Texture feature descriptors such as local binary patterns (LBP) have proven effective for ground-based cloud classification. Traditionally, these texture feature descriptors are predefined in a handcrafted way. In this paper, we propose a novel method which automatically learns discriminative features from labeled samples for ground-based cloud classification. Our key idea is to learn these features through mutual information maximization which learns a transformation matrix for local difference vectors of LBP. The experimental results show that our learned features greatly improves the performance of ground-based cloud classification when compared to the other state-of-the-art methods.

We present a new framework for embedding holographic halftone watermarking data into images by fusion of scale-related wavelet coefficients. The halftone watermarking image is obtained by using error-diffusion method and converted into Fresnel hologram, which is considered to be the initial password. After encryption, a scrambled watermarking image through Arnold transform is embedded into the host image during the halftoning process. We characterize the multi-scale representation of the original image using the discrete wavelet transform. The boundary information of the target image is fused by correlation of wavelet coefficients across wavelet transform layers to increase the pixel resolution scale. We apply the inter-scale fusion method to gain fusion coefficient of the fine-scale, which takes into account both the detail of the image and approximate information. Using the proposed method, the watermarking information can be embedded into the host image with recovery against the halftoning operation. The experimental results show that the proposed approach provides security and robustness against JPEG compression and different attacks compared to previous alternatives.

A digital spatial modulation method has been demonstrated for a wireless power transmission system at 5.8 GHz. Interference of electromagnetic waves, which are radiated from the dual scatterers, successfully realizes the spatial modulation. The spatial modulation is performed with a digital modulation manner by controlling capacitances embedded in one of the dual scatterers so that the interference of the scattered waves is appropriately changed. Switch MMICs based on p-HEMT technology was newly developed for the spatial modulation. Measured insertion losses of the switch MMIC are 1.0 dB and 14 dB for on and off states at 5.8 GHz, respectively. The isolation is more than 20 dB. With the switch MMIC, digital spatial modulation characteristics were experimentally demonstrated at 5.8 GHz. One-bit amplitude shift keying (ASK) for 1 MHz signal was realized at 5.8 GHz, and two levels were clearly discriminated. The modulation factor is 36%. In addition, 2-bit ASK signal was detected at 7.1 GHz.

This paper presents wireless systems for use in disaster recovery operations. The Great East Japan Earthquake of March 11, 2011 reinforced the importance of communications in, to, and between disaster areas as lifelines. It also revealed that conventional wireless systems used for disaster recovery need to be renovated to cope with technological changes and to provide their services with easier operations. To address this need we have developed new systems, which include a relay wireless system, subscriber wireless systems, business radio systems, and satellite communication systems. They will be chosen and used depending on the situations in disaster areas as well as on the required services.

A forward/reverse body bias generator (BBG) which operates under wide supply-range is proposed. Fine-grained body biasing (FGBB) is effective to reduce variability and increase energy efficiency on digital LSIs. Since FGBB requires a number of BBGs to be implemented, simple design is preferred. We propose a BBG with charge pumps for reverse body bias and the BBG operates under wide supply-range from 0.5,V to 1.2,V. Layout of the BBG was designed in a cell-based flow with an AES core and fabricated in a 65~nm CMOS process. Area of the AES core is 0.22 mm$^2$ and area overhead of the BBG is 2.3%. Demonstration of the AES core shows a successful operation with the supply voltage from 0.5,V to 1.2,V which enables the reduction of power dissipation, for example, of 17% at 400,MHz operation.

In this paper, we improve a width-3 joint sparse form proposed by Okeya, Katoh, and Nogami. After the improvement, the representation can attain an asymtotically optimal complexity found in our previous work. Although claimed as optimal by the authors, the average computation time of multi-scalar multiplication obtained by the representation is 563/1574n+o(n)≈0.3577n+o(n). That number is larger than the optimal complexity 281/786n+o(n)≈0.3575n+o(n) found in our previous work. To optimize the width-3 joint sparse form, we add more cases to the representation. After the addition, we can show that the complexity is updated to 281/786n+o(n)≈0.3575n+o(n), which implies that the modified representation is asymptotically optimal. Compared to our optimal algorithm in the previous work, the modified width-3 joint sparse form uses less dynamic memory, but it consumes more static memory.

