著者

伊原 貞敏

出版者

一般社団法人 日本機械学会

雑誌

機械學會誌

巻号頁・発行日

vol.36, no.196, pp.532-535, 1933

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円弧で限られる扇形場内に在る唯一の自由渦の移動が其渦の像渦の有限數の影響として行はれると簡單に考へ等角寫像法に由り平衡渦の中心位置は(θ_0=π/2n, r_0e^<-π/2n>)であり且移動渦の中心軌跡は(A^^*^2+B^^*^2)/(C^^*^2+D^^*^2)=(A^^*_1^2+B^^*_1^2)/(C^^*_1^2+D^^*_1^2)で與へられる事を算出した。但しA^^*=(1+η_0)(η-η_0), B^^*=-(1+η_0)ξ, C^^*=(1-η_0)(η-η_0), D^^*=-(1-η_0)ξ, A^^*_1=(1+η_0)(η_1-η_0), B^^*_1=-(1+η_0)ξ, C^^*=(1-η_0)(η_1-η_0), D^^*=-(1+η_0)ξ_1,ξ=(r^n+r^<-n>)/2・cosnθ, η=(r^n-r^<-n>)/2・sinnθ, θ_n=扇形の夾角=π/n, (ξ_1,η_1)=移動渦の原始座標である。又模型の扇形場に水を滿し回轉円筒で渦を起生させて其移動状態を活動寫眞に撮り且移動跡(實線)を描出し其初期に於ては計算した移動跡(破線)に一致する事を確めた(圖6a, b)。而して移動の中期以後は渦の老衰のため内側に軌跡を反れて歩み最後には平衡渦の位置Q(ξ_0,η_0)に到る事を知った。從て此解法も此場合の説明の一便法たり得る。

著者

鞍谷 文保 北林 研人 小川 渉 吉田 達哉 長村 光造 小出 俊雄 文珠 義之 水田 泰次

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

pp.17-00110, (Released:2017-07-06)

参考文献数

13

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Cymbals are percussion instruments that vibrate and radiate sounds when hit with a stick or when used in pairs. The sound radiated from a cymbal depends on its vibration characteristics. Cymbals are made through spin forming, hammering and lathing processes. The spin forming creates the domed shape of cymbals, determining the basic vibration characteristics. The hammering and lathing make specific sound quality adjustments by changing the vibration characteristics. In this paper, we focus on how the hammering affects the cymbal's vibration characteristics. The hammering produces many shallow dents over the cymbal's surface, generating residual stresses in it. These residual stresses change the vibration characteristics. We perform finite element analysis of the hammered cymbal to obtain its vibration characteristics. In the analysis, we use thermal stress analysis to reproduce the stress distribution and then with this stress distribution we perform vibration analysis. The results show that the effects of thermal load (i.e., hammering) vary depending on the mode: an increase or decrease in the natural frequency. As a result, the peak frequencies and their peak values in the frequency response function change.

著者

岸本 直子 樋口 健 岩佐 貴史

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.2014, pp._A06-1_-_A06-2_, 2014

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近年,衛星搭載のアンテナや太陽電池パネルは,観測周波数の高周波化や高感度化,大電力要求に対応するために,大型化かつ高精度化している.そこで,著者らは,地上ならびに軌道上で,大型構造物の形状を高速かつ高精度に計測する技術の研究開発に取り組んできた.しかし,各種地上試験や軌道上で実用に供するためには,計測装置の小型化とロバスト化が必須である.本研究では,格子投影法を用いた可搬型形状計測装置を用いて,圧縮試験時のスキン付きCFRP製ラティス円筒(直径約2m)および,小型衛星搭載を目指した合成開口レーダー用平面スロットアンテナ(700mm×700mm)の形状計測を実施した計測結果について報告する.可搬型形状計測装置は,基準面を用いたキャリブレーションをあらかじめ実験室でおこなっておき,実際の計測には,プロジェクターとカメラから構成される簡便な計測装置のみを用いた.いずれの場合も,表面形状や変形形状の全視野計測に成功し,ひずみゲージやレーザー変位計による計測では判別しにくい全体の変形モードを取得することができた.

