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4681-4700hit(20498hit)

  • Room Temperature Atomic Layer Deposition of Gallium Oxide Investigated by IR Absorption Spectroscopy

    P. Pungboon PANSILA  Kensaku KANOMATA  Bashir AHMMAD  Shigeru KUBOTA  Fumihiko HIROSE  

     
    PAPER

      Vol:
    E98-C No:5
      Page(s):
    382-389

    Gallium oxide is expected as a channel material for thin film transistors. In the conventional technologies, gallium oxide has been tried to be fabricated by atomic layer deposition (ALD) at high temperatures from 100--450$^{circ}$C, although the room-temperature (RT) growth has not been developed. In this work, we developed the RT ALD of gallium oxide by using a remote plasma technique. We studied trimethylgallium (TMG) adsorption and its oxidization on gallium oxide surfaces at RT by infrared absorption spectroscopy (IRAS). Based on the adsorption and oxidization characteristics, we designed the room temperature ALD of Ga$_{2}$O$_{3}$. The IRAS indicated that TMG adsorbs on the gallium oxide surface by consuming the adsorption sites of surface hydroxyl groups even at RT and the remote plasma-excited water and oxygen vapor is effective in oxidizing the TMG adsorbed surface and regeneration of the adsorption sites for TMG. We successfully prepared Ga$_{2}$O$_{3}$ films on Si substrates at RT with a growth per cycle of 0.055,nm/cycle.

  • Resistance-Switching Characteristics of Si-rich Oxide Evaluated by Using Ni Nanodots as Electrodes in Conductive AFM Measurements

    Akio OHTA  Chong LIU  Takashi ARAI  Daichi TAKEUCHI  Hai ZHANG  Katsunori MAKIHARA  Seiichi MIYAZAKI  

     
    PAPER

      Vol:
    E98-C No:5
      Page(s):
    406-410

    Ni nanodots (NDs) used as nano-scale top electrodes were formed on a 10-nm-thick Si-rich oxide (SiO$_{mathrm{x}}$)/Ni bottom electrode by exposing a 2-nm-thick Ni layer to remote H$_{2}$-plasma (H$_{2}$-RP) without external heating, and the resistance-switching behaviors of SiO$_{mathrm{x}}$ were investigated from current-voltage ( extit{I--V}) curves. Atomic force microscope (AFM) analyses confirmed the formation of electrically isolated Ni NDs as a result of surface migration and agglomeration of Ni atoms promoted by the surface recombination of H radicals. From local extit{I--V} measurements performed by contacting a single Ni ND as a top electrode with a Rh coated Si cantilever, a distinct uni-polar type resistance switching behavior was observed repeatedly despite an average contact area between the Ni ND and the SiO$_{mathrm{x}}$ as small as $sim$ 1.9 $ imes$ 10$^{-12}$cm$^{2}$. This local extit{I--V} measurement technique is quite a simple method to evaluate the size scalability of switching properties.

  • Tunable Threshold Voltage of Organic CMOS Inverter Circuits by Electron Trapping in Bilayer Gate Dielectrics

    Toan Thanh DAO  Hideyuki MURATA  

     
    PAPER

      Vol:
    E98-C No:5
      Page(s):
    422-428

    We have demonstrated tunable extit{n}-channel fullerene and extit{p}-channel pentacene OFETs and CMOS inverter circuit based on a bilayer-dielectric structure of CYTOP (poly(perfluoroalkenyl vinyl ether)) electret and SiO$_{2}$. For both OFET types, the $V_{mathrm{th}}$ can be electrically tuned thanks to the charge-trapping at the interface of CYTOP and SiO$_{2}$. The stability of the shifted $V_{mathrm{th}}$ was investigated through monitoring a change in transistor current. The measured transistor current versus time after programming fitted very well with a stretched-exponential distribution with a long time constant up to 10$^{6}$ s. For organic CMOS inverter, after applying the program gate voltages for extit{n}-channel fullerene or extit{p}-channel pentacene elements, the voltage transfer characteristics were shifted toward more positive values, resulting in a modulation of the noise margin. We realized that at a program gate voltage of 60,V for extit{p}-channel OFET, the circuit switched at 4, 8,V, that is close to half supply voltage $V_{mathrm{DD}}$, leading to the maximum electrical noise immunity of the inverter circuit.

