1,906 results on '"Y. Koike"'
Search Results
2. Suppression of the antiferromagnetic pseudogap in the electron-doped high-temperature superconductor by protect annealing
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M. Horio, T. Adachi, Y. Mori, A. Takahashi, T. Yoshida, H. Suzuki, L. C. C. Ambolode, K. Okazaki, K. Ono, H. Kumigashira, H. Anzai, M. Arita, H. Namatame, M. Taniguchi, D. Ootsuki, K. Sawada, M. Takahashi, T. Mizokawa, Y. Koike, and A. Fujimori
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Science - Abstract
In cuprates, superconductivity exists in a narrow window at high electron doping concentration with strong antiferromagnetic correlations. Here, the authors demonstrate superconductivity with no effect of antiferromagnetic order in a cuprate for a wide electron doping range following a protect anneal process.
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- 2016
- Full Text
- View/download PDF
3. Twist-3 fragmentation effects for ALT in light hadron production from proton–proton collisions
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Y. Koike, D. Pitonyak, Y. Takagi, and S. Yoshida
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Twist-3 effects ,Spin asymmetries ,Fragmentation ,Physics ,QC1-999 - Abstract
We compute the contribution from the twist-3 fragmentation function for light hadron production in collisions between transversely and longitudinally polarized protons, i.e., p↑p→→hX, which can cause a double-spin asymmetry (DSA) ALT. This is a naïve T-even twist-3 observable that we analyze in collinear factorization using both Feynman gauge and lightcone gauge as well as give a general proof of color gauge invariance. So far only twist-3 effects in the transversely polarized proton have been studied for ALT in p↑p→→hX. However, there are indications that the naïve T-odd transverse single-spin asymmetry (SSA) AN in p↑p→hX is dominated not by such distribution effects but rather by a fragmentation mechanism. Therefore, one may expect similarly that the fragmentation contribution is important for ALT. Given possible plans at RHIC to measure this observable, it is timely to provide a calculation of this term.
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- 2016
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- View/download PDF
4. Laser-Like Performance of Side-Pumped Dye-Doped Polymer Optical Fibers
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J. Arrue, M. A. Illarramendi, I. Ayesta, F. Jimenez, J. Zubia, A. Tagaya, and Y. Koike
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Amplified spontaneous emission ,doped polymer optical fibers ,organic dyes ,Applied optics. Photonics ,TA1501-1820 ,Optics. Light ,QC350-467 - Abstract
Mirrorless graded-index polymer optical fibers doped with the organic dye rhodamine 6G result in very compact broadband fiber lasers in the visible region when pumped from the side. The emission spectrum, threshold, and efficiency obtained on both fiber ends depend on the lengths of the directly illuminated region and of the non-excited ones. The paper analyzes such parameters both experimentally and theoretically for the first time.
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- 2015
- Full Text
- View/download PDF
5. Transverse Single-Spin Asymmetries in Proton-Proton Collisions at the AFTER@LHC Experiment
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K. Kanazawa, Y. Koike, A. Metz, and D. Pitonyak
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Physics ,QC1-999 - Abstract
We present results for transverse single-spin asymmetries in proton-proton collisions at kinematics relevant for AFTER, a proposed fixed-target experiment at the Large Hadron Collider. These include predictions for pion, jet, and direct photon production from analytical formulas already available in the literature. We also discuss specific measurements that will benefit from the higher luminosity of AFTER, which could help resolve an almost 40-year puzzle of what causes transverse single-spin asymmetries in proton-proton collisions.
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- 2015
- Full Text
- View/download PDF
6. Robot Control Using Electromyography (EMG) Signals of the Wrist
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C. DaSalla, J. Kim, and Y. Koike
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Biotechnology ,TP248.13-248.65 ,Biology (General) ,QH301-705.5 - Abstract
The aim of this paper is to design a human–interface system, using EMG signals elicited by various wrist movements, to control a robot. EMG signals are normalized and based on joint torque. A three-layer neural network is used to estimate posture of the wrist and forearm from EMG signals. After training the neural network and obtaining appropriate weights, the subject was able to control the robot in real time using wrist and forearm movements.
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- 2005
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7. Inference of Gene Regulatory Networks Using Coefficient of Determination, Tsallis Entropy and Biological Prior Knowledge.
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Camila Y. Koike and Carlos H. A. Higa
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- 2016
- Full Text
- View/download PDF
8. Usefulness and accuracy of segmental adrenal venous sampling on localisation and functional diagnosis of various adrenal lesions in primary aldosteronism
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H, Tannai, K, Makita, Y, Koike, K, Nakai, Y, Tsurutani, K, Okudela, J, Saito, S, Matsui, Y, Kakuta, and T, Nishikawa
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Hydrocortisone ,Adrenal Glands ,Hyperaldosteronism ,Humans ,Radiology, Nuclear Medicine and imaging ,General Medicine ,Aldosterone ,Retrospective Studies - Abstract
To clarify the usefulness and accuracy of segmental adrenal venous sampling (sAVS) on localisation and functional diagnosis of various adrenal lesions in primary aldosteronism.Consecutive patients (n=162) who underwent adrenalectomy and 138 patients indicated for medication following sAVS were analysed retrospectively. Based on immunohistopathological diagnosis, the positive predictive value (PPV) of computed tomography (CT)-detectable aldosterone-producing adenoma (APA) was calculated. Moreover, endocrinological and sAVS characteristics were analysed quantitatively and qualitatively among APA, CT-undetectable aldosterone-producing nodules (APNs), multiple aldosterone-producing micronodules (MAPM), and medication groups.The PPV of APA by sAVS was 137/141 (97.1%; 95% confidence interval, 92.9-99.2%). Compared to the medication cases, the APA group showed stronger disease activity clinically and significant differences in adrenal hormones, such as a higher aldosterone level and aldosterone-to-cortisol ratio, and lower cortisol levels in the adrenal central vein and aldosterone maximum tributaries on the dominant side after cosyntropin stimulation. The APA group shows focal aldosterone hypersecretion, such as mean number of aldosterone elevated segments (1.7 ± 0.7 versus 2 ± 0.9, p=0.003) and presence of aldosterone-not-elevated segments (93% versus 41%, p0.001). Clinically and in terms of sAVS, APN and MAPM showed similar characteristics to APA and to the medication cases, respectively.sAVS can localise functionally active tissues of CT-detectable and CT-undetectable lesions enabling decisions on surgical or medical treatment.
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- 2022
9. A model predictive control strategy to regulate movements and interactions
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A. Takagi, H. Gomi, E. Burdet, and Y. Koike
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Humans are adept at moving the arm to interact with objects and surfaces. The brain is thought to regulate motion and interactions using two different controllers, one specialized for movements and the other for force regulation. However, it remains unclear whether different control mechanisms are necessary. Here we show that the brain can employ a single high-level control strategy for both movement and interaction control. The Model Predictive Control (MPC) strategy introduced in this paper uses an internal model of the environment to plan the arm’s muscle activity whilst updating its predictions using periodic feedback. Computer simulations demonstrate MPC’s ability to produce human-like movements and after-effects in free and force field environments. It can simultaneously regulate both force and stiffness during interactions, and can accomplish motor tasks demanding transitions between motion and interaction control. Model Predictive Control promises to be an important tool to test ideas of motor control as it can handle nonlinear dynamics with changing environments and goals without having to specify the movement duration.
