著者

水谷 昌平 山﨑 楠人 林 隆三 宮澤 邦幸 三浦 義章

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.853, pp.17-00026-17-00026, 2017 (Released:2017-09-25)

参考文献数

10

被引用文献数

1

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Elderly caregivers are increasing by aging of society in Japan. One of the hardest action for them is to make a wheelchair with a person on climb a step. In order to reduce burdens of the caregivers, assistive products to ease burdens of step-climbing action are desired. The purpose of this study is to devise a mechanism to reduce caregivers’ burdens when they make wheelchairs climb steps and to develop casters with the devised mechanism. Prior to the development of the step climbing mechanism, measuring experiments of forces a caregiver apply to a wheelchair in a step-climbing action is conducted using normal casters. In reference to the result of the experiment using the normal casters, the authors devise step-climbing casters with a burden reduction mechanism. It utilizes the reaction force from the step induced by an unnecessary force applied by caregivers in a step-climbing action. Mechanical analysis of a wheelchair with the burden reduction mechanism is carried out numerically to show the effectiveness of the mechanism. Measuring experiments of forces a caregiver apply to a wheelchair in a step-climbing action is conducted using the developed step-climbing casters. The result of the analysis and the experiment indicate that the burden reduction mechanism reduces the total maximum force necessary to make a wheelchair climb a step, leading to the conclusion that the devised burden reduction mechanism is effective.

著者

鈴木 淳史 巽 和也 堀井 悟史 栗山 怜子 中部 主敬

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.853, pp.17-00200-17-00200, 2017 (Released:2017-09-25)

参考文献数

28

被引用文献数

1

---

A fluid temperature measurement technique based on fluorescence polarization is developed and applied to measure the two-dimensional temperature distributions in microchannel. In this measurement method, the fluorescence depolarization due to rotational Brownian motion of the fluorescent molecules in the solution is measured and converted to fluid temperature. Since the fluorescence polarization degree is independent to fluorescence intensity, the measurement is less influenced by the fluorescence quenching effect, which is an issue in laser-induced fluorescence (LIF) method. Experiments were performed using a microchannel with fluorescent molecules solved in water. The effects of the fluorescent molecule concentration, fluid pH and fluid temperature on the fluorescence polarization degree are discussed to evaluate the influence of the quenching effects and to derive the correlation curves. Furthermore, the proposed method was applied to measure the temperature distribution with linear gradient generated in the microchannel. The results showed that the fluorescence polarization is considerably less sensitive to quenching factors compared with the fluorescence intensity measurements. A linear correlation between the polarization degree and the fluid temperature was obtained. This relationship agreed well with the theoretical one. Further, measurement of two-dimensional temperature distribution in the microchannel agreed well with the values obtained by the thermocouple measurements. These results confirmed the validity of the measurements and feasibility of the proposed method.

著者

村上 敬宜 町田 尚 宮川 進 髙城 壽雄

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 (ISSN:21879761)

巻号頁・発行日

vol.83, no.853, pp.17-00231-17-00231, 2017 (Released:2017-09-25)

参考文献数

29

被引用文献数

4

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Recently, recalls for mass production products such as car components have been frequently reported even for the case that the rate of defects is only of the order of ppm or less. The objective of this paper is to propose the solution to avoid the recall problem of the order of ppm for mass production products. Even if the defect rate is of the order of ppm or less, most of remaining safe products have to be recalled and be replaced by new components. Such a recall causes a great cost deficit if the very rare defect is possibly related to fatal accident. However, it is very difficult by the conventional quality control methods to find the defects of the order of ppm or less at the stage of design and production. This paper proposes a new practical quality control method to avoid the defects of the order of ppm or less for mass production products based on the statistics of extremes which has been successfully applied to fatigue strength evaluation of defective materials. First, several examples of the quality control method to avoid the troubles mainly caused by failures and damages of components will be presented. Next, it will be shown that the same approach also can be applied to other problems such as the optimum control of operational parameters and the selection of optimum materials through the index based on the statistics of extremes. It will be also shown that the same method can be applied not only mass production components but also to avoid the troubles and failure accidents for large machine components of small number production. The stress-strength model approach will be reviewed from the viewpoint of the statistics of extremes.