  • A Deduplication-Enabled P2P Protocol for VM Image Distribution

    Choonhwa LEE  Sungho KIM  Eunsam KIM  

     
    LETTER-Information Network

      Pubricized:
    2015/02/19
      Vol:
    E98-D No:5
      Page(s):
    1108-1111

    This paper presents a novel peer-to-peer protocol to efficiently distribute virtual machine images in a datacenter. A primary idea of it is to improve the performance of peer-to-peer content delivery by employing deduplication to take advantage of similarity both among and within VM images in cloud datacenters. The efficacy of the proposed scheme is validated through an evaluation that demonstrates substantial performance gains.

  • Fault Localization Using Failure-Related Contexts for Automatic Program Repair

    Ang LI  Xiaoguang MAO  Yan LEI  Tao JI  

     
    LETTER-Software Engineering

      Pubricized:
    2015/01/08
      Vol:
    E98-D No:4
      Page(s):
    955-959

    Fault localization is essential for conducting effective program repair. However, preliminary studies have shown that existing fault localization approaches do not take the requirements of automatic repair into account, and therefore restrict the repair performance. To address this issue, this paper presents the first study on designing fault localization approaches for automatic program repair, that is, we propose a fault localization approach using failure-related contexts in order to improve automatic program repair. The proposed approach first utilizes program slicing technique to construct a failure-related context, then evaluates the suspiciousness of each element in this context, and finally transfers the result of evaluation to automatic program repair techniques for performing repair on faulty programs. The experimental results demonstrate that the proposed approach is effective to improve automatic repair performance.

  • Robust Visual Tracking Using Sparse Discriminative Graph Embedding

    Jidong ZHAO  Jingjing LI  Ke LU  

     
    PAPER-Image Recognition, Computer Vision

      Pubricized:
    2015/01/19
      Vol:
    E98-D No:4
      Page(s):
    938-947

    For robust visual tracking, the main challenges of a subspace representation model can be attributed to the difficulty in handling various appearances of the target object. Traditional subspace learning tracking algorithms neglected the discriminative correlation between different multi-view target samples and the effectiveness of sparse subspace learning. For learning a better subspace representation model, we designed a discriminative graph to model both the labeled target samples with various appearances and the updated foreground and background samples, which are selected using an incremental updating scheme. The proposed discriminative graph structure not only can explicitly capture multi-modal intraclass correlations within labeled samples but also can obtain a balance between within-class local manifold and global discriminative information from foreground and background samples. Based on the discriminative graph, we achieved a sparse embedding by using L2,1-norm, which is incorporated to select relevant features and learn transformation in a unified framework. In a tracking procedure, the subspace learning is embedded into a Bayesian inference framework using compound motion estimation and a discriminative observation model, which significantly makes localization effective and accurate. Experiments on several videos have demonstrated that the proposed algorithm is robust for dealing with various appearances, especially in dynamically changing and clutter situations, and has better performance than alternatives reported in the recent literature.

  • A Low-Latency DMR Architecture with Fast Checkpoint Recovery Scheme

    Go MATSUKAWA  Yohei NAKATA  Yasuo SUGURE  Shigeru OHO  Yuta KIMI  Masafumi SHIMOZAWA  Shuhei YOSHIDA  Hiroshi KAWAGUCHI  Masahiko YOSHIMOTO  

     
    PAPER

      Vol:
    E98-C No:4
      Page(s):
    333-339

    This paper presents a novel architecture for a fault-tolerant and dual modular redundancy (DMR) system using a checkpoint recovery approach. The architecture features exploitation of SRAM with simultaneous copy and instantaneous compare function. It can perform low-latency data copying between dual cores. Therefore, it can carry out fast backup and rollback. Furthermore, it can reduce the power consumption during data comparison process compared to the cyclic redundancy check (CRC). Evaluation results show that, compared with the conventional checkpoint/restart DMR, the proposed architecture reduces the cycle overhead by 97.8% and achieves a 3.28% low-latency execution cycle even if a one-time fault occurs when executing the task. The proposed architecture provides high reliability for systems with a real-time requirement.

  • Techniques for Measuring Business Process Based on Business Values

    Jihyun LEE  Sungwon KANG  

     
    PAPER-Office Information Systems, e-Business Modeling

      Pubricized:
    2014/12/26
      Vol:
    E98-D No:4
      Page(s):
    911-921

    The ultimate purpose of a business process is to promote business values. Thus, any process that fails to enhance or promote business values should be improved or adjusted so that business values can be achieved. Therefore an organization should have the capability of confirming whether a business value is achieved; furthermore, in order to cope with the changes of business environment, it should be able to define the necessary measures on the basis of business values. This paper proposes techniques for measuring a business process based on business values, which can be used to monitor and control business activities focusing on the attainment of business values. To show the feasibility of the techniques, we compare their monitoring and controlling capabilities with those of the current fulfillment process of a company. The results show that the proposed techniques are effective in linking business values to relevant processes and integrating each measurement result in accordance with the management level.

