The Cargo Fare Class Mix problem for an intermodal corridor: revenue management in synchromodal container transportation

The intermodal hinterland transportation of maritime containers is under pressure from port authorities and shippers to achieve a more integrated, efficient network operation. Current optimisation methods in literature yield limited results in practice, though, as the transportation product structure limits the flexibility to optimise network logistics. Synchromodality aims to overcome this by a new product structure based on differentiation in price and lead time. Each product is considered as a fare class with a related service level, allowing to target different customer segments and to use revenue management for maximising revenue. However, higher priced fare classes come with tighter planning restrictions and must be carefully balanced with lower priced fare classes to match available capacity and optimise network utilisation. Based on the developments of intermodal networks in North West European, such as the network of European Gateway Services, the Cargo Fare Class Mix problem is proposed. Its purpose is to set limits for each fare class at a tactical level, such that the expected revenue is maximised, considering the available capacity at the operational level. Setting limits at the tactical level is important, as it reflects the necessity of long-term agreements between the transportation provider and its customers. A solution method for an intermodal corridor is proposed, considering a single intermodal connection towards a region with multiple destinations. The main purpose of the article is to show that using a limit on each fare class increases revenue and reliability, thereby outperforming existing fare class mix policies, such as Littlewood.Transport Engineering and Logistic

Varadero Beach Erosion Project: Designing a solution for the erosion problem in front of the Iberostar Varadero Hotel

This main objective of this report is to find the cause of the erosion problem and to design a solution for the problematic situation in front of the Iberostar Varadero Hotel, Cuba. This hotel is situated in the eastern part of the Peninsula of Hicacos. For almost 40 years erosion problems are present at this location and need direct attention. To find the causes of erosion the problem is split up in a contribution by basic longshore transport, different cross-shore transports during extreme conditions and transports due to more complex hydrodynamic processes around the Iberostar Hotel. For the basic longshore transport the model Unibest LT is used to calculate the quantities and distribution of the longshore sediment transport over the cross-shore profile. For the contribution of cross-shore processes to the erosion problem, the model XBeach is used. After calibrating the 1D model, the model is extended to a 2D model, with a full 2D wave input by SWAN. For the transport due to more complex hydrodynamic processes Delft3D is used. During the analysis some interesting flow patterns are found, which explains why there is structural erosion at the Iberostar Hotel. It turns out that the causes of erosion can be subscribed to a combination of two processes. Firstly, the general westward directed flow causes erosion west of the headland. Secondly, complex flow patterns occur during northwest wave conditions which often also cause erosion in front of the Iberostar Hotel. The negative influence of both processes on the recovery of the beach after storm and hurricane conditions is important. After explaining the causes of erosion the optimal solution for the structural erosion is investigated. Three final solutions have been checked by a MCA and cost analysis, and in the end the nourishment turned out to be the optimal solution. The nourishment is further optimised and the behaviour is modelled for multiple years. After modelling of the solution it seems that a nourishment of 100,000 m3 is sufficient to provide a good beach width for a period of 5 years. It also turned out that the construction time and construction method of the nourishment are very important. With this in mind, the following solution is proposed. A beach nourishment of 100,000 m3 in front of the Iberostar hotel, with a lifetime of 5 years and an approximate total cost of 1.1 million CUC. Since the erosion problems are structural, new nourishments are needed in the future. When making a nourishment maintenance schedule, costs can be saved. In that case, for a period of 50 years, the costs can be decreased to 12.8 million CUC, taking into account additional nourishments after possibly occurring hurricanes and extreme events. In this way the structural erosion problems can be dealt with in a cost effective, visually attractive and flexible wayCivil Engineering and GeosciencesHydraulic EngineeringCIE4061-0

Managing Knowledge for Future-proof Tunnels in the Netherlands

Determining the scope of (structural) renovation of aging tunnels is a complicated task and modular renovation is becoming increasingly necessary. The COB Tunnel Programme aims at developing the knowledge necessary to renovate these tunnels in a modular fashion, to reduce hindrance as much as possible. Part of this program is the development of a Structural Health Analysis (SHA) for collecting data on the condition of the civil structure of tunnels, which will give tunnel owners insight in the need for research on structural parts of the tunnel, refurbishment and the risks for the tunnel performance in the future. As a lot of knowledge will be gathered and generated, structurally securing of this knowledge is also necessary. To meet this need, the tunnel program also started development of a knowledge management system. This paper describes the aims of the knowledge management system in relation to the overall tunnel program, as well as the tools and methods devised to gather all necessary information for tunnels constructed several decades ago, where not all required information is readily available in digital form, or even in paper archives.Geo-engineerin

High-throughput single-molecule experiments reveal heterogeneity, state switching, and three interconnected pause states in transcription

