Jun‐ichi Takada
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View article: Quantitative Porosity Engineering of Carbon Electrode in Lithium–Oxygen Batteries with Cell‐Level Gravimetric Energy Density Over 1500 Wh kg<sup>−1</sup>
Quantitative Porosity Engineering of Carbon Electrode in Lithium–Oxygen Batteries with Cell‐Level Gravimetric Energy Density Over 1500 Wh kg<sup>−1</sup> Open
Lithium–oxygen batteries (LOBs) offer an extremely high theoretical energy density; however, their practical realization depends strongly on the design of porous carbon positive electrodes. Most prior efforts have emphasized material desig…
View article: Hierarchically porous graphitized carbon membrane for 1-Watt-hour-class rechargeable lithium-oxygen pouch cells
Hierarchically porous graphitized carbon membrane for 1-Watt-hour-class rechargeable lithium-oxygen pouch cells Open
View article: Identification of Interacting Objects and Evaluation of Interaction Loss from Wideband Double-Directional Channel Measurement Data by Using Point Cloud Data
Identification of Interacting Objects and Evaluation of Interaction Loss from Wideband Double-Directional Channel Measurement Data by Using Point Cloud Data Open
This paper proposes an approach to identify interacting objects (IOs) and determine their interaction losses (ILs) using point cloud data from wide-band double-directional channel sounding data. The scattering points (SPs) were identified …
View article: Equivalence of Two Types of Knife-Edge Diffraction Models to Predict Shadowing Effect
Equivalence of Two Types of Knife-Edge Diffraction Models to Predict Shadowing Effect Open
View article: Prediction of Shadowing Gain of 2D Object by Mirror Kirchhoff Approximation With Unequal Interval
Prediction of Shadowing Gain of 2D Object by Mirror Kirchhoff Approximation With Unequal Interval Open
View article: Point Cloud-Based Diffraction Path Extraction for Dynamic Human Body Shadowing Channel at 300 GHz
Point Cloud-Based Diffraction Path Extraction for Dynamic Human Body Shadowing Channel at 300 GHz Open
The broad bandwidth availability of the sub-Terahertz band enables the next generation of mobile communication systems. Since the high-gain antennas are used to compensate for the severe propagation loss, the communication link depends on …
View article: THz Channels for Short-Range Mobile Networks: Multipath Channel Behavior and Human Body Shadowing Effects
THz Channels for Short-Range Mobile Networks: Multipath Channel Behavior and Human Body Shadowing Effects Open
The THz band (0.1-10 THz) is emerging as a crucial enabler for sixth-generation (6G) mobile communication systems, overcoming the limitations of current technologies and unlocking new opportunities for low-latency and ultra-high-speed comm…
View article: Measurement-based Characterization of ISAC Channels with Distributed Beamforming at Dual mmWave Bands and with Human Body Scattering and Blockage
Measurement-based Characterization of ISAC Channels with Distributed Beamforming at Dual mmWave Bands and with Human Body Scattering and Blockage Open
In this paper, we introduce our millimeter-wave (mmWave) radio channel measurement for integrated sensing and communication (ISAC) scenarios with distributed links at dual bands in an indoor cavity; we also characterize the channel in dela…
View article: Factor Graph-Based Technique for Trajectory Tracking of Target with High Mobility
Factor Graph-Based Technique for Trajectory Tracking of Target with High Mobility Open
View article: Site-Specific Radio Channel Representation for 5G and 6G
Site-Specific Radio Channel Representation for 5G and 6G Open
A site-specific radio channel representation (SSCR) takes the surroundings of the communication system into account by considering the environment geometry, including buildings, vegetation, and mobile objects with their material and surfac…
View article: Grid-Based Channel Emulation Technique for Enabling Wireless Channel Emulator in Device-to-Device Communication
Grid-Based Channel Emulation Technique for Enabling Wireless Channel Emulator in Device-to-Device Communication Open
Wireless channel emulator (WCE) allows site-specific evaluation of the wireless system with time- and cost-efficient and reproducible result. In addition to the conventional star topology between devices and a base station (BS), incorporat…
View article: Point Cloud-Based Prediction Models of Dynamic Human Body Shadowing at 58 GHz
Point Cloud-Based Prediction Models of Dynamic Human Body Shadowing at 58 GHz Open
