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10601-10620hit(21534hit)

  • A Flexible Personal Data Disclosure Method Based on Anonymity Quantification

    Miyuki IMADA  Masakatsu OHTA  Mitsuo TERAMOTO  Masayasu YAMAGUCHI  

     
    PAPER

      Vol:
    E90-B No:12
      Page(s):
    3460-3469

    In this paper, we propose a method of controlling personal data disclosure based on LooM (Loosely Managed Privacy Protection Method) that prevents a malicious third party from identifying a person when he/she gets context-aware services using personal data. The basic function of LooM quantitatively evaluates the anonymity level of a person who discloses his/her data, and controls the personal-data disclosure according to the level. LooM uses a normalized entropy value for quantifying the anonymity. In this version of the LooM, the disclosure control is accomplished by adding two new functions. One is an abstracting-function that generates abstractions (or summaries) from the raw personal data to reduce the danger that the malicious third party might identify the person who discloses his/her personal data to the party. The other function is a unique-value-masking function that hides the unique personal data in the database. These functions enhance the disclosure control mechanism of LooM. We evaluate the functions using simulation data and questionnaire data. Then, we confirm the effectiveness of the functions. Finally, we show a prototype of a crime-information-sharing service to confirm the feasibility of these functions.

  • A Modified Soft-Shape-Context ICP Registration System of 3-D Point Data

    Jiann-Der LEE  Chung-Hsien HUANG  Li-Chang LIU  Shin-Tseng LEE  Shih-Sen HSIEH  Shuen-Ping WANG  

     
    PAPER-Biological Engineering

      Vol:
    E90-D No:12
      Page(s):
    2087-2095

    This paper describes a modified ICP registration system of facial point data with range-scanning equipment for medical Augmented Reality applications. The reference facial point data are extracted from the pre-stored CT images; the floating facial point data are captured from range-scanning equipment. A modified soft-shape-context ICP including an adaptive dual AK-D tree for searching the closest point and a modified shape-context objective function is used to register the floating data to reference data to provide the geometric relationship for a medical assistant system and pre-operative training. The adaptive dual AK-D tree searches the closest-point pair and discards insignificant control coupling points by an adaptive distance threshold on the distance between the two returned closest neighbor points which are searched by using AK-D tree search algorithm in two different partition orders. In the objective function of ICP, we utilize the modified soft-shape-context information which is one kind of projection information to enhance the robustness of the objective function. Experiment results of using touch and non-touch capture equipment to capture floating point data are performed to show the superiority of the proposed system.

  • Ubiquitous Networks with Radio Space Extension over Broadband Networks

    Haruhisa ICHIKAWA  Masashi SHIMIZU  Kazunori AKABANE  

     
    PAPER

      Vol:
    E90-B No:12
      Page(s):
    3445-3451

    Many devices are expected to be networked with wireless appliances such as radio frequency identification (RFID) tags and wireless sensors, and the number of such appliances will greatly exceed the number of PCs and mobile telephones. This may lead to an essential change in the network architecture. This paper proposes a new network architecture called the appliance defined ubiquitous network (ADUN), in which wireless appliances will be networked without network protocol standards. Radio space information rather than individual appliance signals is carried over the ADUN in the form of a stream with strong privacy/security control. It should be noted that this is different from the architectural principles of the Internet. We discuss a network-appliance interface that is sustainable over a long period, and show that the ADUN overhead will be within the scope of the broadband network in the near future.

  • A Multipath En-Route Filtering Method for Dropping Reports in Sensor Networks

    Mun Su KIM  Tae Ho CHO  

     
    LETTER-Networks

      Vol:
    E90-D No:12
      Page(s):
    2108-2109

    In this paper, we propose a multipath en-route filtering method to deal with the problems caused by black hole attacks and selective forwarding attacks. Our result shows that the method is more resilient to these problems up to a certain number of compromised nodes than the statistical en-route filtering scheme.

