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[Keyword] CTI(8214hit)

2721-2740hit(8214hit)

  • New POI Construction with Street-Level Imagery

    Chillo GA  Jeongho LEE  Won Hee LEE  Kiyun YU  

     
    LETTER-Data Engineering, Web Information Systems

      Vol:
    E96-D No:1
      Page(s):
    129-133

    We present a novel point of interest (POI) construction approach based on street-level imagery (SLI) such as Google StreetView. Our method consists of: (1) the creation of a conflation map between an SLI trace and a vector map; (2) the detection of the corresponding buildings between the SLI scene and the conflation map; and (3) POI name extraction from a signboard in the SLI scene by user-interactive text recognition. Finally, a POI is generated through a combination of the POI name and attributes of the building object on a vector map. The proposed method showed recall of 92.99% and precision of 97.10% for real-world POIs.

  • A Heuristic Algorithm for Reconstructing a Packet Filter with Dependent Rules

    Ken TANAKA  Kenji MIKAWA  Manabu HIKIN  

     
    PAPER-Network Management/Operation

      Vol:
    E96-B No:1
      Page(s):
    155-162

    Network devices, such as routers or L3 switches, have a feature called packet-filtering for network security. They determine whether or not to pass arriving packets by applying filtering rules to them. If the number of comparisons of packets with rules increases, the time required for a determination will increase, which will result in greater communication delay. Various algorithms for optimizing filtering tables to minimize the load of packet filtering, which directly impacts the communication delay, have been proposed. In this paper, first we introduce an adaptive packet filter based on an algorithm that reconstructs the filtering table according to the frequency distribution of arrival packets. Next, we propose a new reconstruction algorithm based on grouping of dependent rules. Grouping dependent rules makes it possible to sort the rules in the table by the frequency of matching. Finally, we show the effectiveness of our algorithm by comparing it against previously reported algorithms.

  • Numerical Methods for Composite Dielectric Gratings Embedded with Conducting Strips Using Scattering Factors

    Hideaki WAKABAYASHI  Masamitsu ASAI  Keiji MATSUMOTO  Jiro YAMAKITA  

     
    PAPER-Periodic Structures

      Vol:
    E96-C No:1
      Page(s):
    19-27

    We propose a new analytical method for a composite dielectric grating embedded with conducting strips using scattering factors in the shadow theory. The scattering factor in the shadow theory plays an important role instead of the conventional diffraction amplitude. By specifying the relation between scattering factors and spectral-domain Green's functions, we derive expressions of the Green's functions directly for unit surface electric and magnetic current densities, and apply the spectral Galerkin method to our formulation. From some numerical results, we show that the expressions of the Green's functions are valid, and analyze scattering characteristics by composite gratings.

  • Low-Temperature Thermionic Emission from Diamond Micropowders with Sharp Edges

    Tomomi YOSHIMOTO  Tatsuo IWATA  

     
    BRIEF PAPER-Semiconductor Materials and Devices

      Vol:
    E96-C No:1
      Page(s):
    132-134

    The thermionic emission properties of diamond micropowders were investigated. The thermionic emission current was observed at a low temperature of 702 K, and a work function of approximately 1.97 eV was obtained. Band bending in diamond micropowders induced by an applied electric field had a considerable influence on decreasing the work function.

  • Complexity Reduction of Iterative MMSE-ML Signal Detection for MIMO SC-FDMA Systems

    Jaeyoung PARK  Jaekwon KIM  

     
    LETTER-Wireless Communication Technologies

      Vol:
    E96-B No:1
      Page(s):
    344-347

    In this letter, we reduce the computational complexity of the conventional iterative MMSE-ML signal detection method for multiple input multiple output (MIMO) single carrier FDMA (SC-FDMA) systems, without compromising the error performance. Complexity analysis confirms the efficacy of the proposed modification.

  • Complexity Reduced Lattice-Reduction-Aided MIMO Receiver with Virtual Channel Detection

    Shogo YOSHIKAWA  Satoshi DENNO  Masahiro MORIKURA  

     
    PAPER-Wireless Communication Technologies

      Vol:
    E96-B No:1
      Page(s):
    263-270

    This paper proposes a lattice-reduction-aided MIMO-OFDM receiver with virtual channels; the receiver enables an increase in the downlink transmission speed for a user where the number of transmit antennas is considerably higher than that of the receive antennas. However, the receiver has a higher computational complexity than conventional lattice-reduction-aided MIMO receivers. Accordingly, we also propose novel techniques to reduce the computational complexity for the lattice-reduction-aided MIMO receivers with virtual channels. The proposed MIMO receiver achieves superior performance in 102 MIMO-OFDM systems. Furthermore, the proposed techniques are shown to reduce the computational complexity to approximately 40% of the original configuration in the 102 MIMO-OFDM systems.

