Optimization approaches for defining storage strategies in maritime container terminals

In maritime container terminals, yards have a primary role in permitting the efficient management of import and export flows. In this work, a mixed 0/1 linear programming model and a heuristic approach are proposed for defining storage rules in order to minimize the space used in the export yard. The minimization of land space is pursued by defining the rules to allocate containers into the bay-locations of the yard, in such a way as to minimize the number of bay-locations used and the empty slots within them. The main aim of this work is to propose a solution approach for permitting the yard manager to compare yard storage strategies for different transport demands, in such a way to be able to evaluate and, eventually, modify the storage strategy when the characteristics of the transport demand change. Computational experiments, based on both real instances and generated ones, are presented. All instances are derived by a case study related to an Italian terminal

The Cost-Balanced Path Problem: A Mathematical Formulation and Complexity Analysis

This paper introduces a new variant of the Shortest Path Problem (SPP) called the Cost-Balanced Path Problem (CBPP). Various real problems can either be modeled as BCPP or include BCPP as a sub-problem. We prove several properties related to the complexity of the CBPP problem. In particular, we demonstrate that the problem is NP-hard in its general version, but it becomes solvable in polynomial time in a specific family of instances. Moreover, a mathematical formulation of the CBPP, as a mixed-integer programming model, is proposed, and some additional constraints for modeling real requirements are given. This paper validates the proposed model and its extensions with experimental tests based on random instances. The analysis of the results of the computational experiments shows that the proposed model and its extension can be used to model many real applications. Obviously, due to the problem complexity, the main limitation of the proposed approach is related to the size of the instances. A heuristic solution approach should be required for larger-sized and more complex instances

Vector meson decays from the Extended Chiral Quark Model

We derive the the effective lagrangian that describes the interactions among vector, axial-vector mesons and pseudoscalars starting from the extended chiral quark model (ECQM). The results for the low-energy constants of this effective lagrangian have a parametric resemblance with existing predictions based on the Nambu-Jona-Lasinio model (except for some overall signs that we correct), but are numerically different. Therefore a precise measurement of these decay constants can shed some light on the way chiral symmetry breaking is modelled in QCD. Although most of the constants are poorly measured, comparison with phenomenology allows us to determine one of the parameters of the ECQM that could not be fully determined in previous analyses.Comment: 7 pages, revtex

A Constructive Heuristics and an Iterated Neighborhood Search Procedure to Solve the Cost-Balanced Path Problem

This paper presents a new heuristic algorithm tailored to solve large instances of an NP-hard variant of the shortest path problem, denoted the cost-balanced path problem, recently proposed in the literature. The problem consists in finding the origin–destination path in a direct graph, having both negative and positive weights associated with the arcs, such that the total sum of the weights of the selected arcs is as close to zero as possible. At least to the authors’ knowledge, there are no solution algorithms for facing this problem. The proposed algorithm integrates a constructive procedure and an improvement procedure, and it is validated thanks to the implementation of an iterated neighborhood search procedure. The reported numerical experimentation shows that the proposed algorithm is computationally very efficient. In particular, the proposed algorithm is most suitable in the case of large instances where it is possible to prove the existence of a perfectly balanced path and thus the optimality of the solution by finding a good percentage of optimal solutions in negligible computational time

The pivotal role of Public Transport in designing the integration of mobility services and in operating MaaS offer: the concept of Shared Mobility Centre and the experience of Arezzo

The paper identifies the emerging trends and requirements in the mobility demand and the gaps between them and the offer. The paper shows how Public Authorities and Mobility Operators should provide a seamless mobility offer able to answer to mobility demand which is becoming more flexible and varied in typologies and needs. Public Transport must be the backbone of this integrated mobility offer including conventional services for main urban axes/corridors and FTS/ridesharing services for feeder, last mile and target groups services. ITS for Public Transport are the base systems to provide MaaS and Public Transport Operators should leader MaaS initiatives. Central role in the MaaS initiative must be allocated to Shared Mobility Centre as “umbrella” platform/organization able to coordinate conventional different transport services in a seamless mobility offer (from planning to operation to back-office functionalities interesting both Operators and Authorities). The experience of MaaS activated/under development in the city of Arezzo will be the opportunity to highlight some critical factors that must be guaranteed as supporting actions for MaaS

Signal amplification by combining two advanced immunohistochemical techniques

The immunohistochemical techniques known as EnVision™+ System (EVS) and Mirror Image Complementary Antibody (MICA) were recently introduced into laboratory practice because of their high sensitivity. In this paper these techniques were compared and their sequences combined to obtain a new method possibly more sensitive than the original ones. The immunohistochemical staining employing the avidin-biotin complex (ABC), largely used as routine, was adopted as a term of comparison. Samples from the small and large intestine of pigs and sheep were fixed in Bouin and embedded in Paraplast. The primary antibodies utilized were directed against the neuronal nitric oxide synthase (nNOS), vasoactive intestinal polypeptide (VIP) and chromogranin A (Cr A). Targets of these antibodies were nerve structures of the intestinal wall, as well as endocrine cells scattered in the mucosa of the bowel, defined neuroendocrine cells or paraneurons. The EVS method appeared as slightly superior to the MICA method regarding sensitivity of detection. The EVS/MICA (combined) method resulted four/eight times more effective than the original techniques regarding sensitivity of detection and staining intensity, both at low and high dilutions of the primary antibodies. Of these latter, immunopositive structures were still clearly identifiable, at a dilution of 1:256,000. Such efficiency could be explained by the high number of revealing molecules of peroxidase contained in the new sequence. The application of the combined method is recommended when a small quantity of tissue antigens needs to be detected immunohistochemically

Vacuum Properties of Mesons in a Linear Sigma Model with Vector Mesons and Global Chiral Invariance

We present a two-flavour linear sigma model with global chiral symmetry and vector and axial-vector mesons. We calculate pion-pion scattering lengths and the decay widths of scalar, vector, and axial-vector mesons. It is demonstrated that vector and axial-vector meson degrees of freedom play an important role in these low-energy processes and that a reasonable theoretical description requires globally chirally invariant terms other than the vector meson mass term. An important question for meson vacuum phenomenology is the quark content of the physical scalar f0(600) and a0(980) mesons. We investigate this question by assigning the quark-antiquark sigma and a0 states of our model with these physical mesons. We show via a detailed comparison with experimental data that this scenario can describe all vacuum properties studied here except for the decay width of the sigma, which turns out to be too small. We also study the alternative assignment f0(1370) and a0(1450) for the scalar mesons. In this case the decay width agrees with the experimental value, but the pion-pion scattering length $a_{0}^{0}$ is too small. This indicates the necessity to extend our model by additional scalar degrees of freedom.Comment: 22 pages, 6 figure

From the Concept of Flexible Mobility Services to the ‘Shared Mobility Services Agency’

ACKNOWLEDGEMENT This research was supported by the Research Councils UK Digital Economy programme award (reference: EP/G066051/1) to the dot.rural Digital Economy Hub, at the University of AberdeenPostprin

CHANTI: a Fast and Efficient Charged Particle Veto Detector for the NA62 Experiment at CERN

The design, construction and test of a charged particle detector made of scintillation counters read by Silicon Photomultipliers (SiPM) is described. The detector, which operates in vacuum and is used as a veto counter in the NA62 experiment at CERN, has a single channel time resolution of 1.14 ns, a spatial resolution of ~2.5 mm and an efficiency very close to 1 for penetrating charged particles