1,745 research outputs found
Roll-on/roll-off terminals and truck freight : improving competitiveness in a motorways of the sea context
In recent years transport policy at an European Level has been focused on reducing the share of road transportation and promote alternative transportation means in order to reduce road congestion and carbon footprint.
One of the solutions proposed has been promoting Short Sea Shipping (SSS) transportation combined with land transportation to become a door-to-door alternative to the monomodal road alternative. The maritime centered option would hit to birds with a stone: reduce congestion in the most urbanized areas of the European Union and partly replacing heavy polluting truck haulage for an environmentally friendlier option.
The European Commission launched many polices and initiatives to make the modal shift happen, the crown jewel being the launch of multiple initiatives promoting the establishment of a system of Motorways of the Seas. Those are links between ports with higher standards in terms of travel time, costs and flexibility, which can compete one-on-one with road haulage among the countries in the Union.
Despite different efforts from the public administration to kick off MoS lines and ensure their competitiveness, the expected momentum is still yet to come.
In the light of this, this thesis aims at providing tools to assess the competitiveness of existing and MoS line to-be, to quantify the room for improvement available and the effects that some changes at an operational and strategical level might have on the success of any specific line.
Particularly, the thesis presented aims at three specific objectives: (1) to identify the strategic potential of SSS in all its forms, considering the characteristics of the demand (goods to be moved) and the role of RoRo and MoS shipping in the global picture; (2) to identify the most sensible procedures in RoRo terminals operation to be addressed to improve their performance and perception from the end user, and; (3) To understand the costs of the supply chain, and the cost structure of RoRo shipping lines, and their sensitiveness in front of market changes, pricing and public funding policies.
To approach each issue different qualitative, analytical and simulating models are used depending on the concerned problem. The strategic assessment makes use interviews to identify the main requirements that a transporter might face when dealing with SSS.
The role of the terminal is assessed by means of two separate models: from one side an analytical model is used to assess the relationship between capacity and quality by means of quantifying the service time the ship spends in a port and calculate the probability of delays. On the other side, the resilience of the port is assessed with an arborescence interlinking its current vulnerabilities, their causes and effects and their probability to happen.
Finally, and regarding the business models, first a cost and time model is constructed for each of them and tested against variations on some of the variables and from there, a tool to calculate the optimal deployment of the shipping line to ensure the maximum shift (or profit) is provided. In that case, the model is complemented with the adaptation of a transportation discrete choice model.
Overall, the tools should be helpful to assess the potential of a shipping line from its planning level to its final operational deployment.Els darrers anys, la política de transports a nivell europeu s'ha focalitzat en reduir el pes del transport per carretera de mercaderies i promoure mitjans de transport que li siguin alternatius, com a mesures per reduir la congestió a les carreteres i la petjada ecològica. Una de les solucions que s'ha posat sobre la taula, és l'anomenat Transport Marítim de Curta Distància (TMCD o SSS, en les seves sigles en anglès), com a una veritable alternativa bimodal (ferrocarril/carretera combinats amb transport marítim) a l'opció de transport monomodal per carretera. Diversos estudis certifiquen que el transport porta-a-porta transcorregut parcialment amb TMCD acostuma a registrar menors externalitats (bàsicament costos ambientals i de congestió) que el transport per carretera per cada tona transportada. Des d'un punt de vista operatiu, el TMCD i especialment la seva versió en forma d'Autopistes del Mar (AdM o MoS), enteses com a enllaços entre ports amb altes prestacions pel que fa a temps de viatge, flexibilitat i freqüència a un cost competitiu s'han estudiat àmpliament com a una alternativa directa i equivalent al transport per carretera. Però malgrat els esforços fets des de l'administració pública per promoure les línies d'AdM i assegurar-ne la competitivitat, aquestes no han obtingut l'impuls previst inicialment. L'objectiu d'aquesta tesi, de fet, és proveir un conjunt d'eines per tal d'avaluar la competitivitat de qualsevol AdM i quantificar-ne el marge de millora i l'efecte que alguns canvis a nivell operatiu i estratègic podrien tenir en la seva competitivitat , tan a nivell operatiu com estratègic, per tal de garantir-ne la competitivitat futura. De forma més específica, la tesi que aquí es presenta, analitza tres aspectes específics de les AdM: (1) Quines característiques a de tenir el seu mercat potencial a nivell estratègic, (2) con rol prenen les terminals portuàries, enteses com la baula dèbil de la cadena de transport, a nivell de la valoració qualitativa de la cadena de transport per part del seu usuari final i (3), possibles models de negoci pel transportista / propietari de la mercaderia per treure el màxim profit de les AdM. Cada un dels tres aspectes s'adreça mitjançant eines diferenciades que s'adaptin