著者

深野 徹 功能 郁生

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.53, no.494, pp.3034-3037, 1987-10-25 (Released:2008-03-28)

参考文献数

3

被引用文献数

1 2

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It is believed that a helmholtz resonator is a good device for reducing the noise level of a discrete frequency noise, and that the frequency of the resonator can be estimated by a simple theoretical formula. Actually, however, we cannot deny the possibility of an unexpected increase in the noise level due to the resonance between a traveling tone and the resonator. Also, there are few papers which treat of the actual design method of a resonator, especially the dimension of a resonator in relation to the size of a main duct conveying a tone to be reduced. In the present experiment, the theoretically estimated frequency is examined ad to whether its noise level is reduced at that frequency by the resonator or not. The experimental data which are useful for designing a resonator with an optimum geometry are also presented.

著者

北岡 哲子 内田 博志

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.2012, pp._S231013-1-_S231013-5, 2012

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The relation between the subjective evaluation of "iyashi" and the characteristic parameters of the stimulus portraits is analyzed using the approach of quality engineering.20 portraits taken from classical paintings are presented to 113 subjects,and each subject is requested to answer the degree of "iyashi" felt from each portrait by three-grade evaluation.17 facial expression parameters are extracted from each portrait.The model to estimate "iyashi" degree from the expression parameters is created for each subject using the two-sided Taguchi method of quality engineering.The unit space is considered as the weighted average of the 20 portraits,and the weight vector which maximizes the SN ratio of the comprehensive estimation is obtained for each subject.As a result,it is found that among the portraits which have the maximum unit space weight(basis portrait),there exist the pictures on which many subjects concentrate.Similarly,it is found that among the expression parameters which have large SN ratio in the model equation(major expression parameter),there exist the parameters on which many subjects concentrate.As the result of applying the quantification method I to estimate the basis portrait number from the 3 major expression parameters,the multiplecorrelation coefficient is 0.83 and it is shown that a certain relation exists between the basis portrait and the major expression parameters.

著者

細谷 和範 高山 由暉 加藤 学 井上 浩行 曽利 仁 漆原 史朗 杉本 大志

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.2018, pp.2A1-G05, 2018

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<p>In this research, a novel rough terrain track mechanism for agricultural robot and levee weed robots was developed. Soft and long spike track provides enough shear forces by insert the comb like soft spikes on weed covered steep slopes which we can often see along rice field. In addition, spikes are composed of flexible materials to enable running on uneven surfaces and muddy areas. In this report, a relationship between the spike length and the climbing performance on the grass covered slope will be described.</p>

著者

永坂 栄一

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.111, no.1078, pp.776-777, 2008-09-05 (Released:2017-06-21)

参考文献数

3

被引用文献数

1

著者

Liu Chen 藤本 由紀夫 田中 義和 上杉 征 並河 隆浩

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.80, no.816, pp.BMS0244, 2014 (Released:2014-08-25)

参考文献数

7

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When human body is punched by the boxing glove, both of the body surface and the boxing glove deform in a complex shape. The purpose of this study is to develop a flexible sensor that can be used in such interface. Firstly, several mechanical phenomena, which are the cause of error signal of the sensor, are discussed. These are the influences of out-of-plane bending deformation, shear force caused by rubbing force, shear force caused by the Poisson's effect of contact material, and the transverse compressive force caused by the overhanging deformation of flexible material. Then as a sensor that can eliminate the error factors of these, a distribution type impact sensor in which sixteen sensor elements are arranged in a 4x4 matrix is developed. Punching experiments using a boxing glove are carried out by installing the sensor on the load cell, on the concrete wall and on the sandbag. From the experiment, it is found that the impact force can be measured with good accuracy by using the sensor. Despite the sensor has inadequate distribution number of sensor elements, the sensor structure includes mechanical requirements for the flexible impact sensor.

著者

児玉 和也 戸田 和之 山本 誠

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.72, no.724, pp.2894-2900, 2006-12-25 (Released:2011-03-03)

参考文献数

8

被引用文献数

1 1

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With improving a computer hardware and CFD software, the problems treated in industries tend to be more complex, physically and geometrically. The turbulent flow with strong unsteadiness is one of physically complex examples. Since Large Eddy Simulation (LES) is still too time-consuming, a great number of unsteady Reynolds-Averaged Navier-Stokes (RANS) computations have been employed in such engineering applications. However, the applicability of RANS to unsteady flows has not been clear. In the present study, RANS computations for two-dimensional turbulent flow with periodic perturbation over a backward-facing step are performed to verify the performance of a low-Reynolds-number type k-ε turbulence model. Visualizing and investigating the temporal change of the flow pattern and the instantaneous term-by-term budget of the governing equations, it is clarified that the RANS computation can reproduce the unsteady nature satisfactorily, and why the RANS model captures the unsteady turbulent flow reasonably.