著者

江尻 英治 磯野 大樹

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.852, pp.16-00569-16-00569, 2017 (Released:2017-08-25)

参考文献数

23

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A fuel cell with a simple structure and operating at nearly ambient temperature and pressure is suitable for low cost small-sized generator sets ranging from several to tens Watts for home, outdoor and emergency use. This kind of fuel cell is called passive or self-breathing PEFC. Water management is very important and sometimes crucial for a long term stable operation in the passive type PEFC because control of gas temperature and humidity is inherently not easy for the PEFC. In this paper, various performance characteristics regarding the passive type PEFC were experimentally investigated using a rated 55 W fuel cell module with 20 cells laid out in plane. The properties, such as the output voltage of each cell, the temperature, pressure and humidity of hydrogen and air, were measured with time in the dead-end system and the recirculation system for hydrogen supply. The water balance in the fuel cell module was then calculated and the behavior of generated water, which should cause output power breakdown and voltage fluctuation in certain conditions, was also discussed. Results showed that a sudden power breakdown in a long time continuous operation with dead-end hydrogen supply system was caused by flooding in the anode and that this shortcoming was overcome by introducing a simple hydrogen recirculation system with valves and a water trap. Results also showed that 95% of produced water by the reaction was discharged from the cathode to the atmosphere in the form of vapor and that 5% trapped in the form of liquid in the hydrogen recirculation system.

著者

横山 賢介 伊藤 寛明 西宮 康治朗 長 秀雄

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 (ISSN:21879761)

巻号頁・発行日

vol.83, no.852, pp.17-00213-17-00213, 2017 (Released:2017-08-25)

参考文献数

14

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This study aims to evaluate strength of a diamond-like carbon (DLC) film on a metal for glass press molding at high temperature. Static and cyclic indentation tests at high temperature up to 300℃ with AE monitoring technique were performed. AE monitoring reveled crack generation load or cyclic number during the indentation tests. The static strength of the films at each temperature was determined from maximum stress in the film in the radial direction induced by sink-in deformation due to static indentation. The maximum stress at each temperature was estimated with indentation loads at first AE generation and FEM analysis. Thermal stress in DLC film was at each temperature also calculated. The film strength estimated by taking the thermal stresses into account was decreased with an increase of temperature. In cyclic indentation test, AE due to cracks in film was detected after 1.0×104 cycles at the load where no crack generated under one loading cycle. The cyclic number to crack initiation for the sample in 300℃ was 1/50 smaller than that in room temperature.

著者

綿引 壮真 松本 聡 阿部 豊

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.852, pp.16-00476-16-00476, 2017 (Released:2017-08-25)

参考文献数

20

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New viscosity measurement technique by using rotational breakup of electrostatically levitated droplet was developed. The new one-dimensional viscosity measurement equation is derived by integrating three-dimensional momentum equation based on the assumptions with axisymmetric shape and internal flow of levitated droplet. From the measurement result obtained, internal flow around the center of the dumbbell shape droplet is axisymmetric along the elongational axis. This result means that the present proposed new method is appropriate. In the present study, high accuracy image processing technique is applied to obtain the shape and curvature around the center of the dumbbell shape droplet by using the transformation to rotating coordinate system. The present technique can be applicable after the breakup start and before the shape of the droplet becomes asymmetric. This is reason why Euler force becomes so large that the symmetricity cannot be sustained. The newly proposed viscosity measurement technique makes it possible to estimate the viscosity within 10 % error in the range of the viscosity which the previous levitation technique cannot be available.

著者

橋本 翔 小俣 弘樹 松永 久生

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 (ISSN:21879761)

巻号頁・発行日

vol.83, no.852, pp.16-00585-16-00585, 2017 (Released:2017-08-25)

参考文献数

17

被引用文献数

1

---

Rolling contact fatigue (RCF) tests were conducted using rolling bearings with a micro-drilled hole on the raceway. In all the tests, fatigue crack initiated at the edge near the bottom of the hole, and then propagated by shear mode. Even in the unbroken specimens tested up to N = 1×108 cycles, a short fatigue crack was found at the edge. By using stress intensity factor (SIF) range calculated for initial defect size, fatigue life data were uniformly gathered inside a small band irrespective of the diameter and depth of the hole. In addition, it was found that the crack size dependency of threshold SIF range, which is well-known for mode I fatigue crack, also exists in mode II fatigue crack emanating under the rolling contact. The values of threshold SIF ranges obtained by the RCF tests were in good agreement with those obtained in the torsional fatigue tests under a static compression.

