341 research outputs found
Road infrastructure concession practice in Europe
In a road infrastructure concession, a public authority grants specific rights to a private, or semi-public company to construct, overhaul, maintain, and operate infrastructure for a given period. By contract, the public authority charges that company with making the investments needed to create the service at its own cost, and to operate it at its own risk. The price paid to the company comes from the service's users, the public authority, or both. In 1999, out of roughly 51,000 kilometers of European motorways, about 17,000 kilometers (33 percent) were concessioned - 16,400 kilometers by toll, and 670 kilometers by shadow toll (design, build, finance, and operate arrangements). Of these, 73 percent are managed by the public sector, and 27 percent by private companies. State-owned companies have been important in European motorway concessions. Systems vary among countries, for example, in how they share risks between the concession authority, and the concession company. As the motorway network has grown denser, attributing commercial risk has become more difficult. Increasingly, public authorities must play a greater regulatory role. Already, bad experiences have made the private sector reluctant to bear the commercial risk. Ant the commercial risk is sometimes too great to be carried by the concession company alone. Commercial risk should be controlled by mechanisms incorporated in the contract, but control of the commercial risk must not eliminate incentives. In addition to safeguarding the community's interests, the public concession authority, must increase citizen awareness about concession decisions, to ensure their social acceptability. Formulas for determining toll charges, differ through Europe. So do criteria for selecting concession companies. In 1999, the main criteria used were these: 1) the amount of public subsidy required; 2) the credibility of the financial arrangements; 3) the project's technical quality; 4) the operating strategy, and price policy; and, 5) the reputation of the concession company (whether it has a construction company among its shareholders, for example). The increasingly frequent use of private funding, must be taken into account when defining the training required by personnel responsible for monitoring the concessions.Information Technology,Roads&Highways,Economic Adjustment and Lending,Banks&Banking Reform,Public Sector Economics&Finance,Roads&Highways,Toll Roads,Economic Adjustment and Lending,Airports and Air Services,Public Sector Economics&Finance
Modeling Corner Solutions with Panel Data: Application to the Industrial Energy Demand in France
Modeling Corner Solutions with Panel Data: Application to the Industrial Energy Demand in France.
Modeling Corner Solutions with Panel Data: Application to Industrial Energy Demand in France
This paper is providing an initial empirical application of Lee and Pitt's approach to the problem of corner solutions with panel data. This approach deals with corner solutions in a manner consistent with behavioral theory. Furthermore it allows the use of flexible form cost functions and general error structure. In this model energy demand, at industrial plant level, is the result of a discrete choice of type of energy to consume and a continuous choice to define the demand level. The econometric model is essentially an endogenous switching regime model which require the evaluation of multivariate probability integrals. We estimate the random effect model by maximum likelihood using a panel of industrial French plants. We verify that estimations predict globally well the model and we simulate the effects of prices variations and a CO2 tax on energy demand.
Satellite system performance assessment for in-flight entertainment and air traffic control
Concurrent satellite systems have been proposed for IFE (In-Flight Entertainment) communications, thus demonstrating the capability of satellites to provide multimedia access to users in aircraft cabin. At the same time, an increasing interest in the use of satellite communications for ATC (Air Traffic Control) has been motivated by the increasing load of traditional radio links mainly in the VHF band, and uses the extended capacities the satellite may provide. However, the development of a dedicated satellite system for ATS (Air Traffic Services) and AOC (Airline Operational Communications) seems to be a long-term perspective. The objective of the presented system design is to provide both passenger application traffic access (Internet, GSM) and a high-reliability channel for aeronautical applications using the same satellite links. Due to the constraints in capacity and radio bandwidth allocation, very high frequencies (above 20 GHz) are considered here. The corresponding design implications for the air interface are taken into account and access performances are derived using a dedicated simulation model. Some preliminary results are shown in this paper to demonstrate the technical feasibility of such system design with increased capacity. More details and the open issues will be studied in the future of this research work
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