This paper contributes to k-error linear complexity of some generalized cyclotomic binary sequences of length 2pm and pm constructed in recent years. By defining related reference sequences, we find that these sequences possess very low k-error linear complexity for some certain values of the parameter k even though they have high linear complexity. Moreover, we point out that (p-1)-tuple distributions of all these sequences are not span. Thus they should be selected carefully for use in stream cipher systems.

In this paper, a novel and simple one-port de-embedding technique has been applied to through-silicon-via (TSV) characterization and modeling. This method utilized pad, via, and line structures to extract the equivalent circuit model of TSV. The main advantage of this de-embedding method is that it can reduce the chip area to fabricate test element groups (TEGs) for measurements while keeping S-parameter measurement accuracies. We also analyzed the electrical characteristics of substrate coupling and TSV equivalent impedance. Our results shows good agreements between measurement data and the equivalent circuit model up to 20GHz.

In this letter, we consider the global exponential stabilization problem by output feedback for a class of nonlinear systems. Along with a newly proposed matrix inequality condition, the proposed control method has improved flexibility in dealing with nonlinearity, over the existing methods. Analysis and examples are given to illustrate the improved features of our control method.

In order to employ Multiple-Input-Multiple-Output (MIMO) techniques, multiple antenna branches are necessary and as a consequence the installation space requirements are increased. Since the installation space is limited, much attention is now focused on utilizing polarization characteristics in MIMO configurations to relax the requirements. This is called Orthogonal Polarization-MIMO in this paper. To evaluate accurately the performance of Orthogonal Polarization-MIMO, a channel model that can handle the polarization dispersion characteristics of propagation paths is essential. Up to now, the spatial-temporal dispersion characteristics of paths have been investigated in detail. However, there are only a few reports on the polarization dispersion characteristics. In this paper, we propose a new power profile for the rotational polarized angle as an evaluation model for polarization dispersion, and clarify the analyzed power profile based on measurement data in an urban macrocell environment.

The optimal design of an extrapolated impulse response (EIR) filter (in the mini-max sense) is a non-linear programming problem. In this paper, the optimal design of the EIR filter by the semi-infinite programming (SIP) is investigated and an iterative technique for optimally designing the EIR filter is proposed. The simulation experiment validates the effectiveness of the SIP technique and the proposed iterative technique in the optimal design of the EIR filter.

Quantum steganography is to send secret quantum information through a quantum channel, such that an unauthorized user will not be aware of the existence of secret data. The depolarizing channel can hide quantum information by disguising it as channel errors of a quantum error-correcting code. We improve the efficiency of quantum steganography with noisy depolarizing channels, by modifying the twirling procedure and adding quantum teleportation. The proposed scheme not only meets the requirements of quantum steganography but also has higher efficiency.

As more and more software vulnerabilities are exposed, shellcode has become very popular in recent years. It is widely used by attackers to exploit vulnerabilities and then hijack program's execution. Previous solutions suffer from limitations in that: 1) Some methods based on static analysis may fail to detect the shellcode using obfuscation techniques. 2) Other methods based on dynamic analysis could impose considerable performance overhead. In this paper, we propose Lemo, an efficient shellcode detection system. Our system is compatible with commodity hardware and operating systems, which enables deployment. To improve the performance of our system, we make use of the multi-core technology. The experiments show that our system can detect shellcode efficiently.

Mutual information (MI) is a standard measure of statistical dependence of random variables. However, due to the log function and the ratio of probability densities included in MI, it is sensitive to outliers. On the other hand, the L2-distance variant of MI called quadratic MI (QMI) tends to be robust against outliers because QMI is just the integral of the squared difference between the joint density and the product of marginals. In this paper, we propose a kernel least-squares QMI estimator called least-squares QMI (LSQMI) that directly estimates the density difference without estimating each density. A notable advantage of LSQMI is that its solution can be analytically and efficiently computed just by solving a system of linear equations. We then apply LSQMI to dependence-maximization clustering, and demonstrate its usefulness experimentally.