  • Multistage Channel Estimation and Data Detection for Multi-Antenna CDMA Systems with Single Spreading Code Per User

    Shu-Ming TSENG  Hung-Chieh YU  

     
    PAPER-Transmission Systems and Transmission Equipment for Communications

      Vol:
    E90-B No:12
      Page(s):
    3523-3529

    A training-based vector channel estimation method has been proposed for single-user code-division multiple access (CDMA) systems in fast-varying correlated multipath fading channels. In this paper, we extend it in an iterative way to multiuser multiple-input multiple-output (MIMO) CDMA systems where both the transmitter and receiver have multiple antennas. In the training period, we propose to add the minimum mean square error (MMSE) front end before channel estimation to suppress multiuser interference (MUI) from substreams with difference spreading codes, so then we can get good initial vector channel estimation for each user. In the data transmission period, we proposed to add MMSE/parallel interference cancellation (PIC) front end to suppress MUI, interference suppression, and vector channel estimation in an iterative way. The perfect channel estimation is assumed in Liu et al., and the inter-play between channel estimation and multiuser detection is not discussed either. On the contrary, the novelty of the proposed method is that we add MMSE/PIC front end (in addition to matched filter) before channel estimation and we repeatedly switch between MMSE/PIC front end and channel estimation.

  • A Compact Ultrawide Bandpass Filter on Thin-Film Substrate

    Chan-Sei YOO  Ji-Min MAENG  Sang-Sub SONG  Kwang-Seok SEO  Woo-Sung LEE  

     
    PAPER

      Vol:
    E90-C No:12
      Page(s):
    2232-2236

    This paper presents the ultrawideband filters for UWB fullband (range of 3.1-10.6 GHz) applications. This filter consists of ring filter for wide-bandwidth and coupled line structure for suppressing unwanted passband in upper and lower stopbands. Especially, the filter structure was realized on silicon substrate using thin film technology, adequate for wafer level packaging, which can be integrated with CMOS UWB chipset that is currently on development. To minimize the dimension of the filter, the Hilbert structure was applied in ring filter and the meander shaped broadside coupled structure was also adopted in the coupled line structure. The size of the fully realized filter structure is 4.43.6 mm2. The insertion loss in passband is 1.5 dB and the return loss is larger than 15 dB, respectively. The group delay in center frequency is 0.2 ns and the group delay variation is less than 0.15 ns.

  • Wideband 3/4 Elliptical Ring Patch for Millimeter-Wave Communication

    Wei HE  Ronghong JIN  Junping GENG  Guomin YANG  

    This letter was withdrawn by the authors. The withdrawal procedure has been completed on October 24, 2008.
     
    LETTER-Antennas and Propagation

      Vol:
    E90-B No:12
      Page(s):
    3742-3744

    In this study, a wideband 3/4 elliptical ring patch operating millimeter wave band is proposed. Using this structure, the patch antenna is designed for circular polarization and wide-band operation at about 32.1-40 GHz for millimeter wave communication. Simulated and measured results for main parameters such as voltage standing wave ratio (VSWR), impedance bandwidth, axial ratio, radiation patterns and gains are also discussed. The study shows that modeling of such antennas, with simplicity in designing and feeding, can well meet the requirements of millimeter-wave wireless communication systems.

  • Coverage Enhancement in TDD-OFDMA Downlink by Using Simple-Relays with Resource Allocation and Throughput Guarantee Scheduler

    Young Min KI  Dae Wook BYUN  Dong Ku KIM  

     
    LETTER-Wireless Communication Technologies

      Vol:
    E90-B No:12
      Page(s):
    3704-3707

    Simple-relay aided resource allocation (SRARA) schemes are incorporated with throughput guarantee scheduling (TGS) in IEEE 802.16 type time division duplex--orthogonal frequency division multiple access (TDD-OFDMA) downlink in order to enhance service coverage, where the amount of resources at each relay is limited due to either its available power which is much smaller than base station (BS) power or the required overhead. The performance of SRARA schemes is evaluated with both proportional fair (PF) and TGS schedulers at 64 kbps and 128 kbps user throughput requirements when total RS power is set to 500 mW or 1 W. For SRARA with RSs of relatively lower power (500 mW), schemes that put total power into only one subchannel offer larger coverage than when both subchnnels are used with equal power allocation, while the RS with evenly power-allocated two subchannels could provide larger coverage gain for a relatively higher power (1 W). Depending upon the target throughputs it is shown which of the relay scheme or scheduler design would play more important role in improving coverage. In a lower target (64 kbps), more improvement comes from relay scheme rather than scheduler design. For a relatively higher level (128 kbps), it comes from scheduler design rather than relay due to the fact that simple relay can't help using strictly limited amount of resources.

