Prof. Arata Masuda Profile

Prof. Arata Masuda

Professor at Kyoto Institute of Technology

SPIE Involvement:

Author

Publications (43)

Proceedings Article | 28 April 2023 Poster + Paper

Making a brain on a structure: a conceptual study of elastic wave field neural networks for structural health monitoring

Arata Masuda, Ryu Sakai, Konosuke Takashima

Proceedings Volume 12483, 124831J (2023) https://doi.org/10.1117/12.2658694

KEYWORDS: Neurons, Elasticity, Neural networks, Structural health monitoring, Complex amplitude, Sensors, Frequency response, Sensor networks, Brain, Modulation frequency

Read Abstract +

Proceedings Article | 28 April 2023 Presentation + Paper

Physical reservoir-based structural health monitoring: a preliminary study

Arata Masuda, Konosuke Takashima, Ryu Sakai

Proceedings Volume 12483, 1248311 (2023) https://doi.org/10.1117/12.2658742

KEYWORDS: Oscillators, Structural health monitoring, Sensors, Design and modelling, Reservoir computing, Failure analysis, Complex systems, Sensor technology

Read Abstract +

Proceedings Article | 18 April 2022 Presentation + Paper

Effect of temperature on the magnetically coupled return loss of smart gear system

T. Inoue, D. Iba, T. T. Mac, S. Mukai, N. Fujita, R. Takahashi, N. Miura, T. Iizuka, A. Masuda, A. Sone, I. Moriwaki

Proceedings Volume 12046, 120460V (2022) https://doi.org/10.1117/12.2612789

KEYWORDS: Signal attenuation, Antennas, Sensors, Inductive coupling, Temperature metrology, Signal processing, Network security, Thermal imaging cameras, Thermography, Laser sintering

Read Abstract +

In our project, a novel gear health monitoring system called a “smart gear sensor system” has been being developed. This system has a smart gear sensor and a monitoring antenna. The smart gear sensor has been created by using a laser sintering technique that allows a conductive ink to be sintered directly on the gear surface to form a sensor chain. This technique is also used to form an antenna pattern of the monitoring antenna. Experimentally, when the smart gear with the integrated sensor chain is brought parallelly close to the monitoring antenna while this antenna is connected to a network analyzer, a magnetic coupling happens. This wireless magnetic coupling is presented via the return loss signal gained by the network analyzer. Moreover, the conductivity of the sensor chain on the smart gear has been proven to affect the magnetically coupled return loss signal. Specifically, the shape of the return loss signal will be changed correspondingly. Since the sensor chain is sintered directly on the surface of the gear, the physical characteristics of the gear such as healthy or cracked will result in the quality of the sensor conductivity. Therefore, the smart gear's healthy or cracked characteristics can be observed via the return loss signal chart obtained by the network analyzer. In other words, the return loss signal can be considered essential data for the gear health monitoring process. Nevertheless, because the temperature will have a certain influence on the physical state of not only the gear but also the sintered sensor, the evaluation of the temperature to the magnetic coupling and its return loss signal becomes unavoidable. As a result, this study focuses majorly on the consideration of the influence of the temperature so that the accuracy of the proposed gear health monitoring method can be improved. The final experimental result and analysis demonstrate that the temperature also significantly impacts the return loss of the smart gear system.

Proceedings Article | 22 March 2021 Presentation + Paper

An improvement of visualized images from vibration for plastic gear early failure detection using convolutional neural network

D. Taga, D. Iba, B. H. Kien, Y. Tsutsui, N. Miura, T. Iizuka, A. Masuda, I. Moriwaki

Proceedings Volume 11593, 115932N (2021) https://doi.org/10.1117/12.2582637

KEYWORDS: Visualization, Convolutional neural networks, Image visualization

Read Abstract +

Proceedings Article | 22 March 2021 Presentation + Paper

Effect of phase fluctuation at high speed of smart gear on return loss of receiver antenna

T. Mac, D. Iba, Y. Matsushita, S. Mukai, T. Inoue, A. Fukushima, N. Miura, T. Iizuka, A. Masuda, I. Moriwaki

Proceedings Volume 11591, 115910E (2021) https://doi.org/10.1117/12.2582468

KEYWORDS: Antennas, Receivers, Sensors, Signal attenuation, Signal detection, Phase shifts, Magnetism