In the Knill-Laflamme-Milburn (KLM) scheme, quantum teleportation is nearly deterministically carried out with linear optics. To reconstruct an original quantum state, however, a phase shift is required for an output state. We exhibit a proper phase shift to complete quantum teleportation.

We consider uplink multi-carrier code-division multiple access (MC-CDMA) systems in a multi-cell environment. It is assumed that all intra-cell users employ Alamouti's simple space-time block coding (STBC), which is known to the base station receiver, but the receiver has no information on whether inter-cell users employ STBC or not. In this case we propose a blind adaptive minimum output energy (MOE) receiver for uplink STBC MC-CDMA, which is designed to perfectly remove the interference from intra-cell users by using the spreading sequence information on all intra-cell users and to reduce the interference from inter-cell users by minimizing the constrained output energy. Analysis and simulation results show that the proposed adaptive receiver has a faster convergence rate and higher steady-state signal-to-interference plus noise ratio (SINR) than a conventional scheme in which only the spreading code information of the desired user is utilized.

In the recently developed Flexible Wireless System (FWS), the same platform needs to deal with different wireless systems. This increases nonlinear distortion in its wideband power amplifier (PA) because the PA needs to concurrently amplify multi-band signals. By taking higher harmonics as well as inter- and cross-modulation distortion into consideration, we have developed a method to analytically evaluate the adjacent channel leakage power ratio (ACPR) and error vector magnitude (EVM) on the basis of the PA's nonlinear characteristics. We devise a novel method for modeling the PA amplifying dual-band signals. The method makes it possible to model it merely by performing a one-tone test, making use of the Volterra series expansion and the general Wiener model. We then use the Mehler formula to derive the closed-form expressions of the PA's output power spectral density (PSD), ACPR, and EVM. The derivations are based on the assumption that the transmitted signals are complex Gaussian distributed in orthogonal frequency division multiplexing (OFDM) transmission systems. We validate the method by comparing measurement and simulation results and confirm it can appropriately predict the ACPR and EVM performance of the nonlinear PA output with OFDM inputs. In short, the method enables correct modeling of a wideband PA that amplifies dual-band signals merely by conducting a one-tone test.

In this paper, we study on direction-of-arrival (DOA) estimation error reduction by Khatri-Rao (KR) product extended array in the presence of correlated waves. Recently, a simple array signal processing technique called KR product extended array has been proposed. By using the technique, degrees-of-freedom of an array can be easily increased. However, DOA estimation accuracy deteriorates when correlated or coherent waves arrive. Such highly correlated waves often arrive for radar application, hence error reduction technique has been desired. Therefore, in this paper, we propose a new method for error reduction preprocessing scheme by using N-th root of matrix. The N-th root of matrix has a similar effect to the spatial smoothing preprocessing for highly correlated signals. As a result, DOA estimation error due to signal correlation will be reduced. The optimal order of N depends on the data itself. In this paper, a simple iterative method to obtain adaptive N is also proposed. Computer simulation results are provided to show performance of the proposed method.

Recently, it has been shown that electromagnetic radiation from electrical devices leaks internal information. Some investigations have shown that information leaks through the clock frequency and higher harmonic waves. Thus, previous studies have focused on the information leakage from information processing circuits. However, there has been little discussion about information leaks from peripheral circuits. In this paper, we focus on the oscillation frequency of the integrated RC oscillators. In this paper, we use a keyboard as a device that includes a RC oscillator. Then experiments observed information leaks caused by key inputs. Our experiments show that frequency fluctuations cause information leakages and clarify what information can be acquired from the fluctuation. Then, we investigate the possibility of information leaking from peripheral circuits through modulated signals which are radiated by the peripheral circuits.

The linearity analysis of a passive mixer is presented. The distortion mechanism caused by switching operation of a MOS transistor is elucidated from the static and dynamic analysis of passive mixers. Furthermore, the maximum input and output level to keep linear operation and its required bias conditions are expressed by simple equations. The maximum linear output amplitude of the passive mixer is determined only by the local signal amplitude and it does not depend on input and output impedance. The calculated linearity performances agree well with simulated and measured results.

