Short pitch corrugation mitigation by rail constraint design

Short pitch corrugation is a quasi-periodic rail defect that induces a high level of noise and accelerates track degradation. This paper proposes a methodology to mitigate short pitch corrugation by rail constraint design, including four steps. In Step 1, corrugation is numerically reproduced by employing a three-dimensional (3D) finite...

Exploring Schedule Risks in Large Airport Operational Readiness: Risk Identification and the Systematic Model

Large airport operational readiness (LAOR) is a critical factor that directly impacts the opening of airports to the public. However, limited research exists on the risks affecting LAOR schedules. This article explores the risk breakdown structure and risk interactions model of LAOR schedule risk. An empirical investigation was conducted on...

Designing the transition to operations in large inter-organizational projects: Strategy, structure, process, and people

The transition from projects to operations requires a spanning from more temporary, goal-oriented, and evolving organizational forms to more permanent, routine, and ongoing organizational forms. A question of practical and theoretical significance is how to organize the transition to operations in large inter-organizational projects. To...

Experimental analysis of ballast bed state in newly constructed railways after tamping and stabilizing operation

Before the operation of newly constructed railways, tamping and stabilizing machines should be used to improve the quality of ballast beds. With the expansion of the railway network and increase of speeds and axle loads, higher quality and efficiency for tamping and stabilizing operation are required. However, previous studies did not involve...

Robust tube-based model predictive control with Koopman operators

Koopman operators are of infinite dimension and capture the characteristics of nonlinear dynamics in a lifted global linear manner. The finite data-driven approximation of Koopman operators results in a class of linear predictors, useful for formulating linear model predictive control (MPC) of nonlinear dynamical systems with reduced...

Operational risk allocation in urban rail transit public–private partnership projects

Operation risk (OR) has affected sustainable development of urban rail transit (URT) public–private partnership (PPP) projects in China. Balanced distribution of operational risks among stakeholders (the public, government, and private companies) involved in URT PPP projects can maximize overall profit. Quantitative analysis of operational...

Collision prevention of ship towing operation under environmental disturbance

Towing operations are highly reliant on the experience of the towing operators. Safety concerns arise when towing operations are subjected to environmental disturbances and dynamic traffic conditions. However, a systematic framework and approaches to enhance the safety and automation of towing operations remain lacking. This work proposes a...

Discrete Element Analysis on Mechanical Properties of Ballast Bed by Tamping in Railway Turnout Areas

Turnout is the key component of the railway tracks for trains to change direction, which is vital to operational safety and passenger comfort. Therefore, it is of great importance to perform a scientific and reasonable tamping operation for turnout areas. In this paper, based on the commercial software EDEM and RECURDYN, a coupled simulation...

Improving the Service of E-bike Sharing by Demand Pattern Analysis: A Data-driven Approach

E-bike sharing has gradually gained popularity in recent years, while the research in this field is still quite limited. This study applies data-driven methods, mainly demand pattern analysis, to facilitate the development of operational strategies in a cost-effective and operator-friendly way. Demand pattern is analysed in an innovative spatial...

A semi-quantitative methodology for risk assessment of university chemical laboratory

University chemical laboratory is a high-risk place for teaching and scientific research due to the presence of various physical and chemical hazards. In recent years, university chemical laboratory accidents occur frequently. This urges the need to enhance university chemical lab safety. A semi-quantitative methodology comprising Matter...

Multimodal dispersive waves in a free rail: Numerical modeling and experimental investigation

In this paper, we present a solution method based on finite element (FE) modeling to predict multimodal dispersive waves in a free rail. As well as the modal behaviors and wavenumber-frequency dispersion relations, the phase and group velocities of six types of propagative waves are also derived and discussed in detail in the frequency range...

Factors Affecting the Decision-Making Process between Owner and Contractor Mining

When making a decision between conducting owner and contractor mining, it is common for the mine owner to take into consideration a number of factors to assess the suitability of either method for any particular project. This research identifies and investigates the key factors by means of literature review and questionnaires and interviews with...

An indicator system for evaluating operation and maintenance management of mega infrastructure projects in China

Mega infrastructure projects provide a basic guarantee for social development, economic construction, and livelihood improvement. Their operation and maintenance (O&M) management are of great significance for the smooth operation and the realization of the value created by the projects. In order to provide an approach for effectively...

Intentional islanding method based on community detection for distribution networks

Complex network theory is introduced to solve the islanding problem in an emergency of distribution networks. In this study, the authors put forward an intentional islanding method based on community detection. In this method, a new index has been defined called electrical edge betweenness, on the strength of edge betweenness in complex networks...

Development of high-performance gas engine operating at a stoichiometric condition - Effect of Miller cycle and EGR -