The multi-path Traveling Salesman Problem with stochastic travel costs

Given a set of nodes, where each pair of nodes is connected by several paths and each path shows a stochastic travel cost with unknown distribution, the multipath Traveling Salesman Problem with stochastic travel costs aims at finding an expected minimum Hamiltonian tour connecting all nodes. Under a mild assumption on the unknown probability distribution a deterministic approximation of the stochastic problem is given. The comparison of such approximation with a Montecarlo simulation shows both the accuracy and the eciency of the deterministic approximation, with a mean percentage gap around 2% and a reduction of the computational times of two orders of magnitude

The Cagliari Airport impact on Sardinia tourism: a Logit-based analysis

In the field of air transportation management, traditionally, airlines have been the main actors in the process for deciding which new flights open in a given airport, while airports acted only as the managers of the operations. The changes in the market due to the introduction of low cost companies, with consequent reduction of the airports' fares, as well as the increment of the density of regional airports in several European countries are modifying the mutual roles of airlines and airports. The final decision on new flight to be opened, in fact, is nowadays the result of a negotiation between airlines and airports. The airports must prove the sustainability on the new routes and forecast the economic impact on their catchment area. This paper contributes to advance the current state-of-the-art along two axes. From the pure transportation literature point of view, we introduce a Logit model able to predict the passengers flow in an airport when the management introduces a change in the flight schedule. The model is also able to predict the impact of this change on the airports in the surrounding areas. The second contribution is a case study on the tourist market of the Sardinia region, where we show how to use the results of the model to deduce the economic impact of the decisions of the management of the Cagliari airport on its catchment area in terms of tourists and economic growt

A New Taxonomy of Smart City Projects

City logistics proposes an integrated vision of freight transportation systems within urban area and it aims at the optimization of them as a whole in terms of efficiency, security, safety, viability and environmental sustainability. Recently, this perspective has been extended by the Smart City concept in order to include other aspects of city management: building, energy, environment, government, living, mobility, education, health and so on. At the best of our knowledge, a classification of Smart City Projects has not been created yet. This paper introduces such a classification, highlighting success factors and analyzing new trends in Smart City

FACTORS INFLUENCING LOGISTICS SERVICE PROVIDERS' EFFICIENCY IN URBAN DISTRIBUTION SYSTEMS

The increased urbanization and the awareness of freight transportation impacts have stressed the importance of City Logistics (CL) as a comprehensive approach aimed at mitigating the negative effects of distribution activities without penalizing social, cultural, and economic issues. CL faces a relevant degree of complexity due to the characteristics of modern urban areas, such as traffic congestion, lack of parking spaces, high levels of pollution, and restrictions imposed by local regulations. This environment causes uncertainty about planning and managing delivery activities so that, if not properly organized, urban logistics might not meet its goals. In recent years, many models have been developed to optimize the CL process considering the perspectives of the different stakeholders involved. Studies mainly focus on the location and role of distribution warehouses, freight flows, the routing task, vehicle loading, the size and type of vehicles that can enter urban areas, and possible charges for accessing city centers. However, a successful implementation of such models requires internal efficiency by each actor. In this context, a crucial role is played by logistics service providers (LSPs) because they are expected to offer high quality services in congested urban areas and the effectiveness of their activities depends on the interactions among all the CL stakeholders. The paper proposes an empirical analysis on the operational factors determining the level of efficiency of a LSP. Based on the analysis of literature, the efficiency is here assessed through productivity, which in turn is measured as the number of stops that a driver daily makes during his service. Data about a LSP involved in urban freight distribution in Italy are analyzed and a regression analysis is completed. Results highlight that two managerial levers affect the level of productivity. The first one is related to the organization of the distribution network: a more efficient location of warehouses, an extension of the area covered by each driver and a more efficient routing structure can significantly increase the productivity of a LSP. At the same time, the vehicle loading strategy appears to be crucial: as a matter of fact, vehicles should not be excessively loaded, especially with big parcels, so that the business can be performed more efficiently. This study represents an attempt to develop a comprehensive panel of operational variables that support the efficiency of the urban distribution system of LSPs. The potential benefits associated with the enhancement of efficiency are both economic and environmenta

Factor influencing Logistics Service Providers Efficiency’ in Urban Distribution Systems

The increased urbanization and the awareness of freight transportation impacts have stressed the importance of City Logistics (CL) as a comprehensive approach aimed at mitigating the negati ve effects of distribution activities without penalizing social, cultural, and economic issues. In this context, a crucial role is played by logistics service providers (LSPs) . This paper propo ses an empirical analysis on the operational factors determining the level of efficiency of a LSP. This study represents an attempt to develop a panel of operational variables supporting the efficiency of the urban distribution system of LSPs. The potential benefits are both economic and environmental

