Theoretical Approach to Spin-current Absorption at an Interface

Kazuhiro Tsutsui,Takehito Yokoyama,Kazuhiro Hosono 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.62 No.12

We study the spin current induced by an inhomogeneous spin-orbit coupling due to impurities byusing the Keldysh Green’s function formalism. In particular, we focus on the diffusive contributionsand give their analytical expressions. A spin current is found to be generated in the presence ofboth a gradient in the spin-orbit strength and a gradient in the external electric field. The resultingdiffusive spin current indicates the presence of spin-current absorption at the interface between thematerials with different spin-orbit coupling strengths, which is exemplified with an experimentallyrelevantsetup.

Lignin-based Functional Materials from Plant Obtained by Simultaneous Enzymatic Saccharification and Communition

Kazuhiro SHIKINAKA 한국생물공학회 2019 한국생물공학회 학술대회 Vol.2019 No.10

GCT Technologies and their applications

Kazuhiro Kurachi,Kazunori Taguchi,Gourab.Majumdar 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

Continuous development and evermore demanding applications, have led to significant improvements in high power semiconductors devices to date. High power devices such as GTO (Gate Turn Off Thyristor), GCT (Gate Commutated Turn Off Thyristor) and HVIGBT (High Voltage Insulated Gate Bipolar Transistor) module have been widely adopted in large capacity power electronics equipment such as electric railway, power management, power transportation and industrial fields. However, long term reliability is expected from these applications and from the viewpoint of environmental management, reduction in equipment size and improvement in efficiency are required. Until 20 years ago, the mainstream device for high power electronics was the GTO but since the late 1990s, they have been replaced with new devices such as GCTs and HVIGBTs. Here we focus on the press-pack GCT with a hermetic structure that can be expected to have a long lifetime and report on some of the applied technologies and their application.

A Method for Determining Classroom Seating Arrangements by Using a Genetic Algorithm

Kazuhiro Shin-ike,Hitoshi Iima 제어로봇시스템학회 2012 제어로봇시스템학회 국제학술대회 논문집 Vol.2012 No.10

Classroom seating arrangements are important topics that affect each and every students and teachers. In this study we propose a method for determining the classroom seating arrangements considering relationships between students. In order to determine the optimal classroom seating arrangements, a genetic algorithm is applied on the basis of the questionnaire results and the analysis of the observation of behaviors between students. In the genetic algorithm, we propose a procedure named a matrix crossover. Our optimization problem is to determine the combination of classroom seating arrangements in such a way that the minimum of fitness rates of all students is as large as possible. Based on our proposed classroom seating arrangements, we carried out experiments at a national college of technology in Japan. It is found from the experiments that satisfaction of each student for our proposed method is higher than the traditional one. It is also found from another questionnaire that each student is actually comfortable in the classroom because of the relations between other students. It is confirmed from the experimental results that the proposed method was effective.

Development of SVC Control for Suppressing Voltage Fluctuations

Kazuhiro Usuki,Fumio Aoyama,Masayoshi Hanamatsu 전력전자학회 2011 ICPE(ISPE)논문집 Vol.2011 No.5

This paper describes control methods for a line-commutated static var compensator (SVC) and a self-commutated SVC to suppress voltage fluctuations of electric arc furnaces (EAFs) for steel making. In these control methods, the line-commutated SVC and the self-commutated SVC compensate for the fluctuations of the reactive power effectively within their respective rated capacities. This paper also presents practical examples of both SVCs for suppressing voltage fluctuations. In the actual operation of EAFs and SVCs, the authors verified that each SVC effectively suppressed the voltage fluctuations at the point of common coupling.

CHIME dating and age mapping of monazite in granulites and paragneisses from the Hwacheon area, Korea: implications for correlations with Chinese cratons

Kazuhiro Suzuki 한국지질과학협의회 2009 Geosciences Journal Vol.13 No.3

The basement of the Hwacheon area in the northern part of the Gyeonggi massif in the Korean Peninsula comprises granulite and gneiss complexes that are separated by an extensive mylonite zone. Granulites distant from the mylonite zone show little evidence of a retrograde overprint beyond minor growth of biotite along garnet grain boundaries. Monazite grains enclosed in garnet show a core to rim decrease in Y, and those in the matrix show a peripheral enrichment of Y on low-Y interiors. Similarly, garnet grains decrease in Y from core to rim, with peripheral Y-enrichment, which can be attributed to early to peak garnet growth and post-growth modification, respectively. The three chemical domains representing stages of monazite growth show no detectable age difference, together yielding a CHIME age of 1868 ± 24 Ma. Granulites near the mylonite zone show growth of cordierite and biotite aggregates around garnet grains, and yield Permo-Triassic monazite domains on and within predominantly Paleo-proterozoic monazite grains. Mylonitized granulites have a metamorphic overprint characterized by the growth of the sillimanite and K-feldsper assemblage at ca. 241 Ma, subsequent to ductile shearing. Pelitic gneisses in the gneiss complex contain zircon grains with Neoproterozoic detrital cores and monazite grains with unequivocal metamorphic ages of ca. 245 Ma. Geological, petrological and chronological evidence suggests differing evolutional histories between two crustal domains prior to amalgamation. The widespread occurrence of Permo-Triassic paragneisses and mylonites in the Gyeonggi massif can be explained by detachment of the metamorphosed upper crust of the South China block, which was thrust over the Paleoproterozoic granulite complex at ca. 241 Ma during the Sulu orogeny. Permo-Triassic metamorphic overprints on the latter are attributed to contact metamorphism from the hot allochthon.

