検索結果 15022 件
| JaLCDOI | 10.18926/19959 |
|---|---|
| フルテキストURL | Mem_Fac_Eng_OU_44_50.pdf |
| 著者 | 金谷 健一| Niitsuma Hirotaka| Rangrajan Prasanna| |
| 抄録 | We present highly accurate least-squares (LS) alternatives to the theoretically optimal maximum likelihood (ML) estimator for homographies between two images. Unlike ML, our estimators are non-iterative and yield solutions even in the presence of large noise. By rigorous error analysis, we derive a “hyperaccurate” estimator which is unbiased up to second order noise terms. Then, we introduce a computational simplification, which we call “Taubin approximation”, without incurring a loss in accuracy. We experimentally demonstrate that our estimators have accuracy surpassing the traditional LS estimator and comparable to the ML estimator. |
| 出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
| 発行日 | 2010-01 |
| 巻 | 44巻 |
| 開始ページ | 50 |
| 終了ページ | 59 |
| ISSN | 1349-6115 |
| 言語 | 英語 |
| 論文のバージョン | publisher |
| NAID | 120002308986 |
| JaLCDOI | 10.18926/19958 |
|---|---|
| フルテキストURL | Mem_Fac_Eng_OU_44_42.pdf |
| 著者 | 金谷 健一| Rangrajan Prasanna| |
| 抄録 | This paper presents a new method for fitting an ellipse to a point sequence extracted from images. It is widely known that the best fit is obtained by maximum likelihood. However, it requires iterations, which may not converge in the presence of large noise. Our approach is algebraic distance minimization; no iterations are required. Exploiting the fact that the solution depends on the way the scale is normalized, we analyze the accuracy to high order error terms with the scale normalization weight unspecified and determine it so that the bias is zero up to the second order. We demonstrate by experiments that our method is superior to the Taubin method, also algebraic and known to be highly accurate. |
| 出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
| 発行日 | 2010-01 |
| 巻 | 44巻 |
| 開始ページ | 42 |
| 終了ページ | 49 |
| ISSN | 1349-6115 |
| 言語 | 英語 |
| 論文のバージョン | publisher |
| NAID | 120002309054 |
| JaLCDOI | 10.18926/19957 |
|---|---|
| フルテキストURL | Mem_Fac_Eng_OU_44_32.pdf |
| 著者 | 金谷 健一| Niitsuma Hirotaka| Sugaya Yasuyuki| |
| 抄録 | We present an alternative approach to what we call the “standard optimization”, which minimizes a cost function by searching a parameter space. Instead, the input is “orthogonally projected” in the joint input space onto the manifold defined by the “consistency constraint”, which demands that any minimal subset of observations produce the same result. This approach avoids many difficulties encountered in the standard optimization. As typical examples, we apply it to line fitting and multiview triangulation. The latter produces a new algorithm far more efficient than existing methods. We also discuss optimality of our approach. |
| 出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
| 発行日 | 2010-01 |
| 巻 | 44巻 |
