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11.
Anders Bruun Dimitrios Raptis Jesper Kjeldskov Mikael B. Skov 《Behaviour & Information Technology》2016,35(3):233-249
Coolness has recently started to be explored as a design goal for interactive products from practitioners as well as researchers within human–computer interaction (HCI), but there is still a need to further operationalise the concept and explore how we can measure it. Our contribution in this paper is the COOL questionnaire. We based the creation of the questionnaire on literature suggesting that perceived coolness is decomposed to outer cool (the style of a product) and inner cool (the personality characteristics assigned to it). In this paper, we focused on inner cool, and we identified 11 inner cool characteristics. These were used to create an initial pool of question items and 2236 participants were asked to assess 16 mobile devices. By performing exploratory and confirmatory factor analyses, we identified three factors that can measure the perceived inner coolness of interactive products: desirability, rebelliousness and usability. These factors and their underlying 16 question items comprise the COOL questionnaire. The whole process of creating the questionnaire is presented in detail in this paper and we conclude by discussing our work against related work on coolness and HCI. 相似文献
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Kalamaras Ilias Dimitriou Nikolaos Drosou Anastasios Tzovaras Dimitrios 《Multimedia Tools and Applications》2017,76(14):15923-15949
Multimedia Tools and Applications - Traditional multimedia search engines retrieve results based mostly on the query submitted by the user, or using a log of previous searches to provide... 相似文献
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The IP Multimedia Subsystem (IMS) seems to be the technology that will prevail in Next Generation Networks (NGNs), since the interworking environment and the service flexibility that this technology offers to the currently deployed wireless broadband technologies makes it appealing to users, service developers and network operators. In this paper we propose a heterogeneous network model based on the IMS that integrates the Worldwide Interoperability for Microwave Access (WiMAX), Universal Mobile Telecommunications System (UMTS) and Wireless Local Area Network (WLAN) technologies and provides guaranteed QoS. We present the complete signalling flow concerning the authorization, registration, session set up and vertical handoff processes, as well as, an analytic model for cost analysis of the proposed architecture. 相似文献
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For a connected graph G=(V,E), a subset U⊆V is a disconnected cut if U disconnects G and the subgraph G[U] induced by U is disconnected as well. A cut U is a k-cut if G[U] contains exactly k(≥1) components. More specifically, a k-cut U is a (k,?)-cut if V?U induces a subgraph with exactly ?(≥2) components. The Disconnected Cut problem is to test whether a graph has a disconnected cut and is known to be NP-complete. The problems k-Cut and (k,?)-Cut are to test whether a graph has a k-cut or (k,?)-cut, respectively. By pinpointing a close relationship to graph contractibility problems we show that (k,?)-Cut is in P for k=1 and any fixed constant ?≥2, while it is NP-complete for any fixed pair k,?≥2. We then prove that k-Cut is in P for k=1 and NP-complete for any fixed k≥2. On the other hand, for every fixed integer g≥0, we present an FPT algorithm that solves (k,?)-Cut on graphs of Euler genus at most g when parameterized by k+?. By modifying this algorithm we can also show that k-Cut is in FPT for this graph class when parameterized by k. Finally, we show that Disconnected Cut is solvable in polynomial time for minor-closed classes of graphs excluding some apex graph. 相似文献
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Prefetching in Content Distribution Networks via Web Communities Identification and Outsourcing 总被引:1,自引:0,他引:1
Antonis Sidiropoulos George Pallis Dimitrios Katsaros Konstantinos Stamos Athena Vakali Yannis Manolopoulos 《World Wide Web》2008,11(1):39-70
Content distribution networks (CDNs) improve scalability and reliability, by replicating content to the “edge” of the Internet.
Apart from the pure networking issues of the CDNs relevant to the establishment of the infrastructure, some very crucial data
management issues must be resolved to exploit the full potential of CDNs to reduce the “last mile” latencies. A very important
issue is the selection of the content to be prefetched to the CDN servers. All the approaches developed so far, assume the
existence of adequate content popularity statistics to drive the prefetch decisions. Such information though, is not always
available, or it is extremely volatile, turning such methods problematic. To address this issue, we develop self-adaptive
techniques to select the outsourced content in a CDN infrastructure, which requires no apriori knowledge of request statistics.
We identify clusters of “correlated” Web pages in a site, called Web site communities, and make these communities the basic outsourcing unit. Through a detailed simulation environment, using both real and synthetic
data, we show that the proposed techniques are very robust and effective in reducing the user-perceived latency, performing
very close to an unfeasible, off-line policy, which has full knowledge of the content popularity. 相似文献
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Isolde Adler Frederic Dorn Fedor V. Fomin Ignasi Sau Dimitrios M. Thilikos 《Algorithmica》2012,64(1):69-84
Minor Containment is a fundamental problem in Algorithmic Graph Theory used as a subroutine in numerous graph algorithms. A model of a graph H in a graph G is a set of disjoint connected subgraphs of G indexed by the vertices of H, such that if {u,v} is an edge of H, then there is an edge of G between components C u and C v . A graph H is a minor of G if G contains a model of H as a subgraph. We give an algorithm that, given a planar n-vertex graph G and an h-vertex graph H, either finds in time $\mathcal{O}(2^{\mathcal{O}(h)} \cdot n +n^{2}\cdot\log n)$ a model of H in G, or correctly concludes that G does not contain H as a minor. Our algorithm is the first single-exponential algorithm for this problem and improves all previous minor testing algorithms in planar graphs. Our technique is based on a novel approach called partially embedded dynamic programming. 相似文献