  • Extended Algorithm for Calculating Routes with Include Route Constraint in IP Networks

    Rie HAYASHI  Eiji OKI  Kohei SHIOMOTO  

     
    LETTER-Network

      Vol:
    E90-B No:12
      Page(s):
    3677-3679

    This paper proposes an algorithm for calculating routes that considers the include route constraint while minimizing cost. A route with include route constraint has to traverse a group of assigned nodes. The trouble when calculating a route that satisfies an include route constraint is that routes set in different sections may traverse the same link. In order to prevent this violation (overlap), we introduce an alternate route selection policy. Numerical results show that the probability of finding appropriate routes (no overlap) is more than 95% with the proposed algorithm while only 35% with the conventional algorithm.

  • Moving Object Detection for Real Time Video Surveillance: An Edge Based Approach

    M. Julius HOSSAIN  M. Ali Akber DEWAN  Oksam CHAE  

     
    PAPER-Multimedia Systems for Communications

      Vol:
    E90-B No:12
      Page(s):
    3654-3664

    This paper presents an automatic edge segment based algorithm for the detection of moving objects that has been specially developed to deal with the variations in illumination and contents of background. We investigated the suitability of the proposed edge segment based moving object detection algorithm in comparison with the traditional intensity based as well as edge pixel based detection methods. In our method, edges are extracted from video frames and are represented as segments using an efficiently designed edge class. This representation helps to obtain the geometric information of edge in the case of edge matching and shape retrieval; and creates effective means to incorporate knowledge into edge segment during background modeling and motion tracking. An efficient approach for background edge generation and a robust method of edge matching are presented to effectively reduce the risk of false alarm due to illumination change and camera motion while maintaining the high sensitivity to the presence of moving object. The proposed method can be successfully realized in video surveillance applications in home networking environment as well as various monitoring systems. As, video coding standard MPEG-4 enables content based functionality, it can successfully utilize the shape information of the detected moving objects to achieve high coding efficiency. Experiments with real image sequences, along with comparisons with some other existing methods are presented, illustrating the robustness of the proposed algorithm.

  • Effect of Group Delay in RF BPF on Impulse Radio Systems

    Seong-Sik MYOUNG  Bong-Su KWON  Young-Hwan KIM  Jong-Gwan YOOK  

     
    PAPER-Devices/Circuits for Communications

      Vol:
    E90-B No:12
      Page(s):
    3514-3522

    This paper presents an analysis of the effects of RF filter characteristics on the system performance of an impulse radio. The impulse radio system transmits modulated pulses having very short time duration. Information can be extracted in the receiver side based on the cross-correlation between received and reference pulses. Accordingly, the pulse distortion due to in-band group delay variation can cause serious degradation in system performance. In general, RF band pass filters inevitably cause non-uniform group delays to the signal passing through the filter that are proportional to its skirt characteristic due to its resonance phenomenon. In this work, a small signal scattering parameter, S21, which is a frequency domain parameter, and its Fourier transform are utilized to characterize the output pulse waveform under the condition that the input and output ports are matched. The output pulse waveform of the filter is predicted based on the convolution integral between the input pulse and filter transfer function, and the analysis result is compared with previously reported experimental result. The resulting bit error rate performances in a bi-phase modulation and a pulse position modulation based impulse radio system are also calculated. Moreover, improvement of system performance by the pulse shaping method, a potential solution for pulse waveform distortion, is analyzed.

  • Query-Transaction Acceleration Using a DRP Enabling High-Speed Stateful Packet-by-Packet Self-Reconfiguration

    Takashi ISOBE  

     
    PAPER-Reconfigurable System and Applications

      Vol:
    E90-D No:12
      Page(s):
    1905-1913

    Ubiquitous computing and the upcoming broadcast-and-communication convergence require networks that provide very complex services. In particular, networks are needed that can service several users or terminals at various times or places with various application-layer functions that can be changed at a high response speed by adding high-speed processing at the network edge. I present a query-transaction acceleration appliance that uses a dynamic reconfigurable processor (DRP) and enables high-speed stateful packet-by-packet self-reconfiguration to achieve that requirement. This appliance processes at high speeds, has flexible application layer functions that are changeable with a high-speed response, and uses direct packet I/O bypassing memory, hierarchical interconnection of processors, and stateful packet-by-packet self-reconfiguration. In addition, the DRP enables the fabrication of a compact and electric-power-saving appliance. I made a prototype and implemented several transport/application layer functions, such as TCP connection control, auto-caching of server files, uploading cache data for server, and selection/insertion/deletion/update of data for a database. In an experimental evaluation in which four kinds of query-transactions were continually executed in order, I found that the appliance achieved four functions changeable at a high response speed (within 1 ms), and a processing speed (2,273 transactions/sec.) 18 times faster than a PC with a 2-GHz processor.