Since the conventional cascade controller for electric motor drives requires accurate information about the system parameters and load conditions to achieve a desired performance, this paper presents a new practical control structure to improve the robust performance against parameter uncertainties. Two first-order disturbance observers (DOB) are incorporated with the cascade structure, to preserve the nominal performance. The analysis of the robust performance of the DOB is presented by using the singular perturbation theory. Simulation results suggest that the proposed controller can be used effectively as an additional compensator to the conventional cascade scheme.

This work presents a novel counter-based randomization method for use in a flying-adder frequency synthesizer with a cost-effective structure that can replace the fractional accumulator. The proposed technique involves a counter, a comparator and a modified linear feedback shift register. The power consumption and speed bottleneck of the conventional flying-adder are significantly reduced. The modified linear shift feedback register is used as a pseudo random data generator, suppressing the spurious tones arise from the periodic carry sequences that is generated by the fractional accumulator. Furthermore, the proposed counter-based randomization method greatly reduces the large memory size that is required by the conventional approach to carry randomization. A test chip for the proposed counter-based randomization method is fabricated in the TSMC 0.18,$mu $m 1P6M CMOS process, with the core area of 0.093,mm$^{mathrm{2}}$. The output frequency had a range of 43.4,MHz, extasciitilde 225.8,MHz at 1.8,V with peak-to-peak jitter (Pk-Pk) jitter 139.2,ps at 225.8,MHz. Power consumption is 2.8,mW @ 225.8,MHz with 1.8 supply voltage.

Optimizing embedded software is a problem having scientific and practical signification. Optimizing embedded software can be done in different phases of the software life cycle under different optimal conditions. Most studies of embedded software optimization are done in forward engineering and these studies have not given an overall model for the optimization problem of embedded software in both forward engineering and reverse engineering. Therefore, in this paper, we propose a new approach to embedded software optimization based on reverse engineering. First, we construct an overall model for the embedded software optimization in both forward engineering and reverse engineering and present a process of embedded software optimization in reverse engineering. The main idea of this approach is that decompiling executable code to source code, converting the source code to models and optimizing embedded software under different levels such as source code and model. Then, the optimal source code is recompiled. To develop this approach, we present two optimization techniques such as optimizing power consumption of assembly programs based on instruction schedule and optimizing performance based on alternating equivalent expressions.

A novel method was developed to expand and adjust the bandwidth of long-period fiber gratings (LPFGs) as band-rejection filters. The band-rejection filters were constructed by concatenating two LPFGs with an appropriate space, that causes a $pi$-phase shift. The component LPFGs with the same period and the different numbers of periods are designed to have $-$3-dB transmission at wavelengths on both sides of a resonance wavelength symmetrically, and the transmission loss of the concatenated LPFGs peaks at the -3-dB transmission wavelengths. The rejection bandwidth was widened by changing the interval between the -3-dB transmission wavelengths. The concatenated LPFGs were simulated by using a transfer-matrix method based on a discrete coupling model, and were fabricated by a point-by-point arc discharge technique on the basis of the simulation results. It was demonstrated that the rejection bandwidth at 20-dB attenuation reached 26.6,nm and was 2.7 times broader than that of a single uniform LPFG.

This paper proposes an ultra-low power fully on-chip CMOS relaxation oscillator (ROSC) for a real-time clock application. The proposed ROSC employs a compensation circuit of a comparator's non-idealities caused by offset voltage and delay time. The ROSC can generate a stable, and 32-kHz oscillation clock frequency without increasing power dissipation by using a low reference voltage and employing a novel compensation architecture for comparators. Measurement results in a 0.18-$mu$m CMOS process demonstrated that the circuit can generate a stable clock frequency of 32.55,kHz with low power dissipation of 472,nW at 1.8-V power supply. Measured line regulation and temperature coefficient were 1.1%/V and 120,ppm/$^{circ}$C, respectively.

