IEEJ Transactions on Electronics, Information and Systems
Online ISSN : 1348-8155
Print ISSN : 0385-4221
ISSN-L : 0385-4221
Volume 135 , Issue 9
Showing 1-23 articles out of 23 articles from the selected issue
Special Issue on “Laser Processing Technology for Sustainable Society and Advanced Applications”
Preface
Special Issue Review
  • Koji Sugioka
    2015 Volume 135 Issue 9 Pages 1037-1042
    Published: September 01, 2015
    Released: September 01, 2015
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    The rapid development of ultrafast lasers, such as femtosecond and picosecond lasers, has revolutionized materials processing due to its unique characteristics of ultrashort pulse width and extremely high peak intensity. The ultrashort pulse width suppresses the formation of a heat-affected zone (HAZ), which is vital for ultrahigh precision fabrication, whereas the extremely high peak intensity allows nonlinear interactions such as multiphoton absorption and tunneling ionization to be induced in transparent materials, which provides versatility in terms of the materials that can be processed. Thus, ultrafast lasers are currently used widely for not only fundamental research but also practical applications. This review paper describes the characteristics of ultrafast laser processing and then introduces the state-of-the-art of practical applications of ultrafast laser processing.
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  • Mitsuhiro Terakawa, Shuhei Yada
    2015 Volume 135 Issue 9 Pages 1043-1048
    Published: September 01, 2015
    Released: September 01, 2015
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    During the last decades, biodegradable polymers have been attracting increasing attention in tissue engineering and drug delivery due to its high biocompatibility and biodegradability. Chemical structure and surface properties of biodegradable polymers are known to be a key factor to decide its functionality as biomaterials. Among various methods to process or modify biodegradable polymer surfaces, laser processing has advantages in a dry processing which is able to process complex-shaped surfaces without using a toxic chemical component. This review gives an overview of laser processing of biodegradable polymer surfaces for biomedical applications. The formation of laser induced periodic surface structure (LIPSS) on a biodegradable polymer is also discussed.
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Special Issue Paper
<Electronic Materials and Devices>
  • Norio Ichikawa, Kohei Ikeda, Yoshinori Honda, Hiroyuki Taketomi, Koji ...
    2015 Volume 135 Issue 9 Pages 1049-1054
    Published: September 01, 2015
    Released: September 01, 2015
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    Pr:LuAG thin film was deposited by PLD. Before and after thermal treatment, each film was characterized using XRD, SEM and Cathode Luminescence. Thermal treatment led this film to crystallization of Pr:LuAG with garnet structure. And UV emission was obtained from the Pr:LuAG film pumped by irradiating electron beam. We applied this technique to produce a product of a UV light source using Pr:LuAG thin film target pumped by electron beam.
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  • Ikurou Umezu, Takehito Yoshida
    2015 Volume 135 Issue 9 Pages 1055-1059
    Published: September 01, 2015
    Released: September 01, 2015
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    We prepared titanium dioxide (TiO2) nanoparticles by pulsed laser ablation of TiO2 target in O2 background gas. Effects of background gas pressure and substrate target distance on the structure of deposited films are clarified. The primary structure, nanocrystals, changes from rutile to anatase phase with increasing background gas pressure or substrate target distance. The porosity of aggregated structure increases with increasing background gas pressure or substrate target distance. These results indicate that confinement of the plume between target and substrate is important for structural formation. The hierarchical micron- and submicron-sized structures were found by the analysis of scanning electron microscope images. The deposits are composed of primary, secondary and tertiary structures; they are nanoparticles, submicron-sized aggregates and micron-sized aggregates. The non-equilibrium aggregation processes of nanoparticles in the plume and/or on the substrate are essential for the formation of hierarchical structure.
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  • Ryuichi Ishihara, Takuya Sagara, Satoshi Kurumi, Ken-ichi Matsuda, Kao ...
    2015 Volume 135 Issue 9 Pages 1060-1065
    Published: September 01, 2015
    Released: September 01, 2015
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    In this paper, we have investigated the growth technique of graphite-coated nanomagnet particles to apply a sustainable environment technology by millisecond YAG pulsed laser ablation (PLA) method in ethanol solution using Fe bulk-target. To control crystallized forms and/or grain-size of nanomagnet-materials, laser diode (LD) beam was irradiated to the ablation plumes, which were generated by this PLA method. Additionally, magnetic field was applied to the ablation plumes, in order to separate a nanomagnet particle and a non-magnet one. Ablation plumes were observed by high-speed camera images, and they were re-excited by LD laser beam irradiation. In case of magnetic field assist, ablation plumes were attracted to the magnet. This suggested that growth nano-particles had magnetic property. Typical carbon-coated nano-particles, which grown by non-assisted PLA, were observed by TEM images, and these grain sizes were dependent on the pulsed width of PLA source. On the other hand, LD assisted samples showed there were rod-sharped nano-materials, and crystallization of these materials was β-Fe3O4, γ-Fe2O3 surmised by electron diffraction.