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- 2022
10. 919 Alternation of human skin fungal communities under systemic IL-23 inhibition
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Y. Koike, S. Kuwatsuka, D. Motooka, and H. Murota
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Cell Biology ,Dermatology ,Molecular Biology ,Biochemistry - Published
- 2023
11. Ultrafast Control of Magnetic Anisotropy by Resonant Excitation of 4f Electrons and Phonons in Sm0.7Er0.3FeO3
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Takayuki Kurihara, Y. Koike, Alfred Leitenstorfer, Makoto Nakajima, and Gabriel Fitzky
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Physics ,Magnetic anisotropy ,Orthoferrite ,chemistry.chemical_compound ,chemistry ,Phonon ,Lattice (group) ,General Physics and Astronomy ,Electron ,Atomic physics ,Spin (physics) ,Molecular electronic transition ,Excitation - Abstract
We compare the ultrafast dynamics of the spin reorientation transition in the orthoferrite ${\mathrm{Sm}}_{0.7}{\mathrm{Er}}_{0.3}{\mathrm{FeO}}_{3}$ following two different pumping mechanisms. Intense few-cycle pulses in the midinfrared selectively excite either the $f\text{\ensuremath{-}}f$ electronic transition of ${\mathrm{Sm}}^{3+}$ or optical phonons. With phonon pumping, a finite time delay exists for the spin reorientation, reflecting the energy transfer between the lattice and $4f$ system. In contrast, an instantaneous response is found for resonant $f\text{\ensuremath{-}}f$ excitation. This suggests that $4f$ electronic pumping can directly alter the magnetic anisotropy due to the modification of $4f\text{\ensuremath{-}}3d$ exchange at femtosecond timescales, without involving lattice thermalization.
- Published
- 2021
12. OP0112 THE EVER-LARGEST ASIAN GWAS FOR SYSTEMIC SCLEROSIS AND TRANS-POPULATION META-ANALYSIS IDENTIFIED SEVEN NOVEL LOCI AND A CANDIDATE CAUSAL SNP IN A CIS-REGULATORY ELEMENT OF THE FCGR REGION
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Y. Ishikawa, N. Tanaka, Y. Asano, M. Kodera, Y. Shirai, M. Akahoshi, M. Hasegawa, T. Matsushita, S. Kazuyoshi, S. Motegi, H. Yoshifuji, A. Yoshizaki, T. Kohmoto, K. Takagi, A. Oka, M. Kanda, Y. Tanaka, Y. Ito, K. Nakano, H. Kasamatsu, A. Utsunomiya, A. Sekiguchi, H. Niro, M. Jinnin, K. Makino, T. Makino, H. Ihn, M. Yamamoto, C. Suzuki, H. Takahashi, E. Nishida, A. Morita, T. Yamamoto, M. Fujimoto, Y. Kondo, D. Goto, T. Sumida, N. Ayuzawa, H. Yanagida, T. Horita, T. Atsumi, H. Endo, Y. Shima, A. Kumanogoh, J. Hirata, N. Otomo, H. Suetsugu, Y. Koike, K. Tomizuka, S. Yoshino, X. Liu, S. Ito, K. Hikino, A. Suzuki, Y. Momozawa, S. Ikegawa, O. Ishikawa, K. Takehara, T. Torii, S. Sato, Y. Okada, T. Mimori, F. Matsuda, K. Matsuda, I. Imoto, K. Matsuo, M. Kuwana, Y. Kawaguchi, K. Ohmura, and C. Terao
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Rheumatology ,Immunology ,Immunology and Allergy ,General Biochemistry, Genetics and Molecular Biology - Abstract
BackgroundGenome-wide association studies (GWASs) have identified 29 disease-associated single nucleotide polymorphisms (SNPs) for systemic sclerosis (SSc) in non-human leukocyte antigen (HLA) regions (1-7). While these GWASs have clarified genetic architectures of SSc, study subjects were mainly Caucasians limiting application of the findings to Asians.ObjectivesThe study was conducted to identify novel causal variants for SSc specific to Japanese subjects as well as those shared with European population. We also aimed to clarify mechanistic effects of the variants on pathogenesis of SSc.MethodsA total of 114,108 subjects comprising 1,499 cases and 112,609 controls were enrolled in the two-staged study leading to the ever-largest Asian GWAS for SSc. After applying a strict quality control both for genotype and samples, imputation was conducted using the reference panel of the phase 3v5 1,000 genome project data combined with a high-depth whole-genome sequence data of 3,256 Japanese subjects. We conducted logistic regression analyses and also combined the Japanese GWAS results with those of Europeans (6) by an inverse-variance fixed-effect model. Polygenicity and enrichment of functional annotations were evaluated by linkage disequilibrium score regression (LDSC), Haploreg and IMPACT programs. We also constructed polygenic risk score (PRS) to predict SSc development.ResultsWe identified three (FCRLA-FCGR, TNFAIP3, PLD4) and four (EOMES, ESR1, SLC12A5, TPI1P2) novel loci in Japanese GWAS and a trans-population meta-analysis, respectively. One of Japanese novel risk SNPs, rs6697139, located within FCGR gene clusters had a strong effect size (OR 2.05, P=4.9×10-11). We also found the complete LD variant, rs10917688, was positioned in cis-regulatory element and binding motif for an immunomodulatory transcription factor IRF8 in B cells, another genome-wide significant locus in our trans-ethnic meta-analysis and the previous European GWAS. Notably, the association of risk allele of rs10917688 was significant only in the presence of the risk allele of the IRF8. Intriguingly, rs10917688 was annotated as one enhancer-related histone marks, H3K4me1, in B cells, implying that FCGR gene(s) in B cells may play an important role in the pathogenesis of SSc. Furhtermore, significant heritability enrichment of active histone marks and a transcription factor C-Myc were found in B cells both in European and Japanese populations by LDSC and IMPACT, highlighting a possibility of a shared disease mechanism where abnormal B-cell activation may be one of the key drivers for the disease development. Finally, PRS using effects sizes of European GWAS moderately fit in the development of Japanese SSc (AUC 0.593), paving a path to personalized medicine for SSc.ConclusionOur study identified seven novel susceptibility loci in SSc. Downstream analyses highlighted a novel disease mechanism of SSc where an interactive role of FCGR gene(s) and IRF8 may accelerate the disease development and B cells may play a key role on the pathogenesis of SSc.References[1]F. C. Arnett et al. Ann Rheum Dis, 2010.[2]T. R. Radstake et al. Nat Genet, 2010.[3]Y. Allanore et al. PLoS Genet, 2011.[4]O. Gorlova et al. PLoS Genet, 2011.[5]C. Terao et al. Ann Rheum Dis, 2017.[6]E. López-Isac et al. Nat Commun, 2019.[7]W. Pu et al. J Invest Dermatol, 2021.Disclosure of InterestsNone declared
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- 2022
13. Ultrafast Control of Magnetic Anisotropy by Resonant 4f Electronic and Phonon Excitations in Sm0.7Er0.3FeO3
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Takayuki Kurihara, Y. Koike, Makoto Nakajima, Gabriel Fitzky, and Alfred Leitenstorfer
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Magnetic anisotropy ,Orthoferrite ,chemistry.chemical_compound ,Materials science ,chemistry ,Condensed matter physics ,Phonon ,Excited state ,Resonance ,Spin (physics) ,Excitation ,Molecular electronic transition - Abstract
We report on the ultrafast dynamics of spin reorientation using different excitation mechanisms in the orthoferrite Sm 0.7 Er 0.3 FeO 3 . First, intense few-cycle mid-infrared pulses tuned to optical phonon resonance are exploited to excite the lattice system. A finite time delay of the spin reorientation is observed at its initial dynamics, displaying the energy transfer between lattice and 4f system. In contrast, an instantaneous response is found when the f-f electronic transition of Sm3+ is resonantly excited. Our results indicate that 4f electronic pumping can alter the magnetic anisotropy due to the modification of 4f-3d exchange at femtosecond time scales, without involving lattice thermalization.
