Takashi Yasui

ORCID: 0000-0001-8751-7333
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About
Contact & Profiles
Research Areas
  • Photonic and Optical Devices
  • Optical Network Technologies
  • Semiconductor Lasers and Optical Devices
  • Optical Coatings and Gratings
  • Photonic Crystals and Applications
  • Analytical Chemistry and Chromatography
  • Advanced Photonic Communication Systems
  • Analytical chemistry methods development
  • Ruminant Nutrition and Digestive Physiology
  • Advanced Optical Network Technologies
  • Reproductive Physiology in Livestock
  • Electrochemical Analysis and Applications
  • Microwave Engineering and Waveguides
  • Advanced Fiber Optic Sensors
  • Analytical Chemistry and Sensors
  • Molecular Sensors and Ion Detection
  • Industrial Vision Systems and Defect Detection
  • Microwave and Dielectric Measurement Techniques
  • Advancements in Photolithography Techniques
  • Plasmonic and Surface Plasmon Research
  • Electromagnetic Simulation and Numerical Methods
  • Laser and Thermal Forming Techniques
  • Acoustic Wave Resonator Technologies
  • Molecular Junctions and Nanostructures
  • Topology Optimization in Engineering

Kitami Institute of Technology
2014-2024

Nagoya Institute of Technology
2008-2020

Kuraray (Japan)
2020

Cornell University
2013-2018

Ricoh (Japan)
2015

New York State College of Veterinary Medicine
2014-2015

Shimane University
2007-2009

NTT (Japan)
1987-2009

Toyama Prefectural University
2005-2008

NTT Basic Research Laboratories
2003-2004

This experiment was designed to investigate the effects of different concentrations (0, 0.33, 0.66, 0.99, and 1.32 g/L) a twin-strain Saccharomyces cerevisiae live cells on in vitro mixed ruminal microorganism fermentation corn starch, soluble potato sudangrass hay (60.5%, DM basis) plus concentrate mixture (39.5%, basis). Ruminal fluid collected from two dairy cows, with phosphate buffer (1:2), incubated (30 mL) anaerobically at 38°C for 6 24 h or without yeast supplement, using 200 mg (DM...

10.2527/2004.8261847x article EN Journal of Animal Science 2004-06-01

Trace minerals have critical roles in the key interrelated systems of immune function, oxidative metabolism, and energy metabolism ruminants. To date, primary trace elements interest diets for dairy cattle included Zn, Cu, Mn, Se although data also support potentially important Cr, Co, Fe diets. such as are essential with classically defined components antioxidant enzymes proteins. Available evidence indicates that these can modulate aspects function cattle, particularly during transition...

10.2527/jas.2013-7145 article EN Journal of Animal Science 2013-12-05

Feature Issue on Optical Interconnection Networks (OIN). We describe hybrid optical-electrical systems that perform header processing and buffering of ultrafast, asynchronous optical packets. Our are enabled by three key, novel devices: an all-optical serial-to-parallel converter, clock-pulse generator, a photonic parallel-to-serial-converter. These devices allow utilization complementary metal-oxide semiconductor technology for compact, highly functional packet processing. A simplified node...

10.1364/jon.3.000914 article EN Journal of Optical Networking 2004-01-01

We present a photonic random access memory (RAM) that can write and read high-speed asynchronous burst optical packets freely by specifying addresses. The RAM consists of an clock-pulse generator, all-optical serial-to-parallel converter, parallel-to-serial all developed us, complementary metal-oxide-semiconductor as storage medium, features large capacity, long-term storage, at arbitrary timing, low power consumption, compactness. experimentally confirm its basic operation for 40-Gb/s 16-b packets.

10.1109/lpt.2004.824987 article EN IEEE Photonics Technology Letters 2004-04-01

In this paper, in order to optimize wavelength selective photonic devices using the function-expansion-based topology optimization method, several expansion functions are considered and influence on optimized structure based each function was investigated. Although Fourier series is conventionally used sometimes has a complicated refractive index distribution. Therefore, we employed sampling pyramid obtain simpler through optimal design. A triplexer designed by our comparison between...

10.1364/oe.23.003937 article EN cc-by Optics Express 2015-02-09

We fabricated a compact 10-Gb/s-wavelength tunable laser module by integrating DFB array and an InP-based n-i-n Mach-Zehnder modulator in one package. developed multichip assembly technology to realize high optical coupling efficiency achieved continuous-wave output power of +6.5 dBm. demonstrated full C-band 10-Gb/s duobinary transmission with constant modulation voltage 2.4 V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">pp</sub> . And we...

10.1109/jstqe.2009.2013972 article EN IEEE Journal of Selected Topics in Quantum Electronics 2009-01-01

We extend topology optimization method with function-expansion-based refractive index distribution to for three-dimensional optical circuits, in which a design region is expressed by an expansion some analytical functions. Three-branch waveguides have been optimized as numerical examples. Equally branching three-branch are achieved using our method. A limitation of two dimensions and dependency initial structure also shown.

