Measurement of the squeezed vacuum state by a bichromatic local oscillator

We present the experimental measurement of a squeezed vacuum state by means of a bichromatic local oscillator (BLO). A pair of local oscillators at $\pm$5 MHz around the central frequency $\omega_{0}$ of the fundamental field with equal power are generated by three acousto-optic modulators and phase-locked, which are used as a BLO. The squeezed vacuum light are detected by a phase-sensitive balanced-homodyne detection with a BLO. The baseband signal around $\omega_{0}$ combined with a broad squeezed field can be detected with the sensitivity below the shot-noise limit, in which the baseband signal is shifted to the vicinity of 5 MHz (the half of the BLO separation). This work has the important applications in quantum state measurement and quantum informatio

On a conjecture about tricyclic graphs with maximal energy

For a given simple graph $G$, the energy of $G$, denoted by $\mathcal {E}(G)$, is defined as the sum of the absolute values of all eigenvalues of its adjacency matrix, which was defined by I. Gutman. The problem on determining the maximal energy tends to be complicated for a given class of graphs. There are many approaches on the maximal energy of trees, unicyclic graphs and bicyclic graphs, respectively. Let $P^{6,6,6}_n$ denote the graph with $n\geq 20$ vertices obtained from three copies of $C_6$ and a path $P_{n-18}$ by adding a single edge between each of two copies of $C_6$ to one endpoint of the path and a single edge from the third $C_6$ to the other endpoint of the $P_{n-18}$. Very recently, Aouchiche et al. [M. Aouchiche, G. Caporossi, P. Hansen, Open problems on graph eigenvalues studied with AutoGraphiX, {\it Europ. J. Comput. Optim.} {\bf 1}(2013), 181--199] put forward the following conjecture: Let $G$ be a tricyclic graphs on $n$ vertices with $n=20$ or $n\geq22$, then $\mathcal{E}(G)\leq \mathcal{E}(P_{n}^{6,6,6})$ with equality if and only if $G\cong P_{n}^{6,6,6}$. Let $G(n;a,b,k)$ denote the set of all connected bipartite tricyclic graphs on $n$ vertices with three vertex-disjoint cycles $C_{a}$, $C_{b}$ and $C_{k}$, where $n\geq 20$. In this paper, we try to prove that the conjecture is true for graphs in the class $G\in G(n;a,b,k)$, but as a consequence we can only show that this is true for most of the graphs in the class except for 9 families of such graphs.Comment: 32 pages, 12 figure

HTML5 video on mobile browsers

This paper reports on research investigating the current ability of HTML5 to play video in mobile browsers. Smartphones and the Mobile Internet are rapidly becoming an important platform for access to information anytime and anywhere. HTML5, the new HTML standard incorporates features like video playback that have been previously dependent on third-party browser plug-ins but there are no browsers that currently provide 100% support for HTML5. All the tests reported in this paper were carried out using smartphones with screen sizes 3.0 to 4.8 inches and the ability to replay videos of a range of formats, move directly to time points in the video and display closed captions were investigated. Key findings were that: video cannot be started programmatically; only selecting on the screen can trigger playback; no visual elements sitting over the <video> will receive click events while the video is visible (playing or paused); there are many HTML5 video players but MediaElement.js was found to currently be the open source player satisfying the greatest number of requirements

Generating Aspect-oriented Multi-document Summarization with Event-Aspect Model

In this paper, we propose a novel approach to automatic generation of aspect-oriented summaries from multiple documents. We first develop an event-aspect LDA model to cluster sentences into aspects. We then use extended LexRank algorithm to rank the sentences in each cluster. We use Integer Linear Programming for sentence selection. Key features of our method include automatic grouping of semantically related sentences and sentence ranking based on extension of random walk model. Also, we implement a new sentence compression algorithm which use dependency tree instead of parser tree. We compare our method with four baseline methods. Quantitative evaluation based on Rouge metric demonstrates the effectiveness and advantages of our method.

Synote mobile HTML5 responsive design video annotation application

Synote Mobile has been developed as an accessible cross device and cross browser HTML5 webbased collaborative replay and annotation tool to make web-based recordings easier to access, search, manage, and exploit for learners, teachers and others. It has been developed as a new mobile HTML5 version of the award winning open source and freely available Synote which has been used since 2008 by students throughout the world to learn interactively from recordings. While most UK students now carry mobile devices capable of replaying Internet video, the majority of these devices cannot replay Synote’s accessible, searchable, annotated recordings as Synote was created in 2008 when few students had phones or tablets capable of replaying these videos