scholarly journals Finite Memory Distributed Systems

2006 ◽  
Vol 6 (1) ◽  
Author(s):  
Victor Dorofeenko ◽  
Jamsheed Shorish
Keyword(s):  
Distributed System ◽  
Total Population ◽  
Dynamical Evolution ◽  
High Rate ◽  
System Model ◽  
System Of Equations ◽  
Population Densities ◽  
Finite Memory ◽  
Continuous Population ◽  
Simulation Results

A distributed system model is studied, where individual agents play repeatedly against each other and change their strategies based upon previous play. It is shown how to model this environment in terms of continuous population densities of agent types. A complication arises because the population densities of different strategies depend upon each other not only through game payoffs, but also through the strategy distributions themselves. In spite of this, it is shown that when an agent imitates the strategy of his previous opponent at a sufficiently high rate, the system of equations which governs the dynamical evolution of agent populations can be reduced to one equation for the total population. In a sense, the dynamics 'collapse' to the dynamics of the entire system taken as a whole, which describes the behavior of all types of agents. We explore the implications of this model, and present both analytical and simulation results.

From the Oort cloud to Halley-type comets

1999 ◽  
Vol 173 ◽  
pp. 327-338 ◽  
Author(s):  
J.A. Fernández ◽  
T. Gallardo
Keyword(s):  
Total Population ◽  
Complex Function ◽  
Dynamical Evolution ◽  
Oort Cloud ◽  
Capture Process ◽  
Influx Rate ◽  
Short Period ◽  
Dynamical Properties ◽  
Orbital Periods ◽  
Probability Of Capture

AbstractThe Oort cloud probably is the source of Halley-type (HT) comets and perhaps of some Jupiter-family (JF) comets. The process of capture of Oort cloud comets into HT comets by planetary perturbations and its efficiency are very important problems in comet ary dynamics. A small fraction of comets coming from the Oort cloud − of about 10−2− are found to become HT comets (orbital periods < 200 yr). The steady-state population of HT comets is a complex function of the influx rate of new comets, the probability of capture and their physical lifetimes. From the discovery rate of active HT comets, their total population can be estimated to be of a few hundreds for perihelion distancesq <2 AU. Randomly-oriented LP comets captured into short-period orbits (orbital periods < 20 yr) show dynamical properties that do not match the observed properties of JF comets, in particular the distribution of their orbital inclinations, so Oort cloud comets can be ruled out as a suitable source for most JF comets. The scope of this presentation is to review the capture process of new comets into HT and short-period orbits, including the possibility that some of them may become sungrazers during their dynamical evolution.

A Multiregion Model with Capital Accumulation and Endogenous Amenities

2007 ◽  
Vol 39 (9) ◽  
pp. 2248-2270 ◽  
Author(s):  
Wei-Bin Zhang
Keyword(s):  
Capital Accumulation ◽  
Comparative Statics ◽  
The Other ◽  
High Rate ◽  
Unique Equilibrium ◽  
Economic Activities ◽  
Technological Differences ◽  
National Output ◽  
Simulation Results ◽  
Wage Disparities

The author develops a multiregional growth model with endogenous amenity and capital accumulation for any number of regions. The simulation results demonstrate that the national dynamics have a unique equilibrium. Comparative statics analysis shows that, if environmental improvement occurs in the technologically advanced (less advanced) region, the national output rises (falls). As a region improves its technology, the other two regions' aggregated output levels fall—not only in relative, but also in absolute, terms. This implies that if any region has a high rate of technological change and the other regions remain technologically stationary, then economic activities will tend to be concentrated in the technologically advancing region. It is also shown that technological differences appear to play only a small role in accounting for spatial wage disparities and endowments.

