scholarly journals The inverse Frobenius-Perron problem: A survey of solutions to the original problem formulation

2021 ◽  
Vol 6 (10) ◽  
pp. 11200-11232
Author(s):  
André M. McDonald ◽  
◽  
Michaël A. van Wyk ◽  
Guanrong Chen ◽  
◽  
...  
Keyword(s):  
Original Problem ◽  
Problem Formulation ◽  
System Model ◽  
Statistical Characteristics ◽  
Original Formulation ◽  
Practical Application ◽  
Modeling Techniques ◽  
Ergodic Dynamical System ◽  
Future Work ◽  
Source Of Information

<abstract><p>The inverse Frobenius-Perron problem (IFPP) is a collective term for a family of problems that requires the construction of an ergodic dynamical system model with prescribed statistical characteristics. Solutions to this problem draw upon concepts from ergodic theory and are scattered throughout the literature across domains such as physics, engineering, biology and economics. This paper presents a survey of the original formulation of the IFPP, wherein the invariant probability density function of the system state is prescribed. The paper also reviews different strategies for solving this problem and demonstrates several of the techniques using examples. The purpose of this survey is to provide a unified source of information on the original formulation of the IFPP and its solutions, thereby improving accessibility to the associated modeling techniques and promoting their practical application. The paper is concluded by discussing possible avenues for future work.</p></abstract>

Periodic Solutions in Rotor Dynamic Systems With Nonlinear Supports: A General Approach

1989 ◽  
Vol 111 (2) ◽  
pp. 187-193 ◽  
Author(s):  
C. Nataraj ◽  
H. D. Nelson
Keyword(s):  
Dynamic Systems ◽  
Original Problem ◽  
Squeeze Film ◽  
Algebraic Equations ◽  
Trigonometric Collocation ◽  
Nonlinear Algebraic Equations ◽  
The Stability ◽  
Future Work ◽  
Rotor Dynamic ◽  
Large Rotor

A new quantitative method of estimating steady state periodic behavior in nonlinear systems, based on the trigonometric collocation method, is outlined. A procedure is developed to analyze large rotor dynamic systems with nonlinear supports by the use of the above method in conjunction with Component Mode Synthesis. The algorithm discussed is seen to reduce the original problem to solving nonlinear algebraic equations in terms of only the coordinates associated with the nonlinear supports and is a big improvement over commonly used integration methods. The feasibility and advantages of the procedure so developed are illustrated with the help of an example of a typical rotor dynamic system with an uncentered squeeze film damper. Future work on the investigation of the stability of the periodic response so obtained is outlined.

Application of a Genetic Algorithm to Concept Variant Selection

2006 ◽  
Author(s):  
Ryan S. Hutcheson ◽  
Robert L. Jordan ◽  
Robert B. Stone ◽  
Janis P. Terpenny ◽  
Xiaomeng Chang
Keyword(s):  
Genetic Algorithm ◽  
Product Development ◽  
Solution Space ◽  
Variant Selection ◽  
Functional Modeling ◽  
Detailed Design ◽  
Modeling Techniques ◽  
Break Even Point ◽  
Future Work ◽  
Selection Of

This paper outlines a framework for applying a genetic algorithm to the selection of component variants between the conceptual and detailed design stages of product development. A genetic algorithm (GA) is defined for the problem and an example is presented that demonstrates its application and usefulness. Functional modeling techniques are used to formulate the design problem and generate the chromosomes that are evaluated with the algorithm. In the presented example, suitable GA parameters and the break-even point where the GA surpassed an enumerated search of the same solution space were found. Recommend uses of the GA along with limitations of the method and future work are presented as well.

Quantifying the Shape of Pareto Fronts During Multi-Objective Trade Space Exploration

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Mehmet Unal ◽  
Gordon P. Warn ◽  
Timothy W. Simpson
Keyword(s):  
Pareto Front ◽  
Space Exploration ◽  
Problem Formulation ◽  
Shape Index ◽  
Multi Objective ◽  
Conflicting Objectives ◽  
Complex Engineering ◽  
Trade Space Exploration ◽  
Pareto Fronts ◽  
Future Work

Recent advances in simulation and computation capabilities have enabled designers to model increasingly complex engineering problems, taking into account many dimensions, or objectives, in the problem formulation. Increasing the dimensionality often results in a large trade space, where decision-makers (DM) must identify and negotiate conflicting objectives to select the best designs. Trade space exploration often involves the projection of nondominated solutions, that is, the Pareto front, onto two-objective trade spaces to help identify and negotiate tradeoffs between conflicting objectives. However, as the number of objectives increases, an exhaustive exploration of all of the two-dimensional (2D) Pareto fronts can be inefficient due to a combinatorial increase in objective pairs. Recently, an index was introduced to quantify the shape of a Pareto front without having to visualize the solution set. In this paper, a formal derivation of the Pareto Shape Index is presented and used to support multi-objective trade space exploration. Two approaches for trade space exploration are presented and their advantages are discussed, specifically: (1) using the Pareto shape index for weighting objectives and (2) using the Pareto shape index to rank objective pairs for visualization. By applying the two approaches to two multi-objective problems, the efficiency of using the Pareto shape index for weighting objectives to identify solutions is demonstrated. We also show that using the index to rank objective pairs provides DM with the flexibility to form preferences throughout the process without closely investigating all objective pairs. The limitations and future work are also discussed.