As one of the channels used by the wireless gigabit (WiGig) protocol, a 58 GHz band has been deployed to realize a data rate of up to 100 gigabits per second (Gbps). Systems at the 58 GHz band point the main beam of the base station toward…
View article: Small Distance Increment Method for Measuring Complex Permittivity With mmWave Radar
Small Distance Increment Method for Measuring Complex Permittivity With mmWave Radar Open
Measuring the complex permittivity of material is essential in many scenarios such as quality check and component analysis. Generally, measurement methods for characterizing the material are based on the usage of vector network analyzer, w…
View article: Knife-Edge Diffraction Model for Vehicle Shadowing Estimation in Site- and Scenario-Specific Wireless Channel Emulator
Knife-Edge Diffraction Model for Vehicle Shadowing Estimation in Site- and Scenario-Specific Wireless Channel Emulator Open
In developing a site- and scenario-specific wireless channel emulator, a computationally efficient shadowing model for vehicles is essential for dynamic emulation with constrained computational resources. In this work, a single-dominant-ra…
View article: Grid-Based Channel Modeling Technique for Scenario-Specific Wireless Channel Emulator Based on Path Parameters Interpolation
Grid-Based Channel Modeling Technique for Scenario-Specific Wireless Channel Emulator Based on Path Parameters Interpolation Open
Channel model is one of the key components of a wireless channel emulator (WCE) to realistically examine and assert a wireless communication system. The deterministic channel model (DM) enables the simulation of site-specific propagation w…
View article: Multi-Layer Building Material Modeling and Parameter Estimation Method by Wide-Band Free Space Measurement
Multi-Layer Building Material Modeling and Parameter Estimation Method by Wide-Band Free Space Measurement Open
Computer technology has made significant progress recently, and various radio propagation simulation techniques have been utilized for the performance evaluation and design of wireless networks, for example, in cyber-physical systems. As a…
View article: A Case of Cystic Thymoma with Extensive Necrosis Detected in an Asymptomatic Patient
A Case of Cystic Thymoma with Extensive Necrosis Detected in an Asymptomatic Patient Open
View article: A Distributed Sensor-based Recursive Framework for DoA Estimation and Geolocation
A Distributed Sensor-based Recursive Framework for DoA Estimation and Geolocation Open
This paper proposes a distributed sensor-based RECursive Subspace and Factor Graph (REC-SaFG) framework for direction-of-arrival (DoA) estimation and geolocation of a fast-moving target. The whole framework includes two recursive processes…
View article: Equivalence of knife‐edge diffraction model and uniform geometrical theory of diffraction applying Fresnel approximation for an absorbing screen
Equivalence of knife‐edge diffraction model and uniform geometrical theory of diffraction applying Fresnel approximation for an absorbing screen Open
The knife‐edge diffraction model (KED) and the uniform geometrical theory of diffraction (UTD) have been widely used to predict the shadowing effect at millimetre‐wave (mmWave) bands. This letter proposes a mathematical derivation to rigor…
View article: A Community of Practice for Intangible Cultural Heritage: Phenomenographic Insights of Youth’s Experience With Traditional Recital in Luang Prabang, Lao People’s Democratic Republic
A Community of Practice for Intangible Cultural Heritage: Phenomenographic Insights of Youth’s Experience With Traditional Recital in Luang Prabang, Lao People’s Democratic Republic Open
This paper presents preliminary findings of a phenomenographic study on a youth forum on intangible cultural heritage (ICH) in Luang Prabang (LPB), Lao People's Democratic Republic.Youth members participated in workshops for finding commun…
View article: Equivalence of knife-edge diffraction model and uniform geometrical theory of diffraction applying Fresnel approximation for an absorbing screen
Equivalence of knife-edge diffraction model and uniform geometrical theory of diffraction applying Fresnel approximation for an absorbing screen Open
The knife-edge diffraction model (KED) and the uniform geometrical theory of diffraction (UTD) have been widely used to predict the shadowing effect at millimetre-wave (mmWave) bands. This letter proposes a mathematical derivation to rigor…
