Transactions of the JSME (in Japanese)
Online ISSN : 2187-9761
ISSN-L : 2187-9761
Volume 88, Issue 914
Displaying 1-19 of 19 articles from this issue
Special issue on new developments in the field of design and systems engineering 2022
  • Miki YAMAZAKI
    2022 Volume 88 Issue 914 Pages 22-pre02
    Published: 2022
    Released on J-STAGE: October 25, 2022
    JOURNAL OPEN ACCESS
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  • Yutaka NOMAGUCHI, Koki SHODA, Tomoya TACHIBANA, Kikuo FUJITA
    2022 Volume 88 Issue 914 Pages 22-00191
    Published: 2022
    Released on J-STAGE: October 25, 2022
    Advance online publication: October 24, 2022
    JOURNAL OPEN ACCESS

    In the conceptual design phase, generating novel concepts is a cornerstone for producing innovative products. This paper proposes a framework for design concept generation with an extensional conceptual space (ECS). A conceptual space is a geometric space of concepts constructed with concept distance. ECS focuses on the characteristics, i.e., function and physical attribute, each of which is a set of entities that fall under its definition. The concept distant measurement method based on word2vec with Wikipedia corpus is adopted to extract concepts from documents of design cases and to build a concept space. The framework facilitates a designer to explore a concept space containing text and image information with iterative operations, such as function development, and create a new design. This paper demonstrates a case study of chair design to verify the effectiveness of the proposed framework.

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  • Yusuke TSUTSUI, Kotaro YOKOI, Yuya MITAKE, Yoshiki SHIMOMURA
    2022 Volume 88 Issue 914 Pages 22-00168
    Published: 2022
    Released on J-STAGE: October 25, 2022
    Advance online publication: October 11, 2022
    JOURNAL OPEN ACCESS

    In industrialised countries, the competitiveness of the products/services of the manufacturing industries in the global market is declining due to many factors, including products commoditization and rapid technological growth in developing countries. For this reason, engineering designers in industrialised countries are required to enhance their creativity in design with redefining customer value and redesigning advanced solutions. In recent years, the design thinking, which is known as a practical method for user centered creative design, is attracting attention as a practical strategy to accelerate creative innovations in engineering design. However, the logical details in designers’ cognitive process are still not clear, which hinders the practice and dissemination of design thinking. Based on above background, this paper proposes a prescriptive cognitive process model that leads highly creative engineering design. The proposed model is constructed based on the analysis of characteristics of exist engineering design process models and findings from creative thinking processes derived in cognitive science domain. The proposed model comprises following five steps: requirement finding, design solution finding, verification, validation, and documentation. The proposed model was applied to analyse a bicycle design case retrospectively, which is a past actual example that achieved highly innovative design. As a result, the application result demonstrates that the proposed model can explain the mechanism of creative engineering design process and be expected to provide knowledge basis towards creative engineering design.

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  • Masato TOI, Yutaka NOMAGUCHI, Kikuo FUJITA
    2022 Volume 88 Issue 914 Pages 22-00173
    Published: 2022
    Released on J-STAGE: October 25, 2022
    Advance online publication: September 27, 2022
    JOURNAL OPEN ACCESS

    When mathematical optimization is applied to a multi-objective design problem, it is the common practice of decision support to generate Pareto optimal solutions as alternatives and clarify their trade-offs. The decision-maker selects any design solution according to his or her preferences. Although any comparison of alternatives is beneficial for its selection, in the case of combinatorial design problems, a simple comparison study cannot find the significant relationships between alternatives because of their discrete nature. This paper proposes a decision-making support method based on the dendrogram of hierarchical clustering. It is assumed that an optimal solution can be represented as a piling-up of smaller pieces, which correspond to building blocks, in the combinatorial solution space. The distance of alternatives is surveyed using schema representation defined at various levels. The structure of the solution space is reconstructed into a dendrogram through hierarchical clustering. When essential parts of schemas are identified as building blocks, they are organized into a tree-shaped graph. It is expected to help the designer's exploration of the solution space. The effectiveness of the proposed method is verified through two case studies: the global product family design problem and the permutation flowshop scheduling problem. Schemas are defined that consider the characteristics of the problems. The set of alternatives is systematized using a decision bifurcation diagram and the relationships between the building blocks identified are discussed.