著者

伊東 弘行

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 (ISSN:21879761)

巻号頁・発行日

vol.83, no.852, pp.17-00080-17-00080, 2017 (Released:2017-08-25)

参考文献数

30

被引用文献数

5

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To investigate the influence of briquette size and density on the combustion behavior in both flaming and char combustion stage, the combustion experiments with the highly densified columnar briquette made from cypress sawdust were carried out. Three sizes of the briquette, φ30 mm×60 mm, φ35 mm×70 mm and φ40 mm×80 mm, of which diameter/length ratio is kept constant at 1/2 and three types of the briquette density, 900, 1100 and 1300 kg/m3 were employed. The water content of the briquette was kept around 10 wt%. The mass loss rate and the duration in both combustion stages were measured. In the flaming combustion stage, it is observed that the average mass loss rate per unit specific surface area is proportional to the briquette surface area, while it doesn't depend on the briquette density. It is expected by considering Fourier number that the flaming combustion duration is proportional to the product of the inverse square of the specific surface area and the briquette density and it is shown that the experimental results correspond to the expectation. It is found that the relationship between normalized mass loss rate and normalized time is nearly the same regardless of the briquette size and density. In the char combustion stage, normalized mass loss can be approximately expressed with the shrinking core model by assuming the effective oxygen diffusion coefficient in the ash layer for each briquette density used in this study. And it is found that the effective oxygen diffusion coefficient in the ash layer obtained by the shrinking core model decreases with increasing the briquette density.

著者

田辺 実 常盤 匡 小泉 忠由

出版者

The Japan Society of Mechanical Engineers

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.80, no.817, pp.DSM0274-DSM0274, 2014

---

The relationship between the elements included in materials and the fire ball obtained by spark test, that is simple, has been examined by using SEM photographing of the fire ball. From experimental results, the kind of steel material could be estimated from fireballs image of SEM. The following contents would be pointed out as the results. The size of fire ball becomes large with the increase in the contained carbon. The size of alloy steels becomes about the double of fire ball of carbon steel. When nickel element is contained in a material, the surface of fire ball shows the delamination. When the many chromium components are contained the size of fire ball becomes large, and many holes occur in the fireball. The presence of molybdenum element in the steel shows the smooth texture at the surface of the fireball. The wrinkles appear at the surface of the fireball by the presence of tungsten element, and the many holes occur in the fireball. Whether the material is ductile or brittle we would be estimated from the pattern of deformation of the hole of the fire ball. The kind of material would be able to distinguish from the qualitative properties of the fire ball.

著者

大久保 光 野田 悠貴 田所 千治 平田 祐樹 佐々木 信也

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 (ISSN:21879761)

巻号頁・発行日

vol.83, no.850, pp.16-00543-16-00543, 2017 (Released:2017-06-25)

参考文献数

14

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Lightweight Al-Si alloy is expected as a substitute material for the cast iron of engine parts to improve fuel consumption of automobiles. In this study, the tribological properties of Al-Si alloys against diamond-like carbon (DLC) films were examined to comprehend the influences of Si particles on Al-Si alloy surfaces under lubricated with a fully formulated oil. Sliding tests were performed with a hydrogenated amorphous carbon (a-C:H) film coated steel cylinder against the five kind of Al-Si alloy disks with different Si contents. Sliding tests and surface analysis results showed that the friction coefficient of a-C:H/Al-Si tribo-pairs depended on the exposure height of Si particles on the Al-Si alloy surfaces rather than the area ratio of Si particles. The exposure height of Si particles plays important roles in determining the frictional properties of a-C:H/Al-Si tribo-pairs under lubrication with the fully formulated oil.

