Hasil untuk "Railroad engineering and operation"

HE Jia, YUAN Peng

Planning operation curves in parking scenarios for heavy-haul trains equipped with intelligent driving features on the Shenmu-Shuozhou railway faces two primary challenges: maneuvering difficulties stemming from the inherent characteristics of heavy-haul trains and the complexity of the track environments. These factors combine to significantly complicate the planning of operation curves. This paper presents an algorithm designed to address the safety and precision-oriented parking planning requirements for heavy-haul trains on the Shenmu-Shuozhou railway. First, a longitudinal dynamic model was established based on the track characteristics and maneuvering requirements, incorporating relevant constraints. Second, the planning process was divided into air braking and non-air braking stages, with planning strategies formulated according to their respective characteristics. Subsequently, evaluation indicators were proposed, taking into account actual engineering conditions, and an adaptive weight adjustment strategy was employed to enhance the algorithm's adaptability to various parking scenarios. Additionally, a refined adjustment strategy was developed to further reduce planning errors. Finally, a hardware-in-the-loop simulation platform was utilized to test and verify the proposed algorithm in three typical sections. The verification results show that the proposed algorithm achieves an average parking planning error of 1.31 meters while meeting the safety constraints , demonstrating the algorithm’s effectiveness and highlighting its value in practical engineering applications.

Jonathan Ullrich, Matthias Koch, Andreas Vogelsang

With the advent of generative LLMs and their advanced code generation capabilities, some people already envision the end of traditional software engineering, as LLMs may be able to produce high-quality code based solely on the requirements a domain expert feeds into the system. The feasibility of this vision can be assessed by understanding how developers currently incorporate requirements when using LLMs for code generation-a topic that remains largely unexplored. We interviewed 18 practitioners from 14 companies to understand how they (re)use information from requirements and other design artifacts to feed LLMs when generating code. Based on our findings, we propose a theory that explains the processes developers employ and the artifacts they rely on. Our theory suggests that requirements, as typically documented, are too abstract for direct input into LLMs. Instead, they must first be manually decomposed into programming tasks, which are then enriched with design decisions and architectural constraints before being used in prompts. Our study highlights that fundamental RE work is still necessary when LLMs are used to generate code. Our theory is important for contextualizing scientific approaches to automating requirements-centric SE tasks.

Shraddha Surana, Ashwin Srinivasan, Michael Bain

Engineering information systems for scientific data analysis presents significant challenges: complex workflows requiring exploration of large solution spaces, close collaboration with domain specialists, and the need for maintainable, interpretable implementations. Traditional manual development is time-consuming, while "No Code" approaches using large language models (LLMs) often produce unreliable systems. We present iProg, a tool implementing Interactive Structured Inductive Programming. iProg employs a variant of a '2-way Intelligibility' communication protocol to constrain collaborative system construction by a human and an LLM. Specifically, given a natural-language description of the overall data analysis task, iProg uses an LLM to first identify an appropriate decomposition of the problem into a declarative representation, expressed as a Data Flow Diagram (DFD). In a second phase, iProg then uses an LLM to generate code for each DFD process. In both stages, human feedback, mediated through the constructs provided by the communication protocol, is used to verify LLMs' outputs. We evaluate iProg extensively on two published scientific collaborations (astrophysics and biochemistry), demonstrating that it is possible to identify appropriate system decompositions and construct end-to-end information systems with better performance, higher code quality, and order-of-magnitude faster development compared to Low Code/No Code alternatives. The tool is available at: https://shraddhasurana.github.io/dhaani/