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- 2021
14. Adsorption state of NO on Ir(111) surfaces under excess O2 coexisting condition
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S. Masuda, Ryo Toyoshima, Kazuhiko Mase, Naoki Shirahata, T. Nito, Kazuhisa Isegawa, Hiroshi Kondoh, Y. Koike, H. Ikeda, Kiyoshi Ueda, and K. Shiratori
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Materials science ,Analytical chemistry ,chemistry.chemical_element ,02 engineering and technology ,Surfaces and Interfaces ,Platinum group ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Surfaces, Coatings and Films ,Adsorption ,chemistry ,X-ray photoelectron spectroscopy ,Phase (matter) ,Materials Chemistry ,Atomic oxygen ,Iridium ,0210 nano-technology - Abstract
Iridium (Ir) exhibits a good efficiency for reduction of NO under excess O2 coexisting conditions at temperatures higher than 250 °C. On the other hand, the advantage is lost at lower temperatures below 250 °C under O2 existence, compared to any other platinum group metals. In this study, adsorption behavior of NO on Ir(111) single-crystal surfaces under excess O2 coexisting conditions at the temperatures from room temperature to 250 °C has been studied by in-situ X-ray Photoelectron Spectroscopy (XPS). It is revealed that the coexisting O2 induces formation of a high-density chemisorbed atomic oxygen (O) phase and the atomic O phase suppresses adsorption of NO at on-top sites significantly, which suggests that the suppression of NO adsorption causes a decrease in the ability of NO reduction at the lower temperatures.
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- 2019
15. National survey of utilization of continuous water quality monitors in water supply systems in Japan
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Michihiro Akiba, Koji Kosaka, M. Sasaki, Mari Asami, Y. Miyabayashi, K. Saito, Y. Koike, and S. Sato
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010504 meteorology & atmospheric sciences ,business.industry ,0208 environmental biotechnology ,Water supply ,Environmental science ,02 engineering and technology ,Water quality ,business ,Water resource management ,01 natural sciences ,020801 environmental engineering ,0105 earth and related environmental sciences ,Water Science and Technology - Abstract
An investigation of the utilization of water quality monitors at water purification plants throughout Japan was conducted via questionnaire from August to October 2015. The number of types of monitors installed at more than one water purification plant was 34. Chlorine, high sensitivity turbidity, pH, and turbidity monitors were (highly) recommended for installation in four water purification processes (rapid sand filtration, chlorination only, slow sand filtration and membrane treatment), except for high sensitivity turbidity of chlorination only. The number of installations of the monitors recommended and their installation points were dependent upon the processes. Highly recommended points of turbidity were raw water and sedimentation points, which were set for (critical) control points in water safety plans. That of high sensitivity turbidity was the rapid sand filtration point for confirmation of Cryptosporidium control. Chlorine monitors were applied for automatic control, regardless of the water purification processes. Some interesting monitors, such as those for musty odor compounds and trihalomethane, were newly developed and utilized. The results of this study showed that water quality monitors were important for water quality management systems based on water safety plans in Japan.
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- 2019
16. National survey of utilization of continuous water quality monitors in water supply systems in Japan
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K, Kosaka, Y, Koike, Y, Miyabayashi, K, Saito, M, Asami, M, Sasaki, S, Sato, M, Akiba, K, Kosaka, Y, Koike, Y, Miyabayashi, K, Saito, M, Asami, M, Sasaki, S, Sato, and M, Akiba
- Abstract
source:Epub 2019 Jan 11
- Published
- 2021
17. Evaluation for GaN single crystals with high doping concentration by the terahertz ellipsometry
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Y. Koike, Masashi Yoshimura, Makoto Nakajima, Masayuki Imanishi, Kazuhiro Toya, T. Shimizu, Y. Mori, Toshiyuki Iwamoto, Valynn Katrine Mag-usara, and Hideaki Kitahara
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010302 applied physics ,Materials science ,business.industry ,Terahertz radiation ,Doping ,Semiconductor device modeling ,Gallium nitride ,01 natural sciences ,Drude model ,chemistry.chemical_compound ,Semiconductor ,chemistry ,Ellipsometry ,0103 physical sciences ,Evaluation methods ,Optoelectronics ,010306 general physics ,business - Abstract
Gallium nitride (GaN) single crystals with high carrier concentration up to 1020cm−3 order were evaluated by the terahertz time-domain spectroscopic ellipsometry. The electric properties such as carrier density are obtained by the fitting analysis based on Drude model. The terahertz ellipsometry is powerful non-contact and non-destructive evaluation method for semiconductors with high carrier concentration.
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- 2020
18. Manipulation of Ferromagnetic domain by the terahertz free electron laser excitation
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Takayuki Kurihara, Goro Isoyama, Y. Koike, T. Shimizu, and Makoto Nakajima
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010302 applied physics ,Orthoferrite ,Materials science ,Condensed matter physics ,Magnetic domain ,Terahertz radiation ,Free-electron laser ,Physics::Optics ,chemistry.chemical_element ,01 natural sciences ,Erbium ,chemistry.chemical_compound ,chemistry ,Ferromagnetism ,0103 physical sciences ,Magnetic force microscope ,010306 general physics ,Excitation - Abstract
We performed ferromagnetic domain control in Erbium orthoferrite by excitation of the terahertz free electron laser. The magnetic domain structure, which was monitored by faraday microscopy, changes permanently by the irradiation of high-intensity terahertz pulses near the domain edges. The mechanism of the change of the magnetic domain structure was discussed and explained by the combination of the depinning effect and the entropic force induced by the excitation.
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- 2020
19. Terahertz emission amplitude-based 2D mapping of the Fe thickness profile in Fe/Pt spintronic heterostructure
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Masashi Yoshimura, S. Tetsukawa, M. Nishitani, Makoto Nakajima, Valynn Katrine Mag-usara, Hideaki Kitahara, Y. Koike, Masahiko Tani, and Makoto Asakawa
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010302 applied physics ,Materials science ,Spintronics ,business.industry ,Terahertz radiation ,Bilayer ,Heterojunction ,Substrate (electronics) ,Sputter deposition ,01 natural sciences ,Amplitude ,Sputtering ,0103 physical sciences ,Optoelectronics ,010306 general physics ,business - Abstract
We demonstrate the feasibility of mapping metallic layer thickness profile in 2 dimension based on the amplitude of the terahertz emission of a large area spintronic heterostructure. A Fe/Pt bilayer was deposited on glass substrate such that a 100 mm diameter circular space was covered with 4 nm Pt throughout and with a gradient of 0.5 nm to 7 nm thick Fe by magnetron sputtering. The Fe thickness dependence of the spintronic THz emission is clearly observed in just one sample by two-dimensional amplitude mapping.
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- 2020
20. 429 Identification of clinicopathological prognostic factors in recurrent endometrial cancer
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Aikou Okamoto, Y Koike, Koji Yamada, Hirokuni Takano, Y Shoburu, Keisuke Tomita, Jiro Suzuki, S Niimi, A Ikenaga, Masataka Takenaka, Sou Hirose, and Misato Kamii
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Oncology ,medicine.medical_specialty ,Multivariate analysis ,Hysterectomy ,business.industry ,Endometrial cancer ,medicine.medical_treatment ,Medical record ,medicine.disease ,Recurrent Endometrial Cancer ,Metastasis ,Internal medicine ,medicine ,Recurrent disease ,Stage (cooking) ,business - Abstract
Objectives Although, endometrial cancer (EC) is commonly diagnosed at an early stage and has a favorable prognosis, recurrent disease usually shows poor prognosis. However, clinicopathological prognostic factors for recurrent EC have been still unclear. The current study aimed to identify clinicopathological prognostic factors, especially in long term survivors of recurrent EC. Methods We collected 2044 patients who underwent surgery including hysterectomy and were pathologically diagnosed as EC in our hospitals between 2001 and 2018. Clinicopathological information and survival data were retrospectively obtained by the review of medical record. Among 2044, 131 patients were included in this retrospective analysis. In recurrent cases, we analyzed the prognostic factors for long-term survivors of recurrent EC. Then we defined long-term and short-term survivors, as patients who survived x 3 years (n =53) and died within 3 years (n =78) after first recurrence, respectively. The correlation between prognosis and clinicopathological factors was statistically analyzed. Results In the multivariate analysis of long-term survivors, we identified that TTP x 1 year after surgery (P Conclusion TTP x 1 year after surgery, non-peritoneal metastasis, surgical reduction of first recurrence were good prognostic factors of long-term survivors in recurrent EC.
