To overcome the target-aspect sensitivity in radar high resolution range profile (HRRP) recognition, a novel method called Improved Kernel Distance Fuzzy C-means Clustering Method (IKDFCM) is proposed in this paper, which introduces kernel function into fuzzy c-means clustering and relaxes the constraint in the membership matrix. The new method finds the underlying geometric structure information hiding in HRRP target and uses it to overcome the HRRP target-aspect sensitivity. The relaxing of constraint in the membership matrix improves anti-noise performance and robustness of the algorithm. Finally, experiments on three kinds of ground HRRP target under different SNRs and four UCI datasets demonstrate the proposed method not only has better recognition accuracy but also more robust than the other three comparison methods.

Range estimation based on time of arrival (TOA) is becoming increasingly important with the emergence of location-based applications and next-generation location-aware wireless sensor networks. For radar and positioning systems, chirp signals have primarily been used due to their inborn signal properties for decomposition. Recently, chirp signal has been selected as the baseline standard of ISO/IEC 24730-5 and IEEE 802.15.4a in 2.4GHz, organized for the development of a real-time accurate positioning system. When estimating the TOA of the received signals in multipath channel, the super-resolution algorithms, known as estimation of signal parameters via rotational invariance techniques (ESPRIT), multiple signal classification method (MUSIC) and matrix pencil (MP), are preferred due to their superiority in decomposing the received paths. For the super-resolution algorithm-based TOA estimation of chirp signals, the received chirp signals must be transformed into a sinusoidal form for the super-resolution algorithm. The conventional transformation, the de-chirping technique, changes the received chirp signals to sinusoids so that the super-resolution algorithms can estimate the TOA of the received chirp signals through a frequency estimation of the transformed sinusoids. In practice, the initial timing synchronizer at receiver tries to find the maximum energy point at which the received paths are overlapped maximally. At this time, the conventional de-chirping yields lossy transformed sinusoids for the first arrival path from the received samples synchronized to the maximum energy point. The first arrival path is not involved in the transformed sinusoids with the conventional transformation, leading to performance degradation. However, the proposed energy efficient time-frequency transformation achieves lossless transformation by using the extended reference chirp signals. The proposed transformation is incorporated with MUSIC-based TOA estimation. The effectiveness of the proposed transformation is analyzed and verified. The root mean squared error (RMSE) of the proposed transformation is compared with Cramer-Rao lower bound and those for the conventional algorithms such as super-resolution, ESPRIT and matrix pencil algorithm in multipath channel.

We study the problem of transforming one list (vertex) coloring of a graph into another list coloring by changing only one vertex color assignment at a time, while at all times maintaining a list coloring, given a list of allowed colors for each vertex. This problem is known to be PSPACE-complete for bipartite planar graphs. In this paper, we first show that the problem remains PSPACE-complete even for bipartite series-parallel graphs, which form a proper subclass of bipartite planar graphs. We note that our reduction indeed shows the PSPACE-completeness for graphs with pathwidth two, and it can be extended for threshold graphs. In contrast, we give a polynomial-time algorithm to solve the problem for graphs with pathwidth one. Thus, this paper gives sharp analyses of the problem with respect to pathwidth.

Syndrome key equation solution is one of the important processes in the decoding of Reed-Solomon codes. This paper proposes a low power key equation solver (KES) architecture where the power consumption is reduced by decreasing the required number of multiplications without degrading the decoding throughput and latency. The proposed method employs smaller number of multipliers than a conventional low power KES architecture. The critical path in the proposed KES circuit is minimized so that the operation at a high clock frequency is possible. A low power folded KES architecture is also proposed to further reduce the hardware complexity by executing folded operations in a pipelined manner with a slight increase in decoding latency.

In a patch-based super-resolution algorithm, a low-resolution patch is influenced by surrounding patches due to blurring. We propose to remove this boundary effect by subtracting the blur from the surrounding high-resolution patches, which enables more accurate sparse representation. We demonstrate improved performance through experimentation. The proposed algorithm can be applied to most of patch-based super-resolution algorithms to achieve additional improvement.

