Alessandro Avenali

Minimizing the span of d-walks to compute optimum frequency assignments

Abstract.In this paper we deal with the Minimum Span Frequency Assignment Problem (MSFAP), that is the problem of assigning a limited set of radio frequencies to the base stations of a radio network so as the bandwidth occupancy is minimized and the overall interference is not too large. We present a new integer linear formulation for MSFAP in the multidemand case, which is the basis of an exact algorithm to compute both lower and upper bounds for MSFAP. Frequency assignments are represented as walks (sequence of nodes) in a graph. We look for a walk of minimum span, where the span of a walk is defined as the cost of a maximum cost subwalk (subsequence). The new approach is able to find optimum solutions over a large set of classical benchmarks.

A mechanism for supporting collective innovation: the open contract-based challenge

The paper proposes a multi-attribute combinatorial auction-based mechanism, called open contract mechanism (OCM), which allows an organization or an individual (seeker) to dynamically and simultaneously bargain the features of distinct innovation contracts with other organizations and individuals (solvers), in general collective innovation environments. In such contexts, a seeker does not possess specific skills and technical knowledge which are crucial for an innovation or for a part of a new product development project, while some solvers might be willing to provide their relevant know-how to the seeker. To induce collaboration between the seeker and solvers, voluntary and legally enforceable agreements need to be formulated, where a fair evaluation of the intellectual property rights of any party is guaranteed, and all technical and economic aspects are detailed. Therefore, OCM allows the seeker to involve solvers in defining a collection of open contract schemes, related to the supply of the required specific skills and technical knowledge. The solvers must submit offers in terms of contract versions of these contract schemes. In such a way, OCM aims at partially extracting from the solvers their multidimensional private information regarding economic and technical issues, in order to reduce the occurrences of pre- and post-contractual opportunistic behaviours.

Broadband investment and welfare under functional and ownership separation

We study how the vertical industry structure affects investment in network quality and social welfare, with a focus on the prospective deployment of high-speed broadband access networks (the so-called NGA). We model pros and cons of vertical separation, namely, pro-competitive effects and loss of some efficiencies of vertical integration, and distinguish functional separation from ownership separation. Our findings challenge the presumption that (compared with vertical integration) vertical separation reduces investment incentives and involves a trade-off between promoting consumer surplus and ensuring investment. While investment is higher under ownership rather than functional separation, the latter may yield the highest social welfare among vertical industry structures. Furthermore, the incumbent may voluntarily opt for functional separation, but in some of these cases, prohibiting separation improves welfare.

Brokering infrastructure for minimum cost data procurement based on quality-quantity models

Inter-organization business processes involve the exchange of structured data across information systems. We assume that data are exchanged under given condition of quality (offered or required) and prices. Data offer may include bundling schemes, whereby different types of data are offered together with a single associated price and quality. We describe a brokering algorithm for obtaining data from peers, by minimizing the overall cost under quality requirements constraints. The algorithm extends query processing techniques over multiple database schemas to automatically derive an integer linear programming problem that returns an optimal matching of data providers to data consumers under realistic economic cost models.

Resolution Branch and Bound and an Application: The Maximum Weighted Stable Set Problem

We propose a new resolution algorithm, called resolution branch and bound (RBB), where a branch-and-bound scheme is empowered by exploiting the information contained in a family of closed subproblems, collected by a full resolution phase. In particular, we use this information to define a new branching rule that seems able to reduce the risk of incurring inappropriate branchings. We apply RBB and the proposed branching rule to the maximum weighted stable set problem, as its features allow us to speed up a time-consuming step in the full resolution phase. To compute upper bounds, we generalize to the weighted case the polynomial time procedure provided by Mannino and Sassano [Mannino, C., A. Sassano. 1994. An exact algorithm for the maximum stable set problem. Computational Optim. Appl.3 243--258] for the unweighted case. Computational results validate the effectiveness of the provided branching rule and the good performance of RBB on many DIMACS benchmarks.

Un modello per la determinazione del costo standard nei servizi di trasporto pubblico locale su autobus in Italia

We estimate the standard costs in the Italian local bus transport system by means of a top down approach. Commercial speed results the most important cost driver, while economies of scale are low and only present in the case of small transport operators. Medium sized and large operators exhibit diseconomies of scale. We find a positive correlation between investments in bus fleet and service cost. The model aims at introducing policy criteria for the allocation of public funds earmarked to the local public transit sector among Italian regions.

Developing Web-Based Dynamic Negotiation towards Collective Innovation: the Open Contract Mechanism

The scope of this chapter is to propose the design and the implementation of an innovative web-based tool, the Open Contract Mechanism (OCM). OCM allows client companies and suppliers to dynamically and simultaneously bargain the clauses and the characteristics of distinct innovation contracts in general open innovation and collaborative crowdsourcing environments. The OCM can be implemented inside open innovation web-based platforms for evaluating offers and determining the winning one, and therefore guaranteeing valuable binding contract clauses.

Facility management outsourcing through multi-attribute auctions

We introduce a multi-attribute auction-based mechanism with an endogenous score as a means to innovate the procurement of facility management (FM) activities in private and public sectors. The mechanism allows the procurer to request bids on several measurable technical and economic attributes of the supply of FM services. The procurer also assigns weights to such features to signal their importance to the sellers, while the score obtained with respect to each attribute is endogenously determined on the basis of the submitted offers for the attribute. The proposed mechanism mitigates the most relevant drawbacks due to the lack of skills and of crucial information on the outsourced non-core activities, while requiring the procurer very little auction design effort. On the one hand, the mechanism can extract from suppliers valuable private technical knowledge as well as the information on the supply cost. On the other hand, it saves the procurer from detailing ex ante both the score which will be assigned to any possible bid for every attribute and the exact value to require for any technical feature of the supply.

Vertical Control and Parallel Trade under Asymmetric Information

Parallel trade (PT) is a practice related to arbitrage operations in international trade. We provide a rationale for PT as an opportunistic behaviour by an international wholesaler who is privately informed about market demands in two countries where a multinational firm operates. This alternative theory of PT contributes to an explanation of why PT has gained considerable importance in various industries, and why it has not yet resulted in price convergence across relevant countries. Indeed, we find that asymmetric information enlarges the scope for PT, relative to complete information, and possibly increases crosscountry differences in prices. The European Commission supports PT as a means to achieve the integration of national markets, to the benefit of all citizens. However, under asymmetric information, consumers benefit from PT only with a high volume of parallel imports (e.g., when arbitrage costs are low); otherwise competition among wholesalers can be an effective substitute for PT. Furthermore, an important implication of PT is the transfer of profits from the manufacturer to the wholesaler. Therefore, in R&D-intensive industries, such as pharmaceuticals, policy makers should anticipate the likely consequences of PT under asymmetric information on the long-run incentives to innovate.

Can access regulation promote broadband investment and consumer welfare

A facility-based firm invests in network quality and sells wholesale local access to two competing downstream firms, which offer vertically differentiated value-added services. We show that, contrary to common wisdom, access price regulation may simultaneously improve consumer welfare and foster investment incentives compared with regulatory forbearance. This result is robust to a number of different model specifications: (i) the bottleneck owner is vertically integrated, and: (a) the regulator can commit before the investment stage, or: (b) there are first-mover advantages, such as consumer switching costs; (ii) the bottleneck owner is vertically separated. We also show that, under access price regulation, consumer welfare and network quality may be higher under vertical separation than under vertical integration.