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
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
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
1 1 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
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 4

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
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
堀畑 聡 新家 光雄 野崎 隆宏 赤堀 俊和 鈴木 亨 曽根 圭司 庭田 俊一 福田 徳久
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.803, pp.2240-2249, 2013 (Released:2013-07-25)
参考文献数
6

Traditionally, the metal mouthpieces of trumpets have been generally made of brass. However, for musicians who suffer from metal allergies, the use of the mouthpiece sometimes lead to inflammation of the lip if they are taking part in a long performance. This problem can be solved by using allergy-free pure titanium (titanium) and its alloys as the material for the mouthpiece. Therefore, a titanium alloy composed of non-toxic and allergy free elements has been designed. However, because their heat conductivity is generally poor, and they contain α phase with its HCP (hexagonal closed packed structure having structure, which restrict slip systems, forming them into suitable shapes can be very difficult. Therefore, precision casting method, where only final finishing was conducted by machining, applied for fabricating the mouthpieces of trumpets. Important considerations for use in musical instruments are the material characteristics and the sound characteristics of mouthpieces made of titanium alloy. Research on the material characteristics of titanium alloy mouthpieces is currently being undertaken. On the other hand, the sound characteristics of mouthpieces made of titanium alloy have not been examined sufficiently. In this study, the sound and the vibration characteristics of two kinds of mouthpieces made of titanium and Ti-Nb was examined. The adaptability of these materials for use in mouthpieces of trumpets was discussed by comparing the sound characteristics of mouthpieces of trumpets made of titanium, Ti-Nb, and brass.
著者
宇田川 洋一 鈴木 実
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.79, no.808, pp.2818-2825, 2013 (Released:2013-12-25)
参考文献数
22
被引用文献数
1 1

Ballast water is used to stabilize an empty ship on the open sea. It often contains various microorganisms such as plankton and bacteria, and causes serious damage to aquatic ecosystems when it is discharged. Ultra-high pressure underwater shock waves were applied to treat those microorganisms. The imploding detonation of propane-oxygen mixture was used to generate the underwater shock waves in a sample holder having an inner diameter of 10.9 mm. We investigated the imploding detonation wave in approximately hemisphere-shaped combustion chamber having maximum inner diameter of 60 mm and generated underwater shock waves of 100 MPa. As microorganisms of the high pressure treatment experiments Artemia salina, Heterosigma akashiwo and Coliform group were used. We could completely treat Artemia salina and Coliform group by 5 shots and Heterosigma akashiwo by 1 shot of the underwater shock wave that maximum pressure was about 100 MPa.
著者
品川 晃徳 野澤 久幸 内山 裕太郎
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.854, pp.17-00086-17-00086, 2017 (Released:2017-10-25)
参考文献数
4

It is thought that the first step to understanding vehicle movement is to measure and analyze that movement in order to confirm that it falls within the range of the laws of physics. In the case of a four-wheeled vehicle, in general, the friction limit is defined within the circle of longitudinal acceleration and lateral acceleration through the use of a G-G diagram. Then measurements are taken to confirm that the driving state is within that range. Two-wheeled off-road vehicles are mainly ridden on slippery dirt roads that include steep slopes and rough, uneven surfaces. An analysis method for the driving state and the vehicle movement limits that would be suitable for analyzing the movement of such two-wheeled off-road vehicles under these conditions was examined. These movement limits were then formulated by taking into consideration the coefficient of friction and the road surface gradient in accordance with the basic laws of physics and also by focusing on the vehicle movement in the longitudinal direction. Measurements were also taken during actual off-road riding by top-class Japanese off-road motorcycle riders. It was confirmed that this measurement data was distributed within the range of the assumed vehicle movement limits. Consequently, it was confirmed that it is possible to use such measurements to accurately grasp the vehicle movement limits and the associated driving state for two-wheeled off-road vehicles.
著者
奥野 航平 松尾 亜紀子
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.856, pp.17-00369-17-00369, 2017 (Released:2017-12-25)
参考文献数
20

The numerical analysis on the flight stability of the underwater projectiles are performed using computational fluid dynamics code which consists of gas/liquid phases analysis, 2D calculation method. The nose shape effect on the underwater flight stability is conducted. The ogival nose, the flat nose and the spike nose are used for the nose shapes. The static stability is determined by the direction of pressure on the projectile. The pressure on the flat nose makes projectile stable, although pressure on the ogival nose and the horizontal area of flat nose makes projectile unstable. The spike nose is statically unstable, however it is possible to increase the flight stability by changing the spike radius and the spike length. When the part of projectile gets out of the bubble and contacts with water, the water pressure acts as restoring force, which lead to improve the flight stability. This phenomenon is called ‘Tail slapping effect’. Tail slapping effect works most effectively when only backward of the center of gravity of the projectile contacts with water. The Effects is canceled as the angle of attack increases and the front of the projectile contacts with water. As a result, the improvement of stability due to the tail slapping effect is limited.
著者
長尾 不二夫 小早川 隆
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.16, no.54, pp.118-121, 1950-11-20 (Released:2008-03-28)

焼玉機関の圧縮指数を種々な焼玉温度のもとに求め, これを用いて圧縮仕事に対する熱の出入の割合を計算し, さらに圧縮終りの温度を求め, 燃焼が起動時には高温度の焼玉から始り, 運轉時には圧縮された高温度の空氣によるものであることを確かめた.
著者
岸 祐希 金崎 雅博 牧野 好和 松島 紀佐
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.849, pp.16-00454-16-00454, 2017 (Released:2017-05-25)
参考文献数
20

When a wing of airplane is designed, it is necessary to have knowledge regarding planforms considered their optimum airfoils in order to design efficiently, because each wing planform has both of advantage and disadvantage. In this study, the wing design problem for supersonic transport is carried out for different planforms for two different planforms. Multi-objective problem, which is minimization drags for two supersonic cruise conditions (transonic and supersonic flight) is solved to obtain knowledge of the supersonic airfoil from the viewpoint of the multi-point design. Two types of planforms are considered—a cranked arrow wing with a high sweep-back angle and a single tapered wing with a low sweep-back angle. Optimization problems are carried out by efficient global optimization, which is evolutionary algorithm based on the Kriging surrogate model. To acquire design knowledge, a parallel coordinate plot and functional analysis of variance (functional ANOVA) are applied. The design results showed the difference airfoil between two planforms. The optimum airfoil for the single tapered wing has a small or negative camber at the leading edge to minimize the supersonic cruising. On the other hand, the optimum airfoil for the cranked arrow wing has an airfoil with a lower thickness and larger camber at the leading edge.
著者
鈴木 実 安西 竜也
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.79, no.801, pp.799-803, 2013 (Released:2013-05-25)
参考文献数
11
被引用文献数
1 1

Underwater shock wave, generated by the imploding detonation of propane-oxygen mixture, was applied for extinction processing of microbes. We filled the water containing microbe into a stainless steel pipe having inner diameter of 10.9 mm, and transmitted the underwater shock waves which have the maximum pressure of about 100MPa. As microbe of the treatment experiments, Microcystis species were used. We found that the mortarity rate of Microcystis species increases gradually with the increase in the number of times of shock processing. Although the maximum mortality rate of Microcystis species was 99.9% in one day after processing, it turned out that it becomes 100% in one week after processing. The mortality rate became small when the value of the consistency of Microcystis species was large.