Speed Sensorless Control of Ultrasonic Motors Using Neural Network

Yoshida Tomohiro,Senjyu Tomonobu,Nakamura Mitsuru,Urasaki Naomitsu,Funabashi Toshihisa,Sekine Hideomi The Korean Institute of Power Electronics 2006 JOURNAL OF POWER ELECTRONICS Vol.6 No.1

In this paper, a speed sensorless control for an ultrasonic motor (USM) using a neural network (NN) is presented. In the proposed method, rotor speed is estimated by a three-layer NN which adapts nonlinearities associated with load torque and motor temperature into control. The intrinsic properties of a USM, such as high torque for low speeds, high static torque, compact size, etc., offer great advantages for industrial applications. However, the speed property of a USM has strong nonlinear properties associated with motor temperature and load torque, which make accurate speed control difficult. These properties are considered in designing a control method through the application of mathematical models. In these strategies, a detailed speed model of the USM is required which makes actual applications impractical. In the proposed method, a three-layer NN estimates the speed of the USM from the drive frequency, the root mean square value of input voltage and the surface temperature of the USM, where no mechanical speed sensor is needed. The NN speed based estimator enables inclusion of variations in driving conditions due to input signals of the NN involved during the driving state of the USM. The disuse of sensors offers many advantages on both the cost and maintenance front. Moreover, the model free sensorless control method offers practical controller construction within a small number of parameters. To validate the proposed speed sensorless control method for a USM, experiments have been executed under several conditions.

Selective Angiography to Detect Anterior Spinal Artery Stenosis in Thoracic Ossification of the Posterior Longitudinal Ligament

Yoshida Go,Ushirozako Hiroki,Hasegawa Tomohiko,Yamato Yu,Yasuda Tatsuya,Banno Tomohiro,Arima Hideyuki,Oe Shin,Mihara Yuki,Yamada Tomohiro,Ide Koichiro,Watanabe Yuh,Ushio Takasuke,Matsuyama Yukihiro 대한척추외과학회 2022 Asian Spine Journal Vol.16 No.3

Study Design: Single-center prospective study.Purpose: To investigate anterior spinal artery (ASA) status using preoperative selective angiography in patients undergoing surgery for thoracic ossification of the posterior longitudinal ligament (T-OPLL).Overview of Literature: Surgery for T-OPLL has a high risk of neurological complications, which might be associated with insufficient spinal cord blood flow.Methods: This study prospectively examined nine T-OPLL patients who underwent posterior thoracic decompression with kyphosis correction and instrumented fusion at Hamamatsu University School of Medicine between 2017 and 2019. All underwent preoperative selective angiography to detect and evaluate the Adamkiewicz artery and ASA. Intraoperative neuromonitoring and Doppler ultrasonography were performed to analyze neurological complications and spinal cord blood flow.Results: All nine patients showed ASA stenosis in the area of T-OPLL. In all patients, the Adamkiewicz artery was located between T7 and L2 and the area of ASA stenosis corresponded to the level of T-OPLL and greatest spinal cord compression; intraoperative Doppler ultrasonography confirmed the ASA defect at the same spinal level. The number of spinal levels from the Adamkiewicz artery to the most compressive OPLL lesion was greater in the two patients who developed postoperative neurological deficit compared to those who did not (5.5 vs. 2.3, p=0.014).Conclusions: This is the first study to report detection of ASA stenosis in patients with T-OPLL. Maintaining spinal cord blood flow is important in these patients to avoid neurological deterioration.

Speed Sensorless Control of Ultrasonic Motors Using Neural Network

Tomohiro Yoshida,Tomonobu Senjyu,Mitsuru Nakamura,Naomitsu Urasaki,Toshihisa Funabash,Hideomi Sekine 전력전자학회 2006 JOURNAL OF POWER ELECTRONICS Vol.6 No.1

In this paper, a speed sensorless control for an ultrasonic motor (USM) using a neural network (NN) is presented. In the proposed method, rotor speed is estimated by a three-layer NN which adapts nonlinearities associated with load torque and motor temperature into control. The intrinsic properties of a USM, such as high torque for low speeds, high static torque, compact size, etc., offer great advantages for industrial applications. However, the speed property of a USM has strong nonlinear properties associated with motor temperature and load torque, which make accurate speed control difficult. These properties are considered in designing a control method through the application of mathematical models. In these strategies, a detailed speed model of the USM is required which makes actual applications impractical. In the proposed method, a three-layer NN estimates the speed of the USM from the drive frequency, the root mean square value of input voltage and the surface temperature of the USM, where no mechanical speed sensor is needed. The NN speed based estimator enables inclusion of variations in driving conditions due to input signals of the NN involved during the driving state of the USM. The disuse of sensors offers many advantages on both the cost and maintenance front. Moreover, the model free sensorless control method offers practical controller construction within a small number of parameters. To validate the proposed speed sensorless control method for a USM, experiments have been executed under several conditions.

