著者

辻村 真治 飯田 雄章 長野 靖尚

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B編 (ISSN:03875016)

巻号頁・発行日

vol.67, no.659, pp.1762-1769, 2001

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In the Earth's atmosphere, zonal currents with a vertical velocity gradient are induced under the action of rotation and horizontal temperature gradient. These currents satisfying the so-called "thermal wind equation" generate the cyclones and anticyclones through the baroclinic instability, and hence have serious effects on the global circulation. In this study, the generation and development mechanisms of vertical vortices associated with the cyclones and anticyclones are investigated by using direct numerical simulation of the thermal wind. By imposing the stable density stratification in the vertical direction, the effects of the stable stratification and the Reynolds number are studied in detail. As a result, we have found the distinct effects of stable stratification on the anisotropy of the flow field and the generation of the vortical structure. It is also found that the cyclone becomes dominant in comparison to the anticyclone at a relatively low Reynolds number under the weak stable stratification. At a higher Reynolds number, both cyclonic and anticyclonic vortices are enhanced by the nonlinear vortex stretching term, and hence the asymmetry between them becomes negligible. The intensive stable stratification attenuates the nonlinear vortex stretching and contributes to the occurrence of the asymmetry in the vortices even at the higher Reynolds numbers

著者

アギアル デ ソウザ ヴィニシウス 渡邊 育夢 柳田 明

出版者

一般社団法人 日本機械学会

雑誌

M&M材料力学カンファレンス

巻号頁・発行日

vol.2013, pp._OS0805-1_-_OS0805-3_, 2013

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The purpose of this study is to improve and extend a method to estimate the friction coefficient in equal channel angular extrusion (ECAE) including cases with back pressure. Employing three dimensional finite element analysis (FEA) and Coulomb friction model with truncated shear stress, the relationship between the friction coefficient and the reaction force is investigated in ECAE with back pressure. Additionally, the deformation state of the billet after ECAE and the pressing load are compared between the experiment and the simulation results with the same friction coefficient for validation of the numerical model.

著者

青山 絢子 中島 求

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 B編 (ISSN:03875016)

巻号頁・発行日

vol.73, no.734, pp.2018-2026, 2007

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The objective of this study was to investigate the stability during freefall in skydiving, in which the diver has to take various body position in order to control precisely their distance, velocity, and direction relative to the other divers for the group performance. For this objective, the state equation for a simple elliptic cylinder model was firstly derived, considering its equations of motion and the fluid force characteristics. Next, using the form of state equation derived for the elliptic cylinder and the input/output data obtained from the developed simulation method for the body behavior of the skydiver, the state equations of skydiver were identified for various body positions. Finally, roots of the state equations were obtained to investigate the stability. As the results, the causes of instability such as spin and spiral phenomena were clarified as an unstable natural modes, and the stable limit of body position was obtained as a value of parameter which is related to the arch magnitude of the diver's body.

著者

芦田 俊樹 村井 祐一 パク ヒョンジン 田坂 裕司 永井 繁行

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

巻号頁・発行日

vol.86, no.888, pp.20-00184-20-00184, 2020

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<p>Aerodynamic drag on several types of road cones was measured by wind tunnel experiments purposing improvement of anti-fall-down functions against lateral wind blowing. By opening holes on the side surface of cones, drag coefficient decreased so that maximum endurable wind speed increased over 30 m/s in the best case. This finding contributes to three benefits in road safety; reducing the weight of the cone for workers at roads, cost cutting by manufacturers for the synthetic resin material, and also for security aspects by internal visibility preventing from hidden matters. We also found different aerodynamic characteristics due to bottom plate condition of the cones. That is, when the bottom plate opened to the inner space of the cone, small angle of inclination intensified a recovery moment that pulls back the cone to the standing attitude. This effect significantly improved the maximum endurable wind speed and was explained by the flow allowed inside the cone when the side holes were provided. Such a fluid-structure interaction was analyzed theoretically to clarify the endurance mechanism.</p>

著者

平川 賢爾

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 A編 (ISSN:03875008)

巻号頁・発行日

vol.71, no.702, pp.187-190, 2005-02-25 (Released:2011-03-02)

被引用文献数

1

著者

吉田 喜一

出版者

一般社団法人 日本機械学会

雑誌

年次大会 2013 (ISSN:24242667)

巻号頁・発行日

pp._S201046-1-_S201046-4, 2013-09-08 (Released:2017-06-19)

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Fifty years passed after College of Technology started and more than four hundred thousand students graduated. It is found from various statistics datum that children of people which are seriously affected by economic condition enter to College of Technology. Fifty years' history of College of Technology is introduced roughly. The roles of College of Technology are reconfirmed by using various statistics datum (Application rate to College of Technology, Promises of employment of students of High School, Junior College and College of Technology)

著者

湧川 朝宏

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会誌 (ISSN:24242675)

巻号頁・発行日

vol.95, no.884, pp.607-611, 1992-07-05 (Released:2017-06-21)