Read Abstract +

Proceedings Article | 26 May 2020 Paper

Self-powered oscillation of piezoelectric ultrasonic active sensors

Arata Masuda, Masaaki Inoue, Yosuke Fujiwara

Proceedings Volume 11379, 1137913 (2020) https://doi.org/10.1117/12.2559254

KEYWORDS: Ultrasonics, Active sensors, Sensors, Environmental sensing, Smart structures, Embedded systems, Energy harvesting, Capacitors, Structural dynamics

Read Abstract +

Proceedings Article | 22 April 2020 Presentation + Paper

Effect of image size on performance of a plastic gear crack detection system based convolutional neural networks: an experimental study

B. Kien, D. Iba, Y. Tsutsui, A. Kajihata, Y. Lei, N. Miura, T. Iizuka, A. Masuda, A. Sone, I. Moriwaki

Proceedings Volume 11381, 113812I (2020) https://doi.org/10.1117/12.2557977

KEYWORDS: Visualization, Image visualization, Image quality, Image classification, Convolutional neural networks, Feature extraction, Image resolution, Image processing, Data acquisition, Data conversion

Read Abstract +

Proceedings Article | 21 March 2019 Paper

Design and development of a miniaturized mechanically and magnetically-sprung electromagnetic nonlinear energy harvester

Feng Zhao, Yusuke Miyata, So Ushiki, Arata Masuda

Proceedings Volume 10967, 109672P (2019) https://doi.org/10.1117/12.2515208

KEYWORDS: Resonators, Composites, Magnetism, Electromagnetism, Prototyping, Resistance, Bistability, Energy harvesting, Sensors, Photography

Read Abstract +

Proceedings Article | 21 March 2019 Paper

A self-powered nonlinear wideband vibration energy harvester with high-energy response stabilization control

Sou Ushiki, Arata Masuda

Proceedings Volume 10967, 109672N (2019) https://doi.org/10.1117/12.2514785

KEYWORDS: Energy harvesting, Resistance, Circuit switching, Switches, Solar energy, Resonators, Switching, Sensors, Field effect transistors, Control systems, Nonlinear control

Read Abstract +

Proceedings Article | 21 March 2019 Presentation + Paper

Wideband operation of a nonlinear vibration energy harvester with asymmetric restoring force

Arata Masuda, Yusuke Miyata, Sou Ushiki, Feng Zhao

Proceedings Volume 10967, 109670N (2019) https://doi.org/10.1117/12.2515423

KEYWORDS: Resonators, Numerical analysis, Energy harvesting, Oscillators, Resistance, Solids, Mechanical engineering, Motion models, Electromagnetism, Inductance

Read Abstract +

Proceedings Article | 18 March 2019 Paper

Vibration analysis of a meshing gear pair by neural network (Visualization of meshing vibration and detection of a crack at tooth root by VGG16 with transfer learning)

D. Iba, Y. Ishii, Y. Tsutsui, N. Miura, T. Iizuka, A. Masuda, A. Sone, I. Moriwaki

Proceedings Volume 10973, 109730Y (2019) https://doi.org/10.1117/12.2514250

KEYWORDS: Convolutional neural networks, Neural networks, Failure analysis, High speed cameras, Data acquisition

Read Abstract +

Proceedings Article | 18 March 2019 Paper

Development of smart gear system by conductive-ink print (impedance variation of a gear sensor with loads and data transmission from an antenna)

D. Iba, S. Futagawa, N. Miura, T. Iizuka, A. Masuda, A. Sone, I. Moriwaki

Proceedings Volume 10973, 1097309 (2019) https://doi.org/10.1117/12.2515339

KEYWORDS: Antennas, Sensors, Teeth, Laser sintering, Smart sensors

Read Abstract +

Proceedings Article | 27 March 2018 Paper

Conductive ink print on PA66 gear for manufacturing condition monitoring sensors

Shintaro Futagawa, Daisuke Iba, Takahiro Kamimoto, Morimasa Nakamura, Nanako Miura, Takashi Iizuka, Arata Masuda, Akira Sone, Ichiro Moriwaki