  • Meet-in-the-Middle Preimage Attacks on AES Hashing Modes and an Application to Whirlpool

    Yu SASAKI  

     
    PAPER-Hash Functions

      Vol:
    E96-A No:1
      Page(s):
    121-130

    We study the security of AES in the open-key setting by showing an analysis on hash function modes instantiating AES including Davies-Meyer, Matyas-Meyer-Oseas, and Miyaguchi-Preneel modes. In particular, we propose preimage attacks on these constructions, while most of previous work focused their attention on collision attacks or distinguishers using non-ideal differential properties. This research is based on the motivation that we should evaluate classical and important security notions for hash functions and avoid complicated attack models that seem to have little relevance in practice. We apply a recently developed meet-in-the-middle preimage approach. As a result, we obtain a preimage attack on 7 rounds of Davies-Meyer AES and a second preimage attack on 7 rounds of Matyas-Meyer-Oseas and Miyaguchi-Preneel AES. Considering that the previous best collision attack only can work up to 6 rounds, the number of attacked rounds reaches the best in terms of the classical security notions. In our attacks, the key is regarded as a known constant, and the attacks thus can work for any key length in common.

  • Scattering of a Scalar Plane Wave by a Sinusoidal Edge

    Tomoya IZUTSU  Akira KOMIYAMA  

     
    BRIEF PAPER-Scattering and Diffraction

      Vol:
    E96-C No:1
      Page(s):
    55-59

    We deal with the scattering of a scalar plane wave by a half plane with a sinusoidally deformed edge from a straight edge by a physical optics approximation. The normal incidence of a plane wave to an edge is assumed. A contribution of an edge to the field integral is asymptotically evaluated and the basic properties of the scattering caused by the edge deformation is clarified. The scattering pattern has peaks at specific scattering angles, which agree with diffraction angles calculated by the well-known grating formula for normal incidence. Some numerical examples are shown and it is shown that the results are in good agreement with the results obtained by the GTD method for low angle incidence.

  • Implementation of Reflection on Curved Surfaces and Physical Optics in Ray Tracing for Tunnel Propagation

    Yukiko KISHIKI  Jun-ichi TAKADA  Gilbert Siy CHING  Hajime TAKAO  Yoshihiro SUGIHARA  Shigeaki MATSUNAGA  Fumiya UESAKA  

     
    PAPER-Radiowave Propagation

      Vol:
    E96-C No:1
      Page(s):
    42-50

    For the modeling of multipath propagation in every wireless systems, the ray tracing method has been widely studied. However, large errors may result due to the approximation of geometrical optics in curved surfaces. This paper therefore focused on the curved surfaces and edges, which are difficult to handle in ray tracing. Examples of curved surfaces can be found in arched cross-section tunnels which are common in highway networks of mountainous areas. The traditional ray tracing method of dividing the curved surface into smaller flat plates is not so accurate as the size of smaller plates may not satisfy the geometrical optics assumption, and the reflection point which satisfies Fermat's principle may not exist. In this work, a new ray tracing method is proposed with 2 contributions. The first one is the implementation of the reflection coefficient for curved surfaces in ray tracing. The second is applying the physical optics method on the caustics region. To evaluate these methods, path gain simulation results for an arched cross-section model are compared with measurements made inside an arched tunnel. To further improve the simulation results, the effect of rough surface is introduced, and the results are again compared with measurement.

  • On the Construction of Boolean Functions with Optimal Algebraic Immunity Based on Factorization of Numbers of Variables

    Huajin CHEN  Wenfeng Qi  Chuangui MA  

     
    PAPER-Symmetric Key Cryptography

      Vol:
    E96-A No:1
      Page(s):
    15-24

    In this paper, we put forward a new method to construct n-variable Boolean functions with optimal algebraic immunity based on the factorization of n. Computer investigations for small values of n indicate that a class of Boolean functions constructed by the new method has a very good nonlinearity and also a good behavior against fast algebraic attacks.

  • Efficient (Hierarchical) Inner-Product Encryption Tightly Reduced from the Decisional Linear Assumption

    Tatsuaki OKAMOTO  Katsuyuki TAKASHIMA  

     
    PAPER-Public Key Based Protocols

      Vol:
    E96-A No:1
      Page(s):
    42-52

    This paper proposes an inner-product encryption (IPE) scheme, which achieves selectively fully-attribute-hiding security in the standard model almost tightly reduced from the decisional linear (DLIN) assumption, and whose ciphertext is almost the shortest among the existing (weakly/fully) attribute-hiding IPE schemes, i.e., it consists of n+4 elements of G and 1 element of GT for a prime-order symmetric bilinear group (G, GT), where n is the dimension of attribute/predicate vectors. We also present a variant of the proposed IPE scheme that enjoys shorter public and secret keys with preserving the security. A hierarchical IPE (HIPE) scheme can be realized that has short ciphertexts and selectively fully-attribute-hiding security almost tightly reduced from the DLIN assumption.