Dinesh Eswararaj, Ajay Babu Nellipudi, Vandana Kollati

The automotive industry generates vast amounts of data from sensors, telemetry, diagnostics, and real-time operations. Efficient data engineering is critical to handle challenges of latency, scalability, and consistency. Modern data lakehouse formats Delta Parquet, Apache Iceberg, and Apache Hudi offer features such as ACID transactions, schema enforcement, and real-time ingestion, combining the strengths of data lakes and warehouses to support complex use cases. This study presents a comparative analysis of Delta Parquet, Iceberg, and Hudi using real-world time-series automotive telemetry data with fields such as vehicle ID, timestamp, location, and event metrics. The evaluation considers modeling strategies, partitioning, CDC support, query performance, scalability, data consistency, and ecosystem maturity. Key findings show Delta Parquet provides strong ML readiness and governance, Iceberg delivers high performance for batch analytics and cloud-native workloads, while Hudi is optimized for real-time ingestion and incremental processing. Each format exhibits tradeoffs in query efficiency, time-travel, and update semantics. The study offers insights for selecting or combining formats to support fleet management, predictive maintenance, and route optimization. Using structured datasets and realistic queries, the results provide practical guidance for scaling data pipelines and integrating machine learning models in automotive applications.

Shalini Chakraborty, Sebastian Baltes

The IT industry provides supportive pathways such as returnship programs, coding boot camps, and buddy systems for women re-entering their job after a career break. Academia, however, offers limited opportunities to motivate women to return. We propose a diverse multicultural research project investigating the challenges faced by women with software engineering (SE) backgrounds re-entering academia or related research roles after a career break. Career disruptions due to pregnancy, immigration status, or lack of flexible work options can significantly impact women's career progress, creating barriers for returning as lecturers, professors, or senior researchers. Although many companies promote gender diversity policies, such measures are less prominent and often under-recognized within academic institutions. Our goal is to explore the specific challenges women encounter when re-entering academic roles compared to industry roles; to understand the institutional perspective, including a comparative analysis of existing policies and opportunities in different countries for women to return to the field; and finally, to provide recommendations that support transparent hiring practices. The research project will be carried out in multiple universities and in multiple countries to capture the diverse challenges and policies that vary by location.

ZANG Zhichao, DING Minghui, LI Ming

The expansive operational network of urban rail transit presents increased demands and complexities for the operation and maintenance of vehicles. In order to improve the data sharing for un-wheeling repair of subway vehicles in networked operation settings towards a scientific and systematic system, alleviate the work intensity in the design process, and improve work efficiency, this paper presents the development of data sharing and analysis software for urban rail transit, based on various characteristic data involving the aspects such as vehicle base, vehicle operation, vehicle maintenance systems, and un-wheeling repair requirements, using the object-oriented Java programming language. This software is devised to automatically output reports, serving as a basis for auxiliary decision-making to aid related operational management authorities in urban rail transit planning, particular concerning networks and depots. Focusing on sharing un-wheeling repair data, the software is customizable to urban rail transit networks with varying scales and at different stages, and its output could provide a reference for the sustainable and high-quality development of urban rail transit.

CAI Yonghui, ZHOU Wenwei

The deceleration and stopping process of freight trains on downslope sections through air braking, may encounter low converted pressure values of the brake shoes per 100 tons of train weight. Failure to timely reduce train speeds below the braking limit and control train operation within the speed limit could potentially result in hazards such as overspeeding and overrunning. To address this challenge, a calculation method for train braking speed limits was designed, tailored for the locomotive automatic operation system. Based on the train braking speed limit curve, functions for train operation curve planning, driving control, and safety protection were developed, which ensured the operational safety of trains in the automatic operation mode. Results from practical applications show the effectiveness of the proposed approach in improving the efficiency of train operation compared with manual driving.

TANG Jun, GE Qianghua, ZOU Zhirong et al.

The wide application of wireless communication technology has brought about an increase in network security risks for train communication networks. To mitigate these risks, data encryption has emerged as an important means, albeit with additional demand on CPU computing resources. However, train communication network hosts predominantly rely on embedded devices with limited computing resources. This paper proposes a lightweight encryption solution for train communication networks. This solution employs a key negotiation process based on traditional communication encryption scheme, aiming to achieve lightweight encryption in train communication networks and compliance with the authenticity, integrity, and confidentiality requirements of communication data, while greatly reducing hardware demands and computational burdens associated with key management. Experimental verification using the proposed solution yielded a key negotiation time consumption of about 31.9% and reduced the CPU load on devices to about 35.8% when compared to the traditional SM2+SM3+SM4 communication encryption method.

