@article{oai:ipsj.ixsq.nii.ac.jp:00070147, author = {吉田, 年雄 and Toshio, Yoshida}, issue = {8}, journal = {情報処理学会論文誌}, month = {Aug}, note = {本論文では,$x M^{2}_{ u}(x)=x\{J_{ u}^{2}(x)+Y_{ u}^{2}(x)\}$について,変数$x$が大きい場合の能率的な計算法を提案している.ここで,$J_{ u}(x)$および$Y_{ u}(x)$はベッセル関数である.$xM_{ u}^{2}(x)$は$xM_{ u}^{2}(x)=(1/\sqrt{t})M_{ u}^{2}(1/\sqrt{t})=f_{ u}(t)$のように書くことができ,$f_{ u}(t)$は,微分方程式$8t^{3}f_{ u}'''(t)+36t^{2}f_{ u}''(t)+\{(26-8 u^{2})t+8\}f_{ u}'(t)-(4 u^{2}-1)f_{ u}(t)=0$を満足する.上式に$\tau$法を適用すると,$f_{ u}(t)$の近似式が求められ,式の変形や工夫を行うことより,能率的な計算式が得られる., In this paper, we propose an efficient numerical method for $x M^{2}_{ u}(x)=x\{J_{ u}^{2}(x)+Y_{ u}^{2}(x)\}$ with large argument $x$, where $J_{ u}(x)$ and $Y_{ u}(x)$ are Bessel functions. The function $xM_{ u}^{2}(x)$ is written as $xM_{ u}^{2}(x)=(1/\sqrt{t})M_{ u}^{2}(1/\sqrt{t}))=f_{ u}(t)$, where $f_{ u}(t)$ satisfies the differential equation $8t^{3}f_{ u}'''(t)+36t^{2}f_{ u}''(t)+\{(26-8 u^{2})t+8\}f_{ u}'(t)-(4 u^{2}-1)f_{ u}(t)=0$. Applying the $\tau$-method to the above equation, the approximation to $f_{ u}(t)$ is obtained.}, pages = {1394--1401}, title = {{\boldmath $\tau$}法による{\boldmath$x$}が大きい場合の{\boldmath$x\{J_{\nu}^{2}(x)+Y_{\nu}^{2}(x)\}$}の数値計算}, volume = {51}, year = {2010} }