Explanipedia

Usefulness of exercise stress echocardiography in a patient with unilateral pulmonary branch stenosis Open

Ryohei Yokoyama, Yoshihiko Kodama, Kazunari Takamura, Masako Takahashi, Miyo Tanaka , et al. · 2025

An effective approach for deriving and evaluating approximate optimal design solutions of energy supply systems by time series aggregation Open

Ryohei Yokoyama, Yuji Shinano, Tetsuya WAKUI · 2023

It is important to design multi-energy supply systems optimally in consideration of their operations for variations in energy demands. An approach for efficiently solving such an optimal design problem with a large number of periods for va…

Acute Esophageal Necrosis Secondary to Cyanotic Spells Associated with Unrepaired Tetralogy of Fallot Open

Toshinobu Ifuku, Yutaro Ishikawa, Naoto Yamashita, Ryohei Yokoyama, Takumi Yamaji , et al. · 2023

Tetralogy of Fallot (ToF) is the most common cyanotic congenital heart disease. Cyanotic spells occur more frequently after infancy in unrepaired cases. Acute esophageal necrosis (AEN) is a rare disease that causes circumferential mucosal …

Congenital portosystemic venous shunt associated with 22q11.2 deletion syndrome: a case report Open

Toshinobu Ifuku, Sayo Suzuki, Yusaku Nagatomo, Ryohei Yokoyama, Y Yamamura , et al. · 2022

Clinical, Radiological, and Histopathological Characteristics of Periosteal Chondrosarcoma with a Focus on the Frequency of Medullary Invasion Open

Makoto Nakagawa, Makoto Endo, Yosuke Susuki, Nobuhiko Yokoyama, Akira Maekawa , et al. · 2022

Periosteal chondrosarcoma is an extremely rare malignant cartilage-forming tumour that originates from the periosteum and occurs on the surface of bone. Often, it is difficult to distinguish periosteal chondrosarcoma from other tumours, an…

Reduction in platform motion and dynamic loads of a floating offshore wind turbine-generator system by feedforward control using wind speed preview Open

Tetsuya WAKUI, Kouki Tanaka, Ryohei Yokoyama · 2022

To reduce both the platform motion and dynamic loads of floating offshore wind turbine-generator systems, feedforward control for high wind speed regions is developed by combining with the wind speed previewed by a nacelle-mounted lidar. F…

Feedforward control of a floating offshore wind turbine-generator system based on wind speed preview using a nacelle-mounted lidar Open

Tetsuya WAKUI, Kouki Tanaka, Ryohei Yokoyama · 2022

To reduce both the platform motion and dynamic loads of floating offshore wind turbine-generator systems, feedforward control for high wind speed regions is developed by combining with the wind speed previewed by a nacelle-mounted lidar. F…

Operations Management of Power Interchange Networks Using Stochastic Programming Open

Tetsuya WAKUI, Taiki IDA, Ryohei Yokoyama · 2021

The power interchange among multiple consumers can reduce the operation cost because the generated power can be utilized effectively. Involving photovoltaic generation and electric vehicles with a large-capacity battery in the power interc…

Long-term Operational Planning of Energy Storage and Supply Systems Based on Time-Domain Decomposition Open

Tetsuya WAKUI, Zhang BOYUN, Ryohei Yokoyama · 2021

A near-optimal solution method for operational planning problems of energy storage and supply systems is developed by using a time-domain decomposition technique. The MILP-based operational planning problem is first decomposed into the mas…

Optimization of operating condition of vapor-compression type air-conditioning systems based on genetic algorithm and cycle simulation Open

Tetsuya WAKUI, Hiroaki OKAMURA, Ryohei Yokoyama · 2021

To actively control the operation of vapor-compression type air-conditioning systems for energy-saving, a hierarchical optimization framework of their operating condition was developed. The optimization problem to find the operating condit…

Reduction in Platform Motion and Dynamic Loads of a Floating Offshore Wind Turbine-Generator System by Feedforward Control Using Previewed Wind Speed Open

Tetsuya WAKUI, Kouki Tanaka, Ryohei Yokoyama · 2021

In floating offshore wind turbine-generator systems, wind and wave variations cause platform pitching motion and increase fatigue loads. A feedforward control based on the preview of the inflow wind speed to the wind turbine is combined wi…

Reduction in platform motion and dynamic loads of a floating offshore wind turbine-generator system by feedforward control using previewed wind speed Open

Tetsuya WAKUI, Kouki Tanaka, Ryohei Yokoyama · 2021

In floating offshore wind turbine-generator systems, wind and wave variations cause platform motion and increase fatigue loads. A feedforward control based on the preview of the inflow wind speed to the wind turbine is combined with gain-s…

Long-term operational planning of energy storage and supply systems based on time-domain decomposition Open

Tetsuya WAKUI, Boyun Zhang, Ryohei Yokoyama · 2021

A near-optimal solution method for long-term operational planning problems of energy storage and supply systems is developed by using a time-domain decomposition technique. The MILP-based operational planning problem is first decomposed in…

Laparoscopic spleen-preserving distal pancreatectomy for a solid-cystic intraabdominal desmoid tumor at a gastro-pancreatic lesion: a case report Open

K Sugimachi, Tomohiro Iguchi, Mitsuhiko Ohta, Yohei Mano, Terumasa Hisano , et al. · 2020

Model Predictive Control of Floating Offshore Wind Turbine-Generator Systems Based on Preview of Wind Speed and Wave Height Open

Tetsuya WAKUI, Atsushi Nagamura, Ryohei Yokoyama · 2020

The impact of wind condition and sea state on performances of the model predictive control previewing wave height as well as inflow wind speed for a floating offshore wind turbine-generator system is analyzed using an aero-elastic-hydro-co…

Ten-year follow-up results of perioperative chemotherapy with doxorubicin and ifosfamide for high-grade soft-tissue sarcoma of the extremities: Japan Clinical Oncology Group study JCOG0304 Open

Kazuhiro Tanaka, Junki Mizusawa, Norifumi Naka, Akira Kawai, Hirohisa Katagiri , et al. · 2019

This trial was registered at the UMIN Clinical Trials Registry as C000000096 on August 30, 2005.