The Kota of the Nilgiri hills: a demographic study

1976 ◽  
Vol 8 (1) ◽  
pp. 17-26 ◽  
Author(s):  
Aloke Kumar Ghosh
Keyword(s):  
Total Population ◽  
Random Mating ◽  
High Rate ◽  
Moderate Intensity ◽  
Biological Study ◽  
Isolated Population ◽  
Demographic Structure ◽  
Effective Population ◽  
Mating Population ◽  
The Village

A population–biological study of the Kota of the Nilgiri Hills was undertaken between May 1966 and January 1968. This paper discusses the demographic structure of the tribe and its genetic implications.The Kota is a small tribe of 1203 individuals distributed in only seven villages; it is an isolated population with a low rate of fertility and a high rate of infant mortality. The Kota is not a random mating population. The rate of consanguineous marriages is high and the coefficient of inbreeding is almost equal to the highest recorded value. Besides cousin marriages, marriage within the village is very much preferred. The admixture rate (0·29%) among the Kota is very low. The effective population size is only 28·87% of the total population. The coefficient of breeding isolation is 1·01, which indicates that genetic drift may produce important differentiation in this population. The data show that selection is acting with moderate intensity in this population.

A Robust Trajectory Tracking Control Scheme of Two-Link Flexible Manipulator

2011 ◽  
Vol 328-330 ◽  
pp. 2108-2112
Author(s):  
Jing Shuang Lu ◽  
Chun Mei Du ◽  
Rui Zhou ◽  
Na Li
Keyword(s):  
Trajectory Tracking ◽  
Tracking Control ◽  
Vertical Plane ◽  
Flexible Manipulator ◽  
System Model ◽  
Error Signal ◽  
Dynamics Model ◽  
Trajectory Tracking Control ◽  
Control Scheme ◽  
Simulation Results

A simple dynamics model is established based on the two-link flexible manipulator moving within the vertical plane, and a robust simple control scheme is put forward. The advantages of this scheme are simple and good robustness. Only the error signal is needed when designing the control scheme and the acquirement of control signal does not depend on the system model. The simulation results show that this method has a good robustness and stability.

Research on Simulation and Modeling of Split Double-Rotor Motor Based on Indirect Vector Control

2011 ◽  
Vol 317-319 ◽  
pp. 672-677
Author(s):  
Bin Wei ◽  
Ji Bin Hu ◽  
Zeng Xiong Peng
Keyword(s):  
Control System ◽  
Vector Control ◽  
Stable State ◽  
System Model ◽  
Dynamic Capability ◽  
Simulation And Modeling ◽  
Simulation Results ◽  
Set Up ◽  
Vector Control System ◽  
Control Principle

A novel vector control system of the split double-rotor motor based on indirect vector control principle has been proposed. The mathematic models of the primary machine and the secondary machine are set up respectively. Through the coupling of the two models, the system model of the split double-rotor motor is build. Matlab software is used for the simulation and analysis of this indirect vector control system. According to the simulation results, the validity of system model is proved with nicer static and dynamic capability, and without steady-state error in stable state. These are important to analyze and design the double-rotor motor. Furthermore, the results provide the basis for simulation and apply of double-rotor motor in HEV.

Hydraulic Actuator Tuning in the Control of a Rotating Flexible Beam Mechanism

1995 ◽  
Author(s):  
Michael J. Panza ◽  
Roger W. Mayne
Keyword(s):  
Hydraulic Resistance ◽  
System Model ◽  
Flexible Beam ◽  
Hydraulic Actuator ◽  
Control Effort ◽  
Actuation System ◽  
Wide Range ◽  
Position Feedback ◽  
Simulation Results ◽  
Beam Mechanism

Abstract The end point position and vibration control of a rotating flexible beam mechanism driven by a hydraulic cylinder actuator is considered. An integrated nonlinear system model comprised of beam dynamics, hydraulic actuator, control valves, and control scheme is presented. Control based on simple position feedback along with a hydraulic actuation system tuned to suppress beam vibration over a wide range of angular motion is investigated. For positioning to small to moderate mechanism angles, a linear system model with the actuator tuned for good open loop performance is developed. Actuator tuning is accomplished by varying the system hydraulic resistance according to a dimensionless parameter defining the interaction between the actuator and flexible beam. Simulation results for a closed loop system indicate that this simple tuned control provides comparable performance and requires less control effort than an untuned system with a more complex state feedback optimal controller. To compensate for geometric nonlinearities that cause instability when positioning to large mechanism angles, an active actuator tuning scheme based on continuous variation of hydraulic resistance is proposed. The active variable resistance controller is combined with simple position feedback and designed to provide a constant dimensionless actuator-flexible beam interaction parameter throughout the motion. Simulation results are presented to show the stabilizing effect of this control strategy.

