也暗示亟待建设传感论美学理论的迫切性与意义。     

Discriminant analysis under parameter restrictions statistical and computational aspects

In the paper, it is shown that the error rate of the discriminant analysis can be diminished when restrictions for the parameters are valid. To find suitable restrictions, at first the properties of hierarchical and other multivariate systems are investigated. Then, in a practical section, a modification of the discriminant analysis is offered that consists in decreasing the estimated partial correlations. Finally in the theoretical section, it is veri¬fied that an improvement of the discriminant analysis is attained by a suitable correctionof the positive and negative signs of the discriminant function.     

Transmuted two-parameter Lindley distribution

In this study, we propose a new distribution using the quadratic rank transmutation map named as transmuted two-parameter Lindley distribution (TTLD). This distribution is more flexible than the two-parameter Lindley distribution (TLD). The properties of the TTLD are examined, and estimation methods for the parameters of this distribution are discussed. The usefulness of the TTLD is demonstrated on some real data.     

Interval robust design under contaminated and non normal data

Abstract

Robust parameter design (RPD) is an effective tool, which involves experimental design and strategic modeling to determine the optimal operating conditions of a system. The usual assumptions of RPD are that normally distributed experimental data and no contamination due to outliers. And generally the parameter uncertainties in response models are neglected. However, using normal theory modeling methods for a skewed data and ignoring parameter uncertainties can create a chain of degradation in optimization and production phases such that misleading fit, poor estimated optimal operating conditions, and poor quality products. This article presents a new approach based on confidence interval (CI) response modeling for the process mean. The proposed interval robust design makes the system median unbiased for the mean and uses midpoint of the interval as a measure of location performance response. As an alternative robust estimator for the process variance response modeling, using biweight midvariance is proposed which is both resistant and robust of efficiency where normality is not met. The results further show that the proposed interval robust design gives a robust solution to the skewed structure of the data and to contaminated data. The procedure and its advantages are illustrated using two experimental design studies.     

追踪场中宇宙学参量的演化

考虑的宇宙模型为在平坦空间的Friedmann—Robertson—Walker（FRW）宇宙，且宇宙中仅包含具有指数势的标量场与具有正压的暗物质的两种流体；较为详细地数值研究了在宇宙的追踪演化过程中，各个宇宙学参量随标度因子变化的规律，得到的结果不仅与目前观测结果相一致，而且还有助于理解在追踪下各个宇宙学参量的演化行为．     

Staffing Call Centers with Uncertain Arrival Rates and Co‐sourcing

In a call center, staffing decisions must be made before the call arrival rate is known with certainty. Once the arrival rate becomes known, the call center may be over‐staffed, in which case staff are being paid to be idle, or under‐staffed, in which case many callers hang‐up in the face of long wait times. Firms that have chosen to keep their call center operations in‐house can mitigate this problem by co‐sourcing; that is, by sometimes outsourcing calls. Then, the required staffing N depends on how the firm chooses which calls to outsource in real time, after the arrival rate realizes and the call center operates as a M/M/N + M queue with an outsourcing option. Our objective is to find a joint policy for staffing and call outsourcing that minimizes the long‐run average cost of this two‐stage stochastic program when there is a linear staffing cost per unit time and linear costs associated with abandonments and outsourcing. We propose a policy that uses a square‐root safety staffing rule, and outsources calls in accordance with a threshold rule that characterizes when the system is “too crowded.” Analytically, we establish that our proposed policy is asymptotically optimal, as the mean arrival rate becomes large, when the level of uncertainty in the arrival rate is of the same order as the inherent system fluctuations in the number of waiting customers for a known arrival rate. Through an extensive numerical study, we establish that our policy is extremely robust. In particular, our policy performs remarkably well over a wide range of parameters, and far beyond where it is proved to be asymptotically optimal.     

主题关联性阅读模式的建构——兼论语境参数论与TEM-8语篇阅读

探讨了语篇生成之主题关联性机制,并从语境参数论出发,结合TEM-8阅读考试真题分析阐述了建立主题关联性阅读模式的可行性与重要性,强调语境参数对于语篇阅读理解的重要意义.这是提高英语语篇阅读效率与TEM-8阅读考试成绩的有效途径.     

On Minimum Distance Estimation Using Kolmogorov-Lévy Type Metrics

Let X ₁, . . ., X_n be independent identically distributed random variables with a common continuous (cumulative) distribution function (d.f.) F , and F^_n the empirical d.f. (e.d.f.) based on X ₁, . . ., X_n . Let G be a smooth d.f. and Gθ = G (·–θ) its translation through θ∈ R . Using a Kolmogorov-Lévy type metric ρ_α defined on the space of d.f.s. on R , the paper derives both null and non-null limiting distributions of √ n [ ρ_α ( F_n , Gθ_n ) – ρ_α ( F, G_θ )], √ n (θ _n –θ) and √ nρ_α ( Gθ , Gθ ), where θ _n and θ are the minimum ρ_α -distance parameters for F_n and F from G , respectively. These distributions are known explicitly in important particular cases; with some complementary Monte Carlo simulations, they help us clarify our understanding of estimation using minimum distance methods and supremum type metrics. We advocate use of the minimum distance method with supremum type metrics in cases of non-null models. The resulting functionals are Hadamard differentiable and efficient. For small scale parameters the minimum distance functionals are close to medians of the parent distributions. The optimal small scale models result in minimum distance estimators having asymptotic variances very competitive and comparable with best known robust estimators.     

铁基非晶合金非晶形成能力的分子动力学模拟

采用分子动力学方法,模拟了Fe60Cr20Mo20和Fe50Cr20Mo20M10(M=Ni, W) 铁基非晶合金的形成过程,通过加热至熔融态再淬火的方法计算出了Fe60Cr20Mo20、Fe50Cr20Mo20Ni10和Fe50Cr20Mo20W10三种合金形成非晶的临界冷速及一系列热力学参数。结果表明,三种合金形成非晶的临界冷速分别为15.7 K/ps、3.62 K/ps和1.04 K/ps,四元合金较三元合金形成非晶所需的临界冷速大大降低,而W元素的添加更能提高合金的非晶形成能力。另外,通过热力学参     

中国银行业成本效率实证研究(1999-2010)——基于SFA测度方法的应用

以1999-2010年12年间国内14家商业银行样本数据为基础, 基于随机前沿效率分析原理, 利用参数估计SFA(Stochastic Frontier Approach)分析法, 评估金融改革以来银行成本效率的分布及演化趋势。研究表明:(1)样本期内银行整体成本效率呈先改善后趋于平稳态势, 近年来无明显波动。(2)国有商业银行成本效率下降显著, 无效率项影响明显;股份制商业银行成本效率除个别银行外, 大多数呈改善趋势;国有与股份制银行之间成本效率差异呈扩大趋势, 应予以重视。(3)未能发现资产规模、权益与银行成本效率之间的显著性相关关系。(4)国有商业银行成本效率存在明显改善空间, 内部治理和运营管理改革有待进一步强化。