著者
臺丸谷 政志 小林 秀敏
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:18848338)
巻号頁・発行日
vol.77, no.776, pp.638-646, 2011 (Released:2011-04-25)
参考文献数
18
被引用文献数
1 1

The Japanese sword is a weapon peculiar to Japan. The Japanese sword is interesting not only from the viewpoint of traditional crafts of arts, but also from the aspect of modern science and technology because the way of making and its functionality as a weapon are really consistent with science. The present study is concerned with the connection between tohshin (blade) and tsuka (hilt) of the sword. Only one mekugi-take (retaining peg made of bamboo) with about 5mm in diameter holds Nakago (tang) in the hilt. However the slender mekugi might not be broken, even though in the case of violent sword-fighting. This fact has been historically demonstrated in many battles by Japanese swords. In this study, using a Tachi being the typical Japanese sword, it is examined theoretically and experimentally from the viewpoint of impact engineering why a mekugi used in Japanese swords might not be broken. As a result, it is made clear that such a strong force as breaking mekugi-take does not act on it, because of the location of mekugi-ana (a hole for mekugi) in the tang, which has been made by the traditional code of sword-smiths.
著者
丸茂 喜高 清水 勇介 竹内 亮佑 綱島 均 小島 崇
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.817, pp.TL0280-TL0280, 2014 (Released:2014-09-25)
参考文献数
9

This study proposes a driving assistance system to inform the notch operation timing for train drivers. The assistance system indicates visually the notch-off position where the driver releases the accelerator. The notch-off position is calculated by the present vehicle acceleration, velocity and position by assuming the constant acceleration. The assistance system also indicates the brake onset and the predicted stopping positions. Two experiments are conducted by using the train-driving simulator. One experiment examines the effects of the notch-off and brake onset timing on the vehicle velocity and the running time. The assistance system makes it possible to adjust the vehicle velocity and the running time. The other experiment examines the three running patterns by combination of the notch-off and the brake onset positions. With the time recovering pattern, which is combination of the higher notch-off velocity and the later brake onset timing, the assistance system realizes the shorter running time in comparison with the standard running pattern. With the energy saving pattern, which is combination of the lower notch-off velocity and the later brake onset timing, the assistance system prevents the time delay by the later brake timing even if the velocity is lower than the standard running pattern.
著者
土屋 晃佑 妻木 勇一 森 恭一
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.2017, pp.2A2-P03, 2017

<p>Bio-logging method obtains information by a data logger attached to the body of animals for ecological survey. It has great potential to reveal various mysteries of animals. Some researchers of sperm whales try to get the video data of preying sperm whales through the bio-logging, but no one has succeeded it. They can conventionally put a data logger only on the back of sperm whale. It is difficult to get video data around the sperm whale's mouth because of darkness of deep sea. To tackle this problem, we have introduced a "Whale Rover" which is able to move along the surface of sperm whale, and provide mobility for the data logger. Until now, we developed several prototypes of whale rover. In this paper, we introduce a new prototype which is expected to adopt curved surface.</p>
著者
小林 吉之 嶺 也守寛 藤本 浩志
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 C編 (ISSN:03875024)
巻号頁・発行日
vol.73, no.725, pp.274-279, 2007-01-25 (Released:2011-03-04)
参考文献数
14
被引用文献数
1 1

To determine the accuracy of foot position sense in the means of foot placement, young adults were asked to place either medial edge or lateral edge of their feet along the base line on the floor as close as possible, and the edge of placed feet were scanned by using laser displacement gauge. From the collected data, constant error, the distances between the edge of placed feet and the base line on the floor, and absolute error, the absolute distances between the edge of placed feet and the base line on the floor were defined and compared between the medial or lateral trials, and dominant leg or indominant leg. The statistical analysis showed significant differences of constant error between the trials only. The trials to place their medial edge tend to place their feet away from the base line, and the trials to place their lateral edge tend to place their feet in to the base line. These results indicate that we tend to expect the position of our feet more medially than actual, and these discrepancy may be one of a reasons of tripping or banging of our feet to the obstacles while walking.
著者
近藤 千尋 佐野 広季 一宮 暢希 山根 浩二 河﨑 澄
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.85, no.874, pp.18-00340, 2019 (Released:2019-06-25)
参考文献数
9

