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Model predictive control of a floating offshore wind turbine-generator system, in which wave height as well as inflow wind speed is regarded as the previewed disturbances, is developed to stabilize power output and platform motion and reduce dynamic loads at mechanical and supporting components at high wind speeds. First, the internal model to predict dynamic control behaviors to previewed disturbances is identified from an aero-elastic-hydro-control coupled simulation result, in which pseudorandom binary sequence signals are added to the manipulated variables calculated in a gain-scheduling feedback controller of the generator speed to satisfy a persistently exciting condition. Second, an aero-elastic-hydro-control coupled simulation using the developed model predictive control is performed for a 5-MW floating offshore wind turbine-generator system. The identified internal model has a high prediction accuracy of the system outputs by regarding the spatial mean wind speed in the swept area of the wind turbine as a rotor effective wind speed. The simulation results under turbulent wind fields and irregular wave height variations reveal that the stabilization of the power output and platform motion and the dynamic load reduction are achieved by employing the developed model predictive control with a perfect preview of the wind speed and wave height.

Background Primary osteosarcoma in elderly patients are rare malignant tumors. Its optimal treatment has not yet been determined. Methods This retrospective study included 104 patients aged >50 years with resectable, non-metastatic osteosarcoma treated by the members of the Bone and Soft Tissue Tumor Study Group of the Japan Clinical Oncology Group. The effects of adjuvant chemotherapy were estimated by comparing outcomes in patients who received surgery plus chemotherapy with those who underwent surgery alone. Results Median age at presentation was 59 years. Neoadjuvant and adjuvant chemotherapy was administered to 83 (79.8%) patients. Patients who underwent surgery plus chemotherapy and those who underwent surgery alone had 5-year overall survival (OS) rates of 68.6% and 71.7%, respectively (p = 0.780), and 5-year relapse free survival (RFS) rates of 48.2% and 43.6%, respectively (p = 0.64). Univariate analysis showed that resection with wide margins was significantly correlated with better prognosis. Conclusions The addition of chemotherapy to surgery did not improve OS or RFS in patients aged >50 years with resectable, non-metastatic osteosarcoma. Surgery with wide margins was only significantly prognostic of improved survival. The effect of chemotherapy in elderly osteosarcoma patients was unclear.

Background We report a case of an intraabdominal desmoid tumor that occurred at a gastro-pancreatic lesion with spontaneous cystic features, and present the successful laparoscopic resection of the tumor. Case presentation A 20-mm retroperitoneal cystic mass with a solid component was found adjacent to the stomach and pancreatic body in a 52-year-old woman with no history of familial adenomatous polyposis. Laparoscopic spleen-preserving distal pancreatectomy with wedge resection of the stomach was performed, and complete resection was achieved without intraoperative and postoperative complications. Histopathological examination by immunohistochemistry enabled diagnosis of a desmoid tumor that had originated from the stomach and invaded the pancreatic parenchyma with a spontaneous cystic change. We herein report an extremely rare case of an intraabdominal desmoid tumor with a spontaneous cystic change. Conclusion Regardless of its rarity, desmoid tumor should be included in the preoperative differential diagnosis of a cystic intraabdominal mass, and laparoscopic function-preserving surgery may be an optimal treatment option.

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, and reports in the literature are scarce. This study aims to investigate the characteristics of periosteal chondrosarcoma, focusing particularly on medullary invasion. Among 33 periosteal cartilaginous tumours, seven patients with pathologically proven periosteal chondrosarcoma were identified retrospectively. The average tumour size was 5.4 cm in the long axis; two tumours were smaller than 3.0 cm. Six tumours were resected with a wide margin, and the remaining tumour had a marginal margin. Histology revealed that six tumours (85.7%) had invaded the medullary cavity; three of these did not show invasion into the medullary cavity on MRI evaluation. Neither local recurrence nor metastasis was observed among these patients. The frequency of invasion of the medullary cavity was higher than that reported previously. The recommended treatment for periosteal chondrosarcoma is resection with an adequate margin. Therefore, surgeons should consider the possibility of medullary invasion when attempting to achieve a histologically negative margin, even if the tumour does not show invasion into the medullary cavity on MRI.

