24310355
Component-Based Online Learning for Face Detection and Verification
Component detectors can accurately locate facial components, and component-based approaches can be used to build detectors that can handle partial occlusions. This paper proposes a face detection and verification method using component-based online learning. The main difference from previously reported component-based approaches is the use of online learning, which is ideal for highly repetitive tasks. This results in faster and more accurate face detection, because system performance improves with continued use. Further, uncertainty is added by calculating the standard deviation of face components and their relations.
34164098
A New EM Algorithm for Resource Allocation Network
Clustering usually assumes that the number of clusters is known or given. No knowledge of such a priori information is needed to find an appropriate number of clusters. This paper introduces an elliptical clustering algorithm with incremental growth of clusters, which is derived from the batch EM algorithm with a decay factor and a novelty criterion. The proposed algorithm can start with no or a small number of clusters. Whenever unusual data is presented, the algorithm adds a new cluster and finally the number of clusters in the data is obtained after clustering. The usefulness of the proposed algorithm is demonstrated for texture image segmentation and skin image segmentation.
14116288
A Practitioner's Approach to Normalizing XQuery Expressions
XQuery becomes a standard of the XML query language. Just like in SQL, XQuery allows nested expressions. To optimize XQuery processing, a lot of research has been done on normalization, i.e., transforming nested expressions to equivalent unnested ones. Previous normalization rules are classified into two categories – source-level and algebra-level – depending on whether a construct is specified by using a query language or an algebraic expression. In implementation point of view, we contend that the source-level rule is preferable to the algebra-level rule because algebras used for normalization are hard to be directly exploited in a typical DBMS. However, a complete set of source-level rules is yet to be developed. In this paper, we propose source-level rules for normalizing XQuery expressions and present an implementation mechanism. We show that our rules are correct and complete according to the nesting types classified by Kim. Our mechanism is easily implementable since it adapts the well-known Query Graph Model (QGM) representation. We have successfully implemented this mechanism into our XML DBMS named Odysseus/XML.
5225944
Adaptive filtering using constrained subband updates
This paper describes and analyzes a class of subband adaptive filters (SAF) that stems from various approaches of applying subband and multirate techniques in adaptive filtering. This class of SAF has a unique structure of weight-control mechanism where subband error signals are used to actuate the adaptation of a fullband weight vector. In this paper, we show that the recursive weight adaptation can be expressed as an underdetermined least-squares solution. Within this deterministic framework, we show its underlying affinity with the normalized least-mean-square (NLMS) and affine projection (AP) algorithms. We then compare the efficacy of these algorithms in terms of convergence rate and computational complexity.
6735701
Dependency algebra: a theoretical framework for dependency management in real-time control systems
The large and complex dependency relationship between software components is at the root of system instability. A seemingly minor fault can propagate along dependency chains and bring down the system. Therefore, the first step in the development of a robust system is the management and control of dependency relations between software components. The two contributions of this paper are: 1) a refinement of the commonly used failure semantics in the context of a real time control system; 2) the development of a dependency algebra. Component dependency relationships can be described in terms of a set of refined failure semantics mappings, enabling differentiation and comparison of different relationships and designs. The system-wide evaluation and tracking of these dependency relationships are performed using dependency algebra.
2700489
An efficient algorithm for predictive continuous nearest neighbor query processing and result maintenance
Predictive continuous nearest neighbor queries are concerned with finding the nearest neighbor objects for some future time period according to the current object and query locations and their motion information. Existing continuous query processing algorithms are not efficient enough, requiring multiple dataset lookups to evaluate the query results throughout the duration of a continuous query. More importantly, the complete result for the whole query time interval is only available at the moment when all object motion updates have been examined, based on which adjustment of the query result is made. In this paper, we propose an algorithm which requires only one dataset lookup to deliver a complete predictive result. We then apply a differential update technique to maintain the query results incrementally in the presence of object location and motion updates.
2403163
Optimal proxy management for multimedia streaming in content distribution networks
The widespread use of the Internet and the maturing of digital video technology have led to an increase in various streaming media applications. As broadband to the home becomes more prevalent, the bottleneck of delivering quality streaming media is shifting upstream to the backbone, peering links, and the best-effort Internet. In this paper, we address the problem of efficiently streaming video assets to the end clients over a distributed infrastructure consisting of origin servers and proxy caches. We build on earlier work and propose a unified mathematical framework under which various server scheduling and proxy cache management algorithms for video streaming can be analyzed. More precisely, we incorporate known server scheduling algorithms (batching/patching/batch-patching) and proxy caching algorithms (full/partial/no caching with or without caching patch bytes) in our framework and analyze the minimum backbone bandwidth consumption under the optimal joint scheduling and caching strategies. We start by studying the optimal policy for streaming a single video object and derive a simple gradient-descent-based cache allocation algorithm to enable management of multiple heterogeneous videos efficiently. We then show that the performance of our heuristic is close to that of the optimal scheme, under a wide range of parameters.