  • FPGA-Based Intrusion Detection System for 10 Gigabit Ethernet

    Toshihiro KATASHITA  Yoshinori YAMAGUCHI  Atusi MAEDA  Kenji TODA  

     
    PAPER-Reconfigurable System and Applications

      Vol:
    E90-D No:12
      Page(s):
    1923-1931

    The present paper describes an implementation of an intrusion detection system (IDS) on an FPGA for 10 Gigabit Ethernet. The system includes an exact string matching circuit for 1,225 Snort rules on a single device. A number of studies have examined string matching circuits for IDS. However, implementing a circuit that processes a large rule set at high throughput is difficult. In a previous study, we proposed a method for generating an NFA-based string matching circuit that has expandability of processing data width and drastically reduced resource requirements. In the present paper, we implement an IDS circuit that processes 1,225 Snort rules at 10 Gbps with a single Xilinx Virtex-II Pro xc2vp-100 using the NFA-based method. The proposed circuit also provides packet filtering for an intrusion protection system (IPS). In addition, we developed a tool for automatically generating the Verilog HDL source code of the IDS circuit from a Snort rule set. Using the FPGA and the IDS circuit generator, the proposed system is able to update the matching rules corresponding to new intrusions and attacks. We implemented the IDS circuit on an FPGA board and evaluated its accuracy and throughput. As a result, we confirmed in a test that the circuit detects attacks perfectly at the wire speed of 10 Gigabit Ethernet.

  • Improving Performance and Energy Saving in a Reconfigurable Processor via Accelerating Control Data Flow Graphs

    Farhad MEHDIPOUR  Hamid NOORI  Morteza SAHEB ZAMANI  Koji INOUE  Kazuaki MURAKAMI  

     
    PAPER-Reconfigurable Device and Design Tools

      Vol:
    E90-D No:12
      Page(s):
    1956-1966

    Extracting frequently executed (hot) portions of the application and executing their corresponding data flow graph (DFG) on the hardware accelerator brings about more speedup and energy saving for embedded systems comprising a base processor integrated with a tightly coupled accelerator. Extending DFGs to support control instructions and using Control DFGs (CDFGs) instead of DFGs results in more coverage of application code portion are being accelerated hence, more speedup and energy saving. In this paper, motivations for extending DFGs to CDFGs and handling control instructions are introduced. In addition, basic requirements for an accelerator with conditional execution support are proposed. Then, two algorithms are presented for temporal partitioning of CDFGs considering the target accelerator architectural constraints. To demonstrate effectiveness of the proposed ideas, they are applied to the accelerator of a reconfigurable processor called AMBER. Experimental results approve the remarkable effectiveness of covering control instructions and using CDFGs versus DFGs in the aspects of performance and energy reduction.

  • A Novel Technique to Design Energy-Efficient Contexts for Reconfigurable Logic Devices

    Hiroshi SHINOHARA  Hideaki MONJI  Masahiro IIDA  Toshinori SUEYOSHI  

     
    LETTER

      Vol:
    E90-D No:12
      Page(s):
    1986-1989

    High power consumption is a constraining factor for the growth of programmable logic devices. We propose two techniques in order to reduce power consumption. The first is a technique for creating contexts. This technique uses data-dependent circuits and wire sharing between contexts. The second is a technique for switching the contexts. In this paper, we evaluate the capability of the two techniques to reduce power consumption using a multi-context logic device. As a result, as compared with the original circuit, our multi-context circuits reduced the power consumption by 9.1% on an average and by a maximum of 19.0%. Furthermore, applying our resource sharing technique to these circuits, we achieved a reduction of 10.6% on an average and a maximum reduction of 18.8%.

