User Motives for Tagging Video Content

User tagging of video content provides many possibilities for indexing and personalization. To exploit these possibilities, users must be willing to tag the video content they watch. In this paper we present the first results of our ongoing research, by constructing an overview of user motives to tag video content. We present the results of a study in which we elicited possible user motives to tag movies on the internet. The identified motives include the categories ‘indexing’, ‘socializing’ and ‘communicating’. Finally, user barriers to tag video content are discussed

Assessing the Effectiveness and Usability of Personalized Internet Search through a Longitudinal Evaluation

This paper discusses a longitudinal user evaluation of Prospector, a personalized Internet meta-search engine capable of personalized re-ranking of search results. Twenty-one participants used Prospector as their primary search engine for 12 days, agreed to have their interaction with the system logged, and completed three questionnaires. The data logs show that the personalization provided by Prospector is successful: participants preferred re-ranked results that appeared higher up. However, the questionnaire results indicated that people would prefer to use Google instead (their search engine of choice). Users would, nevertheless, consider employing a personalized search engine to perform searches with terms that require disambiguation and/or contextualization. We conclude the paper with a discussion on the merit of combining system- and user-centered evaluation for the case of personalized systems

Entangling ability of a beam splitter in the presence of temporal which-path information

We calculate the amount of polarization-entanglement induced by two-photon interference at a lossless beam splitter. Entanglement and its witness are quantified respectively by concurrence and the Bell-CHSH parameter. In the presence of a Mandel dip, the interplay of two kinds of which-path information -- temporal and polarization -- gives rise to the existence of entangled polarization-states that cannot violate the Bell-CHSH inequality.Comment: 8 pages including 2 figure

Using thematic ontologies for user- and group- based adaptive personalization in web searching

This paper presents Prospector, an adaptive meta-search layer, which performs personalized re-ordering of search results. Prospector combines elements from two approaches to adaptive search support: (a) collaborative web searching; and, (b) personalized searching using semantic metadata. The paper focuses on the way semantic metadata and the users’ search behavior are utilized for user- and group- modeling, as well as on how these models are used to re-rank results returned for individual queries. The paper also outlines past evaluation activities related to Prospector, and discusses potential applications of the approach for the adaptive retrieval of multimedia documents

Dephasing of entangled electron-hole pairs in a degenerate electron gas

A tunnel barrier in a degenerate electron gas was recently discovered as a source of entangled electron-hole pairs. Here, we investigate the loss of entanglement by dephasing. We calculate both the maximal violation E_max of the Bell inequality and the degree of entanglement (concurrence) C. If the initially maximally entangled electron-hole pair is in a Bell state, then the Bell inequality is violated for arbitrary strong dephasing. The same relation E_max=2\sqrt{1+C^{2}} then holds as in the absence of dephasing. More generally, for a maximally entangled superposition of Bell states, the Bell inequality is satisfied for a finite dephasing strength and the entanglement vanishes for somewhat stronger (but still finite) dephasing strength. There is then no one-to-one relation between E_max and C.Comment: 7 pages with 3 figures, special style file included; To appear in a special issue on "Quantum Computation at the Atomic Scale" in Turkish Journal of Physic

Scattering theory of plasmon-assisted entanglement transfer and distillation

We analyse the quantum mechanical limits to the plasmon-assisted entanglement transfer observed by E. Altewischer, M.P. van Exter, and J.P. Woerdman [Nature, 418, 304 (2002)]. The maximal violation S of Bell's inequality at the photodetectors behind two linear media (such as the perforated metal films in the experiment) can be described by two ratio's tau_1, tau_2 of polarization-dependent transmission probabilities. A fully entangled incident state is transferred without degradation for tau_1=tau_2, but a relatively large mismatch of tau_1 and tau_2 can be tolerated with a small reduction of S. We predict that fully entangled Bell pairs can be distilled out of partially entangled radiation if tau_1 and tau_2 satisfy a pair of inequalities.Comment: 4 pages including 2 figures; two references added, plasmon model include

Evaluation of User Support: Factors That Affect User Satisfaction With Helpdesks and Helplines

In addition to technical documentation, face-to-face helpdesks and telephonic helplines are a powerful means for supporting users of technical products and services. This study investigates the factors that determine user satisfaction with helpdesks and helplines. A survey, based on the SERVQUAL framework and questionnaire, shows that the SERVQUAL dimensions of customer satisfaction are not applicable in these contexts. Three quality dimensions were found instead: solution quality, the experience of the consultation, and, in the case of a physical environment, the so-called tangibles. Helpdesk customers base their overall quality perceptions mainly on their experiences during a consultation, while helpline customers focus strongly on the quality of the solution offered.\ud The study also found a connection between the perceived helpline quality and the appreciation of the primary service