Separate Train Research Articles

An approach to railway network sections modeling based on queuing networks

The paper is devoted to the study and long-term forecasting of railway network sections operating. We call a railway network section a set of several railway stations interacting with each other and lines between them. We propose a methodology for mathematical modeling of train traffic on the railway network based on the queuing theory. The resulting models are a set of mathematical descriptions of the incoming train traffic and the train running within the system. Several Markovian Arrival Process are used to describe train arrivals from different directions. Such a description makes it possible to take into account the parameters of separate train flows, which depend on the category of trains and their directions. A queuing network in which all nodes have a finite capacity simulates the movement of trains through the system. This mathematical apparatus allows us to consider the nonlinear structure of the railway network, the operation features of stations, the capacity of railway lines, and the influence of random factors. To apply the methodology, we have chosen two objects that differ in infrastructure and properties of train flows. The first is located in the east of Russia and focused on servicing freight trains. The second is located in Germany, close to Belgium and The Netherlands borders. It is characterized by the predominance of passenger traffic. We construct mathematical models and perform numerical simulations. Based on the results obtained, the maximum allowable load is estimated, and bottlenecks in the structure of transport systems are found. Besides, we give some recommendations on how to increase capacity in the long term.

Regulatory mechanisms of the dynein-2 motility by post-translational modification revealed by MD simulation

Intraflagellar transport for ciliary assembly and maintenance is driven by dynein and kinesins specific to the cilia. It has been shown that anterograde and retrograde transports run on different regions of the doublet microtubule, i.e., separate train tracks. However, little is known about the regulatory mechanism of this selective process. Since the doublet microtubule is known to display specific post-translational modifications of tubulins, i.e., “tubulin code”, for molecular motor regulations, we investigated the motility of ciliary specific dynein-2 under different post-translational modification by coarse-grained molecular dynamics. Our setup allows us to simulate the landing behaviors of dynein-2 on un-modified, detyrosinated, poly-glutamylated and poly-glycylated microtubules in silico. Our study revealed that poly-glutamylation can play an inhibitory effect on dynein-2 motility. Our result indicates that poly-glutamylation of the B-tubule of the doublet microtubule can be used as an efficient means to target retrograde intraflagellar transport onto the A-tubule.

FS-IDS: A framework for intrusion detection based on few-shot learning

Due to the high dependency of traditional intrusion detection method on a fully-labeled large dataset, existing works can hardly be applied in real-world scenarios, especially facing zero-day attacks. In this paper we present a novel intrusion detection framework called “FS-IDS”, including flow data encoding method, feature fusion mechanism and architecture of intrusion detection system based on few-shot learning. We utilize task generator to split the dataset into separate tasks and train model in an episodic way, hoping model to learn general knowledge rather than those specific to a single class. The extraction module and distance metric module are responsible for learning and determining whether the traffic data are benign or not. We conduct three sets of experiments on “FS-IDS”, i.e., comparison study, ablation study and multiclass study. Comparison study firstly determines that the best measure metric for discrimination is Euclidean distance. Based on the optimal implementation, “FS-IDS” achieves comparable performance with existing works by using much fewer malicious samples. Ablation study sets two base models to explore how proposed encoding method and feature fusion mechanism improve detection capacity. Both the image representation and feature fusion achieve more than 2% improvement in accuracy and recall. Finally, to test whether “FS-IDS” can perform well under real-world scenario or not, we design network traffic containing various attacks to simulate complex malicious network environment. Experimental results show that “FS-IDS” maintains more than 90% detection accuracy and recall under the worst circumstances, which composes of various seen or unseen attacks with only a few malicious samples available.

Cooperative Control of Metro Trains to Minimize Net Energy Consumption

With the increasing concerns on energy consumption and operating cost in metro systems, energy saving on train operation attracts significant attentions. Previous studies have mainly focused on optimal control of a single train and energy-efficient train timetabling. The former does not consider the synchronization of motoring and braking trains, which cannot ensure the proper utilization of regenerative energy on the metro lines without energy storage systems. The latter includes scheduling train operations to synchronize motoring and braking trains for the better utilization of regenerative energy. However, the overlapping time of motoring and braking trains is usually as short as a few seconds and the energy reduction might be made impossible by train delays, which are common in practice. This paper presents a model framework, on the extents of motoring/braking of train acceleration and station stopping, as well as the locations of switching train operation modes, for real-time cooperative control of multiple metro trains. The objective is to minimize the net energy consumption with the consideration of utilizing regenerative energy. A cooperative co-evolutionary algorithm is developed to attain the solution of the proposed model. Case studies on a real-life metro line demonstrate the energy saving performance of the proposed approach compared with separate train control and timetable optimization, from no disturbance to a good range of delays. The results also indicate that the partial motoring in train acceleration and partial braking in station stopping achieve better net energy reduction, in comparison with full motoring/braking preferred in previous studies.

