Institution
University of Electro-Communications
Education•Tokyo, Japan•
About: University of Electro-Communications is a education organization based out in Tokyo, Japan. It is known for research contribution in the topics: Laser & Robot. The organization has 8041 authors who have published 16950 publications receiving 235832 citations. The organization is also known as: UEC & Denki-Tsūshin Daigaku.
Topics: Laser, Robot, Fiber laser, Mobile robot, Control theory
Papers published on a yearly basis
Papers
More filters
••
TL;DR: In this paper, a negative group delay (NGD) circuit was employed to equalize a group delay variation in a broadband ultra wideband (UWB) InGaP/GaAs heterojunction bipolar transistor (HBT) monolithic microwave integrated circuit (MMIC) amplifier.
Abstract: A negative group delay (NGD) circuit has been employed to equalize a group delay variation in a broadband ultra-wideband (UWB) InGaP/GaAs heterojunction bipolar transistor (HBT) monolithic microwave integrated circuit (MMIC) amplifier. Using the NGD circuit, a part of a salient group delay characteristic in the operation band of broadband amplifiers can be suppressed without an increase of the entire group delay. The MMIC amplifier has a steep group delay increase in the lower frequency region of the full-band UWB band (3.1-10.6 GHz) due to the sum of phase variations near the cutoff frequencies of the HBTs. The NGD circuit has been inserted to reduce this increase of the group delay in the UWB band. By adding a three-cell NGD circuit while considering input and output matching at the input side of the MMIC amplifier, the group delay variation is decreased by 78%. However, gain was also decreased by insertion of the multistage NGD circuit. In an attempt to avoid this decrease in gain, a one-cell NGD circuit was inserted into the feedback loop of the MMIC amplifier, and as a result, we were able to decrease the group delay variation by 79%, with minimal gain deterioration.
88 citations
••
88 citations
••
TL;DR: Frequency detuning as a result of self-phase modulation that exceeds by four times the primary laser frequency is demonstrated.
Abstract: Frequency detuning as a result of self-phase modulation that exceeds by four times the primary laser frequency is demonstrated. The white light, ranging from the IR to 150 nm, was generated by a self-trapped femtosecond Ti:Al2O3 laser pulse in atmospheric-pressure rare gases. Spectral intensities in the UV and the visible regions are 100 MW/nm and 1 GW/nm, respectively. The beam divergence was measured to be 1 mrad.
88 citations
••
TL;DR: In this paper, the authors theoretically study the Kelvin-Helmholtz instability in phase-separated two-component Bose-Einstein condensates using the Gross-Pitaevskii and Bogoliubov-de Gennes models.
Abstract: We theoretically study the Kelvin-Helmholtz instability in phase-separated two-component Bose-Einstein condensates using the Gross-Pitaevskii and Bogoliubov-de Gennes models. A flat interface between the two condensates is shown to deform into sawtooth or Stokes-type waves, leading to the formation of singly quantized vortices on the peaks and troughs of the waves. This scenario of interface instability in quantum fluids is quite different from that in classical fluids.
88 citations
••
TL;DR: Given an arbitrary position of the Othello game played on an n × n board, the problem of determining the winner is shown to be PSPACE-complete.
88 citations
Authors
Showing all 8079 results
Name | H-index | Papers | Citations |
---|---|---|---|
Mildred S. Dresselhaus | 136 | 762 | 112525 |
Matthew Nguyen | 131 | 1291 | 84346 |
Juan Bisquert | 107 | 450 | 46267 |
Dapeng Yu | 94 | 745 | 33613 |
Riichiro Saito | 91 | 502 | 48869 |
Shun-ichi Amari | 90 | 495 | 40383 |
Shigeru Nagase | 76 | 617 | 22099 |
Ingrid Verbauwhede | 72 | 575 | 21110 |
Satoshi Hasegawa | 69 | 708 | 22153 |
Yu Qiao | 69 | 484 | 29922 |
Yukio Tanaka | 68 | 744 | 19942 |
Zhijun Li | 68 | 614 | 14518 |
Iván Mora-Seró | 67 | 235 | 23229 |
Kazuo Tanaka | 63 | 535 | 27559 |
Da Xing | 63 | 624 | 14766 |