Proceedings Volume 10602, 106020R (2018) https://doi.org/10.1117/12.2295771

KEYWORDS: Sensors, Laser sintering, Printing, Coating

Read Abstract +

Proceedings Article | 16 March 2018 Paper

A tunable nonlinear vibration energy harvester based on a magnetically-sprung resonator using ring magnets

Arata Masuda, Yusuke Miyata, Sou Ushiki, Shingo Kato, Yuichi Nagahata

Proceedings Volume 10595, 105950Y (2018) https://doi.org/10.1117/12.2296985

KEYWORDS: Nonlinear response, Nonlinear dynamics, Resonators, Magnetism, Energy harvesting, Electromagnetism, Bistability, Resistance, Mathematical modeling, Prototyping, Mechanical engineering, Upconversion

Read Abstract +

Proceedings Article | 15 March 2018 Paper

Efficiency and effectiveness of stabilization control of high-energy orbit for wideband piezoelectric vibration energy harvesting

N. Kitamura, A. Masuda

Proceedings Volume 10595, 1059503 (2018) https://doi.org/10.1117/12.2296584

KEYWORDS: Oscillators, Energy efficiency, Energy harvesting, Switches, Resistance, Control systems, Switching, Circuit switching, Piezoelectric effects

Read Abstract +

Proceedings Article | 19 April 2017 Paper

A close inspection and vibration sensing aerial robot for steel structures with an EPM-based landing device

Kazuya Takeuchi, Arata Masuda, Shunsuke Akahori, Yoshiyuki Higashi, Nanako Miura

Proceedings Volume 10169, 101692U (2017) https://doi.org/10.1117/12.2260386

KEYWORDS: Sensors, Inspection, Structural health monitoring, Vibrometry, Prototyping, Absorption, Optical inspection, Magnetism, Adsorption, Motion models

Read Abstract +

Proceedings Article | 12 April 2017 Paper

Development of sensing systems printed with conductive ink on gear surfaces: manufacturing of meander line antenna by laser-sintered silver nano-particles

D. Iba, S. Futagawa, T. Kamimoto, M. Nakamura, N. Miura, T. Iizuka, A. Masuda, A. Sone, I. Moriwaki

Proceedings Volume 10168, 101683G (2017) https://doi.org/10.1117/12.2259864

KEYWORDS: Sensors, Antennas, Manufacturing, Printing, Sensing systems, Laser sintering, Nonimpact printing, Resistance, Laser development, Scanning electron microscopy

Read Abstract +

Proceedings Article | 11 April 2017 Paper

A low-frequency vibration energy harvester based on diamagnetic levitation

Yuta Kono, Arata Masuda, Fuh-Gwo Yuan

Proceedings Volume 10164, 101642T (2017) https://doi.org/10.1117/12.2257877

KEYWORDS: Fermium, Frequency modulation, Magnetism, Double positive medium, Motion models, Resistance, Energy harvesting, Numerical analysis, Structural health monitoring, Vibrometry

Read Abstract +

Proceedings Article | 11 April 2017 Paper

Global stabilization control of high-energy responses of a nonlinear wideband piezoelectric vibration energy harvester using a self-excitation circuit

Norihiko Kitamura, Arata Masuda

Proceedings Volume 10164, 101642L (2017) https://doi.org/10.1117/12.2257858

KEYWORDS: Oscillators, Sensors, Switching, Numerical analysis, Energy harvesting, Resistance, Ferroelectric materials, Switches, Transducers, Amplifiers

Read Abstract +

Proceedings Article | 22 April 2016 Paper

Feasibility study and preliminary design of load-assisting clothes for lumbar protection inspired by human musculoskeletal systems

Riho Hashimoto, Arata Masuda, Hao Chen, Sou Kobayashi

Proceedings Volume 9797, 979712 (2016) https://doi.org/10.1117/12.2219526

KEYWORDS: Safety, Injuries, Spine, Prototyping, Manufacturing, Design for manufacturability, Abdomen, Actuators, Artificial muscles, Scientific research, Human subjects

Read Abstract +

Proceedings Article | 20 April 2016 Paper

Development of three-axis inkjet printer for gear sensors

Daisuke Iba, Ricardo Rodriguez Lopez, Takahiro Kamimoto, Morimasa Nakamura, Nanako Miura, Takashi Iizuka, Arata Masuda, Ichiro Moriwaki, Akira Sone

