Molecular genetic analysis of the Chinese Erhualian pig breed

The Chinese Erhualian is one of the most prolific pig breeds in the world, but it is in danger of being replaced by other exotic pig breeds because of its slow growth rate and high fat content in the body. To obtain some genetic information for conservation, we analysed the Erhualian pigs by using a PCR-RFLP for the calcium-release-channel (CRC) gene, nine polymorphic microsatellites and the complete mtDNA D-loop sequences, and compared these data with those from other pig breeds from Europe and Asian. The PCR-RFLP analysis of the CRC gene showed that the frequency of the C allele associated with stress resistance was 100% in the Erhualian pigs. Neighbour-Joining trees constructed on the basis of mtDNA D-loop sequences and the microsatellite analysis clearly showed that the Erhualian pigs were located in a separate branch. These data suggest that the Erhualian pigs are different from other breeds. Microsatellite analysis showed that the average allele number (5.3/locus) in the Erhualian pig was intermediate as compared with that (4.8-7.0/locus) in the three European pig breeds. The expected heterozygosity was higher in the Erhualian pig (0.78) than that in these European pig breeds (0.59-0.72), whereas the observed heterozygosity was higher in the European breeds (0.51-0.64) than in the Erhualian pig (0.46). In the Erhualian pig, the fixation index (FIS) was as high as 0.41. These data suggest a high level of inbreeding and/or subpopulation in the Erhualian pigs. For conservation of the germplasm in the Erhualian pigs, it is necessary to take measures to reduce inbreeding and/or subpopulation. Keywords: Erhualian pig, Genetic diversity, Conservation, DNA markers South African Journal of Animal Science Vol.33(3) 2003: 159-16

Reliable H ∞ control for affine nonlinear systems

This paper addresses the reliable H ∞-control problems for affine nonlinear systems. Based on the Hamilton-Jacobi inequality approach developed in the H ∞-control problems for affine nonlinear systems, a method for the design of reliable nonlinear control systems is presented. The resulting nonlinear control systems are reliable in that they provide guaranteed local asymptotic stability and H ∞ performance not only when all control components are operational, but also in the case of some component outages within a prespecified subset of control components. A numerical example is also given.published_or_final_versio

An Efficient Approximate kNN Graph Method for Diffusion on Image Retrieval

The application of the diffusion in many computer vision and artificial intelligence projects has been shown to give excellent improvements in performance. One of the main bottlenecks of this technique is the quadratic growth of the kNN graph size due to the high-quantity of new connections between nodes in the graph, resulting in long computation times. Several strategies have been proposed to address this, but none are effective and efficient. Our novel technique, based on LSH projections, obtains the same performance as the exact kNN graph after diffusion, but in less time (approximately 18 times faster on a dataset of a hundred thousand images). The proposed method was validated and compared with other state-of-the-art on several public image datasets, including Oxford5k, Paris6k, and Oxford105k

A DEM investigation of water-bridged granular materials at the critical state

The critical state is an important concept for saturated and partially saturated granular materials as the strength and volume become constant and unique under continuous shear. By incorporating the water bridge effect, the mechanical behaviours of wet granular matters can be studied by the discrete element method (DEM). A series of DEM simulations are performed following the conventional triaxial loading path for dry and wet granular materials, and different suction values are applied at various confining stress levels. Unique critical state behaviours have been observed in both macroscopic and microscopic scales. It shows that the confining stress level plays an important role in the critical state behaviour of wet granular materials. The critical stress ratio for a wet material is not a constant value at different stress levels, and it is found that both the critical stress ratio and void ratio in wet granular matters are also much higher with a low confining stress. A framework is proposed by considering both the contact stress and the capillary stress effects to model the critical state lines. At large strain, the coordination number, the mean inter-particle force and fabric anisotropies evolve to constant critical state values for both dry and wet materials. The macro-parameters formulating the critical state stress ratio are found to be associated with the critical state anisotropies in solid skeleton and water phase fabrics, respectively

Decentralized H ∞-controller design for nonlinear systems

This paper considers the decentralized H ∞-controller design problem for nonlinear systems. Sufficient conditions for the solution of the problem are presented in terms of solutions of Hamilton-Jacobi inequalities. The resulting design guarantees local asymptotic stability and ensures a predetermined L 2-gain bound on the closed-loop system.published_or_final_versio

Decentralized H∞ controller design for nonlinear systems

published_or_final_versio

Stable controller design for linear systems

This paper is concerned with the problem of suboptimal stable mixed H2/H∞ control for linear time-invariant systems. The designed controllers are required to satisfy a prescribed H∞ performance bound or a prescribed degree of stability. By reducing the stable controller synthesis problem to a multiobjective state feedback control problem for two different state models, sufficient conditions for the solvability of the considered problem are given in terms of solutions to algebraic Riccati equations and matrix inequalities. LMI-based iterative algorithms are developed to solve the stable controller synthesis problem. All of the proposed algorithms are shown to be convergent. An example is given to illustrate the proposed methods.published_or_final_versio

Design of reliable controllers for symmetric composite systems:primary contingency case

This paper discusses the reliable controller design problem for symmetric composite systems composed of several identical subsystems. A reliable controller design procedure is presented in terms of the solutions to algebraic Riccati equations. The order of these AREs is much lower than that of the symmetric composite system. The resulting closed-loop system is reliable in that it provide guaranteed internal stability and H∞ performance when all sensors and actuators are operational as well as when the sensors or actuators of a prescribed subsystem experiences an outage.published_or_final_versio