CoPt and Co3Pt alloy thin films are prepared on MgO(111), SrTiO3(111), and Al2O3(0001) single-crystal substrates by varying the substrate temperature in a range from room temperature to 600°C by using an ultra-high vacuum radio-frequency magnetron sputtering system. The formation of metastable ordered phase and the structural thermal stability are briefly investigated. CoPt and Co3Pt films with the close-packed plane parallel to the substrate surface grow epitaxially on these oxide single-crystal substrates. CoPt epitaxial films are also formed by employing Pt, Pd, Cu, Cr, Ti, and Ru underlayers hetero-epitaxially grown on MgO(111) substrates. The crystal structure is evaluated by considering the order degree and the atomic stacking sequence of close-packed plane. Metastable ordered phases of L11, Bh, and D019 are preferentially formed in the CoPt and the Co3Pt films deposited around 300°C. Metastable ordered phase formation is influenced by the substrate temperature, the film composition, and the underlayer material. With increasing the substrate temperature up to around 300°C, the order degree increases. As the substrate temperature further increases, the order degree decreases. Annealing a disordered film at 300°C does not effectively enhance ordering. The CoPt and the Co3Pt films which include metastable ordered phases have flat surfaces and show strong perpendicular magnetic anisotropies reflecting the magnetocrystalline anisotropies of ordered crystals.

We propose a new face relighting method using an illuminance template generated from a single reference portrait. First, the reference is wrapped according to the shape of the target. Second, we employ a new spatially variant edge-preserving smoothing filter to remove the facial identity and texture details of the wrapped reference, and obtain the illumination template. Finally, we relight the target with the template in CIELAB color space. Experiments show the effectiveness of our method for both grayscale and color faces taken from different databases, and the comparisons with previous works demonstrate a better relighting effect produced by our method.

In tooth contour extraction there is insufficient intensity difference in x-ray images between the tooth and dental bone. This difference must be enhanced in order to improve the accuracy of tooth segmentation. This paper proposes a method to improve the intensity between the tooth and dental bone. This method consists of an estimation of tooth orientation (intensity projection, smoothing filter, and peak detection) and PCA-Stacked Gabor with ellipse Gabor banks. Tooth orientation estimation is performed to determine the angle of a single oriented tooth. PCA-Stacked Gabor with ellipse Gabor banks is then used, in particular to enhance the border between the tooth and dental bone. Finally, active contour extraction is performed in order to determine tooth contour. In the experiment, in comparison with the conventional active contour without edge (ACWE) method, the average mean square error (MSE) values of extracted tooth contour points are reduced from 26.93% and 16.02% to 19.07% and 13.42% for tooth x-ray type I and type H images, respectively.

Cloud computing is broadly recognized as as the prevalent trend in IT. However, in cloud computing mode, customers lose the direct control of their data and applications hosted by the cloud providers, which leads to the trustworthiness issue of the cloud providers, hindering the widespread use of cloud computing. This paper proposes a trustworthiness verification and audit mechanism on cloud providers called T-YUN. It introduces a trusted third party to cyclically attest the remote clouds, which are instrumented with the trusted chain covering the whole architecture stack. According to the main operations of the clouds, remote verification protocols are also proposed in T-YUN, with a dedicated key management scheme. This paper also implements a proof-of-concept emulator to validate the effectiveness and performance overhead of T-YUN. The experimental results show that T-YUN is effective and the extra overhead incurred by it is acceptable.

This paper describes the breathing phantom built to test a six-degree-of freedom sensing device designed for use in Respiratory-Gated Radiotherapy (RGRT). It is focussed on the construction of a test bed that was designed to address tumour motion issues while, at the same time, behaving in much the same way as the human tissues when irradiated. The phantom can produce respiratory movement in three dimensions. Shift differences between the motion axes can be introduced. The position error in the worst case scenario is not greater that 0.4 mm. Emphasis is made on the technical limitations of current sensing technologies, especially with regard to acceleration sensitivity. This study demonstrates that the sensitivity of accelerometers used to sense tumour motion should be 0.05 mG or less.

A hybrid approach for the synthesis of square thinned arrays with low sidelobes is presented. The proposed method combines the advantages of a genetic algorithm and combinatorial technique-cyclic difference sets (CDSs). The peak sidelobe level (PSL) and the thinning factor are numerically evaluated to show the effectiveness and reliability of the proposed hybrid method. In the proposed GA-enhanced square arrays with the DS and the best CDS, reductions of the PSL, of 4.16 dB and 2.45 dB, respectively, were achieved as compared to the results of conventional rectangular DS and CDS arrays.