| 開始ページ | 32 |
| 終了ページ | 41 |
| ISSN | 1349-6115 |
| 言語 | 英語 |
| 論文のバージョン | publisher |
| NAID | 120002309124 |
| JaLCDOI | 10.18926/19956 |
|---|---|
| フルテキストURL | Mem_Fac_Eng_OU_44_24.pdf |
| 著者 | 金谷 健一| Sugaya Yasuyuki| |
| 抄録 | We present an improved version of the MSL method of Sugaya and Kanatani for multibody motion segmentation. We replace their initial segmentation based on heuristic clustering by an analytical computation based on GPCA, fitting two 2-D affine spaces in 3-D by the Taubin method. This initial segmentation alone can segment most of the motions in natural scenes fairly correctly, and the result is successively optimized by the EM algorithm in 3-D, 5-D, and 7-D. Using simulated and real videos, we demonstrate that our method outperforms the previous MSL and other existing methods. We also illustrate its mechanism by our visualization technique. |
| 出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
| 発行日 | 2010-01 |
| 巻 | 44巻 |
| 開始ページ | 24 |
| 終了ページ | 31 |
| ISSN | 1349-6115 |
| 言語 | 英語 |
| 論文のバージョン | publisher |
| NAID | 120002309159 |
| JaLCDOI | 10.18926/19955 |
|---|---|
| フルテキストURL | Mem_Fac_Eng_OU_44_13.pdf |
| 著者 | 金谷 健一| Sugaya Yasuyuki| |
| 抄録 | A new numerical scheme is presented for computing strict maximum likelihood (ML) of geometric fitting problems having an implicit constraint. Our approach is orthogonal projection of observations onto a parameterized surface defined by the constraint. Assuming a linearly separable nonlinear constraint, we show that a theoretically global solution can be obtained by iterative Sampson error minimization. Our approach is illustrated by ellipse fitting and fundamental matrix computation. Our method also encompasses optimal correction, computing, e.g., perpendiculars to an ellipse and triangulating stereo images. A detailed discussion is given to technical and practical issues about our approach. |
| 出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
| 発行日 | 2010-01 |
| 巻 | 44巻 |
| 開始ページ | 13 |
| 終了ページ | 23 |
| ISSN | 1349-6115 |
| 言語 | 英語 |
| 論文のバージョン | publisher |
| NAID | 120002309170 |
| JaLCDOI | 10.18926/19954 |
|---|---|
| フルテキストURL | Mem_Fac_Eng_OU_44_7.pdf |
| 著者 | Maetani Noriaki| Kurose Tomoyuki| 鶴田 健二| |
| 抄録 | The lens effect of acoustic waves in a two-dimensional (2D) phononic crystal is studied by numerical simulation based on the finite-difference time-domain (FDTD) method. We calculate the phonon band structure of 2D phononic crystals, consisting of metal cylinders placed periodically in water. Lens effect is observed by the negative refraction of acoustic waves, which results in refocusing of the waves at the point outside the crystal. To increase the focal intensity, we introduce a 2D phononic crystal shield with a different composition of material, which returns the incident waves back to the lens via the perfect reflection. Also, the dependence on filling fraction of metal in the crystal is studied. |
