A generic tool for cost estimating in aircraft design

A methodology to estimate the cost implications of design decisions by integrating cost as a design parameter at an early design stage is presented. The model is developed on a hierarchical basis, the manufacturing cost of aircraft fuselage panels being analysed in this paper. The manufacturing cost modelling is original and relies on a genetic-causal method where the drivers of each element of cost are identified relative to the process capability. The cost model is then extended to life cycle costing by computing the Direct Operating Cost as a function of acquisition cost and fuel burn, and coupled with a semi-empirical numerical analysis using Engineering Sciences Data Unit reference data to model the structural integrity of the fuselage shell with regard to material failure and various modes of buckling. The main finding of the paper is that the traditional minimum weight condition is a dated and sub-optimal approach to airframe structural design.

Application of a Generic Curriculum Change Management Process to Motivate and Excite Students

The School of Mechanical and Aerospace Engineering at Queen’s University Belfast is committed to enhancing the quality of student learning. A plan to implement curriculum change around this goal has been formulated and is already several years underway. A specific part of the plan involved instigating a first year introductory module to engage the students in the practice of their engineering discipline. The complicated nature of devising this type of module with regard to objectives, resources, timeframe and the number of students involved meant that a very systematic approach had to be adopted. This paper presents the simple but definitive change management process that facilitated in the creation of a first year Introduction to Engineering module. The generic nature of this process is described and its application to other facets of curriculum change is discussed. Within this process the importance of collaboration to establish a forward momentum is emphasised. This enables academic staff to progress as a group and build curriculum development based on their own experiences, expertise and established practice

Comparison of a centralised and distributed approach for a generic scheduling system

PEGS (Production and Environmental Generic Scheduler) is a generic production scheduler that produces good schedules over a wide range of problems. It is centralised, using search strategies with the Shifting Bottleneck algorithm. We have also developed an alternative distributed approach using software agents. In some cases this reduces run times by a factor of 10 or more. In most cases, the agent-based program also produces good solutions for published benchmark data, and the short run times make our program useful for a large range of problems. Test results show that the agents can produce schedules comparable to the best found so far for some benchmark datasets and actually better schedules than PEGS on our own random datasets. The flexibility that agents can provide for today's dynamic scheduling is also appealing. We suggest that in this sort of generic or commercial system, the agent-based approach is a good alternative.

Mole-rats from higher altitudes have greater thermoregulatory capabilities

Subterranean mammals (those that live and forage underground) inhabit a challenging microenvironment, with high levels of carbon dioxide and low levels of oxygen. Consequently, they have evolved specialised morphological and physiological adaptations. For small mammals that inhabit high altitudes, the effects of cold are compounded by low oxygen partial pressures. Hence, subterranean mammals living at high altitudes are faced with a uniquely demanding physiological environment, which presumably necessitates additional physiological adjustments. We examined the thermoregulatory capabilities of two populations of Lesotho mole-rat Cryptomys hottentotus mahali that inhabit a 'low' (1600 in) and a 'high' (3200 m) altitude. Mole-rats from the high altitude had a lower temperature of the lower critical point, a broader thermoneutral zone, a lower thermal conductance and greater regulatory non-shivering thermogenesis than animals from the lower altitude. However, minimum resting metabolic rate values were not significantly different between the populations and were low compared with allometric predictions. We suggest that thermoregulatory costs may in part be met by animals maintaining a low resting metabolic rate. High-altitude animals may adjust to their cooler, more oxygen-deficient environment by having an increased non-shivering thermogenesis whilst maintaining low thermal conductance. (c) 2006 Elsevier Inc. All rights reserved.

Differential osmoregulatory capabilities of common spiny mice (Acomys cahirinus) from adjacent microhabitats

The osmoregulatory function of common spiny mice Acomys cahirinus living on opposite slopes of the lower Nahal Oren ('Evolution Canyon') on mount Carmel, Israel, was investigated by increasing the salinity of the water source whilst maintaining a high-protein diet. The southern-facing slope (SFS) of this canyon differs from the northern-facing slope (NFS) as it receives considerably more solar radiation and consequently forms a more xeric, sparsely vegetated habitat. During the summer, mice living on the two opposite slopes significantly differed in their urine osmolality, which also increased significantly as dietary salinity increased. Offspring of wild-captured mice, born in captivity, and examined during the winter, continued to show a difference in osmoregulatory function depending on the slope of origin. However, they differed from wild-captured mice, as they did not respond to the increase in dietary salinity by increasing the concentration of their urine, but rather by increasing the volume of urine produced. This study shows that A. cahirinus occupying different microhabitats may exhibit differences in their ability to concentrate urine and thus in their ability to withstand xeric conditions. We suggest that they may also differ genetically, as offspring from the NFS and SFS retain physiological differences, but further studies will be needed to confirm this hypothesis.

Nonmarket Capabilities and the Prosecution of Trade Remedy Cases in the United States

The study investigates the prosecution of US trade remedy cases as examples of administrative government agency investigations and seeks to identify key capabilities for effective corporate political strategy targeting these institutions. Trade remedy cases are important policy tools, designed to protect domestic firms from ‘unfair’ import competition. The research contributes to the growing literature on corporate political activity and its links with superior outcomes in the marketplace. Three capabilities are identified: the capability to collect market/non-market intelligence, the capability to build and shape the administrative record, and the capability to align business practice with the US trade remedy institutions.

Japan’s Blair Witch: Restraint, Maturity, and Generic Canons in the British Critical Reception of Ring

This essay examines the British critical reception of the Japanese horror ? lm Ring. Critics claimed that Ring was representative of a non-graphic, suggestive tradition in horror, and used the ?lm rhetorically to present a sense of difference from teen horror ?lms such as Scream.

Resource access needs and capabilities as mediators of the relationship between VC firm size and syndication

Drawing from the resource-based view and transaction costs economics, we develop a theoretical framework to explain why small and large firms face different levels of resource access needs and resource access capabilities, which mediate the relationship between firm size and hybrid governance. Employing a sample of 317 venture capital firms, drawn across six European countries, we empirically assess our framework in the context of venture capital syndication. We estimate a path model using structural equation modeling and find, consistent with our theoretical framework, mediating effects of different types of resource access needs and resource access capabilities between VC firm size and syndication frequency. These findings advance the small business literature by highlighting the trade-offs that size imposes on firms that seek to manage their access to external resources through hybrid governance strategies.