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- 2020
21. Weed management assessment for public flower beds©
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K. Matsushima, C. Hirama, Y. Mitarai, and Y. Koike
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Geography ,Agronomy ,Horticulture ,Weed control - Published
- 2017
22. Polarization Control of Terahertz Spintronic Emitter Combined with Liquid Crystal by the External Magnetic and Electric Field
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W. Hu, Z. Shen, Kosaku Kato, Y. Koike, Lei Wang, Hongsong Qiu, Masashi Yoshimura, Makoto Nakajima, and Yan-qing Lu
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010302 applied physics ,Birefringence ,Materials science ,Magnetic domain ,business.industry ,Terahertz radiation ,Physics::Optics ,Polarization (waves) ,01 natural sciences ,Magnetic field ,010309 optics ,Liquid crystal ,Electric field ,0103 physical sciences ,Optoelectronics ,business ,Circular polarization - Abstract
We demonstrate a polarization-tunable terahertz emitter that integrates a ferromagnetic heterostructure and large birefringence liquid crystals by the external magnetic and electric field. The direction of the magnetic field can control the emitted THz wave from linear to circular polarization. The phase retardation in liquid crystal layer between ordinary and extraordinary directions is continuously adjustable by the low-voltage electric field.
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- 2019
23. Ultrafast magnetic response in ε-Fe2O3 nano magnet measured by terahertz-pump optical-Faraday-probe measurement
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Hongsong Qiu, Y. Koike, Marie Yoshikiyo, Kosaku Kato, Kenta Imoto, Masashi Yoshimura, Shin-ichi Ohkoshi, Asuka Namai, S. Miyasita, Shodai Kimoto, and Makoto Nakajima
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Materials science ,Magnetic domain ,business.industry ,Terahertz radiation ,Physics::Optics ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,law.invention ,Magnetic field ,Magnetization ,law ,Magnet ,0103 physical sciences ,Nano ,Optoelectronics ,010306 general physics ,0210 nano-technology ,business ,Faraday cage ,Ultrashort pulse - Abstract
Ultrafast magnetic response in epsilon-iron oxide (e-Fe 2 O 3 ) nano magnet was measured by terahertz-pump optical Faraday probe measurement. Terahertz excitations induce the extremely fast response of the magnetization. The response time is within 400 fs which corresponds to the time duration of the terahertz pulses.
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- 2019
24. The observation of spin reorientation phase transition in Sm1-x Erx FeO3
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Kosaku Kato, Y. Koike, Masashi Yoshimura, Makoto Nakajima, Hongsong Qiu, Kazumasa Hirota, and Shodai Kimoto
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Phase transition ,Materials science ,Condensed matter physics ,Magnetic domain ,Terahertz radiation ,Ultrafast optics ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Temperature measurement ,Magnetization ,0103 physical sciences ,010306 general physics ,0210 nano-technology ,Spin (physics) ,Terahertz time-domain spectroscopy - Abstract
Through the observation of magnetic resonance modes by terahertz time domain spectroscopy (THz-TDS) at the various temperature, we succeeded in observing spin reorientation phase transition (SRPT) which occurs at 310 K for Sm 0.7 Er 0.3 FeO 3 single crystals. Furthermore, THz-pump and optical-Faraday-rotation measurement was introduced and the weak F-mode signals were successfully observed just below SRPT temperature.
- Published
- 2019
25. Enhanced magnetopiezoelectric effect at the Néel temperature in CaMn2Bi2
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Nobuyuki Abe, Yuki Shiomi, Taka-hisa Arima, Hikaru Watanabe, and Y. Koike
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Physics ,Condensed matter physics ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Coupling (probability) ,01 natural sciences ,Ferroelectricity ,Piezoelectricity ,Thermal expansion ,0103 physical sciences ,Antiferromagnetism ,Electric current ,010306 general physics ,0210 nano-technology ,Joule heating ,Néel temperature - Abstract
We have experimentally studied a magnetopiezoelectric effect (MPE), i.e., dynamic distortion caused by AC electric currents, in the antiferromagnetic conductor ${\mathrm{CaMn}}_{2}{\mathrm{Bi}}_{2}$ at low temperatures down to $77\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ using laser Doppler vibrometry. When AC electric currents are applied to ${\mathrm{CaMn}}_{2}{\mathrm{Bi}}_{2}$, dynamic displacement signals which increase in proportion to the current amplitude are clearly observed at $77\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, but their magnitude and temperature dependence strongly depend on Joule heating effects caused by the applied electric currents. Especially, poor thermal contact of ${\mathrm{CaMn}}_{2}{\mathrm{Bi}}_{2}$ samples to the sample holder produces second-harmonic displacement signals owing to thermal expansion due to the Joule heating, and tends to affect the temperature dependence of the MPE signals. In a measurement run without any heating effects, a sharp enhancement of the MPE signal is observed at the N\'eel temperature of ${\mathrm{CaMn}}_{2}{\mathrm{Bi}}_{2}$, which suggests that fluctuations of itinerant Mn moments near the N\'eel temperature play an important role in the MPE. We speculate that electric currents produce nonequilibrium antiferromagnetic moments via the antiferromagnetic Edelstein effect and the induced antiferromagnetic momemts enhance the MPE signal with the help of a large magnetovolume coupling near the N\'eel temperature. The MPE efficiency as a piezoelectric response reaches 300--$500\phantom{\rule{0.16em}{0ex}}\mathrm{pC}/\mathrm{N}$ at a maximum, which is comparable to high values of piezoelectric coefficients detected in the piezoelectric (ferroelectric) ceramics.
- Published
- 2019
26. KIFC1 Inhibitor CW069 Induces Apoptosis and Reverses Resistance to Docetaxel in Prostate Cancer
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Akio Matsubara, Wataru Yasui, Yoshinori Shigematsu, Naoya Sakamoto, Naohide Oue, Jun Teishima, Y. Koike, Yohei Sekino, Masaki Shiota, and Kazuhiro Sentani
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Urology ,lcsh:Medicine ,Article ,CW069 ,03 medical and health sciences ,Prostate cancer ,0302 clinical medicine ,Downregulation and upregulation ,DU145 ,medicine ,Viability assay ,docetaxel resistance ,030304 developmental biology ,0303 health sciences ,business.industry ,lcsh:R ,apoptosis ,Cancer ,General Medicine ,medicine.disease ,prostate cancer ,Docetaxel ,Apoptosis ,Cell culture ,030220 oncology & carcinogenesis ,Cancer research ,KIFC1 ,business ,medicine.drug - Abstract
Kinesin family member C1 (KIFC1) is a minus end-directed motor protein that plays an essential role in centrosome clustering. Previously, we reported that KIFC1 is involved in cancer progression in prostate cancer (PCa). We designed this study to assess the involvement of KIFC1 in docetaxel (DTX) resistance in PCa and examined the effect of KIFC1 on DTX resistance. We also analyzed the possible role of a KIFC1 inhibitor (CW069) in PCa. We used DTX-resistant PCa cell lines in DU145 and C4-2 cells to analyze the effect of KIFC1 on DTX resistance in PCa. Western blotting showed that KIFC1 expression was higher in the DTX-resistant cell lines than in the parental cell lines. Downregulation of KIFC1 re-sensitized the DTX-resistant cell lines to DTX treatment. CW069 treatment suppressed cell viability in both parental and DTX-resistant cell lines. DTX alone had little effect on cell viability in the DTX-resistant cells. However, the combination of DTX and CW069 significantly reduced cell viability in the DTX-resistant cells, indicating that CW069 re-sensitized the DTX-resistant cell lines to DTX treatment. These results suggest that a combination of CW069 and DTX could be a potential strategy to overcome DTX resistance.
