Comparative Application of Methods for Nodes Capacity Assessment

Many capacity analyses using the UIC 406 capacity method for double track lines have been carried out and presented international, but few capacity analyses applying the capacity method to single track lines have been presented. Therefore, the differences between capacity analyses of double track lines and single track lines are discussed in this article. The principles of the UIC 406 of double track lines can be applied to single track lines—at least when more than one train follows each other in the same direction. In a presentation of the UIC 406 for single track operations, it is important to define where to divide the railway lines into line sections and how the conflicts between trains at crossing stations and junctions have to be analysed. The effects on railway networks with single track lines and their impact on capacity consumption are described to enable a consistent capacity statement.

The paper discusses the advantages and shortcomings of alternate double single track (ADST) lines with respect to double track lines for high speed lines. ADST lines consists of sequences of double and single track segments optimally selected in order to reduce the construction and maintenance costs of railway lines and to optimize the timetables used to satisfy a given demand. The single tracks are selected to coincide with expensive segments (tunnels and viaducts) and the double tracks are chosen to coincide with flat areas and only where they are necessary. At the same time, departure times are adjusted for trains to cross at the cheap double track segments. This alternative can be used for new lines and also for existing conventional lines where some new tracks are to be constructed to reduce travel time (increase speed). The ADST proposal is illustrated with some examples of both types (new lines and where conventional lines exist), including the Palencia-Santander, the Santiago-Valparaíso-Viña del Mar and the Dublin-Belfast lines, where very important reductions (90 %) are obtained, especially where a railway infrastructure already exist.DOI: http://dx.doi.org/10.4995/CIT2016.2016.3426

Planning and scheduling efficient heavy rail track maintenance through a Decision Rules Model

Eighteen available doubled haploid wheat lines with a cytologically proven 1A-1R, 1B-1R double translocation, which where derived via anther culture from four crosses of the 1A-1R wheat-rye translocation cv "Amigo" with several 1B-1R wheat-rye translocation forms, were subjected to electrophoretic seed protein analysis. Besides, the five parents used in the crosses and some other wheat cultivars and doubled haploid lines (19 with a 1B-1R single translocation, 10 with a 1A-1R translocation and 7 without any 1R translocation) were also included in the investigation. It was found that the gliadin patterns visualized after SDS polyacrylamide gel electrophoresis of alcohol-soluble seed protein extracts can differentiate not only 1B-1R and 1A-1R translocation forms from wheats without any 1R-translocation chromosome, but also 1B-1R and 1A-1R wheats from each other. Moreover, 1A-1R, 1B-1R double translocation lines can be distinguished as well due to characteristic differences revealed between 1A-1R and 1B-1R translocation forms. Thus, all of tested dh1- and dh2-grains of the double translocation lines showed the expected doublet: the 1A-1R translocation ("Amigo")-typical rye band and the 1B-1R translocation ("Kawkas")-typical rye band. Consequently, gliadin patterns estimated after SDS electrophoresis may be used as markers for the fast detection of the desired 1A-1R, 1B-1R double translocation forms among 1A-1R single translocation lines, 1B-1R single translocation lines and lines without any 1R-translocation in the progenies of appropriate crosses. Furthermore, by means of gliadin tests on the dh2-generation the excellent stability of the double translocation 1A-1R, 1B-1R during more than one propagation phase has been proven. Estimations of high-molecular weight (HMW) glutenin subunits coded by 1A and 1B chromosomes are compatible with the double translocation constitution. A few deviating results can be explained by crossing-over events. Seed protein analysis revealed that it is possible to produce 1A-1R, 1B-1R double translocation lines with good glutenin compositions provided that adequate favourable parents are used.

During the laser cladding process, thermal stresses are induced because of the high-energy input, high temperature gradient, fast cooling rate, and inconsistency of the clad-substrate material. The induced thermal stresses not only increase the crack tendency, but also influence the mechanical performance of the deposited layer. In this study, a three dimensional (3D) uncoupled thermo-mechanical finite element (FE) model was established to simulate the stress evolution of laser cladding of cobalt-based coatings on mild steel A36. The temperature field was simulated first and then used as transient thermal loading to simulate the stress evolution. Stress distributions for three cases: single track on a flat substrate, double-track on a flat substrate, and double-track on a cylindrical substrate, were investigated in detail. To check the accuracy of the simulation results, validation experiments were carried out using an 8-kW high-power direct diode laser. The thermocouples were used to monitor the temperature cycles at several marked points. The cross-sections of single and double tracks on a flat substrate obtained experimentally were compared with the simulation results. The residual stress on the clad was experimentally determined by an X-ray diffraction machine. The experimentally obtained data showed a significant consistency with the prediction results.

