著者

Okubo Susumu Nakata Ryohei Ikeda Shohei Takahashi Naoki Sakurai Takahiro Zhang Wei-Min Ohta Hitoshi Shimokawa Tokuro Sakai Tôru Okuta Koji Hara Shigeo Sato Hirohiko

出版者

The Physical Society of Japan

雑誌

Journal of the Physical Society of Japan (ISSN:00319015)

巻号頁・発行日

vol.86, no.2, 2017-01-12

被引用文献数

11

著者

Zhang Wei 小林 真之 増田 裕次 森本 俊文

出版者

歯科基礎医学会

雑誌

歯科基礎医学会雑誌 (ISSN:03850137)

巻号頁・発行日

vol.44, no.5, 2002-09-20

著者

ZHANG Wei REN Huan JIANG Qingshan

出版者

一般社団法人 電子情報通信学会

雑誌

IEICE Transactions on Information and Systems (ISSN:09168532)

巻号頁・発行日

vol.99, no.4, pp.1062-1070, 2016

被引用文献数

6

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Phishing attacks target financial returns by luring Internet users to exposure their sensitive information. Phishing originates from e-mail fraud, and recently it is also spread by social networks and short message service (SMS), which makes phishing become more widespread. Phishing attacks have drawn great attention due to their high volume and causing heavy losses, and many methods have been developed to fight against them. However, most of researches suffered low detection accuracy or high false positive (FP) rate, and phishing attacks are facing the Internet users continuously. In this paper, we are concerned about feature engineering for improving the classification performance on phishing web pages detection. We propose a novel anti-phishing framework that employs feature engineering including feature selection and feature extraction. First, we perform feature selection based on genetic algorithm (GA) to divide features into critical features and non-critical features. Then, the non-critical features are projected to a new feature by implementing feature extraction based on a two-stage projection pursuit (PP) algorithm. Finally, we take the critical features and the new feature as input data to construct the detection model. Our anti-phishing framework does not simply eliminate the non-critical features, but considers utilizing their projection in the process of classification, which is different from literatures. Experimental results show that the proposed framework is effective in detecting phishing web pages.

著者

Meng Jianwei Jiang Jun Geng Wenping Chen Zhihui Zhang Wei Jiang Anquan

出版者

Institute of Physics

雑誌

Jpn. J. Appl. Phys. (ISSN:00214922)

巻号頁・発行日

vol.54, no.2, 2015-01-19

被引用文献数

3

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We fabricated (00l) BiFeO<inf>3</inf>(BFO) thin films in different growth modes on SrRuO<inf>3</inf>/SrTiO<inf>3</inf>substrates using a pulsed laser deposition technique. X-ray diffraction patterns show an out-of-plane lattice constant of 4.03 Å and ferroelectric polarization of 82 µC/cm²for the BFO thin film in a layer-by-layer growth mode (2D-BFO), larger than 3.96 Å and 51 µC/cm²for the thin film in the 3D-island formation growth mode (3D-BFO). The 2D-BFO thin film at 300 K shows switchable on/off diode currents upon polarization flipping near a negative coercive voltage, which is nevertheless absent from the above 3D-BFO thin film. From a positive-up–negative-down pulse characterization technique, we measured domain switching current transients as well as polarization–voltage (P<inf>f</inf>–V<inf>f</inf>) hysteresis loops in both semiconducting thin films. P<inf>f</inf>–V<inf>f</inf>hysteresis loops after 1 µs-retention time show the preferred domain orientation pointing to bottom electrodes in a 3D-BFO thin film. The poor retention of the domains pointing to top electrodes can be improved considerably in a 2D-BFO thin film. From these measurements, we extracted domain switching time dependence of coercive voltage at temperatures of 78–300 K. From these dependences, we found coercive voltages in semiconducting ferroelectric thin films much higher than those in insulating thin films, disobeying the traditional Merz equation. Finally, an equivalent resistance model in description of free-carrier compensation of the front domain boundary charge is developed to interpret this difference. This equivalent resistance can be coincidently extracted either from domain switching time dependence of coercive voltage or from applied voltage dependence of domain switching current, which drops almost linearly with the temperature until down to 0 in a ferroelectric insulator at 78 K.

著者

Zhang Wei Tsurushima Hideo Oyane Ayako Yazaki Yushin Sogo Yu Ito Atsuo Matsumura Akira

出版者

BioMed Central Ltd.

雑誌

Journal of biomedical science (ISSN:10217770)

巻号頁・発行日

vol.18, pp.62, 2011-08

被引用文献数

28 16

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BackgroundSafe and efficient gene transfer systems are needed for tissue engineering. We have developed an apatite composite layer including the bone morphogenetic protein-2 (BMP-2) gene and fibronectin (FB), and we evaluated its ability to induce bone formation.MethodsAn apatite composite layer was evaluated to determine the efficiency of gene transfer to cells cultured on it. Cells were cultured on a composite layer including the BMP-2 gene and FB, and BMP-2 gene expression, BMP-2 protein concentrations, alkaline phosphatase (ALP) activity, and osteocalcin (OC) concentrations were measured. A bone defect on the cranium of rats was treated with hydroxyapatite (HAP)-coated ceramic buttons with the apatite composite layer including the BMP-2 gene and FB (HAP-BMP-FB). The tissue concentration of BMP-2, bone formation, and the expression levels of the BMP-2, ALP, and OC genes were all quantified.ResultsThe apatite composite layer provided more efficient gene transfer for the cultured cells than an apatite composite layer without FB. The BMP-2 concentration was approximately 100~600 pg/mL in the cell-culture medium. Culturing the cells on the apatite composite layer for 27 days increased ALP activity and OC concentrations. In animal experiments, the tissue concentrations of BMP-2 were over 100 pg/mg in the HAP-BMP-FB group and approximately 50 pg/mg in the control groups. Eight weeks later, bone formation was more enhanced in the HAP-BMP-FB group than in the control groups. In the tissues surrounding the HAP button, the gene expression levels of ALP and OC increased.ConclusionThe BMP-2 gene-FB-apatite composite layer might be useful for bone engineering.

著者

首藤 もと子 小嶋 華津子 キンポ ネイサン サーベドラ ネアントロ フォーシェ キャロル ルイ ジャン=オーグスタン ALICE Sindzingre ANGELA Uforo Shanyo BRAHIMA Songore CLAUDE Sumata EDSON Kenji Kondo 江 時学 MBATIA Hiram Mwangi SAAVEDRA Neantro SEIFUDEIN Adem SHERLON Chi-yin Ip ZHANG Wei Wei

出版者

筑波大学

雑誌

基盤研究(A)

巻号頁・発行日

2008

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本研究は、中国の開発援助がどのような分野で供与され実施されているか、それは受入側の社会でどのように評価され、どのような経済的、社会的変化をもたらしているかについて、主として受入国での現地調査を基に分析した。平成20~22年度に現地調査を行った国は、アフリカ(タンザニア、ケニア、エチオピア、コンゴ、マリ)、東南アジア(インドネシア、フィリピン、ベトナム、メコン流域諸国)および中南米諸国(ブラジル、ペルー、コスタリカ、キューバ)である。現地調査とは別に、中国の対外援助の政策決定過程についての研究も行った。本研究の成果は2011年中に編集作業を進めて英文で出版する計画である。