This paper presents a new technique to smooth speech feature vectors for text-independent speaker verification using an adaptive band-pass IIR filer. The filter is designed by considering the probability density of modulation-frequency components of an M-dimensional feature vector. Each dimension of the feature vector is processed and filtered separately. Initial filter parameters, low-cut-off and high-cut-off frequencies, are first determined by the global mean of the probability densities computed from all feature vectors of a given speech utterance. Then, the cut-off frequencies are adapted over time, i.e. every frame vector, in both low-frequency and high-frequency bands based also on the global mean and the standard deviation of feature vectors. The filtered feature vectors are used in a SVM-GMM Supervector speaker verification system. The NIST Speaker Recognition Evaluation 2006 (SRE06) core-test is used in evaluation. Experimental results show that the proposed technique clearly outperforms a baseline system using a conventional RelAtive SpecTrA (RASTA) filter.

The unconditional stable finite-difference time-domain (US-FDTD) method based on Laguerre polynomial expansion and Galerkin temporal testing is used to model thin-film bulk acoustic wave resonators (TFBAR). Numerical results show the efficiency of the US-FDTD algorithm.

There are many web sites where net users can post and distribute their illustration images. A typical way to draw a digital illustration is first to draw rough lines on a paper and then to trace the lines on a graphics-tablet by hand. The input lines usually contain fluctuation due to hand-drawing, which limits the quality of illustration. Therefore, it is important to remove the fluctuation and to smooth the lines while maintaining sharp features such as corners. Although naive applications of moving average filters can smooth input lines, they may cause over-smoothing artifacts in which sharp features are lost by the filtering. This paper describes an improved line smoothing method using adaptive moving averages, which smoothes input lines while keeping high curvature points. The proposed method evaluates curvatures of input lines and adaptively controls the filter-size to reduce the over-smoothing artifacts. Experiments demonstrated advantages of the proposed method over the previous method in terms of achieving smoothing effect while still preserving sharp feature preservation.

Poor illumination and viewing conditions have negativeinfluences on the quality of an image, especially the contrast of the dark and bright region. Thus, captured and displayed images usually need contrast enhancement. Histogram-based or gamma correction-based methods are generally utilized for this. However, these methods are global contrast enhancement method, and since the sensitivity of the human eye changes locally according to the position of the object and the illumination in the scene, the global contrast enhancement methods have a limit. The spatial adaptive method is needed to overcome these limitations and it has led to the development of an integrated surround retinex (ISR), and estimation of dominant chromaticity (EDC) methods. However, these methods are based on Gray-World Assumption, and they use a general image formation model, so the color constancy is known to get poor results, shown through graying-out, halo-artifacts (ringing effects), and the dominated color. This paper presents a contrast enhancement method using a modified image formation model in which the image is divided into three components: global illumination, local illumination and reflectance. After applying the power constant value to control the contrast in the resulting image, the output image is obtained from their product to avoid or minimize a color distortion, based on the sRGB color representation. The experimental results show that the proposed method yields better performances than conventional methods.

Many researchers have proposed ultrasound imaging techniques for product inspection; however, most of these techniques are aimed at detecting the existence of flaws in products. The acquisition of an accurate three-dimensional image using ultrasound has the potential to be a useful product inspection tool. In this paper we apply the Envelope algorithm, which was originally proposed for accurate UWB (Ultra Wide-Band) radar imaging systems, to ultrasound imaging. We show that the Envelope algorithm results in image deterioration, because it is difficult for ultrasound measurements to achieve high signal to noise (S/N) ratio values as a result of a high level of noise and interference from the environment. To reduce errors, we propose two adaptive smoothing techniques that effectively stabilize the estimated image produced by the Envelope algorithm. An experimental study verifies that the proposed imaging algorithm has accurate 3-D imaging capability with a mean error of 6.1 µm, where the transmit center frequency is 2.0 MHz and the S/N ratio is 23 dB. These results demonstrate the robustness of the proposed imaging algorithm compared with a conventional Envelope algorithm.

Various incidents expose the vulnerability and fragility of the Internet inter-domain routing, and highlight the need for further efforts in developing new approaches to evaluating the trustworthiness of routing information. Based on collections of BGP routing information, we disclose a variety of anomalies and malicious attacks and demonstrate their potential impacts on the Internet security. This paper proposes a systematic approach to detecting the anomalies in inter-domain routing, combining effectively spatial-temporal multiple-view method, knowledge-based method, and cooperative verification method, and illustrates how it helps in alleviating the routing threats by taking advantage of various measures. The main contribution of our approach lies on critical techniques including the construction of routing information sets, the design of detection engines, the anomaly verification and the encouragement mechanism for collaboration among ASs. Our approach has been well verified by our Internet Service Provider (ISP) partners and has been shown to be effective in detecting anomalies and attacks in inter-domain routing.

