Web Video in Numbers - An Analysis of Web-Video Metadata

Web video is often used as a source of data in various fields of study. While specialized subsets of web video, mainly earmarked for dedicated purposes, are often analyzed in detail, there is little information available about the properties of web video as a whole. In this paper we present insights gained from the analysis of the metadata associated with more than 120 million videos harvested from two popular web video platforms, vimeo and YouTube, in 2016 and compare their properties with the ones found in commonly used video collections. This comparison has revealed that existing collections do not (or no longer) properly reflect the properties of web video "in the wild".Comment: Dataset available from http://download-dbis.dmi.unibas.ch/WWIN

The PS-Battles Dataset - an Image Collection for Image Manipulation Detection

The boost of available digital media has led to a significant increase in derivative work. With tools for manipulating objects becoming more and more mature, it can be very difficult to determine whether one piece of media was derived from another one or tampered with. As derivations can be done with malicious intent, there is an urgent need for reliable and easily usable tampering detection methods. However, even media considered semantically untampered by humans might have already undergone compression steps or light post-processing, making automated detection of tampering susceptible to false positives. In this paper, we present the PS-Battles dataset which is gathered from a large community of image manipulation enthusiasts and provides a basis for media derivation and manipulation detection in the visual domain. The dataset consists of 102'028 images grouped into 11'142 subsets, each containing the original image as well as a varying number of manipulated derivatives.Comment: The dataset introduced in this paper can be found on https://github.com/dbisUnibas/PS-Battle

Towards an All-Purpose Content-Based Multimedia Information Retrieval System

The growth of multimedia collections - in terms of size, heterogeneity, and variety of media types - necessitates systems that are able to conjointly deal with several forms of media, especially when it comes to searching for particular objects. However, existing retrieval systems are organized in silos and treat different media types separately. As a consequence, retrieval across media types is either not supported at all or subject to major limitations. In this paper, we present vitrivr, a content-based multimedia information retrieval stack. As opposed to the keyword search approach implemented by most media management systems, vitrivr makes direct use of the object's content to facilitate different types of similarity search, such as Query-by-Example or Query-by-Sketch, for and, most importantly, across different media types - namely, images, audio, videos, and 3D models. Furthermore, we introduce a new web-based user interface that enables easy-to-use, multimodal retrieval from and browsing in mixed media collections. The effectiveness of vitrivr is shown on the basis of a user study that involves different query and media types. To the best of our knowledge, the full vitrivr stack is unique in that it is the first multimedia retrieval system that seamlessly integrates support for four different types of media. As such, it paves the way towards an all-purpose, content-based multimedia information retrieval system

The Long Tail of Web Video

Web Video continues to gain importance not only in many areas of computer science but in society in general. With the growth in numbers, both of videos, viewers, and views, there arise several technical challenges. In order to address them effectively, the properties of Web Video in general need to be known. There is however comparatively little analysis of these properties. In this paper, we present insights gained from the analysis of a data set containing the meta data of over 100 million videos from YouTube. We were able to confirm common wisdom about the relationship between video duration and user engagement and show the extreme long tail of the distribution of video views overall. Such data can be beneficial in making informed decisions regarding strategies for large scale video storage, delivery, processing and retrieval

Monetary Value Assessment of Clam Fishing Management Practices in the Venice Lagoon: Results from a Stated Choice Exercise