Pausing by bacterial RNA polymerase (RNAp) is vital in the recruitment of regulatory factors, RNA folding, and coupled translation. While backtracking and intra-structural isomerization have been proposed to trigger pausing, our mechanistic understanding of backtrack-associated pauses and catalytic recovery remains incomplete. Using high-throughput magnetic tweezers, we examine the Escherichia coli RNAp transcription dynamics over a wide range of forces and NTP concentrations. Dwell-time analysis and stochastic modeling identify, in addition to a short-lived elemental pause, two distinct long-lived backtrack pause states differing in recovery rates. We identify two stochastic sources of transcription heterogeneity: alterations in short-pause frequency that underlies elongation-rate switching, and variations in RNA cleavage rates in long-lived backtrack states. Together with effects of force and Gre factors, we demonstrate that recovery from deep backtracks is governed by intrinsic RNA cleavage rather than diffusional Brownian dynamics. We introduce a consensus mechanistic model that unifies our findings with prior models.BN/Cees Dekker LabBN/Martin Depken LabBN/BionanoscienceBN/Nynke Dekker La

Road Infrastructure Requirements for Improved Performance of Lane Assistance Systems

There is a pressing need for road authorities to take a proactive role in the deployment of automated vehicles on the existing road network. This requires a comprehensive understanding of the road infrastructure requirements that would lead to safe operation of automated vehicles. In this context, a field test with Lane Departure Warning and Lane Keeping Systems-enabled vehicles was conducted in the province of North Holland, The Netherlands. The performance of these automated systems was evaluated using performance indicators such as Mean Lateral Position and Standard Deviation of Lane Position. In this study, the Systems Theoretic Accident Modelling and Processes (STAMP) model was adopted to understand the relationships between the various components of the “Road System”, which in this study include the road authority, the automated vehicle system, elements of the road infrastructure, and weather conditions. Empirical data from the experiment is used to estimate the relationships between the different components, followed by the assessment of their impact on the performance of the automated vehicles. It was found that visibility conditions have a significant effect on detection performance, which worsens in rainy conditions especially under streetlights. It has been also observed that there is a significant difference in Lane Position between Left Curves and Straight sections, and between lane widths less than 250 cms and those that have larger widths. These findings are combined with the results from the STAMP analysis to formulate a set of road infrastructure requirements that would lead to safe performance of Lane Assistance Systems.Transport and PlanningSystem Engineerin

Operational Design Domain Requirements for Improved Performance of Lane Assistance Systems: A Field Test Study in The Netherlands

There is a pressing need for road authorities to take a proactive role in the deployment of automated vehicles on the existing road network. This requires a comprehensive understanding of the driving environment characteristics that affect the performance of automated vehicles. In this context, a field test with Lane Departure Warning (LDW) and Lane Keeping Systems (LKS)-enabled vehicles was conducted in the Netherlands. Empirical data from the experiment was used to estimate the impact of driving environment components such as weather condition and lane width on the performance of the automated vehicles. Driving at night in the presence of streetlights with rain resulted in least detection performance for both the vehicles as compared to other visibility conditions. As for lane-keeping performance, the LKS positioned the vehicle significantly more to the left of the lane on left-curves than on straight sections. The LKS also positioned the vehicle more left on lanes with a width less than 250 cm than on wider lanes. These findings were translated into levels of service of the Operational Design Domain (ODD). Each level of service corresponded to a performance level of the lane assistance systems, classified as “High”, “Medium”, and “Low”, and defined using indicators.Transport and PlanningSystem Engineerin

Simultaneous orientation and 3D localization microscopy with a Vortex point spread function

Estimating the orientation and 3D position of rotationally constrained emitters with localization microscopy typically requires polarization splitting or a large engineered Point Spread Function (PSF). Here we utilize a compact modified PSF for single molecule emitter imaging to estimate simultaneously the 3D position, dipole orientation, and degree of rotational constraint from a single 2D image. We use an affordable and commonly available phase plate, normally used for STED microscopy in the excitation light path, to alter the PSF in the emission light path. This resulting Vortex PSF does not require polarization splitting and has a compact PSF size, making it easy to implement and combine with localization microscopy techniques. In addition to a vectorial PSF fitting routine we calibrate for field-dependent aberrations which enables orientation and position estimation within 30% of the Cramér-Rao bound limit over a 66 μm field of view. We demonstrate this technique on reorienting single molecules adhered to the cover slip, λ-DNA with DNA intercalators using binding-activated localization microscopy, and we reveal periodicity on intertwined structures on supercoiled DNA.ImPhys/Computational ImagingBN/Cees Dekker LabImPhys/Imaging Physic

Wafer-Scale Integration for Semi-Flexible Neural Implant Miniaturization

We present a novel, wafer-based fabrication process that enables integration and assembly of electronic components, such as ASICs and decoupling capacitors, with flexible interconnects. The electronic components are fabricated in, or placed on precisely defined and closely-spaced silicon islands that are connected by interconnects embedded in parylene-based flexible thin film. This fully CMOS compatible approach uses optimized DRIE processes and an SiO2 mesh-shaped mask, allowing for the simultaneous definition of micrometer- to millimeter-sized structures without compromising the flexibility of the device. In a single fabrication flow a unique freedom in dimensions of both the flexible film and the silicon islands can be achieved making this new technique ideal for the realization of semi-flexible/foldable implantable devices, where structures of different sizes have to be combined together for the ultimate miniaturization.EKL ProcessingElectronic Components, Technology and MaterialsPhotovoltaic Materials and Device