7 research outputs found
Optimal Income Crossover for Two-Class Model Using Particle Swarm Optimization
Personal income distribution may exhibit a two-class structure, such that the
lower income class of the population (85-98%) is described by exponential
Boltzmann-Gibbs distribution, whereas the upper income class (15-2%) has a
Pareto power-law distribution. We propose a method, based on a theoretical and
numerical optimization scheme, which allows us to determine the crossover
income between the distributions, the temperature of the Boltzmann-Gibbs
distribution and the Pareto index. Using this method, the Brazilian income
distribution data provided by the National Household Sample Survey was studied.
The data was stratified into two dichotomies (sex/gender and color/race), so
the model was tested using different subsets along with accessing the economic
differences between these groups. Lastly, we analyse the temporal evolution of
the parameters of our model and the Gini coefficient discussing the implication
on the Brazilian income inequality. To our knowledge, for the first time an
optimization method is proposed in order to find a continuous two-class income
distribution, which is able to delimit the boundaries of the two distributions.
It also gives a measure of inequality which is a function that depends only on
the Pareto index and the percentage of people in the high income region. It was
found a temporal dynamics relation, that may be general, between the Pareto and
the percentage of people described by the Pareto tail.Comment: 16 pages, 14 figures, submitted to Physical Review
Genetic learning particle swarm optimization
Social learning in particle swarm optimization (PSO) helps collective efficiency, whereas individual reproduction in genetic algorithm (GA) facilitates global effectiveness. This observation recently leads to hybridizing PSO with GA for performance enhancement. However, existing work uses a mechanistic parallel superposition and research has shown that construction of superior exemplars in PSO is more effective. Hence, this paper first develops a new framework so as to organically hybridize PSO with another optimization technique for “learning.” This leads to a generalized “learning PSO” paradigm, the *L-PSO. The paradigm is composed of two cascading layers, the first for exemplar generation and the second for particle updates as per a normal PSO algorithm. Using genetic evolution to breed promising exemplars for PSO, a specific novel *L-PSO algorithm is proposed in the paper, termed genetic learning PSO (GL-PSO). In particular, genetic operators are used to generate exemplars from which particles learn and, in turn, historical search information of particles provides guidance to the evolution of the exemplars. By performing crossover, mutation, and selection on the historical information of particles, the constructed exemplars are not only well diversified, but also high qualified. Under such guidance, the global search ability and search efficiency of PSO are both enhanced. The proposed GL-PSO is tested on 42 benchmark functions widely adopted in the literature. Experimental results verify the effectiveness, efficiency, robustness, and scalability of the GL-PSO
Learning to Use Chopsticks in Diverse Gripping Styles
Learning dexterous manipulation skills is a long-standing challenge in
computer graphics and robotics, especially when the task involves complex and
delicate interactions between the hands, tools and objects. In this paper, we
focus on chopsticks-based object relocation tasks, which are common yet
demanding. The key to successful chopsticks skills is steady gripping of the
sticks that also supports delicate maneuvers. We automatically discover
physically valid chopsticks holding poses by Bayesian Optimization (BO) and
Deep Reinforcement Learning (DRL), which works for multiple gripping styles and
hand morphologies without the need of example data. Given as input the
discovered gripping poses and desired objects to be moved, we build
physics-based hand controllers to accomplish relocation tasks in two stages.
