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5761-5780hit(20498hit)

  • On Detecting Delay Faults Using Time-to-Digital Converter Embedded in Boundary Scan

    Hiroyuki YOTSUYANAGI  Hiroyuki MAKIMOTO  Takanobu NIMIYA  Masaki HASHIZUME  

     
    PAPER

      Vol:
    E96-D No:9
      Page(s):
    1986-1993

    This paper proposes a method for testing delay faults using a boundary scan circuit in which a time-to-digital converter (TDC) is embedded. The incoming transitions from the other cores or chips are captured at the boundary scan circuit. The TDC circuit is modified to set the initial value for a delay line through which the transition is propagated. The condition for measuring timing slacks of two or more paths is also investigated since the overlap of the signals may occur in the delay line of the TDC in our boundary scan circuit. An experimental IC with the TDC and boundary scan is fabricated and is measured to estimate the delay of some paths measured by the TDC embedded in boundary scan cells. The simulation results for a benchmark circuit with the boundary scan circuit are also shown for the case that timing slacks of multiple paths can be observed even if the signals overlap in the TDC.

  • Generation of Controllable Heating Patterns for Interstitial Microwave Hyperthermia by Coaxial-Dipole Antennas

    Kazuyuki SAITO  Masaharu TAKAHASHI  Koichi ITO  

     
    PAPER-Electromagnetic Theory

      Vol:
    E96-C No:9
      Page(s):
    1178-1183

    Hyperthermia is one of the modalities for cancer treatment, utilizing the difference of thermal sensitivity between tumor and normal tissue. Interstitial microwave hyperthermia is one of the heating schemes and it is applied to a localized tumor. In the treatments, heating pattern control around antennas are important, especially for the treatment in and around critical organs. This paper introduces a coaxial-dipole antenna, which is one of the thin microwave antennas and can generate a controllable heating pattern. Moreover, generations of an arbitrary shape heating patterns by an array applicator composed of four coaxial-dipole antennas are described.

  • Improved Transmit and Detection Scheme for Hybrid STBC in MIMO-OFDM Systems

    Eui-Young LEE  Hyoung-Kyu SONG  

     
    LETTER-Information Network

      Vol:
    E96-D No:9
      Page(s):
    2131-2134

    The conventional hybrid STBC schemes can achieve less BER performance for STBC detection schemes than conventional STBC schemes since SM symbols interfere with STBC symbols. Therefore, this letter proposes the improved scheme for hybrid STBC systems. STBC and SM schemes are combined for the hybrid space-time block code system. Our approach effectively obtains both diversity gain and spectral efficiency gain. The proposed scheme offers improved BER performance since it uses iterative detection. Moreover, it increases the data rate effectively with a little performance loss.

  • On the Cross-Correlation of a p-Ary m-Sequence and Its Decimated Sequences by d=(pn+1)/(pk+1)+(pn-1)/2

    Sung-Tai CHOI  Ji-Youp KIM  Jong-Seon NO  

     
    PAPER-Fundamental Theories for Communications

      Vol:
    E96-B No:9
      Page(s):
    2190-2197

    In this paper, for an odd prime p such that p≡3 mod 4, odd n, and d=(pn+1)/(pk+1)+(pn-1)/2 with k|n, the value distribution of the exponential sum S(a,b) is calculated as a and b run through $mathbb{F}_{p^n}$. The sequence family $mathcal{G}$ in which each sequence has the period of N=pn-1 is also constructed. The family size of $mathcal{G}$ is pn and the correlation magnitude is roughly upper bounded by $(p^k+1)sqrt{N}/2$. The weight distribution of the relevant cyclic code C over $mathbb{F}_p$ with the length N and the dimension ${ m dim}_{mathbb{F}_p}mathcal{C}=2n$ is also derived.