Fisheye Photogrammetry to Survey Narrow Spaces in Architecture and a Hypogea Environment

Nowadays, the increasing computation power of commercial grade processors has actively led to a vast spreading of image-based reconstruction software as well as its application in different disciplines. As a result, new frontiers regarding the use of photogrammetry in a vast range of investigation activities are being explored. This paper investigates the implementation of fisheye lenses in non-classical survey activities along with the related problematics. Fisheye lenses are outstanding because of their large field of view. This characteristic alone can be a game changer in reducing the amount of data required, thus speeding up the photogrammetric process when needed. Although they come at a cost, field of view (FOV), speed and manoeuvrability are key to the success of those optics as shown by two of the presented case studies: the survey of a very narrow spiral staircase located in the Duomo di Milano and the survey of a very narrow hypogea structure in Rome. A third case study, which deals with low-cost sensors, shows the metric evaluation of a commercial spherical camera equipped with fisheye lenses

A novel approach for the purification and proteomic analysis of pathogenic immunglobulin free light chains from serum

An excess of circulating monoclonal free immunoglobulin light chains (FLC) is common in plasma cell disorders. A subset of FLC, as amyloidogenic ones, possess intrinsic pathogenicity. Because of their complex purification, little is known on the biochemical features of serum FLC, possibly related to their pathogenic spectrum. We developed an immunopurification approach to isolate serum FLC from patients with monoclonal gammopathies, followed by proteomic characterization. Serum monoclonal FLC were detected and quantified by immunofixation and immunonephelometry. Immunoprecipitation was performed by serum incubation with agarose beads covalently linked to polyclonal anti-κ or λ FLC antibodies. Isolated FLC were analyzed by SDS-PAGE, 2D-PAGE, immunoblotting, mass spectrometry (MS). Serum FLC were immunoprecipitated from 15 patients with ALλ amyloidosis (serum λ FLC range: 98-2350mg/L), 5 with ALκ amyloidosis and 1 with κ light chain (LC) myeloma (κ FLC range: 266-2660mg/L), and 3 controls. Monoclonal FLC were the prevalent eluted species in patients. On 2D-PAGE, both λ and κ FLC originated discrete spots with multiple pI isoforms. The nature of eluted FLC and coincidence with the LC sequence from the bone marrow clone was confirmed by MS, which also detected post-translational modifications, including truncation, tryptophan oxidation, cysteinylation, peptide dimerization. Serum FLC were purified in soluble form and adequate amounts for proteomics, which allowed studying primary sequence and detecting post-translational modifications. This method is a novel instrument for studying the molecular bases of FLC pathogenicity, allowing for the first time the punctual biochemical description of the circulating forms

Protein Kinase C-α Regulates Insulin Action and Degradation by Interacting with Insulin Receptor Substrate-1 and 14-3-3ϵ

Protein kinase C (PKC)-alpha exerts a regulatory function on insulin action. We showed by overlay blot that PKC alpha directly binds a 180-kDa protein, corresponding to IRS-1, and a 30-kDa molecular species, identified as 14-3-3 epsilon. In intact NIH-3T3 cells overexpressing insulin receptors (3T3-hIR), insulin selectively increased PKC alpha coprecipitation with IRS-1, but not with IRS-2, and with 14-3-3 epsilon, but not with other 14-3-3 isoforms. Overexpression of 14-3-3 epsilon in 3T3-hIR cells significantly reduced IRS-1-bound PKC alpha activity, without altering IRS-1/PKC alpha co-precipitation. 14-3-3 epsilon overexpression also increased insulin-stimulated insulin receptor and IRS-1 tyrosine phosphorylation, followed by increased activation of Raf1, ERK1/2, and Akt/protein kinase B. Insulin-induced glycogen synthase activity and thymidine incorporation were also augmented. Consistently, selective depletion of 14-3-3 epsilon by antisense oligonucleotides caused a 3-fold increase of IRS-1-bound PKC alpha activity and a similarly sized reduction of insulin receptor and IRS-1 tyrosine phosphorylation and signaling. In turn, selective inhibition of PKC alpha expression by antisense oligonucleotides reverted the negative effect of 14-3-3 epsilon depletion on insulin signaling. Moreover, PKC alpha inhibition was accompanied by a > 2-fold decrease of insulin degradation. Similar results were also obtained by overexpressing 14-3-3 epsilon. Thus, in NIH-3T3 cells, insulin induces the formation of multimolecular complexes, including IRS-1, PKC alpha, and 14-3-3 epsilon. The presence of 14-3-3 epsilon in the complex is not necessary for IRS-1/PKC alpha interaction but modulates PKC alpha activity, thereby regulating insulin signaling and degradation