Comprehensive Structure of Novel Voice Priority Queue Scheduling System Model for VoIP Over WLANs

2011 ◽  
Vol 3 (4) ◽  
pp. 50-70 ◽  
Author(s):  
Kashif Nisar ◽  
Angela Amphawan ◽  
Suhaidi B. Hassan
Keyword(s):  
Traffic Flow ◽  
Low Cost ◽  
Local Area ◽  
Priority Queue ◽  
High Rate ◽  
System Model ◽  
Scheduling System ◽  
Queue Scheduling ◽  
Voice Packets ◽  
The Voice

Voice over Internet Protocol (VoIP) has grown quickly in the world of telecommunication. Wireless Local Area Networks (WLANs) are the most performance assuring technology for wireless networks, and WLANs have facilitated high-rate voice services at low cost and good flexibility. In a voice conversation, each client works as a sender or a receiver depending on the direction of traffic flow over the network. A VoIP application requires high throughput, low packet loss, and a high fairness index over the network. The packets of VoIP streaming may experience drops because of the competition among the different kinds of traffic flow over the network. A VoIP application is also sensitive to delay and requires the voice packets to arrive on time from the sender to the receiver side without any delay over WLAN. The scheduling system model for VoIP traffic is an unresolved problem. The objectives of this paper are to identify scheduler issues. This comprehensive structure of Novel Voice Priority Queue (VPQ) scheduling system model for VoIP over WLAN discusses the essential background of the VPQ schedulers and algorithms. This paper also identifies the importance of the scheduling techniques over WLANs.

Isolation by distance in a hierarchically clustered population

1983 ◽  
Vol 20 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Stanley Sawyer ◽  
Joseph Felsenstein
Keyword(s):  
Total Population ◽  
Genetic Relatedness ◽  
Isolation By Distance ◽  
Random Mating ◽  
Physical Distance ◽  
Population Densities ◽  
Total Population Size ◽  
Biological Population ◽  
Equilibrium Probability ◽  
Different Levels

A biological population with local random mating, migration, and mutation is studied which exhibits clustering at several different levels. The migration is determined by the clustering rather than actual geographic or physical distance. Darwinian selection is assumed to be absent, and population densities are such that nearby individuals have a probability of being related. An expression is found for the equilibrium probability of genetic relatedness between any two individuals as a function of their clustering distance. Asymptotics for a small mutation rate u are discussed for both a finite number of clustering levels (and of total population size), and for an infinite number of levels. A natural example is discussed in which the probability of heterozygosity varies as u to a power times a periodic function of log(l/u).

Calculation Method for Thermal-Hydraulic System Simulation

2008 ◽  
Vol 130 (8) ◽  
Author(s):  
Li Chenggong ◽  
Jiao Zongxia
Keyword(s):  
Mathematical Models ◽  
Calculation Method ◽  
Hydraulic System ◽  
System Simulation ◽  
Cross Coupling ◽  
System Model ◽  
Lumped Parameter ◽  
Simulation Results ◽  
Simulation Time ◽  
Hydraulic System Simulation

This paper presents the fundamental approaches of modeling thermal-hydraulic component briefly. A set of lumped parameter mathematical models is developed, which are based on conservation of mass and energy. Subsequently, the connection rule for basic thermal-hydraulic components and the method to automatically generate the complete thermal-hydraulic system model are put forward. The integration methods for solving the cross-coupling thermal-hydraulic equations are also discussed for a position-controlled thermal-hydraulic system. Simulation results show the interaction between pressure and temperature. The simplified representations of thermal-hydraulic differential equations are also proposed in this paper, which can reduce simulation time. The validity of the simplified representations is judged by simulation.

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