With the rapid development of cryptocurrencies, the demand for cross-chain transactions (CCTx) has increased significantly. Although mainstream approaches, such as notary schemes, hash time-lock contracts (HTLC), and relay chains, can enable cross-chain asset transfers, they generally suffer from low efficiency and high cost issues. To address these challenges, this paper proposes a Notary Group-Based Cross-Chain Channel Protocol (NCCP) for secure and scalable interoperable payments, which integrates off-chain payment channels with a notary-based mechanism to achieve efficient and secure CCTx. The protocol facilitates multiple rounds of asset interactions off-chain and submits final settlement to the blockchain only upon channel closure, thereby significantly reducing on-chain overhead. To mitigate security challenges arising from blockchain isolation, a verifiable notary mechanism is designed to ensure consistency of channel states, accompanied by an incentive and penalty scheme to enhance system reliability. A prototype system is implemented on the Ethereum test networks. Security analysis and experimental results demonstrate that NCCP outperforms existing approaches in terms of both performance and security.

We present algorithms to detect and precisely localize curbs and stairways for autonomous navigation. These algorithms combine brightness information (in the form of edgels) with 3-D data from a commercial stereo system. The overall system (including stereo computation) runs at about 4 Hz on a 1 GHz laptop. We show experimental results and discuss advantages and shortcomings of our approach.

Semantic segmentation is critical in video content analysis and retrieval. We propose an approach to semantic video segmentation by integrating multiple video cues into a generic scheme. We define a consistency measurement of contexts, continuity, which has two components, called cohesion and disjunction. As a result we can treat all the features, both low level features and semantic features, in the same way. At each shot boundary, the continuity measurement gives a confidence of being the boundary between two semantic units. The effectiveness of our approach has been demonstrated by experiments on all kinds of live videos.