The Method and Conditions for Completing Soft Coupling of Two Separate Train Sets in Motion

The Method and Conditions for Completing Soft Coupling of Two Separate Train Sets in Motion

Participation of Ukrainian NPPs in Regulating Frequency and Power in the United Energy System: Problem Analysis and Solutions

The issue related to the participation of Ukrainian nuclear power plants in regulating frequency and power in the united energy system of Ukraine is considered in the paper. The dependence of frequency changes in the grid on the imbalance between generation and consumption of active power is presented. This can violate conditions of parallel operation of generators. Three levels of the frequency control system in the power system using backup capacities are examined. The issues of participation of nuclear power units in regulating frequency and power are studied. It is shown that the main factors limiting such participation are the characteristics of fuel assemblies. These characteristics govern the change in reactor power in a narrow range. An obstacle is also the mismatch of the characteristics of the equipment of power units for participation in regulating power system frequency. The complexity of regulating the electric power of a WWER nuclear power unit is under consideration, which is implemented by coordinated regulation of the reactor power and generator power. The regulatory requirements for the characteristics of the primary frequency regulation by nuclear power units is carried out. The possibility of their participation in the normalized primary frequency regulation are analyzed. The paper considers the concept of the National Nuclear Energy Generating Company “Energoatom” for the modernization of systems and equipment of WWER-1000 power units, which provides bringing the characteristics of power units in line with standards. The methodology for preliminary testing of the readiness of Zaporizhzhya NPP Unit 1 (“pilot” power unit) to participate in such regulation is described. The methodology involves testing at two power levels at the beginning and in the end of the fuel campaign. A signal is used to simulate a frequency deviation that is input via a separate train of the control system. The tasks, conditions and criteria for the success of the tests are described. Based on the test results, conclusions will be drawn about the possibility of the safe participation of WWER-1000 power units in the normalized frequency regulation in the united energy system of Ukraine and the necessary measures to modernize the equipment.

Syngas production with thermo-chemically recuperated gas expansion systems: An exergy analysis and energy integration study

In spite of the large degree of energy integration in the modern syngas production units, the highly endothermic reactions of steam methane reforming and the combined steam and power generation still require a huge amount of energy that is typically supplied by an expensive natural gas-fired furnace at very high temperatures. Since normally only half of the energy supplied by the furnace is used to carry out the reforming reactions, the remaining heat recovery must be performed in a separate convection train (HRCT). Additionally, the high temperature effluent of the secondary reformer is generally cooled down by producing low temperature steam, increasing the process irreversibility and the losses associated to the excessive amount of condensate. Thus, in this paper, the advantages of introducing a chemically recuperated gas turbine (CRGT) concept to simultaneously carry out the endothermic chemical reactions and recover the exergy available from the autothermal reformer effluent are discussed. In this way, higher temperatures and higher conversions can be attained with lower driving forces. The power required by the air compression as well as other ancillary systems (e.g. air separation unit, carbon capture system, boiler feedwater pumps and recompressor) can also be supplied, while the exergy of the exhaust gases from the turbine is used more efficiently than in typical steam generation systems. Thus, more compact and integrated syngas production plants can be envisaged. Moreover, by introducing more advanced cogeneration features such as air enrichment, process gas reheating and incremental levels of pressures in the reaction-driven components, energy savings together with drastically reduced atmospheric CO2 emissions and irreversibility can be achieved in the frontend syngas production section. As a result, the average specific exergy destruction and exergy fuel consumption of the proposed CRGT-based configurations are, respectively, 12.0% and 2.7% lower, whereas the specific atmospheric CO2 emissions are cut down up to 25%, when compared to the conventional syngas production process.

In vitro detection of common rhinosinusitis bacteria by the eNose utilising differential mobility spectrometry.