参考文献数

10

著者

藤木 克洋 波多 英寛 藤原 和人 川島 扶美子 坂本 武司 稲尾 大介

出版者

一般社団法人 日本機械学会

雑誌

スペース・エンジニアリング・コンファレンス講演論文集

巻号頁・発行日

vol.2013, pp._A1-1_-_A1-4_, 2013

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Now, in order to elucidate phenomena of high velocity, high velocity launching equipment, such as single stage gas gun, powder gun, and two stage gas guns are used. Generally, powder gun and two stage gas guns can launch a projectile high mass compared with a single stage gas gun. But, the working hours for cleaning the inside of a launch tube are required after launching a projectile, and since gunpowder is used, the deterioration of equipment is large compared with a single stage gas gun. On the other hand, a single stage gas gun can prepare launching projectile in comparatively short time. Moreover, there is an advantage that equipment degradation is small. In this study, the single stage gas gun which can be launched to a portable type and all the directions is developed. And the experimental result which launched various projectiles using the single stage gas gun is reported.

著者

長谷川 泰久 三上 康之 渡邉 航介 フィルズィメール ゼナブ 山海 嘉之

出版者

一般社団法人 日本機械学会

雑誌

ロボティクス・メカトロニクス講演会講演概要集

巻号頁・発行日

vol.2008, pp._2A1-B22_1-_2A1-B22_4, 2008

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This paper introduces a new wearable handring support system for a person who has trouble in motor capability of their upper limb.The support system is used not only for a support system to make their upper limb active in daily life but also for a rehabilitation system to reduce manual loads of physical therapists.The system measures three rotation angles of patient's head: pitch, roll and yaw to control three degrees of freedom of the support system; angle of elbow joint, angle of wrist joint and hand close/open, respectively. Hemiplegia patient who has paralysis on one half of the patient body can use both arms cooperatively by wearing the handling support system on the paralysis side. In our experiments, the system helps pouring task from POP bottle to a glass, while an upper limb on paralysis side of a user grasps the POP bottle and the other upper limb grasps the glass.

著者

高村 俊介 山本 昂太朗 割澤 伸一 橋詰 博行 中島 義和 光石 衛

出版者

一般社団法人 日本機械学会

雑誌

ロボティクス・メカトロニクス講演会講演概要集

巻号頁・発行日

vol.2006, pp._2A1-A30_1-_2A1-A30_3, 2006

著者

西村 営三

出版者

一般社団法人 日本機械学会

雑誌

ロボティクス・メカトロニクス講演会講演概要集

巻号頁・発行日

vol.2000, 2000

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スチュワートプラットホームの位置と姿勢の一計算法が考察された。6本のリンクの実際の長さを読み取り, 3本のリンクからプラットホームを6方向に移動して, それぞれのプラットホームの座標を計算する。残りの3本のリンクの実際の長さと, 計算からでてくる長さの差から分散そして平方根をとったものを誤差を定義する。誤差が最も小さくなるプラットホームの方向に計算をもどす。誤差がある一定の値より小さくなれば計算を終了する。このときの座標が答えになる。

著者

中島 求

出版者

一般社団法人 日本機械学会

雑誌

年次大会

巻号頁・発行日

vol.2013, pp._F112002-1-_F112002-5, 2013

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The swimming motions of animals are quite interesting and useful from the viewpoint of science and engineering. Three dolphin-like robots and a swimming humanoid which were developed by the author's group were introduced in this paper. The dolphin-like robots of Type 1 and Type 2 were developed in order to investigate the performance of the steady straight swimming. Type 1 had one air motor to actuate the caudal fm and one passive joint at the root of the fin. The total length of the robot was 1.75m. The maximum swimming speed of 1.15m/s and the maximum propulsive efficiency of 65% were achieved. Type 2 had the similar structure with Type 1 although the main joint was actuated by an electric motor whose maximum power was 7.4kW. The maximum swimming speed of 1.9m/s was achieved. Type 3 was developed in order to investigate the performance of the maneuverability. A loop-the-loop motion and three-dimensional motion in the water were realized. The swimming humanoid was developed for research of human swimming. It had 20 motors inside and the body size was half of an actual competitive swimmer. The swimming motion in a circulating water tank and the free swimming in a swimming pool were realized, respectively.

著者

吉池 哲也 森川 裕久 孫 啓龍 小林 俊一 中島 求

出版者

一般社団法人 日本機械学会

雑誌

年次大会講演論文集

巻号頁・発行日

vol.2008, pp.89-90, 2008

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It is known that a dolphin swims fast and freely in water. The propulsive performance and the kinetic performance of the dolphin are one of great concern among researchers. We paid attention to the dolphin's tail flukes which has an important role to generate propulsive force. So the experiments on both the propulsive force of the outboard propulsor with the oscillating wing which is similar to the dolphin's tail flukes in shape and the velocity of a small boat equipped with the outboard propulsor were carried out. The propulsive performance of the wing was discussed compared with rectangular wings.

