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Generating an accurate and continuous semantic occupancy map is a key component of autonomous robotics. Most existing continuous semantic occupancy mapping methods neglect the potential differences between voxels, which reconstruct an overinflated map. What is more, these methods have high computational complexity due to the fixed and large query range. To address the challenges of overinflation and inefficiency, this article proposes a novel sharp-edged and efficient continuous semantic occupancy mapping algorithm (SEE-CSOM). The main contribution of this work is to design the Redundant Voxel Filter Model (RVFM) and the Adaptive Kernel Length Model (AKLM) to improve the performance of the map. RVFM applies context entropy to filter out the redundant voxels with a low degree of confidence, so that the representation of objects will have accurate boundaries with sharp edges. AKLM adaptively adjusts the kernel length with class entropy, which reduces the amount of data used for training. Then, the multientropy kernel inference function is formulated to integrate the two models to generate the continuous semantic occupancy map. The algorithm has been verified on indoor and outdoor public datasets and implemented on a real robot platform, validating the significant improvement in accuracy and efficiency.

Methane seeps are widespread at continental margins, and may exert an influence on climate change. However, many details concerning the relationship between methane seepage and climate change in the geological history remain unclear. Geological records of cold seeps at glacial‐interglacial transitions remain scarce due to the lack of relatively complete records. Here we present geochemical data of seep carbonates from a drill core from the South China Sea, which reveals three stages of methane seepage linked to the dissociation of biogenic methane hydrate: ∼130.3 ka BP before, MIS 5 (∼130.3 to 111.4 ka BP) and MIS 1 (∼11.1 to 10.0 ka BP). Our results evidence that methane seepage was induced by warm seawater and subsequently hydrostatic pressure drop during deglaciations. We suspect this process to occur in other world regions and infer that methane seepage might occur more widespread at glacial‐interglacial transitions, which in turn might have accelerated global warming. Gas hydrate, a key future clean energy resources, is a solid formed in sediments from methane and water under low‐temperature and high‐pressure conditions. The dissociation of gas hydrate has the potential to emit large quantities of methane, which is an important contributor to the greenhouse effect and ocean acidification. The factors governing gas hydrate dissociation at ocean margins are still under debate. Changes in temperature or pressure have been regarded as main driving forces triggering seepage events. However, the relationship between global climate change and past methane seepages remain unknown as sampling of seep carbonates, an excellent archive of past seepage activity, are conducted mainly at seafloor, resulting in lack of relatively complete records of methane seeps. Here, we show the mineralogical, geochemical and chronological data of seep carbonate from a long drill core in the South China Sea. Our results indicate massive methane emissions into the seawater column caused by gas hydrate dissociation during glacial terminations. This is likely due to elevated temperature of bottom water and subsequently rapid fall of sea‐level. Thus, we speculate that there are large‐scale dissociation of gas hydrates in the South China Sea during glacial‐interglacial transitions and this is probably a widespread phenomenon. A 130,000‐year‐old history of methane seepage in the South China SeaMethane seepage was induced by warm bottom waters linked to deglaciationThe glacial‐interglacial transitions may play an important role on methane seepage events worldwide A 130,000‐year‐old history of methane seepage in the South China Sea Methane seepage was induced by warm bottom waters linked to deglaciation The glacial‐interglacial transitions may play an important role on methane seepage events worldwide

Many researchers have shown that pretreatment plasma fibrinogen levels are closely correlated with the prognosis of patients with lung cancer (LC). In this study, we thus performed a meta-analysis to systematically assess the prognostic value of pretreatment plasma fibrinogen levels in LC patients.