著者

船井 孝 長津 義之 山口 進吾 鈴木 敬明 加藤 俊文 片岡 弘之 横田 秀夫 姫野 龍太郎

出版者

一般社団法人 日本機械学会

雑誌

バイオエンジニアリング講演会講演論文集 2007.20 (ISSN:24242829)

巻号頁・発行日

pp.231-232, 2008-01-24 (Released:2017-06-19)

被引用文献数

1 1

著者

Quang Anh Tho Tran Azola Edson Closon Herve Chares Robert

出版者

一般社団法人 日本機械学会

雑誌

Proceedings of the ... International Conference on Nuclear Engineering. Book of abstracts : ICONE

巻号頁・発行日

vol.2011, pp._ICONE1944, 2011

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Operational decisions related to plant performance monitoring mainly result from raw process measurement analysis. When first signs of sub-optimal behavior occur, traditional methods mainly focus on the observation of selective pieces of information. The main disadvantages of these methods are: ・Investigation efforts are required to localize the problems, entailing time losses and costs; ・Validity and reliability of the pieces of information cannot be checked as long as the measurements are observed individually. The problem is not the lack of methods and techniques but rather a lack of reliable and consistent data and information across the entire plant. To overcome drawbacks of traditional methods, measurements are considered as interacting with one another. When related to the other measurements of the plant, the observed information becomes of an interest: its incoherency to the others identifies and localizes a problem. The Data Validation and Reconciliation technology (DVR) is based on an advanced process data coherency treatment. By using all available plant information and by closing the plant heat and mass balances based on rigorous thermodynamics, the method generates: ・A single set of reliable and most accurate plant process data; ・Alarms for incoherent measurements, highlighting potential problems; ・Alarms for equipment and process performance degradation; ・Alarms for faulty and drifting measurements. The use of the advanced DVR software package VALI offers various benefits as it allows to base operational decisions on reliable and accurate data.

著者

三上 隆 納土 賢悟 山代 和明 幾久 健 小山 遥陽 杉山 直磯 来田 宣幸

出版者

一般社団法人 日本機械学会

雑誌

シンポジウム: スポーツ・アンド・ヒューマン・ダイナミクス講演論文集 2018 (ISSN:24329509)

巻号頁・発行日

pp.B-14, 2018 (Released:2019-05-25)

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We have spent to walk the majority of the activities of daily living. We can reduce the burden on the foot by putting insoles in the shoes. In addition, insoles are used as part of rehabilitation. It can be proposed for the maintenance of a healthy life by studying the effect on the body due to the shape of the insole. This study focused on the thickness of the insoles and aimed to clarify the influence on the body when to use different insoles of the toe portion and the heel portion. Experimental subjects were opened with resting stance posture, both feet standing position and one-foot standing position. The condition of the insole was 5.5 ㎜ and 7.5 ㎜ in the thickness of the toes, and the heels were 5.0 ㎜ and 7.5 ㎜ in thickness. The experimental participants were four men in their twenties. The measuring device was a force plate. The sampling rate was 1000 Hz. From the result of the total trajectory length, it was confirmed that the center of gravity fluctuation becomes smaller by the insole.

著者

三橋 邦宏 高木 渉 近藤 将弘

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-H13_1-_2A1-H13_4, 2008

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A floor-reaction-force measurement base and joint angle measurement links were created, and man's joint angles and floor reaction forces in a jump were measured. These measured data were inputted into the numerical model of a hopping robot which has a wire rolling-up actuator which attached a spring in series in a wire, and the spring constant which makes a motion of an actuator small was presumed. The motions of a wire rolling-up actuator in consideration of the effect of this spring were approximated by sinusoidal wave forms, and the simulations of man's jumps were carried out. As a result, it was shown that energy of the motor for a jump can be made small to 40% - 60% with a spring as compared with energy without a spring.