  • Channel Condition Number Based Switching Detection Scheme in MIMO-OFDM System

    Jang-Kyun AHN  Seung-Jun YU  Hyoung-Kyu SONG  

     
    LETTER-Communication Theory and Signals

      Vol:
    E96-A No:1
      Page(s):
    387-390

    In this letter, we propose a innovative threshold receiver for MIMO-OFDM system. The proposed scheme calculates the channel condition number and then selects either combined V algorithm and CLLL or combined QRD-M and DFE detection scheme according to channel information. The complexity of the proposed scheme is about 33.3% of the QRD-M for 44 MIMO-OFDM system.

  • Region Diversity Based Saliency Density Maximization for Salient Object Detection

    Xin HE  Huiyun JING  Qi HAN  Xiamu NIU  

     
    LETTER-Image

      Vol:
    E96-A No:1
      Page(s):
    394-397

    Existing salient object detection methods either simply use a threshold to detect desired salient objects from saliency map or search the most promising rectangular window covering salient objects on the saliency map. There are two problems in the existing methods: 1) The performance of threshold-dependent methods depends on a threshold selection and it is difficult to select an appropriate threshold value. 2) The rectangular window not only covers the salient object but also contains background pixels, which leads to imprecise salient object detection. For solving these problems, a novel saliency threshold-free method for detecting the salient object with a well-defined boundary is proposed in this paper. We propose a novel window search algorithm to locate a rectangular window on our saliency map, which contains as many as possible pixels belonging the salient object and as few as possible background pixels. Once the window is determined, GrabCut is applied to extract salient object with a well-defined boundary. Compared with existing methods, our approach doesn't need any threshold to binarize the saliency map and additional operations. Experimental results show that our approach outperforms 4 state-of-the-art salient object detection methods, yielding higher precision and better F-Measure.

  • Dependency Chart Parsing Algorithm Based on Ternary-Span Combination

    Meixun JIN  Yong-Hun LEE  Jong-Hyeok LEE  

     
    PAPER-Natural Language Processing

      Vol:
    E96-D No:1
      Page(s):
    93-101

    This paper presents a new span-based dependency chart parsing algorithm that models the relations between the left and right dependents of a head. Such relations cannot be modeled in existing span-based algorithms, despite their popularity in dependency corpora. We address this problem through ternary-span combination during the subtree derivation. By modeling the relations between the left and right dependents of a head, our proposed algorithm provides a better capability of coordination disambiguation when the conjunction is annotated as the head of the left and right conjuncts. This eventually leads to state-of-the-art performance of dependency parsing on the Chinese data of the CoNLL shared task.

  • A Wide Input Range, High-Efficiency Multi-Mode Active Rectifier for Magnetic Resonant Wireless Power Transfer System

    Hyung-Gu PARK  SoYoung KIM  Kang-Yoon LEE  

     
    PAPER-Electronic Circuits

      Vol:
    E96-C No:1
      Page(s):
    102-107

    In this paper, a wide input range CMOS multi-mode active rectifier is presented for a magnetic resonant wireless battery charging system. The configuration is automatically changed with respect to the magnitude of the input AC voltage. The output voltage of the multi-mode rectifier is sensed by a comparator. Furthermore, the mode of the multi-mode rectifier is automatically selected by switches among the original rectifier mode, 1-stage voltage multiplier mode, and 2-stage voltage multiplier mode. In the original rectifier, the range of the rectified output DC voltage is from 9 V to 19 V for an input AC voltage from 10 V to 20 V. In the multi-mode rectifier, the input-range is wider compared to the original rectifier by 5 V. As a result, the rectified output DC voltage ranges from 7.5 V to 19 V for an input AC voltage from 5 V to 20 V. The proposed multi-mode rectifier is fabricated in a 0.35 µm CMOS process with an active area of around 2500 µm 1750 µm. When the magnitude of the input AC voltage is 10 V, the power conversion efficiency is about 94%.