View article: Scenario-specific radio propagation simulation from LiDAR point cloud data for smart office scenario
Scenario-specific radio propagation simulation from LiDAR point cloud data for smart office scenario Open
Recently, the cyber-physical-system (CPS) has attracted great interest in the information and communications technology (ICT) research field for the virtual test of wireless communication systems. Since the performance of wireless communic…
View article: Development of passive channel sounder using software defined radio and cellular signal
Development of passive channel sounder using software defined radio and cellular signal Open
This paper presents development of passive channel sounder using software defined radio based receivers and commercial transmitter operating in cellular network. Accuracy of developed channel sounder is verified by over-the-air path gain m…
View article: Structure of the Field behind a Dielectric Circular Cylinder in the Lit Side of the Transition Region
Structure of the Field behind a Dielectric Circular Cylinder in the Lit Side of the Transition Region Open
Prediction in the transition region between lit and shadowed regions is important for maintaining stable mobile communication for the beyond 5 th generation.In this paper, as the difference between the reflection and diffraction from a die…
View article: Study on Rician K-factor Estimation from Time-Variant Channel Frequency Response for Performance Evaluation of Deterministic Wireless Channel Emulator
Study on Rician K-factor Estimation from Time-Variant Channel Frequency Response for Performance Evaluation of Deterministic Wireless Channel Emulator Open
Drive testing is necessary prior to system implementation to evaluate the robustness of wireless system to the multipath propagation.Wireless channel emulator (WCE) allows virtually drive testing with less expensive and high reproducible.W…
View article: Design of Parameters of Fast Fourier Transform for Three-Dimensional Split Step Parabolic Equations and Mirror Kirchhoff Approximation
Design of Parameters of Fast Fourier Transform for Three-Dimensional Split Step Parabolic Equations and Mirror Kirchhoff Approximation Open
This paper proposes the simulation parameters of the fast Fourier transform (FFT) for the 3-dimensional (3D) split step parabolic equation (SSPE) and the mirror Kirchhoff approximation (MKA). The SSPE/MKA calculates the forward scattering …
View article: Vehicle Shadowing Modeling for Deterministic Channel Emulator and Electromagnetic Simulation-Based Validation
Vehicle Shadowing Modeling for Deterministic Channel Emulator and Electromagnetic Simulation-Based Validation Open
Due to the development of a deterministic channel emulator for virtual communication system verification, a simple and realistic model for shadowing gain prediction caused by moving objects, e.g., vehicles, is necessary.In this work, a veh…
View article: A Uniform Additional Term Using Fock-type Integral to Unify Edge Diffraction, Creeping Diffraction, and Reflection in Lit and Shadowed Regions
A Uniform Additional Term Using Fock-type Integral to Unify Edge Diffraction, Creeping Diffraction, and Reflection in Lit and Shadowed Regions Open
The uniform geometrical theory of diffraction (UTD) calculating edge diffraction, creeping diffraction, and reflection has been widely used to predict the shadowing problems for the beyond 5th generation.The limitation of the previous work…
View article: Measurement of the Dynamic Radio Channel at Sub-THz Band Affected by Human Body Shadowing
Measurement of the Dynamic Radio Channel at Sub-THz Band Affected by Human Body Shadowing Open
Sub-THz band is an enabler of the 6th generation (6G) of mobile communication systems for the availability of broader bandwidth.To compensate the severe propagation loss at sub-THz band, massive multi-input and multioutput (massive MIMO) a…
View article: Maximum-Likelihood-Based Location, Orientation, Transmitted Power, and Antenna Beamwidth Estimator Utilizing the Angle-of-Arrival and Received Power for Spectrum Sharing at Millimeter Wave Bands
Maximum-Likelihood-Based Location, Orientation, Transmitted Power, and Antenna Beamwidth Estimator Utilizing the Angle-of-Arrival and Received Power for Spectrum Sharing at Millimeter Wave Bands Open
The fifth-generation (5G) system utilizing millimeter wave is available in Japan, but more bandwidth is demanded by the mobile phone operators to accommodate the demand for high data rate. Allocation of the vacant spectrum is impossible du…