  • Analysis and Performance Improvement of Independent Electric Coupled Resonance WPT System with Impedance Transformer

    Cheng YANG  Koichi TSUNEKAWA  

     
    PAPER-Antennas and Propagation

      Vol:
    E98-B No:4
      Page(s):
    630-637

    Wireless power transfer (WPT) based on electric coupled resonance can withstand a great level of variability in antenna separation. In this paper, we propose an independent electrical coupled resonance WPT system to further increase such systems' power transfer distance and ensure flexibility in the antenna location. The proposed system's power transfer function, critical coupling point, and resonance frequency splitting are investigated via the equivalent circuit, simulation, and experiment. Moreover, the input impedance characteristic of two electric coupled resonance antennas is also analyzed according to the transfer distance. In the region of under coupled, an appropriate impedance matching method is required to achieve effective power transfers. Here, we proposed a fixed configuration type matching loop with a series-connecting variable capacitance that can be added into both the source and load antennas. Experimental results demonstrate that the proposed matching loop can convert the two electric coupled resonance antennas' input impedance to the feed port impedance very well at varying transfer distances; these results are in good agreement with the simulation results.

  • An Original Entry Point Detection Method with Candidate-Sorting for More Effective Generic Unpacking

    Ryoichi ISAWA  Daisuke INOUE  Koji NAKAO  

     
    PAPER-Information Network

      Pubricized:
    2015/01/06
      Vol:
    E98-D No:4
      Page(s):
    883-893

    Many malware programs emerging from the Internet are compressed and/or encrypted by a wide variety of packers to deter code analysis, thus making it necessary to perform unpacking first. To do this task efficiently, Guo et al. proposed a generic unpacking system named Justin that provides original entry point (OEP) candidates. Justin executes a packed program, and then it extracts written-and-executed points caused by the decryption of the original binary until it determines the OEP has appeared, taking those points as candidates. However, for several types of packers, the system can provide comparatively large sets of candidates or fail to capture the OEP. For more effective generic unpacking, this paper presents a novel OEP detection method featuring two mechanisms. One identifies the decrypting routine by tracking relations between writing instructions and written areas. This is based on the fact that the decrypting routine is the generator for the original binary. In case our method fails to detect the OEP, the other mechanism sorts candidates based on the most likely candidate so that analysts can reach the correct one quickly. With experiments using a dataset of 753 samples packed by 25 packers, we confirm that our method can be more effective than Justin's heuristics, in terms of detecting OEPs and reducing candidates. After that, we also propose a method combining our method with one of Justin's heuristics.

  • Advantages and Drawbacks of Smartphones and Tablets for Visually Impaired People —— Analysis of ICT User Survey Results ——

    Tetsuya WATANABE  Toshimitsu YAMAGUCHI  Kazunori MINATANI  

     
    PAPER-Rehabilitation Engineering and Assistive Technology

      Pubricized:
    2014/12/26
      Vol:
    E98-D No:4
      Page(s):
    922-929

    A survey was conducted on the use of ICT by visually impaired people. Among 304 respondents, 81 used smartphones and 44, tablets. Blind people used feature phones at a higher rate and smartphones and tablets at lower rates than people with low vision. The most popular smartphone model was iPhone and the most popular tablet model was iPad. While almost all blind users used the speech output accessibility feature and only a few of them used visual features, low vision users used both visual features such as Zoom, Large text, and Invert colors and speech output at high rates both on smartphones and tablets. The most popular text entry methods were different between smartphones and tablets. For smartphones flick and numeric keypad input were popular among low vision users while voice input was the most popular among blind users. For tablets a software QWERTY keyboard was the most popular among both blind and low vision users. The advantages of smartphones were access to geographical information, quick Web browsing, voice input, and extensibility for both blind and low vision users, object recognition for blind users, and readability for low vision users. Tablets also work as a vision aid for people with low vision. The drawbacks of smartphones and tablets were text entry and touch operation difficulties and inaccessible apps for both blind and low vision users, problems in speech output for blind users, and problems in readability for low vision users. Researchers and makers of operating systems (OS) and apps should assume responsibility for solving these problems.

