This paper presents the performance characteristics of a new type of jetting dispenser which can be applicable for modern semiconductor packaging processes. The proposed jetting dispenser is driven by both a piezostac...
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This paper presents the performance characteristics of a new type of jetting dispenser which can be applicable for modern semiconductor packaging processes. The proposed jetting dispenser is driven by both a piezostack actuator and a flexible beam mechanism. After describing the geometric configuration and operational principle of the dispenser, a mathematical model of the system is derived by considering the dynamic behaviors of structural parts such as the piezostack, the flexible beam, the needle structure, and the adhesive fluid dynamics. In the modeling, a lumped parameter method is employed and the governing equation of the whole dispenser is then formulated by integrating the structural model with the fluid model. Based on the proposed model, significant structural components of the dispenser such as the piezostack, the flexible beam, and the actuating spring are designed in order to achieve operational requirements (needle motion amplitude: up to 0.4 mm;operating frequency: up to 700 Hz). Subsequently, dispensing performances such as the dispensing dot size and flow rate are experimentally evaluated. In addition, a control algorithm is designed and empirically realized to demonstrate some benefits of the proposed jetting dispenser such as accurate controllability of dispensing amount.
We introduced a spectral clustering algorithm based on the bipartite graph model for the Manufacturing Cell Formation problem in [Oliveira S, Ribeiro JFF, Seok SC. A spectral clustering algorithm for manufacturing cel...
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We introduced a spectral clustering algorithm based on the bipartite graph model for the Manufacturing Cell Formation problem in [Oliveira S, Ribeiro JFF, Seok SC. A spectral clustering algorithm for manufacturing cell formation. computers and Industrial Engineering. 2007 [submitted for publication]]. It constructs two similarity matrices;one for parts and one for machines. The algorithm executes a spectral clustering algorithm on each separately to find families of parts and cells of machines. The similarity measure in the approach utilized limited information between parts and between machines. This paper reviews several well-known similarity measures which have been used for Group Technology. Computational clustering results are compared by various performance measures. (C) 2008 The Society of Manufacturing Engineers. Published by Elsevier Ltd. All rights reserved.
We present two algorithms that are near optimal with respect to the number of inversions present in the input. One of the algorithms is a variation of insertion sort, and the other is a variation of merge sort. The nu...
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We present two algorithms that are near optimal with respect to the number of inversions present in the input. One of the algorithms is a variation of insertion sort, and the other is a variation of merge sort. The number of comparisons performed by our algorithms, on an input sequence of length n that has I inversions, is at most n log(2) (I/n + 1) + O(n) . Moreover, both algorithms have implementations that run in time O(n log(2) (I/n + 1) + n ) . All previously published algorithms require at least cn log(2) (I/n + 1) comparisons for some c > 1.
This paper addresses the problem of critical point calculations for pairwise comparisons of three normal means. One-sided and two-sided pairwise comparisons are standard multiple comparisons procedures, and while tabl...
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This paper addresses the problem of critical point calculations for pairwise comparisons of three normal means. One-sided and two-sided pairwise comparisons are standard multiple comparisons procedures, and while tables of critical points exist for balanced situations with equal sample sizes, only limited tables of critical points exist for unbalanced cases. A new algorithm is developed in this paper using elementary methods which allows the critical points to be found in all situations using only a one-dimensional numerical integration. Programs have been developed to implement the algorithm which will allow experimenters to easily find the required critical points and p-values. (C) 2008 Elsevier B.V. All rights reserved.
We present a system for streaming live entertainment content over the Internet originating from a single source to a scalable number of consumers without resorting to centralized or provider-provisioned resources. The...
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We present a system for streaming live entertainment content over the Internet originating from a single source to a scalable number of consumers without resorting to centralized or provider-provisioned resources. The system creates a peer-to-peer overlay network, which attempts to optimize use of existing capacity to ensure quality of service, delivering low startup delay and lag in playout of the live content. There are three main aspects of our solution: first, a swarming mechanism that constructs an overlay topology for minimizing propagation delays from the source to end consumers;second, a distributed overlay anycast system that uses a location-based search algorithm for peers to quickly find the closest peers in a given stream;and finally, a novel incentive mechanism that encourages peers to donate capacity even when the user is not actively consuming content.
In this paper we review some theoretical aspects of the dynamics of the mesoscale filaments extending along the magnetic field lines in the edge plasma, which are often called 'blobs'. We start with a brief hi...