Proceedings Volume 9803, 98034F (2016) https://doi.org/10.1117/12.2218951

KEYWORDS: Sensors, Printing, Electronic circuits, Laser sintering, Resistance, Optical microscopes, Manufacturing, Laser processing, Laser systems engineering

Read Abstract +

Proceedings Article | 15 April 2016 Paper

Design principle of a nonlinear robust dynamic vibration absorber

Yuki Koga, Arata Masuda

Proceedings Volume 9799, 97992Z (2016) https://doi.org/10.1117/12.2219533

KEYWORDS: Vibration control, Nonlinear dynamics, Systems modeling, Optimization (mathematics), Numerical simulations, Systems engineering, Manufacturing, Control systems, Surgery, Motion models, Smart structures

Read Abstract +

Proceedings Article | 15 April 2016 Paper

Global stabilization of high-energy resonance for a nonlinear wideband electromagnetic vibration energy harvester

Arata Masuda, Takeru Sato

Proceedings Volume 9799, 97990K (2016) https://doi.org/10.1117/12.2219592

KEYWORDS: Oscillators, Energy harvesting, Electromagnetism, Switching, Circuit switching, Resistance, Prototyping, Adaptive control, Resonators, Numerical analysis, Transducers, Switches

Read Abstract +

Proceedings Article | 2 April 2015 Paper

Wideband piezoelectric energy harvester for low-frequency application with plucking mechanism

Yasuhiro Hiraki, Arata Masuda, Naoto Ikeda, Hidenori Katsumura, Hiroshi Kagata, Hidenori Okumura

Proceedings Volume 9431, 943137 (2015) https://doi.org/10.1117/12.2084551

KEYWORDS: Resistance, Energy harvesting, Energy efficiency, Switching, Circuit switching, Device simulation, Numerical simulations, Switches, Teeth, Molybdenum

Read Abstract +

Proceedings Article | 28 March 2012 Paper

Stabilization of a wide-band nonlinear vibration energy harvester by using a nonlinear self-excitation circuit

Arata Masuda, Atsuko Senda

Proceedings Volume 8341, 83411B (2012) https://doi.org/10.1117/12.915443

KEYWORDS: Oscillators, Resistance, Switching, Numerical analysis, Energy harvesting, Magnetism, Roentgenium, Switches, Circuit switching, Capacitors

Read Abstract +

Proceedings Article | 27 April 2011 Paper

A vibration energy harvester using a nonlinear oscillator with self-excitation capability

Arata Masuda, Atsuko Senda

Proceedings Volume 7977, 79770V (2011) https://doi.org/10.1117/12.880905

KEYWORDS: Resistance, Oscillators, Electromagnetism, Numerical analysis, Roentgenium, Magnetism, Energy harvesting, Solids, Circuit switching, Capacitors

Read Abstract +

Proceedings Article | 9 April 2010 Paper

Detection and localization of contact-type damages via nonlinear impedance modulation of piezoelectric materials bonded on a beam structure

Arata Masuda, Junsuke Aoki, Daisuke Iba, Akira Sone

Proceedings Volume 7650, 765034 (2010) https://doi.org/10.1117/12.848450

KEYWORDS: Modulation, Nondestructive evaluation, Interfaces, Structural health monitoring, Damage detection, Sensors, Acoustics, Ferroelectric materials, Scattering, Complex systems

Read Abstract +

In this paper, a nondestructive, in-service structural integrity monitoring methodology that can detect and characterize local structural damages of contact-type, i.e. damages and failures which come along with generation, growth and/or changes of contacting surfaces, such as cracks, debonding, preload-loss in bolted joints, etc., is presented. The presented monitoring system consists of piezoelectric elements bonded on the structural surface, a high-frequency harmonic voltage source, and a current detector. When the structure is subjected to a vibrational load such as operational load at low-frequencies, the scattering conditions for the high-frequency elastic waves in the vicinity of the contact-type damages will change in synchronization with the structural vibration because of the fluctuation of the contact conditions. This nonlinear effects of vibro-acoustic interaction between the low-frequency vibration and the high-frequency wave field causes the change in the driving-point impedance of the structure at the high frequency range, which leads to the significant modulation of the coupled electro-mechanical impedance (or admittance) of the piezoelectric elements. Therefore, if the piezoelectric elements are driven by a fixed amplitude high-frequency harmonic voltage source, the nonlinear fluctuation of the coupled admittance can be observed as the amplitude and phase modulation of the current flowing through the piezoelectric element. A modeling and analytical study of the nonlinear piezoelectric impedance modulation is presented for a beam structure including a crack, utilizing a linear time-varying system theory. A damage evaluation measure is presented based on the dimensionless modal stiffness fluctuation estimated from the instantaneous admittance reconstructed from the demodulated current responses. Furthermore, fundamental strategies and future directions for damage localization based on the nonlinear piezoelectric impedance modulation are briefly discussed.

