ICI - NOVA-LINCS UBI | Documentos por Auto-Depósito
URI permanente para esta coleção:
Navegar
Percorrer ICI - NOVA-LINCS UBI | Documentos por Auto-Depósito por título
A mostrar 1 - 2 de 2
Resultados por página
Opções de ordenação
- Real-time 2D–3D door detection and state classification on a low-power devicePublication . Ramôa, João Gaspar; Lopes, Vasco; Alexandre, Luís; Mogo, SandraIn this paper, we propose three methods for door state classifcation with the goal to improve robot navigation in indoor spaces. These methods were also developed to be used in other areas and applications since they are not limited to door detection as other related works are. Our methods work ofine, in low-powered computers as the Jetson Nano, in real-time with the ability to diferentiate between open, closed and semi-open doors. We use the 3D object classifcation, PointNet, real-time semantic segmentation algorithms such as, FastFCN, FC-HarDNet, SegNet and BiSeNet, the object detection algorithm, DetectNet and 2D object classifcation networks, AlexNet and GoogleNet. We built a 3D and RGB door dataset with images from several indoor environments using a 3D Realsense camera D435. This dataset is freely available online. All methods are analysed taking into account their accuracy and the speed of the algorithm in a low powered computer. We conclude that it is possible to have a door classifcation algorithm running in real-time on a low-power device.
- A tool for implementing privacy in NanoPublication . Morais, Rui; Crocker, Paul Andrew; Sousa, Simão Melo DeWe present a work in progress strategy for implementing privacy in Nano at the consensus level, that can be of independent interest. Nano is a cryptocurrency that uses an Open Representative Voting (ORV) as a consensus mechanism, a variant of Delegated Proof of Stake. Each transaction on the network is voted on by representatives, and each vote has a weight equal to the percentage of their total delegated balance. Every account can delegate their stake to any other account (including itself) and change it anytime it wants. The goal of this paper is to achieve a way for the consensus algorithm to function without knowing the individual balances of each account. The tool is composed of three different schemes. The first is a weighted threshold secret sharing scheme based on the Chinese Remainder Theorem for polynomial rings [1] and it's used to generate, in a distributed way, a secret that will be a private key of an additive ElGamal cryptosystem over elliptic curves (EC-EG) [2], which is additive homomorphic. The second scheme is the polynomials commitment scheme presented in [3] and is used to make the previous scheme verifiable, i.e., without the need of a trusted dealer. Finally, the third scheme is used to decrypt a ciphertext of the EC-EG cryptosystem without reconstructing the private key and, because of that, can be used multiple times.