5131804
Scalable peer-to-peer networked virtual environment
We propose a fully-distributed peer-to-peer architecture to solve the scalability problem of Networked Virtual Environment in a simple and efficient manner. Our method exploits locality of user interest inherent to such systems and is based on the mathematical construct Voronoi diagram. Scalable, responsive, fault-tolerant NVE can thus be constructed and deployed in an affordable way.
9549886
A case for 3D streaming on peer-to-peer networks
One of the most serious issues holding back the widespread of 3D contents on Internet has been their inaccessibility due to large data volume. Many compression and progressive transmission techniques, as well as format standards, have been proposed in recent years to make 3D streaming increasingly viable for the efficient and accessible delivery of 3D contents. However, existing proposals have yet to seriously address one of the most important issues in practical adoption - a system's scalability in terms of the number of concurrent users. We argue that due to 3D contents' large data volume and interactive nature, client-server architecture, with its inherently fixed resource availability and high cost, will not be suitable to support popular Internet-scale 3D streaming. On the other hand, peer-to-peer (P2P) architectures hold the promise of both scalability and affordability. In this position paper, we describe the potential promises and challenges in adapting 3D streaming to P2P networks, using multi-user networked virtual environment (NVE) as an example. We also propose Flowing LoD (FLoD), a scalable, distributed and fault-tolerant P2P 3D streaming mechanism, that is based on Voronoi-based Overlay Network (VON), a P2P overlay specifically designed for NVE applications.
9344765
An Efficient Algorithm for RLC Buffer Insertion
Traditional buffer insertion algorithms neglect the impact of inductance effect, which often introduces large error in circuit optimization. On the other hand, ultra-fast buffering techniques are always desirable as buffering is such a widely used technique in industry. It is a challenge to design an RLC buffering algorithm which excels in both runtime and solution quality. In this paper, such an algorithm is proposed. The new algorithm works under the dynamic programming framework and runs in provably linear time for multiple buffer types due to two novel techniques: restrictive cost bucketing and efficient delay update. Experiment results on industrial netlists demonstrate that the new algorithm consistently outperforms van Ginneken/Lillis algorithm (van Ginneken, 1990) and (Lillis, 1996) for RC buffering and all known RLC buffering algorithms. Without buffer cost minimization, the new algorithm saves up to 8.5% buffer area and provides up to 4times speedup over Ismail's algorithm (Ismail, 2001), When buffer cost minimization is handled, the new algorithm uses 33.4% fewer buffers than van Ginnenken-Lillis's algorithm, and saves up to 5.3% buffer area and gives up to 5times speedup compared to the algorithm in (Jiang et al., 2006)
32819804
A note on approximation of discrete data by G1 arc splines
Meek and Walton discussed the approximation of discrete data by G1 arc splines in 1992. For a biarc from the start point A to the end point B, they assumed that the sum of two counterclockwise angles of the two arcs was equal to the sum of the counterclockwise angle from the start tangent vector to the vector B–A and that from the vector B–A to the terminal tangent vector. In this note, we show that the relation can be relaxed by the addition or subtraction of 2π.
13139757
Approximate merging of a pair of Bézier curves
This paper deals with the merging problem, i.e. to approximate two adjacent Bezier curves by a single Bezier curve. A novel approach for approximate merging is introduced in the paper by using the constrained optimization method. The basic idea of this method is to find conditions for the precise merging of Bezier curves first, and then compute the constrained optimization solution by moving the control points. “Discrete” coefficient norm in L2 sense and “squared difference integral” norm are used in our method. Continuity at the endpoints of curves are considered in the merging process, and approximate merging with points constraints are also discussed. Further, it is shown that the degree elevation of original Bezier curves will reduce the merging error.
96005
Fast algorithms for slew constrained minimum cost buffering
As a prevalent constraint, sharp slew rate is often required in circuit design which causes a huge demand for buffering resources. This problem requires ultra-fast buffering techniques to handle large volume of nets, while also minimizing buffering cost. This problem is intensively studied in this paper. First, a highly efficient algorithm based on dynamic programming is proposed to optimally solve slew buffering with discrete buffer locations. Second, a new algorithm is developed to handle the difficult cases in which no assumption is made on buffer input slew. Third, an adaptive buffer selection approach is proposed to efficiently handle slew buffering with continuous buffer locations. Experiments on industrial netlists demonstrate that our algorithms are very effective and highly efficient: we achieve > 100times speed up and save up to 40% buffer area over the commonly-used van Ginneken style buffering
14440830
A constructive approach to solving 3-D geometric constraint systems using dependence analysis
Solving geometric constraint systems in 3-D is much more complicated than that in 2-D because the number of variables is larger and some of the results valid in 2-D cannot be extended for 3-D. In this paper, we propose a new DOF-based graph constructive method to geometric constraint systems solving that can efficiently handle well-, over- and under-constrained systems based on the dependence analysis. The basic idea is that the solutions of some geometric elements depend on some others because of the constraints between them. If some geometric elements depend on each other, they must be solved together. In our approach, we first identify all structurally redundant constraints, then we add some constraints to well constrain the system. And we prove that the order of a constraint system after processing under-constrained cases is not more than that of the original system multiplied by 5. After that, we apply a recursive searching process to identify all the clusters, which is shown to be capable of getting the minimum order-reduction result of a well-constrained system. We also briefly describe the constraint evaluation phase and show the implementation results of our method.