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  • Shuya NOZAWA, Heng ZHANG, Xiaopeng ZHANG, Akihiro TAKEZAWA
    2022 Volume 88 Issue 914 Pages 22-00175
    Published: 2022
    Released on J-STAGE: October 25, 2022
    Advance online publication: September 05, 2022
    JOURNAL OPEN ACCESS

    Fiber-reinforced composites are currently considered engaging materials by engineers and researchers in automobile, aerospace, robotics, and other related industries and scholars in academics due to their superior mechanical properties. Using the materials as structural materials allows engineers to make lightweight but high-stiff mechanical structures happen in reality. By adopting a structural optimization methodology, they can explore further and bring out the mechanical properties of composites as much as possible to design innovative composites structures. Based on this background, it has already been a hot research topic to establish a method for concurrent optimization of topology and fiber orientation in the structural optimization research field. This optimization method will be more effective in the real world by considering uncertainties that engineers commonly encounter. However, anisotropic topology optimization researches on this motivation are very rare. In the present work, we propose a robust topology and orientation optimization methodology accounting for fiber manufacturing uncertainty, namely orientation uncertainty. The proposed method is built upon the Phase Field and the Method of Moving Asymptotes based SIMP type topology optimization and EOLE-PCE uncertainty quantification. Numerical analysis is done by the Finite Element Method. The effectiveness of the proposed method is validated through the compliance minimization problem and the fundamental eigenfrequency maximization problem.

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  • Jin-Xing SHI, Masatoshi SHIMODA, Shinobu SAKAI
    2022 Volume 88 Issue 914 Pages 22-00135
    Published: 2022
    Released on J-STAGE: October 25, 2022
    Advance online publication: July 13, 2022
    JOURNAL OPEN ACCESS

    By combining different material properties of two metals, bimetals have been widely designed and manufactured as parts or accessories in automobile, aircraft, marine engineering for providing specific requirements. Hence, shape design optimization of bimetal composite structures performs an important role for obtaining their best mechanical or physical behaviors. In addition, initial stress of bimetal composite structures generated during the manufacturing or assembling process cannot be ignored. In this study, to control the vibrational eigenvalues of bimetals, we develop a shape design optimization method to obtain the optimal shapes of initial stressed bimetal composite structures. In the formulation of the design problem, we use minus vibrational eigenvalues multiplied by weighting coefficients as the objective function. Hence, the present work can treat vibrational eigenvalue maximization or vibrational eigenvalues’ gap maximization by adjusting the weight coefficients. We minimize the objective function subjected to the governing equations of structural analysis for generating the initial stress and vibrational eigenvalue analysis considering the initial stress. We also consider the volume constraint as the constraint condition. Then, we theoretically derive the shape gradient function based the method of Lagrange multiplier and the material derivative method, and use the derived shape gradient function to calculate the optimal shape variation based on the H1 gradient method. At last, we construct the shape design optimization system for determining the optimal shapes of bimetal composite structures conveniently. From the optimal results of design examples, we confirm that the developed shape design optimization method has efficiency and validity for controlling vibrational eigenvalues of bimetal composite structures.

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  • Shogo TSURITA, Satoshi KITAYAMA, Masahiro TAKANO, Yusuke YAMAZAKI, Yos ...
    2022 Volume 88 Issue 914 Pages 22-00048
    Published: 2022
    Released on J-STAGE: October 25, 2022
    Advance online publication: May 06, 2022
    JOURNAL OPEN ACCESS

    In plastic injection molding (PIM), weldline affects the strength and surface quality of products, and it is then important to determine the optimal process parameters for the weldline reduction. Rapid heat cycle molding (RHCM) that actively controls the mold temperatures is an effective PIM technology to weldline reduction, but requires long cycle time. In this paper, variable pressure profile that packing pressure varies during the PIM process is incorporated in the RHCM in order to shorten the cycle time. To determine the process parameters in the proposed RHCM, multi-objective design optimization is performed. The mold temperature is maximized for the weldline reduction, whereas the cycle time is minimized for high productivity. Numerical simulation in the proposed RHCM is computationally so expensive that sequential approximate optimization is used to identify the pareto-frontier. Based on the numerical result, the experiment using PIM machine (MS100, Sodick) is also conducted to examine the validity of the proposed RHCM.

