Modification of Controllability of an Elastic Rotor by Rearrangement of Active Magnetic Bearings

Hiroyuki FUJISAKI,Hirokazu TOMONO,Tasuku KAMEKAWA,Masamitsu SHIGA,Toru WATANABE,Kazuto SETO 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.춘계 No.-

This paper presents a new modeling method and a control system design procedure for a flexible rotor with many elastic modes using active magnetic bearings (AMBs). The purpose of our research is to rotate the rotor for passing through the 1st and the 2nd critical speeds caused by flexible modes. To achieve this, it is necessary to control motion and vibration of the flexible rotor simultaneously. The new modeling method named as Extended Reduced Order Physical Model is presented to express its motion and vibration uniformly. Meanwhile, to solve problem as controllability and observability when elastic rotor is supported at both ends, location of AMBs and the shape of the rotor are modified. Moreover, phase-lead compensator is put to improve stability of experimental equipment and its effect verification is carried out by simulation.

Experimental Research on Complementally Connected Control System using Multiple Connected with Springs and Dampers to Mitigate Stress Concentration

Hiroyuki Toyoda,Takahiro Takano,Tomoyuki Akita,Toru Watanabe,Kazuto Seto 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.춘계 No.-

A novel combination of structures for connected-control mechanism (CCM) has been presented. By coupling base-isolated and ordinary structures, the vibration suppression effect of CCM is expected to be expanded. Experimental structures and CCM mechanism using magnetic dampers were built and excitation experiments were carried out. In the previous study, however, the achieved vibration suppression performance was not satisfactory. In study, to enhance the performance, spring elements are introduced. The spring constants are tuned according to so-called “fixed-point theory” The performance of the designed system is investigated experimentally.

Observation of Discharge Plasma of Liquid Propellant PPT

Hiroyuki KOIZUMI,Yohei FURUTA,Keiko WATANABE,Kimiya KOMURASAKI,Akihiro SASOH,Yoshihiro ARAKAWA 한국추진공학회 2004 한국추진공학회 학술대회논문집 Vol.2004 No.5

A System Concept for EFD/CFD Integration

Shigeya Watanabe,Shigeru Kuchi-ishi,Hiroyuki Kato,Takeshi Aoyama,Keiichi Murakami,Atsushi Hashimoto,Naoyuki Fujita,Yuichi Matsuo 한국항공우주학회 2008 한국항공우주학회 학술발표회 논문집 Vol.- No.-

A trail towards integration of EFD (Experimental Fluid Dynamics) and CFD (Computational Fluid Dynamics), that is. the development of a system called Digital/Analog Hybrid Wind Tunnel, is introduced. The aim of the system is to improve efficiency, accuracy, and reliability of aerodynamic characteristics evaluation in aerospace vehicle developments through mutual support between EFD and CFD. The function of the system consists of optimization of test planning utilizing pretest CFD calculations, an accurate correction of the wind tunnel wall and support interaction effects through CFD, CFD data refinement based on EFD data, the most probable aerodynamic characteristics estimation based on both EFD and CFD data, database including EFD and CFD data at an identical condition, and so forth. Key technical challenges in the system development, such as an automatic grid generation and high-speed solver development for CFD, a highly efficient data reduction technique for image measurement data. and techniques integrating EFD and CFD. are addressed.

Quality indicators for cervical cancer care in Japan

Tomone Watanabe,Mikio Mikami,Hidetaka Katabuchi,Shingo Kato,Masanori Kaneuchi,Masahiro Takahashi,Hidekatsu Nakai,Satoru Nagase,Hitoshi Niikura,Masaki Mandai,Yasuyuki Hirashima,Hiroyuki Yanai,Wataru Ya 대한부인종양학회 2018 Journal of Gynecologic Oncology Vol.29 No.6

