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4041-4060hit(42807hit)

  • An Architecture for Real-Time Retinex-Based Image Enhancement and Haze Removal and Its FPGA Implementation Open Access

    Dabwitso KASAUKA  Kenta SUGIYAMA  Hiroshi TSUTSUI  Hiroyuki OKUHATA  Yoshikazu MIYANAGA  

     
    PAPER

      Vol:
    E102-A No:6
      Page(s):
    775-782

    In recent years, much research interest has developed in image enhancement and haze removal techniques. With increasing demand for real time enhancement and haze removal, the need for efficient architecture incorporating both haze removal and enhancement is necessary. In this paper, we propose an architecture supporting both real-time Retinex-based image enhancement and haze removal, using a single module. Efficiently leveraging the similarity between Retinex-based image enhancement and haze removal algorithms, we have successfully proposed an architecture supporting both using a single module. The implementation results reveal that just 1% logic circuits overhead is required to support Retinex-based image enhancement in single mode and haze removal based on Retinex model. This reduction in computation complexity by using a single module reduces the processing and memory implications especially in mobile consumer electronics, as opposed to implementing them individually using different modules. Furthermore, we utilize image enhancement for transmission map estimation instead of soft matting, thereby avoiding further computation complexity which would affect our goal of realizing high frame-rate real time processing. Our FPGA implementation, operating at an optimum frequency of 125MHz with 5.67M total block memory bit size, supports WUXGA (1,920×1,200) 60fps as well as 1080p60 color input. Our proposed design is competitive with existing state-of-the-art designs. Our proposal is tailored to enhance consumer electronic such as on-board cameras, active surveillance intrusion detection systems, autonomous cars, mobile streaming systems and robotics with low processing and memory requirements.

  • A Broadband Kalman Filtering Approach to Blind Multichannel Identification

    Yuanlei QI  Feiran YANG  Ming WU  Jun YANG  

     
    PAPER-Digital Signal Processing

      Vol:
    E102-A No:6
      Page(s):
    788-795

    The blind multichannel identification is useful in many applications. Although many approaches have been proposed to address this challenging problem, the adaptive filtering-based methods are attractive due to their computational efficiency and good convergence property. The multichannel normalized least mean-square (MCNLMS) algorithm is easy to implement, but it converges very slowly for a correlated input. The multichannel affine projection algorithm (MCAPA) is thus proposed to speed up the convergence. However, the convergence of the MCNLMS and MCAPA is still unsatisfactory in practice. In this paper, we propose a time-domain Kalman filtering approach to the blind multichannel identification problem. Specifically, the proposed adaptive Kalman filter is based on the cross relation method and also uses more past input vectors to explore the decorrelation property. Simulation results indicate that the proposed method outperforms the MCNLMS and MCAPA significantly in terms of the initial convergence and tracking capability.

  • New Ternary Power Mapping with Differential Uniformity Δf≤3 and Related Optimal Cyclic Codes Open Access

    Haode YAN  Dongchun HAN  

     
    LETTER-Cryptography and Information Security

      Vol:
    E102-A No:6
      Page(s):
    849-853

    In this letter, the differential uniformity of power function f(x)=xe over GF(3m) is studied, where m≥3 is an odd integer and $e= rac{3^m-3}{4}$. It is shown that Δf≤3 and the power function is not CCZ-equivalent to the known ones. Moreover, we consider a family of ternary cyclic code C(1,e), which is generated by mω(x)mωe(x). Herein, ω is a primitive element of GF(3m), mω(x) and mωe(x) are minimal polynomials of ω and ωe, respectively. The parameters of this family of cyclic codes are determined. It turns out that C(1,e) is optimal with respect to the Sphere Packing bound.