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  • Yoshinori NISHIO, Yang LIU, Nagato ONO
    2022 Volume 88 Issue 914 Pages 21-00392
    Published: 2022
    Released on J-STAGE: October 25, 2022
    Advance online publication: May 20, 2022
    JOURNAL OPEN ACCESS

    Topology optimization is an advanced design method that is used to generate lightweight and high-performance structures by determining the material distribution. However, one of important drawbacks of the topology optimization, especially performed by the density approach, is that distinct and smooth boundaries cannot be directly obtained owing to checkerboard patterns, grayscales, and irregular shapes with thin parts (point-point connections) or disconnected parts (isolated islands). This drawback makes it difficult manufacture the results of topology optimization. In this paper, a novel methodology is proposed to automatically obtain optimal smooth boundaries of topology optimization results using an efficient boundary smoothing technique and the H1 gradient method, which is a node-based parameter-free optimization method. With this methodology, distinct and smooth optimal boundaries can be determined without any shape design parameterization. Moreover, re-mesh is not necessary in the shape updating process and the process is fully automatic. The validity and practical utility of this method is verified through three numerical examples with respect to a mean compliance minimization problem. They were calculated under the volume constraint, and a shape with a smooth outer shape was obtained with the average compliance reduced while satisfying the volume constraint. It was also confirmed that the shape obtained by using this methodology can be directly manufactured by a home 3D printer by converting it into an STL file.

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  • Takashi OYAMA, Effendi MOHAMAD, Teruaki ITO
    2022 Volume 88 Issue 914 Pages 22-00149
    Published: 2022
    Released on J-STAGE: October 25, 2022
    Advance online publication: July 29, 2022
    JOURNAL OPEN ACCESS

    Human movements vary on trial-by-trial due to signal-dependent noise that is added to motor commands and provokes errors of movements. In some motor tasks, humans have to produce precise movements with overcoming of the noise. This study aimed at considering the motor criteria taking into account movement errors. Three factors affecting movement errors in arm repetitive movements were investigated: the viscous force field, hand laterality, and signal-dependent noise. In the measurement experiment, the participants were asked to move their right and left hands between the target areas specified as the motor task. Pseudo null, positive (resist), and negative (assist) viscous force fields were set in the workspace of the motor task. A two-way analysis of variance involving two factors, hand (right and left) and viscosity (null, resist, and assist), in the movement error was conducted, and it revealed significant main effects of hand and viscosity, and a significant interaction between them. The data obtained from the measurement suggested consistent characteristics for the shape of the paths of the movement trajectories. A simulation experiment was conducted to investigate the shape characteristics which are regarded as the nature of the human motor control system. Under the assumption of signal-dependent noise, results of the experiment revealed that the shape characteristics are associated with lower variance of a movement error directly relating the task achievement rather than an error of a movement endpoint. The lower variance of the movement error is of greater significance as the criteria of motor planning compared to the smoothness of the movement.

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  • Yuya MITAKE, Naoki MURAOKA, Yusuke TSUTSUI, Yoshiki SHIMOMURA
    2022 Volume 88 Issue 914 Pages 22-00162
    Published: 2022
    Released on J-STAGE: October 25, 2022
    Advance online publication: September 05, 2022
    JOURNAL OPEN ACCESS

    With the increasing sophistication of systems and complexity of social problems, co-design, which diverse designers with expertise in various fields participate in design process, is becoming general design practice. In this process, Designers drive design activities to reduce uncertainty (i.e., ambiguities in design requirement) to elaborate a design solution that fulfill the requirement by sharing and adapting each knowledge. Meanwhile, where heterogeneous designers with different backgrounds, beliefs and knowledge participate, uncertainty and its reduction direction are perceived uniquely for each designer. These discrepancies in the uncertainty perception and their reduction directions are barriers to the rational elaboration of design requirement and consensus building among designers. Therefore, it is necessary to proceed with design activities under a converges the discrepancies in their uncertainty perception through sharing the contents of uncertainty and its rationale that explains why designer perceives that uncertainty. This paper develops a typology of discrepancies in uncertainty perception among designers in co-design process. This paper firstly defines uncertainty and its relationship with elaboration of design requirement under the context of co-design through literature review of extant research related to uncertainty in design. Then, we developed a typology of the discrepancies through a set-theoretic formalization of the designers' thinking. The developed typology was applied to design experiment of toilet cleaning machine for identifying the discrepancies in the design process. The all discrepancies identified during its process could be classified into the typology. This result thus demonstrated certain validity and comprehensiveness of the developed typology.

