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12841-12860hit(21534hit)

  • Alternate Route Selection Algorithm for Short-Lived Traffic (ARSAST) in MPLS Network

    Ilhyung JUNG  Hwa Jong KIM  Jun Kyun CHOI  

     
    PAPER-Network

      Vol:
    E88-B No:6
      Page(s):
    2456-2464

    In QoS routing, load balancing routing algorithm for long-lived traffic can be used efficiently to minimize the number of routing update, control traffic overhead and computational overhead which mainly come from network traffic fluctuation. The congestion problem from short-lived traffic is however difficult to handle. A simple and robust algorithm is needed for short-lived traffic to reduce the traffic loss probability. In the paper, we proposed a new hybrid routing schemes for short-lived traffic and long-lived traffic. An alternate routing algorithm is applied for the short-lived traffic when congestion occurs. We restricted the number of additional hops in the path to minimize the negative effect of alternate routing algorithm. The proposed algorithm reduces packet loss probability from 0.6% to 1.7% under various link utilizations. We also compare our proposed algorithms with and without crank-back.

  • Anchor Frame Detection in News Video Using Anchor Object Extraction

    Ki Tae PARK  Doo Sun HWANG  Young Shik MOON  

     
    LETTER

      Vol:
    E88-A No:6
      Page(s):
    1525-1528

    In this paper, an algorithm for anchor frame detection in news video is proposed, which consists of four steps. First, the cumulative histogram method is used to detect shot boundaries in order to segment a news video into video shots. Second, skin color information is used to detect face regions in each video shot. Third, color information of upper body regions is used to extract anchor object. Then, a graph-theoretic cluster analysis algorithm is utilized to classify the news video into anchor-person shots and non-anchor shots. Experimental results have shown the effectiveness of the proposed algorithm.

  • A Novel Image Enhancement Algorithm for a Small Target Detection of Panoramic Infrared Imagery

    Ju-Young KIM  Ki-Hong KIM  Hee-Chul HWANG  Duk-Gyoo KIM  

     
    LETTER

      Vol:
    E88-A No:6
      Page(s):
    1520-1524

    A novel image enhancement algorithm that can efficiently detect a small target of panoramic infrared (IR) imagery is proposed. Image enhancement is the first step for detecting and recognizing a small target in the IR imagery. The essence of the proposed algorithm is to utilize the independent histogram equalization (HE) separately over two sub-images obtained by decomposing the given image through the statistical hypothesis testing (SHT). Experimental results show that the proposed algorithm has better discrimination and lower false alarm rate than the conventional algorithms.

  • Optimization of Routing and Wavelength Assignment for Multicast Traffic in Optical Networks with Limited Splitting Capability Node

    Chunlei ZHANG  Weisheng HU  Yaohui JIN  

     
    LETTER-Switching for Communications

      Vol:
    E88-B No:6
      Page(s):
    2641-2643

    In this paper, a new Mixed Integer Linear Programming algorithm is proposed to resolve the light-tree routing and wavelength assignment with wavelength continuity constraints. The node in our system is limited branching and power-efficient multicast capable OXC. Numerical results are given and discussed to show the efficiency of our algorithm.

  • An Improved Timer-Based Location Management Scheme for Packet-Switched (PS) Mobile Communication Systems

    Yun Won CHUNG  Jae Kyun KWON  Yeong Jin KIM  Dan Keun SUNG  

     
    LETTER-Network

      Vol:
    E88-B No:6
      Page(s):
    2650-2653

    This letter proposes an improved timer-based location management scheme for packet-switched (PS) mobile communication systems. Compared to the conventional timer-based scheme with a single timer threshold, a new timer-based scheme with two timer thresholds is proposed to accommodate the bursty data traffic characteristics of PS service. The location update and paging costs of the proposed scheme are analyzed and compared with those of the conventional scheme. We show that the proposed scheme outperforms the conventional scheme in terms of total cost of both location update and paging with an appropriate selection of timer thresholds.