  • A Study on Nonlinear Effect of Modulated Low-Frequency Electromagnetic Waves on Stimulus Response

    Hiroki SHINODA  Daisuke ANZAI  Jens KIRCHNER  Georg FISCHER  Jianqing WANG  

     
    PAPER

      Pubricized:
    2018/12/25
      Vol:
    E102-B No:6
      Page(s):
    1097-1103

    Stimulus response caused by low-frequency electromagnetic exposure can be used to realize effective medical treatments. However, it is well known that the membrane potential of nerve cells exhibits nonlinearity, particularly in the case of modulated signals, it is important to analyze the nonlinear stimulation effect based on a nerve cell model. This paper adopts the Frankenhaeuser-Huxley (FH) model as the nerve cell model, and evaluates the stimulus response based on the FH model when nerve cells are exposed to low-frequency modulated radio signals such as On-Off Keying (OOK) modulation. This paper investigated the nonlinear effect of the stimulus intensity from the viewpoint of the spike frequency with different modulation parameter values including the induced amplitude and duty cycle. It was confirmed that action potential (AP) rate was higher with OOK-type radio signals than with unmodulated signals.

  • Design of High-Rate Polar-LDGM Codes for Relay Satellite Communications

    Bin DUO  Junsong LUO  Yong FANG  Yong JIA  Xiaoling ZHONG  Haiyan JIN  

     
    PAPER-Fundamental Theories for Communications

      Pubricized:
    2018/12/03
      Vol:
    E102-B No:6
      Page(s):
    1128-1139

    A high-rate coding scheme that polar codes are concatenated with low density generator matrix (LDGM) codes is proposed in this paper. The scheme, referred to as polar-LDGM (PLG) codes, can boost the convergence speed of polar codes and eliminate the error floor behavior of LDGM codes significantly, while retaining the low encoding and decoding complexity. With a sensibly designed Gaussian approximation (GA), we can accurately predict the theoretical performance of PLG codes. The numerical results show that PLG codes have the potential to approach the capacity limit and avoid error floors effectively. Moreover, the encoding complexity is lower than the existing LDPC coded system. This motives the application of powerful PLG codes to satellite communications in which message transmission must be extremely reliable. Therefore, an adaptive relaying protocol (ARP) based on PLG codes for the relay satellite system is proposed. In ARP, the relay transmission is selectively switched to match the channel conditions, which are determined by an error detector. If no errors are detected, the relay satellite in cooperation with the source satellite only needs to forward a portion of the decoded message to the destination satellite. It is proved that the proposed scheme can remarkably improve the error probability performance. Simulation results illustrate the advantages of the proposed scheme

  • Optimal Pricing for Service Provision in Heterogeneous Cloud Market

    Xianwei LI  Bo GU  Cheng ZHANG  Zhi LIU  Kyoko YAMORI  Yoshiaki TANAKA  

     
    PAPER-Network

      Pubricized:
    2018/12/17
      Vol:
    E102-B No:6
      Page(s):
    1148-1159

    In recent years, the adoption of Software as a Service (SaaS) cloud services has surpassed that of Infrastructure as a Service (IaaS) cloud service and is now the focus of attention in cloud computing. The cloud market is becoming highly competitive owing to the increasing number of cloud service providers (CSPs), who are likely to exhibit different cloud capacities, i.e., the cloud market is heterogeneous. Moreover, as different users generally exhibit different Quality of Service (QoS) preferences, it is challenging to set prices for cloud services of good QoS. In this study, we investigate the price competition in the heterogeneous cloud market where two SaaS providers, denoted by CSP1 and CSP2, lease virtual machine (VM) instances from IaaS providers to offer cloud-based application services to users. We assume that CSP1 only has M/M/1 queue of VM instances owing to its limited cloud resources, whereas CSP2 has M/M/∞ queue of VM instances reflecting its adequate resources. We consider two price competition scenarios in which two CSPs engage in two games: one is a noncooperative strategic game (NSG) where the two CSPs set prices simultaneously and the other is a Stackelberg game (SG) where CSP2 sets the price first as the leader and is followed by CSP1, who sets the price in response to CSP2. Each user decides which cloud services to purchase (if purchases are to be made) based on the prices and QoS. The NSG scenario corresponds to the practical cloud market, where two CSPs with different cloud capacities begin to offer cloud services simultaneously; meanwhile, the SG scenario covers the instance where a more recent CSP plans to enter a cloud market whose incumbent CSP has larger cloud resources. Equilibrium is achieved in each of the scenarios. Numerical results are presented to verify our theoretical analysis.