Detection of Phalange Region Based on U-Net

Kazuhiro HATANO,Seiichi MURAKAMI,Huimin LU,Joo Kooi TAN,Hyoungseop KIM,Takatoshi AOKI 제어로봇시스템학회 2018 제어로봇시스템학회 국제학술대회 논문집 Vol.2018 No.10

Osteoporosis is one of the famous bone diseases. It is a major cause of deteriorating the quality of life, and early detection and early treatment are becoming socially important. Visual screening using Computed Radiography (CR) images is effective for diagnosis of osteoporosis, but there are problems of increasing the burden on doctors, variation in diagnostic results due to differences in experiences of doctors, and undetected lesions. In order to solve this problem, we are working on a computer-aided diagnosis (CAD) system for osteoporosis. In this paper, we propose segmentation methods of the phalange region from the phalangeal CR images as a preprocessing of classification of osteoporosis. In the proposed method, we construct a segmentation model using U-Net, which is a type of deep convolution neural network (DCNN). The proposed method was applied to input images generated from CR images of 101 patients with both hands, and evaluated using the Intersection over Union (IoU) values. The result was 0.914 in IoU.

The Variation in the Lumbar Facet Joint Orientation in an Adult Asian Population and Its Relationship with the Cross-Sectional Area of the Multifidus and Erector Spinae

Kazuhiro Sugawara,Masaki Katayose,Kota Watanabe 대한척추외과학회 2016 Asian Spine Journal Vol.10 No.5

Study Design: Cross-sectional study of healthy volunteers. Purpose: We aimed to investigate the variation in the lumbar facet joint orientation in an adult Asian population. The relationship between the facet joint orientation and muscle cross-sectional area (CSA) of multifidus and erector spinae was also clarified. Overview of Literature: Several studies have reported that lumbar pathologies, such as lumbar spondylolysis and degenerative spondylolisthesis, were related to the horizontally shaped lumbar facet joint orientation at the lower lumbar level. However, data regarding variations in the facet joint orientation in asymptomatic subjects have not been well documented. Methods: In 31 healthy male adult Asian volunteers, the facet joint orientation and CSA of multifidus and erector spinae were measured using magnetic resonance imaging at the L4–5 and L5–S1 levels. Variation in the facet joint orientation was examined using coefficients of variation (CV). Pearson’s product-moment coefficient was used to investigate the relationship between the facet joint orientation and CSA of multifidus and erector spinae. Results: Lumbar facet joint orientation had a wider range of variation at L5–S1 (CV=0.30) than at L4–5 (CV=0.18). The L4–5 facet joint orientation had a weak but significant correlation with the CSA of erector spinae (r =0.40; p=0.031). The CSA of the multifidus had no relationship with the facet joint orientation at the L4–5 (r =0.19; p =0.314) and the L5–S1 level (r =0.19; p =0.312). Conclusions: The lumbar facet joint orientation was found to have a wide variation, particularly at the L5–S1 in the Asian adult population, and the facet joint orientation had a relationship with the CSA of the erector spinae at the L4–5.

Capacity Clauses , the Open Skies Policy of the United States and the Japan - United States Aviation Dispute over Capacity

Kazuhiro NAKATANI 한국항공우주정책·법학회 1998 한국항공우주정책·법학회지 Vol.10 No.-

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Experimental study of PID auto-tuning for unsymmetrical processes

Kazuhiro Mimura,Tetsuo Shiotsuki 제어로봇시스템학회 2009 제어로봇시스템학회 국제학술대회 논문집 Vol.2009 No.8

The advent of relay auto-tuning of PID controllers got rid of previous troublesome tuning procedure. However, PID control performance didn"t change so much since the tuning rule was the same as the Ziegler and Nicholsthat only use ultimate gain and ultimate period. In this paper, we propose new tuning rule especially for an unsymmetrical process. The experimental test result showed proposed rule achieved less overshoot and quicker disturbance recovery than conventional tuning rule.