Weihua Zhang, Yuanchen Zeng, Dongli Song et al.

Purpose – The safety and reliability of high-speed trains rely on the structural integrity of their components and the dynamic performance of the entire vehicle system. This paper aims to define and substantiate the assessment of the structural integrity and dynamical integrity of high-speed trains in both theory and practice. The key principles and approaches will be proposed, and their applications to high-speed trains in China will be presented. Design/methodology/approach – First, the structural integrity and dynamical integrity of high-speed trains are defined, and their relationship is introduced. Then, the principles for assessing the structural integrity of structural and dynamical components are presented and practical examples of gearboxes and dampers are provided. Finally, the principles and approaches for assessing the dynamical integrity of high-speed trains are presented and a novel operational assessment method is further presented. Findings – Vehicle system dynamics is the core of the proposed framework that provides the loads and vibrations on train components and the dynamic performance of the entire vehicle system. For assessing the structural integrity of structural components, an open-loop analysis considering both normal and abnormal vehicle conditions is needed. For assessing the structural integrity of dynamical components, a closed-loop analysis involving the influence of wear and degradation on vehicle system dynamics is needed. The analysis of vehicle system dynamics should follow the principles of complete objects, conditions and indices. Numerical, experimental and operational approaches should be combined to achieve effective assessments. Originality/value – The practical applications demonstrate that assessing the structural integrity and dynamical integrity of high-speed trains can support better control of critical defects, better lifespan management of train components and better maintenance decision-making for high-speed trains.

Yvonne Dittrich, Johan Bolmsten, Catherine Seidelin

Action research provides the opportunity to explore the usefulness and usability of software engineering methods in industrial settings, and makes it possible to develop methods, tools and techniques with software engineering practitioners. However, as the research moves beyond the observational approach, it requires a different kind of interaction with the software development organisation. This makes action research a challenging endeavour, and it makes it difficult to teach action research through a course that goes beyond explaining the principles. This chapter is intended to support learning and teaching action research, by providing a rich set of examples, and identifying tools that we found helpful in our action research projects. The core of this chapter focusses on our interaction with the participating developers and domain experts, and the organisational setting. This chapter is structured around a set of challenges that reoccurred in the action research projects in which the authors participated. Each section is accompanied by a toolkit that presents related techniques and tools. The exercises are designed to explore the topics, and practise using the tools and techniques presented. We hope the material in this chapter encourages researchers who are new to action research to further explore this promising opportunity.

Nikhil Patnaik, Joseph Hallett, Awais Rashid

Writing secure code is challenging and so it is expected that, following the release of code-generative AI tools, such as ChatGPT and GitHub Copilot, developers will use these tools to perform security tasks and use security APIs. However, is the code generated by ChatGPT secure? How would the everyday software or security engineer be able to tell? As we approach the next decade we expect a greater adoption of code-generative AI tools and to see developers use them to write secure code. In preparation for this, we need to ensure security-by-design. In this paper, we look back in time to Saltzer & Schroeder's security design principles as they will need to evolve and adapt to the challenges that come with a world of AI-generated code.

Zdeněk Mašek, Michal Závodník

Článek se věnuje experimentálnímu zjištění ztrát vznikajících při AC a DC nabíjení elektromobilu Hyundai Kona electric 64 kWh. U obou typů nabíjení je vyhodnocena celková účinnost nabíjení, round-trip účinnost trakční baterie, vlastní spotřeba vozidla při nabíjení, u AC nabíjení pak ještě účinnost palubní nabíječky vozidla. U DC nabíjení je patrný zásadní vliv teploty trakční baterie na rychlost a účinnost nabíjení. Účinnost nabíjení je vypočtena jako poměr energie spotřebované z trakční baterie v jízdě vůči energii dodané do vozidla následným nabíjením do stejné úrovně nabití trakční baterie jako před jízdou. U elektromobilu Hyundai Kona byla zjištěna průměrná účinnost AC nabíjení 85 %, účinnost DC nabíjení 92,1 % bez zahrnutí účinnosti DC nabíječky. Round-trip účinnost trakční baterie je u AC nabíjení 97,6 %, u DC nabíjení 92,7 %. Podíl spotřeby 12 V palubní sítě vozidla na celkovém příkonu vozidla během nabíjení se pohyboval od 0,3 do 0,9 %. Data pro vyhodnocení byla získána ze záznamů sedmnácti AC nabíjení v létě i v zimě uskutečněných po jízdách na různých typech silnic a tří DC nabíjení uskutečněných po jízdách na dálnici v zimě.