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  • Yoshie Ishikawa, Naoto Koshizaki, Alexander Pyatenko
    2015 Volume 135 Issue 9 Pages 1066-1070
    Published: September 01, 2015
    Released: September 01, 2015
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    Submicrometer-sized spheres of iron oxide were obtained by laser irradiation of cuboidal Fe3O4 particles dispersed in ethanol, acetone, and toluene. Sphere formation condition and sphere size are explained based on a relationship between particle size and laser fluence required for solid-liquid phase transition of Fe3O4, which is calculated by equating the melting enthalpy and the optically absorbed energy derived from Mie theory. FeO was partially formed by laser irradiation at 200 mJ pulse-1 cm-2 in ethanol, acetone and toluene. The reduction reaction is not simply due to thermal decomposition of Fe3O4, but due to the reduction by chemical species generated from solvent surrounding Fe3O4 particles melted by laser irradiation. Ethanol was more reductive than the other two solvents; Fe is formed even at 200 mJ pulse-1 cm-2. This is probably due to chemical rectivity of produced iron oxides and chemical species transiently generated from solvent.
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<Optics, Quantum Electronics>
  • Masayuki Okoshi
    2015 Volume 135 Issue 9 Pages 1071-1074
    Published: September 01, 2015
    Released: September 01, 2015
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    A transparent, hard silica glass (SiO2) layer was formed on a conventional protective coat made of silicone ([SiO(CH3)2]n) on a polycarbonate plate by the 157 nm fluorine (F2) laser-induced photochemical modification of silicone into SiO2. Long exposure of the F2 laser to the sample produced cracks on the surface; a metallic mesh mask was set on the sample during F2 laser irradiation to suppress the cracks successfully. As a result, the thickness of the formed SiO2 layer could increase to approximately 1.3 µm without any crack, and the hardness of the sample also increased to approximately 2.8 GPa.
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  • Erina Miyasaka, Tomoyuki Hamaguchi, Tomoyuki Yatsuhashi
    2015 Volume 135 Issue 9 Pages 1075-1079
    Published: September 01, 2015
    Released: September 01, 2015
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    The decomposition of aqueous chlorohydrocarbons regarded as environmental pollutants has been widely studied. However, it is usually difficult to separate liquid and/or volatile products originated from chlorohydrocarbons from reactant solution. We succeeded to precipitate hydrophobic carbon nanoparticles and their agglomerates from aqueous dichloromethane by femtosecond laser (0.8 µm, 40 fs) irradiation. In the case of water/dichloromethane bilayer solution, the precipitates were produced in abundance when the water layer was exposed to femtosecond laser pulses. The time evolution of pH and transmittance revealed that the precipitation of carbon particles was preceded by dechlorination. Focusing intense femtosecond laser pulses onto water creates a high density of reactive species in a well-confined volume; i.e., plasma filament. The graphitization hence solidification by using laser pulses could be an useful way to remove chlorinated compounds from their aqueous solution.
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  • Yoshiki Nakata, Yoshiki Matsuba, Noriaki Miyanaga
    2015 Volume 135 Issue 9 Pages 1080-1084
    Published: September 01, 2015
    Released: September 01, 2015
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    Interference pattern of two different wavelengths, forming a four-sided pyramid consisting of eight beams, is discussed. By using two wavelengths with relation of λ1=2λ2, interference pattern can be formed in numerical simulation. Phase shift and amplitude variation of interfering beams are useful to obtain a variety of interference patterns. On the other hand, ultra-violet femtosecond laser was applied to interfering femtosecond laser processing. MHA (Metallic-Hole Array) structure was fabricated in 100 nm and 200 nm thick gold thin films successfully by multiple shots. The period was minified to 0.76 µm.
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  • Daisuke Nakamura, Toshinobu Tanaka, Tatsuya Ikebuchi, Takeshi Ueyama, ...