Objective: Choice of hysterectomy and adjuvant treatment for International Federation of Gynecology and Obstetrics (FIGO) 2009 stage II endometrioid endometrial cancer (EEC) is still controversial. Aims of this study were to evaluate survival benefits and adverse effects of different hysterectomies with or without adjuvant radiotherapy (RT), and to identify prognostic factors. Methods: The patients at 14 member hospitals of the Taiwanese Gynecologic Oncology Group from 1992 to 2013 were retrospectively investigated. Patients were divided into simple hysterectomy (SH) alone, SH with RT, radical hysterectomy (RH) alone, and RH with RT groups. Endpoints were recurrence-free survival (RFS), overall survival (OS), disease-specific survival (DSS), adverse effects and prognostic factors for survival. Results: Total of 246 patients were enrolled. The 5-year RFS, OS, DSS and recurrence rates for the entire cohort were 89.5%, 94.3%, 96.2% and 10.2%, respectively. Patients receiving RH had more adverse effects including blood loss (p<0.001), recurrent urinary tract infections (p=0.013), and leg lymphedema (p=0.038). Age over 50-year (HR=9.2; 95% confidence interval [CI], 1.2–70.9) and grade 3 histology (HR=7.28; 95% CI, 1.45–36.6) were independent predictors of OS. Grade 3 histology was an independent predictor of RFS (HR=5.13; 95% CI, 1.38–19.1) and DSS (HR=5.97; 95% CI, 1.06–58.7). Patients receiving adjuvant RT had lower locoregional recurrence (p=0.046), but no impact on survival. Conclusion: Different treatment modalities yield similar survival outcomes. Patients receiving SH with RT had lower locoregional recurrent with acceptable morbidity. Age and tumor grading remained significant predictors for survival among patients with FIGO 2009 stage II EEC. Objective: We aimed to propose a set of quality indicators (QIs) based on the clinical guidelines for cervical cancer treatment published by The Japan Society of Gynecologic Oncology, and to assess adherence to standard-of-care as an index of the quality of care for cervical cancer in Japan. Methods: A panel of clinical experts devised the QIs using a modified Delphi method. Adherence to each QI was evaluated using data from a hospital-based cancer registry of patients diagnosed in 2013, and linked with insurance claims data, between October 1, 2012, and December 31, 2014. All patients who received first-line treatment at the participating facility were included. The QI scores were communicated to participating hospitals, and additional data about the reasons for non-adherence were collected. Results: In total, 297 hospitals participated, and the care provided to 15,163 cervical cancer patients was examined using 10 measurable QIs. The adherence rate ranged from 50.0% for ‘cystoscope or proctoscope for stage IVA’ to 98.8% for ‘chemotherapy using platinum for stage IVB’. Despite the variation in care, hospitals reported clinically valid reasons for more than half of the non-adherent cases. Clinically valid reasons accounted for 75%, 90.9%, 73.4%, 44.5%, and 88.1% of presented non-adherent cases respectively. Conclusion: Our study revealed variations in pattern of care as well as an adherence to standards-of-care across Japan. Further assessment of the causes of variation and non-adherence can help identify areas where improvements are needed in patient care.

Estimated degree of discomfort for instantaneous pulsation generated by motion base system

Hiroshi Watanabe,Hiroyuki Umemura 한국자동차공학회 2008 한국자동차공학회 Symposium Vol.2008 No.9

An issue involved in the recent development of visual-vestibular driving simulator systems is the simulator sickness felt by the observers. While numerous studies have focused on the effect of the optokinetic factor, there are few data on those of the vestibular factor. The major role of a driving simulator’s vestibular cues is to represent the acceleration caused by rotating in 3D space. Observers, thus, might frequently experience the instantaneous pulsation triggered by the accelerating scene in the high-realistic contents. The discomfort appears to be proportional to the amount of rotation; thus, clarifying the extent of human tolerance for such a stimulus should maintain the reality and comfortableness. We report two findings that quantitatively estimate the discomfort for instantaneous pulsation provided generated by motion base system. First, we used a psychophysical method to clarify the threshold of discomfort for pulsations around pitch and roll axes. We also present the effect of the visually predictive sign and observers’ attributions on the threshold. Second, we present various models that, by synthesizing the function of discomfort obtained from the data on the independent direction around pitch and roll, reconstruct observers’ discomfort when they are rotated in the general direction.

