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573 results on '"Kosaka, Takashi"'

68. Dual Inverter-Fed Open Winding IPMSM Drive System for High-Power Premium Class EV

Author

Matsumori, Hiroaki, Maeda, Yuto, Kosaka, Takashi, Matsui, Nobuyuki, and Saha, Subrata

Abstract

Recently, the class of electric vehicles (EVs) with high-power (250 kW) motor drive systems and high energy/high voltage (100 kWh/800 V) batteries has been the prominent focus of various automotive makers. Considering the drive system efficiency, motor acoustic noise, system fail-safe features, and cost, the dual inverter with a dual battery and an open-winding interior permanent magnet motor is considered to be a highly promising drive system configuration for premium class EVs. Therefore, considering the high drive system efficiency and low motor acoustic noise, the authors propose selecting different pulse width modulation (PWM) switching pattern modes in the frequent vehicle operating area based on the vehicle driving modes for the system configuration of premium class EVs. The authors performed suitable simulations and experiments with a 65 kW motor drive system. The experimental results are validated to verify the effectiveness of selecting different PWM switching modes based on the vehicle driving pattern.

Published
2023
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69. A novel approach for circuit-field-coupled time-stepping electromagnetic analysis of saturated interior PM motors

Author

Kano, Yoshiaki, Watanabe, Kyohei, Kosaka, Takashi, and Matsui, Nobuyuki

Subjects
Magnets, Permanent, Electromagnetism, Finite element method, Business, Computers, Electronics, Electronics and electrical industries
Abstract

This paper presents a novel approach for circuit-field-coupled time-stepping electromagnetic analysis of a saturated interior permanent-magnet (IPM) synchronous motor. To predict the drive performance quickly, the proposed approach consists of a dynamic simulator based on a novel nonlinear model of the d--q flux linkages of the IPM motor. The model can take into account not only the magnetic saturation but also the harmonics of inductance distributions and EMF waveforms. The validity of the model is verified from suitable simulation results of the instantaneous current and torque waveforms of the IPM motor. The proposed analysis realizes a dramatic reduction in the computation time compared to circuit-field-coupled time-stepping finite-element analysis, keeping analytical accuracy. A 10-kW 15 000-r/min prototype driven by a pulsewidth-modulation inverter was used for laboratory testing to verify the analysis. The experimental results showed quite reasonable agreement with the predicted instantaneous current. Index Terms--Coupled analysis, interior permanent-magnet (IPM) synchronous motor, magnetic cross saturation, simple expression, space harmonics.

Published
2009

76. Comparison of Converse Ω Anastomosis and Extracorporeal Anastomosis After Laparoscopic Distal Gastrectomy for Gastric Cancer

Author

Tsuchiya, Nobuhiro, primary, Kunisaki, Chikara, additional, Kubo, Hirokazu, additional, Sato, Sho, additional, Tanaka, Yusaku, additional, Sato, Kei, additional, Miyamoto, Hiroshi, additional, Watanabe, Jun, additional, Takeda, Kazuhisa, additional, Kosaka, Takashi, additional, Akiyama, Hirotoshi, additional, Endo, Itaru, additional, and Misumi, Toshihiro, additional

Published
2021
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78. Real-World Therapeutic Outcomes of S-1 Adjuvant Chemotherapy for pStage II/III Gastric Cancer in the Elderly

Author

Kunisaki, Chikara, primary, Sato, Sho, additional, Tsuchiya, Nobuhiro, additional, Kubo, Hirokazu, additional, Watanabe, Jun, additional, Sato, Tsutomu, additional, Takeda, Kazuhisa, additional, Tamura, Yuko, additional, Kasahara, Kohei, additional, Kosaka, Takashi, additional, Akiyama, Hirotoshi, additional, and Endo, Itaru, additional

Published
2021
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81. Simple nonlinear magnetic analysis for permanent-magnet motors

Author

Kano, Yoshiaki, Kosaka, Takashi, and Matsui, Nobuyuki

Subjects
Finite element method -- Research, Business, Computers, Electronics, Electronics and electrical industries
Abstract