| 出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
| 発行日 | 2010-01 |
| 巻 | 44巻 |
| 開始ページ | 7 |
| 終了ページ | 12 |
| ISSN | 1349-6115 |
| 言語 | 英語 |
| 論文のバージョン | publisher |
| NAID | 120002309019 |
| JaLCDOI | 10.18926/19953 |
|---|---|
| フルテキストURL | Mem_Fac_Eng_OU_44_1.pdf |
| 著者 | Nagai Shinji| Umeda Ryosuke| 鶴田 健二| |
| 抄録 | In this paper, we investigate a light-confinement phenomenon in the structure which has triangular latice composed of Double NeGative Metamaterial (DNGM). In geometrical optics consideration, this structure is expected to confine lights completely by sequential refractions in the structure. We demonstrate it by using the two dimensional finite-difference time-domain simulations. We introduce Drude-Lorentz model for dielectric and magnetic dispersion of the material at optical frequencies. We analyze quantitatively the effects of energy loss in the DNGM on the light-confinement efficiency. |
| 出版物タイトル | Memoirs of the Faculty of Engineering, Okayama University |
| 発行日 | 2010-01 |
| 巻 | 44巻 |
| 開始ページ | 1 |
| 終了ページ | 6 |
| ISSN | 1349-6115 |
| 言語 | 英語 |
| 論文のバージョン | publisher |
| NAID | 120002309117 |
| フルテキストURL | Ana_Sci_16_1303.pdf |
|---|---|
| 著者 | 高 雲華| Lee, Kyue-Hyung| 大島 光子| 本水 昌二| |
| 発行日 | 2000-12-10 |
| 出版物タイトル | Analytical Sciences |
| 巻 | 16巻 |
| 号 | 12号 |
| 出版者 | 日本分析化学会 |
| 開始ページ | 1303 |
| 終了ページ | 1308 |
| ISSN | 0910-6340 |
| NCID | AA10500785 |
| 資料タイプ | 学術雑誌論文 |
| 言語 | 英語 |
| OAI-PMH Set | 岡山大学 |
| 著作権者 | 日本分析化学会 |
| 論文のバージョン | publisher |
| DOI | 10.2116/analsci.16.1303 |
| フルテキストURL | Ana_Sci_16_731.pdf |
|---|---|
| 著者 | Lee Kyue-Hyung| 大島 光子| 高柳 俊夫| 本水 昌二| |
| 発行日 | 2000-07-10 |
| 出版物タイトル | Analytical Sciences |
| 巻 | 16巻 |
| 号 | 7号 |
| 出版者 | 日本分析化学会 |
| 開始ページ | 731 |
| 終了ページ | 738 |
| ISSN | 0910-6340 |
| NCID | AA10500785 |
| 資料タイプ | 学術雑誌論文 |
| 言語 | 英語 |
| OAI-PMH Set | 岡山大学 |
| 著作権者 | 日本分析化学会 |
| 論文のバージョン | publisher |
| DOI | 10.2116/analsci.16.731 |
| フルテキストURL | Ana_Sci_17_1285.pdf |
|---|---|
| 著者 | 大島 光子| Wei, Yanlin| Yamamoto, Masaki| Tanaka, Hiroki| 高柳 俊夫| 本水 昌二| |
| 発行日 | 2001-11-10 |
| 出版物タイトル | Analytical Sciences |
| 巻 | 17巻 |
| 号 | 11号 |
| 出版者 | 日本分析化学会 |
| 開始ページ | 1285 |
| 終了ページ | 1290 |
| ISSN | 0910-6340 |
| NCID | AA10500785 |
| 資料タイプ | 学術雑誌論文 |
| 言語 | 英語 |
| OAI-PMH Set | 岡山大学 |
| 著作権者 | 日本分析化学会 |
| 論文のバージョン | publisher |
| DOI | 10.2116/analsci.17.1285 |
| フルテキストURL | Ana_Sci_18_1021.pdf |
|---|---|
| 著者 | 高柳 俊夫| 本水 昌二| |
| 発行日 | 2002-09-10 |
| 出版物タイトル | Analytical Sciences |
| 巻 | 18巻 |
| 号 | 9号 |
| 出版者 | 日本分析化学会 |
| 開始ページ | 1021 |
| 終了ページ | 1025 |
| ISSN | 0910-6340 |
| NCID | AA10500785 |
| 資料タイプ | 学術雑誌論文 |
| 言語 | 英語 |
| OAI-PMH Set | 岡山大学 |
| 著作権者 | 日本分析化学会 |
| 論文のバージョン | publisher |
| DOI | 10.2116/analsci.18.1021 |
| フルテキストURL | Ana_Sci_18_1141.pdf |
|---|---|
| 著者 | 坪井 知則| 平野 義男| 柴田 佳典| 本水 昌二| |
| 発行日 | 2002-10-10 |