  • Cooperative Relaying Channel and Outage Performance in Narrowband Wireless Body Area Network

    Karma WANGCHUK  Minseok KIM  Jun-ichi TAKADA  

     
    PAPER

      Vol:
    E98-B No:4
      Page(s):
    554-564

    To improve the outage performance of a wireless body area network (BAN), exploitation of the diversity in the channel obtained by letting different nodes cooperate and relay signals for each other is an attractive solution. We carry out multi-link channel measurements and modeling for all realistic locations of the on-body sensor nodes and for three different motion scenarios in a typical office environment to develop equivalent channel model for simple and practical cooperative transmission schemes. Using the developed model the performance of the transmission schemes are evaluated and compared. Incremental decode and forward relaying is found to be consistently better than the other schemes with gains of up to 16dB at 10% outage probability, and an average gain of more than 5.9dB for any location of the coordinator node. The best location of the coordinator node based on the performance is also determined. Such insights will be very useful in designing BANs.

  • Supporting Jogging at an Even Pace by Synchronizing Music Playback Speed with Runner's Pace

    Tetsuro KITAHARA  Shunsuke HOKARI  Tatsuya NAGAYASU  

     
    LETTER-Human-computer Interaction

      Pubricized:
    2015/01/09
      Vol:
    E98-D No:4
      Page(s):
    968-971

    In this paper, we propose a jogging support system that plays back background music while synchronizing its tempo with the user's jogging pace. Keeping an even pace is important in jogging but it is not easy due to tiredness. Our system indicates the variation of the runner's pace by changing the playback speed of music according to the user's pace variation. Because this requires the runner to keep an even pace in order to enjoy the music at its normal speed, the runner will be spontaneously influenced to keep an even pace. Experimental results show that our system reduced the variation of jogging pace.

  • Personalized Recommendation of Item Category Using Ranking on Time-Aware Graphs

    Chen CHEN  Chunyan HOU  Peng NIE  Xiaojie YUAN  

     
    PAPER-Natural Language Processing

      Pubricized:
    2015/01/19
      Vol:
    E98-D No:4
      Page(s):
    948-954

    Recommendation systems have been widely used in E-commerce sites, social media and etc. An important recommendation task is to predict items that a user will perform actions on with users' historical data, which is called top-K recommendation. Recently, there is huge amount of emerging items which are divided into a variety of categories and researchers have argued or suggested that top-K recommendation of item category could be very beneficial for users to make better and faster decisions. However, the traditional methods encounter some common but crucial problems in this scenario because additional information, such as time, is ignored. The ranking algorithm on graphs and the increasingly growing amount of online user behaviors shed some light on these problems. We propose a construction method of time-aware graphs to use ranking algorithm for personalized recommendation of item category. Experimental results on real-world datasets demonstrate the advantages of our proposed method over competitive baseline algorithms.

  • Identifying Nonlocal Dependencies in Incremental Parsing

    Yoshihide KATO  Shigeki MATSUBARA  

     
    LETTER-Natural Language Processing

      Pubricized:
    2015/01/13
      Vol:
    E98-D No:4
      Page(s):
    994-998

    This paper describes a method of identifying nonlocal dependencies in incremental parsing. Our incremental parser inserts empty elements at arbitrary positions to generate partial parse trees including empty elements. To identify the correspondence between empty elements and their fillers, our method adapts a hybrid approach: slash feature annotation and heuristic rules. This decreases local ambiguity in incremental parsing and improves the accuracy of our parser.

  • Preliminary Study of Electrical Contact Behaviors of Au-plated Material at Super Low Making/Breaking Velocity

    Wanbin REN  Shengjun XUE  Hongxu ZHI  Guofu ZHAI  

     
    PAPER-Electromechanical Devices and Components

      Vol:
    E98-C No:4
      Page(s):
    364-370

    This paper presents the electrical contact behaviors of Au-plated material at super low making and breaking velocity conditions by introducing our new designed test rig. The fundamental phenomena in the contact voltage and contact force versus piezoactuator displacement curves were investigated under the load current of 1A and velocity of 50,nm/s. From the repetitive experimental results, we found that the adhesion phenomena during the unloading process are closely correlative with the initial contact stage in the loading process. Furthermore, a mathematical model which is relative to the variation of contact force in loading is built, thus the physical mechanism of adhesion and principal factors of gold-plated materials are discussed. Finally, the physical process of molten bridge under the no mechanical contact situation is also analyzed in detail.