Comparative evaluation of obesity-related parameters in junior sumo wrestlers and children with obesity

( Miori Ogawa ),( Hiroyuki Sagayama ),( Shinsuke Tamai ),( Reiko Momma ),( Daisuke Hoshi ),( Akiko Uchizawa ),( Go Ichikawa ),( Osamu Arisaka ),( Koichi Watanabe ) 한국운동영양학회 2021 Physical Activity and Nutrition (Phys Act Nutr) Vol.25 No.3

[Purpose] Exercise is a key factor in preventing obesity and metabolic syndrome. Sumo wrestlers increase their body size from childhood for athletic advantage; however, the risk of metabolic syndrome in junior sumo wrestlers is undetermined. Preventive measures against pediatric obesity should be initiated during childhood to prevent obesity in adulthood, considering its high global incidence. We comparatively evaluated the risk factors for metabolic syndrome in junior sumo wrestlers and children with obesity. [Methods] We enrolled 70 male children (age 9-17 years [sumo group, n = 14] and 9-14 years [other sports and non-exercise groups, n = 28 each]) and evaluated their anthropometric parameters (height, weight, body mass index z-score, obesity rate, waist circumference, waist to height ratio) and hematological parameters (total, low-density, high-density, and non-high-density lipoprotein-cholesterol; triglycerides; plasma glucose, and glycated hemoglobin levels). [Results] The BMI z-score, obesity rate, waist circumference (p < 0.05, along with the non-exercise group), and systolic blood pressure were significantly higher and the high-density cholesterol level was lower in the sumo group than in the other sports group (p < 0.05). The waist to height ratio was significantly higher in the non-exercise group than in the other sports group (p < 0.05). No significant difference was found in other blood lipid, plasma glucose (significantly lower level than the reference range in the sumo group, p < 0.05), and glycated hemoglobin (within the reference range in all groups) levels among the three groups. [Conclusion] Junior sumo wrestlers had a larger body size and higher blood pressure than children with obesity who exercised regularly. This provides direction for future research into targeted preventive interventions against metabolic syndrome for junior sumo wrestlers with large body size.

RECENT DEVELOPMENT IN LARGE AREA MULTICRYSTALLINE SILICON SOLAR CELL AND ITS APPLICATIONS

Kenjiro Kimura,Hiroyuki Watanabe 한국태양에너지학회 1992 한국태양에너지학회 학술대회논문집 Vol.- No.-

Relationship between threatened vascular plants and the human population in Japan

Hayashi, Naoki,Watanabe, Eriko,Matsuda, Hiroyuki The Ecological Society of Korea 2012 Journal of Ecology and Environment Vol.35 No.4

Using data sets for Japan as a whole, as arranged with approximately $10{\times}10$ km squares (a secondary grid), we investigated the relationship between population density and the habitats of threatened vascular plants listed in the Japanese Red Data Book; depopulated areas in the present and future, areas where under-use may be serious, and those with a predominance of elderly people; and the present state of the habitats in terms of a characteristic land use pattern. Regarding the habitats of threatened vascular plants, the progress of deterioration [$(N_{CR}+N_{EN})/(N_{CR}+N_{EN}+N_{VU})$] in depopulated areas has been confirmed, where $N_{CR}$, $N_{EN}$, and $N_{VU}$ are the numbers of species classified as critically endangered, endangered, and vulnerable, respectively. Moreover, in grid squares used by a human such as farmland, the progress of the deterioration simply increases when population density becomes low. However, for many vascular plants, they are particularly endangered in populous areas. Local populations will decrease throughout Japan with the rate of depopulation in and around large cities being relatively slow. We also propose some issues that need further study. The deterioration by human activity may be reduced. On the other hand, some vascular plants may be adversely influenced by depopulation. Additionally, we should keep a close watch on grasslands and water areas in large cities to preserve vascular plants.

Development of a Test Method for Assisted Walking Trolleys

Yoichi Asano,Hiroyuki Jinbo,Naoya Watanabe 제어로봇시스템학회 2019 제어로봇시스템학회 국제학술대회 논문집 Vol.2019 No.10

Manufacturers have recently been developing assistive walking devices with electric motors, based on rollators and walking trolleys, in Japan. These assistive devices have electric motors to assist walking on sloped surfaces. Furthermore, they have a function that automatically suppresses the speed on downhill slopes. Here a walking experiment was conducted to investigate the speed at which the suppression function needed to be applied in various walking conditions. The subjects in the experiment walked while leaning on the assistive device, applying forces of 37 (horizontal) and 204 N (vertical) on downhill slopes. Furthermore, an analysis of the walking data obtained from traditional walking trolleys revealed that 80% of the subjects walked at a speed of 2.5 km/h or more. Two experiments were conducted to develop a test method that analyzed the performance of the suppression function on downhill slopes. The proposed test method results yielded sufficient accuracy.