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In this paper we review some theoretical aspects of the dynamics of the mesoscale filaments extending along the magnetic field lines in the edge plasma, which are often called 'blobs'. We start with a brief historical survey of experimental data and the main ideas on edge and SOL plasma transport, which finally evolved into the modern paradigm of convective very-intermittent cross-field edge plasma transport. We show that both extensive analytic treatments and numerical simulations demonstrate that plasma blobs with enhanced pressure can be convected coherently towards the wall. The mechanism of convection is related to an effective gravity force (e.g. owing to magnetic curvature effects), which causes plasma polarization and a corresponding E x B convection. The impacts of different effects (e.g. X-point magnetic geometry, plasma collisionality, plasma beta, etc.) on blob dynamics are considered. Theory and simulation predict, both for current tokamaks and for ITER, blob propagation speeds and cross-field sizes to be of the order of a few hundred meters per second and a centimeter, respectively, which are in reasonable agreement with available experimental data. Moreover, the concept of blobs as a fundamental entity of convective transport in the scrape-off layer provides explanations for observed outwards convective transport, intermittency and non-Gaussian statistics in edge plasmas, and enhanced wall recycling in both toroidal and linear machines.
This paper gives algorithms for determining real-valued univariate unimodal regressions, that is, for determining the optimal regression which is increasing and then decreasing. Such regressions arise in a wide variet...
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This paper gives algorithms for determining real-valued univariate unimodal regressions, that is, for determining the optimal regression which is increasing and then decreasing. Such regressions arise in a wide variety of applications. They are shape-constrained nonparametric regressions, closely related to isotonic regression. For unimodal regression on n weighted points our algorithm for the L-2 metric requires only Theta(n) time, while for the L-1 metric it requires Theta(n log n) time. For unweighted points our algorithm for the L. metric requires only Theta(n) time. All of these times are optimal. Previous algorithms were for the L-2 metric and required Omega(n(2)) time. All previous algorithms used multiple calls to isotonic regression, and our major contribution is to organize these into a prefix isotonic regression, determining the regression on all initial segments. The prefix approach reduces the total time required by utilizing the solution for one initial segment to solve the next. (C) 2008 Elsevier B.V. All rights reserved.
The random displacement of magnetic field lines in the presence of magnetic turbulence in plasmas is investigated from first principles. A two-component (slab/two-dimensional composite) model for the turbulence spectr...
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The random displacement of magnetic field lines in the presence of magnetic turbulence in plasmas is investigated from first principles. A two-component (slab/two-dimensional composite) model for the turbulence spectrum is employes. An analytical investigation of the asymptotic behavior of the field-line mean square displacement (FL-MSD) is carried out. It is shown that the magnetic field lines behave superdifusively for every large values of the position variable z, since the FL-MSD sigma varies as sigma similar to z(4/3). An intermediate diffusive regime may also possible exist for finite values of z under conditions which are explicitly determined in terms of the intrinsic turbulent plasma parameters. The superdiffusie asymptotic result is confirmed numerically via an iterative algorithm. The relevance to previous resuslts is discussed.
This paper investigates the satisfiability of Propositional Projection Temporal Logic (PPTL) with infinite models. A decision procedure for PPTL formulas is given. To this end, Normal Form (NF) and Labeled Normal Form...
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This paper investigates the satisfiability of Propositional Projection Temporal Logic (PPTL) with infinite models. A decision procedure for PPTL formulas is given. To this end, Normal Form (NF) and Labeled Normal Form Graph (LNFG) for PPTL formulas are defined, and algorithms for transforming a formula to its normal form and constructing the LNFG for the given formula are presented. Further, the finiteness of LNFGs is proved in details. Moreover, the decision procedure is extended to check the satisfiability of the formulas of Propositional Interval Temporal Logic. In addition, examples are also given to illustrate how the decision procedure works.
We consider preemptive offline and online scheduling on identical machines and uniformly related machines in the hierarchical model, with the goal of minimizing the makespan. In this model, each job can be assigned to...
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We consider preemptive offline and online scheduling on identical machines and uniformly related machines in the hierarchical model, with the goal of minimizing the makespan. In this model, each job can be assigned to a subset of the machines which is a prefix of the machine set. We design optimal offline and online algorithms for two uniformly related machines, both when the machine of higher hierarchy is faster and when it is slower, as well as for the case of three identical machines. Specifically, for each one of the three variants, we give a simple formula to compute the makespan of an optimal schedule, provide a linear time offline algorithm which computes an optimal schedule and design an online algorithm of the best possible competitive ratio. (c) 2008 Published by Elsevier Inc.
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