Aluminum Toxicity in Plants under Sodic-Saline Soils Whose Ph is 10

Tomohiro Yoshida,Atsushi Satou,Shigenao Kawai 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Association between Pelvic Parameters and Vaginal Delivery

Yamada Tomohiro,Yamato Yu,Hasegawa Tomohiko,Yoshida Go,Yasuda Tatsuya,Banno Tomohiro,Arima Hideyuki,Oe Shin,Mihara Yuki,Ushirozako Hiroki,Ide Koichiro,Watanabe Yuh,Hosino Hironobu,Matsuyama Yukihiro 대한척추외과학회 2022 Asian Spine Journal Vol.16 No.2

Study Design: Cross-sectional study. Purpose: To investigate the association between vaginal delivery and pelvic parameters and clarify the effect of parity on parameter fluctuations. Overview of Literature: During vaginal delivery, the sacroiliac joint widens and the sacrum nutates (nods). However, the association between these pelvic parameters and parity is unknown. Methods: As part of a 2016 health screening, 320 female volunteers underwent whole-spine radiographs. Age-matched healthy women were grouped according to the number of vaginal deliveries (0, 1–2, or ≥3). Demographic variables and spinopelvic parameters were compared among the three groups. Results: Of the 320 volunteers, 213 were enrolled (mean age, 71.1±7.2 years). The mean number of vaginal deliveries was 2.2. The average pelvic incidence (PI) was 55.6°±11.1° and was significantly higher in the 90 women with three or more vaginal deliveries than in the other two groups (p<0.001). The average sacral slope was 33.4°±11.1° and was significantly higher in the women with three or more vaginal deliveries than in the 18 who did not deliver vaginally (p<0.001). The 105 women with one or two vaginal deliveries had significantly higher PIs and sacral slopes than did those who did not deliver vaginally (p<0.001). Conclusions: This is the first study documenting an association between vaginal delivery and pelvic parameters. Bony birth canal realignment during vaginal delivery can affect postnatal PI. Our study helps in understanding the PI changes over a woman’s life span.

Transient forebrain ischemia induces impairment in cognitive performance prior to extensive neuronal cell death in Mongolian gerbil (Meriones unguiculatus)

Tomohiro Kondo,Suguru Yoshida,Hiroaki Nagai,Ai Takeshita,Masaki Mino,Hiroshi Morioka,Takayuki Nakajima,Ken Takeshi Kusakabe,Toshiya Okada 대한수의학회 2018 Journal of Veterinary Science Vol.19 No.4

In Mongolian gerbils, bilateral common carotid artery occlusion (BCCAO) for several minutes induces ischemia, due to an incomplete circle of Willis, resulting in delayed neuronal cell death in the Cornet d’Ammon 1 (CA1) region of the hippocampus. Neuronal cell death in the hippocampus and changes in behavior were examined after BCCAO was performed for 5 min in the gerbils. One day after BCCAO, the pyramidal neurons of the CA1 region of the hippocampus showed degenerative changes (clumped chromatin in nuclei). At 5 and 10 days after BCCAO, extensive neuronal cell death was observed in the hippocampal CA1 region. Cognitive performance was evaluated by using the radial maze and passive avoidance tests. In the radial maze test, which examines win-stay performance, the number of errors was significantly higher in ischemic gerbils than in sham-operated gerbils on days 1 and 2 post-operation. In the passive avoidance test, the latency and freezing times were significantly shorter in ischemic gerbils than in sham-operated gerbils on the days 1, 2, and 4–6 post-operation. These results indicate that transient forebrain ischemia impairs cognitive performance, even immediately after the ischemic insult when there are only subtle signs of neuronal cell death.

Multi-Rod Constructs Can Increase the Incidence of Iliac Screw Loosening after Surgery for Adult Spinal Deformity

Tomohiro Banno,Tomohiko Hasegawa,Yu Yamato,Daisuke Togawa,Go Yoshida,Sho Kobayashi,Tatsuya Yasuda,Hideyuki Arima,Shin Oe,Yuki Mihara,Hiroki Ushirozako,Yukihiro Matsuyama 대한척추외과학회 2019 Asian Spine Journal Vol.13 No.3