This article focuses on the economic valuation of alternative clam management practices in the Venice Lagoon. The proposed valuation method is characterized by the design of a survey questionnaire next to the fishermen population. In each questionnaire two fishing alternatives are described. The respondent is asked to choose one of them. This valuation method, referred in the article as conjoint valuation, gives sufficient flexibility to set, alter, and combine different management practices. Furthermore, this approach presents an important advantage to the well-known contingent valuation method since it makes the monetary valuation of each management attribute possible. Estimation results of the random utility model show that fishermen’s willingness to pay for a larger clam fishing area is approximately 568 € per year. In addition, an individual fisherman would be willing to pay 1,005 € for a change from today’s fishing situation practice towards a fishing practice exclusively based on vibrant rake system. If we take into account the interaction between fishing management attributes and fishermen characteristics, we can see that the valuation of each management practice differs substantially across the two populations. We can observe that the population of fishermen that operate in the cooperative regime presents not only a higher monetary valuation for an increase in the dimension of the fishing concession, which is now valued at 811 €, but also a stronger willingness to pay for a change from today’s fishing situation towards a fishing practice exclusively based on vibrant rake system, which is now estimated at 2,456 €. Finally, the adoption of a clam fish management practice in Venice Lagoon that is exclusively based on the use of manual rakes, which is associated to the lowest damage to the Lagoon ecosystem, will represent a welfare loss of 5,904 € per fisherman per year. Combining this value with the total number of fishermen currently operating in the Lagoon of Venice, the welfare loss associated with the adoption of such clam management policy that is exclusively based on the use of manual rakes amounts to 11.8 € million per year. This figure can be regarded as an upper bound to the cost of implementation of a clam fishing system anchored in the use of manual, ecosystem friendly rakes.Exotic marine species, Fishing rakes, Manila clam, Fishing effort, Open access, Welfare damages, Policy guidance, Permit price

A Multi-Stream Approach for Video Understanding

The automatic annotation of higher-level semantic information in long-form video content is still a challenging task. The Deep Video Understanding (DVU) Challenge aims at catalyzing progress in this area by offering common data and tasks. In this paper, we present our contribution to the 3rd DVU challenge. Our approach consists of multiple information streams extracted from both the visual and the audio modality. The streams can build on information generated by previous streams to increase their semantic descriptiveness. Finally, the output of all streams can be aggregated in order to produce a graph representation of the input movie to represent the semantic relationships between the relevant characters

La città disvelata. Luoghi e percorsi della giustizia nella Vicenza asburgica

Una città disvelata, percorrendo i meandri inesplorati della documentazione giudiziaria. Alla ricerca, innanzitutto, di personaggi indistinti, in attesa di essere individuati e riportati al di fuori delle secche del passato, inseguendoli attraverso le tracce esili, ma indelebili, da loro lasciate nel calpestio assordante della storia. Una città disvelata nei suoi luoghi più conosciuti, investiti nei secoli da una memoria consolidata ed apparentemente inossidabile. Ma anche una città riscoperta nei suoi spazi più riposti, interstizi di una percezione storica in grado di svelare vicende segrete e ignote. Un gruppo di studiosi ha inteso ricostruire questi percorsi per offrire al lettore le immagini di una città sconosciuta, ma affascinante, accompagnandolo in un tour sorprendente ed inedito

The Management of Fishery in the Lagoon of Venice

Recently, Mediterranean lagoon environment, mainly in the North Adriatic area, has been threatened by the overexploitation of fishery. Fishing has been rapidly growing since clam (Tapes phippinarum) fishery has spread over several lagoons. Fishing growth has been accomplished by capital-intensive fishery equipments increasing harvesting beyond the sustainable biological growth. This pattern is driven by myopic behavior and common property fisheries with free entry or open access. Institutional arrangements on fish resources may encourage a fishing farming matching the biological capacity. In this study a bioeconomic dynamic model is used to describe the optimal resource allocation in case of sole owner of fishery resource. This model has been applied to a specific fish, namely Great green goby (Zosterisessor ophiocephalus), living in the lagoon of Venice. Results confirm biological overfishing and stock depletion has occurred. Mainly factors affecting bioeconomic equilibrium such as prices, interest rate and fishing effort are fixed by market. New institutional arrangements and policy tools such as confining clam fishery, limited-licensing entry and catch quotas may ensure stock rehabilitation, highly productive fisheries as well as environmental protection only if they are supported by adequate market policies.Keywords: clam, overfishing, fishery management, myopic behavior, dynamic programming, limited access, cooperative