著者

服部 篤 岡田 昌志 Kang Chaedong

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.662, pp.2533-2540, 2001-10-25

参考文献数

8

被引用文献数

1

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A water fine particle suspension with a uniform initial temperature and various initial concentration distributions in a rectangular vessel was heated from a vertical wall and cooled from the opposing vertical wall. The particle made of SiO_2 had a narrow size distribution (mean diameter of 2.96μm, standard deviation of 0.023μm). In order to observe phenomena of the natural convection, the temperature distribution, local particle concentration of the suspension and position of first interface were measured under various temperature differences between the opposing vertical walls. To make the influence of initial particle concentration on the phenomena clear, natural convection of suspension with three patterns of concentration, i.e. a naturally or artificially formed gradient, or non-gradient, was investigated. The pattern of formation of layers was classified by Grashof number. Moreover, to make the influence of initial depth of suspension clear, the suspensions with three initial depths, 50,100 or 160mm, were examined.

著者

平松 信昭

出版者

一般社団法人日本機械学会

雑誌

日本機械学會誌 (ISSN:00214728)

巻号頁・発行日

vol.105, no.1009, pp.806-808, 2002-12-05

著者

高木 清志 佐藤 宏司

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.2004, no.10, pp.201-202, 2004-03-03

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This paper deals with damage detection and vibration control of a new smart board designed by mounting the piezoelectric fibers with metal core on the surface of the CFRP composite. The damage of the board is identified on the assumption that the piezoelectric fibers using a sensor and actuators are broken at the damaged location simultaneously. A finite element model a CFRP cantilever is established and the damage location is identified using the input-output signals. Furthermore, the liner fractional transformation (LFT) is formulated considering the damage location and the gain-scheduled controller considering the location is designed. The control performance of the proposed method is verified by simulation.

著者

岩崎 篤 桑原 秀剛 轟 章 杉谷 恒也

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.2004, no.10, pp.207-208, 2004-03-03

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This research is about a statistical diagnostic method for a structural health monitoring which is applicable to existing structures from the present moment. In this method, structural condition is statistically diagnosed by change of a response surface which is regression model of sensor's outputs. Change of response surface is statistically tested with F-test. In the F-test, a threshold value of normal/troubled condition is simply decided from a theoretical F-probability distribution. Therefore, this diagnostic method only requires data of intact condition and does not require the complicated modeling and information of troubled condition. To confirm the effectiveness of the presented method, health monitoring of jet fan is conducted. Load cells are mounted to a supporting system of the jet fan. Response surface is calculated from vibration data measured by the load cells. As a result, structural condition of the jet fan is successfully diagnosed with the method.

著者

西岡 俊久 野村 亮 藤本 岳洋 EPSTEIN J.S.

出版者

一般社団法人日本機械学会

雑誌

材料力学部門講演会講演論文集

巻号頁・発行日

vol.2000, pp.285-286, 2000-10-05

著者

多田 幸生 長嶋 達也 高田 昌紀

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. A編 (ISSN:03875008)

巻号頁・発行日

vol.58, no.551, pp.1115-1121, 1992-07-25

被引用文献数

2

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The brain consists of brain tissue, blood and extracellular fluid. We can thus consider that brain tissue has multi-phasic properties. There is a very important interrelation between the tissue and the fluid. Thus, we consider that the respective factors on brain neurosurgery, the distribution of brain tissue pressure and extracellular fluid flow are very important, and we cannot neglect those factors closely related to metabolism of the brain tissue. This study constructs a two-dimensional consolidation model of the brain using the finite element method (FEM) and simulates the flow and distribution of cerebrospinal fluid (CSF). The two dominant equations on the consolidation theory are approximated numerically in time by the finite difference method and in space by the FEM. The results obtained by computer simulation regarding brain edema using the FEM are compared with the pathological observation with regrad to the flux distribution and flow direction of CSF, and we conclude that they are much the same as those from the view point of the pathological and clinical surgery. We furthermore propose that we should take the boundary conditions of pressure of the subarchanoid space and ventricle into consideration in the simulation of brain edema.