a la problemàtica plantejada. L'anàlisi estratègic es basa en entrevistes a usuaris de cadenes de transport per establir els principals requeriments del transportista que es pugui plantejar l'ús d'una AdM. A partir dels requeriments, es defineixen diversos models de cadena de transport, arribant a la conclusió que les cadenes 'push-pull' i 'push against stock' són les candidates que més es beneficiarien d'una AdM, almenys a nivell estratègic. El rol de la terminal s'analitza qualitativament analitzant-ne dos aspectes per separat: d'una banda es crea un model basat en una combinació de valors d'origen estocàstic, determinista i via simulació, per calcular el temps d'operació mínim d'un buc de càrrega rodada a una terminal marítima i la relació que hi ha entre nivell d'ús de la terminal i la seva capacitat. D'altra banda, també s'estableix un marc per quantificar la vulnerabilitat i resiliència de la terminal davant de elements que afectin la seva normal operació i com aquests poden afectar la qualitat percebuda del servei. Finalment, pel que fa als models de negoci pels transportistes, es construeix un model de costos i temps per cada un d'ells, se n'analitza la sensibilitat i el pes de les principals variables que els afecten com a eina per calcular el model de negoci, les característiques de la línia marítima i les tarifes de base a cobrar des de la perspectiva de la naviliera. Per assolir-ho, el model es complementa amb l'adopció d'un model d'elecció modal. Preses conjuntament, es proporciona una metodologia per ajudar a avaluar el potencial de futures AdM o millorar les existents i l'efecte que hi poden tenir les actuals i futures polítiques de transport
Finding the right RoPax vessel size and freight price. A coste and mode choice model
[EN] Motorways of the sea operated as RoPax services are natural competitors with only-road freight haulage transportation. Cost, time and quality perceived are the determinants that make transporters and shippers use one route or another. This research considers the role that shipping companies and their ship deployment and pricing strategy have in the equation, as incentives for modal shift from road to sea. A model of the ships and transporter costs is developed considering different business models for the transporter (accompanied versus unaccompanied cargo) followed with a discrete choice model that, once calibrated, allows to test the influence that variables such as frequency, ship size and commercial speed might play into the competitiveness of a shipping line. As a result, different pricing strategies for the shipping line are developed and the characteristics of the optimal shipping line for each of them are found, to either maximize the profit of the shipping company or the modal shift.DOI: http://dx.doi.org/10.4995/CIT2016.2016.4148http://ocs.editorial.upv.es/index.php/CIT/CIT2016Morales Fusco, P.; Grau Sala, M.; Saurí Marchán, S. (2016). Finding the right RoPax vessel size and freight price. A coste and mode choice model. Editorial Universitat Politècnica de València. 1456-1470. https://doi.org/10.4995/CIT2016.2015.4148OCS1456147
The Road to 6G: Ten Physical Layer Challenges for Communications Engineers
While the deployment of 5G cellular systems will continue well in to the next
decade, much interest is already being generated towards technologies that will
underlie its successor, 6G. Undeniably, 5G will have transformative impact on
the way we live and communicate, yet, it is still far away from supporting the
Internet-of-Everything (IoE), where upwards of a million devices per
(both terrestrial and aerial) will require ubiquitous,
reliable, low-latency connectivity. This article looks at some of the
fundamental problems that pertain to key physical layer enablers for 6G. This
includes highlighting challenges related to intelligent reflecting surfaces,
cell-free massive MIMO and THz communications. Our analysis covers theoretical
modeling challenges, hardware implementation issues and scalability among
others. The article concludes by delineating the critical role of signal
processing in the new era for wireless communications.Comment: IEEE Communications Magazine, Accepte
An empirical analysis of the resiliency of Ro/Ro and Ro/Pax terminal operations
Regular maritime lines with roll-on roll-off vessels must offer a reliable service without substantial cost increases in order to be competitive. Port terminals need to be able to respond quickly to any disturbance that might appear and return to a smooth operational state in the minimum amount of time (resilient terminals). In this paper a complete taxonomy of the disturbances affecting the operational processes in a roll-on roll-off terminal is introduced together with a system able to assess the performance of any measure used to mitigate them. The study is based on an overview of the existing literature on the topic, a detailed diagram of the operational processes of the terminal, and an exhaustive set of interviews of the staff involved in the processes occurring in a roll-on roll-off terminal, together with field measurements. The main vulnerabilities are identified and possible corrective and preventive measures are pointed out.Postprint (published version
Inter-terminal transfer between port terminals. A continuous mathematical programming model to optimize scheduling and deployment of transport units
[EN] In most large port cities, the challenge of inter-terminal transfers (ITT) prevails due to the
long distance between multiple terminals. The quantity of containers requiring movement
between terminals as they connect from pre-carrier to on-carrier is increasing with the
formation of the mega-alliances.