  • Detection of the Number of Signals with Fewer Sensors than Sources

    Masashi TSUJI  Kenta UMEBAYASHI  Yasuo SUZUKI  

     
    PAPER-Antennas and Propagation

      Vol:
    E96-B No:9
      Page(s):
    2235-2243

    In this paper, a method is introduced that can detect the number of incident signals (NIS) even there are fewer antennas than NIS. Previous works on NIS detection methods assumed that the number of antennas always exceeded NIS. In the DOA estimation field, the DOA estimation is possible, even if NIS exceeds the number of antennas, by extending the degrees of freedom of array (DOFA) using a modified array configuration, such as a nested array (NA). The information of NIS is required in advance to accurately estimate DOA, however, it has not been investigated deeply when NIS is larger than the number of antennas. In this paper, a NIS detection method based on the DOFA extending process using NA is proposed. One of the important issues in NIS detection is the detection metric. As one of the simple metrics, the ratio of adjacent eigenvalues (RAE) has been used. However, the direct application of RAE may not achieve adequate NIS detection performance. Therefore, we propose a metric based on the modified ratio of adjacent eigenvalues (MRAE) avoids the issue of RAE. Numerical results show that the metric based on MRAE can achieve proper NIS detection performance even if NIS is larger than the number of antennas.

  • Practically Feasible Design for Convolutional Network Code

    Songtao LIANG  Haibin KAN  

     
    LETTER-Coding Theory

      Vol:
    E96-A No:9
      Page(s):
    1895-1900

    This paper introduces two schemes to put the decoding of the convolutional network code (CNC) into practice, which are named the Intermittent Packet Transmission Scheme (IPTS) and the Redundancy Packet Transmission Scheme (RPTS). According to the decoding formula of the sink nodes, we can see that, at the time k+δ in order to decode the source packet generated at time k, the sink node should know all the source packets generated before k-1. This is impractical. The two schemes we devised make it unnecessary. A construction algorithm is also given about the RPTS networks. For the two schemes, we analyze the strengths and weaknesses and point out their implemented condition.

  • Scalable and Adaptive Graph Querying with MapReduce

    Song-Hyon KIM  Kyong-Ha LEE  Inchul SONG  Hyebong CHOI  Yoon-Joon LEE  

     
    LETTER-Fundamentals of Information Systems

      Vol:
    E96-D No:9
      Page(s):
    2126-2130

    We address the problem of processing graph pattern matching queries over a massive set of data graphs in this letter. As the number of data graphs is growing rapidly, it is often hard to process such queries with serial algorithms in a timely manner. We propose a distributed graph querying algorithm, which employs feature-based comparison and a filter-and-verify scheme working on the MapReduce framework. Moreover, we devise an efficient scheme that adaptively tunes a proper feature size at runtime by sampling data graphs. With various experiments, we show that the proposed method outperforms conventional algorithms in terms of scalability and efficiency.

  • Techniques of Electromagnetic Compatibility Model Synthesis Based on On-Site Measurement Data

    Gaosheng LI  Peiguo LIU  Yan LI  Zhonghao LU  Dongming ZHOU  Yujian QIN  

     
    PAPER-Electromagnetic Compatibility(EMC)

      Vol:
    E96-B No:9
      Page(s):
    2251-2260

    Regular on-site testing is an elementary means to obtain real-time data and state of Electromagnetic Compatibility (EMC) of electronics systems. Nowadays, there is a lot of measured EMC data while the application of the data is insufficient. So we put forward the concept of EMC model synthesis. To carry out EMC data mining with measured electromagnetic data, we can build or modify models and synthesize variation rules of electromagnetic parameters of equipment and EMC performance of systems and platforms, then realize the information synthesis and state prediction. The concept of EMC reliability is brought forward together with the definition and description of parameters such as invalidation rate and EMC lifetime. We studied the application of statistical algorithms and Artificial Neural Network (ANN) in model synthesis. Operating flows and simulation results as well as measured data are presented. Relative research can support special measurement, active management and predictive maintenance and replenishment in the area of EMC.

