A probabilistic fatigue crack growth life approach to the definition of inspection intervals for railway axles

Different options that rely on fracture mechanics are currently used in engineering during the design and assessment of components. One of the most important aspects is the time taken for a crack to extend to its critical size. If this time is long enough, a design concept based on inspection intervals can be applied, as is it the case of a railway axle component. To define inspection intervals that ensure the continuous and safe operation of a damage-tolerant railway axle, a reliable estimation of its fatigue crack growth life is required. Due to the uncertainties involved in the fatigue process, inspections must be devised not only considering the uncertainties in the performance of the inspection technique, but also based on a probabilistic lifespan prediction. From this premise, this paper presents a procedure for determination of inspection intervals that uses a conservative fatigue crack growth life estimation based on the lifespan probability distribution. A practical example to illustrate the reliability-based inspection planning methodology in a railway axle under random bending loading is given. The inspection intervals are further assessed in terms of overall probability of detecting cracks in successive inspections and in terms of probability of failure, considering the probability of detection curve of the non-destructive testing technique. The procedure developed provides recommendation for the definition of inspection intervals and associated inspection techniques.

Designing alternative scenarios for the provincial region development based on the scenario planning methodology

Subject. This article considers the issues of application of scenario planning techniques in the process of constructing alternative scenarios for the development of spatial socio-economic systems in the context of changes, complexity, and uncertainty. Objectives. The article aims to form a scenario planning algorithm for spatial socio-economic systems and its implementation in relation to the Mari El Republic. Methods. For the study, we used the systems approach and foresight techniques. Results. The article presents four alternative scenarios for the development of the provincial region: intensive, technological, moderately technological and pessimistic. The article presents four alternative scenarios for the development of the provincial region, namely, the intensive, technological, moderate technological, and worst-case ones. Conclusions and Relevance. The technological scenario for the provincial region’s development seems to be the most likely. It assumes moderately favorable prospects for attracting investment, which can stimulate the development of regional key industries. The proposed alternative scenarios can serve as a basis for the policy making by regional and municipal authorities.

Integrated Optimization of Port Rotation Direction and Fleet Deployment for Container Liner Shipping Routes

This paper provides an integrated planning methodology for the optimization of port rotation direction and fleet deployment for container liner shipping routes with consideration of demand uncertainty. We first consider a special case that demand is deterministic. A multicommodity flow network model is developed via minimizing the total network-wide cost. Its decisions are the selection of port rotation direction and fleet deployment and container routings in the shipping network. Afterward, we address the generic case that uncertain demand is considered, which is represented by potentially realizable demand scenarios. We develop a minimax regret model to procure the least maximum regret across all the demand scenarios. The proposed models are applied to an Asia-Europe-Oceania liner shipping network with 46 ports and 12 ship routes. Results could provide the liner company with a comprehensive decision tool to simultaneously determine port rotation direction and fleet deployment when tackling uncertain demand.

DEVELOPMENT OF A HOLISTIC METHODOLOGY FOR STRATEGIC PLANNING OF THE DEVELOPMENT OF THE ARMED FORCES BASED ON CAPABILITIES

Based on the results of the study, a scientific and applied problem was formulated, a hypothesis (multifactorial) was advanced, and partial scientific tasks were identified to develop a holistic methodology for strategic planning of the development of the Armed Forces of Ukraine based on capabilities. The relevance of the study is due to the emergence of new problems in the field of defense and military development, a decrease in the objectivity of strategic decision-making in determining and adjusting the development strategy of the Armed Forces in the long term, and the effectiveness of strategic planning for the development of the Armed Forces as a whole through the introduction of capabilities-based planning methodology in the defense forces. The requirements of modern regulatory legal acts of Ukraine regarding the introduction of planning based on the capabilities, functions of the Ministry of Defense of Ukraine and the General Staff of the Armed Forces of Ukraine, as well as the tasks of the Interdepartmental Working Group on the Defense Review (a temporary subsidiary body of the Ministry of Defense of Ukraine) are analyzed. The reasons for the emergence of problems in the construction and development of the Armed Forces are investigated, as well as contradictions in the definition and adjustment of the strategy for the development of the capabilities of the Armed Forces for the long term are revealed. The strategic planning of the development of the Armed Forces and defense planning are differentiated according to the goal, results and responsibility between the subjects of planning. The scientific and applied problem lies in the need to develop a concept of strategic planning for the development of the Armed Forces of Ukraine based on the capabilities, a set of special methods, techniques and approaches to determine and adjust the strategy for the development of the capabilities of the Armed Forces in the long term. A research hypothesis (multifactorial) about the conditions for achieving the effectiveness of strategic planning for the development of the Armed Forces of Ukraine on the basis of capabilities is put forward and partial scientific tasks are identified, which will be devoted to further research.

