Tungsten film as a hard and compatible carrier for antibacterial agent of silver

Silver-containing tungsten (W–Ag) films for antibacterial applications were deposited on glass, silicon, and 316L stainless-steel substrates by magnetron sputtering with the silver target current of 0–2.0 A. The addition of silver improves adhesion of the films on glass substrate due to the reduced residual stress in the films. SEM and EDX analyses reveal Ag-rich tiny dots (~?20 nm) at the surface of W–Ag films with high silver contents. In XRD patterns, silver peaks are present for the samples deposited at 1.5 and 2.0 A, and tungsten grain size is decreased from?~?23 to 10 nm by silver addition. XPS analysis shows that tungsten is slightly oxidized (WO₃) at the top surface of the film, and silver presents mainly in metallic state. The low Ag/W ratios and the small surface roughness (<?8 nm) indicate that silver segregation at the film surface is not obvious. Microhardness of the samples with ≤?6.7 at.% silver is nearly seven times that of the stainless steel (~?250 HV). The coated samples are hydrophobic tested by contact angle measurement. The potentiodynamic polarization and the soaking test simulating the inflammatory state show that even corrosion occurs and silver addition decreases corrosion resistance of the films. The antibacterial ratio of the coated samples increases with silver content, being 91% at 4.2 at.% silver content tested by agar plate counting method. In agar disk diffusion assay, no inhibition zone is observed for all samples. The antibacterial property of the W–Ag films is localized, long-lasting, and reusable, which would be beneficial for their potential biomedical and environmental applications.     

Data‐Driven Crowd Motion Control With Multi‐Touch Gestures

Controlling a crowd using multi‐touch devices appeals to the computer games and animation industries, as such devices provide a high‐dimensional control signal that can effectively define the crowd formation and movement. However, existing works relying on pre‐defined control schemes require the users to learn a scheme that may not be intuitive. We propose a data‐driven gesture‐based crowd control system, in which the control scheme is learned from example gestures provided by different users. In particular, we build a database with pairwise samples of gestures and crowd motions. To effectively generalize the gesture style of different users, such as the use of different numbers of fingers, we propose a set of gesture features for representing a set of hand gesture trajectories. Similarly, to represent crowd motion trajectories of different numbers of characters over time, we propose a set of crowd motion features that are extracted from a Gaussian mixture model. Given a run‐time gesture, our system extracts the K nearest gestures from the database and interpolates the corresponding crowd motions in order to generate the run‐time control. Our system is accurate and efficient, making it suitable for real‐time applications such as real‐time strategy games and interactive animation controls.     

Dynamic multicast routing and wavelength assignment using generic graph model for wavelength-division-multiplexing networks

The problem of dynamic multicast routing and wavelength assignment (MC-RWA) in the wavelength-routed wavelength-division-multiplexing networks is addressed. Current solutions to this problem always rely on homogeneous network constructions. However, future backbone networks tend to be heterogeneous in nature. Thus, the dynamic MC-RWA problem should be studied in a more realistic situation by considering the heterogeneity of network structures. A new graph model is proposed for the MC-RWA problem. This model is based on layered auxiliary graph which is generic and able to support various node architectures and heterogeneous network structures. Based on this graph model, the dynamic MC-RWA problem can be simply solved by an efficient multicast tree algorithm on various light-splitting and wavelength-conversion scenarios. In general, this graph model provides a universal platform to study different aspects of the dynamic MC-RWA as well as related problems.     

Measurement of the complex polarization mode dispersion vector using Jones matrix analysis

The polarization mode dispersion (PMD) of a nondepolarizing optical system is analyzed. A new method is proposed to calculate the complex PMD vector by measuring two Jones matrices at two different wavelengths.     

On-line simultaneous monitoring of polarization mode dispersion and chromatic dispersion

We have developed new expressions for power fading and average power fading owing to polarization mode dispersion (PMD) and chromatic dispersion in terms of the angle of precession of the output state of polarization about the PMD vector. Based on these expressions, a simple and novel pilot-tone-based technique for simultaneous monitoring of chromatic dispersion and PMD is proposed. Experimental results demonstrate the effectiveness of the proposed technique; these results agree well with the theoretical analysis.     

Hole-assisted lightguide fibers with small negative dispersion and low dispersion slope

A nonzero dispersion shifted fiber design based on hole-assisted lightguide fiber is presented. The proposed fiber has low dispersion slope around -0.01 ps/nm(2)-km and small negative dispersion values over the wavelength range from 1530 to 1620 nm. It can be used as a transmission medium for a long-haul dense wavelength-division-multiplexed system.     

The Design and Construction of a Movable Image-Based Rendering System and Its Application to Multiview Conferencing

Image-based rendering (IBR) is an promising technology for rendering photo-realistic views of scenes from a collection of densely sampled images or videos. It provides a framework for developing revolutionary virtual reality and immersive viewing systems. While there has been considerable progress recently in the capturing, storage and transmission of image-based representations, most multiple camera systems are designed to be stationary and hence their ability to cope with moving objects and dynamic environment is somewhat limited. This paper studies the design and construction of a movable image-based rendering system based on a class of dynamic representations called plenoptic videos, its associated video processing algorithms and an application to multiview audio-visual conferencing. It is constructed by mounting a linear array of 8 video cameras on an electrically controllable wheel chair and its motion is controllable manually or remotely through wireless LAN by means of additional hardware circuitry. We also developed a real-time object tracking algorithm and utilize the motion information computed to adjust continuously the azimuth or rotation angle of the movable IBR system in order to cope with a given moving object in a large environment. Due to imperfection in tracking and mechanical vibration encountered in movable systems, the videos may appear very shaky and a new video stabilization technique is proposed to overcome this problem. The usefulness of the system is illustrated by means of a multiview conferencing application using a multiview TV display. Through this pilot study, we hope to disseminate useful experience for the design and construction of movable IBR systems with improved viewing freedom and ability to cope with moving object in a large environment.