  • Advanced Millimeter-Wave Radar System to Detect Pedestrians and Vehicles by Using Coded Pulse Compression and Adaptive Array

    Takaaki KISHIGAMI  Tadashi MORITA  Hirohito MUKAI  Maiko OTANI  Yoichi NAKAGAWA  

     
    PAPER-Sensing

      Vol:
    E96-B No:9
      Page(s):
    2313-2322

    This paper reports an advanced millimeter-wave radar system to enable detection of vehicles and pedestrians in wide areas around the radar site such as an intersection. We focus on a pulse coding scheme using complementary codes to reduce range sidelobe for discriminating vehicles from pedestrians with high accuracy. In order to suppress sidelobe increase created by RF circuit imperfections, a π/2 shift pulse modulation method with a complementary code pair cycle is presented. Moreover, in order to improve the angular resolution, a high-resolution direction of arrival estimation involving Tx beam scanning is presented. Experiments on a prototype confirm its range sidelobe suppression exceeds 40dB and its angular resolution is 5° for two human's separation at the distance of about 10m in an anechoic chamber. In a trial intersection experiment, a pedestrian detection rate of 95% was achieved at the false alarm rate of 10% in the range from 5m to 40m. The results prove the system's feasibility for future automotive safety application.

  • Arc Length of Break Arcs Magnetically Blown-Out at Arc Extinction in a DC450V/10A Resistive Circuit

    Hitoshi ONO  Junya SEKIKAWA  

     
    PAPER

      Vol:
    E96-C No:9
      Page(s):
    1132-1137

    Silver electrical contacts are separated at a constant speed and break arcs are generated in a DC300V-450V/10A resistive circuit. The transverse magnetic field formed by a permanent magnet is applied to the break arcs. Alumina pipes are placed around the contacts to restrict the motion of break arcs. The dependences of the arc lengthening time and arc length just before arc extinction L on the strength of the magnetic field and supply voltage are investigated. It was found that the arc lengthening time increases with increasing supply voltage E and tends to decrease when the magnetic flux density Bx is increased. The arc length just before arc extinction L increases with increasing E and decreasing Bx. It also increases linearly with increasing arc lengthening time tm when no reignitions occur.

  • Reference-Independent Prosody Evaluation Based on Prosodic Unit Segmentation

    Sixuan ZHAO  Soo Ngee KOH  Kang Kwong LUKE  

     
    LETTER-Educational Technology

      Vol:
    E96-D No:9
      Page(s):
    2143-2146

    This paper proposes prosodic unit based segmentation for prosody evaluation by using pitch accent detection and forced alignment techniques. Support Vector Machine (SVM) is used to evaluate the prosody of non-native English speakers without reference utterances. Experimental results show the superiority of prosodic unit segmentation over word segmentation in terms of classification accuracy and dimension of the feature vectors used by SVM.

  • Degrees of Freedom of the MIMO K-way Relay Channel with Fractional Signal Space Alignment

    Bofeng YUAN  Xuewen LIAO  Xinmin LUO  

     
    PAPER-Wireless Communication Technologies

      Vol:
    E96-B No:9
      Page(s):
    2281-2292

    The multiple-input-multiple-output (MIMO) Gaussian wireless network with K users and an intermediate relay is investigated. In this network, each user with available local channel state information (CSI) intends to convey a multicast message to all other users while receiving all messages from other users via the relay. This model is termed the MIMO K-way relay channel with distributed CSI. For this channel, the sum capacity is shown as MK/(K-1)log(SNR)+o(SNR) where each user and the relay is equipped with M antennas. Achievability is based on the signal space alignment strategy with a K-1 time slot extension. A most general case is then considered, in which each user intends to recover all messages required within T time slots. We provide an improved scheme called fractional signal space alignment which achieves MK/(K-1) degrees of freedom in the general case and the feasibility condition is also explored.