Among the many variations of polymerase chain reaction (PCR)-based mutagenesis procedures, the “megaprimer” method (, , , , ) is probably the simplest and most versatile. The method utilizes three oligonucleotide primers and two rounds of PCR performed on a DNA template containing the cloned gene which is to be mutated. The rationale of the basic method is shown schematically in Fig. 1A, where A and B represent the “flanking” primers that can map either within the cloned gene or outside the gene (i.e., within the vector sequence) and M represents the internal “mutant” primer containing the desired base change. The first round of PCR is performed using the mutant primer (e.g., M1 in Fig. 1) and one of the flanking primers (e.g., A). The double-stranded product is purified and used as one of the primers (hence the name “megaprimer”) in the second round of PCR along with the other flanking primer (B). The wild-type cloned gene is used as template in both PCR reactions. The final PCR product containing the mutation can be used in a variety of standard applications, such as cloning in expression vectors and sequencing, or in more specialized applications, such as production of the gene message in vitro if primer A (or the template sequence downstream of primer A) also contains a transcriptional promoter (e.g., that of SP6 or T7 phage). This basic procedure can be adopted to create site-specific insertions (Fig. 1B), deletions (Fig. 1C), and gene fusions (Fig. 1D). Successful and error-free PCR in the second round often requires special considerations. The reader is, therefore, strongly urged to go through the whole chapter, including Section 4., before proceeding with the actual experiment. Open image in new window Fig. 1. The megaprimer method of site-directed mutagenesis. The general procedure is shown in (A). For insertion (B) and deletion (C) mutagenens, only PCR 1 is shown; the corresponding PCR 2 will use the megaprimer produced in PCR 1 and primer B. The primers A, B, M1, and M2 (as well as the priming strand of the megaprimer, AM1) are indicated by single lines with arrowhead, while the double lines represent the template. For gene fusion (D), the two different genes are shown as narrow and thick double lines. The dots shown on some M primers indicate the desired mutations (base changes) to be introduced into the product via the megaprimer. The primer in (B) (Insertion) and the template in (C) (Deletion) are shown as looped-out, solely to indicate the region to be inserted or deleted; such structures may not necessarily form in actual PCR.

Additive and Epistasis Effects of Quantitative Trait Loci for Plant Height and Its Components in Single Segment Substitution Lines of Rice

The technique for identifying fault types on single circuit lines, suggested by Ferrero et al. (1993) is modified to be suitable for protecting double circuit lines. The modified technique is based on estimating the Fourier coefficients of double circuit line currents using the recursive least square identifier. The sequence components are obtained by a linear transformation of the fundamental frequency phase currents of each circuit. The fuzzy logic inference system processes these components to identify fault type. The computer simulation test results indicate the possibility of using the suggested technique as an effective tool for high speed digital relaying.

Railroads have long been serving the largest portion of freight ton-miles in the U.S. freight shipment market. The rising demand for rail transportation is expected to continue in the foreseeable future, and considerable network congestion and inefficiency will result. Thus, a systematic methodology is needed to predict freight flow concentrations and congestion patterns in the rail network. A customized network assignment model for rail freight shipment demand is proposed; in this model, single-and double-track lines are represented by an equivalent directed graph. A railroad-specific link cost function adjusted for single and double tracks is developed to capture traffic delay, and an adapted convex combination algorithm is developed to find the shipment routing equilibrium. This model is applied to an empirical case study for the U.S. rail network with national freight shipment demand in 2007. The resulting freight flow pattern is visualized graphically and validated with empirical data. The proposed modeling framework could be used to help public agencies and private companies predict rail network traffic and develop infrastructure investment strategies to reduce adverse social impacts imposed by rail traffic delay.

Single-track mainline railway tracks with parallel location of station tracks provided quick preparation of train routes with manual control of switches. However, this system required complete stopping of both freight trains, especially if they were simultaneously received at a separate station from two directions at once. Additional installations of freight trains reduced the throughput capacity of the branch lines with a parallel track arrangement. With the development of interlocking and signalization in the new conditions of technical progress, it became possible to design extended passing-tracks with a longitudinal arrangement of the receiving-and-departure tracks. This measure ensures reduction of time and energy required for train stoppages on the way under crossing on the single-track railway line sections. In this case, the throughput capacity of the sections for single-track lines increases. For the conditions of non-uniformity in traffic, parallel track layouts have higher costs associated with acceleration and deceleration of both freight trains at once. In the case of nonuniformity, the best conditions are created in the case of simultaneous reception of freight trains from two directions at once for longitudinally located tracks.KeywordsCarScheduleRailway transportLocomotiveSingle-track lineTrainJunctionStation