The paper proposes a continuous time mathematical programming model to optimize the
deployment and schedule of trucks and barges to minimize the number of operating
transporters, their makespan, costs and the distance travelled by the containers by
choosing the right combination of transporters and container movements while fulfilling
time window restrictions imposed on reception of the containers.
A multi-step routing problem is developed where transporters can travel from one
terminal to another and/or load or unload containers from a specific batch at each step.
The model proves successful in identifying the costless schedule and means of
transportation. And a sensibility analysis over the parameters used is provided.Morales Fusco, P.; Pedrielli, G.; Zhou, C.; Lee, L.; Chew, E. (2016). Inter-terminal transfer between port terminals. A continuous mathematical programming model to optimize scheduling and deployment of transport units. En XII Congreso de ingeniería del transporte. 7, 8 y 9 de Junio, Valencia (España). Editorial Universitat Politècnica de València. 1471-1481. https://doi.org/10.4995/CIT2016.2015.4149OCS1471148
The erector spinae plane block: a narrative review
Regional anesthesia and pain management have experienced advances in recent years, especially with the advent of fascial plane blocks. The erector spinae plane block is one of the newest techniques to be described. In the past two years, publications referring to ESP block have increased significantly. The objective of this review is to analyze the articles about ESP block that have been published to date. We performed a search in the main databases and identified 368 articles. After a selection of the relevant articles, 125 studies were found eligible and were included in the review. The ESP block is performed by depositing the local anesthetic in the fascial plane, deeper than the erector spinae muscle at the tip of the transverse process of the vertebra. Many cases of its use have been described with satisfactory results in the treatment of both acute pain and chronic pain. The applicability of the technique covers many clinical scenarios. Of the 98 case reports reviewed, 12 and 87 articles, respectively described the technique as a treatment for chronic pain and acute pain. The single-shot was the most frequently used technique. As described in the articles published to date, the technique is easy to perform and has a low rate of complications. However, despite the effectiveness of the technique, further studies are necessary to obtain more evidence of its actions
Assessing customs performance in the Mediterranean ports. KPI selection and Best practices identification as part of the MEDNET project
[EN] The seamless flow of goods, people and investments across the Mediterranean necessitates a well-functioning port and transport system. More efficient port operations enhance seamless logistics and promote safety, efficiency, interoperability and interconnectivity of transport networks in the Mediterranean area.To promote the exchange of knowledge and expertise relevant to port and customs procedures and simplification of clearance for vessels and cargoes in the Mediterranean, the MEDNET project was launched. As part of the project a common evaluation framework for the performance of ports in the form of a set of Key Performance Indicators (KPIs) together with a list of the best practices in terms of operations and customs procedures was developed.In total, 50 ports were analyzed and given a KPI regarding traffic, financial, operational and human resources, sustainability and customs procedures. The values were latter crossed with the current good practices on operation in terms of customs procedures. And a small correlation between KPIs performance and implantation degree of good practices in customs procedures was found. This presentation exposes the methodology to assess the ports’ performance and the best practices identification.Morales Fusco, P.; Saurí Marchán, S.; Lekka, AM.; Karousos, I. (2016). Assessing customs performance in the Mediterranean ports. KPI selection and Best practices identification as part of the MEDNET project. En XII Congreso de ingeniería del transporte. 7, 8 y 9 de Junio, Valencia (España). Editorial Universitat Politècnica de València. 1482-1500. https://doi.org/10.4995/CIT2016.2015.4221OCS1482150