This paper describes how to produce a biodiesel fuel (BDF) from the waste soup of ramen noodles, especially focusing on the recovery process of the oil (triglycerides) from a large amount of waste soup or the oily wastewater disposed of by pouring it down the sink by a ramen restaurant. By combining a semi-transparent bucket (~6 L) with a cock and solvent extraction, it is shown that oil can be recovered easily from 300 or more bowls of ramen noodle waste soup, with an energy profit ratio (EPR) of more than 5.2. The initial cost of the bucket is about 1600 yen, so it has little effect on the price of the BDF produced from the oil in the ramen noodle waste soup, and it is shown that the increase in running cost to produce BDF by this method is about 2.3 yen/L if the rate of recovery of hexane (solvent) is over 99%, which is approximately equivalent to the production cost of waste-cooking-oil BDF production by previously reported methods. Furthermore, in the case of applying the proposed method based on the solvent extraction to the recovery of oil from the oily wastewater disposed of by a ramen noodle restaurant, it is shown that oil can be recovered from the waste soup of ramen noodles just after disposal as well as from the oily wastewater that spent one day in the grease trap. In the former case, EPR is 5.0, and the estimated amount of BDF is greater than 100 L/month for one restaurant. However, in the case of using the oily wastewater from the grease trap, EPR is less than 2.0 because of the reduction of yield of BDF due to a greater oxidation deterioration of the recovered oil, when the alkyl catalyst method is used. Therefore, it is desirable to recover oil from the oily wastewater at the drain pipe just after the sink.
著者
横堀 章一
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 (ISSN:00290270)
巻号頁・発行日
vol.10, no.38-4, pp.38-46, 1944-02-25 (Released:2008-03-28)

戦時下鉄道輸送の重要性は益々増大してゐる。この要求に應ずるために車輌の大増産を必要とする。本論文に於ではこの車輌中特に大量を要する貨車を限定された資材及び労力内でなるべく多量旦迅速に製造するために如何なる努力を排ってゐるかに就て設計を主にして述べる。貨車の戦時設計には在耒ある車輌に増積みする方法と全然新しい形式を設計する方法とがある。鉄道省では両者を並行に採用してみる。後者の例として3袖無蓋車を挙げ、その設計上の要点を述べる。貨車自重1t當りに積載し得る石族最は在耒車が1・16~1・89tであるが、新製3軸車では2・73tとなる。荷重1t當りの製作資材では在耒車の約年分に滅する。而して中梁に生ずる應力を見ても両者の差は著しくない。かかる結果を如何にして得たかに就て説明する。
著者
永瀬 和彦 中村 英男 小林 秀之
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.56, no.523, pp.797-802, 1990-03-25 (Released:2008-02-21)
参考文献数
4
被引用文献数
1

The authors constructed "slipping adhesion test bogie" designed upon a new idea of measuring the coefficient of adhesion continually while running, and have observed the state of adhesion on main lines since 1985. Recently, they placed a car equipped with this bogie on a steep line where wheel-spin and skidding of rolling stock had been frequently the cause of troubles. As the result of runs of the car under various weather conditions such as fine, fog, snow, sleet and frost, influence of the weather condition upon the adhesion between rails and wheels has been made clear and evaluated quantitatively.
著者
三浦 智 鈴木 智裕 小林 洋 藤江 正克
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.850, pp.16-00414, 2017 (Released:2017-06-25)
参考文献数
30
被引用文献数
1 1

Hemiplegic patients often have reduced typing speed due to finger paralysis. Our motivation is to develop a keyboard that enables their typing speed to increase. For this purpose, we have developed a three-dimensional keyboard that reduces the distance that fingers move while typing. In this paper, our objective was to construct the finger model that combines the motion speed and muscle fatigue for design of keyboard that can be typed with fast motion speed and low muscle fatigue. In experiment, we measured the finger position using a magnetic 3D motion device and EMG when the participant pressed the proposed key. The experiment was carried out in a variety of the finger postures. We qualified the motion speed and muscle fatigue at each joint angle. Then, we weighted and combined two of the objective functions. We found out the Pareto solution and get an effective keyboard design straight. In the future, we verify the typing speed and finger muscle fatigue during typing the three-dimensional keyboard that is designed based on our finger model.
著者
円山 重直
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:18848346)
巻号頁・発行日
vol.78, no.796, pp.2127-2141, 2012 (Released:2012-12-25)
参考文献数
13
被引用文献数
2 2 1

An accident scenario of Fukushima Daiichi Nuclear Power Plant, Unit 2 is analyzed from the data open to the public. Phase equilibrium process model was introduced that the vapor and water are at saturation point in the vessels. Proposed accident scenario agrees very well with the data of the plant parameters obtained just after the accident. The estimation describes that the rupture time of the reactor pressure vessel (RPV) was at 22:50 14/3/2011. The estimation shows that the rupture time of the pressure containment vessel (RCP) was at 7:40 15/3/2011. These estimations are different from the ones by TEPCO, however; many measured evidences show good accordance with the present scenario.
著者
伊藤 史斗 長谷 和徳 内田 和男
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 (ISSN:21879761)
巻号頁・発行日
pp.19-00191, (Released:2019-09-11)
参考文献数
15

