Startup Engineering Education Programs in Niigata University: How to Integrate Knowledge to Solve Engineering Problems

Yamagiwa, Kazuaki,Tanabe, Yuji,Harada Shuji,Shimizu Tadaaki,Oka Tetsuo 한국공학교육학회 2012 공학교육연구 Vol.15 No.5

Faculty of engineering, Niigata University has been executing start-up engineering education programs for the first-year students to educate his or her ability to solve engineering problems. They are divided into teams and tackle a task that they expect to easily accomplish. The expected results are hardly obtained. Then they try to seek the gap between the results and their knowledge. They analyze the phenomena and improve the approach. They evaluate the results of second trial and the effectiveness of the measures. That is, the project requires so-called PDCA cycles for students to solve engineering problems. The start-up engineering project is one of the compulsory subjects and seven departments have given the students several tasks based on their technicality. The students exchange their knowledge, ideas and learn how to use knowledge to solve the problems. Their reports and questionnaire survey proved that the projects are highly effective to improve his or her ability to solve engineering problems and give them strong motivation to learn engineering. We introduce the some tasks and the outcomes of the projects set by seven departments; mechanical and production engineering, electrical and electronic engineering, information engineering, biocybernetics, chemistry and chemical engineering, civil engineering and architecture, and material science and engineering.

Power Factor Control for Hybrid Type Power Quality Conditioner

Yamagiwa, Kyohei,Kobayashi, Yuta,Aoki, Mutsumi,Ukai, Hiroyuki,Ueda, Fukashi,Kobayashi, Hiroshi The Korean Institute of Electrical Engineers 2012 The Journal of International Council on Electrical Vol.2 No.4

In recent years, power quality in distribution system becomes to be greatly concerned. There are two power quality problems greatly. One is the voltage rise, the other is harmonics voltage. The voltage rise in distribution system is caused by leading current from Static Capacitors (SCs) which are widely installed at receiving points by consumers to improve power factor. Especially, the voltage rise is caused in light-load time, because of the excessive amount of SCs. On the other hand, the harmonic voltages are caused by nonlinear loads such as power electronics devices. Since harmonic currents from nonlinear loads flow through the line and transformers, the voltage is distorted. To improve those problems of power quality, Hybrid type Power Quality Conditioner (HyPQC) is proposed. HyPQC is consist of the power electronics converter and LC circuit, it could compensate the reactive current and harmonic currents from loads. In order to use for practical application, the experimental test should be performed. From this background, this paper presents the control algorithm to compensate the reactive current and harmonic currents in case of changing the loads. The simulation and experimental results are also presented using the proto type model.

Startup Engineering Education Programs in Niigata University: How to Integrate Knowledge to Solve Engineering Problems

Kazuaki Yamagiwa,Yuji Tanabe,Shuji Harada,Tadaaki Shimizu,Tetsuo Oka 한국공학교육학회 2012 공학교육연구 Vol.15 No.5

Faculty of engineering, Niigata University has been executing start-up engineering education programs for the first-year students to educate his or her ability to solve engineering problems. They are divided into teams and tackle a task that they expect to easily accomplish. The expected results are hardly obtained. Then they try to seek the gap between the results and their knowledge. They analyze the phenomena and improve the approach. They evaluate the results of second trial and the effectiveness of the measures. That is, the project requires so-called PDCA cycles for students to solve engineering problems. The start-up engineering project is one of the compulsory subjects and seven departments have given the students several tasks based on their technicality. The students exchange their knowledge, ideas and learn how to use knowledge to solve the problems. Their reports and questionnaire survey proved that the projects are highly effective to improve his or her ability to solve engineering problems and give them strong motivation to learn engineering. We introduce the some tasks and the outcomes of the projects set by seven departments; mechanical and production engineering, electrical and electronic engineering, information engineering, biocybernetics, chemistry and chemical engineering, civil engineering and architecture, and material science and engineering.

Relationship between Magnetic Field Interference and Electromagnetic Drag in Multicoil Magnetic Sails

Shoko Arita,Yoshiki Yamagiwa 한국항공우주학회 2023 International Journal of Aeronautical and Space Sc Vol.24 No.5

In contrast to single-coil magnetic sails, multicoil magnetic sails do not require active attitude control and can retain a large drag force without increasing their power consumption by selecting the coil to be driven according to the attitude of the magnetic sail. However, determining the optimum position and direction of the magnetic axis from the infinite number of combinations is computationally intensive when using only a parametric study based on the magnetohydrodynamic analysis. The relationship between the magnetic field interference and drag is the basis for system studies of multicoil magnetic sails. Therefore, this paper clarifies the relationship between the magnetosphere shape induced by the arrangement of the coils and the drag force, and the relationship between the drag force and the region where the magnetic field is strengthened, using the three-dimensional magnetohydrodynamic analysis. Furthermore, this paper describes the application of the acquired knowledge to the design of multicoil magnetic sails.

