scholarly journals Discussion upon the Stationarity and the Causality of a Time Series Using the Phase Diagram Representation

2019 ◽  
Vol 2 (2) ◽  
pp. 11-16
Author(s):  
Răzvan Scripcaru ◽  
◽  
Angela Digulescu ◽  
Leontin Tuță ◽  
Alexandru Șerbănescu ◽  
...  
Keyword(s):  
Phase Diagram ◽  
Time Series ◽  
Diagram Representation

scholarly journals Anomalous supply shortages from dynamic pricing in on-demand mobility

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Malte Schröder ◽  
David-Maximilian Storch ◽  
Philip Marszal ◽  
Marc Timme
Keyword(s):  
Game Theory ◽  
Phase Diagram ◽  
Time Series ◽  
Dynamical Systems ◽  
Dynamic Pricing ◽  
Apparent Contradiction ◽  
Demand And Supply ◽  
On Demand ◽  
Self Organized ◽  
Pricing Schemes

Abstract Dynamic pricing schemes are increasingly employed across industries to maintain a self-organized balance of demand and supply. However, throughout complex dynamical systems, unintended collective states exist that may compromise their function. Here we reveal how dynamic pricing may induce demand-supply imbalances instead of preventing them. Combining game theory and time series analysis of dynamic pricing data from on-demand ride-hailing services, we explain this apparent contradiction. We derive a phase diagram demonstrating how and under which conditions dynamic pricing incentivizes collective action of ride-hailing drivers to induce anomalous supply shortages. We identify characteristic patterns in the price dynamics reflecting these supply anomalies by disentangling different timescales in price time series of ride-hailing services at 137 locations across the globe. Our results provide systemic insights for the regulation of dynamic pricing, in particular in publicly accessible mobility systems, by unraveling under which conditions dynamic pricing schemes promote anomalous supply shortages.

scholarly journals A Fractional Supervision Game Model of Multiple Stakeholders and Numerical Simulation

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Rongwu Lu ◽  
Xinhua Wang ◽  
Dan Li
Keyword(s):  
Numerical Simulation ◽  
Phase Diagram ◽  
Time Series ◽  
Numerical Solutions ◽  
Numerical Approach ◽  
Game Model ◽  
Management Problem ◽  
Multiple Stakeholders ◽  
Set Up ◽  
Predictor Corrector

Considering the popular use of a certain kind of supervision management problem in many fields, we firstly build an ordinary supervision game model of multiple stakeholders. Secondly, a fractional supervision game model is set up and solved based on the theory of fractional calculus and a predictor-corrector numerical approach. Thirdly, the methods of phase diagram and time series graph were applied to simulate and analyse the dynamic process of the fractional order game model. Results of numerical solutions are given to illustrate our conclusions and referred to the practice.

scholarly journals Three-dimensional phase diagram representation

1985 ◽  
Vol 6 (6) ◽  
pp. 516-516
Author(s):  
A. Schultz ◽  
Y. -Y. Chuang ◽  
Y. A. Chang
Keyword(s):  
Phase Diagram ◽  
Three Dimensional ◽  
Diagram Representation

Nonparametric Band Business Cycle Clock

2016 ◽  
Vol 63 (4) ◽  
pp. 375-390
Author(s):  
Łukasz Lenart ◽  
Mateusz Pipień
Keyword(s):  
Phase Diagram ◽  
Time Series ◽  
Business Cycle ◽  
Almost Periodic Function ◽  
Almost Periodic ◽  
Seasonal Fluctuations ◽  
Period Function ◽  
Business Fluctuations ◽  
Trend Component ◽  
The Business Cycle

We discuss representation of uncertainty in the business cycle clock. We propose approach utilising description of the unconditional mean of the process, applied for modelling dynamics of macroeco-nomic time series, as a trend component and almost period function in a non-parametric setting. We capture the dynamics over the business cycle, trend component and seasonal fluctuations and possible interactions between these features. A particular values of the almost periodic function are key for representation of the business cycle in a clock, expressing the dynamics according to phase diagram. The set of frequencies interpreted as a properties of the business fluctuations are invariant with respect to filtration methods applied in the procedure.

