334 research outputs found
Quality delivery of mobile video: In-depth understanding of user requirements
The increase of powerful mobile devices has accelerated the demand for mobile videos. Previous studies in mobile video have focused on understanding of mobile video usage, improvement of video quality, and user interface design in video browsing. However, research focusing on a deep understanding of users’ needs for a pleasing quality delivery of mobile video is lacking. In particular, what quality-delivery mode users prefer and what information relevant to video quality they need requires attention. This paper presents a qualitative interview study with 38 participants to gain an insight into three aspects: influencing factors of user-desired video quality, user-preferred quality-delivery modes, and user-required interaction information of mobile video. The results show that user requirements for video quality are related to personal preference, technology background and video viewing experience, and the preferred quality-delivery mode and interactive mode are diverse. These complex user requirements call for flexible and personalised quality delivery and interaction of mobile video
Understanding user experience of mobile video: Framework, measurement, and optimization
Since users have become the focus of product/service design in last decade, the term User eXperience (UX) has been frequently used in the field of Human-Computer-Interaction (HCI). Research on UX facilitates a better understanding of the various aspects of the user’s interaction with the product or service. Mobile video, as a new and promising service and research field, has attracted great attention. Due to the significance of UX in the success of mobile video (Jordan, 2002), many researchers have centered on this area, examining users’ expectations, motivations, requirements, and usage context. As a result, many influencing factors have been explored (Buchinger, Kriglstein, Brandt & Hlavacs, 2011; Buchinger, Kriglstein & Hlavacs, 2009). However, a general framework for specific mobile video service is lacking for structuring such a great number of factors. To measure user experience of multimedia services such as mobile video, quality of experience (QoE) has recently become a prominent concept. In contrast to the traditionally used concept quality of service (QoS), QoE not only involves objectively measuring the delivered service but also takes into account user’s needs and desires when using the service, emphasizing the user’s overall acceptability on the service. Many QoE metrics are able to estimate the user perceived quality or acceptability of mobile video, but may be not enough accurate for the overall UX prediction due to the complexity of UX. Only a few frameworks of QoE have addressed more aspects of UX for mobile multimedia applications but need be transformed into practical measures. The challenge of optimizing UX remains adaptations to the resource constrains (e.g., network conditions, mobile device capabilities, and heterogeneous usage contexts) as well as meeting complicated user requirements (e.g., usage purposes and personal preferences). In this chapter, we investigate the existing important UX frameworks, compare their similarities and discuss some important features that fit in the mobile video service. Based on the previous research, we propose a simple UX framework for mobile video application by mapping a variety of influencing factors of UX upon a typical mobile video delivery system. Each component and its factors are explored with comprehensive literature reviews. The proposed framework may benefit in user-centred design of mobile video through taking a complete consideration of UX influences and in improvement of mobile videoservice quality by adjusting the values of certain factors to produce a positive user experience. It may also facilitate relative research in the way of locating important issues to study, clarifying research scopes, and setting up proper study procedures. We then review a great deal of research on UX measurement, including QoE metrics and QoE frameworks of mobile multimedia. Finally, we discuss how to achieve an optimal quality of user experience by focusing on the issues of various aspects of UX of mobile video. In the conclusion, we suggest some open issues for future study
and : Candidates for charmed-strange mesons
Newly observed two charmed-strange resonances, and
, are investigated by calculating their Okubo-Zweig-Iizuka
allowed strong decays, which shows that they are suitable candidates for the
and states in the charmed-strange meson family. Our study
also predicts other main decay modes of and ,
which can be accessible at the future experiment. In addition, the decay
behaviors of the spin partners of and , i.e.,
and , are predicted in this work, which are still
missing at present. Experimental search for the missing and
charmed-strange mesons is an intriguing and challenging task
for further experiment.Comment: 8 pages, 3 figures and 4 tables. More discussions added and typos
corrected. Accepted by Eur. Phys. J.