China's new Towns in Controversy: A Literature Review

In the past forty years, more than 3,800 new towns emerged and accommodated over 150 million urban inhabitants in China, which drew much attention since they were reported as “ghost cities” by media in the late 2000s. This literature review examines existing research and synthesizes current discussions through a meta-analysis. It concludes that existing literature, led by environmental scientists and designers, exhibits two polarized debates around the new towns’ uniqueness and the future of ghost cities. Gaps exist in national-scale surveys, criticism of planning methodology, and theories that can explain the current disputes.

Multiple Region Coverage Path Planning for Autonomous Underwater Vehicle.

Coverage path planning methodology for an autonomous underwater vehicle to search multiple non-overlapping regions has been proposed in the paper. The proposed methodology is based on the genetic algorithm (GA). The GA used in the proposed methodology has been tuned for the specific problem, using design of experiment on an equivalent travelling salesman problem benchmark instance. Optimality of the generated paths was analysed through simulation studies. Results indicated that the proposed methodology generated shorter paths in comparison to conventional methods.

Collision-Free Path Planning for Efficient Inspection of Free-Form Surface by Using a Trigger Probe

Measurement path planning plays an essential role in on-machine measurement, which is often required to be time-saving and collision-free. This paper proposes a novel path planning methodology and develops an automatic collision avoidance strategy for measurement. Measurement points are generated by Contour section sampling (CSS), Grid mesh sampling (GMS), and Locally dense sampling (LDS) on the free-form surface. Afterwards, a shortest path algorithm (SPA) and a non-interference path algorithm (NIPA) are developed respectively. The simulations show that the proposed method can reduce the total inspection distance to nearly 7.82% than the original one. The presented path planning method can measure the surface of large aerospace parts directly by using a trigger probe.

Regular graph-based free route flight planning approach

Purpose The purpose of this study is to provide an alternative graph-based airspace model for more effective free-route flight planning. Design/methodology/approach Based on graph theory and available data sets describing airspace, as well as weather phenomena, a new FRA model is proposed. The model is applied for near to optimal flight route finding. The software tool developed during the study and complexity analysis proved the applicability and timed effectivity of the flight planning approach. Findings The sparse bidirectional graph with edges connecting only (geographically) closest neighbours can naturally model local airspace and weather phenomena. It can be naturally applied to effective near to optimal flight route planning. Research limitations/implications Practical results were acquired for one country airspace model. Practical implications More efficient and applicable flight planning methodology was introduced. Social implications Aircraft following the new routes will fly shorter trajectories, which positively influence on the natural environment, flight time and fuel consumption. Originality/value The airspace model proposed is based on standard mathematical backgrounds. However, it includes the original airspace and weather mapping idea, as well as it enables to shorten flight planning computations.

Ecocultural networks as grounds for spatial planning. A psychosocial approach applied to coastal development

PurposeThis work critiques the situation of the ecological and cultural heritage in many coastal territories and analyses how current land planning methodologies are responding to it. The study builds a new integrated approach founded on ecocultural values and local knowledge as resources for an effective territorial planning and sustainable development.Design/methodology/approachThe proposed framework was developed through: (1) analysing coastal planning needs and problems in European coastal areas; (2) identifying ecocultural values, including local knowledge, in such areas; (3) selecting best approaches and tools in spatial planning; (4) applying the selected planning approaches to use ecocultural values as resources for spatial planning and sustainable development; and (5) validating the final methodology.FindingsA dynamic approach for maritime-land planning was developed projecting coastal waters and river basins as strategic drivers for sustainable development, based on the natural capacity of water to shape and integrate the ecological and cultural territory. A participatory governance planning methodology supports the new articulations of space based on ecocultural value chains and networks as synergistic vectors, focusing on local knowledge as psychosocial capital for a collective mapping of cultural, historical, social, economic and ecological values into ecocultural littoral plans.Originality/valueThe results show the potentials of combining new approaches applying cultural and ecological heritage into an effective strategy of integration between society and territory as a powerful driver for effective sustainable planning and development.