Cytotoxicity and biocompatibility of high mol% yttria containing zirconia

Kazi Gulsan Ara Sathi,Yamagiwa Ryo 대한치과보존학회 2020 Restorative Dentistry & Endodontics Vol.45 No.4

Objectives: Yttria-stabilized tetragonal phase zirconia has been used as a dental restorative material for over a decade. While it is still the strongest and toughest ceramic, its translucency remains as a significant drawback. To overcome this, stabilizing the translucency zirconia to a significant cubic crystalline phase by increasing the yttria content to more than 8 mol% (8YTZP). However, the biocompatibility of a high amount of yttria is still an important topic that needs to be investigated. Materials and Methods: Commercially available 8YTZP plates were used. To enhance cell adhesion, proliferation, and differentiation, the surface of the 8YTZP is sequentially polished with a SiC-coated abrasive paper and surface coating with type I collagen. Fibroblast-like cells L929 used for cell adherence and cell proliferation analysis, and mouse bone marrow-derived mesenchymal stem cells (BMSC) used for cell differentiation analysis. Results: The results revealed that all samples, regardless of the surface treatment, are hydrophilic and showed a strong affinity for water. Even the cell culture results indicate that simple surface polishing and coating can affect cellular behavior by enhancing cell adhesion and proliferation. Both L929 cells and BMSC were nicely adhered to and proliferated in all conditions. Conclusions: The results demonstrate the biocompatibility of the cubic phase zirconia with 8 mol% yttria and suggest that yttria with a higher zirconia content are not toxic to the cells, support a strong adhesion of cells on their surfaces, and promote cell proliferation and differentiation. All these confirm its potential use in tissue engineering.

Safety and effectiveness of monthly intravenous ibandronate injections in a prospective, postmarketing, and observational study in Japanese patients with osteoporosis

Yasuhiro Takeuchi,Junko Hashimoto,Yosuke Nishida,Chiemi Yamagiwa,Takashi Tamura,Akihide Atsumi 대한골다공증학회 2018 Osteoporosis and Sarcopenia Vol.4 No.1

Objectives: This postmarketing, observational study evaluated the safety and effectiveness of monthly intravenous (IV) ibandronate in Japanese patients with osteoporosis. Methods: Eligible patients received monthly IV ibandronate 1mg for 12 months. Adverse drug reactions (ADRs) were evaluated. Changes in bone mineral density (BMD) and bone turnover markers (BTMs) were assessed using matched t-test analysis. Cumulative fracture rates were analyzed by Kaplan-Meier methodology. Results: In total, 1062 patients were enrolled, of whom 1025 (n= 887 women, n= 138 men) were treated. Mean patient age was 77 years. Seventy-five ADRs were reported in 54 patients (5.26%). Four patients (0.39%) experienced serious ADRs, including one case of osteonecrosis of the jaw. Acute-phase reactions occurred in 21 patients (2.04%), and half of them arose after the first ibandronate injection. No new safety concerns were identified. Significant increases in BMD at 12 months relative to baseline were observed at the lumbar spine (4.84%, n= 187; 95% confidence interval [CI], 3.47%-6.21%), femoral neck (2.73%, n= 166; 95% CI, 1.46%-4.01%), and total hip (1.93%, n= 133; 95% CI, 0.80%-3.07%). Significant reductions were observed in all BTMs at 12 months (n = 174 in tartrate-resistant acid phosphatase-5b, n = 101 in procollagen type 1 N-terminal propeptide at baseline). The cumulative incidence of nontraumatic,new vertebral and nonvertebral fractures was 3.16% (95% CI, 2.12%-4.70%). Analyses in women only showed similar results to the overall population. Conclusions: These findings confirm the favorable safety and consistent effectiveness of ibandronate, and indicate that monthly IV ibandronate would be beneficial in daily practice for the treatment of Japanese patients with osteoporosis.