著者

三橋 邦宏 高木 渉

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.2007, pp._2A2-G05_1-_2A2-G05_3, 2007

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One leg with an ankle joint, a knee joint, and a hip joint was made, and the wire rolling-up type actuator which inserted the spring in series was attached to the knee joint. The relation between joint angular acceleration and a jump was analyzed, and it was shown that rotation of an ankle enlarges jump height. As a result of the experiment, in the time of the second half when a leg is extended, the spring generated large power and it turned out that this power makes a jump possible.

著者

向井 秀明

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会誌

巻号頁・発行日

vol.121, no.1200, pp.20-21, 2018

著者

清水 幸丸 鈴木 利明 松崎 健 森 健次朗

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.64, no.625, pp.2844-2851, 1998

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Sport science progresses step by step in the world. The paper describes, the first, the relationships between fluid drag for a model of woman swimmer and the flow around it. The flow around the model swimmer is very complicated, and includes, for example, wave, some kinds of vortices, hydraulic jumping and so on. The complicated flows are visualized by the surface tufts method and so on. Second, the possibility of the reduction of fluid drag for a woman athlete swimming suit is challenged. The boundary layer control is applied to reduce the fluid drag. The separation occurs around the breast of a woman swimmer. The separation can be suppressed by the boundary layer control. Many beads are distributed on the breast area of a woman swimming suit. As the result, it is found that the fluid drag for the model swimmer can be reduced in a range of 1.5%&sim;2% by the suit with the boundary layer control, which is carried out by many beads.

著者

下田 昌利 山根 滉一

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.79, no.807, pp.4353-4367, 2013 (Released:2013-11-25)

参考文献数

21

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This paper proposes a convenient numerical form-finding method for designing the minimal surface, or the equally tensioned surface, of membrane structures with specified arbitrary boundaries. Area minimization problems are formulated as a distributed-parameter shape optimization problem. The internal volume or the perimeter is added as a constraint according to the structure type such as a pneumatic or a suspension membrane. It is assumed that the membrane is varied in the normal and/or the tangential direction to the surface. The shape sensitivity function for each problem is derived using the material derivative method. The minimal surface is determined without shape parameterization by the free-form optimization method, a gradient method in a Hilbert space, where the shape is varied by the traction force in proportion to the sensitivity function under the Robin boundary condition. The calculated results show the effectiveness and practical utility of the proposed method for optimal form-finding of membrane structures.

著者

文 康一 土井 智晴 小倉 庸敬 山本 孝次 葭谷 安正 松浦 由貴

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.2011, pp._2A1-Q12_1-_2A1-Q12_2, 2011

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The small tricycle type electric vehicle: MEGURU-1 was made by the Yodogawa Manufacturing Ltd. in Osaka Prefecture Moriguchi City in 2009 fiscal year. In this year, the Yodogawa company and Osaka Pref. College of Technology will produce a second model of the vehicle. In this paper, we show that development and evaluation of MEGURU-2. MEGURU-2 is the motorcycle with sidecar in the security standard of the road transport vehicle in Japan. We design the body of MEGURU-2 to suit the security standard of the road transport vehicle in Japan. The power source of MEGURU-2 is the sealed lead acid battery. It is important that knowledge of basic performance of the use battery. There we research the charge and discharge performance.

著者

肥爪 彰夫 倉田 健二 中村 優一 松田 隆男

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:03875024)

巻号頁・発行日

vol.58, no.554, pp.2869-2876, 1992

被引用文献数

1

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Excessively large transient torsional vibration is induced on the rotor system of modern large turbine-generators. This paper reveals that the coupling connecting the adjacent rotors acts as a hysteresis damper, and discusses the effect. First, a model is presented for the damping mechanism of typical shaft coupling. Second, the time-dependent nonlinear transient torsional vibration of the rotor system is investigated, using this model. Third, an improved coupling of higher damping capacity is introduced and investigated in the same way. Thus, the proper direction of the optimal design of coupling is clearly specified.

著者

北野 正典 中村 優一 PILT Kristjan 有本 英伸 角田 直人 山田 幸生

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.2005, pp.61-62, 2005

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Patients of kidney disease remove excess water by hemodialysis. In hemodialysis, blood pressure may fall and the patients may suffer from hypovolemic shock, because body fluid removal rate is normally larger than plasma refilling rate. The aim of our research is to measure water content in issue in order to prevent the hypovolemic shock and to know how much water has to be removed quantitatively. We employ a technique using near infrared spectroscopy for this purpose. It will have advantages of being real-time, noninvasive and continuous.