Acute rhinosinusitis (ARS) is a sudden, symptomatic inflammation of the nasal and paranasal mucosa. It is usually caused by respiratory virus infection, but bacteria complicate for a small number of ARS patients. The differential diagnostics between viral and bacterial pathogens is difficult and currently no rapid methodology exists, so antibiotics are overprescribed. The electronic nose (eNose) has shown the ability to detect diseases from gas mixtures. Differential mobility spectrometry (DMS) is a next-generation device that can separate ions based on their different mobility in high and low electric fields. Five common rhinosinusitis bacteria (Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Staphylococcus aureus, and Pseudomonas aeruginosa) were analysed in vitro with DMS. Classification was done using linear discriminant analysis (LDA) and k-nearest neighbour (KNN). The results were validated using leave-one-out cross-validation and separate train and test sets. With the latter, 77% of the bacteria were classified correctly with LDA. The comparative figure with KNN was 79%. In one train-test set, P. aeruginosa was excluded and the four most common ARS bacteria were analysed with LDA and KNN; the correct classification rate was 83 and 85%, respectively. DMS has shown its potential in detecting rhinosinusitis bacteria in vitro. The applicability of DMS needs to be studied with rhinosinusitis patients.

Transparent lattice characterization with gated turn-by-turn data of diagnostic bunch train

Methods of characterization of a storage ring's lattice have traditionally been intrusive to routine operations. More importantly, the lattice seen by particles can drift with the beam current due to collective effects. To circumvent this, we have developed a novel approach for dynamically characterizing a storage ring's lattice that is transparent to operations. Our approach adopts a dedicated filling pattern which has a short, separate diagnostic bunch train (DBT). Through the use of a bunch-by-bunch feedback system, the DBT can be selectively excited on demand. Gated functionality of a beam position monitor system is capable of collecting turn-by-turn data of the DBT, from which the lattice can then be characterized after excitation. As the DBT comprises only about one percent of the total operational bunches, the effects of its excitation are negligible to users. This approach allows us to localize the distributed quadrupolar wakefields generated in the storage ring vacuum chamber during beam accumulation. While effectively transparent to operations, our approach enables us to dynamically control the beta beat and phase beat, and unobtrusively optimize performance of the National Synchrotron Light Source-II accelerator during routine operations.

Axicons in Action

AbstractAxicon lenses convert incident plane waves into approximations of Bessel beams. The circular profile of an axicon beam brings capabilities that suit the lenses for use in corneal surgery and optical trapping. The unique features of axicon lenses also enable an interesting type of wavefront sensor. Axicons focus light along the optical axis, and the position shifts if aberrations are introduced to the beam. That creates variation in the intensity distribution measured by an image sensor. In addition, the center of an axicon lens, the apex, also scatters some of the incident light. The focused light and the scattered light can interfere with each other, creating a self‐referenced interferogram. A wavefront sensor based on an axicon lens can measure low order aberrations with no need for a separate reference wavefront optical train. Wavefront sensors based on axicons offer an inexpensive, rapid, and compact method of detecting small aberrations in the beam.

Axicons in Action

AbstractAxicon lenses convert incident plane waves into approximations of Bessel beams. The circular profile of an axicon beam brings capabilities that suit the lenses for use in corneal surgery and optical trapping. The unique features of axicon lenses also enable an interesting type of wavefront sensor. Axicons focus light along the optical axis, and the position shifts if aberrations are introduced to the beam. That creates variation in the intensity distribution measured by an image sensor. In addition, the center of an axicon lens, the apex, also scatters some of the incident light. The focused light and the scattered light can interfere with each other, creating a self‐referenced interferogram. A wavefront sensor based on an axicon lens can measure low order aberrations with no need for a separate reference wavefront optical train. Wavefront sensors based on axicons offer an inexpensive, rapid, and compact method of detecting small aberrations in the beam.