著者

日根野 漠 大山 節夫

出版者

一般社団法人日本機械学会

雑誌

日本機械学會誌 (ISSN:00214728)

巻号頁・発行日

vol.57, no.422, pp.208-213, 1954-03-05

著者

久角 喜徳

出版者

一般社団法人日本機械学会

雑誌

熱工学講演会講演論文集

巻号頁・発行日

vol.2001, pp.645-648, 2001-11-03

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二酸化炭素の排出を抑制するには、省エネルギーの促進と非化石燃料エネルギーの導入が最も重要である.省エネルギーは、従来、産業部門および民生部門で積極的に推進が図られてきたが、今後は環境に対する影響をいっそう小さくする観点からさらに強化し、社会全体を省エネルギー型に変えていく必要がある.そのためには、これまでのエネルギー変換尺度を熱量保存則から、エクセルギー評価則に変えることが重要である.ここでは、エクセルギー評価則の理解を深めるため、エクセルギーとエンタルピーの関係を小遣いと給料の関係に当てはめ、熱力学の意味するところを考えてみたい.また都市ガス事業において、実際にエクセルギー評価設計が行われている一例を紹介する.

著者

鈴木 一生 根本 栄治

出版者

一般社団法人日本機械学会

雑誌

茨城講演会講演論文集 : Ibaraki district conference

巻号頁・発行日

vol.2007, pp.121-122, 2007-09-28

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To clarify the relation to the power generation of the fractal and the solar battery, the amounts of power generation when not using it in case of the case to use the fractal figure were compared in this research. The figure prepared two kinds (the Sierpinski carpet and Sierpinski gasket). In addition, each reversing figure was prepared and it experimented. The experiment measured the change in the amount of power generation while changing the complexity in the figure. As a result, it was clarified that the amount of power generation changed when the fractal figure was used

著者

稲葉 英男 森田 慎一

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. B編 (ISSN:03875016)

巻号頁・発行日

vol.61, no.585, pp.1841-1848, 1995-05-25

被引用文献数

3

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This work deals with physical properties of a fine capsulated latent heat storage material-water mixture. The fine capsulated material consists of pentadecane (C_<15>H_<32>, melting point of 283.1 K) as the core latent heat storage material and melamine resin as the coating material. The measured results of the physical properties of the test mixture, i. e. , density, latent heat and viscosity, were analyzed for the temperature region of solid and liquid phases of the core latent heat storage material (pentadecane). It was clarified that the additional properties law could be applied to the estimation of density and latent heat of the fine capsulated latent heat storage material. Moreover it was found that the viscosity of the test mixture increased with an increase in concentration of the fine capsulated latent heat storage material. Useful correlation equations of viscosity for the fine capsulated latent heat storage material-water mixture were derived in terms of temperature and concentration.顕熱に潜熱を上乗せすることによる多量の熱搬送が可能な微細潜熱蓄熱材を分散した混合水は、従来の低温水(顕熱)に代わる有効な熱搬送媒体の一つと考えられる水中に微細潜熱蓄熱体を分散混合する方法としては、エマルション化する方法および微細カプセル化混合する方法などが考えられる。エマルション化は、界面活性剤を用いた潜熱体の微細化そして安定分散化により均質混合水を容易に得ることが可能である。しかし、界面活性剤を用いるために高粘性の混合水となり、管内搬送時の圧力損失が大きくなる欠点を有する。固-液潜熱物質を微細カプセル化し、水と分散混合する方法は、均質な混合水をえるためにカプセル化潜熱物質を十分に微細化する必要がある。この微細カプセル化潜熱物質を分散した混合水は、連続相を水のみとすることができるために、圧力損失の増大を抑えることが可能である。この種の潜熱蓄熱材料は、水中にカプセル化された微細な潜熱体が分散している複雑な系を有することから、その物性の測定方法の検討などで困難な問題を伴い、その結果基礎データとしての物性値の評価が十分になされていない現状にある。本研究は、ペンタデカン(C15H32,凝固点Tfp=283.1K)を芯物質としメラミン樹脂をカプセル被覆とする微細カプセル化潜熱物質を水と混合した潜熱蓄熱材料の基礎データとしての密度、潜熱および粘性の測定結果を示すものである。微細なカプセル化潜熱物質混合水の密度および潜熱量の測定は、試料の温度制御が比較的安易な体積計法および示差走査熱量法により行われた。吉田は、直径100μm程度の多核カプセル化潜熱物質混合水の粘性測定を回転粘度計を用いて行い、非ニュートン挙動が示されることを明らかにすると共にべき乗則モデルによる近似を行っている。この種の混合水の粘性は、一般に非ニュートン挙動を示すことが知られている。本研究にいける粘性測定は、せん断速度を変化可能な回転粘度計を用いて行われた。物性値測定は、芯物質の固-液相変化を伴う温度範囲(T=273.1~298.1K)、そして微細カプセル化潜熱物質の質量割合Cca=10.2~40.8mass%の範囲において行われた。物性値測定の結果は、この種の潜熱蓄冷材料を用いた蓄冷システムの伝熱および流動特性予測に役立つ基礎資料を提供するものと思われる。

