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8321-8340hit(20498hit)

  • An Improved Anchor Shot Detection Method Using Fitness of Face Location and Dissimilarity of Icon Region

    Ji-Soo KEUM  Hyon-Soo LEE  Masafumi HAGIWARA  

     
    LETTER-Image

      Vol:
    E93-A No:4
      Page(s):
    863-866

    In this letter, we propose an improved anchor shot detection (ASD) method in order to effectively retrieve anchor shots from news video. The face location and dissimilarity of icon region are used to reduce false alarms in the proposed method. According to the results of the experiment on several types of news video, the proposed method obtained high anchor detection results compared with previous methods.

  • On the User-Level Satisfactions with User-Level Utility Functions: A Case Study with Scheduling in TDMA Wireless Networks

    Sungyeon KIM  Jang-Won LEE  

     
    LETTER-Wireless Communication Technologies

      Vol:
    E93-B No:4
      Page(s):
    1037-1040

    In most cases in wireless networks, a user has a two-way communication that consists of two sessions: uplink and downlink sessions, and its overall satisfaction to the communication depends on the quality of service of both sessions. However, in most previous approaches in wireless resource allocation, the satisfactions of a user for its uplink and downlink sessions are modeled separately and treated independently, which fails to accurately model user's overall satisfaction to its communication. Hence, in this paper we model user's overall satisfaction to its communication considering both its uplink and downlink sessions. To this end, we propose a novel concept for a utility function to model user's overall satisfaction to its communication, which is called a user-level utility function, considering user's satisfaction to uplink and downlink sessions jointly. To show the appropriateness of our approach, we apply our user-level utility functions to scheduling problems in TDMA wireless networks and show the performance improvement of our approach over the traditional approach that does not treat uplink and downlink sessions of a user jointly.

  • Improving Reliability of Spectrum Analysis for Software Quality Requirements Using TCM

    Haruhiko KAIYA  Masaaki TANIGAWA  Shunichi SUZUKI  Tomonori SATO  Akira OSADA  Kenji KAIJIRI  

     
    PAPER-Requirements Engineering

      Vol:
    E93-D No:4
      Page(s):
    702-712

    Quality requirements are scattered over a requirements specification, thus it is hard to measure and trace such quality requirements to validate the specification against stakeholders' needs. We proposed a technique called "spectrum analysis for quality requirements" which enabled analysts to sort a requirements specification to measure and track quality requirements in the specification. In the same way as a spectrum in optics, a quality spectrum of a specification shows a quantitative feature of the specification with respect to quality. Therefore, we can compare a specification of a system to another one with respect to quality. As a result, we can validate such a specification because we can check whether the specification has common quality features and know its specific features against specifications of existing similar systems. However, our first spectrum analysis for quality requirements required a lot of effort and knowledge of a problem domain and it was hard to reuse such knowledge to reduce the effort. We thus introduce domain knowledge called term-characteristic map (TCM) to reuse the knowledge for our quality spectrum analysis. Through several experiments, we evaluate our spectrum analysis, and main finding are as follows. First, we confirmed specifications of similar systems have similar quality spectra. Second, results of spectrum analysis using TCM are objective, i.e., different analysts can generate almost the same spectra when they analyze the same specification.

  • An Improved Speech / Nonspeech Classification Based on Feature Combination for Audio Indexing

    Ji-Soo KEUM  Hyon-Soo LEE  Masafumi HAGIWARA  

     
    LETTER-Speech and Hearing

      Vol:
    E93-A No:4
      Page(s):
    830-832

    In this letter, we propose an improved speech/ nonspeech classification method to effectively classify a multimedia source. To improve performance, we introduce a feature based on spectral duration analysis, and combine recently proposed features such as high zero crossing rate ratio (HZCRR), low short time energy ratio (LSTER), and pitch ratio (PR). According to the results of our experiments on speech, music, and environmental sounds, the proposed method obtained high classification results when compared with conventional approaches.

  • Distributed Medium Access Control with SDMA Support for WLANs

    Sheng ZHOU  Zhisheng NIU  

     
    PAPER-Terrestrial Radio Communications

      Vol:
    E93-B No:4
      Page(s):
    961-970

    With simultaneous multi-user transmissions, spatial division multiple access (SDMA) provides substantial throughput gain over the single user transmission. However, its implementation in WLANs with contention-based IEEE 802.11 MAC remains challenging. Problems such as coordinating and synchronizing the multiple users need to be solved in a distributed way. In this paper, we propose a distributed MAC protocol for WLANs with SDMA support. A dual-mode CTS responding mechanism is designed to accomplish the channel estimation and user synchronization required for SDMA. We analytically study the throughput performance of the proposed MAC, and dynamic parameter adjustment is designed to enhance the protocol efficiency. In addition, the proposed MAC protocol does not rely on specific physical layer realizations, and can work on legacy IEEE 802.11 equipment with slight software updates. Simulation results show that the proposed MAC outperforms IEEE 802.11 significantly, and that the dynamic parameter adjustment can effectively track the load variation in the network.

