When Is It Optimal to Delegate: The Theory of Fast-Track Authority

With fast-track authority (FTA), the US Congress delegates trade-policy authority to the President by committing not to amend a trade agreement. Why would it cede such power? We suggest an interpretation in which Congress uses FTA to forestall destructive competition between its members for protectionist rents. In our model: (i) FTA is never granted if an industry operates in the majority of districts; (ii) The more symmetric the industrial pattern, the more likely is FTA, since competition for protectionist rents is most punishing when bargaining power is symmetrically distributed; (iii) Widely disparate initial tari§s prevent free trade even with FTA

A disturbance based control/structure design algorithm

Some authors take a classical approach to the simultaneous structure/control optimization by attempting to simultaneously minimize the weighted sum of the total mass and a quadratic form, subject to all of the structural and control constraints. Here, the optimization will be based on the dynamic response of a structure to an external unknown stochastic disturbance environment. Such a response to excitation approach is common to both the structural and control design phases, and hence represents a more natural control/structure optimization strategy than relying on artificial and vague control penalties. The design objective is to find the structure and controller of minimum mass such that all the prescribed constraints are satisfied. Two alternative solution algorithms are presented which have been applied to this problem. Each algorithm handles the optimization strategy and the imposition of the nonlinear constraints in a different manner. Two controller methodologies, and their effect on the solution algorithm, will be considered. These are full state feedback and direct output feedback, although the problem formulation is not restricted solely to these forms of controller. In fact, although full state feedback is a popular choice among researchers in this field (for reasons that will become apparent), its practical application is severely limited. The controller/structure interaction is inserted by the imposition of appropriate closed-loop constraints, such as closed-loop output response and control effort constraints. Numerical results will be obtained for a representative flexible structure model to illustrate the effectiveness of the solution algorithms

Active versus passive damping in large flexible structures

Optimal passive and active damping control can be considered in the context of a general control/structure optimization problem. Using a mean square output response approach, it is shown that the weight sensitivity of the active and passive controllers can be used to determine an optimal mix of active and passive elements in a flexible structure

Fast-Track Authority: A Hold-Up Interpretation.

A central institution of US trade policy is Fast-Track Authority (FT), by whichCongress commits not to amend a trade agreement that is presented to it for ratifica-tion, but to subject the agreement to an up-or-down vote.We offer a new interpretation of FT based on a hold-up problem. If the US gov-ernment negotiates a trade agreement with the government of a smaller economy, asthe negotiations proceed, businesses in the partner economy, anticipating the openingof the US market to their goods, may make sunk investments to take advantage ofthe US market, such as quality upgrades to meet the expectations of the demandingUS consumer. As a result, when the time comes for ratification of the agreement, thepartner economy will be locked in to the US market in a way it was not previously.At this point, if Congress is able to amend the agreement, the partner country hasless bargaining power than it didex ante, and so Congress can make changes that areadverse to the partner. As a result, if the US wants to convince such a partner countryto negotiate a trade deal, it mustfirst commit not to amend the agreementex post.Inthis situation, FT is Pareto-improving

Waterfowl Populations in Eastern Lancaster Sound and Western Baffin Bay

The seasonal distributions of oldsquaws (Clangula hyemalis), common eiders (Somateria mollissima) and king eiders (S. spectabilis) were determined through aerial surveys in eastern Lancaster Sound (1976, 1978 and 1979) and northwest Baffin Bay (1978, 1979). Sightings of geese are summarized in an Appendix. The major spring influx of both eiders occurs about the second week of May but most oldsquaws do not arrive until the first half of June. In spring, all three species are rare in offshore areas, are most abundant along coasts in the northern half of the study area, and tend to depart to nesting areas during the last week of June. Oldsqaws molt along coasts of Lancaster Sound and northwest Baffin Bay, but both species of eiders undertake molt migrations. Three waves of eider out-migration were detected in 1976 and 1978. Distribution and movements within the study area are related to probable migrations routes and ice conditions.Key words: oldsquaw, king eider, common eider, geese, aerial surveys, distribution, molt migration, eastern Arctic, Baffin Bay, Lancaster Soun