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- 2019
27. High temperature superconductivity at the interface Ba0.8Sr0.2TiO3/La2CuO4
- Author
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T. M. Salikhov, I.F. Gilmutdinov, Y. Koike, Tadashi Adachi, R. V. Yusupov, R. F. Mamin, T. Kawamata, V. M. Mukhortov, A. O. Chibirev, D. P. Pavlov, Viktor V. Kabanov, N. N. Garig’yanov, and I. I. Piyanzina
- Subjects
High-temperature superconductivity ,Materials science ,Condensed matter physics ,law ,Interface (Java) ,law.invention - Abstract
We present the results of the investigations of high conducting area and superconductivity at the interfaces between ferroelectric oxide and insulating oxide in heterostructures, isostructural to BaTiO3/La2CuO4. The performed numerical simulations of BaTiO3/La2CuO4 heterostructure show the possibility of high conductivity state at the interface. The temperature dependence of the measured electrical resistance of the Ba0.8Sr0.2TiO3/La2CuO4 heterostructure interface have been studied and the superconducting behaviour with transition temperature Tc about 30K has been found. Therefore, the transition to the state with 2DEG at the interface is demonstrated. The results offer the possibility to design novel electronic devices.
- Published
- 2019
28. Tailoring quasi-two-dimensional high conductivity and superconductivity areas at the interfaces of ferroelectric/dielectric heterostructures
- Author
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Tadashi Adachi, D. P. Pavlov, T. Kawamata, R. F. Mamin, Dmitrii Tayurskii, Viktor V. Kabanov, Y. Koike, V. M. Mukhortov, I. I. Piyanzina, Yu V Lysogorskiy, and A. M. Balbashev
- Subjects
Superconductivity ,Materials science ,High conductivity ,Foundation (engineering) ,Heterojunction ,Dielectric ,Ferroelectricity ,Engineering physics - Abstract
The results of the investigations of high conducting and superconducting areas at the interfaces between ferroelectric oxide and insulating oxide are presented. The numerical simulations of BaTiO3/LaMnO3 and BaTiO3/La2CuO4 heterostructures have been performed. It is found that in the samples of the Ba0.8Sr0.2TiO3/LaMnO3 heterostructure the electrical resistance decreases significantly and exhibits metallic behaviour at low temperatures for the case when the c axis of ferroelectric film is directed along the normal to the surface of the single crystal. The superconducting behaviour with transition temperature Tc about 30K has been found at the interface of the Ba0.8Sr0.2TiO3/La2CuO4 heterostructure. The proposed concept promises the ferroelectrically controlled interface conductivity and superconductivity.
- Published
- 2019
29. Requirements for Hitless MPLS Path Segment Monitoring
- Author
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A. D'Alessandro, L. Andersson, S. Ueno, K. Arai, and Y. Koike
- Published
- 2017
30. 192 Claudin-7 in keratinocyte is downregulated by inhibition of HMG-CoA reductase, and is highly expressed in the stratum granulosum of psoriatic epidermis
- Author
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S. Kuwatsuka, Y. Koike, Y. Kuwatsuka, T. Yamaoka, and H. Murota
- Subjects
Cell Biology ,Dermatology ,Molecular Biology ,Biochemistry - Published
- 2019
31. Q2-Evolution of Nucleon's Chiral-Odd Twist-3 Spin-Structure Function: hL(x, Q2)
- Author
-
Y. Koike and K. Tanaka
- Subjects
Physics and Astronomy (miscellaneous) - Published
- 2013
32. Inference of Gene Regulatory Networks Using Coefficient of Determination, Tsallis Entropy and Biological Prior Knowledge
- Author
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Carlos H. A. Higa and Camila Y. Koike
- Subjects
0301 basic medicine ,Reverse engineering ,Coefficient of determination ,Systems biology ,Tsallis entropy ,0206 medical engineering ,Gene regulatory network ,Inference ,Feature selection ,02 engineering and technology ,Mutual information ,computer.software_genre ,03 medical and health sciences ,030104 developmental biology ,Data mining ,computer ,020602 bioinformatics ,Mathematics - Abstract
In this work, we studied a common problem in Systems Biology, which is the inference or reverse engineering of gene regulatory networks from gene expression data. We addressed this problem using the Boolean formalism, where the expression of a gene is represented only by two possible values: 0 (not expressed) or 1 (expressed). Besides that, our methodology is based on a feature selection approach and we used an algorithm named IFFS - improved forward floating selection. We performed experiments to compare two measures of gene interactions used in the criterion function of the algorithm, the coefficient of determination and the mutual information computed via Tsallis entropy. Besides that, we also incorporated a biological prior knowledge source of gene interactions from a database known as STRING. To validate the methodology, we used data from the DREAM challenge and a dataset from a budding yeast cell-cycle study. The results showed that, generally, the mutual information performs slightly better than the coefficient of determination, and that incorporating biological knowledge improves the results.
- Published
- 2016
33. Excitation Experiments Of A Cone Loudspeaker And Vibration-Acoustic Analysis Using Fem
- Author
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Y. Hu, X. Zhao, T. Yamaguchi, M. Sasajima, and Y. Koike
- Abstract
To focus on the vibration mode of a cone loudspeaker, which acts as an electroacoustic transducer, excitation experiments were performed using two types of loudspeaker units: one employing an impulse hammer and the other a sweep signal. The on-axis sound pressure frequency properties of the loudspeaker were evaluated, and the characteristic properties of the loudspeakers were successfully determined in both excitation experiments. Moreover, under conditions identical to the experiment conditions, a coupled analysis of the vibration-acoustics of the cone loudspeaker was performed using an acoustic analysis software program that considers the impact of damping caused by air viscosity. The result of sound pressure frequency properties with the numerical analysis are the most closely match that measured in the excitation experiments over a wide range of frequency bands.
- Published
- 2016
- Full Text
- View/download PDF
34. Superconducting uctuations above critical temperature in the Bi2Sr2Ca1−xYxCu2O8 single crystals
- Author
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I.I. Gimazov, V.O. Sakhin, Yu.I. Talanov, T. Adachi, T. Noji, and Y. Koike
- Subjects
Condensed Matter::Superconductivity ,high temperature superconductors, superconducting order parameter uctuations, nonresonant microwave absorption, AC-susceptibility - Abstract
The superconducting uctuations above critical temperature in the Bi2Sr2Ca1xYxCu2O8 single crystals are studied. The boundaries of the superconducting uctuations area are de ned by the MWA measurement. The estimation of the uctuations lifetimes is made.
- Published
- 2016
35. Finger angle estimation using musculoskeletal model on thumb and index finger
- Author
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Y. Koike and S. Stapornchaisit
- Subjects
History ,medicine.anatomical_structure ,Computer science ,business.industry ,medicine ,Computer vision ,Index finger ,Artificial intelligence ,Thumb ,business ,Computer Science Applications ,Education - Published
- 2018
36. Association between the neutrophil myeloperoxidase index and subsets of bacterial infections
- Author
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A Yoshioka, Osamu Horie, Kenji Yonezawa, Takako Tenjin, K Shibata, Y Koike, Mitsuhiro Ito, Matsuki S, M Yokoyama, M Yoneda, Norinaga Urahama, Tetsuhiko Nomura, and Tsukamura Y
- Subjects
Tuberculosis ,medicine.diagnostic_test ,Biochemistry (medical) ,Clinical Biochemistry ,Complete blood count ,Inflammation ,Hematology ,General Medicine ,Biology ,medicine.disease ,Sepsis ,Systemic inflammatory response syndrome ,Myeloperoxidase ,Immunology ,medicine ,biology.protein ,Biomarker (medicine) ,Neutrophil Myeloperoxidase Index ,medicine.symptom - Abstract
The mean myeloperoxidase index (MPXI) is calculated during the routine complete blood count performed using the autoanalyzer ADVIA120/2120. The pattern of changes in the neutrophil myeloperoxidase levels in patients with specific infectious diseases was analyzed by assessing the MPXI levels. In patients with bacterial sepsis, identified by positive blood-culture tests, with (n = 29) and without (n = 51) systemic inflammatory response syndrome, the mean MPXI significantly reduced to -3.18 and -2.06, respectively. In contrast, among patients with nontuberculous nonseptic bacterial infections (n = 40), the mean MPXI significantly elevated to 5.51, while tuberculosis patients (n = 37) and patients with viral infection (n = 60) showed an unchanged MPXI (mean values, -0.46 and -1.06, respectively). Among the parameters of inflammation, only the C-reactive protein values showed a weak correlation with the MPXI levels. [Conclusion] These results indicate that MPXI is correlated with some specific infectious states, i.e. MPXI is low in bacterial sepsis and high in nontuberculous nonseptic bacterial infections. MPXI appears to be an independent and useful biomarker for the diagnosis and follow-up of infectious diseases, especially when the MPXI values are obtained at regular intervals during the disease courses of the patients.