Proceedings Article | 8 April 2009 Paper

Nonlinear piezoelectric impedance modulation and its application to crack detection

Arata Masuda, Tomohiro Shinagawa, Daisuke Iba, Akira Sone

Proceedings Volume 7295, 72951X (2009) https://doi.org/10.1117/12.815900

KEYWORDS: Modulation, Structural health monitoring, Ferroelectric materials, Sensors, Phase shift keying, Phase modulation, Interfaces, Ultrasonics, Spectroscopy, Scattering

Read Abstract +

Proceedings Article | 18 April 2008 Paper

Frequency response analysis of vibration system with parametric excitation of damping coefficient

Daisuke Iba, Arata Masuda, Akira Sone

Proceedings Volume 6928, 692821 (2008) https://doi.org/10.1117/12.775997

KEYWORDS: Analytical research, Motion models, Numerical analysis, Xenon, Numerical simulations, Simulink, Systems engineering, Actuators, Smart structures, System integration

Read Abstract +

Proceedings Article | 27 April 2007 Paper

Generation of quasi-resonance by variable damping

Daisuke Iba, Arata Masuda, Akira Sone

Proceedings Volume 6525, 652510 (2007) https://doi.org/10.1117/12.715539

KEYWORDS: Numerical analysis, Motion models, Vibration simulation, Numerical simulations, Simulink, Systems engineering, Smart structures, System integration, Systems modeling, Vibration control

Read Abstract +

Proceedings Article | 10 April 2007 Paper

Monitoring and evaluation of cracked beams based on nonlinear wave modulation

Arata Masuda, Tomohiro Shinagawa, Satoshi Maekawa, Yohei Kinugawa, Daisuke Iba, Akira Sone

Proceedings Volume 6530, 65301E (2007) https://doi.org/10.1117/12.715994

KEYWORDS: Modulation, Ferroelectric materials, Phase shift keying, Receivers, Phase modulation, Transducers, Interfaces, Ultrasonics, Amplitude modulation, Transmitters

Read Abstract +

Proceedings Article | 11 April 2006 Paper

Active sensing and characterization of nonlinear damages by modulated phases and envelopes of scattered waves

Arata Masuda, Yuichiro Yonemura, Akira Sone

Proceedings Volume 6174, 61742B (2006) https://doi.org/10.1117/12.658965

KEYWORDS: Modulation, Phase modulation, Interfaces, Ferroelectric materials, Phase shift keying, Amplitude modulation, Distortion, Transmitters, Receivers, Active remote sensing

Read Abstract +

Proceedings Article | 19 May 2005 Paper

Shock absorption capability of woven SMA skin

Arata Masuda, Akira Sone, Takahiko Yamamura, Qing-Qing Ni, Run-Xin Zhang

Proceedings Volume 5757, (2005) https://doi.org/10.1117/12.599481

KEYWORDS: Shape memory alloys, Absorption, Skin, Composites, Tolerancing, Sensors, Smart materials, Aluminum, Nickel, Systems engineering

Read Abstract +

Proceedings Article | 17 May 2005 Paper

Prototype of sensor network with embedded local data processing

Y. Hashimoto, A. Masuda, A. Sone

Proceedings Volume 5765, (2005) https://doi.org/10.1117/12.600263

KEYWORDS: Sensors, Wavelet transforms, Data processing, Sensor networks, Data acquisition, Computing systems, Local area networks, Wavelets, Prototyping, Microelectromechanical systems

Read Abstract +

Proceedings Article | 17 May 2005 Paper

Flexibility-based damage identification algorithm embedded in sensor network emvironment