application/pdf, article, Energy. 2019, 184, p.45-57

application/pdf, article, Energy. 2019, 181, p.782-792

Predictive management for energy supply networks using photovoltaics generation (PV) units, heat pump water-heating units (HPUs), and battery units is developed by uniquely combining two-stage stochastic schedule programming and rule-based control to enhance their operating performances, including operating cost reduction under low selling prices of the surplus PV output after a feed-in tariff system and uncertain input conditions. The forecast scenarios of input conditions are generated from the probability distributions at each sampling time. The schedule planning problem is formulated using two-stage stochastic mixed-integer linear programming and solved by inputting the forecast scenarios and the initial operation states of network components. In the operation control, the energy flow rates are modulated according to the actual input conditions under the obtained operation schedule. The forecast scenario generation and stochastic schedule planning are updated using a receding horizon approach. The developed management is applied to an annual operating simulation of a residential energy supply network for a housing complex, consisting of a shared PV unit, four sets of an HPU and thermal storage tank, and shared battery unit. The simulation results reveal that the decrease in the annual operating cost reduction by the developed management from the ideal management based on the previously-known PV output is just 1.57% point. Moreover, at the selling price of the surplus PV output higher than 6 yen/kWh, the developed management has an advantage in the annual operating cost over the charging- and exporting-priority managements.

A two-stage optimization approach based on an artificial immune system (AIS) and mixed-integer linear programming (MILP) was developed to efficiently solve large-scale structural design problems of energy supply networks and obtain multiple and diverse design candidates. By focusing on a hierarchical relationship between design and operation variables, a structural design problem, formulated using MILP, is decomposed into an upper-level design problem and a lower-level operation problem. The upper-level design problem is solved using an AIS, in which multiple and diverse sets of suboptimal solutions are searched in a short computation time. In the lower-level optimization, design variables are fixed at the values searched in the upper-level optimization and operation variables are optimized using MILP. Moreover, the lower-level optimization for multiple sets of design variables is separately conducted using parallel computing. The developed approach was applied to the structural design of an energy supply network, consisting of candidates of cogeneration units and heat pump water heating units under power and heat interchange, for a housing complex with four dwellings. The diversity and energy-saving performance of multiple design candidates were analyzed. The computational efficiency was also demonstrated in comparison to the results obtained using only a commercial MILP solver.

To efficiently solve long-term operational planning problems of energy storage and supply systems, a near-optimal solution method based on the shrinking and receding horizon approaches was developed. A lower bound of the original problem is first calculated by solving a simplified problem, in which the number of binary variables is reduced and the related constraints are simplified. Then, a short-term operational planning problem, with a shrunken planning horizon length, is solved by providing the simplified problem results as the terminal condition for stored energy. Within this problem, the original binary variables and constraints are considered. The short-term operational planning is updated using a receding horizon approach, in which the initial and terminal conditions are provided by the previous short-term operational planning results and simplified problem results, respectively. The solution, obtained by connecting the solutions in all the updating horizons, is regarded as a near-optimal solution of the original problem. The developed method was applied to solve a long-term operational planning problem for an energy storage and supply system, which includes a photovoltaic unit and a metal hydride tank with a water electrolyzer. The results showed that the developed method could find a better solution in a shorter computation time than the conventional methods.

A predictive management system for cogeneration unit-based energy supply networks using two-stage multi-objective optimization was developed to tackle a trade-off between energy savings and operating cost reduction. The developed system integrated support vector regression-based energy demand prediction, MILP (mixed-integer linear programming)-based schedule planning, and rule-based operation control. The contribution is to develop two-stage MILP-based multi-objective schedule planning, which is extension of an e-constraint method, and operation control rule of multiple cogeneration units. In the first-stage schedule planning, primary energy consumption in the prediction horizon is minimized, and a reduction rate of primary energy consumption is calculated. In the second-stage schedule planning, an operating cost is minimized additionally subject to satisfaction of partial achievement of the reduction rate of primary energy consumption calculated in the first stage. An energy-saving achievement rate is regarded as a decision-making parameter to control a trade-off between energy savings and cost reduction, of which definition is quantitatively apprehensible for decision makers. Annual operating simulation of an energy supply network using four fuel-cell-based cogeneration units revealed that the developed predictive management system has high controllability to the trade-off between the energy-saving rates (18.9%–21.6%) and the operating cost reduction rate (19.0%–15.6%), caused by a time-of-use power tariff structure.