- Published
- 2010
37. Finite Element Method Analysis of Occluded-Ear Simulator and Natural Human Ear Canal
- Author
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Takao Yamaguchi, Y. Koike, Y. Hu, and M. Sasajima
- Subjects
FEM ,Frequency response ,Human ear ,medicine.diagnostic_test ,Computer science ,Phase (waves) ,Computed tomography ,Finite element method ,viscosity ,human ear canal ,otorhinolaryngologic diseases ,medicine ,Finite element method analysis ,Ear simulator ,sense organs ,Simulation ,Sound wave - Abstract
In this paper, we discuss the propagation of sound in the narrow pathways of an occluded-ear simulator typically used for the measurement of insert-type earphones. The simulator has a standardized frequency response conforming to the international standard (IEC60318-4). In narrow pathways, the speed and phase of sound waves are modified by viscous air damping. In our previous paper, we proposed a new finite element method (FEM) to consider the effects of air viscosity in this type of audio equipment. In this study, we will compare the results from the ear simulator FEM model, and those from a three dimensional human ear canal FEM model made from computed tomography images, with the measured frequency response data from the ear canals of 18 people., {"references":["IEC60318-4, IEC standard, Simulators of human head and ear - Part 4: Occluded-ear simulator for the measurement of earphones coupled to the ear by means of ear inserts 2010.","M. Sasajima, T. Yamaguchi, and A. Hara, \"Acoustic Analysis Using Finite Element Method Considering Effects of Damping Caused by Air Viscosity in Audio Equipment,\" Applied Mechanics and Materials, vol. 36, pp. 282–286, 2010.","M. Sasajima, T. Yamaguchi, M. Watanabe, Y. Koike, \"FEM Analysis of Occluded Ear Simulator with Narrow Slit Pathway,\" International Journal of Mechanical, Aerospace, Industrial, Mechatronic and Manufacturing Engineering vol. 9, No.9, pp. 1430-1433, 2015.","M. A. Biot, \"Theory of propagation of elastic waves in a fluid-saturated porous solid. I. Low-frequency range,\" Journal of Acoustical Society of America, vol. 28, pp. 168–178, 1956.","M. A. Biot, \"Theory of propagation of elastic waves in a fluid-saturated porous solid. II. Higher-frequency range,\" Journal of Acoustical Society of America, vol. 28, pp. 179–191, 1956.","T. Yamaguchi, \"Approximated calculation to damping properties of a closed sound field involving porous materials(proposal of a fast calculation procedure for model damping and damped response),\" Transactions of the Japan Society of Mechanical Engineers, Series C, vol. 66, no. 648, pp. 2563–2569, 2000.","T. Yamaguchi, H. Nakamoto, Y. Kurosawa, and S. Matsumura \"Finite element analysis for damping properties of sound-proof structures having solid body, porous media and air,\" Transactions of the Japan Society of Mechanical Engineers, Series A, vol. 69, no. 677, pp. 34–41, 2003.","T. Yamaguchi, J. Tsugawa, H. Enomoto, and Y. Kurosawa, \"Layout of Sound Absorbing Materials in 3D Rooms Using Damping Contributions with Eigenvectors as Weight Coefficients,\" Journal of System Design and Dynamics, vol. 4-1, pp. 166–176, 2010.","T. Yamaguchi, Y. Kurosawa, and H. Enomoto, \"Damped Vibration Analysis Using Finite Element Method with Approximated Modal Damping for Automotive Double Walls with a Porous Material,\" Journal of Sound and Vibration, vol. 325, pp. 436–450, 2009."]}
- Published
- 2018
38. Transition edge sensor system for material analysis using transmission electron microscope
- Author
-
Kazuo Chinone, Sumio Iijima, Y. Koike, Atsushi Nagata, S. Bandou, Keiichi Tanaka, Satoshi Nakayama, A. Yasaka, and Akikazu Odawara
- Subjects
Superconductivity ,Permalloy ,Materials science ,Physics::Instrumentation and Detectors ,business.industry ,Liquid helium ,Energy Engineering and Power Technology ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,law.invention ,SQUID ,Condensed Matter::Materials Science ,Optics ,law ,Electromagnetic shielding ,Optoelectronics ,Dilution refrigerator ,Electrical and Electronic Engineering ,Transition edge sensor ,business ,Critical field - Abstract
We have developed a Transition Edge Sensor (TES) – Energy Dispersive Spectroscopy (EDS) for Transmission Electron Microscope (TEM) based on a dilution refrigerator. The dilution refrigerator was cooled by liquid helium (L-He), which was supplied from an L-He container separated from the dilution refrigerator. We adopted the hybrid magnetic shields combining a permalloy shield and a NbTi/Nb/Cu superconducting shield to operate the TEM–TES system under a magnetic field of 200 mT. The permalloy shield was used to prevent the ambient magnetic field until the NbTi superconducting shield cooled from room temperature (RT) to 2 K. The critical magnetic field was 220 mT for the TES change from a superconducting state to a normal state. The SQUID – current vs. bias current curve, under the condition that the snout was inserted in the TEM, was equal to the curve of the snout that was out of the TEM. The C (0 0 2) planes could be observed at 120 kV under the condition the snout was inserted in the TEM.
- Published
- 2009
39. Design of bandwidth tunable HTS filter using H-shaped waveguides
- Author
-
Y. Nakagawa, S. Ohshima, Y. Koike, and Naoto Sekiya
- Subjects
High-temperature superconductivity ,Materials science ,business.industry ,Bandwidth (signal processing) ,Energy Engineering and Power Technology ,Condensed Matter Physics ,Microstrip ,Electronic, Optical and Magnetic Materials ,law.invention ,Resonator ,law ,Optoelectronics ,Insertion loss ,Trimming ,Electrical and Electronic Engineering ,Center frequency ,business ,Waveguide - Abstract
We have developed a bandwidth tuning method for use in high-temperature superconducting (HTS) microstrip filters. Several H-shaped waveguides are placed between the resonators, and the bandwidth is adjusted by changing the switch states of the waveguides. The coupling coefficients between the resonators are controlled by switching the connection or isolation of the center gaps of the waveguides so as to tune the bandwidth. The effects of using this method were evaluated by simulation using a filter composed of 3-pole half-wavelength straight-line resonators with an H-shaped waveguide between each pair and additional electric pads for post-tuning trimming. The filter was designed to have a center frequency of 5 GHz and a bandwidth of 100 MHz by using an electromagnetic simulator based on the moment method. The simulation showed that bandwidth tuning of 150 MHz can be obtained by using H-shaped waveguides to adjust the coupling coefficients. It also showed that using additional electric pads around the feed lines, which was previously shown to be useful for trimming to improve insertion loss after center-frequency tuning, is also useful for bandwidth tuning.