  • Social Network and Tag Sources Based Augmenting Collaborative Recommender System

    Tinghuai MA  Jinjuan ZHOU  Meili TANG  Yuan TIAN  Abdullah AL-DHELAAN  Mznah AL-RODHAAN  Sungyoung LEE  

     
    PAPER-Office Information Systems, e-Business Modeling

      Pubricized:
    2014/12/26
      Vol:
    E98-D No:4
      Page(s):
    902-910

    Recommender systems, which provide users with recommendations of content suited to their needs, have received great attention in today's online business world. However, most recommendation approaches exploit only a single source of input data and suffer from the data sparsity problem and the cold start problem. To improve recommendation accuracy in this situation, additional sources of information, such as friend relationship and user-generated tags, should be incorporated in recommendation systems. In this paper, we revise the user-based collaborative filtering (CF) technique, and propose two recommendation approaches fusing user-generated tags and social relations in a novel way. In order to evaluate the performance of our approaches, we compare experimental results with two baseline methods: user-based CF and user-based CF with weighted friendship similarity using the real datasets (Last.fm and Movielens). Our experimental results show that our methods get higher accuracy. We also verify our methods in cold-start settings, and our methods achieve more precise recommendations than the compared approaches.

  • Efficient Algorithm and Fast Hardware Implementation for Multiply-by-(1+2k)

    Chin-Long WEY  Ping-Chang JUI  Muh-Tian SHIUE  

     
    PAPER-VLSI Design Technology and CAD

      Vol:
    E98-A No:4
      Page(s):
    966-974

    A constant multiplier performs a multiplication of a data-input with a constant value. Constant multipliers are essential components in various types of arithmetic circuits, such as filters in digital signal processor (DSP) units, and they are prevalent in modern VLSI designs. This study presents an efficient algorithm and fast hardware implementation for performing multiply-by-(1+2k) operation with additions. No multiplications are needed. The value of (1+2k)N can be computed by adding N to its k-bit left-shifted value 2kN. The additions can be performed by the full-adder-based (FA-based) ripple carry adder (RCA) for simple architecture. This paper introduces the unit cells for additions (UCAs) to construct the UCA-based RCA which achieves 35% faster than the FA-based RCA in speed performance. Further, in order to improve the speed performance, a simple and modular hybrid adder is presented with the proposed UCA concept, where the carry lookahead adder (CLA) as a module and many of the CLA modules are serially connected in a fashion similar to the RCA. Results show that the hybrid adder significantly improves the speed performance.

  • Analysis and Improvement of MaTRU Public Key Cryptosystem

    Jeong Eun SONG  Tae Youn HAN  Mun-Kyu LEE  

     
    PAPER-Cryptography and Information Security

      Vol:
    E98-A No:4
      Page(s):
    982-991

    At Indocrypt 2005, Coglianese and Goi [1] suggested a new public key cryptosystem, MaTRU, which is a variant of NTRU. MaTRU is defined over ring M of k×k matrices whose elements are in the quotient ring R = Z[X]/(Xn-1). In addition, five example parameter sets suitable for this new structure were proposed. In this paper, we prove that it is impossible to generate appropriate key pairs for four parameter sets among the five proposed in [1] according to the key generation procedure described in [1]. The only parameter set where key pair generation is possible is when p, one of the parameters of MaTRU, is 2 and df, another parameter, is odd. Even with this parameter set, however, the decryption operation defined in [1] cannot recover an original plaintext from a given ciphertext because the value of another parameter, q, has been defined too small in [1]. Therefore, we propose an alternative method for key generation and suggest corrected parameter sets. In addition, a refined analysis for the key security of MaTRU is provided, and it is demonstrated that the key security may be significantly lower than that of the original analysis.

  • Fuzzy-Based Adaptive Countering Method against False Data Injection Attacks in Wireless Sensor Networks

    Hae Young LEE  

     
    LETTER-Information Network

      Vol:
    E98-D No:4
      Page(s):
    964-967

    This letter presents a method to adaptively counter false data injection attacks (FDIAs) in wireless sensor networks, in which a fuzzy rule-based system detects FDIAs and chooses the most appropriate countermeasures. The method does not require en-route verification processes and manual parameter settings. The effectiveness of the method is shown with simulation results.

4681-4700hit(20498hit)