Kyutacar : Kyushu Institute of Technology Academic Repository
Not a member yet
9746 research outputs found
Sort by
Optimum Diameter of Studs in Eel-Ladder for Anguilla Japonica Migration
Get PDFダムや堰による魚の遡上阻害を解消するため，魚道が併設されてきた．既往の魚道研究では主に遊泳魚が対象であったが，近年，ウナギのような底生魚も対象になりつつある．欧米では魚道底面にブラシや突起物を設置したウナギ用魚道が提案されている．ただし，遡上に適した突起物の規格は必ずしも明確ではない．本研究ではウナギ用魚道の底面に設置される円柱突起物の直径を12～60mm，ニホンウナギの全長を150～300mmの範囲で変化させ，遡上に適した突起物直径を求めた．その結果，本実験条件下では，遡上に適した突起物直径はニホンウナギの全長の約1～2割と判明した．今後，同規格の他の全長のニホンウナギへの適用性を検証し，河川に生息する全サイズのニホンウナギが遡上可能なウナギ用魚道の規格を提案したい．Fishways have been constructed to eliminate the obstruction of fish migration by dams and weirs. Fishway research over the years has focused mainly on swimming fish, but in recent years, benthic fish such as eels have also become a target. In Europe and the United States, fishways for eels with brushes and studs on the bottom of fishway have been proposed. However, specifications of studs suitable for migration of eels are not always clear. In this study, diameters of studs on bottom of eel-ladder were varied 12-60 mm, and total length of eels was varied 150-300 mm, to analyze effects of these studs on their migratory behavior. Under experimental conditions, diameter of stud suitable for migration depended on total length of Japanese eel, and 10-20% of total length was found to be appropriate. Future studies to determine whether similar criteria can be applied to Japanese eels with total lengths ranging from less than 150 mm to more than 300 mm are expected to provide partial design guidelines for eel-ladder that facilitate migration of Japanese eels and contribute to conservation of Japanese eels.journal articl
Adaptive TDD Slot Allocation Method for Beyond-5G Networks
Get PDFWith the advancement of Internet of Things technology and the widespread rollout of 5G networks, application demands have escalated rapidly. In 5G networks, time-division duplexing (TDD) is used to divide wireless resources into slots, which are then allocated to either uplinks (ULs) or downlinks (DLs). 5G base stations currently employ fixed slot allocation for pre-configured ULs and DLs, making it difficult to satisfy all application demands. In beyond-5G networks, it is anticipated that the use of dynamic base station control features will enable dynamic TDD slot allocation in response to changes in the wireless environment and application requirements [1]. Therefore, this study verifies the effectiveness of adaptive TDD slot allocation.conference pape
A Method for Efficiently Selecting the Number of Dimension in Deep Learning Focusing on Change in Loss in the Early Phase of Learning "jointly worked"
Get PDFjournal articl
Axial electrodynamic suspension in a Hybrid bearingless motor with active and passive axial stabilization
No full textThis paper describes a bearingless motor with both passive and active axial stabilization. Passive stabilization through Null flux coils in the shape of Figure-8 has earlier been proposed in various papers. As the electrodynamic force in the symmetrical configuration increases with the rotational speed, levitation can be achieved only after a threshold speed. The active control of axial force was not possible with the symmetrical rotor configuration. This paper proposes a modification to the stator coil circuit by connecting an external inductance to any one of the coils to achieve active control of axial force with an external supply. The axial force sufficient enough to compensate for rotor weight and any unstable axial forces can be achieved at low rotational speeds. Theoretical equations for axial forces have been derived and the results have been compared with FEA. The rotational speeds at which the levitation occurs have been estimated theoretically and experimentally.journal articl
コンシクエントポールを採用した磁気ギアードモータにおける高速ロータのベアリングレス化の検討
No full textMagnetic geared motors have many advantages over mechanical gearboxes, such as reduced maintenance and overload protection. However, the limited life of the mechanical bearings that hold the high-speed rotor is a problem in terms of durability. In order to solve this problem, the authors proposed a magnetic geared motor with additional three-phase windings to magnetically levitate the high-speed rotor. In this paper, a novel motor that applies the principle of a bearingless motor to a high-speed rotor is proposed for a consequent-pole type magnetic geared motor. Compared to the previously proposed magnetic geared motor with a magnetically suspended high-speed rotor, this method has the advantage of high torque density and improved controllability. In addition, the magnetic suspension and attraction forces in each topology were analyzed by finite element analysis.journal articl
Observation of out-of-plane spin-orbit torque in a polycrystalline Py/IrMn3 heterostructure
Get PDFThe generation of on-demand out-of-plane spin polarization () promises an efficient field-free switching of perpendicular nanomagnet has been limited mostly in the single crystal materials. For a direct technological application, it is desired to have an out-of-plane spin current generation from polycrystalline sputtered films rather than expensive single crystalline films. Here, we report the observation of out-of-plane and in-plane torques generated by the and spin polarization in the polycrystalline antiferromagnet IrMn3/permalloy (Py) heterostructure. A comparatively high value of out-of-plane spin torque ratio of 0.024 has been observed with a large out-of-plane spin Hall conductivity of ≈2.82×104(ℏ/2) (Ωm)−1. Additionally, we have investigated the underline mechanism and the fundamental role of spins in the context of external field-free magnetization switching of a perpendicular magnetic anisotropy (PMA) material. Our findings provide a new perspective on generation and detection of out-of-plane spin polarization in antiferromagnet material and manipulate the magnetization for the development of the next generation high-density, low-power consumption, logic device applications.journal articl
Submodules of normalisers in groupoid C*-algebras and discrete group coactions
Get PDFIn this paper, we investigate certain submodules in C*-algebras associated to effective étale groupoids. First, we show that a submodule generated by normalizers is a closure of the set of compactly supported continuous functions on some open set. As a corollary, we show that discrete group coactions on groupoid C*-algebras are induced by cocycles of étale groupoids if the fixed point algebras contain C*-subalgebras of continuous functions vanishing at infinity on the unit spaces. In the latter part, we prove the Galois correspondence result for discrete group coactions on groupoid C*-algebras.journal articl
Numerical Simulations of Optoelectronic Deep Neural Network Using Trainable Activation Function
Get PDFOptoelectronic deep neural network (OE-DNN) is one implementation of neural network (NN) hardware in which an electronic computing is combined with an optical computing to achieve a large-scale and flexible NNs. The optical computing part realizes the inter-node interactions with high spatial parallelism using spatial light modulator (SLM) and image sensor, whereas the electronic computing part realizes the other computing of NNs which are difficult to realize optically such as applying nonlinear activation function and normalization. However, an activation function commonly used in the conventional NNs such as rectified linear unit (ReLU) and hyperbolic tangent (tanh) functions sometimes decrease the accuracy of NNs when the input values to such activation functions are small and/or non-negative values which often occur in OE-DNNs. Therefore, the activation function needs to be specialized for OE-DNNs.
In this paper, we propose to apply a trainable activation function [1], which can optimize the shape of the activation function for input values. Specifically, the coefficients involved in the activation function are included in the training process. We numerically compare the classification accuracy of input images by the model using activation function with and without trainable parameters. It should be noted that only the results of the image classification using a complex-valued OE-DNN are shown in this paper, though the application of the trainable activation function may not be limited to the complex-valued NNs.conference pape