Arata Masuda, Akira Sone, Masashi Yamashita, Yuito Hashimoto

Proceedings Volume 5765, (2005) https://doi.org/10.1117/12.599505

KEYWORDS: Sensors, Gyroscopes, Sensor networks, Microelectromechanical systems, Data acquisition, Prototyping, Structural health monitoring, Algorithm development, Optical filters, Feature extraction

Read Abstract +

Proceedings Article | 29 July 2004 Paper

Continuous damage monitoring of civil structures using vibratory gyroscopes

Arata Masuda, Akira Sone, Shinya Morita

Proceedings Volume 5391, (2004) https://doi.org/10.1117/12.540063

KEYWORDS: Gyroscopes, Sensors, Time-frequency analysis, Shape analysis, Structural health monitoring, Fourier transforms, Beam shaping, Data acquisition, Signal processing, Sensor networks

Read Abstract +

Proceedings Article | 29 July 2004 Paper

Base isolation system using shape memory alloy wires

Yoshitaka Yamashita, Arata Masuda, Akira Sone

Proceedings Volume 5386, (2004) https://doi.org/10.1117/12.539479

KEYWORDS: Shape memory alloys, Smart materials, Systems engineering, Actuators, Servomechanisms, Sensors, Dynamical systems, Cerium

Read Abstract +

Proceedings Article | 29 July 2004 Paper

Health monitoring of beam structures using traveling waves induced by ambient loads

Arata Masuda, Akira Sone, Shinya Yamamoto

Proceedings Volume 5391, (2004) https://doi.org/10.1117/12.540046

KEYWORDS: Sensors, Wave propagation, Fourier transforms, Data acquisition, Continuous wavelet transforms, Beam propagation method, Actuators, Near field, Time-frequency analysis, Wavelets

Read Abstract +

Proceedings Article | 26 July 2004 Paper

Preliminary characterization and modeling of SMA-based textile composites

Arata Masuda, Qing-Qing Ni, Akira Sone, Run-Xin Zhang, Takahiko Yamamura

Proceedings Volume 5383, (2004) https://doi.org/10.1117/12.540256

KEYWORDS: Shape memory alloys, Composites, Epoxies, Carbon, Structured optical fibers, Active remote sensing, Process modeling, Smart materials, Actuators, Aluminum

Read Abstract +

Proceedings Article | 26 July 2004 Paper

Finite element analysis of shape memory alloy springs designed for base isolation devices

Arata Masuda, Akira Sone, Shogo Kamata, Yoshitaka Yamashita

Proceedings Volume 5383, (2004) https://doi.org/10.1117/12.540273

KEYWORDS: Shape memory alloys, Finite element methods, Matrices, Numerical simulations, Temperature metrology, Model-based design, Shape analysis, Smart materials, Thermodynamics, Data modeling

Read Abstract +

Proceedings Article | 27 June 2002 Paper

Simulation of earthquake-induced structural vibrations in systems with SMA damping elements

Stefan Seelecke, Olaf Heintze, Arata Masuda

Proceedings Volume 4697, (2002) https://doi.org/10.1117/12.472678

KEYWORDS: Shape memory alloys, Earthquakes, Chemical elements, Numerical simulations, Control systems, Smart materials, Motion models, Aerospace engineering, Algorithm development, Systems engineering

Read Abstract +

Proceedings Article | 27 June 2002 Paper

Performance of SMA-based damping devices with optimized hysteretic characteristics

Arata Masuda, Akira Sone, Mohammad Noori

Proceedings Volume 4697, (2002) https://doi.org/10.1117/12.472670

KEYWORDS: Shape memory alloys, Shape analysis, Atrial fibrillation, Numerical analysis, Smart materials, Kinematics, Chemical elements, Systems engineering, Aerospace engineering, Materials science

Read Abstract +

Proceedings Article | 2 July 2001 Paper

Optimal NiTi hybrid tendon system for structural vibration control

Soheil Saadat, Mohammad Noori, Hamid Davoodi, Zhikun Hou, Arata Masuda

Proceedings Volume 4331, (2001) https://doi.org/10.1117/12.432705

KEYWORDS: Shape memory alloys, Buildings, Vibration control, Earthquakes, Mechanical engineering, Systems engineering, Control systems design, Aerospace engineering, Vibration isolation, Smart materials

Read Abstract +

Showing 5 of 43 publications

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Keywords/Phrases

Search In:

Publication Years