The frame stiffness in a racing bicycle might influence not only toughness as the frame structure but also performance of an athlete. The purpose of this study is to clarify biodynamic relations between the frame stiffness in a racing bicycle and the physical loads of an athlete by using a forward dynamics simulation model. The human body structure was represented by the 13-rigid-links and 23-degrees-of-freedom model. Based on the theory of multibody dynamics, the frame structure was expressed by combination of 12 rigid pipes, and the frame stiffness was modeled by rotational springs at the connecting joint between the rigid pipes. Spring coefficients were changed according to the thickness of the frame pipes. The pedaling load from the crank was computed by the angular velocity and angular acceleration of the crank. Moreover, the driving force in the bicycle was additionally defined to consider the influence of the frame weight on the human joint load. The human body model was driven by the joint toques to minimize the cost function consisting of the joint loads in the human body and the driving force in the bicycle, and also to keep desired angular velocity of the crank. Validity of the simulation was evaluated by comparing the joint angles and torques with the measured ones. As for the result, the larger stiffness of the frame resulted in smaller the joint loads in the human body, and optimal stiffness would be determined by the balance between the joint loads in the human body and the driving force in the bicycle.
著者
野中 朋美 中野 冠
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.783, pp.4024-4033, 2011 (Released:2011-11-25)
参考文献数
14
被引用文献数
4 5

The paper proposes a carbon taxation scheme using life cycle assessment (LCA) for clean energy vehicles (CEVs). This taxation scheme can enable to be discussed tax amount, tax revenue and total CO2 emissions by changing the scenarios and parameters, such as: technology development, energy price and total driving distance. The authors figure out the tax rate 28.05[JPY/kg-CO2], which makes the hybrid electric vehicle's life cycle cost (LCC) less than that of conventional gasoline vehicles. The simulation results show that LCC after taxation of electric vehicles (EVs) have lowest total cost when battery cost is 0.14 times the 2007 cost and have lower total cost than that of GVs when driven more than 221,600 km. In addition, EVs have lowest emissions when driven more than 63,000 km considered CO2 emissions in the manufacturing phase, and it is expected that elders who drive shorter distances are best suited for hybrid electric vehicles and gasoline vehicles not electric vehicles considering LCCO2. The proposed tax system can provide consumers with an incentive to choose vehicles with lower CO2 emissions.
著者
神田 睦月 徳田 献一 入部 正継 森田 成昭 齊藤 安貴子 八上 修一 小堀 亮
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 2017 (ISSN:24243124)
巻号頁・発行日
pp.1A1-C02, 2017 (Released:2017-11-25)

In recent years, aging of agricultural workers has progressed, attention is paid to ICT conversion of agriculture and Functional food with health maintenance effect. Raspberry contains a large amount of compounds that have a high health maintenance effect, which takes time and labor for cultivation. The purpose of this research is to construct an image processing system that recognizes color and position information in order to check whether harvesting of raspberries is possible under an indoor environment. As research contents, RGB values of colors of berries at various stages were calculated from spectral analysis results of berries and compared with actual fruit photos. We also classified colors in the image using machine learning and verified its accuracy.
著者
小原 哲郎 大八木 重治 高藤 亮一 蔡 品
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.1680-1686, 2001-07-25 (Released:2008-03-28)
参考文献数
14

Experiments are carried out to investigate behavior of shock wave diffraction from a safety-engineering point of view. Because, once the shock wave is released into an ambience, high pressure and negative pressure lasting for relatively long period have possibility to cause serious damages against human bodies as well as general buildings. Therefore, it should be one of the most significant subjects to attenuate the shock wave efficiently within a short distance from the source. In this report, a cavity is installed at an open end of a shock tube and flow-fields behind diffracted shock wave are visualized using schlieren photography. In addition, piezo-electric pressure transducer is flush mounted on the surface of reflector, which is installed at test section, and pressure histories are recorded with wide frequency response. Lastly, numerical simulation using the TVD finite difference scheme is performed to compare with the experimental results. As a result, (i) the pressure histories on the reflector coincides well between the numerical and experimental results, (ii) flow-fields behind the shock wave are clarified, (iii) maximum pressure behind reflected shock wave can be attenuated by installing several cavities inside the open end of the shock tube.
著者
高藤 亮一 山中 昭央 小原 哲郎 蔡 品 大八木 重治
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.65, no.639, pp.3602-3607, 1999-11-25 (Released:2008-03-28)
参考文献数
12
被引用文献数
2 2

As is well known when a shock wave is emitted from an open end of a tube, an expansion wave and a vortex ring are generated behind the shock wave. Furthermore, a contact surface, slip line and these wave interactions may cause considerably complicate flow-fields. In this study, shock waves of Mach number 1.3, 1.6 and 2.2 are produced utilizing diaphragm-less shock tube of 50 mm diameter and c. a. 10 m total length, and the flow-fields are visualized with an aid of schlieren optical techniques. A cylindrical reflector is installed at test section and stagnation pressure behind reflected shock wave is measured with wide frequency response. A numerical analysis is also carried out to investigate these flow-fields using Predictor-Corrector TVD finite difference scheme. As a result, (i) the contour of diffracted shock wave is well coincided between experimental and numerical results, (ii) pressure histories behind reflected shock wave are clarified, (iii) an empirical formula is obtained between Mach number, non-dimensional distance from the open end of the tube and non-dimensional pressure just behind reflected shock wave.