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Solid Mechanics and Materials Engineering
  • Fumitada IGUCHI, Keisuke HINATA, Yusaku MITARAI, Yiying DONG, Takamich ...
    2022 Volume 88 Issue 914 Pages 22-00058
    Published: 2022
    Released on J-STAGE: October 25, 2022
    Advance online publication: September 12, 2022
    JOURNAL OPEN ACCESS

    To clarify the fundamental issues in the elastic moduli of all-solid-state electrochemical devices such as all-solid-state lithium ion batteries and solid oxide fuel cells, the elastic moduli of the component solid-state-ionics materials: 8 mol% yttria stabilized zirconia (8YSZ) and the composites of lithium cobaltite (LCO) and lithium borate (LBO) were evaluated using the ultrasonic method. For 8YSZ porous materials, variations of up to 10% between the reported Young’s modulus were investigated, and it was suggested that the variation was not due to the influence of the measurement method or porosity, but originated from the elastic properties of the sample. In addition, the porosity dependence of Young’s modulus in 8YSZ porous materials was evaluated and compared with reported models, and a model applicable to porous materials fabricated by solid-phase sintering was obtained. For LCO-LBO composites, the model obtained based on the 8YSZ porous materials was examined for applicability. The Young’s modulus of the composites showed similar porosity dependence to the model based on that of 8YSZ, which was more consistent with the model calculated based on the microstructure consisting of solid spheres. Because the melting point of LBO was close to the sintering temperature, and it was considered to be half melted during sintering, the microstructure of the LCO-LBO composites was likely to be different from that prepared by the solid-phase sintering method. Therefore, the difference in microstructure was suggested to have affected the difference in porosity dependence. From these results, it was confirmed that it was necessary to consider not only the porosity but also the microstructure characteristics to correctly evaluate the elastic modulus of porous materials in the field of solid-state electrochemical devices.

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Thermal, Engine and Power Engineering
  • Yusuke OBAMA, Masanori FUJIMOTO
    2022 Volume 88 Issue 914 Pages 22-00064
    Published: 2022
    Released on J-STAGE: October 25, 2022
    Advance online publication: October 12, 2022
    JOURNAL OPEN ACCESS

    This study has been carried out experimentally to reveal motion behaviors of a water droplet in silicone oil with an electric field. The study used the radial electric field formed by the inner surface of a metal cylinder, and a thin metal wire which had been installed coinciding with the central axis of the cylinder. After a water droplet was supplied between the electrodes, a high voltage of 10 - 16 kV DC was applied between the electrodes. The motion behavior of single water droplet in each experiment was recorded using a high-speed video camera and then observed precisely and analyzed. As a result, it was observed that the water droplet reciprocated repeatedly between each electrode. Detailed observation revealed that the water droplet always stopped a few millimeters in front of the wire electrode, and the water droplet interface contacted and exchanged charges by forming an interface with a shape like a Taylor cone with a pointed tip extending to the surface of the wire electrode. The contact time of the water droplet on each electrode was approximately 5ms in contact with the wire electrode and 25 ms with the inside surface of the cylindrical electrode. From these results, it was clarified that the reciprocating behavior under a non-uniform electric field and the contact behavior for each electrode were different, and especially, water droplets stopped just before the wire electrode. By using the general solution of the equation of motion of the water droplet, its charge quantity was estimated through four view points, and calculated velocity by use of each calculated charge. The evaluation was carried out by comparing the calculated result with the experimental value.