A renal biopsy is a procedure to get a small piece of kidney for microscopic examination. With the development of tissue sectioning and medical imaging techniques, microscope renal biopsy image sequences are consequently obtained for computer-aided diagnosis. This paper proposes a new context-based segmentation algorithm for acquired image sequence, in which an improved genetic algorithm (GA) patching method is developed to segment different size target. To guarantee the correctness of first image segmentation and facilitate the use of context information, a boundary fusion operation and a simplified scale-invariant feature transform (SIFT)-based registration are presented respectively. The experimental results show the proposed segmentation algorithm is effective and accurate for renal biopsy image sequence.

Cell voltage equalizers are necessary to ensure years of operation and maximize the chargeable/dischargeable energy of series-connected supercapacitors (SCs). A two-switch voltage equalizer using a series-resonant voltage multiplier operating in frequency-multiplied discontinuous conduction mode (DCM) is proposed for series-connected SCs in this paper. The frequency-multiplied mode virtually increases the operation frequency and hence mitigates the negative impact of the impedance mismatch of capacitors on equalization performance, allowing multi-layer ceramic capacitors (MLCCs) to be used instead of bulky and costly tantalum capacitors, the conventional approach when using voltage multipliers in equalizers. Furthermore, the DCM operation inherently provides the constant current characteristic, realizing the excessive current protection that is desirable for SCs, which experience 0V and equivalently become an equivalent short-circuit load. Experimental equalization tests were performed for eight SCs connected in series under two frequency conditions to verify the improved equalization performance at the increased virtual operation frequencies. The standard deviation of cell voltages under the higher-frequency condition was lower than that under the lower-frequency condition, demonstrating superior equalization performance at higher frequencies.

Coordinated multi-point (CoMP) transmission and reception is a promising technique for interference mitigation in cellular systems. The scheduling algorithm for CoMP has a significant impact on the network processing complexity and performance. Performing exhaustive search permits centralized scheduling and thus the optimal global solution; however, it incurs a high level of computational complexity and may be impractical or lead to high cost as well as network instability. In order to provide a more realistic scheduling method while balancing performance and complexity, we propose a low complexity centralized scheduling scheme that adaptively selects users for single-cell transmission or different CoMP scheme transmission to maximize the system weighted sum capacity. We evaluate the computational complexity and system-level simulation performance in this paper. Compared to the optimal scheduling method with exhaustive search, the proposed scheme has a much lower complexity level and achieves near optimal performance.

Gallium oxide is expected as a channel material for thin film transistors. In the conventional technologies, gallium oxide has been tried to be fabricated by atomic layer deposition (ALD) at high temperatures from 100--450$^{circ}$C, although the room-temperature (RT) growth has not been developed. In this work, we developed the RT ALD of gallium oxide by using a remote plasma technique. We studied trimethylgallium (TMG) adsorption and its oxidization on gallium oxide surfaces at RT by infrared absorption spectroscopy (IRAS). Based on the adsorption and oxidization characteristics, we designed the room temperature ALD of Ga$_{2}$O$_{3}$. The IRAS indicated that TMG adsorbs on the gallium oxide surface by consuming the adsorption sites of surface hydroxyl groups even at RT and the remote plasma-excited water and oxygen vapor is effective in oxidizing the TMG adsorbed surface and regeneration of the adsorption sites for TMG. We successfully prepared Ga$_{2}$O$_{3}$ films on Si substrates at RT with a growth per cycle of 0.055,nm/cycle.

Robust crater recognition is a research focus on deep space exploration mission, and sparse representation methods can achieve desirable robustness and accuracy. Due to destruction and noise incurred by complex topography and varied illumination in planetary images, a robust crater recognition approach is proposed based on dictionary learning with a low-rank error correction model in a sparse representation framework. In this approach, all the training images are learned as a compact and discriminative dictionary. A low-rank error correction term is introduced into the dictionary learning to deal with gross error and corruption. Experimental results on crater images show that the proposed method achieves competitive performance in both recognition accuracy and efficiency.

