Parallel Genetic Algorithms with GPU Computing

Genetic algorithms (GAs) are powerful solutions to optimization problems arising from manufacturing and logistic fields. It helps to find better solutions for complex and difficult cases, which are hard to be solved by using strict optimization methods. Accelerating parallel GAs with GPU computing have received significant attention from both practitioners and researchers, ever since the emergence of GPU-CPU heterogeneous architectures. Designing a parallel algorithm on GPU is different fundamentally from designing one on CPU. On CPU architecture, typically data or tasks are distributed across tens of threads or processes, while on GPU architecture, more than hundreds of thousands of threads run. In order to fully utilize the computing power of GPUs, the design approaches and implementation strategies of parallel GAs should be re-probed. In the chapter, a concise overview of parallel GAs on GPU is given from the perspective of GPU architecture. The concept of parallelism granularity is redefined, the aspect of data layout is discussed on how it will affect the kernel performance, and the hierarchy of threads is examined on how threads are organized in the grid and blocks to expose sufficient parallelism to GPU. Some future research is discussed. A hybrid parallel model, based on the feature of GPU architecture, is suggested to build up efficient parallel GAs for hyper-scale problems

Recovery of Boundaries and Types for Multiple Obstacles from the Far-field Pattern

We consider an inverse scattering problem for multiple obstacles $D=\cup_{j=1}^ND_j\subset {R}^3$ with different types of boundary of $D_j$. By constructing an indicator function from the far-field pattern of scattered wave, we can firstly determine the boundary location for all obstacles, then identify the boundary type for each obstacle, as well as the boundary impedance in case of Robin-type obstacles. The reconstruction procedures for these identifications are also given. Comparing with the existing probing method which is applied to identify one obstacle in generally, we should analyze the behavior of both the imaginary part and the real part of the indicator function so that we can identify the type of multiple obstacles

Existence and Uniqueness of Periodic Solutions for a Second-Order Nonlinear Differential Equation with Piecewise Constant Argument

Based on a continuation theorem of Mawhin, a unique periodic solution is found for a second-order nonlinear differential equation with piecewise constant argument

Asymptotic Dichotomy in a Class of Third-Order Nonlinear Differential Equations with Impulses

Solutions of quite a few higher-order delay functional differential equations oscillate or converge to zero. In this paper, we obtain several such dichotomous criteria for a class of third-order nonlinear differential equation with impulses