Impact Analysis of Design Conditions on Annual Operating Performances of Large-Scale Vertical Axis-type Wind Turbine-Generator Systems Open

Tetsuya WAKUI, Shota SANO, Ryohei Yokoyama · 2019

A specification decision and performance evaluation framework for large-scale vertical axis wind turbine-generator systems was developed for the design of floating offshore vertical axis wind turbine-generator systems. In this framework, t…

Dynamic Characteristic Identification of a Floating Offshore Wind Turbine-Generator System Based on Closed-loop Behavior Open

Tetsuya WAKUI, Atsushi Nagamura, Ryohei Yokoyama · 2019

A dynamic model of a floating offshore wind turbine-generator system was identified for model predictive control utilizing wind speed and wave height previews. To identify a dynamic model, control inputs and disturbances in learning data m…

Performance Analysis of Vapor-Compression Type Air-Conditioning Systems Using Zeotropic Refrigerant Mixture Open

Tetsuya WAKUI, Hiroaki OKAMURA, Ryohei Yokoyama · 2019

Refrigerants for vapor-compression type air conditioning system have been shifted from hydrofluorocarbon ones to alternative ones with low global warming impacts. Hydrofluoroolefin refrigerants, which contribute to a low global warming pot…

Numerical Analysis for Performance Evaluation of a Multi-Functional CO2 Heat Pump Water Heating System Open

Ryohei Yokoyama, Masashi Ohkura, Takuya Nakamata, Tetsuya WAKUI · 2018

In recent years, CO2 heat pump water heating systems have been developed, and their performances have been enhanced while their functions have been expanded. In a multi-functional system, used for both hot water supply and bath heating, ho…

Prospective comparison of various radiological response criteria and pathological response to preoperative chemotherapy and survival in operable high-grade soft tissue sarcomas in the Japan Clinical Oncology Group study JCOG0304 Open

Kazuhiro Tanaka, Gakuto Ogawa, Junki Mizusawa, Norifumi Naka, Akira Kawai , et al. · 2018

Reduction in Power Output Fluctuations and Platform Motions in a Floating Offshore Wind Turbine-Generator System by Model Predictive Control Open

Tetsuya WAKUI, Daisuke MIYANAGA, Ryohei Yokoyama · 2018

A gain-scheduling approach for model predictive control of a floating offshore wind turbine-generator system is developed to improve the reduction effect of both the power output fluctuation and the platform pitching motion. In our previou…

Operations Management of Energy Supply Networks Based on Two-stage Stochastic Programming Open

Tetsuya WAKUI, Kento Sawada, Ryohei Yokoyama, Hirohisa Aki · 2018

An operations management framework for energy supply networks is developed to improve their operation performances under uncertain input conditions. The developed management hierarchically integrates forecast scenario generation of input c…

Correction: Corrigendum: Dynamics of plant DNA replication based on PCNA visualization Open

Ryohei Yokoyama, Takeshi Hirakawa, Seri Hayashi, Takuya Sakamoto, Sachihiro Matsunaga · 2017

Optimal Structural Design of Energy Supply Networks Using Multiple Power and Heat Supply Devices Open

Tetsuya WAKUI, Yuanyuan Wang, Kento Sawada, Ryohei Yokoyama · 2017

An optimal structural design approach, using hierarchical combination of artificial immune system (AIS) and mixed-integer linear programming (MILP), is developed for energy supply networks using multiple power and heat supply devices. In t…

Performance Simulation of Heat Exchangers Considering Phase Region Changes Open

Tetsuya WAKUI, Hiroaki OKIYAMA, Ryohei Yokoyama · 2017

A numerical simulation model of a plate-fin and tube type heat exchanger, which can switch a three phase state model with superheat, saturation, and subcool states and a two phase model with superheat and saturation states in accordance wi…

Aero-Elastic-Control Coupled Analysis of a Vertical Axis Wind Turbine-Generator System Open

Tetsuya WAKUI, Masanori YONESUGI, Ryohei Yokoyama · 2017

An aero-elastic-control coupled simulation model of on-shore large-scale vertical axis wind turbine-generator systems was developed as the first phase of the development of floating offshore vertical axis wind turbine-generator systems. Th…

Operations Management of Energy Supply Networks Based on Optimization Approaches Open

Tetsuya WAKUI, Kento Sawada, Ryohei Yokoyama, Hirohisa Aki · 2017

An operations management system of energy supply networks, consisting of multiple energy supply devices and a shared battery unit, was developed. This system integrates energy demand prediction by support vector regression, optimal operati…

Impact Analysis of Design Parameters on Performances of Vertical Axis Wind Turbine-Generator System Open

Tetsuya WAKUI, Takuya Nishioka, Masanori YONESUGI, Ryohei Yokoyama · 2017

A specification design and performance evaluation framework for large-scale vertical axis wind turbine-generator systems was developed for the design of floating offshore vertical axis wind turbine-generator systems. In this framework, the…

Reduction in Power Output Fluctuations and Platform Motions in a Floating Offshore Wind Turbine-Generator System by Model Predictive Control Open

Tetsuya WAKUI, Daisuke MIYANAGA, Ryohei Yokoyama · 2017

Sensitivity of weight coefficients of the cost function in a model predictive control approach for a floating offshore wind turbine-generator system was analyzed through an aero-elastic-hydro-control coupled simulation in order to clarify …

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