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Purpose -This paper aims to offer a convenient method to develop an oven recipe for a specific soldering profile in a reflow process. The method is devised to quickly achieve proper profile shape and heating factor Q h , a measure of success for high reliability of the solder joints reflowed. Design/methodology/approach -An in-depth analysis of the heating mechanism and some experiments of the reflow soldering process are performed to research on how to realize a specific shape reflow profile were conducted. Findings -Heating mechanism analysis and experiments demonstrate that the combinatorial parameters based method is feasible to do thermal profiling.Research limitations/implications -The mapping function among a particular configured PCBA, an oven used, a target reflow profile and an optimal range of the heating factor should be further established for fast and reliable production of reflow soldering. Practical implications -Provides a methodology for designing an oven recipe for reflow soldering production. Originality/value -An oven recipe can be quickly attained with the approach established in this paper, facilitating the formation of solder joints with high reliability during the reflow soldering process.

Staircases are main vertical evacuation passages in multi-story buildings characterized by different pedestrian flow from horizontal passages, such as corridors. Experiments were conducted to investigate crowd ascending and descending dynamics with different numbers of pedestrians in both uni- and bidirectional scenarios. Evacuation processes were recorded by video cameras and velocity sensors, and movement parameters were extracted from the recordings. Typical evacuation features on the staircase such as overtaking behavior, queuing behavior, repelling behavior, and packed and staggered motion mode are observed. The study explores velocity on the staircase as well as the fundamental diagram of velocity–density relationship. Experimental results show that ascending pedestrians could move upwards faster than descending pedestrians under emergency conditions. The stair landing can provide a wide and flat place for pedestrians to accelerate in unidirectional evacuation cases, but has a negative effect on evacuation velocity in bidirectional flow. The distribution of velocity in bidirectional evacuation is more convergent than in the unidirectional scenario. The study findings enrich evacuation modeling and improve the assessment of the pedestrians’ performance on staircases.