scholarly journals Analysis of Lithuanian aggregate consumption by means of dynamic programming

2009 ◽  
Vol 50 ◽  
Author(s):  
Audronė Jakaitienė ◽  
Antanas Žilinskas ◽  
Julius Žilinskas
Keyword(s):  
Dynamic Programming ◽  
Bellman Equation ◽  
Structural Parameters ◽  
Household Consumption ◽  
Budget Constraint ◽  
Agent Based ◽  
Aggregate Consumption ◽  
The Given ◽  
Model Household ◽  
Modern Representative

In the paper, we model household consumption from the perspective of the modern representative agent-based approaches. Household chooses a stochastic consumption plan to maximise the expected value of their time-additive nonlinear utility function subject to asset budget constraint. We apply the dynamic programming for this multi-period problem using the Bellman equation. Beforehand we estimate the structural parameters of the given problem. We employ numerical methods to compute equilibrium. Finally we obtain that observed consumption was just below equilibrium in 2008.

scholarly journals Threshold Treewidth and Hypertree Width

2020 ◽  
Author(s):  
Robert Ganian ◽  
Andre Schidler ◽  
Manuel Sorge ◽  
Stefan Szeider
Keyword(s):  
Constraint Satisfaction ◽  
Constraint Satisfaction Problem ◽  
Structural Parameters ◽  
Exact Methods ◽  
Fixed Parameter Tractable ◽  
Computational Costs ◽  
Fixed Parameter ◽  
Account Information ◽  
The Given ◽  
Theoretical Results

Treewidth and hypertree width have proven to be highly successful structural parameters in the context of the Constraint Satisfaction Problem (CSP). When either of these parameters is bounded by a constant, then CSP becomes solvable in polynomial time. However, here the order of the polynomial in the running time depends on the width, and this is known to be unavoidable; therefore, the problem is not fixed-parameter tractable parameterized by either of these width measures. Here we introduce an enhancement of tree and hypertree width through a novel notion of thresholds, allowing the associated decompositions to take into account information about the computational costs associated with solving the given CSP instance. Aside from introducing these notions, we obtain efficient theoretical as well as empirical algorithms for computing threshold treewidth and hypertree width and show that these parameters give rise to fixed-parameter algorithms for CSP as well as other, more general problems. We complement our theoretical results with experimental evaluations in terms of heuristics as well as exact methods based on SAT/SMT encodings.

scholarly journals Agent-Based Spatiotemporal Simulation of Biomolecular Systems within the Open Source MASON Framework

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Gael Pérez-Rodríguez ◽  
Martín Pérez-Pérez ◽  
Daniel Glez-Peña ◽  
Florentino Fdez-Riverola ◽  
Nuno F. Azevedo ◽  
...  
Keyword(s):  
Open Source ◽  
Reaction Rate ◽  
Structural Parameters ◽  
High Specificity ◽  
Biomolecular Systems ◽  
Biological Behaviour ◽  
Agent Based ◽  
Spatiotemporal Simulation ◽  
Diffusion Rates ◽  
Comprehensive Study

Agent-based modelling is being used to represent biological systems with increasing frequency and success. This paper presents the implementation of a new tool for biomolecular reaction modelling in the open source Multiagent Simulator of Neighborhoods framework. The rationale behind this new tool is the necessity to describe interactions at the molecular level to be able to grasp emergent and meaningful biological behaviour. We are particularly interested in characterising and quantifying the various effects that facilitate biocatalysis. Enzymes may display high specificity for their substrates and this information is crucial to the engineering and optimisation of bioprocesses. Simulation results demonstrate that molecule distributions, reaction rate parameters, and structural parameters can be adjusted separately in the simulation allowing a comprehensive study of individual effects in the context of realistic cell environments. While higher percentage of collisions with occurrence of reaction increases the affinity of the enzyme to the substrate, a faster reaction (i.e., turnover number) leads to a smaller number of time steps. Slower diffusion rates and molecular crowding (physical hurdles) decrease the collision rate of reactants, hence reducing the reaction rate, as expected. Also, the random distribution of molecules affects the results significantly.