This paper presents a simple nonlinear magnetic analysis for a surface-mounted permanent-magnet synchronous motor as an assistant design tool of finite-element analysis (FEA). The equivalent magnetic circuit of the motor used in the proposed analysis is composed of the saturable permeance tips in the stator teeth for considering the local magnetic saturation. As a result, the proposed analysis is capable of calculating the flux distribution and the torque characteristics in the presence of magnetic saturation. The effectiveness of the proposed analysis is verified by comparing with three-dimensional (3-D) FEA in terms of the analytical accuracy. The computation time is greatly reduced as short as 1.5 s while the 3-D FEA requires as much as 32 min for the same evaluation. Index Terms--Equivalent magnetic circuit, finite-element analysis (FEA), simple nonlinear magnetic analysis, surface-mounted permanent-magnet synchronous motor (SPMSM).

Published
2005

89. Psoas muscle depletion during preoperative chemotherapy for advanced gastric cancer has a negative impact on long‐term outcomes after gastrectomy.

Author

Horii, Nobutoshi, Kosaka, Takashi, Fujiwara, Ryo, Sato, Sho, Akiyama, Hirotoshi, Kunisaki, Chikara, and Endo, Itaru

Subjects
*PSOAS muscles, *NEOADJUVANT chemotherapy, *STOMACH cancer, *GASTRECTOMY, *TUMOR classification, *PROGNOSIS
Abstract

Aim: The significance of sarcopenia in cancers has been widely recognized. However, few studies have focused on chronological changes in sarcopenia in cancer patients. This study aimed to clarify the clinical significance of changes in the psoas muscle area before and after preoperative chemotherapy. Methods: This study included 39 patients who underwent gastrectomy followed by preoperative chemotherapy for advanced gastric cancer between January 2010 and December 2016 in our hospital. The psoas muscle area was measured at the umbilical level before and after chemotherapy, and the relationship between its chronological changes and the long‐term prognosis was examined. Results: Patients were classified into two groups according to changes in the psoas muscle area before and after preoperative chemotherapy: remarkable muscle depletion and normal groups. No significant differences were observed in clinicopathological factors. Notably, the remarkable muscle depletion group included significantly more male patients (P =.018) and showed a high weight loss rate (P <.001). Although no significant difference was observed in the recurrence‐free survival between the two groups (P =.484), overall survival was significantly worse in the remarkable muscle depletion group (P <.001). Multivariate analysis for prognosis revealed that pathological stage III or higher (P =.022) and decreased psoas muscle area (P =.038) were independent prognostic factors. Conclusions: The present findings suggest that psoas muscle depletion during preoperative chemotherapy is a prognostic factor for poor long‐term outcomes in patients who underwent gastrectomy followed by preoperative chemotherapy for advanced gastric cancer. [ABSTRACT FROM AUTHOR]

Published
2022
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96. Efficacy of Video-assisted Thoracoscopic Esophagectomy for Stage II/III Esophageal Cancer: Analysis Using the Propensity Scoring System

Author

IGUCHI, KENTA, primary, KUNISAKI, CHIKARA, additional, SATO, SHO, additional, TANAKA, YUSAKU, additional, MIYAMOTO, HIROSHI, additional, KOSAKA, TAKASHI, additional, SATO, KEI, additional, AKIYAMA, HIROTOSHI, additional, ENDO, ITARU, additional, YUKAWA, NORIO, additional, RINO, YASUSHI, additional, MASUDA, MUNETAKA, additional, and YAMANAKA, TAKEHARU, additional

Published
2020
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99. Laparoscopic Total Gastrectomy for Gastric Cancer in Elderly Patients

Author

SUEMATSU, HIDEAKI, primary, KUNISAKI, CHIKARA, additional, MIYAMATO, HIROSHI, additional, SATO, KEI, additional, SATO, SHO, additional, TANAKA, YUSAKU, additional, YUKAWA, NORIO, additional, RINO, YASUSHI, additional, KOSAKA, TAKASHI, additional, AKIYAMA, HIROTOSHI, additional, ENDO, ITARU, additional, and MASUDA, MUNETAKA, additional

Published
2020
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