ABSTRACT Tag quality is an important factor to the success of social tagging systems and platforms. Users' domain expertise may influence they perceive tag quality. This study aims to explore how users of different domain experience (frequent user, occasional user, and non-user) perceive the quality of the same tags. We examined an online video community, Bilibili, which specializes in Anime, Comic and Games (ACG) subculture. We asked 60 users to watch 15 videos and rate the 95 tags of these videos, and found that: 1) Users with more domain expertise give higher ratings for tags' relevance to the videos and their retrieval value; 2) Occasional users have the lowest understandability rating, followed by non-users, and frequent users; 3) users think high-frequency tags are less suitable for retrieval. These results may provide insights to high quality tag selection for personalized recommendation and retrieval.
The Ambisonic technique has been widely used for soundfield recording and reproduction recently. However, the basicAmbisonic decoding method will break down when the play-back loudspeakers distribute unevenly. Various methods havebeen proposed to solve this problem. This paper introducesseveral improvements to a recently proposed Ambisonic de-coding method, the matching projection method, for unevenloudspeaker layouts. The first improvement is energy preserv-ing; the second is introducing the “in-phase” weight, and thethird is introducing partial projection coefficients. To eval-uate the improved method, we compared it with the origi-nal one and the all-round Ambisonic decoding method witha 2-dimension unevenly arranged loudspeaker array. The re-sult shows our method greatly improves the original methodwhere the loudspeaker arranges very sparsely or densely.
Aiming at the requirement of miniaturization and high performance of antenna unit in
MMW portable imaging system, a novel approach is presented to decrease the side lobe for
millimeter wave applications using metamaterial (MTM) profile based antennas. The extraction of
effective parameters of a metamaterial unit cell and its effect are also presented. The simulation
results show that the side lobe of the proposed antenna is lower than -17dB at 35GHz.
The bubbles have a huge influence on the passive millimeter-wave (PMMW) radiation of ship wakes. The bubble distribution is able to be simulated based on the semi-empirical formula of Kelvin wake and turbulence energy attenuation spectrum. With the Maxwell-Garnett (MG) theory, the PMMW radiation of bubbles in different conditions can be calculated. Furthermore, the imaging experiment results are in a good agreement with the mathematical calculation results, which confirms the validity of the simulation model.
Li D, Jiang T, Jiang M. Quality Assessment of In-the-Wild Videos, in The 27th ACM International Conference on Multimedia, MM 2019, October 21-25. Nice, France: ACM; 2019:2351–2359. 访问链接
As recent trends in comparing the Han and Roman empires from primarily the point of view of literary evidence has brought forth new frameworks and opportunities of research, one asks how these developments could contribute to the comparison of the two empires' governance behaviors. The paper first surveys current literature published in the past decade and identify common themes in the scholarship on the Han and the Roman metallurgical advances and aspects of their iron industries. Of particular focus is the gradual awareness in the importance of iron semi-products in the Han and the Roman domains. In the second and third section, literary sources from the Qin-Han and the Roman domains are reviewed in order to identify general trends that can be juxtaposed for closer discussion. Particular emphasis is placed on the relationship between the private iron operators with generational legacies in the iron industries even be fore the formation of the Qin-Han and the Roman states, and how the state administrators engage with and adapt to the sophisticated and complex traditions of the Qin-Han and Roman iron industries. The fourth section provides a comparative discussion on issues concerning the states' juridical or statutory approaches to regulating iron mining and smelting operations, and observations on the intersect between semi-products, local ironworks andsmithies, and the needs of agricultural producers.