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71.
Lutz Hofmann Tobias Fischer Thomas Werner Franz Selbmann Michael Rennau Ramona Ecke Stefan E. Schulz Thomas Geßner 《Microsystem Technologies》2016,22(7):1665-1677
This paper discusses approaches for the isolation of deep high aspect ratio through silicon vias (TSV) with respect to a Via Last approach for micro-electro-mechanical systems (MEMS). Selected TSV samples have depths in the range of 170…270 µm and a diameter of 50 µm. The investigations comprise the deposition of different layer stacks by means of subatmospheric and plasma enhanced chemical vapour deposition (PECVD) of tetraethyl orthosilicate; Si(OC2H5)4 (TEOS). Moreover, an etch-back approach and the selective deposition on SiN were also included in the investigations. With respect to the Via Last approach, the contact opening at the TSV bottom by means of a specific spacer-etching method have been addressed within this paper. Step coverage values of up to 74 % were achieved for the best of those approaches. As an alternative to the SiO2-isolation liners a polymer coating based on the CVD of Parylene F was investigated, which yields even higher step coverage in the range of 80 % at the lower TSV sidewall for a surface film thickness of about 1000 nm. Leakage current measurements were performed and values below 0.1 nA/cm2 at 10 kV/cm were determined for the Parylene F films which represents a promising result for the aspired application to Via Last MEMS-TSV. 相似文献
72.
73.
Semi-implicit and Newton-like finite element methods are developed for the stationary compressible Euler equations. The Galerkin discretization of the inviscid fluxes is potentially oscillatory and unstable. To suppress numerical oscillations, the spatial discretization is performed by a high-resolution finite element scheme based on algebraic flux correction. A multidimensional limiter of TVD type is employed. An important goal is the efficient computation of stationary solutions in a wide range of Mach numbers, which is a challenging task due to oscillatory correction factors associated with TVD-type flux limiters. A semi-implicit scheme is derived by a time-lagged linearization of the nonlinear residual, and a Newton-like method is obtained in the limit of infinite CFL numbers. Special emphasis is laid on the numerical treatment of weakly imposed characteristic boundary conditions. Numerical evidence for unconditional stability is presented. It is shown that the proposed approach offers higher accuracy and better convergence behavior than algorithms in which the boundary conditions are implemented in a strong sense. 相似文献
74.
Information systems (IS) integration is among the most challenging tasks in corporate mergers and acquisitions (M&As). In
this paper we propose and illustrate the use of an approach to analyzing and planning post-merger IS integration that extends
general theory for IS planning, considering the specific characteristics of the M&A context. We highlight that planning effectiveness
is possible to achieve in fundamentally different ways, dependent on the characteristics of the merger or acquisition at hand.
相似文献
Stefan HenningssonEmail: |
75.
Andreas Holmström Fredrik Larsson Kenneth Runesson Stefan Edlund 《Structural and Multidisciplinary Optimization》2008,35(1):69-77
At the development of commercial vehicles, it is necessary to develop cost-optimized components with respect to their entire
lifetime. This requires a product development process that utilizes the possibility to simulate the product performance using
modeling of different degrees of sophistication at any predefined level-of-detail (LOD). For example, the mechanical properties
of a cast component depend strongly on the casting process, the simulation of which requires complex modeling at a high LOD.
In this article, we propose an optimization strategy that is based on the LOD concept to develop cost-effective components.
A sizing optimization of a cast model component is carried out with respect to both the mechanical and thermal response to
exemplify the process. In particular, a (novel) global measure of the temperature in energy norm is introduced as an indicator
of the “production fitness” to ensure high quality of the material properties. This measure is the thermal counterpart of
the well-accepted mechanical strain energy. 相似文献
76.
Stefan Gruner 《Innovations in Systems and Software Engineering》2008,4(3):223-231
In Use cases considered harmful, Simons has analyzed the logical weaknesses of the UML use case notation and has recommended to “fix the faulty notion of dependency” (Simons: Use cases considered harmful. 29th Conference on Techn. of OO Lang. and Syst., pp 194–203, 1999). The project sketched in this position paper is inspired by Simons’ critique. The main contribution of this paper is a detailed meta model of possible relations between use cases. Later in the project this meta model is then to be formalized in a natural deduction calculus which shall be implemented in the Prolog. As a result of such formalization a use case specification can be queried for inconsistencies as well as for test cases which must be observable after a software system is implemented based on such a use case specification. Software tool support for this method is also under development. 相似文献
77.