| 出版物タイトル | Analytical Sciences |
| 巻 | 18巻 |
| 号 | 10号 |
| 出版者 | 日本分析化学会 |
| 開始ページ | 1121 |
| 終了ページ | 1125 |
| ISSN | 0910-6340 |
| NCID | AA10500785 |
| 資料タイプ | 学術雑誌論文 |
| 言語 | 英語 |
| OAI-PMH Set | 岡山大学 |
| 著作権者 | 日本分析化学会 |
| 論文のバージョン | publisher |
| DOI | 10.2116/analsci.18.1141 |
| フルテキストURL | Ana_Sci_18_1121.pdf |
|---|---|
| 著者 | Oshita, Koji| 大島 光子| Gao, Yun-hua| Lee, Kyue-Hyung| 本水 昌二| |
| 発行日 | 2002-10-10 |
| 出版物タイトル | Analytical Sciences |
| 巻 | 18巻 |
| 号 | 10号 |
| 出版者 | 日本分析化学会 |
| 開始ページ | 1121 |
| 終了ページ | 1125 |
| ISSN | 0910-6340 |
| NCID | AA10500785 |
| 資料タイプ | 学術雑誌論文 |
| 言語 | 英語 |
| OAI-PMH Set | 岡山大学 |
| 著作権者 | 日本分析化学会 |
| 論文のバージョン | publisher |
| DOI | 10.2116/analsci.18.1121 |
| 著者 | 本水 昌二| 桑原 正良| 大島 光子| |
|---|---|
| 発行日 | 1994-08-05 |
| 出版物タイトル | 分析化学 |
| 巻 | 43巻 |
| 号 | 8号 |
| 資料タイプ | 学術雑誌論文 |
| 著者 | 馬場 直道| 米田 健司| 笹倉 敬司| 繁田 泰民| 岸田 靖弘| 青石 晃宏| 大同 浩子| 中島 修平| 岩佐 順吉| 田原 正一| 金子 孝夫| 松尾 光芳| 清水 昌| |
|---|---|
| 発行日 | 2010-02-01 |
| 出版物タイトル | 岡山大学農学部学術報告 |
| 巻 | 99巻 |
| 号 | 1号 |
| 資料タイプ | 紀要論文 |
| 著者 | ポジャナピモン チャイワット| 福田 文夫| 久保田 尚浩| |
|---|---|
| 発行日 | 2010-02-01 |
| 出版物タイトル | 岡山大学農学部学術報告 |
| 巻 | 99巻 |
| 号 | 1号 |
| 資料タイプ | 紀要論文 |
| 著者 | 藤田 景子| 鈴木 智子| 長谷川 幸子| 目黒 あかね| 杉浦 裕幸| 豊田 和弘| 白石 友紀| 坂口 英| 西村 富生| 久能 均| |
|---|---|
| 発行日 | 2010-02-01 |
| 出版物タイトル | 岡山大学農学部学術報告 |
| 巻 | 99巻 |
| 号 | 1号 |
| 資料タイプ | 紀要論文 |
| JaLCDOI | 10.18926/ESR/19850 |
|---|---|
| タイトル（別表記） | 岡山県に分布する白亜紀前期羽山層砕屑物質の供給源：砕屑粒の鉱物化学組成とモード組成から導かれる制約 |
| フルテキストURL | 016_029_042.pdf |
| 著者 | アシード ダニエル| 鈴木 茂之| 柴田 次夫| |
| 抄録 | Petrographic and phase chemistry studies of detrital grains were carried out on sandstones from the Lower Cretaceous Hayama Formation, Inner Zone of Southwest Japan, to determine their provenance and the tectonic setting during the early Cretaceous. The results of the modal mineralogy suggest that the Hayama Formation has magmatic arc provenance and that deposition of the sediments took place in the back-arc areas with detritus mostly derived from the magmatic arc and rifted continental margins. The chemical compositions of chromian spinel, chlorite and sphene indicate that significant proportions of the detrital grains were derived from mafic and/or ultramafic sources. The source areas are the mafic and ophiolitic rocks in the Sangun-Renge and Akiyoshi terranes and the felsic volcanic rocks probably from either the Akiyoshi terrane or a source not presently exposed in southwest Japan. However, minor amounts of the detritus were derived from the basement rocks; i.e., carbonates and siliciclastic rocks of the Akiyoshi terrane and the metamorphosed mafic rocks of the Chizu terrane. |
| キーワード | modal analysis sandstone mineral chemistry provenance Hayama Formation |
| 出版物タイトル | Okayama University Earth Science Report |
| 発行日 | 2009-12-25 |
| 巻 | 16巻 |
| 号 | 1号 |
| 開始ページ | 29 |
| 終了ページ | 42 |
| ISSN | 1340-7414 |
| 言語 | 英語 |
| 著作権者 | 岡山大学地球科学研究報告編集委員会 |
| 論文のバージョン | publisher |