Probability, Problem Formulation, and Two-Player Games

1994 ◽  
Vol 87 (3) ◽  
pp. 154-159
Author(s):  
Philip G. Buckhiester
Keyword(s):  
Decision Making ◽  
Original Problem ◽  
Problem Formulation ◽  
School Mathematics ◽  
Evaluation Standards ◽  
Probability Problem ◽  
Stated Problem

The Curriculum and Evaluation Standards for School Mathematics (NCTM 1989) states in Standard 11 for grades 9 through 12 that students should have opportunities to “use experimental and theoretical probabilities to represent and solve problems involving uncertainty.” Standard 1 emphasizes the importance of students' learning to “formulate problems from situations within and outside mathematics.” This article discusses a simply stated problem involving uncertainty that students can investigate experimentally or theoretically. The problem places students in the role of problem formulator by giving them opportunities to generate various interesting problems of their own on the basis of a given situation. By changing certain characteristics of the original problem, students can be introduced to some fundamental concepts of decision making in two-player games.

scholarly journals Efektivitas Teknik Modeling Dalam Meningkatkan Rasa Percaya Diri Santri di Pondok Pesantren Assalafi Al-Fithrah Surabaya

TRANSFORMATIF ◽  
2018 ◽  
Vol 2 (1) ◽  
pp. 374
Author(s):  
Muhammad Wildan Romdhoni ◽  
Nurul Faizah
Keyword(s):  
Data Analysis ◽  
Character Development ◽  
Problem Formulation ◽  
Control Group ◽  
Control Group Design ◽  
Group Design ◽  
Self Confidence ◽  
Modeling Techniques ◽  
Modelling Techniques ◽  
Development Of Students

<p>This research is motivated by the inequality of character development of students, particularly confidence when speaking in public. This study aims to answer the problem formulation which is reflected in the research hypothesis that modelling techniques effective in increasing the confidence of students in Pondok Pesantren Assalafi Al-Fithrah Surabaya (H<sub>a</sub>). The approach used is a quantitative approach with the research methods true experimental design, pretest-posttest control group design. Samples were taken by purposive from the population are students of class Isti'dad Ulya  A and B. The results of data analysis showed that the modeling techniques effective in improving students confidence when speaking in public in Pondok Pesantren Assalafi Al-Fithrah Surabaya.</p><p class="Abstract"><strong>Keywords</strong>: Modeling Techniques, Self Confidence</p>

scholarly journals A PERFORATED MOBILE BREAKWATER FOR FIXED AND FLOATING APPLICATION

1966 ◽  
Vol 1 (10) ◽  
pp. 63 ◽  
Author(s):  
Wilbur Marks
Keyword(s):  
Potential Role ◽  
Front Wall ◽  
Test Results ◽  
Practical Application ◽  
Back Wall ◽  
Mooring Lines ◽  
Application Model ◽  
Perforated Breakwater ◽  
Future Work

A mobile breakwater concept based upon a perforated front wall and solid back wall is presented. The principles of energy dissipation by the system is discussed as well as the potential role of such a device within the framework of practical application. Model test results, comparing the perforated breakwater's response to waves with that of a caisson-type breakwater, are discussed. It is shown that the perforated breakwater experiences less force on the structure when it is fixed to the bottom and less force on the mooring lines when afloat than the caisson-type. However, the perforated breakwater is not more effective in reducing waves, for the conditions tested. Visual observations show that scouring is prevalent when the caisson-type is fixed to the bottom; there is no evidence of scouring with the perforated breakwater. Recommendations are made for future work.

Consent-based Access to Core EHR Information

2009 ◽  
Vol 48 (02) ◽  
pp. 144-148 ◽  
Author(s):  
K. E. Berntsen ◽  
V. Heimly
Keyword(s):  
Drug Information ◽  
Healthcare Providers ◽  
Ethnographic Study ◽  
Health Providers ◽  
The Core ◽  
Medication Information ◽  
National Patient ◽  
Regular Work ◽  
Future Work ◽  
Source Of Information