- Published
- 2009
40. Organization and management of the International Space Station (ISS) multilateral medical operations
- Author
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Y. Koike, J. M. Duncan, Filippo Castrucci, Ashot E. Sargsyan, Jean-Marc Comtois, and V.V. Bogomolov
- Subjects
Engineering ,medicine.medical_specialty ,Operations research ,business.industry ,health care facilities, manpower, and services ,media_common.quotation_subject ,Crew ,Aerospace Engineering ,Certification ,Medical support ,Work (electrical) ,health services administration ,International Space Station ,medicine ,Operational framework ,Operations management ,Aviation medicine ,business ,Function (engineering) ,human activities ,media_common - Abstract
The goal of this work is to review the principles, design, and function of the ISS multilateral medical authority and the medical support system of the ISS Program. Multilateral boards and panels provide operational framework for, direct, and supervise the ISS joint medical operational activities. The integrated medical group (IMG) provides front-line medical support of the crews. Results of ongoing activities are reviewed weekly by physician managers. A broader status review is conducted monthly to project the state of crew health and medical support for the following month. All boards, panels, and groups function effectively and without interruptions. Consensus prevails as the primary nature of decisions made by all ISS medical groups, including the ISS medical certification board. The sustained efforts of all partners have resulted in favorable medical outcomes of the initial 15 long-duration expeditions. The medical support system appears to be mature and ready for further expansion of the roles of all Partners, and for the anticipated increase in the size of ISS crews.
- Published
- 2008
41. Natural analogue of the rise and dissolution of liquid CO2 in the ocean
- Author
-
Yoshiaki Maeda, Kiminori Shitashima, Y. Koike, and Takashi Ohsumi
- Subjects
Mineralogy ,Partial pressure ,Management, Monitoring, Policy and Law ,Pollution ,Industrial and Manufacturing Engineering ,Hydrothermal circulation ,Salinity ,chemistry.chemical_compound ,General Energy ,Water column ,chemistry ,Carbon dioxide ,Seawater ,Hydrate ,Dissolution - Abstract
The behavior of natural carbon dioxide (CO 2 ) droplets (8–10 mm in diameter) were observed in a seafloor hydrothermal system at the Okinawa Trough. The natural CO 2 droplet contain 95–98% of CO 2 , 2–3% of H 2 S, and other gas species. The ascending CO 2 droplets were tracked by a remotely operated vehicle (ROV), and depth, temperature, salinity, pH and partial pressure of CO 2 (pCO 2 ) in seawater near the CO 2 droplets were measured during droplet ascent by a conductivity-temperature-depth sensor (CTD) and in situ pH/pCO 2 sensor. The visual images of the rising CO 2 droplets were recorded with a high definition television camera on the ROV. A mapping survey (400 m × 400 m; 4 horizontal layers) revealed a dominant distribution of low pH area over the natural CO 2 venting site. The size and rise rate of CO 2 droplets decreased during their ascent in the water column from depths of 1424 to 679 m (a tracking interval of 745 m). The CO 2 droplets dissolved gradually to become small flakes of CO 2 hydrate while rising, and these ascending flakes were found to disappear at 679 m depth. Although a pH as low as 5 was detected just above the liquid CO 2 venting site on the seafloor, no detectable pH depression in the water column ambient to the rising CO 2 droplets was observed. The results of the pH mapping survey showed only localized pH depression over the CO 2 venting site.
- Published
- 2008
42. Faddeev calculation for neutron-rich nuclei
- Author
-
Eizo Uzu, M. Yamaguchi, Hiroyuki Kamada, and Y. Koike
- Subjects
Physics ,Nuclear and High Energy Physics ,Series (mathematics) ,Excited state ,Neutron ,State (functional analysis) ,Atomic physics ,Ground state ,Isotopes of helium ,Excitation - Abstract
We approach the helium isotopes 6 He, 8 He, and 10 He by using the three-cluster model (core + 2 n ) from the viewpoint that these nuclei make a Borromean-nuclei series. In this report, we check our calculation code on 6 He (or 6 Li) and we study 8 He and 10 He with core excitation. To determine the parameters of potentials between core and n , we make use of the experimental data of the ground and the first excited states of 7 He and 9 He. We check the possible combinations of total J π 's of the ground and the first excited states of 7 He and 9 He for reproducing the ground state of 8 He, and 10 He. The state probabilities for 8 He are reported within our model.
- Published
- 2007
43. Intelligent and Reliable Photonic Cross-Connect System Based on Overlay Model
- Author
-
T. Toide, A. Sutoh, M. Murakami, Y. Koike, and Kazuhiro Oda
- Subjects
Engineering ,business.industry ,computer.internet_protocol ,Testbed ,Multiprotocol Label Switching ,Telecommunications network ,Atomic and Molecular Physics, and Optics ,Intelligent Network ,Packet switching ,Optical Transport Network ,Digital cross connect system ,business ,Internetworking ,computer ,Computer network - Abstract
We developed a carrier-based photonic cross-connect (PXC) system based on an optical switch, which provides wavelength-division-multiplexing transmission, generalized multiprotocol label switching, and optical-transport-network management. This system uses an overlay model in which the administrative authority between the client-network-element (NE) layer and the carrier's PXC layer is completely separated. The PXC system provides user-network interface signaling between the client NEs and the PXCs, which enables automatic optical path setting between the two client NEs through a PXC network. We considered new protection schemes for the PXC system and successfully carried out an experiment in a testbed network using one of the discussed schemes. The new concept of policy control in the control-plane management is introduced, and the feasibility of our PXC system is demonstrated. This system is promising as a prototype for a next-generation optical transport system. Furthermore, the PXC system will enable the creation of a new type of optical transport layer service, accommodate increased Internet traffic demand, and reduce network operation loads and costs for Internet service providers and carriers in the near future.
- Published
- 2007
44. Low-momentum nucleon-nucleon potential and its separability
- Author
-
Ryoji Okamoto, M. Yamaguchi, Shin-ichiro Fujii, Hiroyuki Kamada, Y. Koike, and Eizo Uzu
- Subjects
Physics ,Nuclear and High Energy Physics ,Nuclear Theory ,Binding energy ,Separable space ,Momentum ,Quantum mechanics ,Convergence (routing) ,Effective field theory ,Cutoff ,Nuclear Experiment ,Nucleon ,Legendre polynomials ,Mathematical physics - Abstract
Using the Okubo effective theory a realistic nucleon-nucleon potential is transformed into low-momentum effective one (LMNN). The feature of the LMNN potential is examined by calculating the triton binding energy, in order to see the dependence of the cutoff parameter Λ. Furthermore, the LMNN is expanded in a separable form. We compare the universal separable expansion method with a simple Legendre expansion. Through the calculation of the triton binding energies, the separability for the convergence of these ranks is evaluated. It is found that there is a tendency for the lower Λ of LMNN to gain better separability.