著者

稲垣 洋輔 香川 美仁 森川 広一 岩附 信行 林 巖 細川 俊之

出版者

一般社団法人日本機械学会

雑誌

Dynamics and Design Conference : 機械力学・計測制御講演論文集 : D & D (ISSN:13480235)

巻号頁・発行日

vol.2000, 2000-09-01

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This paper describes the optimization of the case cover of small hard disk drive (HDD) used for personal computers. Small Hard disk drives are one of the main causes of noise radiated from personal computers or workstations. Nowadays the rotational speed of spindle motor used to rotate disks is increased year by year in order to increase the transfer speed. It is afraid that the noise radiated from small HDD is increasing more and more accordingly. Optimization of the shape of ribs which are attached on the case cover are hence tried in order to reduce the noise radiated from small HDD used for personal computers. Firstly, the natural modes of flexural vibration of the case covers of small HDD, which were made of aluminum, steel, and brass, were experimentally determined, and the natural frequencies, mode shapes, and damping coefficients were determined. Secondly, the sound power radiated from the case covers was theoretically estimated dy using the results of FEM modal analysis, was made sure to coincide with the measured values. Finally, the sound powers radiated when the thickness of the case cover was uniformly thickened, and when radial ribs, lattics ribs, or circular ribs were attached on the case cover, were compared. As the results, it has been revealed that the sound power is more reduced as the thickness is increased, the increase of thickness is effective especially to the low modes. For attaching ribs, radial ribs were most effective, and the sound power was more reduced as the number of ribs and/or the height was increased.

著者

小西 義昭

出版者

一般社団法人日本機械学会

雑誌

日本機械学會誌 (ISSN:00214728)

巻号頁・発行日

vol.109, no.1053, 2006-08-05

著者

佐藤 武

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集 (ISSN:00290270)

巻号頁・発行日

vol.22, no.115, pp.181-187, 1956-03-25

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In this paper, free vibrations of the Greek-Crossed Bar, which is formed by two bars intersecting on their middle points at right angles, are studied analytically. And the normal modes of the vibrations and the characteristic equations for determining the natural frequencies are shown. Numerical calcurations are carried out in detail and the influences of the dimensions and the physical prperties of the two bars on the natural frequencies are also discussed.

著者

渋沢 貴久 竹下 孝樹 本多 舞 松井 利一

出版者

一般社団法人日本機械学会

雑誌

ジョイント・シンポジウム講演論文集 : スポーツ工学シンポジウム : シンポジウム:ヒューマン・ダイナミックス : symposium on sports engineering : symposium on human dynamics

巻号頁・発行日

vol.2007, pp.216-221, 2007-11-13

被引用文献数

2

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So far, many kinds of human two-joint arm control models with shoulder and elbow joints have been proposed to simulate human two-point reaching movements. However, in order to simulate human arm movements accurately, it is desirable that the human arm control system should be formulated as a three joint model including a wrist joint. In this research, we extend the modified minimum-torque-change model to a three joint model and incorporate a freezing mechanism into its wrist joint. Actually, the freezing system is a feedback controller to simulate the muscle dynamics contracting agonists and antagonists together. Consequently, it was clarified that the extended model can reproduce two-point reaching movement characteristics for the human three-joint arm system: the end-point variability of hand trajectories and the relationship between end-point variability and movement time (Fitts' law). This suggests that the extended model characterized by the freezing wrist joint functions effectively as a model of the human three joint arm control system.

