著者

長佐古 美奈子

出版者

学習院大学

雑誌

学習院大学史料館紀要 (ISSN:02890860)

巻号頁・発行日

vol.20, pp.1-13, 2014-03

著者

ヘルマン エレラ グラナドス

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.115, no.1126, pp.650-651, 2012-09-05

著者

臼井 則生

出版者

千葉大学

雑誌

千葉大学園芸学部学術報告 (ISSN:00693227)

巻号頁・発行日

vol.52, pp.165-175, 1998-03-31

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オランダ病(Dutch Disease)ならびに近年注目されているリソース・カース命題(Resource Curse Thesis)は,資源保有途上国の経済開発が当初期待されたほど容易なものではなく,むしろ豊かな天然資源の存在と,それに起因する輸出ブームが経済発展を阻害する効果を持ちうることを明らかにした.この問題に関する研究を通じて明らかになりつつあることは,資源保有途上国は天然資源を経済開発のための後ろ盾(backbone)としてではなく,あくまでボーナス(bonus)と見做し,特に輸出ブームの過程においては慎重なマクロ経済運営を行う必要があるという点である.本稿では,輸出ブームのなかでのマクロ経済政策のひとつの側面として対外借入を取り上げ,輸出ブームによる国際的信用の改善による対外資金の流入が持ちうる効果をオランダ病の理論的枠組みのなかで分析し,さらに1970年代末,ともに原油ブームを経験したインドネシアとメキシコについて,その対外借入政策の比較分析を行った.メキシコは原油ブームのなかで拡張的経済運営を行い,それに起因する対外不均衡を是正するため対外資金への依存度を急速に高めたのに対し,インドネシアの借入額は許容範囲内であった.さらに,対外債務の構成においても,インドネシアの債務は長期低利資金のシェアーが大きいという点で,変動金利の短期資金の取り込みを急増させたメキシコと大きな対照をなしている.インドネシアがオランダ病を回避し,輸出構造の多様化を通じて高成長を達成しえた要因のひとつは,こうした慎重な対外借入政策にあるものと考えられる.一方,メキシコの野心的な経済運営は,オランダ病による経済停滞のみならず1982年の債務危機につながっている.本稿の分析結果は,資源保有途上国の経済政策に関する上記のコンセンサスを支持するものである.インドネシアのこうした慎重な政策運営を支えた要因は,スカルノ体制末期の経済混乱からの回復過程で確立したテクノクラートによるマクロ経済運営と,原油ブームのなかでのプルタミナ危機(Pertamina Crisis)によるナショナリストへの打撃にある.また,メキシコの経済政策の背景には,人民主義(Populism)にもとづく政府主導の積極的開発政策を求める強力な政治的圧力がある.経済政策の方向性は,それぞれの国が置かれた政治経済的ならびに歴史的要因に規定される.しかし,各国固有のこうした要因を除いて考えてみても,オランダ病を回避し,長期的な経済発展を推し進めるためには,あくまで慎重なマクロ経済運営が求められること,この点は資源保有途上国の経済開発に対する両国の経験から導かれる知見として共有されてよいものと考えられる.

著者

本荘 晴朗 神谷 香一郎 佐久間 一郎 児玉 逸雄 山崎 正俊 荒船 龍彦

出版者

名古屋大学

雑誌

新学術領域研究(研究領域提案型)

巻号頁・発行日

2010-04-01

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多階層生物現象である心臓興奮伝播を高分解能光学マッピングを用いて定量的に解析し、そのダイナミクスが心筋イオンチャネル機能と細胞間電気結合および組織構築の相互作用により規定されることを示した。また、旋回性興奮(スパイラル・リエントリー)では興奮波の形状が興奮伝播を規定する重要な要因であることが明らかにした。スパイラル・リエントリーは細動や頻拍など頻脈性不整脈の基本メカニズムであり、旋回中心の不安定化が細動や頻拍の停止を促す不整脈治療戦略となることが示された。

出版者

[東北農業試験研究協議会]

雑誌

東北農業研究 (ISSN:03886727)