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Dynamics & Control, Robotics & Mechatronics
  • Fumihiko HAKODA
    2022 Volume 88 Issue 914 Pages 22-00099
    Published: 2022
    Released on J-STAGE: October 25, 2022
    Advance online publication: September 30, 2022
    JOURNAL OPEN ACCESS

    This paper presents a real-time system identification method for the monitoring or anomaly detection of control systems. Real-time system identification technique is an extension of ordinary one to on-line, which is usually performed off-line due to its computational load. An application of real-time system identification enables us to construct numerical models reflecting on the instantaneous properties or behavior of control objects by using hardware acceleration. First, we explain that the ARX model, which has the simplest representation in system identification models, is suitable for hardware design and its implementation on field programmable logic devices shortens the calculation time of parameter estimation comparable to the servo cycles of control systems. Then, we discuss some difficulties derived from closed-loop system identification and the consequent ill-conditions in its calculation. As real-time system identification is supposed to be used for actual machine operations, their reference signals for control are sometimes set to constant values which are understandably not sufficient for system identification. This problem can be addressed by a modified estimation procedure considering reference signal conditions and a model with partially fixed values. Finally, the effectiveness of these designs is investigated by numerical simulations and experiments. They show us that both of accuracy and stability of parameter estimation are obtained.

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  • Masafumi OKADA, Kazuki WATANABE, Ken MASUYA
    2022 Volume 88 Issue 914 Pages 22-00100
    Published: 2022
    Released on J-STAGE: October 25, 2022
    Advance online publication: October 03, 2022
    JOURNAL OPEN ACCESS

    Accurate identification of minimum set of dynamics parameters is required for high-precision and high-speed motion control. The identification uses the dynamical model and its motion data. This motion data does not always satisfy the equations in the dynamical model because of unmodeled dynamics and unexpected noise. The least squares method is generally used for approximated model. It may well satisfy the equations in the dynamical model, however, the optimality as a model for control system design has to be discussed. In this paper, we propose a stochastic identification method of minimum set of dynamic parameters. In conventional least squares method, the error of dynamic equation is assumed to be white gaussian and its square mean is minimized while in the proposed method, the error is assumed to be due to parameter fluctuation, and its covariance is optimized so that the sensitivity of velocity field in the state space with respect to dynamic parameter is small, which means advantageous parameter for controlled system. The simulation and experimental results show the effectiveness of the proposed method.

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  • Katsushi OGAWA, Akihiro YAMADA, Hiroki AOYAMA, Kazuo YONENOBU, Seonghe ...
    2022 Volume 88 Issue 914 Pages 22-00176
    Published: 2022
    Released on J-STAGE: October 25, 2022
    Advance online publication: September 30, 2022
    JOURNAL OPEN ACCESS

    In Japan, which is an aging society, the number of people with reduced walking ability is expected to increase. Maintaining and improving walking ability is an issue in the rehabilitation field. Therefore, early detection of the risk of falls in the elderly is an important issue. TUG (Timed Up and Go test) is used as one of the evaluation methods for fall risk in many situations. It is thought that TUG can be divided for each movement, measured and analyzed in detail, and indicators for fall risk assessment and walking independence judgment can be defined. However, if it takes time and effort to install a large device or measuring instrument for TUG, the advantage of TUG that it can be easily carried out decreases. By using the IoRT (Internet of Robotic Things) walker developed as gait training device, it is possible to easily and automatically measure the gait of the TUG without any special operation or equipment. In this paper, we propose an automatic classification method for gait sections in TUG test using IoRT walker. The proposed method can detect the walking state using motion information obtained from the walker, and can automatically classify the gait section in the TUG test into ”Sit to stand, Walk 1, Turn Around, Walk 2, Turn and Stand to sit” sections. The effectiveness of the proposed method was confirmed by the TUG Test, which was conducted on various pseudo-impaired gaits.

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Design, Machine Element & Tribology, Information & Intelligent Technology, Manufacturing, and Systems
  • Takefumi OTSU
    2022 Volume 88 Issue 914 Pages 22-00122
    Published: 2022
    Released on J-STAGE: October 25, 2022
    Advance online publication: October 07, 2022
    JOURNAL OPEN ACCESS

    This paper describes rheological properties of hydrodynamic and elastohydrodynamic lubrication (EHL) film under various contact pressure conditions using the fluorescence measurement method. In this measurement method, the viscosity and the information about the state of the lubricant (liquid or solid) can be obtained via the analysis of fluorescence spectrum of a pyrene excimer emission. Previous research revealed that the intensity of excimer emission decreased with increasing of viscosity. In addition, the intensity ratio between the excimer peak and lubricant 5P4E fluorescence peak was introduced for the analysis, and the ratio decreased with increasing viscosity of lubricant. In this study, the viscosity profile obtained from the relationship between the intensity ratio and viscosity showed that the state of lubricant in the lubrication film corresponded almost exactly to the lubrication regime proposed in previous researches. It is concluded that the viscosity measurement technique proposed in this study is useful method for practical uses in hydrodynamic and elastohydrodynamic conditions, while in the high viscosity range, the measured viscosity varies widely due to the variation of intensity ratio.