We use Schnyder woods of 3-connected planar graphs to produce convex straight-line drawings
on a grid of size
The parameter
depends on the Schnyder wood used for the drawing. This parameter is in the range
The algorithm is a refinement of the face-counting algorithm; thus, in particular, the size of the grid is at most
The above bound on the grid size simultaneously matches or improves all previously known bounds for convex drawings, in particular
Schnyder's and the recent Zhang and He bound for triangulations and the Chrobak and Kant bound for 3-connected planar graphs.
The algorithm takes linear time. The drawing algorithm has been implemented and tested. The expected grid size for the drawing
of a random triangulation is close to
For a random 3-connected plane graph, tests show that the expected size of the drawing is
相似文献
78.
Stefan Porschen 《Annals of Mathematics and Artificial Intelligence》2007,51(1):27-54
We show that the NP-hard optimization problems minimum and maximum weight exact satisfiability (XSAT) for a CNF formula C over n propositional variables equipped with arbitrary real-valued weights can be solved in O(||C||20.2441n ) time. To the best of our knowledge, the algorithms presented here are the first handling weighted XSAT optimization versions in non-trivial worst case time. We also investigate the corresponding weighted counting problems, namely we show that the number of all minimum, resp. maximum, weight exact satisfiability solutions of an arbitrarily weighted formula can be determined in O(n 2·||C||?+?20.40567n ) time. In recent years only the unweighted counterparts of these problems have been studied (Dahllöf and Jonsson, An algorithm for counting maximum weighted independent sets and its applications. In: Proceedings of the 13th ACM-SIAM Symposium on Discrete Algorithms, pp. 292–298, 2002; Dahllöf et al., Theor Comp Sci 320: 373–394, 2004; Porschen, On some weighted satisfiability and graph problems. In: Proceedings of the 31st Conference on Current Trends in Theory and Practice of Informatics (SOFSEM 2005). Lecture Notes in Comp. Science, vol. 3381, pp. 278–287. Springer, 2005). 相似文献
79.
Vangelis Gazis Nancy Alonistioti Nikos Houssos Maria Koutsopoulou Stefan Gessler Juergen Quittek 《Journal of Network and Systems Management》2006,14(2):221-241
Mobile communications beyond 3G will integrate different (but complementary) access technologies into a common platform to deliver value-added services and multimedia content in an optimum way. However, the numerous possible configurations of mobile networks complicated the dynamic deployment of mobile applications. Therefore, research is intensely seeking a service provisioning framework that is technology-independent, supports multiple wireless network technologies, and can interwork high-level service management tasks to network management operations. This paper presents an open value chain paradigm, a model for downloadable applications and a mediating platform for service provisioning in beyond 3G mobile settings. Furthermore, we introduce mechanisms that support a coupled interaction between service deployment and network configuration operations, focusing on the dynamic provisioning of QoS state to data path devices according to the requirements of dynamically downloadable mobile value-added services (VAS).
相似文献
Vangelis GazisEmail: |
80.
Illustrative context-preserving exploration of volume data 总被引:2,自引:0,他引:2
Bruckner S Grimm S Kanitsar A Gröller ME 《IEEE transactions on visualization and computer graphics》2006,12(6):1559-1569
In volume rendering, it is very difficult to simultaneously visualize interior and exterior structures while preserving clear shape cues. Highly transparent transfer functions produce cluttered images with many overlapping structures, while clipping techniques completely remove possibly important context information. In this paper, we present a new model for volume rendering, inspired by techniques from illustration. It provides a means of interactively inspecting the interior of a volumetric data set in a feature-driven way which retains context information. The context-preserving volume rendering model uses a function of shading intensity, gradient magnitude, distance to the eye point, and previously accumulated opacity to selectively reduce the opacity in less important data regions. It is controlled by two user-specified parameters. This new method represents an alternative to conventional clipping techniques, sharing their easy and intuitive user control, but does not suffer from the drawback of missing context information 相似文献