scholarly journals Polynomial Time Instances for the IKHO Problem

2012 ◽  
Vol 2012 ◽  
pp. 1-10
Author(s):  
Romeo Rizzi ◽  
Luca Nardin
Keyword(s):  
Dynamic Programming ◽  
Polynomial Time ◽  
Broad Class ◽  
Structural Parameters ◽  
Polynomial Time Algorithm ◽  
Time Algorithm ◽  
The Other ◽  
Heuristic Optimization ◽  
Negative Fact

The Interactive Knapsacks Heuristic Optimization (IKHO) problem is a particular knapsacks model in which, given an array of knapsacks, every insertion in a knapsack affects also the other knapsacks, in terms of weight and profit. The IKHO model was introduced by Isto Aho to model instances of the load clipping problem. The IKHO problem is known to be APX-hard and, motivated by this negative fact, Aho exhibited a few classes of polynomial instances for the IKHO problem. These instances were obtained by limiting the ranges of two structural parameters, c and u, which describe the extent to which an insertion in a knapsack in uences the nearby knapsacks. We identify a new and broad class of instances allowing for a polynomial time algorithm. More precisely, we show that the restriction of IKHO to instances where is bounded by a constant can be solved in polynomial time, using dynamic programming.

The High Performance Concrete Curing Agent Based on Polyacrylic Emulsion with Hydroxyl Monomer HPMA

2014 ◽  
Vol 584-586 ◽  
pp. 1126-1129 ◽  
Author(s):  
Rui Wang ◽  
Lei Li ◽  
Hong Song Wang ◽  
Wen Bin Wang ◽  
Wei Wang ◽  
...  
Keyword(s):  
High Performance ◽  
Water Retention ◽  
High Performance Concrete ◽  
Retention Rate ◽  
Structural Parameters ◽  
Positive Influence ◽  
Hydroxyl Groups ◽  
Curing Agent ◽  
Agent Based ◽  
Chemical Structures

The influence of the chemical structures of styrene/butyl acrylate/hydroxyl propyl methacrylate emulsion on some properties of ordinary Portland cement concretes has been investigated as concrete curing agent. The structural parameters that are varied included the fractions of HPMA and the polymer structure of the shell-core. The result of the study showed that the hydroxyl monomer HPMA played an important role on the improvement of water retention and the optimal proportion is about 5 wt% of the polymer. In addition, the shell-core structure of the emulsion with HPMA located in shell polymer can further enhance the water-retention rate. Besides, the emulsion with hydroxyl groups could smooth the surface of the concrete, inhibit the carbonation and had positive influence on the compressive strength.

Square Pyramid Partial Double Layer of Schwedler Spherical Reticulated Shell Parametric Design and Mechanical Analysis

2014 ◽  
Vol 670-671 ◽  
pp. 687-690
Author(s):  
Xiao Yang Lu ◽  
Feng Cheng Liu ◽  
Da Liang Zhang ◽  
Qiao Sha Wang ◽  
Bo Lu Shao ◽  
...  
Keyword(s):  
Double Layer ◽  
Mechanical Performance ◽  
Parametric Design ◽  
Structural Parameters ◽  
Mechanical Analysis ◽  
Parametric Modeling ◽  
Symmetric Region ◽  
Static Performance ◽  
Rule Analysis ◽  
The Given

Using ANSYS software comes with parametric design language APDL, developed a square pyramid partial double layer of Schwedler spherical reticulated shell parametric design macro program; achieved this kind of spherical shell parametric modeling with the given shell span S, vector high F, the thickness (height) of the pyramid, ring copies of the symmetric region Kn and radial nodes laps Nx. Analyzed the static performance of the spherical reticulated shell under different structural parameters, studied the displacement of the structure and the distribution of the stress change with macroscopic geometric parameter change rule. Analysis results of eight kinds of conditions showed that the square pyramid partial double layer of Schwedler spherical reticulated shell has good mechanical performance. The result of the analysis provides a theoretical basis for the relevant engineering design.

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