著者

チョウ シュントウ 大野 英隆

出版者

一般社団法人 日本機械学会

雑誌

年次大会

巻号頁・発行日

vol.2016, 2016

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<p>This research is aimed at the ordinary family type cleaning robot to carry on the transformation. There are still a lot of problems with the common household cleaning robot. The biggest problem is that it can't clean the narrow area. This research is trying to solve this problem.</p>

著者

鳴尾 丈司 溝田 武人 下園 仁志

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 B編 (ISSN:03875016)

巻号頁・発行日

vol.70, no.697, pp.2371-2377, 2004-09-25 (Released:2011-03-03)

参考文献数

8

被引用文献数

1 1

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A device to rotate a real golf ball at a maximum of 10 000 rpm in the wind with a maximum speed of 80 m/s was developed. Aerodynamic forces and torque acting on the ball were measured under various flight conditions in a wind tunnel flow. As a result, it was found that drag, lift, and torque coefficients under the real conditions depended on the spin parameter but were independent of the Reynolds number. Using the measured aerodynamic force coefficients and a ball initial condition measured by ejection experiments, mathematical calculation of trajectory equation was made by time integral calculus. Ejection experiments were conducted by a robot. The correctness of the trajectory analysis and measured aerodynamic force was verified by comparing the calculated results with measured results.

著者

大和 秀彰 古田 貴之 富山 健

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C編 (ISSN:18848354)

巻号頁・発行日

vol.77, no.776, pp.1441-1453, 2011 (Released:2011-04-25)

参考文献数

27

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This paper presents a new methodology of attitude estimation for cost-effective and small-size inertial measurement units, consisting of tri-axial gyroscope sensors, accelerometers and geo-magnetometers. Introduced for the algorithm development is a quaternion feedback structure, where bias terms in the gyroscope rate information, appearing in the phase-locked loop, are identified with the theoretical guarantee of the global and asymptotical stability. The bias-term identification and modification process is performed continuously without the influence of the disturbance by applying the proposed disturbance detection scheme and a conventional vector matching method. Practical validity of the presented framework is fully evaluated by experiments. The evaluation result shows that the approach in this paper can offer superior drift-free performance with property of disturbance rejection under arbitrary high-frequency test motion of spatial rotation and translation.

著者

山田 涼介 近藤 典夫

出版者

一般社団法人 日本機械学会

雑誌

計算力学講演会講演論文集

巻号頁・発行日

vol.2019, 2019

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<p>The phenomenon which a cylindrical structure vibrates in a direction perpendicular to the wind flow when the wind velocity is fast is called vortex excitation. This is a vibration that occurs due to the mutual interference between the periodic vortices generated behind the cylinder and the vibration of the cylinder itself, and it is necessary to estimate the amplitudes of the displacements from the viewpoint of wind safety and maintenance of the structure . In this study, it is aimed to capture the hydrodynamic force characteristics and the hydrodynamic oscillation of the cylinder at the Reynolds number of the critical region where the Reynolds number drops sharply. The reduced speed <i>U_r</i> is set to 2 to 15.</p>

著者

上西園 武良 山田 浩 角谷 明子

出版者

一般社団法人 日本機械学会

雑誌

東海支部総会講演会講演論文集

巻号頁・発行日

vol.2005, pp.195-196, 2005

著者

小畠 厳貴 和田 雄高 徳重 克彦 辻村 学 當間 康 鈴木 作 小寺 章

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会関東支部総会講演会講演論文集

巻号頁・発行日

vol.2008, pp.407-408, 2008

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In this paper, polishing performance of ECP-C, which is a kind of ECMP(Electro-Chemical Mechanical Polishing), at Cu clear process is discribed. After Cu clear, it was found that erosion was below 10nm and Cu residue was not observed. However, it was also found that dishing was over 100nm and it significantly increased with over polish time. This increase is assumed of electrochemical ething due to low electrical insulation property of Cu complex formed in ECP-C. Therefore, it is considered that the improvement in electrical insulation property is necessary for applying ECP-C to Cu clear process.

著者

都丸 孝之 中野 冠

出版者

一般社団法人 日本機械学会

雑誌

生産システム部門講演会講演論文集

巻号頁・発行日

vol.2015, pp.127-128, 2015

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カーナビゲーション、ゲーム機、複写機などさまざまな民生機器においてハードディスクドライブ(HDD)が搭載されている。HDDの故障率は他の電子デバイスに比べ高く、民生機器メーカーにとってHDDの故障率を如何にして低減させるかが大きな課題である。特に民生機器メーカーや一般顧客で発生したHDDの不具合の半数近くがNot problem found(NPF)、すなわちハードウェア上の故障ではないことから、ソフトウェア上の故障を見極めることが重要である。本論文では、HDDのハードウェアだけでなくソフトウェア上の不具合を検知し、自動修復できるようなHDD故障診断機能を提案する。本診断機能を、複写機やプリンタに導入し、HDDの故障率の効果について検証を行う。