NH3 in IRC plus 10216

Ammonia was detected in the circumstellar envelope of IRC +10216 by means of three infrared absorption lines in the nu sup 2 band around 950/cm. The lines are fully resolved at a resolution of 0.22 km/sec and indicate that most of the circumstellar gas is accelerated to expansion velocities around 14 km/sec within a few stellar radii. The NH3 profiles indicate a rotational temperature between 400 and 700 K, and H2 density between 10 to the 8th power/cu cm and 10 to the 10th power/cu cm, and NH3 column density of 10 to the 17th power/sq cm. The H2 density indicates that the mass of the circumstellar envelope within a 1 arcsec radius is approximately 0.1 solar masses

Clothing longevity perspectives: exploring consumer expectations, consumption and use

The production, distribution, use and end-of-life phases of the clothing lifecycle all have significant environmental impacts, but complete lifecycle assessment has identified that extending the active life of garments through design, use and re-use is the single most effective intervention in reducing the overall impact of the clothing industry (WRAP, 2011). In response, Government funded clothing longevity research seeks to develop and test industry-led design strategies to influence and enable consumers to keep garments in active use for longer (Cooper et al., 2014). While recent UK research has indicated significant potential to influence more sustainable consumer behaviour (Langley et al., 2013; YouGov, 2012), up-to-date qualitative research is required to discover how consumer attitudes, expectations and behaviours in relation to clothing lifetimes affects garment care and clothing use. This will help to inform industry-led strategies by understanding where effective changes can be made that will potentially have most impact. This paper presents preliminary findings from a Defra funded action based research project, ‘Strategies to improve design and testing for clothing longevity’. Qualitative research methods are used to explore consumer attitudes, expectations and behaviours at purchase, use and disposal stages of garment lifetimes, and gather data on practices of garment wash, wear, care and maintenance in everyday life. The research findings are discussed in relation to industry-led strategies aimed at extending the life of clothes

Spring Migration and Habitat Use by Seabirds in Eastern Lancaster Sound and Western Baffin Bay

The status and distribution, during spring and early summer, of northern fulmars (Fulmarus glacialis), black-legged kittiwakes (Rissa tridactyla), thick-billed murres (Uria lomvia) and black guillemots (Cepphus grylle) were studied during aerial surveys in eastern Lancaster Sound (1976, 1978, 1979) and western Baffin Bay (1978, 1979). Fulmars were present in the study area by early May but most undertook a pre-laying exodus in late May before returning in early June to nest. During June and the first half of July, they were common along coasts and in offshore areas throughout the region. Kittiwakes returned in late May and numbers increased through June, both along coasts and offshore. Numbers offshore decreased after nesting, which begins in mid- to late June. Murres returned to the study area around mid-May and were abundant during June, especially near their colonies. Densities were generally highest along fast ice edges. Guillemots returned to the study area in the last half of May and were widespread along coasts, ice edges and in offshore areas during June. Densities were much lower after nesting, which commences in late June. Densities of fulmars, murres and guillemots were much higher along fast ice edges than along ice-free coasts: the opposite was true of kittiwakes. Offshore, fulmars and kittiwakes preferred waters with little or no pack ice, whereas murres and guillemots preferred moderate to heavy pack ice. These habitat preferences affected the distributions of the species within the region. Ice conditions in eastern Lancaster Sound were markedly different during each of the three years of study. Effects of different ice conditions on the species' distributions are assessed. Seabird distributions in six parts of the region are summarized.Key words: fulmar, kittiwake, murre, guillemot, distribution, habitat use, Lancaster Sound, Baffin Ba

Effect of homogenisation conditions on recrystallisation in the Al-Mg-Mn alloy AA5454

The purpose of the present work is to understand the microstructure development and, particularly, to control the progress of recrystallisation in hot strip in the Al-Mg-Mn alloy AA 5454, which is typically used for the manufacture of structural automotive components. The chemical composition, together with the thermomechanical processing history of this material, has a strong influence on the microstructure of the product and the resulting properties as it is supplied to the customer. Electrical conductivity measurements, thermal analysis and electron microscopy have been carried out to characterise the evolution of precipitation state at various stages in the processing route. The conditions of the homogenisation heat treatment have been varied, and the effect on subsequent recrystallisation after hot rolling has been evaluated in both the as cast and rough rolled condition by optical microscopy techniques. Results indicate that the conditions of homogenisation heat treatment and roughing rolling are critical for the generation of a suitable recrystallised microstructure in AA 5454 hot strip. A new two stage homogenisation practice has been developed to expedite post-rolling recrystallisation in this alloy