巻号頁・発行日

no.55, pp.249-250, 2002-12

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シンフォリカルポスはスイカズラ科シンフォリカルポス属に分類され、北アメリカからメキシコが原産地の洋種枝物花木である。1本の枝から数本の側枝が発生し、その先端に10数個の果実からなる果房を形成する。この果実は8月下旬以降に肥大し、直径1cm前後の球形状となり、品種により白色またはピンク色に着色する。収穫は果房の3分の1以上が肥大した頃に行い、葉付きで出荷される。暖地・中間値では実付きが悪くなりやすく、秋冷の早い寒冷地が栽培適地で、日本国内の主な生産地として長野県、群馬県などがある。この品目は最近注目されている枝物花木の一つであるが、消費者段階では果実および葉の萎れ、枯れが発生しやすく、改善が望まれている。近年、切り花の品質保持に及ぼす抗菌剤や糖の影響が明らかにされてきており、切り枝類にも効果が期待される。そこで、本研究ではシンフォリカルポス切り枝における抗菌剤とスクロースの連続吸水処理が鮮度保持に及ぼす影響について調査した。なお、本研究では平成12年から実施している新技術地域実用化促進事業「寒冷地における枝物花木類の栽培技術体系の確立」の一部をまとめたものである。

著者

小池 関也 下嶋 浩 山家 勝裕

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.61, no.590, pp.3999-4006, 1995-10-25

参考文献数

16

被引用文献数

1

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A simple method is presented for controlling the motion and gripping force in dual flexible manipulators without calculating inverse dynamics. The gripping force is converted into a velocity vector according to the proposed force/velocity conversion law considering the flexibility of the manipulator. The velocity vector of contact point is calculated from the velocity of the object. The desired velocity vector is obtained as a sum of the above two velocity vectors, and is converted into angular velocity vector considering defectional velocity of the flexible links. The desired angular velocity vector is obtained as a sum of the above angular velocity vector and strain feedback term. Coordinative control is performed using DC motors whose desired values are equal to the above desired angular velocity vector. The characteristics of gripping force response of control system is also considered. Computer simulations and experimental analyses are carried out to clarify the validity of the proposed method.

著者

梶原 逸朗 福田 将直 下嶋 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. C編 (ISSN:03875024)

巻号頁・発行日

vol.64, no.621, pp.1668-1675, 1998-05

参考文献数

5

被引用文献数

5

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Approach for modeling and feedback noise control of a one-dimensional duct based on experimental modal analysis and LMI is presented in this paper. The modal parameters of a coupled acoustical-structural system are derived from measured noise and vibration data. The state equation of the duct is described by the identified modal parameters. An active noise controller is designed based on LMI approach in which an optimization problem is defined as a mixed H_2/H_∞ control problem. The performances of the noise reduction and the robust stability are described with H_2 and H_∞ norms of the closed loop system, respectively. Frequency response shaping is performed by the presented approach with weighted modal matrix and frequency weighting functions. Simulations and experiments are carried out and the desired performances are obtained by the presented approach.

著者

雉本 信哉 下嶋 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. C編 (ISSN:03875024)

巻号頁・発行日

vol.62, no.598, pp.2272-2277, 1996-06-25

参考文献数

7

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In active noise control, the transfer characteristic of an acoustic feedback path has a considerable influence on the stability of the control system. When the acoustic system has a feedback path, the control system often causes unstable behavior called howling. An adaptive howling canceler designed to prevent thin howling is studied in this paper. This adaptive howling canceler estimates the acoustic feedback path and acts to suppress the howling. In this paper, the effect of this adaptive howling canceler was considered for two different adaptive noise control algorithms. One was the conventional filtered-x LMS (least mean squares) algorithm and the other was the frequency-domain adaptive algorithm proposed by the authors. From computer simulations, it was shown that the howling canceler works effectively with the filtered-x LMS algorithm. On the other hand, the control system became unstable with the frequency-domain adaptive algorithm. To alleviate this unstable behavior, variable output gain was considered. A good result was obtained with this variable gain.

著者

下嶋 浩 松永 義弘 小池 関也 梶原 逸朗

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. C編 (ISSN:03875024)

巻号頁・発行日

vol.65, no.633, pp.1849-1856, 1999-05

参考文献数

7

被引用文献数

2

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An approach for feedback active noise control of a one dimensional duct with multiple control sources based on modal analysis is presented in this paper. Based on experimental modal analysis, the modal parameters of an acoustical system are derived from measured multiple frequency response functions. The state equation of the duct is described by the identified modal parameters. Considering eigenvectors of the acoustical system calculated by finite element method, control sources are located to the duct. A feedback active noise controller is designed based on mixed H_2/H_∞ problem in addition to H_∞ problem, preventing the increase in dimensions of the controllers. Simulations are carried out using the designed controllers. Moreover experiments are carried out using identified controllers based on modal analysis to reduce dimensions of the controllers. The desired performances are obtained by the presented approach.