Link and node trustworthiness are important metrics in wireless ad hoc networks. Many existing wireless ad hoc network routing algorithms assume the availability of precise trustworthiness information. This, however, is an unrealistic assumption given the dynamics of wireless ad hoc networks. Therefore, a realistic method is needed to evaluate trustworthiness by mitigating uncertainty in the estimation process. In this paper, we propose a novel trustworthiness estimation model that accounts for uncertainty as well as two uncertainty mitigation schemes. We then illustrate the effectiveness of our schemes using a utility-oriented routing algorithm as a sample application. An extensive simulation study shows that these two uncertainty mitigation schemes significantly increase path stability and the long-term total benefit of the wireless ad hoc network.

We fabricated solution-processed organic complementary inverters based on α,ω-bis(2-hexyldecyl)sexithiophene (BHD6T) for p-channel and C60-fused N-methylpyrrolidine-meta-dodecyl phenyl (C60MC12) for n-channel. The BHD6T and C60MC12 thin-film transistors showed high field-effect mobilities of 0.035 and 0.057 cm2/Vs, respectively. The complementary inverter with a supply voltage of 50 V exhibited inverting voltages of 26.8 V for forward and 27.0 V for backward sweeps and a high gain of 76.

This report describes a crystallization method we developed for amorphous (a)-Si film by using 405-nm laser diodes (LDs). The proposed method has been used to fabricate bottom gate (BG) microcrystalline (µc)-Si TFTs for the first time. A µc-Si film with high crystallinity was produced and high-performance BG µc-Si TFTs with a field effect mobility of 3.6 cm2/Vs and a current on/off ratio exceeding 108 were successfully demonstrated. To determine the advantages of a 405-nm wavelength, a heat flow simulation was performed with full consideration of light interference effects. Among commercially available solid-state lasers and LDs with wavelengths having relatively high optical absorption coefficients for a-Si, three (405, 445, and 532 nm) were used in the simulation for comparison. Results demonstrated that wavelength is a crucial factor for the uniformity, efficiency, and process margin in a-Si crystallization for BG µc-Si TFTs. The 405-nm wavelength had the best simulation results. In addition, the maximum temperature profile on the gate electrode through the simulation well explained the actual crystallinity distributions of the µc-Si films.

We have studied effects of additive elements into the channel layers of amorphous IGZO TFTs on threshold voltage shift issues under light illumination stress condition. By addition of Hf or Si element, the Vth shift under light illumination and negative bias-temperature stress and illumination stress conditions was drastically suppressed while the switching operation of TFTs using IGZO with Mn or Cu was not observed. It was found that the addition of Si or Hf element into the IGZO channel layer leads to reducing the hole trap sites formed at or near the gate insulator/IGZO channel interface.

Dependence of within-die delay variations on power supply voltage (VDD) is measured down to 0.4 V. The VDD dependence of the within-die delay variation of manual layout and irregular auto place and route (P&R) layout are compared for the first time. The measured relative delay (=sigma/average) variation difference between the manual layout and the P&R layout decreases from 1.56% to 0.07% with reducing VDD from 1.2 V to 0.4 V, because the random delay variations due to the random transistor variations dominate total delay variations instead of the delay variations due to interconnect length variations at low VDD.

A method based on covariance differencing for a uniform linear array is proposed to counter the problem of direction finding of narrowband signals under a colored noise environment. By assuming a Hermitian symmetric Toeplitz matrix for the unknown noise, the array covariance matrix is transformed into a centrohermitian matrix in an appropriate way allowing the noise component to be eliminated. The modified covariance differencing algorithm provides accurate direction of arrival (DOA) estimation when the incident signals are uncorrelated or just two of the signals are coherent. If there are more than two coherent signals, the presented method combined with spatial smoothing (SS) scheme can be used. Unlike the original method, the new approach dispenses the need to determine the true angles and the phantom angles. Simulation results demonstrate the effectiveness of presented algorithm.

We report on the enhancement of system detection efficiency in a superconducting nanowire single-photon detector (SNSPD) by applying the optical cavity structure. The nanowire was made using 4-nm-thick NbN thin films and covered with an SiO cavity and Au mirror designed for 1300-1600 nm wavelengths. The device is mounted into fiber-coupled packages, and installed in a practical multichannel system based on GM cryocoolers. System detection efficiency depends on the absorptance of cavity structure, and reached 28% and 40% at 1550 nm and 1310 nm wavelengths, respectively. These values were considerably higher than an SNSPD without optical cavity.

In this paper, we propose a new motion vector smoothing algorithm using weighted vector median filtering based on edge direction for frame interpolation. The proposed WVM (Weighted Vector Median) system adjusts the weighting values based on edge direction, which is derived from spatial coherence between the edge direction continuity of a moving object and motion vector (MV) reliability. The edge based weighting scheme removes the effect of outliers and irregular MVs from the MV smoothing process. Simulation results show that the proposed algorithm can correct wrong motion vectors and thus improve both the subjective and objective visual quality compared with conventional methods.