Graph extension with constant connectivity

In the field of the scaling-up of communication networks, numbers of communication stations (nodes) and the corresponding communication links (edges) are increasing rapidly. The reliability of the networks then becomes important. To keep the reliability of the networks, the connectivity (invulnerability) of the networks should not decrease. In this article, a method of increasing the nodes of a graph with a constant connectivity is proposed, and some examples of graph extension are shown to realize the extended networks. This work was presented in part at the 11th International Symposium on Artificial Life and Robotics, Oita, Japan, January 23–25, 2006     

Robust and efficient content-based digital audio watermarking

This paper proposes a set of digital watermarking schemes for WAV audio, WAV-table synthesis audio and compressed audio. The watermark embedding scheme is closely related to audio content and based on the human auditory system. The experimental results in listening and robustness illustrate that the proposed watermarking schemes can achieve an optimal balance between audibility and robustness of the watermarked audio. The proposed methods are also very useful and effective for copyright protection, tracing illegal distribution and other applications.     

Examining Factors Influencing the Disruptiveness of Notifications in a Mobile Museum Context

Ubiquitous computing environments continuously infer our context and proactively offer us context aware services and information, suggested by notifications on our mobile devices. However, notifications come with a cost. They may interrupt the user in the current task and be annoying in the wrong context. The challenge becomes how to notify the user about the availability of relevant services while minimizing the level of disruptiveness. Thus, an understanding of what affects the subjective perception of the disruptiveness of the notification is needed. As yet, most of the research on disruptiveness of notifications focused on stationary, task-oriented environments. In this study, we examine the effect of notifications in a special leisure scenario—a museum visit. In two user studies conducted in a museum setting, participants used a context-aware mobile museum guide to receive information on various museum exhibits while periodically receiving notifications. We examined how the user’s activity, the modality of the notification, and the message content affected the perceived level of disruption that the notifications created. We discuss our results in light of existing work in the desktop and mobile domains and provide a framework and recommendations for designing notifications for a mobile museum guide system.     

Nonequilibrium Carrier Dynamics Studied in Underdoped Bi2212 by Polarized Optical Pump-Probe Spectroscopy

We investigate nonequilibrium quasiparticle dynamics measured by ultrafast optical spectroscopy on underdoped Bi2212 crystals, which provide direct evidence that superconducting (SC) and pseudogap (PG) quasiparticles coexist below T _c . We verify that the ratio of signals from SC and PG quasiparticles depends on both excitation energy and polarization of the probe beam due to the anisotropy of the probe transition matrix elements and the interband transition probability. Based on this property, we successfully separate the SC or PG component and precisely evaluate the temperature dependence of them across T _c .     

Cluster ranking with an application to mining mailbox networks

We initiate the study of a new clustering framework, called cluster ranking. Rather than simply partitioning a network into clusters, a cluster ranking algorithm also orders the clusters by their strength. To this end, we introduce a novel strength measure for clusters—the integrated cohesion—which is applicable to arbitrary weighted networks. We then present a new cluster ranking algorithm, called C-Rank. We provide extensive theoretical and empirical analysis of C-Rank and show that it is likely to have high precision and recall. A main component of C-Rank is a heuristic algorithm for finding sparse vertex separators. At the core of this algorithm is a new connection between vertex betweenness and multicommodity flow. Our experiments focus on mining mailbox networks. A mailbox network is an egocentric social network, consisting of contacts with whom an individual exchanges email. Edges between contacts represent the frequency of their co–occurrence on message headers. C-Rank is well suited to mine such networks, since they are abundant with overlapping communities of highly variable strengths. We demonstrate the effectiveness of C-Rank on the Enron data set, consisting of 130 mailbox networks.     

Gram-negative enteric bacteremia in children in the Negev (1989-1994)

During 1989-1994, there were 322 episodes of Gram-negative enteric bacteremia in 308 children. The incidence increased from 31/100,000 in children younger than 15 years of age during 1989-1991, to 50/100,000 during 1992-1994. The most common pathogens were Klebsiella, E. Coli, Salmonella and Enterobacter. 39% of episodes were nosocomial and a significant increase was recorded for each species during the last 3 years of the study. Klebsiella represented the most common pathogen causing nosocomial bacteremia, while E. coli and Salmonella were the main pathogens causing community-acquired bacteremia. In this study in southern Israel, the incidence of Gram-negative enteric bacteremia was significantly higher in Bedouin children, with the exception of bacteremia due to Salmonella, which occurred mainly in Jewish children.     

Improvement of the resonance scattering treatment in MCNP in view of HTR calculations

The importance of an advanced neutron scattering treatment for heavy nuclei with strong energy dependent cross-sections such as the pronounced resonances of ²³⁸U has been discussed in various publications where the full double differential scattering kernel was derived. In this study the double differential kernel is confirmed by a purely stochastic approach. We evaluate the impact of this improved resonance kernel on High Temperature Reactors (HTR) using the Monte Carlo Code MCNPX. A comparison between the standard MCNPX scattering kernel and the new one is introduced. For the analyzed HTR-10 unit cells the new kernel leads to a decrease in criticality of 170–600 pcm depending on TRISO packing factor and fuel temperature and to an increase in magnitude of the Doppler reactivity coefficient by about 10%. The ²³⁹Pu inventory increases by up to 2.5% at the end of cycle.     

Tracking by Affine Kernel Transformations Using Color and Boundary Cues

Kernel-based trackers aggregate image features within the support of a kernel (a mask) regardless of their spatial structure. These trackers spatially fit the kernel (usually in location and in scale) such that a function of the aggregate is optimized. We propose a kernel-based visual tracker that exploits the constancy of color and the presence of color edges along the target boundary. The tracker estimates the best affinity of a spatially aligned pair of kernels, one of which is color-related and the other of which is object boundary-related. In a sense, this work extends previous kernel-based trackers by incorporating the object boundary cue into the tracking process and by allowing the kernels to be affinely transformed instead of only translated and isotropically scaled. These two extensions make for more precise target localization. A more accurately localized target also facilitates safer updating of its reference color model, further enhancing the tracker's robustness. The improved tracking is demonstrated for several challenging image sequences.     

Formation of a Third Liquid Phase and Its Reuse for Dibenzyl Ether Synthesis in a Tetraalkylammonium Salt Phase Transfer Catalytic System

This paper describes the formation of a third liquid phase in a phase transfer catalytic system in the presence of benzyl alcohol and potassium hydroxide, where dodecane and tetraalkylammonium bromide serve as organic solvent and catalyst, respectively. In this kind of system, a symmetrical ether (dibenzyl ether) was synthesized from benzyl chloride and benzyl alcohol at 323 K. In particular, the investigation demonstrates that the observed reaction rate constant depends on the length of the alkyl group of the catalyst. Tetrabutylammonium bromide exhibits the highest catalytic activity among the catalysts explored. With respect to the reuse of the third liquid phase, the results confirm that there is no decrease in phase transfer catalytic activity in three consecutive runs.