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  • Ikuo TANABE
    2022 Volume 88 Issue 914 Pages 22-00179
    Published: 2022
    Released on J-STAGE: October 25, 2022
    Advance online publication: September 27, 2022
    JOURNAL OPEN ACCESS

    In recent years, FEM (Finite Element Method) simulation has been commonly used in the design field; FEM simulation can be classified into static implicit and dynamic explicit methods. In particular, static implicit FEM simulation is very commonly and usefully used in industry. In machine tool design, FEM thermal simulation is also used to develop high-precision machine tools. However, the phenomenon of heat build-up in the machine tool structure and the analysis of forced air intake and exhaust by a fan to the machine structure are difficult to be analyzed by FEM thermal simulation. Therefore, in this study, four virtual models for air intake, exhaust air, heat transfer and convection were developed, and the analysis methods for the phenomenon of heat build-up and forced intake and exhaust air were developed and evaluated. As a result, it was concluded that (1) the phenomenon of heat build-up in the structure and forced intake and exhaust to the structure can be analysed, (2) the FEM thermal analysis with the four developed virtual models has high calculation accuracy and short calculation time, and (3) the proposed method is very effective in the design.

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Bio, Medical, Sports and Human Engineering
  • Riku MURAKAMI, Hiroya MAMORI, Takeshi MIYAZAKI, Naoya TAKAHASHI
    2022 Volume 88 Issue 914 Pages 22-00199
    Published: 2022
    Released on J-STAGE: October 25, 2022
    Advance online publication: September 12, 2022
    JOURNAL OPEN ACCESS

    Archery at the Olympic games is a competition that hits a target 70 m away. The shooting performance of bows has improved, and athletes are required to have high accuracy shooting at the 10-point zone with a diameter of 122 mm. It is important to know the flight trajectory and attitude of arrow shot to improve the competitive ability. For this purpose, it is necessary to analyze an image of each arrow shot by a high-speed video camera with high accuracy. In this study, an automatic image analysis software for analyzing the velocity and attitude of archery arrows in free flight was developed. In order to confirm the reliability of the analysis results, we measured the velocity and attitude of arrows launched at various initial velocities by a shooting machine using compressed air, and also the arrows shot from bows by an athlete and a robot. Consistency between the results of the conventional visual analysis and those of the automatic image analysis was confirmed. The analysis time was reduced to 1/10 or less. Based on the information obtained from the automatic image analysis, it became possible to examine the flight characteristics of arrow shots, such as the variations in the initial arrow velocity, the initial angle of attack and the velocity decay rate. Knowing these flight characteristics on site will contribute to the optimization of arrow parts composition and the improvement of the athletes’ competitive ability.

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  • Isamu NISHIDA, Tomoyuki NISHIKAWA, Kenji HARIMA, Yuusuke TOMITA
    2022 Volume 88 Issue 914 Pages 22-00208
    Published: 2022
    Released on J-STAGE: October 25, 2022
    Advance online publication: September 15, 2022
    JOURNAL OPEN ACCESS

    Bicycles have been recognized for their advantages such as low environmental impact, health improvement, and maintenance of transportation function in times of disaster, and demand for bicycles is increasing as social conditions change. The pedaling of a conventional bicycle nowadays turns a crank to rotate the front gear, which is transmitted to the rear gear by a chain, and turns the rear axle to rotate the rear wheel. Since bicycles require human power to pedal, a structure that allows bicycles to be pedaled with a low load has been considered so that more people can easily use bicycles. This study developed a new bicycle power transmission system that enables bicycles to be pedaled with a low load without using gearbox or external power such as motor. In order to verify the effectiveness of the newly developed bicycle power transmission device, a prototype bicycle with the proposed device was fabricated and tested. Participants quantitatively evaluated the physical load with and without the device by pedaling the bicycle. The experimental results showed that the developed bicycle power transmission device can reduce the physical load.

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