Strictly positive definite kernels on the 22-sphere: beyond radial symmetry

The paper introduces a new characterisation of strictly positive definiteness for kernels on the 2-sphere without assuming the kernel to be radially (isotropic) or axially symmetric. The results use the series expansion of the kernel in spherical harmonics. Then additional sufficient conditions are proven for kernels with a block structure of expansion coefficients. These generalise the result derived by Chen et al. 2003 for radial kernels to non-radial kernels

Why do masterplans fail?

Planning systems are in general addressed to make spatial projects conform to a plan, by assigning use rights in land through legally binding zoning maps and implementation rules, as it was possible to predict and impose sequences of actions and reactions in the realm of urban development. The cultural ideals of hierarchy and of dirigisme, based on the assumption that the State is the keeper of the collective interest, lie at the root of such ‘conforming' setting of modern planning systems. Neither the reiterated evidence of failure nor the acknowledgment that collective interest is usually the primary victim of planning ineffectiveness have led to conceive true alternatives so far. However, the exception of few countries where plans are non-binding and public authorities can evaluate which specific development projects are deserving new land use rights (the UK is one rare but prominent example), on the one hand, and the increasing experience of EU urban and spatial development programmes implying responsible evaluation mechanisms for co-funding projects, on the other, might let reflect about a possible model of ‘performing' planning syste

Whatever happened to planning? Italy after EU intervention

As clearly stated by the Conference's proposal, after a decade of European urban and spatial policies, it seems the time now for a deeper reflection on their influences in spatial and urban planning practices in the EU countries. A brief survey on what concerns Italy allows us to observe that EU planning intervention has affected practically all the levels of territorial government, through many dimensions of what is first and foremost a material innovation, triggered as if by contamination by the arrival on the scene of the new institutional player. Changes are mainly visible in: - the shaping of spatial frameworks for planning policies; - the proliferation of new, different tools for regional and urban planning; - a progressive re-equilibrium between "central" and "peripheral" regions; - new institutional and administrative attitudes to negotiation and partnership; - the cultural way of treating urban problems and conceiving planning; - new emerging competences and "jobs" for planners. A reflection on the deepest meaning of those many changes - and, more generally, on the substantial reasons of the (not institutionalised) EU intervention in planning policies - could contribute to better understanding on what, not only in Italy, can be expected from EU planning and what, consequently, can be improved in European development strategie

Conforming and performing planning systems in Europe: an unbearable cohabitation

Two planning system models currently cohabit in Europe: a more traditional and widespread one, aspiring to ‘conform' single projects to a collective strategy; and a different and less institutionalised one, promoting those projects capable of ‘performing' a collective strategy. Historical and cultural reasons may explain the major diffusion and persistence of the former, but current needs of territorial governance lead to consider the latter as preferable. This is especially so in the light of the EU integration process, such cohabitation is no longer bearable and conforming ambitions should be definitively abandone

Conforming and performing planning: an unbearable cohabitation

Territorial governance in Europe is managed by two models of planning: a more traditional and common one, aspiring to ‘conform' single projects to a collective strategy; a novel and less institutionalised one, promoting projects able to ‘perform' the collective strategy. The present contribution argues that current cohabitation of these two models is no longer bearable and that, particularly, conforming ambitions should be abandone

Cohesion and subsidiarity: towards good territorial governance in Europe

The message of this paper is twofold: (a) the pursuit of territorial cohesion, the importance of which the new European Constitution recognises, requires coordination of national planning systems; and (b) subsidiarity, a Community principle usually invoked to counteract it, should instead become the principle underlying a feasible and effective form of such coordination at the EU (European Union) level. Indeed, the Constitution should at least encourage planners to discuss principles of good EU territorial governance by addressing the performance of statutory planning systems in the common area of territorial cohesion. In brief, these principles might be termed vertical subsidiarity, horizontal subsidiarity, and the coordination between subsidiarity and cohesion

A general time element using Cartesian coordinates: Eccentric orbit integration

A general time element, valid with any arbitrary independent variables, and used with Cartesian coordinates for the integration of the elliptic motion in orbits, is examined. The derivation of the time element from a set of canonical elements of the Delaunay type, developed in the extended phase space, is presented. The application of the method using an example of a transfer orbit for a geosynchronous mission is presented. The eccentric and elliptic anomaly are utilized as the independent variable. The reduction of the in track error resulting from using Cartesian coordinates with the time element is reported

Editorial: Roots—the hidden provider

No abstract available

Are Prices Really Affected by Mergers?

During the 80s, several empirical studies have shown a positive correlation between concentration, prices and profits. It is well known that these estimates all suffer from simultaneity bias: market structure and prices are affected by common factors, some of which are not observable, which rules out any causal interpretation of cross-sectional correlations. Mergers are an interesting instrument to identify the (static) impact of concentration on prices, since they induce breaks in strategic interactions between actors. The few ex post studies on mergers that are currently available are difficult to generalize, because they pertain to specific markets. This study looks more systematically to selling prices in 63 sectors observed between 1989 and 2002. The approach that has been chosen is a difference in differences approach, applied to price movements around mergers. The rate of inflation in a sector where a merger has occurred is compared to a counterfactual. In a simple framework, in line with previous studies (McCabe 2002), this counterfactual would be built as the mean of inflation rates in other sectors. This paper focuses on more relevant estimates, provided by a factor model. This methodology allows tracking the profile of prices around mergers. We separate mergers between French firms and mergers between other European firms controlled by European authorities (and thus assumed to have affected the common market). We also distinguish mergers having led to an in-depth inquiry by competition authorities (« phase 2 ») and those benefiting from a shorter procedure (« phase 1 »). We observe an acceleration of price movements around the most important of French mergers, but not for the ones authorized under phase 1. We also observe a break in price movements for mergers between foreign firms examined by the European Commission, generally in the other direction.mergers, prices, factor models