  • Electrical and Mechanical Characteristics of Au-, Pt-, and Pd-Doped Carbon Thin Films

    Mitsunori YABE  Shigeru UMEMURA  Shigeru HIRONO  

     
    BRIEF PAPER-Electromechanical Devices and Components

      Vol:
    E93-C No:4
      Page(s):
    527-530

    To achieve conductive and wear-durable carbon thin films by metal doping, we deposited Au-, Pt-, and Pd-doped carbon thin films by RF sputtering, and evaluated the dopant concentrations, resistivity, and scratch hardness. Among the doped films, the Pt-doped film with low Pt concentration was most suitable from a practical perspective.

  • Facial Image Recognition Based on a Statistical Uncorrelated Near Class Discriminant Approach

    Sheng LI  Xiao-Yuan JING  Lu-Sha BIAN  Shi-Qiang GAO  Qian LIU  Yong-Fang YAO  

     
    LETTER-Image Recognition, Computer Vision

      Vol:
    E93-D No:4
      Page(s):
    934-937

    In this letter, a statistical uncorrelated near class discriminant (SUNCD) approach is proposed for face recognition. The optimal discriminant vector obtained by this approach can differentiate one class and its near classes, i.e., its nearest neighbor classes, by constructing the specific between-class and within-class scatter matrices and using the Fisher criterion. In this manner, SUNCD acquires all discriminant vectors class by class. Furthermore, SUNCD makes every discriminant vector satisfy locally statistical uncorrelated constraints by using the corresponding class and part of its most neighboring classes. Experiments on the public AR face database demonstrate that the proposed approach outperforms several representative discriminant methods.

  • On Detecting Target Acoustic Signals Based on Non-negative Matrix Factorization

    Yu Gwang JIN  Nam Soo KIM  

     
    LETTER-Pattern Recognition

      Vol:
    E93-D No:4
      Page(s):
    922-925

    In this paper, we propose a novel target acoustic signal detection approach which is based on non-negative matrix factorization (NMF). Target basis vectors are trained from the target signal database through NMF, and input vectors are projected onto the subspace spanned by these target basis vectors. By analyzing the distribution of time-varying normalized projection error, the optimal threshold can be calculated to detect the target signal intervals during the entire input signal. Experimental results show that the proposed algorithm can detect the target signal successfully under various signal environments.

  • Interference Avoidance and Resource Allocation for OFDMA Downlink of Femtocells with Distributed Power Control

    Hyunduk JUNG  Jechan HAN  Jaiyong LEE  

     
    LETTER-Terrestrial Radio Communications

      Vol:
    E93-B No:4
      Page(s):
    1061-1064

    OFDMA femtocells in the macrocellular network of which frequency reuse factor is 1 cause serious interference to macrocell users, while the femtocells improve the performance of indoor users. In this letter, a novel downlink resource allocation algorithm for OFDMA femtocell networks is proposed to reduce interference between the macrocells and the femtocells. This algorithm allocates femtocell subchannels to avoid interference to macrocell users in the femtocell coverage, and minimizes the total transmission power of the femtocell to reduce the negative effect on the performance of the macrocell. Simulation results are provided to present the performance of the proposed algorithm.

  • Energy Efficient Communication Using Relationships between Biological Signals for Ubiquitous Health Monitoring

    Songjun LEE  Doosu NA  Bonmin KOO  

     
    LETTER

      Vol:
    E93-B No:4
      Page(s):
    842-845

    Wireless sensor networks with a star network topology are commonly applied for health monitoring systems. To determine the condition of a patient, sensor nodes are attached to the body to transmit the data to a coordinator. However, this process is inefficient because the coordinator is always communicating with each sensor node resulting in a data processing workload for the coordinator that becomes much greater than that of the sensor nodes. In this paper, a method is proposed to reduce the number of data transmissions from the sensor nodes to the coordinator by establishing a threshold for data from the biological signals to ensure that only relevant information is transmitted. This results in a dramatic reduction in power consumption throughout the entire network.

  • Increasing the Strength of Odors Produced by an Odor-Emitting Technology Using Odor Capsules

    Ayako NISHIMURA  Minoru SAKAIRI  Daisuke SUZUKI  

     
    PAPER-Multimedia Pattern Processing

      Vol:
    E93-D No:4
      Page(s):
    903-908

    We have developed an odor-emitting apparatus for application of odor to information technology. This apparatus consists of a chemical capsule cartridge including chemical capsules of odor ingredients and valves to control odor emission using an artificial metal muscle. In this method, multiple valves can be opened using the current for a single artificial muscle because the expansion and contraction time constant for the artificial muscles is large. We have developed a new multi-valve sequence mode that uses multiple odor capsules to increase odor strength, and we have been able to increase the strength produced by a factor of two. In addition, we evaluated the change in odor strength using a mock-up of the back seat of an automobile, and all of the ten test subjects reported sensing a stronger odor.

