27917358
Continuous dependence on initial values for impulsive delay differential equations
This paper studies the property of continuous dependence of solutions with respect to initial values for impulsive delay differential equations. Criteria on continuous dependence of solutions with respect to initial functions are established. It is shown, however, that due to the discontinuities of the function space and the time delays in the system, continuous dependence with respect to the initial time, or more generally with respect to the entire initial data, is unfortunately not generally satisfied.
23517581
Global exponential stability of high order Hopfield type neural networks
This paper studies the problem of global exponential stability for a class of high order Hopfield type neural networks. By utilizing Lyapunov functions, several sufficient conditions for the global exponential stability of equilibrium point are obtained. The exponential convergence rate of the equilibrium point is also estimated. As a special case, several new criteria on global exponential stability for the corresponding first order Hopfield neural networks are obtained. Those criteria generalize some of the recent results reported in the literature.
2568010
Stability of nontrivial solution of delay differential equations with state-dependent impulses
This paper considers the stability problem of nontrivial solutions of delay differential equations with state-dependent impulses. By using the concepts of reduced system and quasi-stability, the stability problem of a nontrivial solution of the impulsive delay differential equation with state-dependent impulses is converted to that of the trivial solution of the impulsive delay differential equation with fixed impulses. Several stability criteria are then established utilizing the known results for systems with fixed impulses.
1752593
RITC: repeater insertion with timing target compensation
This paper investigates the problem of repeater insertion for global interconnects under given timing constraints. A novel technique is proposed to aggressively reduce the positive timing slack for maximal repeater reduction while maintaining timing closure. Our scheme is both fast and effective due to the judicious combination of accurate SPICE simulations and the simple Elmore delay model. In comparison with other repeater insertion solvers, our scheme achieves up to 41% reduction in total repeater width in comparable runtimes.
16232707
A weighted sum validity function for clustering with a hybrid niching genetic algorithm
Clustering is inherently a difficult problem, both with respect to the construction of adequate objective functions as well as to the optimization of the objective functions. In this paper, we suggest an objective function called the Weighted Sum Validity Function (WSVF), which is a weighted sum of the several normalized cluster validity functions. Further, we propose a Hybrid Niching Genetic Algorithm (HNGA), which can be used for the optimization of the WSVF to automatically evolve the proper number of clusters as well as appropriate partitioning of the data set. Within the HNGA, a niching method is developed to preserve both the diversity of the population with respect to the number of clusters encoded in the individuals and the diversity of the subpopulation with the same number of clusters during the search. In addition, we hybridize the niching method with the k-means algorithm. In the experiments, we show the effectiveness of both the HNGA and the WSVF. In comparison with other related genetic clustering algorithms, the HNGA can consistently and efficiently converge to the best known optimum corresponding to the given data in concurrence with the convergence result. The WSVF is found generally able to improve the confidence of clustering solutions and achieve more accurate and robust results.
5155570
Low-power repeater insertion with both delay and slew rate constraints
In this paper, a novel repeater insertion algorithm is presented to minimize the power dissipation of interconnect trees under given timing budgets and slew rate constraints. In contrast to traditional bottom-up dynamic programming approaches, the proposed algorithm combines a Lagrangian relaxation framework and a graph-based search method to derive possible solutions in a top-down fashion. As a result, it is capable of analyzing repeater slew rates efficiently. In addition, our scheme incorporates accurate circuit models and is therefore able to capture the precise delay and slew rate information, leading to high-quality interconnect designs. We have applied our scheme to interconnects of different topologies and various timing and slew rate constraints. Experimental results demonstrate the effectiveness of our approach in comparison with previous low-power repeater insertion schemes. Under tight timing constraints, our scheme can always derive repeater insertion solutions that meet both delay and slew rate requirements, whereas other schemes often fail. Under loose timing constraints, our algorithm achieves up to a 23% average power dissipation reduction for different interconnects specifications with shorter runtimes
1063503
Mutual anonymous overlay multicast
Multicast services are demanded by a variety of applications. Many applications require anonymity during their communication. However, there has been very little work on anonymous multicasting and such services are not available yet. Due to the fundamental differences between multicast and unicast, the solutions proposed for anonymity in unicast communications cannot be directly applied to multicast applications. In this paper we define the anonymous multicast system, and propose a mutual anonymous multicast (MAM) protocol including the design of a unicast mutual anonymity protocol and construction and optimization of an anonymous multicast tree. MAM is self-organizing and completely distributed. We define the attack model in an anonymous multicast system and analyze the anonymity degree. We also evaluate the performance of MAM by comprehensive simulations.
2696332
A boosting approach for motif modeling using ChIP-chip data
MOTIVATION
Building an accurate binding model for a transcription factor (TF) is essential to differentiate its true binding targets from those spurious ones. This is an important step toward understanding gene regulation.


RESULTS
This paper describes a boosting approach to modeling TF-DNA binding. Different from the widely used weight matrix model, which predicts TF-DNA binding based on a linear combination of position-specific contributions, our approach builds a TF binding classifier by combining a set of weight matrix based classifiers, thus yielding a non-linear binding decision rule. The proposed approach was applied to the ChIP-chip data of Saccharomyces cerevisiae. When compared with the weight matrix method, our new approach showed significant improvements on the specificity in a majority of cases.