Nonlinear Hierarchical MPC for Maximizing Aircraft Thermal Endurance

2020 ◽  
Author(s):  
Daniel D. Leister ◽  
Justin P. Koeln
Keyword(s):  
High Performance ◽  
Linear Models ◽  
Critical Role ◽  
Effective Control ◽  
Thermal Management System ◽  
Short And Long Term ◽  
Upper Level ◽  
Control Of Linear Systems ◽  
High Computational Efficiency

Abstract In modern high-performance aircraft, the Fuel Thermal Management System (FTMS) plays a critical role in the overall thermal energy management of the aircraft. Actuator and state constraints in the FTMS limit the thermal endurance and capabilities of the aircraft. Thus, an effective control strategy must plan and execute optimized transient fuel mass and temperature trajectories subject to these constraints over the entire course of operation. For the control of linear systems, hierarchical Model Predictive Control (MPC) has shown to be an effective approach to coordinating both short- and long-term system operation with reduced computational complexity. However, for controlling nonlinear systems, common approaches to system linearization may no longer be effective due to the long prediction horizons of upper-level controllers. This paper explores the limitations of using linear models for hierarchical MPC of the nonlinear FTMS found in aircraft. Numerical simulation results show that linearized models work well for lower-level controllers with short prediction horizons but lead to significant reductions in aircraft thermal endurance when used for upper-level controllers with long prediction horizons. Therefore, a mixed-linearity hierarchical MPC formulation is presented with a nonlinear upper-level controller and a linear lower-level controller to achieve both high performance and high computational efficiency.

Management of competition among sellers and its performance implications for business-to-business electronic platforms

2015 ◽  
Vol 6 (2) ◽  
pp. 199-222 ◽  
Author(s):  
Xiaoling Li ◽  
Xingyao Ren ◽  
Xu Zheng
Keyword(s):  
Longitudinal Research ◽  
Time Windows ◽  
Customer Relationship ◽  
Effective Control ◽  
Marketing Tactics ◽  
Long Term Effects ◽  
Content Type ◽  
Short And Long Term ◽  
Term Performance

Purpose – This paper aimed to analyze the short- and long-term effects of the breadth and depth of seller competition on the performance of platform companies, and investigated the underlying mechanisms of customers’ two-sided marketing tactics on the structure of the competition between sellers. Design/methodology/approach – A longitudinal research design was adopted by gathering daily market objective data on e-commerce platforms for 250 days, and the dynamic evolution effects was analyzed by using a vector autoregression model which compared the differences between the short- and long-term effectiveness of different customer relationship management (CRM) strategies. Findings – The breadth of competition amongst sellers improves the performance of platforms, whilst the depth of competition among sellers has a positive effect on the short-term performance. However, it has a negative effect on the long-term performance of their platforms. In both the short and long terms, advertising tactics that attract new buyers contribute more to increases in the breadth of seller competition than those that attract existing buyers do. Subsidies for new sellers decrease the depth of seller competition more than those for old sellers. Research limitations/implications – Further research could be undertaken to investigate the validity of marketing tactics other than advertising tactics, and thus expand the time windows of the available data. Practical implications – It is imperative for platform companies to implement effective control over seller competition to balance the interests of the sellers and of themselves. Originality/value – The dyadic paradigm of CRM research has been extended by considering the perspective of the electronic platform company, how the tactics of exploitation and exploration of two-sided customers impact upon seller competitive structures have been delved into and why new customers have a unique value to platform companies has been identified.

Non–ST-Segment Elevation Acute Coronary Syndrome

2011 ◽  
Vol 22 (2) ◽  
pp. 113-124
Author(s):  
Susan D. Housholder-Hughes
Keyword(s):  
Critical Role ◽  
Long Term Outcomes ◽  
Recommended Care ◽  
St Segment Elevation ◽  
Coronary Syndrome ◽  
St Segment ◽  
Coronary Syndromes ◽  
Pharmacologic Management ◽  
Short And Long Term

Of the nearly 1.4 million hospitalizations for acute coronary syndromes in 2006, approximately two-thirds were for unstable angina (UA) or non–ST-segment elevation myocardial infarction (NSTEMI). Given the high risk for in-hospital ischemic events and late mortality in patients with UA/NSTEMI, it is critical to accurately and rapidly diagnose these patients, stratify their level of risk, and provide appropriate pharmacologic and nonpharmacologic treatment that maximizes anti-ischemic benefit and minimizes risk of bleeding. Appropriate in-hospital care following intervention is critical for optimizing both short- and long-term outcomes. However, evidence suggests that up to 26% of opportunities to provide guidelines-recommended care are missed. Nurses can play a critical role in ensuring that patients receive guidelines-based care. This review examines the most recent recommendations for the diagnosis and pharmacologic management of patients with UA/NSTEMI and discusses ways in which nursing staff can contribute to minimizing patient risk and optimizing patient benefit.