  • Analytical Expressions for End-to-End Throughput of String-Topology Wireless Full-Duplex Multi-Hop Networks

    Chikara FUJIMURA  Kosuke SANADA  Kazuo MORI  

     
    PAPER-Network

      Pubricized:
    2018/12/25
      Vol:
    E102-B No:6
      Page(s):
    1160-1169

    Wireless Full-Duplex (FD) communication can double the point-to-point throughput. To obtain the full benefits of the FD technique in multi-hop networks, its potential throughput performance in multi-hop networks should be clarified qualitatively and quantitatively. Developing an analytical model for FD multi-hop networks is effective and useful for not only clarifying such network dynamics but also developing the optimal protocol design. However, generalized analytical expression for the end-to-end throughput of FD multi-hop networks has not been proposed. This paper proposes analytical expressions for the end-to-end throughput of string-topology wireless FD multi-hop networks. Our approach is to integrate with the analytical model of the airtime expression, which is an effective analytical approach of the throughput analysis for Half-Duplex (HD) multi-hop networks, and the Markov-chain model considering the FD MAC operation. The proposed model clarify the detailed effect of the FD MAC operation on the throughput performance in multi-hop networks. In particular, it can obtain the end-to-end throughput of FD multi-hop networks for arbitrary number of hops, arbitrary payload size and arbitrary value of the minimum contention window. The analytical expressions verified by comparisons with the simulation results. From the comparisons with the results in HD multi-hop networks, we confirm the effectiveness of the FD communication in multi-hop networks.

  • Mutual Interference Suppression and Signal Restoration in Automotive FMCW Radar Systems

    Sohee LIM  Seongwook LEE  Jung-Hwan CHOI  Jungmin YOON  Seong-Cheol KIM  

     
    PAPER-Electromagnetic Compatibility(EMC)

      Pubricized:
    2018/12/11
      Vol:
    E102-B No:6
      Page(s):
    1198-1208

    This paper presents an interference suppression and signal restoration technique that can create the clean signals required by automotive frequency-modulated continuous wave radar systems. When a radar signal from another radar system interferes with own transmitted radar signal, the target detection performance is degraded. This is because the beat frequency corresponding to the target cannot be estimated owing to the increase in the noise floor. In this case, advanced weighted-envelope normalization or wavelet denoising can be used to mitigate the effect of the interference; however, these methods can also lead to the loss of the desired signal containing the range and velocity information of the target. Therefore, we propose a method based on an autoregressive model to restore a signal damaged by mutual interference. The method uses signals that are not influenced by the interference to restore the signal. In experiments conducted using two different automotive radar systems, our proposed method is demonstrated to effectively suppress the interference and restore the desired signal. As a result, the noise floor resulting from the mutual interference was lowered and the beat frequency corresponding to the desired target was accurately estimated.

  • Relationship of Channel and Surface Orientation to Mechanical and Electrical Stresses on N-Type FinFETs

    Wen-Teng CHANG  Shih-Wei LIN  Min-Cheng CHEN  Wen-Kuan YEH  

     
    PAPER

      Vol:
    E102-C No:6
      Page(s):
    429-434

    The electric properties of a field-effect transistor not only depend on gate surface sidewall but also on channel orientation when applying channel stain engineering. The change of the gate surface and channel orientation through the rotated FinFETs provides the capability to compare the orientation dependence of performance and reliability. This study characterized the <100> and <110> channels of FinFETs on the same wafer under tensile and compressive stresses by cutting the wafer into rectangular silicon pieces and evaluated their piezoresistance coefficients. The piezoresistance coefficients of the <100> and <110> silicon under tensile and compressive stresses were first evaluated based on the current setup. Tensile stresses enhance the mobilities of both <100> and <110> channels, whereas compressive stresses degrade them. Electrical characterization revealed that the threshold voltage variation and drive current degradation of the {100} surface were significantly higher than those of {110} for positive bias temperature instability and hot carrier injection with equal gate and drain voltage (VG=VD). By contrast, insignificant difference is noted for the subthreshold slope degradation. These findings imply that a higher ratio of bulk defect trapping is generated by gate voltage on the <100> surface than that on the <110> surface.