著者

前田 慎市 倉持 悠希 小野 涼 小原 哲郎

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.850, pp.17-00049-17-00049, 2017 (Released:2017-06-25)

参考文献数

21

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This study addressed a deflagration-to-detonation transition (DDT) process after interaction of the convex flame with a planar shock wave. High-speedvideo cameras and schlieren optical technique were utilized to observe the DDT as well as shock-flame interaction processes. A double-diaphragmshock tube was used to produce the shock wave, while the flame was produced by igniting a premixed gas of stoichiometric methane-oxygenat the observation section. Experiments were conducted by changing Mach number of the incident shock wave, Ms and a distance of flame front from the end wall, x0. As a result of schlieren photographs, flame propagation behaviors at initial stage were classified into four patterns, named as (a) coupling, (b) concave, (c) partial coupling and (d) convex type. The propagation patterns of flame were highly dependent on the initial position of flame front, x0. Under the experimental conditions, DDT was not observed when the flame had been propagated revealing (a) coupling (observed with the conditions of x0 > 110 mm) and (d) convex type (x0 < 50 mm). However, the DDT was observed following that the flame had been propagated revealing (b) concave or (c) partial coupling (50 < x0 < 110 mm). Furthermore, it was elucidated that DDT was typically caused through the following processes. (i) When the convex flame interacted with planar shock, the unburned gas was penetrated into burned gas inducing Richtmyer-Meshkov instability. (ii) The flame was highly accelerated at boundary layers behind the reflected shock. (iii) After accelerated flame propagated through the unburned shocked region, local explosion was occurred on the wall followed by detonation onset.

著者

大嶋 元啓 松村 恵理子 千田 二郎 石田 耕三

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.16-00491-16-00491, 2017 (Released:2017-05-25)

参考文献数

12

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In this study, the novel flame synthesis method using flash boiling spray is proposed in order to form the homogeneous characteristics nanoparticle. In this method, the precursors are injected and the injected precursors are evaporated by flash boiling. The evaporated precursors form vapor and the nanoparticles are formed at high temperature with flame. The factors for homogeneous characteristics of nanoparticles are precursor, flash boiling spray, flame characteristics and nozzle. These factors affect each other and affect to the nanoparticle characteristics as diameter distribution and crystal characteristics. It is necessary to optimize these factors to form homogeneous characteristics particles. In the previous study, TiO2 nanoparticles were formed and the relationship between the flame and injection characteristics, and the particle characteristics were investigated. From the result, the equivalence ratio affects to the nanoparticle crystal characteristics and injection condition affect to the particle diameter and mass fraction of anatase phase. In this paper, TiO2 nanoparticles were produced and the particle property influenced by ambient pressure and particle trapping position is investigated. As the result, the mass fraction of TiO2 anatase phase decreases by increasing ambient pressure. The rutile phase is formed at the short nanoparticle trapping position. The factors such as precursors, injection condition and fuel/oxygen flow ratio for producing the anatase phase particle in this method was discussed.

著者

加藤 学 高橋 勉

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.17-00007-17-00007, 2017 (Released:2017-05-25)

参考文献数

12

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The technique to measure planar elongation viscosity from both mechanical and optical measurements by using two-dimensional opposing jets nozzle flow has been developed. This technique generates planar elongational flow between both nozzles and simultaneously measures reaction force acting on the nozzle and flow birefringence at the stagnation point. The correctness of elongational viscosity measured by this technique was verified from experimental results for Newtonian fluid and Maxwell fluid. Starch syrup aqueous solution and CTAB/NaSal surfactant solution are used for the Newtonian fluid and the Maxwell fluid respectively. As the results, transient behavior of nozzle reaction force and flow birefringence for Maxwell fluid show good agreement. It indicates that this technique can evaluate planar elongation viscosity for not only fluids that obey stress-optical rule but also fluids have flow birefringence property. In addition, Trouton ratio of optical results become 4 and it indicates the results from optical technique are accurate. On the other hand, the data from mechanical technique provide Trouton ratio with range 15 to 20. Trouton ratio of Newtonian fluid also shows 10 ~ 20 and these results conclude that mechanical data should be limited for qualitative evaluation. However, Trouton ratio of mechanical technique is independent from sample viscosity and elongaitonal rate. Therefore, it can provide quantitatively valuable result by using correction factor.