Summary Objective: Lack of access to updated drug information is a challenge for healthcare providers in Norway. Drug charts are updated in separate EHR systems but exchange of drug information between them is lacking. In order to provide ready access to updated medication information, a project for consent-based access to a core EHR has been established. Methods: End users have developed requirements for additions to the medication modules in the EHR systems in cooperation with vendors, researchers and standardization workers. The modules are then implemented by the vendors, tested in the usability lab, and finally tested by the national testing and approval service before implementation. An ethnographic study, with focus on future users and their interaction with other actors regarding medicines and medication, has included semi-/unstructured interviews with the involved organizational units. Results: The core EHR uses the EHR kept by the patient’s regular GP as the main source of information. A server-based solution has been chosen in order to keep the core EHR accessible outside the GP’s regular work hours. The core EHR is being tested, and the EHR-vendors are implementing additions to their systems in order to facilitate communication with the core EHR. All major EHR-system vendors in Norway participate in the project. Conclusions: The core EHR provides a generic basis that may be used as a pilot for a national patient summary. Examples of a wider use of the core EHR can be: shared individual plans to support continuity of care, summary of the patient’s contacts with health providers in different organizations, and core EHR information such as important diagnoses, allergies and contact information. Extensive electronic cooperation and communication requires that all partners adjust their documentation practices to fit with other actors’ needs. The implementation effects on future work practices will be followed by researchers.

The Simulation and Application in Eliminating Noise of Adaptive Filter

2013 ◽  
Vol 364 ◽  
pp. 449-452
Author(s):  
Fei Qiao Xiong ◽  
Bang Qian Ao
Keyword(s):  
Adaptive Filter ◽  
Noise Suppression ◽  
Statistical Characteristics ◽  
Practical Application ◽  
Noise Elimination ◽  
Analytical Results ◽  
Filtering Effect

In practical application, signal and noise statistical characteristics are often unknown or not informed, fixed filter is difficult to process these signals and the filtering effect is poor. To address the issue, this paper design the adaptive filter which is based on the algorithm LMS and RLS. By simulation in the MATLAB environment, we can compare the analytical results of the two algorithms and observe the effect of noise elimination, the adaptive filter can be a good noise suppression.

scholarly journals Development of the Regional Arctic System Model (RASM): Near-Surface Atmospheric Climate Sensitivity

2017 ◽  
Vol 30 (15) ◽  
pp. 5729-5753 ◽  
Author(s):  
John J. Cassano ◽  
Alice DuVivier ◽  
Andrew Roberts ◽  
Mimi Hughes ◽  
Mark Seefeldt ◽  
...  
Keyword(s):  
Sea Ice ◽  
Surface Temperature ◽  
Sea Surface ◽  
System Model ◽  
Cold Surface ◽  
Radiative Fluxes ◽  
Near Surface ◽  
Surface Climate ◽  
Radiative Impact ◽  
Future Work

The near-surface climate, including the atmosphere, ocean, sea ice, and land state and fluxes, in the initial version of the Regional Arctic System Model (RASM) are presented. The sensitivity of the RASM near-surface climate to changes in atmosphere, ocean, and sea ice parameters and physics is evaluated in four simulations. The near-surface atmospheric circulation is well simulated in all four RASM simulations but biases in surface temperature are caused by biases in downward surface radiative fluxes. Errors in radiative fluxes are due to biases in simulated clouds with different versions of RASM simulating either too much or too little cloud radiative impact over open ocean regions and all versions simulating too little cloud radiative impact over land areas. Cold surface temperature biases in the central Arctic in winter are likely due to too few or too radiatively thin clouds. The precipitation simulated by RASM is sensitive to changes in evaporation that were linked to sea surface temperature biases. Future work will explore changes in model microphysics aimed at minimizing the cloud and radiation biases identified in this work.

Multi-Speed Gearbox Design Using Multi-Objective Evolutionary Algorithms

2003 ◽  
Vol 125 (3) ◽  
pp. 609-619 ◽  
Author(s):  
Kalyanmoy Deb ◽  
Sachin Jain
Keyword(s):  
Original Problem ◽  
Problem Formulation ◽  
Optimization Techniques ◽  
Nsga Ii ◽  
Nondominated Solutions ◽  
Multi Objective ◽  
Decision Variables ◽  
Mathematical Expressions ◽  
Different Types ◽  
Important Design

Optimal design of a multi-speed gearbox involves different types of decision variables and objectives. Due to lack of efficient classical optimization techniques, such problems are usually decomposed into tractable subproblems and solved. Moreover, in most cases the explicit mathematical expressions of the problem formulation is exploited to arrive at the optimal solutions. In this paper, we demonstrate the use of a multi-objective evolutionary algorithm, which is capable of solving the original problem involving mixed discrete and real-valued parameters and more than one objectives, and is capable of finding multiple nondominated solutions in a single simulation run. On a number of instantiations of the gearbox design problem having different complexities, the efficacy of NSGA-II in handling different types of decision variables, constraints, and multiple objectives are demonstrated. A highlight of the suggested procedure is that a post-optimal investigation of the obtained solutions allows a designer to discover important design principles which are otherwise difficult to obtain using other means.

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