Shavindra Wickramathilaka, Ingo Mueller

One of the main reasons that cause seniors to face accessibility barriers when trying to use software applications is that the age-related user interface (UI) needs of seniors (e.g., physical and cognitive limitations) are not properly addressed in software user interfaces. The existing literature proposes model-driven engineering based UI adaptations as a prominent solution for this phenomenon. But in our exploration into the domain, we identified that the existing work lacks comprehensiveness when it comes to integrating accessibility into software modelling tools and methods when compared to a well-recognised accessibility standard such as the Web Content Accessibility Guidelines (WCAG). Thus in this paper, we outline a research roadmap that aims to use WCAG as a reference framework to design domain-specific languages that model the diverse accessibility scenarios of senior users via user context information and UI adaptation rules modelling so that they meet the accessibility standards specified in WCAG.

Patrick Chadbourne, Nasir Eisty

Causal inference is a study of causal relationships between events and the statistical study of inferring these relationships through interventions and other statistical techniques. Causal reasoning is any line of work toward determining causal relationships, including causal inference. This paper explores the relationship between causal reasoning and various fields of software engineering. This paper aims to uncover which software engineering fields are currently benefiting from the study of causal inference and causal reasoning, as well as which aspects of various problems are best addressed using this methodology. With this information, this paper also aims to find future subjects and fields that would benefit from this form of reasoning and to provide that information to future researchers. This paper follows a systematic literature review, including; the formulation of a search query, inclusion and exclusion criteria of the search results, clarifying questions answered by the found literature, and synthesizing the results from the literature review. Through close examination of the 45 found papers relevant to the research questions, it was revealed that the majority of causal reasoning as related to software engineering is related to testing through root cause localization. Furthermore, most causal reasoning is done informally through an exploratory process of forming a Causality Graph as opposed to strict statistical analysis or introduction of interventions. Finally, causal reasoning is also used as a justification for many tools intended to make the software more human-readable by providing additional causal information to logging processes or modeling languages.

Lorenz Graf-Vlachy

Software engineering capabilities are increasingly important to the success of economic and political blocs. This paper analyzes quantity and quality of software engineering research output originating from the US, Europe, and China over time. The results indicate that the quantity of research is increasing across the board with Europe leading the field. Depending of the scope of the analysis, either the US or China come in second. Regarding research quality, Europe appears to be lagging the other blocs, with China having caught up to and even having overtaken the US over time.

Tingting Wu, Matthew D. Lew

Fluorescent molecules are versatile nanoscale emitters that enable detailed observations of biophysical processes with nanoscale resolution. Because they are well-approximated as electric dipoles, imaging systems can be designed to visualize their 3D positions and 3D orientations, so-called dipole-spread function (DSF) engineering, for 6D super-resolution single-molecule orientation-localization microscopy (SMOLM). We review fundamental image-formation theory for fluorescent di-poles, as well as how phase and polarization modulation can be used to change the image of a dipole emitter produced by a microscope, called its DSF. We describe several methods for designing these modulations for optimum performance, as well as compare recently developed techniques, including the double-helix, tetrapod, crescent, and DeepSTORM3D learned point-spread functions (PSFs), in addition to the tri-spot, vortex, pixOL, raPol, CHIDO, and MVR DSFs. We also cover common imaging system designs and techniques for implementing engineered DSFs. Finally, we discuss recent biological applications of 6D SMOLM and future challenges for pushing the capabilities and utility of the technology.