    2015 Volume 135 Issue 9 Pages 1085-1089
    Published: September 01, 2015
    Released: September 01, 2015
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    We have succeeded in synthesiing the ZnO microspheres by laser ablation of a ZnO sintered target in air, and we have demonstrated ultraviolet whispering-gallery-mode (WGM) lasing from the sphere under ultraviolet pulsed laser excitation. In this study, we investigated the dependence of the laser fluence and the spot size on the growth of the ZnO microspheres. Large size of more than 30 µm microspheres were synthesized with increasing the laser fluence up to 440 J/cm2. Although undesired nanoparticles and fragments were also generated at high fluence and large ablation spot size, selective collection of the microspheres can be expected because of different emitting distribution of the microspheres and other fragments.
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<Systems, Instrument, Control>
  • Takeshi Tsuji, Isami Takade, Masaharu Tsuji, Yoshie Ishikawa, Naoto Ko ...
    2015 Volume 135 Issue 9 Pages 1090-1095
    Published: September 01, 2015
    Released: September 01, 2015
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    Laser irradiation for colloidal gold nanoparticles stabilized by Na2CO3 was carried out to prepare submicron-sized spherical particles of gold. The source gold nanoparticles stabilized by Na2CO3 (CO32-) were prepared using laser ablation in an aqueous solutions containing Na2CO3 and then non-focused laser irradiation for the source nanoparticles was carried out to induce the agglomeration and fusion of the nanoparticles. Similarly to the case using the source nanoparticles stabilized by citrate, submicron particles were obtained. It was found that the formation process and size of the submicron particles strongly depend on the stabilizing reagents.
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Special Issue Letter
<Electronic Materials and Devices>
Paper
<Information and Communication Technology>
  • Naoya Ohnishi, Tooru Takanaka, Hiroshi Nakatani
    2015 Volume 135 Issue 9 Pages 1098-1105
    Published: September 01, 2015
    Released: September 01, 2015
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    When a large-scale disaster occurs in control systems for social infrastructure, field equipments and control programs of the control systems might be lost. We have proposed the control system which operates control processing on cloud servers for rapid recovery from a disaster. This paper proposes architecture for cloud control system and a method for balancing the processing load of cloud servers. We examine the response time of the control processing operated by the cloud control system built on Amazon Web Services (AWS).
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<Biomedical Engineering>
  • Tomoki Amemiya, Takahiro Noda, Tomoyo I. Shiramatsu, Ryohei Kanzaki, H ...
    2015 Volume 135 Issue 9 Pages 1106-1111
    Published: September 01, 2015
    Released: September 01, 2015
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    Repetitive sound sequences are easily distinguished from other background sounds. The present study investigated the neural mechanisms underlying the perception of repetitive sound sequences. We measured neural responses at the layer IV in auditory cortex of anesthetized rats and compared evoked responses to repetitive tone sequences and those to random tone sequences. Our results demonstrated that repetition of tone sequences modulated both amplitude and band-specific phase coherence of auditory evoked responses. The amplitude of evoked responses depended on a preceding tone in a given sequence, possibly due to the forward masking. The phase coherence tended to be higher during the repetitive sequences than during random sequences, specifically in the low-gamma band. The enhancement of amplitude to a specific tone was associated with an increase of phase coherence in the low gamma band. Thus, the co-modulation of amplitude and phase coherence of evoked responses plays an important role in perception of sound regularity.
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  • Rie Hitsuyu, Tomoyo Isoguchi Shiramatsu, Takahiro Noda, Ryohei Kanzaki ...
    2015 Volume 135 Issue 9 Pages 1112-1119
    Published: September 01, 2015
    Released: September 01, 2015
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    Vagus nerve stimulation (VNS) causes neuromodulatory effects in the cerebral cortex, which are useful not only for therapy on intractable epilepsy but also for enhancement of higher brain functions such as cognition and memory. Recently, it has been reported that VNS may also affect auditory-evoked neural activities. However, it remains to be elucidated how and where VNS modulates neural activities in the auditory cortex. Here we examined effects of VNS on adaptation of neural activities in response to repeated stimuli in the rat auditory cortex. Both a surface and depth microelectrode array recorded auditory evoked potentials in response to click trains and oddball stimuli. We quantified a repetition rate transfer function (RRTF) and common stimulus-specific adaptation (SSA) index (CSI) from the amplitude of middle-latency response (P1). Consequently, VNS affected temporal response property and increased SSA in the layer 1 and 5/6 of auditory cortex. This result suggests that VNS strengthens adaptation in the auditory cortex in a layer-specific manner.
