Asymptotic Theory for Kernel Estimators under Moderate Deviations from a Unit Root, with an Application to the Asymptotic Size of Nonparametric Tests

We provide new asymptotic theory for kernel density estimators, when these are applied to autoregressive processes exhibiting moderate deviations from a unit root. This fills a gap in the existing literature, which has to date considered only nearly integrated and stationary autoregressive processes. These results have applications to nonparametric predictive regression models. In particular, we show that the null rejection probability of a nonparametric t test is controlled uniformly in the degree of persistence of the regressor. This provides a rigorous justification for the validity of the usual nonparametric inferential procedures, even in cases where regressors may be highly persistent.Comment: Author accepted version for Econometric Theory. 26 pp. + 8 pp. supplemen

Patricia A. Duffy: Lifetime Achievement Award

Teaching/Communication/Extension/Profession,

An analysis of design reuse benefits

Although the concept of design reuse is accepted as a valid approach to design, little attempt has been made to formalise the elements that constitutes design reuse. The few approaches formalising design reuse, e.g. 'Concept Reuse Approach for Engineering Design Problem Solving', tend to be prescriptive, detailing procedures and functions that have to be carried out in order to reuse designs. Such procedural methods fail to identify the underlying processes and knowledge resources of design reuse and tend to relate to an approach or method of tackling reuse rather than reuse itself. It would seem that the only current model encompassing design reuse is 'The Design Reuse Process Model'. The elements of this reuse process model have been used as a basis upon which to identify and analyse the benefits of design reuse when considering key metrics relating to competitive product development,that is time, cost, quality and performance

Preparation of Translationally Competent tRNA by Direct Chemical Acylation

Nonsense codon suppression for unnatural amino acid incorporation requires the preparation of a suppressor aminoacyl-tRNA. Chemical acylation strategies are general but inefficient and arduous. A recent report (J. Am. Chem. Soc. 2007, 129, 15848) showed acylation of RNA mediated by lanthanum(III) using amino acid phosphate esters. The successful implementation of this methodology to full-length suppressor tRNA is described, and it is shown that the derived aminoacyl-tRNA is translationally competent in Xenopus oocytes

3D Simulation of Partial Discharge in High Voltage Power Networks

Open accessPartial discharge (PD) events arise inside power cables due to defects of cable’s insulation material, characterized by a lower electrical breakdown strength than the surrounding dielectric material. These electrical discharges cause signals to propagate along the cable, manifesting as noise phenomena. More significantly, they contribute to insulation degradation and can produce a disruptive effect with a consequent interruption of power network operation. PD events are, therefore, one of the best ‘early warning’ indicators of insulation degradation and, for this reason, the modeling and studying of such phenomena, together with the development of on-line PDs location methods, are important topics for network integrity assessment, and to define methods to improve the power networks’ Electricity Security. This paper presents a 3D model of PD events inside a void in epoxy-resin insulation cables for High Voltage (HV) power networks. The 3D model has been developed using the High Frequency (HF) Solver of CST Studio Suite® software. PD events of a few µs duration have been modelled and analyzed. The PD behavior has been investigated using varying electrical stress. A first study of the PD signal propagation in a power network is described

EFFECTS OF AN EXPORT SUBSIDY ON THE U.S. COTTON INDUSTRY

In this study, the effects of an export subsidy for cotton are analyzed using a linear elasticity model. The study explicitly addresses the interaction of current domestic policies with the proposed export subsidy. An export subsidy may be a successful method of reducing the government costs of the cotton program.International Relations/Trade,

ICI optical data storage tape

Optical data storage tape is now a commercial reality. The world's first successful development of a digital optical tape system is complete. This is based on the Creo 1003 optical tape recorder with ICI 1012 write-once optical tape media. Several other optical tape drive development programs are underway, including one using the IBM 3480 style cartridge at LaserTape Systems. In order to understand the significance and potential of this step change in recording technology, it is useful to review the historical progress of optical storage. This has been slow to encroach on magnetic storage, and has not made any serious dent on the world's mountains of paper and microfilm. Some of the reasons for this are the long time needed for applications developers, systems integrators, and end users to take advantage of the potential storage capacity; access time and data transfer rate have traditionally been too slow for high-performance applications; and optical disk media has been expensive compared with magnetic tape. ICI's strategy in response to these concerns was to concentrate its efforts on flexible optical media; in particular optical tape. The manufacturing achievements, media characteristics, and media lifetime of optical media are discussed

Agricultural Economics and Interdisciplinary Work

Teaching/Communication/Extension/Profession,