  • Standing Wave Radar Capable of Measuring Distances down to Zero Meters

    Tetsuji UEBO  Yoshihiro OKUBO  Tadamitsu IRITANI  

     
    PAPER-Sensing

      Vol:
    E88-B No:6
      Page(s):
    2609-2615

    Various types of radars have been developed and used until now--such as Pulse, FM-CW, and Spread Spectrum. Additionally, we have proposed another type of radar which measures distances by using standing wave. We have named it as "Standing Wave Radar." It has a shorter minimum detectable range and higher accuracy compared to other types. However, the radar can not measure distances down to zero meters like other types of radars. Minimum detectable range of the standing wave radar depends on a usable frequency range. A wider frequency range is required if we need to measure shorter distances. Consequently, we propose a new method for measuring distances down to zero meters without expanding the frequency range. We use an analytic signal, which is a complex sinusoidal signal. The signal is obtained by observing the standing wave with multiple detectors. We calculate distances by Fourier transform of the analytic signal. Moreover, we verify the validity of our method by simulations based on numerical calculation. The results show that it is possible to measure distances down to zero meters. In our method, measurement errors are caused by deviations of position and gain of the detectors. They are around 10cm at the largest if the gain deviations are up to 1% and the position deviations are up to 6% of the spacing between the detectors. Prevalent radars still have a common defect that they can not measure distances from zero to several meters. We expect that the defect will be eliminated by putting our method into practical use.

  • Screen Pattern Removal for Character Pattern Extraction from High-Resolution Color Document Images

    Hideaki GOTO  Hirotomo ASO  

     
    LETTER-Image Recognition, Computer Vision

      Vol:
    E88-D No:6
      Page(s):
    1310-1313

    Screen pattern used in offset-printed documents has been one of great obstacles in developing document recognition systems that handle color documents. This paper proposes a selective smoothing method for filtering the screen patterns/noise in high-resolution color document images. Experimental results show that the method yields significant improvements in character pattern extraction.

  • Adjacent Channel Interference Cancellation Scheme for Low-IF Receiver in Multi-Channel Reception

    Anas Muhamad BOSTAMAM  Yukitoshi SANADA  

     
    PAPER-Wireless Communication Technologies

      Vol:
    E88-B No:6
      Page(s):
    2532-2538

    In this paper a new adjacent channel interference (ACI) cancellation scheme for multi-channel signal reception with low-IF receivers is investigated through the experiment. In the low-IF receivers, the signal in the mirror frequency causes interference to the desired signal. In the proposed analog-digital signal processing scheme, channel selection is made by analog complex band pass filter and the signal is reconstruct by Wiener filter to eliminate the interference effect in order to improve the performance.

  • Analysis of Reflector and Horn Antennas Using Adaptive Integral Method

    Wei-Bin EWE  Le-Wei LI  Qun WU  Mook-Seng LEONG  

     
    PAPER

      Vol:
    E88-B No:6
      Page(s):
    2327-2333

    This paper presents an analysis of electrically large antennas using the adaptive integral method (AIM). The arbitrarily shaped perfectly conducting surfaces are modeled using triangular patches and the associated electric field integral equation (EFIE) is solved for computing the radiation patterns of these antennas. The method of moments (MoM) is used to discretize the integral equations and the resultant matrix system will be solved by an iterative solver. The AIM is employed in the iterative solver to speed up the matrix-vector multiplication and to reduce the memory requirement. As specific applications, radiation patterns of parabolic reflectors and X-band horns are computed using the proposed method.

  • On the Orthogonal Drawing of Outerplanar Graphs

    Kumiko NOMURA  Satoshi TAYU  Shuichi UENO  

     
    PAPER-Graphs and Networks

      Vol:
    E88-A No:6
      Page(s):
    1583-1588

    In this paper we show that an outerplanar graph G with maximum degree at most 3 has a 2-D orthogonal drawing with no bends if and only if G contains no triangles. We also show that an outerplanar graph G with maximum degree at most 6 has a 3-D orthogonal drawing with no bends if and only if G contains no triangles.

  • Combiner-Based MOS OTAs

    Koichi TANNO  Kenya KONDO  Okihiko ISHIZUKA  Takako TOYAMA  

     
    LETTER-Analog Signal Processing

      Vol:
    E88-A No:6
      Page(s):
    1622-1625

    In this letter, two kinds of MOS operational transconductance amplifiers (OTAs) based on combiners are presented. Each OTA has the following advantages; one of the proposed OTAs (OTA-1) can be operated at low supply voltage and the other OTA (OTA-2) has wide bandwidth. Through HSPICE simulations with a standard 0.35 µm CMOS device parameters, the operation under the supply voltage of 1.5 V for OTA-1 and the -3 dB bandwidth of several gigahertz for OTA-2 are confirmed.