著者

中山 江利 グエン タイ タット ホアン 戸倉 直 萩原 一郎

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.81, no.829, pp.15-00268-15-00268, 2015 (Released:2015-09-25)

参考文献数

9

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A tsunami is caused by a large coastal earthquake. We devise the foldable tsunami pod on which evacuees can get, when tsunami is approaching. The 3D model for the foldable ellipsoid body is generated by FEM software “LS-PREPOST”. We perform a numerical simulation, and confirm the safety by von Mises equivalent stress and Head Injury Criterion (HIC). As the result of the 1st simulation, it is proved that the initial model is weak to the impact force from rigid wall and obstacles and can be strained in the central part. On the other hand, an occupant hits against the inner side of the wall and can be injured. So, a seat and upper and lower bars are added to the initial model. Von Mises equivalent stress for the modified model is decreased, however is still over the ultimate strength of the 1st simulation. While, HIC value is decreased largely which is much less than the HIC safety level. This is because an occupant isn’t hit by the internal wall for an occupant restraint system. Moreover, we optimize the form and property for a tsunami pod on condition of its mass is minimized by uncoupled analysis. Finally, we confirm the validity of the optimal model by an original condition of coupled analysis.

著者

大久保 光 坪井 涼 田所 千治 佐々木 信也

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 (ISSN:21879761)

巻号頁・発行日

vol.81, no.824, pp.14-00656-14-00656, 2015 (Released:2015-04-25)

参考文献数

12

被引用文献数

1 5

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This research studied the effects of Zinc Dialkyldithiophosphate (ZnDTP) additives on the tribological properties of a H-free Diamond-like Carbon (DLC) film under boundary lubrication with oils that contained organic friction modifiers (FMs). The tribological properties were evaluated using the reciprocating type cylinder-on-disk tribo-tester. ZnDTP and three types of organic additives (GMO, glycerol mono-oleoyl ether (GME), and tallow diethanol amine (TDEA)) were added to poly-alpha olefin (PAO). Friction tests were carried out for the DLC/Steel tribo-pair under lubrication with PAO and PAO-based oils containing GMO, GME, TDEA, ZnDTP, GMO + ZnDTP, GME + ZnDTP, and TDEA + ZnDTP additives. Raman spectroscopy, Scanning Electron Microscopy (SEM), energy-dispersive X-ray analysis (EDX) and X-ray photoelectron spectroscopy (XPS) were used for analyses of worn surface on the H-free DLC film. The H-free DLC film lubricated with PAO + FMs reached an ultralow friction coefficient of 0.02 - 0.03. On the other hand, The H-free DLC film lubricated with PAO + FMs + ZnDTP had increased friction coefficients compared to the PAO + FMs oils. For the lubrication added ZnDTP additive, the surface analyses demonstrated that the chemical composition of the ZnDTP-derived tribofilm depended on the combination of ZnDTP and each FM. It was concluded that the chemical composition of the ZnDTP-derived tribofilm played an important role in the friction behavior of the H-free DLC films that were lubricated with PAO + ZnDTP and PAO + FMs + ZnDTP.

著者

大久保 光 福田 宙央 坪井 涼 田所 千治 佐々木 信也

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 (ISSN:21879761)

巻号頁・発行日

vol.82, no.838, pp.15-00679-15-00679, 2016 (Released:2016-06-25)

参考文献数

13

被引用文献数

1

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Tribological properties of a diamond-like carbon film were investigated under lubrication with commercial fully formulated oils. Friction tests were carried out for a hydrogenated amorphous carbon (a-C:H)/steel tribopair under lubrication with the four types of fully formulated oil using a reciprocating type ball-on-disk tribo-tester. To clarify the friction and wear mechanisms, surface analysis, such as Raman spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDS) and atomic force microscopy (AFM), were conducted on the wear tracks of a-C:H disks. The results of friction tests and surface analysis show that the properties of tribofilms on DLC films play important roles in determining the tribological properties of DLC films under lubrication with fully formulated oils.

