Assess reliability of a tourism transport network considering limited-budget and late arrivals

Tourism transport is becoming a crucial part of the tourism industry. Determining the reliability of tourism transport networks is required by travel agencies and other practitioners. However, much of recent reliability assessments cannot utilize directly for tourism transport networks. Moreover, there exists a lack of passengers-oriented reliability evaluation that involves the impacts of latency. Therefore, this study assesses reliability regarding carrying the required number of passengers to their destination under budget and time constraints when considering late arrivals. For reliability assessment, an algorithm, which combines the concept of the minimal path adding a searching procedure with the Recursive Sum of Disjoint Products method, is proposed. An illustrative example is adopted to provide travel agencies with an intuitive visualization of the proposed algorithm. Reliability analysis suggests improving the performance of tourism transport networks.

Small-time fluctuations for the bridge of a sub-Riemannian diffusion

We consider small-time asymptotics for diffusion processes conditioned by their initial and final positions, under the assumption that the diffusivity has a sub-Riemannian structure, not necessarily of constant rank. We show that, if the endpoints are joined by a unique path of minimal energy, and lie outside the sub-Riemannian cut locus, then the fluctuations of the conditioned diffusion from the minimal energy path, suitably rescaled, converge to a Gaussian limit. The Gaussian limit is characterized in terms of the bicharacteristic flow, and also in terms of a second variation of the energy functional at the minimal path, the formulation of which is new in this context.

Geometry and complexity of path integrals in inhomogeneous CFTs

In this work we develop the path integral optimization in a class of inhomogeneous 2d CFTs constructed by putting an ordinary CFT on a space with a position dependent metric. After setting up and solving the general optimization problem, we study specific examples, including the Möbius, SSD and Rainbow deformed CFTs, and analyze path integral geometries and complexity for universal classes of states in these models. We find that metrics for optimal path integrals coincide with particular slices of AdS3 geometries, on which Einstein’s equations are equivalent to the condition for minimal path integral complexity. We also find that while leading divergences of path integral complexity remain unchanged, constant contributions are modified in a universal, position dependent manner. Moreover, we analyze entanglement entropies in inhomogeneous CFTs and show that they satisfy Hill’s equations, which can be used to extract the energy density consistent with the first law of entanglement. Our findings not only support comparisons between slices of bulk spacetimes and circuits of path integrations, but also demonstrate that path integral geometries and complexity serve as a powerful tool for understanding the interesting physics of inhomogeneous systems.

A Minimal Path-Based Method for Computing Multistate Network Reliability

Most of modern technological networks that can perform their tasks with various distinctive levels of efficiency are multistate networks, and reliability is a fundamental attribute for their safe operation and optimal improvement. For a multistate network, the two-terminal reliability at demand level d, defined as the probability that the network capacity is greater than or equal to a demand of d units, can be calculated in terms of multistate minimal paths, called d-minimal paths (d-MPs) for short. This paper presents an efficient algorithm to find all d-MPs for the multistate two-terminal reliability problem. To advance the solution efficiency of d-MPs, an improved model is developed by redefining capacity constraints of network components and minimal paths (MPs). Furthermore, an effective technique is proposed to remove duplicate d-MPs that are generated multiple times during solution. A simple example is provided to demonstrate the proposed algorithm step by step. In addition, through computational experiments conducted on benchmark networks, it is found that the proposed algorithm is more efficient.

Minimal path set importance in complex systems

To find the best mode for system design in reliability optimization, risk engineers around the world use the importance measure as a basic tool. This paper introduces a new importance measure taking into account minimal path sets of the system. It helps to optimize the system designs that occur in many situations. For instance, this importance measure can be used (a) in identifying important components of any complex system and (b) solving constrained redundancy optimization problems. This is illustrated by providing two heuristic algorithms. In the first algorithm, this measure is used to find important components of any complex system ensuring improved system reliability. The second algorithm is used to solve a constrained redundancy optimization problem for any general coherent system giving (near) optimal solutions in 1-neighborhood. The results show that the new importance measure is easily applicable, unlike the classical ones. Hence, it serves as a very useful tool in measuring the important component(s) and solving constrained redundancy optimization problems of complex systems. Thus, it can be considered as a good alternative to the existing importance measures.

Inspection Order by Importance Measure Under Imperfect Inspection

Maintenance decision making, which is based on a result of imperfect inspection, sometimes causes problems with system operation. In order to reduce opportunities of misjudgment by imperfect inspection, inspection threshold is effective. The impact of component’s failure under the system operation is an important issue on maintenance decision making. It is also important to identify the weaknesses in the system. A minimal path-cut method is a concept that can express the system structure from the functional aspect. In this paper, it derives system importance measures under imperfect inspection using minimal path-cuts, and conduct basic research on the planning of inspection execution plans according to the inspection order.