著者

雉本 信哉 下嶋 浩 柴原 章宏

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.62, no.596, pp.1397-1402, 1996-04-25

参考文献数

10

被引用文献数

1

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A new adaptive control algorithm in the frequency domain was proposed. This frequency domain approach is an alternative to the ordinary filtered-x least mean squares (LMS) algorithm in the time domain. A transfer characteristic of an acoustic path is identified adaptively in the frequency domain using the fast Fourier transform (FFT). The real-time control of the noise reduction in an L-formed duct model was carried out. A digital signal processor and a personal computer were used for the active noise control. The maximum noise reduction level of about 30 dB and the average reduction level of about 7 dB were obtained through the experiment. As a result, it was shown that this frequency domain adaptive algorithm has faster convergence compared to the ordinary filtered-x LMS algorithm.

著者

小池 関也 山家 勝裕 下嶋 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. C編 (ISSN:03875024)

巻号頁・発行日

vol.64, no.622, pp.2094-2101, 1998-06

参考文献数

15

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A hybrid control method for a flexible manipulator based on an angular velocity control is presented, which is applicable to curved constraint surfaces. The error of contact force is converted into a velocity vector according to the force/velocity conversion law which consideres both force respose characteristics and variational angular velocity with respect to normal direction of the surface. The velocity vector which is tangent to the constraint surface is calculated using the velocity control law. The desired velocity vector is obtained as a sum of the above two velocity vectors, and is converted into angular velocity vectors. A vibration control law is proposed to reduce overshoot of end point velocity response. The desired angular velocity vector is obtained as a sum of the above angular velocity vector and vibration control term. Motion and force controls without calculating inverse dynamics is performed using DC motors whose desired values are equal to the above desired angular velocity vectors. Computer simulations and experimental analyses are carried out to clarify the validity of the proposed method.

著者

雉本 信哉 下嶋 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. C編 (ISSN:03875024)

巻号頁・発行日

vol.61, no.589, pp.3581-3586, 1995-09-25

参考文献数

9

被引用文献数

4

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A new adaptive control algorithm in frequency domain was proposed. This frequency domain approach corresponds to the ordinary filtered-x least mean square (LMS) algorithm in discrete time domain. In this approach, the fast Fourier transform (FFT) was used for converting signals between frequency domain and discrete time domain. Since the computaion processes in these two domains are almost independent with each other, this algorithm can be realized effectively by using two processors. Computer simulations were carried out for investigating convergence characteristics of this approach. As the result of these simulations, it was shown that this algorithm has faster convergence with less computation comparing to the ordinary filtered-x LMS algorithm.

著者

梶原 逸朗 山家 勝裕 下嶋 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. C編 (ISSN:03875024)

巻号頁・発行日

vol.64, no.626, pp.3839-3846, 1998-10-25

参考文献数

9

被引用文献数

1

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Dynamics of multi-link manipulators are highly nonlinear and depend on the time varying configuration. This paper presents a method of gain scheduling which consists in designing an linear time invariant (LTI) controller for each operating point and in switching controller when the operating conditions change. Each LTI controller is designed based on LMI approach in which an optimization problem is defined as a mixed H_2/H_∞ control problem with pole placement. The performances of the force and the position controls are defined by the H_2 norm, and the robust stability according to gain scheduling is evaluated with the H_∞ norm and the pole placement of the closed-loop system. The effectiveness and the practicability of the proposed method are verified by both simulations and experiments with 2-link manipulator system.

著者

小池 関也 小林 優揮 飯田 裕 下嶋 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. C編 (ISSN:03875024)

巻号頁・発行日

vol.67, no.654, pp.321-328, 2001-02-25

参考文献数

10

被引用文献数

2

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This paper proposes an active noise controller applicable to a moving evaluation point in one dimensional acoustic field. A combined adaptive feedforward/feedback controller based on filtered-x LMS algorithm is proposed. The feedforward controller is utilized for the noise reduction, and the feedback controller is utilized for the reduction of howling, which occurs with use of acoustic reference signal at feedforward controller. For the sake of stable noise control under moving evaluation point, necessity for a real time identificator of transfer function of the error path, which uses a microphone fixed in the neighborhood of the control speaker, is shown. Stable noise reduction without howling is realized by using above combined controller and the real time identificator with use of acoustic reference signal aiming practical use. A straight duct is chosen as a one dimensional acoustic field. Computer simulations and experimental analyses are carried out to clarify the validity of the proposed controller.

