Proof-of-Prestige: A Useful Work Reward System for Unverifiable Tasks

As cryptographic tokens and altcoins are increasingly being built to serve as utility tokens, the notion of useful work consensus protocols, as opposed to number-crunching PoW consensus, is becoming ever more important. In such contexts, users get rewards from the network after they have carried out some specific task useful for the network. While in some cases the proof of some utility or service can be proved, the majority of tasks are impossible to verify. In order to deal with such cases, we design Proof-of-Prestige (PoP) - a reward system that can run on top of Proof-of-Stake blockchains. PoP introduces prestige which is a volatile resource and, in contrast to coins, regenerates over time. Prestige can be gained by performing useful work, spent when benefiting from services and directly translates to users minting power. PoP is resistant against Sybil and Collude attacks and can be used to reward workers for completing unverifiable tasks, while keeping the system free for the end-users. We use two exemplar use-cases to showcase the usefulness of PoP and we build a simulator to assess the cryptoeconomic behaviour of the system in terms of prestige transfer between nodes.Comment: 2019 IEEE International Conference on Blockchain and Cryptocurrency (ICBC 2019

Nieważność i zaczepialność międzynarodowych aktów prawnych

Digitalizacja i deponowanie archiwalnych zeszytów RPEiS sfinansowane przez MNiSW w ramach realizacji umowy nr 541/P-DUN/201

Représentation compacte des adresses pour le routage par caractéristiques

International audienceNous nous intéressons à la représentation compacte des adresses afin de pouvoir router des paquets vers des destinations identifiées par leurs caractéristiques. Ce type de routage nécessite le stockage des caractéristiques de manière compacte dans l'adresse destination des paquets et dans les tables de routage. Nous étudions plusieurs solutions dans le cadre des réseaux de capteurs, où les ressources sont très limitées et les adresses suivent le format IPv6

Generation of virtual anatomical models from the multimodal medical image data

In this work we present and discuss some methodological issues associated with the generation of the computer based anatomical models. The importance of the virtual patient models is becoming increasingly recognized in modern medicine. The advantages of using such biomedical virtual models are analogous to those of real system behavior simulation in the engineering or material sciences. Particularly significant is its role in the simulation of various pathogenic physiological processes and therapeutical procedures. Such models enable as well the optimization of many diagnostic and therapeutical subroutines. Segmentation, registration, measurement, interaction and visualization modules constitute actually the main pool of the software engineering tools, which enables the surgeon to create a virtual patient-specific anatomical model of the region of interest. Based on this model the physician can simulate and plan different treatment approaches as well as carry out quantitative measurements to identify the optimal therapeutical procedure

Computer based framework for cranio-maxillofacial surgery planning

Nowadays the process of surgical planning is a crucial point of every operation in the craniofacial region. In this work we focus on the planning of graft reconstructive surgery for autologous osseous grafts. The planning method consists of two stages. The non-automatic graft design step is followed by a fully automatic procedure to find the best harvesting site in the predefined donor region. The main idea of the proposed method is based on the registration paradigm. The optimal donor site is identified by performing an optimization of the surface based similarity measure between the donor region and the designed graft template. An efficient optimization method based on the Levenberg-Marquardt algorithm has been implemented

WEAVE : routage géographique efficace dans les réseaux à grande échelle

International audienceNous proposons WEAVE, un protocole de routage géographique 2D/3D reposant sur l'utilisation de points d'étapes, waypoints, et de points de passage, checkpoints, pour acheminer le trafic à destination. Les noeuds obtiennent leur information de routage à partir de traces partielles collectées dans les paquets relayés et utilisent un système de points intermédiaires associés à des portions de chemin pour tisser (to weave) des chemins de bout en bout proches des plus courts chemins. WEAVE ne génère aucun paquet de contrôle, permet le routage en 2D comme en 3D et ne fait aucune hypothèse forte sur le graphe sous-jacent, telle que disque unitaire ou graphe planaire. WEAVE présente d'excellentes performances comparé aux protocoles existants, à la fois en simulation et lors d'expérimentations réelles

Diversity of vertebrate remains from the Lower Gogolin Beds (Anisian) of southern Poland

Middle Triassic (Muschelkalk) limestones and dolostones of southern Poland contain vertebrate remains, which can be used for palaeoecological and palaeogeographical analyses. The results presented concern vertebrate remains uncovered at four localities in Upper Silesia and one on Opole Silesia, a region representing the south-eastern margin of the Germanic Basin in Middle Triassic times. The most abundant remains in this assemblage are fish remains, comprising mostly actinopterygian teeth and scales. Chondrichthyan and sauropsid remains are less common. Reptilian finds include vertebrae, teeth and fragments of long bones, belonging to aquatic or semi-aquatic reptiles, such as nothosaurids, pachypleusorosaurids, and ichthyosaurids. Also, coprolites of possibly durophagous and predacious reptiles occur. In the stratigraphic column of Mikołów, actinopterygian remains are the most numerous and no distinct changes of the taxonomic composition occur. Although this assemblage differs from those described at other localities (Ząbkowice with numerous chondrichthyans, Żyglin, and Płaza with common sauropsid fossils), sampling bias has to be considered