Integrated Access and Backhaul (IAB) plays a central role in enabling scalability and high-throughput in wireless networks, especially in areas where wired backhaul is not feasible. Optimizing the topology of IAB networks is a complex task, involving trade-offs between path loss, node capacity, and link quality. To address this, this project investigates a Monte Carlo Tree Search (MCTS)-based approach to improve overall network performance by maximizing the capacity of network, considering Signal-to-Noise Ratio (SNR) on wireless links. MCTS provides a guided search mechanism to construct topologies efficiently under the constraints and is evaluated against baseline topologies. Experimental results show that our MCTS-based approach consistently produces topologies with higher minimum capacity and better SNR under a range of node constraints and network configurations.

<p>In improving the accessibility of the capital of Belgium by train, the railway company wants to increase the number of tracks from 2 to 4 tracks for the main railway lines in the direction of Brussels. In the urbanized and densely populated area near the capital, the design of the new infrastructure in extending the tracks, one on each side of the double track line, must be done with respect to existing historic bridges dating from the early 30’s. The paper describes the extension of a 3-span concrete multiple arch bridge over the canal Brussels-Charleroi by two new continuous 3- span concrete bridges with external post-tensioning and a total length of 102 m. The new one track superstructure is a fully concrete deck in U-shape having a width of 6,1 m and is continuous over 3 spans of respectively 30, 42 and 30 meter. Four extradosed post-tensioning cables make the construction a modern concrete structure contracting the existing arches. The paper describes the integral design of the railway bridge and the extradosed post-tensioning, as well as the construction method. In the design, special attention is given to the modeling of the post-tensioning cables taking into account that these cables are free from the deck in horizontal direction. The influence of this modeling on the cable force variation and the friction in the cables is considered. Finally, attention is given to fatigue in the extradosed cables. During and after the construction phase, continuing strain gauge measurements for a long period will be carried out in both the deck and the cables.</p>

<p>Deficient bridges and track structures form weak points on railways, which limit safety, comfort and the travel speed. A new modernisation programme for Polish Railways was introduced several years ago; however, this had to be preceded by a “weak spot removal” programme, where highly deficient structures were upgraded or replaced. This paper describes three railway bridges which were rebuilt during the programme. The bridges are located on main double track lines and were designated for upgrade by their regional railway agencies. The bridges were rebuilt using different techniques such as refurbishing and strengthening of an existing structure, partial rebuilding with replacement of the superstructure and full replacement. For the new superstructures, ballast track was used. The different techniques adopted for rebuilding the defective bridges ensured that the removal of weak spots was successful, but not without problems.</p>

Although everybody agrees that education reform is needed, there is little agreement on the nature of the problems, and certainly not on the remedies; nevertheless, there is a central focus on curriculum issues. Three principal points are addressed in this paper: (a) new approaches in education are urgently needed, (b) new educational approaches require revised concepts of the nature and development of human abilities, and (c) those new concepts must lead inevitably to emphasis on the acquisition, growth, and application of systematic processes of logical thinking, which is to say, “cognitive” or “metacognitive” education. The author presents a “transactional perspective” on human abilities, with three principal components: intelligence, cognitive processes, and intrinsic motivation. Intelligence and cognitive processes differ with respect to their respective sources, their relative modifiability, their composition, methods of assessment, and the role of parents and teachers in their development. Individual differences in intrinsic motivation are associated with differences in learning effectiveness that are not accounted for by the other two components of the transactional model, which is transactional rather than merely interactive because the ability of any one of the three principal components to influence development of either or both of the other two changes with each effect of one upon another. Two programs of cognitive education, one for preschool children, the other for older children, adolescents, and adults, are described and data are presented showing that systematic classroom application of such programs by well trained teachers can lead to enhancement of cognitive development, intrinsic motivation, and even IQ. Further, relatively long‐term evaluative studies demonstrate that there are positive and long‐lasting effects of cognitive education on subsequent learning and school achievement. Figure 11. School achievement scores, grades 1 and 2, of Bright Start and low‐SES control children (Paour et al., 2000). Figure 10. Percentage of passing grades in French and Math on a national examination, for the national standardisation sample, the high‐SES controls, the low‐SES Bright Start children, and the low‐SES control children. (Paour et al., 2000).

Simulation of the Laser Beam Melting Process – Approaches for an Efficient Modelling of the Beam-material Interaction