  • TCP Reassembler for Layer7-Aware Network Intrusion Detection/Prevention Systems

    Miyuki HANAOKA  Makoto SHIMAMURA  Kenji KONO  

     
    PAPER-Dependable Computing

      Vol:
    E90-D No:12
      Page(s):
    2019-2032

    Exploiting layer7 context is an effective approach to improving the accuracy of detecting malicious messages in network intrusion detection/prevention systems (NIDS/NIPSs). Layer7 context enables us to inspect message formats and the message exchanged order. Unfortunately, layer7-aware NIDS/NIPSs pose crucial implementation issues because they require full TCP and IP reassembly without losing 1) complete prevention, 2) performance, 3) application transparency, or 4) transport transparency. Complete prevention means that the NIDS/NIPS should prevent malicious messages from reaching target applications. Application transparency means not requiring any modifications to and/or reconfiguration of server and client applications. Transport transparency is not to disrupt the end-to-end semantics of TCP/IP. To the best of our knowledge, none of the existing approaches meet all of these requirements. We have developed an efficient mechanism for layer7-aware NIDS/NIPSs that does meet the above requirements. Our store-through does this by forwarding each out-of-order or IP-fragmented packet immediately after copying the packet even if it has not been checked yet by an NIDS/NIPS sensor. Although the forwarded packet might turn out to be a part of an attack message, the store-through mechanism can successfully defend against the attack by blocking one of the subsequent packets that contain another part of attack message. Testing of a prototype in Linux kernel 2.4.30 demonstrated that the overhead of our mechanism is negligible compared with that of a simple IP forwarder even with the presence of out-of-order and IP-fragmented packets. In addition, the experimental results suggest that the CPU and memory usage incurred by our store-through is not significant.

  • Wideband NRD Guide and Rectangular Waveguide H-Plane Transition at 60 GHz Band

    Takashi SHIMIZU  Tsukasa YONEYAMA  

     
    LETTER

      Vol:
    E90-C No:12
      Page(s):
    2263-2265

    A wideband NRD guide and rectangular waveguide H-plane transition is proposed to transfer millimeter waves from a dielectric strip to the outer conductor surface of NRD guide through a short length of waveguide made through the conductor plate. As a result, it has a bandwidth about 6.7 GHz of |S11| -15 dB and a low transition loss about 0.35 dB at 60 GHz band.

  • Compiler for Architecture with Dynamic Reconfigurable Processing Unit by Use of Automatic Assignment Method of Sub-Programs Based on Their Quantitative Evaluation

    Takefumi MIYOSHI  Nobuhiko SUGINO  

     
    PAPER-Reconfigurable Device and Design Tools

      Vol:
    E90-D No:12
      Page(s):
    1967-1976

    For a coarse grain dynamic reconfigurable processing unit cooperating with a general purpose processor, a context selection method, which can reduce total execution cycles of a given program, is proposed. The method evaluates context candidates from a given program, in terms of reduction in cycles by exploiting parallel and pipeline execution of the reconfigurable processor. According to this evaluation measure, the method selects appropriate contexts for the dynamic reconfigurable processing unit. The proposed method is implemented on the framework of COINS project. For several example programs, the generated codes are evaluated by a software simulator in terms of execution cycles, and these results prove the effectiveness of the proposed method.

  • FEC-Based Reliable Transmission for Multiple Bursts in OBS Networks

    Satoshi ARIMA  Takuji TACHIBANA  Yuichi KAJI  Shoji KASAHARA  

     
    PAPER-Switching for Communications

      Vol:
    E90-B No:12
      Page(s):
    3541-3551

    In this paper, we consider consecutive burst transmission with burst loss recovery based on Forward Error Correction (FEC) in which redundant data is transmitted with multiple bursts. We propose two burst generation methods: Out-of Burst Generation (OBG) and In-Burst Generation (IBG). The OBG generates a redundant burst from redundant data, while the IBG reconstructs a burst from an original data block and a part of the redundant data. For both methods, the resulting bursts are transmitted consecutively. If some bursts among the bursts are lost at an intermediate node, the lost bursts can be recovered with the redundant data using FEC processing at the destination node. We evaluate by simulation the proposed methods in a uni-directional ring network and NSFNET, and compare the performances of the proposed methods with the extra-offset time method. Numerical examples show that the proposed methods can provide a more reliable transmission than the extra-offset time method for the OBS network where the maximum number of hops is large. Moreover, it is shown that the end-to-end transmission delay for our proposed methods can be decreased by enhancing the FEC processor or by increasing the number of FEC processors.

  • State Machines as Inductive Types

    Kazuhiro OGATA  Kokichi FUTATSUGI  

     
    LETTER-Concurrent Systems

      Vol:
    E90-A No:12
      Page(s):
    2985-2988

    We describe a way to write state machines inductively. The proposed method makes it possible to use the standard techniques for proving theorems on inductive types to verify that state machines satisfy invariant properties. A mutual exclusion protocol using a queue is used to exemplify the proposed method.

10601-10620hit(21534hit)