| NAID | 120002309000 |
| JaLCDOI | 10.18926/ESR/19849 |
|---|---|
| タイトル（別表記） | ガーナ，アシャンティ火山帯南部に分布する古原生代変火山岩類のSr-Nd 同位体組成 |
| フルテキストURL | 016_009_028.pdf |
| 著者 | ダムパリ サムエル| 柴田 次夫| アシード ダニエル| 岡野 修| マーヌ ジョンソン| サチ パトリック| |
| 抄録 | Neodymium (Nd) and strontium (Sr) isotopic data are presented for Paleoproterozoic metavolcanic rocks in the southern part of the Ashanti volcanic belt of Ghana. The metavolcanic rocks are predominantly basalts/basaltic andesites and andesites with minor dacites. Two types of basalts/basaltic andesites (B/A), Type I and Type II, have been identified. The Type I B/A are stratigraphically overlain by the Type II B/A, followed by the andesites and the dacites. The analyzed volcanic rocks commonly have low initial (87)Sr/(86)Sr ratios consistent with previous studies on Paleoproterozoic rocks from the West African craton. The LREE-depleted, tholeiitic Type I B/A exhibit back-arc basin geochemical signatures and show high positive epsilon Nd (i.e., ε(Nd) (2.1 Ga) = +3.89 to +7.21), which suggest a long term depleted source and also indicate that they were produced in an entirely oceanic environment devoid of influence of continental crust. The isotope signatures are thus consistent with the previously published trace element data of the Type I basalts/basaltic andesites in suggesting that their parent magma was generated from a depleted mantle. The Type I B/A have Nd model ages (T(DM2)) of 1.83–2.09 Ga similar to their formation ages, suggesting that they were juvenile at their time of formation. The andesites and the Type II B/A andesites show LREE-enriched patterns and exhibit characteristics of subduction zone-related magmas, and show initial ε(Nd) (2.1Ga) values of –1.15 to + 1.35 and Nd model ages (T(DM2)) of 2.32–2.58 Ga. The LREE-enriched dacitic porphyry also exhibits characteristics of subduction zone-related magmas, and have initial ε(Nd) (2.1Ga) value of –2.24 and Nd model ages (T(DM2)) of 2.64 Ga. The Nd isotopic data confirms the juvenile character of the Birimian crust, but also suggests some contributions of a pre-Birimian crustal material (or Archean?) in the genesis of some of the metavolcanic rocks. Our isotopic result is consistent with the island arc complex model which views Paleoproteozoic terranes of West Africa in the context of subduction–accretion processes. |
| キーワード | Sr–Nd isotopes petrogenesis tectonic setting Birimian metavolcanics Ashanti volcanic belt |
| 出版物タイトル | Okayama University Earth Science Report |
| 発行日 | 2009-12-25 |
| 巻 | 16巻 |
| 号 | 1号 |
| 開始ページ | 9 |
| 終了ページ | 28 |
| ISSN | 1340-7414 |
| 言語 | 英語 |
| 著作権者 | 岡山大学地球科学研究報告編集委員会 |
| 論文のバージョン | publisher |
| NAID | 120002308985 |
| 著者 | Department of Earth Sciences, Faculty of Science, Okayama University| |
|---|---|
| 発行日 | 2009-12-25 |
| 出版物タイトル | Okayama University Earth Science Report |
| 巻 | 16巻 |
| 号 | 1号 |
| 資料タイプ | その他 |