A four-pixel-array superconducting transition-edge sensor (TES) microcalorimeter with a mushroom-shaped absorber was fabricated for the energy dispersive spectroscopy performed on a transmission electron microscope. The TES consists of a bilayer of Au/Ti with either a 50-nm or 120-nm thickness. The absorber of 5.0,$mu$m thick is made from a Au layer and its stem is deposited in the center of the TES surface. A Ta$_{2}$O$_{5}$ insulating layer of 100-nm thickness is inserted between the overhang region of the absorber and the TES surface. A selected pixel of the TES microcalorimeter was operated for the detection of Np L X-rays emitted from an $^{241}$Am source. A response of the TES microcalorimeter to L X-rays was obtained by analyzing detection signal pulses with using the optimal filter method. An energy resolution was obtained to be 33,eV of the full width at half maximum value at 17.751,keV of Np L$_{eta 1}$ considering its natural width of 13.4,eV. Response to L X-rays emitted from a mixture source of $^{238}$Pu, $^{239}$Pu and $^{241}$Am was obtained by operating the selected pixel of the TES microcalorimeter. Major L X-ray peaks of progeny elements of $alpha$ decay of Pu and Am isotopes were clearly identified in the obtained energy spectrum. The experimental results demonstrated the separation of $^{241}$Am and plutonium isotopes by L X-ray spectroscopy.

This paper presents 2-(hydroxyl) quinoline lithium (Liq) used as an n-type dopant to improve white hybrid organic light-emitting diode (WHOLEDs) performance. The Liq doped tris(8-hydroxyquinolinato) aluminum (Alq$_{3})$ layer possessed enhanced electron injection, efficient hole and electron balance in the emitting layer, as one of the most essential issues for device applications. This work investigates the optimum recipe (Liq concentration and thickness) of Alq$_{3}$:Liq n-type doped electron injection layer (EIL) for WHOLED devices by comparing the current density and efficiency results with conventional Alq$_{3}$/LiF technique. A blocking layer or interlayer is inserted between emitting layer and EIL to avoid excitons quenched. In this work suitable material and optimum thickness for blocking layer are studied, a white small-molecular organic light-emitting diode (SM-OLEDs) based on a 1,3,5-tris (N-phenylbenzimidazol-2-yl) benzene (TPBi) stamping transfer process is investigated. The proposed stamping transfer process can avoid the complexity of the vacuum deposition process.

An all-digital time-domain ADC, abbreviated as TAD, is presented in this paper. All-digital structure is intrinsically compatible with the scaling of CMOS technology, and can satisfy the great demand of miniaturized and low-voltage sensor interface. The proposed TAD uses an inverter-based Ring-Delay-Line (RDL) to transform the input signal from voltage domain to time domain. The voltage-modulated time information is then digitized by a composite architecture namely “4-Clock-Edge-Shift Construction” (4CKES). TAD features superior voltage sensitivity and 1st-order noise shaping, which can significantly simplify the power-hungry pre-conditioning circuits. Reconfigurable resolution can be easily achieved by applying different sampling rates. A TAD prototype is fabricated in 65nm CMOS, and consumes a small area of 0.016mm2. It achieves a voltage resolution of 82.7µV/LSB at 10MS/s and 1.96µV/LSB at 200kS/s in a narrow input range of 0.1Vpp, merely under 0.6V supply. The highest SNR of TAD prototype is 61.36dB in 20kHz bandwidth at 10MS/s. This paper also analyzes the nonideal effects of TAD and discusses the potential solutions. As the principal drawback, nonlinearity of TAD can be compensated by the differential-setup and digital calibration.