Ni nanodots (NDs) used as nano-scale top electrodes were formed on a 10-nm-thick Si-rich oxide (SiO$_{mathrm{x}}$)/Ni bottom electrode by exposing a 2-nm-thick Ni layer to remote H$_{2}$-plasma (H$_{2}$-RP) without external heating, and the resistance-switching behaviors of SiO$_{mathrm{x}}$ were investigated from current-voltage ( extit{I--V}) curves. Atomic force microscope (AFM) analyses confirmed the formation of electrically isolated Ni NDs as a result of surface migration and agglomeration of Ni atoms promoted by the surface recombination of H radicals. From local extit{I--V} measurements performed by contacting a single Ni ND as a top electrode with a Rh coated Si cantilever, a distinct uni-polar type resistance switching behavior was observed repeatedly despite an average contact area between the Ni ND and the SiO$_{mathrm{x}}$ as small as $sim$ 1.9 $ imes$ 10$^{-12}$cm$^{2}$. This local extit{I--V} measurement technique is quite a simple method to evaluate the size scalability of switching properties.

This paper proposes a novel iterative multiple-input multiple-output (MIMO) receiver for orthogonal frequency division multiplexing (OFDM) systems, named as an “iterative MIMO receiver employing virtual channels with a Turbo decoder.” The proposed MIMO receiver comprises a MIMO detector with virtual channel detection and a Turbo decoder, between which signals are exchanged iteratively. This paper proposes a semi hard input soft output (SHISO) iterative decoding for the iterative MIMO receiver that achieves better performance than a soft input soft output (SISO) iterative decoding. Moreover, this paper proposes a new criterion for the MIMO detector to select the most likely virtual channel. The performance of the proposed receiver is verified in a 6×2 MIMO-OFDM system by computer simulation. The proposed receiver achieves better performance than the SISO MAP iterative receiver by 1.5dB at the bit error rate (BER) of 10-4, by optimizing the number of the Turbo iteration per the SHISO iteration. Moreover, the proposed detection criterion enables the proposed receiver to achieve a gain of 3.0dB at the BER of 10-5, compared with the SISO MAP iterative receiver with the Turbo decoder.

Nitrogen adsorption on thermally cleaned Si(100) surfaces by pure and plasma excited NH$_{3}$ is investigated by extit{in situ} IR absorption spectroscopy and ex-situ X-ray photoelectron spectroscopy with various temperatures from RT (25$^{circ}$C) to 800$^{circ}$C and with a treatment time of 5,min. The nitrogen coverage after the treatment varies according to the treatment temperature for both pure and plasma excited NH$_{3}$. In case of the pure NH$_{3}$, the nitrogen coverage is saturated as low as 0.13--0.25 mono layer (ML) while the growth of the nitride film commenced at 550$^{circ}$C. For the plasma excited NH$_{3}$, the saturation coverage was measured at 0.54,ML at RT and it remained unincreased from RT to 550$^{circ}$C. This indicates that the plasma excited NH$_{3}$ enhances the nitrogen adsorption near at RT. It is found that main species of N is Si$_{2}=$ NH in case of the plasma excited NH$_{3}$ at RT while the pure NH$_{3}$ treatment gives rise to the Si--NH$_{2}$ passivation with Si--H at RT. We discuss the mechanism of the nitrogen adsorption on Si(100) surfaces with the plasma excited NH$_{3}$ in comparison with the study on the pure NH$_{3}$ treatment.

Subcarrier mapping (SCM) is considered to be crucial for capacity-maximization in orthogonal frequency division multiplexing (OFDM) relaying networks and has been investigated extensively. However, no study has examined its exact or approximate close-form analysis under Nakagami-m fading. This paper considers the ordered subcarrier pairing schemes, i.e., worst-to-best (WTB) SCM and best-to-best (BTB) SCM, for the analysis of bit error rate (BER) and capacity of a dual-hop OFDM amplify-and-forward (AF) relay system. The system-analysis is presented for Nakagami-m fading with emphasis on two special cases: one-sided Gaussian fading ($(m=rac{1}{2})$) and Rayleigh fading (m=1). Close-form expressions for the probability density function (PDF) and moment generating function (MGF) of end-to-end SNR are derived while considering fixed gain AF relays. The classical MGF and PDF based approaches are used to compare the BER performance of the system with WTB SCM and BTB SCM schemes. Close-form expressions for the upper bound on ergodic capacity are derived by analyzing Jensen's inequality. Accurate analysis is presented for integer m while the non-integer m values allow the derivations of approximate expressions. The accuracy of the suggested approximation is verified analytically as well as numerically. The simulation results validate the analysis in Nakagami-m fading channel.