The restricted likelihood ratio test at the boundary in autoregressive series

Abstract.  The restricted likelihood ratio test, RLRT, for the autoregressive coefficient in autoregressive models has recently been shown to be second-order pivotal when the autoregressive coefficient is in the interior of the parameter space and so is very well approximated by the     distribution. In this article, the non-standard asymptotic distribution of the RLRT for the unit root boundary value is obtained and is found to be almost identical to that of the     in the right tail. Together, these two results imply that the     distribution approximates the RLRT distribution very well even for near unit root series and transitions smoothly to the unit root distribution.     

Repressive adaptation in children with cancer.

The constructs of repressive adaptive style and avoidant coping (blunting) were assessed as possible explanatory factors for previously reported findings of lower self-reported depression in children with cancer. Pediatric oncology patients 7–16 years old (n?=?107) and healthy control participants (n?=?442) completed measures of depressive symptoms, trait anxiety, defensiveness, and approach and avoidant coping. Oncology patients scored significantly lower on measures of depression and trait anxiety, and higher on defensiveness. Applying the adaptive style paradigm, the oncology group showed a significant excess of repressors. Depressive symptoms differed as a function of adaptive style, with repressors demonstrating the lowest levels of self-reported depression. Children with cancer also reported greater use of blunting, but this difference was small and appeared unrelated to depression scores. Within the cancer group, repressive adaptation was unrelated to time elapsed since diagnosis. These findings are discussed with reference to the ongoing controversy regarding cancer–personality style associations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Assessment of damage tolerance in composites

Damage tolerance to processing and normal service damage has been assessed for carbon epoxy coupons and built-up panels in uniaxial loading. In coupons, the low velocity impact damage is more severe than damage in holes, delaminations or porosity and it causes compression strength loss from 58% at the barely visible threshold to 73% at the easily visible threshold. Damaged coupon fatigue ($\text{R}\text{= 10}$) S-N curves are relatively flat with 67% strength loss at 10⁶ cycles for impact damage. In built-up panels representing multispar (M-S) and multirib (M-R) wing designs, again impact damage is more severe than delaminations and the impacted M-R design is stronger than the impacted M-S design. Damage in two adjacent M-S midbays and at the edge of the M-R stringer flange are the critical locations for impact, but damage area strongly depends on the panel configuration. Impact damage grows under constant amplitude fatigue ($\text{R}\text{= 10}$) with peak load at 65% of damaged static strength for both M-S and M-R designs. Built-up configuration of the panels provides a significant increase in impact damage tolerance over that of coupons.     

Genetic adaptive search model of hot metal desulphurization

Genetic adaptive search (GAS) techniques, based on the mechanics of natural genetics, are used in this paper to find an optimal model of desulphurization process of iron-melt by powder injection. Industrial data on 400 t torpedo are used to evaluate contributions of transitory and permanent contact reactions to the overall desulphurization process during calcium carbide powder injection. The results obtained with GAS agree more closely with the plant data than the theoretical model. GAS solutions are also found to be better than regression models. These results suggest immediate application of GAS in similar metallurgical problems.     

Process Control and Optimization of the AOD Process Using Genetic Algorithm

The AOD process of making stainless steel is very popular because of its fast rate of decarburization and excellent control of composition and temperature. Both static and dynamic models are available for process control. The objective of the present study is to demonstrate the applicability of GA in adapting a process control model to a particular plant environment and subsequently optimize the blowing scheme to reduce overall costs. Deviation of the predicted results of the process control model, from the actual plant data, is first minimized by adjusting the chemical reaction rate parameters and heat balance equation. It is found that the adaptation of the process control model to an actual situation is feasible only below 0.8% carbon. After adapting the model, optimization is done through GA wherein the objective function contains the cost of refractory, process time, chromium loss etc. It is thus possible to devise a blowing scheme to arrive at the desired end point composition and temperature at the lowest cost.     

Nanoengineered Light‐Activatable Polybubbles for On‐Demand Therapeutic Delivery

Vaccine coverage is severely limited in developing countries due to inefficient protection of vaccine functionality as well as lack of patient compliance to receive the additional booster doses. Thus, there is an urgent need to design a thermostable vaccine delivery platform that also enables release of the bolus after predetermined time. Here, the formation of injectable and light‐activatable polybubbles for vaccine delivery is reported. In vitro studies show that polybubbles enable delayed burst release, irrespective of cargo types, namely small molecule and antigen. The extracorporeal activation of polybubbles is achieved by incorporating near‐infrared (NIR)‐sensitive gold nanorods (AuNRs). Interestingly, light‐activatable polybubbles can be used for on‐demand burst release of cargo. In vitro, ex vivo, and in vivo studies demonstrate successful activation of AuNR‐loaded polybubbles. Overall, the light‐activatable polybubble technology can be used for on‐demand delivery of various therapeutics including small molecule drugs, immunologically relevant protein, peptide antigens, and nucleic acids.     

Stokes flow past a swarm of porous approximately spheroidal particles with Kuwabara boundary condition

The solution of the problem of symmetrical creeping flow of an incompressible viscous fluid past a swarm of porous approximately spheroidal particles with Kuwabara boundary condition is investigated. The Brinkman equation for the flow inside the porous region and the Stokes equation for the outside region in their stream function formulations are used. As boundary conditions, continuity of velocity and surface stresses across the porous surface and Kuwabara boundary condition on the cell surface are employed. Explicit expressions are investigated for both inside and outside flow fields to the first order in a small parameter characterizing the deformation. As a particular case, the flow past a swarm of porous oblate spheroidal particles is considered and the drag force experienced by each porous oblate spheroid in a cell is evaluated. The dependence of the drag coefficient on permeability for a porous oblate spheroid in an unbounded medium and for a solid oblate spheroid in a cell on the solid volume fraction is discussed numerically an and graphically for various values of the deformation parameter. The earlier known results are then also deduced from the present analysis.