Most learning-based super-resolution methods neglect the illumination problem. In this paper we propose a novel method to combine blind single-frame super-resolution and shadow removal into a single operation. Firstly, from the pattern recognition viewpoint, blur identification is considered as a classification problem. We describe three methods which are respectively based on Vector Quantization (VQ), Hidden Markov Model (HMM) and Support Vector Machines (SVM) to identify the blur parameter of the acquisition system from the compressed/uncompressed low-resolution image. Secondly, after blur identification, a super-resolution image is reconstructed by a learning-based method. In this method, Logarithmic-wavelet transform is defined for illumination-free feature extraction. Then an initial estimation is obtained based on the assumption that small patches in low-resolution space and patches in high-resolution space share a similar local manifold structure. The unknown high-resolution image is reconstructed by projecting the intermediate result into general reconstruction constraints. The proposed method simultaneously achieves blind single-frame super-resolution and image enhancement especially shadow removal. Experimental results demonstrate the effectiveness and robustness of our method.

This paper addresses the ambiguity of radar altimetry related to the statistical nature of the Earth's surface roughness. A hypothetic altimetry method, which provides a simple way to quantify the measures of ambiguity, is proposed. Cramer-Rao lower bounds on the variances of estimates for the mean altitude and root-mean-square height of the sea surface are suggested as such quantitative measures. The accuracy of some types of air- and spaceborne radar altimeters is numerically analyzed against the derived lower bounds.

This paper analyses the autocorrelation function of return waveforms in high precision radar altimeters employing chirp-pulse transmit signal under the condition of near-nadir deviations of the antenna boresight axis. It is shown that in case of ultra wideband transmit signals providing very high time resolution the correlation function can be approximated by a product of two separate functions of time.

Eye tracking is a useful tool for accurately mapping where and for how long an individual learner looks at a video/image, in order to obtain immediate information regarding the distribution of a learner's attention among the elements of a video/image. This paper describes a quantitative investigation into the effect of voice navigation in web-based learning materials.

In this letter, we propose a new approach to incremental coding of the subfield codes for plasma display panels (PDPs). The proposed approach suppresses the halftone noise of the PDPs, while completely eliminating false contour noise, as do existing incremental subfield codes, by selecting an optimal incremental subfield code adaptively for a given input image. The proposed method maps the problem of selecting the optimal incremental subfield code onto a special-case shortest path problem. Results of experiment using 109 sample images illustrated that the proposed method improved the average peak signal-to-noise ratio by 4.4-6.2 dB in halftone noise compared with existing incremental subfield coding methods.

With the rapid increase of link speed in recent years, packet sampling has become a very attractive and scalable means in collecting flow statistics; however, it also makes inferring original flow characteristics much more difficult. In this paper, we develop techniques and schemes to identify flows with a very large number of packets (also known as heavy-hitter flows) from sampled flow statistics. Our approach follows a two-stage strategy: We first parametrically estimate the original flow length distribution from sampled flows. We then identify heavy-hitter flows with Bayes' theorem, where the flow length distribution estimated at the first stage is used as an a priori distribution. Our approach is validated and evaluated with publicly available packet traces. We show that our approach provides a very flexible framework in striking an appropriate balance between false positives and false negatives when sampling frequency is given.

This paper presents an ultra wideband (UWB) channel sounding scheme with a technique for estimating time of arrival (TOA) and angle of arrival (AOA) using measurement signals. Since the power spectrum over the UWB bandwidth can be measured in advance, we propose a signal model using the measurement power spectrum to design the proper UWB signals model. This signal model is more similar to measurement signals than the flat spectrum model which is an ideal model. If more than three waves impinge on a receiver, we must determine the proper grouping of the elements of TOA vector and AOA vector. It is difficult to determine the grouping using only measurement signals because of many degradation factors. We also propose pairing the elements of TOA vector and that of AOA vector using correlation method based on measurement signals and the proposed signal model. This technique is available for more than the case of three paths if pairing the estimated TOAs and AOAs of measurement signals is not accurately determined. We evaluated the proposed techniques for a vector network analyzer (VNA) with a three-dimensional virtual antenna array.

We propose a packet sampling strategy called fixed-period sampling, which selects at most one packet in every fixed-length period. Under the fixed-period sampling, the number of flow-cache lookups during a unit of time or the number of entries in a flow cache is bounded by a constant, which is simply expressed by a few tuning parameters. As an application of the fixed-period sampling, we also focus on the flow-rate estimation from fixed-period sampled packet streams. In particular, we propose a simple estimator based solely on the sampling frequency. We have conducted simulation experiments using two real traces to show basic characteristics of the fixed-period sampling for the comparison with the fixed-period sampling. We also show the accuracy of the proposed flow-rate estimator through simulations.