JIA Zhenwei, SHEN Ping, GU Linzhu et al.

Linear eddy current braking has the potential to become a new type of braking method for high-speed EMUs due to its non-adhesive braking characteristics. At present, there is a lack of relevant research on the electromagnetic interference of the eddy current braking system on the existing track signal equipment, which hinders the further application of this technology. In this paper, the axle counter was selected as a typical track signal device. On the basis of theoretical analysis, ANSYS Maxwell and Twin Builder were used to establish simulation models of eddy current brake electromagnetic system and axle counter respectively. Then, based on the Twin Builder platform, the eddy current brake system model and the axle counter model were jointly simulated to analyze the electromagnetic interference of the eddy current brake system to the axle counter. The experimental result shows that the simulation results of the eddy current brake electromagnetic system model are consistent with the theoretical calculation results. The inductance voltage of the axle counter is 8.94 mV when the train without the eddy current brake system passes, which verifies the correctness of the established model. The axle counter induction coil will generate an interference voltage with a peak value of about 50 mV when the train with an eddy current brake system passes. The interference may make the inductive voltage of the axle counter exceed the set threshold and cause misjudgment, resulting in the occupation situation of the track section is inaccurate, which affects driving safety. The co-simulation model can assist in the design of eddy current brake devices, thereby promoting its application.

Andriy Miranskyy, Mushahid Khan, Jean Paul Latyr Faye et al.

Quantum computers (QCs) are maturing. When QCs are powerful enough, they may be able to handle problems in chemistry, physics, and finance that are not classically solvable. However, the applicability of quantum algorithms to speed up Software Engineering (SE) tasks has not been explored. We examine eight groups of quantum algorithms that may accelerate SE tasks across the different phases of SE and sketch potential opportunities and challenges.

Srinivasan Arunachalam, Seymour M. J. Spence

As inelastic design for wind is embraced by the engineering community, there is an increasing demand for computational tools that enable the investigation of the nonlinear behavior of wind-excited structures and subsequent development of performance criteria. To address this need, a probabilistic collapse assessment framework for steel structures is proposed in this paper. The framework is based on the integration of a high-fidelity fiber-based nonlinear structural modeling environment with a wind-tunnel-informed stochastic wind load model to perform nonlinear time history analysis. General uncertainty is propagated using a stratified sampling scheme enabling the efficient estimation of reliabilities associated with rare events. The adopted models for simulating high-fidelity nonlinear structural behavior were found, in general, to be adequate for capturing phenomena, including progressive yielding, buckling, and low-cycle fatigue, that are essential for wind induced collapse analysis. In particular, the adopted fatigue model was found to be capable of predicting damage and potential fiber/section fracture associated with non-fully reversing stress-strain cycles that are characteristic of wind loading. Through illustration on a 45-story archetype steel building, critical discussions on the types of observed collapse mechanisms, the difference between alongwind and acrosswind nonlinear behavior, reliabilities associated with first yield, and collapse are presented. A probabilistic description of the residual and peak story drifts is also provided through development of fragility functions.

T. I. Nabatchikova, S. N. Naumenko, A. V. Kostin et al.

Delivery of perishable freights in proper quality essentially depends on the correct choice of a special vehicle and the correct calculation of the delivery time. According to the requirements of the Rules for the transportation of perishable freights by rail, all special vehicles by January 1, 2022 must obtain certificates of compliance with the standards established by the Agreement on the International Transportation of Perishable Foodstuffs and on special vehicles intended for these transports. This requirement applies to special vehicles used both in international traffic and for transport of perishable freights within the country. The article presents a brief classification of special vehicles used for the transportation of perishable freights. Formulas are given that allow calculating duration of transportation of such freights and average temperature of the outside air along the entire route. Procedure for choosing a special vehicle for the already known duration of freight transportation has been developed. It is concluded that the procedure proposed by the authors allows choosing the optimal special vehicle for the transportation of perishable freights. Using this sequence of calculations makes it possible to take into account the maximum number of external factors that affect the duration of transportation.