Zichen Zhu

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The paper proposes a dynamic method, Recursive SBDS (ReSBDS), for efficient partial symmetry breaking. We first demonstrate how (partial) Symmetry Breaking During Search (SBDS) misses important pruning opportunities when given only a subset of symmetries to break. The investigation pinpoints the culprit and in turn suggests rectification. The main idea is(More)
This paper describes the development of the altimeter for micro aerial vehicles (MAVs) and its application in altitude-holding flight. The potential missions for MAVs include military missions and commercial applications, such as visual reconnaissance, communications relay, search and rescue and field research. For these missions, the altitude control is(More)
The generation and GAC enforcement of a large number of weak nogoods in Symmetry Breaking During Search (SBDS) is costly and often not worthwhile in terms of prunings. In this paper, we propose weak-nogood consistency (WNC) for nogoods and a lazy propagator for SBDS (and its variants) using watched literal technology. We give formal results on the strength(More)
The suspension and hydrodynamic characteristics of the Yellow River Delta during storms were analyzed based on suspended samples obtained using automatic samplers during a storm event in the Yellow River Delta. Synchronous data for winds, waves, and tides were also collected from a nearby station. The results show that under wind speeds of 5-15 m/s and wave(More)
Symmetries are common in many constraint problems. They can be broken statically or dynamically. The focus of this paper is the symmetry breaking during search (SBDS) method that adds conditional symmetry breaking constraints upon each backtracking during search. To trade completeness for efficiency, partial SBDS (ParSBDS) is proposed by posting only a(More)
Restarts are an important technique to make search more robust. This paper is concerned with how to maintain and propagate nogoods recorded from restarts efficiently. It builds on reduced nld-nogoods introduced for restarts and increasing nogoods introduced for symmetry breaking. The paper shows that reduced nld-nogoods extracted from a single restart are(More)
The paper proposes a dynamic method, Recursive Symmetry Breaking During Search (ReSBDS), for efficient partial symmetry breaking. We first demonstrate how Partial Symmetry Breaking During Search (ParSBDS) misses important pruning opportunities when given only a subset of symmetries to break. The investigation pinpoints the culprit and in turn suggests(More)