Higher bottom and bottom-strange mesons
Motivated by the recent observation of the orbital excitation by
CDF collaboration, we have performed a systematical study of the mass spectrum
and strong decay patterns of the higher and mesons. Hopefully the
present investigation may provide valuable clues to further experimental
exploration of these intriguing excited heavy mesons.Comment: 13 pages, 11 figures, 10 tables. More discussions and references
added. Accepted by Phys. Rev.
The , decays in the perturbative QCD approach
Nonleptonic two body decays including radially excited or
mesons in the final state are studied using the perturbative QCD
approach based on factorization. The charmonium distribution amplitudes
are extracted from the Schrdinger states for the
harmonic oscillator potential. Utilizing these distribution amplitudes, we
calculate the numerical results of the
transition form factors and branching fractions of decays. The ratio between two decay modes and is compatible with the experimental
data within uncertainties, which indicate that the harmonic oscillator wave
functions for and work well. It is found that the
branching fraction of , which is dominated by the
twist-3 charmonium distribution amplitude, can reach the order of . We
hope it can be measured soon in the LHCb experiment.Comment: 9 pages, 3 figures,3 Table
A characterization of metacirculants
AbstractMetacirculants were introduced by Alspach and Parsons in 1982 and have been a rich source of various topics since then, including the Hamiltonian path problem in metacirculants. A metacirculant has a vertex-transitive metacyclic subgroup of automorphisms, and a long-standing interesting question in the area is if the converse statement is true, namely, whether a graph with a vertex-transitive metacyclic automorphism group is a metacirculant. We shall answer this question in the negative, and then present a classification of cubic metacirculants
Expressions of Wingless and Int1 (Wnt)-induced secreted protein 1 in paraquat-poisoned patients
Purpose: To study the expression of Wingless & Int1 (Wnt)-induced secreted protein 1 (WISP1) in paraquat (PQ)-poisoned patients.Methods: A total of 37 PQ-poisoned patients were enrolled in the study, and divided into non-survivor group (NS) and survival group (S) based on the final therapeutic outcome. Besides, another normal control group (NC) comprised of normal healthy people. Serum PQ concentration was determined by high performance liquid chromatography (HPLC), while reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) were used to evaluate WISP1 in the serum of PQ poisoned patients.Results: PQ intake in NS and S groups were 23.58 ± 26.23 and 143.18 ± 263.04 mL, respectively, while serum PQ concentration was 2.07 ± 0.67 and 4.12 ± 1.74 mg/L, respectively. Significant correlation was found between the outcome of patients and serum PQ concentration (OR = 1.434, p < 0.01). Serum PQ concentration was closely correlated with WISP1 gene expression levels (OR = 0.621, p < 0.01) and serum WISP1 protein levels (OR = 0.596, p < 0.01) on the first day after poisoning. Furthermore, a correlation between serum PQ concentration and WISP1 levels was found on the third after poisoning (OR = 0.447, p < 0.01).Conclusion: WISP1 is over-expressed in PQ-poisoned patients, and serum PQ concentration may be a useful index for the prognosis of PQ poisoned patients.Keywords: Wingless & Int1 (Wnt)-induced secreted protein 1, Poison, Paraquat, Prognosis, Correlatio
NarraSum: A Large-Scale Dataset for Abstractive Narrative Summarization
Narrative summarization aims to produce a distilled version of a narrative to
describe its most salient events and characters. Summarizing a narrative is
challenging as it requires an understanding of event causality and character
behaviors. To encourage research in this direction, we propose NarraSum, a
large-scale narrative summarization dataset. It contains 122K narrative
documents, which are collected from plot descriptions of movies and TV episodes
with diverse genres, and their corresponding abstractive summaries. Experiments
show that there is a large performance gap between humans and the
state-of-the-art summarization models on NarraSum. We hope that this dataset
will promote future research in summarization, as well as broader studies of
natural language understanding and generation. The dataset is available at
https://github.com/zhaochaocs/narrasum.Comment: EMNLP Findings 202
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