  • Low Temperature Formation of Pd2Si with TiN Encapsulating Layer and Its Application to Dopant Segregation Process

    Rengie Mark D. MAILIG  Shun-ichiro OHMI  

     
    PAPER

      Vol:
    E102-C No:6
      Page(s):
    447-452

    We investigated the low temperature formation of Pd2Si on Si(100) with TiN encapsulating layer formed at 500°C/1 min. Furthermore, the dopant segregation process was performed with ion dose of 1x1015 cm-2 for B+. The uniform Pd2Si was successfully formed with low sheet resistance of 10.4 Ω/sq. Meanwhile, the PtSi formed on Si(100) showed rough surface morphology if the silicidation temperature was 500°C. The estimated Schottky barrier height to hole of 0.20 eV (qφBp) was realized for n-Si(100).

  • Micro-Expression Recognition by Leveraging Color Space Information

    Minghao TANG  Yuan ZONG  Wenming ZHENG  Jisheng DAI  Jingang SHI  Peng SONG  

     
    LETTER-Image Recognition, Computer Vision

      Pubricized:
    2019/03/13
      Vol:
    E102-D No:6
      Page(s):
    1222-1226

    Micro-expression is one type of special facial expressions and usually occurs when people try to hide their true emotions. Therefore, recognizing micro-expressions has potential values in lots of applications, e.g., lie detection. In this letter, we focus on such a meaningful topic and investigate how to make full advantage of the color information provided by the micro-expression samples to deal with the micro-expression recognition (MER) problem. To this end, we propose a novel method called color space fusion learning (CSFL) model to fuse the spatiotemporal features extracted in different color space such that the fused spatiotemporal features would be better at describing micro-expressions. To verify the effectiveness of the proposed CSFL method, extensive MER experiments on a widely-used spatiotemporal micro-expression database SMIC is conducted. The experimental results show that the CSFL can significantly improve the performance of spatiotemporal features in coping with MER tasks.

  • Design of Integrated High Voltage Pulse Generator for Medical Ultrasound Transmitters

    Deng-Fong LU  Chin HSIA  Jian-Chiun LIOU  Yen-Chung HUANG  

     
    PAPER

      Pubricized:
    2018/12/28
      Vol:
    E102-B No:6
      Page(s):
    1121-1127

    Design of an equivalent slew-rate monolithic pulse generator using bipolar-CMOS-DMOS (BCD) technology for medical ultrasound transmitters is presented in this paper. The pulse generator employs a floating capacitive coupling level-shifter architecture to produce a high-voltage (Vpp=80V) output. The performance of equivalent slew-rate in the rising and falling edge is achieved by carefully choosing the value of coupling capacitors and the size of the final stage high-voltage MOSFETs of the pulse generator. The measured output pulses show the rising and falling time of 8.6nsec and 8.5nsec, respectively with second harmonic distortion down to -40dBc, indicating the designed pulse generator can be used for advanced ultrasonic harmonic imaging systems.

  • Burst-Mode CMOS Transimpedance Amplifier Based on a Regulated-Cascode Circuit with Gain-Mode Switching

    Takuya KOJIMA  Mamoru KUNIEDA  Makoto NAKAMURA  Daisuke ITO  Keiji KISHINE  

     
    LETTER-Circuit Theory

      Vol:
    E102-A No:6
      Page(s):
    845-848

    We present a novel burst-mode transimpedance amplifier (TIA) with a gain-mode switching. The proposed TIA utilizes a regulated-cascode (RGC) input stage for broadband characteristics. To expand a dynamic range, the RGC controls a linear operating range depending on transimpedance gains by adjusting bias conditions. This TIA is implemented using the 0.18μm-CMOS technology. The experimental results show that the proposed TIA IC has a good eye-opening and can respond quickly to the burst data.