‘The Long March through Leipzig’: Train Terminal Chaos and the Transmigrant Registration Station, 1904–1914

Responding to a cholera scare in the 1890s, German steamship companies, backed by the state, set up transmigrant control stations along eastern Prussian borders. Millions of Eastern European emigrants passed through these medical and financial checkpoints as they made their way by rail to northern European harbour cities, where steamships carried them across the Atlantic. In 1904, officials opened a registration station in the Saxon city of Leipzig. A major European railway hub, Leipzig seemed an ideal location. However, the city layout soon proved problematic. Leipzig had no fewer than six separate train stations, one an hour’s walk from the registration station. Saxon police and shipping officials needed to direct transmigrants arriving in Leipzig to the registration station, despite logistical problems and sometimes uncooperative migrants. Building upon a growing scholarship on the continental journey of transoceanic migrants, this article demonstrates how a single city could affect an intricate transatlantic network.

Muscle Activity, and the Association between Core Strength, Core Endurance and Core Stability

Introduction: Core training is often divided into the training approaches core endurance-, core stability- and core strength training. The aim of the study was to compare the association between core strength, core endurance and core stability testing 52 healthy males and females. Methods: The core strength and endurance tests were tested isometric in hip flexion, extension and lateral flexion. The time maintaining the positions in the core endurance tests, maximal force output in the core strength tests and total displacement in the core stability tests were examined with electromyography measurement of the core muscles in randomized order. Results: There were no significant correlations between the variables core strength, core stability or core endurance (p = 0.102 – 0.965, r = 0.01 – 0.23), except for the endurance lateral flexion which correlated significantly with the core strength (extension and lateral flexion) and the core stability using the left leg (p = 0.001 – 0.048, r = 0.29 – 0.44). Generally, the muscle activity of the core muscle decreased from strength < endurance < stability tests, respectively. Conclusion: There were no systematic correlations between core endurance, core strength or core stability indicating that these capacities are largely independent from each other. Coaches, training instructors or physical therapists needs to address the core endurance, core strength and core stability as separate capacities and train them accordingly based on the aim of the training.

TIME RESERVES DURING THE ORGANISATION OF FREIGHT TRAIN MOVEMENT ON SCHEDULE

Purpose. The article is devoted to the development of estimation methods of time reserves that should be formed at the train schedule and the schedule for the turnover of freight trains, required to ensure the sustained interaction of technological processes of industrial enterprises and railways for the transportation of freight on schedule. Methodology . The paper considers the issues of bulk conveyance organization between industrial enterprises on schedule. In order to ensure the arrival of trains at the destination station to the specified time, the schedules of rolling stocks turnover must have some time reserves. These reserves, in their turn, should be sufficient for correction action of destabilizing factors. The methods of mathematical statistics were used to study the schedule performance quality of separate trains. Currently the movement of the main part of freight trains is performed on preparedness and occupation processes of separate schedule train paths by some depots are not fixed. Therefore, the analyses of the schedule performance of freight trains do not allow receiving the material for research. And, due to the lack of statistical material on the punctuality of the schedule for the movement of freight trains, research of the passenger trains movement with subsequent dissemination of results on freight movement were carried out by the authors. Findings. The research proved that the trains arrival at the destination station according to the schedule should be ensured by permissible rating of delay as well as increase the operating time of trains and running intervals. The values of the additional time reserves that should be included in the schedule of trains, and the schedule for the turnover of freight trains to provide conditional interaction of railroads and industrial enterprises in Ukraine were proposed. Originality . On the basis of the research development graph methods of trains turnover, providing transportation of goods on schedule were improved. Practical value. The obtained results can be used for the technical-and-economic calculations of transition effectiveness of industrial enterprises for maintenance on schedule as well as in the development of schedule on the initial stages of testing technology.