Head-to-Tail Intramolecular Interaction of Herpes Simplex Virus Type 1 Regulatory Protein ICP27 Is Important for Its Interaction with Cellular mRNA Export Receptor TAP/NXF1
Herpes simplex virus type 1 (HSV-1) protein ICP27 has many important functions during infection that are achieved through interactions with a number of cellular proteins. In its role as a viral RNA export protein, ICP27 interacts with TAP/NXF1, the cellular mRNA export receptor, and both the N and C termini of ICP27 must be intact for this interaction to take place. Here we show by bimolecular fluorescence complementation (BiFC) that ICP27 interacts directly with TAP/NXF1 during infection, and this interaction failed to occur with an ICP27 mutant bearing substitutions of serines for cysteines at positions 483 and 488 in the C-terminal zinc finger. Recently, we showed that ICP27 undergoes a head-to-tail intramolecular interaction, which could make the N- and C-terminal regions accessible for binding to TAP/NXF1. To determine the importance of intramolecular association of ICP27 to its interaction with TAP/NXF1, we performed BiFC-based fluorescence resonance energy transfer (FRET) by acceptor photobleaching. BiFC-based FRET showed that the interaction between ICP27 and TAP/NXF1 occurred in living cells upon head-to-tail intramolecular association of ICP27, further establishing that TAP/NXF1 interacts with both the N and C termini of ICP27
INFN What Next: Ultra-relativistic Heavy-Ion Collisions
This document was prepared by the community that is active in Italy, within
INFN (Istituto Nazionale di Fisica Nucleare), in the field of
ultra-relativistic heavy-ion collisions. The experimental study of the phase
diagram of strongly-interacting matter and of the Quark-Gluon Plasma (QGP)
deconfined state will proceed, in the next 10-15 years, along two directions:
the high-energy regime at RHIC and at the LHC, and the low-energy regime at
FAIR, NICA, SPS and RHIC. The Italian community is strongly involved in the
present and future programme of the ALICE experiment, the upgrade of which will
open, in the 2020s, a new phase of high-precision characterisation of the QGP
properties at the LHC. As a complement of this main activity, there is a
growing interest in a possible future experiment at the SPS, which would target
the search for the onset of deconfinement using dimuon measurements. On a
longer timescale, the community looks with interest at the ongoing studies and
discussions on a possible fixed-target programme using the LHC ion beams and on
the Future Circular Collider.Comment: 99 pages, 56 figure
Multiplicity dependence of jet-like two-particle correlations in p-Pb collisions at = 5.02 TeV
Two-particle angular correlations between unidentified charged trigger and
associated particles are measured by the ALICE detector in p-Pb collisions at a
nucleon-nucleon centre-of-mass energy of 5.02 TeV. The transverse-momentum
range 0.7 5.0 GeV/ is examined,
to include correlations induced by jets originating from low
momen\-tum-transfer scatterings (minijets). The correlations expressed as
associated yield per trigger particle are obtained in the pseudorapidity range
. The near-side long-range pseudorapidity correlations observed in
high-multiplicity p-Pb collisions are subtracted from both near-side
short-range and away-side correlations in order to remove the non-jet-like
components. The yields in the jet-like peaks are found to be invariant with
event multiplicity with the exception of events with low multiplicity. This
invariance is consistent with the particles being produced via the incoherent
fragmentation of multiple parton--parton scatterings, while the yield related
to the previously observed ridge structures is not jet-related. The number of
uncorrelated sources of particle production is found to increase linearly with
multiplicity, suggesting no saturation of the number of multi-parton
interactions even in the highest multiplicity p-Pb collisions. Further, the
number scales in the intermediate multiplicity region with the number of binary
nucleon-nucleon collisions estimated with a Glauber Monte-Carlo simulation.Comment: 23 pages, 6 captioned figures, 1 table, authors from page 17,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/161
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