著者

土谷 圭央 日下 聖 田中 孝之 松尾 祥和 小田 まこと 笹木 工 神島 保 山中 正紀

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.82, no.843, pp.16-00072-16-00072, 2016 (Released:2016-11-25)

参考文献数

22

被引用文献数

6

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Anteflexion of the spine is essential for many physical activities of daily living. However, this motion places the lumbar disks because it generats heavy load due to changes in the shape of the lumbar spine and can lead to low back pain. In older to reduce low back pain, here we proposed a wearable sensor system configuration that can estimate lumbosacral alignment and lumbar load by measuring the shape of the lumbar skin when the lumbosacral alignment changes. The shape of the lumbar skin and posture angle are measured by using curvature sensors and accelerometers. In addition, the system must be constructed in consideration of the physique, in order to absorb in a variety of human. We proposed this system by measuring the body parameters of anteflexion and studied the change in dimensions of the lumbar spine from changes in posture. By extracting the dimensions of the lumbosacral spine in X-ray images, the attitude angle, body surface area and the dimensions of the lumbosacral spine have relevance. The lumbosacral dimensions calibration method was developed by using that relation. Lumbosacral alignment estimation considering the difference in physiques is developed, and lumbosacral spine alignment was to improve the estimation accuracy. The proposed method could improve accuracy lumbosacral alignment estimation.

著者

髙村 藤寿 太田 順子 尾崎 光則 西澤 泉

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.16-00070, (Released:2016-10-07)

参考文献数

24

被引用文献数

2

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In this paper, Technology Circulation Model is proposed as a new management method for companies with existing business domains that plan and execute industry-university collaborations to make innovations. Based on this model, we discuss concepts for effective planning and execution of industry-university collaborations through real cases. Technology Circulation means a flow of Science - Technology - Engineering - Manufacturing & Services, then to Science again. We show the effectiveness of the framework of industry-university collaborations, in which; empirically used techniques are visualized, complicated phenomena are explained simply, new sciences are established, and current industrial technologies are made more sophisticated. By starting from visualization of currently used technologies, it becomes possible to execute efficient industry-university collaborations matching the directions of business needs and academic seeds.

著者

郭 鐘声 小竹 元基 鎌田 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 (ISSN:21879761)

巻号頁・発行日

pp.16-00092, (Released:2016-09-07)

参考文献数

20

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In a bathing environment, it is needed to evaluate an emotional effect quantitatively and continuously at stage of the product design for improving stress-relaxation effect. This study aimed to propose an index which can evaluate the comfort quantitatively and continuously on bathing. To search the physiological indices correlated to the comfortable feeling, we measured subjective evaluation of comfortable feeling in one-minute increments, with continuous measurement of physiological parameter before bathing, on bathing, after bathing. We analyzed the relationship between time-series data of the subjective evaluation and the physiological parameter. As a result, we proposed the evaluation index of comfortable feeling by using HF content obtained from spectral analysis of heart rate variability, and confirmed that the evaluation index can evaluate comfortable feeling quantitatively and continuously including the effect of personal preferences related to bathing.

著者

淺井 裕斗 村田 滋 田中 洋介

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.81, no.823, pp.14-00348-14-00348, 2015 (Released:2015-03-25)

参考文献数

11

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This paper presents a normalized deconvolution approach for a digital holographic particle measurement in order to decrease the elongation of the reconstructed particles along the depth direction. The performance of this approach is evaluated using numerical simulations, and its practicality is experimentally demonstrated. In the numerical simulations, the performance is evaluated mainly based on the cross-correlation between the true distribution and the deconvolution results. Tests were carried out for two types of recording systems and three kinds of reconstructed information. The results indicate that the most accurate particle images were obtained using the phase-shifting observation method and reconstructed quantities that contain phase information, such as the complex amplitude. Furthermore, the RMS error in the particle depth position is found to be improved especially for higher number density within the particle distribution. Experimental measurements with standard particles confirm that particle elongation along the depth direction can be successfully suppressed using the normalized deconvolution method. The experimental results thus confirm that this method is useful for real particle measurements.