  • A Range-Extended and Area-Efficient Time-to-Digital Converter Utilizing Ring-Tapped Delay Line

    Xin-Gang WANG  Fei WANG  Rui JIA  Rui CHEN  Tian ZHI  Hai-Gang YANG  

     
    PAPER-Electronic Circuits

      Vol:
    E96-C No:9
      Page(s):
    1184-1194

    This paper proposes a coarse-fine Time-to-Digital Converter (TDC), based on a Ring-Tapped Delay Line (RTDL). The TDC achieves the picosecond's level timing resolution and microsecond's level dynamic range at low cost. The TDC is composed of two coarse time measurement blocks, a time residue generator, and a fine time measurement block. In the coarse blocks, RTDL is constructed by redesigning the conventional Tapped Delay Line (TDL) in a ring structure. A 12-bit counter is employed in one of the two coarse blocks to count the cycle times of the signal traveling in the RTDL. In this way, the input range is increased up to 20.3µs without use of an external reference clock. Besides, the setup time of soft-edged D-flip-flops (SDFFs) adopted in RTDL is set to zero. The adjustable time residue generator picks up the time residue of the coarse block and propagates the residue to the fine block. In the fine block, we use a Vernier Ring Oscillator (VRO) with MOS capacitors to achieve a scalable timing resolution of 11.8ps (1 LSB). Experimental results show that the measured characteristic curve has high-level linearity; the measured DNL and INL are within ± 0.6 LSB and ± 1.5 LSB, respectively. When stimulated by constant interval input, the standard deviation of the system is below 0.35 LSB. The dead time of the proposed TDC is less than 650ps. When operating at 5 MSPS at 3.3V power supply, the power consumption of the chip is 21.5mW. Owing to the use of RTDL and VRO structures, the chip core area is only 0.35mm × 0.28mm in a 0.35µm CMOS process.

  • Positions of Arc Spots of Break Arcs Occurring between Carbon Contacts When Transverse Magnetic Field Is Applied

    Tomoaki SASAKI  Junya SEKIKAWA  

     
    BRIEF PAPER

      Vol:
    E96-C No:9
      Page(s):
    1138-1141

    Break arcs are generated between carbon contacts in a DC48V and 10A resistive circuit. The external transverse magnetic field formed by a permanent magnet is applied to break arcs. The position of the cathode spot region of the break arcs occurring between carbon contacts is investigated and the following results are shown. The cathode and anode spot regions moves together with and without the magnetic field. The position of the break arcs just before arc extinction tends to shift upward with increase of the magnetic flux density of the transverse magnetic field.

  • Experimental and Calculated Cyclic Elasto-Plastic Deformations of Copper-Based Spring Materials

    Yasuhiro HATTORI  Kingo FURUKAWA  Fusahito YOSHIDA  

     
    PAPER

      Vol:
    E96-C No:9
      Page(s):
    1157-1164

    The reliability of a connector depends on the contact force generated by the spring in the terminal of a connector. The springs are commonly formed by stamping from a strip of spring material. Therefore, the prediction of the force — displacement relation by the finite element (FE) method is very important for the design of terminals. For simulation, an accurate model of stress-strain (s-s) responses of the materials is required. When the materials are deformed in the forward and then the reverse directions, almost all spring materials show different s-s responses between the two directions, due to the Bauschinger effect. This phenomenon makes simulation difficult because the s-s response depends on the prior deformation of the material. Hence, the measurement of the s-s response is the elementary process, by cyclic tension and compression testing in which materials deform elastically and plastically. Then, the s-s responses should be described accurately by mathematical models for FE simulation. In this paper, the authors compare the experimental s-s responses of copper-based materials with conventional mathematical models and the Yoshida-Uemori model, which is a constitutive model having high capability of describing the elastic and plastic behavior of cyclic deformation. The calculated s-s responses only by Yoshida-Uemori model were in very good agreement with the corresponding experimental results. Therefore, the use of this model for FE simulation would be recommended for a more accurate prediction of force-displacement relation of the spring.