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<Systems, Instrument, Control>
  • Lei Wang, Zining Zhen, Xiaolin Zhang
    2015 Volume 135 Issue 9 Pages 1120-1130
    Published: September 01, 2015
    Released: September 01, 2015
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    Parallax adjustment is still playing a very difficult part in stereoscopic shooting, because each factor changes, such as baseline, convergence, view angle, would change the perceptual distances of the whole image. In this paper, we estimated the effect about these factors in stereoscopic shooting, and proposed a parallax adjustment method for active stereo camera system. The proposed method can provide the optimal baseline and convergence value by feedback calculation in the following cases. 1. Specified parallax range of the scene. 2. Specified perceptual distances of a given object. We implement the method on an active stereo camera system. With this system, users can pay their attention on the stereo effect, the baseline and convergence will be real-time controlled automatically to achieve the stereo effect which users want to obtain. We evaluated the method in natural environment, and it is shown that the specified stereo effect can be obtained faster and more accurate.
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<Speech and Image Processing, Recognition>
  • Tatsumi Sugiyama, Fumihiko Saitoh
    2015 Volume 135 Issue 9 Pages 1131-1135
    Published: September 01, 2015
    Released: September 01, 2015
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    Image template matching is applied to various fields such as industrial image applications. This paper proposes a method for image template matching that is based on the order of density in local image area. This method sorts gray-levels of neighboring pixels to the horizontal direction in ascending order and position relations at that time are used for matching is performed between the templates that have the density order table of the pixels and an objective gray-scaled image. The experimental results show that the proposed method had equal or better robustness to shading, inclination, occlusion, off-focus, and noise in comparison with the conventional method.
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  • Wee-Hong Ong, Leon Palafox, Takafumi Koseki
    2015 Volume 135 Issue 9 Pages 1136-1141
    Published: September 01, 2015
    Released: September 01, 2015
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    At current stage, the majority of the human activity recognition (HAR) technologies are based on supervised learning, where there are labeled data to train an expert system. In this paper, we proposed a framework based on the unsupervised learning to autonomously discover, learn and recognize atomic activities, i.e., the actions. The input to the HAR framework is a sample pool of unlabeled observations of an unknown number of actions. An incremental action discovery algorithm based on K-means is used to discover new actions. For each new action discovered, a learning algorithm is used to model it through an automated training and cross-validation cycle. The algorithm uses Mixture of Gaussians Hidden Markov Model (HMM) to model the actions, and the algorithm autonomously determines the appropriate number of Gaussian components and states. The framework deals with the dynamic and noisy nature of the data. We evaluated the proposed framework on a third party dataset of daily activities and the results show its performance is in-par with that achieved using a supervised learning algorithm to recognize the activities from the same dataset.
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<Softcomputing, Learning>
  • Masaki Kadota, Toshiyuki Yasuda, Yoshiyuki Matsumura, Kazuhiro Ohkura
    2015 Volume 135 Issue 9 Pages 1142-1148
    Published: September 01, 2015
    Released: September 01, 2015
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    Differential Evolution (DE) is a population-based stochastic search method for real-valued function optimization. Like other metaheuristic algorithms, DE finds optimal or near-optimal solutions without a priori knowledge about the function being optimized. However, DE generally shows largely different performance according to the DE parameters adopted. Therefore, various DE variants have been developed in order to obtain more stable and better performance. A DE variant called SHADE is one of the highly competitive DE variants so far. SHADE introduces parameter archives for parameter adaptation to generate better optimization results. In this paper, SHADE is extended in such a way that parameter archives are managed by novel three strategies so that DE parameters are robust against fixation which may occur by trapping the evolutionary search into local optima. We call this method the robust SHADE, i.e., RSHADE. The computer simulations are conducted to examine the performance of RSHADE on 28 benchmarks.
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Letter
<Speech and Image Processing, Recognition>
  • Shuji Inada, Yusuke Kajiwara, Hiromitsu Shimakawa
    2015 Volume 135 Issue 9 Pages 1149-1150
    Published: September 01, 2015
    Released: September 01, 2015
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    The evaluation of past processes of production from farming records enables job-changing middle or advanced farmer to work more effectively. The paper proposes a method to discriminate farm works from viewpoint videos, reducing the load of farmers. In this method, farmers wear a camera embedded in a glasses to acquire viewpoint videos during their farm works. To confirm the effectiveness of the method, it is applied to the discrimination of watering, plowing, adding fertilizer, disbudding, and seeding. As a result, the method has discriminated watering and plowing with high accuracy using routing information of farm works. In addition, this paper has discussed important factor for farm-works discrimination and the problem of viewpoint video.
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