  • Extracting Partial Parsing Rules from Tree-Annotated Corpus: Toward Deterministic Global Parsing

    Myung-Seok CHOI  Kong-Joo LEE  Key-Sun CHOI  Gil Chang KIM  

     
    PAPER-Natural Language Processing

      Vol:
    E88-D No:6
      Page(s):
    1248-1255

    It is not always possible to find a global parse for an input sentence owing to problems such as errors of a sentence, incompleteness of lexicon and grammar. Partial parsing is an alternative approach to respond to these problems. Partial parsing techniques try to recover syntactic information efficiently and reliably by sacrificing completeness and depth of analysis. One of the difficulties in partial parsing is how the grammar might be automatically extracted. In this paper we present a method of automatically extracting partial parsing rules from a tree-annotated corpus using the decision tree method. Our goal is deterministic global parsing using partial parsing rules, in other words, to extract partial parsing rules with higher accuracy and broader expansion. First, we define a rule template that enables to learn a subtree for a given substring, so that the resultant rules can be more specific and stricter to apply. Second, rule candidates extracted from a training corpus are enriched with contextual and lexical information using the decision tree method and verified through cross-validation. Last, we underspecify non-deterministic rules by merging substructures with ambiguity in those rules. The learned grammar is similar to phrase structure grammar with contextual and lexical information, but allows building structures of depth one or more. Thanks to automatic learning, the partial parsing rules can be consistent and domain-independent. Partial parsing with this grammar processes an input sentence deterministically using longest-match heuristics, and recursively applies rules to an input sentence. The experiments showed that the partial parser using automatically extracted rules is not only accurate and efficient but also achieves reasonable coverage for Korean.

  • Three Beam Switched Top Loaded Monopole Antenna

    Naobumi MICHISHITA  Yuji NAKAYAMA  Hiroyuki ARAI  Kohei MORI  

     
    PAPER

      Vol:
    E88-B No:6
      Page(s):
    2291-2296

    The three beam-switched top-loaded antenna is suited to be applied to a wireless local area network to switch the radiation pattern by arranging several unidirectional antennas. In this paper, a three beam switched top loaded monopole antenna is proposed to realize its small size and planar structure. Three top loaded monopole antennas are arranged around a parasitic hexagonal patch at intervals of 120 degrees. The feed element is selected by the switching device to switch the radiation pattern. This antenna allows for reduction in the number of elements as well as downsizing. The front to back ratio (F/B) becomes 23 dB by selecting suitable parameters.

  • Attenuation Characteristics of the SAR in a COST244 Phantom with Different EM Source Locations and Sizes

    Shoichi KAJIWARA  Atsushi YAMAMOTO  Koichi OGAWA  Akihiro OZAKI  Yoshio KOYANAGI  

     
    PAPER

      Vol:
    E88-B No:6
      Page(s):
    2391-2400

    This paper addresses the variation of the attenuation characteristics of the Specific Absorption Rate (SAR) in a lossy medium as a function of the distance between an antenna and the medium with different EM-source sizes. Analysis and measurements were performed using a dipole antenna at 900 MHz and a COST244 cubic phantom. From this, an empirical equation has been derived, representing the attenuation characteristics of the SAR. The equation takes into consideration an energy loss due to the spatial spread of electromagnetic waves. In the case where an antenna is placed more than λ/2π away from the medium, the attenuation characteristics of the SAR are those obtained from plane waves in the lossy medium. In the case where a half-wavelength dipole antenna is located close to the medium, at a distance of less than λ/2π, the attenuation characteristics of the SAR are calculated from an equation that includes a loss caused by the spread of energy as a cylindrical wave. Moreover, when the length of antenna is short, it is found that a spatial attenuation factor appropriate to a spherical wave should be taken into account.

  • Complex EGI Based 3D-Mesh Watermarking

    Jong-Won LEE  Suk-Hwan LEE  Ki-Ryong KWON  Kuhn-Il LEE  

     
    LETTER

      Vol:
    E88-A No:6
      Page(s):
    1512-1519

    We proposed 3D-mesh watermarking using CEGI distribution that has robustness against mesh simplification, cropping, vertex randomization, and rotation and which does not need the original model for detection the watermark. The proposed algorithm embeds the watermark bits into the normal vector direction of meshes that are mapped into the cells that have the large magnitude of complex weight in patch CEGIs. The watermark can be detected based on the known center point of each patch and the rank table of the cell in each patch instead of original model. Experimental results verified that the proposed algorithm has robustness against the attacks.