Background Soft tissue sarcomas (STS) are rare malignant tumors. The efficacy of preoperative chemotherapy for STS is evaluated using various tumor size-based radiological response criteria. However, it is still unclear which set of criteria would show the best association with pathological response and survival of the patients with STS. Methods We compared radiological responses to preoperative chemotherapy for operable STS by the Response Evaluation Criteria in Solid Tumors (RECIST), modified RECIST, World Health Organization criteria, Japanese Orthopaedic Association criteria, and modified Choi criteria and analyzed the association with pathological response and survival using the data from the Japan Clinical Oncology Group (JCOG) study JCOG0304, a phase II clinical trial evaluating the efficacy of perioperative chemotherapy for STS in the extremities. Results Seventy eligible patients in JCOG0304 were analyzed. The results demonstrated that none of the size-based radiological response criteria showed significant association with pathological response to preoperative chemotherapy for STS. The difference between overall survival of the patients assessed as partial response and stable disease/progressive disease by RECIST was not significant (hazard ratio 1.37, p = 0.63), and calculated C-index was 0.50. All other response criteria also could not exhibit significant association between radiological responses and survival. Conclusion In the present study, none of the radiological response criteria analyzed demonstrated association of response to preoperative chemotherapy with pathological response or survival of the patients with operable STS. Further prospective investigation is required to develop criteria to evaluate not only tumor shrinkage but biological effects of preoperative chemotherapy for the patients with localized STS. Trial registration UMIN Clinical Trials Registry C000000096. Registered 30 August, 2005 (retrospectively registered).

application/pdf, Article, Energy. 153, p.159-169

An energy management system (EMS) that achieves optimal operation by combining heat sources with different characteristics and using energy interchanges between residential dwellings was developed. Commercial fuel cell combined heat and power (FC-CHP) systems and CO2 heat pump water heaters (CO2HP) with high generation efficiencies have penetrated the Japanese residential market. In this real environment, the types or models of the installed heat sources vary between residential dwellings, and their energy demand is unknown. The EMS predicts energy generation and consumption and develops an optimum operational strategy that it uses to control energy equipment. It also continually revises the strategy and adjusts equipment controls to reflect actual conditions. The EMS is evaluated using a case study of a group of four residential dwellings with two different heat sources. Subsequent quantitative analysis shows that the EMS reduced energy costs by 10%. A sensitivity analysis also confirmed that it operates optimally even when energy prices are changed.

Giant cell tumors of bone (GCTBs) are characterized by mononuclear stromal cells and osteoclast-like giant cells; up to 95% have H3F3A gene mutation. The RANKL inhibitor denosumab, when used for the treatment of GCTB, leads to histological changes such as new bone formation and giant cell depletion. Here we assessed the diagnostic utility of immunohistochemical staining with the antibodies against histone H3.3 G34W, G34R and G34V mutant proteins for GCTB and other histologically similar bone and joint lesions. H3.3 G34W, G34R and G34V expressions were detected in mononuclear stromal cells in 47/51 (92%), 1/51 (2%) and 3/51 (6%) cases of primary GCTBs, respectively, in a mutually exclusive manner. All recurrent/metastatic GCTBs (n=14), post-denosumab GCTBs (n=8) and secondary malignant GCTBs (n=2) were positive for H3.3 G34W. The immunohistochemical results were essentially correlated with the H3F3A genotype determined by mutation analysis. In post-denosumab GCTBs, H3.3 G34W expression was seen in immature bone-forming cells. H3.3 G34W, G34R and G34V were negative in 121/122 cases of non-GCTB, including chondroblastoma, osteosarcoma, primary aneurysmal bone cyst and other giant cell-rich lesions. The exception was a single case of undifferentiated high-grade pleomorphic sarcoma that was positive for H3.3 G34W, suggesting the possibility of sarcomatous overgrowth of primary malignant GCTB. Therefore, H3.3 G34W/R/V mutant-specific antibodies are useful surrogate markers for the H3F3A genotype and helpful for the diagnosis of GCTB and its variants. The expression of H3.3 G34W mutant protein in post-denosumab GCTB suggests that neoplastic stromal cells may play a role in new bone formation.

An approach for multiple-feedback control of generator power and nacelle fore-aft speed employing blade pitch and generator torque manipulations was developed for a spar-type floating offshore wind turbine-generator system. The development of this approach was carried out through numerical analysis using the aeroelastic simulation model (FAST), measured high wind speed data, and simulated irregular sea waves. The novelty of this multiple-feedback control approach is the increase of the generator torque in response to the platform pitching motion to the leeward side and the control of the generator power instead of the rotational speed. First, theoretical analysis of the open loop transfer function revealed that the multiple-feedback control approach improves the stability of the generator power control in the floating offshore wind turbine-generator system. Then, the optimal parameter settings of the multiple-feedback control were determined and the effectiveness of employing a first-order lag filter for the nacelle fore-aft speed was shown through a sensitivity analysis. A comparison of system performances demonstrated that the multiple-feedback control approach reduces the power output fluctuation, the platform pitching motion, and the damage equivalent fatigue load of the fore-aft bending moment at the tower-base part by 52%, 22%, and 16%, respectively, relative to the gain-scheduled feedback control of the rotational speed.

application/pdf, Energy. 2021, 229, P.120343(1-12)

application/pdf, Energy. 2021, 228, P.120505 (1-13)