著者

下嶋 浩 雉本 信哉 佐藤 治 前田 秀 斎藤 敦

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.59, no.562, pp.p1803-1808, 1993-06

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Motions of human arms are analyzed kinetically and kinematically with respect to smoothness. A kinematic arm model with 6 degrees of freedom is suggested and spatial motions are simulated considering the sum of the weighted square of joint displacements, which approximately equals kinetic energy of the whole arm. A low-pass filter is applied for smoothing the kinetic state variables, i. e. , displacement, velocity, and acceleration, and the smoothing transfomation is optimized from the aspect of characteristics of response and vibration. Such transformation is also applied to the human arm model, and the effects are investigated through simulations.

著者

雉本 信哉 下嶋 浩 田窪 崇行

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 C編 (ISSN:03875024)

巻号頁・発行日

vol.60, no.571, pp.p850-855, 1994-03

被引用文献数

1

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An approach for active noise control using structural vibration was proposed. No acoustic instruments such as loud speakers and microphones are necessary in this approach. The adaptive FIR filter using the LMS algorithm was used in the control system. Both a computer simulation and an experiment were carried out. The importance of using a howling canceler with the adaptive FIR filter was shown by the simulation. In the experiment, the vibration of the sidewalls of the duct was used for control. Good results were acquired using the simple controller.

著者

小池 関也 小林 優揮 飯田 裕 下嶋 浩

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 = Transactions of the Japan Society of Mechanical Engineers. C (ISSN:03875024)

巻号頁・発行日

vol.67, no.660, pp.2521-2527, 2001-08-25

参考文献数

13

被引用文献数

2

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A basic noise control system applicable to a moving evaluation point was proposed in the previous report, and its effectiveness was examined numerically and experimentally. Although the results showed that the proposed system is effective, it can only handle the case of slow evaluation point velocity. This restriction seemed to be due to the slow convergent speed of the adaptive filter. In this paper the cause of restriction is examined in detail, and an advanced control system is proposed. The features of the proposed system are as follows : 1) Improved feedback controller where main filter is less affected by the movement of the evaluation point. 2) Introduction of IIR filter together with the learning identification method to the error path identifier. The new system is examined both in simulation and experiment and shows great improvement compared with the basic model.

著者

佐藤 治 下嶋 浩 李 丁 長友 聖二

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.60, no.572, pp.p1344-1350, 1994-04

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Equations of motion of a closed-type manipulator are derived in consideration of characteristics of the step motors. Vibration control is achieved using two types of forcing functions. The first is the function of the pulse width modulation to avoid exciting resonance, and the second is the bang-bang control function on each step function. Dynamic characteristics of the system controlled by these method are analyzed theoretically and investigated experimentally.

著者

小池 関也 下嶋 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 C編 (ISSN:03875024)

巻号頁・発行日

vol.60, no.575, pp.p2323-2330, 1994-07

被引用文献数

2

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This paper presents a simple hybrid method for controlling both the motion and contact force of a manipulator without calculating inverse dynamics. The contact force is converted into a velocity vector according to the force/velocity conversion law. The velocity vector which is tangent to the constraint surface is calculated by the velocity servo. The desired velocity vecotor is obtained as a sum of the above two velocity vectors. The desired axial velocity vector is calculated from the desired velocity vector using inverse Jacobian matrix. Motion and force control is performed using DC motors whose desired values are the above desired axial velocity vector. The stability of the motion control system is also considered.

著者

丸山 剛生 柴山 憲文 竹内 博之 下嶋 浩 中原 凱文

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.63, no.616, pp.4224-4230, 1997-12-25

参考文献数

11

---

Equipment to measure the surface hardness of the human body has been designed for the purpose of estimating muscle generating force from the physiological view point. The surface hardness is defined as the reaction force of the body surface under predetermined thrust displacement. The sensor described here is suitable for analysis of human motion and multipoint measurements because of its compactness. From the results of experiments on elbow joints, a relationship was found between the measured hardness and the joint torque. The results also showed that body surface hardness was a function of the joint angle. Moreover, it was shown that muscle forces could be estimated by a neural network when the hardness and joint angle were given.