  • A Unified Statistical Rating Method for Team Ball Games and Its Application to Predictions in the Olympic Games Open Access

    Eiji KONAKA  

     
    PAPER-Artificial Intelligence, Data Mining

      Pubricized:
    2019/03/11
      Vol:
    E102-D No:6
      Page(s):
    1145-1153

    This study tries to construct an accurate ranking method for five team ball games at the Olympic Games. First, the study uses a statistical rating method for team ball games. A single parameter, called a rating, shows the strength and skill of each team. We assume that the difference between the rating values explains the scoring ratio in a match based on a logistic regression model. The rating values are estimated from the scores of major international competitions that are held before the Rio Olympic Games. The predictions at the Rio Olympic Games demonstrate that the proposed method can more accurately predict the match results than the official world rankings or world ranking points. The proposed method enabled 262 correct predictions out of 370 matches, whereas using the official world rankings resulted in only 238 correct predictions. This result shows a significant difference between the two criteria.

  • A Robust Indoor/Outdoor Detection Method Based on Spatial and Temporal Features of Sparse GPS Measured Positions

    Sae IWATA  Kazuaki ISHIKAWA  Toshinori TAKAYAMA  Masao YANAGISAWA  Nozomu TOGAWA  

     
    LETTER-Intelligent Transport System

      Vol:
    E102-A No:6
      Page(s):
    860-865

    Cell phones with GPS function as well as GPS loggers are widely used and we can easily obtain users' geographic information. Now classifying the measured GPS positions into indoor/outdoor positions is one of the major challenges. In this letter, we propose a robust indoor/outdoor detection method based on sparse GPS measured positions utilizing machine learning. Given a set of clusters of measured positions whose center position shows the user's estimated stayed position, we calculate the feature values composed of: positioning accuracy, spatial features, and temporal feature of measured positions included in every cluster. Then a random forest classifier learns these feature values of the known data set. Finally, we classify the unknown clusters of measured positions into indoor/outdoor clusters using the learned random forest classifier. The experiments demonstrate that our proposed method realizes the maximum F1 measure of 1.000, which classifies measured positions into indoor/outdoor ones with almost no errors.

  • Characterization of Electron Field Emission from Multiple-Stacking Si-Based Quantum Dots

    Yuto FUTAMURA  Katsunori MAKIHARA  Akio OHTA  Mitsuhisa IKEDA  Seiichi MIYAZAKI  

     
    PAPER

      Vol:
    E102-C No:6
      Page(s):
    458-461

    We have fabricated multiple-stacked Si quantum dots (QDs) with and without Ge core embedded in a SiO2 network on n-Si(100) and studied their field electron emission characteristics under DC bias application. For the case of pure Si-QD stacks with different dot-stack numbers, the average electric field in dot-stacked structures at which electron emission current appeared reached minimum value at a stack number of 11. This can be attributed to optimization of the electron emission due to enhanced electric field concentration in the upper layers of the dot-stacked structures and reduction of the electron injection current from the n-Si substrate, with an increased stack number. We also found that, by introducing Ge core into Si-QDs, the average electric field for the electron emission can be reduced below that from pure Si-QDs-stacked structures. This result implies that the electric field is more concentrated in the upper Si-QDs with Ge core layers due to deep potential well for holes in the Ge core.

  • Characterization and Modeling of a GaAsSb/InGaAs Backward Diode on the Basis of S-Parameter Measurement Up to 67 GHz

    Shinpei YAMASHITA  Michihiko SUHARA  Kenichi KAWAGUCHI  Tsuyoshi TAKAHASHI  Masaru SATO  Naoya OKAMOTO  Kiyoto ASAKAWA  