First, kinematic trajectories are synthesized for the chopsticks and hand in a
motion planning stage. The key components of our motion planner include a
grasping model to select suitable chopsticks configurations for grasping the
object, and a trajectory optimization module to generate collision-free
chopsticks trajectories. Then we train physics-based hand controllers through
DRL again to track the desired kinematic trajectories produced by the motion
planner. We demonstrate the capabilities of our framework by relocating objects
of various shapes and sizes, in diverse gripping styles and holding positions
for multiple hand morphologies. Our system achieves faster learning speed and
better control robustness, when compared to vanilla systems that attempt to
learn chopstick-based skills without a gripping pose optimization module and/or
without a kinematic motion planner
A hybrid PSO-BFGS strategy for global optimization of multimodal functions
Particle swarm optimizer (PSO) is a powerful optimization algorithm that has been applied to a variety of problems. It can, however, suffer from premature convergence and slow convergence rate. Motivated by these two problems, a hybrid global optimization strategy combining PSOs with a modified Broyden-Fletcher-Goldfarb-Shanno (BFGS) method is presented in this paper. The modified BFGS method is integrated into the context of the PSOs to improve the particles' local search ability. In addition, in conjunction with the territory technique, a reposition technique to maintain the diversity of particles is proposed to improve the global search ability of PSOs. One advantage of the hybrid strategy is that it can effectively find multiple local solutions or global solutions to the multimodal functions in a box-constrained space. Based on these local solutions, a reconstruction technique can be adopted to further estimate better solutions. The proposed method is compared with several recently developed optimization algorithms on a set of 20 standard benchmark problems. Experimental results demonstrate that the proposed approach can obtain high-quality solutions on multimodal function optimization problems. © 2011 IEEE
Circuit Design
Circuit Design = Science + Art! Designers need a skilled "gut feeling" about circuits and related analytical techniques, plus creativity, to solve all problems and to adhere to the specifications, the written and the unwritten ones. You must anticipate a large number of influences, like temperature effects, supply voltages changes, offset voltages, layout parasitics, and numerous kinds of technology variations to end up with a circuit that works. This is challenging for analog, custom-digital, mixed-signal or RF circuits, and often researching new design methods in relevant journals, conference proceedings and design tools unfortunately gives the impression that just a "wild bunch" of "advanced techniques" exist. On the other hand, state-of-the-art tools nowadays indeed offer a good cockpit to steer the design flow, which include clever statistical methods and optimization techniques.Actually, this almost presents a second breakthrough, like the introduction of circuit simulators 40 years ago! Users can now conveniently analyse all the problems (discover, quantify, verify), and even exploit them, for example for optimization purposes. Most designers are caught up on everyday problems, so we fit that "wild bunch" into a systematic approach for variation-aware design, a designer's field guide and more. That is where this book can help! Circuit Design: Anticipate, Analyze, Exploit Variations starts with best-practise manual methods and links them tightly to up-to-date automation algorithms. We provide many tractable examples and explain key techniques you have to know. We then enable you to select and setup suitable methods for each design task - knowing their prerequisites, advantages and, as too often overlooked, their limitations as well. The good thing with computers is that you yourself can often verify amazing things with little effort, and you can use software not only to your direct advantage in solving a specific problem, but also for becoming a better skilled, more experienced engineer. Unfortunately, EDA design environments are not good at all to learn about advanced numerics. So with this book we also provide two apps for learning about statistic and optimization directly with circuit-related examples, and in real-time so without the long simulation times. This helps to develop a healthy statistical gut feeling for circuit design. The book is written for engineers, students in engineering and CAD / methodology experts. Readers should have some background in standard design techniques like entering a design in a schematic capture and simulating it, and also know about major technology aspects
Circuit Design
Circuit Design = Science + Art! Designers need a skilled "gut feeling" about circuits and related analytical techniques, plus creativity, to solve all problems and to adhere to the specifications, the written and the unwritten ones. You must anticipate a large number of influences, like temperature effects, supply voltages changes, offset voltages, layout parasitics, and numerous kinds of technology variations to end up with a circuit that works. This is challenging for analog, custom-digital, mixed-signal or RF circuits, and often researching new design methods in relevant journals, conference proceedings and design tools unfortunately gives the impression that just a "wild bunch" of "advanced techniques" exist. On the other hand, state-of-the-art tools nowadays indeed offer a good cockpit to steer the design flow, which include clever statistical methods and optimization techniques.Actually, this almost presents a second breakthrough, like the introduction of circuit simulators 40 years ago! Users can now conveniently analyse all the problems (discover, quantify, verify), and even exploit them, for example for optimization purposes. Most designers are caught up on everyday problems, so we fit that "wild bunch" into a systematic approach for variation-aware design, a designer's field guide and more. That is where this book can help! Circuit Design: Anticipate, Analyze, Exploit Variations starts with best-practise manual methods and links them tightly to up-to-date automation algorithms. We provide many tractable examples and explain key techniques you have to know. We then enable you to select and setup suitable methods for each design task - knowing their prerequisites, advantages and, as too often overlooked, their limitations as well. The good thing with computers is that you yourself can often verify amazing things with little effort, and you can use software not only to your direct advantage in solving a specific problem, but also for becoming a better skilled, more experienced engineer. Unfortunately, EDA design environments are not good at all to learn about advanced numerics. So with this book we also provide two apps for learning about statistic and optimization directly with circuit-related examples, and in real-time so without the long simulation times. This helps to develop a healthy statistical gut feeling for circuit design. The book is written for engineers, students in engineering and CAD / methodology experts. Readers should have some background in standard design techniques like entering a design in a schematic capture and simulating it, and also know about major technology aspects