著者
酒井 英樹
出版者
一般社団法人 日本機械学会
雑誌
日本機械学会論文集 (ISSN:21879761)
巻号頁・発行日
vol.83, no.854, pp.17-00064-17-00064, 2017 (Released:2017-10-25)
参考文献数
10

This paper considers ways to increase stability of wheelset hunting. The aim of this study is to introduce formulas which represent the damped natural frequency and its damping. This has been done by analytical and not by numerical calculation. These formulas are functions of mass, creep coefficient and other wheelset parameters. These formulas are obtained with a 2 degree of freedom wheelset model whose radius of gyration of yaw equals to a half of gauge and whose creep coefficient is isotropic, in the first part of this paper. In the second part, based on one of these formulas, ways to increase damping of wheelset hunting are discussed. First, it is shown that a longer wavelength of geometrical hunting is effective in reducing hunting at all vehicle speeds. Secondly, it is shown that at speeds slower than a certain speed, the damping is increased when the ratio of the wheelset mass to the creep coefficient is larger. Further, a symbolic formula for this boundary speed is obtained. Thirdly, if it is assumed that the wheelset mass is proportional to the square of the wheel radius, then at speeds higher than a certain speed, the damping is increased when the wheel radius is larger. Moreover a symbolic formula for this boundary speed is also obtained.

1 0 0 0 OA 本草図譜

著者
岩崎常正<岩崎潅園>//著
巻号頁・発行日
vol.第6冊 巻43菽豆類,
著者
長谷川 昌士 河井 秀夫 西脇 健司 向井 公一 北山 淳 三谷 保弘 高見 栄喜 Masashi Hasegawa Hideo Kawai Kenji Nishiwaki Kouiti Mukai Atsushi Kitayama Yasuhiro Mitani Hidenobu Takami
出版者
四條畷学園大学
雑誌
四條畷学園大学リハビリテーション学部紀要 = Annual reports of Faculty of Rehabilitation, Shijonawate Gakuen University (ISSN:18806856)
巻号頁・発行日
vol.6, pp.13-18, 2010

高校吹奏楽部所属の1~3年生160名に、楽器の練習が影響していると考えられる身体症状についてアンケート調査を実施した. 結果は、チューバ奏者の多くが腰痛を訴えていた. サックス奏者やチューバ奏者には顎関節の痛みが発生していた. サックス奏者やチューバ奏者ならびにパーカッション奏者では利き手側の手関節や手指関節に関節痛が集中していた. また、整形外科的症状以外にも、頭痛、めまい、過呼吸、耳なり、倦怠感などの内科的症状が多くの学生に発生していた. これらの症状が改善できないまま学生は練習を継続していることもわかり、予防や対処法を検討していく必要があると考える.I carried out questionary survey about the physical symptom that it was thought that the exercise of the musical instrument influenced 160 1-3 year students of the high school brass band club position. Most of tubists appealed to the result for low back pain. To a saxophone player and a tubist, the pain of the temporomandibular joint occurred. In a saxophone player and a tubist and the percussion players, arthralgia concentrated on a wrist and finger joint of the handedness side. In addition, as well as an orthopedic symptom, medical symptoms such as a headache, dizziness, hyperpnoea, ringing in the ears, the lassitude occurred to many students. The student practices being able to improve these symptoms and thinks that it is necessary to examine the prevention and actions to be taken.

1 0 0 0 OA 諸宗作事図帳

出版者
巻号頁・発行日
vol.[6] 百三十二 〔二〕 (浄土宗),
著者
Takahashi Rohta Umemura Masayuki
出版者
Oxford University Press
雑誌
Monthly Notices of the Royal Astronomical Society (ISSN:00358711)
巻号頁・発行日
vol.464, no.4, pp.4567-4585, 2017-02
被引用文献数
12

We present a general relativistic radiative transfer code, ARTIST (Authentic Radiative Transfer In Space–Time), that is a perfectly causal scheme to pursue the propagation of radiation with absorption and scattering around a Kerr black hole. The code explicitly solves the invariant radiation intensity along null geodesics in the Kerr–Schild coordinates, and therefore properly includes light bending, Doppler boosting, frame dragging, and gravitational redshifts. The notable aspect of ARTIST is that it conserves the radiative energy with high accuracy, and is not subject to the numerical diffusion, since the transfer is solved on long characteristics along null geodesics. We first solve the wavefront propagation around a Kerr black hole that was originally explored by Hanni. This demonstrates repeated wavefront collisions, light bending, and causal propagation of radiation with the speed of light. We show that the decay rate of the total energy of wavefronts near a black hole is determined solely by the black hole spin in late phases, in agreement with analytic expectations. As a result, the ARTIST turns out to correctly solve the general relativistic radiation fields until late phases as t ∼ 90 M. We also explore the effects of absorption and scattering, and apply this code for a photon wall problem and an orbiting hotspot problem. All the simulations in this study are performed in the equatorial plane around a Kerr black hole. The ARTIST is the first step to realize the general relativistic radiation hydrodynamics.
著者
劉 靚 Liu Liang
出版者
新潟大学
巻号頁・発行日
2015

終了ページ : 160
著者
PANKHURST C.
雑誌
Lancet
巻号頁・発行日
vol.1, 1989
被引用文献数
1