  • Analytical Inductance Calculation of Superconducting Stripline by Use of Transformation into Perfect Conductor Model

    Yoshinao MIZUGAKI  Akio KAWAI  Ryuta KASHIWA  Masataka MORIYA  Tadayuki KOBAYASHI  

     
    BRIEF PAPER

      Vol:
    E93-C No:4
      Page(s):
    486-488

    We present analytical expression for inductance of a superconducting stripline, a strip sandwiched by two superconducting ground planes. In our method, we utilize the analytical formula for a perfect-conducting stripline derived by Chang in 1976. To utilize Chang's formula, we first transform the structure of a superconducting stripline into that of a perfect-conducting stripline by reducing the thicknesses of the superconducting layers. The thickness reduction is "λ coth (t/λ)" for each (upper or lower) side, where λ and t are the field penetration depth and the layer thickness, respectively. Then, we apply Chang's formula to the transformed stripline model. The calculated results are in good agreement with the numerical and experimental results.

  • Interference-Aware Energy-Efficient Geographical Routing for IEEE 802.15.4a Networks

    Junseok KIM  Younggoo KWON  

     
    LETTER-Network

      Vol:
    E93-B No:4
      Page(s):
    1024-1028

    The IEEE 802.15.4a standard enables geographical routing in ZigBee networks but previous geographical routing algorithms can suffer high packet loss due to the interference effects. This letter proposes an interference-aware energy-efficient geographical routing algorithm for the IEEE 802.15.4a networks. The proposed algorithm estimates the energy cost by considering the interference effects and forwards a packet to the neighbor with the lowest energy cost to advance. Experimental results show that the proposed algorithm outperforms the previous algorithms in terms of the delivery ratio and the energy consumption.

  • A Dynamic CFP Allocation and Opportunity Contention-Based WBAN MAC Protocol

    Young-Sun SEO  Dae-Young KIM  Jinsung CHO  

     
    LETTER

      Vol:
    E93-B No:4
      Page(s):
    850-853

    WBANs provide communication services in the vicinity of the human body. Since WBANs utilize both MICS frequency band for implant medical applications and ISM frequency band for medical and consumer electronics (CE) applications, MAC protocols in WBAN should be designed considering flexibility between medical and CE applications. In this letter, we identify the requirements of WBAN MAC protocols and propose a WBAN MAC protocol which satisfies the requirements. In order to provide transmission flexibility for various applications, we present the dynamic CFP allocation and opportunity period. Extensive simulation results show that the proposed protocol achieves improved throughput and latency in WBAN environment compared with IEEE 802.15.4.

  • Efficient Network Coding-Based Loss Recovery for Reliable Multicast in Wireless Networks

    Kaikai CHI  Xiaohong JIANG  Baoliu YE  Susumu HORIGUCHI  

     
    PAPER-Terrestrial Radio Communications

      Vol:
    E93-B No:4
      Page(s):
    971-981

    Recently, network coding has been applied to the loss recovery of reliable multicast in wireless networks, where multiple lost packets are XOR-ed together as one packet and forwarded via single retransmission, resulting in a significant reduction of bandwidth consumption. In this paper, we first prove that maximizing the number of lost packets for XOR-ing, which is the key part of the available network coding-based reliable multicast schemes, is actually a complex NP-complete problem. To address this limitation, we then propose an efficient heuristic algorithm for finding an approximately optimal solution of this optimization problem. Furthermore, we show that the packet coding principle of maximizing the number of lost packets for XOR-ing sometimes cannot fully exploit the potential coding opportunities, and we then further propose new heuristic-based schemes with a new coding principle. Simulation results demonstrate that the heuristic-based schemes have very low computational complexity and can achieve almost the same transmission efficiency as the current coding-based high-complexity schemes. Furthermore, the heuristic-based schemes with the new coding principle not only have very low complexity, but also slightly outperform the current high-complexity ones.

  • Development of Generation System of Simplified Digital Maps

    Keiichi UCHIMURA  Masato KAWANO  Hiroki TOKITSU  Zhencheng HU  

     
    PAPER

      Vol:
    E93-A No:4
      Page(s):
    700-710

    In recent years, digital maps have been used in a variety of scenarios, including car navigation systems and map information services over the Internet. These digital maps are formed by multiple layers of maps of different scales; the map data most suitable for the specific situation are used. Currently, the production of map data of different scales is done by hand due to constraints related to processing time and accuracy. We conducted research concerning technologies for automatic generation of simplified map data from detailed map data. In the present paper, the authors propose the following: (1) a method to transform data related to streets, rivers, etc. containing widths into line data, (2) a method to eliminate the component points of the data, and (3) a method to eliminate data that lie below a certain threshold. In addition, in order to evaluate the proposed method, a user survey was conducted; in this survey we compared maps generated using the proposed method with the commercially available maps. From the viewpoint of the amount of data reduction and processing time, and on the basis of the results of the survey, we confirmed the effectiveness of the automatic generation of simplified maps using the proposed methods.

