9527664
Vertex-Disjoint Triangles in Claw-Free Graphs with Minimum Degree at Least Three
. Our main result is as follows: For any integer , if G is a claw-free graph of order at least and with minimum degree at least 3, then G contains k vertex-disjoint triangles unless G is of order and G belongs to a known class of graphs. We also construct a claw-free graph with minimum degree 3 on n vertices for each such that it does not contain k vertex-disjoint triangles. We put forward a conjecture on vertex-disjoint triangles in -free graphs.
30994252
An extension of a theorem on cycles containing specified independent edges
We give an alternative proof of a conjecture due to Wang (J. Graph Theory 26 (1997) 105) in a stronger form. The main theorem states that for any integer k ≥ 2 if G is a graph of order n ≥ 4k - 1 and d(u) + d(υ) ≥ n + 2k - 2 for each pair of non-adjacent vertices u and υ of G, then, for any k independent edges e1,... ,ek of G, there exist k vertex-disjoint cycles C1,..., Ck in G such that (i) ei ∈ E(Ci) for all 1 ≤ i ≤ k, (ii) V(C1)∪ ... ∪V(Ck) = V(G), and (iii) #{i ≤ k||Ci| a > n - 4k + 2). It strengthens the conjecture of Wang, which was first proven by Egawa et al. (Graphs Combin. 16 (2000) 81).
5245849
On Independent Cycles in a Bipartite Graph
Abstract. Let G=(V1,V2;E) be a bipartite graph with 2k≤m=|V1|≤|V2|=n, where k is a positive integer. We show that if the number of edges of G is at least (2k−1)(n−1)+m, then G contains k vertex-disjoint cycles, unless e(G)=(2k−1)(n−1)+m and G belongs to a known class of graphs.
39356858
Vertex-disjoint quadrilaterals in graphs
Let k be a positive integer and G a graph of order n. In (Discrete Math. 203 (1999) 229), we proved that if n=4k and @d(G)>=2k then G contains k-1 vertex-disjoint quadrilaterals. In this paper, we investigate vertex-disjoint quadrilaterals in G with n@?0(mod4), and we have found the best minimum degree condition @d(G)>=@?12n@? such that G contains @?14n@? vertex-disjoint quadrilaterals. As a result of our method, we have improved our previous result as follows: If n=4k and @d(G)>=2k-1 then G contains k-1 vertex-disjoint quadrilaterals.
43159264
P2p-factorization of a complete bipartite graph
10626
All trees contain a large induced subgraph having all degrees 1 (mod k)
We prove that, for integers n ? 2 and k ? 2, every tree with n vertices contains an induced subgraph of order at least 2?(n + 2k ? 3)/(2k ? 1)? with all degrees congruent to 1 modulo k. This extends a result of Radcliffe and Scott, and answers a question of Caro et al.
37659089
Temperature dependence of DC characteristics of NpN InP/GaAsSb/InP double heterojunction bipolar transistors: an analytical study
An analytic study of DC characteristics based on the drift-diffusion approach has been performed for the InP/GaAsSb DHBTs. The current transport of InP/GaAsSb/InP DHBTs has been investigated focusing the device temperature dependence. Our simulation results show that, at room temperature, the DC characteristics of the InP/GaAsSb/InP DHBTs similar to the conventional InP-based HBT using InGaAs as the base layer although a type-II energy band alignment is presented in the InP/GaAsSb HBT. However, due to different mechanisms for the electron injection from the emitter induced by the different conduction band alignments, the InP/GaAsSb HBTs may present a different temperature dependent behavior in term of device current gain as compared to the conventional InP/InGaAs HBTs. Higher current gain could be achieved by the InP/GaAsSb HBTs at elevated temperature.
14869090
CPR: Composable performance regression for scalable multiprocessor models
Uniprocessor simulators track resource utilization cycle by cycle to estimate performance. Multiprocessor simulators, however, must account for synchronization events that increase the cost of every cycle simulated and shared resource contention that increases the total number of cycles simulated. These effects cause multiprocessor simulation times to scale superlinearly with the number of cores. Composable performance regression (CPR) fundamentally addresses these intractable multiprocessor simulation times, estimating multiprocessor performance with a combination of uniprocessor, contention, and penalty models. The uniprocessor model predicts baseline performance of each core while the contention models predict interfering accesses from other cores. Uniprocessor and contention model outputs are composed by a penalty model to produce the final multiprocessor performance estimate. Trained with a production quality simulator, CPR is accurate with median errors of 6.63, 4.83 percent for dual-, quad-core multiprocessors. Furthermore, composable regression is scalable, requiring 0.33x the simulations required by prior regression strategies.
19061048
A minimized zero mean entropy approach to networked control systems
A novel control method is proposed for networked control systems with nonlinear process, probably non-Gaussian process noise and time delays. The performance index of closed loop control system consists of entropy, mean value and control energy constraint. Two stochastic control methods for networked control systems are given under the same general frame. One method utilizes gradient optimal techniques to obtain an optimal control law, and the stability of closed loop systems is analyzed. The other method gives the optimal solution of control law directly. The implementation issues are emphasized. The sliding window techniques and non-parametric probability density function estimation techniques are employed to obtain the entropy of tracking error recursively. As a result, the controller can be on-line tuned. Finally, the methodology is illustrated by simulations.
29063745
A New Graph Approach to Minimizing Processor Fragmentation in Hypercube Multiprocessors
The authors propose a new approach for subcube and noncubic processor allocations for hypercube multiprocessors. The main idea is to represent available processors in the system by means of a prime cube graph (PC-graph). The PC-graph maintains the inter-relationships between free subcubes and hence reduces both internal and external processor fragmentations. Their simulation results show that the PC-graph approach outperforms the existing allocation strategies by 25% to 50% under certain load conditions. >
7971167
Robust minimum entropy tracking control with guaranteed stability for nonlinear stochastic systems under modeling errors
In this paper, robust minimum entropy tracking control problem is considered for nonlinear stochastic systems. The controlled systems are described by nonlinear non-Gaussian difference equations with the un-modeled uncertainty and modeling error, as well as time delays. Entropy is adopted to characterize the uncertainty of the tracking error. The nonlinear multi-step-ahead predictive cost function is used and the relationship between the probability density functions of the input and the tracking error via the uncertain mapping is established. With these formulations, the cost function can be bounded as a nonlinear functional of the control input and the known bounds of the errors. Explicit design algorithms are presented for the robust suboptimal controller and further for the stabilization controllers. The Renyi's entropy has also been used to simplify the cost function. Simulations are given to demonstrate the effectiveness of the proposed control algorithm.