- Published
- 2007
45. FEM Analysis of Occluded Ear Simulator with Narrow Slit Pathway
- Author
-
M. Sasajima, T. Yamaguchi, M. Watanabe, and Y. Koike
- Subjects
FEM ,Computer Science::Sound ,viscosity ,Ear simulator ,simulation - Abstract
This paper discusses the propagation of sound waves in air, specifically in narrow rectangular pathways of an occluded-ear simulator for acoustic measurements. In narrow pathways, both the speed of sound and the phase of the sound waves are affected by the damping of the air viscosity. Herein, we propose a new finite-element method (FEM) that considers the effects of the air viscosity. The method was developed as an extension of existing FEMs for porous, sound-absorbing materials. The results of a numerical calculation for a three-dimensional ear-simulator model using the proposed FEM were validated by comparing with theoretical lumped-parameter modeling analysis and standard values., {"references":["M. A. Biot, \"Theory of propagation of elastic waves in a fluid-saturated\nporous solid. I. Low-frequency range,\" Journal of Acoustical Society of\nAmerica, vol. 28, pp. 168–178, 1956.","M. A. Biot, \"Theory of propagation of elastic waves in a fluid-saturated\nporous solid. II. Higher-frequency range,\" Journal of Acoustical Society\nof America, vol. 28, pp. 179–191, 1956.","T. Yamaguchi, H. Nakamoto, Y. Kurosawa, and S. Matsumura \"Finite\nelement analysis for damping properties of sound-proof structures having\nsolid body, porous media and air,\" Transactions of the Japan Society of\nMechanical Engineers, Series C, vol. 69, no. 677, pp. 34–41, 2003.","Y. Kurosawa and S. Matsumura \"Finite element analysis for damping\nproperties of sound-proof structures having solid body, porous media and\nair,\" Transactions of the Japan Society of Mechanical Engineers, Series\nC, vol. 69, no. 677, pp. 34–41, 2003.","T. Yamaguchi, J. Tsugawa, H. Enomoto, and Y. Kurosawa, \"Layout of\nSound Absorbing Materials in 3D Rooms Using Damping Contributions\nwith Eigenvectors as Weight Coefficients,\" Journal of System Design and\nDynamics, vol. 4-1, pp. 166–176, 2010.","T. Yamaguchi, Y. Kurosawa, and H. Enomoto, \"Damped Vibration\nAnalysis Using Finite Element Method with Approximated Modal\nDamping for Automotive Double Walls with a Porous Material,\" Journal\nof Sound and Vibration, vol. 325, pp. 436–450, 2009.","M. Sasajima, T. Yamaguchi, and A. Hara, \"Acoustic Analysis Using\nFinite Element Method Considering Effects of Damping Caused by Air\nViscosity in Audio Equipment,\" Applied Mechanics and Materials, vol.\n36, pp. 282–286, 2010.","IEC60318-4, IEC standard, Simulators of human head and ear - Part 4:\nOccluded-ear simulator for the measurement of earphones coupled to the\near by means of ear inserts 2010.","S. Jonsson, B. Liu, A. Schuhmacher and L. Nielsen, \"Simulation of the\nIEC 60711 occluded ear simulator,\" Audio Engineering Society 116th\nconvention, 2004."]}
- Published
- 2015
- Full Text
- View/download PDF
46. Magnetization dynamics in the normal and superconducting phases of UPd2Al3: I. Surveys in reciprocal space using neutron inelastic scattering
- Author
-
G. H. Lander, Yoshichika Onuki, N. Bernhoeft, Naoto Metoki, Y. Koike, Yoshinori Haga, Naofumi Aso, Noriaki K. Sato, B. Roessli, Takemi Komatsubara, and Arno Hiess
- Subjects
Reciprocal lattice ,Magnetization dynamics ,Condensed matter physics ,Chemistry ,Dynamic structure factor ,General Materials Science ,Neutron ,Inelastic scattering ,Neutron scattering ,Condensed Matter Physics ,Inelastic neutron scattering ,Neutron spectroscopy - Abstract
This topical review presents results from neutron inelastic scattering experiments on single crystals of UPd2Al3. The focus is on the experimental situation, while the sequel paper advances theoretical perspectives. We present a detailed and complete characterization of the wavevector- and energy-dependent magnetization dynamics in UPd2Al3 as measured by neutron inelastic scattering primarily in the form of extensive surveys in energy–momentum space under a wide range of experimental conditions, and put our observations in context with data that has been published previously by two independent groups. In this way we emphasize the robustness of the results, which indicate the intricate nature of the dynamic magnetic susceptibility of this material. This study yields unique insight into the low-temperature ground state, which exhibits a microscopic coexistence of antiferromagnetism and superconductivity, making UPd2Al3 one of the most accessible heavy-fermion superconductors that can be fully characterized by neutron spectroscopy.
- Published
- 2006
47. Separability of a Low-Momentum Effective Nucleon-Nucleon Potential
- Author
-
M. Yamaguchi, S. Fujii, Y. Koike, Ryoji Okamoto, Eizo Uzu, and Hiroyuki Kamada
- Subjects
Physics ,Physics and Astronomy (miscellaneous) ,Nuclear Theory ,Binding energy ,Separable space ,Momentum ,Simple (abstract algebra) ,Convergence (routing) ,Cutoff ,Nucleon ,Nuclear Experiment ,Legendre polynomials ,Mathematical physics - Abstract
A realistic nucleon-nucleon potential is transformed into a low-momentum effective one (LMNN) using the Okubo theory. The separable potentials are converted from the LMNN with a universal separable expansion method and a simple Legendre expansion. Through the calculation of the triton binding energies, the separability for the convergence of these ranks is evaluated. It is found that there is a tendency for the lower momentum cutoff parameter $\Lambda$ of LMNN to gain good separability., Comment: 6 pages, 1 table
- Published
- 2006
48. Four-Body Faddeev-Yakubovsky Calculation Using the Finite Range Expansion Method
- Author
-
Eizo Uzu and Y. Koike
- Subjects
Elastic scattering ,Physics ,Faddeev equations ,Physics and Astronomy (miscellaneous) ,Quantum electrodynamics ,Nuclear Theory ,Mathematical analysis ,Convergence (routing) ,Order (group theory) ,Finite range ,Nucleon - Abstract
The finite range expansion method [Y. Koike, Prog. Theor. Phys. 87 (1992), 775], which gives well converged solutions of the three-body Faddeev equations, is extended to the three-body and two-two subsystems in order to solve the four-body Faddeev-Yakubovsky equations. A feasibility study is carried out to check the convergence in a four-nucleon system at 3.45 MeV below the four-body break-up threshold, which is in between the 2N-2N and 2N - N - N break-up thresholds. We obtain a converged phase shift and inelasticity parameter to 6 digits for 3N + N elastic scattering.
- Published
- 2006
49. Effects of Dietary Supplementation with Branched-chain Amino Acids (BCAAs) during Nursing on Plasma BCAA Levels and Subsequent Growth in Cattle
- Author
-
Noboru Manabe, Masugi Nishihara, D. S. Chen, Y. Koike, K. Suzuki, Junyou Li, and Tomohiro Yonezawa
- Subjects
chemistry.chemical_classification ,Branched-chain amino acid ,Animal husbandry ,Beef cattle ,Amino acid ,chemistry.chemical_compound ,chemistry ,Nursing ,Valine ,Animal Science and Zoology ,Dietary supplementation ,Isoleucine ,Leucine ,Food Science - Abstract
To determine the effects of short-term dietary supplementation of branched-chain amino acids (BCAAs) during nursing (from 3 to 28 days of age) on plasma BCAA levels and subsequent growths in cattle, 12 nursing male Holstein calves, randomly assigned to control and treatment groups (n = 6 in each group), orally received a daily supplement of essential BCAAs (2 g/kg body weight/day; 1:1:1 of valine, leucine and isoleucine) or not. The plasma BCAA levels increased linearly after the administration. During the treatment period, average daily gain (ADG) was lower in the treatment group (0.43±0.07 kg/day) than the controls (0.71±0.07 kg/day, p
- Published
- 2005
50. New Screened Coulomb Potentials and Renormalization
- Author
-
H. Kamada, M. Yamaguchi, and Y. Koike
- Subjects
Renormalization ,Physics ,Coulomb scattering ,Theoretical physics ,Phase factor ,Physics and Astronomy (miscellaneous) ,Scattering ,High Energy Physics::Lattice ,Phase (waves) ,Coulomb ,Yukawa potential ,Function (mathematics) - Abstract
We introduce a new screening function which is useful for the few-body Coulomb scattering problem in ``screening and renormalization'' scheme. The new renormalization phase factor of the screening function is analytically shown. The Yukawa type of the screening potential has been used in several decades, we modify it to make more useful. As a concrete example, we compare the proton-proton scattering phase shifts calculated from these potentials. The numerical results document that high precision calculations of the renormalization are performed by the new screening function.
- Published
- 2005
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