     
    BRIEF PAPER

      Vol:
    E102-C No:6
      Page(s):
    462-465

    We fabricate and characterize a GaAsSb/InGaAs backward diode (BWD) toward a realization of high sensitivity zero bias microwave rectification for RF wave energy harvest. Lattice-matched p-GaAsSb/n-InGaAs BWDs were fabricated and their current-voltage (I-V) characteristics and S-parameters up to 67 GHz were measured with respect to several sorts of mesa diameters in μm order. Our theoretical model and analysis are well fitted to the measured I-Vs on the basis of WKB approximation of the transmittance. It is confirmed that the interband tunneling due to the heterojunction is a dominant transport mechanism to exhibit the nonlinear I-V around zero bias regime unlike recombination or diffusion current components on p-n junction contribute in large current regime. An equivalent circuit model of the BWD is clarified by confirming theoretical fitting for frequency dependent admittance up to 67 GHz. From the circuit model, eliminating the parasitic inductance component, the frequency dependence of voltage sensitivity of the BWD rectifier is derived with respect to several size of mesa diameter. It quantitatively suggests an effectiveness of mesa size reduction to enhance the intrinsic matched voltage sensitivity with increasing junction resistance and keeping the magnitude of I-V curvature coefficient.

  • In situ Observation of Immobilization of Cytochrome c into Hydrophobic DNA Nano-Film

    Naoki MATSUDA  Hirotaka OKABE  Ayako OMURA  Miki NAKANO  Koji MIYAKE  Toshihiko NAGAMURA  Hideki KAWAI  

     
    BRIEF PAPER

      Vol:
    E102-C No:6
      Page(s):
    471-474

    Hydrophobic DNA (H-DNA) nano-film was formed as the surface modifier on a thin glass plate working as a slab optical waveguide (SOWF). Cytochrom c (cytc) molecules were immobilized from aqueous solution with direct contacting to the H-DNA nano-film for 30 minutes. From SOWG absorption spectral changes during automated solution exchange (SE) processes, it was found that about 28.1% of cytc molecules was immobilized in the H-DNA nano-film with keeping their reduction functionality by reducing reagent.

  • A Lightweight System to Achieve Proactive Risk Management for Household ASIC-Resistant Cryptocurrency Mining

    Guoqi LI  

     
    LETTER-Dependable Computing

      Pubricized:
    2019/03/20
      Vol:
    E102-D No:6
      Page(s):
    1215-1217

    Nowadays, many household computers are used to mine ASIC-resistant cryptocurrency, which brings serious safety risks. In this letter, a light weight system is put forward to achieve proactive risk management for the kind of mining. Based on the system requirement analysis, a brief system design is presented and furthermore, key techniques to implement it with open source hardware and software are given to show its feasibility.

  • An Effective Feature Selection Scheme for Android ICC-Based Malware Detection Using the Gap of the Appearance Ratio

    Kyohei OSUGE  Hiroya KATO  Shuichiro HARUTA  Iwao SASASE  

     
    PAPER-Dependable Computing

      Pubricized:
    2019/03/12
      Vol:
    E102-D No:6
      Page(s):
    1136-1144

    Android malwares are rapidly becoming a potential threat to users. Among several Android malware detection schemes, the scheme using Inter-Component Communication (ICC) is gathering attention. That scheme extracts numerous ICC-related features to detect malwares by machine learning. In order to mitigate the degradation of detection performance caused by redundant features, Correlation-based Feature Selection (CFS) is applied to feature before machine learning. CFS selects useful features for detection in accordance with the theory that a good feature subset has little correlation with mutual features. However, CFS may remove useful ICC-related features because of strong correlation between them. In this paper, we propose an effective feature selection scheme for Android ICC-based malware detection using the gap of the appearance ratio. We argue that the features frequently appearing in either benign apps or malwares are useful for malware detection, even if they are strongly correlated with each other. To select useful features based on our argument, we introduce the proportion of the appearance ratio of a feature between benign apps and malwares. Since the proportion can represent whether a feature frequently appears in either benign apps or malwares, this metric is useful for feature selection based on our argument. Unfortunately, the proportion is ineffective when a feature appears only once in all apps. Thus, we also introduce the difference of the appearance ratio of a feature between benign apps and malwares. Since the difference simply represents the gap of the appearance ratio, we can select useful features by using this metric when such a situation occurs. By computer simulation with real dataset, we demonstrate our scheme improves detection accuracy by selecting the useful features discarded in the previous scheme.

4041-4060hit(42807hit)