  • Enhanced RBF Network by Using ART2 Algorithm and Fuzzy Control Method

    Kwang-Baek KIM  Sung-Kwan JE  Young-Ju KIM  

     
    LETTER

      Vol:
    E88-A No:6
      Page(s):
    1497-1501

    This paper proposes an enhanced RBF network that enhances learning algorithms between input layer and middle layer and between middle layer and output layer individually for improving the efficiency of learning. The proposed network applies ART2 network as the learning structure between input layer and middle layer. And the auto-tuning method of learning rate and momentum is proposed and applied to learning between middle layer and output layer, which arbitrates learning rate and momentum dynamically by using the fuzzy control system for the arbitration of the connected weight between middle layer and output layer. The experiment for the classification of number patterns extracted from the citizen registration card shows that compared with conventional networks such as delta-bar-delta algorithm and the ART2-based RBF network, the proposed method achieves the improvement of performance in terms of learning speed and convergence.

  • A Reasonable Throughput Analysis of the CSK/SSMA Unslotted ALOHA System with Nonorthogonal Sequences

    Nobuyoshi KOMURO  Hiromasa HABUCHI  

     
    PAPER

      Vol:
    E88-A No:6
      Page(s):
    1462-1468

    In this paper, the throughput performance of the CSK/SSMA ALOHA system with nonorthogonal sequences which combines the ALOHA system with Code Shift Keying using nonorthogonal sequences is analyzed. In this system, the nonorthogonal sequences are constructed by concatenating Mcon orthogonal sequences. The throughput performance of the CSK/SSMA ALOHA system with nonorthogonal sequences is analyzed in consideration that the number of packets changes at intervals of one orthogonal sequence. Moreover, the throughput performance of our system with Channel Load Sensing Protocol (CLSP) is also analyzed. We also examine the influence of unreachable control signal of CLSP. Consequently, it is found that the throughput performance of our system decreases significantly by this analysis. It is also found that the throughput performance of our system improves greatly by using CLSP. However, the unreachable control signal affects the throughput performance of this system, seriously.

  • Interface for Barge-in Free Spoken Dialogue System Combining Adaptive Sound Field Control and Microphone Array

    Tatsunori ASAI  Hiroshi SARUWATARI  Kiyohiro SHIKANO  

     
    LETTER-Speech and Hearing

      Vol:
    E88-A No:6
      Page(s):
    1613-1618

    This paper describes a new interface for a barge-in free spoken dialogue system combining an adaptive sound field control and a microphone array. In order to actualize robustness against the change of transfer functions due to the various interferences, the barge-in free spoken dialogue system which uses sound field control and a microphone array has been proposed by one of the authors. However, this method cannot follow the change of transfer functions because the method consists of fixed filters. To solve the problem, we introduce a new adaptive sound field control that follows the change of transfer functions.

  • An Addition Algorithm in Jacobian of C34 Curve

    Seigo ARITA  

     
    PAPER-Information Security

      Vol:
    E88-A No:6
      Page(s):
    1589-1598

    This paper gives an efficient algorithm to compute addition in Jacobian of C34 curves, aiming at C34 curve cryptosystems. Using C34 curves for cryptosystems has two advantages. The first is safety and the second is the short size of the base field. In the paper, we modify the addition algorithm of for Cab curves in the specific manner to C34 curves. We classify all of the forms of the Groebner bases of ideals involved in the algorithm and eliminate the use of Buchberger algorithm from it. Our resulting algorithm computes the addition in Jacobian of C34 curves in about 3 times amount of computation of the one in elliptic curves, when the sizes of groups are set to be the same.

  • A Distributed Task Assignment Algorithm with the FCFS Policy in a Logical Ring

    Atsushi SASAKI  

     
    PAPER-Algorithms and Data Structures

      Vol:
    E88-A No:6
      Page(s):
    1573-1582

    This paper presents a distributed task assignment algorithm in a logical unidirectional ring, which guarantees that almost all tasks are assigned to servers with the first come first served (FCFS) policy without a global clock. A task assignment for a process is obtained in the time period needed for a message to circle the ring. This time period is almost optimal for a unidirectional ring. The FCFS policy is very important in terms of task fairness and can also avoid starvation and provide an efficient response time. Simulation results show that the algorithm generally works better than conventional task assignment or load balancing schemes with respect to both mean response time and task fairness.

12841-12860hit(21534hit)