THE EFFICIENCY OF FORMATION TWO-UNIT TRAINS IN THE OPERATIONAL CONDITIONS OF THE ORGANIZATION OF MAGNOPOTAMION

The presence of substantial of competition from automobile transport and the need to attract more clients are makes us look the leadership of railway transport measures for reducing down freight costs and improve the quality of work. In the first place should be considered such measures that do not require additional capital expenses for their implementation. Improvement of the system organizations of wagonflows is a perspective direction to improve the of railway transport in the modern conditions of operation. One of the most effective methods of improvement is the application of operative management of the organization of wagonflows using the making two-unit trains. For a more complete account of the operative situation prompted the notion of efficiency is applied at the moment when there is the possibility of formation of two-unit trains taking into account the forecast of receipts these wagons passing the plan of trains formation appointments from the certain period of time. Consider the influence the operational formation two-unit trains on the basis of single-group destinations the formation plan on the main indicators of the expluatation work of the station of the railway direction. Determined by the costs of organizing wagonflows in the operating conditions for a variety of approaches to operational destination two-unit trains. Displaying the effectiveness of this approach to the management of the organization wagonflows taking into account main influencing factors. Studies have shown that the issue of management of process of formation of trains in operative environment requires an integrated approach that involves determining the of formation of each separate two-unit train taking into account all expenses railway direction, not just the parent the technical station. Moreover, is proved that the processing technology two-unit trains passing on technical station greatly affects the costs of organizing wagonflows in the train. At the same time it is proved that in the operational management should take into account the impact of such basic factors as the power wagonflows and presence the need to change locomotive train. Further improvement of the system organizations wagonflows is possible by consideration the combination of a larger number of passing appointments plan formation, search and given the large number influencing factors, taking into account economy of means, by reducing the turnover of the wagons. Also, it shall be possible introduction of these solutions in the respective the automated workplaces operating personnel at various levels of management formation trains and use of existing on the railway database.

Methodical approach to definition of the rational zone of the address of the separate day high-speed train

Methodical approach to definition of the rational zone of the address of the separate day high-speed train

Scientific principles of determination of efficiency of running a separate passenger train

Determination of economic efficiency of the management of separate passenger train depends on the correct calculation of sum of charges on carrying passengers by a concrete train. Material is given in relation to determination of charges on running a separate passenger train including the passenger, locomotive, motor-car and infrastructural components. It allows correctly setting profitability or unprofitableness of train and the same to promote profitability of passenger trains in distant traffic.

ANALYSIS OF THE IMPACT OF THE OPERATIONAL FORMATION TWO GROUP TRAINS ON THE INDIVIDUAL PERFORMANCE OF THE WORK

The research of operative management by the organization of wagon flows in trains on a railway direction is executed. It is proved the expediency of introduction of a rational combination of formation of single-unit trains and two-unit trains with the purpose of acceleration of delivery of cargoes. The duration of planning period is offered as a condition for decision-making on determination of category of a separate train. The economic effect of introduction of operative management is obtained.

Development of a clinical decision model for thyroid nodules

BackgroundThyroid nodules represent a common problem brought to medical attention. Four to seven percent of the United States adult population (10–18 million people) has a palpable thyroid nodule, however the majority (>95%) of thyroid nodules are benign. While, fine needle aspiration remains the most cost effective and accurate diagnostic tool for thyroid nodules in current practice, over 20% of patients undergoing FNA of a thyroid nodule have indeterminate cytology (follicular neoplasm) with associated malignancy risk prevalence of 20–30%. These patients require thyroid lobectomy/isthmusectomy purely for the purpose of attaining a definitive diagnosis. Given that the majority (70–80%) of these patients have benign surgical pathology, thyroidectomy in these patients is conducted principally with diagnostic intent. Clinical models predictive of malignancy risk are needed to support treatment decisions in patients with thyroid nodules in order to reduce morbidity associated with unnecessary diagnostic surgery.MethodsData were analyzed from a completed prospective cohort trial conducted over a 4-year period involving 216 patients with thyroid nodules undergoing ultrasound (US), electrical impedance scanning (EIS) and fine needle aspiration cytology (FNA) prior to thyroidectomy. A Bayesian model was designed to predict malignancy in thyroid nodules based on multivariate dependence relationships between independent covariates. Ten-fold cross-validation was performed to estimate classifier error wherein the data set was randomized into ten separate and unique train and test sets consisting of a training set (90% of records) and a test set (10% of records). A receiver-operating-characteristics (ROC) curve of these predictions and area under the curve (AUC) were calculated to determine model robustness for predicting malignancy in thyroid nodules.ResultsThyroid nodule size, FNA cytology, US and EIS characteristics were highly predictive of malignancy. Cross validation of the model created with Bayesian Network Analysis effectively predicted malignancy [AUC = 0.88 (95%CI: 0.82–0.94)] in thyroid nodules. The positive and negative predictive values of the model are 83% (95%CI: 76%–91%) and 79% (95%CI: 72%–86%), respectively.ConclusionAn integrated predictive decision model using Bayesian inference incorporating readily obtainable thyroid nodule measures is clinically relevant, as it effectively predicts malignancy in thyroid nodules. This model warrants further validation testing in prospective clinical trials.