The MCG Filtering Based on the Phase Diagram Representation Domain

2018 ◽  
Author(s):  
Georgiana Rosu ◽  
Angela Digulescu ◽  
Ion Candel ◽  
Alexandru Serbanescu ◽  
Anisia Culea-Florescu ◽  
...  
Keyword(s):  
Phase Diagram ◽  
Diagram Representation

The MCG Filtering Based on the Phase Diagram Representation Domain

2018 ◽  
Author(s):  
Georgiana Rosu ◽  
Angela Digulescu ◽  
Ion Candel ◽  
Alexandru Serbanescu ◽  
Anisia Culea-Florescu ◽  
...  
Keyword(s):  
Phase Diagram ◽  
Diagram Representation

Phase Relationships in Chemical Flooding

1978 ◽  
Vol 18 (05) ◽  
pp. 325-338 ◽  
Author(s):  
R.C. Nelson ◽  
G.A. Pope
Keyword(s):  
Phase Diagram ◽  
Phase Equilibrium ◽  
Phase Diagrams ◽  
Single Phase ◽  
Phase Region ◽  
Chemical Flooding ◽  
Two Phase ◽  
Equilibrium Phases ◽  
Flow Experiments ◽  
Diagram Representation

Abstract Results of laboratory chemical floods are presented to show that equilibrium phases observed presented to show that equilibrium phases observed in test tubes are representative of phases produced in core flow experiments. Consequently, many performance characteristics of chemical floods can performance characteristics of chemical floods can be explained and predicted from equilibrium surfactant-brine-oil phase diagrams. An oil reservoir under chemical flooding can be visualized as a series of connected cells with phase equilibrium attained in each. Fluid flow from phase equilibrium attained in each. Fluid flow from one cell to the next is governed, not so much by initial properties of the oil, brine, or chemical slug and drive, as by properties of equilibrium phases formed from those fluids. Three types of equilibrium phase environment are defined. Results of interfacial tension measurements and laboratory flow experiments indicate that chemical floods should be designed to keep as much surfactant as possible for as long as possible in the "Type III" phase environment while the surfactant is traversing the reservoir. Introduction Recent research shows that when certain surfactants of interest in chemical flooding are equilibrated with brine and oil, the phases formed can be represented by relatively simple triangular phase diagrams. Furthermore, Healy and Reed phase diagrams. Furthermore, Healy and Reed revealed that surfactant-rich equilibrium phases, while immiscible with brine and oil, can displace waterflood residual oil effectively. Other papers involving phases of chemical flooding systems have appeared subsequently. This paper extends the use of phase diagrams in chemical flooding research by presenting laboratory evidence that the same phases, observed when surfactant, brine, and oil are equilibrated in sample tubes, form and transport in a core under a chemical flood. This interrelationship between surfactant-brine-oil phase behavior and the characteristics of chemical flooding is reminiscent of the interrelationship between alcohol-brine-oil phase behavior and the characteristics of alcohol flooding as described by Tabor et al. We discuss here some consequences of local phase equilibrium in an oil reservoir under a chemical flood. First, we review briefly the phase diagram representation. Next, visualizing the core as a series of connected mixing cells in each cell of which phase equilibrium is attained, we prescribe conditions for effluent liquids, based on phase diagrams for surfactant-brine-oil systems. Then, we compare results of flow experiments with those prescribed conditions. prescribed conditions. PHASE DIAGRAM REPRESENTATION PHASE DIAGRAM REPRESENTATION Following Healy et al., Fig. 1 illustrates three types of generalized phase diagram for three quasi-single components - surfactant, brine, and oil. These phase diagrams represent what we define as "phase environments." A surfactant-brine-oil system in any of the three phase-environment types can equilibrate as a single phase or as multiple phases, depending on the over-all composition of phases, depending on the over-all composition of the system. At high-surfactant concentrations, all phase environments ideally are single phase. At lower-surfactant concentrations in a Type II(-) phase environment, two equilibrium phases are phase environment, two equilibrium phases are present. As indicated by the tielines in the present. As indicated by the tielines in the two-phase region, one phase is essentially pure oil and the other is a homogeneous phase containing surfactant, brine, and oil. Here, we shall call such a phase a "microemulsion." We use this term only to describe a phase containing surfactant, brine, and oil apparently in thermodynamic equilibrium with one or more other phases. The term does not suggest a particular concept regarding the structure of that phase. Thus, in a Type II(-) phase environment, the maximum number of equilibrium phases is two. When surfactant, brine, and oil are plotted as in Fig. 1, the tielines in the two-phase region have a negative slope; hence the "II(-)" designation. SPEJ P. 325

Three-dimensional phase diagram representation

1985 ◽  
Vol 6 (4) ◽  
pp. 304-316 ◽  
Author(s):  
A. Schultz ◽  
Y. -Y. Chuang ◽  
Y. A. Chang
Keyword(s):  
Phase Diagram ◽  
Three Dimensional ◽  
Diagram Representation
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