In this paper, we propose a novel unsupervised constellation model learning algorithm based on voting weight control for accurate scale, rotation, and translation invariant face localization without manual selection of feature points. The constellation model is learned by controlling the expected voting weights of the local features to obtain their perceptual boundaries and the distribution of voting weights, and selecting most common features as the representative features among them. The proposed constellation model can be learned incrementally to successfully localize faces when the previously learned model fails to localize them accurately. Through experiments, it is shown that the proposed constellation model can accurately localize faces of various size, orientation, and location. 相似文献
One of the founders of social choice theory, Marquis de Condorcet, assigned truth degrees to propositions expressing preferences
over options. Although his work is often discussed in terms of probability theory, it is arguable that his truth degree lends
itself to a more natural interpretation as a fuzzy preference. We shall review some of Condorcet’s results in the light of
this interpretation. The first twentieth century applications of fuzzy concepts to social choice appeared rather shortly after
the introduction by L. A. Zadeh of the concept of fuzzy binary relation in early 1970s. The early applications dealt with
experimental anomalies and their accountability with the aid of fuzzy preference relations and fuzzy goal states. Considerable
literature now exists on various solution concepts in fuzzy voting games and many important theorems of traditional social
choice theory have found their counterpart in fuzzy social choice. The natural next step would seem to be the design of fuzzy
mechanisms and institutions.
The author wishes to thank—without implicating—Didier Dubois, Javier Montero and Rudolf Seising for useful comments on an
earlier draft. 相似文献
This paper proposes a framework to translate certain subclasses of differential equation systems into practical protocols
for distributed systems. The generated protocols are intended for large-scale distributed systems that contain several hundreds
to thousands of processes. The synthesized protocols are state machines containing probabilistic transitions and actions,
and they are proved to show equivalent stochastic behavior to the original equations. The protocols are probabilistically
scalable and reliable, and have practical applications in large-scale distributed systems, e.g., peer to peer systems. In
order to illustrate the usefulness of the framework, it is used to generate new solutions for the problems of (a) responsibility
migration (giving rise to a novel model of dynamic replication), and (b) majority selection. We present mathematical analysis
of these two protocols, and experimental results from our implementations. These two protocols are derived from natural analogies
that are represented as differential equations—endemics and the Lotka–Volterra model of competition, respectively. We believe
the design framework could be effectively used in transforming, in a very systematic manner, well-known natural phenomena
into protocols for distributed systems. 相似文献
Control in behavior-based systems is distributed among a set of specialized behaviors. To achieve efficient implementation, behaviors exploit specific assumptions about a given task and environment. Thus they become vulnerable to deviations that render these assumptions invalid. Yet it is important to provide appropriate responses to unforeseen situations.
We demonstrate that, using voting techniques, a model-free approach may be provided to construct reliable behaviors from a multitude of less reliable ones. A team of complementary behaviors vote for the set of possible actions, and the action which is most favored is selected for controlling the system. We conjecture that selecting actions according to this scheme can improve the probability of success.
Our conjecture is investigated through two sets of experiments. In the first, a team of obstacle avoidance behaviors vote to guide a mobile robot platform in the most appropriate direction. In the second, four object tracking modules are integrated to perform smooth pursuit with a camera head. 相似文献
To make a joint decision, agents (or voters) are often required to provide their preferences as linear orders. To determine a winner, the given linear orders can be aggregated according to a voting protocol. However, in realistic settings, the voters may often only provide partial orders. This directly leads to the Possible Winner problem that asks, given a set of partial votes, whether a distinguished candidate can still become a winner. In this work, we consider the computational complexity of Possible Winner for the broad class of voting protocols defined by scoring rules. A scoring rule provides a score value for every position which a candidate can have in a linear order. Prominent examples include plurality, k-approval, and Borda. Generalizing previous NP-hardness results for some special cases, we settle the computational complexity for all but one scoring rule. More precisely, for an unbounded number of candidates and unweighted voters, we show that Possible Winner is NP-complete for all pure scoring rules except plurality, veto, and the scoring rule defined by the scoring vector (2,1,…,1,0), while it is solvable in polynomial time for plurality and veto. 相似文献
Symmetry detection is significant for object detection and recognition since symmetries are salient cues for distinguishing geometrical structures from cluttered backgrounds. This paper proposes a unified framework to detect rotation, reflection and translation symmetries simultaneously on unsegmented real-world images. The detection is performed based on affine invariant contour features, and is applicable under skewed imaging with distortions. Contours on a natural image are first matched to each other to find affine invariant matching pairs, which are then classified into three groups using a sign change criterion corresponding to the three types of symmetries. The three groups are used to vote for the corresponding symmetries: the voting for rotation utilizes a scheme of short line segments; the voting for reflection is based on a parameterization of axis equation, and the voting for translation uses a cascade-like approach. Experimental results of real-world images are provided with quantitative evaluations, validating that the proposed framework achieves desired performance. 相似文献