  • Constriction Resistance Behavior of a Tin or Silver Plated Layer for an Electrical Contact

    Shigeru SAWADA  Kaori SHIMIZU  Yasuhiro HATTORI  Terutaka TAMAI  

     
    PAPER-Electromechanical Devices and Components

      Vol:
    E93-C No:4
      Page(s):
    521-526

    Electrical contacts are an important part of electrical circuits and many reliability problems are related to electrical contact failure. It is important to investigate the relationship between load and contact resistance which is an important factor of contact reliability. In this study, the effect of plated material and plated thickness on contact resistance was examined. The samples were constructed of a copper alloy with tin or silver plating. Contact configuration was hemispherical-flat contact. The contact resistance was measured by using a four-probe method with a load up to 40 N. The relation between indentation contact area (i.e. apparent contact area) and contact resistance was determined. As experimental results, the contact resistance depends on the indentation of the contact area. In the same contact area, tin-plated samples have higher resistance than those that are silver-plated due to their own resistivity. The constriction resistance of a plated layer, which depends on contact area, plated material and plated thickness, is analyzed by a theoretical solution, which is shown by R=Φρ /2a, using a surface resistance coefficient Φ . The theoretical results show almost good agreement with the experimental results. Thus, the indentation contact area (i.e. apparent contact area) is almost the same as the real contact area in this study.

  • Adaptive Spread-Transform Dither Modulation Using a New Perceptual Model for Color Image Watermarking

    Lihong MA  Dong YU  Gang WEI  Jing TIAN  Hanqing LU  

     
    PAPER-Information Network

      Vol:
    E93-D No:4
      Page(s):
    843-857

    Major challenges of the conventional spread-transform dither modulation (STDM) watermarking approach are two-fold: (i) it exploits a fixed watermarking strength (more particularly, the quantization index step size) to the whole cover image; and (ii) it is fairly vulnerable to the amplitude changes. To tackle the above challenges, an adaptive spread-transform dither modulation (ASTDM) approach is proposed in this paper for conducting robust color image watermarking by incorporating a new perceptual model into the conventional STDM framework. The proposed approach exploits a new perceptual model to adjust the quantization index step sizes according to the local perceptual characteristics of a cover image. Furthermore, in contrast to the conventional Watson's model is vulnerable to the amplitude changes, our proposed new perceptual model makes the luminance masking thresholds be consistent with any amplitude change, while keeping the consistence to the properties of the human visual system. In addition, certain color artifacts could be incurred during the watermark embedding procedure, since some intensity values are perceptibly changed to label the watermark. For that, a color artifact suppression algorithm is proposed by mathematically deriving an upper bound for the intensity values according to the inherent relationship between the saturation and the intensity components. Extensive experiments are conducted using 500 images selected from Corel database to demonstrate the superior performance of the proposed ASTDM approach.

  • A Feasibility Study on Inter-Vehicle Communication System for Practical Use in Urban Area Based on Multi-Vehicle Experiment

    Ken NAKAOKA  Mamoru YOKOTA  Kunihiko SASAKI  Tetsuo HORIMATSU  

     
    PAPER

      Vol:
    E93-A No:4
      Page(s):
    689-699

    This paper studies the feasibility of 700 MHz band inter-vehicle communication system when it is put into practical use in urban area. To verify the system, a large-scale demonstration experiment in a quasi-street test course is performed. In the experiment, a number of vehicles which are equipped with communication devices conforming to ITS FORUM RC-006 specifications are employed. A simulation method that is applicable to large-scale communication model is also designed, and the validity of the method is verified by utilizing the results derived from the experiment. Based on this model, the quality of the inter-vehicle communication system in urban area communication environment is estimated. The results show that the system's performance satisfies the requirements of representative prevention scenes of traffic accident, and the feasibility of the 700 MHz band inter-vehicle communication system specified in RC-006 is verified in the practical use in urban communication environment.

  • Performance of Robust OFDM Channel Estimation with Strong Interference Detector

    Tsui-Tsai LIN  

     
    LETTER-Wireless Communication Technologies

      Vol:
    E93-B No:4
      Page(s):
    1053-1056

    In this letter, DFT-based channel estimation (CE) with a strong interference detector is proposed for OFDM systems. Computer simulations demonstrate that the proposed scheme achieves similar performance to an interference-free system and is a significant enhancement over conventional methods.

8321-8340hit(20498hit)