Comparison of post-operative threedimensional and two-dimensional evaluation of component position for total knee arthroplasty

( Osamu Tanifuji ),( Tomoharu Mochizuki ),( Hiroshi Yamagiwa ),( Takashi Sato ),( Satoshi Watanabe ),( Hiroki Hijikata ),( Hiroyuki Kawashima ) 대한슬관절학회 2021 대한슬관절학회지 Vol.33 No.-

Purpose: The purpose of this study was to evaluate the post-operative three-dimensional (3D) femoral and tibial component positions in total knee arthroplasty (TKA) by the same co-ordinates’ system as for pre-operative planning and to compare it with a two-dimensional (2D) evaluation. Materials and methods: Sixty-five primary TKAs due to osteoarthritis were included. A computed tomography (CT) scan of the femur and tibia was obtained and pre-operative 3D planning was performed. Then, 3D and 2D postoperative evaluations of the component positions were performed. KneeCAS (LEXI, Inc., Tokyo, Japan), a lowerextremity alignment assessment system, was used for the 3D post-operative evaluation. Standard short-knee radiographs were used for the 2D post-operative evaluation. Differences between the pre-operative planning and post-operative coronal and sagittal alignment of components were investigated and compared with the results of the 3D and 2D evaluations. Results: According to the 3D evaluation, the difference between the pre-operative planning and actual postoperative sagittal alignment of the femoral component and the coronal and sagittal alignments of the tibial component were 2.6° ± 1.8°, 2.2° ± 1.8° and 3.2° ± 2.4°, respectively. Using the 2D evaluation, they were 1.9° ± 1.5°, 1.3° ± 1.2° and 1.8° ± 1.4°, making the difference in 3D evaluation significantly higher (p = 0.013, = 0.003 and < 0.001). For the sagittal alignment of the femoral component and the coronal and sagittal alignment of the tibial component, the outlier ( > ± 3°) ratio for the 3D evaluation was also significantly higher than that of the 2D evaluation (p < 0.001, = 0.009 and < 0.001). Conclusions: The difference between the pre-operative planning and post-operative component alignment in the 3D evaluation is significantly higher than that of the 2D, even if the same cases have been evaluated. Twodimensional evaluation may mask or underestimate the post-operative implant malposition. Three-dimensional evaluation using the same co-ordinates’ system as for pre-operative planning is necessary to accurately evaluate the post-operative component position.

Effectiveness of monthly intravenous ibandronate injections in a realworld setting: Subgroup analysis of a postmarketing observational study

Yasuhiro Takeuchi,Junko Hashimoto,Hiroyuki Kakihata,Yousuke Nishida,Michiko Kumagai,Chiemi Yamagiwa 대한골다공증학회 2019 Osteoporosis and Sarcopenia Vol.5 No.1

Objectives: The favorable safety and consistent effectiveness of monthly intravenous (IV) ibandronate injections was demonstrated in a prospective, postmarketing, observational study in Japanese patients with osteoporosis. Here, we present subgroup analyses from the study. Methods: Lumbar spine (L2e4) bone mineral density (BMD) gains were assessed in the following subgroups: aged <75 or 75 years, absence or presence of vertebral fractures, previous bisphosphonate (BP) treatment, and concomitant versus naïve osteoporosis drug treatment. The cumulative incidence of fractures and relative change in bone turnover markers were also examined. Results: Of 1062 enrolled patients, 1025 received monthly IV ibandronate 1mg and were assessed for 12 months. BMD gains with ibandronate were comparable, irrespective of older age or prevalent fractures. Overall, 515 patients (50.2%) had previously received osteoporosis treatment; of these, 166 (16.1%) received other BPs. Mean BMD changes were 3.69% (95% confidence interval [CI], 0.89%e6.50%) in patients previously treated with other BPs, and 4.26% (95% CI, 2.88%e5.64%) in patients who had not received prior osteoporosis treatment. Among the 510 patients (49.7%) concomitantly prescribed active vitamin D drugs, mean BMD changes were 5.74% (95% CI, 2.53%e8.95%) with eldecalcitol versus 3.54% (95% CI, 1.98%e5.10%) with ibandronate alone. The lowest fracture incidence was observed with the combination of ibandronate and eldecalcitol, but differences between the subgroups were not statistically significant. Conclusions: Monthly IV ibandronate demonstrated comparable BMD gains in the patient subgroups analyzed. Concomitant use of ibandronate with eldecalcitol showed a trend of higher BMD gains and lower fracture incidence than ibandronate alone.