Study Design: A retrospective study. Purpose: To investigate the incidence of iliac screw loosening with a two-rod vs. multi-rod construct and the effect on clinical and radiographic outcomes after surgery for adult spinal deformity (ASD). Overview of Literature: Multi-rod construct is useful for preventing rod fracture in ASD surgery. However, limited information is available regarding the incidence of iliac screw loosening after corrective fusion surgery using a multi-rod construct. Methods: Total 106 patients with ASD (24 men and 82 women; mean age, 68 years) who underwent corrective fusion surgery using bilateral iliac screws and were followed up for at least 1 year were reviewed. The following variables were compared between patients who underwent surgery with a two-rod and multi-rod construct: age, sex, bone mineral density (BMD), fusion level, high-grade osteotomy, L5/S interbody fusion, screw loosening (upper instrumented vertebra [UIV], S1, and iliac), rod fracture, proximal junctional kyphosis, spinopelvic parameters, and Oswestry Disability Index (ODI) score. We also compared patients with and without iliac screw loosening in the multi-rod construct group. Results: Of the 106 patients, 55 underwent surgery with a conventional two-rod construct and 51 with a multi-rod construct (three rods in 16, four rods in 35). Iliac and UIV screw loosening was observed in 24 patients (21%) and 35 patients (33%), respectively. The multi-rod group showed significantly higher incidence of iliac and UIV screw loosening and lower incidence of rod fracture. Patients with iliac screw loosening had a lower BMD than those without screw loosening; however, no significant differences were observed in the spinopelvic parameters or the ODI score. Conclusions: The use of multi-rod constructs led to a higher incidence of junctional screw loosening than the use of conventional two-rod constructs, especially in patients with osteoporosis. Iliac screw loosening did not affect sagittal alignment or clinical outcome in the short term.

Natural History of Early Gastric Cancer: a Case Report and Literature Review

Tomohiro Iwai,Masao Yoshida,Hiroyuki Ono,Naomi Kakushima,Kohei Takizawa,Masaki Tanaka,Noboru Kawata,Sayo Ito,Kenichiro Imai,Kinichi Hotta,Hirotoshi Ishiwatari,Hiroyuki Matsubayashi 대한위암학회 2017 Journal of gastric cancer Vol.17 No.1

Early detection and treatment decrease the mortality rate associated with gastric cancer (GC). However, the natural history of GC remains unclear. An 85-year-old woman was referred to our hospital for evaluation of a gastric tumor. Esophagogastroduodenoscopy identified a 6 mm, flat-elevated lesion at the lesser curvature of the antrum. A biopsy specimen showed a well-differentiated tubular adenocarcinoma.

Comparison of Characteristics of Streptococcus dysgalactiae subsp. equisimilis Isolates Causing Repetitive vs Single Infections

Tomohiro Fujita,Haruno Yoshida,Shunsuke Osaka,Yoneji Hirose,Mieko Goto,Noriyuki Nagano,Takashi Takahashi 대한진단검사의학회 2019 Annals of Laboratory Medicine Vol.39 No.5

No study has described Streptococcus dysgalactiae subsp. equisimilis (SDSE) isolates that cause repetitive infections (recurrence and reinfection). We compared the microbiological characteristics of SDSE causing repetitive infections with those causing single infections. Three patients with invasive infections were identified based on their medical records, and multiple SDSE isolates were collected at intervals over three weeks, using a laboratory repository. Isolates from 12 patients with single-episode infections served as controls. Six isolates were collected from three patients with first and second episodes of infection. All isolates causing either repetitive or single-episode infection were subjected to emm typing, multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), and random amplified polymorphic DNA (RAPD) analyses. Amplification of five virulence genes (sicG, prtF1, prtF2, lmb, and cbp), biofilm formation (BF), and cell invasion abilities (CIAs) were measured as virulent phenotypes. We observed close genetic similarities in the data obtained by emm typing, MLST, PFGE, and RAPD in four isolates from two patients, suggesting recurrence, whereas two isolates from one patient indicated genetic differences in these data, suggesting re-infection. The presence of the five virulence genes and the BF and CIA measurements appeared not to contribute to repetitive infections, compared with isolates causing single-episode infection. In conclusion, clinicians encountering patients with repetitive infections should be aware of both possibilities: recurrence with closely related strains and reinfection with different strains.

Natural History of Early Gastric Cancer: a Case Report and Literature Review

Iwai, Tomohiro,Yoshida, Masao,Ono, Hiroyuki,Kakushima, Naomi,Takizawa, Kohei,Tanaka, Masaki,Kawata, Noboru,Ito, Sayo,Imai, Kenichiro,Hotta, Kinichi,Ishiwatari, Hirotoshi,Matsubayashi, Hiroyuki The Korean Gastric Cancer Association 2017 Journal of gastric cancer Vol.17 No.1

Early detection and treatment decrease the mortality rate associated with gastric cancer (GC). However, the natural history of GC remains unclear. An 85-year-old woman was referred to our hospital for evaluation of a gastric tumor. Esophagogastroduodenoscopy identified a 6 mm, flat-elevated lesion at the lesser curvature of the antrum. A biopsy specimen showed a well-differentiated tubular adenocarcinoma. The depth of the lesion was estimated to be intramucosal. Although the lesion met the indications for endoscopic resection, periodic endoscopic follow-up was performed due to the patient's advanced age and comorbidities. The mucosal GC invaded into the submucosa 3 years later, and finally progressed to advanced cancer 5 years after the initial examination. The patient died of tumor hemorrhage 6.4 years after the initial examination. In this case, mucosal GC progressed to advanced GC, eventually leading to the patient's death from GC. Early and appropriate treatment is required to prevent GC-related death.