In this paper, we shall describe about a basic theory based on the concept of set-valued operators, suitable for available operation of extremely complicated large-scale network systems. Fundamental conditions for availability of system behaviors of such network systems are clarified in a form of fixed point theorem for system of set-valued operators. Here, the proof of this theorem is accomplished by the concept of Hausdorff's ball measure of non-compactness.

When a linearly polarized light is launched into a birefringent material, the output light is generally elliptically polarized. The ratio of the major and minor axes of the polarization ellipse varies depending on the angle between the polarization direction of the input light and the birefringent axis of the medium. The maximum ratio is determined only by the retardation due to the birefringence. Utilizing this phenomena, birefringence of a medium whose principal axis direction is unclear is measured with high precision by measuring the maximum extinction ratio for various input light polarization directions. Ambiguity in retardation associated with angular function solution is removed by measurement at two adjacent wavelengths. The measurement principle of the new method is confirmed by applying it to a quarter wave plate made of quartz. Birefringence of a 3 m long ribbon fiber as small as 10-7 is successfully measured.

We design M(≥3)-phase spreading sequences of Markov chains optimal in terms of bit error probabilities in asynchronous SSMA (spread spectrum multiple access) communication systems. To this end, we obtain the distributions of the normalized MAI (multiple access interference) for such systems and find a necessary and sufficient condition that the distributions become independent of the phase shifts.

IP (Intellectual Property) reuse plays an important role in modern IC design so that IP Protection (IPP) technique is get concerned. In this paper, we introduce a new efficient watermarking system for IPP on post-layout design stage. The signature (which indicates the designer) is encrypted with a secret key by DES (Data Encryption Standard) to produce a bit string, which is then embedded into the layout design as constraints by using a specific incremental router. Once the design is watermarked successfully, the signature can be extracted accurately by the system. The system also has a strong resistance to the attack on watermarking due to the DES functionality. This watermarking technique uniquely identifies the circuit origin, yet is difficult to be detected or fabricated without our tool. We evaluated the watermarking system on IBM-PLACE 2.0 benchmark suites. The results show the system robustness and strength: the system success probability achieves 100% in suitable time with no extra area and wire length cost on design performances.

The article describes recent adaptive estimation algorithms over distributed networks. The algorithms rely on local collaborations and exploit the space-time structure of the data. Each node is allowed to communicate with its neighbors in order to exploit the spatial dimension, while it also evolves locally to account for the time dimension. Algorithms of the least-mean-squares and least-squares types are described. Both incremental and diffusion strategies are considered.

A novel type Brillouin optical time-domain analysis (BOTDA), called double-pulse BOTDA (DP-BOTDA), is proposed for measuring distributed strain and temperature in a fiber with a centimeter spatial resolution. The DP-BOTDA system transmits a double-pulsed light instead of a conventional single-pulsed light into a fiber to interact with a counter-propagating continuous-wave light through the induced acoustic wave in the fiber. The interference between acoustic waves induced by the front and rear pulses of the double-pulsed light produces broad but oscillatory Brillouin gain spectra that make it possible to measure the Brillouin frequency shift accurately despite the very narrow pulse width. Our numerical simulation, which includes an estimation of the signal-to-noise ratio of the system, shows that it is possible to measure the distributed Brillouin frequency shift with a spatial resolution of 4 cm and accuracies of 1-2 MHz for a 5-km long fiber.

Internet access traffic follows hourly patterns that depend on various factors, such as the periods users stay on-line at the access point (e.g. at home or in the office) or their preferences for applications. The clustering of Internet users may provide important information for traffic engineering and billing. For example, it can be used to set up service differentiation according to hourly behavior, resource optimization based on multi-hour routing and definition of tariffs that promote Internet access in low busy hours. In this work, we propose a methodology for clustering Internet users with similar patterns of Internet utilization, according to their hourly traffic utilization. The methodology resorts to three statistical multivariate analysis techniques: cluster analysis, principal component analysis and discriminant analysis. The methodology is illustrated through measured data from two distinct ISPs, one using a CATV access network and the other an ADSL one, offering distinct traffic contracts. Principal component analysis is used as an exploratory tool. Cluster analysis is used to identify the relevant Internet usage profiles, with the partitioning around medoids and Ward's method being the preferred clustering methods. For the two data sets, these methods lead to the choice of 3 clusters with different hourly traffic utilization profiles. The cluster structure is validated through discriminant analysis. It is also evaluated in terms of several characteristics of the user traffic not used in the cluster analysis, such as the type of applications, the amount of downloaded traffic, the activity duration and the transfer rate, resulting in coherent outcomes.