  • Catching the Behavioral Differences between Multiple Executions for Malware Detection

    Takahiro KASAMA  Katsunari YOSHIOKA  Daisuke INOUE  Tsutomu MATSUMOTO  

     
    PAPER-System Security

      Vol:
    E96-A No:1
      Page(s):
    225-232

    As the number of new malware has increased explosively, traditional malware detection approaches based on pattern matching have been less effective. Therefore, it is important to develop a detection method which relies on not signatures but characteristic behaviors of malware. Recently, malware authors have been embedding functions for countermeasure against malware analyses and detections into malware. Accordingly, modern malware often changes their runtime behaviors in each execution to tolerate against malware analyses and detections. For example, when malware copies itself on a file system, it can randomly determine its file name for avoiding the detections. Another example is that when malware tries to connect its command and control server, it randomly chooses a domain name from a hard-coded domain name list to avoid being blocked by a static blacklist of malicious domain names. We assume that such evasive behaviors are unnecessary for benign software. Therefore the behaviors can be the clues to distinguish malware from benign software. In this paper, we propose a novel behavior-based malware detection method which focuses attention on such characteristics. Our proposed method conducts dynamic analysis on an executable file multiple times in same sandbox environment so as to obtain plural lists of API call sequences and plural traffic logs, and then compares the lists and the logs to find the difference between the multiple executions. In the experiments with 5,697 malware samples and 819 benign software samples, we can detect about 70% malware samples and the false positive rate is about 1%. In addition, we can detect about 50% malware samples which were not detected by each Anti-Virus Software engine. Therefore we confirm the possibility the proposed method may be able to improve the accuracy of malware detection utilizing in combination with other existing methods.

  • Cognitive Fixed-Gain Amplify-and-Forward Relay Networks under Interference Constraints

    Dac-Binh HA  Vo Nguyen Quoc BAO  Xuan-Nam TRAN  Tuong-Duy NGUYEN  

     
    LETTER-Wireless Communication Technologies

      Vol:
    E96-B No:1
      Page(s):
    375-378

    In this work, we analyze the performance of cognitive amplify-and-forward (AF) relay networks under the spectrum sharing approach. In particular, by assuming that the AF relay operates in the semi-blind mode (fixed-gain), we derive the exact closed-form expressions of the outage probability for the cognitive relaying (no direct link) and cognitive cooperative (with direct link) systems. Simulation results are presented to verify the theoretical analysis.

  • Multiple Symbol Differential Detection with Majority Decision Method for DQPSK in LOS Channel

    Hiroyasu ISHIKAWA  Hideyuki SHINONAGA  

     
    LETTER-Satellite Communications

      Vol:
    E96-B No:1
      Page(s):
    384-388

    This letter proposes a multiple symbol differential detection (MSDD) with majority decision method for differentially coded quadrature phase-shift keying (DQPSK) in Rician fading channels. The proposed method shows better BER performance than the conventional MSDD. Simulation results show that the proposed MSDD with a majority decision method improves the system's BER performance for DQPSK signals under the AWGN channel and it approaches asymptotically the theoretical BER performance of coherent detection. Furthermore, the proposed method shows better BER performance under the Rician fading channel with large frequency offsets especially for the range of C/M > 12 dB in comparison with the conventional MSDD.

  • Efficient Secure Auction Protocols Based on the Boneh-Goh-Nissim Encryption

    Takuho MITSUNAGA  Yoshifumi MANABE  Tatsuaki OKAMOTO  

     
    PAPER-Public Key Based Protocols

      Vol:
    E96-A No:1
      Page(s):
    68-75

    This paper presents efficient secure auction protocols for first price auction and second price auction. Previous auction protocols are based on a generally secure multi-party protocol called mix-and-match protocol based on plaintext equality tests. However, the time complexity of the plaintext equality tests is large, although the mix-and-match protocol can securely calculate any logical circuits. The proposed protocols reduce the number of times the plaintext equality tests is used by replacing them with the Boneh-Goh-Nissim encryption, which enables calculation of 2-DNF of encrypted data.

  • Extension of the LTV Phase Noise Model of Electrical Oscillators for the Output Harmonics

    Seyed Amir HASHEMI  Hassan GHAFOORIFARD  Abdolali ABDIPOUR  

     
    PAPER-Electronic Circuits

      Vol:
    E95-C No:12
      Page(s):
    1846-1856

    In this paper, using the Linear Time Variant (LTV) phase noise model and considering higher order harmonics generated by the oscillator output signal, a more general formula for transformation of the excess phase to the output signal is presented. Despite the basic LTV model which assumes that the total carrier power is within the fundamental harmonic, in the proposed model, the total carrier power is assumed to be distributed among all output harmonics. For the first harmonic, the developed expressions reduce to the basic LTV formulas. Simulation and experimental results are used to ensure the validity of the model.

2721-2740hit(8214hit)