We present a time-to-digital converter (TDC) achieving sub-picosecond resolution and high precision for all-digital phase-locked-loops (ADPLLs). The basic idea is using a charge pump to translate time interval into charge, and a successive-approximation-register-analog-to-digital converter (SAR-ADC) to quantize the charge. With this less complex configuration, high resolution, high precision, low power, and small area can be achieved all together. We analyzed the noise contribution from the charge pump and describe detailed design and implementation for sizing the capacitor and transistors, with the awareness of noise and linearity. The analysis demonstrates the proposed TDC capable of sub-picosecond resolution and high precision. Two prototype chips were fabricated in 65nm CMOS with 0.06mm2, and 0.018mm2 core areas, respectively. The achieved resolutions are 0.84ps and 0.80ps, in 8-bit and 10-bit range, respectively. The measured single-shot-precisions range from 0.22 to 0.6ps, and from 0.66 to 1.04ps, respectively, showing consistent trends with the analysis. Compared with state-of-the-arts, best performance balance has been achieved.

This article introduces a self-organizing model which builds the topology of a DHT mapping system for ICN. Due to its self-organizing operation and low average degree of maintenance, the management overhead of the system is reduced dramatically, which yields inherent scalability. The proposed model can improve latency by around 10% compared to an existing approach which has a near optimal average distance when the number of nodes and degree are given. In particular, its operation is simple which eases maintenance concerns. Moreover, we analyze the model theoretically to provide a deeper understanding of the proposal.

This paper deals with the problem of reconstructing a high-resolution digital image from a single low-resolution digital image and proposes a new intra-frame super-resolution algorithm based on the mixed lp/l1 norm minimization. Introducing some assumptions, this paper formulates the super-resolution problem as a mixed l0/l1 norm minimization and relaxes the l0 norm term to the lp norm to avoid ill-posedness. A heuristic iterative algorithm is proposed based on the iterative reweighted least squares (IRLS). Numerical examples show that the proposed algorithm achieves super-resolution efficiently.

In non-destructive testing (NDT), ultrasonic echo is often an overlapping multi-echo signals with noise. However, the accurate estimation of ultrasonic time-of-flight (TOF) is essential in NDT. In this letter, a novel method for TOF estimation through envelope is proposed. Firstly, the wavelet denoising technique is applied to the noisy echo to improve the estimation accuracy. Then, the Hilbert transform (HT) is used in ultrasonic signal processing in order to extract the envelope of the echo. Finally, the TOF of each component of multi-echo signals is estimated by the local maximum point of signal envelope. Furthermore, the time resolution of time-overlapping ultrasonic echoes is discussed. Numerical simulation has been carried out to show the performances of the proposed method in estimating TOF of ultrasonic signal.

Recent progress in research on the finite element method (FEM) for optical waveguide design and analysis is reviewed, focusing on the author's works. After briefly reviewing fundamentals of FEM such as a theoretical framework, a conventional nodal element, a newly developed edge element to eliminate nonphysical, spurious solutions, and a perfectly matched layer to avoid undesirable reflections from computational window edges, various FEM techniques for a guided-mode analysis, a beam propagation analysis, and a waveguide discontinuity analysis are described. Some design examples are introduced, including current research activities on multi-core fibers.

Instantaneous ambiguity resolution techniques are methods employed to achieve real-time high-accuracy positioning. The advent of the Chinese BeiDou system enables us to evaluate the performance of the combined GPS/BeiDou/QZSS dual-frequency ambiguity resolution and BeiDou three-frequency ambiguity resolution. It is known that the increasing number of satellites used can increase the reliability as well as the availability of single-epoch real-time kinematic (RTK) information. Therefore, performance improvement of single-epoch RTK by adding BeiDou satellites is strongly expected because many BeiDou satellites are operated in Asian regions. The first objective of this study is to conduct an initial assessment of the single-epoch RTK performance, as well as standalone positioning/code relative positioning using GPS/BeiDou/QZSS. The second objective of this study is to evaluate the performance of the longer-baseline single-epoch ambiguity resolution using the three-frequency observation data. Furthermore, the possibility of future single-epoch RTK service is discussed in this paper.