A near-optimal solution method of a large-scale design problem of a distributed energy network, consisting of multiple energy-supply systems under power and heat interchanges, is developed by hierarchically combining variable- and constraint-based decompositions. The design problem is formulated using mixed-integer linear programming, and its scale increases with the number of connected energy-supply systems and daily patterns of energy demand. By focusing on the hierarchical relationship between design and operation variables, the original problem is decomposed into an upper-level design problem and lower-level coordinated operation problems based on the Benders decomposition. By focusing on power- and heat-interchange constraints, the coordinated operation problem is further decomposed into a master problem concerning power and heat interchanges and subproblems for energy supply in each energy-supply system based on the Dantzig-Wolfe decomposition. A near-optimal solution is calculated through a two-level iterative calculation, consisting of delayed constraint generation between the design problem and the coordinated operation problems and delayed column generation between the master problem and the subproblems in each coordinated operation problem. The near-optimal solution method is applied to the structural design problem of distributed energy networks incorporating 5–100 cogeneration systems, in which suboptimal solutions cannot be found in the conventional solution method.

application/pdf, Article, Energy. 137, p.888-897

application/pdf, Article, Energy. 137, p.878-887

An optimal operations management system of residential energy supply networks employing power and heat interchanges among cogeneration units and storage tanks was developed. This system integrated energy demand prediction, operation scheduling to predicted energy demand using mixed-integer linear programming, and real-time control for the cogeneration units and the heat interchange hierarchically. The energy demand prediction and operation scheduling were updated using a receding horizon approach. The novelty of the study is characterized by developing an operations management framework for heat interchange among storage tanks and by proposing an event-driven receding horizon approach. The developed operations management system was applied to annual operating simulation of a residential energy supply network, consisting of four fuel cell-based cogeneration units and four storage tanks. The results showed that employing the power and heat interchanges increases a reduction rate of annual primary energy consumption by 3.24 and 5.63 percentage points relative to the power interchange operation and separate operation of the cogeneration units, respectively. Moreover, the event-driven receding horizon approach based on heat interchange schedule maintained an energy-saving performance subequal to the conventional receding horizon approach and reduced the daily receding number by 46.7% of the conventional receding horizon approach.

An operation management system for residential energy-supplying networks using multiple cogeneration units was developed by hierarchically integrating energy demand prediction, operational planning, and operational control, using optimization approaches. The energy demand for multiple dwellings was predicted by support vector regression with information on occupant behavior as well as forecasted weather and energy demand history. Mixed-integer linear programming was employed for the operational planning of the cogeneration units to the predicted energy demand. The energy demand prediction and operational planning were updated using a variable frequency receding horizon approach. This was done to limit the unnecessary shutdown and start-up of the cogeneration units and to reduce the influences of prediction errors for energy demand. Regarding the operational control, the actual on–off schedule of the cogeneration units conformed to the operational planning result. Additionally, the power and heat outputs of the cogeneration units and the heat supply from the storage tanks were modulated in response to the actual energy demand, based on predefined rules. The developed operation management system was applied to annual operation simulation of a residential energy-supplying network consisting of four cogeneration units using fuel cells in a housing complex. For comparative analysis, history-based approaches for energy demand prediction and separate operation of each cogeneration unit were also considered. The results revealed the effectiveness of the developed operation management system as well as the high energy-saving performance of the residential energy-supplying network.

BACKGROUND The survival rate in patients with Ewing sarcoma family of tumors (ESFT) in Japan was reported to be

Residential fuel cell based combined heat and power (FC-CHP) systems have been commercialized and are penetrating the marketed in Japan. In order to utilize FC-CHP systems efficiently, operational strategies are required. Energy interchange among consumers improves efficiency by allowing flexible operation of equipment. An energy management system (EMS), which is installed at the consumer dwelling, can integrate the control and management of energy equipment by using an optimized planning approach that incorporates the energy interchange and can operates equipment whilst adjusting to real conditions. An EMS has been developed, which achieves optimal operation of FC-CHP systems with energy interchange between dwellings in a residential area. Case studies were performed to evaluate the EMS model by using evaluation indices including energy costs, CO2 emissions, and primary energy consumption. The results showed that 1) energy management and energy interchange were effective and contributed to cost reductions, CO2 mitigation, and reduction of primary energy consumption and 2) the developed EMS model achieved optimal operations.

