arXiv subjects

Peter B. Luh

Publications and source records attributed to Peter B. Luh.

4 recordsLinked to original sources

arXiv2026

Fluid-Based Analysis of Pedestrian Crowd at Bottlenecks

In emergency egress crowd behavior critically affects egress efficiency and public safety. By integrating psychological principles to Newtonian motion of crowd, a fluid-based equation is derived in this paper to explore how energy in different forms is balanced when pedestrian crowd pass through a bottleneck. Such fluid-based analysis helps to bridge a gap among psychological findings, pedestrian models and simulation results, and it further provides a new perspective to understand how the faster-is-slower effect is caused and how disastrous events (e.g., jamming and stampede) occur at a bottleneck passage.

physics.soc-ph↗

arXiv2025

Binary Decision Process in Pre-Evacuation Behavior

In crowd evacuation the time interval before decisive movement towards a safe place is defined as the pre-evacuation phase, and it has crucial impact on the total time required for safe egress. This process mainly refers to situation awareness and response to an external stressors, e.g., fire alarms. Due to the complexity of human cognitive process, simulation is used to study this important time interval. In this paper a binary decision process is formulated to simulate pre-evacuation time of many evacuees in a given social context. The model combines the classic opinion dynamics (the French-DeGroot model) with binary phase transition to describe how group pre-evacuation time emerges from individual interaction. The model parameters are quantitatively meaningful to human factors research within socio-psychological background, e.g., whether an individual is stubborn or open-minded, or what kind of the social topology exists among the individuals and how it matters in aggregating individuals into social groups. The modeling framework also describes collective motion of many evacuee agents in a planar space, and the resulting multi-agent system is partly similar to the Vicsek flocking model, and it is meaningful to explore complex social behavior during phase transition of a non-equilibrium process.

physics.soc-ph↗

arXiv2023

Novel Quality Measure and Efficient Resolution of Convex Hull Pricing for Unit Commitment

Electricity prices determined by economic dispatch that do not consider fixed costs may lead to significant uplift payments. However, when fixed costs are included, prices become non-monotonic with respect to demand, which can adversely impact market transparency. To overcome this issue, convex hull (CH) pricing has been introduced for unit commitment with fixed costs. Several CH pricing methods have been presented, and a feasible cost has been used as a quality measure for the CH price. However, obtaining a feasible cost requires a computationally intensive optimization procedure, and the associated duality gap may not provide an accurate quality measure. This paper presents a new approach for quantifying the quality of the CH price by establishing an upper bound on the optimal dual value. The proposed approach uses Surrogate Lagrangian Relaxation (SLR) to efficiently obtain near-optimal CH prices, while the upper bound decreases rapidly due to the convergence of SLR. Testing results on the IEEE 118-bus system demonstrate that the novel quality measure is more accurate than the measure provided by a feasible cost, indicating the high quality of the upper bound and the efficiency of SLR.

eess.SY↗

arXiv2021

Distributed and Asynchronous Operational Optimization of Networked Microgrids

Smart programmable microgrids (SPM) is an emerging technology for making microgrids more software-defined and less hardware-independent such that converting distributed energy resources (DERs) to networked community microgrids becomes affordable, autonomic, and secure. As one of the cornerstones of SPM, this paper pioneers a concept of software-defined operation optimization for networked microgrids, where operation objectives, grid connection, and DER participation will be defined by software and plug-and-play, and can be quickly reconfigured, based on the development of modularized and tightened models and a novel asynchronous price-based decomposition-and-coordination method. Key contributions include: (1) design the architecture of the operational optimization of networked microgrids which can be readily implemented to ensure the programmability of islanded microgrids in solving the distributed optimization models, (2) realize a novel discrete model of droop controller, and (3) introduce a powerful distributed and asynchronous method Distributed and Asynchronous Surrogate Lagrangian Relaxation (DA-SLR) to efficiently coordinate microgrids asynchronously. Two case studies are tested to demonstrate the efficiency of developed DA-SLR, and specifically, the testing results show the superiority of DA-SLR as compared to previous methods such as ADMM.

eess.SY↗