  • Development of RFID Antenna for Detection of Urination

    Hiromasa NAKAJIMA  Masaharu TAKAHASHI  Kazuyuki SAITO  Koichi ITO  

     
    PAPER-Antennas and Propagation

      Vol:
    E96-B No:9
      Page(s):
    2244-2250

    This paper introduces a radio frequency identification (RFID) tag for urination detection. The proposed tag is embedded into paper diapers in order to detect the patient's urination immediately. For this tag, we designed an RFID tag antenna at 950MHz, which matches the impedance of the associated integrated circuit (IC) chip. In addition, we calculate the antenna characteristics and measure the reflection coefficient (S11) and radiation pattern of the antenna. The results show that this system can be used to detect urination.

  • Noncontact PIM Measurement Method Using Partial Impedance-Matching Method

    Kensuke SAITO  Daijiro ISHIBASHI  Nobuhiro KUGA  

     
    BRIEF PAPER

      Vol:
    E96-C No:9
      Page(s):
    1151-1154

    In this letter, we propose a partial impedance-matching method using a two-strip resonator for noncontact Passive Intermodulation (PIM) measurements using a coaxial tube. It is shown that the strip closer to the inner tube of the coaxial tube is dominant in the observed PIM characteristics while both strips are excited equally. The ideal efficiency of power to each strip is 50%, which is a significant improvement in comparison with conventional methods.

  • Low-Overhead Fault-Secure Parallel Prefix Adder by Carry-Bit Duplication

    Nobutaka KITO  Naofumi TAKAGI  

     
    PAPER

      Vol:
    E96-D No:9
      Page(s):
    1962-1970

    We propose a low-overhead fault-secure parallel prefix adder. We duplicate carry bits for checking purposes. Only one half of normal carry bits are compared with the corresponding redundant carry bits, and the hardware overhead of the adder is low. For concurrent error detection, we also predict the parity of the result. The adder uses parity-based error detection and it has high compatibility with systems that have parity-based error detection. We can implement various fault-secure parallel prefix adders such as Sklansky adder, Brent-Kung adder, Han-Carlson adder, and Kogge-Stone adder. The area overhead of the proposed adder is about 15% lower than that of a previously proposed adder that compares all the carry bits.

  • Analyzing Deterioration in Optical Performance of Fiber Connections with Refractive Index Matching Material Using Incorrectly Cleaved Fiber Ends

    Mitsuru KIHARA  Yuichi YAJIMA  Hiroshi WATANABE  

     
    PAPER-Optical Fiber for Communications

      Vol:
    E96-B No:9
      Page(s):
    2206-2212

    We experimentally investigate and analyze faults in optical fiber connections with refractive index matching material that have incorrectly cleaved fiber ends. We explain that incorrectly cleaved fiber ends, which are not ideal because they are uneven and not perpendicular to the fiber axis, are caused by defective optical fiber cleavers. We discover that the optical performance of field installable connections using incorrectly cleaved fiber ends might change greatly. We also infer that the significant change in insertion and return losses might be attributed to partially air-filled gaps by using scatter diagrams of measured insertion and return losses. Our experiment results reveal that the optical performance might deteriorate to more than 40dB in terms of insertion loss and less than 30dB in terms of return loss.

  • Simplification of Service Functions Resulting from Growth in Scale of Networks

    Nagao OGINO  Hideyuki KOTO  Hajime NAKAMURA  Shigehiro ANO  

     
    PAPER-Network

      Vol:
    E96-B No:9
      Page(s):
    2224-2234

    As a network evolves following initial deployment, its service functions remain diversified through the openness of the network functions. This indicates that appropriate simplification of the service functions is essential if the evolving network is to achieve the required scalability of service processing and service management. While the screening of service functions is basically performed by network users and the market, several service functions will be automatically simplified based on the growth of the evolving network. This paper verifies the simplification of service functions resulting from the evolution of the network itself. First, the principles that serve as the basis for simplifying the service functions are explained using several practical examples. Next, a simulation model is proposed to verify the simplification of service functions in terms of the priority control function for path routing and load balancing among multiple paths. From the results of the simulation, this study clarifies that the anticipated simplification of service functions is actually realizable and the service performance requirements can be reduced as the network evolves after deployment. When the simplification of service functions can improve network quality, it accelerates the evolution of the network and increases the operator's revenue.

5761-5780hit(20498hit)