In this paper, we present a directional interpolation filter in which the minimum and maximum pixels in the given window are excluded. Image pixels within a predefined window are ranked and classified as minimum-maximum or exclusive level, and then passed through the interpolation and identity filters, respectively. Extensive simulations show that the proposed filter performs better than other nonlinear filters in preserving desired image features while reducing impulse noise effectively.

A de-embedding technique for the measurement of very small parasitic capacitances of package or small module interconnects is presented. At high frequencies small parasitic capacitances become important, and measurement probes can strongly affect measurement results. The present technique is based on additional measurements with only one tip of the probe touching one conductor, while the second tip is kept floating on the substrate. A necessary condition for its application is that the measured capacitance does not depend on the position of the floating probe tip. Measurements with inverted probe tip polarities are also used. In this way, the capacitances between probe tips and DUT can be estimated together with the parasitic capacitances of interest. Depending on the required accuracy, de-embedding of different orders have been introduced, which consider capacitance configurations of increasing complexity. The technique requires the solution of one or more systems of non-linear equations. In the present example the minimization of the norm of the residual of the system has been treated as a least squares problem, and has been solved numerically with MATLAB. The accuracy of the measurement can be also approximately estimated with the residual. As application example, a small module with power and ground planes has been considered. Two different probes have been used. Even though the stray capacitances of the probes are very different, the values of the extracted parasitic capacitances are in agreement with each other. The accuracy has been verified also with simulation results. To this purpose, a combination of known formulas from the literature, a 2D Finite Element Method (FEM) tool and a 3D Boundary Element Method (BEM) tool have been used. A high accuracy can be obtained, even when a strong capacitive coupling between probe ground and DUT is present. The technique can be applied also when only a subset of measurement results are available.

In this research, the performance degradation of the digital electronic equipment under electromagnetic (EM) disturbance was studied in order to investigate the interference of intra-equipment. To develop the evaluation method of the performance degradation, some communication indexes were measured under EM disturbance. From some experimental results, it is known that the performance degradation of the electronic equipment was estimated by the degradation of "through-put," one of the communication performance indexes. For further investigation of the interference of intra-equipment, the near EM field from a PCB of the electronic equipment and its performance degradation under EM disturbance were measured and compared. From the measured results, the relationship between near field measurement and performance degradation could be obtained in some extent. These facts enable us that the weak area under the EM disturbance application on PCB can be foreseen by measuring the near field emission from the equipment and vise versa.

A new method of cancellation of IM3 using current feedback has been proposed for a multi-stage RFIC amplifier. In order to cancel the IM3 present in an output signal of the amplifier, the IIP3 level and IM3 phase of the amplifier are adjusted by means of feedback circuit techniques, so that the target specification is satisfied. By estimating the IIP3 level and IM3 phase variations for two states in situations with and without feedback possessing linear factors, the parameters of a feedback circuit can be calculated. To confirm the validity of the method, we have investigated two approaches; one including an analytical approach to designing a two-stage feedback amplifier, achieving an IIP3 level improvement of 14.8 dB. The other method involves the fabrication of single-stage amplifiers with and without feedback, operating at 850 MHz, both of which were designed as an integrated circuit using a 0.18 µm SiGe BiCMOS process. The fabricated IC's were tested using a load-pull measurement system, and a good agreement between the estimated and measured IIP3 level and IM3 phase variations has been achieved. Further studies show that the error in these variations, as estimated by the method, has been found to be less than 1.5 dB and 15 degrees, respectively, when the load admittance at 1701 MHz was greater than 1/50 S.

This paper describes a capacitive voltage probe (CVP) that can measure a common-mode voltage on a cable without touching its conductor. This CVP has two coaxial electrodes: the inner electrode works as a voltage pickup and the outer one shields the inner electrode. These electrodes separate into two parts for clamping to the cable. Using a high input impedance circuit, this probe measures the common-mode voltage by detecting the voltage difference between the two electrodes. The probe characteristics are evaluated by measuring its linearity and frequency response. The results show that this probe has a dynamic range of 100 dB and flat frequency response from 10 kHz to 30 MHz. Deviations in sensitivity due to the position of the clamped cable in the inner electrode and to differences in the cable radius are evaluated theoretically and experimentally. The results indicate that the influence of the cable position can be calibrated. Finally, measured data obtained using both an impedance stabilizing network (ISN) and a CVP are compared to confirm the validity of the CVP. The results show that data measured by the CVP closely agreed with that obtained by the ISN. Therefore, the CVP is useful for EMC measurements to evaluate common-mode disturbances.