An energy management system (EMS) that controls energy equipment in residential dwellings contributes to energy conservation and cost reduction. A hot energy demand prediction method is necessary for the EMS to provide the best possible performance. A prediction method using a bottom-up approach based on end-use analysis with detailed energy consumption measurement was developed. One of the advantages of the proposed prediction method is that it provides good accuracy without needing large computational resources. Since the method is based on end-use analysis, the EMS can revise the prediction and controls when necessary. The performance of the developed prediction method was evaluated by comparing it with results produced by support vector regression. An operational simulation was performed to evaluate performance in a more practical environment. The simulation indicated that the proposed method showed the best performance.

Novel parameter settings for gain-scheduled feedback control of rotational speed using collective blade pitch manipulation in a spar-buoy floating offshore wind turbine–generator system were developed in order to reduce both power-output fluctuation and platform motion. The development was conducted through numerical simulation using the aeroelastic simulation model (FAST), measured high wind speed data, and simulated irregular sea waves. In this gain-scheduled feedback control of rotational speed, a proportional-plus-integral action was employed, and the proportional gain was varied to the blade pitch angle. First, the sensitivity analysis of the control parameter settings, that is, the proportional gain, integral time, and the generator torque manipulation strategy, to the system performances was carried out. Then, a new guideline of parameter settings for the gain-scheduled feedback control was theoretically revealed by investigating the damped oscillation characteristics of the feedback control loop. Novel parameter settings yielded a natural frequency of the feedback control loop higher than that of the platform pitching motion and a damping coefficient larger than 1.0. Under these parameter settings, the platform pitching motion was similar to that under settings previously developed for this floating offshore system, while the power-output fluctuation was drastically reduced. High power–generation performance and a significant reduction in the damage equivalent fatigue loads at the main parts of the system were also obtained.

An optimal structural design model of residential power and heat supply devices (R-PHDs), including cogeneration and heat pump units, was developed by considering their operational and capital recovery constraints. The structure of R-PHDs with peripheral devices, sizes of energy storage devices, and their multi-period operation were determined so as to minimize annual primary energy consumption. In addition to various operational constraints for a cogeneration unit and a battery unit, an operable-hours constraint and daily selection of outlet water temperature were newly formulated for heat pump units. The capital recovery by reducing energy cost was also considered in order to select R-PHDs that have high energy-saving effects but are presently expensive. The developed model took the form of a mixed-integer linear programming problem. The model was applied to the structural design of R-PHDs, whose candidates are three types of cogeneration units (gas engine, polymer electrolyte fuel cell, and solid oxide fuel cell), heat pump unit, storage tank, battery unit, and peripheral devices. The result revealed a trade-off between energy savings and initial cost in the optimal structures. A sensitivity analysis of the initial costs of expensive devices was also carried out to clarify their initial cost targets.

A near-optimal solution method for coordinated operation-planning problems of power- and heat-interchange networks using column generation-based decomposition was developed to enhance computational efficiency and scalability. The coordinated operation-planning problem, based on a mixed-integer linear programming (MILP) approach, was decomposed into a master problem concerning power and heat interchanges and subproblems for energy-supply systems on the basis of the Dantzig-Wolfe reformulation. To determine a near-optimal solution, heuristic finalization was developed, in which a final MILP problem is solved after fixing part of binary variables based on the lower bound result obtained through two-stage iterative column generation. The developed method was then applied to the coordinated operation planning of power- and heat-interchange networks consisting of 5–100 cogeneration systems using a 150-kWe gas engine and a 45-kWe polymer electrolyte fuel cell on a winter representative day. In the case of using 100 cogeneration systems, 93% of the binary variables expressing the on/off status of the cogeneration units and heat-interchange pumps were fixed in the heuristic finalization. The near-optimal solution, which has a lower daily energy cost than in the conventional solution method, can be obtained without optimization termination due to limits of computation time and memory usage.

Low-grade central osteosarcoma (LG-COS) is an uncommon variant of osteosarcoma (OS) that sometimes progresses to high-grade OS post-recurrence. We herein present a case of dedifferentiated LG-COS with extensive cystic change arising in the right iliac bone of a 26-year-old man. The LG-COS was initially diagnosed and managed as a simple bone cyst. The lesion recurred thrice, and high-grade OS was diagnosed during the third recurrence. The first lesion appeared as a typical benign cystic mass on radiography. However, a huge malignant osteoblastic mass subsequently developed in the right pelvis at the third recurrence. Extended hemipelvectomy with ipsilateral hemisacral resection was performed. Histologic analysis showed tumor necrosis and irregular neoplastic tumor osteoid, while immunohistochemistry revealed that the tumor was diffusely positive for MDM2 and CDK4. The histologic diagnosis was high-grade OS dedifferentiated from a preceding cystic lesion. Our final diagnosis of the primary lesion was LG-COS with extensive cystic change.