Predicting the Short- and Long-Term Helpfulness of Premarital Counseling: The Critical Role of Counseling Quality

2010 ◽  
Vol 9 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Walter R. Schumm ◽  
Anthony B. Walker ◽  
R. Roudi Nazarinia ◽  
Darwin A. West ◽  
Cynthia Atwell ◽  
...  
Keyword(s):  
Critical Role ◽  
Premarital Counseling ◽  
Short And Long Term

Auscultation d'une culée du pont de Portneuf à l'aide d'une inclusion de béton instrumentée (CIUS)

1996 ◽  
Vol 23 (5) ◽  
pp. 1129-1136
Author(s):  
Axel-Pierre Bois ◽  
Mohamed Lachemi ◽  
Gérard Ballivy
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Coefficient Of Thermal Expansion ◽  
Concrete Bridge ◽  
Thermal Gradients ◽  
Bridge Monitoring ◽  
Shrinkage And Creep ◽  
First Results ◽  
Short And Long Term

The Portneuf Bridge, built in 1992, is the first air-entrained high-performance concrete bridge in North America. To understand its short and long term behaviour, an auscultation program has been set. Hence, a cylindrical concrete inclusion of the Université de Sherbrooke was installed in one of the abutments of the bridge. The aim of this study is to present the first results thus acquired. The analysis of the results allowed to calculate the coefficient of thermal expansion of the concrete and to assess deformation variations due to shrinkage and creep and the effects of rebar–concrete interaction in the upper abutment region. Moreover, the presence of thermal gradients, which creates nonisotropic deformations, has been established. Key words: high-performance concrete, deformations, thermal gradients, instrumentation, bridge, monitoring. [Journal translation]

scholarly journals Short and Long-Term Properties of High-Performance Concrete Containing Silica Fume for Bridge Deck Overlay

2005 ◽  
Vol 17 (5) ◽  
pp. 743-750
Author(s):  
Jong-Pil Won ◽  
Jung-Min Seo ◽  
Chang-Soo Lee ◽  
Hae-Kyun Park ◽  
Myeong-Sub Lee
Keyword(s):  
Silica Fume ◽  
High Performance ◽  
Bridge Deck ◽  
High Performance Concrete ◽  
Short And Long Term ◽  
Bridge Deck Overlay

Claiming Credit: Stories of Movement Influence as Outcomes

2006 ◽  
Vol 11 (3) ◽  
pp. 281-298 ◽  
Author(s):  
David Meyer
Keyword(s):  
Social Movement ◽  
Critical Role ◽  
Essential Element ◽  
Social Protest ◽  
Analytical Problem ◽  
Protest Movements ◽  
Institutional Politics ◽  
Desirable Outcome ◽  
Short And Long Term

Taking credit for achieving some desirable outcome is an essential element of politics, and the stakes of doing so are particularly high for social protest movements. Popular narratives of social change assign some movements a critical role for promoting change, but ignore the influence of others. Winning acceptance of a preferred narrative of influence is a neglected, but important, social movement outcome. I use disparate stories of movement success in claiming credit to underscore the analytical problem of why some challengers end up deriving credit, both in the short and long term, for their efforts, while others don't. Movement activists and their competitors offer narratives of past influence as a kind of claims-making activity to serve current political goals. In this way, the process of claiming credit is analogous to that of establishing a reputation. I examine contextual factors likely to affect why some social movements, and some social movement actors, may be better positioned, or more interested, in promoting a narrative of their own influence than others. I argue that movement factions that place identifiable individuals in prominent positions in institutional politics are more likely to be able to promote their story of influence, but paradoxically this comes with a narrative that emphasizes the importance of mainstream politics. I conclude with a call for more research on the process and the outcomes of contests for credit.

scholarly journals Model-Free Time-Aggregated Predictions for Econometric Datasets

Forecasting ◽  
2021 ◽  
Vol 3 (4) ◽  
pp. 920-933
Author(s):  
Kejin Wu ◽  
Sayar Karmakar
Keyword(s):  
Data Analysis ◽  
High Performance ◽  
Prediction Performance ◽  
Financial Data ◽  
New Method ◽  
Model Free ◽  
Short And Long Term ◽  
Forecasting Volatility ◽  
Long Term Prediction

Forecasting volatility from econometric datasets is a crucial task in finance. To acquire meaningful volatility predictions, various methods were built upon GARCH-type models, but these classical techniques suffer from instability of short and volatile data. Recently, a novel existing normalizing and variance-stabilizing (NoVaS) method for predicting squared log-returns of financial data was proposed. This model-free method has been shown to possess more accurate and stable prediction performance than GARCH-type methods. However, whether this method can sustain this high performance for long-term prediction is still in doubt. In this article, we firstly explore the robustness of the existing NoVaS method for long-term time-aggregated predictions. Then, we develop a more parsimonious variant of the existing method. With systematic justification and extensive data analysis, our new method shows better performance than current NoVaS and standard GARCH(1,1) methods on both short- and long-term time-aggregated predictions. The success of our new method is remarkable since efficient predictions with short and volatile data always carry great importance. Additionally, this article opens potential avenues where one can design a model-free prediction structure to meet specific needs.

Robustness in the Business Models of the Organizations Embedded in the Circular Economy

2020 ◽  
pp. 19-53
Author(s):  
Adam Jabłoński
Keyword(s):  
Business Model ◽  
Circular Economy ◽  
High Performance ◽  
Business Models ◽  
Research Question ◽  
Business Continuity ◽  
Decision Making Processes ◽  
Short And Long Term

The dynamics of ongoing market changes require a new look at business management mechanisms. Often the key element of the organization's operation is to ensure business continuity, which is not easy. This requires strong embeddedness in the decision-making processes resulting from the properly built business model of the organization. A business model becomes a crucial determinant of the organizational success today. The aim of the chapter is to present the place and role of robustness in shaping the business models of organizations embedded in the circular economy. The scope of the chapter includes studies of listed companies that implement the principles of responsible business to ensure their robustness in the short and long term. In the chapter, the author poses a research question: Can the skillful use of the concept of business model robustness in circular economy companies guarantee the organization's ability to ensure business continuity and its high performance?

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