3705093
MINMAX optimal video summarization
The need for video summarization originates primarily from a viewing time constraint. A shorter version of the original video sequence is desirable in a number of applications. Clearly, a shorter version is also necessary in applications where storage, communication bandwidth and/or power are limited. In this paper, our work is based on a MINMAX optimization formulation with viewing time, frame skip and bit rate constraints. New metrics for missing frame and video summary distortions are introduced. Optimal algorithm based on dynamic programming is presented along with experimental results.
1229745
Fast Video Shot Retrieval with Luminance Field Trace Indexing and Geometry Matching
Efficient indexing is a key in content-based video retrieval solutions. In this paper we represent video sequences as traces in an appropriate low dimensional space via luminance field scaling and PCA projection, and develop an efficient indexing scheme and trace geometry matching algorithms for fast and robust video retrieval. Simulation results demonstrate that the proposed solution is very fast and accurate in retrieval performance.
6048187
Fast video shot retrieval by trace geometry matching in principal component space
Content-based video retrieval technology holds the key to the efficient management and sharing of video content from different sources, in different scales, across different platforms, and shared over different communication channels. In this work we present a fast retrieval algorithm based on matching the geometry of video sequence traces in the principal component space. Techniques to address scale (spatial and temporal) issues, as well as, noise and other possible distortions, such as frame dropping, are discussed. Experimental results demonstrate the effectiveness of the proposed approach.
6468095
Factoring systems of linear PDEs with finite-dimensional solution spaces
A D-finite system is a finite set of linear homogeneous partial differential equations in several independent and dependent variables, whose solution space is of finite dimension. Let L be a D-finite system with rational function coefficients. We present an algorithm for computing all hyperexponential solutions of L, and an algorithm for computing all D-finite systems whose coefficients are also rational functions, and whose solutions are contained in the solution space of L.
1327847
On achieving maximum multicast throughput in undirected networks
The transmission of information within a data network is constrained by the network topology and link capacities. In this paper, we study the fundamental upper bound of information dissemination rates with these constraints in undirected networks, given the unique replicable and encodable properties of information flows. Based on recent advances in network coding and classical modeling techniques in flow networks, we provide a natural linear programming formulation of the maximum multicast rate problem. By applying Lagrangian relaxation on the primal and the dual linear programs (LPs), respectively, we derive a) a necessary and sufficient condition characterizing multicast rate feasibility, and b) an efficient and distributed subgradient algorithm for computing the maximum multicast rate. We also extend our discussions to multiple communication sessions, as well as to overlay and ad hoc network models. Both our theoretical and simulation results conclude that, network coding may not be instrumental to achieve better maximum multicast rates in most cases; rather, it facilitates the design of significantly more efficient algorithms to achieve such optimality.
5937656
Complexity analysis and speedup techniques for optimal buffer insertion with minimum cost
As gate delays decrease faster than wire delays for each technology generation, buffer insertion becomes a popular method to reduce the interconnect delay. Several modern buffer insertion algorithms (e.g., [7, 6, 15]) are based on van Ginneken's dynamic programming paradigm [14]. However, van Ginneken's original algorithm does not control buffering resources and tends to over-buffering, thereby wasting area and power. It has been a major open problem whether it is possible to optimize slack and at the same time minimize the buffer usage.This paper settles this open problem by showing that for arbitrary integer cost functions, the problem is NP-complete. We also extend the pre-buffer slack technique [12] to minimize the buffer cost. This technique can significantly reduce the running time and memory in buffer cost minimization problem. The experimental results show that our algorithm can speed up the running time up to 17 times and reduces the memory to 1/30 of traditional best know algorithm. Finally, we show how to efficiently deal with multiway merge in buffer insertion.
130258
Longest-path selection for delay test under process variation
Under manufacturing process variation, a path through a fault site is called longest for delay test if there exists a process condition under which the path has the maximum delay among all paths through that fault site. There are often multiple longest paths for each fault site in the circuit, due to different process conditions. To detect the smallest delay fault, it is necessary to test all longest paths through the fault site. However, previous methods are either inefficient or their results include too many paths that are not longest.This paper presents an efficient method to generate the longest path set for delay test under process variation. To capture both structural and systematic process correlation, we use linear delay functions to express path delays under process variation. A novel path-pruning technique is proposed to discard paths that are not longest, resulting in a significantly reduction in the number of paths compared with the previous best method. The new method can be applied to any process variation as long as its impact on delay is linear.
12948247
Interprocedural Analysis Based on Guarded Array Regions
Array data flow information plays an important role for successful automatic parallelization of Fortran programs. This chapter proposes a powerful symbolic array data flow summary scheme to support array privatization and loop parallelization for programs with arbitrary control flow graphs and acyclic call graphs. Our approach summarizes array access information interprocedurally, using guarded array regions. The use of guards allows us to use the information in IF conditions to do path-sensitive data flow summary and thereby to handle difficult cases. We also provide a mechanism to overcome the disadvantages of nonclosed union and difference operations. This improves not only the exactness of summaries, but also the efficiency of the summarizing procedure. Our preliminary result on array privatization shows that our summary scheme is fast and powerful.