A new algorithm is proposed for finding all solutions of piecewise-linear resistive circuits using separable programming. In this algorithm, the problem of finding all solutions is formulated as a separable programming problem, and it is solved by the modified simplex method using the restricted-basis entry rule. Since the modified simplex method finds one solution per application, the proposed algorithm can find all solutions efficiently. Numerical examples are given to confirm the effectiveness of the proposed algorithm.

We propose a parameterized multisurface fitting method for multi-frame super-resolution (SR) processing. A parameter assumed for the unknown high-resolution (HR) pixel is used for multisurface fitting. Each surface fitted at each low-resolution (LR) pixel is an expression of the parameter. Final SR result is obtained by fusing the sampling values from these surfaces in the maximum a posteriori fashion. Experimental results demonstrate the superiority of the proposed method.

New media processing applications such as image recognition and AR (Augment Reality) have become into practical on embedded systems for automotive, digital-consumer and mobile products. Many-core processors have been proposed to realize much higher performance than multi-core processors. We have developed a low-power many-core SoC for multimedia applications in 40nm CMOS technology. Within a 210mm2 die, two 32-core clusters are integrated with dynamically reconfigurable processors, hardware accelerators, 2-channel DDR3 I/Fs, and other peripherals. Processor cores in the cluster share a 2MB L2 cache connected through a tree-based Network-on-Chip (NoC). Its total peak performance exceeds 1.5TOPS (Tera Operations Per Second). The high scalability and low power consumption are accomplished by parallelized software for multimedia applications. In case of face detection, the performance scales up to 64 cores and the SoC consumes only 2.21W. Moreover, it can execute the 1080p 48fps H.264 decoding about 520mW by 28 cores and the 4K2K 15fps super resolution about 770mW by 32 cores in one cluster. Exploiting parallelism by low power processor cores, the many-core SoC provides several tens of times better energy efficiency than that of a high performance desk-top quad-core processor.

Traditional face swapping technologies require that the faces of source images and target images have similar pose and appearance (usually frontal). For overcoming this limit in applications this paper presents a pose-free face swapping method based on personalized 3D face modeling. By using a deformable 3D shape morphable model, a photo-realistic 3D face is reconstructed from a single frontal view image. With the aid of the generated 3D face, a virtual source image of the person with the same pose as the target face can be rendered, which is used as a source image for face swapping. To solve the problem of illumination difference between the target face and the source face, a color transfer merging method is proposed. It outperforms the original color transfer method in dealing with the illumination gap problem. An experiment shows that the proposed face reconstruction method is fast and efficient. In addition, we have conducted experiments of face swapping in a variety of scenarios such as children's story book, role play, and face de-identification stripping facial information used for identification, and promising results have been obtained.

In signal restoration problems, we expect to improve the restoration performance with a priori information about unknown target signals. In this paper, the parametric Wiener filter with linear constraints for unknown target signals is discussed. Since the parametric Wiener filter is usually defined as the minimizer of the criterion not for the unknown target signal but for the filter, it is difficult to impose constraints for the unknown target signal in the criterion. To overcome this difficulty, we introduce a criterion for the parametric Wiener filter defined for the unknown target signal whose minimizer is equivalent to the solution obtained by the original formulation. On the basis of the newly obtained criterion, we derive a closed-form solution for the parametric Wiener filter with linear constraints.

In this paper, we propose a time and memory efficient Ultra Wide Band Short Range Radar (UWB SRR) system for measuring relative target velocities of up to 150km/hr. First, for the proposed detector, we select the required design parameters for good performance. The parameters are the number of coherent integrations, non-coherent integrations, and FFT points. The conventional detector uses a Fast Fourier Transform (FFT) to extract the range and velocity of the target simultaneously. Therefore, it requires high computation effort, high FFT processing time, and a huge amount of memory. However, the proposed pulse radar detector first decides the target range and then computes the target velocity using FFT sequentially for the decided range index. According to our theoretical and simulation analyses, the FFT processing time and the memory requirement are reduced compared to those of the conventional method. Finally, we show that the detection performance of the proposed detector is superior to that of the conventional detector in a background of Additive White Gaussian Noise (AWGN).