A directional lapped orthogonal transform (DirLOT) is an orthonormal transform of which basis is allowed to be anisotropic with the symmetric, real-valued and compact-support property. Due to its directional property, DirLOT is superior to the existing separable transforms such as DCT and DWT in expressing diagonal edges and textures. The goal of this paper is to enhance the ability of DirLOT further. To achieve this goal, we propose a novel image restoration technique using multiple DirLOTs. This paper generalizes an image denoising technique in [1], and expands the application of multiple DirLOTs by introducing linear degradation operator P. The idea is to use multiple DirLOTs to construct a redundant dictionary. More precisely, the redundant dictionary is constructed as a union of symmetric orthonormal discrete wavelet transforms generated by DirLOTs. To select atoms fitting a target image from the dictionary, we formulate an image restoration problem as an l1-regularized least square problem, which can efficiently be solved by the iterative-shrinkage/thresholding algorithm (ISTA). The proposed technique is beneficial in expressing multiple directions of edges/textures. Simulation results show that the proposed technique significantly outperforms the non-subsampled Haar wavelet transform for deblurring, super-resolution, and inpainting.

This paper describes a small size broadband fractional-N RF synthesizer for an RF test module with a high throughput and multiple resources installed in RF Automated Test Equipment (ATE) systems. The core device is the PLL-LSI composed of the 13-band asymmetrical tournament form voltage-controlled oscillators (VCOs) and the proposed 48-bit ΔΣ modulator with the infinite impulse response (IIR) filter. The single-loop PLL RF synthesizer is constructed in the form of systems in package (SiP) including the PLL-LSI and the active loop filter. The RF synthesizer SiP features a small size of 20mm × 20mm × 3mm, a high frequency resolution of smaller than 50µHz, and a phase noise of better than -110dBc/Hz at offset frequency of 1MHz across a frequency range of 100MHz to 13.4GHz. In addition, a frequency settling time of 150 µs that is faster than our conventional dual-loop PLL synthesizers using the discrete VCOs or the YIG-tuned oscillators (YTOs) is achieved. The synthesizer SiP significantly contributes to the realization of small size, high throughput RF test modules for RF ATEs.

Digital watermarking techniques have been used to assert the ownerships of digital images. The ownership information is embedded in an image as a watermark so that the owner of the image can be identified. However, many types of attacks have been used in attempts to break or remove embedded watermarks. Therefore, the watermark should be very robust against various kinds of attacks. Among them, the print-and-scan (PS) attack is very challenging because it not only alters the pixel values but also changes the positions of the original pixels. In this paper, we propose a watermarking system operating in the discrete cosine transform (DCT) domain. The polarities of the DCT coefficients are modified for watermark embedding. This is done by considering the properties of DCT coefficients under the PS attack. The proposed system is able to maintain the image quality after watermarking and the embedded watermark is very robust against the PS attack as well.

We present a round addition differential fault analysis (DFA) for some lightweight 80-bit block ciphers. It is shown that only one correct ciphertext and two faulty ciphertexts are required to reconstruct secret keys in 80-bit Piccolo and TWINE, and the reconstructions are easier than 128-bit CLEFIA.

In this paper, we present a real-time hand pose recognition method to provide an intuitive user interface through hand poses or gestures without a keyboard and a mouse. For this, the areas of right and left hands are segmented from the depth camera image, and noise compensation is performed. Then, the rotation angle and the centroid point of each hand area are calculated. Subsequently, joint points and end points of a finger are detected by expanding a circle at regular intervals from a centroid point of the hand. Lastly, the hand pose is recognized by matching between the current hand information and the hand model of previous frame and the hand model is updated for the next frame. This method enables users to predict the hidden fingers through the hand model information of the previous frame using temporal coherence in consecutive frames. As a result of the experiment on various hand poses with the hidden fingers using both hands, the accuracy showed over 95% and the performance indicated over 32fps. The proposed method can be used as a contactless input interface in presentation, advertisement, education, and game applications.