著者

徐 章 池田 郁雄

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.59, no.557, pp.117-123, 1993

被引用文献数

1

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The destructive phenomenon of brittle and fatigue fracture is becoming extremely important in the problem of structures' safety. In this paper, to elucidate the fracture mechanism, it is tested experimentally to explicate the destructive phenomenon of the fractured section and fissure progression occurring due to thermal shock in typical brittle glass materials. Specifically, by the application of the newly developed method of applying electric resistance-vacuum evaporated thin films, it became possible to accurately measure the velocity of fissure propagation and also each block of glass and ceramics. As a result, the maximum velocity of fissure propagation for the glass was approximately 1 500-1 700 m/s and its average velocity was 650 m/s. It is also found that the velocity of fissure propagation in the glass by thermal shock under the condition of adding load by four-points bending is almost approximatrely 3 000 m/s.

著者

西村 秀和 加山 竜三

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. C編 (ISSN:03875024)

巻号頁・発行日

vol.68, no.676, pp.3644-3651, 2002-12-25

被引用文献数

7

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In this paper we design a controller for a semi-active suspension using a magneto rheological (MR) damper. We formulate the linear-parameter-varying system taking account of the mechanism of a fictitious damper model includes valve stroke of the orifice and the damping coefficient restriction. The gain-scheduled controller is obtained with linear matrix inequalities and we confirm that the controller according to the varying parameters is superior to the semi-active damper utilizing the sky-hook damper theorem by simulation. Furthermore, we propose the control method using the relation between the input current and the damping coefficient of the MR damper that is experimentally obtained. By carrying out experiments it is verified that the designed controller for the semiactive suspension using the MR damper has the desired good performance.

著者

西村 正治 後藤 知伸 松岡 裕和

出版者

一般社団法人日本機械学会

雑誌

環境工学総合シンポジウム講演論文集

巻号頁・発行日

vol.2003, no.13, pp.91-94, 2003-06-24

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We, human being, hear 'twitter of birds', 'stream sound' etc. as comfortable sound. On the other hand, we hear 'sound scratching window', 'sound scrubbing styrene foam' etc. as uncomfortable noise. What is the difference between them? In this paper, the uncomfortable rates of 16 daily hearing sounds were evaluated at first, using method of paired comparison. Then, those sounds were analyzed by the human auditory model and wavelet analysis in order to find out causes of discomfort. Such characteristics of comfort and discomfort were found out that the former has calm rising up and down and the later has steep rising up and down, and that the former has sinusoidal vibratos in high frequency region and the later has irregular ones. But the auditory indexes which can evaluate the noisiness of machines were proved hardly to have correlation with uncomfortable rate.

著者

市川 直樹 細川 和生 前田 龍太郎 三澤 雅樹

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 : JSME annual meeting

巻号頁・発行日

no.1, pp.183-184, 2001-08-22

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In this paper, we describe experimental results of PIV (Particle Imaging Velocimetry) technique applied to visualize flow in microchannels. 100μm width×60μm height channels were fabricated with PDMS transparent silicone rubber, and 1μm diameter fluorescent particles were used for tracers. Flow visualization was successfully carried out, and large disturbance of flow velocities caused by interaction of gas-liquid interface and a trapped liquid droplet at corners were observed. Relatively large focal length and Brownian motion of the tracer particles are found to be serious problems on micro-PIV techniques.

著者

団村 芳和

出版者

一般社団法人日本機械学会

雑誌

日本機械学會誌 (ISSN:00214728)

巻号頁・発行日

vol.112, no.1087, pp.464-465, 2009-06-05

著者

佐藤 幹夫

出版者

一般社団法人日本機械学会

雑誌

年次大会講演資料集

巻号頁・発行日

vol.2004, no.8, pp.171-172, 2004-09-04