10.1109/jlt.2013.2288107 article EN Journal of Lightwave Technology 2013-11-19

An efficient gradient-based topology optimal design approach using beam propagation method (BPM) for a 3-D semi-vectorial problem of optical waveguide devices is proposed.A finite-difference BPM (SVFD-BPM) based on an alternating direction implicit (ADIM) employed the wave analysis in our approach.In comparison to conventional approaches, it expected that can reduce its computational cost and which too long analyze finite element or time/frequency-domain method.In this paper, we several...

10.1364/oe.25.028210 article EN cc-by Optics Express 2017-10-30

ABSTRACT This experiment was designed to investigate the effects of different concentrations cellobiose (CB) or a twin strain Saccharomyces cerevisiae live cells (YST) (20, 40 and 60 mg/60 mL), CB + YST (60 20, 40, mL) on mixed ruminal microorganism fermentation in vitro . Ruminal fluid collected from cow, with phosphate buffer (1:2) incubated anaerobically at 38°C for 24 h without supplement plus 400 mg (dry matter [DM] basis) substrate (hay concentrate, 1.5:1). The medium pH numerically...

10.1111/j.1740-0929.2006.00366.x article EN Animal Science Journal 2006-08-01

We present a gradient-based topology optimization method of optical waveguide devices using the beam propagation (BPM). Efficient an is available by our approach because it utilizes adjoint variable for sensitivity analysis, and BPM numerical analysis. In this paper, way evaluating sensitivities design longitudinally varying waveguides newly described in case that density finite difference are employed. addition, validity availability proposed verified optimizing S-bend Y-branch waveguides.

10.1109/jlt.2016.2597308 article EN Journal of Lightwave Technology 2016-08-02

We present a new design approach of shape and topology optimization utilizing the full-vectorial beam propagation method (FV-BPM) so as to achieve efficient for high-refractive-index contrast optical waveguides devices based on gradual mode-evolution. In our approach, material distribution is represented via normalized density parameters, these parameters are updated with sensitivity computed an adjoint variable (AVM). The analysis procedure offered in specific case where method, AVM, FV-BPM...

10.1109/jlt.2020.2964781 article EN Journal of Lightwave Technology 2020-01-08

A beam propagation method (BPM) based on the finite element (FEM) is described for analysis of both transverse electric (TE) and magnetic (TM) waves propagating in nonlinear optical waveguides. perfectly matched layer introduced to avoid spurious reflections from computational window edges. For wide-angle analysis, Pade approximation differential operator along direction. In order improve numerical accuracy efficiency, a mesh reference refractive index are adaptively renewed at each step,...

10.1109/50.793775 article EN Journal of Lightwave Technology 1999-01-01

The design scheme for an erbium-doped fiber amplifier (EDFA) with automatic channel-by-channel gain and power regulation function is discussed much emphasis on the pump control requirement feedback circuitry. Based both wavelength time-resolved simulation technique, repeater employing novel high-speed (AGC) level (ALC) functions designed implemented. AGC ALC can suppress transient fluctuation of a surviving channel caused by adding or dropping all other channels less than 0.45 dB keep output...

10.1109/50.964078 article EN Journal of Lightwave Technology 2001-01-01

This paper describes the design, fabrication, and electric performances of planar inductors with Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.76</sub> B xmlns:xlink="http://www.w3.org/1999/xlink">0.12</sub> Si xmlns:xlink="http://www.w3.org/1999/xlink">0.04</sub> C xmlns:xlink="http://www.w3.org/1999/xlink">0.08</sub> (Fe-B-Si-C) flakes composite. These were designed help an analytical magnetic circuit calculation, a finite-element...

10.1109/tmag.2015.2452902 article EN IEEE Transactions on Magnetics 2015-07-10

Trace minerals have important roles in immune function and oxidative metabolism; however, little is known about the relationships between supplementation level source with outcomes dairy cattle. Multiparous Holstein cows (n=48) beginning at 60 to 140 days milk were utilized determine effects of trace mineral amount on aspects metabolism responses intramammary lipopolysaccharide (LPS) challenge. Cows fed a basal diet meeting National Research Council (NRC) requirements except for no added...

10.1017/s1751731118002525 article EN cc-by-nc-nd animal 2018-10-16

We expand the difference-field boundary element method (DFBEM) to calculate wave scattering from a variety of local periodic structure defects. The DFBEM is numerical for simulating diffraction caused by surface-relief with defect. Although it more efficient than conventional techniques such as finite-difference time-domain (FDTD) method, original limited projection Here, we derive integral equations and expressions crack buried-pillar defects, also demonstrate some analyses, validating...

10.1364/josaa.32.000751 article EN Journal of the Optical Society of America A 2015-04-09
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